The specifications contained in this article
shall govern the installation of all waterworks utilities in the Town
of Marblehead unless otherwise determined by the Board.
Fittings shall be short body mechanical joint,
all bell, cast iron or ductile iron, minimum pressure rating of 250
psi, meeting the requirements of ANSI 21.10-1971 (AWWA C110-71), or
latest revision thereto. Fitting joint shall also meet the requirements
of ANSI A21.11-1972 (AWWA C111-72), or latest revision thereto.
Valves shall meet requirements of AWWA C500,
or latest revision, and shall be iron body resilient wedge design,
open right, for all valves four inches through 12 inches. All gates
larger than 12 inches shall be double disk with bronze disc rings
and bronze body seat rings. Stem shall be nonrising type, with two
"O" ring seals, two-inch operating nut, open right. Six-inch through
twelve-inch valves shall be designed for 200 psi working pressure,
400 psi hydrostatic test, and fourteen-inch and sixteen-inch valves
for 150 psi working pressure, 400 psi hydrostatic test. Joint type
shall be mechanical and shall include all accessories.
Valve boxes shall be cast iron, 5 1/4 inch
diameter, two-piece, sliding type, with lids marked "Water" providing
a minimum overlap of six inches.
A.
Hydrants shall be darling, or approved equal, meeting
Marblehead standards, five-inch with two two-and-one-half-inch diameter
hose nozzles and one four-and-one-half-inch diameter steamer nozzle,
a two-piece barrel with break-off flange at ground line and mechanical
joint base for six-inch connection, opening right with barrel of normal
trench depth (four-foot six-inch cover), nozzle threads and operating
nut to be Marblehead standard.
B.
Hydrant extension, if approved by the engineer, shall
be provided by the same manufacturer as the hydrants and shall include
barrel, rod, couplings, bolts, gaskets and all other accessory equipment
for a complete installation.
Service pipe from main to meter shall be Type
K copper tubing of 3/4 inch minimum size. Sizes larger than two
inches shall be cast iron or other materials approved by the Department.
Each service shall have a corporation cock at the main, Mueller Std.
with C.C. thread and Compression Connection, a curb cock in the sidewalk,
Mueller Blue top enclosed in a five-foot "Buffalo" box, and a shutoff
valve on the street side of the meter.
A.
Trenches for pipelaying shall be excavated in earth
and rock where encountered at the locations approved by the Board.
Trenches shall be straight in line and grade and at a uniform distance
from the side line. All trenches shall be excavated to depths so as
to provide four-foot six-inch cover over pipe below the established
finish grade of the surface (four feet six inches for hydrant branches).
B.
In rock excavation, depths shall be sufficient to
provide the specified cover and six inches' clearance between the
bottom of the pipe and the rock and nine inches to either side of
the pipe. The intervening space shall be filled with compacted gravel
or fine crushed stone.
A.
All pipe and fittings shall be laid in accordance
with best waterworks practice and the applicable requirements of the
Standard Specifications for Installation of Cast Iron Mains of the
American Waterworks Association (AWWA C600-54T). Pipe shall be laid
true to line and grade as given by the engineer and properly supported
and braced and backfill thoroughly tamped around and under the pipe
and fittings to provide proper support.
B.
Fittings shall be carefully aligned and supported,
retainer glands secured, and shall be braced with a concrete thrust
block. Mechanical joints shall be assembled in accordance with manufacturer's
recommendations and shall be thoroughly wire brushed before assembly
to remove loose rust or foreign matter. End of pipe, bell socket,
and gasket shall be brushed with soapy water just prior to assembly.
Glands shall be brought up evenly and bolts tightened with torque
measuring or indicating wrenches for 75 foot-pounds torque, or as
otherwise recommended by the manufacturer. Pipe shall not be deflected
either vertically or horizontally in excess of that recommended by
the manufacturer and only with the approval of the engineer. When
pipelaying is not in progress, the open end of pipes shall be closed
by approved means to prevent the entry of dirt or trench water into
the line. No pipe shall be laid in water, or on frozen trench bottom,
or when, in the opinion of the engineer, the trench conditions or
the weather are unsuitable for such work.
C.
When pipe cutting is required, it shall be carefully
and accurately accomplished, leaving a smooth clean cut, and particular
care must be exercised to prevent damage to the cement lining.
D.
Hydrants and valves shall be set plumb and secured
with operating stems vertical and boxes centered to provide for ready
application of wrench. Hydrants and valves shall be provided with
concrete blocking, stone bed, supports and retainer glands as shown
on contract drawings, or as directed by the engineer. Care shall be
taken when placing concrete thrust block behind hydrant to keep drip
clear of all obstructions.
E.
Copper service pipe shall have compression joints
as approved and standardized by the Department.
Bends, tees, hydrants and other fittings shall
be provided with reaction or thrust blocking by placing concrete between
solid ground and the fittings to be anchored. Concrete shall be 1:2 1/2:5
mix, Class B, placed as directed.
Ductile-iron retainer glands shall be required
on all six-inch valves, hydrants, and main bends, as shown on contract
drawings or as directed by the engineer. Glands shall be cast of high-strength
ductile iron, fitting with cup point, square head, double-heat-treated
steel set screws, and tightened to 75 foot-pounds torque.
Trenches for waterworks utilities shall be backfilled
with the best of excavated material. Selected material shall be used
to bed the pipe, and no rock shall be permitted nearer than two feet.
Backfill shall be hand tamped under and around the pipe and to a depth
of 18 inches over the top of the pipe. Machine backfilling for the
remainder of the depth shall be fully tamped to prevent subsequent
settlement, and where applicable the provisions of the Regulations
for Street Excavation approved by the Board of Selectmen shall apply.[1]
All required connections to existing water mains will be made by the Department unless authorized otherwise. For water mains to be installed in private property or private developments, the owner shall do all excavation at the existing main and furnish the fittings required at the main. The Department will install the fitting in accordance with § 268-14G. The owner shall then install the main, beginning at the outlet bell of the fitting, completely at his expense. For all service connections at existing mains, the Department will make the connections as part of the service (as detailed in Article III), but the owner shall do all excavation at the existing main.
A.
After completion of tests, the pipelines shall be
disinfected by application of chlorine either as calcium hypochlorite
or liquid sodium hypochlorite in an amount to produce a solution of
50 ppm for a contact period of 24 hours and afterward flushed until
the chlorine residual is reduced to less than 1.5 ppm. Chlorine dosage
shall be applied by pumping into the line to be treated a sufficient
count of chlorine in solution which, when mixed with the water in
the pipeline, will meet the required concentration. The mixture shall
be pumped through the section being treated and shall be discharged
and monitored at a point farthest from the point of introduction of
the chlorine. When the solution reaches the required concentration
of 50 ppm, the pump and discharge valve shall be closed, with the
liquid left in the section being chlorinated for 24 hours.
B.
The contractor shall furnish all materials and equipment
for the sterilization of the mains, but the Water Department will
furnish necessary assistance in flushing and the operation of gate
valves.
All new water mains shall be tested for leakage
as a measure of the quality of the workmanship and materials. The
main or system of mains shall be isolated by gating, filled with water
and all air exhausted. A metered connection shall be provided and
water introduced to the main or mains under a pressure of 50 pounds
per square inch greater than the normal operating pressure in the
test area. Leakage outward from the main in excess of 2.5 gallons
in 15 minutes per 1,000 feet of eight-inch pipe will be considered
as a condition which must be corrected before work will be accepted
by the Board as part of the Town system.
Layout and construction of water mains and appurtenances installed by private owners or developers will be subject to approval by the Department or its representative as detailed in Article I and § 268-14 of Article II. The engineer as authorized by the Board may also approve the plans and installation of waterworks utilities in public ways and private easements. In all cases the decisions, interpretations of the specifications, inspection and testing by the engineer, from time to time as the work progresses, shall be final, and final acceptance of the work by the Board will be based on a favorable recommendation by the engineer.
New and replacement water supply systems must
be designed to minimize or eliminate infiltration of floodwater into
the system.
