Drinking water and wastewater systems account
for approximately 2 percent of energy use in the
United States, costing ratepayers approximately
$3 billion and adding over 45 million tons of
greenhouse gases to the atmosphere annually.

Energy-efficient water-
source heat pumps
like the one installed
at the Stockbridge
Drinking Water Plant
in Massachusetts
reduce energy use
and greenhouse gas
emissions.

AEPA

Energy Efficient Water
Plants around the
Nation

Many other utilities also have
turned to heat pumps and
other innovative technologies and
processes to save money and reduce
energy use. The Philadelphia Water Department,
the Metropolitan Water Reclamation District of
Greater Chicago, the Washington County Wastewater
Treatment Plant in New York, and many others have put
wastewater to use in their heating and cooling systems.
In addition to water-source heat pumps, electric air-
source heat pumps can be cost-effective and lower your
carbon footprint, especially when coupled with solar
panels to increase system performance.

In addition, changes to blower technology and usage,
optimizing dissolved oxygen control set points, and
reducing IJV lamp usage are other ways utilities
lower energy costs while also lowering greenhouse
gas emissions and nitrogen levels in plant effluent.
When used in combination, these improvements can
significantly reduce energy consumption and cut costs.

For more information on heat pumps and
other energy-efficient technologies visit:

U.S. Department of Energy Heat Pump Systems

www.energv.gov/energvsaver/heat-pump-svstems

U.S. Environmental Protection Agency
Sustainable Water Infrastructure

www.epa.gov/sustainable-water-infrastruc.ture/
energv-efficiencv-water-utilities

Database of State Incentives for
Renewables and Efficiency

www.dsireusa.org

United States
Environmental Protection
Agency

Reducing Operating Costs
and Energy Consumption
at Water Utilities

with
Water-Source
Heat Pump
Systems

Homeowners aren't the only
ones looking for ways to reduce
their heating and cooling bills.

Water utility managers face the same financial challenges.
Due to their unique combination of high energy usage and
potential for significant savings, utilities are turning to
energy-efficient technologies to help save money.

Annual

Cost
Savings

Percent
Reduction in
Electric Bill

Annual Energy
Savings

Pay Back
Period*

*3-month pay back achieved with GAP Funding

"The money we saved by installing the new
system was used to add an HMI (human machine
interface) to our existing setup so
we can view what's going on with
all the plant processes when we
are off-site."

— Michael Buffoni, Water Superintendent,

Town of Stockbridge Water Department



$19,600

83,300 kilowatt
hours

2.24
years

Stockbridge Drinking Water Plant
Massachusetts

The Town of Stockbridge's drinking water plant treats
and delivers 55-60 million gallons of drinking water to
1,548 customers every year. In 2015, the facility installed
an open-loop, water-source heat pump that replaced its
electric resistance heating system installed when the
plant was constructed in 1996. The new system consists
of two 6-ton heat pumps capable of air conditioning
and heating, and the open loop has a recycle feature
that sends the used water to their plant filters to be
retreated. The total project cost was $44,000. The
town received a $39,000 grant from the Massachusetts
2014 Gap Funding program.

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Reducing Operating Costs and Energy
Consumption at Water Utilities with
Water-Source Heat Pump Systems
Drinking water and wastewater treatment plants are
the largest energy consumers in many cities, often
accounting for 30-40 percent of total energy consumed
by the city. A large portion of the facilities' operating
costs goes toward energy bills—making it very
important to find ways to
lower costs.

Many utilities are turning
to innovative, energy-
efficient technologies and
operational improvements
to help reduce costs while
still meeting environmental
requirements and customer
expectations. Water-source heat pump systems are
one way utility managers are saving money. As an
added bonus, reducing reliance on fossil-fuel generated
electricity also reduces their carbon footprint.

By incorporating energy-
efficient practices into
water and wastewater plant
operations, municipalities
and utilities can save 15-30
percent, saving thousands
of dollars with payback
periods of only a few
months to a few years.

£c

MASSACHUSETTS
CLEAN ENERGY
CENTER

Renewable Heating & GHG

Estimated Annual Greenhouse Gas Emissions in
Massachusetts - Example Residence

Water-Source Heat Pump Technology 101

Water-source heat pumps work in the same way as
air- or ground-source heat pumps—by moving heat
from warm areas to cool areas. Instead of extracting
heat from the air or ground a water-source heat pump
extracts it from groundwater or wastewater. At a
drinking water plant, processed drinking water heated
by the ground from which it was removed is used as the
source. This type of system is also called a geothermal
heat pump. At a wastewater plant, some of the plant's
wastewater effluent is diverted to a heat exchanger,
where heat is extracted or added.

Because heat pumps move heat instead of generating
heat, they are cost-saving alternatives to furnaces
and air conditioners. Although they are more costly to
install, water-source heat pumps have lower operating
costs because the heat transfer rate from water is
higher than from air or the ground. In addition, the
temperature of the water used as the heat source
(whether groundwater or wastewater) generally stays
constant throughout the year, which leads to higher
efficiency. Water-source heat
pumps can reduce energy
use by 30-60 percent, control
humidity, are sturdy and
reliable, and can work in a
wide variety of buildings.

Clean Heating & Cooling
Technologies

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