HomeMy WebLinkAboutCouncil Workshop Packet 02.20.2024
AGENDA
CITY OF LAUREL
CITY COUNCIL WORKSHOP
TUESDAY, FEBRUARY 20, 2024
6:30 PM
COUNCIL CHAMBERS
Public Input: Citizens may address the Council regarding any item of City business that is not on
tonight’s agenda. The duration for an individual speaking under Public Input is limited to three
minutes. While all comments are welcome, the Council will not take action on any item not on the
agenda. Because of the Rules that govern public meetings, Council is not permitted to speak in response
to any issue raised that is a non-Agenda item. The Mayor may provide factual information in response,
with the intention that the matter may be addressed at a later meeting. In addition, City Council may
request that a particular non-Agenda item be placed on an upcoming Agenda, for
consideration. Citizens should not construe Council’s “silence” on an issue as an opinion, one way or
the other, regarding that non-Agenda matter. Council simply cannot debate an item that is not on the
Agenda, and therefore, they must simply listen to the feedback given during public input. If a citizen
would like to speak or comment regarding an item that is on tonight’s agenda, we ask that you wait until
the agenda item is presented to the Council by the Mayor and the public is asked to comment by the
Mayor.
Be advised, if a discussion item has an upcoming public hearing, we would request members of the
public to reserve your comments until the public hearing. At the public hearing, the City Council will
establish an official record that will include all of your comments, testimony, and written evidence.
General Items
1. Appointment of Dennis Eaton to the Public Works Committee.
Executive Review
2. Resolution - Resolution Of The City Council Of Intent To Adopt An Official Schedule Of Fees
And Charges For The City Of Laurel And Repealing All Previous Resolutions That Set Fees Or
Charges That Conflict With The Schedule Attached Hereto Upon Its Effective Date.
3. Resolution - A Resolution Of The City Council Approving The Standards For Public Works
Manual For The City Of Laurel Public Works Department.
4. Resolution - A Resolution Of The City Council Approving Amendments To Appropriations
And Revenues For The City Of Laurel’s Fiscal Year 2023-2024 Budget.
5. Resolution - A Resolution Of The City Council Authorizing The Mayor To Reschedule City
Council Meetings Set On 2024 Holidays.
Council Issues
6. MoCones Public Hearing
7. Sprinkler System at Kiwanis Park Discussion
Other Items
Attendance at Upcoming Council Meeting
Announcements
1
The City makes reasonable accommodations for any known disability that may interfere with a person’s ability to participate
in this meeting. Persons needing accommodation must notify the City Clerk’s Office to make n eeded arrangements. To make
your request known, please call 406-628-7431, Ext. 5100, or write to City Clerk, PO Box 10, Laurel, MT 59044, or present
your request at City Hall, 115 West First Street, Laurel, Montana.
2
File Attachments for Item:
1. Appointment of Dennis Eaton to the Public Works Committee.
3
4
File Attachments for Item:
2. Resolution - Resolution Of The City Council Of Intent To Adopt An Official Schedule Of
Fees And Charges For The City Of Laurel And Repealing All Previous Resolutions That Set
Fees Or Charges That Conflict With The Schedule Attached Hereto Upon Its Effective Date.
5
R24-____ Intent to Adopt Schedule of Fees and Charges
RESOLUTION NO. R24-_____
RESOLUTION OF THE CITY COUNCIL OF INTENT TO ADOPT AN OFFICIAL
SCHEDULE OF FEES AND CHARGES FOR THE CITY OF LAUREL AND
REPEALING ALL PREVIOUS RESOLUTIONS THAT SET FEES OR CHARGES
THAT CONFLICT WITH THE SCHEDULE ATTACHED HERETO UPON ITS
EFFECTIVE DATE.
WHEREAS, the City Council previously adopted Resolution No. R24-04 establishing
the City of Laurel’s fees and charges for various services into a Schedule of Fees and Charges,
to enable citizens to have immediate access to the various fees and charges levied by the City
for various services, in a format that is easy to obtain and simple to understand;
WHEREAS, the Laurel Municipal Code requires the City Council to review, modify,
and/or update its fees and charges on an annual basis through further Resolution of the City
Council;
WHEREAS, at the direction of the City Council, City Staff prepared the attached
Schedule of Fees and Charges for the City Council's consideration;
WHEREAS, the City Council desires to have at least one public hearing to gather
public input and comments prior to adopting the Resolution approving the proposed Schedule
of Fees and Charges; and
WHEREAS, a public hearing is set to gather public input and comments prior to
adopting a Resolution approving the proposed Schedule of Fees and Charges.
NOW THEREFORE BE IT RESOLVED that the City Council hereby approves the
Resolution of Intent to adopt the Schedule of Fees and Charges attached hereto and
incorporated by reference herein; and
THEREFORE BE IT RESOLVED that a public hearing is set on the ______ day of
_____________, 2024 at 6:30 p.m.
Introduced at a regular meeting of the City Council on the ______ day of
_____________, 2024 by Council Member _____________________.
PASSED and APPROVED by the City Council of the City of Laurel, Montana on the
______ day of _____________, 2024.
APPROVED by the Mayor on the ______ day of _____________, 2024.
6
R24-____ Intent to Adopt Schedule of Fees and Charges
CITY OF LAUREL
___________________________
Dave Waggoner, Mayor
ATTEST:
_______________________________
Kelly Strecker, Clerk-Treasurer
APPROVED AS TO FORM:
______________________________
Michele L. Braukmann, Civil City Attorney
7
FY 24 Schedule of Fees and Charges
______, 2024
Resolution No. R24-__
Page 1 of 15
CITY OF LAUREL
SCHEDULE OF FEES AND CHARGES
AS OF TUESDAY, __________, 2024 / RESOLUTION NO. R24-__
Administrative, City Attorney, and Court Fees and Charges (except Library)
Item Fee
Returned Check $50.00
Document Photocopying
First three pages No Charge
Copies in excess of three pages per page $0.25
Discovery Fee
Fee for production of discovery documents – Flat fee for USB Drive $10.00
Additional Discovery Fee for Mailed Documents $10.00
Public Records Request/FOIA Request
Research City Records (Per Hour) $50.00
Research by Contracted Staff (Per Hour) $150.00-
$250.00
Research by City Attorney (Per Hour) $250.00
Dog License Fees and Renewals before April 1 (Must be renewed each year)
Spayed Female/Neutered Male $20.00
Un-spayed Female/Un-neutered Male $30.00
Dog License Renewals after April 1
Spayed Female/Neutered Male $30.00
Un-spayed Female/Un-neutered Male $40.00
Dog Kennel before April 1 (Must be renewed each year)
Non-Commercial $50.00
Commercial $75.00
Chicken License Fee – Flat Fee $25.00
Business License
General $100.00
Beer and/or Wine $400.00
Three Apartments $50.00
Four Apartments $60.00
Five or more Apartments $95.00
Pawn Shop $200.00
Utilities $400.00
Amusement Machines $100.00
Live Music $100.00
Junk $100.00
Liquor $500.00
Franchises $400.00
Sexually Oriented Business $750.00
8
FY 24 Schedule of Fees and Charges
______, 2024
Resolution No. R24-__
Page 2 of 15
Police Department Fees and Charges
Item Fee
Victims Report $10.00
Case Report $40.00
Case Report with Pictures $55.00
Vehicle Accident Report – Form Only $20.00
Vehicle Accident Report with Pictures $35.00
Audio Recording $75.00
Vehicle Impound – Per Day 1st Week $45.00
Vehicle Impound – Per Day after 1st Week $70.00
Dog Impound Fee – 1st in Calendar Year $35.00
Dog Impound Fee – Subsequent in Calendar Year $50.00
Dog Boarding Fee – 24 Hours After Notification – Per Day $100.00
Fingerprint Card $35.00
Subsequent Fingerprint Cards – Per Card $5.00
False Alarm – 3rd and Consecutive in Calendar Year $100.00
Library
Item Fee
Photocopy Fees – per page
Black & White $0.10
Color $0.20
Printer Fees – per page
Black and White $0.10
Color $0.20
Lost or Damaged Book Cost
Library Cards for Non-Residents No Charge
Interlibrary Loan Postage (per item not available via Courier – after 3) $5.00
Community Room
Use during library hours – for profit fee charged - per hour $3.00
Use after hours (per hour or any portion of an hour – for profit) $30.00
Refundable Cleaning Deposit $30.00
Library Card Replacement Fee (per card) $2.00
Fax Fees (per page)
Send No Charge
Receive $0.10
9
FY 24 Schedule of Fees and Charges
______, 2024
Resolution No. R24-__
Page 3 of 15
Fire Department Fees and Charges
Item Fee
Incident Report (NFIRS Copy) $50.00
Photograph Copies – Digital (USB) $35.00
Fire Suppression Fees Charged to Non-Resident or for Code or Ordinance
Violations
Base Rate for First Hour of Response for Working Fires, Rescue
Operations, Hazmat or Large-Scale Incidents
$2,000.00
Base Rate for First Hour of Service Assist Calls or Minor Calls $1,500.00
For Each Fireman – Per Hour $50.00
Base Rate for Assist and Investigate – Per Hour $250.00
Rates for Additional Hours after the First Hour of Any Response
(Time Calculated from Time of Response to Return to Service)
Engine #1 $500.00
Engine #2 $500.00
Engine #4 $500.00
Squad 5 $500.00
Tender #1 $225.00
Tender #2 $225.00
Support #1 $225.00
Command 1 $250.00
Command 2 $250.00
Brush #3 $250.00
Brush #4 $250.00
Brush #5 $250.00
Business Inspections within jurisdiction – Marketing Fireworks, Firecrackers,
and other Pyrotechnics
$250.00
False Fire Alarms – Per Calendar Year
First No Charge
Second $400.00
Third $800.00
Fourth+ $1,000.00
Fire Extinguisher Training
10 Students $250.00
Additional Per Student $25.00
10
FY 24 Schedule of Fees and Charges
______, 2024
Resolution No. R24-__
Page 4 of 15
Ambulance Service Fees
Code Definition Charge
A0425 Ambulance Mileage (per loaded mile) $20.00
A0428 Transport, BLS non-emergent $850.00
Out of District Fee $150.00
A0429 Transport, BLS emergent $1,200.00
Out of District Fee $150.00
A0426 Transport, ALS non-emergent $1,000.00
Out of District Fee $150.00
A0427 Transport, ALS emergent $1,400.00
Out of District Fee $150.00
A0433 Transport, ALS 2 emergent $1,600.00
Out of District Fee $150.00
A0434 Specialty Care Transport $2,000.00
A0424 Extra Ambulance Attendant $100.00
A0382 BLS routine supplies $100.00
A0398 ALS routine supplies $200.00
A0384 Defibrillation supplies $160.00
A0394 IV Supplies $75.00
A0396 Intubation $175.00
A0422 Oxygen $75.00
A0420 Waiting time (with patient) $75.00
Stand by Rate QRU (1 person) (per hour) $75.00
Stand by Rate Ambulance (2 person) (per hour) $100.00
TNT1 Simple response (lift assist, etc.) $25.00
TNT2 Response, treatment using BLS Supplies / no transport $50.00
TNT3 Response, treatment using ALS or ALS2 Supplies / no transport $100.00
Glucagon $300.00
Patient Care Report Copy (HIPAA Compliant) $25.00
11
FY 24 Schedule of Fees and Charges
______, 2024
Resolution No. R24-__
Page 5 of 15
Water Rates & Charges
Item Fee
See Current Resolution (Resolution No. R11-110)
System Development Fees (Based on Line Size) - Water
¾ Inch $2,500.00
1 Inch $4,475.00
1 ¼ Inch $6,950.00
1 ½ Inch $10,000.00
2 Inch $17,850.00
3 Inch $40,000.00
4 Inch $71,425.00
Connections to the water system with meters larger than 4 inches or when the
unique usage characteristics of a large water user may require, the City will
determine the system development fee at that time if the City can provide the
services as requested.
Curb Box Repair Insurance Fee – Per Month Per Water Account $1.00
Utility Hook-Up Fees
Water Tapping – Two Inches or Less $250.00
Water Tapping – Greater Than Two Inches Fee x 1.25
Labor/Operator Rate Per Hour $60.00
Heavy Equipment Rate Per Hour $100.00
Other Fees for Repairs, etc.
Frozen or Damaged Meter
Replacement Meter or Meter Parts Cost + 25%
Plus the Labor/Operator Rate Per Hour $60.00
OR Overtime Hourly Rate if Called Out After Hours $90.00
Hydrant Meter Rental – Per Month (Prorated Plus the Total Usage) $476.00
Utility Billing Fees and Deposits
New Accounts or Re-Establishing an Account $35.00
Restoring Service to a Delinquent Account $75.00
Deposit for New Meter Accounts, No Service in Previous Year $170.00
Charge for Check Returned by Bank as Unpaid $50.00
12
FY 24 Schedule of Fees and Charges
______, 2024
Resolution No. R24-__
Page 6 of 15
Wastewater Rates & Charges
Item Fee
See Current Resolution (Resolution No. R11-110)
Septic Dump Fee - $60.00
Minimum
up to 1,000
Gallons plus
$0.06 per
gallon
thereafter
Septic Clean-up Fee for Spillage (Resolution No. R15-96) $40.00
System Development Fees (Based on Line Size) – Sewer
Residential – Each Housing Unit (Duplex=2 units; Triplex=3 units;
Four-plex=4 units; etc.
$2,700.00
Commercial – Based on Water Meter Size; Includes Subdivision for
Rent or Lease
¾ Inch $2,700.00
1 Inch $4,833.00
1 ¼ Inch $7,506.00
1 ½ Inch $10,800.00
2 Inch $19,278.00
3 Inch $43,200.00
4 Inch $77,139.00
Connections to the wastewater system with water meters larger than 4 inches or
when the unique usage characteristics of a large water user may require, the City
will determine the system development fee at that time if the City can provide
the service as requested.
13
FY 24 Schedule of Fees and Charges
______, 2024
Resolution No. R24-__
Page 7 of 15
Solid Waste Fees and Charges
Item Fee
See Current Resolution (Resolution No. R22-77)
Multiple Containers – Non-Residential users who use multiple containers shall
be assigned a volume of use variable for each container used.
Roll Off Container Set/Reset $30.00
Roll Off Container Haul $150.00
Roll Off Container Cost per Ton Current Billings
Landfill Rates
Replacement Waste Container – Due to Negligence Cost x 1.50
All Tires – Per Tire $5.00
Container Site Waste – Business and Non-City Residents and/or City Residents
that do not use City Solid Waste Services
Minimum $10.00
Per Additional Cubic Yard $10.00
Non-Residential Garbage Disposal Rate Schedule – See Current Resolution
(R22-77)
Park and Recreation Fees and Charges
Item Fee
Shelter Reservation $50.00
Special Event Application Fee $35.00
Special Event in Parks
One Day Closure $100.00
Two Day Closure $150.00
Youth Activities Fee can be
waived by
the Mayor
Garbage Cans for Special Events – Per 100 Gallons – Prepaid Residential
Garbage
Rate
Special Event Clean-Up Fee – Per Hour/Per Employee $45.00
Riverside Park Camping Fees
Tent Space (per night) $20.00
Back-in Space (per night) $25.00
Pull Through Space (per night) $30.00
Riverside Park Building Reservation Fee
Small Meeting Room $50.00
Large Meeting Room W/ Kitchen $400.00
Damage/Cleaning Deposit – Refundable Upon Inspection $400.00
Monthly Meetings in Small Room W/ Use of Large Room Once – Per
Year
$750.00
14
FY 24 Schedule of Fees and Charges
______, 2024
Resolution No. R24-__
Page 8 of 15
Cemetery Fees
Item Fee
Please Note: Cemetery Caretaker must be present at all interments.
Please Note: Burials are not permitted on Sundays, holidays, or Saturday
afternoons.
City Residents
Full Grave $550.00
Baby Grave $400.00
Non-Residents
Full Grave $700.00
Baby Grave $450.00
Opening and Closing
Full Grave $380.00
Full Grave on Saturday mornings $480.00
Baby Grave $300.00
Baby Grave on Saturday mornings $350.00
Cremation $250.00
Cremation on Saturday mornings $300.00
Two Cremations on single plot $325.00
Two Cremations on single plot on Saturday mornings $400.00
Set Cremation Urn at existing Headstones $40.00
Private Sale of any plot – Transfer Processing Fee $45.00
Disinterment Fee for full burial $400.00
Disinterment Fee for cremains $325.00
15
FY 24 Schedule of Fees and Charges
______, 2024
Resolution No. R24-__
Page 9 of 15
Planning Item
Item Fee Notes
Annexation into the City of Laurel (80 acres or less) $ 750.00 + $35.00/acre
Annexation into the City of Laurel (81 acres or more) $ 750.00 + $55.00/acre
Cash in Lieu of Parking spaces outside of the Central
Business District $ 850.00 + $25.00/space
Conditional Use Application (Commercial) $ 1,350.00
Conditional Use Application (Residential) $ 850.00
Floodplain Permit $ 300.00
Home Occupations $ 200.00
Outdoor Seating $ 300.00 +$25.00/day
Planned Unit Development Concept Plan $ 850.00
Planned Unit Development Preliminary Plan $ 1,350.00 +$50.00/acre
Planned Unit Development Final Plan $ 1,600.00 +$25.00/acre
Review of Buildings for Lease or Rent $ 350.00
Site Plan Review Fee (Commercial) $ 600.00
Site Plan Review Fee (Residential) $ 350.00
Special Review (Commercial) $ 1,350.00
Special Review (Residential) $ 850.00
Special Review Applications resubmitted within one
year of a withdrawal request made after the legal
advertising
$ 600.00
Staff Research $ 50.00 Per Hour
Temporary Use Permit $ 450.00
Vacation of Street or Alley $ 350.00
Variance (Commercial) $ 1,350.00
Variance (Residential) $ 850.00
Variance Applications resubmitted within one year of
a withdrawal request made after the legal advertising $ 850.00
Zone Change $ 1,350.00 + $45.00/acre
Zone Change Applications resubmitted within 1 year
of a withdrawal request made after the legal
advertising
$ 850.00
Zoning Compliance/Verification Letter $ 200.00
Zoning Map Amendment $ 1,750.00 + $45.00/acre
16
FY 24 Schedule of Fees and Charges
______, 2024
Resolution No. R24-__
Page 10 of 15
Subdivision
Item Fee Notes
Corrections or Adjustments to Plats, Conditions, and
Supporting Documents after Preliminary Plat
Approval: $ 350.00
Corrections or Vacations of Recorded Final
Subdivision Plats or Supporting Documents $ 350.00
Exempt Subdivision $ 400.00
Preliminary Plat (Minor) $ 1,950.00 + $50.00/lot
Final Plat (Minor) $ 1,350.00
Preliminary Plat, Major Subdivision, 6 to 40 lots $ 2,250.00 + $25.00/lot
Final Plat, Major Subdivision, 6 to 40 lots $ 1,750.00
Preliminary Plat, Major Subdivision, 41 to 200 lots $ 2,950.00 + $25.00/lot
Final Plat, Major Subdivision, 41 to 200 lots $ 2,500.00
Preliminary Plat, Major Subdivision, Over 200 lots $ 3,750.00 + $25.00/lot
Final Plat, Major Subdivision, Over 200 lots $ 3,500.00
Major Adjustments for Minor Subdivisions $ 750.00
Major Adjustments for Major Subdivision, 6 to 40
lots $ 1,350.00
Major Adjustments for Major Subdivision, 41 to 200
lots $ 1,850.00
Major Adjustments for Major Subdivision, Over 200
lots $ 2,350.00
Minor Adjustments, Major and Minor Subdivisions $ 350.00
Pre-Application Meeting $ 750.00 + $25.00/lot
Subdivision for Rent or Lease, Final Plan $ 1,500.00
Subdivision for Rent or Lease, Preliminary Plan $ 1,250.00
All Appeals the same as the Application Fee
17
FY 24 Schedule of Fees and Charges
______, 2024
Resolution No. R24-__
Page 11 of 15
Building Permit
Item Fee Notes
Additional Plan Review required by changes,
additions or revisions to plans (minimum charge - one
half hour) $ 100.00
Per Hour
Additional Re-Inspection Fee $ 100.00
Building Permit - See Appx. A
Deck Permit $25.00 Per sq.ft.
Demolition Permit – Residential $500.00
Demolition Permit – Commercial - See Appx. A
Encroachment Permit $ 150.00
Fence Permit $ 100.00
Fire Inspection (includes one follow-up inspection) $ 100.00
Mobile Home Blocking Permit (includes two-meter
inspections) $ 100.00
Moving Permit $ 250.00
Photocopies (over 3 pages) $ 0.25 Per Page
Plan Review (Commercial) -
65% of
Building
Permit Fee
Plan Review (Residential) -
50% of
Building
Permit Fee
Plotter Photocopies $ 10.00 Per page
Right-of-way Excavation Permit (Gravel) $ 150.00
Right-of-way Excavation Permit (Paved) $ 200.00
Roofing Permit (Commercial) $ 250.00
Roofing Permit (Residential) $ 150.00
Siding Installation Permit $ 100.00
Sidewalk, Driveway Approach, Curb & Gutter Permit $ 150.00
Sign Permit $1.00 Per sq.ft.
Sign Plan Review Fees $2.00 Per sq.ft.
Sign – Face Change $30.00 Per face
Solar Permit Residential $250.00
Solar Permit Commercial $300.00
Temporary Sign Permit $ 75.00
Temporary Structure Permit $ 150.00
Window and/or Door Replacement Installation
Permit – No Structural Modifications $ 75.00
Per structure
or building
18
FY 24 Schedule of Fees and Charges
______, 2024
Resolution No. R24-__
Page 12 of 15
APPENDIX A: BUILDING PERMIT FEES
Building permit fees are determined by the total valuation of the project. For new construction
and additions, the total valuation is determined by the most recent valuation data published by
the International Code Council. For remodel projects, the total valuation is based on the
documented project cost. (RPR is Residential Plan Review, CPR is Commercial Plan Review)
Valuation Building
Permit
Residential Plan
Review
Commercial Plan
Review
From To
$ 1.00 $ 500.00 $ 36.00 $ 18.00 $ 23.40
$ 501.00 $ 600.00 $ 40.50 $ 20.25 $ 26.33
$ 601.00 $ 700.00 $ 45.00 $ 22.50 $ 29.25
$ 701.00 $ 800.00 $ 49.50 $ 24.75 $ 32.18
$ 801.00 $ 900.00 $ 54.00 $ 27.00 $ 35.10
$ 901.00 $ 1,000.00 $ 58.50 $ 29.25 $ 38.03
$ 1,001.00 $ 1,100.00 $ 63.00 $ 31.50 $ 40.95
$ 1,101.00 $ 1,200.00 $ 67.50 $ 33.75 $ 43.88
$ 1,201.00 $ 1,300.00 $ 72.00 $ 36.00 $ 46.80
$ 1,301.00 $ 1,400.00 $ 76.50 $ 38.25 $ 49.73
$ 1,401.00 $ 1,500.00 $ 81.00 $ 40.50 $ 52.65
$ 1,501.00 $ 1,600.00 $ 85.50 $ 42.75 $ 55.58
$ 1,601.00 $ 1,700.00 $ 90.00 $ 45.00 $ 58.50
$ 1,701.00 $ 1,800.00 $ 94.50 $ 47.25 $ 61.43
$ 1,801.00 $ 1,900.00 $ 99.00 $ 49.50 $ 64.35
$ 1,901.00 $ 2,000.00 $ 103.50 $ 51.75 $ 67.28
$ 2,001.00 $ 3,000.00 $ 125.50 $ 62.25 $ 80.93
$ 3,001.00 $ 4,000.00 $ 145.50 $ 72.75 $ 94.58
$ 4,001.00 $ 5,000.00 $ 166.50 $ 83.25 $ 108.23
$ 5,001.00 $ 6,000.00 $ 187.50 $ 93.75 $ 121.88
$ 6,001.00 $ 7,000.00 $ 208.50 $ 104.25 $ 135.53
$ 7,001.00 $ 8,000.00 $ 229.50 $ 114.75 $ 149.18
$ 8,001.00 $ 9,000.00 $ 250.50 $ 125.25 $ 162.83
$ 9,001.00 $ 10,000.00 $ 271.50 $ 135.75 $ 176.48
$ 10,001.00 $ 11,000.00 $ 292.50 $ 146.25 $ 190.13
$ 11,001.00 $ 12,000.00 $ 313.50 $ 156.75 $ 203.78
$ 12,001.00 $ 13,000.00 $ 335.50 $ 167.25 $ 217.43
$ 13,001.00 $ 14,000.00 $ 355.50 $ 177.75 $ 231.08
$ 14,001.00 $ 15,000.00 $ 376.50 $ 188.25 $ 244.73
$ 15,001.00 $ 16,000.00 $ 397.50 $ 198.75 $ 258.38
$ 16,001.00 $ 17,000.00 $ 418.50 $ 209.25 $ 272.03
$ 17,001.00 $ 18,000.00 $ 439.50 $ 219.75 $ 285.68
19
FY 24 Schedule of Fees and Charges
______, 2024
Resolution No. R24-__
Page 13 of 15
$ 18,001.00 $ 19,000.00 $ 460.50 $ 230.25 $ 299.33
$ 19,001.00 $ 20,000.00 $ 481.50 $ 240.75 $ 312.98
$ 20,001.00 $ 21,000.00 $ 502.50 $ 251.25 $ 326.63
$ 21,001.00 $ 22,000.00 $ 523.50 $ 261.75 $ 340.28
$ 22,001.00 $ 23,000.00 $ 544.50 $ 272.25 $ 353.93
$ 23,001.00 $ 24,000.00 $ 565.50 $ 282.75 $ 367.58
$ 24,001.00 $ 25,000.00 $ 586.50 $ 293.25 $ 381.23
$ 25,001.00 $ 26,000.00 $ 601.50 $ 300.75 $ 390.98
$ 26,001.00 $ 27,000.00 $ 616.50 $ 308.25 $ 400.73
$ 27,001.00 $ 28,000.00 $ 633.00 $ 316.50 $ 411.45
$ 28,001.00 $ 29,000.00 $ 648.00 $ 324.00 $ 421.20
$ 29,001.00 $ 30,000.00 $ 663.00 $ 331.50 $ 430.95
$ 30,001.00 $ 31,000.00 $ 678.00 $ 339.00 $ 440.70
$ 31,001.00 $ 32,000.00 $ 693.00 $ 346.50 $ 450.45
$ 32,001.00 $ 33,000.00 $ 708.00 $ 354.00 $ 460.20
$ 33,001.00 $ 34,000.00 $ 723.00 $ 361.50 $ 469.95
$ 34,001.00 $ 35,000.00 $ 738.00 $ 369.00 $ 479.70
$ 35,001.00 $ 36,000.00 $ 753.00 $ 376.50 $ 489.45
$ 36,001.00 $ 37,000.00 $ 768.00 $ 384.00 $ 499.20
$ 37,001.00 $ 38,000.00 $ 784.50 $ 392.25 $ 509.93
$ 38,001.00 $ 39,000.00 $ 799.50 $ 399.75 $ 519.68
$ 39,001.00 $ 40,000.00 $ 814.50 $ 407.25 $ 529.43
$ 40,001.00 $ 41,000.00 $ 829.50 $ 414.75 $ 539.18
$ 41,001.00 $ 42,000.00 $ 844.50 $ 422.25 $ 548.93
$ 42,001.00 $ 43,000.00 $ 859.50 $ 429.75 $ 558.68
$ 43,001.00 $ 44,000.00 $ 874.50 $ 437.25 $ 568.43
$ 44,001.00 $ 45,000.00 $ 889.50 $ 444.75 $ 578.18
$ 45,001.00 $ 46,000.00 $ 904.50 $ 452.25 $ 587.93
$ 46,001.00 $ 47,000.00 $ 919.50 $ 459.75 $ 597.68
$ 47,001.00 $ 48,000.00 $ 934.50 $ 467.25 $ 607.43
$ 48,001.00 $ 49,000.00 $ 949.50 $ 474.75 $ 617.18
$ 49,001.00 $ 50,000.00 $ 964.50 $ 482.25 $ 626.93
$ 50,001.00 $ 51,000.00 $ 976.50 $ 488.25 $ 634.73
$ 51,001.00 $ 52,000.00 $ 987.00 $ 493.50 $ 641.55
$ 52,001.00 $ 53,000.00 $ 997.50 $ 498.75 $ 648.38
$ 53,001.00 $ 54,000.00 $ 1,008.00 $ 504.00 $ 655.20
$ 54,001.00 $ 55,000.00 $ 1,018.50 $ 509.25 $ 662.03
$ 55,001.00 $ 56,000.00 $ 1,029.00 $ 514.50 $ 668.85
$ 56,001.00 $ 57,000.00 $ 1,039.50 $ 519.75 $ 675.68
$ 57,001.00 $ 58,000.00 $ 1,050.00 $ 525.00 $ 682.50
$ 58,001.00 $ 59,000.00 $ 1,060.50 $ 530.25 $ 689.33
20
FY 24 Schedule of Fees and Charges
______, 2024
Resolution No. R24-__
Page 14 of 15
$ 59,001.00 $ 60,000.00 $ 1,071.00 $ 535.50 $ 696.15
$ 60,001.00 $ 61,000.00 $ 1,081.50 $ 540.75 $ 702.98
$ 61,001.00 $ 62,000.00 $ 1,092.00 $ 546.00 $ 709.80
$ 62,001.00 $ 63,000.00 $ 1,102.50 $ 551.25 $ 716.63
$ 63,001.00 $ 64,000.00 $ 1,113.00 $ 556.50 $ 723.45
$ 64,001.00 $ 65,000.00 $ 1,123.50 $ 561.75 $ 730.28
$ 65,001.00 $ 66,000.00 $ 1,134.00 $ 567.00 $ 737.10
$ 66,001.00 $ 67,000.00 $ 1,144.50 $ 572.25 $ 743.93
$ 67,001.00 $ 68,000.00 $ 1,155.00 $ 577.50 $ 750.75
$ 68,001.00 $ 69,000.00 $ 1,165.50 $ 582.75 $ 757.58
$ 69,001.00 $ 70,000.00 $ 1,176.00 $ 588.00 $ 764.40
$ 70,001.00 $ 71,000.00 $ 1,186.50 $ 593.25 $ 771.23
$ 71,001.00 $ 72,000.00 $ 1,197.00 $ 598.50 $ 778.05
$ 72,001.00 $ 73,000.00 $ 1,207.50 $ 603.75 $ 784.88
$ 73,001.00 $ 74,000.00 $ 1,218.00 $ 609.00 $ 791.70
$ 74,001.00 $ 75,000.00 $ 1,228.50 $ 614.25 $ 798.53
$ 75,001.00 $ 76,000.00 $ 1,239.00 $ 619.50 $ 805.35
$ 76,001.00 $ 77,000.00 $ 1,249.50 $ 624.75 $ 812.18
$ 77,001.00 $ 78,000.00 $ 1,260.00 $ 630.00 $ 819.00
$ 78,001.00 $ 79,000.00 $ 1,270.50 $ 635.25 $ 825.83
$ 79,001.00 $ 80,000.00 $ 1,281.00 $ 640.50 $ 832.65
$ 80,001.00 $ 81,000.00 $ 1,291.50 $ 645.75 $ 839.48
$ 81,001.00 $ 82,000.00 $ 1,302.00 $ 651.00 $ 846.30
$ 82,001.00 $ 83,000.00 $ 1,312.50 $ 656.25 $ 853.13
$ 83,001.00 $ 84,000.00 $ 1,323.00 $ 661.50 $ 859.95
$ 84,001.00 $ 85,000.00 $ 1,333.50 $ 666.75 $ 866.78
$ 85,001.00 $ 86,000.00 $ 1,344.00 $ 672.00 $ 873.60
$ 86,001.00 $ 87,000.00 $ 1,354.50 $ 677.25 $ 880.43
$ 87,001.00 $ 88,000.00 $ 1,365.00 $ 682.50 $ 887.25
$ 88,001.00 $ 89,000.00 $ 1,375.50 $ 687.75 $ 894.08
$ 89,001.00 $ 90,000.00 $ 1,386.00 $ 693.00 $ 900.90
$ 90,001.00 $ 91,000.00 $ 1,396.50 $ 698.25 $ 907.73
$ 91,001.00 $ 92,000.00 $ 1,407.00 $ 703.50 $ 914.55
$ 92,001.00 $ 93,000.00 $ 1,417.50 $ 708.75 $ 921.38
$ 93,001.00 $ 94,000.00 $ 1,428.00 $ 714.00 $ 928.20
$ 94,001.00 $ 95,000.00 $ 1,438.50 $ 719.25 $ 935.03
$ 95,001.00 $ 96,000.00 $ 1,449.00 $ 724.50 $ 941.85
$ 96,001.00 $ 97,000.00 $ 1,459.50 $ 729.75 $ 948.68
$ 97,001.00 $ 98,000.00 $ 1,470.00 $ 735.00 $ 955.50
$ 98,001.00 $ 99,000.00 $ 1,480.50 $ 740.25 $ 962.33
$ 99,001.00 $ 100,000.00 $ 1,491.00 $ 745.50 $ 969.15
21
FY 24 Schedule of Fees and Charges
______, 2024
Resolution No. R24-__
Page 15 of 15
$100,001 - $500,000: $1491.00 for the first $100,000, plus $6.40 for each additional
$1,000 or portion thereof.
$500,001 - $1,000,000: $4,051.00 for the first $500,000 plus $5.47 for each additional
$1,000 or portion thereof.
$1,000,000 and up: $6,239.00 for the first $1,000,000 plus $4.58 for each additional
$1,000 or portion thereof.
Residential Plan Review = 50% of Permit Fee
Commercial Plan Review = 65% of Permit Fee
If work has started prior to issuance of a permit, the Building Permit Fee will double.
Basements
o Finished - $50 per sq.ft.
o Unfinished – refer to the most recent ICC Building Valuation Table
22
File Attachments for Item:
3. Resolution - A Resolution Of The City Council Approving The Standards For Public Works
Manual For The City Of Laurel Public Works Department.
23
R24-____ Approve Standards for Public Works Improvements Manual
RESOLUTION NO. R24-_____
A RESOLUTION OF THE CITY COUNCIL APPROVING THE STANDARDS FOR
PUBLIC WORKS MANUAL FOR THE CITY OF LAUREL PUBLIC WORKS
DEPARTMENT.
BE IT RESOLVED by the City Council of the City of Laurel, Montana,
Section 1: Approval. The Standards for Public Works Manual for the City of Laurel
Public Works Department (hereinafter “Standards for Public Works Manual”), a copy attached
hereto and incorporated herein, is hereby approved.
Section 2: Execution. The Mayor is hereby given authority to execute the Standards
for Public Works Manual on behalf of the City.
Introduced at a regular meeting of the City Council on the _____ day of February, 2024,
by Council Member ________________.
PASSED and APPROVED by the City Council of the City of Laurel the _____ day of
February, 2024.
APPROVED by the Mayor the _____ day of February, 2024.
CITY OF LAUREL
___________________________
Dave Waggoner, Mayor
ATTEST:
_______________________________
Kelly Strecker, Clerk-Treasurer
APPROVED AS TO FORM:
______________________________
Michele L. Braukmann, Civil City Attorney
24
Standards For
Public Works Improvements
for the
City of Laurel, MT
January 2024
KLJ
2611 Gabel Road
Billings, MT. 59102
(406) 245-5499
Project No. 1894-02569
25
KLJ #1804-02569 City of Laurel Standards for Public Works Improvements
Table of Contents Page 1 of 3
Standards for Public Works Improvements
City of Laurel, MT
Table of Contents
Contents Page
Part 1 – General Provisions 1-1
1. Provisions 1-1
2. Defini�ons 1-1
Part 2 – General Engineering Submital Requirements 2-1
1. Complete Submital Package 2-1
2. Right-of-Way and Easement Plats and Legal Descrip�ons, if needed 2-3
3. Soils and Geotechnical Report 2-3
4. Stormwater Analysis and design report 2-3
Part 3 – Construc�on Changes/Revisions Reserved 3-1
Part 4 – As-Built Plan Reserved 4-1
Part 5 – Street Design Technical Standards 5-1
1. General Condi�ons 5-1
2. Design Criteria for Streets 5-1
3. Grading 5-2
4. Pavement, Structural Sec�ons 5-2
5. U�lity Placement Within Streets 5-3
6. Site Triangle 5-3
7. Alleys 5-3
8. Curb and Guter, Sidewalks 5-4
9. Driveways 5-4
10. Street Sign Names 5-5
11. Survey Monuments 5-5
12. Repairing U�lity Cuts 5-5
13. Street Ligh�ng 5-6
Part 6 – Sewer Design 6-1
1. Purpose 6-1
2. Reference 6-2
3. Approval of Alterna�ve Materials or Methods 6-2
4. Montana Department of Environmental Quality Standards 6-2
5. Special Problems 6-2
6. Design Plans and Profiles 6-2
7. Specifica�ons 6-4
8. Addi�onal Items of Concern 6-4
9. General Design Considera�ons 6-4
10. Capacity 6-5
11. Design Flows Factors of considera�ons 6-5
12. Size 6-5
13. Pipe Materials 6-6
14. Excava�on, Pipe Bedding and Backfill 6-6
15. Grade 6-8
26
KLJ #1804-02569 City of Laurel Standards for Public Works Improvements
Table of Contents Page 2 of 3
16. Minimum Depth 6-8
17. Loca�on 6-8
18. Alignment 6-9
19. Change in Pipe Size 6-9
20. Manholes and Cleanouts 6-9
21. Pipe Joints 6-13
22. Service Lateral (Side Sewer or House Branch) Connec�ons 6-13
23. House or Building Sewers 6-13
24. Separate Connec�on Required 6-13
25. Steep Slope Protec�on 6-14
26. Drainage Ditch or Stream Crossings 6-14
27. Aerial Crossings 6-14
28. Protec�on of Water Supplies 6-14
29. Sewer Services and Plumbing 6-16
30. Design Standards for Alterna�ve Sewer Systems 6-16
31. Li� Sta�ons 6-18
Part 7 – Water Design 7-1
1. Purpose 7-1
2. References 7-1
3. Approval of Alterna�ve Materials or Methods 7-1
4. Special Problems 7-2
5. Design Plans and Profiles 7-2
6. Specifica�ons 7-3
7. Addi�onal Items of Concerns 7-4
8. General Design Considera�ons 7-4
9. Capacity 7-5
10. Size 7-6
11. Pipe Materials 7-6
12. Minimum Depth 7-8
13. Dead Ends 7-8
14. Valve 7-8
15. Hydrants 7-8
16. Loca�on 7-8
17. Pipe Joints 7-9
18. Service Line Connec�ons 7-9
19. Separate Connec�on Required 7-9
20. Drainage Ditch or Stream Crossings 7-9
21. Aerial Crossings 7-10
Part 8 – Storm Sewer Design 8-1
1. Introduc�on 8-1
2. Project Classifica�on 8-1
3. Plan Submital Requirements 8-5
4. Rainfall 8-8
5. Runoff 8-10
6. Hydraulic Analysis and Design 8-15
7. Erosion and Sediment Control 8-26
Appendix A Preliminary Drainage Report App-A
Appendix B Final Drainage Report App-B
Appendix C Geotechnical/ Hydrogeological Report App-C
27
KLJ #1804-02569 City of Laurel Standards for Public Works Improvements
Table of Contents Page 3 of 3
Appendix D Opera�ons and Maintenance App-D
Appendix E HOA Agreement Requirements App-E
28
Part 1 – General Provisions 1-1
Part 1 - General Provisions
1.1 ESTABLISHMENT OF MINIMUM STANDARDS
These Standards for Public Works Improvements are prepared for the purpose of
adop�ng minimum standards for the design of improvements, kind and use of
materials, methods of construc�on, and the prepara�on of plans for construc�on,
repair, or altera�on of streets, roadways, alleys, drainage, sewer, or water facili�es
which lie within the City of Laurel.
1.2 UNIFORMITY OF ENGINEERING AND CONSTRUCTION PRACTICES
These Standards for Public Works Improvements are established to promote the
maximum uniformity of engineering and construc�on prac�ces within the
community and thereby reduce design, supply, construc�on, and maintenance
costs.
1.3 General Specifica�ons
Use Latest Edi�on of Montana Public Works Standard Specifica�ons Including
Addendums Thereto and as Supplemented Herein.
1.4 General Design Standards
Use Latest Edi�on of State of Montana Department of Environmental Quality Water
Quality Division Circulars and as Supplemented Herein.
1.5 Adherence to Standards
It will be the policy of the Department of Public Works to require adherence to
the Standards set forth herein; however, where unique circumstances of design
considera�on make it imprac�cal to follow the Standards and where such
adherence would actually create problems detrimental to the public interest, the
Department of Public Works will consider alternate solu�ons and may approve
departures from Standards when substan�ated by design analysis.
2.Defini�ons
2.1 For the purposes of these specifica�ons, the words and phrases set out in the
following ar�cles shall have the meanings as follows:
•“Alley” means a narrow public thoroughfare, providing access to the rear of the
abu�ng proper�es. It also serves primarily as a service access to individual lots.
29
Part 1 – General Provisions 1-2
•"Appurtenances" refers to machinery, appliances, or auxiliary structures
atached to the sewer or water system to enable it to func�on, but not
considered an integral part of it.
•“Bicycle Path” and/or “Walkway” is an access way for non-motored use, primarily
for recrea�on use.
•“Boulevard” within the City is that area within any street, avenue, or highway right-
of-way not occupied by street paving, curb and guter, and sidewalks. An “inside
boulevard” is the boulevard area on the property line side of the sidewalk. An
“outside boulevard” is the boulevard areas on the street side of the sidewalk.
•"Building Sewer" means the privately-owned extension of the building drain to
the public sanitary sewer or other place of disposal.
•"City" or "City of Laurel" means the City of Laurel in the County of Yellowstone and
State of Montana.
•“Collector Street” is a street used for major traffic flow. Access to residen�al lots
should be discouraged, and access to business lots should require turning lanes.
•"Combined Sewer" shall mean a sewer receiving both surface runoff and sewage.
•“Cross-slope” is the gradient determined by dividing the difference in eleva�on
from crown to pavement edge by the horizontal distance from crown to
pavement edge, expressed as a percentage.
•“Crown” is the highest part of the street shape between paving edges.
•"Curb Cut" means the total street curbing that is removed to place a driveway
and slopes.
•"Curb Return" means the curved por�on of a street curb at drive approaches.
•"Customer" means any person receiving municipal u�lity service either
directly or indirectly from the municipal water supply system/municipal
wastewater system.
•"Discharge" is the direct or indirect introduc�on of treated or untreated
wastewater into the waters of the State of Montana, either through the
municipal wastewater system and municipal wastewater treatment plant or
30
Part 1 – General Provisions 1-3
through a point source into State waters.
•"Domes�c Wastes" means liquid wastes
from the non-commercial prepara�on, cooking, and handling of food, or
containing human excrement and similar mater from the sanitary
conveniences of dwellings, commercial buildings, industrial facili�es, and
ins�tu�ons.
•"Driveway" means that area on private property where vehicles are operated,
parked, or allowed to stand.
•"Driveway Apron" means the area, construc�on or improvement between the
curb cut or proposed curb line and the back edge of walk or proposed walk line,
to provide ingress and egress for vehicles from the alley, street or roadway to a
definite area of the private p roperty.
•"Driveway Width" means that por�on of the street curbing that is removed
excluding curb returns or transi�ons to provide ingress to and egress from
abu�ng property.
•"Environmental Protec�on Agency" or "EPA", means the U.S. Environmental
Protec�on Agency, or, where appropriate, the terms may also be used as a
designa�on for the administrator or other duly authorized official of EPA.
•"Excava�on" shall mean and include any ditch, trench, cut, hole or change of
grade, including changes made by road grading by means of a blade or other
device that removes, alters or adds dirt, gravel, or alters the crown of a street or
alley or affects drainage.
•"Extension" means the act or process of extending, adding to, or enlarging the
municipal water supply system/municipal wastewater system on the City's
side of the point of delivery/point of connec�on to provide municipal u�lity
services to a prospec�ve customer or group of prospec�ve customers.
•"Fire Hydrant Meter" means the meter which is owned by the municipal u�lity
and which is used to measure the amount of water delivered to a customer
through a fire hydrant.
•"Fireline" means all service pipes, curb stops and/or valves, curb boxes and/or
valve boxes, backflow preven�on devices, check valves, inside
31
Part 1 – General Provisions 1-4
piping, fi�ngs, fixtures, and any other apparatus on customer's side of the
point of delivery that is used for, and limited to, the providing of water to
customers for fire suppression ac�vi�es.
•“Grade” is the slope of the longitudinal road profile generally measured along
the centerline, expressed as a percentage.
•"Holding Tank Waste" means any waste from holding tanks such as vessels,
chemical toilets, campers, trailers, recrea�onal vehicles, or septage haulers.
•"Individual Extension" means an extension of the u�lity system to provide
u�lity service to an individual customer.
•"Industrial" means of or pertaining to industry, manufacturing, agriculture,
commerce, trade, or business.
•"Industrial User" means (a) any person or source that introduces or discharges
wastewater from industrial processes into the municipal wastewater system or
(b) any non-domes�c user or source regulated under Sec�ons 307(b), (c), or (d)
of the Clean Water Act.
•"Industrial Wastes" or "Industrial Wastewater'' means all liquid or water-
carried wastes other than domes�c wastes. The terms includes, by way of
example and not by limita�on, the trade wastes produced by food processing
and botling plants, food manufacturing plants, slaughtering plants, tallow
works, pla�ng works, disposal services, industrial cleaning plants, fer�lizer
plants, car and truck washing opera�ons, vehicle repair facili�es, commercial
laundries and cleaning establishments, cooling plants, industrial plants,
factories, feedlots, and chemical treatment installa�ons.
•"Interceptor Sewer" means a public sanitary sewer having a size greater than 24
inches that was installed by the City for the principal purpose of collec�ng and
conveying wastewater from several district trunk sewers to the municipal
wastewater treatment plant for treatment and disposal.
•"Intersec�on" means that area embraced within the prolonga�on or connec�on
of the lateral curb lines, or if none, then the lateral boundary lines of the
roadways which join each other at, or approximately at, right angles, or the area
within which vehicles traveling upon different roadways joining at any other
angle may come in conflict.
•“Local Street” is a street which provides access to individual lots or areas. Cul-
de-sacs are within this category. Traffic flow of 400 vehicles per day or less.
32
Part 1 – General Provisions 1-5
•"Main" means a pipe or conduit carrying water for domes�c, industrial, fire
suppression, and other similar uses.
•"Meter" means the instrument, including any auxiliary equipment, which is
used to measure the amount of water delivered to a customer from the
municipal water supply system or the amount of wastewater contributed to
the municipal wastewater system by a user.
•"Municipal Wastewater Treatment Plant" means the wastewater treatment
plant owned and controlled by the City of Laurel.
•"Municipal Water Meter" means the meter, including the meter horn and
remote read equipment, which is owned by the u�lity and which is used to
measure the amount of water delivered to a customer through the customer's
water service line.
•"Municipal U�lity" or "U�lity" means the Public Works Department of the City of
Laurel.
•"Natural Outlet" means any outlet into a water course, pond, ditch, lake, or
other body of surface or ground water.
•"Person" means any firm, company, partnership, public or private corpora�on,
associa�on, group or society, governmental agency, or other en�ty as well as a
natural person.
•"pH" refers to the nega�ve logarithm of the hydrogen ion concentra�on in
moles per liter of solu�on. pH is an indicator of the acid or base content of the
solu�on.
•"Point of Connec�on" means the point at which the municipal wastewater
system connects physically to a user's building sewer. The point of connec�on
shall be located at and include the user's service tee or wye fi�ng, which, in
turn, is normally atached to the public sanitary sewer located in the public right-
of-way that abuts and fronts the property to be served.
•"Point of Delivery" means the point at which the municipal water supply
system connects physically to a customer's corpora�on stop, which, in turn, is
normally atached to the public water main located in the public right-of way
that abuts and fronts the property to be served.
•"Pollutant" means any dredged soil, solid waste, incinerator residue, sewage,
garbage, sep�c waste, sewage sludge, muni�ons, chemical wastes, biological
33
Part 1 – General Provisions 1-6
materials, radioac�ve materials, heat, wrecked or discharged equipment, rock,
sand, cellar dirt, and industrial, municipal, and agricultural waste discharges
into water.
•"Pollu�on" means the altera�on of the chemical, physical, biological, or
radiological integrity of water by human ac�vity.
•"Polluted Waters" means water that contains objec�onable wastes or
suspended solids as a result of human ac�vity.
•"Pretreatment" or "Treatment" means the reduc�on of the amount of
pollutants, the elimina�on of pollutants, the altera�on of the rate of their
introduc�on into the municipal wastewater system, or the altera�on of the
nature of pollutant proper�es in wastewater to a less harmful state, prior to or
in lieu of discharging or otherwise introducing such pollutants into a
municipal wastewater system. The reduc�on or alterna�on can be achieved by
physical, chemical, or biological processes, process changes, or by other
means, except as prohibited by 40 CFR Sec�on 403.6(d).
•"Pretreatment Requirement" means any substan�ve or procedural
requirement related to pretreatment, including Na�onal Categorical
Pretreatment Standards, imposed on an industrial user.
•“Private Water Service” means the water line owned by the property owner to
include curb stop, curb box, service line, meter loop and all internal building
piping excluding the water meter.
•"Public Building" means any building held, used, or controlled exclusively for
public purposes by any department or branch of government, federal, state,
county, or municipal, without reference to the ownership of the building or of the
realty upon which it is situated.
•"Public Sanitary Sewer'' means the sewer directly controlled by the City and
laid in the street or other right-of-way for the collec�on of wastewaters from
users' building sewers.
•"Public Service Commission" refers to the elected body of Public Service
Commissioners and their staff of the State of M ontana.
•"Public Water Main" means the main directly controlled by the City and laid in
the street or other right-of-way for the distribu�on of water to customers’
water service lines.
34
Part 1 – General Provisions 1-7
•"Rate Schedule" means a resolu�on approved by the City Council which sets
forth the charges and condi�ons for a par�cular class or type of u�lity service.
•"Readily Accessible" means safely and easily reached and not being under
"lock and key", "fenced in", "covered up", or otherwise obstructed.
•“Residen�al street” is a street which provides main ingress and egress to a
subdivision or neighborhood. Traffic flows of 400 vehicles per day to 4500
vehicles per day.
•” Right-of-Way” means public property dedicated for streets, alleys, or other
public uses.
•“Roadway” means that por�on of the street improved, designed, and customarily
used for vehicular travel, exclusive of the berm or shoulder.
•"Sanitary Sewer'' means a sewer that carries wastewater or sewage.
•"Sanitary Sewer Service Line" or 'Wastewater Service Line" means that por�on of
the privately-owned building sewer extending from the property served to the
public sanitary sewer.
•"Secondary Wastewater Meter'' or "Secondary Meter" means a meter which is
furnished, installed, and maintained by a user, and which is used to
determine the amount of wastewater contributed by such user to the
municipal wastewater system.
•"Septage" means the mixed liquid and solid contents pumped from sep�c
tanks used for receiving primarily segregated domes�c wastes or wastes from
sanitary conveniences.
•"Septage Disposal Permit" means a writen receiving �cket issued by the City of
Laurel permi�ng the discharge of septage into the City of Laurel's approved
loca�on in accordance with the provisions of these rules and regula�ons.
•"Septage Hauler" means a person having a valid City of Laurel business license,
when appropriate, and, in addi�on, licensed by state and local government
agencies to operate a business for the purpose of cleaning sep�c tanks and
transpor�ng septage to an approved septage disposal facility.
•"Sewer'' means a pipe or conduit for carrying wastewater or drainage.
•"Shall" is mandatory; "May" is permissive.
35
Part 1 – General Provisions 1-8
•“Sidewalk” means that por�on of a street between curb lines or the outer lateral
lines of a roadway, and the adjacent property lines, intended for use of
pedestrians.
•"Source" means any building, structure, facility, or installa�on from which
there may be a discharge of pollutants.
•"Sprinkling Meter" means a municipal water meter that is installed on a water
service line for the purpose of measuring the water delivered by the u�lity to a
customer exclusively for lawn and garden irriga�on.
•"State" means the State of Montana.
•"Storm Sewer'' or "Storm Drain" means a sewer which carries storm and
surface waters and drainage but excludes wastewater and polluted industrial
wastes.
•“Street” means the en�re width between the boundary lines of the right-of-way
publicly maintained when any part thereof is open to the use of the public for
purposes of vehicular travel.
•"Subdivision Extension" means an extension of the wastewater system or provide
water or wastewater service to serve a subdivision, Cer�ficate of Survey,
commercial or industrial development, or any other similar type annexed parcel
of land wherein the extended water or wastewater system facili�es within the
development are to be owned by the City, not including any privately-owned
facili�es.
•"Sub Meter" means a meter or meters which are furnished, installed, and
maintained by a customer, and which are installed downstream of the
municipal water meter by the customer for the purpose of propor�oning
municipal u�lity charges between various tenants.
•"Suspended Solids" means solids that either float on the surface or are in
suspension in water, wastewater, or other liquids, and which are removable by
laboratory filtering.
•"System Development Fees" means one-�me charge paid by new development as
a propor�onate share of the "general benefit" to finance the construc�on of
public facili�es needed to serve the development.
•''Tampering" means damaging, altering, adjus�ng, or in any manner
interfering with or obstruc�ng the opera�on or func�on of any metering
36
Part 1 – General Provisions 1-9
device that is used for measuring or registering municipal u�lity service.
•"User'' or "Customer" means any person receiving municipal water
wastewater service either directly or indirectly from the municipal water
supply system or municipal wastewater system.
•'Waste Disposal Site" means the City of Laurel's designated waste disposal
sta�on for the purposes of disposing of septage.
•'Wastewater" or "Sewage" means the liquid and water carrying industrial or
domes�c wastes from dwellings, commercial buildings, industrial facili�es,
and ins�tu�ons, together with any ground water, surface water, and storm
water that may be present, whether treated or untreated, which is discharged
into or permited to enter the municipal wastewater system.
•'Wastewater Meter" means a meter which is furnished, installed, and
maintained by a user, and which is used to measure the amount of wastewater
contributed by such user to the municipal wastewater system.
•'Wastewater Service" or "Municipal Wastewater Service" means the act of
either directly or indirectly discharging wastewater into the municipal
wastewater system from users' building sewers for the purpose of collec�ng,
transpor�ng, trea�ng, and disposing of users' wastewater.
•'Wastewater Service Area" means that par�cular territory which has been
officially adopted by the City Council as the area it intends to provide with
municipal wastewater service.
•'Wastewater System" or "Municipal Wastewater System" means any
wastewater facili�es, including interceptor sewers, ou�all sewers, wastewater
collec�on systems, and wastewater treatment facili�es, controlled by the City of
Laurel.
•'Water Service" or "Municipal Water Service" means the supply of water
directly or indirectly from the municipal water supply system, or the
availability of water supplied either directly or indirectly from the municipal
water supply system, at the point of delivery and also the water so delivered
or used.
•'Water Service Area" means that par�cular territory which has been officially
adopted by the City Council as the area it intends to serve with municipal water
service.
37
Part 1 – General Provisions 1-10
•"Water Service Line" means all privately owned facili�es, including service
saddle, service pipe, corpora�on stop, curb stop, curb box, municipal water
meter box or vault, backflow preven�on device, expansion tanks, pressure
reducing valve, inside piping, appliances, and other apparatus on the customer's
side of the point of delivery, except the municipal water meter and any other
equipment owned by the City of Laurel.
•"Water Supply System" or "Municipal Water Supply System" means any
devices, facili�es, structures, equipment, land or works controlled by the City
for the purpose of the processing, treatment, transmission, storage,
distribu�on, pumping, and measurement of water supplied to customers.
2.2 The following abbrevia�ons shall have the designated meanings:
•“APWA” means the American Public Works Associa�on.
•“ASTM” means the American Society for Tes�ng and Materials.
•“AWWA” means the American Water Works Associa�on.
•“DEQ” means Montana Department of Environmental Quality.
•“EPA” means the Environmental Protec�on Agency.
•“MCA” means Montana Code Annotated.
•“MPWSS” means Montana Public Works Standard Specifica�ons.
•“PUD” is the Laurel Public U�li�es Department.
•“PWD” is the Laurel Public Works Director
38
Part 2 - General Engineering Submital Requirements 2-1
Part 2 - General Engineering Submital Requirements
The following items, if they apply, will be required before the checking of plans can be
completed. As many items as possible should be submited with the ini�al submital. Items not
included in the ini�al submital may add addi�onal rechecks to the checking procedure. A
complete list of requirements will be returned with the first check.
1.COMPLETE SUBMITTAL PACKAGE
1.1 Plans
A complete set of plans shall be drawn to include the following:
1.1.1 Title Sheets
The �tle sheet shall be sheet 1 of each set of plans and will include
the following items:
A.Suitable �tle that is descrip�ve of the project.
B.Legal descrip�on or address of the area to be worked.
C.Name and Contact informa�on (address & phone #) of the persons
responsible for the work.
D.Name and Contact informa�on (address & phone #) of the persons
designing the work.
E.Loca�on and/or Vicinity Map w/north arrow at a scale that encompasses
the en�re project area and shows physical loca�on.
F.Involved En��es and their contact informa�on
G.Engineer's signature, seal, & date
H.Index of Included Sheets with sheet number and title
1.1.2 Notes & Detail Sheets
A.General notes and details that provide enough informa�on for the
complete construc�on of improvements
B.Basis of bearing and Eleva�on Datum
C.Legend
D.Abbreviations (if used)
39
Part 2 - General Engineering Submital Requirements 2-2
1.1.3 U�lity Improvement Sheets
A.Adjacent streets, property lines, u�lity easements, and references thereto.
B.Loca�on, material, and size of Water, Sanitary Sewer, Storm Sewer and
associated appurtenances.
C.Loca�on of water courses, wells, streams and railroad crossings,
water mains, gas mains, culverts and underground power, CATV or other
u�lity wherever possible.
D.Limits of hard surface improvements with dimension references.
E.Loca�on and size of property to be used for the development with respect
to known references such as roads, streams, sec�ons lines, or streets.
F.Topography of exis�ng and proposed contours at intervals not greater than
two (2) feet.
G.Profile views to show highest and lowest eleva�ons of exis�ng and
proposed grades and installed below ground u�li�es.
H.Size, length, and materials of proposed construc�on.
I.Suitable �tle plate with scale, north arrow, date, drawings number, and
name, address and telephone of engineer.
1.1.4 Site Improvements Sheets
A.Street Sec�on Typical
B.Show type of pavement, curb, and sidewalk for each street (by name) in
the project. Par�al street improvements (using asphalt concrete
paving) that do not terminate with a curb shall have an extra 1 foot of
asphalt concrete paving width at the edge of right-of-way.
C.Dimensions Shown. Right-of-way, centerline to curb, curb to property
line sidewalk, and sidewalk to property line.
D.Sta�oning
E.Scale. One (1) inch equals 50 feet (1"=50') horizontal and 1 inch equals 5
feet ver�cal (1"=5') is the recommended scale to be used for the plan and
profile.
F.Original Drawings. All sheets must be drawn in black India ink on 11-inch by
17-inch (11"x17").
40
Part 2 - General Engineering Submital Requirements 2-3
G. Exis�ng and New Improvements and Easements. Exis�ng and new
improvements and easements shall show width. Exis�ng easements
should also show the document number and the receipt date.
1.1.5 Landscape and Irriga�on Sheets (op�onal)
1.1.6 Addi�onal Items
A.Street Names
B.Subdivision Boundary
C.Lot Lines and Numbers
D.Pavement Shaded
E.Concrete Symbol on Sidewalk, etc.
F.Size, Material and Length of Each Run of Pipe
G.Centerline, Curb, Storm Drain, Sewer, and Water Data
H.All roads and improvements that are not public are to be labeled
"Private"
2.RIGHT-OF-WAY AND EASEMENT PLATS AND LEGAL DESCRIPTIONS, IF NEEDED
3.SOILS AND GEOTECHNICAL REPORT
See Part 8, Appendix C for Geotechnical Report requirements.
4.STORMWATER ANALYSIS AND DESIGN REPORT
See Part 8 for stormwater report guidelines and requirements.
41
Part 3 – Construc�on Changes/Revisions 3-1
Part 3 – Construc�on Changes/Revisions (Reserved)
42
Part 4 – As-Built Plan 4-1
Part 4 – As-Built Plans (Reserved)
43
Part 5 – Street Design Technical Standards 5-1
Part 5 - Street Design Technical Standards
1.GENERAL CONDITIONS
1.1 All maintenance and repairs of public streets, alleys, sidewalks and other public ways
shall be under the supervision of the PWD.
1.2 It is unlawful to construct or lay any pavement on any public street, sidewalk, alley or
other public way, or to repair the same, without having first secured a permit therefor.
Applica�ons for such permits shall be made to the City Clerk-Treasurer, and approved
by the PWD, and shall state the loca�on of the intended pavement or repairs, the
extent thereof, and the person or firm who is to complete the construc�on.
1.3 The arrangement, type, extent, width, grade, and loca�on of all new streets must be
considered in their rela�on to exis�ng and planned streets, to topographical
condi�ons and to public convenience and safety, and in their rela�on to the proposed
uses of the land to be served by them.
1.4 All roads must meet the appropriate regula�ons within Title 12.04.030 “Streets” of
the City of Laurel Municipal Code.
1.5 Proposed roads which will intersect State and/or County roads shall be permited by
en��es having jurisdic�on of said roads.
1.6 All roadway improvements including pavement, curbs, guters, sidewalks, and
drainage must be constructed in accordance with the specifica�ons and standards
prescribed in the latest edi�on of the Standards for Public Works Improvements for
the City of Laurel.
1.7 Plans, specifica�ons, and special provisions for street construc�on projects must be
sealed by a Professional Engineer licensed in the State of Montana and submited with
the permit applica�on.
1.8 All street improvements shall be inspected during the course of construc�on by an
inspector appointed by the PWD.
2.DESIGN CRITERIA FOR STREETS
2.1 Minimum centerline radius of horizontal curvature shall be based on the latest edition
of the AASHTO Geometric Design of Highways and Street for the following design
speeds. The road classification will be as determined by the City Public Works
Director.
Table 5.1 – *Roadway design speeds (mph)
Arterial Collector Local Alley
50 40 30 20
*or as approved by the PWD
44
Part 5 – Street Design Technical Standards 5-2
2.2 Intersec�ons
2.1.1 Intersec�on design should follow the latest edi�on of “A Policy on Geometric
Design of Highways and Streets” as modified by the following.
2.1.2 Maximum grade of approach to an intersec�on must not exceed 5% for 50’
from the edge of traveled way.
2.3 Where a sight-distance problem may be an�cipated, addi�onal easements or Right of
Way may be required by the PWD.
3.GRADING
3.1 All grading or excava�ng in public right-of-way and encroachments shall be first
authorized by a valid encroachment permit.
3.2 Addi�onal grading beyond the right-of-way may be required to provide for safe sight-
distance and to control drainage.
3.3 Easements shall be provided for all property where grading will be required outside of
the right-of-way.
4.PAVEMENT, STRUCTURAL SECTIONS
All streets shall be surfaced in accordance with the following specifica�ons:
4.1 All design shall conform to the latest edi�on and revisions of the MPWSS.
4.2 Road surfacing shall be Type B asphal�c concrete with a PG 64-28 binder.
4.3 Structural sec�on shall be determined using a Geotechnical analysis and design report
prepared by a Professional Engineer licensed in the State of Montana.
4.4 Exis�ng street patches or restora�on shall include asphalt and a crushed base course
per table 5.2
Table 5.2 – Asphalt Thickness for Road Restoration
Road Classification Asphalt Thickness Crushed Base Course
Arterials Min 4” or Match Existing Min 14” or Match Existing
Collectors Min 4” or Match Existing Min 10” or Match Existing
Local Commercial 4” 10”
Local Residential 3” 10”
4.5 Street cross slopes to be designed with a minimum of 2%, maximum of 5% and a
preferred cross slope of 3%.
4.6 Alley surfacing shall be of 4 inches of ¾-inch minus crushed base course, and 4
inches of 3-inch minus crushed sub-base course.
45
Part 5 – Street Design Technical Standards 5-3
5.UTILITY PLACEMENT WITHIN STREETS
Water and sewer u�li�es to be constructed in streets shall be installed according to Part 6 and
Part 7.
6.SITE TRIANGLE
6.1 At Alley intersec�ons a clear vision triangle shall measure ten (10) feet parallel to the
alley and twenty (20) feet parallel to the street as measured from the property line
corner.
6.2 At uncontrolled intersec�ons, a clear vision triangle shall measure seventy-six (76) feet
in both direc�ons as measured from the intersec�on of the centerlines in the adjoining
street intersec�on.
6.3 At controlled intersec�ons (stop sign or traffic signal) a clear vision triangle shall
measure twenty (20) feet in both direc�ons as measured from the property line
corner. Excep�ons include the exis�ng downtown business district. See zoning code
for Central Business District (CBD).
6.4 Any fence, wall, signs, plant material or other material shall provide an unobstructed
cross-visibility at a level between 3 feet and 8 feet above the street surface eleva�on.
Trees having over eight (8) feet of clear trunk as measured from the surface eleva�on
with limbs and foliage trimmed in such a manner as not to extend into the cross-
visibility area and complying with sec�on 7.2.3 of Division 2 of the Rules and
Regula�ons Governing U�lity Services and Streets of the City of Laurel, Montana, are
permited in the clear vision triangle.
6.5 Vehicles shall not be parked in the public right-of-way to obstruct the line of site
created by the clear vision triangle. In the Central Business District where line of site
is restricted by zero building setback, vehicles shall not be parked in the public right-
of-way that obstruct site distance or as per Montana Department of Transporta�on
standards where applicable.
7. ALLEYS
7.1 Alleys
Alleys shall be designed and improved by the developer.
7.1.1 Right of way shall be a minimum of 20 feet in width.
7.1.2 There shall be no intersecting alleys.
7.1.3 Road surface shall be 15 feet wide, except at intersections with streets
where standard returns shall be constructed.
46
Part 5 – Street Design Technical Standards 5-4
8. CURB AND GUTTER, SIDEWALKS
8.1 Sidewalks shall be constructed of 4” Portland Cement Concrete over 3” of ¾”
crushed base course.
8.2 Sidewalks shall typically be constructed parallel to the curb line. Other sidewalks
shall be constructed only if authorized by the PWD.
8.3 Curb, gutter and sidewalks shall be constructed at the total cost of developers or
property owners.
8.4 Sidewalks shall be ADA compliant.
8.5 Warning Plates are to be Cast Iron Truncated Domes.
9.DRIVEWAYS
9.1 Residen�al Driveway
9.1.1 Driveways serving property used solely as a single family, two-family, or three-
family residence shall be residential type driveways with approaches
conforming to the latest edition of the MPWSS Standard Drawings.
9.1.2 Driveways widths shall be 12-foot minimum/30-foot maximum, measured at
the base of the driveway.
9.2 Commercial Driveway
9.2.1 All driveways other than residen�al driveways shall be commercial driveways
with approaches conforming to the latest edi�on of the MPWSS Standard
Drawings.
9.2.2 Commercial driveway widths shall be 12-foot minimum/50-foot maximum,
measured at the base of the driveway.
9.3 Driveway Separa�on/Distance from the Property Line
9.3.1 For residen�al driveways, except for approved joint-use driveways and
driveways of lots having 25-feet of frontage or less, shall be located at least 5
feet from the side property line. Excep�ons are allowed for cul-de-sacs.
Mul�ple driveways for a single lot may be approved on a case-by-case basis.
9.3.2 All commercial driveways shall be approved by the PWD.
9.4 Loca�on
9.4.1 Driveways shall be so located to minimize interference with the free
movement of normal traffic or the proper functioning of highway signs,
signals, lighting, fire hydrants or other devices that affect traffic operation.
47
Part 5 – Street Design Technical Standards 5-5
9.4.2 All commercial driveways shall be designed such that vehicles entering, or
egressing shall not be required to back from or into a street right-of-way.
9.4.3 Any necessary adjustments to utility facilities, light standards, fire hydrants,
catch basins, street signs, signals, underground conduits for street lighting or
fire alarm systems, or other public improvements or installations shall
be accomplished without cost to the City.
9.5 Frontages
Frontages of sixty (60) feet or less shall be limited to one (1) driveway. Not more
than two (2) driveways shall be provided to any single property tract or
business establishment, except where the property frontage exceeds six hundred
(600) feet, there may be one (1) addi�onal driveway for each addi�onal three
hundred (300) feet of frontage. In cases where lots have more than one street
frontage, each frontage shall be treated separately when determining the allowed
number of driveways.
9.6 Right-of-Way Distances
Gasoline pump islands or other installa�ons with parking parallel to the right-of-way
line shall be at least 10 feet outside of the right-of-way line. Buildings or
other installa�ons with an angle of ninety degrees parking between it and the right-
of-way line shall be at least 30 feet outside the right-of-way line.
9.7 Culverts
Driveway culverts shall only be allowed by approval of the PWD. If permited,
culverts shall be maintained by the property owner.
Culverts used for the crossing of irriga�on ditches shall be approved by the
associated ditch company.
10.STREET NAME SIGNS
10.1 Street name signs shall be installed in accordance with the Manual of Uniform Traffic
Control Devices and at all new intersections.
11.SURVEY MONUMENTS
Boundary, lot corner and street survey monuments shall be installed or preserved as with all
street improvements as follows:
•During construction or development of any street other than in a new subdivision,
Contractor shall reset or preserve all existing monuments affected by the street
improvements.
12.REPAIRING UTILITY CUTS
12.1 When requested by the PWD, construction equipment and procedures to be used
48
Part 5 – Street Design Technical Standards 5-6
shall be described in the permit application.
12.2 Pipe installation shall be done according to the requirements of the appropriate
agency specifications in use. Any required granular backfill material shall meet the
material requirements for Select Granular Fill in the MPWSS, latest edition.
12.3 Pavement shall be saw cut in a neat line at termination points of pavement
replacement.
12.4 Pavement and shoulder removal shall be done in a manner that provides for proper
restoration of the replacement section.
12.5 Straight vertical cuts of the pavement are required. Pavement surfaces that become
undermined shall be cut back and removed.
12.6 Excavations shall be filled at the end of each workday unless approved otherwise by
the PWD. Any excavations that are allowed to remain open must be properly signed
and barricaded. The longest length of trench to remain open overnight shall not
exceed 50 lineal feet.
12.7 Construction which adversely affects the subsurface drainage of the pavement
structure shall be corrected by the addition of surface or subsurface drain.
12.8 Pavement replacement limits shall extend a minimum of 24-inches, in all directions,
beyond the limits of disturbed soil and far enough such that all existing pavement to
remain, is supported firmly by the existing underlying base material. The new
pavement patch shall be restored to the proper grade, cross-slope, and smoothness.
All joints shall be tacked.
12.9 The City PWD requires inspection and testing of utility repairs and surface restoration.
12.10 All street cuts shall be parallel and perpendicular to the street centerline. No diagonal
cuts shall be accepted.
12.11 If remaining asphalt width between asphalt cut and asphalt edge is less than or equal
two (2) feet, it shall be removed and replaced.
12.12 Asphalt removed shall be replaced at the thicknesses designated in Table 5.2 or match
existing, whichever is the greater.
12.13 Non-shrink backfill may be required by the PWD.
13.STREET LIGHTING
Streetlights shall be installed and shall comply with Montana Department of Transporta�on
standards.
49
Part 6 – Sewer Design Technical Standards 6-1
PART 6 - SEWER DESIGN TECHNICAL STANDARDS
1.PURPOSE
The purpose of this design criteria is to provide engineers, designers, engineering technicians,
and others, in reference form, the City's minimum standards for sanitary sewer design.
These criteria are intended to cover the design of main line sanitary sewers and apply to any
sewer systems, public or private, 6 inches in diameter or greater. Private on-site sewer systems
serving mobile home parks, condominiums or apartments may be designed in accordance
with the uniform plumbing code and approved by the appropriate building inspector.
The design criteria set forth below are intended to result in sewers which will:
1.1 Be consistent with the Sewer Master Plan, Preliminary Engineering Report or other
latest governing body accepted planning document.
1.2 Be consistent with Montana Department of Environmental Quality (DEQ) Circular DEQ
2, latest edi�on.
1.3 Be consistent with the latest edi�on of the Montana Public Works Standard
Specifica�ons (MPWSS).
1.4 Be of adequate size to carry the expected flow, within their design life, and at sufficient
depth to serve adjacent proper�es.
1.5 Have sufficient grade to maintain a minimum velocity of 2 feet per second when flowing
half full.
1.6 Be strong enough to resist all external loads which may be imposed.
1.7 Be of materials resistant to both corrosion and erosion.
1.8 Be economical and safe to build and to maintain.
1.9 Prevent infiltra�on or inflow of ground and surface waters.
1.10 Be designed for municipal wastewater only, not storm water roofs, streets, or ground
waters.
Alternate materials and methods will be considered for approval on the basis of these
objec�ves.
2.REFERENCES
2.1 Circular DEQ-2, Design Standards for Public Sewage Systems, Montana Department of
Environmental Quality, latest edi�on.
50
Part 6 – Sewer Design Technical Standards 6-2
2.2 Montana Public Works Standards Specifica�ons, latest edi�on and revisions.
3.APPROVAL OF ALTERNATE MATERIALS OR METHODS
Approval of any major devia�on from these standards will be in writen form.
4.MONTANA DEPARTMENT OF ENVIRONMENTAL QUALITY STANDARDS
Montana Department of Environmental Quality Circulars are hereby incorporated into this
document. The document with the more stringent standards shall govern.
5.SPECIAL PROBLEMS
The design of the following are considered special problems and are not covered in detail in
these standards: These items will be reviewed and approved on an individual basis. The
following is a brief list of items but shall not be considered all encompassing.
5.1 Pump of Li� Sta�ons
5.2 Force Main
5.3 Inverted Syphons
5.4 Relining of Exis�ng Sewers
5.5 Internal Sealing of Exis�ng Sewers
5.6 Treatment Plants
5.7 Ou�all Sewers
5.8 Energy Dissipaters
5.9 Regula�ng Devices
5.10 Flow Measurement Devices
6.DESIGN PLANS AND PROFILES
Plans will be required for all new or extended sanitary sewers and shall include both a vicinity
map and a general layout map of the area showing the loca�on of exis�ng facili�es and of the
proposed improvements. Plans should be accurate, legible and properly detailed. Dimensions
should be either from right-of-way centerline or property lines.
The City of Laurel u�lizes the NAD_1983_StatePlane_Montana_FIPS_2500 coordinate system
and the Lambert Conformal Conic Projec�on for all mapping purposes.
51
Part 6 – Sewer Design Technical Standards 6-3
6.1 Engineering Drawings (Plans)
Plans for sewer lines should contain at least the following informa�on:
6.1.1 Adjacent streets, property lines, u�lity easements, and references thereto.
6.1.2 Loca�on of sewer lines and appurtenances. Each manhole shall be numbered
and sta�oned to facilitate checking the plans with the profiles.
6.1.3 Loca�on of water courses, wells, stream and railroad crossings, water mains,
gas mains, culverts and underground power, CATV, or other u�li�es wherever
possible.
6.1.4 Limits of hard surface paving with dimension references.
6.1.5 Adequate details, specifica�ons, and other informa�on for Contractor to be
able to install the proposed improvements.
6.1.6 Suitable �tle plate with scale, north point, date, drawing number, and name,
address and telephone of engineer, and the Registered Professional Engineer's
(RPE) signature.
6.1.7 Profiles
6.2 Profiles for the individual sewer lines should contain at least the following informa�on:
6.2.1 Loca�on of manholes and other appurtenances with each manhole numbered
and sta�oned.
6.2.2 Profile of exis�ng and proposed ground surface and sewer invert.
6.2.3 Size, material, pipe class, slope, and length of sewer between consecu�ve
manholes.
6.2.4 Depth of bury and surface restora�on.
6.2.5 Eleva�on of original ground and finished grade shall be shown graphically, and
sewer inverts specified at each manhole.
6.2.6 Depth and loca�on of major u�li�es and pipelines that cross the plan view of
the sewer line. U�lity service lines shall be shown if requested by the PWD.
6.2.7 Suitable �tle plate with the scale, date, drawing number, and the Registered
Professional Engineer’s (RPE) signature.
6.2.8 Limits of street improvements will be shown including a typical sec�on of the
subject street.
52
Part 6 – Sewer Design Technical Standards 6-4
6.2.9 Separate plans shall be submited for public sewers installed in combina�on
with private sewers or site plumbing. "Site plumbing" drawings are not
acceptable. Public sanitary sewer plans may be combined with other public
improvement plans, provided that the plans must be legible and properly
detailed.
6.2.10 Appropriate labeling of the services as "Public" or "Private" will be done on
both the plan view and profile view.
7.SPECIFICATIONS
7.1 Engineering consultants are encouraged to develop specifica�ons and special
provisions for each project. Specifica�ons and special provisions shall incorporate the
latest edi�on of the MPWSS. Special specifica�ons pertaining to materials and
workmanship, if developed, shall be submited to the City for review and approval,
together with check prints of the project.
7.2 In general, the sewer specifica�ons should cover pipe material, excava�on, laying of
sewer pipe, join�ng, backfilling, tes�ng, etc. Strict supervision will be required by the
City during construc�on to assure compliance with the specifica�ons. Developer shall
provide full �me engineering inspec�on services during Construc�on ac�vi�es. The
City reserves the right to review or audit the inspec�on services being provided.
8.ADDITIONAL ITEMS OF CONCERN
8.1 Tes�ng
8.1.1 Sanitary sewers will be required to pass tests specified in MPWSS, Sec�on
02730, Sanitary Sewer Collec�on Systems.
8.1.2 The internal (T.V.) inspec�on shall be performed prior to issuance of the final
acceptance. T.V. inspec�on will not be performed un�l the City’s inspector has
completed a final inspec�on and is sa�sfied that all construc�on is complete.
The T.V. inspec�on video shall be become the property of the City.
8.1.3 Results of all tes�ng shall be reported to the City on a bi-weekly basis.
9.GENERAL DESIGN CONSIDERATIONS
9.1 Sanitary sewers should be designed to remove the domes�c sewage from houses,
business buildings and other public and private establishments, but not the street,
roof, or subsurface drainage. Each main building on a parcel or residence shall be
served by a separate sewer lateral.
9.2 Storm water, including street, roof, or foo�ng drainage, shall be removed by a system
of storm sewers or by some other method separate from the sanitary sewer system.
53
Part 6 – Sewer Design Technical Standards 6-5
9.3 In general, sewer systems should be designed to care for future flows which may
reasonably be expected within a period of 20 years, and for ul�mate development of
the specific drainage basin concerned.
10.CAPACITY
Public sanitary sewers and appurtenances 10 inches and smaller shall be designed to
accommodate peak hourly flows when flowing one half full. Public sanitary sewers and
appurtenances 12 inches and larger shall be designed to accommodate peak hourly flows,
when flowing three quarters full.
11.Design flows shall be determined by considera�on of the following factors:
11.1 Drainage Basin Area to Be Served
11.2 Popula�on Within the Area to Be Served
11.3 Land Use Within the Area to Be Served
11.4 Per Capita Sewage Flow
11.5 Commercial, Industrial, or Ins�tu�onal Users to Be Served
11.6 Infiltra�on Allowance
11.7 Peaking Factors
In the absence of flow data or other reliable informa�on, the Designer shall use peaking
factors in conformance with factors outlined in DEQ Circular-2 or others specified by the City.
Design calcula�ons shall include es�mates of average and maximum daily flows. The
submission of design calcula�ons will be required; engineers should be prepared to
substan�ate pipe sizes, layout, popula�on es�mates, land uses or other design assump�ons.
12.SIZE
Main line sewers shall be a minimum of 8-inch inside diameter, except that the sewer service
within private property which will not be extended may be of 4-inch inside diameter for
residen�al services and 6-inch for commercial proper�es.
54
Part 6 – Sewer Design Technical Standards 6-6
13.PIPE MATERIALS
13.1 Gravity Sewers
The following pipe materials and fi�ngs are approved
MATERIAL SPECIFICATIONS
Concrete Pipe, Reinforced ASTM C 76, Class III, IV, or V
Duc�le Iron Pipe: Class 2 ANSI A21.51 or AWWA C151
Polyvinyl chloride (PVC); 4" to 15" ASTM C 3034, SDR 35; or ASTM F 789
PVC Sewer Pipe; 18" and larger ASTM F 679: ASTM F 794, Series 46
13.2 Force Mains
The following materials are approved for force mains:
MATERIAL SPECIFICATIONS
Duc�le Iron Pipe; Class 52 ANSI A21.51 or AWWA C151
Polyvinyl chloride (PVC) AWWAC900
13.3 Other Uses
Pipe materials for special uses such as for liner pipe, temporary construc�on, stream
crossing, bridge crossings, etc., will be considered special design cases and are not
covered further in these standards.
14.EXCAVATION, PIPE BEDDING AND BACKFILL
14.1 Details - Standard details are the latest edi�on of the MPWSS.
14.2 Installa�on
Installa�on of pipe shall conform to the following:
14.2.1 MPWSS, latest edi�on.
14.2.2 Contractor Quality Control and Owner Quality Assurance
55
Part 6 – Sewer Design Technical Standards 6-7
Table 6.1 below outlines the minimum frequency of quality assurance tes�ng. This tes�ng may
be reduced at the discre�on of the City. This tes�ng does not replace an appropriate Contractor
quality control tes�ng program as described earlier in this sec�on. In the case of a conflict
between QC and QA tes�ng, the QA tes�ng shall govern.
Table 6.1 - Laurel Materials Testing Requirements
EARTHWORKS
Test Specification/Material Test Method Minimum Required Frequency
Trench Backfill Moisture-Density (MPWSS
02221)
1 Sub/soil type encountered
1 Submittal/borrow source
Trench Compaction In-Place Density (MPWSS
02221/1.4) 97% Minimum
1 test/lift/200 LF
Trench Compaction (laterals
outside the road template,
structures, valves, hydrants
and manholes)
In-Place Density (MPWSS
02221/1.4) 97% Minimum
1 test/for each 2 ft of vertical depth/2 ft from
edge of structure, valve, hydrant, or manhole
Pipe Bedding Type I Bedding gradation &
Plasticity Index / Type II Bedding
Gradation (MPWSS 02221)
1 Submittal
Subgrade and Embankment Moisture-Density (MPWSS
02230)
1 Submittal per soil type encountered / 1
Submittal per borrow source
Compaction of subgrade
under curbs, gutters, and
sidewalks
In-Place Density (MPWSS
02230/1.3) 95% Minimum
1 test/lift/200 LF (C &G) or 1 test/lift/1000 SF
(flatwork)
Compaction of subgrade and
embankment for roadways
In-Place Density (MPWSS
02230/1.3) 95% Minimum
1 test/lift/4000 SF
Sub Base Course Gradation - Moisture Density –
Fractured Faces (Crushed) - LA
Abrasion, LL, PL, and PI (MPWSS
02234)
1 Submittal
Compaction of Sub Base
Course for roadways
In-Place Density (MPWSS
02234/1.3)95% Minimum
1 test/lift/4000 SF
Crushed Base Course Gradation - Moisture Density –
Fractured Faces (Crushed) - LA
Abrasion, LL, PL, and PI (MPWSS
02235)
1 Submittal
Compaction of crushed base
course under curbs, gutters,
and sidewalks
In-Place Density (MPWSS
02235/1.3) 95% Minimum
1 test/lift/200 LF (C &G) or 1 test/lift/1000 SF
(flatwork)
Compaction of crushed base
course for roadways
In-Place Density (MPWSS
02235/1.3) 95% Minimum
1 test/li�/4000 SF
14.3 Water settling of backfill material is prohibited.
56
Part 6 – Sewer Design Technical Standards 6-8
15.GRADE
15.1 The Designer shall use minimum grades in conformance with those outlined in DEQ
Circular-2 or others specified by the City
15.2 Slopes slightly less than those described may be considered if substan�al jus�fica�on
can be demonstrated. There must be enough live sewer intercep�ons to ensure that
the average depth of sewage flow will be 0.3 of the pipe inside diameter.
15.3 Maximum pipe slope shall be governed by terrain and available fall between
manholes. Maximum velocity in the pipes shall not exceed 8 fps, unless specifically
approved by the City.
16.MINIMUM DEPTH
16.1 All sewers shall be laid at a depth sufficient to drain and be protected against damage
from traffic. Sewers laid in areas subject to wheel loads shall have a minimum cover
of 6 feet measured from top of pipe to finished grade or be otherwise protected from
damage by traffic; except that minimum cover may be reduced to 4 feet with specific
approval. Encasement will be required for depths less than 4 feet.
16.2 Under normal condi�ons, main line sewers in residen�al areas should be laid at an
average depth of 8 to 9 feet. Services to adjacent proper�es from such sewers should
normally be laid so that the depth of the service lateral at property line is at least 5
feet. Insula�on shall be provided for sewers that are less than 5-� deep.
17.LOCATION
17.1 Rela�on to Water Lines and Wells
No sanitary sewer mains should be less than 10 feet from any well, spring, or other
source of domes�c water supply. All sanitary sewers or parts thereof which are located
within 50 feet from any such source of domes�c water supply shall be constructed of
cement lined, duc�le or PVC with water�ght joints. Sanitary sewers and domes�c
water lines shall not be laid in the same trench. Parallel water and sewer lines
wherever possible should be located at least 10 feet apart horizontally.
When physical condi�ons render this spacing impossible or imprac�cal, then duc�le
iron water pipe with water�ght joints or concrete encasement is required for the
sewer line. Wherever it is necessary for sewer and water lines to cross each other, the
crossing should be at an angle of approximately 90 degrees and the sewer shall either
be located 18 inches or more below the water line or be cement lined, constructed of
duc�le or PVC pipe with water�ght joints for a distance of 10 feet on both sides of the
water line.
57
Part 6 – Sewer Design Technical Standards 6-9
17.2 Sewers in Streets or Easements
Under normal condi�ons, sewers should be located in street right-of-way 6 feet north
or east of the street right-of-way centerline. Sewers shall be located in centerline of
alleys and easements, if possible. When it is necessary to locate sewers in easements,
such easement shall be at least 20 feet in width. Sewers 24 inches in diameter or larger,
or over 12 feet in depth, may require wider easements.
18.ALIGNMENT
18.1 Sewer lines shall be laid on straight alignment and uniform grade between consecu�ve
manholes.
18.2 Horizontal and ver�cal curves in sewers are not recommended. However, in cases
where jus�fica�on can be shown, limited use of such designs will be considered.
Where curved alignments are u�lized, the City may require the following:
18.2.1 Slope greater than minimum slope for the size of pipe.
18.2.2 Manhole spacing of less than 250 feet.
18.2.3 City may require that the developer or contractor shall provide a licensed
professional land surveyor or engineer to con�nuously monitor installa�on of
the curved sewer during construc�on.
18.2.4 Television inspec�on of curved sewers is required prior to final acceptance.
19.CHANGE IN PIPE SIZE
19.1 When a smaller sewer joins a large one, the invert of the larger sewer should be
lowered sufficiently to maintain the same energy gradient. An approximate method
for securing these results is to place the 0.8 depth point of both sewers at the same
eleva�on.
19.2. Sewer extensions should be designed for projected flows even when the diameter of
the receiving sewer is less than the diameter of the proposed extension. Special
considera�on should be given to minimizing turbulence when designing a flow
channel within a manhole where there is a change in pipe size. The appropriate
reviewing agency may require a schedule for construc�on of future downstream
sewer relief.
20.MANHOLES AND CLEANOUTS
20.1 Details - Standard Drawings are found in the MPWSS, latest edi�on
58
Part 6 – Sewer Design Technical Standards 6-10
20.2 Manhole Construc�on
20.2.1 Construc�on shall be water�ght. If ground water or surface drainage can be
expected to flood the top of the manhole, water�ght frame and covers shall
be used. A 100-year-recurrence-interval storm shall be used in determining
flooding eleva�ons.
20.2.2 Manholes located in easements outside of public right-of-way shall have
locking frame and covers.
20.2.3 For rigid pipe, there shall be flexible connec�ons provided at the inlets and
outlets of each manhole. For all pipes, the flexible joint shall be within 1-1/2
pipe diameters, not to exceed 12 inches, of the exterior wall of the manhole.
A flexible connec�on "boot"/or insert may be u�lized in lieu of a flexible joint.
20.2.4 Generally, a 0.1 foot minimum drop from inlet to outlet is required for bends
between 120 and 240 degrees. A 0.2 foot minimum drop for all bends outside
those angles. Maximum drop in flow line eleva�on or all inverts shall be 0.4
feet. However, where grade considera�ons are considered cri�cal, the design
engineer may request a waiver from the City if sufficient jus�fica�on exists.
20.3 Manhole Loca�on
20.3.1 Manholes shall be located as follows:
A.At the end of each public sanitary sewer.
B.Every change in grade or alignment of sewer.
C.Every point of change in size of sewer or pipe material.
D.Each intersection or junction of sewer.
E.Upper end of all lateral sewers.
F.At the beginning and end of all 24-inch diameter and smaller sewers on
curved alignment.
G.At intervals of 400 feet or less as approved by the City.
H.At each and every street intersection unless approved by City.
Cleanouts shall not be subs�tuted for manholes nor installed at the end of
public sanitary sewers unless approved by the City.
59
Part 6 – Sewer Design Technical Standards 6-11
20.4 Cleanout Loca�ons
A.A cleanout shall be installed 5-� outside of the building at the connec�on
point.
B.A cleanout shall be installed on a service line whenever the total degree of
bends is equal to or more than 45° on any single run of sewer pipe.
C.Cleanouts will not be approved as subs�tutes for manholes.
20.5 Manhole Covers
A.Standard Cast iron cover as outlined in MPWSS, used in public right-of-way.
B.Locking, may be required.
C.Inflow Protector Covers are required for all installa�ons within the 100-
year flood or where directed by the City Public Works Department.
20.6 Drop Manholes
Drop manholes shall be avoided whenever possible during the design and
construc�on of wastewater extensions. They shall only be used when it is proven
imprac�cal to steepen the incoming sewer.
A.Outside drop assemblies shall be provided for pipes 12 inches in diameter
and smaller when entering a manhole at a distance of more than 24 inches
above the invert of the manhole. Larger pipe should be introduced into the
manhole at the manhole invert.
B.Inside drop assemblies will be considered only in special cases involving
connec�ons to exis�ng manholes. Special approval for all drop assemblies
is required from the City.
20.7 Cleanouts
Cleanouts will not be approved as subs�tutes for manholes.
20.8 Diameter
The minimum diameter of manholes shall be 48 inches; larger diameters are
preferable for large diameter sewers. A minimum access diameter of 24 inches shall
be provided.
60
Part 6 – Sewer Design Technical Standards 6-12
20.9 Flow Channel
The flow channel straight through a manhole should be made to conform as closely as
possible in shape and slope to that of the connec�ng sewers. For pipes greater than 8
inches in diameter, the channel walls should be formed or shaped to the full height of
the crown of the outlet sewer in such a manner to not obstruct maintenance,
inspec�on or flow in the sewers. For pipes 8 inches or less in diameter, the channel
shall be formed at least to the spring line of the pipe. When curved flow channels are
specified in manholes, including branch inlets, or when entrance or exit losses are
significant, minimum slopes shall be increased to maintain acceptable veloci�es.
20.10 Bench
A bench shall be provided on each side of any manhole channel when the pipe
diameter(s) are less than the manhole diameter. The bench should be sloped no less
than ½ inch per foot (4%). No lateral sewer, service connec�on, or drop manhole pipe
shall discharge onto the surface of the bench.
20.11 Water Tightness
A.Manholes shall be of the pre-cast concrete or poured-in-place concrete type.
Manholes shall be waterproofed on the exterior. Pre-cast concrete manhole
sec�ons manufactured in accordance with ASTM C 478M-93 are exempt from the
exterior waterproofing requirement.
B.Inlet and outlet pipes shall be joined to the manhole with a gasketed flexible
water�ght connec�on or any water�ght connec�on arrangement that allows
differen�al setlement of the pipe and manhole wall to take place.
C.Inflow protector covers are to be used wherever the manhole tops may be
flooded by street runoff or high water. Locked manhole covers may be desirable in
isolated easement loca�ons or where vandalism may be a problem.
20.12 Manhole Adjus�ng Rings
Adjus�ng rings installed in manholes on public sanitary sewers shall have a total height
of not less than 2 inches and not more than 6 inches.
20.13 Manhole Frames and Covers
Frames and covers used on manholes for public sewers shall be made of cast iron or
duc�le iron, shall have a clear opening no less than 24 inches, shall have a total weight
of not less than 410 pounds, and shall have machined surfaces to ensure a �ght fit
between cover and frame.
61
Part 6 – Sewer Design Technical Standards 6-13
20.14 Manhole Steps
All manholes used for public sanitary sewers shall be equipped with steps of the
polypropylene-coated steel type mee�ng applicable OSHA requirements for fixed
ladders. The steps shall withstand a single concentrated load of 400 pounds, have a
minimum width of 12 inches, and shall have ribbed, skid-resistant treads with drop
fronts to prevent side slip. All manhole steps shall be installed with the center of the
rung a minimum of 7 inches from the manhole wall.
21.PIPE JOINTS
All pipe joints must be constructed water�ght. Rubber rings or other approved joint sealing
material shall be used. Joint deflec�ons shall be controlled such that the water�ght integrity
of the joint is maintained.
22.SERVICE LATERAL (SIDE SEWER OR HOUSE BRANCH) CONNECTIONS
All service laterals with the excep�on of house branches from a main sewer to serve an
individual building shall be of a minimum size of 6 inches in diameter within public right-of-
way or within public easements. House branches to serve single family residences and mul�-
family residences up to a Two (2) plex may be 4-inch diameter in size. Laterals shall be laid at
a minimum slope of 2%. Construc�on of laterals shall conform to the same standards as for
main sewer construc�on.
During the construc�on or extension of a public wastewater system, a wastewater service line
shall be stubbed to the property line of each lot and/or parcel of property included in the
extension applica�on. All wastewater lines so installed shall be subject to and fully comply
with the provisions set forth in this sec�on.
All wastewater service laterals shall be marked with a permanent indicator of loca�on in the
nearest hard surfacing (i.e. “S” stamp in adjacent curb, sidewalk or driveway”
23.HOUSE OR BUILDING SEWERS
As a minimum criterion, construc�on of the house or building sewers (on site) shall be of the
same quality and meet the same requirements as the public sewer with regard to materials,
water �ghtness and loca�on. In addi�on, these sewers shall conform to the Uniform Plumbing
Code, latest edi�on. No roof, surface, founda�on, or other storm water drain lines shall be
connected to the public sanitary sewers.
24.SEPARATE CONNECTION REQUIRED
24.1 Each main building or legal lot (except a private garage) shall be separately connected
to a public sewer. Except that main buildings or dwellings located on a single parcel
may be connected to a private sewer discharging into the public sewer, provided that
an approved statement of maintenance responsibility is recorded with the �tle to the
62
Part 6 – Sewer Design Technical Standards 6-14
property and permited through MT Dept. of Environmental Quality. Examples of such
private systems are mobile home parks, residen�al or office condominiums
(unit/owner associa�on by-laws to have statement of maintenance responsibility); or
apartment complexes.
24.2. A manhole shall be required at the point of connec�on of a private sewer system to a
public system with a clean out placed at the property line. A monitoring or sampling
manhole is required for connec�ons from industrial users.
25.STEEP SLOPE PROTECTION
Sewers on slopes of 20 percent or more may require special anchoring.
26.DRAINAGE DITCH OR STREAM CROSSINGS
26.1 Sewers entering or crossing drainage ditches or streams shall be constructed of
water�ght pipe. The pipe and joints shall be tested in place, shall not exhibit
infiltra�on, and shall be designed, constructed, and protected against an�cipated
hydraulic and physical, longitudinal, ver�cal, and horizontal loads, erosion, and
impact.
26.2 Sewer crossing of drainage ditches must be protected from freezing through either
depth of bury or insula�on.
27.AERIAL CROSSINGS
Support shall be provided for all joints in pipes u�lized for aerial crossings. The supports shall
be designed to prevent frost heave, overturning, and setlement.
28.PROTECTION OF WATER SUPPLIES
When wastewater sewers are proposed in the vicinity of any water supply facili�es,
requirements of Circular DEQ-1 should be used to confirm acceptable isola�on distances in
addi�on to the following requirements.
28.1 Cross Connec�ons Prohibited
There shall be no physical connec�ons between a public or private potable water
supply system and a sewer, or appurtenance thereto which would permit the passage
of any wastewater or polluted water into the potable supply. No water pipe shall pass
through or come in contact with any part of a sewer manhole.
28.2 Rela�on to Water Works Structures
28.2.1 Sewers shall not be located within 50 feet of a public water supply well.
63
Part 6 – Sewer Design Technical Standards 6-15
28.2.2 All exis�ng waterworks units, such as basins, wells, or other treatment units,
within 100 feet of the proposed sewer shall be shown on the engineering
plans.
28.3 Rela�on to Water Mains
28.3.1 Horizontal Separa�on.
A.Sewers shall be laid at least 10 feet horizontally from any exis�ng or
proposed water main. The distance shall be measured edge to edge.
B.If the proper horizontal separa�on as described above cannot be obtained,
the design engineer shall submit a request for a devia�on to the DEQ along
with a descrip�on of the problem and jus�fying circumstances. If the
devia�on is granted, the sewer shall be designed and constructed with the
following minimum condi�ons:
C.Copy of MT DEQ approved devia�on request shall be provided to the City.
D.Sewer pipe shall be PVC with nominal 20-foot lengths.
E.The sewer shall pass low pressure air tes�ng in accordance with UniBell
Recommended Prac�ce UNI-B-6-90.
F.Sewer services u�lizing in-line fi�ngs and extending to at least property
lines shall be provided and tested in the area of the encroachment. Saddles
are not acceptable.
28.4 Crossings
28.4.1 Sewers crossing water mains shall be laid to provide a minimum ver�cal
distance of 18 inches between the outside of the water main and outside of
the sewer. This shall be the case where the water main is either above or below
the sewer. The crossing shall be arranged so that the sewer joints will be
equidistant and as far as possible from the water main joints. Where a water
main crosses under a sewer, adequate structural support shall be provided for
the sewer to maintain line and grade and to prevent damage to the water
main.
28.4.2 If the proper ver�cal separa�on as described above cannot be obtained, the
design engineer shall submit a request for a devia�on to the DEQ along with a
descrip�on of the problem and jus�fying circumstances. If the devia�on is
granted, the sewer shall be designed and constructed with the following
minimum condi�ons:
64
Part 6 – Sewer Design Technical Standards 6-16
A.Minimum ver�cal separa�on at crossings between water and sewer mains
shall be 6 inches.
B.Sewer pipe shall be PVC with normal 20-foot lengths.
C.At crossings, one standard length of new pipe shall be centered at
approximately a 90 degree angle with respect to the exis�ng pipe.
D.The sewer shall pass low pressure air tes�ng in accordance with UniBell
Recommended Prac�ce UNl-8-6-90.
E.Sewer services u�lizing in-line fi�ngs and extending to at least property
lines shall be provided and tested within 10 feet of the crossing. Saddles
are not acceptable.
F.If the minimum separa�on is not viable, the water line must be relocated.
In these cases, minimum ver�cal separa�on at crossings between water
and sewer mains shall be 18 inches.
29.SEWER SERVICES AND PLUMBING
29.1 Plumbing
Sewer services and plumbing should conform to relevant local and state plumbing
codes.
30.DESIGN STANDARDS FOR ALTERNATIVE SEWER SYSTEMS
These standards shall be used for design of alternate sewer systems. Variances may be
allowed where adequate jus�fica�on is provided by the design engineer. These standards may
be modified as the technology evolves.
30.1 Small Diameter Gravity Sewer Design
30.1.1 Design flow shall be based upon water use records where available. If water
use records are not available, 100 gpcd per residen�al connec�on shall be used
and an appropriate peaking factor.
30.1.2 Hydraulic calcula�ons shall use the Manning's formula with a roughness
coefficient of n = 0.013.
30.1.3 Hydraulic design shall be based upon an approximately ½ pipe at 20-year peak
design flow.
30.1.4 Minimum design velocity of 2.5 fps in controlling sec�ons should be used
considering exis�ng peak flow condi�ons.
65
Part 6 – Sewer Design Technical Standards 6-17
30.1.5 All mains shall be 6-inch diameter pipe or larger.
30.1.6 To minimize poten�al sources of infiltra�on, 20-foot minimum pipe lengths
and in-line service fi�ngs should be used.
30.1.7 Turbulence should be minimized wherever possible.
30.1.8 Performance tests shall be u�lized for determining water-�ghtness, deflec�on
and alignment of installed pipes.
30.1.9 Service lines and main lines shall be designed and constructed to prevent
freezing of the wastewater within the lines.
30.2 Manholes/Cleanouts
30.2.1 The limited use of manholes is encouraged to minimize infiltra�on, reduce
odor poten�al, limit introduc�on of extraneous materials and reduce cost.
Manholes are to be located at major junc�ons of three or more pipes and
limited to strategic loca�ons for cleaning purposes.
30.2.2 Water-�ght manhole covers are recommended for odor control and to limit
inflow.
30.2.3 Manholes located in groundwater shall be waterproofed and should be of the
type which has the base riser sec�on cast with integral floor.
30.2.4 Clean outs should be used in place of manholes at changes in grade, alignment,
and at intersec�ons of pipe. Spacing of clean outs shall be dependent upon
cleaning capabili�es. A maximum of 600 feet for mechanically cleaned and jet-
cleaned systems and a maximum of 1000 feet for systems cleaned by pigging.
30.2.5. Clean outs located in traffic areas shall be designed to withstand normal traffic
loads without damage.
30.3 Design Standards for Pump Sta�ons for Alterna�ve Collec�on Systems
The use of wastewater pumping sta�ons to provide wastewater services for said areas,
or por�ons thereof shall be avoided whenever it can be feasibly accomplished.
In addi�on to other requirements, the following standards shall apply to pump
sta�ons which pump sep�c tank effluent.
30.3.1 Pumps other than those capable of passing spheres of at least 3 inches in
diameter are not acceptable. Screens should be considered where this type of
pump is used.
66
Part 6 – Sewer Design Technical Standards 6-18
30.3.2 The inlet pipe shall be extended below the low water eleva�on in the wet well
in order to reduce turbulence and odors.
30.3.3 The li� sta�on wet well cover shall be water-�ght for odor control.
30.3.4 A vent shall be provided with odor control. The vent can be connected to a
buried gravel bed or to a charcoal filter.
30.3.5 Materials in the wet well shall be protected from corrosion. Stainless steel,
plas�c, or bronze materials are recommended.
30.3.6 The force main sizing shall be based upon hydraulic requirements using a
minimum design velocity of 2.0 �/sec based on a Manning's roughness
coefficient of n = 0.013. The minimum pipe diameter for force mains shall be
1.5 inches.
30.3.7 The force main shall be designed and constructed to prevent freezing.
30.4 Sep�c Tank/Effluent Pumps
30.4.1 Typically, one sep�c tank and one effluent pump per household will be
provided. Mul�ple units may be considered where serving mul�ple family
dwellings or trailer courts. Duplex pumps, each capable of handling maximum
flow, may be required in these situa�ons.
30.4.2 Pumping units will be ac�vated by appropriate level control switches. High-
and low-level alarms will be required with audio-visual alarms recommended.
Low level pump deac�va�on controls shall be provided. A control panel with
appropriate circuit protec�on and electrical safety devices shall be used. The
alarm circuit should be separately wired from the pump circuit. All applicable
electrical codes must be sa�sfied. The power cables to the pump shall be
designed to facilitate maintenance of the pumping unit. Wiring shall be
exterior to the residence for maintenance purposes.
30.4.3 Screens limi�ng solids carryover into the pump shall be, provided. Pipe fi�ngs
used should be commonly available. Appropriate isola�on, check, and air
release valves must be used with ease of maintenance in mind. All components
shall be protected from freezing.
30.4.4 All sep�c tanks shall be vented.
30.5 Sep�c Tanks
Sep�c tanks are not allowed within the City limits.
67
Part 6 – Sewer Design Technical Standards 6-19
31.LIFT STATIONS
31.1 Li� sta�ons will be designed by a Registered Professional Engineer.
31.2 All new sewage li� sta�ons shall be equipped with a backup, redundant level control
system.
31.3 The City requires emergency power on any new li� sta�on. All new Li� sta�ons shall
be equipped with an emergency power receptacle and an Automa�c transfer switch.
31.4 All new Li� sta�ons shall be equipped with an alarm system detec�ng unauthorized
entry, power interrup�on, high water, and high pump temperature condi�ons. The
alarm signal shall be directed to op�onal remote loca�ons by telephone dialer system.
31.5 All new pumping sta�on shall be equipped with an electro-magne�c flow meter with
4-20 ma output signal, flow totalizer, and chart recorder and/or electronic recorder.
68
Part 7 – Water Design Technical Standards 7-1
PART 7 - WATER DESIGN TECHNICAL STANDARDS
1.PURPOSE
The purpose of this design criteria is to provide engineers, designers, engineering technicians,
and others, in handy reference form, the City's minimum standards for water system design.
These criteria are intended to cover the design of water mains and apply to any water systems,
public or private, 4 inches in diameter or greater. Private on-site water systems serving mobile
home parks, condominiums or apartments shall be designed in accordance with the uniform
plumbing code and approved by the appropriate building inspector.
The design criteria set forth below are intended to result in water systems which will:
1.1 Be consistent with the Water Master Plan
1.2 Be consistent with Montana Department of Environmental Quality (DEQ).
1.3 Be consistent with the latest edition of the MPWSS.
1.4 Be of adequate size and pressure to meet expected demands, within their design life.
1.5 Have sufficient flows to meet fire flow requirements.
1.6 Be strong enough to resist all external loads which may be imposed.
1.7 Be of materials resistant to both corrosion and erosion.
1.8 Be economical and safe to build and to maintain.
Alternate materials and methods may be considered for approval on the basis of these
objec�ves.
2.REFERENCES
2.1 Circular DEQ 1, Standards for Water Works, Montana Department of Environmental
Quality latest edition.
2.2 Montana Public Works Standards Specifications, latest edition and revisions.
2.3 Uniform Plumbing Code, latest edition and revisions.
3.APPROVAL OF ALTERNATE MATERIALS OR METHODS
Request for any major devia�on from these standards will be submited to the PWD in writen
form for approval.
69
Part 7 – Water Design Technical Standards 7-2
4.SPECIAL PROBLEMS
The design of the following are considered special problems and are not covered in detail in
these standards: DEQ 1 provides general guidelines for most of these items.
4.1 Air relief valves
4.2 Water loading stations
4.3 Source development
4.4 Chemical application
4.5 Treatment plants
4.6 Pumping stations
4.7 Water storage
5.DESIGN PLANS AND PROFILES
Plans will be required for all new or extension of water mains and shall include both a vicinity
map and a general layout map of the area showing the loca�on of exis�ng facili�es and of the
proposed improvements. Plans should be accurate, legible and properly detailed. Dimensions
should be either from right-of-way centerline or property lines.
5.1 Engineering Drawings (Plans)
Plans for water mains should contain at least the following informa�on:
5.1.1 Adjacent streets, property lines, u�lity easements, and references thereto.
5.1.2 Loca�on of water lines and appurtenances.
5.1.3 Loca�on of water courses, wells, stream and railroad crossings, water mains,
sewer main, gas mains, culverts and underground power, CATV, or other
u�li�es wherever possible.
5.1.4 Limits of hard surface paving with dimension references.
5.1.5 Adequate details, specifica�ons, and other informa�on for Contractor to be
able to install the proposed improvements.
5.1.6 Suitable �tle plate with scale, north arrow, date, drawing number, and name,
address and telephone of engineer, and the Registered Professional Engineer's
(RPE) signature.
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Part 7 – Water Design Technical Standards 7-3
5.2 Profiles
Profiles for the individual water lines should contain at least the following informa�on:
5.2.1 Loca�on of valves, hydrant tee, and other appurtenances
5.2.2 Profile of exis�ng and proposed ground surface.
5.2.3 Size, pipe type, length of water line.
5.2.4 Suitable �tle plate with the name and address of owner, scale, date, drawing
number, and the name, PE number.
5.2.5 Limits of street improvements will be shown including a typical sec�on of the
subject street.
5.2.6 Depth of bury
5.2.7 surface restora�on
5.2.8 new and exis�ng services
5.3 Separate Drawings
5.3.1 Separate plans shall be submited for public water mains installed in
combina�on with private water lines or site plumbing. "Site plumbing"
drawings are not acceptable. Public water main plans may be combined with
other public improvement plans, provided that the plans must be legible and
properly detailed.
5.3.2 Appropriate labeling of the services as "Private" will be done on both the plan
view and profile view.
6.SPECIFICATIONS
6.1 Engineering consultants are encouraged to develop specifica�ons and special
provisions for each project. Specifica�ons and special provisions shall incorporate the
latest edi�on of the MPWSS. Special specifica�ons pertaining to materials and
workmanship, if developed, a hard copy shall be submited to the City for review and
approval, together with plans of the project.
6.2 In general, the water specifica�ons should cover pipe material, excava�on, laying of
water main, join�ng, backfilling, tes�ng, etc. Strict supervision will be required by the
City during construc�on to assure compliance with the specifica�ons.
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Part 7 – Water Design Technical Standards 7-4
7.ADDITIONAL ITEMS OF CONCERN
7.1 Hydrosta�c Tes�ng
Hydrosta�c and leakage tes�ng shall be performed in accordance with the American
Water Works Associa�on C600. MPWSS Sec�on 02713, 'Water Mains" outlines
procedure.
7.2 Cleaning Water Mains
Before chlorina�on, except when hypochlorite tablets are used, the mains shall be
flushed thoroughly a�er the pressure and leakage test are completed. MPWSS Sec�on
02713, 'Water Mains" outlines procedure.
7.3 Disinfec�ng Water Mains
7.3.1 General. All water mains shall be disinfected in accordance with AWWA C651,
"Disinfec�ng Water Mains", and MPWSS Sec�on 02713, 'Water Mains", before
placing the main in service. The interior of all pipe, fi�ngs, and appurtenances
shall be kept free from dirt, heavy, and foreign par�cles.
7.3.2 Redisinfec�on. If the ini�al disinfec�on fails to produce approved
bacteriological or turbidity samples, the main shall be reflushed and
resampled. If check samples show bacterial contamina�on, the main must be
re-chlorinated un�l approved results are obtained.
8.GENERAL DESIGN CONSIDERATIONS
Water mains should be designed to serve houses, commercial and industrial buildings and
any establishments that needs water service in the building. Each main building on a parcel
or residence on each parcel shall be served by a separate water service.
8.1 Domes�c Flows
8.1.1 Water mains shall be designed in accordance with "Circular DEQ 1, Standards
for Water Works" published by the State of Montana Department of
Environmental Quality. Water mains shall be sized to provide a combined fire
flow and peak day flow in accordance with the standards shown below.
8.2 Fire Flows
8.2.1 For design purposes, minimum fire flows shall be 1000 gpm in low and medium
density residen�al areas, 2500 gpm in commercial and high density residen�al
areas, and 3500 gpm in industrial areas. The design shall provide for the system
to provide the minimum fire flow at each fire hydrant, assuming one hydrant
flowing at any given �me and a minimum pressure of 20 psi.
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Part 7 – Water Design Technical Standards 7-5
8.2.2 Where special condi�ons exist, greater or lesser design fire flows may be
approved by the Fire Chief (as per Fire Code) for new and exis�ng buildings.
8.3 Pressure
8.3.1 Water systems shall be designed to provide a minimum pressure of 35 psi with
no fire flow. With fire flow, a minimum pressure of 20 psi is required in all areas.
Water systems shall be designed by consul�ng the latest water system model
of pressure zones. Pumping sta�ons and pressure reducing valves may be
required to lower high pressure concerns. Pipes shall be specified to withstand
the maximum test pressures but in no case shall pipes be classed less than 150
psi. The designer should contact the PWD for informa�on on the pressure
zones and water supply available for the area.
8.3.2 In general, water systems should be designed to accommodate for future flows
which may reasonably be expected within a period of 20 years, and for
ul�mate development of the specific service area.
8.3.3 Specific approval of booster pump sta�ons, storage and addi�onal sources, will
be required from the City.
9.CAPACITY
9.1 Design flows shall be determined by considera�on of the following factors:
9.1.1 Service area to be served
9.1.2 Popula�on within the area to be served
9.1.3 Land use within the area to be served
9.1.4 Per capita water consump�on
9.1.5 Commercial, industrial, or ins�tu�onal users to be served
9.1.6 Fire flow requirements
9.1.7 Peaking factors
9.2 In the absence of flow data or other reliable informa�on, the design factors from Table
9.1 may be assumed. Appropriate peaking ra�os should be applied to determine flows,
where specified by the City.
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Part 7 – Water Design Technical Standards 7-6
Table 7.1 Design Factors Average Designation Adverse Flow Peaking Factor
Residential 100 gpcd min, *
Commercial 1,200
gpd/acre
*
Industrial 1,200
gpd/acre
*
* Peaking factor means of calcula�ons outline in latest edi�on of MT Circular DEQ-1
It is recommended that design calcula�ons include es�mates of average daily,
maximum daily, and peak instantaneous flows. The submission of design
calcula�ons will not ordinarily be required but engineers should be prepared to
substan�ate pipe sizes, layout, popula�on es�mates, land uses or other design
assump�ons as may be requested.
10.SIZE
Water mains shall be a minimum of 8 inches inside diameter for those systems incorpora�ng
fire protec�on. Fire hydrant lead lines shall be a minimum of 6-inch inside diameter.
11.PIPE MATERIALS
The following pipe materials and fi�ngs are approved:
Table 7.2
Material Specifications
Ductile Iron Pipe; Class 52 ANSI/AWWA C151/A21.51-17
(polyethylene film wrapped or encased)
Polyvinyl chloride (PVC) AWWA C900 for pipe 4” to 12”, Pressure Class
150
AWWA C905 for pipe 14” to 48”, DR 18 Pipe
Concrete Cylinder Pipe Not allowed
Cast Iron Pipe Not allowed
Valves 10” and under shall be resilient seated gate
valves w/ iron body, bronze mounted non-rising
stem, set for 200 psi working pressure.
12” and over shall be butterfly valves class 150B,
tight closing, for underground service.
MJxMJ All mechanical joint bolts, nuts, and washers shall
be Type 304 stainless steel.
Tapping Valve Tapping Saddle Stainless Steel Resilient Seat Tapping Valve with
150 psi working pressure or approved equal.
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Part 7 – Water Design Technical Standards 7-7
Valve Boxes Cast iron, 5-1/4” diameter, screw type
adjustable, and have the word “Water” stamped
thereon.
Corporation Stops ¾-inch to 2-inch – Ground Key Valve with AWWA
taper threaded inlets and Compression
Connection for outlet piping.
Or approved equal.
Service Saddles All Stainless Steel service saddle with 304 SS nuts
and bolts a Buna-N nitrile gasket and a minimum
working pressure of 150 psi.
Or approved equal.
Service Pipe Main to Building
1.Type K Copper
2.PE Pipe (CTS) SDR 7-¾-inch &
1-inch
3.PE Tube (CTS) SDR 7-1-1/2-inch
& 2-inch (200 PSI)
Curb Stop ¾-inch to 2-inch cop x cop or CTS,
For PE pipe use compression fittings with
stainless steel inserts.
Curb Boxes 6’ extension boxes with stationary one-piece
stainless steel rod.
Joint Restraint Megalug 2000 or thrust blocks
Fire-Hydrant AWWA C502 w/ two 2 -1/2” hose nozzles and one
4-1/2” pumper nozzle with National Standard
Thread.
Manhole F/c D&L Foundry or approved equal
Meters All meters-Neptune, Remote Read
Backflow Preventers All new construction ¾-inch and 1-inch use dual
check valve
Dual Check Valve
¾-inch McDonald 11-3NA-43
1-inch McDonald model 18-4-10-XD
1½-inch Febco 805Y-BV-S #45410;
Or approved equal.
EPA 570/9-89-007
Larger check valves to be approved by Public
Works Dept.
Alternate materials not listed must be approved by the Public Works Director.
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Part 7 – Water Design Technical Standards 7-8
12.MINIMUM DEPTH
All water lines shall be laid at a depth sufficient to prevent freezing and be protected against
damage from traffic. Water mains shall have a minimum cover of 6 feet measured from top
of pipe to finished grade or be otherwise protected from damage by traffic or freezing.
13.DEAD ENDS
13.1 In order to provide increased reliability of service and reduce head loss, dead ends
shall be minimized by making appropriate �e-ins whenever prac�cal.
13.2 Where dead end mains occur, they shall be provided with a fire hydrant for flushing
purposes. Flushing devices should be sized to provide flows which will give a velocity
of at least 2½ feet per second in the water main being flushed. No flushing device shall
be directly connected to any sewer.
14.VALVES
14.1 Valves
Valves should be located at not more than 500-foot intervals in· commercial districts
and at not more than 1 block or 800-foot intervals in other districts.
14.2 Line Valves in Distribu�on Pipe
Four valves shall be installed at a "cross" intersec�on. Three valves shall be installed
at a "Tee" intersec�on.
14.3 Air Relief
Air relief will be required at the high point in any water main. Pipe grade design shall
minimize the use of air relief valves wherever possible. Air relief can be provided by
means of a flushing hydrant, fire hydrant, or designated air release valve.
15.HYDRANTS
15.1 Spacing
Fire hydrant spacing shall not exceed 500 feet measured along the curb line in areas
zoned R-1 or R-2 and shall not exceed 450 feet in other areas. The Fire Chief may
require addi�onal hydrants in accordance with Uniform Fire Code. All hydrants will
have secondary valves.
16.LOCATION
16.1 Rela�on to Sewer Lines and Wells
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Part 7 – Water Design Technical Standards 7-9
Sanitary sewers and domes�c water lines shall not be laid in the same trench. Parallel
water and sewer lines wherever possible should be located at least 10 feet apart
horizontally from outside edge to outside edge of the pipe. When physical condi�ons
render this spacing impossible or imprac�cal, then water pipe with water�ght joints is
required for the sewer line. Wherever it is necessary for sewer and water lines to cross
each other, the crossing should be at an angle of approximately 90 degrees and the
sewer shall either be located 18 inches or more below the water line or be flow filled,
constructed of duc�le or PVC pipe with water�ght joints for a distance of 10 feet on
both sides of the water line.
16.2 Wate r Mains in Streets or Easements
Under normal condi�ons, water mains should be located in street right-of-way 6 feet
south or west of the street right-of-way centerline. Water mains shall be located in
centerline of alleys and easements. When it is necessary to locate waterlines in
easements, such easement shall be at least 20 feet in width.
17.PIPE JOINTS
All pipe joints must be constructed water�ght. Rubber rings or other approved joint sealing
material shall be used. Joint deflec�ons shall be controlled such that the water�ght integrity
of the joint is maintained.
18.SERVICE LINE CONNECTIONS
All service laterals from a water main to serve an individual building shall be of a minimum
size of ¾-inch in diameter within public right-of-way or within public easements. Construc�on
of service lines shall conform to the same standards as for water main construc�on.
All curb boxes shall be marked with a permanent indicator of loca�on in the nearest hard
surfacing (i.e. “W” stamp in adjacent curb, sidewalk, or driveway)
19.SEPARATE CONNECTION REQUIRED
19.1 Each main building or legal lot (except a private garage) shall be separately connected
to a public water main. Except that main buildings or dwellings located on a single
parcel may be connected to a private line, provided that an approved statement of
maintenance and billing responsibility is recorded with the �tle to the property.
19.2 A valve shall be required at the point of connec�on of a private water system to a
public system.
20.DRAINAGE DITCH OR STREAM CROSSINGS
Water lines entering or crossing drainage ditches or streams shall be constructed with care.
The pipe and joints shall be tested in place, and shall be designed, constructed, and protected
77
Part 7 – Water Design Technical Standards 7-10
against an�cipated hydraulic and physical, longitudinal, ver�cal, and horizontal loads, erosion,
and impact.
All ditch crossings shall require approval of the ditch company.
21.AERIAL CROSSINGS
Support shall be provided for all joints in pipes u�lized for aerial crossings. The supports shall
be designed to prevent frost heave, overturning, and setlement. The crossings shall also
provide protec�on from freezing.
78
Part 8 – Storm Sewer Design 8-1
PART 8 – STORM SEWER DESIGN
1.INTRODUCTION
1.1 Applicability
These design standards shall apply to all development, redevelopment, and
construc�on ac�vi�es on public and private property within the City of Laurel.
1.2 Policy Requirements
Drainage plans shall be prepared by a Professional Engineer licensed in the State of
Montana and shall be submited to the City PWD for review and approval.
2.PROJECT CLASSIFICATIONS
2.1 All Developments
2.1.1 Impact to water quality and quan�ty because of development shall be
mi�gated through design and construc�on of on-site or regional stormwater
management facili�es provided in accordance with these standards.
2.1.2 Stormwater discharge to private irriga�on ditches, drains and laterals is
acceptable provided approval has been granted by such facility
owner/operator and discharge is controlled to ensure the ditch, drain or lateral
facility is not adversely impacted beyond exis�ng condi�ons. An agreement
shall be signed between the facility owner/operator and developer with the
City named as a third party. Agreement must state at a minimum the following:
•Development’s discharge requirements,
•Condi�ons of use,
•Maintenance responsibili�es
2.1.3 Provisions sta�ng that the City shall have the first right to accept the automa�c
transfer of all interests and easements of the ditch/drain facility should the
ditch/drain facility operator abandon their facility adjacent to the
development. +
2.2 Residen�al Lot Developments
These requirements apply to residen�al lot development, including single family
homes, duplexes, townhomes, and condo developments construc�ng two or less
living units on a single lot and for “minor” construc�on projects in which
improvements create more than 1,000 SF of impervious surface.
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Part 8 – Storm Sewer Design 8-2
2.2.1 Site grading requirements shall follow specific requirements established in/on
the subdivision plat, SIA or any covenants within the subdivision.
2.2.2 Runoff generated from a residen�al site (or new improvements) shall not drain
from that site to a neighboring property.
2.2.3 Stormwater features shall be preserved per the ini�al design and maintained
by the property owner.
2.2.4 The eleva�on of residen�al dwellings must be established in recogni�on of the
storm runoff flows allowed in the guter flowline of adjacent streets during
major storms.
2.2.5 Submit a Site Stormwater Plan (SSP)in accordance with sec�on 3.1.1 detailing
lot grading and drainage plans.
2.3 Commercial Property Developments
2.3.1 These requirements apply to all commercial, industrial, and residen�al
projects construc�ng three or more living units on a single lot. They shall apply
to commercial expansion projects in which the improvements create more
than 2,500 SF of impervious surface.
2.3.2 Stormwater Management facili�es shall be design and constructed in
accordance with sec�on 2.4.
2.3.3 Runoff from the 10 and 100-year storm events shall not exceed 50-percent of
the runoff rate of natural (pre-developed) condi�ons, prior to subdividing or
developing the land. Alterna�vely, in special cases, subject to City approval,
development may discharge at a higher rate than specified above if engineer
provides adequate jus�fica�on that discharge will not create nuisance,
flooding or property damage downstream of the development. Pre-
developed rates used to jus�fy maximum allowable discharge rate, shall be
subject to approval by City reviewer and shall be based on minimal value
an�cipated from range of values within common accepted engineering
prac�ce for the exis�ng hydrological condi�ons.
2.3.4 If a new connec�on to the City’s storm drain system is installed the
development’s stormwater system which connects to the City storm drain
system shall be brought into compliance with the requirements of this sec�on.
2.3.5 Due to the poten�al for increased stormwater pollutant runoff, some sites may
require addi�onal regulatory and design requirements.
2.3.5.1 Facili�es requiring addi�onal pollutant removal are:
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Part 8 – Storm Sewer Design 8-3
A.Fueling sta�on – require oil and metals treatment,
B.Facility storing/transpor�ng more than 1,500 gallons of petroleum
products – require oil treatment,
C.Hydraulic equipment storage – require oil and metals treatment,
D.Property zoned heavy industrial – require oil and metals treatment,
E.Vehicle maintenance/repair – require oil and metals treatment,
F.Nurseries – require nutrient treatment,
G.Lawn care/fer�lizer facility – require nutrient treatment,
H.agricultural or animal care facility, or other similar facili�es –
require nutrient treatment,
I.Facility specific as determined necessary by the City
2.3.5.2 Pollutant removal applies to stormwater runoff of the above facili�es
and shall treat the below areas:
A.Oil Treatment
•required for all high use and high traffic areas that may contain
oils and grease,
•Provide for no ongoing or recurring visible sheet and reduce
Total Petroleum Hydrocarbons (TPH) to less than 10 mg/l
B.Metals Treatment
•Removal is achieved by basic removal of total suspended solids
(TSS),
•Removal should be from 20 to 85% depending on design,
metal state, and influent concentra�on,
C.Nutrient Treatment
•Nitrogen and phosphorus should achieve 50% reduc�on of
total phosphorus and 35% reduc�on of total nitrogen
2.3.6 Above ground storage in parking lots may not pond to a depth greater than 12
inches during the major storm.
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Part 8 – Storm Sewer Design 8-4
2.3.7 Where infiltra�on is used for storm water discharge a geotechnical and
hydrogeologic evalua�on shall be performed that analyzes the capacity of
ground to accept discharge.
2.3.8 A comprehensive Drainage Plan (CDP) in accordance with Sec�on 3.1.2 shall
be submited.
2.3.9 The Owner shall call for City inspec�on of drainage features prior to backfilling
and a TV report shall be submited for storm drain connec�ons within the
public right-of-way.
2.3.10 All facili�es shall be owned, operated, and maintained by the property owner.
2.4 Subdivisions
Subdivisions shall comply with sec�on 2.3 above as well as the following:
2.4.1 The requirements of this sec�on apply to subdivisions within City Limits as well
as tracts of land under review for annexa�on.
2.4.2 Stormwater management facili�es shall be provided and designed to avoid
impact to downstream drainage infrastructure and proper�es in accordance
with this sec�on. Points of discharge from the development shall be at
loca�ons where runoff flows from the site in the pre-developed drainage
condi�on and shall mimic the type of flow that exists in the pre-developed
condi�on to prevent erosion, flooding or other damage to downstream
infrastructure or downstream proper�es. Where mul�ple points of discharge
exist for one development, each point of discharge shall comply with these
provisions individually. Excep�ons may be made for downstream facili�es that
are designed to handle increase flow rates and volumes. In those cases, these
standards will be assessed at the downstream end of those facili�es.
2.4.3 Runoff entering the Subdivision from upstream proper�es shall be evaluated
and either included in the composite rate and volume of runoff from the
subdivision, or diverted through or around the subdivision, back into natural
pre-developed drainage courses as the off-site run-off existed prior to
development.
2.4.4 The eleva�on of residen�al dwellings, buildings, or other permanent facili�es
must be established in recogni�on of the depth of flow in the guter flowline
of adjacent streets during the Major Storm. Established minimum building
eleva�ons shall be documented in the SIA, plat or other applicable recorded
document.
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Part 8 – Storm Sewer Design 8-5
2.4.5 A copy of the HOA agreement, O&M Manuals, and BMP inspec�on checklist
shall be submited and include provisions for maintenance and opera�on of all
privately owned stormwater management facili�es.
2.4.6 Curb cuts for drive approaches installed during ini�al subdivision construc�on
shall be constructed to accommodate guter flow to the full curb depth
throughout the subdivision.
2.4.7 If off-site discharge onto neighboring proper�es is required where it has not
historically occurred, a drainage easement must be obtained through the
downstream neighboring proper�es to the point at which the runoff is
collected in a public drainage facility.
2.4.8 Stormwater facili�es within a subdivision, excluding conveyance facili�es
within public Right of Ways (ROW), shall be owned, operated and maintained
by the subdivision HOA. Stormwater facili�es outside of the ROW shall be
located within a lot owned by the HOA and shall include a plated easement
and associated access to the ROW. Easement shall detail property owner/HOA
use and maintenance of easement area. Landscape plans shall be submited
with the development plans.
2.5 Maintenance Ac�vi�es
The ac�vi�es listed below are considered to be “maintenance” and are therefore not
governed by the requirements of this manual. Exclusion from these stormwater
management requirements does not relieve the development of other required
permits and submitals. Contact the City Public Works Office to determine what (if
any) permits or submitals are required.
2.5.1 Replacement of exis�ng infiltra�on facili�es; i.e., boulder pits or French drains.
2.5.2 Resurfacing of an exis�ng parking lot, including reconstruc�on of base gravel
if grades of the parking lot have not altered drainage paterns.
2.5.3 City of Laurel maintenance or rehabilita�on projects.
2.5.4 Private u�lity improvement projects disturbing less than one-acre of land
surface.
2.5.5 If a new connec�on is made to the City’s storm drain system, the development
shall meet the requirements of 2.4.
3.PLAN SUBMITTAL REQUIREMENTS
3.1 Site Stormwater Plan (SSP) Stormwater Drainage Plans are divided into two categories
based upon the development type; Site Stormwater Plan (SSP) and Comprehensives
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Part 8 – Storm Sewer Design 8-6
Drainage Plan (CDP). The applicability and requirements for each are described as
follows:
3.1.1 Site Stormwater Plan (SSP)
A.The SSP applies to all developments listed in Sec�on 2.2 and shall be
reviewed and accepted prior to issuance of a building permit. The following
shall be addressed in an SSP submital:
•Inform the City as to the drainage plan, the nature of the construc�on,
project schedule, downstream conveyances, and project contact
informa�on. Plan shall include all finished floor eleva�ons, drainage
flow paths, top back of curb eleva�ons, downspout, window well
loca�ons and similar cri�cal eleva�ons.
•Iden�fy the drainage patern of adjacent lots to ensure a common
drainage approach within the development area is being met.
•Show all easements within lot and show/iden�fy all site-specific criteria
and requirements listed within the subdivision SIA, if applicable.
B.If a�er review of the SSP, the City determines that more detail or
informa�on is required, the City may require a Comprehensive Drainage
Plan.
3.1.2 Comprehensive Drainage Plan (CDP)
A.The CDP applies to all developments listed in Sec�ons 2.3 and 2.4 and shall
be reviewed and accepted prior to issuance of a building, right-of-way
permit, preliminary plat approval or final plat approval, as applicable. Table
8.1 shall be used to iden�fy required informa�on to be submited for
various development ac�vi�es. Addi�onal informa�on to guide these
submitals is provided in the referenced appendices.
B.Preliminary Drainage Report
The Preliminary Drainage Report is to be provided at the �me of preliminary
plat applica�on and is to iden�fy and describe site drainage impacts and
illustrate preliminary solu�ons to the drainage system and any
problems which may occur on-site and off-site as a result of the
development. The report shall be based on the outline in Appendix A.
C.Final Drainage Report
•The Final Drainage Report is to provide in depth details and calcula�ons
to address the drainage issues and present sizing and loca�ons for all
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Part 8 – Storm Sewer Design 8-7
proposed improvements. The report shall be based on the outline
provided in Appendix B.
•In addi�on to details and calcula�ons, the Final Drainage Report shall
include a narra�ve describing in detail how the site and site features
will func�on for the water quality storm and the Minor and Major
storm events.
•If infiltra�on to underlying soils will be used to manage any por�on of
the site runoff, refer to procedures outlined in Appendix C and the
geotechnical/hydrogeological requirements of this manual.
Table 8.1 – Comprehensive Drainage Plan (CDP) Submittals
Required Submittal
Development
Activity
Preliminary
Drainage
Report
Final
Drainage
Report
Geotechnical/
Hydrogeological
Report (If
infiltration is
used)
O&M HOA SIA Reference
Commercial X X X Appendix
B, C, & D
Preliminary
Plat X X X Appendix
A & C
Subdivision
Construction
Permit
X X X X
Appendix
B, C, D, &
E
3.1.3 Geotechnical/ Hydrogeological Report
A.The Geotechnical/Hydrogeological Report is to provide informa�on such
that reviewer has a clear understanding of underlying soils and
groundwater characteris�cs and how those will interact with an be
impacted by the proposed development. The report shall be based upon
the outline provided in Appendix C.
B.In addi�on to the report, a leter from the geotechnical or hydrogeological
professional shall be submited sta�ng the impacts that the stormwater
runoff will have to groundwater levels, structures, and facili�es both within
85
Part 8 – Storm Sewer Design 8-8
and outside the limits of developments. If impacts are iden�fied, the report
shall provide mi�ga�on solu�ons for the development.
3.1.4 Opera�on and Maintenance (O&M) Plan
The O&M plan is to iden�fy the party responsible for opera�ons and
maintenance of the stormwater facility, detail maintenance
schedules/ac�vi�es and to ensure adherence with approved design opera�ng
condi�ons.
3.1.5 Homeowners’ Associa�on (HOA) Agreement
For subdivision development, an HOA agreement shall be submited and
approved to ensure perpetual legal validity and financial stability of the party
responsible for ownership and maintenance of the stormwater facility and the
template form found in Appendix E.
4.RAINFALL
4.1 Applica�on
4.1.1 This chapter provides design storm frequency and precipita�on data to be
used in the design of stormwater management facili�es within the City of
Laurel. The informa�on provided for the Water Quality Storm is intended for
use in the design of permanent water quality treatment facili�es.
4.2 Design Storm Frequency
4.2.1 The design storm frequency varies depending on the development type as well
as the street classifica�on as shown in Tables 8.2 and 8.3.
Storm drain conveyance systems shall be designed and constructed where needed to assure
that flow depths and spread in street do not exceed allowances for the various storm scenarios
specified in Table 8.2.
4.3 Design storm depth and intensity
Table 8.2 – Design Storm Frequency by Street Classification
Public Street Classification2 Design Storm Frequency (Recurrence
Interval, Year)
Minor Major
Local Streets 2 100
Collector / Commercial Subdivision Street 5 100
Industrial / Central Business Streets 10 100
Arterial Streets 10 100
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Part 8 – Storm Sewer Design 8-9
4.3.1 Rainfall depths and intensi�es are provided in Table 8.3 and 8.4 for the City of
Laurel, including dura�ons from 5 minutes up to 24 hours and recurrence
intervals from 2 years up to 100 years. This informa�on was derived using
precipita�on data available from the Na�onal Clima�c Data Center (NCDC) for
Billings Logan Interna�onal Airport (NCDC Coopera�ve Sta�on Number
240807 (NCDC, 2014) for the period of record from July 1948 through
September 2013.
Based on DOWL Precipitation Analysis (2015)
Table 8.4 – Precipitation Intensity ‐ Duration
(Intensity In Inches per Hour)
Duration 2-year 5-year 10-year 25-year 50-year 100-year
5-min 3.26 5.02 6.18 7.75 8.96 10.16
10-min 2.33 3.45 4.19 5.20 5.98 6.75
15-min 1.87 2.74 3.31 4.11 4.72 5.32
20-min 1.50 2.24 2.73 3.39 3.89 4.38
25-min 1.29 1.93 2.35 2.91 3.33 3.76
30-min 1.12 1.68 2.05 2.55 2.94 3.33
35-min 1.01 1.52 1.85 2.29 2.62 2.95
40-min 0.92 1.38 1.68 2.08 2.38 2.68
45-min 0.84 1.26 1.54 1.91 2.18 2.45
Table 8.3 – Precipitation Depth – Duration
(Depth In Inches)
Duration 2-year 5-year 10-year 25-year 50-year 100-year
5-min 0.27 0.42 0.51 0.65 0.75 0.85
10-min 0.39 0.58 0.70 0.87 1.00 1.13
15-min 0.47 0.68 0.83 1.03 1.18 1.33
20-min 0.50 0.75 0.91 1.13 1.30 1.46
25-min 0.54 0.80 0.98 1.21 1.39 1.56
30-min 0.56 0.84 1.02 1.28 1.47 1.66
35-min 0.59 0.89 1.08 1.34 1.53 1.72
40-min 0.61 0.92 1.12 1.39 1.59 1.78
45-min 0.63 0.95 1.16 1.43 1.64 1.84
50-min 0.65 0.97 1.19 1.47 1.68 1.89
55-min 0.67 1.00 1.22 1.50 1.72 1.93
1-hr 0.68 1.03 1.26 1.55 1.76 1.97
2-hr 0.76 1.11 1.34 1.63 1.85 2.07
3-hr 0.85 1.18 1.40 1.68 1.88 2.09
6-hr 1.05 1.38 1.60 1.88 2.08 2.28
12-hr 1.29 1.67 1.92 2.23 2.46 2.70
24-hr 1.57 2.05 2.37 2.78 3.08 3.38
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Part 8 – Storm Sewer Design 8-10
50-min 0.78 1.17 1.43 1.76 2.02 2.27
55-min 0.73 1.09 1.33 1.64 1.88 2.11
1-hr 0.68 1.03 1.26 1.55 1.76 1.97
2-hr 0.38 0.55 0.67 0.82 0.93 1.03
3-hr 0.28 0.39 0.47 0.56 0.63 0.70
6-hr 0.18 0.23 0.27 0.31 0.35 0.38
12-hr 0.11 0.14 0.16 0.19 0.21 0.22
24-hr 0.07 0.09 0.10 0.12 0.13 0.14
Based on DOWL Precipitation Analysis (2015)
4.3.2 The rainfall depth for a 24-hour storm in Table 8.3 shall be used together with
the SCS (NRCS) Type II rainfall distribu�on to develop the 24-hour storm
hyetograph for runoff hydrograph analyses. The rainfall intensi�es listed in
Table 8.4 for the corresponding dura�ons (�mes of concentra�on) shall be
used in the Ra�onal Method to determine peak runoff rates.
4.4 Water Quality Storm
4.4.1 The water quality design storm shall be used to size runoff treatment and
water quality BMPs. Runoff treatment BMPs should be sized based on either
the water quality volume or flow rate in order to achieve the required
treatment efficiencies.
4.4.2 The water quality runoff volume and/or flow rate for post-development
condi�ons shall be based on the 0.5-inch rainfall event. This storm was
selected by the Montana DEQ and issued in the General Permit and has been
adopted by the City of Laurel as the water quality design storm.
5.RUNOFF
5.1 Applica�on
This chapter discusses criteria for drainage basin delinea�on and for selec�on of
acceptable stormwater runoff calcula�on methods to be used for drainage design
within the City of Laurel.
5.2 Drainage Basin Area
5.2.1 The total area, including upstream offsite areas, contribu�ng to the point of
interest shall be included in the delinea�on of drainage basins. Runoff from
upstream undeveloped land, not part of the proposed project shall be included
in the design calcula�ons. Runoff from upstream developed property must be
determined based on the exis�ng condi�ons or approved drainage plans. A
detailed contoured map with the best informa�on available shall be used to
iden�fy off-site areas. Contribu�ng drainage areas should take into
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Part 8 – Storm Sewer Design 8-11
considera�on poten�al for overflow of exis�ng ditches or other facili�es
upstream of the project.
5.3 Selec�on of Runoff Calcula�on Methods
5.4 NRCS (SCS) Hydrograph Method
5.4.1 The SCS Hydrograph Method shall be employed using the procedures detailed
in Sec�on 3.2.4 of the HEC-22 Manual
(htp://www.�wa.dot.gov/engineering/hydraulics/pubs/10009/10009.pdf).
Table 8.5 – Acceptable Runoff Calculation Methods
Runoff
Calculation
Method Applications Limitations/Notes
Rational
Method
-Used for determining peak
runoff rates for sizing
conveyance systems
-Should not be used when
routing of runoff
hydrographs is required
-Should only be used for developments and
basins of 5 acres or less
-Should only be used for basins with
homogeneous land uses
Modified
Rational
Method
-A simplified method used
to approximate storage
requirements for small
drainages
-Should only be used for developments and
basins of 5 acres or less
NRCS (SCS)
Method
-Used for determining peak
runoff rates and runoff
hydrographs for large
drainage basins
-Used for determining
storage requirements for
detention or retention
facilities
-Should be used for developments and basins
larger than 5 acres
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Part 8 – Storm Sewer Design 8-12
5.4.2 Use site-specific soils informa�on for the project site when available, or the
Natural Resources Conserva�on Service (NRCS) Soil Survey of Yellowstone
County to iden�fy the soils and corresponding hydrologic soil groups for each
drainage basin
5.4.3 Time of Concentra�on
The �me of concentra�on (TC) shall be calculated using the procedures detailed
in TR-55 Method
(htps://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb1044171.pdf).
Sheet flow lengths shall be limited to no more than 100’ When TC is used to
es�mate pre-developed flow rates to jus�fy maximum allowable discharge rate,
upper end of poten�al TC range shall be assumed.
5.4.4 Curve Numbers
Curve numbers (CNs) to be used shall be as set forth in Table 8.6. Depending
on basin area, mul�ple CNs with associated flow proper�es may be required.
A conserva�ve approach shall be used when determining CN values. When CNs
are used to es�mate pre-developed flow rates to jus�fy maximum allowable
discharge rates, lower end of poten�al CN range for given condi�ons shall be
assumed.
Table 8.6 – Runoff Curve Numbers for Urban Areas
(Average Watershed Condition, Ia = 0.2 SR)
Land Use Description
Curve Numbers for Hydrologic Soil Group
A B C D
Fully Developed Urban Areas (Vegetation Established)
Lawns, open spaces, parks, golf courses, cemeteries, etc.
Good condition; grass cover on 75% or more of the area 39 61 74 80
Fair condition; grass cover on 50 to 75% of the area 49 69 79 84
Paved parking lots, roofs, driveways, etc. 98 98 98 98
Streets and roads
Paved with curbs and storm sewers 98 98 98 98
Gravel 76 85 89 91
Dirt 72 82 87 89
Paved with open ditches 83 89 92 93
Average % impervious*
Commercial and business areas 85 89 92 94 95
Industrial districts 72 81 88 91 93
Residential Lots: Average % impervious*
65 77 85 90 92
38 61 75 83 87
30 57 72 81 86
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Part 8 – Storm Sewer Design 8-13
25 54 70 80 85
*Interpolate as necessary
Developing Urban Areas (No Vegetation Established)
Newly graded area 77 86 91 94
Native Ground Cover
Herbaceous – mixture of grass, weeds and low growing brush,
with brush the minor element (30%-70% ground cover)
71 81 89
Herbaceous – mixture of grass, weeds and low growing brush,
with brush the minor element (>70% ground cover)
62 74 85
Sagebrush with grass understory 35 47 55
Pasture, grassland or range – continuous forage for grazing 39 61 74 80
Meadow – continuous grass, protected from grazing, mowed for
hay
30 58 71 78
Cultivated Agricultural Lands
Row crops 67 78 85 89
Close-seeded or broadcast legumes or rotation meadow 58 72 81 85
Small grain crops 63 75 83 87
5.5 Ra�onal Method
5.5.1 The Ra�onal formula is given as follows:
Q = CfCIA
Where: Q = Flow in cfs,
Cf = correc�on factor for infrequent storms,
C = a dimensionless runoff coefficient,
I = rainfall intensity in inches per hour, and
A = drainage area in acres
5.5.2 The Ra�onal Method shall be applied using the procedures detailed in Sec�on
3.2.2 of the HEC-22 Manual
(htp://www.�wa.dot.gov/engineering/hydraulics/pubs/10009/10009.pdf).
5.5.3 Frequency Correc�on Factors. Table 8.7 lists the correc�on factor to be used
for infrequent storm events.
Table 8.7 – Frequency Correction Factors for Rational Method
Recurrence Interval (years) Adjustment Factor Cf
2 and 10-year 1.00
25-Year 1.10
50-Year 1.20
100-Year 1.25
NOTE: C*Cf should not exceed 1.00
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Part 8 – Storm Sewer Design 8-14
5.5.4 Runoff Coefficients
Runoff Coefficients to be used shall be as set forth in Table 8.8. A
conserva�ve approach shall be used when determining coefficient values.
When “C” is used to es�mate pre-developed flow rates, lower end of
poten�al “C” rage for given condi�ons shall be assumed.
*Higher values are usually appropriate for steeply sloped areas and longer return periods as
infiltra�on and other losses have a propor�onally smaller effect on runoff in these cases
5.6 Modified Ra�onal Method
5.6.1 The Modified Ra�onal Method approximates the volume of runoff for various
storm dura�ons, with peak flows based on the �me of concentra�on for each
respec�ve dura�on. The difference between the volume of runoff into the
Table 8.8 – Runoff Coefficients ("C") for the Rational Method
Type of Drainage Area Runoff Coefficient, C*
Residential:
Neighborhood areas 0.70
Single-family areas 0.50
Multi-units, detached 0.60
Multi-units, attached 0.75
Apartment dwelling areas 0.70
Industrial:
Light areas 0.80
Heavy areas 0.90
Parks, cemeteries 0.10 – 0.25
Playgrounds 0.20 – 0.40
Railroad yard areas 0.20 – 0.40
Unimproved areas (forest) 0.10 – 0.30
Lawns:
Sandy soil, flat, 2% 0.10
Sandy soil, average, 2-7% 0.15
Sandy soil, steep, 7% 0.20
Heavy soil, flat, 2% 0.17
Heavy soil, average 2-7% 0.22
Heavy soil, steep, 7% 0.35
Streets, parking lots and other paved areas:
Asphaltic and concrete 0.95
Brick 0.85
Drives, walks and roofs 0.95
Gravel Areas 0.70-.85
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Part 8 – Storm Sewer Design 8-15
facility and the ou�low from the facility, computed for the various storm
dura�ons is used to establish the maximum required deten�on storage.
5.6.2 This simplified approach is valid for basins with contribu�ng areas less than 5
acres.
5.7 Computer Aided Design So�ware
5.7.1 Use of computer aided design so�ware is allowed. However, designer shall
provide a detailed, writen explana�on, within the body of the CDP, detailing
selec�on of input parameters, descrip�on for how program calculates results,
and a detailed explana�on of those results. Appurtenant results pages shall
be provided in an appendix of the CDP.
6.HYDRAULIC ANALYSIS AND DESIGN
6.1 Applica�on
This chapter provides criteria to be used in the design of both public and private storm
drainage infrastructure including inlets, manholes, storm drain, open channels,
culverts, and bridges to safely convey storm runoff for projects within the City of
Laurel.
6.2 Guter Flow
The City allows the use of streets for drainage within the limita�ons specified in Tables
8.9 and 8.10 Contact the PWD for determina�on of a street’s classifica�on.
1Where no curbing exists, encroachment shall not extend beyond property lines, except at drainage easements.
Table 8.9 – Allowable Use Of Streets For Minor Storm Runoff
Street Classification Maximum Street Encroachment
Local No curb overtopping. Flow may spread to crown of street.1
Collectors No curb overtopping. Flow spread must leave at least one, 11’ lane
free of water, five feet either side of the street crown. 1
Arterials No curb overtopping. Flow spread must leave at least two, 11’
lanes free of water, ten feet each side of the street crown or
median. 1
Arterials (more than 6
lanes)
No curb overtopping. Flow spread must leave at least four, 11’
lanes free of water, twenty feet each side of the street crown or
median. 1
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Part 8 – Storm Sewer Design 8-16
6.2.1 Hydraulics
Guter flow encroachment and hydraulics shall be evaluated using the
methods presented in Sec�on 4.3 of the HEC-22 Manual
(htp://www.�wa.dot.gov/engineering/hydraulics/pubs/10009/10009.pdf).
6.2.2 Minimum Guter Slope
Guters shall be constructed at slopes no flater than 0.3 percent for retrofit
condi�ons and 0.5 percent for new construc�on. For new guter sec�ons in
ver�cal curves, the k-value shall be less than or equal to 167 to provide for
adequate drainage. If the k-value exceeds 167, special considera�on shall be
given to promote drainage.
6.2.3 Inlet Spacing and Loca�on General
The intercep�on capacity of inlets and required spacing shall be determined in
accordance with the procedures described in Sec�ons 4.3 and 4.4 of the HEC-
22 Manual.
6.2.3.1 Recommended Loca�ons for inlets
A.Away from ADA ramps
B.Prior to pedestrian crossings
C.At low points in the guter grade
D.Where significant flows from off the right-of-way are expected
E.On horizontal curves where a change from normal crown to super-
eleva�on may cause water to sheet-flow across the road
F.Where lay-down curb (e.g., at approaches) may allow the flow to
escape and cause flooding
G.Where necessary to maintain guter flow widths and depths within
the allowable limits set forth in Tables 8.9 and 8.10
H.Mid-block inlets within subdivisions, shall be located along
property lines to minimize impacts to future driveways and other
development features
I.Where a curbed roadway crosses a bridge, the guter flow should
be intercepted and not permited to flow onto the bridge.
6.2.3.2 Inlets Are Not for Flood Preven�on
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Part 8 – Storm Sewer Design 8-17
Inlets shall not be considered as the sole defense for flood protec�on.
Grading design shall not allow water to back up and flood any parts of
a building during a major storm event in the event that an inlet is
blocked.
6.2.3.3 Inlet Types
Allowed storm inlet types include grated and combina�on (grated with
curb opening or grated with curb opening plus sloted drain) inlets. The
City of Laurel standard inlets include Type II inlets in sag loca�ons and
Type III inlets for on-grade installa�ons for streets without curb and
guter, these inlets may not be appropriate, and another inlet may be
selected with City approval.
•Inlets in low point along road profile – calculated inlet capacity at
low points shall assume 50 percent plugging by debris.
•Inlets along straight graded sec�ons of road profile– calculated inlet
capacity in straight grade areas shall assume 25 percent plugging by
debris.
•Inlets installed within the right-of-way, or are adjacent to trails,
sidewalks, and bike lanes must have grates that are designated for
pedestrian and bicycle traffic. Approval by the City is required for
inlets within the right-of-way that are not designated for pedestrian
and bicycle.
6.3 Storm Drain
6.3.1 Hydraulics
Use the methods set forth in Chapter 7 of the HEC-22 Manual for the hydraulic
design of storm drains, except as modified herein
(htp://www.�wa.dot.gov/engineering/hydraulics/pubs/10009/10009.pdf).
6.3.2 Diameter, Slope, and Velocity Limits
A.Minimum slopes for storm drainpipes shall be as required to maintain a
full-flow velocity of at least 2.5 feet per second during the Minor Storm
Event.
B.Minimum diameter for storm drain lines and laterals, which will be part of
the public storm drainage system, shall be 12 inches. Minimum diameter
for private connec�ons into the public storm drainage system shall be 6
inches. Pipe sizes shall not decrease in the downstream direc�on and
transi�ons from smaller pipes to larger pipes shall occur by matching the
inside top (crown) of the pipes where prac�cable. Where it is not possible
95
Part 8 – Storm Sewer Design 8-18
to match crowns, the 67-percent diameter points of the pipes shall be
matched at a minimum, where prac�cable; or, upon approval from the City
Public Works Office, inverts may be matched if the HGL does not exceed
the street eleva�on during a minor storm event.
6.3.3 Maintenance Access
A.All stormwater pipe and facili�es shall be accessible for opera�on and
maintenance.
B.When vehicle access is necessary, for facili�es constructed outside of the
street sec�on, access roads shall be provided in access easements. The
minimum clear driving lane width of access roads is 12 feet. Access roads
shall have a maximum grade of 9% and shall be constructed with gravel,
pavement, concrete or an appropriate all-season surface.
C.Gates and/or bollards are required when necessary to restrict access to
stormwater facili�es. Cables and/or chains stretched across access roads
are not acceptable.
6.3.4 Manning “n” Values
The Manning’s “n” value used for the design for storm drains shall be as
shown in Table 8.10.
Table 8.10 – Manning’s Coefficients (n) for Storm Drain Conduits
Pipe Material Roughness or Corrugation Manning’s n
Concrete Pipe Smooth 0.013
Concrete Boxes Smooth 0.015
Spiral Rib Metal Pipe Smooth 0.013
Corrugated Metal Pipe, Pipe-
Arch and Box
2-2/3 by 1/2 in Annular
2-2/3 by 1/2 in Helical
2-6 by 1 in Helical
5 by 1 in
3 by 1 in
6 by 2 in Structural Plate
9 by 2-1/2 in Structural Plate
0.027
0.023
0.025
0.026
0.028
0.035
0.037
Poly Based Thermoplastic Smooth
Corrugated
0.015
0.025
PVC Based Thermoplastic Smooth 0.011
*Published values may differ; however, values presented in this table assume long term use of pipe
which leads to increased roughness. Manufacturer recommendations shall be used if values are
higher than presented above.
6.4 Materials
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Part 8 – Storm Sewer Design 8-19
6.4.1 Access Manholes
A.Access manholes are required when joining pipes of different types, sizes,
at horizontal or ver�cal bends in the alignment, at lateral connec�ons, and
at the upstream terminus of storm drain mains.
B.Required Size
The required minimum manhole size shall be 48-inches and larger when
required by pipe sizes and geometry to sa�sfy applicable ASTM
specifica�ons.
C.Required Spacing
The maximum manhole spacing along storm drains is as set forth in Table
8.11.
6.4.2 Maximum Manhole Depth
Manhole depths shall not exceed 20 feet without special safety provisions such
as intermediate pla�orms and minimum diameter risers of 48 inches.
6.4.3 Drop Manholes
The difference between the highest trunk line pipe invert entering a manhole
and the invert leaving shall not exceed 24 inches. Manholes with drops
exceeding 24 inches shall be designed as drop manholes. Drop manholes with
drop heights exceeding six feet shall be designed with high strength (6,000psi)
concrete.
6.5 Clearance from Other U�li�es
The following u�lity clearances shall be maintained where possible. All clearance are
based on the outside edge of the storm drain to the outside edge of the other
u�li�es.
6.5.1 Horizontal clearances from storm main:
• Cable TV, Gas, Power 5 feet
Table 8.11 – Maximum Allowable Manhole Spacing
Storm Drain Diameter Maximum Spacing
12” to 36” 400’
42” to 60” 500’
66” and Larger 600’
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Part 8 – Storm Sewer Design 8-20
•Sewer 6 feet
•Telephone, Fiber Op�cs 5 feet
•Water 10 feet
6.5.2 Ver�cal clearances from storm main:
•Cable TV, Gas, Power 1 feet
•Sewer 1 feet
•Telephone, Fiber Op�cs 1 feet
•Water 1.5 feet
•Misc. Private U�li�es 1 feet
6.5.3 Water main crossings shall be designed to prevent freezing due to minimal
clearance from storm drains.
6.5.4 Avoid crossing other u�li�es at highly acute angles. The angle measure
between u�li�es shall be between 45 and 90 degrees where possible.
6.6 Private Drainage System Connec�ons
Private drainage system connec�ons to the public storm drain system shall comply
with the following criteria. Such connec�ons shall be en�rely owned and maintained
to the main by development in which the connec�on was installed and/or serves.
6.6.1 All private stormwater connec�ons shall include backflow preven�on to
prevent stormwater from the City’s storm drain system from surcharging onto
private property unless such backflow is not possible due to grades. Backflow
preventer must be installed on-site and not within the public right-of-way.
A.Minimum pipe diameter discharging to the City’s storm drain system shall
be 6 inches. The maximum pipe diameter allowed will depend on an
evalua�on of the capacity of the City’s storm drain system and
approval from the City Public Works Office.
B.Directly connected pumped connec�ons to the City’s storm drain system
are not allowed. Developments may install a pump to mi�gate stormwater
runoff per the requirements of this manual; however, stormwater runoff
shall be pumped to a manhole or other feature prior to making a gravity
connec�on to the City’s system.
C.Directly connected pumped connec�ons to the connec�ons shall only
be made at a structure.
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Part 8 – Storm Sewer Design 8-21
6.7 Ou�alls
6.7.1 General
•Use the methods set forth in Chapter 7.1.5 of the HEC-22 Manual, as
modified herein.
•Invert eleva�ons of ou�alls shall be no lower than the bank-full water
surface eleva�on (2-yr flood) in open channels or streams, where prac�cal.
•Ou�alls downstream of deten�on facili�es shall be designed to prevent
backwater into those facili�es.
•Ou�alls within ditches/drains shall be constructed with fire-proof material.
6.7.2 Erosion Protec�on
Erosion protec�on is required at the outlet to prevent erosion of the ou�all
channel bed and bank.
6.7.3 Energy Dissipa�on/Rip-Rap
A.Where flow veloci�es exceed 10 feet-per-second at the ou�all, during the
design storm, energy dissipa�on, in addi�on to erosion protec�on may be
required. Design energy dissipa�on measures in accordance with FHWA
HEC-14, “Hydraulic Design of Energy Dissipaters for Culverts and Channels”
(htps://www.�wa.dot.gov/engineering/hydraulics/pubs/06086/hec14.p
df).
B.Rip-Rap size and classifica�on shall be based upon flow rates to be
mi�gated. Rip-Rap sizing shall follow MDT’s guidelines within their
Standard Specifica�ons, Division 700:
htp://www.mdt.mt.gov/other/webdata/external/const/specifica�ons/20
14/division_700.pdf
6.7.4 Maintenance Access
All stormwater pipe and facili�es shall be accessible for opera�on and
maintenance.
When vehicle access is necessary, for facili�es constructed outside of the street
sec�on, access roads shall be provided in dedicated access easements. The
minimum clear driving lane width of access roads is 12 feet. Access roads shall
have a maximum grade of nine percent and shall be constructed with gravel,
pavement, concrete or an appropriate all- season surface.
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Part 8 – Storm Sewer Design 8-22
Gates and/or bollards are required when necessary to restrict access to
stormwater facili�es. Cables and/or chains stretched across access roads are
not acceptable.
6.8 Open Channel Conveyances
6.8.1 General
A.New or altered channels shall be lined with grass, rocks or other erosion
resistant materials adequate to prevent erosion during maximum design
flow scenario. Concrete or asphalt shall not be used unless approved by
the City Public Works Director.
B.Design open channels in accordance with the methods provided in Chapter
5 of HEC-22 except as modified herein.
6.9.2 Clearance
Channels shall be located no closer than ten feet from any structure founda�on
as measured horizontally from the edge of the swale at the top of freeboard
eleva�on.
6.8.3 Erosion Control
A.Channel segments shall be designed according to the permissible trac�ve
force (shear stress) methodology set forth in Sec�on 5.3 of HEC-22 and
Hydraulic Engineering Circular 15
(htp://www.�wa.dot.gov/engineering/hydraulics/pubs/10009/10009.pdf,
htp://www.�wa.dot.gov/engineering/hydraulics/pubs/05114/05114.pdf,
respec�vely)
B.Both the bare soil condi�on immediately following construc�on and the
an�cipated vegetated condi�ons of the channel shall be evaluated. If the
channel is determined to be unstable during the maximum design storm
event for either of these condi�ons, the appropriate long-term, temporary,
and transi�onal linings shall be installed.
C.Erosion control structures, such as check drops or check dams, may be
required to control flow veloci�es.
6.8.4 Freeboard Requirements
A minimum freeboard of one-foot from the water surface during Major
Storm event to the top of bank shall be provided for open channel
conveyances.
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Part 8 – Storm Sewer Design 8-23
6.8.5 Fric�on Factors (n)
Use Manning’s roughness factors (n) set forth in Table 5-1 of HEC-22. The
design shall consider the channel roughness both immediately a�er
construc�on and when vegeta�on is fully established. Roughness factors,
which are representa�ve of unmaintained channel condi�ons, shall be used
for the analysis of water surface profiles. Roughness factors, which are
representa�ve of well-maintained channel condi�ons, shall be used to
determine maximum velocity.
6.8.6 Side Slopes
Side slopes shall be no steeper than 4H:1V for maintained grass-lined channels,
3H:1V for unmaintained na�ve grass-lined channels and 2H:1V for riprap-lined
channels.
6.8.7 Maintenance Access
Provide maintenance access for inspec�on, mowing opera�ons, and debris
removal by conven�onal equipment along the length of the conveyance
channel. The type of equipment needing access is dependent on the size of the
channel. Large channels will need access for dump trucks and loaders. For
small channels, foot or pick-up truck access may suffice. Channels may need to
be offset within the easement to facility maintenance.
6.8.8 Opera�on & Maintenance of Private Open Channels
A.Open channels require periodic maintenance. The degree of maintenance
is dependent on the loca�on, the specific type of facility, and the liner
material (grass, rock, etc.).
B.Maintenance of open channels is required to insure the conveyance
capacity of the facility is maintained and that channel erosion does not
occur. The condi�on of open channels should be checked on a periodic
basis, especially a�er large storms or extended periods of high flow or
immediately following periods of high intensity winds (erosion may occur
during high flows, from scour caused by localized debris blockage or from
debris blown into the channel). Debris should be removed to prevent
channel plugging, channel scour and loss of channel conveyance. Erosion
shall be repaired or stabilized.
C.Vegetated channels shall be maintained to ensure that vegeta�on does not
limit the conveyance capacity of the facility. If conveyance restric�ons are
apparent, the vegeta�on should be trimmed to restore capacity.
101
Part 8 – Storm Sewer Design 8-24
D.Emergent vegeta�on (spirogyra, elodea, watercress, etc.) in conveyance
channels may also become a problem if it is allowed to constrict the
conveyance capacity of the facility. Vegeta�on above the ordinary high
water mark shall also be monitored primarily for its ability to retain bank
stability without reducing channel capacity at maximum design flows.
6.9 Culverts
Culverts shall be designed using the methods set forth in the Federal Highway
Administra�on (FHWA) Hydraulic Design Series No. 5 (HDS-5), “Hydraulic Design of
Highway Culverts”, Publica�on No. FHWA-NHI-01-020 except as modified herein
(htp://www.�wa.dot.gov/engineering/hydraulics/pubs/12026/hif12026.pdf)
6.9.1 Street Overtopping
Culverts shall be sized such that the depth of street overtopping is limited as
set forth in Table 8.12.
6.9.2 Headwater Depth
A.The headwater (HW) depth shall be limited according to the following
ra�os to diameter (D):
•For culverts with a cross sec�onal area less than or equal to 30 square
feet: HW/D ≤1.5
•Culverts must also be sized without crea�ng significant flow
constric�on, such that exis�ng channels upstream are not overtopped
during the design flow event.
6.9.3 Allowable Veloci�es
Table 8.12 – Allowable Street Overtopping Depths at Culvert Crossings
Street
Classification
Minor Storm Major Storm
Local and
Collector
None
Six inches at the street crown. Residential dwellings
and public, commercial, and industrial buildings shall
not be inundated at the ground line unless flood-
proofed.
Arterial None
No overtopping allowed. Provide 1-ft of clearance
between the crown of the culvert and the water
surface elevation where practicable, for drainage
basins greater than one square miles.
102
Part 8 – Storm Sewer Design 8-25
A.Culverts shall be designed to maintain a minimum velocity of2.5 feet-per-
second during the Minor Storm to prevent sediment accumula�on and
shall be designed with a minimum slope of 0.5 percent, where prac�cable.
B.Culverts shall be sized to limit veloci�es in order to minimize erosion
poten�al during the Major Storm Events. For exit veloci�es in excess of 10
feet-per-second during the Major Storm, energy dissipa�on, in addi�on to
erosion protec�on may be required. Design energy dissipa�on measures in
accordance with FHWA HEC-14, “Hydraulic Design of Energy Dissipaters for
Culverts and Channels”
(https://www.fhwa.dot.gov/engineering/hydraulics/pubs/06086/hec1
4.pdf)
6.10.4 Materials
A.Culverts shall be constructed of concrete, corrugated polyethylene pipe, or
polyvinyl chloride corrugated sewer pipe with a smooth interior. Efforts
should be made to eliminate corrugated steel pipe.
B.Culvert wall strengths and coa�ngs shall be suitable for the soil condi�ons
design depths, and trench details. Culvert strength shall be designed
assuming HS-20 live load capacity unless unique condi�ons of the crossing
warrant a higher load capacity (i.e., Hs-25 or E-80).
C.When an abrasive bed load is an�cipated or when veloci�es exceed 10 feet
per second, protec�ve measures shall be implemented to limit pipe
damage. Corrosion, abrasion and other appropriate observa�ons of field
culvert materials and be considered in determining appropriate culvert
materials and joint types. Corrosion resistance shall be evaluated based on
minimum resis�vity, pH, sulfate content and chlorine content of the soil
and groundwater.
6.10.5 End Treatments
Culverts shall be designed with appropriate end treatments at their inlets and
outlets such as flared end sec�ons, headwalls, or wingwalls to provide smooth
transi�ons to/from the drainage channel or ditch and to conform to
embankment slopes. In addi�on to the pipes, end treatments installed within
ditches/drains shall be fire-proof. Erosion protec�on or energy dissipaters shall
be provided as necessary to limit erosion due to turbulent flow and high
veloci�es. Depending on the culvert loca�on, a safety grate or trash rack may
need to be installed.
6.10.6 Maintenance Access
103
Part 8 – Storm Sewer Design 8-26
Provide maintenance access to the upstream and downstream ends of
culverts for inspec�on and debris removal.
7.EROSION AND SEDIMENT CONTROL
7.1 Regulatory Requirements And Permit Coverage
Developer shall comply with all applicable state and federal requirements associated
with stormwater pollu�on preven�ons, including coverage under the States Na�onal
Pollu�on Discharge Elimina�on System Permit to Discharge Stormwater Associa�on
with Construc�on Ac�vi�es (NPDES Permit), when required.
7.2 Construc�on
Regardless of requirement for coverage under the NPDES Permit, construc�on ac�vity
shall implement BMPs and good housekeeping prac�ces to minimize impacts
including, but not limited to, erosion and sediment transport into public right-of-way
or onto adjoining property. Homebuilders/contractors are responsible for managing
BMPs on individual lots within a subdivision and/or master plan area and are required
to follow the requirements in the No�ce of Intent (NOI) and Stormwater Pollu�on
Preven�on Plan (SWPPP), when applicable.
7.3 Best Management Prac�ces (Bmp)
Temporary erosion and sediment control BMPs may be selected, designed, and
installed using the methodology discussed in the most current edi�on of the Montana
Department of Transporta�on Erosion and Sediment Control Best Management
Prac�ces Manual, available on MDT’s website
(htps://www.mdt.mt.gov/publica�ons/docs/manuals/env/bmp-manual-jan15.PDF).
In addi�on, the Montana Department of Environmental Quality developed the Storm
Water Management During Construc�on Field Guide for Best Management Prac�ces
reference document which may help in developing a BMP plan. Contact their office
for a copy of this document.
104
Appendix A – Preliminary Drainage Report App -A
Appendix A Preliminary Drainage Report
105
Appendix A – Preliminary Drainage Report App -A
The purpose of the preliminary drainage report is to describe and illustrate the
preliminary solutions to the drainage problems which may occur on-site and off-site as
a result of the development or any phase of the development. The drainage report shall
be submitted during the subdivision process with the application for Preliminary Plat.
Preliminary drainage reports shall provide an appropriate level of detail to address
drainage issues and present the overall plan for the property. The report shall be based
on the following outline and include appropriate background information, supporting
data, calculations and plan drawing(s).
TITLE PAGE
1. Type of Report (Concept)
2. Project Name
3. Prepared for/by
4. Date
5. P.E. Seal and Signature
INTRODUCTION
1. Location
a. City, County, State Highway and local streets within and adjacent to the site,
or the area to be served by the drainage improvements.
b. Names of surrounding developments, properties or landmarks.
2.Description of Property
a. Area in acres
b. Ground cover (type of ground cover and vegetation)
c. Existing land uses and known and foreseeable future land uses
d. Topographic features, steepness of slopes
e. Major drainage ways and receiving channels
f. Existing drainage facilities
g. Flood Hazard Zones
h. Geologic Features (if applicable)
i. Previous drainage studies for the property (if any)
3. Proposed Project Description
a. Land uses
b. Changes to existing facilities
c. Changes to floodplains
d. Proposed system improvements
4. Drainage Criteria
a. Minor and Major Storm Analysis
b. Geotechnical/Hydrogeological Analysis
106
Appendix A – Preliminary Drainage Report App -A
c. Hydrologic Methods
i.Rainfall
ii.Design Storms
iii. Runoff methods and computer models
d. Hydraulic Methods
i.Design standards
ii.Hydraulic models
iii. Detention Pond sizing
e. State or Federal Regulations (if applicable).
HISTORIC DRAINAGE SYSTEM
1. Major Basin Description
a. Reference to major drainage way planning studies such as flood hazard
delineation report, major drainage way planning reports, and flood insurance
rate maps.
b. Major basin drainage characteristics and structures, existing and planned land
uses within the basin.
c. Summary of off-site and on-site basin characteristics and runoff rates.
PROPOSED DRAINAGE SYSTEM
1. Design Concepts
a. Discussion of concept and typical drainage patterns.
b. Discussion of compliance with off-site runoff considerations.
c. Discussion of proposed drainage patterns and improvements including
streets, storm sewer, culverts, open channels and detention storage.
d. Discussion of the content of tables, charts, figures, plates, or drawings
presented in the report.
e. Discussion of geotechnical and hydrogeological impacts of development.
SUMMARY
1. Relation to off-site drainage features.
2. Summary of proposed improvements.
a. Storm sewer
b. Culverts
c. Open channels
d. Detention Storage
e. On-site and off-site impact and mitigation measures
3. Floodplain impacts.
4. State or Federal regulations.
5. Compliance with applicable regulations and standards.
REFERENCES
107
Appendix A – Preliminary Drainage Report App -A
Reference all criteria, master plans, and technical information used in support of
concepts and calculations.
APPENDICES Background Data
1. Floodplain maps
2. Applicable reports or report excerpts.
3. Key correspondence with adjacent property owners or utilities.
PRELIMINARY REPORT DRAWING CONTENTS
All drawings shall be submitted as back-up materials with the Preliminary Plat. A map
shall be provided in sufficient detail to identify drainage flows entering and leaving the
development and general drainage patterns. The map shall identify any major facilities
from the property (i.e., development, existing detention facilities, culverts, storm
sewers) along the flow path to the nearest major drainage way.
Floodplain Information: The location of the subject property shall be included with the
report. All major drainage ways shall have the floodplain defined and shown on the
report drawings.
Drainage Plan shall show the following:
1. Existing topographic contours at two (2) feet maximum intervals. The contours
shall extend a minimum of one-hundred (100) feet beyond the property lines.
2. All existing drainage facilities.
3. Approximate flooding limits based on available information.
4. Conceptual major drainage facilities including detention basins, storm sewers,
swales, riprap, and outlet structures in the detail consistent with the proposed
development plan.
5. Major drainage boundaries and sub-basin boundaries.
6. Any off-site features influencing development.
7. Proposed flow directions and, if available, proposed contours.
108
Appendix B – Final Drainage Report App -B
Appendix B Final Drainage Report
109
Appendix B – Final Drainage Report App -B
The purpose of the Final Drainage Report is to present the final design details for the
drainage facilities discussed in the Preliminary Drainage Plan. Any changes to the
preliminary concept must be presented and fully explained.
Drainage plan shall provide an appropriate level of detail to address the drainage
issues and present sizing and locations for all proposed improvements. The report shall be
based on the following outline and include appropriate background information and
supporting data and calculations and plan drawing(s).
TITLE PAGE
1. Type of Report (Final)
2. Project Name
3. Prepared for/by
4. Date
5. P.E. Seal and Signature
INTRODUCTION
1. Location
a. City, County, State Highway and local streets within and adjacent to the site, or
the area to be served by the drainage improvements.
b. Names of surrounding developments, properties or landmarks.
2. Description of Property
a. Area in acres
b. Ground cover (type of ground cover and vegetation)
c. Existing land uses and known and foreseeable future land uses
d. Topographic features, steepness of slopes
e. Major drainage ways and receiving channels
f. Major drainage ways and receiving channels
g. Existing drainage facilities
h. Flood Hazard Zones
i. Geologic Features (if applicable)
3. Previous drainage studies for the property (if any)
a. Proposed Project Description
b. Land uses
c. Changes to existing facilities
d. Changes to floodplains
e. Proposed system improvements
f. Right-of-way conveyance or acquisition required
4. Drainage Criteria
a. Application Standards or exceptions
b. Minor and Major Storm Frequencies
110
Appendix B – Final Drainage Report App -B
c. Hydrologic Methods
i.Rainfall
ii.Design Storms
iii.Runoff methods and computer models
iv.Geotechnical/Hydrogeological Analysis (Attach Reports)
d. Hydraulic Methods
i.Design standards
ii.Hydraulic models
iii.Detention Pond sizing
e. State or Federal Regulations (if applicable)
HISTORIC DRAINAGE SYSTEM
1. Major Basin Description
a. Reference to major drainage way planning studies such as flood hazard
delineation report, major drainage way planning reports, and flood
insurance rate maps.
b. Major basin drainage characteristics and structures, existing and planned
land uses within the basin.
c. Summary of off-site and on-site basin characteristics and runoff rates.
2. Sub-Basin Description
a. Discussions of historic drainage patterns of the property.
b. Discussion of off-site drainage flows and flow patterns and impact on
development under existing and fully developed basin conditions.
c. Summary of off-site and on-site basin characteristics and runoff rates.
PROPOSED DRAINAGE SYSTEM
1. Design Concepts
a. Discussion of minor and major drainage patterns, impacts, flows and
volumes.
b. Discussion of compliance with off-site runoff considerations.
c. Discussion of proposed drainage patterns and improvements including
streets, storm sewer, culverts, open channels and detention storage.
d. Discussion of the tables, charts, figures, drawings, etc. presented in the
report.
2. Design Details
a. Discussion of problems encountered and solutions at specific design
points.
b. Discussion of detention storage and outlet design.
c. Discussion of maintenance and access aspects of the design.
d. Discussion of impacts of concentrating the flow on the downstream
properties.
111
Appendix B – Final Drainage Report App -B
e. Summary of basin characteristics and runoff rates.
f. Discussion of geotechnical and hydrogeological impacts of development.
g. Discuss flooding hazards and describe minimum building elevations.
SUMMARY
1. Relation to off-site drainage features.
2. Summary of proposed improvements.
a. Storm sewer
b. Culverts
c. Open channels
d. Detention Storage
e. Geotechnical/Hydrologic impacts
f. On-site and off-site impacts and mitigation measures
3. Floodplain impacts.
4. State or Federal regulations.
5. Compliance with applicable regulations and standards.
REFERENCES
Reference all criteria, master plans, and technical information used in support of
concepts and calculations.
APPENDICES
1. Background Data
a. Floodplain maps.
b. Applicable reports or report excerpts.
c. Key correspondence with adjacent property owners or utilities.
2. Hydrologic Computations
a. Land uses regarding adjacent properties.
b. Soil types, coverage and loss coefficients
c. Proposed land uses for project by basin.
d. Time of concentration and runoff coefficients for each basin.
e. Basin parameters used for modeling including basin area, length, slope,
distance to centroid and routing elements.
f. Initial and major storm runoff at specific design points for off-site and on-site
flows.
g. Off-site, historic and fully developed runoff computations at specific design
points.
h. Hydrographs at critical design points.
112
Appendix B – Final Drainage Report App -B
i.Schematic diagram of hydrology model showing basins and routing
elements and combination elements.
3.Hydraulic Computations
a.Culvert Capacities and inlet and outlet protection.
b.Storm sewer capacity, including energy grade line (EGL) and hydraulic grade
line (HGL) elevations.
c.Gutter capacity as compared to allowable.
d.Storm inlet capacity including roughness coefficients, trickle channels
freeboard, hydraulic grade line, and slope protection.
e.Check and/or channel drop placement.
f.Detention area volume capacity and outlet capacity calculations; depths of
detention basins, outlet configuration.
g.Downstream/outfall capacity to the Major Drainage way system.
4.Miscellaneous Information
a.Other documents relating to drainage conditions on the property.
b.Agreements with property owners or other agencies.
c.Permits, etc.
113
Appendix C – Geotechnical/Hydrogeological Report App -C
Appendix C Geotechnical/Hydrogeological Report
114
Appendix C – Geotechnical/Hydrogeological Report App -C
1. The evaluation shall include at a minimum:
a. A review of available geologic, hydrogeological, and topographic conditions to
identify any site conditions that could impact the use of the storm drainage
systems or the construction of sub-level structures. This review shall include all
available previous geotechnical engineering reports for the development.
Citations to possibly useful references are provided at the end of this appendix.
b. Where access to adjacent properties is unavailable, the project owner shall rely
upon the best known information for the area, supplemented with
available information, including any existing engineering reports or studies for
sites in the vicinity.
c. A surface and subsurface reconnaissance of the site and an inspection of
adjacent properties to assess potential impacts from the proposed
stormwater system and to verify that the conditions are consistent with the
mapped information.
d. The level of data for the hydrogeological assessment required will be
dependent on the amount of stormwater to be managed, the type of
infiltration system proposed, and the surface and subsurface soil conditions at
the site. The assessment will be conducted by a professional with
experience collecting and analyzing hydrogeological data.
e. An assessment of hydrogeological conditions that indicate the potential for
infiltrated stormwater to impact on- or off-site, facilities or structures. The
assessment will also demonstrate that impacts to groundwater elevation or
flow, resulting from the proposed infiltration system will be confined to the
property. A groundwater mounding calculation shall be provided to identify the
impacts of infiltrated stormwater runoff. An example calculation method and
spreadsheet is made available from the United States Geological Survey (USGS);
however, other approved, similar calculation methods may be accepted. This
information can be found at the following link:
https://pubs.usgs.gov/sir/2010/5102/
f. The Geotechnical/Hydrogeological report will contain the signed project
certification cover sheet found in Appendix G.
2. The Report Narrative shall include:
a. A brief project description including size, number of lots proposed, project
location (section, township and range), and background information
relevant for drainage design;
115
Appendix C – Geotechnical/Hydrogeological Report App -C
a. A discussion of the study investigations including methods and results
of field assessments, testing and analyses performed;
b. A description of the soil units and subsurface geologic conditions on the
site and in the vicinity of the site;
c. A description of the site including surface, soil, and groundwater
conditions, etc.
3. Test Method Documentation shall include:
a. A map with the location of all subsurface field explorations, sampling
locations and any in- place field tests;
b. A description of the field test and any difficulties encountered during
excavation and testing;
c. A description of the equipment used to perform the field explorations or
tests. When applicable, describe the type of fabric lining and gravel backfill
used;
d. Logs of subsurface borings shall identify the depth to groundwater, the
presence of any limiting layers and the target soil layer; include test pit or
excavation dimensions. Borings intended to characterize hydrogeologic
conditions for infiltrations systems should extend a minimum of 10-feet
below the base of the proposed infiltration system, or a minimum of 25-feet
below the ground surface, whichever is deeper;
e. Report test data documenting any infiltration testing, calculations, results
problems encountered; and,
f. A description of the condition of any existing facilities being tested, noting
any silt build-up, water level, connections to other structures (including
distance to inverts of any interconnecting pipes), measured depths and
dimensions, etc.
4. Results of field and laboratory testing conducted, including the grain size
analysis represented both graphically and in tabular format;
5. A summary of field testing conducted and the measured and proposed design
infiltration rates for infiltration systems. Approved test methods for infiltration
testing are found in Appendix H;
6. Results of the sub-level structure feasibility study and a summary of the
property boundary and down-gradient analysis as applicable; and,
116
Appendix C – Geotechnical/Hydrogeological Report App -C
7. A geologic cross-section of the stormwater disposal area drawn to scale, with the
proposed stormwater disposal facilities superimposed on the cross-section. All
relevant geologic units shall be clearly identified including the target disposal
layer and limiting layers.
8. Conclusions and recommendations.
a. The Site Plan shall include:
b. Project boundaries (including all existing and proposed property lines);
c. Labeled topographic contours, extending beyond the project and drainage
basin. Projects in an urban area shall use a maximum contour spacing of 1
foot;
d. Location of the soil and geologic units identified;
e. Location of significant structures, properties or geologic features on site and in
the project vicinity;
f. Location of existing natural or constructed drainage features on site and in
the project vicinity; and,
g. Location of proposed site infrastructure including roadways and drainage
features such as ponds, drywells, etc.
Water Information Center Database:
SUGGESTED SOURCES:
• Montana Ground
http://mbmggwic.mtech.edu/
•Lopez, D.A., and Sims, M., 2003, Areas of potential swelling-clay hazard in the Billings
area, Yellowstone County, Montana: Montana Bureau of Mines and Geology Geologic
Map 61D, 1 sheet, scale 1:48,000.
•Lopez, D.A., 2002, Geologic map of the Billings area, Yellowstone County, Montana:
Montana Bureau of Mines and Geology Geologic Map 61A, 1 sheet, scale 1:48,000.
•Lopez, D.A., 2000, Geologic map of the Billings 30' x 60' quadrangle, Montana:
Montana Bureau of Mines and Geology Geologic Map 59, 1 sheet, scale 1:100,000.
•Olson, J.L., and Reiten, J.C., 2002, Hydrogeology of the west Billings area: Impacts of
land-use changes on water resources: Montana Bureau of Mines and Geology Report of
Investigation 10, 32 p., 2 sheets.
•Olson, J.L., and Reiten, J.C., 2001, Basic hydrogeologic data for the West-Billings area
117
Appendix C – Geotechnical/Hydrogeological Report App -C
(1999-2000), Yellowstone County, Montana: Montana Bureau of Mines and Geology
Open-File Report 436, 110 p. United States Geological Survey (USGS). Scientific
Investigations Report 2010-5102. Simulation of Groundwater Mounding Beneath
Hypothetical Stormwater Infiltration Basins. Glen B. Carleton.
http://pubs.usgs.gov/sir/2010/5102.
118
Appendix D – Opera�ons and Maintenance Requirements App -D
Appendix D Operations and Maintenance
Requirements
119
Appendix D – Opera�ons and Maintenance Requirements App -D
OPERATION AND MAINTENANCE
An Operations and Maintenance Manual is required for Subdivision and Commercial
Property development. The O&M Manual summarizes the tasks required for perpetual
maintenance to ensure the proper operation of stormwater facilities. The O&M
manual shall include at a minimum:
•Contact information for the party responsible for O&M.
•Description of the maintenance tasks to be performed and their frequency.
•An inspection checklist to be used for annual maintenance. Template forms found in
Appendix G.
•List of the expected design life and replacement schedule of each component.
•Site plan showing the overall layout of the development.
•Copy of recorded HOA Agreement and SIA, if applicable.
•Other information as necessary.
The O&M Manual shall first be submitted to the City’s Environmental Affairs Division for
review and comment. After acceptance by the Environmental Affairs Division, the O&M
Manual shall be recorded at the Yellowstone Clerk and Recorders Office in a format
acceptable to them.
120
Appendix E – HOA Agreement Requirements App -E
Appendix E HOA Agreement Requirements
121
Appendix E – HOA Agreement Requirements App -E
HOMEOWNERS’ ASSOCIATIONS REQUIREMENTS
For stormwater systems within subdivisions, a homeowner’s association (HOA) shall be
formed to maintain and operate the facilities.
A draft copy of the SIA and/or CC&Rs for the HOA in charge of operating and
maintaining the facilities associated with the stormwater system shall be submitted at
the time of Preliminary Plat submittal. Final copies are required at the time of initial
Private Contract Submittal. The SIA/CC&Rs shall summarize the maintenance and fiscal
responsibilities of the HOA. In addition, the SIA/CC&R’s shall state that any proposed
changes to the stormwater system/facilities shall first be approved by the City
Engineer’s Office. The O&M manual shall also be submitted at this time. A financial
plan is required in order to provide the entity responsible for maintenance with
guidance in regard to financial planning for maintenance and replacement costs. The
financial plan shall include the following items:
•A list of all stormwater-related facilities and their expected date of replacement and
associated replacement costs.
•Sinking fund calculations that take into consideration probable inflation over the life of
the infrastructure and estimates the funds that need to be set aside annually.
•A mechanism for initiating and sustaining the sinking fund account demonstrating
that perpetual maintenance of all facilities associated with the stormwater system will be
sustained.
Homeowners’ associations are to be non-profit organizations. A standard business
license is not acceptable for this purpose. The HOA shall remain in good standing with
the requirements of the State of Montana. Developer shall sign HOA Agreement
stating ownership and responsibilities prior to approval of development.
122
File Attachments for Item:
4. Resolution - A Resolution Of The City Council Approving Amendments To Appropriations
And Revenues For The City Of Laurel’s Fiscal Year 2023-2024 Budget.
123
R24-____ Approve Budget Amendments
RESOLUTION NO. R24-_____
A RESOLUTION OF THE CITY COUNCIL APPROVING AMENDMENTS TO
APPROPRIATIONS AND REVENUES FOR THE CITY OF LAUREL’S FISCAL
YEAR 2023-2024 BUDGET.
WHEREAS, the City of Laurel (hereinafter “the City”) adopted all funds revenues and
appropriations for Fiscal Year 2023-2024 on September 5, 2023;
WHEREAS, it is necessary to amend certain budgets as required by Mont. Code Ann.
§ 7-6-4006(3) and (4); and
WHEREAS, the increase in appropriations and revenues are due to unbudgeted
amounts that will be offset by a decrease in reserves.
NOW, THEREFORE, BE IT RESOLVED by the City Council of the City of Laurel,
Montana, that the City Council hereby directs the Clerk-Treasurer to amend the budget as
reflected on the attached Exhibit “A” in order to comply with Mont. Code Ann. § 7-6-4006(3)
and (4); and
BE IT FURTHER RESOLVED that the above amendments are retroactive to June 30,
2023.
Introduced at a regular meeting of the City Council on the _____ day of February, 2024
by Council Member ________________.
PASSED and APPROVED by the City Council of the City of Laurel the _____ day of
February, 2024.
APPROVED by the Mayor the _____ day of February, 2024.
CITY OF LAUREL
___________________________
Dave Waggoner, Mayor
124
R24-____ Approve Budget Amendments
ATTEST:
_______________________________
Kelly Strecker, Clerk-Treasurer
APPROVED AS TO FORM:
______________________________
Michele L. Braukmann, Civil City Attorney
125
EXHIBIT A
Budget Amendment
Fiscal Year 2023-2024
Fund 2250 – Planning Appropriations
Original Appropriation $ 136600.00
Amended Appropriation $ 168135.00
Increase in Appropriation: $ 31535.00
The City had to contract with KLJ to help with the planning duties and demands. The cost
of this contract was considerably higher than the cost of a staff position. The Planning
Department was granted a grant reimbursement for zoning regulations this year to offset
these additional appropriations.
____________________________________
Fund 2250 – Planning Revenues
Original Budgeted Revenues $ 118135.00
Amended Budgeted Revenues $ 168135.00
Increase in Revenues: $ 50000.00
The Planning Department received a grant reimbursement for zoning regulations this year.
____________________________________
Fund 2821 – HB 473 – Gas Tax
Original Appropriation $ 450000.00
Amended Appropriation $ 650000.00
Increase in Appropriation: $ 200000.00
Increase appropriations due to new gas tax laws.
____________________________________
Fund 2821- HB 473- Gas Tax
Original Budgeted Revenues $ 279598.00
Amended Budgeted Revenues $ 615521.00
Increase in Revenues: $ 335923.00
Unanticipated Revenue due to new gas tax laws.
126
Fund 3508 – SID #118 – S Washington Ave Sidewalks
Original Revenue $ 13132.00
Amended Revenue $ 14072.00
Increase in Revenue : $ 940.00
Error when inputting budget numbers in budget book. This will have no effect on cash
reserves.
____________________________________
Fund 2850 – 911 Emergency
Original Revenue $ 57504.00
Amended Revenue $ 68055.00
Increase in Revenue: $ 10551.00
Error in budget book. The wrong revenue amount was entered. This will not affect cash
reserves.
____________________________________
Fund 2310 – TIFD
Original Appropriation $ 2564901.00
Amended Appropriation $ 3423839.00
Increase to Appropriation: $ 858938.00
There was a miscalculation in the budget book on the number of mills we receive from
county for this fund. We were able to increase appropriation due to increased mills
_____________________________________
Fund 2310 – TIFD
Original Revenue $ 1013800.00
Amended Revenue $ 1364738.00
Increase in Revenue : $ 350937.00
There was a miscalculation in the budget book on the number of mills we receive from
county for this fund.
127
Fund 2880 – Library Grant
Original Revenue $ 4883.00
Amended Revenue $ 6105.00
Increase in Revenue : $ 1222.00
The library received more revenue this year than expected. Increase revenue for
unexpected increase.
____________________________________
Fund 2992 – ARPA
Original Appropriation $ 1759302.00
Amended Appropriation $ 2857302.00
Increase in Appropriation: $ 1098000.00
This is a budget correction for phase two of the ARPA allocated monies. This was left out
of the budget due to grant completion.
____________________________________
Fund 2992 – APRA
Original Revenue $ 15000.00
Amended Revenue $ 113000.00
Increase in Revenue: $ 1098000.00
This is a budget correction for phase two of the ARPA allocated monies. This was left out
of budget due to grant completion.
____________________________________
Fund 7030 – Library Federation
Original Appropriation $ 4467.00
Amended Appropriation $ 7397.00
Increase in Appropriation: $ 2930.00
Unanticipated Revenue from the state Library. Increase appropriation to offset the
unexpected revenue.
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Fund 7030 – Library Federation
Original Revenue $ 5100.00
Amended Revenue $ 8030.00
Increase in Revenue: $ 2930.00
Unanticipated Revenue from the State Library. Increase appropriation to offset the
unexpected revenue.
129
File Attachments for Item:
5. Resolution - A Resolution Of The City Council Authorizing The Mayor To Reschedule City
Council Meetings Set On 2024 Holidays.
130
R24-____ Approve Reschedule of City Council Meetings
RESOLUTION NO. R24-_____
A RESOLUTION OF THE CITY COUNCIL AUTHORIZING THE MAYOR TO
RESCHEDULE CITY COUNCIL MEETINGS SET ON 2024 HOLIDAYS.
WHEREAS, the City Council for the City of Laurel (hereinafter “the City”) has
regularly-scheduled City Council Meetings on November 5, 2024 at 6:30 p.m. and December
24, 2024 at 6:30 p.m.;
WHEREAS, November 5, 2024 is the recognized holiday of Election Day;
WHEREAS, December 24, 2024 is the recognized holiday of Christmas Eve;
WHEREAS, the City Council desires to move the November 5, 2024 City Council
Meeting to November 4, 2024, beginning at 6:30 p.m.; and
WHEREAS, the City Council desires to move the December 24, 2024 City Council
Meeting to December 23, 2024, beginning at 6:30 p.m.
NOW, THEREFORE, BE IT RESOLVED by the City Council of the City of Laurel,
Montana, that the November 5, 2024 City Council Meeting is hereby moved from November
5, 2024 at 6:30 p.m. to November 4, 2024 at 6:30 p.m., and the December 24, 2024 City Council
Meeting is hereby moved from December 24, 2024 at 6:30 p.m. to December 23, 2024 at 6:30
p.m.
Introduced at a regular meeting of the City Council on the _____ day of February, 2024,
by Council Member ________________.
PASSED and APPROVED by the City Council of the City of Laurel the _____ day of
February, 2024.
APPROVED by the Mayor the _____ day of February, 2024.
CITY OF LAUREL
___________________________
Dave Waggoner, Mayor
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ATTEST:
_______________________________
Kelly Strecker, Clerk-Treasurer
APPROVED AS TO FORM:
______________________________
Michele L. Braukmann, Civil City Attorney
132
File Attachments for Item:
6. MoCones Public Hearing
133
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Page 1 of 1
LAUREL CITY-COUNY PLANNING DEPARTMENT
STAFF REPORT
TO: Laurel City Council
FROM: Kurt Markegard Planning Director
RE: Laurel School Board’s decision to let MoCones operate on public lands
DATE: March 16, 2024
DESCRIPTION/LOCATION:
INTRODUCTION:
Del Henman investigated operating his ice cream business on school property. Mr. Henman was
advised to inform the Laurel School District that they needed to inform the City of their
intentions to use public lands contrary to City of Laurel’s zoning regulations as allowed per
MCA 76-2-402. The Planning Director requested a review of state law with the City Attorney
and the conclusion was made that the Laurel School District can use their land for this purpose if
the City Council holds a Public Hearing, and the School District sends a representative to the
hearing.
City Council is given no authority in state law to approve or deny the Laurel School District
intentions to use public land contrary to local zoning regulations.
FINDINGS OF FACT:
The Laurel City Council is given no authority in state law to approve or deny the Laurel School
District intentions to use public land contrary to local zoning regulations.
Montana Code Annotated 2023
TITLE 76. LAND RESOURCES AND USE
CHAPTER 2. PLANNING AND ZONING
Part 4. Application to Governmental Agencies Group and Foster Homes
Local Zoning Regulations -- Application To Agencies
76-2-402. Local zoning regulations -- application to agencies. (1) Whenever an agency
proposes to use public land contrary to local zoning regulations, a public hearing must be held
and the agency shall attend the public hearing.
(2) The local governing body shall hold a hearing within 30 days of the date the agency gives
notice to the local governing body of its intent to develop land contrary to local zoning regulations.
History: En. Sec. 2, Ch. 397, L. 1981; amd. Sec. 1, Ch. 362, L. 2021.
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Exhibit “A” Location for MoCones
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