Drinking Water and Wastewater Treatment Plants
Water and wastewater facilities often make up the largest portion of a community's energy bill, accounting for up to 35% of typical US municipal energy budgets. Because energy is required for all stages in the water treatment process, operating water and wastewater plants is very energy intensive and often expensive. However, communities can reduce energy usages and costs at their water and wastewater plants by making energy efficiency improvements.
Common energy efficiency improvements at water and wastewater plants
- Water plants: 90% of a typical water utility's energy consumption is used to pump water. Water utilities may achieve significant savings by improving pump efficiency and installing variable speed drives. Other common actions include installing more efficient lights and HVAC, as well as repairing or replacing distribution pipes to stop leaks.
- Wastewater plants: Approximately 50% of a typical wastewater utility's energy consumption is used in the aeration treatment process. Utilities may benefit from adopting improved system controls (such as oxygen sensor devices), efficient aeration blowers, and efficient bubble diffuser technologies. Wastewater plants may also benefit from efficient pumps, variable speed drives, lighting, and HVAC.
Funding and Financing Opportunities
- The Community Development Block Grant (CDBG) program is a good resource for eligible communities that face an environmental consent decree to improve their water or wastewater plant's performance. Low-to-moderate income communities can use CDBG grants to meet environmental regulations and/or reduce water utility rates. Communities have the option of incorporating an energy efficient element into their overall grant
- Indiana's Wastewater State Revolving Loan Fund (SRF) provides low-interest loans for treatment improvements and upgrades. The SRF loan program offers the Green Project Reserve (GPR) Sustainability Incentive Program, which encourage SRF loan program participants to reduce resource consumption, such as energy and water. Based on the type and cost of the green component, a community may be eligible for improved ranking on the SRF project priority list as well as an interest rate break of up to 0.5% of its SRF loan.
- Utility rebates: Water and wastewater utilities that pay into their electric or gas utility's energy efficiency programs may be eligible for rebates for items such as efficient pumps, lighting, or variable speed drives. Some utilities may offer custom programs.
- A Guaranteed Energy Savings Contract (GESC), as detailed by Indiana Code 36-1-12.5, allows a water or wastewater treatment plant to fund the project without a large upfront investment of capital. After an energy audit, a contract is signed between a qualified provider and a building owner to reduce the energy and operating cost of a building by a specified amount. Then the building owner pays back the qualified provider over time from the monetary savings that result from the energy efficiency project. GESC payments do not constitute an indebtedness of a political subdivision within the meaning of a constitutional or statutory debt limit.
- Energy Star Portfolio Manager for wastewater treatment plants is a free tool that provides feedback on a plant's performance.
- How to use Energy Star for Wastewater Treatment Plants
- EPA Water Wastewater Energy Guidebook
- EPA website on Energy Efficiency for Water and Wastewater Utilities