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Water Services

Biosolids For Beneficial Reuse

Aerial view of Central waste water treatment plant

In our wastewater treatment process, we reclaim water and solids from the wastewater (sewage). Clean water is reclaimed and returned to the Cumberland River safe for recreation and wildlife. The solids are reclaimed to create a Class A Exceptional Quality Biosolid used for agriculture.

We create the pelletized Biosolids at our Central Biosolids Facility, which opened in 2009.

How are our Biosolids made?

  1. Anaerobic digestion – The solids are digested, similar to how your stomach works, to reduce pathogens and odors.
  2. Thermal Drying – The solids are dried to destroy any remaining pathogens and remove moisture. This is similar to pasteurization. We power our dryers by reusing the methane gas produced during the digestion process.

How are our Biosolids tested?

Exceptional Quality (EQ) Biosolids are highly regulated. They must meet low-pollutant and pathogen reduction standards to be virtually absent of pathogens. We test our biosolids regularly at our state certified laboratory. They are safe to handle and have their own distinctive odor, which can be described as slightly musty.

Biosolids Use

Exceptional Quality Biosolids may be reused as a fertilizer, soil amendment, or as an alternative fuel source.

Biosolids produced at the Central Biosolids Facility are distributed through a third party contractor, TYCOWA, LLC and marketed as Music City Gold.

For more information, visit the TYCOWA website.

Biosolids Benefits

  • Annual cost to landfill since October 2018 has been $0
  • Reused 309 million cubic feet of digester gas
  • Saved $1 million in natural gas costs by reusing digester gas
  • Produced 18,500 tons of beneficial reuse product
  • Saved $4 million a year in disposal costs
  • Created a 5-5-0 nitrogen, phosphorus, potassium (NPK) fertilizer
  • Become a better neighbor by reducing odors