Cedar Grove Quality Products,

providing you with the best there is.

Product Certification & Testing

Since its inception, Cedar Grove Composting has been the subject of an extensive testing program sponsored by the City of Seattle in addition to its own, on-going quality assurance program. The goals of these programs have been to ensure production of high quality compost and to generate information for the development of standards for clean green compost products. Tests have included a wide range of characteristics including:

• Nutrient content
• C/N ratio, pH levels, moisture holding capacity and conductivity
• Pesticide and herbicide residues
• Weed seeds and seed germination
• Heavy metals
• Plant and human pathogens

In addition to these laboratory tests, plant growth trials and other field testing of Cedar Grove Compost were conducted at the University of Washington's Center for Urban Horticulture. The results of the University tests showed that using Cedar Grove Compost as a soil amendment or mulch increased crop yields significantly more than adding fertilizer.

Cedar Grove Compost contains significant amounts of both the major and minor nutrients required for healthy plant growth. In addition, Cedar Grove Compost releases its nutrients gradually decreasing the need for frequent fertilizer applications.

Since test results of Cedar Grove Compost have been used to help establish standards for the industry, they have been examined for the presence of a wider range of possible contaminants than are most comparable products. Most of the chemical compounds tested for were not detected in Cedar Grove Compost, and none were present at levels considered significant to affect plants or human health. Additionally, the Washington State Department of Ecology's Interim Compost Quality Guidelines assure that compost products do not contain concentrations of toxic metals, human pathogens, salts and other contaminants that are potentially harmful in the long term to human health and the environment. The guidelines define a "Class AA" compost suitable for any use, including vegetable gardens. Cedar Grove Compost consistently meets the "Class AA" threshold standards.

Cedar Grove Compost has been tested to examine its effects on seed germination and to determine if any viable weed seeds survived the composting process. In nursery tests, tomato, marigold, perennial rye grass and radish seedlings germinated well when sown in pure Cedar Grove Compost. No weed seeds germinated in any test situation.

Nutrient Content of Cedar Grove Compost
Cedar Grove Compost contains significant amounts of both major and minor nutrients required for healthy plant growth. In addition, Cedar Grove Compost stores nutrients supplied by organic fertilizers and gradually releases them for steady plant growth. This slow release action reduces the need for frequent fertilizer applications and prevents runoff of nutrients into surface water. The following chart shows the nutrient levels in Cedar Grove Compost.

Characteristics of Cedar Grove Compost:
Test	Cedar Grove Compost
PH	5.7 - 7.5
Nitrogen %	1.3 - 1.5
Soluble N %	.03 - .08
Phosphorus %	.15 - .22
Potassium %	.44 - .60
Conductivity	2.1 - 3.2
Water Retention	115 - 138

Cedar Grove Composting presently participates in the Washington State Department of Agriculture Organic Food Program. Cedar Grove Composting is continuing to monitor incoming feedstocks for clopyralid. We perform bioassay tests onsite on 100% of our batches with the most sensitive plants 3 to 6 months before will sell the product. We retest through bioassay testing at the time of sale each batch to approve the product for sale. If we find negative effects on the most sensitive plants performed on a worst-case bioassay of 75% compost, Cedar Grove Composting will not sell that product to the general consumer. We will sell for commercial turf application only.