COMPONENTS FOR SUCCESSFUL COMPOST FACILITY OPERATIONS SCAP Biosolids Committee Meeting August 2, 2012
Feb 23, 2016
COMPONENTS FOR SUCCESSFUL COMPOST FACILITY OPERATIONSSCAP Biosolids Committee MeetingAugust 2, 2012
page 2
AGENDA
• Facility Siting Considerations• Composting Technologies• Permitting• Regulatory Compliance• Process Control• Compost Quality
page 3
FACILITY SITING CONSIDERATIONS
• Location, Location, Location!– Regulations– Nearby Compost Market– Sensitive Receptors
• Public Education/Politics– Education Begins Early– Keep it Simple– Remember the Benefits
• Diversion• Soil Enhancement• Erosion Control
– Don’t ignore the public/politics
page 4
COMPOSTING TECHNOLOGY
• Windrow• Negative Aerated Static Pile with
Biofiltration• In-vessel
page 5
COMPOSTING TECHNOLOGY: Negative Aerated Static Pile Composting
page 6
COMPOSTING TECHNOLOGY: Negative Aerated Static Pile Composting
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PERMITTING
• Local Conditional Use Permit• CEQA• CA Solid Waste Facility Permit
– Report of Compost Site Information– Odor Impact Minimization Plan
• Regional Water Quality Control Board• Local Air District Permit• U.S. EPA Registration
page 8
REGULATORY
• Inbound Materials Monitoring– Biosolids– Carbon Feedstocks
• Process Water Management• Ground Water Monitoring• Special Occurrences• Source Testing• Compost Sampling
– C.C.R. Title 14, Chapter 3.1, Article 7• Metals Concentrations (max)• Pathogen Reduction (PFRP) • Sampling Requirements
page 9
PROCESS CONTROL PARAMETERS
• Control Points– Feedstock Handling– Mix Ratios– Moisture– Aeration Rates– Temperature/PFRP
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THE COMPOSTING PROCESS
Feedstocks
Microorganisms
OxygenWater
Compost
CO2WaterOdors?
Heat
page 11
COMPOST FACILITY FEEDSTOCK-PROCESS-MARKETIdentify and
quantify Feedstocks
Analyze Markets
Develop and adjust recipes
Collect or receive feedstocks
Process:Grind, Mix, Compost,
Cure, Screen, etc.
Market and distribute
AssessCompost Facility
Start here or
here
page 12
THE KEY PROCESS VARIABLES for Control of the Composting Process
1. Initial feedstock mix2. Pile moisture3. Pile aeration4. Pile shape and size5. Pile temperature6. Composting retention time
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FEEDSTOCKS: YOUR RAW MATERIAL
• Chemical Composition– Organic Matter, Nutrients, Degradability
• Physical Characteristics– Moisture, Bulk density, Heterogeneity
• Other– Contamination, Cost, Availability, Regulations
page 14
FEEDSTOCK SUMMARY
• Each feedstock has certain attributes• The RECIPE is how feedstocks are combined• Composting system designed for feedstocks• Regulations are always partly based on feedstock
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OTHER CONSIDERATIONS
• Health & Safety• Initial Mix Ratios• Moisture• Aeration• Temperature• Time• Curing/Maturity• Testing
page 16
SUMMARY: Key Initial Parameters for Composting
Condition Reasonable range Preferred range Moisture % 40 — 65 50 — 60 C:N 20:1 — 60:1 25:1 — 40:1 Oxygen % Greater than 5 Greater than 10 Temperature oF oC
113 — 160 45 -- 71
120 — 150 49 -- 66
pH 5.5 — 9.0 6.5 — 8.0 Particle size 1/8 to 2 inches
.3-5 cm Depends on feedstocks
and use for compost Porosity:
Bulk density lbs/ yd3
(kg/l)
Free Air Space %
Less than 1200
(.7) 40-60
800-1000 (.45-.6) 50-60