Utilities Division
NORTH ATTLEBOROUGH WASTEWATER
TREATMENT FACILITY
NITROGEN AND PHOSPHORUS REMOVAL UPGRADE
GROUNDBREAKING CEREMONY
OCTOBER 6, 2011
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Wastewater Treatment
The North Attleborough Wastewater Treatment Facility
(WWTF) collects and treats an average of 3.1 million
gallon per day of industrial and domestic wastewater
from the Town as well as the Town of Plainville.
History:
North Attleborough’s original sewer system was
built over 100 years ago. Since that time, the system
has been periodically expanded to accommodate additional
residential and industrial users. In 1909, F.A. Barbour
designed the Town’s first wastewater treatment
facility, which consisted of settling tanks, a dosing
tank, and intermittent sand filter beds. In 1948, major
improvements to the treatment facilities were designed,
which included a primary clarifier, trickling filter,
secondary clarifier, and reuse of the sand filter beds.
A chlorine contact facility was added in 1959.
The effluent from the treatment facility discharges
into the Ten-Mile River, an interstate stream that serves
as a source of public water supply in Rhode Island.
By the early 1960’s, the facility could no longer
properly handle the Town’s growing sewage flows.
Over loading of the plants various components caused
unsatisfactory wastewater treatment and environmental
problems.
Consequently, in 1964, North Attleborough commissioned
Whitman & Howard, Engineering Inc., to evaluate its
existing water pollution control facilities and develop
a long range, comprehensive pollution control program.
The resultant 1965 report recommended increasing the
capacity and efficiency of this plant, specifically
by constructing a secondary treatment facility, which
would incorporate some segments of the existing plant
and by rehabilitating the sand filter beds to insure
more efficient operation and improved treatment. However,
because effluent from the North Attleborough's treatment
facility significantly affected the water quality of
the Ten Mile River, a higher level of treatment was
mandated in 1969 by the Massachusetts Water Resources
Commission, Division of Water Pollution Control.
The Federal Water Pollution Control Act Amendments
of 1972 established new federal guidelines and regulations
for sewage treatment projects. As a result, the Town
was required to satisfy many new regulatory requirements
before the preparation of construction plans and specifications
could begin in the fall of 1976. The construction contract
for the treatment facility was advertised for bids in
September 1977, and awarded a few months later to the
lowest of six bidders who submitted proposals.
The construction phase of this project encompassed two
of the stormiest winters in the area’s history.
Yet, sewage was diverted from the former treatment plant
to the Town’s new facility on March 3, 1980 - seven
months before the contract completion date.
North Attleborough’s 4.6 mgd water pollution control
facility was designed to treat all wastewater from the
Town of North Attleborough and neighboring Town of Plainville
until approximately the year 2000, thus helping to stimulate
substantial industrial and residential development in
the area. A regional interceptor was also constructed
as part of this project, which conveys wastewater from
PlainviIle to the treatment plant and eliminated the
routine overflowing of the old interceptor. This $17,500,000
program was funded by grants of $12.5 million from the
Federal Government and $2.5 million from the Massachusetts
Division of Water Pollution Control. North Attleborough’s
share of the total project cost was $1.6 million. As
a joint user of the facility, the Town of Plainville
also contributed $.6 million for its share of construction
within the Town of North Attleborough.
For the past thirty years North Attleborough has worked
to formulate a cost effective, environmentally sound
program for wastewater collection and treatment. As
a result the Town now has a water pollution control
facility, which has abated ongoing degradation of the
area’s water quality, improved the aesthetic value
of the Ten-Mile River and protected the public and environmental
health of the community. Completion of this water pollution
control facility has made the Town’s sewage treatment
system available to additional areas of the Town through
extensions of the sewage collection system.
In the early 1980's, the Board of Public Works initiated
a study the effects of local industrial wastes. This
study determined the character of these wastes, assessed
their relative compatibility with the sewerage system,
and established industrial pretreatment regulations
for all incompatible wastes. As a result of this study
the Industrial Pretreatment Division was created.
In June 1989 the Town of North Attleborough reached
another major milestone in its ongoing sewer extension
program with the completion of the East Side Interceptor
and Patrick P. Grimaldi Pumping Station. A $1,700,000
grant from the U.S. Environmental Protection Agency
and a matching $2,670,000 grant from the Massachusetts
Division of Water Pollution Control funded the interceptor
and pumping station projects. Sewer main construction
was funded by a $1,040,000 grant from the Massachusetts
Division of Water Pollution Control under the Chapter
557 program. North Attleborough’s share of these
projects, $4,000,000, was appropriated at the October
1985, Semi-Annual Town Meeting.
North Attleborough Waste Water Treatment Facility that
was completed in 1980 was designed as an advanced wastewater
treatment plant in the 1970’s using treatment processes
understood at that time that were capable of meeting
what was considered to be stringent effluent limitations. The facility has seen several major upgrades of aging equipment throughout the last several years. These improvements and upgrades along with a diligent and dedicated staff have resulted in the facility receiving th e 2009 Plant Performance Award, which is given annually by the Massachusetts Water Pollution Control Association.
Treatment facilities at the plant include screening,
aerated grit chambers, primary clarifiers, first-stage
aeration tanks and clarifiers, second-stage aeration
tanks and clarifiers, gravity sand filters, chlorine
contact tanks, dechlorination facilities, and post aeration
tanks. Sludge handling facilities include flotation
thickeners and centrifuges.
Flow to the facility includes wastewater from two influent sewers and septage. The headwork's of the facility provides screening, grit removal, commutation and chemical addition for phosphorous removal in the primary clarifiers. Two-stage mechanical aeration provides for biological treatment of Biochemical Oxygen Demand (BOD) and nitrogenous wastes. The gravity sand filters provide final polishing of the effluent. Chlorine is injected into the effluent to destroy pathogens. The effluent is then de-chlorinated to eliminate any chlorine by products that could have a toxic effect on organisms that inhabit the river. The post aeration tank is provided to maintain adequate dissolved oxygen levels in the effluent to support aquatic life in the river. Sludge handling is accomplished by thickening the sludge in the thickeners to approximately 5% solids and is then trucked off site for further treatment and disposal.
In January of 2007 a new NPDES Permit was jointly issued by the US EPA and the MA DEP, the new permit contained reduced limits for phosphorous and nitrogen, which when combined with other discharges, be it from treatment plants or storm water run off, are considered the be the root cause of eutrification of the impoundments downstream of the treatment facility and ultimately causing environmental harm to the Narragansett Bay eco-system. The new limits imposed on North Attleborough’s Wastewater Treatment Facility will require an upgrade to the existing treatment facilities. The improvements are currently in the design process, and although costly, will enhance the Ten Mile River’s, and Narragansett Bay’s esthetic and recreational uses. These upgrades will be completed by June, 2013.
There are seven publicly owned pump stations in the
wastewater collection system and one privately owned:
Patrick P. Grimaldi Pump Station
Industrial Park Pump Station
Falls Pump Station
Metcalf Road Pump Station
Dodge Ave Pump Station
Edmund Corrigan Pump Station
Walden Woods Pump Station
Norton Rd. (privately owned)
In addition to the pump stations, the collection system
has two metering stations; the Plainville metering station
at Kelly Blvd. and at Moran Street.
NITROGEN AND PHOSPHORUS REMOVAL UPGRADE
The upgrade project includes three major components:
1. Nitrogen Removal-Nitrogen will be removed biologically through an advanced 5 stage Bardenpho system that will be capable of reducing the effluent total nitrogen concentration of less than 5 milligrams per liter (projected future limit). The system includes installation of energy-efficient high-speed turbo blowers for aerating the wastewater.
2. Phosphorous Removal-Phosphorous will be removed biologically through the 5 stage Bardenpho system and chemically through addition of a metal salt coagulant and solids removal with a cloth-media filtration system. This will be the first wastewater treatment plant in the United States designed to achieve a total phosphorus permit limit of 0.1 milligrams per liter using the cloth-media filtration technology.
3. Other Upgrades-Various systems will be upgraded, including pumping and electrical systems to accommodate the new equipment and to replace aging infrastructure.
er day of industrial and domestic wastewater
from the Town as well as the Town of Plainville.
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