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AMENDMENT NO. 1AGREEMENT FOR PROFESSIONAL SERVICES This Amendment No. 1 to Agreement for Professional Services is made and entered into as of October 30, 2023, by and between Carollo Engineers, Inc., a Delaware corporation Consultant, and the City of Santa Maria, a California Municipal Corporation and charter city , in Santa Maria, California, based on the following recitals: WHEREAS, on June 30, 2023, the City and the Consultant entered into an Agreement for Professional Services concerning Wastewater Treatment Plant Program Management Services ; and WHEREAS, the City now requires additional urgent services related to the existing percolation pond capacity, of which such services are also of a professional, technical, and temporary nature; and WHEREAS, the City continues to not have available employees to perform the specialized services for the Project; and WHEREAS, the City has requested the Consultant continue to perform services for the Project; and WHEREAS, the Consultant remains registered or licensed in California to perform professional and technical services for the Project; and WHEREAS, the Consultant remains qualified, willing, and able to perform the work required by the City to complete the Project, as an amendment to the Agreement referenced above. NOW, THEREFORE, IT IS AGREED: 1. Recitals true. The above recitals are true. 2. Amendments. Exhibit A-1 Services to be Provided. Exhibit A-1is hereby attached and incorporated. Exhibit C-1 Payment. Exhibit C-1 is hereby attached and incorporated. 3. Other terms and conditions remain the same. All other terms and conditions of the original Agreement dated June 30, 2023, as modified by this Amendment No. 1 dated October 30, 2023, remain the same. CONTINUED ON NEXT PAGE ATTACHMENT "A-2"
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ContractorCAROLLO ENGINEERS, INC.CITY OF SANTA MARIAa Delaware corporation, authorized to do a political subdivisionbusiness in the State of California of the State of CaliforniaBy: By:GRAHAM JUBY SHAD S. SPRINGER, P.E., MPAVice President Director of UtilitiesBy:ATTESTANNE PRUDHELSenior Vice PresidentBy:ALEXANDRA VALADEZAssistant City ClerkAPPROVED AS TO FORMRisk ManagerCity Attorney
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Percolation Pond Focus and Objectives Daily influent flow to the WWTP has increased over time and is now around 8.0 mgd. This is a threshold number because the NOA stipulates that the WWTP capacity is linked to the percolation pond capacity, which was stated in the NOA as 8.0 mgd. Accordingly, some of the planned percolation pond work, including some field work, has been brought forward to address the percolation pond capacity issue. Short Term Goal the short-term goal of the percolation pond evaluation is to establish a defensible percolation pond capacity based on the existing pond area. This will allow the City to approach the Water this stilling wells and level transducers will be installed in some wells to measure the percolation rate. The additional scope for this work is detailed below. Long Term Goal the long-term goal for the percolation pond evaluation and for the percolation ponds themselves is to develop an approach to sustain the percolation capacity. Tons of fine organic solids are deposited in the ponds each year due to the quality of the secondary effluent. These solids need to be removed from the ponds periodically to sustain performance. Understanding the soil makeup in the ponds will also help to decide on the best long term operational strategy for ponds on either the west side or east side of Black Road. Most of the work related to the long-term pond performance will be addressed as part of the larger Phase 1 project scope. Additional Percolation Pond Scope of Work for Short Term Completion Carollo and sub-consultants will oversee a flow monitoring effort to characterize percolation rates in the existing ponds. Some field activities will be needed now, but most will occur upon execution of the Phase 1 agreement and Scope of Work. The following is to be completed to address the short-term goal, as part of the interim timeframe.
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Flow Monitoring Efforts (Hydrogeological):1. Develop a percolation pond evaluation plan in consultation with the City to decide how to go about monitoring the percolation rates in each pond and the objectives of the study. 2. Set up three stilling wells and deploy three pressure transducers with telemetry capabilities to capture pond levels. The locations of the stilling wells will be agreed during a site visit and will and rain gauge will be installed to quantify evaporation and rainfall. 3. Record water inflow into the percolation ponds over a span of approximately two months. Data acquisition will happen through on-site visits and remote telemetry-enabled data loggers. 4. Compare level data to correlate current percolation rates in all ponds. 5. Develop a water balance to demonstrate percolation pond capacity. Understanding the influent drone images if possible), the average evaporation rate, rainfall amounts, and the change in pond level, will allow a water balance to be developed which will yield the pond capacity. 6. Utilize monitoring processes to understand how much percolation pond performance has changed since prior work was completed. This will help with understanding the required frequency for maintenance activities. 7. Prepare a technical memorandum documenting the percolation pond performance and capacity. The contents of this document will be used to approach the Regional Water Board to request an adjustment to the pond, and therefore the WWTP, capacity. Geotechnical Investigations: 1. Collect previous historical geotechnical data and reports, maintenance records and other data from the City. Extract all boring/exploration maps and laboratory data from the available documents. 2. Submit a survey to plant staff regarding pond performance and past efforts regarding maintenance in order to understand the activities performed and the frequency of the maintenance efforts. 3. Prepare a set of summary maps showing locations of previous subsurface explorations. Also, develop a map to show recommended exploration locations for borings, CPT soundings and test pits for the field work to be conducted as part of the Phase 1 scope. Recommended explorations will depend on review of data, information provided by plant staff on pond performance, and the need to fill gaps in the data for pond performance assessment. 4. Prepare a technical memorandum summarizing the historical data together with a work plan and exploration map for the field investigations to be completed as part of the Phase 1 scope of work. Deliverablesmemorandum in electronic PDF electronic PDF format. The above scope of work will not recommend pond capacity improvements for the long term, although much of the information will be used for such recommendations. The recommendations for pond capacity improvements for the long-term will be provided later as part of the long term Phase 1 scope of work in conjunction with estimates for the future plant capacity.
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I. II.