Efficient New Technology to

Improve Missouri’s Largest

Biosolids Composting Operation

Bill Malach, P.E.

City of St. Peters, Missouri

Presentation Overview

Background & History of Facility

Evolution of Organic Resource Recycling in

St. Peters

Implementation of Aerated Static Pile

Composting Facility

Capital Investment, Operating Costs,

Revenues

Sustainable Markets for Biosolids Compost

Biosolids:

The nutrient-rich organic materials resulting

from the treatment of domestic sewage at a

wastewater treatment facility.

When treated and processed, sewage sludge

becomes biosolids which can be safely

recycled and applied as soil amendment to

sustainably improve and maintain

productive soils and stimulate plant growth.

City of St. Peters Population

1970 470

1980 17,029

1990 45,779

2000 51,381

2010 56,500

0

20,000

40,000

60,000

1970 1980 1990 2000 2010

Population

Compost Facility

6 MGD Water Plant

9.5 MGD Wastewater Plant

Compost Facility

Recycling Center/

Transfer Station

Headworks

Oxidation Basins

Aerated Sludge

Holding

Final Clarifiers

UV Disinfection

Dewatering Building

Biofilters

ASP Composting

Evolution of Organic Resource

Recycling Program

Started with Liquid Biosolids Land

Application Program in 1980’s

Pilot Biosolids/Yardwaste Composting

Project 1997 to 2000

Full Scale Windrow Composting in 2001

Aerated Static Pile Composting in 2010

Liquid Land Application

Program (1980 -2009)

Applied 5 Million Gallons Annually

1,200 Dry Tons of Biosolids

Required 450 Acres Annually

Over 1,200 Acres in Program

200 Acre City-owned Farm

Partnership with Farmers

Problems with Liquid Biosolids

Application Program

Dependent on Private Ground

Seasonal Application & Weather Dependent

Class “B” Biosolids Regulation Restrictions

Odors Released During Lagoon Mixing &

Pumping Operations

Benefits of Composting

EPA Approved Process to Further Reduce

Pathogens to Produce Class “A” Material

Creates a Marketable Product

Reduces Dependency on Private Land

Generates Income to Offset Expenses

Sustainable Recycling Process that is

Environmentally Beneficial

St. Peters Organic Feedstocks

30,000 -50,000 CY of Yard Waste

Curbside Collection & Drop-off

Branches, Leaves, Grass

6,000 Wet Tons of Biosolids

Drop-Off Area

First Step is Grinding

Biosolids Dewatering/Mixing

Biosolids Dewatering

Mixing

Mixing by Weight Proportion for

Targeted C/N Ratio

Dewatering Building

Biofilters

ASP Composting

Aerated Static Pile System

Loading Aeration Zone

Temperature Probe

Temperature Probes

Computer Controlled Process

Air Distribution & Biofilter

Curing

Screening Cured Compost

Testing

Aerated Static Pile Composting

Proven Technology

Simple to Operate

Flexible for Future Needs

Benefits of Aerated Static Pile

Composting Process

Aerobic Piles are Less Odorous

Exhaust Air Can be Filtered

Computer Controlled Process Improves

Composting Efficiency

Requires Less Space

Implementation Steps

Selected the “Engineered Compost System”

(ECS) Process

Negotiated a Process Design / Equipment

Procurement Agreement

Selected Local Engineer for Structural &

Sitework Design

Bid Facility Construction & Equipment

Installation

Aerated Static Pile Compost

Facility Costs

Process Equipment & Software $461,000

Site & Structural Engineering $ 99,000

Construction Contract $1,200,000

$1,760,000

Aerated Static Pile Compost

Operation Costs

Salaries & Benefits $ 195,700

Fuel for Equipment $ 66,000

Electric $ 9,100

Equipment Maintenance $ 12,000

Contract Screening $ 30,000

$312,800

Aerated Static Pile Compost

Operation Revenues

Yard Waste Tipping Fees $ 295,000

Compost Sales (Residential) $ 22,820

(Commercial) $ 74,861

Mulch Sales $ 26,806

Topsoil Sales $ 6,206

$425,693

Income from Compost

Operations

Operation Revenues $425,693

Operation Expenses (312,800)

Revenues $112,893

St. Peters GHG Reduction

From Composting

Carbon Sequestering

US EPA Waste Reduction Model (WARM)

-2,790 MTCO2E

533 Passenger Vehicles

6,477 Barrels of Oil

24 Acres of Deforestation

Quality is Essential

USEPA 503 Regulations

US Composting Council Seal of Testing

Assurance (STA) Member

Certified Filtrexx Supplier

Compost Product Markets

Commercial Landscapers

Erosion Control Contractors

Residential Landscaping

Wetland Mitigation Projects

Soil Remediation Projects

Bulk Mulch and Compost Suppliers

Private Customer Loading

Loading Blower Truck

Roadway Re-vegetation

Harvester Road

Wooded Wetland Mitigation Site Area Prepared for Compost 11-2-06

Wooded Wetland Mitigation Site Compost Spreading 11-2-06

Wooded Wetland Mitigation Site Spreading Completed 11-2-06

Wooded Wetland Mitigation Site K Seeding Completed 11-4-06

Planting Trees

Planting

5-Months Later Spring Growth 05-06-07

4 - Years Later (9-24-10)

Benefits of Composting

Combines Organic Resource Streams to

Produce Useful Products

Revenues Help Offset Expenses

Sustainable Process with Negative Carbon

Footprint “Carbon Sink”

Improves Soil Quality & Productivity

City of St. Peters

Organic Resource Recycling

Program

2010 Gold Excellence Award

Composting

US EPA

2008 Exemplary Biosolids

Management

Awards

Organic Resource Recycling is Cost-

Effective and Sustainable

REDUCE

REUSE RECYCLE