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New Hampshire Department of Environmental Services

Media Center

DATE: May 2, 2019
CONTACT: Sharon Nall, (603) 271-2508

Wastewater Treatment Plants Recognized For Improvements in Energy Efficiency
WWTPs Recognized Include Epping, North Conway, Pittsfield, Somersworth, Troy, Winnipesaukee River Basin Program

Concord, NH - Over the past four years, the New Hampshire Department of Environmental Services (NHDES), in partnership with NHSaves, has made a concerted effort to help New Hampshire wastewater treatment plant (WWTP) operators and owners improve the energy efficiency of their facilities. This effort started with a grant from the US Department of Energy and will continue going forward using funding from both the Clean Water State Revolving Fund (CWSRF) and a continued partnership with NHSaves. NHDES is focusing on this effort because WWTPs are commonly the highest energy user for municipalities.

For wastewater treatment, energy use intensity is typically based on the volume of flow treated by a WWTP in million gallons per day (MGD) or the strength or pollutant loading of the wastewater measured in pounds of biological oxygen demand (lbs BOD). The driving factor, flow or waste loading, for each WWTP varies. BOD is the amount of dissolved oxygen used by microorganisms in the biological process of metabolizing organic matter in water. As the pollutant loading in wastewater increases, the BOD increases accordingly.

Through the initial four years of this program, energy efficiency champions have been identified. To recognize their hard work, we are proud to announce the winners of the first annual NHDES/NHSaves WWTP energy efficiency awards in two categories: Most Efficient and Most Improved.

Overall Most Energy Efficient WWTPs

Winnipesaukee River Basin Program (WRBP)/Franklin: Based on Flow
WRBP's energy use of 853 kilowatt-hour per million gallons of treated wastewater (kWh/MG treated), when compared to available national benchmarks for similar sized activated sludge WWTPs (ranging from 1,200 to 2,400 kWh/MG treated), shows the staff at WRBP is doing a fantastic job with energy efficiency on a national level as well as within New Hampshire.

Somersworth: Based on Pollutant Loading
Somersworth's energy use of 0.62 kilowatt-hour per pound of biological oxygen demand removed (kWh/lb BOD Removed), when compared to available national benchmarks for similar-sized activated sludge WWTPs (ranging from 0.7 to 2.2 kWh/lb BOD Removed), shows the staff at the Somersworth WWTP is also doing great work with energy efficiency, especially when considering most of the equipment at the Somersworth WWTP is 30+ years old.

Most Improved (Based on Flow):

  • Pittsfield: 63% Reduction in kWh/MG Treated (2012-2018)
  • North Conway Water Precinct: 44% Reduction in kWh/MG Treated (2012-2018)

Most Improved (Based on Pollutant Loading):

  • Troy: 56% Reduction in kWh/lb BOD Removed (2015-2018)
  • Epping: 48% Reduction in kWh/lb BOD Removed (2012-2018)

Over the four years, the program has:

  • Benchmarked the electric energy use of 66 municipally-owned WWTPS.
  • Conducted nine educational workshops for wastewater and drinking water system owners, operators, managers and engineers.
  • Performed 30 comprehensive energy audits of selected WWTPs.
  • Performed 11 comprehensive energy audits of selected drinking water facilities (DWFs) using set aside funds from the Drinking Water State Revolving Fund (DWSRF).

The WWTP energy audits have identified $5.5 million worth of projects that are estimated to save approximately $1.5 million annually in energy costs. Moving forward the program will use available NHSaves incentive programs and CWSRF principal forgiveness to encourage the implementation of these projects. Also, the energy audit program will continue for both WWTPs and DWFs using CWSRF and DWSRF funds, respectively.

NHDES and NHSaves will make formal award presentations at each award winning WWTP at a scheduled time in May/June so that owners, operators, management and interested community representatives may attend. For more information about this initiative, please contact Sharon Nall, NHDES Wastewater Engineering Program, at (603) 271-2508.

NHSaves is a collaboration of New Hampshire's electric and natural gas utilities working together to provide NH customers with information, incentives and support designed to save energy, reduce costs, and protect our environment statewide.

NH Department of Environmental Services | 29 Hazen Drive | PO Box 95 | Concord, NH 03302-0095
(603) 271-3503 | TDD Access: Relay NH 1-800-735-2964 | Hours: M-F, 8am-4pm

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