Short-Lived Climate Pollutant Strategy Outlines a Role for POTWs in Organic Waste Diversion


March 31, 2017

In its recently adopted Short-Lived Climate Pollutant (SLCP) Strategy, the California Air Resources Board (ARB) identifies POTWs as key components of the state’s strategy to reduce methane emissions. The SLCP Strategy, adopted on March 23, 2017, outlines ARB’s approach to achieve state mandates to reduce emissions of these potent greenhouse gases including methane, black carbon, and hydroflourocarbons. The SLCP Strategy does not propose direct regulation of POTW methane emissions at this time. Instead, ARB outlines its plans to pursue the use of surplus digester capacity at POTWs as a key component to in the state’s upcoming efforts to divert organic waste from landfills.

The SLCP Strategy includes the groundwork for compliance with SB 1383, adopted in September 2016, which mandates a statewide reduction of methane emissions of 40 percent below 2013 levels by 2030. To help achieve this goal, SB1383 requires CalRecycle to adopt regulations that will drastically reduce disposal of organic waste in landfills by 50% of 2014 levels by 2020 and 75% by 2025. In addition to increases in composting facility capacity and programs to recover food to feed people, ARB believes that using excess digester capacity at POTWs to co-digest food waste and fats, oil, and grease (FOG) is a viable pathway to achieving these diversion goals. The methane generated from digestion would be captured and beneficially used as biofuel or to produce electricity.

ARB recognizes that there are several regulatory and financial barriers that must be overcome to realize these opportunities at POTWs. ARB intends to work with POTWs and with state agencies, including CalRecycle, the California Energy Commission, and the State Water Resources Control Board, to identify funding and achieve financial stability for these projects. In the near term, this may include grants from Cap-and-Trade revenue, but in the long-term this will require removing barriers to sell the excess electricity and biofuels generated by the POTWs. In addition, POTWs may face obstacles in air permits or have difficulty finding outlets for the increase in digested biosolids.

We will continue to track developments regarding the role of POTWs in the state’s greenhouse gas reduction strategies.