Water Conservation and Our Carbon Footprint

Bill Wombacher, CEES 1L Volunteer

       When most people hear the phrase “energy conservation” they think about compact fluorescent light bulbs, turning the thermostat down, or switching their computer off at night. However, people don’t usually know about the impact that water use can have on their carbon footprints. As part of the CEES’ Colorado Energy Profile (CEP), three CEES volunteers recently visited the Boulder Wastewater Treatment Plant (WWTP) to have a tour and discussion with its Coordinator, Floyd Bebler, about the energy impacts of the process of wastewater treatment.

    Figures from the U.S. Environmental Protection Agency (EPA) estimate that wastewater treatment accounts for a full 3% of the overall electricity demand in the U.S. Initial research by CEES also suggests that energy requirements for treating water could be up to 50% of the City of Boulder’s total electricity bill. However, concerns about this amount were eased after meeting with Mr. Bebler and learning that energy efficiency is a major consideration in almost all decisions made at the Boulder WWTP.

The Bolder WWTP collects and treats approximately 5.4 billion gallons of water each year. Over 90% of this water comes from households in the Boulder area. Last year, the plant was able to treat approximately 725 gallons of wastewater per kilowatt hour (kWh) of energy consumed. The plant is currently in the process of expanding and upgrading to improve treatment and allow for municipal growth. Although these improvements are projected to increase the plant’s energy consumption by 15-25%, significant efforts are being made to improve efficiency and offset energy costs through onsite generation and optimization.

Recently, the Boulder WWTP has agreed to lease a portion of its land for the construction of a battery of solar panels, which will produce an estimated 1.5 to 1.7 million kWhs per year. This could provide for roughly 20% of the plants current yearly energy consumption. The plant also currently captures methane generated during treatment. This methane was used to generate 1.7 million kWh in 2006. Combined, these practices account for close to half of the 7.4 million kWhs the plant consumes annually.

On the tour, CEES volunteers were also surprised and impressed to learn that the volume of water being sent to the Boulder WWTP has been decreasing for the last eight years. Mr. Bebler attributes this decrease to public outreach concerning water  conservation and efforts to fix leaky pipes that allow groundwater to enter the system.

Although Boulder residents are fortunate to have an environmentally responsible and progressive water utility, there are still many simple water conservation measures that people can take to reduce their water-related carbon footprint. Energy is consumed not only at the Boulder WWTP, but also when drinking water is treated and heated in homes. Conserving water reduces energy consumption on both ends of treatment and can lead to lower utility bills for both the city and its residents. Consequently, installing low flow showerheads and toilets, taking shorter showers, and using bathwater to water your lawn can lead to significant reductions in our carbon footprints. 

Colorado’s Response (continued...)

Another key figure in Governor Ritter's environmental arsenal, Tom Plant, Director of the Governor's Energy Office, then discussed the significant steps that Colorado is taking toward achieving the goals of the Climate Action Plan. Plant indicated that the key component in Colorado's efforts is a focus on building codes.