HomeMy WebLinkAbout09.b. Receive the 2023 National Pollutant Discharge Elimination System Annual ReportItem 9.b.
F ebruary 22, 2024
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 :A L A N W E E R , P L A NT 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:G R E G NO R B Y, D E P UT Y G E NE R A L MA NA G E R - 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 T HE 2023 NAT I O NA L P O L L UTA NT D I S C HA R G E E L I MI NAT I O N
S YS T E M A NNUA L R E P O RT
T he 2023 National P ollutant Discharge E limination System (NP D E S ) A nnual R eport was submitted to the
C alif ornia Regional Water Quality Control Board, San F rancisco Bay Section, on J anuary 31, 2024.
Plant Operations Division Manager A lan Weer will present the highlights f rom the annual report.
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
AT TAC HM E NT S :
D escription
1. P resentation
February 22, 2024 Special Board Meeting Agenda Packet - Page 65 of 128
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2023 National
Pollutant Discharge
Elimination System
Annual Report
Board of Directors Meeting
Alan R. Weer
Plant Operations Division Manager
February 22, 2024
2023 National Pollutant Discharge
Elimination System Annual Report
Carbonaceous Biochemical Oxygen Demand
•A measure of oxygen used by microorganisms
Enterococci
•A measure of bacteria
Total Suspended Solids
•A measure of suspended particles
Bioassay
•A measure for evaluating the potential harmful
effects of effluents discharged into surface waters
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ATTACHMENT 1
February 22, 2024 Special Board Meeting Agenda Packet - Page 66 of 128
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Total Influent Flow Treated = 15.9 billion gallons (12.4 in 2022)
Average Daily Effluent Flow = 42.7 million gallons (32.5 in 2022)
Average Daily Influent Flow = 43.5 million gallons (33.9 in 2022)
Peak Hourly Flow = 160 million gallons per day (MGD) on January 16, 2023
(166 MGD on December 31, 2022)
Average Dry Weather Flow = 31.5 MGD (30.9 MGD in 2022)
Ash Disposal = 3,220 tons (wet weight for soil amendment), (3,510 tons in 2022)
2023 National Pollutant Discharge
Elimination System Annual Report
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2023 National Pollutant Discharge
Elimination System Annual Report
Average dry weather flow (ADWF): the average daily influent flow from the three lowest consecutive influent flow months
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25
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2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023
MG
D
Average Dry Weather Flow and Annual Average Influent Flow
Average Dry Weather Flow (MGD)
Annual Average Influent Flow (MGD)
February 22, 2024 Special Board Meeting Agenda Packet - Page 67 of 128
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2023 National Pollutant Discharge
Elimination System Annual Report
•Carbonaceous Biochemical Oxygen Demand
•Monthly Average (AVG) (mg/L,
milligrams per liter) = 6.7 mg/L (Limit = 25 mg/L)
•% Removal AVG = 96.1% (Limit = Minimum of 85%)
•Total Suspended Solids
•Monthly AVG (mg/L) = 8.6 mg/L (Limit = 30 mg/L)
•% Removal AVG = 95.8% (Limit = Minimum of 85%)
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2023 National Pollutant Discharge
Elimination System Annual Report
•Enterococcus
•90th Percentile MAX = 162 MPN/100 mL (Limit = <1,100 MPN/100 mL)
•6-Week Rolling Avg MAX = 26 MPN/100 mL (Limit = <290 MPN/100 mL)
•Acute Bioassay
•3-Sample Median MIN = 100% (Limit = >90%)
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Most Probable Number (MPN) Milliliter (mL) Maximum (MAX) Minimum (MIN)
February 22, 2024 Special Board Meeting Agenda Packet - Page 68 of 128
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2023 National Pollutant Discharge
Elimination System Annual Report
•100 percent compliance with National Pollutant Discharge Elimination System
Permit requirements
•National Association of Clean Water Agencies Platinum Award – 26th
consecutive year
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Environmental Laboratory
Operations Department
Engineering Department
Administration Department
Board of Directors
Acknowledgements
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February 22, 2024 Special Board Meeting Agenda Packet - Page 69 of 128
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Recommendation
Receive the 2023
National Pollutant Discharge
Elimination System Annual Report
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February 22, 2024 Special Board Meeting Agenda Packet - Page 70 of 128
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