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Solid Waste Management. David M. Crohn Department of Environmental Sciences University of California, Riverside. U. S. Waste Disposal. AB939. AB 939 Requires 50% diversion of waste to beneficial uses by the end of this year (2000). U. S. Waste Production. U. S. Waste Production.
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Solid Waste Management David M. CrohnDepartment of Environmental SciencesUniversity of California, Riverside
AB939 AB 939 Requires 50% diversion of waste to beneficial uses by the end of this year (2000)
United States MSW, 1996 USEPA, 1998
California MSW Disposal and Diversion CIWMB, 2000
AB 939 and California MSW Diversion CIWMB, 2000
Shasta County • West Central Landfill • Managed by City of Redding • 17 years permitted space • 65 years potential space • Abernathy Lane Compost Facility • 1998 diverted 38% of waste stream • Also Anderson Landfill • Commercial • Managed by Waste Management, Inc. • Co-Generation Facility
Why Compost? • To eliminate disease organisms • Animal • Plant • Human • To produce a stable soil amendment • Nutrients • Odors
Why Use Compost? • To control disease • To hold nutrients • To promote good aeration • To manage water • To replace more expensive materials
Concerns Are Manageable • Communicates disease? • Immobilizes nutrients? • Weeds? • Trash? • Phytotoxicity? • Uncertain fertilizer potential?
Aerobic Processes Microbes, Carbon, & Oxygen Carbon Dioxide, Water, Compost, &Heat
Air Movement CO2, H2O O2 O2
Problems Are Avoidable Composts should be • Heated thoroughly • Well-cured • Screened to • Proper particle size • Clear trash
Typical Compost Composition Composting Council, 1996
Permitted (metals, pathogens, and ash standards) Feedstocks Used % Moisture % Organic matter Salinity Bulk density pH Particle size California Compost Quality Council (CCQC) Parameters
Biosolids Metals Limits Ceiling Cum. Clean Container Conc. Load Conc. Limit Pollutant mg/kg kg/ha mg/kg kg/ha-yr Arsenic 75 41 41 2.0 Cadmium 85 39 39 1.9 Copper 4300 1500 1500 75 Lead 840 300 300 15 Mercury 57 17 17 .85 Molybdenum 75 - 18 .90 Nickel 420 420 420 21 Selenium 100 100 36 5.0 Zinc 7500 2800 2800 140
Restrictions on Class B Amended Soils • For 1 month • no harvesting of food, fiber, or seed crops • no grazing of animals • no public access (low exposure areas) • For 1 year • no turf harvesting for high exposure areas • no public access (high exposure areas)
Restrictions on Class B Amended Soils (cont’d) • For 14 months • no harvesting of aboveground food crops with sludge contact • For 20 months • no harvesting of below-ground food crops if sludge is on ground more than 4 months • For 38 months • no harvesting of below-ground food crops if sludge is on ground less than 4 months
Conclusions • California does not face an immediate crisis • Depends on cooperation of Agriculture to meet its needs