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HomeMy WebLinkAboutResolution - 2005-R0241 - Amendment To Agreement - Daniel B Stephens & Associates - Environmental Services - 06_09_2005Resolution No. 2005-RO241 June 9, 2005 Item 23 RESOLUTION BE IT RESOLVED BY THE CITY COUNCIL OF THE CITY OF LUBBOCK: THAT the Mayor of the City of Lubbock BE and is hereby authorized and directed to execute for and on behalf of the City of Lubbock a First Amendment to Agreement to Provide Environmental Science and Engineering Services between the City of Lubbock and Daniel B Stephens & Associates, Inc., and any other related documents. Said First Amendment to Agreement is attached hereto and incorporated in this Resolution as if fully set forth herein and shall be included in the minutes of the Council. Passed by the City Council this 9th day of _j,,,,P 2005. ATTEST: Rebecca Garza, City Secretary APPROVED AS TO CONTENT: ' Chester Carthel Water Planning Engineer APPROVED AS TO FORM: Richard K. Casner First Assistant City Attorney ml/ccdocs/ DanielStephens.I' Amend to EnvironmentalContract.res June 1, 2005 Resolution No. 2605-RO241 CONTRACT NO. 00006118 FIRST AMENDMENT TO AGREEMENT TO PROVIDE ENVIRONMENTAL SCIENCE AND ENGINEERING SERVICES This First Amendment to Agreement to Provide Environmental Science and Engineering Services (the "Amendment"), is made effective this 9t' day of June, 2005, by and between the City of Lubbock, a Texas home rule municipal corporation (the "City") and Daniel B. Stephens & Associates, Inc., a Texas corporation ("Stephens"). WHEREAS, on or about May 6, 2004, Resolution No. 2004-R0232, the City and Stephens entered into that certain Agreement to Provide Environmental Science and Engineering Services (the "Original Agreement"), for services to be performed by Stephens related to Pump Station 10, as described therein; WHEREAS, the City is in need of additional environmental and engineering services regarding Pump Station 10; WHEREAS, Stephens, which has significant environmental and engineering expertise regarding the subject matter thereof, is amenable to performing such additional services; WHEREAS, the Original Agreement provided for a fifteen (15) month period of time for completion of all tasks required of Stephens therein; WHEREAS, the additional services to be provided by Stephens, as set forth in this First Amendment to Agreement to Provide Environmental Science. and Engineering Services, requires additional time for performance; WHEREAS, the City and Stephens now desire to amend the Original Agreement to provide for such additional services and extended time for performance. NOW, THEREFORE, the City and Stephens agree to amend the Original Agreement in the following manner: 1. The "Additional Project Scope and Budget for Groundwater Analysis for City of Lubbock PS-10 Project", attached hereto as Exhibit "A", is hereby added to the Original Agreement the same as if the Original Agreement originally provided for such activities. Consideration to paid to Stephens for the activities contained within the "Additional Project Scope and Budget for Groundwater Analysis for City of Lubbock PS-10 Project" shall not exceed the sum of Forty -Three Thousand, One Hundred Seventy Dollars and no/100 ($43,170). 2. All work to be performed pursuant to the Original Agreement, as amended herein, shall be completed on or before June 1, 2006. The Original Agreement, as amended herein, shall expire on June 1, 2006 3. Except as expressly modified or amended herein, the Original Agreement shall remain valid and effective as originally provided. EXECUTED and effective as of the date above first written. CITY OF LUBBOCK, TEXAS GAL, MAYOR ATTEST: Q,L",- -- --s2- Rebecca Garza, City Secretary APPROVED AS TO CONTENT: Chester Carthel Water Planning Engineer APPROVED AS TO FORM: Richard K. Casner First Assistant City Attorney DANIEL B. STEPHENS & ASSOCIATES, INC. Name: Title: mMchard/Stephens.Amendment to agreement -PS 10 May 24, 2005 Exhibit " A " Additional Project Scope and Budget for Groundwater Analysis for City of Lubbock PS-10 Project May 17, 2005 Introduction This document has been prepared by Daniel B. Stephens & Associates, Inc. (DBS&A) as the hydrogeologic analysis component of the Pump Station 10 (PS-10) Groundwater Utilization and Treatment Project. The scope of work and estimated cost is divided into 6 tasks outlined below. Total estimated cost is $43,170. Notwithstanding such estimate, the amount payable for the tasks described herein shall not exceed r`�or k-,4 rf 2-Tvzusa-d, (03, 1 "1 b ) Some suggestions for groundwater sampling and aquifer testing procedures are also provided below. If so noted, the City intends to undertake these tasks on their own, but has asked DBS&A to provide input regarding useful or necessary items. The suggestions provided below are proposed with the intent of minimizing costs yet obtaining a necessary minimum amount of baseline information on which useful decisions might be made; certainly more detailed field testing and evaluation programs could be devised that would lead to more accurate aquifer parameters, but at substantially greater cost to the City. Task 1 - Project Management and Coordination This task covers project coordination, direction and updating issues, as well as communication with Parkhill, Smith & Cooper (PSC) and Black & Veatch as required. Project coordination and communication will occur between DBS&A's Project Manager, Mr. Neil Blandford, and the City of Lubbock Project Leader. Conference calls with the City and engineering consultants will be held to discuss project issues as required, and project issues can also be discussed in Page 1 of 6 Daniel B. Stephens & Associates, Inc. conjunction with Groundwater Utilization Study project meetings. It is assumed that one additional meeting in Lubbock will be required for this project that would not otherwise have been required as part of the Groundwater Utilization Study. Estimated Cost: $4,020 Task 2 - Geologic Logging of Production Wells The City plans to construct and pump test 16 production wells on the south side of the Loop 289. This task involves the geologic logging of each well. To reduce costs, we propose that rather than have a geologist "sit" the well, the geologic logs be constructed based on cuttings that the driller will be required to set out. Cuttings should be saved at 10 ft intervals and at all major changes in lithology, in descending order. Estimated cost for geologic logging (supply hand written log): $5,200 Task 3 - Aquifer Test, Analysis This task involves the evaluation of aquifer parameters from the pump testing of the new production wells that will be conducted by the City. At this point, DBS&A proposes to analyze the results of the field testing using standard approaches, but we have not budgeted for any field work related to this task. We will evaluate the field data using standard aquifer test solutions. Estimated Cost: $4,440 The City shall conduct the following tasks: • Pump each new production well continuously for at least one week (or until observed drawdown in the well is stable) at its apparent maximum sustainable rate once well development is complete. The pumping rate should be maintained Page 2 of 6 Daniel B. Stephens & Associates, Inc. as steady as possible. Continuously monitor the water level in the pumping well using a pressure transducer installed in a stilling tube both during pumping conditions and until the water level after pumping reaches 90% of the original level once the pump is turned off. • If other wells exist nearby (such as City monitor wells in the same park area), the City should conduct continuous monitoring of those wells both during the pumping and recovery periods using pressure transducers. Task 4 - Incorporation of Newly Collected Data into the Groundwater Flow Model As part of the Groundwater Utilization Study, a groundwater flow model of the City of Lubbock area will be developed using the telescopic grid approach, with the Southern Ogallala GAM serving as the regional model from which the local (Lubbock) model is developed. The purpose of the groundwater flow model is to assess the sustainability of groundwater resources for various alternative use scenarios. This task involves incorporation of the newly collected aquifer data into the groundwater flow model, and more detailed calibration and evaluation of the model in the vicinity of the newly constructed supply wells than would otherwise be conducted as part of the Groundwater Utilization Study. This task is necessary to ensure that the model is suitable for the estimation of the future capture zone for each production well. The capture zone is the region of the aquifer from which each supply well obtains the water that it pumps; determination of the well capture zone will allow the evaluation of potential contaminant sources that reside within the capture zone. Determination of the capture zone is sensitive to not only the simulated water levels, but also the simulated hydraulic gradient and the direction of groundwater flow. In the modeling performed for the Groundwater Utilization Study, detailed simulation of the groundwater flow direction for the determination of well capture zones is not a scope of work item. Page 3 of 6 Daniel B. Stephens & Associates, Inc. If appropriate or necessary, analytical solutions can also be used (in addition to or in lieu of numerical modeling) to evaluate production well capture zones. Estimated Cost: $14,450 Task 5 - Water Quality Evaluation and Pumping Strategy Design This task consists of the evaluation of the supply well source water quality based on existing information and samples collected from the pumping wells during testing. The City will collect and be responsible for all new water samples. For productive well sites that appear to be promising locations for prolonged pumping, groundwater samples should be collected at the beginning (after 1/2 hour of the pump being turned on) and end of pumping (immediately before the pump is shut off), and that field parameters (e.g. temperature, specific conductance, turbidity) be collected at more frequent intervals (at least daily). In addition, the City will collect and/or analyze the following and provide the results of such analysis to DBS&A: • Playa water samples and field parameters at the onset of pumping if the production well lies near a playa lake • Groundwater samples from any. observation wells (either City wells or HPUWCD monitor wells) that lie in the vicinity of the production wells • In addition to those regulatory parameters (fluoride, nitrate, arsenic, total dissolved solids, etc.) already planned for sampling by the City, specific groundwater constituents that could impact the required treatment processes — dissolved oxygen, dissolved gas, turbidity, silica, concentration and nature of iron, manganese, and sulfide present in the groundwater -- should also be analyzed Page 4 of 6 Daniel B. Stephens A Associates, Inc. Items to be completed by DBS&A as part of this task include Determination of well capture zones using the groundwater flow model as completed under Task 4 • Determination of possible or known sources of contamination within each capture zone. This information will be useful for design of a pumping strategy. We anticipate that the model and associated capture zone results may also be used to evaluate 3-4 different pumping strategies and effects on the local capture zones of the PS-10 production wells. Note that the particle tracking method will be used to determine well capture zones; solute transport modeling will not be performed due to insufficient information. The particle tracking method is sufficient to determine the sources of water for the pumping wells, but it will not provide a predicted concentration of a given solute. This task also includes the evaluation and compilation of existing groundwater quality data near the new supply wells, to the extent that that data has not been compiled already as part of the Groundwater Utilization Study and is readily available. One source of new data will be the sampling conducted by the City, but additional data may also be available from select production wells or monitor wells near existing contaminated sites. DBS&A will obtain water quality data from the most recent sampling event from the well owner or TCEQ records, if available. Estimated Cost: $10,600 Page 5 of 6 Daniel B. Stephens & Associates, Inc. Task 6 - Reporting Documentation of the groundwater flow model will be provided as part of the Groundwater Utilization Study. However, it is anticipated that a letter report, suitable in form to the City, will be required to document the results of the above tasks directly relevant to the PS-10 project. Estimated Cost: $4,460 Project Timeline The proposed scope of work items are scheduled for completion within three months of completion of the production wells, or as otherwise agreed to by the City. A comprehensive project schedule has been developed and previously provided to the City, and will be maintained by PSC. The work proposed herein is listed under the "Groundwater Supply Assistance-DBS" portion of that schedule. mMchard/PS-10 GW_Scope of Work.rdin Page 6 of 6