Division 1 - Materials of Construction
1. General
All materials shall be new and undamaged. All materials shall meet the requirements for water system materials and additives in accordance with WAC 246-290-220, or the applicable code at the time of installation.
2. Ductile Iron Fitting
Mechanical Joint and Flanged x Mechanical Joint Fittings
Mechanical joint (M.J.) fittings shall be ductile iron, with specification and dimensions in accordance with AWWA C153. Cement mortar lining shall be in accordance with AWWA C104.
Rubber gaskets, tee-headed bolts, nuts and lubricant used for (M.J.) assembly shall be in accordance with AWWA C111. Rubber gaskets shall be made of vulcanized styrene butadiene rubber (SBR). Tee-headed bolts shall meet the minimum characteristic values detailed in AWWA C111 and coated with a corrosion inhibitor. Lubricant used in M.J. joint assembly shall meet NSF 61 and shall not degrade gaskets.
Where restrained M.J. is required, a restraint gland shall be utilized. Restraints shall be Romac ROMAGRIP (for D.I. pipe) or PVC ROMAGRIP (for PVC pipe), or approved equal.
M.J. x Flange couplings shall be restrained. Alternatively, a restrained flange coupling adapter will be permitted for adapting from plain end pipe to a flange connection. Restrained flange coupling adapter shall be Romac RFCA (for D.I. pipe) or RFCA-PVC (for PVC pipe), or approved equal.
Upon request, the Installer shall furnish certification from the manufacturer of the fittings, hardware and gaskets being supplied, that the inspections of all the specified tests have been made, and the results thereof comply with the requirements of this standard.
Flanged Fittings
Fittings shall be cast iron short-body with ASME B 16.1 Class 125 flanges in accordance with AWWA C110.
Cement mortar lining shall be standard thickness in accordance with AWWA C104.
Rubber gaskets, bolts and nuts for flange assembly shall be in accordance with AWWA C111. Bolts and nuts shall be zinc plated or hot dipped galvanized ASTM A307 Grade B. Higher-strength bolts may be required where determined necessary by the District. Gaskets for flanges shall be 1/8-inch SBR. Alternative (NBR) gasket material may be required by the District where soil contamination is present or suspected.
The Installer shall furnish certification from the manufacturer of the fittings and gaskets being supplied that the inspections of all the specified tests have been made and the results thereof comply with the requirements of this standard.
Ductile iron fittings shall be Tyler Union, Sigma or approved equal.
3. Flexible Coupling
Where shown on plans approved by the District, flexible couplings may be used to connect two plain ends of pipe. Special consideration shall be made by the installer to ensure that the flexible coupling is appropriate for the pipe materials and pipe dimensions to be connected.
For connections to existing asbestos cement pipe, flex coupling shall be Romac XR501, or approved equal.
For unrestrained connections between D.I. or PVC pipe, flex coupling shall be Romac Macro HP, or approved equal.
For restrained connections between D.I., PVC or HDPE pipe, flex coupling shall be Romac Alpha, or approved equal.
4. Fire Hydrant
Fire hydrants shall be in conformance with AWWA C502 as a compression-type hydrant with a minimum of 5 ¼ -inch main valve opening, with 6-inch mechanical-joint connection, two 2 ½ - inch hose connections (NST), 4-inch pumped connection (NST), and ¾ -inch Pentagon operating nut. Hydrant shall close with water pressure and be of traffic type with designed replaceable break points. Hydrant shall allow full 360° rotation by loosening flange bolts and turning nozzle screw. A 4-inch (FNST) x 5-inch Storz Coupling shall be installed on all fire hydrants.
Hydrant shall be Mueller Centurion®, AFC Waterous Pacer, M&H 129S or approved equal.
5. Gate Valve
Gate valves shall be resilient wedge type, non-rising stem, 2-inch operating nut manufactured in accordance with AWWA C509 and fusion epoxy coated inside and out in accordance with AWWA C550. Maximum working pressure rating shall not be less than 250 psi.
Gate valve shall be Mueller 2362 Series Resilient Wedge gate valve, or approved equal.
6. Gate Valve Box
Gate valve boxes shall be cast iron, two-piece, rated for H-20 traffic loading. Valve boxes will be Olympic Foundry Inc. #950, or approved equal..
7. Valve Marker Post
Valve marker posts shall be reinforced concrete posts, 5 x 4 inches on one end and 6 x 6 inches on the other end, 42 inches long. Valve marker posts shall be set at all valves or valve clusters, except hydrant valves. Valve marker posts shall be Fog-Tite Meter Seal Co. valve marker or approved equal.
8. Water Main
Polyvinyl Chloride Pipe (PVC)
The pipe shall be manufactured to cast iron size (C.I.O.D.) outside dimensions, color blue and manufactured in compliance with AWWA Standard C900. The pipe shall bear markings indicating approval by Factory Mutual (FM) and the Underwriter's Laboratories (U/L) for use in underground fire protection service. Laying length shall be 20 feet for all sizes, except that up to 15 percent of the footage may be in random lengths of not less than 10 feet.
The pipe shall have an integral bell end, and the gasket seal shall be reinforced with a steel band or other rigid material. The joint shall be in compliance with the requirements of ASTM D-3139, Joints for Plastic Pressure Pipes Using Flexible Elastomeric Seals.
The pipe marking shall include:
1) Nominal size and O.D. base (e.g., 8-inch C.I.O.D.).
2) Material code designation (PVC 1120).
3) Dimension ratio number (DR 18).
4) Pressure class (235).
5) AWWA designation number (AWWA C900).
6) Manufacturer's name or trademark and production code.
7) Seal of the testing agency that verified the suitability of the pipe material for potable water service (NSF).
Each length of pipe (standard or random), including the integral bell, shall be pressure tested to four times the rated pressure for a minimum of five seconds by the manufacturer.
Pipe shall meet all additional test requirements as described in AWWA C900.
Pipe shall be JM Eagle Blue Brute pipe with rubber gasketed joint or approved equal.
High Density Polyethylene (HDPE) pipe and fittings
HDPE pipe and fittings shall conform to the current revision of AWWA C906.
HDPE pipe and fittings shall be made from HDPE having a material designation of PE4710 meeting ASTM D3350 cell classification PE445574C-CC3. The material shall be listed in PPI (Plastics Pipe Institute) TR-4 with a Hydrostatic Design Basis rating of 1600 psi at 73°F, and shall be listed and approved for potable water use in accordance with NSF/ANSI 61.
The pipe marking shall include:
• Nominal size and O.D. base (IPS).
• Dimension ratio number (DR 9 or 11).
• Material code designation (PE 4710).
• Cell classification (PE 445574C).
• PE compound oxidative resistance for potable water (CC3).
• Pressure class (200 psi minimum)
• AWWA designation number (AWWA C906).
• Manufacturer's name or trademark and production code.
• Seal of the testing agency that verified the suitability of the pipe material for potable water service (NSF).
HDPE butt fusion fittings shall be molded, manufactured, tested and marked per ASTM D3261.
HDPE pipe shall be JM Eagle HDPE pressure-rated HDPE, or approved equal.
Ductile Iron Pipe
Ductile iron pipe shall be manufactured in accordance with AWWA C151. Cement mortar lining shall be standard thickness in accordance with AWWA C104. Rubber gasket joints shall be in accordance with AWWA C111.
Ductile iron pipe shall be American Fastite Joint pipe, US Pipe Tyton Joint pipe or approved equal.
Where restrained ductile iron pipe is required, pipe shall be American Fastite Joint pipe with Fast-Grip gasket or US Pipe Tyton Joint pipe with Field Lok gasket, or approved equal.
9. Water Meter
Water meters shall be in conformance with AWWA C700, C701, C702 or C708. The register must read in one (1) cubic foot increments.
Selection of the meter type and size shall be made by the District based on the application and maximum daily, maximum continuous, and peak instantaneous flow requirement (GPM).
Water meters shall meet the specifications shown in the design typical exhibit. Contact the District for specification on meters over 2-inch.
Meter specifications:
- For residential applications, a Badger Meter M25 5/8 x 3/4-inch shall be used, with a positive displacement disc capable of a maximum flow of 25 GPM. The register shall be a Badger ADE technology, with Itron inline connector and Itron 100W ERT.
- 1-inch Badger Meter M70, positive displacement disc capable of a maximum flow of 70 GPM. The register shall be a Badger ADE technology, with Itron inline connector and Itron 100W ERT.
- 1-1/2-inch Badger Meter M120, positive displacement disc capable of a maximum flow of 120 GPM. The Badger M120 shall have Elliptical Flanges and a 1-inch test plug so that the meter can be tested in place. The register shall be a Badger ADE technology, with Itron inline connector and Itron 100W ERT.
- 2-inch Badger Meter M170, positive displacement disc capable of a maximum flow of 170 GPM. The Badger M170 shall have Elliptical flanges and a 1-inch test plug so that the meter can be tested in place. The register shall be a Badger ADE technology, with an Itron inline connector and Itron 100W ERT.
- Contact the District for specifications on all meters over 2 inches.
10. Service Saddle
Service saddles shall be ductile iron body with nylon coating, stainless steel strap and nuts. Service saddles shall be manufactured in accordance with AWWA C-800.
Service saddles for D.I. and PVC pipe shall be Romac 101NS with IPT tap, or approved equal.
Service saddles for HDPE pipe shall be Romac 101N-H with IPT tap, or approved equal.
11. Corporation Stop
Corporation stops shall be all brass, with MIPT connections.
Corporation stops shall meet the specifications shown in the design typical exhibit. On ¾” services corporation stops shall be A.Y. McDonald #73131, or approved equal, and installed so operating lever is located on the side.
12. Service Line Pipe
Service line pipe shall be high-strength PE tubing in conformance with AWWA C901. Service pipe shall be copper tubing size (CTS) with the nominal pipe size shown in the design typical exhibit. Pipe shall be clearly marked showing:
• Nominal size and O.D. base (CTS).
• Standard dimensional ratio (SDR 9).
• Material code designation (PE 4710).
• Cell classification (PE 445574C).
• PE compound oxidative resistance for potable water (CC3).
• Pressure class (250 psi minimum)
• AWWA designation number (AWWA C901).
• Manufacturer's name or trademark and production code.
• Seal of the testing agency that verified the suitability of the pipe material for potable water service (NSF).
Service pipe shall be ADS PolyFlex Potable Water Service Pipe (CTS PE4710), or approved equal.
13. Meter Setter
Meter setters shall be tandem, 9 or 12 inches tall, all copper and brass construction with full port angle stop, dual check valve and double purpose connections. Setter shall be manufactured in accordance with AWWA C800.
Meter setters shall meet the specifications shown in the design typical exhibit. ¾” Meter setters shall be A.Y. McDonald #750209QADD33, or approved equal.
14. Pressure-Reducing Valve (Services)
Pressure-reducing valves for water service installations shall be brass, have an integral strainer and adjustability between 25-70 psi. Pressure-reducing valves shall be equal to Watts LF25AUB- Z3.
15. Service Pipe Adapters
Service pipe adapters shall meet the specifications shown in the design typical exhibit.
Service pipe adapters to connect corporation stops to polyethylene service pipe shall have FIPT x CTS pack joint. For 1-inch lines, such service pipe adapter shall be A.Y. McDonald #74754-22 or approved equal.
Service pipe adapters to connect meter setters to polyethylene service pipe shall have MNPT x CTS pack joint. For 1-inch lines, such service pipe adapter shall be
A.Y. McDonald #74753-22 or approved equal.
16. Brass & Galvanized Fittings
Brass and hot dipped galvanized fittings shall be Sch 40, NSF 61 certified for potable water and only be used as shown in the design typical drawings. Any other use of brass of galvanized fittings in water system construction requires approval by the District.
17. Meter Box
Water meter boxes and meter box extensions for non-traffic installations shall be manufactured from high density polyethylene. Such water meter boxes shall have a lid with integral reader door. Water meter boxes shall meet the specifications shown in the design typical exhibit.
Water meter boxes and lids installed in light traffic areas such as gravel driveways or sidewalks shall have a minimum load rating of 20,000 lbs. For water meter boxes to be installed in locations with moderate to heavy traffic, contact the District.
18. Locate Wire
Locate wire shall be 10-gauge stranded copper wire with 600-volt insulation; Essex or approved equal.
Splices on locate wire shall be made with twist on connectors protected by a fully encapsulating direct bury splice kit filled with moisture resistant gel. Direct bury splice kit shall be 3M Direct Bury Splice Kit DBR/Y, or approved equal.
19. Tapping Sleeve
Tapping sleeve shall be all stainless steel with a full circumferential seal. The body and bolts shall be 18-8 Type 304 Stainless Steel. The branch outlet shall be heavy stainless-steel pipe with an ANSI 150 lb. flange. Gasket shall be full circumferential gasket compounded for use on water, salt solutions, mild acids/bases and sewerage. Sleeve shall meet or exceed ANSI/AWWA C-223 and the MSS-SP 124 Standards as applicable. Sleeve shall be JCM 432 All Stainless-Steel Tapping Sleeve or approved equal.
20. Tapping Valve
Tapping valves shall be resilient wedge type, non-rising stem, 2-inch operating nut manufactured in accordance with AWWA C509 and fusion epoxy coated inside and out in accordance with AWWA C550. Maximum working pressure rating shall not be less than 250 psi. Tapping valve shall be FLXFL or FLXMJ depending on application.
Tapping valve shall be Mueller 2362 Series Resilient Wedge gate valve, or approved equal.
21. Air/Vacuum Valve
Air/vacuum valves shall be combination air valve manufactured in accordance with AWWA C512. Air/vacuum valves shall meet the specifications shown on the design typical exhibits.
A 1-inch Air/vacuum valve shall be APCO #143C or approved equal.
22. Casing (Service Lines)
Casing for 1-inch service pipe shall be 2-inch PVC (200 psi) water pipe or approved equal. Casing for larger diameter service pipe shall be in accordance with the currently effective applicable design typical exhibits.
23. Casing (Water Mains)
Casing for water mains shall be steel, PVC (DR18) or HDPE (DR17) pipe. Steel casing pipe shall have a minimum yield strength of 35,000 psi with a wall thickness meeting or exceed the values shown in Table 1. Casing type will be determined by the District based on application.
The inner diameter of casing pipe shall be no less than 2 inches greater than the largest outside dimension of water main carrier pipe or restraints. Water main carrier pipe inside casing shall be supported by purpose-built casing spacers such that carrier pipe does not rest on bells inside casing.
Table 1 Steel Casing Pipe Wall Thickness Chart
| Min. Wall Thickness | Diameter of Casing Pipe |
| 1/4" (0.2500") | 12" or less |
| 5/16" (0.3125") | 12"-18" |
| 3/8" (0.3750") | 18"-22" |
| 7/16" (0.4375") | 22"-28" |
| 1/2" (0.5000") | 28"-34" |
Division 2 - Methods of Construction
1. General
Except as otherwise noted herein, all work shall be accomplished in conformance with applicable American Waterworks Association (AWWA) manuals and specifications and according to the recommendations of the manufacturer of the material or equipment used.
2. Alignment
Unless otherwise specified, the location of the water mains, valves, hydrants, and principal fittings, including modifications, shall be staked out by the by the Installer to the satisfaction of the District. Alignment deviation shall not exceed 0.5 feet.
Curved pipe alignments shall not have less than the manufacturer’s recommended minimum radius of curvature. Curved pipe alignments for PVC C-900 water mains shall not be achieved by bending the pipe.
Maximum joint deflection for PVC C-900 shall be 1o at the joint, which is equivalent to a 4-inch offset per 20-foot joint. Maximum joint deflection for D.I. water mains shall be 3o at the joint, which is equivalent to a 12-inch offset per 20-foot joint.
3. Placement of Other Utilities
No other utilities shall be placed in the water main trench without prior approval from the District. Primary electrical trenches shall be located a minimum of 5 feet laterally from a water main trench. Non-potable piping shall be located a minimum of 10 feet laterally from a water main trench. Culverts open to atmosphere are exempt from the non-potable separation requirements.
Where water mains cross buried primary electrical, vertical separation shall be 12-inches minimum, with electrical crossing below water.
Where non-potable piping must cross water mains, the water main must be located a minimum of 18” above the non-potable water piping. If an 18” vertical separation is unavoidable, or the potable main must cross below the non-potable piping, a minimum of 20-foot continuous stick of water main casing shall be installed, centered on the crossing. Where these vertical separation requirements cannot be met, special construction methods will be implemented in accordance with DOH/ODW Water System Design Manual section 8.4.4.
4. Trench Excavation
Any area where personnel must enter the trench shall be excavated in accordance with Chapter 296-155 WAC of the Washington State Safety Code. See Section II-Division 2-Part 4-Timbering, Sheeting and Shoring for further details.
Trenches shall be excavated to the line and depth designated by plans approved by the District to provide a minimum of 36 inches of cover over the pipe, and/or 30 inches of cover when crossing the existing roadway ditch, unless otherwise shown on the contract drawings. The trench sides shall be excavated vertically and the trench width shall be excavated to such widths as are necessary for adequate working space. The minimum trench width shall be 24-inches greater than the pipe O.D.
The trench shall be kept free from water until jointing is complete. Surface water shall be diverted so as not to enter the trench. The Installer shall maintain sufficient pumping equipment on the job to ensure that these provisions are carried out.
Gravel required in the bottom of the trench due to action of weather or workers shall be furnished by the Installer. Boulders, rocks, roots, and other obstructions shall be entirely removed or cut out to the width of the trench and to a minimum depth of 6 inches below water main grade. If the native material 6 inches below water main grade is unsuitable for foundation purposes or will have difficulty providing uniform bearing for the pipe, such material shall be removed and replaced with a minimum of 12 inches of compacted foundation material. Imported foundation material shall be Class A or B as described in Section 9 of the WSDOT Standard Specifications and shall be provided by the Installer.
Trenching operations shall not proceed more than 300 feet in advance of pipe laying, except with written approval of the District.
When trenching operations cut through pavement, the pavement shall be cut ahead of the trenching to prevent ragged edges. Pavement shall be removed to a width of 12 inches outside the top of the trench (each side) before repaving. The pavement shall be cut on a straight line with appropriate equipment to the satisfaction of the District or other agency having jurisdiction.
Any time potential historic or pre-historic cultural resources or human remains are discovered during trenching or excavation, work must be stopped and appropriate Clallam PUD project management personnel must be notified immediately. Work will not recommence without notice from the Clallam PUD project manager. Failure to comply with this procedure may expose the contractor to criminal liability under RCW 27.53.060.
5. Timbering, Sheeting, and Shoring
The Installer shall provide and install timbering, sheeting, and shoring as necessary to protect workers, the work, and existing buildings, utilities, and other properties. Removal of timbering, sheeting, and shoring shall be accomplished in such a manner that there will be no damage to the work or to other properties. Any trench exceeding four feet in depth shall be provided with adequate safety/protective systems meeting the requirements of WISHA, Chapter 49.17 RCW, Title 296 WAC, Title N, and all regulations adopted pursuant thereto. Contractor shall have a structural engineer review and stamp any and all shoring plans and calculations. The Contractor alone shall be responsible for worker safety and the District shall assume no responsibility.
6. Hot Tapping in Service Water Main
Hot taps on in service water mains shall be performed by Installers qualified in accordance with Section 1.2 of the District’s General Specifications.
Potholing and O.D. measurement of the water main to be tapped is a prerequisite for hot tap approval. Hot taps shall not be located on sections of water main on or near repairs, couplings or within three feet of another connection to the water main.
Hot taps shall be scheduled at least one week in advance and a District Inspector shall be on-site during the hot tap installation.
Hot taps shall be performed in accordance with pipe manufacturer’s recommendations and sanitary working conditions shall be maintained. The hot tap coupon shall be provided to the District inspector upon request. Appropriate disposal of the hot tap coupon is the responsibility of the installer.
7. Gasketed Pipe Installation
The Installer shall refer to the manufacturer’s installation instructions and/or industry recognized standards, recommendations and special considerations for installing gasketed pipe. Industry recognized standards for installing gasketed pipe include, but are not limited to:
• AWWA M41;
• AWWA C105;
• AWWA C600;
• Ductile Iron Pipe Research Association (DIPRA) Installation Guide for Ductile Iron Pipe;
• DIPRA Polyethylene Encasement Installation Guide;
• AWWA M23;
• AWWA C605;
• AWWA C900;
• Uni-Bell/PVC Pipe Association Installation Guide for Gasketed-Joint PVC Pressure Pipe; and
• Uni-Bell/PVC Pipe Association PVC Pressure Pipe Tapping Guide.
In the event of a conflict between the above listed references, the Installer shall consult the District for assistance with interpretation and resolution.
When left unattended, a suitable plug shall be installed in the end of laid pipe to inhibit contamination.
The District may require the use of restrained gasketed pipe or bell restraints in lieu of, or in addition to, typical thrusting and blocking.
8. Mechanical Joint Pipe and Fittings Installation
The Installer shall refer to the manufacture’s installation instructions and/or industry recognized standards, recommendations and special considerations for installing M.J. connections. Industry recognized standards for installing mechanical joints include, but are not limited to:
• AWWA C110
• AWWA C111
• AWWA C600
• AWWA 605
• AWWA M55
• DIPRA Ductile Iron Pipe Joints and Their Uses
• Uni-Bell PVC Pipe Association Installation of PVC Pipe into a Mechanical Joint
In the event of a conflict between the above listed references, the Installer shall consult the District for assistance with interpretation and resolution.
The District may require the use of restrained M.J. connections (R.J.) in lieu of, or in addition to, typical thrusting and blocking.
9. HDPE Pipe Installation
Unless otherwise specified in plans approved by the District, all HDPE joints shall be thermally butt fused. Any Installer performing butt-fusion on pipe which will be connected to the District’s system must provide documentation that their butt-fusion procedure complies with industry recognized quality assurance and quality control standards. Also, documentation showing fusion personnel are qualified on their procedures must be submitted as a prerequisite for construction.
Industry recognized standards for HDPE pipe installation include, but are not limited to:
• AWWA M55;
• AWWA C906;
• PPI Handbook of Polyethylene Piping;
• PPI TN-38;
• ASTM D2774; and
• ASTM 2620.
In the event of a conflict between the above listed references, the Installer shall consult the District for assistance with interpretation and resolution.
Joint recording and fusion reports shall be required for each fusion joint performed on the project. Specific requirements of the fusion joint report shall include:
• Pipe Size, Outer Dimension, and Dimension Ratio.
• Machine Manufacturer and Model.
• Fusion Technician Identification.
• Job Identification.
• Fusion Number.
• Drag Pressure, Heating Pressure, and Fusion Pressure.
• Heat Plate Temperature.
• Open/Close Times.
• Heat Soak and Cool Down Time of Fusion.
• Ambient Temperature.
Note: It is a common practice and accepted industry “Rule of Thumb” when fusing pipes of unlike SDR’s to fuse a maximum mismatch of one SDR.
Connections between HDPE pipe and DI pipe or fittings shall be restrained by flanged joint or restrained MJ joint adapter, as shown on the Contract Drawings. Flanges and MJ adapters shall have a pressure rating equal to the pipe to which it is jointed.
HDPE flange adapter shall consist of molded HDPE pipe with a flange that has been butt fusion welded to the new HDPE pipeline, with the flange bolted to the DI fitting using a DI backup ring. Flanges shall be made in accordance with ASTM F2880. Hardware and work practices utilized to make up the flanged connection shall be in accordance with TN-38. Grade A307 bolts will not be permitted for flanged connections on HDPE pipe.
10. Casing for Water Mains
Casing shall be installed for watermains when:
• There is insufficient separation with non-potable stormwater and/or wastewater collection lines.
• When a water main crosses under an arterial road or highway
• As required by the District or other agency having jurisdiction
Casing shall be installed in conformance with the requirements for Alignment, Trenching and Excavation, Pipe Installation, and Backfill. Inner diameter of casing pipe shall not be less than 2-inches greater than the maximum outer diameter of the carrier pipe. Carrier pipe installed in casing shall be supported by purpose build casing spacers per the manufacturer’s recommendations.
Casing ends shall be sealed such that debris cannot enter the annular space between casing and carrier pipes. In contaminated soils, measures must be taken to ensure casing ends are sealed such that groundwater cannot enter the casing pipe.
The District may require water main installed inside casing to be restrained in addition to appropriate thrust blocking.
11. Gate Valve Installation
Gate valves shall be set in the ground with operation nut level to ground surface and valve body supported by concrete blocks on compacted bedding. Valves shall be blocked in accordance with Blocking Details to resist thrust when used as an isolation boundary. Maximum distance between in-line valves on distribution mains is subject to District approval. At water main intersections, valves shall be placed on 4 out of 4 legs at each cross, and 3 out of 3 legs at each tee, unless an alternative configuration is approved by the District. For fire hydrant auxiliary valves and blowoffs see Exhibits.
12. Gate Valve Box Installation
Gate valve boxes shall be installed on all underground valves and shall be set flush in roads or as required by the District. Upper and lower valve box castings must be installed such that they are supported by compacted backfill material, asphalt and/or concrete. Valve boxes in traffic areas shall be installed such that they do not transmit traffic loads to the valve body or water main.
13. Locate Wire and Detector Tape Installation
The locate wire and detector tape shall be installed in the same ditch and in accordance with the water main trench typical exhibit.
Underground splices on locate wire shall be avoided. When a splice on locate wire is made, a Direct Bury Splice Kit shall be utilized. Locate wire shall be brought into each gate valve, water meter, air/vacuum valve and blow off enclosure along the water main alignment. A sufficient amount of extra locate wire shall be coiled inside each enclosure such that the locate wire may be extended to reach the grade level of the enclosure lid plus two feet.
14. Backfilling
The limits of the pipe bedding zone is 6-inches below and 6-inches above the
pipe or as shown on plans approved by the District. Pipe zone bedding material shall be import Crushed Surface Base Course which meets the requirements in Section 9 of the WSDOT Standard Specifications.
The pipe zone bedding material shall be carried up evenly on both sides of the pipe simultaneously in approximately 6-inch layers and each layer thoroughly compacted with appropriate tools in such manner as to avoid injuring or
disturbing the completed pipeline. All import bedding and native material shall be stored away from the edges of excavation and off the paved roadway and shoulder.
Backfilling and surface restoration shall closely follow installation and testing of the pipe, so that not more than 300 feet of trench is left open without express approval of the District. The remaining backfill shall be compacted select material or approved native material; except that under driveways and roadways, all backfill material shall be CBSC placed in layers not more than 6 inches thick and compacted to the density of the existing sub-grade. Where agencies other than the District have jurisdiction over roadways, the backfill and compaction shall be done to the satisfaction of the agency having jurisdiction. No pipe shall be backfilled until the District's Inspector has inspected and approved of the pipe's thrusting and bedding.
15. Concrete Blocking
Concrete blocking shall meet the requirement of WSDOT Specification 6-02.3(2)B. Blocking shall have a minimum of 1/2-square foot bearing against the fitting and 2 square feet bearing against undisturbed soil. Blocking shall bear against fittings only and shall be clear of joints so as to permit taking up or dismantling joint. All hydrants, elbows, gate valves, and tees shall be blocked in accordance with plans approved by the District and the Blocking Details exhibits. The Installer shall install blocking which is adequate to withstand full test pressure as well as to continuously stand operating pressures under all conditions of service.
All hydrants, gate valves, and fittings shall be supported by 8" x 16" x 4" solid concrete block(s) on compacted bedding.
Note: A District representative must inspect the trench excavation prior to installing any thrust block. Failure to notify the District prior to installing concrete may require removal of concrete to facilitate the trench excavation inspection. Situations may occur that require special size, shape and/or configuration of concrete thrust blocks.
When required, they will be designed by the Developer’s engineer and installed as approved by the District and directed by the District's Inspector.
16. Blowoff Installation
The purpose of a blowoff is to allow for flushing and sampling of the water main. A blowoff shall be installed at the end of any new water main except when approved by the District. In some instances, the District may require a mainline sized inline gate valve prior to a blowoff assembly. See Exhibits for blowoff designs.
17. Service and Meter Installation
Water meter setters shall be set vertically in center of meter box with Inlet/Outlet of setter flush with the bottom of meter box. Meter box shall be set where staked resting on concrete blocks with top flush and level to final grade elevation. One (1) meter box extension shall be used per each meter box to obtain an acceptable depth. Meter setter shall be held vertical with stakes approved by the District.
Special materials and installation provisions are required when water services are to be installed in sidewalks or traffic locations.
Taps on PVC C-900 water mains shall be a minimum of 36-inches apart and 24-inches from the bell. Only District crews or personnel approved by the District may complete a service tap on a water main which is in service.
18. Casing for Service Lines
Casing shall be installed for all water service lines which extend under non-potable lines, roads, concrete or as determined necessary by the District. The ends of casing shall be sealed so that material cannot enter the annular space between casing and carrier pipes.
19. Hydrostatic Testing
Note: New water mains shall not be directly connected to the existing distribution system during hydrostatic testing. Connection to a closed gate valve constitutes a direct connection.
New water mains and/or fire hydrants shall be filled with water and all air removed prior to starting the test. The test shall be accomplished by pumping the main up to the required pressure at the lowest elevation of the test section (1.5 times the operating pressure or 200 psi, whichever is greater); stop the pump for twenty (20) minutes; and then pump up to the test pressure again. The quantity of water required to restore the pressure shall be accurately determined by pumping through a positive displacement water meter with a sweep unit hand registering 1 gallon per revolution, or a calibrated barrel. For D.I. and PVC C-900 water mains, acceptability of the test will be determined by two factors: (a) there shall not be an appreciable or
abrupt loss in pressure during the twenty (20) minute test period; (b) the quantity of water lost from the main shall not exceed the following table. Gauges used in the test shall be accompanied with satisfactory certifications of accuracy from a laboratory approved by the District.
Table of Allowable Water Loss in 20-Minute Test Period
(U.S. Gallons Per Hour Per 1000 Feet of Pipe)
| Pipe Size | Test Pressure (psi) |
| Inches | 200 | 250 |
| 4 | 0.38 | 0.43 |
| 6 | 0.57 | 0.64 |
| 8 | 0.76 | 0.85 |
| 10 | 0.96 | 1.07 |
| 12 | 1.15 | 1.28 |
| 14 | 1.34 | 1.5 |
| 16 | 1.53 | 1.71 |
Hydrostatic testing of HDPE water mains shall follow Plastic Pipe Institute TN-46: Guidance for Field Hydrostatic Testing of High Density Polyethylene Pressure Pipelines: Owner’s Considerations, Planning, Procedures, and Checklists.
Prior to calling out the District to witness the pressure test, the Installer shall have all equipment set up completely ready for operation and shall have successfully performed the test to assure themselves that the pipe is in a satisfactory condition. Final hydrostatic tests shall be performed in the presence of the District inspector.
20. Sterilization and Flushing of Water Mains and Appurtenances
Note: New water mains shall not be directly connected to the existing distribution system during disinfection. Connection to a closed gate valve constitutes a direct connection.
Sterilization of water mains and fire hydrants shall be accomplished by the Installer in accordance with AWWA Standard for Water Main Disinfection (C651), the requirements of Washington State Department of Health and in a manner satisfactory to the District. Sections will ordinarily be sterilized between adjacent in-line gate valves unless, in the opinion of the District, a longer section may be satisfactorily handled. Hydrants along the chlorinated section shall be opened during application until the presence of chlorine has definitely been detected.
When a chlorine concentration of not less than 50 mg/L has been established throughout the main, the valves shall be closed and the main left undisturbed for 24 hours.
The Installer shall then thoroughly flush the water main and/or fire hydrant(s), disposing of all highly chlorinated water in accordance with AWWA C651 and Washington State Department of Ecology requirements, exercising special care to avoid damage to surrounding property.
The District shall be on site to operate all valves during filling and flushing. Installers shall not operate valves connected to the District's system.
21. Coliform Bacteria Analysis
Note: New water mains shall not be directly connected to the existing distribution system until satisfactory coliform bacteria analysis results have been received. Connection to a closed gate valve constitutes a direct connection.
Upon satisfactorily completing hydrostatic testing, disinfection and flushing of the water main, the Installer shall submit a coliform bacteria analysis sample (bacteriological samples) to the Clallam County Department of Health or State-approved laboratory, Monday through Wednesday only. Laboratory certification and bacterial analysis method performed will comply with 40 CFR 141.852. The coliform bacteria sampling regimen shall be in accordance with AWWA C651.
22. Restoring Road Surfacing
The Installer shall restore all roadway and driveway surfaces excavated or disturbed to a condition acceptable to agency having jurisdiction over the road and/or the District. The Installer shall obtain a right of way permit and provide sufficient notification to the agency having jurisdiction over the right of way prior to beginning work and upon completion of work.
23. Cross Connection Control
The District has a Cross Connection Control Policy. For utility placement specifications of non-potable water piping, see Division 2, Section 3 - Placement of Other Utilities. See the District’s Cross Connection Control Policy for all other related issues pertaining to backflow prevention.
