DC and Maryland residents are in luck. Using state-of-the-art equipment, DC Water is now producing and selling Bloom, a soil conditioner made from Class A biosolids. According to DC Water, Bloom can increase organic content in the soil, increase drought resistance in plants, and provide essential plant nutrients such as nitrogen and phosphorus. Bloom can be used by gardeners for establishing flower and vegetable gardens, remediating poor soil, planting trees and shrubs, and improving and establishing lawns.
Biosolids are organic matter recycled from sewage, which have been treated and processed in order to be used as a soil conditioner. “Drinking and waste water — everything that goes down the drain – comes to DC Water to be cleaned up,” explained Bill Brower, program manager for Biosolids at DC Water. “Our equipment pulls out the solids, the organic matter, before the water goes to the Chesapeake Bay. The solids are heated to 200 degrees Fahrenheit to kill pathogens.” Class B has a reduced number of pathogens and is not used for gardening while Class A has essentially no pathogens; thus safe for homeowners and gardeners. By purchasing new equipment, DC Water has been able to create a Class A product with the intent to further their recycling efforts.
Using biosolids as a soil conditioner is not new in our country. Other cities such as Seattle, Tacoma, Austin, Houston, and Boston also use and sell their high quality biosolid soil amendment products. One of the more well-known brands among gardeners is Milwaukee’s Milorganite, which can be purchased in bags at garden centers.
“Adding Bloom to your garden is like adding compost,” said Bill. “Bloom breaks up clay, helps to build tilth, and helps to increase the community of microbes. Over time, Bloom increases drought-resistant properties in plants.”
Some people are concerned that using a biosolid product will have an offensive odor but Bill reassured me that Bloom does not. “Bloom has an earthy odor,” said Bill. “I was showing it to school children the other day and they said it smelled like burnt wood or like dirt.” Part of Bill’s job is to serve as community ambassador, introducing Bloom to gardening clubs and people who manage school and community gardens. About 30 school and community gardens in the Washington DC area use Bloom in their soil.
Currently, DC Water produces two “varieties”: Fresh and Cured. Fresh is cheaper than cured at $2.50 per cubic yard but more alkaline than cured (8.47 pH) and contains more moisture. Because it contains more moisture, it is heavier and more difficult for a person to lift with a shovel. Thus the Fresh is ideal for landscapers who can use spreading equipment. Cured is $5.00 per cubic yard with a more neutral pH (6.79 pH) and less moisture. Because it is dryer, it does not stick as much to a shovel and is lighter to lift.
DC and Maryland residents can order by calling or completing the online order form. They can have Bloom delivered for a delivery fee or drive to Blue Plains Advanced Wastewater Treatment Plant, 5000 Overlook Avenue, SW, Washington DC, to have staff load their truck.
The Bloom website is very informative and lists the lab analysis of samples of both varieties with specific amounts of nutrients, metals, pathogens, etc. Both have nutrients that plants need such as nitrogen and phosphorus, essentially no pathogens, and low concentrations of heavy metals. The presence of heavy metals is similar to the amount found in typical soils and is far below the level found to pose a risk to human health. Bloom meets all U.S. Environmental Protection Agency standards for use in homes and gardens.