DC turning wastewater solids into gardeners compost
Using new equipment, DC Water is turning what used to be classified as waste into a desirable product for landscapers.
“There’s a lot of materials we don’t want in our rivers, because it’s filled with nutrients, and if it’s in the water it causes algae to grow and uses up the oxygen and causes a tremendous problem for the ecosystem in the (Potomac) river,” said Hawkins.
However, Hawkins said that nutrients aren’t always a bad thing: “That’s what’s in every fertilizer. That’s what’s in good soil.”
The District is not the first city to turn it’s waste water biosolids into something gardeners want.
“Milwaukee has been doing this for years with Milorganite,” said Hawkins. “It’s the same idea.”
DC Water’s thermal hydrolysis and anaerobic digestion facility uses high heat and pressure, along with favorable microbes, to create what is labeled Class A biosolids — clean enough to be used for growing crops for human consumption.