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Home My WebLink About17.c. December 11, 2023 – Engineering & Operations Committee – Chair Pilecki and Member McGill Page 1 of 13 Item 17.c. CENTRAL SAN adfAhmm CENTRAL CONTRA COSTA SANITARY DISTRICT December 21, 2023 TO: HONORABLE BOARD OF DIRECTORS FROM: KATIE YOUNG, SECRETARYOF THE DISTRICT SUBJECT: DECEMBER 11, 2023 - ENGINEERING & OPERATIONS COMMITTEE - CHAIR PILECKI AND MEMBER MCGILL Attached are minutes of the above Committee meeting. ATTACHMENTS: 1. Engineering & Operations Minutes 12-11-23 December 21, 2023 Regular Board Meeting Agenda Packet- Page 449 of 461 Page 2 of 13 CENTRAL SAN CENTRAL CONTRA COSTA SANITARY DISTRICT 5019 IMHOFF PLACE, MARTINEZ, CA 9A553-A37 BOARD OF DIRECTORS: REGULAR MEETING OF THE BARBARA D.HOCKETT CENTRAL CONTRA COSTA President SANITARY DISTRICT MARlAHN President Pro LnProTEN Tem ENGINEERING & OPERATIONS MICHAELR.MCGIEE TAD J. NGTOI COMMITTEE FLORENCE T WEDINGTON MINUTES PHONE: (925)228-9500 FAX- (925)372-0192 Monday, December 1 1, 2023 'vww.centralsan.org 9:00 a.m. Committee: Chair Tad Pilecki Member Mike McGill Guests: Courtly Stevens Roberts, Residents of Cedar Lane (left after Item 3.b.) Christopher Roberts, Residents of Cedar Lane (left after Item 3.b.) Staff. Roger S. Bailey, General Manager J. Leah Castella, District Counsel (joined during Item 3.b.) Katie Young, Secretary of the District Greg Norby, Deputy General Manager— Operations Danea Gemmell, Planning and Development Services Division Manager Edgar Lopez, Capital Projects Division Manager Paul Seitz, Collection System Operations Division Manager Dan Frost, Senior Engineer Dana Lawson, Senior Engineer (left after Item 3.a.) Sasha Mestetsky, Senior Engineer Thomas Brightbill, Senior Engineer (left after Item 3.a.) Steve Sauter, Superintendent, Operations and Maintenance (left during Item 4.a.) Shari Deutsch, Risk Management Administrator Chris Carpenter, Senior Community Affairs Representative (joined during Item 3.b.) Stacey Durocher, Administrative Services Assistant 1. Call Meeting to Order Chair Pilecki called the meeting to order at 9:02 a.m. December 21, 2023 Regular Board Meeting Agenda Packet- Page 450 of 461 Page 3 of 13 Engineering &Operations Committee Minutes December 11, 2023 Page 2 2. Public Comments None. 3. Items for Committee Recommendation to Board a. Review draft Position Paper to consider adopting (1) Resolution of Intention No. 2023-XXX to initiate the formation of the Cordell Court Contractual Assessment District (CAD) No. 2023-3 for the purpose of installing sewer improvements on Cordell Court in Danville, (2) Resolution No. 2023-XXX approving the boundary for the proposed CAD; and (3) find the Project is exempt from the California Environmental Quality Act The Committee had no questions. COMMITTEE ACTION: Recommended Board approval. *b. Review draft Position Paper to approve a $1,200,000 contingency project for the Cedar Lane Sewer Modifications; transfer $600,000 from the Collection System Sewer Renovation — Phase 2, District Project 100039; and find the Project is exempt from the California Environmental Quality Act Mr. Lopez provided an overview of the project and prepared a presentation for discussion purposes (Attached). He stated that Central San has sewers within easements along several properties on Cedar Lane and Cedar Terrace. Due to record storm events in late December early January of 2023, a landslide occurred at 10 Cedar Lane and 14 Cedar Lane in Orinda. The slide damaged the 6"sewer main at the sewer connection for 14 Cedar. The landslide disrupted service to four properties with two being red tagged at 10 and 14 Cedar Lane. Staff was able to install temporary pumping systems and laterals to reconnect sewer service at 6 Cedar Lane and 40 Cedar Terrace. 18 Cedar Lane is being serviced by gravity. Member McGill asked how 10 and 14 Cedar Lane properties were affected by the landslide. Mr. Lopez stated that 14 Cedar Lane moved significantly as shown in the PowerPoint picture, and 10 Cedar Lane was also impacted but by other factors, and both houses are unoccupied. In response to a question posed by Mr. Bailey regarding an email and photographs that were sent to the Board, Mr. Seitz stated that staff was dispatched to the area the same day to begin repairs and returned the next day to finish installation. December 21, 2023 Regular Board Meeting Agenda Packet- Page 451 of 461 Page 4 of 13 Engineering &Operations Committee Minutes December 11, 2023 Page 3 Chair Pilecki asked how much soil remains above the original elevation where the sewer was installed. Mr. Lopez stated approximately six to eight feet when last inspected. Chair Pilecki also asked if the removal of 14 Cedar Lane was an engineered soil repair or a cleanup. Mr. Lopez said it was a safety cleanup effort to remove the house and other debris. In response to Chair Pilecki's question about how the line in this area was maintained by Central San prior to the landslide, Mr. Seitz stated staff serviced the line from a manhole located in the court of Cedar Lane and down to manhole. Chair Pilecki asked if the homeowners at 10 Cedar Lane have been contacted to inquire about any plans they may have to reoccupy the property. Mr. Lopez said they have been in touch with Central San's Risk Management. Chair Pilecki stated that it would be helpful to add arrows on Slide 1 to indicate the direction of flow. In response to Chair Pilecki's question about the condition of the sewer line running parallel to 22 Cedar Lane, Mr. Lopez responded that the condition of this line has not been recently assessed but staff will evaluate it once the project is started as we do for all neighboring sewers. As for now, this sewer was not identified or on the replacement list. Cedar Lane resident, Ms. Roberts clarified that there are two pumps on their property. One of the pumps is the lift pump for 40 Cedar Terrace located at the northern corner of their property, and the primary pump for their residence is located on the western portion of the property. She stated that there is a hole with a pump in it on the ravine side of their property that needs addressing. She asked when discussions will be happening so they can prepare for what needs to be done per the Geological Report that has been completed. Mr. Bailey asked staff to coordinate a meeting with all affected homeowners as soon as possible. Chair Pilecki requested that staff add a slide to the presentation on how the existing pumping system works. Member McGill requested information be added regarding how the system worked prior to the landslide and that staff include a list of options for repair and/or replacement. COMMITTEE ACTION: Recommended Board approval with proposed changes to the PowerPoint. December 21, 2023 Regular Board Meeting Agenda Packet- Page 452 of 461 Page 5 of 13 Engineering &Operations Committee Minutes December 11, 2023 Page 4 4. Other Items a. Receive Wet Weather updates Mr. Norby provided a detailed overview of the presentation included in the agenda materials. It was noted that there were no Collection System Overflows observed and no National Pollutant Discharge Elimination System permit violations from the past wet weather events in 2022-23. Mr. Bailey inquired about the kind of liner that is being used in the basins. Chair Pilecki stated that there is no liner. It was noted that an updated evaluation regarding the wet weather basins was received from Brown & Caldwell. A discussion ensued regarding the overflow basins, the volume estimation of the basins and the frequency of storms as indicated by science and climate change. Mr. Norby stated that improvements are going to be made that will substantially improve the District's ability to move wet weather flows through the primary, secondary and disinfection as well as through the outfall. Chair Pilecki asked if the pumps that run the outfall are able to pump 140 million gallons per day (MGD) at high tide or king tide. Mr. Lopez stated no but confirmed that pumping is included in the Capital program and will be addressed sooner rather than later to match the UV project timeline. In response to Chair Pilecki's comment regarding Basin A South, Mr. Lopez stated that Basin A South is only used if needed. Mr. Norby asked if Basin A South was included in Brown & Caldwell's analysis. Mr. Lopez said yes, however using Basin A South as storage is a last resort. Chair Pilecki asked staff to verify the information in Brown & Caldwell's report to understand the total volume capacity of the basins. Member McGill inquired about the Walnut Creek/Grayson Creek and whether the effort is to keep the water in the basins or is it to keep the water from flowing into the basins or is it both. Ms. Gemmell stated the project includes both. She explained that the District is currently going through the National Environmental Policy Act (NEPA) process in partnership with the Flood Control District and the design plans are 95 percent complete. December 21, 2023 Regular Board Meeting Agenda Packet- Page 453 of 461 Page 6 of 13 Engineering &Operations Committee Minutes December 11, 2023 Page 5 Chair Pilecki asked if the Walnut Creek/Grayson Creek project included the Pacheco slough. Ms. Gemmell said it does not, but staff is working on this internally and will be using the information provided by the Flood Control District. Mr. Bailey mentioned previous conversations with staff regarding where the biggest inflow and infiltration (1 & l) are coming from. He asked staff to determine how much additional flow is coming into the plant from the City of Concord. The problem is when the flow reaches a certain point, the meter shuts off and they are no longer being charged. He emphasized that this needs to be looked at as soon as possible. Mr. Bailey asked if there was a way to model when the system is receiving more 1 & 1 and where it is coming from. Mr. Norby indicated that representative data could be captured as seasons go on through technology and science. Member McGill thanked Mr. Norby for a thorough presentation. He suggested staff to try and anticipate a storm and inform the public on what Central San is doing to prevent wet weather disasters. Chair Pilecki mentioned that the public has interest in knowing what the District is doing in regard to climate change and what is being done to protect the plant. Chair Pilecki mentioned a topic for future discussion regarding the flow at the Moraga Pump Station and expressed concern about the ability to divert flows and install gates. Mr. Seitz stated that the gates are located at the treatment plant, and staff has over a decade of experience with installing the gates. He also said a plan on when to install the gates will be developed. COMMITTEE ACTION: Received the update. 5. Announcements Mr. Bailey informed the Committee of an upcoming meeting with the Bureau of Reclamation. December 21, 2023 Regular Board Meeting Agenda Packet- Page 454 of 461 Page 7 of 13 Engineering &Operations Committee Minutes December 11, 2023 Page 6 6. Suggestions for Future Agenda Items a. Receive list of upcoming agenda items and provide suggestions for any other future agenda items • Moraga Pump Station pumping capacity for wet weather conditions. COMMITTEE ACTION: Received the list and provided input to staff. 7. Future Scheduled Meetings Wednesday, January 3, 2024 at 8:30 a.m. Wednesday, February 7, 2024 at 8:30 a.m. Wednesday, March 6, 2024 at 8:30 a.m. 8. Adjournment— at 11:10 a.m. * Attachment December 21, 2023 Regular Board Meeting Agenda Packet- Page 455 of 461 December 11, 2023 titi Etta - -- Item 3.b. Laf;r�x#e - (Handout) CEDAR LANE o Detail SEWER Area MODIFICATIONS gaMm 25 Ueclar Ln y y 11 CEdw Ln 17 Ceder Ln 21 Cwbr Ln t I cedar Ln _ 6 Cal Lfi —— Engineering and Operations kL , 1 ti 10 Cedar Ln Committee Meeting cedar Ter y 28 cider Ln 4 y 14 Cedar Ln 22 C&er Ln 1 ti Edgar J. Lopez, P.E. + 18iarLn Division Manager r T 73C1-M�8 rt ; N y Sasha Mestetsky, P.E. Senior Engineer 59 Cedar Ter December 21, 2023 Regular Board Meeting Agenda Packet- Page 456 of 461 RP (111V Backgroundh � '4e Central San has sewers within easements along several properties on Cedar Lane and Cedar Terrace. i This 6" cast iron sewer main was installed in 1962 4 to serve five (5) properties. �r. 49 The easement is at a lower elevation from the houses and roadway. ' ' = Record storm events occurred late December '. n _ through January of 2023. 1x w s California declared a state of emergency in early _ January as..A. . -� r r :► � � - December 21, 2023 Regular Board Meeting Agenda Packet- Page 457 of 461 4'It� n Landslide On January 19, 2023, a landslide occurred at 10 and 14 Cedar Lane in Orinda. IN w - The landslide damaged the 6" sewer main at the side sewer connection and deposited soil and debris above the easement. The landslide disrupted service for 4 properties. R, - � . t The landslide left two properties unoccupied. .' '! .�..�. � � �� -. 1 `, rr�y '+�►� .sue - - y'� ._ - . +-•+r,-� �. Filar," AM Lk .�±; f J y �. J��• � 'jE��f rI SSA r •J r - December 21, 2023 Regular Board Meeting Agenda Packet- Page 458 of 461 r' CSO Response n -;•` _ Yf _fit^ r /V R CSO installed temporary lateral pumps for the two occupied properties. CSO continues to maintain these pumping t systems. �. r There is one property downstream of the - t damaged main and is still serviced by gravity. 7, _ + s a : _ I:J . �r y ? , i rq�rr. iT I� / G w • .fy y, mrJ. J •vim "SAS t E L 1 d 1 i 1:� • i - l 1 I k Y `R . ivy Y� December 21, 2023 Regular Board Meeting Agenda Packet- Page 459 of 461 e F: �/�• Engineering 5 l hi The District has been coordinating with FEMA and others. The damaged residence at 14 Cedar Lane was removed by the property owner by November L 2023 Soil and debris along the sewer easement were r not removed. Staff has preliminary evaluated multiple options for supplying permanent service for these S t. properties. Repair or replacement of the sewer in the easement is not recommended for safety concerns at this time. r _5! Staff recommends a project to further evaluate _ and provide permanent service to the impacted L customers. y December 21, 2023 Regular Board Meeting Agenda Packet- Page 460 of 461 d:'•=,. '`, w Questions? ,I A _ �e `P` ket- Page 461 of 461 =