The American Recovery and Reinvestment Act (ARRA), Green Project Reserve of 2009, through the Clean Water State
                      Revolving Fund, provided funding for a wide variety of qualifying projects in the categories of: green infrastructure, energy
                      efficiency, water efficiency, and other innovative projects. For more information on projects that have been funded by the
                      Green Project Reserve and for additional details, visit www.epa.gov/ow/eparecovery.
                                       Achieving  Zero-Net  Energy
                                                at  Drinking Water  and
                                                  Wastewater  Facilities
                                                           Adopting zero-net energy
                                                           principles  to  realize both
                                                         cost savings and increased
                                                                      energy efficiency.
BACKGROUND   Providing safe drinking water and reliable wastewater treatment is extremely
                    energy-intensive. An estimated 3% of total national energy consumption is
                    used for drinking water and wastewater services.
  If the water and
 wastewater sector
could reduce energy
  use by just 10%,
collectively it would
  save about$400
  million annually.
By applying zero-net energy (or ZNE) principles,
water and wastewater utilities can reduce their
energy consumption, achieve greater energy
independence, realize significant cost savings,
and add to their bottom lines.

A zero-net energy facility is one that has
greatly decreased its dependence on outside
energy supplies moving toward a goal of
total energy independence. Facilities striving
to reach ZNE should first reduce the plant's
total energy needs through investment in
renewable technologies, reduced energy
consumption equipment, and operational
efficiencies using a variety of approaches,
including those described in EPA's Energy
Management Guidebook for Wastewater and
Water Utilities, available at www.epa.gov/
energymanagement.pdf. Achieving ZNE is
also an important element of effective utility
management consistent with the Attributes of
Effectively Managed Utilities supported by EPA
and major water sector associations.

Once the total operational energy needs
have been mitigated, alternative or "green"
power sources can be used for on-site energy
production. Through the use of low-cost, locally
available, nonpolluting, renewable energy
sources—such as solar cells, methane-powered
microturbines, and wind turbines—a utility can
generate enough renewable energy on site to
equal or even exceed its annual energy use.

  Case Study
Read about what three facilities in Massachusetts
have done to reach zero- or close to zero-net
energy through a combination of state and
2009 American Reinvestment and Recovery
Act (ARRA) funding. These facilities also
participated in a pilot program managed by the
Massachusetts Department of Environmental
Protection to help utilities across the
Commonwealth identify ways to improve their
overall energy efficiency. For more information
on this pilot program and its future expansion
to all 370 Massachusetts water and wastewater
treatment plants, visitwww.mass.gov/dep/
wate r/wa ste wate r/e m p i I ot. ht m.
Photo courtesy of Rose Forbes,
United States Air Force
The Town of Falmouth operates an advanced
nutrient-removal system that processes
approximately 0.4 million gallons of wastewater
per day. The facility treats wastewater and
domestic septage for the community.
Zero-Net Energy Upgrades:
 • A town-funded ($4,692,000) 1.65 MW wind
  turbine (installed in Nov. 2009 and operational
  by March 2010; is the Commonwealth's first
  utility-scale municipal wind turbine)
 • An SRF/ARRA-funded ($4,865,000) 1.65 MW
  wind turbine (currently under construction)
Anticipated Results:
 • Approximately $508,000 in annual energy savings
 • Since installation, the town-funded wind turbine
  has generated 882,266 kW of clean energy or
  the equivalent of enough power an Average
  American Home for 79 years
 • ARRA-funded wind turbine is projected to
  generate 3,624 MWh per year, thus reducing the
  Town's carbon emissions by 20%
 • Achieve positive cash flow in first year by utilizing
  Massachusetts long-term Renewable Energy
  Credit incentives
 Community Contact:
 Heather Harper, Assistant Town Manager
 (508) 495-7320; hharper@falmouthmass.us
                          The City of Pittsfield operates an advanced nutrient-
                          removal treatment facility that processes approximately
                          10.8 million gallons of wastewater per day. The facility
                          treats municipal and industrial wastes from the City of
                          Pittsfield and the surrounding communities.
                          Zero-Net Energy Upgrades:
                           • Upgrading the aeration system from a mechanical
                             mixing system to a fine bubble mixing system
                           • Performing heating and lighting upgrades
                           • Upgrading the existing anaerobic biomass
                             (sludge) digestion system by installing a 195 kW
                             biomass cogeneration system for on-site electric
                             power generation
                                                 • Installing a 1,575 kW solar photovoltaic system
                                                Anticipated Results:
                                                 • Approximately $647,000 in total annual energy savings
                                                 • 3,263,000 kW hours of annual green power
                                                   generation from solar photovoltaic and Combined
                                                   Heat and Power [CHP] (approximately 69% total
                                                   power generation)
                                                 • 3,252 tons of carbon dioxide emission reductions
                                                 Community Contact:
                                                 Bruce Collingwood, DPW Director
                                                 (413) 499-9330; bcollingwood@pittsfieldch.com
                          TheTown of Lee operates a surface water treatment plant
                          that treats and distributes more than 308 million gallons
                          of drinking waterfor 2,055 customers annually. The facility
                          currently utilizes an 80 kW hydroelectric turbine at the
                          plant that generates nearly 50% of its on-site electric
                          power needs, saving the facility $28,000 annually.
                          Zero-Net Energy Upgrades:
                           • Installing Variable Speed Drives (VSDs) and
                            optimizing batching, premium motor, lighting,
                            and heating upgrades
                           • Installing a 34 kW solar photovoltaic system on site
                           • Optimizing the existing 80 kW hydroelectric
                            microturbine system to increase on-site renewable
                            power generation
                                                Anticipated Results:
                                                 • Over 90% production of the plant's electricity needs
                                                 • Approximately $34,000 in annual energy savings
                                                 • 114 kW of green power generation
                                                 • 153 tons of carbon dioxide emission
                                                  reductions annually
                                                 Although these upgrades were 100% funded by
                                                 ARRA, the Town of Lee would have realized positive
                                                 cash flow in the first year by combining its annual
                                                 energy cost savings with Massachusetts'existing
                                                 solar Renewable Energy Credit incentives.1
                                                 Community Contact:
                                                 Christopher Pompi, DPW Superintendent
                                                 (413) 243-5520; cpompi@town.lee.ma.us