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Compost Air Emissions. Association of Compost Producers Dec. 2, 2010. This Presentation. CalRecycle commitment to composting Past CalRecycle emissions studies Current CalRecycle emissions studies Compost and climate change Title 1, Title 5 and fugitive emissions.
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Compost Air Emissions Association of Compost Producers Dec. 2, 2010
This Presentation • CalRecycle commitment to composting • Past CalRecycle emissions studies • Current CalRecycle emissions studies • Compost and climate change • Title 1, Title 5 and fugitive emissions
The HierarchyCA Public Resources Code Section 40051 State and local government SHALL promote the following waste management practices in order of priority: • Source reduction. • Recycling and composting. • Environmentally safe transformation and environmentally safe land disposal…
Massive investment Private Private Public
CIWMB Strategic Directive 6.1Reduce organics sent to the landfill by 50% by 2020 Compostable organics Everything else Materialsstill going to California landfills
CalRecycle proactive efforts • 20 years of support for composting • Fund basic research on compost use and compost emissions • Work with stakeholders to determine reasonable best management practices • Work with other regulators to foster efficient, effective rulemaking
2002 CIWMB StudyTierra Verde Industries, Irvine, CA • High C:N windrow (67:1) emitted 63% less VOC than low C:N ratio windrow (22:1) • Turned windrows emitted more VOC than static windrows, but matured faster • Ammonia not a concern in green waste compost operations
2006 CIWMB StudyCity of Modesto Compost Facility • Measure life-cycle (60 days) VOC emissions for greenwaste and food waste windrows • Test efficacy of two potential emissions-reducing practices (BMPs) • Additives: one feeds microbes; other forms crust on windrow (Cost: $1.50 per ton) • Pseudo-biofilter: Cover “active” windrows with a layer of finished compost (60 cents per ton)
Windrows as seen from above Putting on the “pseudo-biofilter” compost cap
Modesto study conclusions • 70-80% of VOCs emitted during first two weeks of composting • 70-85% of VOC emissions vent through top of windrows as opposed to middle or sides • “Pseudo-biofilter” compost cap reduced VOC emissions up to 75% for first two weeks. • Additives reduced VOC emissions 42% for first week; 14% for first two weeks. • Greenwaste emissions factor @ 1 lb/ton • 15% food waste roughly doubled emissions
Wide range ofgreenwaste emissions factors Pounds of VOC per ton feedstock
Food waste likely toincrease emissions? Pounds of VOC per ton feedstock
2009-10 CalRecycle-led study4 Locations in the San Joaquin Valley • Not all VOCs make ozone; reactivity strongly impacts ozone formation • Focus on types of VOC and ozone formation, instead of how much total VOC • Compost emissions mostly alcohols, very weak ozone formation in all samples • 3-week old windrows slightly more potent than young windrows • Compost cap made of “overs” reduces ozone formation
Compost & Climate change • Organics in landfills release methane • Methane (CH4): GHG Factor 21 • Synthetic N fertilizers used in farming made from fossil fuels, release N2O • Compost piles also release methane and probably release N2O • Nitrous oxide (N20): GHG Factor 296 • ARB analysis shows very slight GHG benefit for composting
CalRecycle GHG Study • $450,000 contract with UC Davis • Study plan finalized November, 2010 • Will study CH4 & N2O from piles • Are there ways to reduce GHG emissions? • Will study impacts of compost use in ag lands, both alone and in conjunction with synthetic N use
Increasing compost use… …may decrease use of less sustainable methods.
The Backstory • Very low thresholds in bad-air basins for federal “major source” polluter status • San Joaquin Valley APCD saying all new compost facilities will go through Title 1 New Source Review • Will composters be subject to Title 5 permitting too?
What is Title I? • Authorized by federal Clean Air Act • Known as “New Source Review” • Applies to new or modified facility with an increase in 2 lbs. per day of pollutants • Requires facility to adopt “best available control technology” (BACT) • Even after BACT, facilities must purchase offsets for all emissions over threshold • VOC offsets run up to $40,000 per ton in SJV; many owned by oil companies
What is Title V? • Federal permit program, authorized by Clean Air Act, implemented by local air pollution control districts • Monitoring, record-keeping and reporting requirements • Fees to apply for, review & revise permit, and also for annual renewal • USEPA can inspect, issue fines • Opportunities for public input
Title V Permits are the same permits used for oil refineries, chemical factories, etc.
Fugitive emissions? • Fugitive emissions cannot “reasonably” be passed through a “stack, chimney, vent or functionally equivalent opening” • Fugitive emissions generally do NOT count toward a facility’sTitle I or Title V emissions threshold • USEPA guidance, but no case law • CalRecycle position: compost pile emissions ARE fugitive.
Robert.Horowitz@calrecycle.ca.gov 916-341-6523 http://www.calrecycle.ca.gov/Organics/Air/default.htm