Town of Williamstown, MA Utilities

Catch basins shall be installed on both sides of the roadway at intervals not to exceed 300 feet and at such other places as deemed necessary by the Department to assure adequate drainage of all low points and to provide proper runoff of stormwater. In no instances shall catch basins be located along a driveway cut. Each catch basin shall have a sump a minimum of two feet and six inches below the invert of the lowest drain.

Manholes shall be constructed to the required depth at each junction point with a maximum spacing of 300 feet. All lines shall be straight between manholes both as to line and grade.

All drains, including catch basin laterals, shall be at least 12 inches in diameter.

The minimum cover shall be two feet six inches for the drainage system, one foot for driveway culverts.

All lots upgradient of the road drainage system shall be provided with an individual connection to the storm sewer or drainage facilities for footing drain and/or sump pump connections unless an alternate method is available. Pipe size shall be a minimum of four inches.

The movement, or piping, of groundwater through pipe bedding material shall be taken into account during design, especially in areas where roads are constructed in heavier soils, on steep road grades or where groundwater may be present. The use of clay trench dams downgradient of drainage structures with weep holes, the use of subdrains or other appropriate methods shall be employed.

(7)

Water velocities shall be between two and 15 feet per second in the pipes, not over five feet per second in grass swales and not over 12 feet per second in lined swales, where such are allowed.

Materials.

Pipe.

Polyvinyl chloride (PVC) pipe shall be PVC gravity sewer pipe with a smooth interior and meeting the material requirements of ASTM D3034 for SDR 35 or ASTM F679, or for ribbed exterior pipe, ASTM F794. All pipe shall have a minimum pipe stiffness at 5% deflection of 46 pounds per square inch, as tested by ASTM D2412. Joints shall be gasketted bell and spigot meeting ASTM D3212.

High-density polyethylene (HDPE) pipe shall consist of an exterior corrugated wall and smooth wall interior polyethylene tubing, with gasketted couplings and fittings. Materials, dimensions, physical properties and fabrication shall be in conformance with AASHTO M294.

Reinforced concrete pipe (RCP) shall conform to ASTM C76, Class IV, with bell-and-spigot-type joints conforming to ASTM C443.

Storm sewers and culverts up to 36 inches in diameter shall be RCP, PVC or HDPE meeting MDPW Standard Specifications requirements.

All storm sewers greater than 36 inches in diameter shall be RCP unless otherwise approved by the Department. All culverts greater than 36 inches shall be RCP or precast concrete box culverts, meeting the requirements of AASTHO, Standard Specifications for Highways and Bridges, 1989. The use of corrugated metal pipe (CMP) or pipe arch culverts may be appropriate in some instances, and the Department will review and approve on a case-by-case basis. Corrugated metal pipes and pipe arches shall conform to MDPW Standard Specification M5.03.0.

Perforated six-inch PVC or corrugated HDPE pipe shall be used for subdrains. All culverts shall be designated with adequate inlet and outlet protection taking into account the design flow, velocity and soil conditions. Concrete headwalls, flared-end sections, riprap or other appropriate methods shall be used to protect the culvert, road, embankment and drainage course.

Catch basins and manholes.

All materials shall conform to MDPW Standard Specifications, as follows:

	Description	Material Specification
	Clay brick	M4.05.2
	Cement concrete brick	M4.05.0
	Cement concrete block	M4.05.1
	Cement mortar	M4.02.15
	Gravel borrow	M1.03.0, Type A
	Precast units	M4.02.14

The standard frame and grate to be supplied for catch basins shall be LeBaron, Catalog Number LF248-2, or approved equal.

The frame and cover to be supplied for manholes shall be LeBaron, Catalog Number LF268-3, with three-inch lettering to read "Drain," or approved equal.

Gravel and stone. Screened gravel shall conform to MDPW Standard Specifications, M1.03.0, Type C. The Type C gravel borrow shall conform to the gradation requirements, as previously described in § 113-8B(1) but shall have a maximum stone size in the largest dimension of two inches and shall conform to MDPW Standard Specifications, M1.03.0, Type A. Crushed stone shall conform to MDPW Standard Specifications, M2.01.4., as previously described in § 113-10B(2).

Construction.

PVC and HDPE pipe shall be jointed in accordance with the recommendations of the latest ASTM standards and detailed instructions of the manufacturer. No single piece of pipe shall be laid unless it is generally straight.

All pipe shall be sound and clean before laying. As soon as the excavation is complete to normal grade of the bottom of the trench, screened gravel or crushed stone bedding shall be placed, compacted and graded to provide firm, uniform and continuous support for the pipe. Bell holes shall be excavated so that only the barrel of the pipe bears upon the bedding. The pipe shall be laid accurately to the lines and grades indicated on the design drawings. Blocking under the pipe will not be permitted.

Screened gravel, or crushed stone, shall be placed evenly on each side of the pipe to mid-diameter and hand tools shall be used to force the bedding under the haunches of the pipe and into the bell holes to give firm continuous support for the pipe. Screened gravel, or crushed stone, shall be placed to a minimum of 12 inches above the top of the pipe. The initial three feet of backfill above the screened gravel, or crushed stone, backfill shall be placed in one-foot layers and carefully compacted. Generally, the compaction shall be done evenly on each side of the pipe, and compaction equipment shall not be operated directly over the pipe until sufficient backfill has been placed to ensure that compaction equipment will not have a damaging effect on the pipe.

Each length of PVC pipe shall be shoved home against the pipe previously laid and held securely until enough backfill has been placed to hold the pipe in place. Joints shall not be pulled or cramped.

Before any joint is made, the pipe shall be checked to assure that a close joint with the next adjoining pipe has been maintained and that the inverts are matched and conform to the required grade. The pipe shall not be driven down to grade by striking it.

Reinforced concrete pipe (RCP) shall be installed in accordance with MDPW Standard Specifications, Section 230.

(7)

Excavation and backfilling shall conform to MDPW Standard Specifications, Sections 120.60, 150.60 and 150.64.

(8)

Basins, manholes and inlets shall be built to the lines, grades, dimensions and design shown on the plans and as directed, with the necessary frames, gratings, covers, etc., and in accordance with these specifications.

(9)

Brick and concrete blocks shall be soaked in water before laying. All joints in the brick structures shall be thoroughly flushed full of mortar, and no joint on the inside face shall be greater than 1/4 inch. After the bricks are laid, the joints shall be pointed on the inside. As brick walls are laid up, the outside of the structure shall be plastered with one-half-inch thick mortar coat. As circular concrete block walls are laid up, the horizontal joints and keyways shall be flushed full with mortar. As rectangular blocks are laid up, all horizontal and vertical joints shall be flushed full with mortar.

(10)

Plastering of the outside of block structures will not be required. The joints in precast units shall be wetted and completely mortared immediately prior to setting a section. No structure shall be backfilled until all mortar has completely set. When the floors of structures are made of concrete sectional plates the opening in the floor shall be filled with brick chips and mortar or cement concrete.

(11)

Frame castings for basins and manholes shall be set in full mortar beds true to the lines and grades, as directed.

(12)

Where directed, the castings shall be temporarily set at such grades as to provide drainage during the construction.

(13)

The castings of structures located within the pavement area shall not be completely set to the established grade until the bottom course of pavement has been laid.

(14)

The final setting of all other castings shall be performed at the proper stage of construction, as directed.

(15)

Cement concrete collars shall be placed around the castings after the final setting, as shown on the plans, and as directed.

(16)

Unless otherwise directed, two weep holes shall be built into the walls of all new basins and precast units, as shown on the plans. Each weep hole shall consist of a section of four-inch pipe, or equivalent opening, to carry water through the wall of the structure.

(17)

The ends of the pipe, if used, shall be saw cut and left flush with the walls of the structure.

(18)

The outside end of the pipe or opening shall be covered with a one-fourth-inch mesh galvanized wire screen 23 gage satisfactorily fastened against the wall. The drain to the weep hole shall be excavated and backfilled with two cubic feet of crushed stone conforming to MDPW Standard Specifications, M2.01.4. The stone shall be placed against, and over, the end of the pipe or opening to prevent the entrance of the finer filling material. Only one type of weep hole shall be used throughout the project.

(19)

The structure shall be backfilled with gravel borrow and compact.

§ 113-15 Sanitary sewers.

Design.

Minimum size sewer shall be eight inches. Minimum size house service shall be four inches. In general, sewers shall be designed deep enough to drain basement fixtures of all houses to be connected to the sewer, but in no case shall the depth of cover be less than five feet, unless written approval from the Department is obtained.

The sanitary sewer shall be located in the center of the street, or as close thereto as possible when the street is curved.

All sanitary sewers shall be designed and constructed in straight lines between manholes. The sewer lines shall be designed for a minimum flow velocity of two feet per second (fps).

All manholes shall be precast concrete and be spaced at a maximum of 300 feet on straight runs, and at every intersection, change in grade and/or alignment, change in size and at the end of each line.

Where a gravity sewer is not feasible, a pressure sewer shall be installed.

The pressure system may be designed with individual grinder pump units or a duplex pump station. Individual grinder pump units shall be maintained by the individual property owner. The duplex pump station shall be designed so that the wet well is separate from the pumps and controls. The design shall meet the requirements of the Williamstown DPW.

Materials.

Gravity sewer pipe and fittings.

Pipe and fittings shall be PVC gravity sewer pipe with a smooth interior meeting the material requirements of ASTM D1784. The pipe shall also meet the requirements of ASTM D3034 for SDR 35 or ASTM F679, or for ribbed exterior pipe ASTM F794. All pipe shall have a minimum pipe stiffness of five-percent deflection of 46 pounds per square inch, as tested by ASTM D2412. Saddle wyes will not be allowed.

PVC pipe and fittings shall have bell-and-spigot push-on joints, meeting ASTM D3212. The bell shall consist of an integral wall section with a solid cross-section elastomeric gasket securely locked in place to prevent displacement during assembly. Elastomeric gaskets shall conform to ASTM F477.

All fittings and accessories shall have bell-and/or-spigot configurations compatible with the pipe.

Precast manholes. Precast concrete barrel sections and transition top sections shall conform to Specifications for Precast Reinforced Concrete Manhole Sections, ASTM C478, and meet the following requirements:

The wall thickness shall not be less than five inches for forty-eight-inch diameter reinforced barrel sections.

Top sections shall be eccentric, except that flat concentric top sections shall be used where shallow cover requires a top section less than four feet, as shown on drawings.

Barrel sections shall have tongue-and-groove joints with approved round rubber O-ring gaskets, or a preformed flexible joint sealant.

All sections shall be cured by an approved method and shall not be shipped, nor subjected to loading, until the concrete compressive strength has attained 3,000 pounds per square inch, and not before five days after fabrication, whichever is longer.

Precast concrete barrel sections with precast top slabs and precast concrete transition sections shall be designed for a minimum of H-20 loading, plus the weight of the soil above.

The date of manufacture and the name and trademark of the manufacturer shall be clearly marked on the inside of each precast section.

Precast concrete bases shall be constructed and installed, as shown on the drawings. The thickness of the bottom slab of the precast bases shall not be less than the manhole barrel sections or top slab, whichever is greater.

Type II cement shall be used except as otherwise approved.

All exterior surfaces of sanitary manholes shall be given two coats of waterproof coating.

Sanitary sewer drop connection manholes shall be of the internal drop connection type, as shown in the details.[1] The minimum size manhole will be five feet internal diameter.

[1]

Editor's Note: Details are included at the end of this chapter.

Brick masonry.

The bricks shall be good, sound, hard and uniformly burned, regular and uniform in shape and size, of compact texture and satisfactory to the Department. Underburned or salmon brick will not be acceptable, and only whole brick shall be used unless otherwise permitted. In case bricks are rejected by the Department, they shall be immediately removed from the site of the work and satisfactory bricks substituted therefor.

Bricks for the channels and shelves shall comply with the latest specifications for ASTM C32 for Sewer Brick, Grade SS (from clay to shale), except that the mean of five tests for absorption shall not exceed 8%, and no individual brick shall exceed 11%.

Bricks for building up and leveling manhole frames shall conform to ASTM C62.

Mortar used in the brickwork shall be composed of one part Type II portland cement conforming to ASTM C150 to two parts sand to which a small amount of hydrated lime, not to exceed 10 pounds to each bag of cement, shall be added.

The sand used shall be washed, cleaned, screened, sharp and well graded as to different sizes and with no grain larger than that which will pass a No. 4 sieve. It shall be free of organic matter, loam, organic or other materials of such nature or of such quantity as to render it unsatisfactory.

The hydrated lime shall also conform to ASTM C207, Type S.

Manhole frame and cover.

Manhole frames and covers shall be of good quality, strong, tough, even-grained cast iron which is smooth, free from scale, lumps, blisters, sand holes and defects of any kind which render them unfit for the service for which they are intended. Manhole covers and frame seats shall be machined to a true surface. Castings shall be thoroughly cleaned and subject to hammer inspection. Before shipment from the foundry, castings shall be given one coat of coal tar pitch varnish which shall present a casting that is smooth and tough, but not brittle. Cast iron shall conform to ASTM A48, Class 30.

Manhole covers shall have a diamond pattern, pick holes and the word "sewer" centered on the cover in three-inch letters.

Standard manhole frames and covers for all applications shall provide a twenty-four-inch clear opening. Manhole frames and covers shall be LeBaron Foundry No. LB-268-1, or approved equal.

Precast manhole section joints.

Tongue-and-groove joints of precast manhole sections shall be sealed with either a round rubber O-ring gasket or a preformed flexible joint sealant.

If round rubber O-ring gaskets are used, they shall conform to ASTM C443. They shall be designed and manufactured so that the completed joint will withstand an internal water pressure in excess of 15 pounds per square inch without showing any leakage by the gasket or displacement of it.

The contractor shall provide facilities for testing the effectiveness of the joints against leakage. Such tests shall be made by an internal pressure against the joint of at least 15 pounds per square inch.

Manhole rungs.

Manhole rungs shall be steel reinforced copolymer polypropylene plastic. Rungs shall be 14 inches wide.

Copolymer polypropylene shall be Type II, Grade 16906, meeting ASTM Specification 2146. Steel reinforcing shall be three-eights-inch in diameter, Grade 60, conforming to ASTM Specification A615 and shall be continuous throughout the rung. The portion of the legs to be embedded in the precast section shall have fins and be tapered to ensure a secure bond.

(7)

Pipe connections to manholes. Manhole pipe connections may be accomplished in the following ways:

The "Lock Joint Flexible Manhole Sleeve" shall be cast in the precast manhole base. The stainless steel strap and exposed sleeve shall be protected from corrosion with a bituminous coat.

"A-Lok" shall be a rubber-like gasket cast in the precast manhole base. The rubber gasket shall be cast into a formed opening in the manhole.

"KOR-N-SEAL" joint shall be installed as recommended by the manufacturer. The stainless steel clamp shall be protected from corrosion with a bituminous coat.

"Res-Seal" shall be a rubber-like O-ring set in a formed opening in the manhole. Once the pipe is in place, the O-ring and pipe shall be secured in place by means of a cast-iron follower or compression flange. All exposed metal shall be protected from corrosion with a bituminous coat.

(8)

Pump station. Duplex pump stations shall be constructed of reinforced concrete, precast or cast-in-place, and shall be supplied with nonclog pump controls, wiring, shut-off valves, access hatches and other required appurtenances.

(9)

Nonclog submersible pump.

Type: single-speed, submersible centrifugal nonclog sewage pump; solids handling capacity, three inch sphere minimum.

Casing: cast iron with corrosion protective coating with oil-filled motor chamber; all exposed hardware shall be corrosion resistant stainless steel.

Pump: centrifugal type, impeller shall be cast iron or enameled cast iron, fully enclosed, keyed to stainless steel shaft.

Seals: two mechanical seals with carbon and ceramic faces, oil lubricated, with oil-filled seal chamber between seals.

Motor: close-coupled, constant speed motor, preferably three phases.

Overload protection: automatic reset type thermal overload thermostat incorporated into the pump motor.

Motor controls: duplex control panel with weatherproof NEMA 4 outer enclosure with dead front panel; all components mounted within inner NEMA 1 enclosure; main disconnect switch and starter with overload and short circuit protection for each pump; control circuit main switch with short circuit and adjustable thermal trip protection; hand-off automatic switch for each pump; transformer 230 V.-110 V.-24 V.; relay for automatic alternation of pumps; control fuses; green running light for each pump; all necessary terminal strips; control relays, panel powered for high wet well level alarm switch; one-hundred-ten-volt red high wet well level alarm light in weatherproof enclosure; 110 V. yellow lead pump off alarm light in weatherproof enclosure; one elapsed-time meter for each pump; hermostatically controlled space heater; convenience outlet, duplex receptacle for auxiliary power with manual transfer switch mounted within the enclosure; control panel shall be UL approved.

Level controls: mercury switch level sensors with corrosion and shock-resistant casing with firmly bonded electrical cable; cable shall be permanently bonded to metal enclosed mercury switch with entire assembly encapsulated for water and impact-resistant unit; switch shall be weighted and designed to actuate but not float; level controls system shall include support brackets to allow the suspension of the switches at the proper levels in the wet well; duplex stations shall have level controls for high-level alarm, low-level alarm, lead pump on, lag pump on and all pumps off;

Cables: electric and control cables shall be of the size and type applicable to the pump motor and control system requirements. Junction boxes shall be located within the pump station.

(10)

Screened gravel: Screened gravel shall conform to MDPW Standard Specifications M1.03.0, Type C, as previously described in § 113-8B(1).

(11)

Crushed stone. Crushed stone shall conform to MDPW Standard Specifications M2.01.4, as previously described in § 113-10B(2).

Construction.

Pipe installation.

Care shall be taken in shipping, handling and laying to avoid damaging the pipe and fittings. Extra care will be necessary during cold weather construction.

Any pipe or fitting showing a crack or which has received a blow that may have caused an incipient fracture, even though no such fracture can be seen, shall be marked as rejected and removed at once from the work area.

All pipe ends shall be square after cutting.

While stored, pipe shall be adequately supported from below at not more than three-foot intervals to prevent deformation. Pipe shall not be stacked higher than six feet. Pipe and fittings shall be stored in a manner which will keep them at ambient outdoor temperatures.

Temporary shading, as required, to meet this requirement shall be provided. Simple covering of the pipe and fittings which allows temperature buildup when exposed to direct sunlight will not be permitted.

PVC sewer pipe and fittings shall be jointed in accordance with the recommendations of the latest ASTM standards and detailed instructions of the manufacturer.

All manhole connections shall be equipped with an integral O-ring or other sealant such that a positive watertight seal is established.

No single piece of pipe shall be laid unless it is generally straight.

The centerline of the pipe shall not deviate from a straight line drawn between the centers of the openings at the ends of the pipe by more than 1/16 of an inch per foot of length. If a piece of pipe fails to meet this requirement check for straightness, it shall be rejected and removed from the site. Laying instructions of the manufacturer shall be explicitly followed.

Any pipe or fitting discovered to be defective after laying shall be removed and replaced with a sound piece.

The Engineer may examine each bell-and-spigot end to determine whether any preformed joint has been damaged prior to installation.

Any pipe having defective joint surfaces shall be rejected, marked as such and immediately removed from the job site.

All pipe shall be sound and clean before laying. When laying is not in progress, including lunch time, the open ends of the pipe shall be closed by watertight plugs or other approved means. Good alignment shall be preserved in laying.

Pipe and fittings shall be installed in accordance with the instructions of the manufacturer, ASTM D2321, and as specified herein.

(o)

As soon as the excavation is complete to normal grade of the bottom of the trench, screened gravel or crushed stone bedding shall be placed, compacted and graded to provide firm, uniform and continuous support for the pipe. Bell holes shall be excavated so that only the barrel of the pipe bears upon the bedding. The pipe shall be laid accurately to the lines and grades indicated on the definitive plan. Blocking under the pipe will not be permitted. Bedding shall be placed evenly on each side of the pipe to mid-diameter, and hand tools shall be used to force the bedding material under the haunches of the pipe and into the bell holes to give firm continuous support for the pipe. The bedding material shall be placed a minimum of 12 inches above the top of the pipe and carefully compacted. The initial three feet of backfill above the bedding material backfill shall be placed in one-foot layers and carefully compacted. Generally, the compaction shall be done evenly on each side of the pipe, and compaction equipment shall not be operated directly over the pipe until sufficient backfill has been placed to ensure that such compaction equipment will not have a damaging effect on the pipe.

(p)

Each length of the pipe shall be shoved home against the pipe previously laid and held securely until enough backfill has been placed to hold the pipe in place. Joints shall not be pulled or cramped.

(q)

(r)

Precautions shall be taken to prevent flotation of the pipe in the trench.

(s)

When movable trench bracing, such as trench boxes, movable sheeting, shoring or plates, is used to support the sides of the trench, care shall be taken in placing and moving the boxes or supporting bracing to prevent movement of the pipe, or disturbances of the pipe bedding and the screened gravel backfill. Trench boxes, movable sheeting, shoring or plates shall not be allowed to extend below mid-diameter of the pipe. As trench boxes, movable sheeting, shoring or plates are moved, screened gravel shall be placed to fill any voids created, and the screened gravel and backfill shall be recompacted to provide uniform side support for the pipe.

(t)

All fittings shall be furnished by the same manufacturer that furnishes the pipe.

(u)

Wye branches shall be furnished and installed and capped for all lots. Service connections shall be installed at a minimum slope of 2% to the edge of the right-of-way. In each case the end shall be capped and backed with a four-inch by four-inch wood post extending to the finished ground surface.

(v)

All wye branches and capped ends shall have their exact locations documented and include tie dimensions on as-built plans.

(w)

PVC manhole drops shall be installed as internal drop connection manholes, as shown on the details.

(x)

Pipe stubs for manhole connections shall not exceed four feet in length unless directed otherwise by the Engineer. Install caps where required.

Testing and cleaning of pipe.

For making low-pressure air tests, the developer shall use equipment specifically designed and manufactured for the purpose of testing sewer pipelines using low-pressure air. The equipment shall be provided with an air regulator valve or air safety valves so set that the internal air pressure in the pipeline cannot exceed nine pounds per square inch gauge. The leakage test using low-pressure air shall be made on each manhole-to-manhole section of pipeline. Pneumatic plugs shall have a sealing length equal to, or greater than, the diameter of the pipe to be tested. Pneumatic plugs shall resist internal test pressure without requiring external bracing or blocking.

All air used shall pass through a single control panel.

Low-pressure air shall be introduced into the sealed line until the internal air pressure reaches four pounds per square inch gauge greater than the maximum pressure exerted by groundwater that may be above the invert of the pipe at the time of the test. However, the internal air pressure in the sealed line shall not be allowed to exceed nine pounds per square inch gauge. When the maximum pressure exerted by the groundwater exceeds five pounds per square inch gauge, the developer shall conduct only an infiltration test. At least two minutes shall be allowed for the air pressure to stabilize in the section under test. After the stabilization period, the low-pressure air supply hose shall be quickly disconnected from the control panel. The time required in minutes for the pressure in the section under test to decrease from 3.5 to 2.5 pounds per square inch gauge (greater than the maximum pressure exerted by groundwater that may be above the invert of the pipe) shall not be less than that calculated using the test time equation below as found in the Recommended Practice for Low-pressure Air Testing of Installed Sewer Pipe, UNI-B-6-90, Uni-Bell PVC Pipe Association's latest revision.

T = 0.085 (DK/Q)
Where:
T	=	Shortest time, in seconds, allowed for the air pressure to drop to 1.0 pounds per square inch gauge
K	=	0.000419 DL, but not less than 1.0
Q	=	0.0015 cubic feet/minute/square feet of internal surface
D	=	Normal pipe diameter in inches
L	=	Length of pipe being tested in feet

If the pipe section does not pass the air test, sectionalize the section tested to determine the location of the leak. Once the leak has been located, repair and retest.

A Mandril Test shall be performed on the sewer system. Pipe segments exceeding the allowable deflection limits shall be located, repaired and retested.

Manhole installation.

Manholes shall be constructed to the dimensions as specified in these Road Construction Standards. All work shall be protected against flooding and flotation.

The precast bases of manholes shall be placed on a bed of twelve-inch screened gravel or crushed stone. The manhole shall be set at a grade to assure that a maximum of eight-inch thickness of brickwork will bring the manhole frame and cover to final grade.

Precast concrete barrel sections shall be set so as to be vertical and with sections in true alignment with a one-fourth-inch maximum tolerance to be allowed. The joints of precast barrel sections shall be sealed with either a rubber O-ring set in a recess or the preformed flexible joint sealant used in sufficient quantity to fill 75% of the joint cavity. The outside and inside joint shall be filled with nonshrink mortar and finished flush with the adjoining surfaces.

Allow joints to set for 24 hours before backfilling. Backfilling shall be done in a careful manner, bringing the fill up evenly on all sides. If any leaks appear in the manholes, the inside joints shall be caulked with lead wool, or another method that is satisfactory to the Engineer. The developer shall install the precast sections in a manner that will result in a watertight joint.

Holes in the concrete barrel sections required for handling or other purposes shall be plugged with nonshrinking grout or nonshrinking grout in combination with concrete plugs, and finished flush on the inside.

Where holes must be cut in the precast sections to accommodate pipes, cutting shall be done prior to setting manhole sections in place to prevent any subsequent jarring which may loosen the mortar joints.

Manhole pipe connections shall be accomplished in the ways specified hereinbefore. Pipe stubs for future extensions shall also be connected and the stub end closed by a suitable watertight cap.

Steel reinforced polypropylene plastic manhole rungs shall be driven into tapered holes in the precast riser and cone sections during the manufacture of the sections. Holes for rungs shall be performed during the casting of the sections and shall not be drilled out after casting. The preformed holes shall be a minimum of 3 1/2 inches deep and shall taper from 1 1/8 inches to 1 3/8 inches diameter. Precast sections having rungs which are mortared or grouted in place shall not be accepted.

Mortar shall be mixed only in such quantity as required for immediate use and shall be used before the initial set has taken place. Mortar shall not be retained for more than 1 1/2 hours and shall be constantly worked over with hoe and shovel until used. Antifreeze mixtures will not be allowed in the mortar.

No masonry shall be laid when the outside temperature is below 40° F., unless provisions are made to protect the mortar, bricks and finished work from frost by heating and enclosing the work with tarpaulins or other suitable material. The Department's decision as to the adequacy of protection against freezing shall be final.

Channels and shelves shall be constructed of brick and concrete.

The brick-line channels shall correspond in shape with the lower half of the pipe. The top of the shelf shall be set at the elevation of the crown of the highest pipe and shall be sloped one inch per foot to drain toward the channel. Brick surfaces exposed to sewage flow shall be constructed with the nominal two-inch by eight-inch face exposed (i.e., bricks on edge).

Manhole covers and frames shall be set in a full mortar bed and bricks, a maximum of eight inches thick, and shall be utilized to assure frame and cover are set to final grade prior to placement of permanent paving.

All new manholes shall be thoroughly cleaned of all silt, debris and foreign matter of any kind, prior to final inspection.

Pump station installation.

Excavate soil in accordance with lines and levels required for installation of the pump station.

Pump station shall be set on a properly compacted twelve-inch bedding of screened gravel or crushed stone.

Suitable backfill material shall be placed and compacted in layers not to exceed eight inches.

Install pump station effluent gravity sewer connection and provide for pressure sewer discharge pipe, as specified.

Install exterior electrical wiring for pump station, as specified.

Pump tests.

[1]

Each unit installed shall be subjected to field pump tests, as described below, after determination that:

[a]

Proper service voltage is supplied.

[b]

Proper rotation of pump has been established.

[2]

During the pump test, no cooling of the unit by forced or circulated air shall be allowed.

[3]

The following field pump tests shall be performed:

[a]

Dry run test of the unit in which no liquid is to be allowed to enter the inlet of the pump. The pump exterior shall begin dry and remain dry during the test.

[b]

Dry pumping test of the unit in which liquid shall be at a level sufficient to keep the pump volute submerged to its center line during the test. The pump shall be operated at the system design point.

[c]

Snore test, in which "snore" is defined as that state when the pump is alternately pumping liquid and air, would occur when the pump pumps the liquid down to expose the inlet. The unit under test shall be submerged with just enough liquid to accomplish "snore" and allowed to run for the stated time.

§ 113-16 Water.

Design.

In general, all water mains shall be sized to adequately deliver both maximum daily consumption and fire flow requirements. In sizing mains, due consideration shall be given to the location of the mains in regard to the distribution system so that pressure losses are held to a minimum. The minimum size for any main shall be eight inches, however, the sizes of all water mains shall meet with the approval of the Williamstown DPW.

The minimum size for house services shall be 3/4 of an inch.

All water mains shall be adequately valved at all street intersections.

Hydrants shall be spaced a maximum of 500 feet. Hydrant laterals shall be six inches in diameter and each shall be provided with a gate valve. Between intersections all mains shall be valved at intervals not greater than 1,000 feet. These valves shall preferably be spaced between hydrant locations so that not more than two hydrants will be taken out of service at one time.

Materials.

Pipe.

Ductile iron pipe shall be cement lined and shall conform to ANSI A21.51 and AWWA C151, Class 52. The pipe shall be supplied in lengths not in excess of 20 feet. Pipe shall be standard mechanical joint or push-on type pipe, as manufactured by the American Cast Iron Pipe Company, or US Pipe and Foundry Company, Clow Corp., or approved equal. Fittings shall be mechanical joint ductile iron Class D. Fittings shall meet the requirements of ANSI, NEWWA and AWWA specifications, as applicable. Rubber gasket joints shall be Super Bell-Type, Tyton or MJ push-on joints conforming to ANSI A21.11. To provide electrical conductivity across the pipe joints, cable bond conductors or serrated bronze wedges gaskets shall be used, as manufactured by the pipe supplier. Bolts shall be Ductile Durabolts and shall meet the requirements of ANSI C-111 and AWWA A211-80. All pipe and fittings shall have a cement mortar lining on the inside and a coal tar enamel coat on the outside, in accordance with ANSI A21.4, except that cement mortar lining shall be 1/8 inch in thickness for pipe two inches to 12 inches in diameter, with a plus tolerance of 1/8 inch. Each pipe and fitting shall have cast on it, or stamped into the metal, the initials of the maker's name and the year cast. Cast iron or ductile iron fittings shall conform to ANSI Specifications A21.10 for mechanical joints. Solid sleeves, plugs and caps shall conform to AWWA Specification C110, Class D.

All fittings shall have restrained joints. Bends, reducers, tees, valves, dead ends and hydrants are among the places where thrust forces create unbalanced forces in the piping and where the pipe and fittings shall be restrained. The minimum length of pipe to be restrained on either side of the joint shall be as shown in the table below:

Fitting		Number of Joints to Restrain on Either Side of Fitting (based on 18 feet of pipe length)
90 bend		2
45 bend		1
22.5 bend		1
Tee:
	Branch	2
	Run	2

No restraining is required in the direction of an existing pipe if only a short length of it is exposed in the trench for making a new connection.

Concrete thrust blocks, instead of restrained joints, shall be used at locations where no sufficient length of pipe is available for restraining.

Gate valves. Valves shall be rated for 200 pounds per square inch minimum working pressure and a minimum 400 pounds per square inch test pressure. Valves shall be mechanical joint, have a cast-iron body, nonrising bronze stem, O-ring seals and be of the resilient seal seat type gate valve meeting the requirements of AWWA C509. For standardization purposes, all gate valves shall be waterous resilient wedge valves. The operating nut shall be standard AMA two-inch square. Gate valves shall open left or counterclockwise.

Tapping sleeves and gate valves. Tapping valves shall meet the requirements of AWWA C500. The valves shall be flanged by mechanical joint outlet with nonrising stem, designed for vertical burial and shall be the O-ring type. Operating nut shall be AWWA standard two-inch square. The valve shall be provided with an overload seat to permit the use of full size cutters. Gaskets shall cover the entire area of flange surfaces. Tapping sleeves shall be 200 pounds per square inch minimum working pressure with cadmium-plated cast-iron nuts and bolts. Sleeves shall be mechanical joint for ductile iron and/or cast-iron pipe. Tapping sleeves and valves shall be manufactured by Mueller.

Valve boxes.

Each gate valve shall be accompanied by a valve box of the adjustable type, of heavy pattern, constructed of cast iron and provided with cast-iron cover.

The upper section of each box shall have a flange at the top, having sufficient bearing area to prevent settling. The bottom of the lower section shall enclose the operating nut of the valve and be base belled and have a forty-eight-inch base in length and a twenty-six-inch or thirty-six-inch top section with no bottom flange.

The box top will be the sliding type. Boxes shall be of lengths consistent with the pipe depths. In general, all pipe installed will have five feet minimum of cover. Covers shall have the word "water" cast in the top.

Hydrants. Hydrants shall be Mueller Centurian, and shall conform to the Standard Specifications for Fire Hydrants for Ordinary Water Works Service, AWWA C502, and, in addition, shall meet the specific requirements and exceptions which follow:

Hydrants shall be according to manufacturers standard pattern and of standard size and shall have one four-and-one-half-inch pumper nozzle and two two-and-one-half-inch hose nozzles.

Hydrant inlet connections shall have mechanical joints for six-inch ductile iron pipe.

Hydrant valve opening shall have an area at least equal to that area of five-and-one-fourth-inch minimum diameter circle and be obstructed only by the valve rod. Each hydrant shall be able to deliver 500 gallons minimum through its two two-and-one-half-inch hose nozzles when opened together with loss of not more than two pounds per square inch in the hydrants.

Each hydrant shall be designed for installation in a trench that will provide five feet of cover. Hydrant extensions shall be manufactured by the company furnishing the hydrants and of a style appropriate for the hydrants finish.

Hydrants shall be hydrostatically tested, as specified in AWWA C502.

All nozzle threads shall be National Standard Thread.

Each nozzle cap shall be provided with a Buna N rubber washer.

Hydrants shall be so arranged that the direction of outlets may be turned 90° without interference with the drip mechanism and without the mechanism obstructing the discharge from any outlet.

Hydrants must be capable of being extended without removing any operating parts.

A bronze nut and check nut shall be provided to hold the main hydrant valve on its stem.

Hydrants must open by turning operating nut to the left (counterclockwise) and must be marked with an arrow and word "open" to indicate the direction to turn stem to open hydrant.

All iron work to be set below ground, after being thoroughly cleaned, shall be painted with two coats of asphalt varnish specified in AWWA C502 and iron work to be left above ground shall be shop painted with two coats of paint of quality and color to correspond with the present standard of the owner.

Each hydrant shall be designed such that the hydrant valve closes with line pressure preventing loss of water and consequent flooding in the event of traffic damage.

Each hydrant shall be furnished with a steel chain holder, double steel cap chain, steel pumper cap chain and any other hooks and/or appurtenances required for proper use.

(o)

Drain rings on each hydrant shall be plugged.

Service connections.

Corporation stops will be Mueller 110 compression connection, or a Mueller flared connection.

Curb stops will be Mueller Oriseal Full Flow 110 conductive compression or floated fitting without drain.

Curb valve boxes will be for 3/4 inch service connections, Erie type extension, or Minneapolis pattern, sixty-six-inch length; one inch pipe screw cap.

Valve boxes will be for one- to two-inch inside diameter, cast iron construction.

Copper tubing shall be Type K, soft temper, conforming to ASTM B88. The name or trademark of the manufacturer and type shall be stamped at intervals along the pipe.

Water services shall be minimum of 3/4 inch diameter.

Construction.

Pipe and fittings.

Care shall be taken in loading, transporting and unloading to prevent injury to the pipe or coatings. Pipe or fittings shall not be dropped. All pipe or fittings shall be examined before laying, and no piece shall be installed which is found to be defective. Any damage to the pipe coatings shall be repaired, as directed by the Engineer.

If any defective pipe is discovered after it has been laid, it shall be removed and replaced with a sound pipe. All pipe and fittings shall be thoroughly cleaned before laying, shall be kept clean until they are used in the work and when laid, shall conform to the lines and grades required. Ductile iron pipe and fittings shall be installed in accordance with requirements of AWWA Standard Specification C600 except as otherwise provided herein. A firm, even bearing throughout the length of the pipe shall be constructed by tamping select material at the sides of the pipe up to one foot over the top of the pipe.

Blocking will not be permitted.

All pipe shall be sound and clean before laying. When laying is not in progress, including lunch time, the open ends of the pipe shall be closed by a watertight plug or other approved means. Good alignment shall be preserved in laying. The deflection at joints shall not exceed that recommended by the manufacturer. Fittings, in addition to those shown on the plans, shall be provided, if required, in crossing utilities which may be encountered upon opening the trench. Solid sleeves shall be used only where approved by the Engineer.

When cutting pipe is required, the cutting shall be done by machine, leaving a smooth cut at right angles to the axis of the pipe.

Cut ends of pipe to be used with a Tyton bell shall be beveled to conform to the manufactured spigot end. Cement lining shall be undamaged.

Mechanical joints shall be in accordance with the Notes on Method of Installation under ANSI Specification A 21.11 and the instructions of the manufacturer. To assemble the joints in the field, the contractor shall thoroughly clean the joint surfaces and rubber gasket with soapy water before tightening the bolts.

Bolts shall be tight ended to the specified torque with a torque wrench.

Under no condition shall extension wrenches or pipe over handle or ordinary ratchet wrench be used to secure greater leverage.

The water mains shall be subjected to a hydrostatic pressure of 250 pounds per square inch for the pressure test, and this pressure shall be maintained for at least two hours. The leakage test shall be conducted concurrently with the pressure test at a pressure of 250 pounds per square inch, and this pressure shall be maintained for at least two hours. New hydrant branch gate valves shall remain open and tapping sleeve gate valves closed during the testing.

The amount of leakage permitted shall be in accordance with AWWA Specification C600, current edition. If any leaks occur during either test, they shall be repaired to the satisfaction of the Engineer.

The developer shall make any taps and furnish all necessary caps, plugs, etc., as required in conjunction with testing the pipe. He shall also furnish a test pump, gages and any other equipment required in conjunction with carrying on the hydrostatic tests. He shall at all times protect the new water mains and the existing water mains against the introduction of polluting material.

Before being placed in service, all new water pipelines shall be chlorinated in accordance with AWWA C601, Starting Procedure for Disinfecting Water Mains. The procedure shall be approved by the Engineer, in advance.

The location of the chlorination and sampling points will be determined by the Engineer in the field. Taps for chlorination and sampling shall be installed by the developer. The developer shall uncover and backfill the taps, as required.

(o)

The general procedure for chlorination shall be first to flush all dirty or discolored water from the lines, and then introduce chlorine in approved dosages through a tap at one end, while water is being withdrawn at the other end of the line. The chlorine solution shall remain in the pipeline for about 24 hours.

(p)

Following the chlorination period, all treated water shall be flushed from the lines at their extremities and replaced with water from the distribution system. Bacteriological sampling and analysis of the replacement water may then be made by the Engineer in full accordance with AWWA Specification C601. The developer will be required to rechlorinate, if necessary, and the line shall not be placed in service until the requirements of the Massachusetts Public Health Department are met.

(q)

Special disinfecting procedures shall be used in connections to existing mains, and where the method outlined above is not practical.

Gate valves. Gate valves and boxes shall be set with the operating stem vertically aligned in the center of the valve box. Valves shall be set on a firm foundation and supported by tamping selected excavated material under and at the sides of the valve. Gate valves shall be tied to the pipe with a mechanical joint anchoring tee of 3/4 inch diameter tie rods and clamps.

Tapping sleeves and valves.

Installation shall be made under pressure and the flow of water through the existing main shall be maintained at all times. The diameter of the tap shall be a minimum of 1/4 inch less than the inside diameter of the branch line.

The entire operation shall be conducted by workmen thoroughly experienced in the installation of tapping sleeves and valves.

The developer shall determine the location of the existing main to be tapped to confirm the fact that the proposed position for the tapping sleeve will be satisfactory and no interference will be encountered, such as the presence of existing utilities or of a joint or fitting at the location proposed for the connection. No tap will be made closer than three feet from a pipe joint.

Tapping valves shall be set in vertical position and be supplied with a two-inch square operation nut.

Tapping sleeves and valves with boxes shall be set vertically and squarely centered on the main to be tapped. Adequate support shall be provided under the sleeve and valve during the tapping operation. Sleeves shall be no closer than three feet from water main joints. Thrust blocks shall be provided behind all tapping sleeves.

Proper tamping of supporting earth around and under the valve and sleeve is mandatory. After completing the tap, the valve will be flushed to ensure that the valve seat is clean.

Valve boxes. Valve boxes shall be installed vertically, centered over the operating nut, and the elevation of the tap shall be adjusted to conform with the finished surface of roadway or other surface at the completion of the contract. Boxes shall be adequately supported during backfilling to maintain vertical alignment.

Hydrants.

Hydrants shall be set at the location designated by the Engineer and as shown on the definitive plan, and shall be bedded on a firm foundation. Each hydrant shall be set in true vertical alignment and shall be properly braced. Each hydrant shall be restrained with three-fourths-inch tie rods back to the hydrant gate valve/hydrant tee assembly.

The hydrant gate valve shall be restrained using a mechanical joint hydrant anchoring tee, or equal. Hydrants shall be touched up with matching paint, as required after installation.

Service connection.

At the time the new water main is being installed, new corporation stops, copper tubing, curb stops and curb boxes shall also be installed, as specified. Protection shall be provided for the threads of corporation stops. The new corporation stops shall remain closed until the copper tubing and curb stop is installed.

Service connections shall be installed for each lot, as required.

Curb stops shall be installed two feet beyond the right-of-way property line. In each case the end shall be capped and backed with a four-inch by four-inch wood post extending to four feet below the finished surface.

The developer shall be careful to obtain the exact location of each connection and record the tie dimensions on as-built plans before it is covered.

§ 113-17 Streetlights.

Design. Streetlights shall be installed as specified by the Williamstown Fire District.

Materials. Streetlights shall conform to the type and style in general use in the Town of Williamstown unless otherwise specified by the Williamstown Planning Board and Williamstown Fire District.

Construction. Streetlight stanchions shall be located at such intervals as required by the Williamstown Planning Board in the grass plot, and shall be installed in accordance with the procedure required by the Williamstown Planning Board and utility company.

§ 113-18 Other utilities.

Other utilities include natural gas, electrical, CATV and telephone lines.

Design.

Gas mains may be installed if gas connection is available. Electric, CATV and telephone lines shall be installed in underground conduits, or direct burial.

Transformers, switches and other such equipment shall be placed in approved aboveground locations outside the right-of-way. Gas mains, electric, CATV and telephone lines shall be installed outside of the paved road surface, generally as shown on the road cross-section details.