United States Prepared by the February 1981
Environmental Protection Operations & Maintenance Section
Agency Water Division
Region I Boston, MA
&EPA Energy Conservation
In Wastewater Treatment
Chapter II
Considerations For Design
Concepts and Operational
Parameters
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ENERGY CONSERVATION IN WASTEWATER TREATMENT
Considerations for
Design Concepts and Operational Parameters
Chapter II
Prepared by
Hibbard E. Armour, Chief
S<
Nicholas B. McCamy
Environmental Engineer
Operation & Maintenance Section
Water Division
United States Environmental Protection Agency
Region 1
William R. Adams, Jr.
Regional Administrator
January, 1981
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Environmental Protection Agency
Region 1
TABLE OF CONTENTS
Page
Introduction 1
Wilton, Maine Wastewater Treatment Plant (A Major Case History) 3
Minor Case Histories 11
New Technology 15
Conclusion 17
Acknowledgments 18
Bibliography . .....20
Additional References ...... 20
Cover: The Wilton, ME Wastewater Treatment Plant - Photo and dUjOLQftam COUHtQAy
the. design zngim&u i'lnJjght, Viatica, Basinet, Wyman Englne&u o{)
Top&ham, ME. The design makes use of passive and hydronic solar
collectors, along with digester gas, to heat and otherwise fuel the
facility.
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Energy Conservation in Wastewater Treatment
Consideration for Design Concepts
and Operational Parameters
U.S. EPA Region 1
Introduction
This document is the second in a series prepared in response to a
National effort directing our immediate attention to excessive use of
energy in the treatment of the Nation's wastewater streams. Subsequent
chapters will be written to update the information contained herein and to
present new case histories of energy-efficient plant designs and operations
as we learn of their existence.
The first chapter identified general energy conservation measures
being employed by treatment facilities in Region 1, and recommended new
measures that should be considered when planning and designing future
wastewater treatment plants.
Three sections are presented in this chapter. The first section
focuses on energy-saving design concepts employed by the Wilton, Maine
Wastewater Treatment Facility. The Wilton plant combines a total energy-
conscious design approach with the latest technology in wastewater treat-
ment. We have presented the Wilton facility as a major case history of
energy-conscious design. The manner in which the plant achieves effective
treatment with low energy consumption is explored in detail.
The second section looks at energy conservation through the eyes of the
plant operator. We have learned of many practical measures operators are
taking to conserve energy through daily operation and maintenance procedures.
Presented herein are some of the more imaginative ideas we received from
plant operators in New England.
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The final section presents a summary of energy-saving new technology
employed by wastewater treatment plants in New England. With fuel and
electricity costs rising, the increasing need for energy conservation has
challenged operators and engineers to develop better ways to treat waste-
water at lower energy demands. This section presents wastewater treatment
projects that have been identified by EPA as innovative technology or
important examples of energy-conscious design.
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OCLC Connexion
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Dates 1981 ,
EHA *b eng *e rda #c EHA
EPA 901-R-81-009
EPA 901-R-81-009
EHAD
Armour, Hibbard E., +e author.
0 Energy conservation in wastewater treatment. *n Chapter II: #b considerations for design concepts
and operational parameters / *c prepared by Hibbard E. Armour, Chief & Nicholas B. McCamy,
Environmental Engineer, Operation & Maintenance Section Water Division.
1 Boston, MA: *b United States Environmental Protection Agency, Region I, Operations &
Maintenance Section, Water Division, *c 1981.
26 pages : #b table ; #c 28 cm
text #b txt +2 rdacontent
unmediated *b n +2 rdamedia
volume *b nc +2 rdacarrier
"January, 1981."
"William R. Adams, Jr., Regional Administrator."
"February 1981"-Cover.
Includes bibliographical references (pages 20-26)
0 Waterworks +x Energy conservation.
0 Sewage disposal plants *x Energy conservation.
7 Sewage disposal plants *x Energy conservation. +2 fast +0 (OCoLC)fstO1113956
7 Waterworks *x Energy conservation. +2 fast +0 (OCoLC)fst01172817
McCamy, Nicholas B., *e author.
United States. #b Environmental Protection Agency. #b Region I. *b Operations and Maintenance
Section. *b Water Division, *e issuing body.
Delete Holdings- Export- Label- Produce- Submit- Replace- Report Error- Update Holdings- Validate C
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MAJOR CASE HISTORY
The Wilton Wastewater Treatment Plant
New England has a number of treatment facilities that were designed
with energy conservation in mind. The Wilton, Maine plant is presented in
this report as a major case history of energy-efficient plant design and
operation. The facility was designed to provide effective treatment with
low energy demands.
The Wilton plant was designed to provide secondary treatment of waste-
water with a minimum amount of commercial energy. The 450,000 GPD plant,
located in the west-central mountain region of Maine, serves a community
of 4,200 residents.
The treatment processes employed in the facility were chosen for
their energy-conserving operation and maintenance. Preliminary treatment
consists of trash screening, grit removal, comminution and bar screening,
flow measuring and sampling. Primary treatment is accomplished by roto-
strainers. Secondary treatment consists of rotating biological contactors
and final clarification. The effluent is disinfected and discharged
into the Wilson River.
Sludge screenings from the primary rotostrainers are combined with
sludge from the final clarifiers and pumped to anaerobic digesters for
stabilization. Sludge is then dewatered and hauled to fields for land
application.
The Wilton plant combines an energy-conscious design approach with the
latest technology in wastewater processing. Direct solar energy, backed by
methane gas produced from the anaerobic digesters, may supply as much as three-
fourths of the heat required to run the plant, thereby reducing the dependency
on commercial energy. Recycling of waste heat energy further contributes to
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the overall efficiency of the plant. Energy-efficient rotating biological
contactors provide secondary treatment. The 450,000 GPD facility takes
maximum advantage of site location, natural terrain, and novel building
construction to minimize energy needs.
SITE LOCATION
The site location for the Wilton plant was carefully chosen to take
full advantage of sunlight and natural terrain. Maximum utilization of
sunlight was achieved by orienting the main building to face directly
south. Gravity flow is used throughout most of the plant to minimize
the need for energy-consuming pumps. Treatment processes are grouped for
maximum gravity flow and heat utilization. Snow covering and earth place-
ment provide natural insulation.
Landscaping allows winter sunlight to reflect off the snow onto the
solar panels for better efficiency. Low-profile trees have been planted
to provide a windbreak. An area, near the plant, has been set aside for
storage of sludge for future use as a soil conditioner to supplement high-
energy fertilizer.
BUILDING DESIGN
Energy conservation is evident in the design of the treatment plant
buildings. The main building was designed to trap snow on its roof and
against its walls for insulation. All building materials were especially
chosen for their low maintenance and high durability characteristics.
Light colored stone chips provide a reflective coating on the roof to reduce
heat gain in the summer and radiation loss in the winter. Maximum control
of heat loss is achieved by partitioning the interior of the building into
separate areas according to temperature requirements. All windows and
doors have been fully insulated.
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The main building's interior was also designed to provide for a pleasant
working atmosphere with a minimum amount of space to be heated and a maximum
amount of natural illumination. Interior room partitions are constructed
of translucent fiberglass to allow maximum utilization of available light.
Interior walls not intended to transmit light are painted light colors to
provide maximum reflection.
PLANT PROCESSES
Headworks
The plant processes were especially chosen for their energy-efficient
operation. Screw pumps lift the wastewater to a height sufficient to allow
gravity flow throughout the remainder of the plant. Screw pumps were selected
because they use less power than centrifugal pumps, require no appreciable
wet well, are easily accessible for maintenance, and can handle variable
flows without changing speed.
Primary Processes
Primary solids removal is achieved by self-cleaning primary roto-
strainers rather than by conventional primary settling tanks. The strainers
consist of cylindrical stainless-steel wedgewire screens rotated by a
half-horsepower motor. The motor that drives the strainers consumes less
power than conventional sludge pump-motors. The screens are continuously
cleaned by a wiper blade. The screenings are deposited by gravity into a
sludge hopper directly below the rotostrainers. Particles not removed by
the blade are removed by backwash action.
Secondary Processes
The Wilton plant uses rotating biological contactors (RBC's) for secondary
treatment. Final clarifiers provide the physical separation process. The
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secondary system will achieve 85 - 95% removal of BOD and total suspended
solids.
The RBC system employs a fixed-film biological mass supported on
thin, closely-spaced plastic discs. There are four units of RBC's used in
Wilton. In each unit, the discs are mounted on a shaft in two separate
groups. The shafts rotate to allow the microorganisms exposure to oxygen
as well as contacting the waste water. The motors that rotate the shafts
use less energy than the motor-driven mechanical aerators or the blowers
that are usually employed in biological treatment systems. The average
detention time in the RBC process is only 30 minutes, and because of the
high biomass concentration that is maintained, high organic loading may be
treated effectively.
Flexibility is an important advantage of the RBC system. The RBC's
are arranged so that two, three, or four units may be used at any time
depending on plant operating conditions. The efficiency of the RBC process
is temperature dependent. Four units are usually required during the
winter months. However, during the summer, the operator may be able to
achieve effective treatment with two or three units. This flexible arrange-
ment also allows for maintenance of the units during normal downtime.
Final Clarifiers
Two peripheral-feed final clarifiers process the effluent from the RBC
units. Skirts are positioned in the tanks to distribute flow equally
around the periphery and direct the flow to the bottom of the tanks. This
in turn helps prevent short-circuiting. The overflow launder located in
the center is adjustable to ensure proper flow.
Unlike the activated sludge process, no recycling of sludge is required
in the RBC system. RBC's, therefore, operate at a lower energy demand
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than the more conventional activated sludge systems. However, the sludge
must be removed from the clarifiers on a regular basis. Generally speaking,
RBC sludge is characterized by large floe particles that exhibit good
settleability. The particles dewater more easily than sludge produced in
an activated sludge process. These qualities favor potential energy savings.
Disinfection
The effluent from the final clarifiers passes through a flow-metering
system, and is then dosed with a solution of sodium hypochlorite produced
on-site. The sodium hypochlorite is generated electrochemically at a
rate of 250 lbs. per day, by converting sodium chloride to sodium hypochlo-
rite. The cost is comparable to commercial chlorine gas. The generation
of sodium hypochlorite at the plant greatly reduces the safety problems
and supply uncertainties inherent with gaseous chlorine.
SOLAR ENERGY
The application of passive and active solar heating is one of the most
significant energy conservation measures used within the facility. Fourteen
thousand square feet of active solar panels are located on the south roof
of the main building. The pitch of the roof was set at 60 degrees to
achieve maximum winter radiation from the sun. The solar panels can function
primarily as heat collectors for the anaerobic digesters. An antifreeze
solution, pumped through the panels, is heated to a temperature of between
120 and 140 degrees Fahrenheit. Through heat exchangers, this heats water
which then may heat the digesters. The heat may also be passed on to the
building's heating system. A methane-fired boiler, and as a last resort,
a heat pump extracting energy from the plant effluent, provide backup for
prolonged cold and cloudy weather.
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Passive solar energy, transmitted through translucent fiber-glass
panels, is the only source of heat for some of the buildings. An exception
is the RBC building where very little sunlight is allowed because the
growth of algae is counter productive for RBC operation.
HEATING SYSTEM
A small treatment facility such as the Wilton plant would ordinarily
need all the methane gas produced in winter to heat the anaerobic digesters.
The Wilton plant, however, uses solar energy to heat the digesters,
thereby freeing the methane gas to be stored for use in heating the building
and running an electric generator. Methane is more economical to store
than solar heated water and is much more flexible to use. The methane
heating system itself is tailored to interface with numerous heat recovery
systems located throughout the plant. Excess heat is recovered from the
effluent water, exhaust air, and from the generator coolant, for re-use
within the building. Heat recovered from exhaust air in the ventilation
system is used to preheat cold air drawn into the plant. The effluent,
normally discharged at a temperature of 50° F., acts as a heat source for a
heat pump. The pump extracts heat from the effluent and captures as much
as 12 degrees of heat energy from 450,000 gallons of effluent flow.
Operating Costs
Operating costs for the Wilton plant are presented below. These are
estimates based on the 1977 calendar year. This information was extracted
from Water & Wastes Engineering, March 1976> p. 20.
A conventional system with no heat recovery and no additional controls
would require approximately 900 x 10® BTU/year of #2 fuel oil.
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90QX106
140,000x .7 = 9184 gallons/year
At 48 cents/gallon (1977)
9184 x .48 = $ 4408/year saved by not using #2 oil.
The Wilton plant was designed to use approximately 586 x 10® BTU/year
Building requires: 586 x 10® BTU/year
Heat supplied by solar: 356 x 10® BTU/year
Heat supplied by methane: 200 x 10® BTU/year
Net commercial energy required: 31 x 10® BTU/year
Heat pump coefficient performance =2.8 electric use.
31 x 10®
2.8 x 3.4 = 3256 KWHR/year (1977) = $ 114/year
3256 KWHR x $.035/KWHR = 700/year
Total Cost $814/year
Additional electricity savings from pumps and fans, and excess methane used
to generate electricity: 25000 KWHR/year x $.035 = $875/year savings.
Total Savings of System = 4408 - 814 + 875 = 4469/year (1977)
Savings per square foot floor area = $4469/13494 = $.33/sq. ft./year.
Note: Present 1981 fuel oil prices result in far greater
savings than those listed above, and this trend
will surely continue. However, since today's costs
are not readily available, there will be no attempt
to update the savings presented. It is safe to
say that with the inflated and rising power costs
that we now have with us, any means to conserve
energy through design will pay off.
The Wilton plant clearly demonstrates a conscious effort to provide
effective wastewater treatment with minimum energy demand. Although the
Wilton plant features extraordinary design concepts, it is not alone in the
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application of new technology now taking place. Many features of the
Hillsborough Treatment Plant in New Hampshire parallel those of the Wilton
plant. Further information on the Wilton or Hillsborough plant may be
obtained from the reference listings at the end of the this report.
The next chapter of this Energy Conservation Series will continue the
focus on wastewater facility designs that demonstrate outstanding efforts
to conserve energy.
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MINOR CASE HISTORIES
Many plant operators in our region have used their ingenuity and
experience to save energy. To tap this source of information, operators
throughout New England were approached through their associations and
asked to share their experiences and case histories with us. It was
encouraging to find the degree of interest in energy conservation that
exists among the operators.
Interest in energy conservation is becoming paramount in the minds of
designers and operators alike. Rapid increases in power and heating costs
have led to plant designs and operations that may well be oriented more
toward saving energy than to reliable wastewater treatment. Designers may
elect to reduce mechanical processes in favor of more labor-intensive
units. This could have adverse effects if the labor intensive operations
are neglected by plant personnel. Similarly, plant operators may want to
conserve energy by reducing power or heating costs at the expense of
treatment quality. Actions taken by operators to reduce aeration, lower
temperature, decrease pumping, or otherwise modify the plant's operation,
must be carefully weighed to assure that efficient process performance
is not being impaired. Energy conservation is not an acceptable excuse
for effluent violations.
The following examples were chosen from operator responses to show
the spectrum of activities being practiced to conserve energy. These
activities range from simple common-sense changes to complete modification
of process operations. All have an energy savings impact. The impact, if
any, on plant efficiency will clearly show on discharge monitoring reports.
° Somersworth Wastewater Treatment Facility, Somersworth, New Hampshire
Superintendent: Mark Gauthier
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Plant Description: The 2.4 MGD plant accomplishes secondary treatment
by complete mix extended aeration. The sludge processing consists of
floatation thickeners and vacuum filters.
Operators at the Somersworth facility have been making a conscious
effort to save energy, chemicals, and manpower. They bypass their
floatation thickeners during the winter months and use secondary clari-
fiers as gravity thickeners. This process saves both energy and chemicals,
and provides adequate concentration of the sludge prior to coil filtra-
tion. Sludge thickening is accomplished by installing timers on the return
pumps, set to run for 10 minutes out of each hour. The concentrated
sludge is then pumped directly into holding tanks. This modification
in the wasting schedule cut the operating time of the sludge pumps by
60 percent, and reduced much of the need for operator surveillance. A
polymer-feed line was installed on the coil filter to improve sludge
conditioning, and thereby reduce the amount of chemicals used in dewatering.
Considering manpower, electricity, and chemicals, there is a saving of
$2,600 per month when gravity thickening is employed.
Two wood stoves were installed to reduce oil consumption. One of
the stoves was tied into the plant's air handling system to warm the
main building. Ceiling fans were installed to circulate heat down
to work areas rather than allowing heat to escape through the roof.
A homemade stove was installed at the other end of the building and
a fan placed behind it to circulate the heat. With both stoves operating,
the plant was able to cut oil consumption by 60%. All operators cut wood
from city-owned property adjacent to the plant, eliminating the need to
purchase wood.
The operators are taking measures to save on electricity. The
public-utility company changed the plant's electric meter to a magnetic
tape system that provides them a print-out of electricity used at half-hour
intervals during the entire month. This enables them to determine when
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their highest demands occur and make appropriate adjustments. Starting
pumps at different intervals and running equipment during off-peak
demand periods has greatly reduced power costs.
Several plants have invited utility companies to conduct energy audits.
The recommendations from such audits usually result in substantial energy
savings.
Optimization of heat in the digesters often produces excellent results
with minimal commercial fuel use.
James Deile has saved $106,000 this past year by burning waste crankcase
oil in their fluidized-bed incinerator (Torrington WWTP, Harwinton, CT).
Substantial savings in the cost of electric power can be achieved by
monitoring dissolved oxygen levels closely to match aeration to changing
needs. CAUTION: Do not sacrifice process quality to save power!
Common-sense energy-conservation measures will reduce fuel and electri-
city costs. These include weather stripping windows and doors, keeping
thermostats down, rewiring lights to illuminate selected areas of large
rooms, and turning off lights that are not needed.
Woonsocket Wastewater Treatment Facility, Woonsocket, Rhode Island
Chemist: Adel Banoub
Plant Description: The 16-MGD plant achieves secondary treatment by
conventional activated sludge processing. Sludge is thickened by gravity
thickeners and dewatered by vacuum filtration.
A considerable number of kilowatt-hours have been saved by closer
monitoring and control of dissolved oxygen concentrations in the aeration
tanks. Results of a kilowatt-hour survey conducted throughout the
plant revealed that one blower could be used instead of two for much of
the time, and still maintain effective treatment. The savings in power
in the last year are summarized in the following table:
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1 1
1 1
Power Consumed,
KWH
1 1
1 1
I KWH Saved |
1 1
I Month |
1 1
1
1979 |
1980
1 1
| April |
1 |
1
634,200 |
1
491,400
1 1
| 142,000 |
i |
1 1
1 ^y 1
| |
1
593,600 |
|
446,600
1 1
| 147,000 |
1 |
1 1
| June |
1 |
1
618,800 |
1
446,600
1 1
| 228,200 |
| |
1 1
I July |
1 1
1
632,800 |
1
450,800
| 182,000 1
1 1
° Larry Spencer has been able to save an average of 300 gallons of fuel
oil per day by changing his incinerator sludge-burning schedule. He was
burning sludge on a daily basis, but now he burns sludge 24 hours a day
for three to four days and then puts the incinerator on standby for
three days. (Merrimack WWTP, Merrimack, NH).
° William Royce saves an average of 4,000 gallons of No. 2 fuel oil annually
by changing his incinerator sludge burning-schedule. He has also
installed an 80-gallon electric water heater to save on fuel oil.
Water is heated by the electric heater in the summer and by an oil-fueled
boiler in the winter. This saves the plant 3,000 to 3,500 gallons of
No. 2 fuel oil annually. (Newport WWTP, Newport, NH).
0 Charles Buttrick fills adjoining tanks in winter months to reduce heat
loss through tank walls. He also puts plywood covers on the gratings
over sludge holding tanks to keep heat in during the winter. (Greenville
WWTP, Greenville, NH).
° Joel Goode bypasses most of the instrumentation and automatic controls
on his heating and ventilation system. By running the system in the
manual mode, the operator has saved 200 to 700 gallons of oil weekly.
(Berlin WWTP, Berlin, NH).
0 Staggered running of pumps and motors may reduce peak demands of electricity.
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New Technology
The Clean Water Act of 1977 clearly established the intent of Congress
to encourage the use of innovative and alternative technology (I/A). The
I/A program is a part of the Federal Construction Grant program, and all
municipalities in the U.S. that can apply for a normal 75% Federal Construc-
tion Grant to construct improved wastewater treatment works may also be
eligible for an I/A (85%) grant. The objectives of the I/A program are to:
~Reclaim, re-use water
~Recycle wastewater constituents
~Eliminate surface discharge
~Conserve or recover energy
~Lower total costs
The active I/A Technology Program has been established as further
inducement for the consideration of innovative technologies. This program
is a joint effort of the EPA Construction Grants and Reserach and Development
Program.
The overall thrust of this program is to: (1) identify recently emerging
I/A technologies ready for implementation, (2) identify and recommend project
sites throughout the country that may potentially benefit from emerging
technology (3) assist local communities and their consulting engineers with
assessment and analysis of emerging technologies that may be applicable to
their specific wastewater treatment control or management problems, (4) to
provide consulting engineers with detailed planning and engineering assistance
on a project-by-project basis.
The following are innovative or alternative projects in Region 1
either approved or under consideration that provide for some degree of
energy reduction. (The Wilton plant was designed prior to the enactment
of the I/A program and is therefore not included in the listing):
° Hillsborogh, New Hampshire
Total energy concept: Solar heated anaerobic digesters; active and
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passive solar building heat; energy conservation building technology;
effluent heat pump; rotating biological contactors.
° Kennebunk and Dexter, Maine
Ultraviolet Radiation Disinfection System: Eliminates energy-intensive
pumps and evaporators normally required in gaseous chlorine systems.
No residual disinfection exists, thus eliminating the possible need for
dechlorination or reaeration. Dangers associated with the production of
hazardous chlorinated hydrocarbons are also eliminated.
° Cranston, Rhode Island
Improved Aeration System: Provides high oxygen transfer efficiency at
low power levels. The aeration system utilizes draft-tube, submerged
turbine aerators in deep (25 to 30 foot tanks). Air is introduced
approximately mid-depth, immediately below the axial-flow turbine, thus
reducing blower discharge pressure. The flow is carried down to the
bottom of the tank where pressure increases oxygen absorption before
undissolved gases rise to the surface.
0 Isleboro, Maine; Vassaboro, Maine; Sabattus, Maine; Weare, New Hampshire;
Ossipee, New Hampshire:
Subsurface Septic Tanks and Leaching System: On-site treatment eliminates
the need for energy-demanding pumps, aeration equipment, and other
processes required by a wastewater treatment plant.
There have been other projects approved by EPA Region 1 that, although
do not qualify under the I/A program, do incorporate enerqv-saving devices
or processes. The following is a list of some of these projects. This
list will be expanded in subsequent reports:
° Framingham, Massachusetts (Saxonville Pump Station)
Heat Utilization: The pump station is independent of commercial electric-
ity. The pumps are driven by D-8 caterpillar tractor engines fueled by
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natural gas. Generators driven by the pump engines provide electricity
for lights and equipment. The engines heat the building and provide
snow-melt heating of the walks and driveway.
0 Ellsworth, Maine
Energy Saving Concept: Methane gas from anaerobic digesters is used to
heat the digesters and the building. Passive solar heating of buildings.
Rotostrainers provide primary treatment, and RBC's provide secondary.
Conclusion
We have looked at several existing plants that take advantage of
effective energy-conservation measures in their design and operation. The
Wilton plant demonstrates the kinds of energy-saving measures that can be
incorporated into the design of a treatment plant. The Somersworth and
Woonsocket plants are impressive examples of conscious efforts by operators
to minimize energy demand from existing equipment or processes. It is
hoped that this document will encourage operators and design engineers to
give more attention to energy conservation.
Our next report will present new case histories of energy-conserving
treatment plants. We will also discuss in more detail how some of the
latest energy conservation devices or processes work.
It is requested that the consulting engineers, the State and Federal
reviewers, and the operators of facilities, all make an effort to provide
us with suggestions, case histories, or other data that can be used to
promote the energy conservation cause in the treatment of wastewater.
Your contribution should be sent to:
Hibbard E. Armour, Chief
Operations & Maintenance Section
Environmental Protection Agency - Rm. 2113
Water Division
JFK Federal Building
Boston, MA 02203
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Acknowledgments
We want to thank the following operators for their contribution to the
report:
Frank D. Arnold (Somerset, MA WWTP)
Kenneth Baily (New Milford, CT WWTP)
Adel Banoub (Woonsocket, RI WWTP)
John A Bickford (New London, NH WWTP)
John Biggerstaff (Suffield, CT WWTP)
Robert M. Brinck (Hinsdale, NH WWTP)
Charles Buttrick (Greenville, NH WWTP)
Jim Carleton (Westport, CT WWTP)
Joseph W. Cass (Seymour, CT WWTP)
Edward J. Cichon, Sr. (Williamantic, CT WWTP)
James Conway (East Greenwich, RI WWTP)
Tom Costick (Goshen, CT WWTP)
George Daigle (Madawaska, ME WWTP)
James Deile (Torrington WWTP, Harwinton, CT)
R.A. Draper (Elmhurst WWTP, Portsmouth, RI)
Robert J. Gaipo (East Providence WWTP, Riverside, RI)
Mark Gauthier and Greg Mack (Somersworth, NH WWTP)
Alphonse Girard (Sprague WWTP, Baltic,. CT)
Joel Goode (Berlin, NH WWTP)
John Gorman (Fort Fairfield, ME WWTP)
Thomas Hastings (Keene, NH WWTP)
James Hirshberg (Huntington, MA WWTP)
Gerald W. Holcomb (Winchester, NH WWTP)
Bruce M. Kudrick (Hooksett, NH WWTP)
Gorden A. Lambert (West Lebanon, NH WWTP)
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Edward Lane (Lenox, MA WWTP)
George Laney (Newmarket, NH WWTP)
Michael Lannon (Thompson WWTP, Mechanicsville, CT)
Arthur LeBlanc (Norwich, CT WWTP)
Gerald J. Loso (Suncook, NH WWTP)
Alfred R. Maheu (Warner Village Fire District WWTP, Warner, NH)
Ralph F. Mandeville, Jr. (Glastonbury, CT WWTP)
A. Joseph Mattera (Cranston, RI WWTP)
Samuel Moncata (Middletown, CT WWTP)
Bruno Nicolai (Meriden WWTP, South Meriden, CT)
James Noel (Crane & Co. WWTP, Dolton, MA)
Jack Norton (West Haven, CT WWTP)
Frank O'Neill (Newport, RI WWTP)
William Royce (Newport, NH WWTP)
C. F. Shaw (South Windsor, CT WWTP)
Kenneth A. Shilinsky (Webster, MA WWTP)
Jeffery Shortell (Shelton, MA WWTP)
E. R. Sousa (Bristol, RI WWTP)
Larry Spencer and Kenneth Sherwood (Merrimack, NH WWTP)
Louis Theriault (Southington WWTP, Plantsville, CT)
Greg Wedman (Danbury, CT WWTP)
Tom Weeks (Peterboro, NH WWTP)
James P. Whalen (Town of Salisbury WWTP, Lakeville, CT)
Rich Williams (East Windsor WWTP, Warehouse Point, CT)
John R. Wood, Sr. (Plymouth, NH WWTP)
Michael Wrabel (Windsor Locks, CT WWTP)
Robert J. Young (Manchester, CT WWTP)
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BIBLIOGRAPHY
The material used in the development of the Wilton case history and the
new technology section was obtained from the following documents:
Frank, A., "Something Old . . . Something New - Applying Solar Technology to
Sludge Management," Research and Technology, pp. 22 - 26, March - April,
1980.
United States Environmental Protection Agency, Office of Water Program
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Wilke, D. A., "There is Something New Under the Sun!" Water and Wastes
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Wright, Pierce, Barnes and Wyman Engineers, "Operation Manual - Wilton
Maine Wastewater Treatment Plant," Vol. I and II, Chapters
IV, V, VI, X, July, 1977.
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1979
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