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Home My WebLink About16.a. Receive update for the District’s response to the Wet-Weather events from December 2022 to January 2023Item 16.a. May 4, 2023 T O: HO NO R A B L E B O A R D O F D I R E C TO R S F RO M :PA UL S E I T Z , C O L L E C T I O N S YS T E M O P E R AT I O NS D I V I S I O N MA NA G E R RE V IE WE D B Y:NE I L ME YE R, P R O V I S I O NA L D I R E C TO R O F O P E R AT I O NS R O G E R S. B A I L E Y, G E NE R A L MA NA G E R S UB J E C T: R E C E I V E UP D AT E F O R T HE D I S T R I C T ’S R E S P O NS E TO T HE W E T- W E AT HE R E V E NT S F R O M D E C E MB E R 2022 TO J A NUA RY 2023 T his presentation will provide the C ommittee with additional inf ormation regarding the response activities related to the storm events f rom late D ecember 2022 to mid-J anuary 2023. Strategic Plan Tie-I n G O A L O N E: Customer and C ommunity Strategy 1 – Deliver high-quality customer service G O A L TW O: Environmental Stewardship Strategy 1 - Achieve compliance in all regulations G O A L S I X: I nfrastructure Reliability Strategy 1 - Manage assets optimally AT TAC HM E NT S : D escription 1. P resentation May 4, 2023 Regular Board Meeting Agenda Packet - Page 148 of 218 Page 1 of 14 1 WET WEATHER RESPONSE December 2022– January 2023 Board of Directors Meeting May 4, 2023 Paul A. Seitz Collection System Operations Division Manager Introduction 2 •Six storms brought hazardous conditions to the Bay Area from December 26, 2022, to January 17, 2023 May 4, 2023 Regular Board Meeting Agenda Packet - Page 149 of 218 Page 2 of 14 2 Introduction (continued) •Our service area experienced 10–20 inches of rain during the late December to early January storm events •Storm events were referred to as “Bomb Cyclones” and “Atmospheric Rivers” •Three weeks were the wettest in the Bay Area since 1862, 161 years •In California, these events caused 700 landslides, approximately 30 billion dollars in damages, and 20 deaths •In general: •There were no Sanitary Sewer Overflows (SSOs) in the collection system or at the pumping stations •Our treatment plant experienced high flows and bypassed the basins while not violating any permit conditions •This presentation will provide the committee with additional details concerning Central San’s response to the storm events 3 Collection System •Division 1 – Pleasant Hill and Martinez •No SSO in Division 1 •New site list: •F Street, Martinez – to Engineering (ENG) •Foot bridge and storm drain failure •Hawthorne Road, Pleasant Hill •Pipe exposed in creek channel •Assisted at Subdivision 6, Stonehurst Waste Treatment Plant, Martinez •High flows from storm water 4 May 4, 2023 Regular Board Meeting Agenda Packet - Page 150 of 218 Page 3 of 14 3 Collection System •Division 2 – Lafayette, Moraga, and Orinda •No SSO in Division 2 •New site list: •Poppy Lane, Orinda – to ENG •Creekbank failure •Cricket Hill, Orinda – to ENG •Pipe exposed in creek channel •Green Hills Road, Lafayette •Storm drain failure •Cedar Lane, Orinda – to ENG •Slide that caused structure damage •Sleepy Hollow Lane, Orinda – to ENG •Erosion at creek crossing support •Crescent Drive, Orinda •Slide near manhole •La Espiral, Orinda – site added since Engineering and Operations Committee Meeting •Slide near sewer main 5 Collection System •Division 2 – Lafayette, Moraga, and Orinda (continued) •Existing site list: •Hall Drive, Orinda – to ENG •Storm drain failure •St. Mary’s Culvert, Moraga •Continued maintenance for storm events •Tappan Terrace, Orinda – to ENG •Continued monitoring of existing slide 6 May 4, 2023 Regular Board Meeting Agenda Packet - Page 151 of 218 Page 4 of 14 4 Collection System •Division 3 – Walnut Creek •No SSO in Division 3 •New site list: •Citrus Creek Crossing, Walnut Creek – to ENG •Erosion at creek crossing •Quandt Drive, Walnut Creek •Slide covering manhole •Holly Hill, Walnut Creek •Slide near rodding inlet •Blade Court, Walnut Creek •Slide near sewer main •Existing site list: •Tice Creek Culvert, Walnut Creek •Sewer through culvert 7 Collection System •Division 4 – Danville •No SSO in Division 4 •New site list: •Montair Drive, Danville •Creekbank failure near sewer main •Green Valley Road, Danville •Tree fell on creek crossing •Canyon Hills, Danville •(2) Slides at Canyon Lakes Golf Course near sewer main •Roberts Court, Danville •Creekbank failure near sewer main 8 May 4, 2023 Regular Board Meeting Agenda Packet - Page 152 of 218 Page 5 of 14 5 Collection System •Division 5 – San Ramon •No SSO in Division 5 •There are no new or existing sites in San Ramon that are being monitored by Collection System Operations (CSO) 9 Plant Operations 10 •Rain and Elevated Flows December 26 – January 17 •Ground saturated •Large single day totals •Multi-day events •Each storm/event building on top of the prior rain Danville Library Orinda FS 43 Ygnacio Valley FS DATE PPT INCHES PPT INCHES PPT INCHES 12/26/22 0.19 0 0.20 12/27/22 2.15 2.02 1.27 12/28/22 0 0.01 0 12/29/22 0.47 0.32 0.32 12/30/22 1.59 1.75 0.56 12/31/22 5.14 4.49 3.23 1/1/23 0 0.01 0 1/2/23 0.48 0.48 0.34 1/3/23 0.05 0.05 0 1/4/23 0.95 0 1.20 1/5/23 1.00 0 0.56 1/6/23 0.01 0 0.01 1/7/23 0.09 0.20 0.11 1/8/23 0.74 0.29 0.56 1/9/23 1.66 2.22 1.13 1/10/23 1.15 1.07 0.67 1/11/23 0.47 0.39 0.22 1/12/23 0 0 0 1/13/23 0 0 0 1/14/23 1.77 2.08 1.39 1/15/23 0.97 1.25 0.68 1/16/23 0.86 0.83 0.59 1/17/23 0 0 0 Flow Station (FS) Precipitation (PPT) May 4, 2023 Regular Board Meeting Agenda Packet - Page 153 of 218 Page 6 of 14 6 On December 31: •Very high influent flows •Already received 4-5” of rain since December 26 •Received additional 3.5-6” on December 31 across the service area •Influent Pump #4 (75 million gallons per day (MGD)) was out of service/offsite •Influent flow peaked at 239 MGD at 3pm 11 Plant Operations Wet Weather Basins •Very near basin capacity •Basin A North – 18.6 million gallons (MG) •Basin A South – 18.1 MG •Basin B – 93.5 MG •Basin C – 33.9 MG •Basin D – 7.8 MG •172 MG total capacity with 6” freeboard 12 Plant Operations B A South C D A North May 4, 2023 Regular Board Meeting Agenda Packet - Page 154 of 218 Page 7 of 14 7 January 16: •Near or at capacity in Basin B, Basin C, and Basin A North •Pumping from Basin C into Basin D •CSO staff cut trench across gravel road to allow water to gravity from Basin C into Basin D •Filling Basin A South from 5pm to 11:30pm on January 16 •Plant influent flow dropped under 110 MGD at 11:30pm on January 16 13 Grayson Creek looking Southeast Plant Operations •January 15 at 5pm-6pm 14 Plant Operations May 4, 2023 Regular Board Meeting Agenda Packet - Page 155 of 218 Page 8 of 14 8 •January 16at 4:30pm & 6:00pm 15 Plant Operations •January 18 16 Plant Operations May 4, 2023 Regular Board Meeting Agenda Packet - Page 156 of 218 Page 9 of 14 9 Plant Maintenance Pumping Stations Operations •Pumping Stations Normal Flows vs Wet Weather Flows 17 Pumping Stations Normal Flow [MGD] Wet Weather Flow [MGD] Operation 1/3-6/2023 Operation 1/8-12/2023 Martinez 1.0 6.0 3 WW pumps 2 WW pumps San Ramon 2.5-3.0 10.8 3 WW pumps 1 WW pump Moraga 1.0 14.4 1 WW, 1DW 3 DW pumps Crossroads 8.0 14.4 1 WW pump 3 DW pumps Wet Weather (WW) Dry Weather (DW) Plant Maintenance Before Wet Weather •Preventative Maintenance (PM) Program •Wet Weather Preparation •Sandbagged electrical substations •Cleaned out storm drains, area drains, and gutters •Tree trimming throughout plant site by Expert Tree •Checked operation of basin sump pumps •Evaluate Standby Coverage •Check/Test Standby Equipment •Checked Pumping Stations Equipment Fuel •Portable generators, bypass pumping, and fuel trailer 18 May 4, 2023 Regular Board Meeting Agenda Packet - Page 157 of 218 Page 10 of 14 10 Plant Maintenance During Wet Weather •Expanded Standby Coverage •Pumping Stations had all available crew members on standby •Doubled the amount of plant maintenance on call staff •Call outs – 155 Hours Total •Buildings & Grounds – 6 Call outs •Mechanical – 5 Call outs •Electric – 3 Call outs •Instrument – 6 Call outs 19 Plant Maintenance Between Wet Weather •CSO Vacuum Truck - Grit Removal •PM/Corrective Work •Replaced and rebuilt rake teeth •Removed packed grit in washer compactor and sluice troughs 20 May 4, 2023 Regular Board Meeting Agenda Packet - Page 158 of 218 Page 11 of 14 11 21 Engineering – Capital Projects Collection System: •Worked with CSO on several sites through the service area. •Monitored ongoing construction projects in Walnut Creek and Danville. •Pumping Station Phase 1 completed, Orinda Crossroads and Flushkleen performed as designed and still had capacity. •However, Moraga Pumping Station was at 100% capacity and handled high flows. Station is being evaluated. 22 Engineering – Capital Projects Treatment Plant: •Expedited repair on motor for Pump No. 4 at Headworks. •Installed motor on January 4 and in service January 5. •Improvements on Influent Pump Electrical Project were fully tested and performed as designed! •Monitored ongoing construction projects, especially Filter Plant Improvements. •Assisted Operations with bar screen failure at Headworks. May 4, 2023 Regular Board Meeting Agenda Packet - Page 159 of 218 Page 12 of 14 12 Engineering – Capital Projects 23 LESSONS LEARNED: •Re-evaluate and develop new strategies with Operations to handle the intensity of the rain events experienced. •Develop and implement wet weather basin and collection system management system for Operations. WHAT’S NEXT: •Incorporate information to projects such as the Wet Weather Basin Improvements, Ultraviolet (UV) Disinfection Replacement, Filter Plant & Clearwell Improvements, etc. •Include staff’s input and potential new scope for projects at Headworks, Supervisory control and data acquisition (SCADA), and other locations at the treatment plant for the next Capital Improvements Budget 2024. Lessons Learned 24 LESSONS LEARNED: •Important to be up to date with Preventative Maintenance •Ensure emergency equipment is ready to be deployed and pre-stage as much as possible •Allocate additional on-call staffing •Improve monitoring and transfer of flow between wet weather basins •Prepare for large amounts of grit to be received •Increase Plant capacity when there is an opportunity May 4, 2023 Regular Board Meeting Agenda Packet - Page 160 of 218 Page 13 of 14 13 Questions 25 May 4, 2023 Regular Board Meeting Agenda Packet - Page 161 of 218 Page 14 of 14