623.01 623-1 SECTION 623 IRRIGATION SYSTEM DESCRIPTION
623.01 This 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
623.02 General. 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 .
623.03 Backflow 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.
623.04 Automatic 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 b e 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 bod y to allow for crossflow ventilation.
623.05 Remote 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. 623.06 623-2 623.06 Control 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 val ve. 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 White "common" or ground wire
623.07 Sprinkler 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.
623.09 Drip 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 i nstalled 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.
623.10 Plastic 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.
623.11 Valves.
623.12 Valve 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.”
623.13 Strainer. 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. 623.14 623-5 CONSTRUCTION REQUIREMENTS
623.14 General. 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.
623.15 Site 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.
623.16 Excavation and Backfill. Excavation and backfill shall conform to the requirements of
Section 206 and subsection 703.08(b) (Class 2 Structure Backfill), except that compaction 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.
623.17 Pipe Installation. Minimum cover for irrigation pipe shall be as follows:
Table 623 -2 MINIMUM COVER FOR IRRIGATION PIPE Mainline Pipes 24 inches below finished grade Lateral Pipes 18 inches below finished grade Pipe under roadways 30 inches below subgrade finished grade Irrigation sleeving 30 inches below finished grade 623.18 623-6 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 drai ns 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.
623.18 Kick Blocks . Concrete kick blocks shall be installed when the following conditions
occur on 4 inch or greater mainline pressure pipe :
623.19 Wiring. 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.
623.20 Drip 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. 623.21 623-7 623.21 Valve 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 insta lled in low areas subject to standing water.
623.22 System 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.
623.23 Pressure 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 sh all 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.
623.24 Inspections. 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.
623.25 Irrigation 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:
623.26 Maintenance 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:
623.27 Warranty. 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:
623.29 Cleanup. Upon completion of the work, the Contractor shall restore ground surfaces to
required elevations and remove excess materials, debris, and equipment from the site.
623.30 Keys 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:
623.31 Irrigation Scheduling . The Contractor shall submit recommendations for the project’s
initial irrigation operating schedule for optimum plant establishment to the Engineer . METHOD OF MEASUREMENT
623.32 Automatic 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 . 623.33 623-10 BASIS OF PAYMENT
623.33 The 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. 623.33 623-11 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. 623.33 623-12 THIS PAGE INTENTIONALLY LEFT BLANK 624.01 624-1 SECTION 624 DRAINAGE PIPE DESCRIPTION
624.01 This work consists of furnishing and installing pipe defined by class for culverts (cross
drains), side drains, and storm sewers per these specifications and in conformity with the lines and grades shown on the plans or established. MATERIALS
624.02 Materials shall meet the requirements in the Contract and in the following subsections.
Abbreviation Description Subsection CSP Corrugated Steel Pipe 707.02 Bit. Co. CSP Bituminous Coated Corrugated Steel Pipe 707.03