(1) Water Mains and Fittings. Water mains to be installed shall be ductile iron pipe for all sizes, unless specifically noted otherwise. All ductile iron water pipe shall be delivered to the site with wrapping to cover the ends of the pipe or with pipe plugs. Either method used shall remain in unbroken condition until the pipe is installed.
The ductile iron pipe shall conform to AWWA C151 and shall be Class 52. Grade of iron shall be a minimum of 60-42-10. The pipe shall be cement lined to a minimum thickness of one-sixteenth-inch meeting NSF standards for potable water and the exterior shall be coated with an asphaltic coating.
Each length shall be plainly marked with the manufacturer’s identification, year cast, thickness, class of pipe and weight. The pipe shall be furnished with mechanical joint or push-on type joint, except where plans call for flanged ends. Joints shall conform to AWWA C111.
Restrained joint pipe shall be push-on joint pipe with FIELD LOK® or TR FLEX® gaskets as furnished by U.S. Pipe, or approved equal.
Restrained joint shall be used in fill areas, critical areas or as required by district.
All pipe shall be joined by the manufacturer’s standard coupling, be all of one manufacturer, and be carefully installed in complete compliance with the manufacturer’s recommendations.
Joints shall be “made up” in accordance with the manufacturer’s recommendations. Standard joint materials, including rubber ring gaskets, shall be furnished with the pipe. Material shall be suitable for the specified pipe size and pressures.
All fittings shall be short-bodied, ductile iron complying with AWWA C110 or C153 for 350 psi pressure rated mechanical joint fittings and 250 psi pressure rated flanged fittings. All fittings shall be cement mortar lined per the ductile iron pipe specifications and either mechanical joint or flanged.
Fittings in areas requiring restrained joints shall be mechanical joint fittings with a mechanical joint restraint device. The mechanical joint restraint device shall have a working pressure of at least 250 psi with a minimum safety factor of 2:1 and shall be EBAA Iron, Inc., MEGALUG, or approved equal.
All couplings shall be ductile iron mechanical joint sleeves.
The pipe and fittings shall be inspected for defects before installation. All lumps, blisters and excess coal tar coating shall be removed from the bell and spigot end of each pipe, and the outside of the spigot and the inside of the bell shall be wire-brushed and wiped clean and dry, and free from oil and grease before the pipe is laid.
Every precaution shall be taken to prevent foreign material from entering the pipe while it is being placed in the line. After placing a length of pipe in the trench, the spigot end shall be centered in the bell and pipe forced home and brought to correct line and grade. The pipe shall be secured in place with select backfill tamped under it. Precaution shall be taken to prevent dirt from entering the joint space. At times when pipe laying is not in progress, the open ends of pipe shall be closed by a watertight plug. If water is in the trench when work resumes, the seal shall remain in place until the trench is pumped completely dry. No pipe shall be laid in water or when trench conditions are unsuitable.
The cutting of pipe for inserting fittings or closure pieces shall be done in a neat and workmanlike manner, without damage to the pipe or cement lining, and so as to leave a smooth end at right angles to the axis of the pipe. When a pipe length is cut, the outer edge of the cut shall be beveled to prevent damage to the gasket during jointing of the pipes.
Pipe shall be laid with bell ends facing in the direction of the laying, unless approved otherwise by the district. Wherever it is necessary to deflect pipe from a straight line, the amount of deflection allowed shall not exceed pipe manufacturer’s recommendations.
For connection of mechanical joints, the socket, plain end of each pipe and gasket shall be cleaned of dirt before jointing, and shall be jointed according to manufacturer’s directions. Bolts shall be tightened alternately at top, bottom, and sides, so pressure on gasket is even.
For connection of push-on type joints, the jointing shall be done according to manufacturer’s recommendations, with special care used in cleaning gasket seat to prevent any dirt or sand from getting between the gasket and pipe. Lubricant to be used on the gasket shall be non-toxic and free from contamination.
Valves, fittings, plugs, and caps shall be set and jointed to pipe in the manner as required. All dead-ends on new mains shall be closed with dead-end M.J. caps.
Fittings shall be “blocked” with poured-in-place 3,000 psi strength concrete, with a firm minimum bearing against an undisturbed earth wall. Timber blocking will not be permitted. Thrust blocks shall be poured as soon as possible after setting the fittings in place to allow the concrete to “set” before applying the pressure test. The concrete thrust blocks shall be in place before beginning the pressure test. Anchor blocks shall be allowed to set sufficiently to develop the necessary bond strength between the reinforcing rods and the concrete anchor before beginning the pressure test. A visqueen barrier shall be provided to protect glands, bolts and other miscellaneous materials required for this type of connection from the connector.
Fittings and adjacent pipe lengths that cannot be blocked against an undisturbed earth wall shall be restrained. Concrete blocking is required and shall be installed as if blocked against undisturbed earth.
All of the new piping, valves and blocking shall have been installed, disinfected, and tested up to the point of cutting into existing lines before the crossover is made. The crossover to the existing system shall be in full readiness, including the cut and sized specials. Forty-eight-hour notice shall be given the district in advance of the planned “cut-ins.” All sleeves shall be ductile iron.
All backfill in roadway sections shall be placed and compacted in accordance with Snohomish County, city and/or state requirements and copies of the compaction results shall be provided to the district. All backfill in easements shall be placed and compacted to a minimum of 90 percent of modified proctor dry maximum density per ASTM D1557. Copies of compaction results for all water system trenches shall be provided to the district. Recycled concrete is not allowed for use in district trench sections, no exceptions.
(2) Valves. All valves 14 inches and larger shall be butterfly valves. All valves 12 inches and smaller shall be resilient seat gate valves.
(a) Resilient Seat Gate Valves. The gate valves shall be ductile iron body valves, iron disk completely encapsulated with polyurethane rubber and bronze, nonrising stem with “O” ring seals conforming to AWWA C509 or C515. The valves shall open counterclockwise and be furnished with two-inch square operating nuts except valves in vaults shall be furnished with handwheels. All surfaces, interior and exterior shall be fusion bonded epoxy coated, acceptable for potable water.
For applications with working pressure above 175 psi, a valve rated as 250 psi or higher shall be used.
Valves shall be Clow, M&H, Kennedy, U.S. Pipe, Mueller, American Flow Control, or approved equal.
(b) Butterfly Valves. Butterfly valves shall be ductile iron body of the tight closing rubber seat type with rubber seat either bonded to the body or mechanically retained in the body with no fasteners or retaining hardware in the flowstream. The valves shall meet the full requirements of AWWA C504, Class 150B except the valves shall be able to withstand 150 psi differential pressure without leakage. The valves may have rubber seats mechanically affixed to the valve vane. Where threaded fasteners are used, the fasteners shall be retained with a locking wire or equivalent provision to prevent loosening. Rubber seats attached to the valve vane shall be equipped with stainless steel seat ring integral with the body, and the body internal surfaces shall be epoxy coated to prevent tuberculations buildup, which might damage the disc-mounted rubber seat. Use of butterfly valves are a special case and shall only be allowed with district approval.
No metal-to-metal sealing surfaces shall be permitted. The valves shall be bubble-tight at rated pressures with flow in either direction, and shall be satisfactory for applications involving valve operations after long periods of inactivity. Valve discs shall rotate 90 degrees from the full open position to the tight shut position.
Valves shall be Henry Pratt Company “Groundhog,” Dresser “450” or Mueller “Lineseal III.”
(c) Tapping Sleeves and Tapping Valves. The tapping sleeves shall be rated for a working pressure of 250 psi minimum and furnished complete with joint accessories. Tapping sleeves shall be constructed in two sections for ease of installation and shall be assembled around the main without interrupting service.
Mechanical joint style sleeves shall be ductile iron or fabricated steel style sleeves. Ductile iron mechanical joint style sleeves are required for all size-on-size connections. Mechanical joint sleeves shall be cast by Clow, Dresser, Mueller, Tyler, U.S. Pipe or approved equal.
Fabricated steel style sleeves shall be fusion bonded epoxy-coated, acceptable for potable water. Fabricated steel style sleeves will not be allowed for size-on-size connections.
Tapping valves shall be provided with a standard mechanical joint outlet for use with ductile iron pipe and shall have oversized seat rings to permit entry of the tapping machine cutters. In all other respects, the tapping valves shall conform to the resilient seat gate valves herein specified with regards to operation and materials.
The tapping sleeve and valve shall be tested to 100 psi (air) prior to tapping the main.
The installation contractor for the tapping sleeves and valves shall be approved by the district.
(d) All Valves. The valves shall be set with stems vertical. The axis of the valve box shall be common with the axis projected off the valve stem. The tops of the adjustable valve boxes shall be set to the existing or established grade, whichever is applicable.
All valves with operating nuts located more than four feet below finished grade shall be equipped with extension stems to bring the operating nut to within 18 inches of the finished grade.
At the top of the extension stem, there shall be a two-inch standard operating nut, complete with a centering flange that closely fits the five-inch pipe encasement of the extension stem. The valve box shall be set in a telescoping fashion around the five-inch pipe cut to the correct length to allow future adjustment up or down. Cast iron soil pipe shall be used to extend the top valve box section to grade in deep areas.
Each valve shall be provided with an adjustable two-piece cast iron valve box of five inches minimum inside diameter. Valve boxes shall have a top section with an 18-inch minimum length. The valve boxes and covers shall be Olympic Foundry No. 940 or equal. The district may require locking valve covers in high traffic areas, or as directed by district. Locking covers shall be Olympic Foundry No. 045 DT or equal.
Valves located in easements or outside of paved areas shall have concrete collars with a minimum size of two-foot diameter by four inches thick.
(e) Valve Markers. Provide a blue Carsonite valve marker post for each valve outside of asphalt.
Markers shall be placed at the edge of the right-of-way opposite the valve and set so as to leave two feet of the post exposed above grade. The distance in feet and inches to the valve shall be clearly stenciled on the side facing the valve in black numerals two inches in height.
(3) Fire Hydrants. All fire hydrants shall be approved by the National Board of Fire Underwriters and conform to AWWA C502, break-away type, in which the valve will remain closed if the barrel is broken. The hydrant barrel shall have a diameter of not less than seven inches, and the valve diameter shall be not less than five and one-quarter inches. Each hydrant shall be equipped with two two-and-one-half-inch hose ports (National Standard Thread), and one four-and-one-half-inch pumper connection (National Standard Thread). A permanent anodized short profile style Storz hydrant adapter and anodized Storz blind flange shall be installed on the pumper port. The size of the adapter shall be four inches. Each hydrant shall be equipped with a suitable positive acting drain valve and one-and-one-quarter-inch pentagonal operating nut (counter-clockwise opening).
Fire hydrants shall be Mueller Centurion, Clow Medallion, M&H Style 929, Waterous Pacer, or East Jordan Watermaster 5CD250.
The holding spools between the gate valve and fire hydrant shall be made from six-inch Class 52 ductile iron pipe. The hydrant and gate valve shall be anchored in place using holding spools and mechanical joint restraint device. Holding spools shall be one piece unless the length is in excess of 17 feet or if approved by the district. The joints shall be supplied with a mechanical joint sleeve and mechanical joint restraint device, or with Field Lok gaskets.
The fire hydrants shall be painted with two coats of Sherwin Williams 8084-31084 cat yellow enamel paint. Distance to the hydrant valve shall be clearly stenciled in black numerals two inches in height on the fire hydrant below the pumper port. Align the stenciled distance on the hydrant to face the hydrant valve. Top of fire hydrant shall be painted as per service level (see Detail V-W2).
Between the time that the fire hydrant is installed and the completed facility is placed in operation, the fire hydrant shall at all times be wrapped in burlap, or covered in some other suitable manner to clearly indicate that the fire hydrant is not in service.
(4) Blow-Offs and Air Relief Assemblies. A two-inch blowoff assembly shall be installed at the terminus of all dead-end water mains eight-inch diameter and smaller. Water mains greater than eight-inch diameter shall have a fire hydrant assembly installed at the terminus of dead-end mains. Field location to be in paved surface.
A one-inch or two-inch air and vacuum release valve (as approved by the district) shall be installed at principal high points in the system.
The installation of these items shall include connection piping, gate valve, valve box, and all accessories.
(5) Service Connections. Individual services to each property shall be installed and connected to the new water mains by developer prior to acceptance.
New meters two inches and smaller will be installed by the district at the developer’s expense. New services from existing mains will be installed by the district. The developer shall be responsible for permitting, traffic control, excavation to expose main, shoring to protect district employees, backfilling trench, and completion of all restoration.
Upon completion of the installation of the water main (before testing and disinfection) services shall be installed by connecting to the water main and extending the service line to the property line as shown on the standard details or approved equal. Service lines for residential property up to one-inch meter installation shall be Type “K” one-inch (minimum size) continuous copper service lines meeting the ASTM Specifications B-88-47. Services up to two-inch meter installation shall be two-inch diameter Type “K” copper. Larger service lines shall be of the type and style as designated in the standard details and shown on the plans.
Projects that require meters larger than two inches shall be installed per the district standards and as shown on the standard details.
All services other than single-family residential and duplexes shall be provided with appropriate Washington State-approved backflow protection located immediately behind and on the property side of the water service box. Irrigation services, including residential irrigation if using chemical injection, shall be fitted with an RPBA at the service connection (meter). All water features, including decorative ponds, pools and fountains requiring make-up water shall be protected from backflow into the public water supply by a minimum of an approved air-gap (AG) to be located at the fill point of the pond or water feature. The AG shall be inspected by the district CCS prior to filling and shall be inspected annually by a Washington State-certified backflow assembly tester (BAT), with test results submitted to the district. In all instances, the water supply used for filling purposes shall be protected by a minimum of a double check valve assembly (DCVA) installed behind the meter.
Corporation stops and the single meter shut-off valves shall be Mueller, Ford, or A.Y. McDonald with the type and style noted on the standard details or approved equal. Included as a part of the service connection shall be the furnishing and installation of the meter box complete with lid, set flush with the proposed finished grade of the lot in the designated location near the property line, all as shown on the standard details. The angle type of shut-off valve and angle type dual check valve shall be set inside the meter box in a proper position for installation of a future meter by the district.
Service lines between the main and the property line shall be placed at a trench depth sufficient to maintain a three-foot cover over the top of the service line for its full length, taking into consideration the final finished grade of the proposed street and the final finished grade of any storm ditches.
Upon completion of each service line as indicated herein, the developer shall flush the service line to remove the debris that may interfere with the future meter installation, and further verify that the service line has full pressure and flow to the meter box.
(6) Meters Greater than Two Inches. If extensions require water meters greater than two inches, then such entire meter installation, including valves, piping, vaults or meter boxes, drain lines and meters shall be furnished and installed by the developer conforming to district standards. Activation of meter is subject to conformance with district requirements and payment of connection fees.
(7) Pressure Reducing Valves. If extensions require main line pressure reducing valves as determined by the district, then such entire installation, including strainers, valves, piping, vaults, and drain lines shall be installed by the developer conforming to district standards.
The pressure reducing installation shall be a prefabricated and plumbed vault and shall include two Cla-Val globe type pressure reducing valves, sized for the area to be served downstream of the installation. [Res. 735 § 1, 2017.]