Washington State Department of Ecology

Composting

Welcome to the Department of Ecology's composting page.

Composting is an important component of our statewide strategy for "closed loop" recycling of organic residuals. By composting, we can transform "wastes" such as yard debris, food scraps, manure, and crop residues into valuable products.

Guidelines for "On-Farm Composting of Livestock Mortalities"

The 2005 Legislature passed Substitute Senate Bill 5602 focusing on composting of bovine and equine carcasses when feedstock and curing quantities exceed 1000 cubic yards and finished compost is distributed off-site. This bill was codified in R.C.W. 70.95.306 and requires that these guidelines be followed in order for certain agricultural livestock composting activities to remain exempt from solid waste permitting. WAC 173-350-220, Solid Waste Handling Standards, provides other agricultural exemptions and these guidelines may prove useful to anyone wishing to understand more about the methods of compost large livestock.

Managing Food Scraps at Institutions and Agencies

As we in Washington State look for ways to save money and resources, focusing on what else we can keep out of the trash becomes essential. Food and other organic scraps should not be wasted in the garbage. Institutions and agencies can corral the organic portion (food scraps, paper towels, etc.) of their trash—sometimes over 60 percent—and turn it into a valuable resource called compost.

However, many hospitals, jails, government offices, and schools, do not have the time or money to start from scratch and develop their own food scrap management program. Ecology can help…we can provide guidance documents, graphics to use for signage, and lessons from experience of composting on-site.

Beyond Waste

In November 2004, Ecology issued the Summary of the Washington State Hazardous Waste Management Plan and Solid Waste Management Plan: Final Plan (Pub# 04-07-022). This document is a summary of the work Ecology has conducted in the Beyond Waste Project and contains all of the plan’s recommendations and goals. This project includes long-range strategic plans for decreasing solid and hazardous wastes, increasing recycling, properly managing wastes that remain, and reducing the use of toxic substances.

One of the key initiatives of the Beyond Waste Plan is "Increasing Recycling for Organic Materials." In addition to information found in the summary document, the Background Paper for Final Beyond Waste Summary: Increasing Recycling for Organic Materials (Pub# 04-07-027) discusses ways to increase recycling of organic materials, including closed loop reuse.

Current Composting Facilities in Washington

2006 Compost Facilities

Composting facilities are regulated according to the solid waste regulation, Chapter 173-350 WAC, Solid Waste Handling Standards. The Composting Facility Standards (WAC 173-350-220) were developed to promote composting while protecting human health and the environment. These standards include:

Exemption categories (identifying those operations that do not need solid waste handling permits.
Design and operating standards for permitted facilities.
Compost quality testing requirements.

Ecology based the new composting facility standards on two former resources, Compost Facility Resource Handbook (publication 97-502) and the Interim Guidelines for Compost Quality (publication 94-038). These two documents are no longer available. (Additional technical assistance materials are under preparation).

Amount of Materials Composted

2006 Materials Composted

One of the requirements of the Composting Facility Standards (WAC 173-350-220) is for the submittal an annual report to local jurisdictional health departments and the Department of Ecology.

For additional data on recycling and diversion of waste in the state see Solid Waste and Recycling Data.

Links

Washington Organic Recycling Council (WORC) http://www.compostwashington.org.

Washington State University (WSU) http://www.puyallup.wsu.edu/soilmgmt/Composts.htm.

King County Solid Waste Division - Composting http://metrokc.gov/dnrp/swd/composting/index.asp.