Landscape Irrigation
Remade from scratch to the authoring rules: defaults asserted only where four of five projects would choose them, and scope boundaries matched to the neighboring standards
Showing changes from Rev 7
to Rev 8
in Landscape Irrigation.
−---
−title: Landscape Irrigation
−category: Sitework
−toc_depth: 3
−description: >
− When to use: Underground automatic landscape irrigation systems for commercial, institutional, and industrial sites, including the point of connection and backflow prevention, buried mainline and lateral piping, isolation and zone control valves and valve boxes, spray heads and gear-driven rotors with matched-precipitation-rate nozzles, drip and micro-irrigation and subsurface drip for planting beds, smart weather/ET-based and soil-moisture-based controllers, master valve and flow sensor, rain and freeze sensors, sleeving and boring under paving and hardscape, coverage and hydrozoning design principles, pressure and coverage testing, winterization, and as-built controller programming. Emphasizes water efficiency, EPA WaterSense criteria, and local water-purveyor and code requirements.
− Not intended for: Potable water service and interior building distribution piping upstream of the irrigation point of connection (see [[sync/domestic-water-piping]]); the backflow prevention assembly's testing, certification, and selection criteria, which are governed by [[sync/backflow-prevention]] and the local cross-connection control program (this standard covers only its integration into the irrigation system); agricultural and crop irrigation; golf course irrigation (governed by project-specific design and not this standard); decorative fountains, water features, and pools; stormwater reuse and graywater treatment systems upstream of the irrigation supply (the connection to a reuse source is covered, but the treatment and storage are not); landscape planting, soil preparation, and establishment (a separate landscape standard); and trenching, bedding, and backfill earthwork, which is governed by [[sync/earthwork]] and supplemented here only for irrigation-specific requirements.
−---
−
−# Scope {toc}
−
−## This standard covers the materials, installation, testing, and commissioning of underground automatic landscape irrigation systems that distribute water from a defined point of connection to turf, planting beds, trees, and other landscape areas through buried piping, automatic valves, sprinkler heads, rotors, and drip or micro-irrigation devices under the control of an automatic controller. {note}
−## The scope begins at the downstream side of the irrigation point of connection — immediately downstream of the irrigation meter, isolation valve, and backflow prevention assembly — and extends through the mainline, zone control valves, lateral piping, emission devices, and the low-voltage control wiring and controller that operate the system. {note}
−
−## Landscape irrigation is the site scope most directly responsible for the long-term survival of the landscape investment and for the project's water-efficiency performance. An irrigation system that is poorly zoned, that mixes incompatible emission devices on a single valve, or that applies water faster than the soil can absorb it does not fail dramatically — it fails by producing dry spots and runoff at the same time, by over-watering some hydrozones while under-watering others, and by consuming far more water than the landscape requires. Because water is metered and, increasingly, restricted by local purveyors and drought ordinances, the efficiency of the installed system is a continuing operating cost to the Owner for the life of the landscape. This standard establishes the material quality, the zoning and coverage principles, and the installation and testing protocols within which the irrigation design drawings operate. {note}
−
−## This standard does not include the hydraulic design of the irrigation system. The irrigation designer or landscape architect of record establishes the water demand, the hydrozone layout, the head and emitter selection and spacing, the zone valve grouping, the pipe sizing, the controller program, and the point-of-connection sizing. {note}
−
−## Head and emitter locations, spacing, nozzle selection, zone boundaries, pipe sizes, and routing are [[drawing: as indicated on the irrigation plans, the zone schedule, and the irrigation legend]].
−
−## The Contractor shall install the system as designed.
−
−## The Contractor shall report to the designer of record any field condition that would prevent the designed system from being constructed as drawn — including inadequate static pressure or flow at the point of connection, conflicts with other utilities, insufficient cover, or coverage gaps created by hardscape or planting changes made after the irrigation design was completed.
−
−## The Contractor shall coordinate work under this standard with [[sync/backflow-prevention]] for the backflow assembly at the point of connection, with [[sync/domestic-water-piping]] for the potable supply upstream of the point of connection, and with [[sync/earthwork]] for trench excavation, bedding, and backfill.
−
−# Referenced Standards {toc}
−
−## Materials, components, and installation shall comply with the latest adopted edition of the following standards and codes.
−
−| Standard | Title |
−|----------|-------|
−| ASTM D1784 | Standard Specification for Rigid Poly(Vinyl Chloride) (PVC) Compounds and Chlorinated Poly(Vinyl Chloride) (CPVC) Compounds |
−| ASTM D1785 | Standard Specification for Poly(Vinyl Chloride) (PVC) Plastic Pipe, Schedules 40, 80, and 120 |
−| ASTM D2241 | Standard Specification for Poly(Vinyl Chloride) (PVC) Pressure-Rated Pipe (SDR Series) |
−| ASTM D2466 | Standard Specification for Poly(Vinyl Chloride) (PVC) Plastic Pipe Fittings, Schedule 40 |
−| ASTM D2467 | Standard Specification for Poly(Vinyl Chloride) (PVC) Plastic Pipe Fittings, Schedule 80 |
−| ASTM D2464 | Standard Specification for Threaded Poly(Vinyl Chloride) (PVC) Plastic Pipe Fittings, Schedule 80 |
−| ASTM D2564 | Standard Specification for Solvent Cements for Poly(Vinyl Chloride) (PVC) Plastic Piping Systems |
−| ASTM D2855 | Standard Practice for the Two-Step (Primer and Solvent Cement) Method of Joining PVC or CPVC Pipe and Piping Components with Tapered Sockets |
−| ASTM D3139 | Standard Specification for Joints for Plastic Pressure Pipes Using Flexible Elastomeric Seals |
−| ASTM F477 | Standard Specification for Elastomeric Seals (Gaskets) for Joining Plastic Pipe |
−| ASTM D2239 | Standard Specification for Polyethylene (PE) Plastic Pipe (SIDR-PR) Based on Controlled Inside Diameter |
−| ASTM D3035 | Standard Specification for Polyethylene (PE) Plastic Pipe (DR-PR) Based on Controlled Outside Diameter |
−| ASTM D3350 | Standard Specification for Polyethylene Plastics Pipe and Fittings Materials |
−| ASTM D2774 | Standard Practice for Underground Installation of Thermoplastic Pressure Piping |
−| ASSE 1013 | Performance Requirements for Reduced Pressure Principle Backflow Prevention Assemblies |
−| ASSE 1015 | Performance Requirements for Double Check Backflow Prevention Assemblies |
−| ASSE 1020 | Performance Requirements for Pressure Vacuum Breaker Assemblies |
−| NSF/ANSI 61 | Drinking Water System Components — Health Effects |
−| NSF/ANSI/CAN 372 | Drinking Water System Components — Lead Content |
−| ANSI/ASABE S627 | Weather-Based Landscape Irrigation Control Systems |
−| EPA WaterSense | Specification for Weather-Based Irrigation Controllers; Specification for Soil Moisture-Based Irrigation Controllers; Specification for Spray Sprinkler Bodies |
−| ANSI/ASABE S376 | Design, Installation, and Performance of Underground, Thermoplastic Irrigation Pipelines |
−| UL 1951 | Standard for Electric Plumbing Accessories (irrigation controllers / transformers) |
−| NFPA 70 | National Electrical Code (low-voltage control wiring and controller power) |
−
−## Where the contract documents, the Authority Having Jurisdiction (AHJ), the local water purveyor, or a referenced standard impose conflicting requirements, the more stringent requirement shall govern unless the designer of record directs otherwise in writing.
−
−## The adopted plumbing code and the local cross-connection control program shall take precedence on any matter of backflow protection.
−
−## The local water purveyor's rules and the jurisdiction's cross-connection control program shall be identified by the Contractor during pre-construction.
−
−## Many jurisdictions require a permit for the irrigation meter and backflow assembly, require certified testing of the backflow assembly by a licensed tester before the meter is activated, and enforce watering-day and watering-time restrictions that the controller program must accommodate. {note}
−
−## Where the project pursues a green building rating (such as LEED or a local water-efficient landscape ordinance), the irrigation system shall meet the water-budget and equipment requirements of that program in addition to this standard.
−
−# Submittals {toc}
−
−## Action Submittals {toc}
−
−### The Contractor shall submit the following for the designer of record's review and acceptance prior to procurement or installation:
−
−- Product data for all pipe and fittings, indicating the manufacturer, the applicable ASTM standard, the pressure class or schedule, the joining method (solvent weld, gasketed, or insert-fitting), and NSF/ANSI 61 and NSF/ANSI/CAN 372 certification where the system is connected to a potable supply
−- Product data for the backflow prevention assembly, coordinated with [[sync/backflow-prevention]], including the ASSE listing, the assembly type, and the approval listing required by the local cross-connection control program
−- Product data for all isolation valves, zone control (remote control) valves, the master valve, and quick-coupling valves, indicating body and seat material, pressure rating, flow-control capability, and solenoid voltage
−- Product data for all spray heads, rotors, and nozzles, including the manufacturer's precipitation-rate and radius performance tables at the design operating pressure, and identification of matched-precipitation-rate nozzle sets by arc
−- Product data for all drip and micro-irrigation components, including emitter flow rate, pressure-compensation range, emitter spacing, the pressure regulator setting, the required filtration mesh or micron rating, and air/vacuum relief and flush devices
−- Product data for the controller, indicating WaterSense and ANSI/ASABE S627 listing (for weather-based controllers) or WaterSense soil-moisture listing, the number of stations, the surge and lightning protection, and the communication method (on-board, internet, or central control)
−- Product data for the flow sensor, rain sensor, freeze sensor, and any soil-moisture sensors, with the controller-compatibility documentation
−- Valve box product data, indicating the box size, load rating, and lid marking
−- Low-voltage control wire and splice product data, indicating conductor type, insulation rating for direct burial, and the waterproof splice connector type
−- A zone schedule (Contractor's coordination set) listing each zone number, the emission device type, the design flow in gallons per minute (GPM), the design operating pressure, the controller station assignment, and the hydrozone served
−- An as-built record-set procedure describing how the Contractor will maintain a daily-updated markup showing actual mainline routing, valve locations, sleeve locations, and wire paths
−
−```datasheet
−label: Action Submittals Required
−type: checkbox
−options:
− - "Pipe and fitting product data (with NSF 61/372 where potable-supplied)"
− - "Backflow prevention assembly product data and AHJ approval listing"
− - "Valve product data (isolation, zone control, master, quick-coupling)"
− - "Spray head, rotor, and nozzle product data with precipitation tables"
− - "Drip and micro-irrigation component product data"
− - "Controller product data (WaterSense / ANSI-ASABE S627 listing)"
− - "Flow sensor, rain sensor, freeze sensor, and soil-moisture sensor data"
− - "Valve box product data"
− - "Low-voltage control wire and waterproof splice product data"
− - "Zone schedule (Contractor coordination set)"
− - "As-built record-set procedure"
−default: "Pipe and fitting product data (with NSF 61/372 where potable-supplied)"
−```
−
−### Work shall not proceed on any system or zone until the corresponding submittals have been reviewed and returned.
−
−## Closeout Submittals {toc}
−
−### Prior to substantial completion the Contractor shall provide the following:
−
−- As-built irrigation record drawings showing actual mainline and lateral routing dimensioned from permanent reference points, the location and station assignment of every zone valve, the location of the master valve and flow sensor, the location of every sleeve and the size and contents of each, the routing of all control wire, and the location of all isolation valves, quick-coupling valves, and drain valves
−- A controller programming record showing the final program for every station: run time, start times, watering days, seasonal adjustment (percent), cycle-and-soak settings, and any sensor-based overrides, as left at turnover
−- Field test reports for the mainline pressure test, the lateral coverage test, and the operational test of every zone, signed by the Contractor's superintendent and the witnessing inspector
−- The backflow assembly's initial certification test report from a licensed backflow tester, as required by the local cross-connection control program
−- Operation and maintenance (O&M) manuals for the controller, the backflow assembly, the master valve and flow sensor, and all specialty devices, including the manufacturer's seasonal start-up and winterization procedures
−- A laminated zone map mounted at or adjacent to the controller, identifying each station number and the area it serves
−- Manufacturer warranties for all products carrying a warranty
−- A spare-parts inventory turned over to the Owner as specified in the Spare Parts section
−
−```datasheet
−label: Closeout Submittals Required
−type: checkbox
−options:
− - "As-built irrigation record drawings"
− - "Controller programming record (as-left program)"
− - "Field test reports (mainline pressure, lateral coverage, zone operation)"
− - "Backflow assembly initial certification test report"
− - "Operation and maintenance (O&M) manuals"
− - "Laminated zone map mounted at controller"
− - "Manufacturer warranties"
− - "Spare-parts inventory turned over to Owner"
−default:
− - "As-built irrigation record drawings"
− - "Controller programming record (as-left program)"
− - "Field test reports (mainline pressure, lateral coverage, zone operation)"
− - "Backflow assembly initial certification test report"
− - "Operation and maintenance (O&M) manuals"
− - "Laminated zone map mounted at controller"
− - "Manufacturer warranties"
− - "Spare-parts inventory turned over to Owner"
−```
−
−# Quality Assurance {toc}
−
−## Installer Qualifications {toc}
−
−### Landscape irrigation systems shall be installed by a contractor regularly engaged in the installation of commercial irrigation systems, with verifiable experience on at least three projects of comparable size and complexity within the preceding five years.
−
−### Where the jurisdiction licenses irrigation contractors or requires a certified irrigation technician, the Contractor shall hold the applicable license or shall employ certified personnel as required by the AHJ.
−
−## Backflow Tester Certification {toc}
−
−### The backflow prevention assembly shall be tested and certified upon installation by a tester certified under the local cross-connection control program.
−
−### The Contractor shall coordinate this certification with the requirements of [[sync/backflow-prevention]].
−
−### The Contractor shall not place the irrigation system in service until the assembly has passed its initial certification test and the test report has been filed with the water purveyor where required.
−
−## Pre-Installation Conference {toc}
−
−### Prior to beginning irrigation installation the Contractor shall participate in a pre-installation conference attended by the Contractor's superintendent, the irrigation designer or landscape architect of record, the general contractor's site superintendent, and the landscape installer.
−
−### The conference shall review the point-of-connection arrangement and verified static pressure and flow, the hydrozone layout and zone schedule, the sleeve locations and the coordination of sleeving with paving and hardscape operations, the controller location and power source, and the sequence of irrigation work relative to grading, planting, and paving.
−
−## Verification of Available Pressure and Flow {toc}
−
−### Before installing any piping the Contractor shall verify the actual static water pressure and available flow at the point of connection by field measurement, and shall compare the measured values to the design assumptions stated on the irrigation drawings.
−
−### The performance of every spray head, rotor, and drip device depends on the operating pressure delivered to it; an irrigation system designed for a static pressure that the site does not actually provide will under-perform at every zone, and the deficiency is far cheaper to discover before trenching than after. {note}
−
−### The Contractor shall report any discrepancy between measured and design pressure or flow to the designer of record before proceeding.
−
−# Environmental and Service Conditions {toc}
−
−## Water Source and Quality {toc}
−
−### The water source determines the backflow protection required, the filtration required for drip and micro-irrigation, and, for reclaimed water, the marking and separation requirements imposed by the jurisdiction. {note}
−
−### The irrigation water source shall be as indicated on the drawings — potable supply, non-potable reclaimed/reuse supply, well, or surface water.
−
−```datasheet
−label: Irrigation Water Source
−type: select
−drawing_ref: true
−options:
− - "Potable municipal supply through dedicated irrigation meter"
− - "Potable municipal supply, shared with domestic service (separate backflow)"
− - "Reclaimed / reuse (purple-pipe) supply"
− - "On-site well"
− - "Surface water (pond, lake, harvested stormwater)"
−default: "Potable municipal supply through dedicated irrigation meter"
−```
−
−### Where the source is reclaimed or reuse water, all piping, valve boxes, and appurtenances shall be identified in accordance with the jurisdiction's reclaimed-water requirements — typically purple (Pantone 522C) pipe or purple identification tape, purple valve box lids embossed with a non-potable warning, and the separation distances from potable lines required by the adopted plumbing code.
−
−### On a reclaimed system, quick-coupling valves and hose bibs shall use a non-interchangeable coupler keyed differently from potable connections so that a hose cannot be cross-connected.
−
−## Freeze Exposure {toc}
−
−### In climates subject to freezing, the system shall be designed and installed to permit complete winterization by draining or by compressed-air blow-out.
−
−### Components subject to freeze damage — the backflow assembly, exposed piping, and valves above the frost line — shall be protected, drained, or insulated as indicated.
−
−### The mainline and laterals shall be installed at a depth and on a grade that permits draining toward manual or automatic drain valves at low points where a drain-down winterization method is used.
−
−## Soil and Slope Conditions {toc}
−
−### The application rate of the emission devices shall not exceed the intake (infiltration) rate of the soil for the slope on which they are installed; otherwise the excess application runs off, wasting water and eroding the landscape.
−
−### On slopes and on tight (clay) soils, the irrigation design addresses runoff with cycle-and-soak scheduling, with low-precipitation-rate nozzles, or with drip irrigation. {note}
−
−### The Contractor shall install the emission devices and program the controller to deliver the cycle-and-soak run times indicated on the zone schedule.
−
−### The Contractor shall report any field condition (such as a steeper finished slope than the design assumed) that would produce runoff.
−
−# Point of Connection and Backflow Prevention {toc}
−
−## Point of Connection {toc}
−
−### The point of connection shall be made as indicated on the drawings, downstream of the irrigation meter (or downstream of the building service tap for a shared supply) and shall include an isolation valve, the backflow prevention assembly, and a means of draining the assembly for winterization where required.
−
−### The point-of-connection assembly shall be supported independently of the piping so that the weight of the backflow assembly and valves is not carried by the buried mainline.
−
−## Backflow Prevention Assembly {toc}
−
−### For landscape irrigation a reduced-pressure-principle assembly is typical because it provides protection against both backsiphonage and backpressure and is accepted for high-hazard applications. {note}
−
−### A backflow prevention assembly shall be provided at the point of connection to protect the potable supply from the irrigation system, which the plumbing code classifies as a high-hazard cross-connection because of the potential for fertilizer, pesticide, and soil contaminants to be drawn back through the irrigation piping.
−
−### The assembly type shall be as required by the local cross-connection control program and as indicated on the drawings.
−
−```datasheet
−label: Backflow Prevention Assembly Type
−type: select
−drawing_ref: true
−options:
− - "Reduced-pressure-principle assembly (ASSE 1013) — typical for irrigation high-hazard"
− - "Double check valve assembly (ASSE 1015) — where permitted for the hazard level"
− - "Pressure vacuum breaker assembly (ASSE 1020) — backsiphonage only, no chemical injection"
−default: "Reduced-pressure-principle assembly (ASSE 1013) — typical for irrigation high-hazard"
−```
−
−### The reduced-pressure-principle assembly is the recognized choice where any chemical injection (fertigation), where backpressure from elevated zones, or where high-hazard contaminants are possible. {note}
−
−### A pressure vacuum breaker protects only against backsiphonage and shall not be used where chemical injection is present or where the assembly can be subjected to backpressure.
−
−### The detailed selection, installation height, freeze protection, and certification testing of the assembly are governed by [[sync/backflow-prevention]] and the local program; this standard requires only that an approved assembly of the correct type be provided and integrated into the irrigation system, and that the irrigation system not be energized until the assembly has passed its initial certification.
−
−## Pressure Regulation at the Point of Connection {toc}
−
−### Excess pressure mists spray nozzles into fine droplets that drift and evaporate, wastes water, and accelerates wear on every component; pressure regulation at the point of connection (in addition to, or in place of, pressure-regulating heads) is the most reliable way to control it. {note}
−
−### Where the static supply pressure exceeds the maximum operating pressure of the system components, a pressure-reducing valve or a master pressure regulator shall be provided downstream of the backflow assembly to limit the system pressure to the design value.
−
−```datasheet
−label: System Pressure Regulation at Point of Connection
−type: radio
−drawing_ref: true
−options:
− - "Not required — supply pressure within component operating range"
− - "Master pressure-reducing valve at point of connection"
− - "Pressure regulation at each zone valve"
− - "Pressure-regulating spray bodies / rotors only (no master regulator)"
−default: "Not required — supply pressure within component operating range"
−```
−
−# Piping Materials {toc}
−
−## Mainline and Lateral Piping Material {toc}
−
−### PVC pipe is the predominant material for buried commercial irrigation in most of the United States; polyethylene pipe is used where its flexibility, freeze tolerance, or suitability for trenchless pulling is advantageous, and is common in northern climates and on rocky sites. {note}
−
−### The pipe material for the mainline and laterals shall be as indicated on the drawings.
−
−```datasheet
−label: Mainline Piping Material
−type: select
−drawing_ref: true
−options:
− - "PVC Schedule 40 (ASTM D1785), solvent-welded"
− - "PVC Class 200 / SDR-PR (ASTM D2241), solvent-welded"
− - "PVC Class 200 / SDR-PR (ASTM D2241), gasketed (3 in. and larger)"
− - "Polyethylene (ASTM D2239 or D3035), insert or fusion fittings"
−default: "PVC Class 200 / SDR-PR (ASTM D2241), solvent-welded"
−```
−
−```datasheet
−label: Lateral Piping Material
−type: select
−drawing_ref: true
−options:
− - "PVC Class 200 / SDR-PR (ASTM D2241), solvent-welded"
− - "PVC Schedule 40 (ASTM D1785), solvent-welded"
− - "Polyethylene (ASTM D2239 or D3035), insert fittings"
−default: "PVC Class 200 / SDR-PR (ASTM D2241), solvent-welded"
−```
−
−### The mainline operates under continuous (constant) pressure between the point of connection and the zone valves, and therefore warrants the more conservative material — Schedule 40 PVC or a heavier pressure class — and gasketed joints on larger diameters to accommodate thermal movement. {note}
−
−### Laterals operate under pressure only while their zone is running, so Class 200 PVC is commonly used for laterals as an economical pressure-rated choice. {note}
−
−### The Contractor shall not use Schedule 40 cellular-core (foam-core) PVC, drain-waste-vent (DWV) pipe, or sewer pipe for any pressurized irrigation piping.
−
−### Only pressure-rated pipe marked with the applicable ASTM pressure designation shall be installed under pressure.
−
−## PVC Pipe {toc}
−
−```datasheet
−label: PVC Pressure Class — Laterals
−type: select
−unit: psi
−drawing_ref: true
−options:
− - "Class 200 (SDR 21) — typical for laterals"
− - "Class 315 (SDR 13.5) — high-pressure or small-diameter laterals"
− - "Schedule 40 — where indicated for laterals subject to handling stress"
−default: "Class 200 (SDR 21) — typical for laterals"
−```
−
−### PVC pipe shall be manufactured from a Class 12454 PVC compound conforming to ASTM D1784, and shall be marked with the manufacturer's name, the nominal size, the applicable ASTM standard (D1785 for schedule-rated or D2241 for SDR pressure-rated pipe), the pressure rating or schedule, and the NSF mark where the system is supplied from a potable source.
−
−### PVC pipe shall be stored under cover or otherwise shaded prior to installation; prolonged ultraviolet exposure degrades the pipe surface and embrittles PVC over time.
−
−## PVC Fittings and Solvent-Weld Joints {toc}
−
−```datasheet
−label: PVC Joining Method
−type: radio
−drawing_ref: true
−options:
− - "Solvent weld with primer and cement (ASTM D2855 two-step)"
− - "Gasketed bell-and-spigot (ASTM D3139, F477 gaskets) — mainline 3 in. and larger"
− - "Threaded (Schedule 80 fittings only, ASTM D2464) — at valves and transitions"
−default: "Solvent weld with primer and cement (ASTM D2855 two-step)"
−```
−
−### Solvent-weld socket fittings for Schedule 40 pipe shall conform to ASTM D2466.
−
−### Socket fittings for Schedule 80 pipe shall conform to ASTM D2467.
−
−### Threaded fittings shall conform to ASTM D2464 and shall be Schedule 80 where threaded, because Schedule 40 threaded PVC is prone to splitting at the threads.
−
−### Slip-fit fittings used with Class 200 pipe shall be pressure-rated socket fittings compatible with the pipe's outside diameter.
−
−### Solvent cement shall conform to ASTM D2564 and primer to the cement manufacturer's specification.
−
−### Joints shall be made by the two-step primer-and-cement method in accordance with ASTM D2855.
−
−### Every solvent-weld joint shall be primed and cemented; the use of cement without primer ("one-step" cement) is not acceptable for buried pressure piping under this standard, because the primer softens and cleans the bonding surfaces and is what produces a reliable solvent weld.
−
−### The cured joint shall be allowed to set and cure for the time specified by the cement manufacturer for the pipe size and ambient temperature before the line is pressurized.
−
−### Pressurizing or backfilling a green (uncured) solvent weld is a frequent cause of joint failure. {note}
−
−### Threaded connections shall be made with PTFE tape or a non-hardening pipe-thread sealant and hand-tightened plus the manufacturer's specified turns; over-tightening threaded PVC splits the female fitting.
−
−## Polyethylene Pipe {toc}
−
−### PE is well suited to freeze-prone climates because it expands rather than splitting under residual ice, and to rocky or trenchless conditions because it can be pulled through a bored path. {note}
−
−### Polyethylene pipe, where indicated, shall conform to ASTM D2239 (controlled inside diameter) or ASTM D3035 (controlled outside diameter), manufactured from a PE compound conforming to ASTM D3350.
−
−### PE pipe shall be joined with the manufacturer's barbed insert fittings secured with stainless steel pinch clamps or screw clamps, or by thermal fusion where indicated for larger diameters.
−
−```datasheet
−label: Polyethylene Pipe Joining
−type: radio
−drawing_ref: true
−options:
− - "Barbed insert fittings with stainless steel clamps (two clamps per fitting)"
− - "Thermal fusion (larger-diameter mainline)"
−default: "Barbed insert fittings with stainless steel clamps (two clamps per fitting)"
−```
−
−# Valves and Valve Boxes {toc}
−
−## Isolation Valves {toc}
−
−### Isolation (shutoff) valves shall be provided at the point of connection, at the base of each mainline branch serving a group of zones, and at locations that allow portions of the system to be isolated for maintenance without draining the entire mainline.
−
−### Isolation valves shall be resilient-wedge gate valves, ball valves, or brass gate valves as indicated, rated for the working pressure of the mainline, and installed in a valve box for access.
−
−## Zone Control (Remote Control) Valves {toc}
−
−```datasheet
−label: Zone Control Valve Solenoid
−type: radio
−options:
− - "24 VAC solenoid (standard, hard-wired controller)"
− - "DC latching solenoid (battery / two-wire decoder systems)"
− - "Per controller type"
−default: "24 VAC solenoid (standard, hard-wired controller)"
−```
−
−```datasheet
−label: Zone Valve Flow Control
−type: radio
−drawing_ref: true
−options:
− - "Flow-control stem at each valve (recommended for balancing)"
− - "No flow control (fixed) — where zones are pressure-regulated elsewhere"
−default: "Flow-control stem at each valve (recommended for balancing)"
−```
−
−### Each irrigation zone shall be controlled by an electrically actuated remote control valve that opens when its controller station energizes the valve solenoid and closes when the station de-energizes.
−
−### Zone control valves shall be globe- or angle-pattern diaphragm valves with a 24-volt AC solenoid, a manual internal/external bleed for field operation, and a flow-control stem where indicated to throttle the zone flow.
−
−### Zone control valve body and bonnet shall be glass-filled nylon, PVC, or brass as indicated, rated for the system working pressure.
−
−### Zone valves should include a manual bleed so that a single zone can be operated in the field for testing and maintenance without the controller.
−
−### Zone valves should include a flow-control stem so that flow to each zone can be throttled to balance the system.
−
−### Only one type of emission device shall be served by a single zone valve — spray heads, rotors, and drip devices shall never be mixed on one zone, because they apply water at radically different precipitation rates and cannot be scheduled together without grossly over- or under-watering one of them.
−
−### Single-emission-device zoning is the single most important zoning principle in irrigation and is addressed further in the Hydrozoning principles applied throughout this standard. {note}
−
−## Quick-Coupling Valves {toc}
−
−### Quick-coupling valves shall be provided where indicated to allow hose connection for hand-watering, syringing, and washdown without an exposed hose bib.
−
−### Quick-coupling valves shall be brass, connected to the mainline, and installed in a valve box.
−
−### On reclaimed-water systems the coupler shall be of a non-interchangeable key type so that it cannot accept a potable hose connector.
−
−## Valve Boxes {toc}
−
−```datasheet
−label: Valve Box Load Rating by Location
−type: select
−drawing_ref: true
−options:
− - "Standard duty — turf and planting bed areas (pedestrian only)"
− - "Heavy duty / traffic-rated — driveways, parking, and vehicular areas"
−default: "Standard duty — turf and planting bed areas (pedestrian only)"
−```
−
−### All zone valves, isolation valves, master valves, flow sensors, quick-coupling valves, wire splices, and drain valves shall be installed in valve boxes for access.
−
−### Valve boxes shall be high-density polyethylene or structural-foam polypropylene with a locking or bolt-down lid, sized so that the valve and its wiring can be serviced without excavation, and load-rated for the location.
−
−### Valve boxes shall be set flush with finished grade (or 1 inch above finished grade in turf areas where mowing equipment passes, as indicated), on a base of gravel or crushed stone that provides drainage and prevents the valve box from settling and trapping water around the valve and splices.
−
−### Valve box lids shall be marked or color-coded to identify the contents — control valve, master valve, isolation, or, on reclaimed systems, the non-potable warning.
−
−### Boxes set below grade fill with water and silt, corrode wire splices, and make valves impossible to service. {note}
−
−# Sprinkler Heads, Rotors, and Nozzles {toc}
−
−## Spray Heads {toc}
−
−```datasheet
−label: Spray Head Pop-Up Height
−type: select
−unit: in
−drawing_ref: true
−options:
− - "4 in. — turf areas"
− - "6 in. — taller turf and groundcover"
− - "12 in. — shrub and tall groundcover beds"
− - "Shrub adapter on riser — shrub beds"
−default: "4 in. — turf areas"
−```
−
−```datasheet
−label: Pressure-Regulating Spray Bodies
−type: radio
−drawing_ref: true
−options:
− - "Pressure-regulating spray bodies (WaterSense-labeled, integral regulator)"
− - "Standard spray bodies (pressure regulated at zone valve or point of connection)"
−default: "Pressure-regulating spray bodies (WaterSense-labeled, integral regulator)"
−```
−
−### Spray heads (fixed spray, or spray bodies fitted with fixed or adjustable nozzles) shall be pop-up bodies with the pop-up height indicated for the area served.
−
−### Spray heads shall be fitted with the matched-precipitation-rate nozzles indicated on the drawings so that all heads within a zone apply water at the same depth per unit time regardless of arc.
−
−### Spray bodies should be pressure-regulating (with an integral pressure regulator) and should incorporate a check valve where heads at low points would otherwise drain the lateral between cycles.
−
−### A 4-inch pop-up is standard for turf because it clears typical mowed turf height while retracting flush when not operating. Pressure-regulating spray bodies that hold the nozzle at its design pressure (commonly 30 psi for fixed sprays, 40 psi for many rotary nozzles) are the most effective single measure for spray-zone efficiency, because they eliminate the misting and fogging that occurs when an unregulated body is fed at a higher pressure than the nozzle is designed for. WaterSense labels spray sprinkler bodies that incorporate integral pressure regulation. {note}
−
−## Rotors (Gear-Driven Rotary Heads) {toc}
−
−### Rotors apply water at a lower precipitation rate than spray heads, which makes them better suited to slopes and tight soils but means they must never be combined on the same zone as spray heads.
−
−```datasheet
−label: Rotor Nozzle Matching Strategy
−type: radio
−drawing_ref: true
−options:
− - "Matched-precipitation nozzle set sized by arc (quarter, half, full)"
− - "Separate zones by arc (quarter heads, half heads, full heads on distinct zones)"
−default: "Matched-precipitation nozzle set sized by arc (quarter, half, full)"
−```
−
−### Rotors (gear-driven rotary sprinklers) shall be used for larger turf areas where their longer throw and lower precipitation rate suit the area and the soil intake rate.
−
−### Rotors shall be fitted with the nozzle set indicated on the drawings, selected so that the precipitation rate is matched across the arcs within the zone.
−
−### Because a full-circle rotor covers four times the area of a quarter-circle rotor, applying the same flow to both produces four times the precipitation rate on the quarter — the corner gets soaked while the open area stays dry. The design corrects this either by installing a proportionally larger nozzle in the wider-arc heads (so a full-circle head receives roughly four times the flow of a quarter-circle head) or by separating the arcs onto different zones. {note}
−
−### The Contractor shall install the specific nozzle assigned to each head on the drawings and shall not field-substitute nozzles, because the substitution destroys the matched precipitation the designer established.
−
−## Matched Precipitation Rate {toc}
−
−### Within any single zone, all emission devices shall apply water at a matched precipitation rate so that a single run time waters the entire zone uniformly.
−
−### Matched precipitation is achieved by selecting nozzles whose flow is proportional to the arc each head covers. {note}
−
−### A zone that mixes mismatched precipitation rates cannot be scheduled correctly: any run time that adequately waters the low-rate heads over-waters the high-rate heads, producing simultaneous dry spots and runoff. Matched precipitation is the reason emission devices, arcs, and nozzles are specified by the designer rather than chosen in the field. {note}
−
−## Head-to-Head Coverage {toc}
−
−### This overlap is required because the application depth from a single sprinkler is heaviest near the head and tapers to nearly nothing at the edge of its throw; without overlap, the areas between heads receive far less water than the areas near them, producing the characteristic ring or doughnut dry pattern. {note}
−
−### Spray heads and rotors shall be installed at the spacing indicated on the drawings to achieve head-to-head coverage — each head's throw reaches the adjacent heads, so that every point in the zone receives water from at least two heads.
−
−```datasheet
−label: Head Spacing Basis
−type: radio
−drawing_ref: true
−options:
− - "Head-to-head (100 percent of radius) spacing per design layout"
− - "Reduced spacing in high-wind areas (per design, less than full radius)"
−default: "Head-to-head (100 percent of radius) spacing per design layout"
−```
−
−### The Contractor shall install heads at the design spacing and shall not increase spacing to economize on heads, because head spacing greater than the head-to-head design destroys distribution uniformity.
−
−### Where field conditions (hardscape edges, planting changes, obstructions) prevent the design spacing, the Contractor shall report the condition to the designer rather than leaving a coverage gap.
−
−## Swing Joints and Risers {toc}
−
−### Every spray head and rotor connected to a lateral shall be installed on a flexible swing joint (a triple-swing assembly of marlex/PVC street ells, or a flexible PVC riser) between the lateral fitting and the head.
−
−### The swing joint allows the head to be set precisely to finished grade and to the correct vertical position, and absorbs the impact of foot traffic, mowers, and vehicles without transmitting the load to the buried lateral fitting. {note}
−
−### Heads installed on a rigid nipple directly into a lateral tee crack the fitting the first time the head is kicked or driven over; the swing joint is not optional on quality commercial work. {note}
−
−# Drip and Micro-Irrigation {toc}
−
−## Drip and micro-irrigation shall be used for planting beds, shrub masses, groundcover, individual trees, and other non-turf areas as indicated, and for turf only where subsurface drip is specifically designed for the area.
−
−## Drip irrigation applies water slowly and directly to the root zone, achieving very high application efficiency and eliminating the wind drift and evaporation losses of spray irrigation; it is the preferred method for beds and is frequently required by water-efficient landscape ordinances for all non-turf plantings. {note}
−
−## Drip Zone Control Assembly {toc}
−
−### The filter protects the small emitter passages from clogging and the pressure regulator holds the drip line at the low pressure (commonly 15 to 40 psi) at which the emitters are rated; both are essential, and a drip zone fed at an unregulated, unfiltered pressure will clog and blow apart. {note}
−
−### Each drip zone shall be served by a zone control assembly consisting of, in order, the remote control valve, a line-size filter, and a pressure regulator, sized for the zone flow and set to the design operating pressure of the drip product.
−
−```datasheet
−label: Drip Zone Filtration
−type: select
−drawing_ref: true
−options:
− - "150 mesh (approximately 100 micron) — typical for emitter tubing"
− - "200 mesh (approximately 75 micron) — fine emitters or marginal water quality"
− - "Disc or screen filter sized to zone — per drip product requirement"
−default: "150 mesh (approximately 100 micron) — typical for emitter tubing"
−```
−
−```datasheet
−label: Drip Zone Pressure Regulation
−type: select
−unit: psi
−options:
− - "30 psi regulator — typical for inline-emitter dripline"
− - "25 psi regulator — point-source emitters and micro-spray"
− - "40 psi regulator — high-flow / high-elevation dripline"
− - "Per drip product requirement"
−default: "30 psi regulator — typical for inline-emitter dripline"
−```
−
−## Emitters and Dripline {toc}
−
−### Emitter flow rate and spacing are selected for the plant water demand and the soil's lateral wetting characteristics. {note}
−
−### Drip devices shall be pressure-compensating so that every emitter delivers the same flow regardless of its position along the line or its elevation, which is what allows long runs and sloped beds to water uniformly.
−
−### Inline-emitter dripline (tubing with emitters factory-installed at a fixed spacing) shall be used for bed and groundcover coverage.
−
−### Point-source emitters on distribution tubing shall be used at individual trees and specimen plants as indicated.
−
−### Emitter flow rate and spacing shall be as indicated on the drawings, selected for the plant water demand and the soil's lateral wetting characteristics.
−
−```datasheet
−label: Dripline Emitter Flow Rate
−type: select
−unit: GPH
−drawing_ref: true
−options:
− - "0.6 GPH per emitter — typical for clay and loam soils"
− - "0.9 GPH per emitter — typical for loam"
− - "1.0 GPH per emitter — sandy soils and higher demand"
−default: "0.9 GPH per emitter — typical for loam"
−```
−
−```datasheet
−label: Dripline Emitter Spacing
−type: select
−unit: in
−drawing_ref: true
−options:
− - "12 in. emitter spacing — typical for beds"
− - "18 in. emitter spacing — wider plant spacing / sandy soil"
− - "9 in. emitter spacing — tight spacing / clay soil"
−default: "12 in. emitter spacing — typical for beds"
−```
−
−## Air/Vacuum Relief and Flushing {toc}
−
−### The air/vacuum relief valve admits air when the zone shuts down so that the emptying line does not develop a vacuum and draw soil and debris back into the emitters; the flush point allows accumulated sediment to be flushed from the line. {note}
−### Without these, dripline progressively clogs from the ends inward and from soil ingestion at shutdown. {note}
−
−### Each drip zone shall include an air/vacuum relief valve at the high point of the zone and a flush point (flush valve or flush cap) at the end of each dripline run or at a manifolded flush header.
−
−```datasheet
−label: Drip Zone Air/Vacuum Relief and Flush
−type: checkbox
−options:
− - "Air/vacuum relief valve at zone high point"
− - "Flush valve or flush cap at end of each dripline run"
− - "Manifolded flush header (large bed systems)"
−default: "Air/vacuum relief valve at zone high point"
−```
−
−## Subsurface Drip {toc}
−
−```datasheet
−label: Subsurface Dripline Burial Depth
−type: select
−unit: in
−drawing_ref: true
−options:
− - "4 in. — turf and shallow-rooted groundcover"
− - "6 in. — shrub beds"
−default: "6 in. — shrub beds"
−```
−
−### Where subsurface drip irrigation is indicated — for turf, for medians, or where surface drip would be a trip or vandalism concern — the dripline shall be buried at the depth indicated and shall use dripline with integral check valves (to hold water in the line and prevent backflow of soil at shutdown) and with root-intrusion protection (chemical-impregnated or copper-shielded emitters) to prevent roots from growing into and blocking the emitters.
−
−### Subsurface drip shall include the same air/vacuum relief and flush provisions as surface drip.
−
−### The subsurface drip zone shall be mapped on the as-builts because the lines are not visible after installation.
−
−# Controllers, Sensors, and Control Wiring {toc}
−
−## Controller {toc}
−
−```datasheet
−label: Controller Type
−type: select
−drawing_ref: true
−options:
− - "Weather/ET-based smart controller (WaterSense, ANSI/ASABE S627)"
− - "Soil-moisture-based smart controller (WaterSense)"
− - "Central-control / cloud-managed controller (multi-site)"
−default: "Weather/ET-based smart controller (WaterSense, ANSI/ASABE S627)"
−```
−
−```datasheet
−label: Controller Station Count
−type: range
−unit: stations
−drawing_ref: true
−options:
− min: 4
− max: 48
− setpoints: [4, 6, 8, 12, 16, 24, 32, 48]
−default: 12
−```
−
−### The system shall be operated by an automatic controller with the number of stations indicated, plus spare stations for future expansion.
−
−### The controller shall be a smart controller that adjusts watering based on local conditions: a weather-based (evapotranspiration, or ET) controller listed under EPA WaterSense and ANSI/ASABE S627, or a soil-moisture-based controller listed under the WaterSense soil-moisture specification.
−
−### Conventional time-clock controllers that water on a fixed schedule regardless of weather shall not be specified for new commercial systems where a WaterSense-labeled controller is available for the station count, because they waste water by irrigating during and after rain.
−
−### A weather-based controller is the default because it adjusts each zone's run time to the measured or forecast ET demand and is the most widely available smart-controller type for commercial station counts. Soil-moisture-based control is selected where direct measurement of root-zone moisture is preferred, such as on athletic fields or where the landscape palette has well-defined moisture targets. {note}
−
−### The station count shall include not fewer than two spare stations beyond the installed zones to accommodate future landscape expansion without replacing the controller.
−
−## Controller Location and Power {toc}
−
−```datasheet
−label: Controller Mounting
−type: radio
−drawing_ref: true
−options:
− - "Exterior wall / pedestal in NEMA-rated outdoor enclosure"
− - "Interior wall mount (mechanical/electrical room or similar)"
−default: "Exterior wall / pedestal in NEMA-rated outdoor enclosure"
−```
−
−### The controller shall be installed at the location indicated, in an enclosure suited to its environment — a NEMA-rated outdoor enclosure for exterior mounting, or an interior wall mount as indicated.
−
−### Line-voltage power to the controller shall be provided on a dedicated circuit in accordance with NFPA 70, with the controller's low-voltage transformer (listed to UL 1951) stepping the supply down to the 24-volt AC control voltage.
−
−### Surge and lightning protection shall be provided on the power supply and on the field-wiring common and station outputs, because the long buried control runs of an irrigation system act as antennas for lightning-induced surges that destroy unprotected controller outputs.
−
−## Master Valve {toc}
−
−### The master valve protects the site against the continuous risk of a mainline leak or a stuck-open zone valve dumping water for hours or days while the system is unattended; combined with the flow sensor it is the basis of automatic leak detection. {note}
−
−### A normally-closed master valve shall be installed on the mainline immediately downstream of the backflow assembly (or as indicated) and wired to the controller so that the mainline downstream of the master valve is pressurized only when a zone is calling for water.
−
−```datasheet
−label: Master Valve
−type: radio
−drawing_ref: true
−options:
− - "Normally-closed master valve (recommended — mainline pressurized only on demand)"
− - "Normally-open / no master valve (mainline continuously pressurized)"
−default: "Normally-closed master valve (recommended — mainline pressurized only on demand)"
−```
−
−## Flow Sensor {toc}
−
−### The flow sensor lets the controller learn the expected flow of each zone and detect abnormal flow — a broken lateral or a sheared head shows up as flow higher than the zone's expected value, and a clogged zone or a stuck-closed valve shows up as flow lower than expected. {note}
−### On detecting an abnormal flow, the controller can shut the master valve and alarm, limiting the loss to a single cycle rather than days of leakage. {note}
−
−### A flow sensor shall be installed on the mainline downstream of the master valve and wired to the controller where the controller supports flow monitoring.
−
−```datasheet
−label: Flow Sensor and High-Flow Shutdown
−type: radio
−drawing_ref: true
−options:
− - "Flow sensor with controller high-flow shutdown (recommended)"
− - "Flow sensor for monitoring only (no automatic shutdown)"
− - "No flow sensor"
−default: "Flow sensor with controller high-flow shutdown (recommended)"
−```
−
−## Rain and Freeze Sensors {toc}
−
−```datasheet
−label: Climate Sensors
−type: checkbox
−options:
− - "Rain sensor / rain shutoff device (commonly code-required)"
− - "Freeze / low-temperature sensor (freeze-prone climates)"
− - "Wind sensor (high-wind or coastal sites)"
− - "On-site weather station (large or campus sites)"
−default: "Rain sensor / rain shutoff device (commonly code-required)"
−```
−
−### A rain sensor (rain shutoff device) shall be provided and wired to the controller to suspend irrigation during and immediately after measurable rainfall; many jurisdictions require a functioning rain sensor on every automatic irrigation system by code.
−
−### In freeze-prone climates a freeze (temperature) sensor shall also be provided to suspend irrigation when the temperature approaches freezing, both to avoid wasting water and to prevent the hazard of ice on walks and pavement.
−
−### The rain sensor's function shall be verified at commissioning by triggering the device and confirming that the controller suspends irrigation.
−
−### A rain sensor that is installed but not wired through the controller's sensor circuit, or that is mounted where roof overhang or tree canopy shields it from rain, provides no benefit. {note}
−
−### The Contractor shall mount sensors in open exposure and shall demonstrate the shutoff function at turnover.
−
−## Low-Voltage Control Wiring {toc}
−
−```datasheet
−label: Spare Control Conductors
−type: select
−drawing_ref: true
−options:
− - "One spare conductor to every valve box"
− - "Two spare conductors to every valve box (larger systems)"
−default: "One spare conductor to every valve box"
−```
−
−### Control wiring between the controller and the zone valves, master valve, and sensors shall be direct-burial-rated irrigation control cable (solid-copper, UF-rated or AWG irrigation wire) sized for the run length so that the voltage delivered to the solenoid at the most distant valve remains within the solenoid's operating range.
−
−### A separate, distinctly colored common (ground) conductor shall serve all valves.
−
−### At least one spare conductor shall be run with every wire bundle to every valve location for future use and for troubleshooting.
−
−### Control wire shall be installed in the mainline trench below the mainline where practical, bundled and taped at intervals, with an expansion loop at each valve and at each change of direction.
−
−### All wire connections and splices shall be made inside a valve box using waterproof, gel-filled or epoxy-filled splice connectors listed for direct burial.
−
−### Twisted-and-taped splices, wire nuts, and any splice made outside a valve box are not acceptable; a buried connection that is not waterproof corrodes within a season and is the most common cause of dead zones in an irrigation system.
−
−### No splice shall be buried outside a valve box.
−
−# Sleeving and Trenching {toc}
−
−## Sleeves Under Paving and Hardscape {toc}
−
−### The sleeve allows the pipe or wire to be installed, repaired, or replaced without cutting the pavement, and protects the pipe from the load and the saw-cutting that pavement work involves. {note}
−
−### Pipe and control wire crossing under paving, sidewalks, curbs, or other hardscape shall be installed in sleeves placed before the paving is constructed.
−
−### Sleeves shall be Schedule 40 PVC (or other approved conduit) sized at not less than twice the diameter of the pipe or bundle they carry, extend not less than 12 inches beyond the edge of paving on each side, and be marked at each end so they can be located after paving.
−
−```datasheet
−label: Sleeve Material and Sizing
−type: radio
−drawing_ref: true
−options:
− - "Schedule 40 PVC sleeve, minimum twice the pipe/bundle diameter"
− - "Schedule 80 PVC sleeve under heavy vehicular paving"
−default: "Schedule 40 PVC sleeve, minimum twice the pipe/bundle diameter"
−```
−
−### Pipe sleeves and wire sleeves shall be separate; control wire shall not share a sleeve with a pressure pipe, so that a pipe repair does not require disturbing the wire and vice versa.
−
−### The Contractor shall coordinate sleeve installation with the paving and hardscape schedule under [[sync/earthwork]] and the paving scopes; a missed sleeve discovered after paving requires either boring under the finished pavement or saw-cutting and patching it, both of which are far more expensive than placing the sleeve in advance.
−
−## Boring and Trenchless Crossings {toc}
−
−### Where a crossing is required under existing paving, under a tree protection zone, or where open trenching is not permitted, the crossing shall be made by boring (horizontal directional drilling or auger boring) and the pipe or sleeve pulled or pushed through the bored path.
−
−### Bored crossings shall maintain the minimum cover and clearance from other utilities indicated, and the entry and exit pits shall be located outside the protected feature.
−
−## Trenching and Cover {toc}
−
−### Trench excavation, dewatering, and backfill shall conform to [[sync/earthwork]]; the requirements specific to irrigation are stated here.
−
−```datasheet
−label: Minimum Cover Over Pipe
−type: select
−unit: in
−drawing_ref: true
−options:
− - "Mainline (constant pressure): 18 in. minimum"
− - "Laterals: 12 in. minimum"
− - "Drip dripline (surface-buried under mulch): 2 to 4 in."
− - "Deeper cover in agricultural / deep-tillage or freeze-prone areas per drawings"
−default: "Laterals: 12 in. minimum"
−```
−
−### Trench excavation, dewatering, and backfill shall conform to [[sync/earthwork]].
−
−### Pipe shall be installed on a firm trench bottom free of rock and debris, and bedded and backfilled with material free of rock larger than the manufacturer's limit so that point loads do not damage the pipe.
−
−### Minimum cover shall be as indicated on the drawings and not less than the values above for the pipe function.
−
−### The deeper cover on the mainline reflects that it is pressurized continuously and is more critical to protect from surface loads and aeration/cultivation equipment than the laterals, which are pressurized only during their cycle. {note}
−
−### In freeze-prone regions the cover and the winterization method shall be coordinated so that the system can be reliably drained or blown out; deeper burial alone does not substitute for winterization where ground frost reaches the pipe.
−
−# Testing {toc}
−
−## Mainline Pressure Test {toc}
−
−```datasheet
−label: Mainline Hydrostatic Test
−type: radio
−drawing_ref: true
−options:
− - "Hydrostatic test at 1.5x working pressure, held per spec (typical)"
− - "Hydrostatic test at fixed pressure per local purveyor requirement"
−default: "Hydrostatic test at 1.5x working pressure, held per spec (typical)"
−```
−
−### The mainline (the constant-pressure piping from the point of connection to the zone valves) shall be hydrostatically pressure-tested after the joints have cured and before the trench is backfilled above the pipe, with the zone valves closed or capped.
−
−### The line shall be filled with water, purged of air, and pressurized to the test pressure indicated — typically 1.5 times the system working pressure, and not exceeding the rating of the lowest-rated component on the line — and held for the duration indicated.
−
−### Any pressure drop beyond that attributable to thermal change and a small amount of pipe relaxation indicates a leak, which shall be located and repaired before backfill.
−
−### Compressed air or any gas shall never be used to test solvent-welded irrigation piping.
−
−### A solvent-welded thermoplastic line under air pressure stores a large amount of energy and can fail explosively, propelling pipe fragments and fittings; all pressure testing of solvent-welded pipe shall be done with water.
−
−### This prohibition on air testing is absolute and applies regardless of pipe size or test pressure.
−
−## Lateral Flushing {toc}
−
−### Before the heads, emitters, or drip devices are installed, every lateral shall be flushed by running water through the open lateral ends to carry out the dirt, solvent-cement shavings, and debris that accumulate during assembly.
−
−### Flushing shall continue until the discharge runs clean.
−
−### Debris left in the laterals lodges in head nozzles and emitter passages and is a leading cause of clogged and erratic emission devices at start-up; flushing before installing the emission devices is far more effective than trying to clear debris through the installed nozzles. {note}
−
−## Coverage and Operational Test {toc}
−
−```datasheet
−label: Coverage Verification Method
−type: select
−drawing_ref: true
−options:
− - "Visual operational test of every zone (typical)"
− - "Visual test plus catch-can distribution uniformity audit on turf zones"
−default: "Visual operational test of every zone (typical)"
−```
−
−### After all heads, emitters, and devices are installed and the controller is programmed, each zone shall be operated and observed for full operational performance: every head and emitter shall operate, heads shall pop up and rotate (rotors) through their assigned arcs, spray patterns shall be adjusted to keep water on the landscape and off pavement and buildings, and coverage shall be verified to be uniform with no dry gaps and no excessive overspray or runoff.
−
−### Coverage of turf zones may be verified by observation and, where required, by a catch-can distribution-uniformity test in accordance with recognized audit procedures.
−
−### The Contractor shall adjust each head's arc and radius and each nozzle's pattern during this test so that water is applied to the intended landscape and not to walks, walls, windows, or pavement.
−
−### Overspray onto hardscape is wasted water and a slip and staining hazard, and is a frequent cause of post-occupancy complaints. {note}
−
−### Any head or emitter that does not operate correctly, any coverage gap, and any overspray shall be corrected and the zone re-tested.
−
−## Backflow Assembly Test {toc}
−
−### The backflow prevention assembly shall be tested and certified by a certified tester as required by the local cross-connection control program before the system is placed in service, coordinated with [[sync/backflow-prevention]].
−
−### The certification test report shall be included in the closeout submittals and filed with the water purveyor where required.
−
−# Commissioning and Controller Programming {toc}
−
−## Controller Programming {toc}
−
−```datasheet
−label: Controller Program Documentation at Turnover
−type: checkbox
−options:
− - "Station-by-station run times, start times, and watering days recorded"
− - "Seasonal adjustment / ET source configured and documented"
− - "Cycle-and-soak settings for slope and tight-soil zones"
− - "Rain, freeze, and flow-sensor responses configured and tested"
− - "Laminated zone map posted at controller"
−default:
− - "Station-by-station run times, start times, and watering days recorded"
−```
−
−### After all testing is complete, the Contractor shall program the controller for the as-installed system and shall set up the smart-controller features for the site.
−
−### Programming shall include, for each station: the assigned zone and its emission-device type, the run time and number of start times computed for the plant demand and the soil intake rate (using cycle-and-soak where the intake rate is exceeded), the allowed watering days and times consistent with any local watering restrictions, the seasonal-adjustment or ET-source configuration, and the rain, freeze, and flow-sensor responses.
−
−### The as-left program shall be recorded in the closeout submittals and posted at the controller.
−
−## Owner Instruction {toc}
−
−### The Contractor shall instruct the Owner's personnel in the operation of the controller, including manual operation of zones, adjustment of run times and seasonal adjustment, response to sensor alarms, and the seasonal start-up and winterization procedures.
−
−### The instruction shall be documented and shall be supported by the O&M manuals provided in the closeout submittals.
−
−# Winterization {toc}
−
−## Winterization Method {toc}
−
−### Excessive air pressure ruptures fittings and over-speeds rotor gears. {note}
−
−### In freeze-prone climates the system shall be winterized at the end of each watering season by isolating the supply, draining the backflow assembly and exposed components, and clearing water from the buried piping either by gravity drainage to drain valves at low points or by compressed-air blow-out.
−
−```datasheet
−label: Winterization Method
−type: select
−drawing_ref: true
−options:
− - "Compressed-air blow-out (zone-by-zone, pressure limited per material)"
− - "Gravity drain to manual/automatic drain valves at low points"
− - "Combination drain plus blow-out"
− - "Not required — non-freezing climate"
−default: "Not required — non-freezing climate"
−```
−
−### Where the winterization method is compressed-air blow-out, the air supply shall be regulated so that the blow-out pressure does not exceed the lowest-rated component on the zone being cleared, and in no case exceeds 80 psi for PVC piping or 50 psi for polyethylene piping.
−
−### The blow-out air shall be introduced through a dedicated blow-out connection downstream of the backflow assembly, never through the backflow assembly itself.
−
−### The blow-out shall be performed zone by zone, energizing one zone at a time so that the air clears the line at a controlled velocity; blowing all zones at once over-pressurizes the mainline and starves each lateral of the airflow needed to clear it.
−
−### The first seasonal start-up after winterization shall re-pressurize the system slowly with the zone valves open to purge air, and shall be followed by an operational check of every zone.
−
−### The Contractor's first-season winterization (where it falls within the warranty period) and the start-up the following spring shall be included in the work or in the O&M instruction as indicated.
−
−# Warranty {toc}
−
−## Warranty Coverage {toc}
−
−```datasheet
−label: Irrigation System Warranty Period
−type: select
−options:
− - "1 year from substantial completion"
− - "2 years from substantial completion"
− - "Per contract documents"
−default: "1 year from substantial completion"
−```
−
−### The Contractor shall warrant the irrigation system, including all piping, valves, heads, emitters, drip components, controller, sensors, wiring, and the workmanship of installation, against defects in materials and workmanship for the project warranty period beginning at substantial completion.
−
−### Warranty obligations include correction of leaks, failed valves and solenoids, clogged or failed emission devices not attributable to Owner neglect, settlement at trenches that exposes or damages piping, and controller or sensor failures.
−
−### Manufacturer warranties for the controller, valves, heads, and specialty devices, where they extend beyond the Contractor's installation warranty, shall be passed through and assigned to the Owner at closeout.
−
−### The warranty does not relieve the Contractor of liability for latent defects discovered after the warranty period — including pipe installed at insufficient cover, splices made outside valve boxes, mixed emission devices on a single zone, or substituted nozzles that defeat matched precipitation — which remain the Contractor's responsibility whenever discovered.
−
−# Spare Parts {toc}
−
−## Spare-Parts Inventory {toc}
−
−```datasheet
−label: Spare Parts Inventory
−type: checkbox
−options:
− - "Spare nozzles — representative quantity of each type installed"
− - "Spare spray bodies and rotor internal assemblies"
− - "Spare drip emitters and fittings"
− - "Quick-coupler key(s) and controller key(s)"
− - "Special service tools for installed heads and valves"
− - "Spare waterproof wire-splice connectors"
−default: "Spare nozzles — representative quantity of each type installed"
−```
−
−### The Contractor shall turn over to the Owner at closeout a spare-parts inventory to support routine maintenance without immediate reordering.
−
−### The inventory shall include a representative quantity of each type of nozzle installed, spare drip emitters and fittings, the special tools required to service the heads and valves installed (including the quick-coupler key and the controller key), and spare waterproof wire-splice connectors.
+---
+title: Landscape Irrigation
+category: Sitework
+description: >
+ When to use: Underground automatic landscape irrigation on commercial, institutional, industrial, campus, and multi-family sites, from the irrigation point of connection through the mainline, isolation and zone control valves, the master valve and flow sensor, lateral piping, spray bodies and gear-driven rotors, drip and subsurface drip, the controller with its rain, freeze, flow, and soil moisture sensors and its field wiring, sleeving under paving, irrigation-specific pipe zone and cover requirements, hydrostatic and coverage testing, controller programming, winterization, record documents, warranty, and spare parts. Read alongside the irrigation plan, legend, zone schedule, and details, which carry the head and emitter layout, spacing, nozzle assignments, zone flows and pressures, pipe sizes, and routing this standard defers to them.
+ Not intended for: The backflow preventer as a product, its selection by degree of hazard, its enclosure, and its testing and certification (see [[sync/backflow-prevention]]); the water service, meter, and site water mains upstream of the irrigation point of connection (see [[sync/water-distribution-piping]] and [[sync/site-utilities]]); potable distribution piping inside a building (see [[sync/domestic-water-piping]]); trench excavation, backfill above the pipe zone, compaction, and dewatering (see [[sync/earthwork]]); plant material, topsoil, soil preparation, seeding, sodding, and the establishment period (see [[sync/planting-and-soil-preparation]]); temporary erosion prevention, sediment control, and temporary stabilization (see [[sync/erosion-and-sediment-control]]); the treatment, storage, and pumping of reclaimed, rainwater, graywater, well, or surface-water supplies upstream of the point of connection, and irrigation booster pumps, which no SynC standard currently covers; agricultural and crop irrigation; golf course and athletic field irrigation designed to their own criteria; and fountains, water features, and pools.
+---
+
+# Scope {toc}
+
+## This standard governs the materials, installation, testing, programming, and seasonal care of an underground automatic landscape irrigation system that carries water from a defined point of connection to turf, planting beds, trees, and other landscape areas through buried piping, automatic valves, sprinkler heads, rotors, and drip emission devices under the control of an automatic controller. {note}
+
+## The scope begins at the irrigation point of connection, immediately downstream of the irrigation meter or the tap on the site water main, and extends through the backflow assembly location, the mainline, the zone control valves, the laterals, the emission devices, and the controller and field wiring that operate them. {note}
+
+## The backflow prevention assembly is specified in [[sync/backflow-prevention]], which governs the assembly as a product, its selection by degree of hazard, its enclosure, and its testing and certification; this standard locates the assembly in the irrigation layout and governs the point of connection and everything downstream of the assembly. {note}
+
+## An irrigation system rarely fails in a way anyone notices on the day it is accepted. It fails over the first two seasons as a zone that mixes sprays and rotors produces dry rings and runoff at the same time, as a splice made outside a valve box corrodes and a zone goes dead, as a lateral pulled under a sidewalk with no sleeve is cut by the next utility, and as a controller left on a fixed schedule waters through the rain. The metered water those defects waste is a continuing cost to the Owner for the life of the landscape, and the plant loss they cause is charged back to the planting contractor who could not keep the material alive. This standard sets the material quality, the installation rules, and the tests that keep those failures out of the finished work. {note}
+
+## The hydraulic and horticultural design of the system is the irrigation designer's and is carried on the irrigation drawings: the water demand, the hydrozone boundaries, the head and emitter selection and spacing, the nozzle assignments, the zone grouping, the design flow and operating pressure of each zone, the pipe sizes, and the point of connection sizing. {note}
+
+## The following are outside this standard: {note}
+
+- The backflow assembly as a product, its hazard-based selection, its enclosure, and its testing and certification, under [[sync/backflow-prevention]]
+- The water service, meter, and site mains upstream of the point of connection, under [[sync/water-distribution-piping]] and [[sync/site-utilities]], and building distribution piping under [[sync/domestic-water-piping]]
+- Trench excavation, shoring, dewatering, backfill above the pipe zone, and compaction, under [[sync/earthwork]]
+- Plant material, topsoil, soil amendments, seeding, sodding, mulch, and the establishment period, under [[sync/planting-and-soil-preparation]]
+- Temporary erosion and sediment control and temporary stabilization, under [[sync/erosion-and-sediment-control]]
+- Treatment, storage, and pumping of a reclaimed, rainwater, graywater, well, or surface-water supply upstream of the point of connection, and irrigation booster pumps, which no SynC standard currently covers
+
+## Head and emitter locations, spacing, pop-up heights, nozzle assignments, emitter flow rates, zone boundaries, zone flows and operating pressures, pipe sizes, and routing shall be as indicated on [[drawing: the irrigation plan, legend, and zone schedule]].
+
+## The Contractor shall install the system as designed and shall not change head spacing, nozzle assignments, zone grouping, or pipe size without the irrigation designer's written direction.
+
+## The Contractor shall report to the irrigation designer, before trenching in the affected area, any field condition that would prevent the system from being built as drawn, including a static pressure or flow at the point of connection below the design basis, a conflict with another utility, insufficient cover, and a coverage gap created by a hardscape or planting change made after the irrigation design was completed.
+
+## The Contractor shall coordinate work under this standard with [[sync/backflow-prevention]] for the assembly at the point of connection, with [[sync/water-distribution-piping]] for the meter and tap upstream of it, with [[sync/earthwork]] for trench excavation and backfill above the pipe zone, with [[sync/planting-and-soil-preparation]] for the sequence of irrigation and planting and for establishment watering, with [[sync/erosion-and-sediment-control]] for the transition from temporary stabilization to permanent vegetation, and with the paving scopes for sleeve placement before paving.
+
+# Referenced Standards {toc}
+
+## Materials, components, and installation shall comply with the latest adopted edition of each of the following unless a specific edition is cited.
+
+## Where the Contract Documents, the Authority Having Jurisdiction, the water purveyor, and a referenced standard impose conflicting requirements, the more stringent requirement shall govern unless the irrigation designer directs otherwise in writing.
+
+| Standard | Title |
+|----------|-------|
+| ASTM D1784 | Rigid Poly(Vinyl Chloride) (PVC) Compounds and Chlorinated Poly(Vinyl Chloride) (CPVC) Compounds |
+| ASTM D1785 | Poly(Vinyl Chloride) (PVC) Plastic Pipe, Schedules 40, 80, and 120 |
+| ASTM D2241 | Poly(Vinyl Chloride) (PVC) Pressure-Rated Pipe (SDR Series) |
+| AWWA C900 | Polyvinyl Chloride (PVC) Pressure Pipe and Fabricated Fittings, 4 In. Through 60 In. |
+| ASTM D2466 | Poly(Vinyl Chloride) (PVC) Plastic Pipe Fittings, Schedule 40 |
+| ASTM D2467 | Poly(Vinyl Chloride) (PVC) Plastic Pipe Fittings, Schedule 80 |
+| ASTM D2464 | Threaded Poly(Vinyl Chloride) (PVC) Plastic Pipe Fittings, Schedule 80 |
+| ASTM D2564 | Solvent Cements for Poly(Vinyl Chloride) (PVC) Plastic Piping Systems |
+| ASTM F656 | Primers for Use in Solvent Cement Joints of Poly(Vinyl Chloride) (PVC) Plastic Pipe and Fittings |
+| ASTM D2855 | Two-Step (Primer and Solvent Cement) Method of Joining Poly(Vinyl Chloride) (PVC) or Chlorinated Poly(Vinyl Chloride) (CPVC) Pipe and Piping Components with Tapered Sockets |
+| ASTM D3139 | Joints for Plastic Pressure Pipes Using Flexible Elastomeric Seals |
+| ASTM F477 | Elastomeric Seals (Gaskets) for Joining Plastic Pipe |
+| ASTM D2239 | Polyethylene (PE) Plastic Pipe (SIDR-PR) Based on Controlled Inside Diameter |
+| ASTM D3035 | Polyethylene (PE) Plastic Pipe (DR-PR) Based on Controlled Outside Diameter |
+| ASTM D3350 | Polyethylene Plastics Pipe and Fittings Materials |
+| ASTM D2609 | Plastic Insert Fittings for Polyethylene (PE) Plastic Pipe |
+| ASTM D2683 | Socket-Type Polyethylene Fittings for Outside Diameter-Controlled Polyethylene Pipe and Tubing |
+| ASTM D3261 | Butt Heat Fusion Polyethylene (PE) Plastic Fittings for Polyethylene (PE) Plastic Pipe and Tubing |
+| ASTM F2620 | Heat Fusion Joining of Polyethylene Pipe and Fittings |
+| ASTM D2774 | Underground Installation of Thermoplastic Pressure Piping |
+| ANSI/ASABE S376 | Design, Installation and Performance of Underground, Thermoplastic Irrigation Pipelines |
+| ASABE/ICC 802 | Landscape Irrigation Sprinkler and Emitter Standard |
+| EPA WaterSense | Specification for Weather-Based Irrigation Controllers |
+| EPA WaterSense | Specification for Soil Moisture-Based Irrigation Controllers |
+| EPA WaterSense | Specification for Spray Sprinkler Bodies |
+| NSF/ANSI/CAN 61 | Drinking Water System Components: Health Effects |
+| NSF/ANSI/CAN 372 | Drinking Water System Components: Lead Content |
+| UL 1951 | Electric Plumbing Accessories |
+| NFPA 70 | National Electrical Code |
+| ASIC Guideline 100 | Earth Grounding Electronic Equipment in Irrigation Systems (American Society of Irrigation Consultants) |
+| IA BMP | Landscape Irrigation Best Management Practices (Irrigation Association) |
+
+# Submittals {toc}
+
+## Action Submittals {toc}
+
+### The Contractor shall submit the following for the irrigation designer's review before the material it describes is procured:
+
+- Product data for each pipe and fitting, giving the material, the ASTM or AWWA designation, the pressure class or schedule, the joining method, and the potable-contact certification where the supply is potable
+- Product data for each isolation valve, zone control valve, master valve, quick-coupling valve, and drain valve, giving the body and seat materials, the pressure rating, the solenoid type, and the flow control and pressure regulation features
+- Product data for each spray body, rotor, and nozzle, with the manufacturer's performance table of radius, flow, and precipitation rate at the design operating pressure and the matched-precipitation nozzle sets by arc
+- Product data for each drip component, giving the emitter flow rate and spacing, the pressure compensation range, the regulator setting, the filter type and fineness, and the air relief and flush devices
+- Product data for the controller, giving the WaterSense label where one is required, the station capacity, the surge protection, the enclosure rating, and the communication method
+- Product data for the flow sensor, the rain and freeze sensors, and any soil moisture sensors, with the controller compatibility listing for each
+- Product data for valve boxes, giving the size, the load rating, and the lid color and marking
+- Product data for control conductors, splice connectors, and grounding components
+- Product data for sleeves and for detectable marking tape or tracer wire
+- A zone schedule prepared by the Contractor listing each zone number, its emission device type, its design flow and operating pressure, its controller station, and the hydrozone it serves
+- A record drawing procedure describing how the Contractor will keep a current field markup of mainline routing, valve, sleeve, and splice locations, and wire paths
+
+```datasheet
+label: Action Submittals Required
+type: checkbox
+options:
+ - "Pipe and fitting product data"
+ - "Valve product data"
+ - "Spray body, rotor, and nozzle product data with performance tables"
+ - "Drip component product data"
+ - "Controller product data"
+ - "Sensor product data with controller compatibility listing"
+ - "Valve box product data"
+ - "Control conductor, splice, and grounding product data"
+ - "Sleeve and locating material product data"
+ - "Contractor zone schedule"
+ - "Record drawing procedure"
+default: ["Pipe and fitting product data", "Valve product data", "Spray body, rotor, and nozzle product data with performance tables", "Drip component product data", "Controller product data", "Sensor product data with controller compatibility listing", "Valve box product data", "Control conductor, splice, and grounding product data", "Contractor zone schedule", "Record drawing procedure"]
+```
+
+### Installation of any component shall not begin until the submittal describing it has been reviewed and returned.
+
+### Review of a submittal does not relieve the Contractor of responsibility for compliance with the Contract Documents.
+
+## Informational Submittals {toc}
+
+### The Contractor shall submit the following before the work each one supports begins:
+
+- The static pressure and flow measurement at the point of connection, with the date, time, method, and instrument used and the design basis it is compared against
+- The control conductor sizing for the longest run on each controller, showing the voltage delivered to the most distant solenoid
+- The qualification records of the installing superintendent and of each person who will make heat fusion joints
+- The proposed winterization procedure, including the blow-out connection location and the air pressure limit for each pipe material installed
+
+```datasheet
+label: Informational Submittals Required
+type: checkbox
+options:
+ - "Point of connection pressure and flow measurement"
+ - "Control conductor sizing"
+ - "Superintendent and fusion joiner qualification records"
+ - "Winterization procedure"
+default: ["Point of connection pressure and flow measurement", "Control conductor sizing", "Superintendent and fusion joiner qualification records"]
+```
+
+## Closeout Submittals {toc}
+
+### The Contractor shall submit the following before substantial completion:
+
+- Record drawings showing the installed mainline and lateral routing, every isolation, zone control, master, quick-coupling, and drain valve with its station number, the flow sensor, every sleeve with its size and contents, every splice location, and the control wire routing, located by the method specified in this standard
+- The controller programming record, listing for every station the run time, start times, watering days, cycle and soak settings, seasonal adjustment or ET source, and the rain, freeze, and flow sensor responses as left at turnover
+- A laminated zone map identifying each station number and the area it serves, installed inside the controller enclosure
+- Test reports for the mainline hydrostatic test, the lateral flushing, the operational test of every zone, the coverage verification, and the sensor demonstrations, signed by the Contractor's superintendent and by the witness
+- The backflow assembly certification report required under [[sync/backflow-prevention]], included so the irrigation closeout package is complete
+- Operation and maintenance manuals for the controller, sensors, valves, emission devices, and drip components, including the manufacturer's seasonal start-up and winterization instructions
+- Manufacturer warranties for every product that carries one, assigned to the Owner
+- A signed receipt from the Owner for the spare parts and tools delivered
+
+```datasheet
+label: Closeout Submittals Required
+type: checkbox
+options:
+ - "Record drawings"
+ - "Controller programming record"
+ - "Laminated zone map in the controller"
+ - "Test reports"
+ - "Backflow assembly certification report"
+ - "Operation and maintenance manuals"
+ - "Manufacturer warranties"
+ - "Spare parts receipt"
+default: ["Record drawings", "Controller programming record", "Laminated zone map in the controller", "Test reports", "Backflow assembly certification report", "Operation and maintenance manuals", "Manufacturer warranties", "Spare parts receipt"]
+```
+
+# Quality Assurance {toc}
+
+## Installer Qualifications {toc}
+
+### The irrigation system shall be installed by a firm regularly engaged in commercial landscape irrigation installation that has completed not fewer than three systems of comparable size within the preceding five years.
+
+### Where the jurisdiction licenses irrigation contractors or requires a certified irrigation technician on the work, the Contractor shall hold that license or shall employ the certified personnel the jurisdiction requires.
+
+### Heat fusion joints in polyethylene pipe shall be made only by personnel who have completed the pipe or fitting manufacturer's training for the fusion method and equipment used.
+
+### The Contractor shall keep a superintendent experienced in commercial irrigation on the site whenever irrigation work is in progress.
+
+## Pre-Installation Conference {toc}
+
+### Before irrigation work begins, the Contractor shall convene a conference attended by the Contractor's irrigation superintendent, the irrigation designer, the general contractor's site superintendent, the planting contractor, and the paving contractor.
+
+### The conference shall review the point of connection arrangement and the measured pressure and flow, the zone schedule, the sleeve locations and the paving sequence, the controller location and its power source, the record drawing procedure, and the sequence of irrigation work relative to grading, paving, and planting.
+
+## Verification of Supply Pressure and Flow {toc}
+
+### Before any piping is installed, the Contractor shall measure the static pressure and the available flow at the point of connection and shall compare them with the design basis stated on the irrigation drawings and with [[parameter: site-water-supply-pressure-maximum]].
+
+### Every spray body, rotor, and emitter is rated at a design operating pressure, and a system designed for a static pressure the site does not deliver under-performs at every zone; the discrepancy costs a redesign before trenching and a rebuild after it. {note}
+
+### The Contractor shall report a measured static pressure or flow below the design basis, or a static pressure above the rating of any component on the submittals, to the irrigation designer before proceeding.
+
+## Field Changes and Substitutions {toc}
+
+### The Contractor shall not substitute a nozzle, emitter, or head model for the one assigned on the irrigation legend without the irrigation designer's written acceptance of the substitute's performance table.
+
+### Where a hardscape edge, a planting change, or an obstruction prevents a head from being set at its designed location, the Contractor shall report the condition to the irrigation designer rather than relocate the head or omit it.
+
+### Where the parties disagree whether a field condition prevents the system from being built as drawn, the irrigation designer shall make the initial determination.
+
+# Water Supply and Site Conditions {toc}
+
+## Irrigation Water Supply {toc}
+
+### The source of the irrigation supply shall be as indicated in the datasheet.
+
+```datasheet
+label: Irrigation Water Supply
+type: select
+options:
+ - "Potable supply through a dedicated irrigation meter"
+ - "Potable supply tapped from the building water service"
+ - "Reclaimed or recycled water supply"
+ - "Harvested rainwater or stormwater"
+ - "On-site well"
+ - "Surface water from a pond, lake, or canal"
+drawing_ref: "the point of connection detail on the irrigation plan"
+default: deferred
+```
+
+### A dedicated irrigation meter puts the landscape water on its own bill, which many purveyors price without the sewer charge, and gives the system a point of connection that does not share flow with the building; a tap off the building service saves the meter and its fees where the purveyor permits it, at the cost of sharing supply pressure with building demand. A reclaimed supply is the lowest-cost water where a purveyor offers it and brings the marking, separation, and hazard-signage rules of the jurisdiction's reclaimed water program with it. Harvested rainwater, well water, and surface water each carry sediment, algae, or dissolved minerals that set the filtration the drip zones need and may need treatment or a booster pump that is outside this standard. {note}
+
+### Where the supply is potable, every pipe, fitting, valve, and appurtenance between the point of connection and the backflow assembly shall be certified to NSF/ANSI/CAN 61 and NSF/ANSI/CAN 372.
+
+### Where the supply is potable, the Contractor shall evaluate [[parameter: site-water-supply-hardness]] against the emitter manufacturer's published scaling limit and shall report an exceedance to the irrigation designer before drip components are ordered.
+
+### Where the supply is a well, surface water, or harvested water, the Contractor shall obtain a water analysis for suspended solids and iron and shall submit it with the drip filtration product data.
+
+## Reclaimed and Non-Potable Supply {toc}
+
+### Requirements in this article apply where the datasheet selects a reclaimed, recycled, harvested, well, or surface-water supply.
+
+### Where a non-potable supply is selected, all pipe shall be purple or shall carry continuous purple identification tape, and all valve box lids shall be purple and embossed or labeled with a non-potable warning, in accordance with the jurisdiction's reclaimed water program.
+
+### Where a non-potable supply is selected, quick-coupling valves shall be of a non-interchangeable key type that does not accept a potable-system coupler.
+
+### Where a non-potable supply is selected, non-potable piping shall be separated from potable piping by the horizontal and vertical distances [[parameter: adopted-plumbing-code]] requires, and shall be installed below potable piping where the two cross.
+
+### Where a non-potable supply is selected, the Contractor shall post the warning signage the jurisdiction's reclaimed water program requires at the controller and at each quick-coupling valve.
+
+### The reclaimed water program also sets the hours during which reclaimed water may be applied and the setbacks from drinking fountains, outdoor eating areas, and property lines, and the controller program and the head layout both have to honor them. {note}
+
+## Freezing Climate {toc}
+
+### Where [[parameter: site-ambient-temperature-minimum]] is below 32°F, the system shall be arranged to be winterized each season as specified in this standard, with a blow-out connection and drain provisions at the point of connection and with the mainline and laterals graded or drainable to the extent the winterization method requires.
+
+### Where [[parameter: frost-depth]] exceeds the mainline cover indicated in the datasheet, burial shall not be relied on as the freeze protection for the piping, and the winterization method shall remove the water from the pipe before the ground freezes.
+
+### Irrigation piping is laid above the frost line on nearly every site because burying a lateral grid below it would cost more than the system, so the pipe survives the winter by being emptied rather than by being deep; the frost depth matters because it says how little protection the cover gives, not because the pipe is placed below it. {note}
+
+## Soil Intake and Slope {toc}
+
+### The emission devices on each zone and the cycle and soak settings on each station shall be those the irrigation drawings assign, and the Contractor shall report any finished slope steeper than the grading plan shows in an irrigated area.
+
+### Water applied faster than the soil absorbs it runs off, and on a slope it runs off downhill onto the pavement below; the designer answers that with lower-precipitation rotors or rotary nozzles, with drip, or with cycle and soak scheduling that splits the run time into pulses the soil can take, and a finished slope steeper than the design assumed defeats all three. {note}
+
+# Point of Connection {toc}
+
+## Point of Connection Arrangement {toc}
+
+### The point of connection shall be made downstream of the irrigation meter or at the tap indicated on the site water distribution drawings, and its location and arrangement shall be as indicated on [[drawing: the point of connection detail on the irrigation plan]].
+
+### The point of connection assembly shall include, in order of flow, an isolation valve, the backflow prevention assembly, a blow-out connection where winterization is required, the master valve where one is selected, the flow sensor where one is selected, and the pressure-reducing valve where one is selected.
+
+### The point of connection assembly shall be supported independently of the buried mainline so that the weight of the backflow assembly and valves is carried to grade rather than by the pipe.
+
+### A drain valve shall be provided at the low point of the point of connection assembly, discharging to a gravel sump or to daylight.
+
+## Backflow Prevention Boundary {toc}
+
+### The backflow prevention assembly at the point of connection shall be furnished, selected for the degree of hazard, installed, enclosed, tested, and certified under [[sync/backflow-prevention]].
+
+### Under [[sync/backflow-prevention]], a landscape irrigation connection is classed by the degree of hazard the irrigation system presents to the supply, and the assembly type follows from that class and from whether the irrigation system can produce back-pressure; a fertilizer or chemical injector, or a booster pump downstream of the assembly, raises the hazard class and changes the assembly. {note}
+
+### The backflow assembly shall be located in the irrigation layout as indicated on [[drawing: the point of connection detail on the irrigation plan]], with the clearances for testing and the drainage for a relief-valve discharge that [[sync/backflow-prevention]] requires.
+
+### The Contractor shall not pressurize the irrigation mainline until the backflow assembly has passed the certification test required under [[sync/backflow-prevention]].
+
+### Where a chemical or fertilizer injector is added to the irrigation system at any time, the Contractor shall notify the irrigation designer so the hazard classification of the assembly can be re-evaluated under [[sync/backflow-prevention]].
+
+## Pressure Regulation {toc}
+
+### Spray nozzles fed above their design pressure break the stream into a mist that drifts and evaporates before it lands, rotors fed above theirs overspeed and wear, and every joint and valve downstream sees the excess for the life of the system. Regulation can be applied once at the point of connection, at each zone valve, in each spray body, or at more than one of those levels, and the levels are independent of one another. {note}
+
+### A pressure-reducing valve at the point of connection shall be provided or omitted as indicated in the datasheet.
+
+```datasheet
+label: Pressure-Reducing Valve at the Point of Connection
+type: radio
+options:
+ - "Provided"
+ - "Not provided"
+derived: "[[parameter: site-water-supply-pressure-maximum]] compared against the maximum operating pressure of the lowest-rated component downstream of the point of connection"
+default: derived
+```
+
+### Where a pressure-reducing valve is provided at the point of connection, it shall be installed in a valve box with an isolation valve on each side and a pressure gauge port downstream, and shall be set to the mainline design pressure stated on the irrigation drawings.
+
+### Pressure regulation at each zone control valve shall be provided or omitted as indicated in the datasheet.
+
+```datasheet
+label: Zone Valve Pressure Regulation
+type: radio
+options:
+ - "Pressure-regulating module on every zone control valve"
+ - "Pressure-regulating module on drip zone control valves"
+ - "No zone valve pressure regulation"
+```
+
+### A regulating module on every zone valve holds each zone at its own design pressure regardless of the mainline pressure and elevation, at the cost of a module per valve; regulating the drip zones alone covers the devices with the narrowest pressure tolerance and leaves the spray and rotor zones to the point of connection or to the spray bodies; no zone regulation suits a site where the mainline pressure is already held close to the design pressure of every zone. {note}
+
+## Master Valve and Flow Sensor {toc}
+
+### A master valve shall be provided on the mainline as indicated in the datasheet.
+
+```datasheet
+label: Master Valve
+type: radio
+options:
+ - "Normally closed master valve"
+ - "Normally open master valve"
+ - "No master valve"
+default: "Normally closed master valve"
+```
+
+### A normally closed master valve keeps the mainline unpressurized except while a zone is running, so a mainline break or a stuck zone valve leaks for one cycle instead of for the days until someone notices; it depends on a controller output and fails closed, which stops the system if the controller or the valve wiring fails. A normally open master valve leaves the mainline pressurized and closes only when the controller commands a shutdown on a flow alarm, so a controller fault leaves the system able to run; it gives no protection against a mainline break while the controller is idle. Omitting the master valve suits a short mainline with few joints where the Owner accepts the leak exposure in exchange for the simplest system. {note}
+
+### Where a master valve is provided, it shall be a diaphragm valve of the same construction and rating as the zone control valves, sized for the full mainline flow, and installed in a valve box immediately downstream of the backflow assembly unless the irrigation drawings locate it elsewhere.
+
+### A mainline flow sensor shall be provided as indicated in the datasheet.
+
+```datasheet
+label: Mainline Flow Sensor
+type: radio
+options:
+ - "Provided"
+ - "Not provided"
+```
+
+### A flow sensor lets the controller learn the normal flow of each zone and recognize a broken lateral or sheared head as flow above it and a clogged zone or stuck-closed valve as flow below it; with a master valve the controller can then close the mainline on a high-flow alarm. It costs the sensor, a controller that reads it, and a straight pipe run on each side to read accurately. Without one, a leak is found by the water bill or by the wet spot. {note}
+
+### Where a flow sensor is provided, it shall be installed on the mainline downstream of the master valve in a valve box, with the straight upstream and downstream pipe lengths the sensor manufacturer publishes, and shall be wired to the controller.
+
+### Where both a flow sensor and a master valve are provided, the controller shall be programmed to close the master valve and raise an alarm on a zone flow that exceeds the learned flow by the margin set during commissioning.
+
+# Mainline and Lateral Piping {toc}
+
+## Pipe Material Selection {toc}
+
+### The mainline is pressurized continuously between the point of connection and the zone valves, so it carries the full static pressure and every surge for the life of the system; a lateral is pressurized only while its zone runs, and it is also the pipe most often cut by a planting spade, so the two are selected separately. {note}
+
+### The mainline pipe material shall be as indicated in the datasheet.
+
+```datasheet
+label: Mainline Pipe Material
+type: select
+options:
+ - "PVC Schedule 40, ASTM D1785"
+ - "PVC Class 200, SDR 21, ASTM D2241"
+ - "PVC Class 315, SDR 13.5, ASTM D2241"
+ - "PVC DR 18, AWWA C900"
+ - "Polyethylene, ASTM D2239"
+ - "Polyethylene, ASTM D3035"
+```
+
+### Schedule 40 PVC carries a wall thickness that falls off in pressure rating as the diameter grows, so it is the heavy, cheap choice in small mainlines and the thin one above 3 in.; Class 200 and Class 315 PVC hold a constant pressure rating at every diameter and are joined by solvent cement or by gaskets, so they are the usual mainline above 2 in. and the Class 315 wall is the answer where the static pressure or the surge margin is high; AWWA C900 DR 18 is the gasketed water-main pipe, used for a long or large irrigation mainline where the pipe has to tolerate thermal movement and rock without a glued joint every 20 ft. Polyethylene survives a freeze with water left in it, pulls through a bored path, and bends around a tree without a fitting, and it is the mainline material across the northern states and on rocky sites; its insert joints are the limit on its pressure and its diameter, and its fused joints need qualified personnel. {note}
+
+### The lateral pipe material shall be as indicated in the datasheet.
+
+```datasheet
+label: Lateral Pipe Material
+type: select
+options:
+ - "PVC Class 160, SDR 26, ASTM D2241"
+ - "PVC Class 200, SDR 21, ASTM D2241"
+ - "PVC Class 315, SDR 13.5, ASTM D2241"
+ - "PVC Schedule 40, ASTM D1785"
+ - "Polyethylene, ASTM D2239"
+ - "Polyethylene, ASTM D3035"
+```
+
+### Class 200 PVC is the lateral in most of the sunbelt because a lateral never sees more than the zone operating pressure and the thinner wall is the lower cost; Class 160 saves a little more where the operating pressure is low and the pipe is 1-1/2 in. and larger, and Class 315 or Schedule 40 earns its wall where a small lateral is pressure-regulated at the valve but still sees a high static pressure, or where the lateral is shallow and gets hit. Polyethylene laterals are the lateral in freezing climates and wherever laterals are pulled in with a vibratory plow rather than trenched, since the coil goes in without a joint between heads. {note}
+
+### Where the irrigation drawings state a pipe material or class for a specific run that differs from the datasheet, the drawings shall govern for that run.
+
+### Every pipe installed under pressure shall carry the manufacturer's name, the nominal size, the applicable ASTM or AWWA designation, the pressure rating or schedule, and, where the supply is potable, the NSF mark.
+
+### Cellular-core PVC, drain-waste-vent pipe, sewer pipe, and any pipe without a pressure rating shall not be installed in any pressurized irrigation line.
+
+## PVC Pipe and Fittings {toc}
+
+### Requirements in this article apply where the datasheet selects a PVC material for the mainline or the laterals.
+
+### PVC pipe shall be manufactured from a Class 12454 compound conforming to ASTM D1784.
+
+### The joining method for PVC mainline pipe shall be as indicated in the datasheet.
+
+```datasheet
+label: PVC Mainline Joint Type
+type: radio
+options:
+ - "Solvent-cemented socket joints"
+ - "Gasketed bell-and-spigot joints"
+```
+
+### A solvent-cemented joint is rigid and restrained, so it needs no thrust blocking and is the joint on every small mainline, but every joint has to cure before it sees pressure and the rigid line carries thermal stress; a gasketed joint accepts thermal movement and misalignment and goes together in wet weather, and it is the joint on long and large mainlines, at the cost of thrust blocks or restrained fittings at every change of direction and a minimum diameter below which gasketed pipe is not made. {note}
+
+### Solvent-cemented joints in PVC laterals and in PVC mainline where selected shall be made with socket fittings conforming to ASTM D2466 for Schedule 40 fittings or ASTM D2467 for Schedule 80 fittings, with solvent cement conforming to ASTM D2564 and primer conforming to ASTM F656, by the two-step method of ASTM D2855.
+
+### Every solvent-cemented joint shall be primed before cement is applied, and one-step cement without primer shall not be used on buried pressure piping.
+
+### The primer softens and cleans the mating surfaces so the cement fuses them; cement applied to an unprimed socket sits on the surface and makes a joint that holds the test and lets go a season later. {note}
+
+### A solvent-cemented joint shall not be pressurized, backfilled, or moved before the cure time the cement manufacturer publishes for the pipe size and the ambient temperature has elapsed.
+
+### Gasketed joints shall conform to ASTM D3139 with gaskets conforming to ASTM F477, shall be assembled with the lubricant the pipe manufacturer supplies, and shall be inserted to the depth mark and no farther.
+
+### Gasketed PVC mainline shall be restrained against thrust at every bend, tee, reducer, dead end, and valve by a concrete thrust block or by restrained joint fittings sized for the test pressure.
+
+### Threaded connections at valves, swing joints, and transitions shall be made with Schedule 80 threaded fittings conforming to ASTM D2464, sealed with PTFE tape or a non-hardening thread sealant compatible with PVC, and tightened by hand plus the turns the fitting manufacturer publishes.
+
+### Threaded Schedule 40 PVC splits at the root of the thread under the hoop stress of tightening, which is why the thread is cut only in the thicker Schedule 80 wall. {note}
+
+### PVC pipe and fittings shall be stored under cover or shaded until installed.
+
+## Polyethylene Pipe and Fittings {toc}
+
+### Requirements in this article apply where the datasheet selects a polyethylene material for the mainline or the laterals.
+
+### Polyethylene pipe shall conform to ASTM D2239 or ASTM D3035 as selected, manufactured from a compound conforming to ASTM D3350, and shall carry a pressure rating not less than the design pressure of the line.
+
+### The joining method for polyethylene mainline pipe shall be as indicated in the datasheet.
+
+```datasheet
+label: Polyethylene Mainline Joint Type
+type: select
+options:
+ - "Insert fittings with stainless steel clamps"
+ - "Compression fittings"
+ - "Butt heat fusion"
+ - "Socket or electrofusion"
+```
+
+### Insert fittings with clamps are the joint every irrigation crew makes in polyethylene up to 2 in., and each insert reduces the bore at the fitting and relies on the clamp staying tight; compression fittings grip the outside of the pipe and leave the bore intact, and they are the usual transition to a valve or a PVC fitting; butt fusion makes a joint as strong as the pipe with no fitting inside it and is the joint on a large or long polyethylene mainline, at the cost of fusion equipment and trained personnel; socket and electrofusion fittings fuse without a facing machine and suit a repair or a tight spot. {note}
+
+### Insert fittings shall conform to ASTM D2609 and shall be secured with the number of stainless steel clamps the fitting manufacturer requires and with not fewer than two clamps per insert on mainline joints.
+
+### Heat fusion joints shall be made with fittings conforming to ASTM D2683 or ASTM D3261 by the procedure of ASTM F2620, at the ambient temperatures the pipe manufacturer permits, and shall be left undisturbed for the cooling time the procedure requires.
+
+### Polyethylene laterals shall be joined with insert fittings conforming to ASTM D2609 and stainless steel clamps unless the irrigation drawings indicate another method.
+
+### Polyethylene pipe shall be snaked in the trench with slack for thermal contraction and shall not be pulled taut between fittings.
+
+### Polyethylene contracts enough on a cold night to pull a taut run out of an insert fitting, and the slack laid into the trench on a warm afternoon is what keeps the joint together in January. {note}
+
+# Valves and Valve Boxes {toc}
+
+## Isolation Valves {toc}
+
+### Isolation valves shall be provided at the point of connection, at the take-off of each mainline branch serving a group of zones, on each side of a pressure-reducing valve, and at the locations indicated on [[drawing: the irrigation plan]].
+
+### The isolation valve type shall be as indicated in the datasheet.
+
+```datasheet
+label: Isolation Valve Type
+type: select
+options:
+ - "Bronze gate valve"
+ - "Resilient-seated gate valve"
+ - "Brass ball valve"
+ - "PVC true-union ball valve"
+ - "Butterfly valve"
+```
+
+### A bronze gate valve is the long-standing irrigation isolation valve in sizes to 2 in., closes gradually enough not to hammer the mainline, and is operated with a key through a box; a resilient-seated gate valve is the water-works valve for mainlines 3 in. and larger and seals bubble-tight after years in the ground; a brass ball valve closes in a quarter turn, which is convenient at a blow-out connection and a surge risk on a long mainline; a PVC true-union ball valve matches the pipe, is unbolted for replacement without cutting, and is the lowest-cost valve where the pressure is moderate and the box protects it from sunlight; a butterfly valve is compact at 4 in. and above and needs a gear operator to close slowly. {note}
+
+### Isolation valves shall be rated for not less than the mainline test pressure, installed in a valve box, and provided with an operating key or wheel reachable through the box.
+
+## Zone Control Valves {toc}
+
+### Each zone shall be controlled by an electrically actuated diaphragm valve that opens when its controller station energizes the solenoid and closes when the station de-energizes.
+
+### Zone control valves shall be globe or angle pattern, rated for not less than the mainline test pressure, and shall include a manual internal or external bleed for operating the zone without the controller.
+
+### The zone control valve body material shall be as indicated in the datasheet.
+
+```datasheet
+label: Zone Control Valve Body Material
+type: select
+options:
+ - "Glass-filled nylon"
+ - "PVC"
+ - "Brass or bronze"
+default: "Glass-filled nylon"
+```
+
+### Glass-filled nylon is the body of nearly every commercial zone valve because it holds its shape under pressure and heat, resists the chemicals in reclaimed water, and costs a fraction of a metal body; a PVC body is lighter in price and strength and suits low-pressure zones; a brass or bronze body is the answer where the static pressure exceeds the plastic valve's rating or where the Owner wants a valve that survives a hundred years of key wrenches. {note}
+
+### A flow control stem on each zone control valve shall be provided or omitted as indicated in the datasheet.
+
+```datasheet
+label: Zone Valve Flow Control Stem
+type: radio
+options:
+ - "Flow control stem on every zone control valve"
+ - "No flow control stem"
+default: "Flow control stem on every zone control valve"
+```
+
+### The flow control stem lets a zone be throttled to the pressure its heads want and lets a leaking valve be closed by hand without a key; it costs little and is on most commercial valves, and it is left off where every zone is pressure-regulated and the Owner's staff will never balance a zone. {note}
+
+### The solenoid type on each zone control valve shall be as indicated in the datasheet.
+
+```datasheet
+label: Zone Valve Solenoid Type
+type: radio
+options:
+ - "24 VAC solenoid"
+ - "DC latching solenoid"
+derived: "the controller type selected in the datasheet, with a DC latching solenoid where a battery-operated controller is selected"
+default: derived
+```
+
+### Only one type of emission device shall be served by any one zone control valve, and spray bodies, rotors, and drip devices shall not be mixed on a zone.
+
+### Sprays, rotors, and drip apply water at precipitation rates that differ by an order of magnitude, so no single run time can water a zone that mixes them; whichever device the run time is set for, the others are drowned or starved. {note}
+
+### Zone control valves shall be installed in valve boxes with not less than 2 in. of clearance between the valve and the box wall on every side and with the solenoid accessible from above.
+
+## Quick-Coupling Valves {toc}
+
+### Quick-coupling valves shall be provided on the mainline at the locations indicated on [[drawing: the irrigation plan]].
+
+### Quick-coupling valves shall be brass or bronze with a locking rubber cover, connected to the mainline on a swing joint, and installed in a valve box or on a stabilizer stake with the cover at finished grade.
+
+### Where the supply is non-potable, quick-coupling valves shall be of the non-interchangeable key type specified in this standard.
+
+## Valve Boxes {toc}
+
+### Every zone control valve, isolation valve, master valve, pressure-reducing valve, flow sensor, drain valve, wire splice, and drip zone control assembly shall be installed in a valve box.
+
+### Valve boxes shall be high-density polyethylene or structural-foam polypropylene with a bolt-down or locking lid, sized so the valve and its wiring can be serviced without excavating around the box.
+
+### The valve box load rating shall be as indicated in the datasheet.
+
+```datasheet
+label: Valve Box Load Rating
+type: select
+options:
+ - "Standard duty"
+ - "Heavy duty"
+ - "Traffic rated"
+default: "Standard duty"
+```
+
+### A standard-duty box carries foot traffic and mowers and is the box in turf and beds; a heavy-duty box carries an occasional light vehicle and is set at the edge of a drive or a service path; a traffic-rated box is set in a pavement or a drive and is the box wherever a vehicle can park on the lid. {note}
+
+### Valve boxes set in a pavement, a drive, or a parking area shall be traffic rated regardless of the datasheet selection.
+
+### Valve boxes shall be set on a bed of clean gravel not less than 4 in. deep that extends the full footprint of the box, with the gravel below the valve and the splices.
+
+### A box set on soil fills with water and silt from the bottom, and the valve and splices sit in mud for the life of the system; the gravel drains the box and carries it on firm ground so it does not settle. {note}
+
+### Valve boxes shall be set with the lid flush with finished grade in turf and at paving, and 2 in. above the finished soil grade in mulched planting beds.
+
+### Valve box lids shall be marked to identify the contents as a zone valve, master valve, isolation valve, or splice, and zone valve lids shall carry the station number.
+
+# Sprinkler Heads and Rotors {toc}
+
+## Spray Bodies and Nozzles {toc}
+
+### Spray bodies shall be pop-up bodies with a retraction spring, a wiper seal, and a filter screen under the nozzle, in the pop-up heights and with the nozzle assignments the irrigation legend assigns.
+
+### Spray bodies shall be pressure-regulating or non-regulating as indicated in the datasheet.
+
+```datasheet
+label: Spray Body Pressure Regulation
+type: radio
+options:
+ - "Pressure-regulating spray bodies carrying the WaterSense label"
+ - "Non-regulating spray bodies"
+default: "Pressure-regulating spray bodies carrying the WaterSense label"
+```
+
+### A pressure-regulating body holds its nozzle at the nozzle's design pressure whatever the lateral pressure is, which removes the misting a high-pressure zone produces and is the single largest efficiency gain available on a spray zone; WaterSense labels the bodies that meet its regulation test, and several states and water-efficient landscape ordinances require the label on new spray bodies. A non-regulating body costs less and performs identically where the zone pressure is already held at the nozzle design pressure by a regulating zone valve. {note}
+
+### Check valves in spray bodies shall be provided as indicated in the datasheet.
+
+```datasheet
+label: Spray Body Check Valves
+type: select
+options:
+ - "Integral check valve in every spray body"
+ - "Integral check valve in spray bodies at the low points of each zone"
+ - "No spray body check valves"
+```
+
+### A check valve holds the water in the lateral when the zone shuts off, so the low heads do not drain the lateral onto the pavement after every cycle and the zone does not have to refill before the high heads come up; a check in every body is the simplest to specify and costs a few dollars a head, a check at the low heads alone catches the drainage where it happens on a sloped site and depends on the installer putting it in the right heads, and no check valves suits a level site where a lateral holds its water on its own. {note}
+
+### Nozzles shall be the matched-precipitation-rate nozzles assigned on the irrigation legend, so that every head on a zone applies water at the same rate regardless of its arc.
+
+### A quarter-circle head and a full-circle head on the same zone cover areas that differ by four times, so unless the full-circle nozzle passes four times the flow the corner gets four times the water of the open turf; the designer matches the nozzle flow to the arc, and a substituted nozzle undoes it. {note}
+
+### Spray bodies on a zone that includes a rotary nozzle shall carry the inlet pressure regulation the rotary nozzle manufacturer requires.
+
+## Gear-Driven Rotors {toc}
+
+### Rotors shall be gear-driven pop-up rotors with a retraction spring, a wiper seal, an adjustable arc, and interchangeable nozzles, with the nozzle set the irrigation legend assigns.
+
+### Rotor riser construction shall be as indicated in the datasheet.
+
+```datasheet
+label: Rotor Riser Construction
+type: radio
+options:
+ - "Plastic riser"
+ - "Stainless steel riser sleeve"
+```
+
+### A plastic riser is the standard rotor and the lower cost; a stainless steel sleeve over the riser resists the vandal who pries at a head on a public frontage and the mower that catches a head set a little high, and it is specified in parks, streetscapes, and athletic turf. {note}
+
+### Rotors shall include a check valve where the irrigation legend indicates one and on every rotor on a zone with more than 5 ft of elevation change.
+
+### Rotors shall be set with the arc and radius adjusted so the throw reaches the adjacent heads and water does not land on pavement, walls, or glazing.
+
+## Head Connections and Swing Joints {toc}
+
+### Every spray body and rotor shall be connected to its lateral through a flexible or articulated swing joint, and no head shall be installed on a rigid riser directly into a lateral fitting.
+
+### The swing joint lets the head be set to grade and plumb, and it takes the kick, the mower wheel, and the truck tire without transmitting the load to the lateral tee; a head on a rigid nipple snaps the tee the first time it is hit, and the break is under the ground where it is found only by the wet spot. {note}
+
+### The spray body connection shall be as indicated in the datasheet.
+
+```datasheet
+label: Spray Body Connection
+type: select
+options:
+ - "Flexible polyethylene swing pipe with spiral barb fittings"
+ - "Preassembled swing joint with O-ring sealed joints"
+ - "Triple swing joint assembled from threaded street elbows and nipples"
+default: "Flexible polyethylene swing pipe with spiral barb fittings"
+```
+
+### Flexible swing pipe is the spray connection on most work because it is cut to length, bends to any position, and absorbs a load in every direction; a preassembled swing joint gives a spray body a rigid setting that stays plumb under repeated traffic; a triple swing joint built from street elbows is the field-assembled version of the same thing and relies on three threaded joints made correctly. {note}
+
+### The rotor connection shall be as indicated in the datasheet.
+
+```datasheet
+label: Rotor Connection
+type: select
+options:
+ - "Preassembled swing joint with O-ring sealed joints"
+ - "Triple swing joint assembled from threaded street elbows and nipples"
+ - "Flexible polyethylene swing pipe with spiral barb fittings"
+default: "Preassembled swing joint with O-ring sealed joints"
+```
+
+### A rotor passes more flow than a spray and is set deeper, so the preassembled swing joint with its full-bore nipples and O-ring seals is the rotor connection on commercial work; the field-built triple swing is its equivalent where the crew has the parts; swing pipe is used under a rotor where the flow is low enough that the small bore does not starve the nozzle. {note}
+
+### Swing joints shall be of a length that allows the head to be set at finished grade with the lateral at its specified cover.
+
+## Head Placement and Coverage {toc}
+
+### Heads shall be installed at the spacing indicated on the irrigation plan, and the Contractor shall not increase spacing to reduce the head count.
+
+### A single head applies the most water near its body and almost none at the edge of its throw, so every point on the zone has to be reached by at least two heads; spacing stretched past the design opens a dry ring between heads that no run time fills without flooding the rest of the zone. {note}
+
+### Spray bodies and rotors shall be set plumb with the top of the body at finished grade in turf and 2 in. above finished soil grade in planting beds, and shall be set back from the edge of paving by not less than 2 in. and not more than 6 in.
+
+### A head set above finished grade in turf is hit by the mower, and a head set below it is buried by the first top-dressing and sprays into the grass blades instead of over them. {note}
+
+### Where a head would spray a wall, a window, a walkway, or a parked car, the Contractor shall report the condition to the irrigation designer before the lateral is installed.
+
+# Drip and Micro-Irrigation {toc}
+
+## Drip Zone Control Assembly {toc}
+
+### Each drip zone shall be served by a zone control assembly consisting of, in order of flow, the zone control valve, a filter, and a pressure regulator, installed in a valve box.
+
+### The emitter passages in a dripline are small enough to clog on the grit a spray nozzle would never notice, and the emitters are rated at a pressure a fraction of the mainline's, so the filter and the regulator are not accessories to a drip zone, they are what makes the zone work. {note}
+
+### The drip zone filter type shall be as indicated in the datasheet.
+
+```datasheet
+label: Drip Zone Filter Type
+type: radio
+options:
+ - "Screen filter"
+ - "Disc filter"
+```
+
+### A screen filter is the compact, low-cost filter on a potable or reclaimed supply and is cleaned by rinsing the element; a disc filter holds more debris between cleanings and catches organic matter and algae a screen passes, so it is the filter on a well, pond, or harvested-water supply. {note}
+
+### The filtration fineness of each drip zone filter shall be as indicated in the datasheet.
+
+```datasheet
+label: Drip Zone Filtration Fineness
+type: range
+unit: mesh
+min: 80
+max: 200
+setpoints: [80, 100, 120, 140, 150, 200]
+derived: "the minimum filtration the emission device manufacturer publishes for the dripline and emitters furnished, and the irrigation water supply selected in the datasheet"
+default: derived
+```
+
+### The outlet pressure setting of each drip zone pressure regulator shall be as indicated in the datasheet.
+
+```datasheet
+label: Drip Zone Regulator Pressure
+type: range
+unit: psi
+min: 10
+max: 50
+setpoints: [10, 15, 20, 25, 30, 40, 50]
+derived: "the rated operating pressure of the drip emission device furnished, as published by its manufacturer"
+default: derived
+```
+
+### Drip zone filters and regulators shall be sized for the design flow of the zone stated on the zone schedule, and the regulator shall be a preset type unless the irrigation drawings indicate an adjustable one.
+
+## Dripline and Emitters {toc}
+
+### Dripline shall be polyethylene tubing with factory-installed pressure-compensating emitters at the flow rate and spacing the irrigation legend assigns.
+
+### Point-source emitters on polyethylene distribution tubing shall be pressure-compensating and shall be installed at the trees and individual plants, and in the number per plant, indicated on the irrigation drawings.
+
+### A pressure-compensating emitter delivers its rated flow across the pressure range the manufacturer publishes, so the emitter at the end of a long run and the emitter at the top of a slope deliver the same water as the one next to the valve; a non-compensating emitter cannot do that, and a bed on a grade waters unevenly with it. {note}
+
+### Dripline on a slope with more than 5 ft of elevation change within a zone shall incorporate check-valve emitters that hold the line full at shutdown.
+
+### Where the supply is non-potable, dripline and distribution tubing shall be purple or shall carry the purple marking the jurisdiction's reclaimed water program requires.
+
+### Surface dripline shall be laid on the finished soil grade before mulch is placed, staked at the interval the dripline manufacturer publishes and not more than 5 ft on center and at every change of direction, and covered by the mulch.
+
+### Dripline and distribution tubing shall be connected with the insert, compression, or locking fittings the dripline manufacturer lists for the tubing dimension furnished.
+
+### Dripline runs shall not exceed the maximum lateral length the dripline manufacturer publishes for the emitter flow, spacing, and inlet pressure furnished.
+
+## Air Relief and Flushing {toc}
+
+### Each drip zone shall include an air relief valve at the high point of the zone and a flush outlet at the end of each dripline run or at a manifolded flush header.
+
+### When a drip zone shuts off the line drains, and without an air relief valve the vacuum it forms pulls soil into the emitters at the low end; the flush outlet lets the fines that pass the filter be flushed out of the end of the line before they settle in the last emitters. {note}
+
+### The flush outlet type shall be as indicated in the datasheet.
+
+```datasheet
+label: Drip Flush Outlet Type
+type: radio
+options:
+ - "Manual flush cap or valve in a valve box"
+ - "Automatic flush valve"
+```
+
+### A manual flush outlet is opened by the maintenance staff at the start of each season and costs a box and a cap; an automatic flush valve purges a small volume at the start of every cycle without anyone remembering to, and it costs the valve and the water it discharges on each start. {note}
+
+### Air relief valves and flush outlets shall be installed in valve boxes or in the manufacturer's access sleeves set to finished grade.
+
+## Subsurface Dripline {toc}
+
+### Requirements in this article apply where the irrigation drawings indicate subsurface dripline.
+
+### Subsurface dripline shall be buried at the depth and lateral spacing indicated on [[drawing: the drip zone details]].
+
+### Subsurface dripline shall incorporate root intrusion protection as indicated in the datasheet.
+
+```datasheet
+label: Subsurface Dripline Root Intrusion Protection
+type: select
+options:
+ - "Copper-shielded emitters"
+ - "Herbicide-impregnated emitters"
+ - "Emitter outlet geometry without an additive"
+```
+
+### Copper in the emitter outlet deters root growth into the emitter for the life of the tubing without a chemical release; an herbicide impregnated into the emitter releases slowly and is effective for the period the manufacturer publishes, after which the protection is gone; an emitter whose outlet geometry alone resists intrusion carries no additive and relies on regular operation to keep the outlet flushed, which suits turf and groundcover rooted less aggressively than trees and shrubs. {note}
+
+### Subsurface dripline shall incorporate check-valve emitters that hold the line full at shutdown.
+
+### Subsurface dripline shall include the air relief and flush provisions specified for surface dripline, with the flush outlets and air relief valves brought to grade in access sleeves.
+
+### Subsurface dripline shall be located on the record drawings by the method specified in this standard, since no part of it is visible after installation.
+
+# Controller and Sensors {toc}
+
+## Controller Type {toc}
+
+### The system shall be operated by an automatic controller of the type indicated in the datasheet.
+
+```datasheet
+label: Controller Type
+type: select
+options:
+ - "Weather-based smart controller carrying the WaterSense label"
+ - "Soil-moisture-based smart controller carrying the WaterSense label"
+ - "Central control system with a site satellite controller"
+ - "Conventional time-based controller"
+ - "Battery-operated controller"
+default: "Weather-based smart controller carrying the WaterSense label"
+```
+
+### A weather-based controller adjusts each station's run time to the measured or forecast evapotranspiration and is the smart controller made in every commercial station count, so it is what most new commercial systems install; a soil-moisture controller waters on the measured moisture of the root zone and suits athletic turf and a landscape with a well-defined moisture target, at the cost of buried sensors that have to be placed and maintained; a central control system runs many sites from one platform and is specified on a campus or by an Owner with a portfolio; a conventional time-based controller waters on a fixed schedule whatever the weather does, costs the least, and is what a water-efficient landscape ordinance or energy code may no longer permit on new work; a battery-operated controller runs where no line voltage can be brought, such as a median or a remote bed, and drives DC latching solenoids. {note}
+
+### Where [[parameter: adopted-energy-code]] or a local water-efficient landscape ordinance requires a weather-based or soil-moisture-based controller on a new automatic irrigation system, a conventional time-based controller shall not be furnished.
+
+### A weather-based or soil-moisture-based controller shall carry the EPA WaterSense label under the applicable WaterSense specification.
+
+### The controller shall provide for each station a run time, not fewer than four start times, a watering-day schedule that can honor the purveyor's watering-day restrictions, cycle and soak scheduling, a seasonal adjustment, and a sensor input that suspends irrigation.
+
+### The controller shall be listed to UL 1951.
+
+## Controller Capacity {toc}
+
+### The controller station capacity shall be as indicated in the datasheet.
+
+```datasheet
+label: Controller Station Capacity
+type: range
+unit: stations
+min: 2
+max: 240
+step: 1
+drawing_ref: "the controller schedule on the irrigation plan"
+default: deferred
+```
+
+### The controller shall provide not fewer than the number of spare stations beyond the installed zones indicated in the datasheet.
+
+```datasheet
+label: Spare Controller Stations
+type: range
+unit: stations
+min: 0
+max: 8
+setpoints: [0, 1, 2, 4, 6, 8]
+default: 2
+```
+
+### The controller shall support the master valve output, the flow sensor input, and the rain, freeze, and soil moisture sensor inputs selected in this standard.
+
+## Controller Enclosure and Mounting {toc}
+
+### The controller enclosure rating shall be as indicated in the datasheet.
+
+```datasheet
+label: Controller Enclosure Rating
+type: select
+options:
+ - "NEMA Type 1"
+ - "NEMA Type 3R"
+ - "NEMA Type 4"
+ - "NEMA Type 4X"
+ - "NEMA Type 12"
+default: "NEMA Type 3R"
+```
+
+### A Type 1 enclosure is the controller's own cabinet in a dry mechanical or electrical room; Type 3R sheds rain and is the outdoor wall and pedestal cabinet; Type 4 is hosed down and is specified where the controller sits in a washdown yard; Type 4X adds corrosion resistance for a coastal or chemical exposure; Type 12 keeps dust out of a controller in a maintenance shop. {note}
+
+### A controller installed outdoors shall be in an enclosure rated NEMA Type 3R or better.
+
+### A controller installed within 1 mile of a saltwater coast, or where fertilizer or de-icing chemicals are stored or handled nearby, shall be in an enclosure rated NEMA Type 4X.
+
+### The controller mounting shall be as indicated in the datasheet.
+
+```datasheet
+label: Controller Mounting
+type: radio
+options:
+ - "Wall mounted"
+ - "Pedestal mounted"
+```
+
+### A wall-mounted controller uses an existing wall and power source and is the mounting wherever a building wall faces the landscape; a pedestal brings the controller to the middle of the site it serves, shortens every wire run, and stands where no wall exists, at the cost of the pedestal, its footing, and a power feed to it. {note}
+
+### The controller location shall be as indicated on [[drawing: the irrigation plan]].
+
+### The controller enclosure shall be lockable, and the controller shall be mounted with its display between 48 in. and 60 in. above the finished floor or grade.
+
+## Controller Power, Grounding, and Surge Protection {toc}
+
+### Line-voltage power to the controller shall be a dedicated circuit installed under NFPA 70, with a disconnecting means at the controller.
+
+### The controller shall include surge protection on the incoming power and on every station output and the common.
+
+### The controller shall be grounded through a grounding electrode system installed in accordance with ASIC Guideline 100, with a measured resistance to earth not exceeding 10 Ω.
+
+### The buried control wires of an irrigation system are a long antenna, and a lightning strike within a mile of the site induces a surge in them that arrives at the controller terminals; the surge protection diverts it, and it has nowhere to go unless the controller is tied to a low-resistance ground. {note}
+
+### The Contractor shall measure the grounding electrode resistance after installation and shall record the result in the test reports.
+
+## Controller Communication {toc}
+
+### The controller communication method shall be as indicated in the datasheet.
+
+```datasheet
+label: Controller Communication
+type: select
+options:
+ - "Local operation at the controller"
+ - "Owner's network or Wi-Fi connection"
+ - "Cellular connection"
+ - "Central control communication"
+```
+
+### Local operation needs no connection and no account, and every program change is made at the cabinet; a connection to the Owner's network or Wi-Fi gives remote programming and alarms through the manufacturer's platform where the Owner's IT department allows the device on its network; a cellular connection does the same with no dependence on the Owner's network, for a recurring service charge; central control communication ties a satellite controller to the Owner's central system by the wired, radio, or network link that system uses. {note}
+
+### Where a weather-based controller receives its evapotranspiration data over a communication link, the controller shall continue to operate on its last schedule when the link is lost.
+
+## Rain and Freeze Sensors {toc}
+
+### A rain shutoff sensor shall be provided and connected to the controller so that irrigation is suspended during and after measurable rainfall.
+
+### Several states require a functioning rain shutoff device on every automatic irrigation system, and a weather-based controller that receives rain data over a link does not satisfy that requirement in every jurisdiction; the physical sensor is specified so the system complies wherever it is built. {note}
+
+### The rain sensor connection shall be as indicated in the datasheet.
+
+```datasheet
+label: Rain Sensor Connection
+type: radio
+options:
+ - "Wired rain sensor"
+ - "Wireless rain sensor"
+```
+
+### A wired sensor needs a wire run from the controller to an open-sky mounting, which is short when the controller is on a wall and long when it is on a pedestal in the landscape; a wireless sensor is mounted wherever the sky is open and costs a battery to maintain. {note}
+
+### A freeze sensor shall be provided as indicated in the datasheet.
+
+```datasheet
+label: Freeze Sensor
+type: radio
+options:
+ - "Provided"
+ - "Not provided"
+derived: "[[parameter: site-ambient-temperature-minimum]], with a freeze sensor provided where it is below 32°F"
+default: derived
+```
+
+### Where a freeze sensor is provided, it shall suspend irrigation when the air temperature falls to the set point indicated in the datasheet.
+
+```datasheet
+label: Freeze Sensor Set Point
+type: range
+unit: °F
+min: 32
+max: 40
+setpoints: [32, 35, 37, 40]
+default: 37
+```
+
+### Rain and freeze sensors shall be mounted in open exposure clear of roof overhangs, tree canopy, and spray from the irrigation itself.
+
+## Soil Moisture Sensors {toc}
+
+### Requirements in this article apply where the datasheet selects a soil-moisture-based controller or where the irrigation drawings indicate soil moisture sensors.
+
+### Soil moisture sensors shall be of a type the controller manufacturer lists for the controller, installed in the root zone at the depth and in the representative hydrozones indicated on [[drawing: the irrigation plan]].
+
+### Soil moisture sensor locations shall be recorded on the record drawings and marked at grade with a valve box or marker.
+
+# Control Wiring {toc}
+
+## Wiring Architecture {toc}
+
+### The field wiring architecture shall be as indicated in the datasheet.
+
+```datasheet
+label: Field Wiring Architecture
+type: radio
+options:
+ - "Conventional multi-wire with a conductor per station and a common"
+ - "Two-wire decoder path"
+```
+
+### Conventional wiring runs a conductor from the controller to every valve plus a common, which is simple to troubleshoot with a meter and grows into a thick bundle on a site with many zones or a long mainline; a two-wire path runs one twisted pair past every valve and a decoder at each valve addresses it, which cuts the wire on a large site to a fraction and lets valves be added anywhere on the path, at the cost of decoders, a grounding grid along the path, and a technician who can read the path's diagnostics. {note}
+
+### Where a two-wire path is selected, the path shall be grounded with surge arrestors and grounding electrodes at the intervals the controller manufacturer requires and at the end of every path.
+
+## Conductors {toc}
+
+### Control conductors shall be solid copper, insulated and jacketed for direct burial, rated for the controller's output voltage, and of a type the controller manufacturer lists for the wiring architecture selected.
+
+### The minimum control conductor size shall be as indicated in the datasheet.
+
+```datasheet
+label: Minimum Control Conductor Size
+type: select
+options:
+ - "18 AWG"
+ - "16 AWG"
+ - "14 AWG"
+ - "12 AWG"
+ - "10 AWG"
+default: "14 AWG"
+```
+
+### A 14 AWG conductor carries a solenoid current the length of most commercial sites without the voltage falling below what the solenoid needs, and it is the size most commercial specifications set as the floor; 18 and 16 AWG are made as multi-conductor jacketed cable and suit a short run from a wall controller to a nearby manifold; 12 and 10 AWG are set for the common and for the longest station runs on a large site, where the voltage drop on 14 AWG would leave the farthest solenoid too weak to open. {note}
+
+### Conductors shall be sized so that the voltage delivered to the most distant solenoid on each station is within the range the valve manufacturer publishes, and the Contractor shall submit the sizing for the longest run on each controller.
+
+### Station conductors shall be a color other than white, the common shall be white, and spare conductors shall be a third color, with the same color scheme held throughout the system.
+
+### Not fewer than the number of spare conductors indicated in the datasheet shall be run with every conventional wire bundle to every zone control valve box.
+
+```datasheet
+label: Spare Control Conductors per Valve Box
+type: range
+unit: conductors
+min: 0
+max: 4
+setpoints: [0, 1, 2, 3, 4]
+default: 1
+```
+
+### A spare conductor to every box lets a cut station wire be swapped without excavating the run, and a second spare lets a zone be added; the spares cost wire, and a two-wire path needs none because a new decoder is clipped anywhere on the path. {note}
+
+## Splices and Wire Installation {toc}
+
+### Every splice and connection in the field wiring shall be made inside a valve box with a waterproof connector that is gel-filled or epoxy-filled and listed for direct burial.
+
+### No splice shall be made outside a valve box, and no splice shall be made with a twist-on connector, tape, or a connector not listed for direct burial.
+
+### A buried connection that is not sealed corrodes within a season, and a corroded splice is the most common cause of a dead zone; the valve box is where a technician can find and remake it. {note}
+
+### Control conductors shall be installed in the mainline trench beside or below the mainline, bundled and taped at intervals not exceeding 10 ft, with an expansion loop of not less than 24 in. of slack at every valve box, every splice, and every change of direction.
+
+### Where control conductors cross under paving, they shall be installed in a sleeve separate from the pipe sleeve as specified in this standard.
+
+### Control conductors not installed in the mainline trench shall be buried at not less than the lateral cover indicated in the datasheet.
+
+# Sleeving, Trenching, and Cover {toc}
+
+## Sleeves Under Paving {toc}
+
+### Pipe and control conductors crossing under paving, sidewalks, curbs, walls, and other hardscape shall be installed in sleeves placed before the paving is constructed, at the locations indicated on [[drawing: the sleeving plan]].
+
+### A sleeve lets the pipe or wire be pulled and replaced without cutting the pavement, and it keeps the pavement's sawcut, compaction, and load off the pipe; a sleeve missed before paving is replaced by a bore under the finished pavement or a sawcut and patch, either of which costs many times the sleeve. {note}
+
+### The sleeve material shall be as indicated in the datasheet.
+
+```datasheet
+label: Sleeve Material
+type: select
+options:
+ - "PVC Schedule 40"
+ - "PVC Schedule 80"
+ - "HDPE conduit"
+default: "PVC Schedule 40"
+```
+
+### Schedule 40 PVC is the sleeve under walks, drives, and parking because it is on every truck and carries the load once the pavement spreads it; Schedule 80 is set under a heavy-vehicle pavement or where the sleeve is shallow; HDPE conduit is the sleeve pulled through a bored crossing because it comes in a coil and bends with the bore. {note}
+
+### Sleeves shall have an inside diameter not less than twice the nominal diameter of the pipe or wire bundle they carry, and not less than 2 in.
+
+### Sleeves shall extend beyond the edge of the paving on each side by not less than the distance indicated in the datasheet.
+
+```datasheet
+label: Sleeve Extension Beyond Paving Edge
+type: range
+unit: in
+min: 12
+max: 36
+setpoints: [12, 18, 24, 36]
+default: 12
+```
+
+### Pipe sleeves and wire sleeves shall be separate, and a control conductor shall not share a sleeve with a pressure pipe.
+
+### Each sleeve end shall be capped until used and marked at finished grade by a method that survives paving, and each sleeve location shall be recorded on the record drawings with its size and contents.
+
+### The Contractor shall coordinate sleeve placement with the paving contractor so that every sleeve is in place and inspected before base course is placed over it.
+
+## Trenchless Crossings {toc}
+
+### Where a crossing is required under existing paving, under a tree protection zone, or where open trenching is not permitted, the crossing shall be made by horizontal boring and the pipe or sleeve pulled through the bore.
+
+### Bored crossings shall maintain the cover specified in this standard and the clearance from other utilities the utility owners require, and the entry and exit pits shall be outside the protected feature.
+
+### Vibratory plow installation of polyethylene laterals shall be permitted or prohibited as indicated in the datasheet.
+
+```datasheet
+label: Vibratory Plow Installation of Polyethylene Laterals
+type: radio
+options:
+ - "Permitted"
+ - "Not permitted"
+```
+
+### Plowing pulls a polyethylene lateral into a slit in the turf at production rates no trench can match and leaves almost no surface disturbance, and it is how most polyethylene lateral grids go into an existing or finished lawn; it gives no view of the pipe's bed or of what the blade passed through, and it is not permitted where rock, other utilities, or tree roots in the path cannot be ruled out. {note}
+
+### Where plowing is permitted, the plowed depth shall be not less than the lateral cover indicated in the datasheet, and every fitting shall be hand-excavated and set in an open hole.
+
+## Trenching and Pipe Zone {toc}
+
+### Trench excavation, worker protection, dewatering, and backfill above the pipe zone shall conform to [[sync/earthwork]], and the pipe zone of the irrigation trench shall be as specified in this article.
+
+### The trench bottom shall be firm, continuous, and free of rock, debris, and frozen material, and shall be graded to drain to the drain valves where a drain-down winterization method is selected.
+
+### The pipe zone material from the trench bottom to 4 in. above the pipe crown shall be as indicated in the datasheet.
+
+```datasheet
+label: Pipe Zone Material
+type: select
+options:
+ - "Native soil screened free of rock larger than 1 in."
+ - "Clean sand"
+ - "Clean gravel or crushed stone passing a 3/4 in. sieve"
+default: "Native soil screened free of rock larger than 1 in."
+```
+
+### Screened native soil is the pipe zone on most irrigation trenches because the trench is shallow, the pipe is plastic, and the excavated soil goes back where it came from; clean sand is imported where the native soil is rocky or is a clay that cannot be worked around a small pipe, and it is the envelope on a mainline that has to be found and repaired without damage; gravel or crushed stone drains a wet trench and supports a large mainline, and it abrades a small polyethylene lateral that moves against it. {note}
+
+### Pipe shall be laid on the trench bottom with no voids under the pipe, and the pipe zone shall be placed by hand and compacted around and over the pipe before the trench is backfilled above the pipe zone.
+
+### Mainline and laterals shall be installed in separate trenches, or in a common trench with the mainline below the laterals and not less than 4 in. of pipe zone material between them.
+
+### The Contractor shall backfill and compact the trench above the pipe zone under [[sync/earthwork]] to the compaction target for the surface above it, and shall restore the surface to the grade it was at before trenching.
+
+### A trench that settles after the lawn is seeded is a trough the mower scalps and the Owner remembers; the compaction target is the one the surface above needs, not the one the pipe needs. {note}
+
+## Minimum Cover {toc}
+
+### Cover over the mainline, measured from finished grade to the top of the pipe, shall be not less than the depth indicated in the datasheet.
+
+```datasheet
+label: Minimum Mainline Cover
+type: range
+unit: in
+min: 12
+max: 36
+setpoints: [12, 18, 24, 30, 36]
+default: 18
+```
+
+### Cover over laterals shall be not less than the depth indicated in the datasheet.
+
+```datasheet
+label: Minimum Lateral Cover
+type: range
+unit: in
+min: 6
+max: 24
+setpoints: [6, 8, 12, 18, 24]
+default: 12
+```
+
+### The mainline is under pressure all the time and is the pipe whose failure floods the site, so it is set deeper than the laterals, out of reach of an aerator or an edging spade; 18 in. keeps it below the deepest turf maintenance tool and 24 in. or more is set where the mainline crosses a planting bed that will be cultivated or where a heavier pipe needs the soil load to hold it. A lateral at 12 in. clears the aerator and the sod cutter, and a shallower lateral is set where the soil is thin over rock or the swing joint would otherwise be too long. {note}
+
+### Cover beneath paving shall be measured from the bottom of the pavement section to the top of the sleeve, and the sleeve shall have not less than 12 in. of cover below the pavement section.
+
+### Where the irrigation drawings indicate a greater cover for a specific run, the drawings shall govern for that run.
+
+## Mainline Locating {toc}
+
+### The mainline shall be made locatable after backfill by the method indicated in the datasheet.
+
+```datasheet
+label: Mainline Locating Provision
+type: select
+options:
+ - "Detectable marking tape above the mainline"
+ - "Tracer wire on the mainline"
+ - "None"
+```
+
+### Detectable marking tape laid 6 in. above the mainline is found by a locator and read as a warning by whoever digs down to it, and it is cut by the first spade through it; a tracer wire bonded to the pipe and brought to grade in the valve boxes is traced with a locator for the life of the system and needs its continuity kept; no locating provision relies on the record drawings alone, which suits a small system with a short, straight mainline. {note}
+
+### Where tracer wire is selected, it shall be brought to grade inside every valve box on the mainline and its continuity shall be verified before the trench is backfilled.
+
+# Testing and Commissioning {toc}
+
+## Mainline Hydrostatic Test {toc}
+
+### The mainline, from the point of connection to the zone control valves, shall be hydrostatically tested with water after every solvent-cemented joint has cured and before the trench is backfilled above the pipe zone, with the zone control valves closed and the joints exposed for inspection.
+
+### The mainline test pressure shall be not less than the pressure indicated in the datasheet, not less than 1.5 times the static supply pressure measured at the point of connection, and not more than the pressure rating of the lowest-rated component on the mainline.
+
+```datasheet
+label: Mainline Test Pressure
+type: range
+unit: psi
+min: 100
+max: 200
+setpoints: [100, 125, 150, 175, 200]
+default: 150
+```
+
+### The test pressure shall be held for not less than the duration indicated in the datasheet.
+
+```datasheet
+label: Mainline Test Duration
+type: range
+unit: hours
+min: 1
+max: 24
+setpoints: [1, 2, 4, 8, 24]
+default: 2
+```
+
+### The pressure loss over the test duration shall not exceed the value indicated in the datasheet, and there shall be no visible leakage at any joint.
+
+```datasheet
+label: Allowable Mainline Test Pressure Loss
+type: range
+unit: psi
+min: 0
+max: 10
+setpoints: [0, 2, 3, 5, 10]
+default: 5
+```
+
+### A long mainline relaxes slightly under pressure and its temperature changes over two hours, so a few psi of loss on a tight line is ordinary; zero loss is set where the mainline is short and solvent-cemented, and a larger allowance is set on a long gasketed line where AWWA practice admits a small makeup volume. {note}
+
+### Compressed air or any other gas shall not be used to pressure test any plastic irrigation piping.
+
+### A solvent-cemented plastic line under air pressure stores energy that water does not, and a failing joint releases it as a burst that throws pipe fragments; the prohibition on air testing applies at every pipe size and every test pressure. {note}
+
+### Leaks found during the test shall be repaired and the test repeated until the mainline passes, and the cost of retesting shall be borne by the Contractor.
+
+### The test shall be witnessed by the irrigation designer or the Owner's representative, and the Contractor shall give not less than 48 hours notice of each test.
+
+## Lateral Flushing and Operation {toc}
+
+### Before heads, emitters, or drip devices are installed, every lateral shall be flushed with the zone operating at full pressure through the open lateral ends until the discharge runs clear.
+
+### Debris left in a lateral lodges in the nozzle screens and the emitter passages as soon as the zone first runs, and clearing it through the installed nozzles takes far longer than flushing it out of the open pipe. {note}
+
+### After the emission devices are installed, every zone shall be operated at its design pressure and inspected for leaks at every joint and fitting, and every leak shall be repaired before the trench is backfilled above the pipe zone.
+
+### Drip zones shall be flushed through the flush outlets after the dripline is connected and before the zone is accepted.
+
+## Coverage Verification {toc}
+
+### After all heads and emitters are installed and the controller is programmed, each zone shall be operated and observed, every head shall pop up and rotate through its assigned arc, every emitter shall discharge, and the arc, radius, and pattern of every head shall be adjusted to keep water on the landscape and off pavement, walls, and glazing.
+
+### A distribution uniformity audit of turf zones shall be performed as indicated in the datasheet.
+
+```datasheet
+label: Distribution Uniformity Audit
+type: radio
+options:
+ - "Catch-can audit of every turf spray and rotor zone"
+ - "Visual coverage check only"
+```
+
+### A catch-can audit measures how evenly a zone applies water and gives a number the design can be held to, and it takes a trained auditor an hour or more per zone; a visual check finds the dry gap, the broken head, and the overspray that an audit would find, and it does not quantify uniformity, which suits a site where the Owner is not going to hold the system to a measured value. {note}
+
+### Where a catch-can audit is performed, the lower-quarter distribution uniformity of each turf zone shall be not less than the value indicated in the datasheet.
+
+```datasheet
+label: Minimum Lower-Quarter Distribution Uniformity
+type: range
+min: 0.5
+max: 0.85
+step: 0.05
+```
+
+### A zone that fails the coverage inspection or the audit shall be corrected by the Contractor and re-tested at the Contractor's cost.
+
+### Overspray onto pavement is wasted water, a slip hazard, a stain on the building, and the complaint the Owner receives first. {note}
+
+## Controller Programming and Sensor Demonstration {toc}
+
+### After testing is complete, the Contractor shall program the controller for the installed system, with each station's run time, start times, watering days, and cycle and soak settings set from the zone schedule and the purveyor's watering restrictions, and with the seasonal adjustment or evapotranspiration source configured.
+
+### The Contractor shall demonstrate the rain sensor, the freeze sensor where provided, the master valve, and the flow sensor alarm where provided, by triggering each device and confirming the controller's response in the presence of the Owner's representative.
+
+### Where a flow sensor is provided, the Contractor shall run the controller's flow learning for every zone and shall set the high-flow and low-flow alarm margins.
+
+### The as-left program shall be recorded in the controller programming record and the laminated zone map shall be installed inside the controller enclosure.
+
+## Owner Training {toc}
+
+### The Contractor shall instruct the Owner's maintenance personnel in operating the controller, running a zone manually, adjusting run times and the seasonal adjustment, responding to sensor and flow alarms, cleaning the drip filters, and performing the seasonal start-up and winterization, for not less than the duration indicated in the datasheet.
+
+```datasheet
+label: Owner Training Duration
+type: range
+unit: hours
+min: 1
+max: 8
+setpoints: [1, 2, 4, 8]
+default: 2
+```
+
+### The training shall be given at the controller with the system operating, and the Contractor shall record the date, the attendees, and the topics covered.
+
+# Winterization and Seasonal Start-Up {toc}
+
+## Requirements in this section apply where [[parameter: site-ambient-temperature-minimum]] is below 32°F.
+
+## The system shall be winterized at the end of each watering season by closing the point of connection isolation valve, draining the backflow assembly as [[sync/backflow-prevention]] directs, draining the point of connection assembly, and removing the water from the mainline and laterals by the method indicated in the datasheet.
+
+```datasheet
+label: Winterization Method
+type: select
+options:
+ - "Compressed-air blow-out through a dedicated connection"
+ - "Gravity drainage through manual drain valves at low points"
+ - "Automatic drain valves at low points"
+ - "Compressed-air blow-out with drain valves at low points"
+```
+
+## Blow-out clears every lateral regardless of grade and is how nearly every commercial system north of the frost line is winterized, at the cost of a compressor visit each fall and a crew that knows the pressure limits; gravity drainage through manual drains needs every pipe graded to a drain and a valve box at every low point, and it clears a lateral only where the grade actually falls to the drain; automatic drains open at every shutdown and drain the laterals each cycle, which wastes a little water on every run and leaves the mainline to be drained another way; blow-out with drain valves clears the laterals by air and drains the mainline low points by gravity, and is set where the mainline is large enough that air alone will not clear it. {note}
+
+## Where blow-out is selected, air shall be introduced through a dedicated blow-out connection downstream of the backflow assembly and never through the backflow assembly.
+
+## Blow-out air pressure shall not exceed 80 psi in PVC piping, 50 psi in polyethylene piping, or the rating of the lowest-rated component on the zone being cleared, whichever is least, and the compressor shall be regulated to that limit before air is admitted.
+
+## Air at a pressure the pipe would hold as water still overspeeds a rotor until its gears strip and bursts a fitting at the end of a lateral when the water ahead of it is gone; the limits are set well below the pipe rating for that reason. {note}
+
+## Blow-out shall be performed one zone at a time, with each zone open until it discharges only air, and no zone shall be blown out more than twice in succession without a pause for the compressor to cool the air.
+
+## The first start-up of each season shall fill the mainline slowly with a zone valve open to purge air, shall be followed by an operational check of every zone, and shall include replacement of any head, emitter, or valve damaged by freezing.
+
+## The Contractor shall perform the first winterization and the following spring start-up as indicated in the datasheet.
+
+```datasheet
+label: Seasonal Services by the Contractor During Warranty
+type: radio
+options:
+ - "First winterization and following spring start-up included"
+ - "Not included"
+```
+
+## Including the first winterization keeps the system's first winter in the hands of the party warranting it, so a frozen fitting the next spring cannot be argued over; excluding it suits an Owner whose own staff winterizes every system on the site and who would rather be trained than wait for the Contractor. {note}
+
+# Establishment Support and Stabilization Transition {toc}
+
+## The irrigation system serving a landscape area shall be installed, tested, and programmed, and the backflow assembly shall be certified under [[sync/backflow-prevention]], before permanent planting, seeding, or sodding of that area begins under [[sync/planting-and-soil-preparation]].
+
+## The planting, topsoil, permanent seed mix, and the establishment period are specified in [[sync/planting-and-soil-preparation]]; where [[sync/erosion-and-sediment-control]] carries an area from temporary stabilization to permanent vegetation, the permanent seeding is that standard's and this standard supplies the irrigation that keeps it alive. {note}
+
+## Where [[sync/erosion-and-sediment-control]] relies on permanent vegetation to achieve final stabilization of an irrigated area, the Contractor shall have the irrigation zones serving that area operational before the permanent seeding or planting is placed and shall keep them operating through the establishment period.
+
+## During the establishment period defined in [[sync/planting-and-soil-preparation]], the controller shall be programmed to the establishment watering schedule the planting contractor requests in writing, and shall be reprogrammed to the maintenance schedule in the controller programming record when the establishment period ends.
+
+## The party responsible for establishment watering is assigned in [[sync/planting-and-soil-preparation]]; where the Owner's irrigation is the only water supply, the party operating the controller during the establishment period shall be confirmed in writing before the establishment period begins.
+
+## New plantings die in the gap between the irrigation contractor leaving and the planting contractor arriving, or in the week when nobody knows who owns the controller; the written hand-off exists so that the gap does not open. {note}
+
+# Record Documents {toc}
+
+## The Contractor shall keep a field markup current through the work showing the installed location of every mainline run, valve, sleeve, splice, sensor, and subsurface dripline run, and shall transfer it to the record drawings at closeout.
+
+## Record drawing locations shall be established by the method indicated in the datasheet.
+
+```datasheet
+label: Record Drawing Location Method
+type: select
+options:
+ - "Dimensioned from two permanent site features"
+ - "GPS coordinates"
+ - "Dimensioned from two permanent site features and GPS coordinates"
+default: "Dimensioned from two permanent site features"
+```
+
+## A dimension from two permanent features such as a building corner and a curb return is found with a tape by anyone, and it fails where the features are later removed; GPS coordinates survive a site change and are found by anyone with a receiver, and they depend on a receiver accurate to the foot and on the Owner having one; recording both costs the Contractor a receiver and gives the Owner either path to the valve. {note}
+
+## Dimensioned locations shall be measured to the nearest 6 in. from permanent features that will remain after the project is complete.
+
+## The record drawings shall identify each zone control valve by its station number and each sleeve by its size and contents, and shall match the laminated zone map installed in the controller.
+
+# Warranty {toc}
+
+## The Contractor shall warrant the irrigation system, including the piping, valves, heads, emitters, drip components, controller, sensors, wiring, and the installation, against defects in material and workmanship for the period indicated in the datasheet, beginning at substantial completion.
+
+```datasheet
+label: Irrigation System Warranty Period
+type: range
+unit: years
+min: 1
+max: 5
+setpoints: [1, 2, 3, 5]
+default: 1
+```
+
+## A one-year warranty matches the general correction period of most construction contracts and carries the system through one winterization and one spring start-up; a two-year or longer period is set where the Owner wants the second winter covered, where the planting warranty runs two years and the Owner wants the irrigation warranty to match it, or where the system is large enough that a latent defect in a splice or a solvent joint is likely to surface in the second season. {note}
+
+## Warranty correction shall include repair of leaks, replacement of failed valves, solenoids, heads, emitters, sensors, and controller components, repair of trench settlement that exposes or damages piping or disturbs the finished surface, and restoration of the landscape and paving disturbed by the correction, at the Contractor's expense.
+
+## Where the parties disagree whether a failure is attributable to defective material or workmanship or to a cause outside the Contractor's control, the irrigation designer shall make the initial determination.
+
+## Manufacturer warranties on the controller, valves, heads, and specialty devices that extend beyond the Contractor's warranty shall be assigned to the Owner at closeout.
+
+## The warranty does not limit the Owner's remedies for a latent defect discovered after the warranty period, including pipe installed at less than the specified cover, a splice made outside a valve box, mixed emission devices on a zone, and a substituted nozzle that defeats the matched precipitation rate.
+
+# Spare Parts {toc}
+
+## The Contractor shall deliver to the Owner at closeout the spare parts and tools indicated in the datasheet, in the quantities stated below, and shall obtain the Owner's signed receipt for them.
+
+```datasheet
+label: Spare Parts and Tools Delivered
+type: checkbox
+options:
+ - "Spare nozzles of each type installed"
+ - "Spare spray bodies and rotors of each type installed"
+ - "Spare drip emitters, dripline fittings, and filter elements"
+ - "Spare zone control valve solenoids and diaphragms"
+ - "Spare waterproof splice connectors"
+ - "Quick-coupling keys and hose swivels"
+ - "Controller enclosure keys and valve box lid keys"
+ - "Service tools for the heads and valves installed"
+default: ["Spare nozzles of each type installed", "Spare drip emitters, dripline fittings, and filter elements", "Spare waterproof splice connectors", "Quick-coupling keys and hose swivels", "Controller enclosure keys and valve box lid keys", "Service tools for the heads and valves installed"]
+```
+
+## Spare nozzles shall be delivered at not less than 5 percent of the quantity of each nozzle type installed and not fewer than two of each, and spare emitters, fittings, and splice connectors at not less than 2 percent of the quantity installed.
+
+## Two quick-coupling keys with hose swivels, two sets of controller enclosure keys, and two valve box lid keys shall be delivered where the system includes the devices they serve.