WaterSmart Compost

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A Beneficial Reuse of Biosolids

This rich compost made with biosolids is an excellent soil amendment for landscaping and gardens. Biosolids are a nutrient-rich, organic* byproduct of the wastewater treatment process that containplant macronutrients like nitrogen, phosphorus, and potassium, as well as supplementary nutrients such as sulfur, magnesium, calcium, copper, and zinc. 

Our WaterSmart Compost, made with biosolids and green waste is an excellent amendment for landscaping and gardening, closing the recycling loop locally and sustainably. 

Using WaterSmart Compost as a Soil Amendment

WaterSmart Compost is a beneficial, sustainable resource that can be used to improve soil quality and as a fertilizer replacement for crops. Most of the nitrogen in biosolids is organic*, acting as a slow-release fertilizer providing nitrogen when the plants need it, rather than all at once. It can reduce the use of expensive (often petroleum based) commercial fertilizers, and that means less environmental impact from fertilizer run-off into waterways.

*Organic material is derived from a living organism. Biosolids are not certified organic under the USDA’s National Organic Standards.

Benefits of WaterSmart Compost

•             Retains Moisture
•             Provides Nutrients
•             Improves Soil Quality
•             Increases Organic* Matter

Father and daughter plantingWaterSmart Compost Application

Planting Beds
1-2” thick layer, then incorporate the compost to a depth of 6-8 inches until the compost is uniformly mixed. Plant seeds and water.

Top Dressing for Lawns
¼" thick layer. Apply after aerating or re-seeding, then water.

Annuals and Perennials
1 - 2" thick layer.

Trees and Shrubs
1-3" thick layer. Be sure to keep mulch at least 3-6" from the trunks.

Composting
Apply to your compost pile with a 1-3” thick layer to accelerate the composting process.

As with all composts, wash hands after handling.

Health and Safety



To fully ensure public and environmental health, all aspects of biosolids use are carefully planned and implemented according to comprehensive federal, state, and local regulations. The federal biosolids rule is contained in the US Environmental Protection Agency’s 4O CFR Part 5O3.

Santa Rosa Water takes great pride in providing the highest quality, completely sustainable, biosolids compost to its community and surrounding areas. Santa Rosa is a member of the US Composting Council’s Seal of Testing Assurance Program. The City’s Biosolids Management Program was developed under the guidance of the National Biosolids Partnership.

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