HomeMy WebLinkAboutPublic Works Committee Minutes 11.13.2017 MINUTES
PUBLIC W4RK5 COMMITTEE
NOVEM�ER 13, 2017 6:00 P.M.
COUNCIL CHAMBERS
MEMBERS PRESENT: Emelie Eaton
Bill Mauntsier
Chuck Dickerson
Dan Kach
Richard Herr
OTHERS PRESENT: K.urt Markegard
Public Inaut: Nane
Review Minutes from October 16, 2017 meetin�
The minutes of the October 16�', 201'7, meeting were approved as written.
Moving Public Work Meetin�to third Mondav af the month
Bi1I asked if moving the Public Works meeting would interfere with the Ernergency Services Meeting.
Emelie stated that the meeting date was so that items braught up at the Public Works rneeting could then
be discussed with the entire City Council and the warkshop the next night as apposed to a regular City
Council rneeting. Richard said that he braught it up because Marv Carter had asked hirn at the October
meeting to move the xneeting date so that he could attend. Richard wants to make sure that this does nat
interfere with any other meetings and maved ta table this item until the December meeting. Bill seconded
the motian and all were in favor of discussing the issue at the next meetin,g.
Water Flant Sedimentation Desi�n Questions
Richard asked for the item to be placed an tonight's agenda. Kurt did same research on the need to
replace the sedimentatian basins at the water treatment plant and informed the committee of his findings.
Kurt reviewed reparts frorn engineers at Great West, HKM, and Morrison Maierle.
Kurt also faund a report from Stevens, Thompsan and Ryan from ]973 that investigateci the candition of
the water treatment plant. In the 1973 report frazn Stevens, Thampson and Ryan they reported that during
the surnmer months af 19'74 and 1971 the water plant was at capacity of four million gallons per day and
on peak days exceeded the design capacity. Stevens, Thampsan and Ryan recommended additional
capacity immediately at the water treatment plant. This report also recommended mechanical chemical
mixing, dealing with the ice in the sedirnentation basins and also providing twa trains of treatment. The
second train of treatment would provide the City with the ability to perform maintenance of the
sedimentation basins and take one train of treatment down in order ta accomplish the maintena.nce, This
report also had ideas on haw to rebuild the sedimentation basins and provide the necessary water
treatment for the City.
The report from HKM in 1994 was used as a basis to build the Clear Well Building in order to have the
necessary chlorine contact time. This new building would prevent diseases from entering the water
supply. This report also recommendecl to cover the mud basins and the sedimentatian basins to allaw year
round operation. At that time the City was bypassing the mud charnbers and the uncavered sedimentation
basins to avoid damage from ice during the winter months. The report recommended to continue using
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the sedimentation basins but to install a new floor and mechanical mud and sludge rernoval system ta
prevent taste and odor problems in the treated water. Adding a new sludge system would reduee the
capacity af the sedimentation basins. The final recommendation from this report was to install plate or
tube settlers in the future,
Richard said that his thought was to add a higher wall to the sedirnentation basins and it would be a lot
less than seuen million dallars.
A report fram Morrison Maierle in 2006 statecl that the water plant was deficient in the following ways;
1. Lack af a mixing system for the chemical addition.
2, Deteriorating concrete in the flocculation and sedimentatian basins.
3, Lack af a second flocculation basin for firm capacity.
4. Lack of sludge removal fram the sedimentation basins,
5. Absence af a cover over one of the sedimentation basins and the flacculation basin.
6. Lack of firrn capacity for the sedimentatian basins for future water demands.
Morrison Maierle recomrnended three optians for the city ta cansider;
l. To add a new Conventional Flocculation and Sedirnentatian Basins.
2. Conventianal Flocculation and Sedirnentatian with tube or plate settlers.
3. Ballasted Flocculation and Sedimentation.
Great West Engineering in 2008 adopted Morrison Maierle's recornmendatian ta replace the
sedimentatian basins in part due to a structural report Morrison Maierle had ccanducted on the
sedimentation basins. This structural report of the sedimentation basins was performed by doing concrete
core tests. This report is attached to the minutes.
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The camrnittee discussed the structural report for the sedimentation basins. Richard stated he thaught the
City shouid have had more options on the replacement of the sedimentation basins.
Kurt infarmed the committee of the timeline of the water treatment plant improvements over the last ten
years in order to keep up with the water demand. The improvements included replacing the water filter
system ta make the filtration more functional, The thought was to get the filters done first and deal with
the sedirnentation basins as funding became available. A TSEP grant was applied for in 2014 for the ,
2015 legislative session. The City was granted $500,000 to replace the sedimentation basins.
Kurt infarrned the cc�mmittee that in 2010 the City raised water and sewer rates in order ta create a capital
replacement fund to deal with the water and sewer plants. The water rates were raised in order to replace
the sedimentatian basins. Kurt went an to inform the cornmittee of the need to get CHS Refinery off the
treate�i water when the river is muddy. CHS refinery wauld be put an settled water with the replacement
on the sedimentation basins. This change to CHS wauld allow more treated water for the city withaut the
need ta expand the water plant's filters. Dan asked if CHS had their own water line to the refinery and
Kurt said that they did ha�e their own line. Emelie ask if the future plan was to anly have CHS on the
settled water when the river was muddy. Kurt said that was the thinking.
Emelie clased out the discussion asking Kurt if there was the possibility Eo review same optians for the '
replacemer�t af the seciimentation basins and Kurt indicated he would be looking into the issue and see if
there are alternatives ta bring back to the cammittee.
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Parkirn�at the High School
Bill informed the carnrnittee that during the recent snaw storm the yellow curb painting was covered aver
and cars were parked close to the intersection at 1 S� Avenue and 8`h street. Bill thinks that the yellow
painting should be painted anather 20 to 25 feet in order to see safely. Kurt stated that he talked to the
Police Chief again about the parking issue and the Police chiefdid not recornrnend any changes. Kurt and
the Palice Chief agreed that Kurt shauld ask the State Departrnent of Transpartatian for recammendations
and clarity on the standards for street painting. Emelie stated that certain situations may require different
requirernents that are not standard. Emelie also said it may beneficial to contact the State and see if the if
this situation needs a different solution.
Kurt said that he wauld call a State Department of Transportatian emplayee and seek his guidance and
report back at the next meeting.
Other
Dan asked if gravel cauld be placed on Montana Avenue between Third and Fourth Streets where the
parking lanes are just gravel and Kurt said that he would drive by there on the way home tanight and take
a laok at it.
Richard wanted to inform the committee that the septic dump station has brought in since April $17,500.
Richard thaught that a letter clarifying the hours of the dump station would help the haulers. Emelie
asked haw much the City was expecting from the septic dump station and Kurt stated arcaund twa
thousand a rnonth. Kurt reported that the septic haulers are naw operating on Saturdays more often than
was expected. There is only one waste water treatment operator on the weekend and hopefully we only
receive a few loads a Saturdays.
Emelie asked if the rock weir was still in the river and K.urt said that it was as the river was still at a high ;
water flow. Richard said the river was higher than norm,al as he goes down to Riverside Park often.
Emelie asked that if we don't get the rock weir out this winter that we have permissian to wait until next
fall if needed and Kurt stateci that was conect.
It was maved and seconded to adjourn the meeting, all were in favor.
The meeting adjaurned at 7:40p.m.
Attached; Structural Memo of the Sedimentatian Basins from Marrison Maierle ,
Respectfull submitted,
Kurt Markegard
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TO: fJave Mosser
FROM: Phififip Green
DATE: July 11 , 1995 R+evised 81i 1196
SUBJECT: Laurel-Water Treatment Facility lmprovernents
Structural Repairs
tt was anticipated that by this date we wauld have the results of tests performed upon concrete
cy{inders taken fr�c�m the settting basin/flocculation basin structuce and the existing 1.4 m.g.
canerete reservoir and some field data describing the genera} condition of each stxucture. However,
due tn the wet weather since eariy spring concrete core sampling has �een delayed.
We have been able to take 8 cancrete cor�s fram the�lac basins and tt�e settling basins. However,
there has not been su�cieni time ta conduct tesis to determine analyticalty the quality af the
concrete represented by the core specimen�. We have al�o taken some phatos af�tt�e stnsctures to
assist in the evaluation of the sttvctures.
The following summary and cost estimates are based upan the limited visuai and photcu,�raphic data
that we were able ta obtain during the our initial inspections.
Settiing Basirt
Plant superintendent, Qave Michael, indicated ta the best of his knowiedge there is vety little leak�ge
from the settiing/fiocxulatian basin system. When cleaning af the exterior basins is perfarmed,
howsver, tlte water levsl in the cov�red setiling basin must be (oweted (abaut 4 fieet) to reduc�the
pressure on the concrete wa{! separating the cavered and open settling basins. Mr. Michaef
commented that previous concr�te cores taken fr�m the sloping walls of the open settting basin
revealed severai older over-iaymen#s. Ta review a copy of this previous tes#ing and investigation
wauld be very benefieiaf.
Concrete cares taken as a part of aur investigation indicate the basin has received one overlaymer�t
It appears ttte slopicrg sidewails were firs#stabiiized with a very thin tayer af cancr�te (iess than 2"
thick� which was given a coating o# bituminous material, and then a 4 or 5 inch thick concrete slab
poured to create tf�e basin surface. The floor slab was apparently constructed as a simple�t to 5
inch thick sEab piaced directty upon the earth subgrade. All concrete cores ir►dicate the concrete
slabs have besn placed directiy upon tfze r�ative siity c#ay whieh was found to be wet and saft(i.e.
a�e coutd easily penetrate the soil witt� a fingec). Ai ane core {oc�tian in the flaor slab, sligttt hydro-
static pressure was noted (i.e. groundwater came up throu�h the core hol�?.
Later(cfate unknawn} the basin slabs were averlaid with 4 inch tl�tictc con�crete. At�rii care hc�tes, the
tapging slab was found to be ur�banded to the origina! lov+rer slab.
The gen�ral quality af the e�cisting slab overlayment is considered to be poor with significant
cracfcing, spalting and same dispiacement. �
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MEMd:CS7EST3.WP0 8!1 t�95 �
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��� ��ExI.E, c�c.
Floor Slab
Cracked, spalling
Same"hallay,d' sounding areas indi�cate delamination of exrsting concrete
Floor surface is uneven, poorly sloped€�rr drainage
Jaint seals have failed
Sloper! Walis
Cracked, spalling
Joint seals have failed
Some "hollow" sounding areas indtcate delaminatir�n af existing cancrete
Co�crete Baffle Wafls
Newer canstruction
Displaced and cracked by ice Porces
Braced with pipe struts#o stabifize baffle walls (considered inadequ�te)
Sma11 cpening through ane wail at base for cteaning
Comman WaCI Between Open and Gavered Basins
Structural strength questionable
Wall is cracked, shows signs af leaking
Upper portions c�f wail deteriot�ated due to freezelthaw cyel�s
Portion af waU braced by diagonal pipe strut
Conerete pilasters have severe concrete deterioration �
Suppart of top of wvail at roof unknown
Hydraulic Devices
4utlek recessed below slab due to several overlayments, condition unkr�own
Gate vaives aid, corroded
Ovec#low concrete encasement deteriorated and cracked
Flow contral apenings have old wood panels
Methads for renovating and repairing the cancrete surtaces would include (1) another cast-in-place
concrete averiaymertt, {2} a pneuma#ically appiied cancret� overfayment (shcrt-crete}, or(3) a
praprietarY tYpe elastomenc coeting p�aced over ihe existir�g slab after the existing cracks have been
fitled or repaired.
�,t Seu���.P��ins
Cancrete cc►res taken in the floc basins indicate the original flaor siabs consisted af a 2 inch thick
concrete sEab ptaced over a bituminous coating sprayed directfy upan the native clayey silt sub-soil.
Sometime later, the floc basins were repaired or renavated by frst coating ths originai floor slab wi� ;
a bituminous material and then p(acing a new 2 inch thick cnncrete overiayment As a part of this ;
repair or perhaps a little tater, the wails of the floc basin were aiso repaired vtinth an encasement of 4 ;
inch thick concrete. That is, new concrete was p#aced c�n the top and aga'rrrst the interior surface of
the exteriar perimeter wa!!s; and placed on each side and on tap af the intecior baffle walls. �
The concre#e cores have revealed that the concrete encasement of the basin walls has become '�i
unbanded to the originat concrete. Visualiy, it is easy to see that the cancrete encasement is atsa
r.�ack�d ar�d spalted. It is alsa apparent tha#some settl�men#of th� floor slab has occe�rred as �
evidenced by a s�paration at the bottam of all basin walls. '�
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MEMO:GSTES73.WPD 8/11i95
2 I
r' �/IORRISt�N
■� MAIERLE, L�C.
Fiocr Siabs
Fine tappirtg aggregate wam away exposing coarse aggregate
Some basins have siab cracks
Generaily sound concrete with som� local `hollow sounding" areas indicating delamir�atiot�
Extecior Perimeter Walls
Appear to be socrnd, very few cracks
Have been ovetiaid with 4" to 6"COCICI@t�Ott th@ lt1t6t10C St1fESC� �ttd SCtOSS#h� i0�
Construction surface joint delamination at slide gake r�cesses
!n#er�or Separation! Baffte Walis
interior wa!!s are thick�greater than 16")
Have been re-swrfaced, "hoilow' sound in some areas
Wa(is pfovide iaterai �upport far eacterior walls and settting basin wali
�arge cracics at opening thraugh watts {generaily faund ta be 4 inches deep}
Gancre#e beam acrass large openings seem inadequaEe
Bottam of walls separated from floar slab
Surface Skirnme�Beams
Most have failed or are failing
Remove and replace ali skimmer beams
�tac Basin i Settling Basin Comman Wafii
Cracked
Top of wali h�s been pushed up du� ta ice f4rces
Clutflow opening severely cracked, possible leakage ttrrough cracks
Repiace tap af wail and aut#fow apening
Nydraulic �evices
inie#at floor level
Stide gates {6) oid, coRoded, ail inaperable
Baf#1e waEl openings hav�poo�ttow controE, otc# lumber ftaw baards`tacked' in place
Because of the manner in which the walis have been restored and the degre� of delarninatian or lack
af band between the new concrete and the oid concrete that exists, another coating of concret� or
elastomeric mate�ial is nat cc�nside�ed ko be an economical method of repair sinc� its service iife is
expacted to b�very shoR. Therefor, sather#han incur a retatively large cost of repair far a very
limited "life' it rrray be better economic�tiy to perform rather limited `spat` r�pairs unlil su�c�ent funds
are avaiiabte or to commit funds naw to totaily repiace the floc basins.
Ftoccu[a ia�l�ettli g sin �epairs ;
Ignoring the option for performing`spot" repair of the floc basins, suggested repairs to th�
flccctrtation and settling basin structure have been prioritiz�d and the reconstruc#ion cost estimated I
for�ach i#em af wark as fc!laws;
MEtw�l(?:CSi'EST3.WPD 8111t�3$
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��� Mo�uusoN
Ni��TERi,E, �c.
1. Sektiing 8asin - Reinforce commQn wail befin+een open 8� ciosed basins 542,130
2. Floc Basin - Re-buitd outflow 10,620
3. Floc Basin!S�ttlir�g Basin- cepair top o€cammon wall 28,280
4. Settiing Basin- Resurface sloped wa{Is 24,984
5. Settiing Basin - Resurface floor slab 34,480
6. FEoc Bas"sn- Remove and repiace skimmer baffies 10,000
7. Floc 8asin- Resurface floo�slab 't9,940
8. �1a� B�sin- Repair cor�crete wai! at slide gates 4,260
9. �loc Basin! Settling �3asin - Resurface cammon separation wall 11,5Q0
't0. Settiing Basin -Stabilize existing baffie wails � •9 420
Total estimated cost �195,67C}
The above casts inciude 10%for contingencies. A more detailed itemization of these pr�liminary
estirr�ated costs is attacl�ed. As more infarmatian is avaiiabie from an-site observatians and
cancrete core tests, khese �sts can be updated. Ca� do nat included cost�or re�lacina
hY4�r'�1'I'��ic d vices.
The abave cas#s inciude $84,6Cit}for repairs to the flac basin. tt is estimated that the cost for
camglete remaval and recanstructio�of the flac basins wou{d be approximateiy�13't,000.
'�.d M.G. Concrete Resery�oir
No obse�+ra#ians have been made of the ex3sting cancrete reservair. Because af its age, it is nat
uncornmc►n for the taps of exposed concrete walls to expe�ience sigc►i#ic�nt freezelthaw damage.
Therefor, it has been assumed that a small portion of the wa8s will need to be removed and replaced
ko provid+� adequate bearing clasure far the roof structure.
It is estimated that a structura! steel raof frame (gainted stee! oper�-web joist girders and roof joists}
and painted st�e1 deck (zincalum, fo�added service life)will ccst about$91,�00. An itemizatinn af
the estimated preliminary is attacttied.
A conc�ete roof system will�ravide a longef service lite (say 40 to 50 years} thart#3'�e stee! system �
(say 20 to 25 years}, Hawever, its cost is estimated to be about$150,000. �
As more in#ormaticrn is available from on-sit�observatians and ca�crete care tests, ihese costs can i
be upda#ed. ;
MEMO:GSTE51'3.WP0 8/tt196
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