Bristol County Water Authority

Bristol County Water Authority
System Operation

The system is divided into two distinct production and distribution systems: the Bristol-Warren system, which is supplied by water from the four impounding reservoirs, and the Barrington system, which is supplied by a well and the two distribution systems which are interconnected at the Warren River.
The Child Street Plant in Warren treats all water from the impounding reservoirs, and has a rated capacity of 4.0 MGD. The Nayatt Road Plant in Barrington treats all water from the gravel packed well. The rated pumping capacity of the plant is 2.0 MGD.
The major Service gradient, which includes the Bristol-Warren system, has a gradient elevation of 180'. This system has two storage facilities with a combined capacity of 2.47 MG.
The Barrington system has an overflow elevation of 157' and is referred to as the Barrington gradient. This system has one distribution storage tank with a capacity of 0.846 MG.
There is one additional gradient fed by the major Service gradient. This is the Metacom Avenue High Service gradient which has an overflow elevation of 264'. This system includes one distribution storage tank facility with a capacity of 0.25 MG.


Source of Supply

SURFACE SUPPLY
Supply is provided by a system of four reservoirs in two watersheds all feeding into the Kickemuit Reservoir located at the station. The Palmer River watershed consists of Anawan Reservoir, which flows by stream to Shad Factory Reservoir. Water is then transferred to the Kickemuit Reservoir through seven miles of 18, 20, and 21 inch pipeline. This pipeline will carry 0.7 MGD by gravity. The Kickemuit River watershed consists of Swansea Reservoir which flows by stream to the Kickemuit Reservoir.

KICKEMUIT RESERVOIR
This reservoir, the original source of supply, is located upon the Kickemuit River in the Town of Warren and has a capacity of 41 million gallons at spillway elevation of 4.2'. Water is impounded by an earth filled rubble faced dam. The concrete spillway is a 50' gravity type concrete weir, over which are placed twenty cast iron tide gates topped by a 24" steel plate flashboard. The dam was originally built in 1883 and improved several times since.

SWANSEA RESERVOIR
This reservoir is located in the Town of Swansea, Massachusetts, and has a capacity of 154 million gallons at spillway elevation of 66'. Water from this reservoir is released when needed and flows through a natural stream bed approximately 3 ½ miles to the Kickemuit Reservoir. Water is impounded by a rip-rap faced, clay core, earth embankment dam, constructed in 1883. The dam section is approximately 1100' long and has an average height of 9'. The spillway is a simple concrete crested weir, 124' long with a rubble wing wall.

SHAD FACTORY RESERVOIR
This reservoir is located in the Town of Rehoboth, Massachusetts, on the Palmer River, 5 ½ miles north of Warren, and has a capacity of 39 million gallons at 15.3' elevation. Water from this reservoir flows into the Kickemuit Reservoir through an 18" cast iron transmission main 34,000' long. The dam, constructed in 1912, is earth embankment, 10' wide at the top by 400' long, with a concrete spillway and outlet at each end.

ANAWAN RESERVOIR
This reservoir is located in the Town of Rehoboth, Massachusetts, and has a capacity of 226 million gallons at the top of the wickets at elevation 99.75'. So long as Shad Factory remains full, no water is drained from storage at Anawan. When water is required, it is released through the outlet pipe and flows through the natural channels of Bad Luck Brook and the Palmer River approximately 6 ½ miles to the Shad Factory Reservoir. Water is impounded by an earth filled dam, 750' long, with a 55' gravity type concrete spillway, constructed in 1912, with steelplate wickets being added in 1945.

WELL
The Authority operates one groundwater treatment plant located on Nayatt Road in the Town of Barrington. The plant is supplied by a gravel packed, deep well situated on Authority-owned property. Water from the well is treated for iron.

TREATMENT FACILITIES
CHILD STREET STATION
Child Street Filter Plant is a conventional alum coagulation filtration facility originally built in 1908 with additions in 1921 and 1947. It has a rated capacity, as determined by a filtration rate of 2 GPM per square foot, or 4 MGD. It is manned by three shifts of operators 24 hours a day. The station supplies water to the major Service gradient.
Raw water is drawn from the Kickemuit Reservoir through a concrete intake structure. The intake is equipped with both bar and wire mesh screens. Coagulant chemicals are added just inside the intake screens. Four low service pumps with a total capacity of 14.42 MGD take their suction from the intake and deliver to the clarifier. The balance of the flow through the plant is accomplished by gravity.
The clarifier is an open cylindrical steel tank 75' I.D. with an outer sidewall height of 18'4". A steel curtain 34' in diameter and extending down 10' from the surface forms the two functional zones of flocculation and settling.
Coagulated water enters the unit through a central column and discharges into the flocculating zone just below the surface. The water then passes under the curtain into the settling zone. The floc settles to the bottom, then collected by radial sweep arms to be discharged as sludge, and the clarified water is collected at the surface through a series of eight radial steel troughs, each fitted with 96 V-notch weirs. The troughs connect with a peripheral collecting launder that carries the water to the primary sedimentation basin. Chlorine dioxide treatment to the raw water provides disinfection without the production of excessive trihalomethanes.
The sedimentation basin, a 84' x 84' x 21' concrete tank, is used primarily for additional settling time, although it can be used as an adjunct to the clarifier.
Water from the primary sedimentation basin transferred to the secondary sedimentation basin, a concrete tank 35' x 35' x 21', and from here is then distributed over eight filters of conventional sand-gravel rapid sand design. Each filter bed is rated at a 0.5 MGD and is equipped with hydraulic control valves. Filter wash water is supplied by a 2.32 MGD pump drawing directly from the clearwell.
Filtered water is collected in a 50,000 gallon clearwell located directly under the filters. Delivery to the distribution system is accomplished by three high service pumps with a total capacity of 10.30 MGD. Two venturi meters measure the plant output.
Natural gas and diesel engines on the low and high service pumps plus a natural gas-powered generator for chemical feeders and lights make operations without commercial electric power possible.

WASTEWATER TREATMENT
There are two sources of wastewater in the plant: filter wash water and clarifier sludge. Filter wash water is collected in a 0.05 MG concrete wastewater clarifier and allowed to settle; the sludge is then collected by a radial sweep arm and pumped to the sludge equalization basin. Clarifier sludge is discharged by gravity to the sludge equalization basin. The sludge is metered and pumped from the equalization basin into the municipal sewer system. The equalization basin and pumping facility was constructed in 1985.

NAYATT ROAD WELL STATION
Nayatt Road Well Station is an iron-manganese removal plant employing aeration, oxidation, filtration and pH adjustment. It is an unmanned station that is designed to operate semi-automatically, needing only daily routine maintenance and filter backwashing. Station output is determined by either distribution system pressure and/or the level of the Fountain Avenue standpipe.
The source of water is the Barrington well field consisting of a 12" gravel-packed well 73 to 84 feet deep. The well pumps into a common header that discharges into the aerator on the roof of the station. From this point, all flows are by gravity to the clearwell. At the aerator, hydrated lime and chlorine are added before the water is piped to the clarifier.
The clarifier is 42.5' in diameter and 12' in height, with a capacity of 0.121 MG and a detention time of 2.42 hours at 1.2 MGD. In the clarifier, the iron in the water is converted to an insoluble state and settles to the bottom to be collected by the radial sweep arms to be discharged as sludge. The clarified water is collected by a peripheral weir into a collecting launder.
The launder discharges into the raw water basin, which then acts as a hydraulic buffer for the control system, and from the raw water basin to the filters.
The six filters have a combined rated capacity of 2 MGD; each is equipped with a variable rate-of-flow controller on its effluent line.
From the filters, the water is collected in a clearwell located under the raw water basin. Two high service pumps rated at 1 MGD each deliver the finished water to the distribution system.
A 200 KW propane-powered generator has the capacity to handle all operations in case of disruption of commercial electric power service.
Filters are washed from the distribution system. Backwash water is discharged into the wastewater clarifier. There, after an adequate settling time, the supernatant is pumped back up to the aerator and the sludge is collected by the sweep arm and discharged together with the sludge from the pretreatment clarifier and then to the Barrington sewer system.
SHAD FACTORY PIPELINE
AND PUMPING STATION


STORAGE FACILITIES


EAST BAY PIPELINE
& PUMPING STATION



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