8-03Irrigation Systems

8-03.1 Description

This Work consists of installing irrigation systems in accordance with these Specifications and the details shown in the Plans or as approved by the Engineer.

8-03.1(1) Definitions

Catch Can Test – A test utilizing containers spaced at regular intervals for collecting water for use in a water audit. Critical Root Zone – The International Society of Arboriculture (ISA) defines CRZ as an area equal to 1 foot radius from the base of the tree’s trunk for each 1 inch of the tree’s diameter at 4.5 feet above grade (referred to as diameter at breast height). Drip Irrigation – A system of irrigation involving the controlled delivery of water directly to individual plants through a network of tubes or pipes and emitters. Emitters – Low volume emission devices including but not limited to pressure compensating emitters, self-flushing emitters, non-flow restricting barbed couplers or in-line drip emitter tubing. Flushing – A cleansing by causing large quantities of water to pass through the pipe or conduit. Hydrostatic Pressure Testing – A test used to determine the integrity of the pipeline after installation before it’s placed into service. Irrigation Audit – Procedure to collect and present information concerning the uniformity of application, precipitation rate, and general condition of an irrigation system and its components. Irrigation Head – Nozzle or device, which may or may not rotate for distributing water under pressure through the air including but not limited to impact drive, rotor, or spray head. Irrigation Sleeve – Casing, pipe or conduit that is installed under hardscapes or structures for the purpose of running irrigation piping or wiring. Lateral Lines – All supply pipe and fittings between the irrigation control valves and the connections to the irrigation heads. Swing joints, thick-walled PVC or polyethylene (poly) pipe, flexible risers, rigid pipe risers, and associated fittings are not considered part of the lateral line but incidental components of the sprinkler heads. Main Lines – All supply pipe and fittings between the water meter and the irrigation control valves. Sprinkler Irrigation System – Type of irrigation using mechanical devices with above ground or pop-up irrigation heads to distribute by converting water to a high velocity discharge stream or streams.

8-03.1(2) Regulations and Code

Cross-Connections – WAC 246-290-490 Section 8-20.1(1 ), Illumination, Traffic Signal Systems, Intelligent Transportation Systems, and Electrical – Regulation and Code Section 8-20.1(2) , Illumination, Traffic Signal Systems, Intelligent Transportation Systems, and Electrical – Industry Codes and Standards Waterworks Operator Certification – WAC 246-292 Page 8-38 M 41-10

8-03 Irrigation Systems8-03.2 Materials

Materials shall meet the requirements of the following sections: Sand 9-03.2(1) Crushed Surfacing 9-03.9(3) Gravel Backfill for Dry Wells 9-03.12(5) Irrigation Materials 9-15 Electrical Wire and Splices 9-15.17 Detectable Warning Tape 9-15.18 Electrical Systems 9-29 Steel Casing 9-29.1(7)

8-03.3 Construction Requirements

8-03.3(1) General Requirements

Location of pipe, tubing, irrigation heads, emitters, valves, cross-connection devices, irrigation sleeves and other equipment shall be as shown in the Plans and shall be of the size and type indicated. Potable water supplies shall be protected against cross-connections in accordance with applicable regulations for the Washington State Department of Health and the local health authority. Construction of irrigation electrical systems shall conform to applicable portions of Sections 8-20.

8-03.3(2) Submittals

When required, the Contractor shall submit the following:

8-03.3(3)A Locating Irrigation Sleeves

All buried pipe under structures, vehicular and pedestrian surfaces and as indicated in the Plans shall be protected by irrigation sleeving. Irrigation sleeves placed during general construction prior to installation of the irrigation system shall be marked at both ends with a 2 by 4 wood stake extending a minimum of 6 inches above finish grade and painted blue on the exposed end. At any point during construction, the stake shall be embedded 24-inches. Irrigation sleeving shall extend a minimum 2 feet beyond the limits of pavement, curb, or pedestrian surface. Existing underground irrigation sleeve ends shall be located by potholing.

8-03.3(4) Irrigation Water Service

All water meter(s) shall be installed by the serving utility. It shall be the Contractor’s responsibility to:

8-03.3(5) Irrigation Electrical Service

All electrical service(s) shall be installed by the serving utility. It shall be the Contractor’s responsibility to:

8-03 Irrigation Systems8-03.3(6) Excavation

8-03.3(6)A Trenches

8-03.3(6)A1 General

Pipe trenches shall be no wider at any point than is necessary to lay the pipe or install equipment. Trench bottoms shall be relatively smooth and consist of sand or other suitable material free from rocks, stones, or any material that might damage the pipe. Trenches through rock or other material unsuitable for trench bottoms and sides shall be excavated 6-inches below the required depth and shall be backfilled in accordance with

8-03.3(6)A2 Within Critical Root Zone

Mechanical trenching within the Critical Root Zone of existing trees shall not be allowed.

8-03.3(6)A3 Detectable Marking Tape

Detectable marking tape shall be placed in all trenches 6 inches directly above, parallel to, and along the entire length of all nonmetallic water pipes, sleeving, wiring, conduits, and casing pipes. Detectable marking tape shall meet the requirements of Section 9-15.18.

8-03.3(6)B Trenchless Construction

All jacking, directional drilling or boring operations shall be performed in accordance with an approved plan as indicated in Section 8-03.3(2). Construction shall be in accordance with the requirements of Section 8-20.3(5)E3, Section 8-20.3(5)E4 and Section 8-20.3(5)E5.

8-03.3(7) Piping

8-03.3(7)A Irrigation Piping

All irrigation pipe shall be a minimum of 18 inches below finished grade measured from the top of the pipe or as shown in the Plans. Where possible, mains and laterals shall be placed in the same trench. All lines shall be placed a minimum of 3 feet from the edge of concrete sidewalks, curbs, guardrails, walls, fences, and traffic barriers. Pipe pulling will not be allowed for installation and placement of irrigation pipe. Pipe trenches shall not be backfilled until hydrostatic pressure testing is completed and accepted by the Engineer. All plastic materials shall be protected from direct sunlight in accordance with Section 1-06.4.

8-03.3(7)B Irrigation Sleeves

Irrigation sleeving shall be Schedule 80 PVC unless otherwise indicated in the Plans. The minimum diameter of the sleeve shall be twice as large as the proposed piping size being buried. When the plans indicate a sleeve larger than twice the diameter, the larger sleeve shall be installed. Irrigation wiring shall be sleeved in separate sleeving or conduit unless indicated otherwise in the Plans. Irrigation sleeving installed under existing pavement shall use steel casing in lieu of Schedule 80 PVC sleeves and shall be installed in accordance with Section 8-20.3(5)E3, Section 8-20.3(5)E4 or Section 8-20.3(5)E5. M 41-10 Page 8-41 Irrigation Systems 8-038-03.3(8) Jointing During construction, pipe ends shall be capped to prevent entry of foreign objects.

8-03.3(8)A Joining Similar Materials

All galvanized steel pipe shall have sound, clean cut, standard pipe threads well fitted. All pipes shall be reamed to the full diameter and burrs removed before assembly. Threaded galvanized steel joints shall be constructed using either a nonhardening, non- seizing multipurpose sealant, PTFE pipe thread tape or paste as recommended by the pipe manufacturer or as shown in the Plans. Threaded galvanized steel joints shall be constructed using either a nonhardening, non-seizing multipurpose sealant, PTFE pipe thread tape or paste as recommended by the pipe manufacturer. All threaded joints shall be made tight with wrenches without the use of handle extensions. Joints that leak shall be cleaned and remade with new material. Caulking or thread cement to make joints tight shall not be permitted. PVC pipe, couplings, and fittings shall be handled and installed in accordance with the manufacturer’s recommendation. PVC pipe ends shall be cut 90 degrees to their longitudinal axis, cleaned of all cutting burrs and free of dirt prior to solvent welding. Pipe and fittings shall be joined by solvent welding utilizing a two-step solvent/cement process according to the manufacturer’s recommendation. Solvents used must penetrate the surface at both pipe and fitting, which shall result in complete fusion at the joint. Use solvent and cement as recommended by the pipe manufacturer. Before hydrostatic pressure testing the system, all solvent welded joints shall be fully cured following the solvent weld manufacturer’s recommendation. Threaded PVC joints shall be assembled using PTFE pipe thread tape as recommended by the pipe manufacturer. Polyethylene pipe, tubing and associated fittings shall be installed in accordance with the manufacturer’s recommendations. The ends of the polyethylene pipe shall be cut square, reamed smooth inside and out, and inserted to the full depth of the fitting. Clamps for insert fittings shall be stainless steel and have a tightening mechanism.

8-03.3(8)B Joining Dissimilar Materials

On PVC or polyethylene-to-metal connections, complete the metal connection first. Use a nonhardening compound on threaded connections. Connections between metal and PVC or polyethylene are to be threaded using female threaded PVC adapters with threaded Schedule 80 PVC nipples only.

8-03.3(9) Irrigation System Installation

8-03.3(9)A General

The Contractor shall coordinate new irrigation water service connections with the serving utility. The Contractor shall follow the serving utilities’ standards for connections from meter through cross-connection control device. Cross-connections devices and enclosures shall be installed according to the Plans.

8-03.3(9)B Irrigation Heads

Unless otherwise indicated in the Plans, final position of irrigation heads shall be flush with the finished grade in grass or mulch areas as measured from the top of the irrigation head. All irrigation heads adjacent to walks, curbs, and pavement shall be placed as shown in the Plans. Polyethylene (poly) pipe for connections to irrigation heads shall be with fittings recommended by the manufacturer of the poly pipe to produce a flexible swing joint assembly between the lateral line and the irrigation head. The length of thick-walled poly pipe at each flexible swing joint assembly shall be 18 inches minimum to 36 inches maximum. Risers shall be sized as shown in the Plans. Page 8-42 M 41-10

8-03 Irrigation Systems8-03.3(9)C Valve, Valve Boxes, Hose Bibs

All automatic control valves, quick coupler valves, hose bibs, flow control valves, ball valves and pressure reducing valves shall be installed in accordance with manufacturer’s recommendations unless otherwise indicated in the Plans. Valve boxes shall have a minimum 3 inches and maximum 18 inches of clearance on sides and lid. There shall be one valve or irrigation component for each valve box unless approved by the Engineer. The bottom of all valve boxes shall be set firmly on crushed surfacing base course. Extensions designed for use with the valve box consistent with matching manufacturer shall be used to reach the required surface elevation. Install double-sided valve identification tags on each valve. Stamped tag number to match zone valve number on controller and in as-built drawings. Final elevation of valve boxes and quick coupler valves shall be between ½ and 1 inch above finished grade or bark or wood chip mulch surface, or as shown in the Plans. Quick coupler valves and hose bibs shall be installed in valve boxes, either separately or within a control valve assembly box upstream of the control valves. Valves, quick couplers, and hose bibs shall have 3 inches of clearance on all sides within the valve box.

8-03.3(9)D Drip Irrigation

Drip irrigation tubing, emitter tubing and associated drip tubing fittings shall be installed in accordance with the manufacturer’s recommendations and as shown on the Plans. Drip tubing shall be installed horizontal to the ground contours to make a parallel distribution pattern. Drip tubing shall be secured to the ground using commercially available wire stakes every 5 feet and at each fitting or change of direction unless otherwise shown in the Plans. Drip tubing shall be free from kinks or damage. Single kinks shall be cut out and undamaged sections of drip tubing coupled using approved fittings. Drip tubing runs with multiple, regular kinks as determined by the Engineer shall be replaced. Install drain valves, when specified at the lowest point of each zone in a minimum 10 inch diameter round valve box over 2 cubic feet of gravel backfill for dry wells.

8-03.3(9)E Controller

Locate automatic controller pedestals and container cabinets as shown in the Plans and in accordance with the manufacturer’s recommendations. Provide three galvanized metal or PVC electrical wire conduits through the base and 3 inches minimum beyond the edge or side of the base, both inside and outside of the pedestal. Conduits shall be sized to accommodate all wires according to Section 8-20. Conduit shall not be smaller than 1 inch diameter.

8-03.3(9)F Cross-Connection Control Device Installation

Cross-connection control devices shall be installed and inspected, and then tested by a certified cross-connection control specialist or designee in accordance with applicable portions of WAC 246-290-490 and other applicable regulations as set forth by the Washington State Department of Health and local authority. Inspections and tests shall be conducted at the time of initial installation, after repairs, and annually each Spring prior to reactivation of the irrigation system. These inspections and tests shall be completed, and the results recorded by a licensed Backflow Assembly Tester (BAT). The inspection shall document that the devices are in good operating condition prior to flushing and testing of any downstream water lines. Devices that are defective shall be repaired or replaced and retested. M 41-10 Page 8-43 Irrigation Systems 8-03Inspection and test results shall be recorded on the Backflow Prevention Assembly Test Report (WSDOT Form 540-02) and other forms as may be required by the serving utility. The completed forms shall be submitted to the appropriate health authority, the serving utility and the Engineer.

8-03.3(9)G Electrical Wire Installation

All electrical work shall be performed in accordance with Section 8-20. Electrical wiring between the automatic controller and automatic valves shall be direct burial and may share a common neutral wire. Separate control conductors shall be run from the automatic controller to each valve. When more than one automatic controller is required, a separate common neutral wire shall be provided for each controller and the automatic valves it controls. Electrical wire shall be installed in the trench adjacent to or above the irrigation pipe, but no less than 12 inches deep. Plastic tape or nylon tie wraps shall be used to bundle wires together at 10 foot intervals. If it is necessary to run electrical wire in a separate trench from the irrigation pipe, the wire shall be placed at a minimum depth of 18 inches and “snaked” from side to side in the trench. Each circuit shall be identified at both ends and at all splices with a permanent marker identifying zone and/or station. Wiring placed under pavement and walls, or through walls, shall be placed in an electrical conduit or within an irrigation sleeve. Electrical conduit shall not be less than 1 inch in diameter. Splices will be permitted only in electrical junction boxes, valve boxes, pole bases, or within control equipment boxes or pedestals. A minimum of 18 inches of excess conductor shall be left at all splices, terminals, and control valves to facilitate inspection and future splicing. The excess wire shall be neatly coiled to fit easily into the boxes. All 120-volt electrical conductors and conduit shall be installed by a licensed electrician, including all wire splices and wire terminations. All wiring shall be tested in accordance with Section 8-20.3(11) . Circuits below 115 volts nominal shall follow the procedure described for circuits below 115 volts nominal, with a minimum insulation resistance of not less than 2 megaohms to ground for 24-volt direct burial circuits.

8-03.3(10) Flushing and Testing

8-03.3(10)A General Testing Requirements

All gauges used in the testing of water pressures shall be certified as accurate by an independent testing laboratory immediately prior to use on the project, with documentation submitted to the Engineer for verification. Gauges shall be retested when required by the Engineer. The automatic controller shall be tested for a period of two weeks under normal operating conditions. The Contractor shall make all necessary adjustments or corrections according to the manufacturer’s recommendations and retested until its operation is accepted by the Engineer.

8-03.3(10)B Mainline or Lateral Flushing

All main lines shall receive two fully open flushings to remove debris that may have entered the line during construction: the first before the placement of valves and the second after placement of valves and prior to hydrostatic pressure testing. All lateral lines shall receive one fully open flushing prior to placement of irrigation heads, emitters, and drain valves. The flushing shall be of sufficient duration to remove all dirt or debris that has entered the lateral lines during construction. Page 8-44 M 41-10

8-03 Irrigation Systems8-03.3(10)C Mainline or Lateral Hydrostatic Pressure Testing

All main lines shall be purged of air and tested with a minimum hydrostatic water pressure of 150 psi for 60 minutes without the introduction of additional service or pumping pressure. Testing shall be done with one pressure gauge installed on the line, in the location approved by the Engineer. For systems using a pump, an additional pressure gauge shall be installed at the pump. Lines that show leaks or loss of pressure exceeding 5 psi at the end of specified test periods will be rejected. All lateral lines shall be purged of air and tested in place at operating line pressure with a pressure gauge and with all fittings capped or plugged. The operating line pressure shall be maintained for 30 minutes with valves closed and without the introduction of additional service or pumping pressure. Lines that show leaks or loss of pressure exceeding 5 psi at the end of specified test periods will be rejected. The Contractor shall correct and retest main and lateral line installations that have been rejected. Throughout the life of the Contract, the Contractor shall repair, flush, and test all main and lateral lines that have sustained a break or disruption of service. Upon restoration of the water service, the affected lines shall be brought up to operating pressure. The Contractor shall then conduct a thorough inspection of all irrigation heads, emitters, or other components located downstream of the break or disruption of service and make all needed repairs to ensure the entire irrigation system is operating properly.

8-03.3(10)D Drip Line Testing

All Polyethylene Pipe and Drip Tubing shall be capped, purged of air, and tested in place at operating line pressure with a pressure gauge prior to the installation of all distribution tubing, drip emitters, or other emission devices. The operating line pressure shall be maintained for 30 minutes with valves closed and without the introduction of additional service or pumping pressure. Lines that show leaks in the pipe or fittings, or loss of pressure exceeding 5 psi at the end of specified test periods will be rejected. The Contractor shall correct and retest Polyethylene Pipe or Drip Tubing installations that have been rejected.

8-03.3(11) Backfill

Backfill shall not be allowed until all piping has been inspected, tested, and accepted in writing by the Engineer except where roots are encountered as described in Section

8-03 3(6)A2, after which backfilling shall be completed as soon as possible. All backfill

material placed within 6 inches of the pipe shall be sand or other approved material free of rocks, roots, concrete, and construction debris that might cut or otherwise damage the pipe. Backfill shall not contain material one inch or greater in diameter. Backfill from the bottom of the trench to approximately 6 inches above the pipe shall be compacted in a manner that will not damage pipe or wiring and shall proceed evenly on both sides of the pipe. The remainder of the backfill shall be compacted, except that heavy equipment shall not be used within 18 inches of any pipe. Backfill shall be placed and compacted in layers not to exceed 12 inches. Backfill shall be compacted to a minimum of 85 percent of the maximum density and may be tested at the discretion of the Engineer. The top 6 inches of the backfill shall be of topsoil material or the first 6 inches of material removed in the excavation.

8-03.3(12) Adjusting System

Before final inspection, the Contractor shall adjust and balance all irrigation heads or emitters to provide adequate and uniform coverage. Spray patterns shall be balanced by adjusting individual irrigation heads with the adjustment screws or replacing nozzles to produce a uniform pattern. Overspray onto impervious surfaces, signs or other structures will not be allowed. M 41-10 Page 8-45 Irrigation Systems 8-03Irrigation Sprinkler Systems shall receive a landscape irrigation audit performed by a Certified Landscape Irrigation Auditor (CLIA) in good standing with the Irrigation Association (IA). The audit shall be conducted in accordance with the current edition of the IA’s Irrigation Auditor Guidelines. The audit report shall include the following information:

8-03.3(13) As-Built Plans, M&O Manuals, and Operating Tools

8-03.3(13)A As-Builts

The Contractor shall submit as-built Plans consisting of corrected shop drawings, schematic circuit diagrams, zoning chart, timing schedule and other details necessary to show the Work as constructed. Locations of all irrigation system(s) equipment including, but not limited to, water meters, cross-connection control devices, electrical services, pipe and wire runs, irrigation sleeves, splice boxes, controllers, valves, heads, emitters, and other equipment shall be clearly shown and labeled on the as-built Plans. All buried pipe and wires shall be labeled with layout dimensions locating trenches from visible site features (curb, edge of pavement, valve box, etc.). Grouping of pipe(s) and wire(s) shall be identified when located in the same trench. The as-built Plans shall include all notes pertaining to damage, repairs, and maintenance to the system during installation and operation through the end of the Plant Establishment period. In the event that repairs, or adjustment are made after the initial submittal of the as-built plans, the notes pertaining to those damage, repair or maintenance shall be submitted as a supplement. These drawings shall be on sheets conforming in size to the provisions of Section 1-05.3 . All drawings must be complete and legible. All corrections ordered by the Engineer shall be made by the Contractor prior to acceptance.

8-03.3(13)B Maintenance & Operations Manuals

The Contractor shall provide the Engineer with an electronic pdf and one copy of the system operations manual. The manual shall include a parts list, catalog cuts, equipment manuals, a summary of operations with startup/winterize techniques, controller programming, valve cleaning requirements, irrigation head or emitter adjustment instructions, backflow device catalog cut and other applicable instructions to ensure normal operation after Physical Completion. Page 8-46 M 41-10

8-03 Irrigation Systems8-03.3(13)C Operating Tools

All locks or locking devices shall be keyed alike, and three sets of keys shall be provided to the Engineer prior to Physical Completion. Three sets of keys shall be provided for all components requiring keys, including automatic controller valves, drain valves, and manual control valves. Three sets of specialty keys or manufacturer provided tools for operating components shall be provided. When handles are included as an integral part of a three-way valve, the Contractor shall remove them and give them to the Engineer. Laminated copies of the timing and valve schedule shall be placed in the controller boxes or in locations specified by the Engineer.

8-03.3(14) System Operation

8-03.3(14)A General

The irrigation system shall be completely installed, tested, and automatically operable prior to planting in a unit area except where otherwise specified in the Plans or approved by the Engineer. The Contractor shall be fully responsible for all maintenance, repair, testing, inspecting, and automatic operation of the entire system until all Work is considered complete as determined by the final inspection specified in Section 1-05.11. This responsibility shall include, but not be limited to, draining the system prior to winter and reactivating the system in the spring and at other times as required by the Engineer. The final inspection of the irrigation system will coincide with Physical Completion or the end of first-year plant establishment, whichever is later. The Contractor shall be responsible for having annual inspections and tests performed on all cross-connection control devices as required the Washington State Department of Health through Physical Completion. Inspections and tests shall be conducted at the time of initial activation and each spring prior to reactivating the irrigation system. Potable water shall not flow through the cross-connection control device to any downstream component until tested and approved for use by the local health authority in accordance with Section 8-03.3(9)F. The irrigation system shall be deactivated and drained for winterization. Storage of components during the winterized period shall be the responsibility of the Contractor for the life of the Contract. Winterization includes evacuation of all water in main, lateral, and drip lines, opening of drain valves, insulation or temporary removal and storage of the backflow devices, and closure of all ball valves upstream of the master valve in the Backflow Assembly. Winterizing the irrigation system shall occur between the following periods. Western Washington1 (West of the Cascade Mountain Crest)Eastern Washington (East of the Cascade Mountain Crest) October 1 through October 15 October 1 through November 15 1Winterizing may be allowed outside these dates when allowed by the Engineer. In the spring, when the irrigation system is in full operation, the Contractor shall make a full inspection of all valves, controllers, emitters and irrigation heads. This shall involve visual inspection under operating conditions. All adjustments, flushing, or replacements to the system shall be made at this time to ensure the proper operation of all irrigation components. The Contractor shall activate the irrigation system between March 15th and March 31st of each year through Physical Completion, unless allowed otherwise by the Engineer. Activation includes backflow inspection, testing, repair, and reporting, an annual system inspection with the Engineer, all required system repairs, annual battery replacement in all battery-operated controller units, and reprogramming for specific site M 41-10 Page 8-47 Irrigation Systems 8-03conditions. Start up or resumption of fully automatic system operation shall be May 1st, or as allowed by the Engineer. Automatic controllers shall be programmed according to the Plans or as allowed by the Engineer.

8-03.3(14)B Irrigation System Orientation Meeting

An irrigation system orientation meeting shall be held when the irrigation system is complete, and the system is operational. The purpose of the meeting is to discuss system operation and maintenance procedures and demonstrate and confirm functionality of irrigation components including the Contracting Agency’s central control system where applicable. The meeting shall be conducted by the Contractor or irrigation contractor at the project site. Those attending shall include:

8-03.4 Vacant

8-03.5 Payment

Payment will be made for the following Bid items when included in the Proposal: “Irrigation System”, lump sum. All costs for furnishing, installing, and operating the irrigation system as detailed in the Plans shall be included in the lump sum price for the complete irrigation system. This includes all costs for initial and annual inspections, tests performed on cross- connection control devices, electrical wire testing during the life of the Contract, system maintenance and repair, annual winterization and startup, irrigation audits, and as-built Plans as shown in the Plans. When the plans indicate connections to existing irrigation, sleeves or other components, potholing shall be included in the lump sum price for irrigation system. As the irrigation system is installed, the payment schedule will be as follows: