Metro Nashville officials are weighing an environmental infrastructure agreement that could transform municipal wastewater byproducts into a lucrative source of green energy and generate millions of dollars for local coffers. Under a proposed partnership currently before the Metro Nashville Council, the city's utility would capture gas generated during sewage treatment and convert it into commercial-grade fuel.
The proposed initiative involves two formal agreements between Metro Water Services and Burnham, an infrastructure development firm headquartered in Arlington, Virginia. If granted final legislative authorization, the private developer will construct, own, and manage a specialized facility capable of purifying raw biogas into renewable natural gas, which will subsequently be fed directly into a regional pipeline network.
The legislative measure authorizing the land lease and gas rights advanced past its second reading on September 15. To become fully enacted, the proposal must secure a third and final approval from the council. Should the measure cross the finish line, city officials project that the newly constructed processing plant could take approximately two years to become operational.
Under the terms negotiated by the municipal utility, Burnham will shoulder the financial and operational responsibilities of the endeavor. The company is slated to oversee the complete financing, engineering, construction, and day-to-day operation of the renewable natural gas facility, relieving local taxpayers of direct development and management costs.
In exchange for supplying the raw biogas feedstock from its nearby wastewater operations, the city will receive substantial recurring compensation. A fiscal analysis submitted to the council indicates that Nashville will collect quarterly royalties amounting to 70% of the net revenue generated from the sale of the renewable gas produced on-site.
The financial framework guarantees that Burnham will pay Metro Water Services a baseline royalty of at least $1 million per calendar year. Additional revenue is anticipated to flow to the city as the processed gas enters the distribution pipeline and begins generating certified renewable energy credits.
According to guidance from the U.S. Environmental Protection Agency, these renewable credits are generated whenever one megawatt-hour of electricity is produced from a renewable source and supplied to the power grid. The certification system exists to distinguish clean energy from conventional fossil-fuel generation feeding into the common grid, permitting corporate and residential buyers to purchase credits to offset their overall power usage.
The venture relies on two long-term agreements that each span an initial duration of 20 years. Both the gas rights and site lease arrangements provide mutual options for two successive five-year extensions, potentially extending the operational partnership for up to three decades if both parties agree.
To host the conversion infrastructure, the municipal utility has agreed to lease a 1.2-acre parcel located at 1815 Cement Plant Road to Burnham. In consideration for utilizing the site to construct its proprietary facilities, the developer will pay Metro Water Services a nominal annual rent of $1 throughout the lifetime of the agreement.
The contract outlines a strict development timeline once the authorization becomes legally effective. Burnham must officially break ground and initiate site construction within 18 months of the agreement's effective date, with a contractual mandate to achieve full commercial operations within six months of commencing construction.
The facility's fuel source originates from standard wastewater collected across the metropolitan area. Wastewater consists of used water containing a complex mix of domestic and industrial materials, including human waste, discarded food scraps, grease, and household chemicals.
When this used water reaches municipal treatment infrastructure, mechanical and biological processes separate liquids from solid matter. These collected solids are subsequently treated to form nutrient-rich, semisolid material known as biosolids. As defined by the Environmental Protection Agency, biosolids are treated sewage sludge that satisfies rigorous federal safety standards, allowing them to be repurposed as organic soil conditioners or agricultural fertilizers.
During the treatment and stabilization of these biosolids, organic matter is broken down through anaerobic digestion, a biological process in which specialized bacteria decompose organic waste in the absence of oxygen. This breakdown naturally generates large volumes of methane-rich biogas.
The Metro Water Services biosolids facility, situated at 1810 Cement Plant Road in Nashville's Germantown neighborhood, produces an average of approximately 1.5 million cubic feet of biogas every single day. Under the plant's existing setup, the majority of this potent gaseous byproduct is routinely flared and burned off through on-site waste gas burners without being captured for energetic use.
Implementing the new processing facility would drastically modernize the site's environmental footprint by ending the routine flaring of waste gas. According to municipal agenda records, the partnership will enable the city to achieve the beneficial reuse of 100% of the biogas generated at the Germantown biosolids plant, turning an otherwise wasted byproduct into a sustainable municipal revenue stream.
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