Guest Column | December 16, 2024

How A City's Sewage System Can Generate Renewable Natural Gas Production And Earn Royalties

By Travis Payne

Recycling, water treatment plant-GettyImages-517814463

Imagine if wastewater treatment plants (WWTPs) — typically associated with managing sewage — could instead become known for fueling a more sustainable future.

As wastewater flows through WWTPs, it generates methane, a highly potent greenhouse (GHG) gas that drives climate change. In fact, wastewater utilities account for 5% of global GHG emissions, with wastewater treatment alone making up a staggering 70%, according to the World Economic Forum.

In the U.S., methane emissions from landfills and wastewater facilities rank as the third-largest source. But here’s the issue: most of the methane is slipping away uncaptured, unutilized, and unmonetized — a lost resource with enormous potential.

This presents a valuable opportunity for the wastewater industry to play a role in producing cheaper, clean, proven U.S.-made natural gas. By capturing methane emissions from WWTPs, these facilities can turn waste into revenue while at the same time reducing their carbon footprint. It’s an economically smart, sustainable shift.

How Does It Work?

Waste naturally produces methane as it decomposes, and when methane is released into the atmosphere, it contributes to global warming. But methane is also the main component of renewable natural gas (RNG), which offers an immediate solution to methane emissions.

RNG has the same chemical composition as fossil fuel natural gas but is produced without the same carbon footprint. It is created by capturing methane and other emissions from landfills and wastewater treatment plants and refining them into pipeline-quality gas. Without the production of RNG, waste at these facilities would break down and release biogas — consisting largely of methane — into the atmosphere and contribute significantly to annual GHG emissions.

At RNG production plants, waste from feedstock undergoes a transformation process. RNG plants are able to capture the biogas at the source — such as landfills, which are typically around 50% methane, or WWTPs, which can contain up to 65% methane — before it escapes into the atmosphere.

The impurities are then removed, leaving only methane, or RNG. From there, RNG can be injected straight into the nation’s network of pipelines for distribution across different RNG fueling facilities and power plants.

Benefits Of RNG

RNG is more than just a solution for climate change — it can also offer financial and economic benefits. By selling RNG and its renewable fuel credits, WWTPs can unlock additional revenue for municipalities and other owners without investing capital and taking market risk by partnering with a reputable RNG developer like Nopetro, which also offers CNG solutions. Plus, national, state, and local incentives may be available depending on the end use, particularly if the RNG is used for vehicle fuel. Additionally, the construction and operation of RNG systems create jobs, boost local economies, and provide skilled employment in the growing clean energy sector. At the same time, it also offers the advantage of being locally produced, eliminating transportation costs associated with natural gas, and providing 24/7 energy production compared to solar.

Apart from the economic benefits, methane mitigation reduces the overall carbon footprint of WWTPs, allowing these facilities to meet their sustainability goals. By replacing fossil fuels with a low-emissions solution, it reduces the nation’s dependence on foreign energy sources. The benefits of RNG extend to heavy transportation and power generation, where carbon emissions can be reduced by up to 400% when RNG replaces traditional fuels. By participating in the waste-to-energy process, WWTPs contribute to a circular economy, turning what was once waste into a renewable energy source.

A Sustainable Future Awaits

RNG projects are gaining momentum across the country, but there is still a massive opportunity for WWTPs to benefit from this innovative approach. While wastewater reclamation facilities are producing RNG in a dozen states, landfills producing RNG can be found in more than 25 states. Landfills are increasingly taking advantage of this economic strategy, as the wastewater industry lags behind.

With greater adoption, WWTPs can play a critical role in turning waste into a usable product that’s also renewable. As these projects continue to grow, waste will become a powerful driver of energy independence and economic growth.

Travis Payne is the Senior Vice President, Renewable Natural Gas Development for Nopetro Energy.