Biosolids Compost Blooms

King County contracts with a local private company (GroCo, Inc.) to make a biosolids compost which is marketed in the Greater Seattle area as GroCo.

Three parts sawdust and one part biosolids are blended and composted to create a fine-textured, Class A biosolids product. Biosolids compost improves soils and provides plant nutrients.

Landscaping
GroCo compost has many uses, on golf courses and parks, in home and school gardens and to enhance highway medians. Biosolids compost can be used as a soil conditioner and as a mulch around plantings.By increasing soil aeration, compacted soils are made more porous. Sandy soils benefit from the addition of organic matter which improves water retention.

Gardening
Biosolids compost improves soil characteristics and encourages vigorous plant growth in both planting beds and flower pots.

Community Involvement
GroCo is used in numerous community beautification projects, such as landscaping (before and after photos below) at Seattle's Eckstein Middle School.

Compost "Regreening"

GroCo compost has been used in an innovative project to rehabilitate logging roads and help stabilize mountain slopes by enhancing the growth of native vegetation.

GroCo is available throughout the greater Seattle area.
For information: 206-622-4321

Wastewater Treatment Division

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