S.F. Bay Area Biosolids How Much are We Talking About? Presented By: Jim Sandoval, CH2M HILL June 2, 2008 BACWA Biosolids Workshop Photo By:

Overview  Infrastructure  Production  Management

Infrastructure Infrastructure

Current Biosolids Infrastructure in the Nine-County Bay Area  55 municipal wastewater treatment plants (WWTPs) –Operated by 53 wastewater treatment agencies –Together treated an est. avg. dry weather flow (ADWF) of 660 million gallons per day (mgd) in 2003 –Produced est. 504 dry tons per day (dtpd) biosolids in 2003  i.e. 184,000 dry tons per year (dtpy)

Bay Area WWT by County (2003) COUNTYADWF(MGD) BIOSOLIDS PRODUCTION (dtpy) Alameda ,300 Contra Costa ,200 Marin20.35,300 Napa17.24,300 San Francisco ,000 San Mateo ,300 Santa Clara 14559,900 Solano43.211,000 Sonoma39.411,600 TOTALS660183,900

Influent Data (2003)  Range of WW flow rates received at plants –0.3 mgd at the City of St. Helena –100 mgd at the San Jose/Santa Clara Water Pollution Control Plant  The average WWTP flow treated in Bay Area was 12.5 mgd

Biosolids Data (2003)  Range of solids contents of treated biosolids –4% solids at Dublin-San Ramon Services District  biosolids are dredged from facultative lagoons & injected into a dedicated land disposal site –85% solids at Oro Loma Sanitary District  biosolids are dried in solar drying beds  Many plants use mechanical dewatering (e.g. belt filter presses or centrifuges) –solids contents % –Vallejo Sanitation & Flood Control District yielded 32% using lime- stabilized biosolids & belt filter presses  Plants that nitrify ammonia & filter effluent had higher biosolids production rates –e.g. San Jose/Santa Clara WPCP dry tons per million gallons treated –Plants that do not nitrify or filter - average of 0.62 dry tons per million gallons treated

Production

Population Projections (2003)  Bay Area WW agencies served approx million people –Approx. 95% of the nine-county population  By 2010, 7.08 million people  By 2030, 7.72 million people –15.6% increase over 2003

Breakdown of Population Served in each County County Increase( ) Alameda1,449,0001,544,0001,583,0001,645,0001,709, % Contra Costa 881,000916,000936,000989,0001,041, % Marin247,000252,000254,000264,000272, % Napa112,000116,000121,000128,000133, % San Francisco 777,000790,000799,000813,000827,0006.4% San Mateo 669,000686,000694,000715,000741, % Santa Clara 1,697,0001,762,0001,805,0001,907,0001,999, % Solano380,000407,000426,000458,000496, % Sonoma429,000450,000463,000490,000504, % TOTALS POP SERVED 6,681,0006,923,0007,081,0007,409,0007,722, % BAY AREA POP. 7,030,0007,194,0007,405,0008,045,0008,657, % Source: Association of Bay Area Governments (ABAG)

Distribution by County of Population Served in 2003

Biosolids Production Projections  Future biosolids production rates estimated using: –Current biosolids production rates –Projected population growth  Projected biosolids production growth: –183,900 dry tons in 2003 (i.e. 504 dtpd) –192,600 dry tons in 2008 (i.e. 528 dtpd) –229,000 dry tons in 2030 (i.e. 626 dtpd) –19% increase from 2008 to 2030  Projected biosolids production > projected population increase…why? –Much of the population growth will occur in service areas that require nitrification of ammonia and filtration (e.g. San Jose/Santa Clara)

Estimated Biosolids Production Rates (dtpy) County Increase( ) Alameda30,30030,80032,00034,60037, % Contra Costa 28,20028,70030,20033,10034, % Marin5,3005,4005,7006,0006, % Napa4,3004,4004,6004,9005, % San Francisco 22,00022,20022,60023,60025, % San Mateo 11,30011,50011,70012,70013, % Santa Clara 59,90061,30064,60071,60077, % Solano11,00011,40012,20014,00015, % Sonoma11,60011,80012,40013,20013, % TOTALS183,900187,500196,000213,700229, % Daily Production % *Total volume generated in California in 2007 was 799,000 dtpy

Review of Biosolids Classes CFR Title 40, Part 503  Class A biosolids –Treated to reduce pathogens to below detectable levels –Can be used without pathogen-related restrictions at application site –Can be bagged and sold to the public, if other requirements are met  Class B biosolids –Treated to reduce pathogens but still contain detectable levels –Have site restrictions to minimize the potential for human and animal exposure until environmental factors, such as heat, sunlight, and desiccation, have reduced pathogens further –Cannot be sold or given away in bags or other containers or used at sites with public use  Sewage sludge that is not treated to meet land-application standards –Disposed at landfills –Disposed at surface disposal sites that contain only sewage sludge –Incinerated

Class A and Class B in the Bay Area  Most Bay Area WWTPs produce Class B biosolids  Some plants produce Class A with biosolids solar drying beds –Solar drying not explicitly listed as a Class A process under Part 503 Rule –Requires special testing to verify Class A standards met

Distribution of Class A and Class B in the Bay Area (2006) Source: EPA Region 9

Distribution of Class A and Class B in the California (2006) Source: EPA Region 9

Management Management

Bay Area Biosolids Management Practices  Bay Area WWTPs manage biosolids in many ways  Most biosolids managed by private companies –Applied to agricultural and pasture land to improve soil conditions –Hauled to landfills for use as alternative daily cover (ADC) Disposed of in landfills

Bay Area Biosolids Management Practices  Other practices: –Incineration  Palo Alto RWQCP & Central Contra Costa Sanitary District  Ash disposed in landfills –Dedicated land disposal sites  DSRSD & Novato Sanitary District  Owned/used these sites many years

Distribution of Reuse/Disposal Options California vs. Bay Area Source: EPA Region 9

California Biosolids Management Practices  Trends: –Southern California agencies, rely heavily:  Land application  Compost –Northern California agencies, combination:  Landfill ADC/disposal  Land application  Incineration

End Uses in Bay Area by County Source: EPA Region 9 Bulk for landfill uses

Closing – The Common Thread  Diverse array of options utilized in California for biosolids reuse & disposal  Frequently, agencies use multiple options for robust programs  Land application –Plays a significant role in reuse –Viewed as highest & best use for Class B biosolids  Bay Area agencies seeking innovative new outlets for biosolids reuse –Changing political & regulatory trends: ADC & land app. –Limited capacities –Today’s subsequent presentations…

Questions? Questions?

Backup Slides  The average cost of biosolids management in 2003: –$21.71 per wet ton at 20% solids concentration  or $ per dry ton –Prices ranged from $5.50 per wet ton to $52 per wet tons  Dedicated land disposal and incineration operations have costs similar to the costs incurred by agencies that dewater or dry biosolids