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HomeMy WebLinkAboutMorrison-Maierle, Inc. MORRISON MAIERLE, t c. An Employee-Owned Company August 14, 2006 Mr. Richard Knatterud, TSEP Engineer Montana Department of Commeme PO Box 200523 Helena, MT 59620-0523 ENGINEERS SURVEYORS PLANNERS SCIENTISTS 1 ENGINEERING PLACE · RO. BOX 6147 · HELENA, M3: · 59604 · 406-442-3050 · FAX: 406-442-7862 CFt'Y OF L,,.,Ui: EL RE: Laurel Wastewater Facility TSEP Application - Engineering Review Comments Dear Mr. Knatterud: We ara writing in rasponse to the draft technical review comments completed for the City of Laurel's 2006 TSEP Application. These comments are being provided on behalf of the City of Laurel. The reviewer did a thorough review of the Praliminary Engineering Report (PER). Some general comments am provided, followed by specific rasponses to selected comments. Where we felt it was appropriate or helpful, we have repeated the reviewer's comments in italics preceding our rasponse. We have also enclosed the 150 word summary statement on health and safety issues. GENERAL RESPONSE TO REVIEW COMMENTS The reviewer performed a very thorough raview of the PER in comparison to the uniform outline requirements. The uniform report outline requirements are written to cover a wide range of projects from (for wastewater traatment only as an example) total retention lagoons to complex, mechanical facilities. The PER process (and the uniform outline) is intended to address the "big picture" issues for wastewater projects that will ultimately affect the approach to treatment and effluent quality, the general means by which it will be accomplished, and ultimately the cost of its accomplishment. For example, in the case of a total retention lagoon, an analysis of the type of lagoon liner material may be very appropriate in a PER, because it represents a large portion of the project cost, whereas in the latter case of a mechanical WWTP a similar effort would not be warranted for analyzing the liner of a sludge storage lagoon. They ara similar applications, but a different level of importance in the overall concept of the project, and the overall cost of the project. Many of our subsequent, specific, comments are analogous to this comparison. The reviewer points out deficiencies in the level of analysis for components of the VWVTP that, in our opinion, are either minor or better developed in a subsequent predesign or design phase. In the scope and level of effort for a PER with a complex mechanical WWTP, some analyses simply cannot be afforded or are not warranted. We hope that this perspective can be considered in revising many of the review comments. The following ara responses to specific review comments: "Providing resources in partnership with clients to achieve their goals" MORRISON MAIERLE, c City of Laurel 2006 TSEP Technical Review Response August 14, 2006 Page 2 of 8 TSEP STATUATORY PRIORITY 1 a. "Does a serious deficiency exist in a basic or necessary community public facility or service.;,.." Reviewer's Comments (first bullet, page 1, Collection): "Costs for collection system repairs are not part of the work currently requesting grant funds. This seems to be a very sedous deficiency that not only utilizes collection system capacity and lift station capacity but also disrupts the treatment plant process and capab#ity". Response: It was unclear what the reviewer meant in the phrasing of this comment. We would like to make it clear that the recommendation of collection system replacement over a 30-year period is something we are recommending as a sound planning practice for a community with a very old collection system and little record of past upgrades. We encourage Laurel and all communities to preactively plan for capital facility replacement. The recommendation is not directly related to the community's infiltration conditions. Unless service lines are also replaced, it is quite possible that the replacement of collection system lines will result in little or no additional infiltration reduction. Typically, communities cannot or will not force service line repairs on residential property unless failure or collapse can be documented. The 2003 TSEP assisted project and the 2004 CDBG assisted collection system projects are intended to cost effectively remove a majority of the infiltration in those areas without many service connections. Response to Reviewer's Comments (fifth bullet, page 2, RBC): As with the previous comment, it was unclear if the reviewer was trying to make a specific ~point about capacity, etc. in the comments. However, we would refer to Section 6.3.3 of the 2003 Report plus all the earlier information presented in order to make the conclusions of the referenced section. The existing RBC units have adequate organic treatment capacity at current flows/loads plus an additional 10-15 percent. However, this is only if all units are in service. This situation does not meet current general MDEQ2 design practice requirements for redundancy of treatment equipment, nor general good engineering practice. With one unit of service, the facility has capacity for no more than 50-60 percent of its currant treatment requirements. As documented on page 6-20 of the 2003 Report, the operations staff must carefully time summertime maintenance events in order to keep monthly averages within permit limits. This approach, while necessary, is at best a "trick" that achieves the letter of the law for environmental compliance, but certainly not the intended spirit. The reviewer is correct that as of the writing of the report, only percent removal violations had occurred. However, if monthly averages were adjusted from calendar month to relling month, concentration based violations would also be realized. The City has been '?ortunate" to be able to plan for maintenance that straddl.es end of month periods. This situation may not be repeatable in the future. -~ MORRISON ~] MAIERLE, INC City of Laurel 2006 TSEP Technical Review Response August 14, 2006 Page 3 of 8 "Have serious public health or safety problems clearly attributable to a deficiency occurred ..... " Response to Reviewer's Comments (first and second bullet, page 3, Collection and Lift Stations): We believe the reviewer may interpret that the PER suggests that sewage backup into homes will continue until the entire collection system is replaced. That is not the intended interpretation of the documentation in Chapters 5 and the proposed solutions in Chapter 7. The documented backup conditions have occurred in very specific locations, generally on the "one month lines" documented in the report. These lines have the most problematic due to root intrusion, cracks, etc. One exception . was the line replaced as part of the Phase lA (2003 TSEP) project. The other locations are manageable when serviced by City crews on a monthly basis. As the PER documents and recommends in Chapter 9, these one month lines can be replaced when the City determines that the cost of the monthly maintenance becomes too great in comparison to the availability of capital for replacement. The recommended lift station improvements are to prevent impending backup problems. The design deficiencies with the lift stations are documented in the PER. Replacement of the Main/Elm St. lift station is recommended due to the age of the existing facility. Rehabilitation is, based on engineering judgment, not a viable alternative. Response to Reviewer's Comments (fourth bullet, page 3, plant water): While Circular DEQ 2 may not refer to fire protection, and specific fire code reference documentation was not provided in the PER, we don't believe it should be suggested in the review that fire protection of a major public facility is not necessary or desirable. Common sense would suggest otherwise. Response to Reviewers Comments (sixth bullet, page 3, RBC): Please refer to the comments above on the RBCs and their performance. Again, we wish to emphasize that the only reason percent removal violations have occurred, and not concentration violations, is because of the specific month-end timing of maintenance that required removal of RBC units. This is, long term, an unacceptable condition that will ultimately result in concentration-based effluent permit violations. They would already be realized if 30~day rolling average concentrations were monitored. c. "Is the problem existing, continual, and long term ..... ?" Response to Reviewers Comments (second bullet, page 4, Lift Station): We ask that the reviewer consider whether the standard of documentation that is being required for this component is higher than for other components, or for other reviews. The written description implies this to us. On-site inspections, discussions w/City staff and related analysis were used by us to determine what components could and should be rehabilitated or replaced, etc. Several licensed professional engineers used best MOP. SON MAIERLE, City of Laurel 2006 TSEP Technical Review Response August 14, 2006 Page 4 of 8 professional judgment and to call this into question (as we interpret th~ comments) seems to be counter to the spirit of the review process. d. "Is the entire community, or a substantial percentage of the community ..... ?" Response in General: Figure 5-1 gives a general idea of the contributory area to each lift station. We would suggest that any deficiency at the WVVTP affects the entire community, as they are the public owners of the facility. Any violations, fines, costs due to safety issues, fire affects, etc. will be bourn by the entire community as users and owners of the system. We believe this is the correct interpretation based on past TSEP review practices. e. ,,is there clear documentation that the current condition ..... ?" Response in General: We simply ask that the reviewer's approach to health and safety standard documentation for conditions that are clearly "unsafe" be uniformly applied to other documents. We are sure that the review committee will see to this end. As for docUmentation of permit violations, this was done in the past TSEP and CDBG applications (and recognized by the review committee) as part of the application (i.e, not included in the PER). It was an oversite to not include the letters in the PER appendix~ as the current uniform PER outline suggests. TSEP STATUATORY PRIORITY 3 a. "Does the PER provide all of the information as required by the Uniform PER outline...?" Response to Reviewer's General Comments: The reviewer is referred to Appendix A for some direction on location of required information. It is agreed that to appropriately study, analyze and document a collection system and mechanical wastewater treatment facility for a community of over 6000 people is a much more complex task than the similar scope document for, say, a small community with a lagoon-based treatment system. We have found that to organize information precisely as described in the Uniform PER outline further complicates the report and its length, particularly for a mechanical WWTP. We de wish there was a way to better comply with the specific organization of the PER outline, yet present information that is most logical and usable to City staff and elected officials for planning purposes. With respect to some of the items that the reviewer identifies as missing from the document, we offer the following response: MORRISON [] MAIERLE, mc City of Laurel 2006 TSEP Technical Review Response August 14, 2006 Page 5 of 8 Bullet one response - The latest CPE is over a dozen years old and does not accurately reflect the current facility condition. It was our judgment that to have included this might have caused confusion. The TSEP program has made it very clear to engineers preparing reports and applications that only recent information or data is of consequence to evaluating projects. We do not believe this to be a report deficiency. More recent regular permit inspection reports could have been included, but they would not have added any information to the detailed level of analysis in the PER. Bullet two response - This information was not required for analysis of the lift station condition. It is unclear how the reviewer would use this information if provided. We do not believe this to be a report deficiency. Bullet three response - The City and engineer have the information. It is unclear how the reviewer would use this information if provided. We do not believe this to be a report deficiency. Bullet four response - See Section 6.3.3 of the report and earlier comments in this document. Bullet five response - This analysis was performed and supported other conclusions. The data was not included in the report, and since new information cannot be included, we accept this comment. Bullet six response - An oversight, accepted as noted. Bullet seven response - The 20-year life comments are generally accepted engineering practice. It is for this reason that facility plans (PERs) are generally done for a 20-year period and SRF loans have a duration of 20 years, etc. We do not believe this comment has validity and ask that it be stricken from the write-up. Bullets eight through ten response - A facility plan (PER) is intended to be a high level overview of engineering approaches (please refer to opening, general comments). We strongly believe that the type of analyses or alternative screening described in bullets eight through ten as being "missing" for these elements are more aptly handled at the pre-design stage, or simply through engineering judgment at a later time. A facility plan for a complex mechanical WWTP simply cannot address all the detailed design issues suggested. It is neither cost-effective, nor appropriate. The PER does present alternative analysis for unit processes that affect plant effluent performance, approach to effluent quality, etc. We ask that these three bullets be stricken from the write up. Bullet eleven response - Section 8.4.1.3 summarized the reasons for not evaluating "Natural" treatment further than it was. Wetlands treatment was a component of Alternative UB2. As presented by the reviewer, the terms "slow rate and rapid rate land MOP dSON MAIE E, c. City of Laurel 2006 TSEP Technical Review Response August 14, 2006 Page 6 of 8 application" refer to treatment approaches that are not currently in common practice in the United States for reasons that are too numerous to expound on in this response. If the reviewer is referring to land application as a potential disposal means (ie, not treatment - MDEQ does not recognize land application as a treatment step), this could be a viable disposal means in the future combined w/one or more of the treatment alternatives presented. Based on the information at the time of the PER preparation, there were no apparent water quality reasons to analyze diversion of effluent from the Yellowstone. If this were done it would only add cost to the alternative presented unless there were also a corresponding revenue for use of the effluent. The City does not own any agricultural land for purpose of irrigation, further complicating a speculative analysis. In the context presented above, we believe that the comment about "a sound justification was not provided for eliminating natural treatment alternatives" is not warranted. We ask that this comment be stricken from the write-up. Bullet twelve response - We are unsure how to respond to this comment. Any W~NTP will respond favorably to I&l reduction. The PER recommends that the City's first two projects address the largest infiltration contributors (primarily trunk mains traveling through agricultural lands without significant service connections), then tackle the plant upgrade requirements. The City is pursuing this approach. As mentioned several times earlier in this document, the reduction in infiltration will help the WWTP, but does not directly address the fact that in order to do any maintenance to the RBC system, it must remove 50% (1 of 2 trains) of its treatment capacity at one time. The proposed project will address this issue. Bullet thirteen.fifteen response - Similar to the response for bullets eight through ten, the details and comparative analysis suggested as being missing is more appropriately addressed in subsequent engineering documentation. We ask that these comments be stdcken from the write-up. Bullet sixteen response - It is unclear what hydraulic calculations are missing? Again, this is a PER, not a predesign or basis of design report. We believe all appropriate analysis have been completed to prepare a comprehensive plan. Bullet seventeen response - An oversight. Since new information is not allowed, this situation cannot be corrected. d. "Were all reasonable alternatives thoroughly considered...?" Response to Reviewer's General Comments: Our response to this is similar to many others above. We do not believe that the level of analysis suggested is appropriate or necessary in a PER for the items noted. Detailed analysis was performed on all important issues that related to large project elements that affect effluent quality or cost. We really believe that the items being called out as insufficient are simply unfair for a report of this type looking at the complex treatment and effluent quality issues analyzed. ~,~ MORPJSON MA~,iNc City of Laurel 2006 TSEP Technical Review Response August 14, 2006 Page 7 of 8 e. "Does the technical design proposed thoroughly address the deficiencies...?" Response to Reviewer's Comments on paragraph 1. The reviewer points out an obvious point: the uncertainty associated with population projections and growth is an issue that any community in a growing area must wrestle with. Section 8.6.6 of the 2006 PER update addresses these concerns as best can be done at this time. Rather than say that "the LB solution preposed may not be compatible with the longer term scenario ..." it would be more accurate to substitute the word "optimized" for "compatible". The LB scenado can be incorporated into any long-range solution, but may not represent the optimized (cost-wise) solution. The comments in this paragraph would seem to "mark down" the appreach and proposed solution for honestly and accurately pointing out risks to the community. These risks are inherent in any solution, even when they may not be so honestly pointed out. Response to Reviewer's Comments paragraph 2. inaccurate and speculative information is presented for which there is no documentation. We asked that it be removed. Proprietary equipment use is common practice in the water and wastewater treatment industry, with established procedures to ensure fair prices. The cost estimates prepared have considered the lack of competition for this equipment. Response to Reviewer's Comments paragraph 4. The reviewer rightly points out the difficulty of projecting infiltration reduction and correctly points out that future collection system extensions should result in less leakage. Table 4-5, 4-6 and 4-7 of the original 2003 PER present per capita flow information. Table 4-7 shows how the 146 gpcd is arrived at. The conclusion is based on engineering judgment that could be debated. Comparison of the approach that was taken in the PER and the approach suggested by the reviewer results in similar, although not identical, total flow numbers, depending on the assumptions made about the level of infiltration reduction. We would suggest that the numbers in the PER are acceptable and other reasonable approaches (as suggested by the reviewer) would not result in estimates that would materially affect the results or conclusions in the PER. f. "Are all projected costs .... Response to Reviewer's Comments paragraph 1. See comments above about level of detail on certain components of the WWTP. We have endeavored to provide adequate contingency and cost escalation factors to ensure that the project is well funded. More detailed alternative comparisons of minor individual components will be made, as apprepdate, during detailed design. MORPJSON MAIE , City of Laurel 2006 TSEP Technical Review Response August 14, 2006 Page 8 of 6 Thank you for the opportunity to comment on the review and to provide the summary statement on health and safety issues. Sincerely, MORRISON-)VIAIERLE, INC. Scott B. ML~:~"y, P.E., DEE Project Manager CC: Larry McCann, PUD, City of Laurel /,~nneth OIsen, Jr., Mayor, City of Laurel Cad Anderson, MMI Jeremy Perlinski, MMI City of Laurel 2006 TSEP Grant Application Health and Safety Statement Serious public health and safety problems clearly attributable to Laurel's wastewater facilities are likely to occur without completing the improvements proposed in the PER. Deficiencies at the existing lift stations, specifically equipment age and condition and the lack of a secondary power source, make failure of the sewage lift stations increasingly probably over time. Failure could cause sewage to back up into residences, resulting in serious consequences such as illness and substantial property loss. Without improvements to correct hydraulic deficiencies and add secondary treatment equipment redundancy at the WWTP, process failure will place downstream users at risk of exposure to partially treated or untreated wastewater - a clear health risk. Since Laurel's WWTP serves all of the residents, the entire community equally shares in the dsks associated with the deficiencies. The proposed projects are part of a prioritized long-range plan to eliminate all health and safety problems with the wastewater facilities. R:\0703\011.11 WW Facility Plan~TSEP~TSEP 150 word summaG'.doc