HomeMy WebLinkAbout12.a. Receive 2022 National Pollutant Discharge Elimination System annual report Page 1 of 6
Item 12.a.
CENTRALSAN
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CENTRAL CONTRA COSTA SANITARY DISTRICT
March 2, 2023
TO: HONORABLE BOARD OF DIRECTORS
FROM: ALAN WEER, PLANT OPERATIONS DIVISION MANAGER
REVIEWED BY: PAUL SEITZ, PROVISIONAL DIRECTOR OF OPERATIONS
ROGER S. BAILEY, GENERAL MANAGER
SUBJECT: RECEIVE THE 2022 NATIONAL POLLUTANT DISCHARGE ELIMINATION
SYSTEM ANNUAL REPORT
The 2022 National Pollutant Discharge Elimination System (NPDES)Annual Report was submitted to the
California Regional Water Quality Control Board, San Francisco Bay Section, on January 27, 2023.
Plant Operations Division Manager Alan Weer will present the highlights from the annual report.
Strategic Plan re-In
GOAL ONE: Customer and Community
Strategy 1—Deliver high-quality customer service
GOAL TWO: Environmental Stewardship
Strategy 1 -Achieve compliance in all regulations
ATTACHMENTS:
1. Presentation
March 2, 2023 Regular Board Meeting Agenda Packet- Page 77 of 313
Page 2 of 6
2022 National
Pollutant Discharge
Elimination System
Annual Report
Board of Directors Meeting
March 2,202374
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Alan R.Weer
Plant Operations Division Manager
2022 National Pollutant Discharge
Elimination System Annual
Report
CBOD—Carbonaceous Biochemical Oxygen Demand
A measure of oxygen used by microorganisms
Entero—Enterococci
A measure of bacteria
1
TSS—Total Suspended Solids
A measure of suspended particles f
Bioassay
A measure for evaluating the potential harmful
effects of effluents discharged into surface waters
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March 2, 2023 Regular Board Meeting Agenda Packet- Page 78 of 313 1
Page 3 of 6
!1:
Highlight of Changes the is
New Permit
New permit effective August 1,2022-July 31,2027
Enterococcus monitoring parameters changes(no changes to
frequency)
Previously,monthly geometric mean(not to exceed 35 MPN(most
L .
probable number)/100 mL(milliliter))
Now,
Six-week rolling geometric mean evaluated weekly(not to
exceed 290 MPN/100 mL)
Monthly limit not to exceed 1,100 MPN/100 mL for>_10%of
samples
Acute bioassay frequency reduced from monthly to quarterly
Previously,11-sample Median and 11-sample 90th Percentile
Now,3-sample Median
s
Ammonia mass effluent limit(still in the permit but will sunset)
Will be superseded by limits in Nutrient Watershed Permit;
expected 2024
2022 National Pollutant Discharge
Elimination System Annual Report
Total Influent Flow Treated = 12.4 billion gallons (12.6 in 2021)
Average Daily Effluent Flow= 32.5 million gallons (33.1 in 2021)
Average Daily Influent Flow= 33.9 million gallons (34.6 in 2021)
Peak Hourly Flow= 166 MGD (million gallons per day)on December 31, 2022
(174 MGD on October 24, 2021)
Average Dry Weather Flow= 30.9 MGD (29.5 MGD in 2021)
Ash Disposal = 3,510 tons (wet weight for soil amendment), (3,627 tons in 2021)
n
March 2, 2023 Regular Board Meeting Agenda Packet- Page 79 of 313 2
Page 4 of 6
2022 National Pollutant Discharge
Elimination System Annual Report
Average Dry Weather Flow and Annual Average Influent Flow
50
45
40
0 35
C7
230
25
20
15
2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022
—Average Dry Weather Flow (MGD) —Annual Average Influent Flow(MGD)
ADW F(average dry weather flow):the average daily influent flow from the three lowest influent flow months
s
2022 National Pollutant Discharge
Elimination System Annual Report
'i
Carbonaceous Biochemical Oxygen Demand (CBOD)
Monthly Average(AVG)(mg/L,
milligrams per liter)=7.3 mg/L (Limit=25 mg/L)
Removal AVG=96.4% (Limit=Minimum of 85%)
Total Suspended Solids (TSS) 1001-1`
.046W..
Monthly AVG(mg/L)=9.7 mg/L (Limit=30 mg/L) yF
%Removal AVG=95.9% (Limit=Minimum of 85%) ti r � j5•
March 2, 2023 Regular Board Meeting Agenda Packet- Page 80 of 313 3
Page 5 of 6
2022 National Pollutant Discharge
Elimination System Annual Report
Enterococcus
January-July 2022(Old Permit)
Monthly Geometric Mean MAX=9 MPN/100 mL (Limit=<35 MPN/100 mL)
August-December 2022(New Permit)
901h Percentile MAX=10 MPN/100 mL (Limit=<1,100 MPN/100 mL)
6 Week Rolling Avg MAX=4 MPN/100 mL (Limit=<290 MPN/100 mL)
Acute Bioassay
January-July 2022(Old Permit)
I
11-Sample Median MIN=100% (Limit=>90%) _
11-Sample 901h Percentile MIN=95% (Limit=>70%)
August-December 2022(New Permit)
3-Sample Median MIN= 100% (Limit=>90%)
MAX(maximum) MIN(minimum)
2022 National Pollutant Discharge
Elimination System Annual Report
100 percent compliance with National Pollutant Discharge Elimination System
Permit requirements
NACWA Platinum Award —25th Consecutive Year
Peak
Performance 00�
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^ A W A R D S Water Boards
March 2, 2023 Regular Board Meeting Agenda Packet- Page 81 of 313 4
Page 6 of 6
Acknowledgements
Environmental Laboratory
Operations Department
Engineering Department
Administration Department
Board of Directors-61 1 e_�Vn a w w III A
= _ y
Recommendation
Receive the 2022
National Pollutant . •
• . � ' • •
t
r
March 2, 2023 Regular Board Meeting Agenda Packet- Page 82 of 313 5