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Home My WebLink About15.b. Committee Minutes-Engineering and Operations 07-10-2023Page 1 of 11 Item 15.b. July 20, 2023 110ENTRAL SAN IN MINE IWAII 'I IQ, 11111]1111111111 111:111 nowia 0 111 M&I"s M& FROM: KATIE YOUNG, SECRETARY OF THE DISTRICT SUBJECT: JULY 10, 2023 - ENGINEERING & OPERATIONS COMMITTEE - CHAIR PILECKI AND MEMBER MCGILL Attached are minutes of the above Committee meeting. Strategic Plan Tie -In GOAL ONE: Customer and Community Strategy 1— Deliver high-quality customer service GOAL FOUR: Governance and Fiscal Responsibility Strategy 1 - Promote and uphold ethical behavior, openness, and accessibility, Strategy 2 - Encourage and facilitate public participation ATTACHMENTS: 1. 07-10-23 Engineering & Operations Committee minutes July 20, 2023 Regular Board Meeting Agenda Packet - Page 95 of 112 Page 2 of 11 LCENTRAL SAN Monday, July 10, 2023 PHONE: (925) 228-9500 9:00 a.m. FAX.- (925) 372-0192 www.centralsan.org Committee: Chair Tad Pilecki Member Mike McGill Guest: Tracy Stigers, Brown and Caldwell Staff. - Katie Young, Secretary of the District Greg Norby, Deputy General Manager — Operations Philip Leiber, Deputy General Manager — Administration (arrived during Item 3.a.) Edgar Lopez, Provisional Director of Engineering and Technical Services Neil Meyer, Provisional Director of Operations Danea Gemmell, Planning and Development Services Division Manager (joined during Item 3. a.) Nitin Goel, Operations Optimization Division Manager Alan Weer, Plant Operations Division Manager (joined during Item 4.a.) Clint Shima, Senior Engineer Craig Mizutani, Senior Engineer Michael Cunningham, Associate Engineer William Grant, Associate Engineer Stacey Durocher, Administrative Services Assistant Call Meeting to Order Chair Pilecki called the meeting to order at 9:00 a.m. 2. Public Comments None. July 20, 2023 Regular Board Meeting Agenda Packet - Page 96 of 112 BOARD OF DIRECTORS: REGULAR MEETING OF THE BARBARA D.HOCKETT CENTRAL CONTRA COSTA President SANITARY DISTRICT MARIAHNLEN President Pro Pro Teen ENGINEERING & OPERATIONS MICHAEL R.MCGILL COMMITTEE MINUTES CKI FLORENCE TAD EDI TON T WEDINGTON Monday, July 10, 2023 PHONE: (925) 228-9500 9:00 a.m. FAX.- (925) 372-0192 www.centralsan.org Committee: Chair Tad Pilecki Member Mike McGill Guest: Tracy Stigers, Brown and Caldwell Staff. - Katie Young, Secretary of the District Greg Norby, Deputy General Manager — Operations Philip Leiber, Deputy General Manager — Administration (arrived during Item 3.a.) Edgar Lopez, Provisional Director of Engineering and Technical Services Neil Meyer, Provisional Director of Operations Danea Gemmell, Planning and Development Services Division Manager (joined during Item 3. a.) Nitin Goel, Operations Optimization Division Manager Alan Weer, Plant Operations Division Manager (joined during Item 4.a.) Clint Shima, Senior Engineer Craig Mizutani, Senior Engineer Michael Cunningham, Associate Engineer William Grant, Associate Engineer Stacey Durocher, Administrative Services Assistant Call Meeting to Order Chair Pilecki called the meeting to order at 9:00 a.m. 2. Public Comments None. July 20, 2023 Regular Board Meeting Agenda Packet - Page 96 of 112 Page 3 of 11 Engineering & Operations Committee Minutes July 10, 2023 Page 2 3. Items for Committee Recommendation to Board *a. Review draft Position Paper to award a construction contract in the amount of $11,449,000 to C. Overaa & Co., the lowest responsive and responsible bidder for Aeration Basins Diffuser Replacement, Phase 1, District Project 100019; include award of an additive bid item in the amount of $1,213,000 for seismic upgrades; execute a professional engineering services agreement in an amount not to exceed $1,000,000 with HDR Engineering, Inc. to provide engineering services during construction; and find the project is exempt from the California Environmental Quality Act (CEQA) Mr. Grant reviewed the presentation included in agenda materials. Chair Pilecki inquired about the seismic scope of work. Mr. Grant stated that the additive bid item is for Fiber -Reinforced Polymer (FRP) seismic strengthening. The FRP wrap will be installed at strategic locations in the tanks to strengthen the concrete and bring the aeration basins up to seismic code. Member McGill asked if the new air piping system will be placed above the floor as opposed to the current system being underneath the floor of the tank. Mr. Grant stated the new system will be placed slightly above the floor allowing debris to be washed away and drain properly as opposed to settling on the bottom. Mr. Grant responded to questions posed by Chair Pilecki regarding the existing plenums and the purpose of the baffle walls stating that the existing plenums will be demolished and a new properly sloped concrete slab will be added in place of the plenums, and the baffle walls will allow staff to operate in a step feed mode in the future should nutrient removal requirements change. Mr. Lopez added that the baffle walls are not only being added as part of the seismic retrofit but will allow for better efficiency and for staff to control flows as well as the aeration process better. He stated the plenums were rehabilitated many years ago and were difficult to maintain and was where most of the leaks were coming from. Member McGill inquired whether staff can still see air leaking during the rain. Mr. Lopez stated that most of those issues were resolved under another project, but leaks are more common in the tunnels now due to cracking. Chair Pilecki asked if the hissing noises in the groundwater relief valves were still problematic and if those were being addressed. Mr. Lopez stated the relief valves will also be rehabilitated. July 20, 2023 Regular Board Meeting Agenda Packet - Page 97 of 112 Page 4 of 11 Engineering & Operations Committee Minutes July 10, 2023 Page 3 Member McGill inquired about the engineers' estimate being so high. Mr. Grant responded that some of the quotes received from suppliers during design were high. For example, the stainless-steel piping quote was high but the price that came in during bidding was approximately $1 million lower. Other contributing reasons for this include staff time spent with the contractors resulting in comprehensive bids and competitive pricing, as well as the diffuser system being pre -purchased by Central San and installed by the contractor. Member McGill asked if the project was eligible for grant funding. Ms. Gemmell stated that staff did apply for government funding but was not selected. She stated future funding could be possible but would be a few years out. Chair Pilecki recommended adding a sentence to the end of the 3rd paragraph in the Background section stating that Phase 2 will address the remainder of the project and is scheduled for 2026-27. In response to Chair Pilecki regarding escrow documents, Mr. Lopez stated that the District often requests escrow documents on projects over $10 million in addition to the normal bid documents. Chair Pilecki asked if the aeration tanks will be retrofitted to seismic level 4. In response, Mr. Lopez stated they will be retrofitted to the current standard for wastewater facilities. COMMITTEE ACTION: Recommended Board approval. b. Review draft Position Paper and authorize the General Manager to purchase natural gas through an existing service agreement with Shell Energy North America, LP for the period of January 1, 2025 through December 31, 2025 up to 1,200 dekatherms per day at a price not to exceed $7.00 per dekatherm, excluding transportation service costs Mr. Shima reviewed the draft Position Paper included in agenda materials. In response to a question posed by Member McGill about how much money is spent in total for natural gas during the year, Mr. Shima stated approximately $3 million including commodity and transportation costs. Chair Pilecki asked if there was a cap on landfill gas and if staff anticipates being over budget. Mr. Shima said that landfill gas has a cap of $6 per dekatherm and should not be over budget, however electricity will be over budget due to an unscheduled outage on Cogen. Chair Pilecki also asked if staff knew how long landfill gas would be available. Mr. Shima stated based on the information he has received approximately 10 years. July 20, 2023 Regular Board Meeting Agenda Packet - Page 98 of 112 Page 5 of 11 Engineering & Operations Committee Minutes July 10, 2023 Page 4 Chair Pilecki asked if staff plans to do a study on landfill gas, and whether it is anticipated that natural gas prices will continue to rise given the current political climate. Mr. Shima said prices per dekatherm are quite low for natural gas, and the five-year average supply looks good. Mr. Shima also stated that staff has been working with a natural gas consultant and has received no indications of major changes to affect future supply. Member McGill asked if landfill gas counts against cap and trade. Mr. Shima stated minimally, but not as much as natural gas usage. In response to Member McGill's question regarding possibly acquiring natural gas from Keller Canyon, Mr. Shima responded stating that staff has not explored that option but will look at it. The Committee had no further questions. COMMITTEE ACTION: Recommended Board approval. 4. Other Items a. Receive update for the Solids Handling Facilities Improvements, Phase 2, District Project 100030 Mr. Goel provided an overview of the presentation included in the agenda materials. Member McGill suggested a workshop for the entire Board on this subject in the future. Mr. Goel stated the existing multiple hearth furnaces have been reliably converting solids from wastewater to ash for more than 45 years. The Solids Handling Facilities Improvement Project, Phase 1A will address immediate needs such as seismically reinforcing the building, replacing equipment, and upgrading air pollution control equipment. The Solids Handling Improvement Phase 2 planning when complete will identify the future solids handling process. Member McGill inquired if the public would buy the ash instead of paying for delivery and removal. Mr. Lopez stated staff has looked at other uses for the ash in the past but has not done a Request for Proposal (RFP) for other users to purchase the ash. Ms. Stigers also responded stating Brown and Caldwell has explored various viable outlets, and there may be some additional uses in the future, but the market for ash today in the Bay Area is too small and there July 20, 2023 Regular Board Meeting Agenda Packet - Page 99 of 112 Page 6 of 11 Engineering & Operations Committee Minutes July 10, 2023 Page 5 is not enough awareness or desirability, so this would be more of a market development activity to see if there were other users willing to pay for the ash. Chair Pilecki commented that the only other alternative would be to landfill the ash and pay fees, and staff has already determined having it hauled away is the most cost-effective way to dispose of our ash at this time. Staff responded to all questions, and the Committee suggested having bi- yearly updates as well as a workshop for the entire Board in the future. COMMITTEE ACTION: Received the update. 5. Announcements None. 6. Suggestions for Future Agenda Items a. Receive list of upcoming agenda items and provide suggestions for any other future agenda items As mentioned in Item 4.a., a Board workshop regarding the Solids Handling Facilities Improvements, Phase 2. COMMITTEE ACTION: Received the list and provided input to staff. 7. Future Scheduled Meetinas Monday, August 14, 2023 at 9:00 a.m. Monday, September 11, 2023 at 9:00 a.m. Monday, October 23, 2023 at 9:00 a.m. 8. Adjournment — at 11:18 a.m. *Attachment: Presentation (Handout) July 20, 2023 Regular Board Meeting Agenda Packet - Page 100 of 112 Page 7 of 11 Project Background and Drivers In 2019 Central San initiated a comprehensive asset evaluation of the secondary process facilities at the treatment plant, and identified the Diffuser System in the Aeration Basins as an aging asset that is beyond its useful life. The existing aeration system is not able to reliably maintain consistent dissolved oxygen levels across the basins due to the aging original diffuser system. The concrete basin plenums have been a problem for many years and waste energy. Aeration Basins Diffuser Replacement, Phase 1 will address the west half of the Basins. The scope renovation of Aeration Basins (A/N Tank) 1A, 16, 1C & 1D, and includes demolition, structural, mechanical, electrical, instrumentation, and controls. associated with diffuser replacement in the Basins. July 20, 2023 Regular Board Meeting Agenda Packet - Page 101 of 112 Project Improvements sem' Old and New Diffuser System Page 8 of 11 Aeration Basin Structure • Replace plenum with new concrete slab • Rehabilitate concrete walls in the Aeration Basins Aeration Diffuser Svs+r • Replace aeration header piping, valves and drop legs • Replace diffusers with pre -purchased fine bubble type diffuser system • Replace motor control centers (MCCs) at Substation 32F and install new wiring and instrumentation • Install new gates including drainage gates, isolation gates, and stop logs • Install new mixed liquor recirculation pumps —.A July 20, 2023 Regular Board Meeting Agenda Packet - Page 102 of 112 2 Page 9 of 11 Bid Results Engineer's Estimate: $16,000,000 Seven (7) bids received Lowest Bidder: C. Overaa & Co. No. Bidder Total Bid 1 C. Overaa & Co. $11,449,000 2 GSE Construction Company, Inc. $12,996,600 3 W.M. Lyles Co. $14,444,800 4 Mountain Cascade, Inc. $15,290,964 5 Garney Pacific, Inc. $16,070,000 6 Anvil Builders, Inc. $16,963,000 7 Myers & Sons Construction LLC $17,885,100 Total Estimated Project Cost No. Item Description Amounts %Construction Cast 1 CONSTRUCTION a. Construction Contract $11,449,000 b. Additive Bid Item - Seismic FRP $1,213.000 a Contingency at 15% $1,717,000 d. Equipment Pre -purchase (DiBuserlBreakers) $950,000_ SUBTOTAL - CONSTRUCTION $15,329.000 1001, 2 CONSTRUCTION MANAGEMENT a. District Forces - Operations $250,000 • Construction Management $1,050,400 b. Outside Services - Inspection $550,000 - Specia€ V inspection and material testing $250,000 - Engineering Support (HDR) $1.000.000 SUBTOTAL - CONSTRUCTION MANAGEMENT $3,200.000 21% 3 PREBID EXPENDITURES a. Engineering (Stat and Consultant) $2.350.000 SUBTOTAL- PREBID EXPENDITURES $2,350.DC0 15% 4 TOTAL PROJECT COST $20,879,000 July 20, 2023 Regular Board Meeting Agenda Packet - Page 103 of 112 3 Page 10 of 11 Project Schedule _A Award: July 20, 2023 441 Anticipated NTP: August 2023�� Project Completion: December 2025 Committee Recommendation: Staff recommends approval of the following: Award a construction contract in the amount of $11,449,000 for the construction of the Aeration Basins Diffuser Replacement, Phase 1, District Project 100019, to C. Overaa & Co., the lowest responsive and responsible bidder; Award the additive bid item for fiber -reinforced polymer seismic strengthening in the amount of $1,213,000, increasing the construction contract to $12,662,000; Authorize the General Manager to execute the Contract Documents subject to submittal requirements; Authorize the General Manager to execute a professional engineering services MW aim agreement in an amount not to exceed $1,000,000 with HDR Engineering, Inc. to provide engineering support during construction services; and Find the project is exempt from the California Environmental Quality Act (CEQA). July 20, 2023 Regular Board Meeting Agenda Packet - Page 104 of 112 4 Page 11 of 11 Questions? July 20, 2023 Regular Board Meeting Agenda Packet - Page 105 of 112