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HomeMy WebLinkAbout1992-01-27 92-101 ORDERfictionConsent Oate 1/27/92 Item No. 92-101 Item/Subject: Authorizing Amendment to CH221-Hill Contract - Secondary Treatment Plant Responsible Department: Engineering Commentary: This is a proposed modification to the Treatment Plant which would provide an effective means u of solving a portion of a combined sewer overflow problem in the future. It is felt that the work should be done chile the Plant is presently under construction, to prevent the need of tearing up the completed facility within the next few years. subject to the approval of DEP and EPA. This Order is recommended for passage. Depertmem Xaad Manager's Comments;�y,� dm'dJagj tFUALWd iD MG/ a Odf7M1dX , -aXXP ttle(�-e_ao rdd 4IX� + l`hf� Fig y dA.Lod°" oIQTQTn.Jbsv4 (�MWYXIi. try A es,j r Associated Information: y r CHa - Budget Approva0 Fina mDire Legal Approval: fey Sri ..ror For Page —of_ 92-101 Mr qued to CommOnr 3ragg, January 27, 1992 CITY OF BANGOR (TITLE.) Wrb2Ty._Amendment to CH2M Hill Gpntracx secondary ........... Treatment Plant By aid city cpyNett arae city ofReagan ORDRRED, TEAT , WHEREAS, preliminary findings of the combined sewer overflow study have indicated that storm water detention and possible treatment appears to be a feasible alternative in some instances pertaining to certain combined sewer overflows; and WREREAS, the opportunity exists to provide the treatment of up to 13 BCD of storm water by undertaking piping and process modifications at .the treatment plant as part of the existing construction project' NOW, THEREFORE, Be It OBDER®, THAT the City Manager be and hereby is authorized to execute n Amendment to the existing Contract with CH2M-Hill to undertake a study of said plant modifications, including the review of said modifications with the Contractor, EPA and DEP ate cost of $40,000.00, and t0 sub- sequently undertake design of said modifications for a fee of $65.000.00 upon receipt of approval of the study by EPA and DEP, and subject to subsequent approval of the Finance Committee to proceed with the design phase: and be it further ORDERED, THAT the sum of $105.000.00 be transferred from Account No. 80-70-10-99 (Contingency) to Account No. 80-70-10-85 (Survey and Design) to cover the coat of said engineering work. In City Council January 27PI992 paasssed ity Clerk 91-101 0R D I R Title, Authmleing Rmendment to CH2 Hili Contract Secondary Treatment Plant ...................................... ............ ....:..... ..... ... uneilrtun w CITY OF EANCOR, MAINE Engineering Department NEED January 8, 1992 To: Edward A. Barrett, City Manager - From: John T. Frawley, City Engineer Subject: Secondary Treatment Plant - CSO Treatment You will find attached a proposal from CH M -Bill to conduct a preliminary study and possible final design of an additional piping system at the Secondary Treatment Plant which would give u the future capability of providing secondary treatment for excess storm flow, which now appears to be a very favorable means for eventually treating some Of our combined sewer overflow. The existing Interceptor Sewer to the plant has a capacity of 43 MGD, whereas the new plant will have a capacity of 30 MGD. Haile the new plant capacity is based upon peak 30 -day flow, and isv a than adequate to a all of the City's future needs, thereisthe other potential problem of attempting to either eliminate combined sewer overflows, or to provide some ort of detention or treatment. The proposed projectwould provide for secondary treatment of a significant portion of the excess flaw during storm periods by the installation of additional pumps, yard piping, and possibly an additional primary clarifier. The total estimated Cost of the project, Including engineering, is expected to range between $1 million and $1.4 million. Both the staff and our consultants feel that this work should be accomplished as part of the present construction, since it would eventually be a very cost effective way of dealing with some of our CSO problem. especially Barkersville, the largest of our remaining Combined sewer overflows. It 38 felt that the work should be accomplished v rather than being faced with the possibility w O£ tearing up the completed project at same time during the next few years. It is also thought that we may be able to use this additional work a of extending the completion date o of the construction contract,nthereby hopefully avoiding penalties if we do not meet the December 31, 1992 date contained In the Consent Decree. The proposal is broken into two phases: A study phase and a design phase. The Council order would authorize the study phase to be undertaken immediately, and the design phase to be undertaken upon subsequent approval of the Finance Committee if the project is found to be feasible, and approved by DEP and EPA. -1- We will need to proceed with this work in the very near future in order to avoid unnecessary delays n the completion of remaining work. Consequently, would propose to place this item on the City Council Agenda for the January 27th meeting, and would hope to discuss it with the Finance Committee on January 22nd. We will also need to examine the status of our current funding between now and January 22nd, but it would appear that there is sufficient funds within previous authorizations to cover this work. Bre. If you have any questions, please call. -2- MON, y'W-M( '— Engineers — Planners © Ecorxxnisis _. — Scientists January 7, 1992 BOSMS1.B2 Mr. JOhn T. Frawley, P.E. City Engineer Gty of Bangor 73 Harlow Street Bangor, Maine 04401 Dear Mr. Frawley: Subject CSO Improvements - Fee Estimate The CSO Facility Plan presently being prepared by CH2M HILL will indicate that a cost-effective method of treating CSO in Bangor would be to expand the peak Dow capacity of the wastewater treatment plant from 30 mgd to 43 mgd. Based on this recommendation, we have prepared a feeestimate to incorporate the proposed modifications to the treatment plant. The proposed work would consist of two phases. The study phase would further define the implementation of the proposed improvements as well as analyzing the procurement options and delay impact should these improvements be incorporated by Change Order to the existing contract. tuning the design phase we would prepare the drawings and spedfications necessary to construct the identified improvements. Improvements potentially required to upgrade the plant to a peak flow capacity of 43 mgd consist of the following: o One new raw wastewater pump with a variable frequency drive. Thefourexisting pumps may require new impellers, motors, or possibly new pumps. o One new primary clarifier. o Additional yard piping between the raw wastewater pumps and the secondary clarifiers. CRoM NW Boston once WV<ni aria van n.v' 61ZU122W apNey AbRxho[em aN f62sr] Mr. John T. Frawley, P.E. - Page 2 January 9, 1992 BOS28581.132 _ o Modifications to the Biofilter Influent Pumps. o One new chorine contact basin. o Modifications to the chemical feed pumps used for disinfection and dechlorination. The actual scope of the improvements will be defined during the study phase and all of the above improvements probably will not be required. The scope of work for the study phase consists of the following tasks: 0 Process analysis of the impact of the additional 13 mgtl on the treatment facility. This would include analysis on the need for an additional primary clarifier and an additional chlorine contact basin. o Hydraulic analysis of the impact of the additional 13 mild on the existing pumping/piping infrastructure. o Layouts for the proposed improvements. o Procurement analysis to determine whether to proceed with a Change Order or prepare a separate bid package. o Cost estimate of the proposed improvements. 0 Timing/Delay impact analysis should these improvements be issued as a Change Order. The proposed level of effort for the study phase is presented in Table 1. The fee estimate for the study phase is $40,000. The design phase would require the preparation of new drawings as well as modification of existing drawings. Additional drawings and specifications would be required if this project was procured under a separate construction contract. The proposed sheet list for the design is as follows: Mr. John T. Frawley, P.E. Page 3 January 9, 1992 BOS2MI.B2 Discipline Sheet Title M Raw Wastewater Pump Station - Plan and Section A/E Raw Wastewater Pump Station - Plan S/M Primary Clarifier - Foundation Plan S/M Primary Clothier - Upper Plan S/M Primary Chandler - Sections and Details S/M Primary Clarifier - Sections and Details M Yard Piping Modifications M Yard Piping Modifications M Yard Piping Modifications S/M. Chlorine Contact Basin - Foundation Plan S/M Chlorine Contact Basin - Upper Plan S/M Chlorine Contact Basin -. Sections and Details S/M Chlorine Contact Basin - Sections C Site Plan Modifications C - Site Plan Modifications M Chemical Pump Area Modifications E Chemical Pump Area Modifications This sheet list assumes that all of the improvements listed earlier will be required and that the method of procurement will be by Change Order to the evsting contract. The total fee estimate for the design phase based on the above assumptions of $65,000. We are available to discuss with you this fee estimate at your convenience. Please call should you have any questions. Very truly yours, CHZM HILL James L Hawley, P. . ap/b:csoimprove Table i Study Phase Tavel of Effort Senior Paul Ned Task Consultant DeKeyser Johnson Tech W/P Process Analysis 8 40 Hydraulic Analytical - 16 92 Review Layouts 8 8 48 48 Procurement Analysis 8 Cost Estimate 8 Timing Analysis 4 4 Prepare TM 8 16 so 16 Meetings 8 8 8 .Totals 44 100 228 48 16