623Irrigation System

Irrigation System

Description

623.01This work consists of furnishing and constructing an irrigation system per these

specifications and in conformity with the lines and grades shown on the plans or established.

Materials

623.02General. All materials and equipment incorporated into the irrigation system shall be

new and of recognized standard quality. In the case of computer software or hard coded instructions, the latest available version from the manufacturer is required. All materials shall be of a standard line from a name brand manufacturer or must be approved.

623.03Backflow Preventer. Pressure vacuum breakers shall be the pressure type with a

bronze body and a machined valve seat. Reduced pressure-type backflow preventers shall include two check valves, a relief valve, two gate or ball valves, and test cocks for field testing. Vacuum breakers and reduced pressure-type backflow preventers shall meet the requirements in the Colorado Department of Health, Cross Connection Manual, and shall have a non-shock cold-water rating of at least 150 psi.

623.04Automatic Controllers. The automatic controller shall be an electro-mechanical or

microprocessor based/microelectronic solid-state type capable of operating in an automatic or manual mode. The controller shall have a minimum of six stations. Each station shall be programmed to operate for 1 to 99 minutes, or 0.1 to 9.9 hours. The controller shall have two independent programs with three automatic starts per day for each program. Each station on the controller shall be assigned to either or both programs. The controller shall be capable of watering any day or sequence of days on a six or seven-day cycle. The controller shall operate on a minimum of 117 volts AC power input. Controller electrical output shall be capable of 26.5 volts AC at 1.5 amps. The controller shall have a reset circuit breaker (1.5 amps holding and 2.5 amps break) to protect it from power overload. Primary surge protection for 117-volt lines and valve (24 volt) output surge protection shall be installed to protect the controller. The automatic controller shall be grounded using two 5/8-inch x 8-foot copper clad grounding rods driven into the soil. A #10 AWG bare copper wire shall be used to connect the ground rods to the automatic controllers’ protective grounding circuit. The resistance of the ground shall not exceed 5 ohms. The controller enclosure (including satellite controllers) shall be of a vandal and weather- resistant nature, manufactured entirely of metal or steel mill-treated with zinc for rust resistance. The main housing shall have louvers in the upper and lower body to allow for crossflow ventilation.

623.05Remote Control. Remote control shall consist of an FM, AM, UHF, or VHF radio

transmitter/receiver pair with a minimum range of one mile in congested areas and shall include battery charger and replacement battery. The receiver shall plug into a receptacle installed in the enclosure or panel of the automatic controller. Remote control shall be capable of turning on/off any station in any order. Remote control shall comply with all applicable FCC rules and regulations.

623.06

623.06Control Wiring 24 Volt. Connection between automatic controller and automatic

control valves, flow sensors and moisture sensors shall be made with direct burial copper, 600 volt, UF, UL approved wire. Minimum wire size shall be #14 AWG. One wire shall be provided for each valve. Wires shall be color coded according to the basic plant materials irrigated by the lateral. Wire colors shall be: Table 623-1 Control Wiring Color Key Wire Color Plant Materials Black Master (power) Purple Spares Green Turf Brown Tree Yellow Perennials

Red Shrubs "common" or ground White wire

623.07Sprinkler Heads. The sprinkler head shall be of the pop-up spray and pop-up rotor

internal drive type. All sprinkler heads shall be capable of accepting a check valve where head elevation varies more than 5 feet within a control zone.

heavy-duty plastic. Spray heads shall have the following components:

retracts into the case to prevent stem and nozzle from sticking in the up position.

of regulating the radius and flow.

positive pop-down.

components from the top without removing the body from the ground. Minimum pop-up height for turf heads shall be 4 inches. Spray head pop-up height for turf in roadway medians shall be at least 6 inches, and shrub, flower, and ground cover spray heads shall be at least 12 inches.

plastic housings and non-corrosive internal components. The rotor head shall have a soft pressure-activated wiper seal for cleaning debris from the pop-up stem as it retracts into the case, to prevent the stem and nozzle from sticking in the up position. The rotor head shall have a screen to protect it from clogging and a strong stainless-steel retracting spring for positive pop-down. Minimum pop-up height for rotor heads shall be 3 inches. The rotor head shall have a fully adjustable arc or full circle capability and an adjustable break-up pin capable of reducing the radius up to 25 percent.

623.08

623.08Flow Sensor. The flow sensor shall be an in-line type and shall transmit an electronic

pulse through conductors to a compatible automatic controller with interface unit for subsequent transmission to a compatible central computer.

623.09Drip Emitters. The drip emitter shall be of the pressure compensating type with flow

rates of 0.5, 1, or 2 gallons per hour plus or minus a 10 percent deviation at 10 to 40 psi. The emitter shall be constructed of durable plastic with a barbed inlet, and the outlet shall be capable of a watertight connection compatible with the polyethylene capillary tubing. Emitters shall be of the self-flushing type and capable of clog-free operation with a 150-mesh strainer. Emitters shall be multi-outlet (six outlets) and shall be installed on the polyethylene drip lateral line. The ends of the capillary tubing shall be installed on 6-inch plastic stakes with debris caps on the end of the tubing.

623.10Plastic Pipe and Fittings. All pipe shall be identified with the following indelible

markings: manufacturer's name, nominal pipe size, schedule or class of pipe, pressure rating in pounds per square inch, date of extrusion, and NSF seal of approval.

chloride (PVC) compound per ASTM D1784 and D2241, cell classification 12454-B, Type I, Grade I. Pipe sizes 3 inches and smaller shall be of the solvent weld type, and sizes larger than 3 inches shall have rubber gasketed fittings. Fittings shall be standard weight schedule 40 injection molded PVC conforming to ASTM D1784 and D2466, cell classification 12454-B. Threaded nipples shall be schedule 80 PVC with molded threads conforming to ASTM D2464. Threaded fittings shall be kept to a minimum. Cement and cleaner for solvent weld pipe and fittings shall conform to ASTM D2564.

virgin material in conformance with ASTM D2239 and designated as PE 2306 or PE 3408. Pipe size shall not exceed 2 inches. Fittings shall be injected-molded schedule 40 PVC conforming to ASTM D2609, cell classification 12454-B. Pipe shall be clamped onto the fitting using 100 percent stainless-steel screw clamps (two clamps on 1 1/2 inch and 2-inch pipe).

be made of linear low density, UV resistant polyethylene with a pressure rating of 50 psi.

Swing joints shall consist of threaded fittings combined with elastomer seals and solvent weld or threaded fittings when attaching to supply line, valve, or sprinkler head. The swing joint assembly shall consist of injection-molded schedule 40 PVC conforming to ASTM D1784 and D2466, cell classification 12454-B, Type I, Grade I.

tape for installation above all mainline pipe, which does not have control wire placed in the same trench.

623.11Valves

AC, 60-cycle solenoid actuated globe or angle pattern, diaphragm type valve. The valve body and bonnet shall be heavy duty glass filled nylon or brass and internal components (not including diaphragm and seat disc) shall be non-corrosive brass, bronze, stainless-steel, or a combination thereof. Control valve diaphragms shall be of a one-piece molded reinforced fabric. Control valve shall have a non-shock cold-water rating of at least 150 psi.

623.12 Control valves shall function manually (without electrical power) by means of an internal bleeder device on the bonnet assembly. Control valves 1 inch or greater shall have manual flow control capacity. Control valves shall be constructed so that the bonnet assembly and all operating parts can be removed without disturbing the valve body. Valve closure time (measured in actual seat disc movement time) shall be at least 0.5 second.

shock cold water rating of at least 150 psi, and 1-inch female pipe threads at the base. The quick-coupler valve shall be designed to permit operation with a special connecting device (lug type coupler) designed for this purpose. The quick-coupler shall be provided with a rubber-like vinyl hinged locking cover. Quick-coupler keys and hose swivels shall be compatible with the quick-coupler valves furnished. Hose swivels shall be of all brass construction designed to rotate freely.

adjustable, pre-set type, consisting of a two-piece body molded from sturdy long lasting plastic. The internal spring shall be of stainless-steel. Each pressure-reducing valve shall have a minimum flow range of 0.5 gallons per minute with a regulated outlet pressure of 20 to 35 psi, with an inlet pressure range of 35 to 100 psi.

spring cage construction type with a bronze body, renewable stainless-steel seat, and stainless-steel integral strainer. Valves larger than 2 inches shall be the balanced piston type with a ductile-iron or cast-iron body.

bronze and machined brass. The drain valve shall be a rising stem globe valve with a non- shock cold water rating of at least 150 psi. The drain valve shall have a reverse flow capability, removable bonnet, and cast bronze cross handle.

port ball valves with a bronze body and have a stainless-steel ball and Teflon seat. The valves shall have a blow-out proof stem and be rated at a minimum of 400 psi, WOG. Mainline isolation valves larger than 3 inches in size shall be resilient seated gate valves with a cast iron body and have a 2-inch square nut operator. All isolation valves shall be rated at 200-psi differential pressure.

623.12Valve Box. The valve box, cover and necessary extensions shall be as shown on the

plans, and shall be manufactured or molded, virgin plastic materials conforming to ASTM D638 and D648. Box extensions shall be used as necessary to completely expose the remote- control valve and shall seat in place under the valve box. Valve box lids shall be imprinted “Irrigation Control Valve.”

623.13Strainer. Strainer shall be a wye pattern type with a polypropylene body. The

strainer shall contain a 150 mesh stainless-steel screen accessed by removing a threaded non-corrosive cap. Strainer shall be flushed via a ball valve located on the strainer.

623.14

Construction Requirements

623.14General. Irrigation systems shall be installed in conformity with applicable local

codes. Information on the plans shows general locations only. The Contractor shall establish exact locations of all irrigation equipment to fit field conditions, and locations will be approved by the Engineer before start of construction. Contractor shall maintain and protect the approved staking layout. Before purchase of any irrigation equipment, the Contractor shall submit a list of suppliers and specification sheets for all irrigation components. This submittal must be approved by the Engineer before any equipment purchase is made. At the submittal stage, all changes in equipment shall be brought to the attention of the Engineer.

623.15Site Review. At least 14 days before the start of irrigation work on the project, a Pre-

construction Conference shall be held. During irrigation installation, monthly meetings shall be held. Those in attendance shall be a representative of the Contractor's staff, the Landscape and Irrigation Subcontractors, the Engineer, and a CDOT Landscape Architect. A written description of work methods, and time schedules and milestone dates shall be presented. The Contractor shall notify the Engineer before mainline pressure testing, coverage tests, and final review. The Contractor shall provide two radio transceivers with necessary personnel or remote-control devices to operate automatic controllers during coverage tests and final review.

623.16Excavation and Backfill. Excavation and backfill shall conform to the requirements of

backfill outside of the roadway prism may be done by water flooding, with the approval of the Engineer. The Contractor shall maintain bottoms of trenches flat to permit all piping to be supported on an even grade. Where lines occur under paved areas, dimensions shall be considered to be below the subgrade. All mainline pipe shall be bedded in sand to allow a minimum of 2 inches of sand on all sides. Rock larger than 1 inch shall not be placed in the backfill material.

Where it is necessary to excavate adjacent to existing trees or shrubs, the Contractor shall use all possible care to avoid injury to the plant root system.

623.17Pipe Installation. Minimum cover for irrigation pipe shall be as follows:

Table 623-2 Minimum Cover for Irrigation Pipe 24 inches below finished Mainline Pipes grade 18 inches below finished Lateral Pipes grade 30 inches below subgrade Pipe under roadways finished grade 30 inches below finished Irrigation sleeving grade

623.18 All pipes under roadways shall be encased in a steel pipe sleeve that shall be jacked or placed in a hole bored under present roadways, or in a steel or plastic pipe sleeve placed by trenching on new construction. At least 4 inches of clearance shall be provided between lines and at least 4 feet of clearance between lines of other trades. Parallel pipes shall not be installed directly over any other line. Manual drain valves shall be installed at all low points in the mainline. Minimum grade of pipe to drains shall be 3 inches per 100 feet. Plastic threaded fittings shall be assembled using teflon tape applied to male pipe threads only. Threaded fittings shall be kept to a minimum. The Contractor shall tape all open ends of the pipe during installation to prevent entry of any foreign matter into the system.

623.18Kick Blocks. Concrete kick blocks shall be installed when the following conditions

occur on 4 inch or greater mainline pressure pipe:

623.19Wiring. All 24-volt wire to automatic control valves and flow sensor wiring shall be

installed at a minimum depth of 28 inches below finished grade. Power source wire shall conform to subsection 715.07. Wiring shall be installed at the side of and under mainline whenever possible. When more than one wire is placed in a trench, the Contractor shall tape wires together with electrical tape at intervals of 15 feet or less. A 24-inch coiled expansion loop shall be provided every 300 feet along wire run, before controller enclosure, at each connection, and at directional changes. Each automatic controller shall have its own separate ground wire, colored green. Wiring between automatic controller and automatic control valves or sensors shall be continuous. At locations where splicing is approved by the Engineer, moisture proof splices shall be made in a valve box. Two extra wires shall be installed along the entire mainline pipe from each automatic controller to the last automatic control valve. Wire splices shall be compatible in effectiveness to wire coating. All wire under roadways shall be encased in a separate steel or plastic conduit. Wires not following the mainline shall be installed using open trench excavation. Wiring shall not be installed using a vibratory plow. Tubing shall be installed to an even grade in an open trench. Flush valve assemblies shall be installed at all ends of the drip lateral lines. Before backfilling, all capillary drip lines shall be staked with an approved staple, 6 feet on center.

623.20Drip Systems. Drip lateral lines and capillary tubing shall be installed after 5 gallon

and larger plant materials are in place and finished grade is established. The Contractor shall tape all open ends of pipe during installation to prevent entry of debris into the system. All pipe shall be cut with a knife or blade type pipe cutter to prevent entry of pipe debris into the system; a saw shall not be used. Tubing shall be installed to an even grade in an open trench. Flush valve assemblies shall be installed at all ends of the drip lateral lines.

Before backfilling, all drip lines shall be staked with an approved staple, 6 feet on centers.

623.21

623.21Valve Boxes. All valve boxes shall be installed flush with the finished grade. A

“branding iron” type of tool shall be used to imprint the automatic control valve number (letters and numbers 2 inches high) on the valve box lid. Valve numbering system shall be as indicated on the plans. Geotextile filter fabric shall be placed under valve box and extend a minimum of 4 inches beyond bottom rim of valve box. Valves shall be grouped so that three or four valves are located together. Valves shall not be installed in low areas subject to standing water.

623.22System Flushing. After all irrigation pipelines and valves are in place and connected,

and before installation of irrigation sprinklers, rotary heads, etc., the Contractor shall thoroughly flush all lines with water at system operating pressure.

623.23Pressure and Coverage Tests, and Adjustments. After installation of valves, pipe, and

fittings, mainlines shall be inspected for leaks after a minimum 90 psi static pressure (or point- of-connection static pressure if higher) has been maintained for four hours in a hydro static test. Mainline pipes shall not be buried until completion of the test. If the system does not pass the test, the Contractor shall detect and correct problems until the system reaches the acceptable test standard. This test shall be passed before payment for the pipe. Gasketed pipe shall be tested using a volumetric (make up water) test and leak rates supplied by the pipe manufacturer and commonly accepted in the industry.

The Contractor shall perform coverage tests in the presence of the Engineer, after the irrigation system is completed and before any planting, seeding or sodding to assure that all irrigated areas are watered completely and uniformly. The Contractor shall make all necessary adjustments to provide required coverage as directed.

Drip lateral and emitter coverage tests shall be performed after planting and before backfilling of lateral lines and emitters.

623.24Inspections. Inspections by the Engineer or the Engineer’s representative can be made

at any point during construction. Milestone progress dates shall be established at the Pre- construction Conference and 72-hour notice shall be given by the Contractor when a milestone event is approaching.

623.25Irrigation As-Constructed Plans. The Contractor shall dimension from two permanent

reference points, building corners, sidewalk corners, road intersections or any permanent structures, the location of the following items:

The Contractor shall provide an accurately detailed irrigation as-constructed layout of the irrigation system at the same scale as the design plans and on 24-inch by 36-inch waterproof medium within 90 days after installation is complete and before notice of substantial landscape completion as defined in subsection 214.04. An in-progress as-constructed plan shall be kept on the construction site at all times and available for impromptu review by the Engineer or the Engineer’s representative.

623.26 Provision of the final as-constructed plan is a condition for final acceptance and release of retainage. All changes in the irrigation system layout, including lateral layout, shall also be indicated on irrigation as-constructed plans. The Contractor shall provide finalized as-constructed plans to the Engineer at the time of Final Landscape Acceptance.

623.26Maintenance Manuals and Training. Before Final Landscape Acceptance, the

Contractor shall provide two individually bound maintenance manuals to the Department for the irrigation system, and shall train the owner’s maintenance personnel in the proper operation of all irrigation equipment, including winterization procedures. Each manual shall contain the following:

person to contact.

maintenance personnel to understand, operate, and maintain the equipment. A printout of the as-constructed plans shall be provided, showing the area covered by that automatic controller. The area of coverage of each automatic control valve shall be identified using a distinctly different pastel color, drawn over the entire area of coverage.

Following approval of charts by the Engineer, they shall be hermetically sealed between two layers of plastic sheet, each 20 mils thick.

623.27Warranty. The Contractor shall warranty the irrigation system for the duration of

the Landscape Establishment period specified in subsection 214.04. To ensure proper operation of the system, the Contractor shall perform, as required, warranty activities including, but not limited to the following:

clogged emitters, malfunctioning automatic controllers and other components.

In an emergency the Contractor shall correct all deficiencies within 24 hours of notification by the Engineer. The Contractor shall perform irrigation system inspections at least once per week and after each mowing. The Contractor shall make corrections as necessary to ensure proper operation. The Contractor shall document each inspection in writing and submit it to the Engineer.

623.28

623.28Final Landscape Acceptance. Before final landscape acceptance is granted, the

Contractor shall perform an overall operation and pressure test and confirm the irrigation system is correctly functioning. This includes two weeks on “Flow” to be verified by the CDOT “Central Computer”. The Contractor shall inspect every sprinkler and as necessary, raise or lower those sprinklers that are no longer at the proper elevation relative to the finish grade as shown in the plans. The Contractor shall complete Spring start-up (pressurization) and repair all damage to the irrigation system.

623.29Cleanup. Upon completion of the work, the Contractor shall restore ground surfaces to

required elevations and remove excess materials, debris, and equipment from the site.

623.30Keys and Repair Components. Three keys shall be furnished for manual operation of

valves. When valves require different kinds of keys, three keys of each kind shall be furnished. Keys shall be of adequate length and made of non-corrosive metal.

The following sprinkler components shall be furnished for system repair:

623.31Irrigation Scheduling. The Contractor shall submit recommendations for the project’s

initial irrigation operating schedule for optimum plant establishment to the Engineer.

Method of Measurement

623.32Automatic controller will be measured by the number of units of each size installed and

accepted, including concrete pad, conduit, bolts, enclosure, ground wire, and all other items necessary to complete the work as shown on the plans.

Drip emitters will be measured by the number of multi-outlet emitters and shall include the capillary tubing, tubing stakes, enclosure box, and debris caps. Each drip emitter shall have six outlets. Emitter valve assemblies will be measured by the number of units of each size installed. Vacuum breakers, backflow preventers, strainers, and all other valves of the various types and sizes, including fittings, valve boxes, copper risers, and sleeves, will be measured by the number of units installed and accepted. Quick couplers, sprinkler of the various types and sizes including risers, check valves, swing joints and fittings, will be measured by the number of units installed and accepted. Plastic and copper pipe will be measured by the linear foot installed and will include the cost of the detectable underground marking tape. Power source wire and 24-volt wire will be measured by the linear foot installed. Water meter pay item includes all appurtenant fittings, valves, meter pit, and related equipment.

623.33

Basis of Payment

623.33The accepted quantities will be paid for at the contract unit price for the various

items below that appear in the bid schedule. Payment will be made under: Pay Item Pay Unit Shrubbery Spray and Flood Irrigator Each _____Inch Pop-up Spray Sprinkler Each _____Inch Pop-up Rotary Sprinkler Each _____Inch Above Ground Rotary Sprinkler Each _____Inch Above Ground Spray Each Hose Swivel Each Hose Bib Each _____Inch Copper Pipe Linear Foot _____Inch Plastic Pipe Linear Foot _____Inch Hose Linear Foot _____Inch Valve Box Each _____Inch Backflow Preventer Each _____Inch Pressure Reducing Valve Each _____Inch Drain Valve Each _____Inch Automatic Drain Valve Each _____Inch Manual Control Valve Each _____Inch Automatic Control Valve Each Power Source Wire Linear Foot _____Inch Quick-Coupler Valve Each _____Inch Gate Valve Each _____Inch Mainline Isolation Valve Each _____Inch Water Meter Each _____Inch Station Automatic Controller Each _____Inch Station Satellite Controller Each Control Wire, 24 Volt Linear Foot _____Inch Strainer Each Automatic Controller Transmitter/Receiver Unit Each Drip Emitter Each Emitter Valve Assembly Each _____Inch Flush Unit Each

Water lines will be paid for as provided in Section 619.

Kick blocks, unions, fittings, filter fabric, valve access sleeves, valve boxes, piping and wire inside boxes, keys, and aggregate for valves will not be paid for separately but shall be included in the work.

623.33

Structure excavation and backfill including compaction and water will not be paid for separately but shall be included in the work.

Concrete pad, bolts, enclosure, ground wire, and all other items necessary to complete the work shall be included in the price of the automatic controller.

Capillary tubing, tubing stakes, enclosure box and debris caps shall be included in the price of the drip emitter.

System flushing and adjustment, pressure and coverage tests, maintenance manuals, and training will not be paid for separately but shall be included in the price of the work.

The backflow preventer enclosure and pad will not be paid for separately but shall be included in the work.

Detectable Underground Marking Tape will not be paid for separately but shall be included in the work.

Advisor Message Receiver pagers and handheld two-way radios will not be paid for separately but shall be included in the work.

Warranty work will not be measured and paid for separately but shall be included in the work.

623.33

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624.01