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

page 7

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

page 10

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

page 13

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

page 15

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