Report Prepared by: Ken F. Elwin, PE, Director of Public Works
Title
SUBJECT: Approval of a First Amendment to Professional Services Agreement with Stantec Consulting Services, Inc., for Engineering Design Services for the Wastewater Treatment Facility Phase VI Improvement Upgrades for a Total Additional Amount not to Exceed $1,673,800
REPORT IN BRIEF
Considers authorizing a first amendment to professional services agreement with Stantec Consulting Services, Inc., for engineering design of wastewater treatment facility improvement upgrades in a total additional amount of $1,673,800.
RECOMMENDATION
City Council - Adopt a motion approving a first amendment to agreement for professional services with Stantec Consulting Services, Inc., in the not to exceed additional amount of $1,673,800 and, authorizing the City Manager or the Deputy City Manager to execute the necessary documents.
Body
ALTERNATIVES
1. Approve, as recommended by staff; or,
2. Approve, subject to modifications as conditioned by City Council; or,
3. Refer to staff for reconsideration of specific items; or,
4. Deny.
AUTHORITY
Charter of the City of Merced, Section 200, et seq. and Section 3.04.120 of the Merced Municipal Code.
Services with an estimated value greater than $34,000.00 are made by written contract in accordance with Merced Municipal Code, Title 3 - Revenue and Finance, Chapter 3.04.
CITY COUNCIL PRIORITIES
As provided for in the 2021-2022 Adopted Budget.
DISCUSSION
Wastewater generated within the City of Merced city limits is processed at the Wastewater Treatment Facility (WWTF), located southwest of the City at 10260 Gove Road. Currently, the City’s WWTF is designed with a capacity of 12 million gallons per day (MGD). In achieving this wastewater flow capacity, the following upgrades were completed:
In 2011, Phase IV upgrades included adding tertiary treatment, a new headworks, a third primary clarifier, and ultra-violet disinfection. These allowed a safe and suitable form of effluent water reuse and discharge to the Hartley Slough sensitive aquatic habitat.
In 2013, the Phase V solids handling project improved the sludge drying practices by diverting digested sludge from earthen drying beds to a modern cement lined active solar drying facility. Centrifuges were installed for biosolids thickening, along with a solids holding tank, methane gas storage capability, a septage receiving station, and other related solids handling facilities.
In 2016, a new laboratory was constructed to improve quality control during the analysis of the treatment plant’s water samples.
At the June 15, 2020 meeting, Council approved an agreement with Stantec Consulting Services, Inc. (“Stantec”) for a not to exceed amount of $451,900 to evaluate alternatives for cost effective upgrades to achieve the 16 or 20 MGD capacity and meet regulatory requirements. Future regulatory items of concern include, but are not limited to; virus disinfection, salinity control, ammonia control, recycled water use, and nitrogen loading to groundwater due to land application of generated waste solids. The contract for the development of the WWTP Phase VI Preliminary Design Report included the following major tasks:
• Evaluate existing water treatment systems and performance;
• Evaluate current and future Regional Water Quality Control Board regulatory wastewater discharge requirements;
• Evaluate options for improvement and expansion to include methane gas utilization;
• Evaluate costs associated with alternatives;
• Prepare a Preliminary Design Report with select recommendations;
• Assist with a State Revolving Fund application and associated requirements.
At the June 21, 2021 Council meeting, a report presentation was given to present and discuss the results of the WWTP Phase VI Preliminary Design Report findings. Direction was provided to Staff during the meeting to proceed with the design elements contained in the First Amendment as presented for approval.
First Amendment
Stantec has provided a cost proposal to provide design services for the proposed WWTF Phase VI Improvement Projects identified in the Merced WWTP Phase VI Preliminary Design Report. The improvements project will be designed to improve treatment reliability, enhance biogas utilization, and reduce energy costs. The proposed design includes the following components:
• Influent Flow Monitor, Influent Pump Station, and Headworks
• Secondary Treatment - Replacement of Reactor Basins 1 & 2
• UV Disinfection System - Recoating of the UV concrete channels
• Sludge Thickening - Upgrade DAFT and replace retention tank
• Solids Dewatering and Drying - Add parallel conveyor and add supplemental heat to active solar dryers
• Septage Receiving Station
• Hybrid Digestion Pilot Testing
The Stantec fee proposal for completing the above tasks is for the not-to-exceed sum of $1,673,800.
IMPACT ON CITY RESOURCES
This project was established as a Capital Improvement Project and accounts 553-1108-637.65-00-118015 and 551-1157-637.65-00-118015 contain sufficient funding to complete the project.
ATTACHMENTS
1. First Amendment