County_Standards_-_Section_20_Landscaping.pdf

SECTION 20 - LANDSCAPING

TABLE OF CONTENTS

Section Page

20-1 GENERAL ....................................................................................................................20.1 20-2 MATERIALS .................................................................................................................20.1

20-2.01 Root Control Barrier ...............................................................................................20.1 20-2.02 Topsoil ...................................................................................................................20.1 20-2.03 Soil Amendment ....................................................................................................20.2 20-2.04 Liquid Green Dye ...................................................................................................20.2 20-2.05 Mulch .....................................................................................................................20.2 20-2.06 Header Boards ........................................................................................................20.2

20-3 EROSION CONTROL ...................................................................................................20.2 20-3.01 Seeding Application ...............................................................................................20.2 20-3.02 Measurement and Payment ...................................................................................20.3

20-4 IRRIGATION SYSTEMS...............................................................................................20.3 20-4.01 Maintain Existing Water Supply ..............................................................................20.3 20-4.02 Trenching in Existing Landscape .............................................................................20.4 20-4.03 Electrical Service for Electric Automatic Irrigation System .......................................20.4 20-4.03A Components .........................................................................................................20.4 20-4.03B Controllers ............................................................................................................20.4 20-4.03C Control Wire, Electrical Conduit and Pull Boxes ....................................................20.5 20-4.03.D Testing .................................................................................................................20.5 20-4.04 Installation ...............................................................................................................20.6 20-4.04.A General ................................................................................................................20.6 20-4.04.B Irrigation Sleeving ................................................................................................20.6 20-4.04.C Water Line Crossovers .......................................................................................20.6 20-4.04.D Trenching and Backfilling .....................................................................................20.7 20-4.05 Pipe .........................................................................................................................20.7 20-4.05.A Subsurface Dripperline ........................................................................................20.9 20-4.05.C Flush Valve ..........................................................................................................20.9 20-4.05.D Sprinklers and Emitters ........................................................................................20.9 20-4.05.E Deep Watering Pipe ........................................................................................... 20.10 20-4.06 Valves ................................................................................................................... 20.10 20-4.06 .A Valve Boxes ...................................................................................................... 20.10 20-4.06.B Quick Coupling Valve ......................................................................................... 20.11 20-4.07 Backflow Preventers.............................................................................................. 20.12 20-4.08 Flow Sensor .......................................................................................................... 20.12 20-4.09 Pressure Testing ................................................................................................... 20.11 20-4.10 Repairs and Coverage .......................................................................................... 20.12 20-4.11 Irrigation Audit ....................................................................................................... 20.12

20-5 PLANTING.................................................................................................................. 20.13 20-5.01 Pesticides .............................................................................................................. 20.13 20-5.02 Preparing Planting Areas ...................................................................................... 20.13 20-5.03 Planting ................................................................................................................. 20.14 20-5.03.A Preperation for Ground Covers .......................................................................... 20.15 20-5.03.B Preperation for Trees and Shrubs ...................................................................... 20.16 20-5.03.C Preperation for Turf ............................................................................................ 20.16

20-5.04 Watering .............................................................................................................. 20.17 20-5.05 Plant Replacement ............................................................................................... 20.17 20-5.06 Inspection for Plant Establishment Period ............................................................ 20.18 20-5.07 Inspection Prior to Final Acceptance of Landscape ............................................... 20.19 20-5.08 Final Acceptance of Landscape ............................................................................ 20.19

20-6 RECORD DRAWINGS AND CONTROLLER CHARTS ............................................... 20.20 20-7 MEASUREMENT AND PAYMENT ................................................................................. 20.21

Section 20 - Landscaping

20.1

SECTION 20 -LANDSCAPING

20-1 GENERAL

Landscaping work shall consist of performing roadway planting, park landscaping, irrigation installation, and other work necessary for improving the appearance of the roadside and park facilities, as shown on the Plans and in accordance with these Specifications.

20-2 MATERIALS

Landscaping materials must conform to the requirements in Section 50-43, “Landscaping

Materials”, and these Specifications.

20-2.01 Root Control Barrier The Contractor shall install 24-inch tree root control barrier along the interior perimeter of all planter tree wells, medians, and planters, as shown on the landscape plans and details. Root control barrier shall be in accordance with Section 50-43.14, “Root Control Barrier,” of the Standard Construction Specifications. Root control barrier must be installed prior to topsoil placement or by means of trenching against existing surfaces. Panels must be installed vertical in planter, flush against edge of pavement or header board. Top of barrier must be one-inch (1”) higher than planter finish grade. Top of barrier must be covered from view by mulch layer. Barrier deflectors must face inward towards root ball. Root control panels must provide a continuous barrier along the perimeter of each median planter, tree well, sidewalk, or other hardscape surface. Contractor must take measures to prevent separation, sagging, warping and damage to root barriers during construction.

Root barrier panels not installed properly are to be excavated and re-installed. Root barrier damaged during construction shall be replaced by the Contractor as necessary or as directed by the Engineer.

20-2.02 Topsoil

Topsoil shall be import topsoil from an approved commercial source in accordance with Section 50-43.01, “Topsoil,” of the Standard Construction Specifications. Imported topsoil shall be placed in excavated planters and provided to replace lost topsoil in existing planters affected by grading and construction. Imported topsoil quantities shall reflect the amount of backfill needed to achieve finish grade(s) indicated on the Plans and shall also allow for compaction and settling of topsoil during installation.

Topsoil shall be placed and spread to the line and grade as shown on the Plans or as directed by the Agency. Prior to placement of topsoil, the Contractor shall remove and dispose of all rocks greater than one-inch (1”) in diameter, weeds, trash, construction debris, and other deleterious material from the excavated area. The bottom of excavated planters shall be scarified to a depth indicated in the Plans or Special Provisions. Topsoil shall be placed in approximately one foot (1’) lifts and compacted to eighty percent (80%) relative compaction (refer to section 5), unless otherwise indicated in the Special Provisions. Topsoil in tree or shrub pits shall be lightly tamped by hand so as to form a firm setting for the plant, but not hinder growth. Mechanical tamping will not be permitted.

After spreading the topsoil, any extraneous or unacceptable material not previously removed must be raked off and removed from the topsoil area. Spreading and compacting must be completed in such a manner that seeding, sodding, or planting can proceed without additional grading.

Immediately before planting, the topsoil must be cultivated and raked to provide a uniformly smooth, firm, friable, fine textured finished surface. No grading equipment will be permitted on the topsoil after the area has been finish graded and prepared for planting.

20.2

20-2.03 Soil Amendment Soil amendment must be uniformly spread at the rate specified and thoroughly incorporated with a rotary cultivator to obtain a homogeneously blended soil six inches (6”) in depth, unless specified otherwise in the Special Provisions.

20-2.04 Liquid Green Dye Liquid green dye used in erosion control and hydroseeding work must be 48-hour colorfast, applied at the rate of two (2) quarts per acre, unless otherwise specified in the Special Provisions.

20-2.05 Mulch Mulch must be top dressed, where specified, to a minimum depth of three inches (3”) over

Section soil level. Ground cover areas planted from containers less than one-gallon in size may receive a minimum depth of two-inches (2”) of mulch. Do not bury or cover over plant material with mulch layer. Taper mulch away from the crowns of all newly planted and existing trees.

Following the installation of plants, but prior to spreading mulch layer, the Contractor shall apply pre-emergent weed control to planting areas that conforms to Section 50-43.05, “Pre-emergent Herbicide,” of these Specifications. The Contractor shall follow the manufacturer’s recommendations for proper application rate, precautions, and safety measures and apply with a properly calibrated applicator that will distribute granules uniformly on the surface of planting area.

After application, remove all excess granules from plant foliage. Do not apply to wet foliage.

20-2.06 Header Boards Header boards must conform to Section 50-43.12, "Lumber", of these Specifications and must be installed in accordance with Standard Drawing L-37.

Header board stakes must be of the size and shape shown on the Plans. Each stake must be driven flush with the top edge of the header board and the stake top must be beveled away from the header board on a forty-five-degree (45°) angle. Stakes must be at four feet (4’) on center along the length of the header board. Stakes must be attached to header boards with a minimum of two

(2) 12-penny hot-dip galvanized common nails per stake.

Where asphalt concrete or portland cement concrete surfacing must be removed to permit the installation of header boards, and no joint exists between the surfacing to be removed and surfacing to remain in place, the surfacing must be cut in a neat line to a minimum depth of 0.17-foot with a power driven saw before the surfacing is removed.

20-3 EROSION CONTROL

Erosion control materials must conform to Section 50-43, “Landscaping Materials”, the Special

Provisions, and these Specifications.

20-3.01 Seeding Application Seeding application must conform to the Special Provisions and these Specifications.

If the Contractor elects to hydroseed, a minimum of fifteen hundred (1,500) pounds of fiber per acre must be mixed and applied with the seed, and fertilizer (if required) may be mixed with the seed and fiber and applied in the hydroseeding operation.

The Contractor must scarify to a depth of six inches (6”) and uniformly fine grade so that proper drainage of the entire ground cover is assured. All rocks, soil lumps, and other deleterious materials larger than one inch (1”) must be removed and the area raked smooth.

The Contractor must avoid any compaction of the soils after treatment, and must not permit traffic over such areas. In case of such compaction, the areas must be recultivated by the Contractor, at the Contractor’s expense.

Areas to be treated for weed control must be treated as shown or specified in the Contract .

Equipment for hydroseeding application must have a built-in agitation system with an operating

20.3 capacity sufficient to agitate, suspend, and homogeneously mix a slurry of fiber, fertilizer, seed, and water. The discharge line must provide even distribution of the slurry on the slopes to be seeded.

The slurry tank must have a minimum capacity of one thousand (1,000) gallons.

The slurry preparation must begin by adding water to the tank. When the water level has reached the height of the agitator shaft, the stabilizing agent must be added. Seed and fertilizer must then be added, followed by the fiber mulch. The combined materials must then be uniformly blended prior to application. Spraying must commence within two (2) hours after the tank is full.

The Contractor must perform hydroseeding during calm wind conditions. The operator must spray the slopes with a uniform, visible coat, using the color of the mulch as a guide. The slurry must be applied in a sweeping motion to allow the fibers to build on each other, until a good coat is achieved. Unless otherwise specified in the Special Provisions, the application rates must be:

Material Application Rate per Acre Mulch 1,500 pounds 6-20-20 fertilizer 400 pounds Seed Mix See Plans or Special Provisions Liquid Green Dye 2 quarts Stabilizing Emulsion As approved by the Agency

20-3.02 Measurement and Payment The quantity of erosion control to be paid for by the square foot, square yard, acre or as designated in the Contract will be calculated on the basis of actual or computed slope measurements.

The price paid per square foot, square yard, or acre includes compensation for furnishing all labor, materials, tools, equipment, and incidentals and for doing all the work involved in performing erosion control work and hydroseeding, complete in place, including site preparation, hydroseeding application, and clean-up as shown on or specified in the Contract, as specified in these Specifications, and as directed by the Agency.

20-4 IRRIGATION SYSTEMS

Irrigation system materials must be as specified in Section 50-43, “Landscaping Materials” of these Specifications.

Recycled, reclaimed, and non-potable irrigation systems must also comply with the requirements of Section 41-22, “Recycled Water,” of these Specifications.

This Section 20-4 shall not apply to any portion of a water system upstream of a Water Utility water meter. Refer to Section 41, “Water Distribution Systems,” of these Specifications for requirements for water meters and the upstream water system.

20-4.01 Maintain Existing Water Supply The Contractor must notify the Agency and the property owner, manager, or tenant at least forty-eight (48) hours prior to shutting off the water supply to any portion of an existing irrigation system.

The Agency and the property owner, manager, or tenant must also be notified when the water supply is returned to said portion of the irrigation system.

Where work is performed on an existing irrigation system, the system must be checked by the Contractor for proper operation after the work is completed and any malfunctions resulting from the Contractor's operations must be corrected at the Contractor's expense. If the work will interrupt the water supply for more than twenty-four (24) hours, the Contractor must water existing landscaping, including that being maintained by Agency landscape maintenance forces, in the area irrigated from that water supply as often as necessary to maintain healthy plant growth. The watering will be at the Contractor’s expense. At the option of the Contractor, temporary connections to an operational existing irrigation system may be made as approved by the Agency until the interrupted water supply

20.4 has been restored.

20-4.02 Trenching in Existing Landscape

Attention is directed to Section 10-13, “Protection of Existing Trees,” and 15-1.02, “Trees, Shrubs, Ground Cover, and Lawn,” of these Specifications. While trenching for new irrigation facilities is performed in areas planted with existing trees or shrubs, the trenching alignment shall be adjusted as necessary to avoid damage to such trees or shrubs and their root systems. Alternate trenching methods such as hand digging, direct boring, or use of an air-spade may be used if indicated on the Plans, if directed by a certified arborist, and/or if directed by the Engineer.

Where trenching for new irrigation facilities is performed in existing ground cover or turf, sufficient plant material must be removed to permit the proper installation of such facilities, but in no case shall the removal width exceed five feet (5’). All turf repair or ground cover replacement planting must be performed before the start of the plant establishment period, or at least fourteen (14) Calendar Days prior to the acceptance of the Contract if there is no plant establishment period.

20-4.03 Electrical Service for Electric Automatic Irrigation System

Electrical service for electric automatic irrigation systems shall conform to Section 49, “Signals, Lighting and Electrical Systems,” of these Specifications and Standard Drawing 5-9.

20-4.03A Components

Electrical components for electric automatic irrigation systems must include irrigation controllers with weatherproof enclosures; remote control valves; valve boxes; pull boxes; conductors between controllers, pumps and valves; moisture sensors; rain/weather sensors; and all appurtenances, incidentals, and accessories required for proper installation and operation of the electrical portions of such systems.

Electrical components requiring modifications to conform to the specified requirements must have such modifications made by the manufacturer before shipment to the project. Components must also include the electric service pedestal for the irrigation controller.

20-4.03B Controllers Controllers shall conform to Section 50-43.21, “Automatic Irrigation Controllers,” of these

Specifications and shall be installed in accordance with Standard Drawings L-21 (conventional) and L-22 (two-wire).

Controllers and controller enclosures shall be the type and model specified in the Plans and Special Provisions.

All wiring to and from the controller must be through color-coded plugs and sockets. The Contractor shall mount controller onto approved panel backing within the pedestal enclosure and connect control wires to an intermediate terminal strip. A bare copper wire welded to a ground rod or ground plate shall be connected to the controller, as called out on the Plans and Special Provisions.

All controller locations are essentially diagrammatic and must be confirmed in the field prior to installation by the Contractor with the Agency representative.

All necessary wiring from the controller to the remote control valves, master valve and sensors, as well as a controller hot test, and all necessary programming shall be included. Controller installation shall include grounding as shown on the Plans. All components shall be new, and factory manufactured using the latest upgrades and versions of software. Installation shall include GFI outlet/power switch and terminals and Northern Technologies 110-volt surge protector.

A complete maintenance and operations manual for each type of controller installed must be submitted to the Agency.

The controller housing enclosure must house the irrigation controller and moisture sensor control panel (if specified) and must be installed according to the Standard Drawings

20.5

20-4.03C Control Wire, Electrical Conduit and Pull Boxes

Control wire must conform to Section 50-43.34, “Irrigation Control Wires”, of these Specifications. Unless otherwise stated in the Special Provisions, the color of the control wire from the controller must be red, the common wire must be white, all spare wires must be yellow, and the wires from the master valve must be orange. Pull boxes must conform to Section 50- 43.35, “Pull Boxes”, of these Specifications.

Where control wires are installed in the same trench or opening as irrigation pipe, such control wires must be placed at the same depth or below the pipe.

Sharp bends or kinks in the control wires will not be permitted. Control wires shall be unreeled in place alongside or in the trench and shall be carefully placed along the bottom of the trench and installed in conduit when under pavement. Open conduit ends shall be filled with expanding foam or electricians putty after control wiring is placed and inspected prior to backfilling of trenches. Under no condition shall the cable be unreeled and pulled into the trench from one end. The Contractor shall sweep conduit into pull box.

Not less than one foot (1’) of cable slack must be left on each side of all splices at all points where cable is connected to field equipment. The slack cable must be placed in the trench in a series of “S” curves.

Conductors must be run continuous without splices from controller enclosure to the valve boxes.

Splices must be made only in pull boxes or valve boxes. Splices must be clamped and sealed with waterproof connectors. When splices are necessary, the wire color must not change along the wire run. Conductors from controllers to valves must be wrapped together with electrical tape at ten-foot (10') intervals. An eighteen-inch (18”) wire loop must be provided at each valve.

All pull boxes must be made of reinforced concrete with lids marked ‘irrigation’. Unless otherwise stated in the Special Provisions, pull boxes set in the roadway must be traffic rated with a steel cover. Pull boxes must be installed at the following locations:

1. At all control wire splices, except splices made in valve boxes.

2. At intervals not to exceed two hundred fifty feet (250’) along any low voltage, neutral and control wire runs. Valve boxes installed along a control wire run must not be considered as pull boxes in determining the spacing.

3. Within five feet (5’) of irrigation controllers or within five feet (5’) of cabinets housing one (1) or more controllers.

4. At ends of electrical conduits.

5. At other locations shown on the Plans.

When approved by the Agency, the Contractor may install additional pull boxes to facilitate the work. Additional pull boxes installed for the Contractor’s convenience will be at the Contractor’s expense.

The tops of all pull boxes must be flush with the surrounding finished grade.

20-4.03.D Testing Field tests must be performed by the Contractor to demonstrate that electrical components of the irrigation systems function as specified and the system is operational.

A field test must be satisfactorily completed prior to the start of planting, the plant establishment period, and Final Acceptance, unless otherwise authorized by the Agency. Field test must be done to determine that all sprinklers function according to manufacturer’s data. The Contractor must replace any sprinklers/emitters not functioning as specified; otherwise, correct system to provide satisfactory performance and retest.

The controller must be tested in the automatic, semi-automatic, and manual operation modes.

20.6

20-4.04 Installation

20-4.04.A General

Foreign material must be prevented from entering the irrigation system during installation.

Immediately prior to assembling, all pipes, valves, and fittings must be cleaned. All unattached ends of pipe, fittings, and valves must be plugged or capped pending attachment of additional pipe or fittings. All lines must be thoroughly flushed out prior to attachment of sprinklers, emitters, and other terminal fittings. Repair of irrigation systems must be made within one (1) Calendar Day after a malfunction or damage to any portion of the system has occurred, unless otherwise directed by the Agency.

The system must completely, efficiently, and evenly irrigate all areas, and must be left ready for operation to the satisfaction of the Agency.

The Contractor shall install the specified pipe, valves, fittings, wiring, switches, controls, and appurtenances shown on the Plans. The irrigation system as shown on the Plans, except for sprinkler locations, is diagrammatic. The Agency will, or direct the Contractor to, determine specific locations.

The Contractor must provide, at the work site, temporary facilities required for the safe and proper storage of materials, tools, etc. These facilities must be constructed only in locations approved by the Agency or as designated on the Plans and must not interfere with the work of any other contractor. At such times as the Contractor’s facilities interfere with the proper installation and completion of the Work, they must be removed by the Contractor, at the Contractor’s expense, within three (3) Calendar Days after having been notified by the Agency that such removal is necessary.

20-4.04.B Irrigation Sleeving Sleeving for water line crossovers and sprinkler control crossovers shall conform to Section 43-

19, “Irrigation Sleeve Conduit,” of these Specifications and shall be installed in accordance with Standard Drawing L-24.

Control wire, water supply line or lateral line pipe crossovers must be installed in conduits or as shown on the Plans. Tracer wire shall be installed at crossings for all pipe sleeves that are installed under roadways. The Contractor shall use solid strand copper wire. PVC sleeves of various sizes indicated on the Plans under pavement shall be Schedule 40, unless otherwise noted. Conduit shall conform to Section 50-43.19, “Irrigation Sleeve Conduit,” of these Specifications. After completing conduit backfill and prior to performing the pressure test on a water line crossover, the Contractor must demonstrate that the water line crossover can be moved longitudinally within the conduit.

Where water line crossovers are installed for future use, the ends of such crossovers must be capped immediately after testing.

Conduits must extend a minimum of twelve inches (12”) beyond edge of paving unless otherwise noted on the Plans. At perpendicular crossings, the Contractor must install a No. 5 pull box at each end of the conduit, with eighteen-inch (18”) wire loop.

The location of each conduit must be designated by cementing a Type A pavement marker to the paved shoulder near each end and over the centerline of the conduit using a standard set type adhesive. Type A pavement markers and adhesive must conform to the provisions in the State Specifications and must not conflict with existing markers within the project site.

20-4.04.C Water Line Crossovers Water line crossovers are supply line or lateral line pipes installed in conduits.

Water line crossovers must be polyvinyl chloride (PVC) plastic pipe, Class 315 or Schedule 40, with a minimum pressure rating of three hundred fifteen (315) pounds per square inch and must be sized as shown or specified in the Contract.

After completing conduit backfill and prior to performing the pressure test on a water line crossover, the Contractor must demonstrate that the water line crossover can be moved longitudinally within the conduit. The water line crossover must then be positioned to extend at least

20.7 one (1) foot beyond each end of the conduit.

Where water line crossovers are installed for future use, the ends of such crossovers must be capped immediately after testing.

20-4.04.D Trenching and Backfilling Trenching and backfilling must be in accordance with Standard Drawing L-23. Trenches must be excavated only as far in advance of pipe laying as is permitted by the Agency. Excavated material must be piled in a manner that will not endanger the Work and will avoid obstructing sidewalks and driveways. Open trenches and piles of dirt must be marked and lighted as to provide safety to all pedestrians and to vehicular traffic.

Rock, pavement, and other debris encountered during trenching operation must be removed and disposed of outside of the project limits at the Contractor's expense. The size and quantity of material to be disposed of will be determined by the Agency.

Trenches for plastic pipe must be smooth and free of jagged rubble or sharp objects which will cause bending stress and uneven weight distribution to pipes, conduits and conductors during backfilling operations. Trenches for solvent-cemented plastic pipe supply lines must be of sufficient width to permit snaking of the pipe. Other trenches must not be excavated wider than necessary for the proper installation of pipe supply lines.

Except as otherwise specified in this Section, backfill material must be material excavated from the trenches, compacted by an Agency-approved method other than ponding or jetting with water until the backfill material, after settlement, is level with the surrounding soil. When any backfilled area has settled excessively, said area must be refilled and compacted by the Contractor at the Contractor’s expense, including furnishing, placing, and compacting the fill material.

Trenches for pipe and electrical conductors may be excavated manually or with mechanical trenching equipment. Trenching equipment must be essentially vertical so that a minimum of surface is disturbed. Blades of road graders must not be used to excavate trenches. Trenches for pipe must be excavated to the depths shown on the Plans.

Pipe must have a firm, uniform bearing for the entire length of each pipe line. Wedging or blocking of pipe will not be permitted.

Trenches must not be excessively wet and must not contain pools of water during backfilling operations.

Extreme care must be exercised by the Contractor while backfilling. Any materials or equipment damaged while backfilling must be repaired or replaced by the Contractor as directed by the Agency, at no cost to the Agency.

Trenching and backfilling for irrigation conduit and sleeves in paved surfaces shall be made by earth saw trenching in accordance with the Plans and Section 49-2.02.A, “Earth Saw Trenching,” of these Specifications.

20-4.05 Pipe

Plastic pipe supply lines, plastic pipe irrigation lines, and fittings must be installed in accordance with the pipe and fitting manufacturers' printed instructions and these Specifications. Irrigation system trenching must be in accordance with Standard Drawing L-23.

PVC pipe one and one-half inches (1-1/2”) or less in diameter must be cut with "PVC cutters”, not by sawing. Pipe greater than one and one-half inches (1-1/2”) in diameter must be cut with a fine-toothed hacksaw and any burrs must be removed. All pipe must be cut straight and true.

The outside surface of the pipe and the inside surface of the fittings must be wiped with a clean cloth to remove all dirt and moisture before the solvent cement solution is applied. Solvent cement welding must be done in accordance with the printed instructions of the solvent manufacturer.

The male portion of each threaded plastic pipe and fitting connection must be wrapped with at least two (2) layers of approved pipe thread sealant tape. Pipe from the service connection through a backflow preventer assembly to plastic pipe supply lines must be copper, bronze, or as shown on the Plans, and must be wrapped with six (6) mil plastic tape.

Plastic pipe supply lines must be installed not less than twenty-four inches (24”) below the

20.8 finished grade, measured from the top of pipe, unless otherwise shown or specified in the Contract.

Thrust blocks shall be used on all plastic supply lines and shall conform to Section 41-6, “Thrust Blocks and Restrained Joints,” and Standard Drawing 8-3A, “Thrust Block Bearing Area,” of these Specifications.

Plastic lateral lines shall be installed not less than twelve inches (12”) below the finished grade, measured from the top of pipe and not less than twenty-four (24”) when installed under a root control barrier.

Valves and fittings must be designed for and must meet the requirements for service at an operating pressure of one hundred fifty pounds per square inch (150 psi), unless otherwise specified.

Valves and fittings must have connections compatible with the type of pipe joint selected by the Contractor. If mechanical joints or slip-type joints are used, the Contractor must furnish and install necessary Portland cement concrete thrust blocks as specified by the Agency.

Guarantee must cover workmanship of materials from the plastic pipe manufacturer for all plastic pipe and fittings. Main irrigation lines must be Schedule 40 for lines two-inches (2”) and smaller and Class 315 PVC for lines two-and-one-half to three-inches, and Schedule 40 PVC rubber ring and gasket for lines four-inches and larger. Lateral irrigation lines must be Schedule 40 PVC. PVC pipe must conform to CS 256 and ASTM Designation: D 2241.

Pipe fittings must be of the same material as pipe where applicable and recommended by the pipe manufacturer for the particular type of pipe to which they are to be connected and must conform to the following specifications.

All slip-joint PVC fittings must be Schedule 40. All Schedule 40 PVC couplings four inches (4”) in diameter or larger must be a minimum of seven inches (7”) in length.

The Contractor must use only the solvent supplied and recommended by the manufacturer to attach PVC pipe and pipe joints. The pipe and fittings must be thoroughly cleaned of dirt, dust, and moisture before applying solvent.

The Contractor must make solvent weld joints with non-synthetic bristle brush in the following sequence:

Apply a liberal, even coat of purple PVC primer to the pipe and fitting immediately before applying the solvent.

Apply a liberal even coat of solvent to the inside of the fitting and then to the outside of the pipe, making sure that the coated area is equal to the depth of the fitting socket.

Insert the pipe quickly into the fitting and turn the pipe approximately one-quarter (1/4) turn to distribute the solvent and remove air bubbles. Hold the joint for approximately fifteen (15) seconds so the fitting does not push off the pipe.

Use a clean rag and wipe off all excess solvent.

To prevent disturbing the last completed joint, the pipe must not be twisted when making subsequent joints.

Allow at least fifteen (15) minutes setup time for each welded joint before moving.

On plastic to steel connections, the Contractor must work the steel connections first. For all PVC threaded connections use thread sealing paste with virgin Teflon. In no event must an oil base joint compound be used on a PVC joint.

The Contractor must exercise care in handling, loading, unloading, and storing plastic pipe and fittings. All plastic pipe and fittings must be stored under cover before using and must be transported in a vehicle that can support the entire length of pipe. The Agency will inspect all pipe before it is laid and will reject any section that is damaged or is found to be defective to a degree which will materially affect function and service of pipe. Any section of pipe that has been bent, dented, or damaged must be discarded until said section of pipe is cut out and rejoined with a coupling.

The Contractor must install the pipe to line and grade, as staked by the Agency. The Contractor's facilities for lowering the pipe into the trench must be such that neither the pipe nor the trench will be damaged.

All pipes must be assembled free from dirt, pipe scale, and burrs. Each section of lateral pipe

20.9 must be flushed out before sprinkler heads or emitters are attached.

Plastic pipe must not be laid when there is water in the trench.

20-4.05.A Subsurface Dripperline Subsurface dripperline shall conform to Section 50-43.18, “Subsurface Dripperline,” of these

Specifications and shall be installed in accordance with Standard Drawings L-16, L-17, and L-18.

Dripperlines must be installed four inches (4”) below finish grade unless otherwise specified on the Plans or in the Special Provisions. The Contractor shall use corresponding manufacturer’s barbed fittings, flush valve, and other in-line components for dripperline installation and shall not mix products, unless otherwise approved by the Engineer. Dripperlines must be installed at the spacing distance specified on the Plans or in the Special Provisions. Install dripperlines with orifices facing down and as shown on the Plans.

Dripperlines must be installed using barbed fittings only. Subsurface dripperline systems must be installed with flush valves and air vacuum relief valves, as recommended by the manufacturer.

The Contractor shall install an in-line isolation ball valve along the lateral piping to allow separation of horizontal dripperline areas from the dedicated tree deep watering pipes as shown on Plans. The Contractor shall install isolation ball valves using PVC slip adaptors at each end of lateral pipe. Ball valve shall be the same size as the lateral pipeline.

20-4.05.B Air Vacuum Relief Valve

Air vacuum relief valve must conform to Section 50-43.31, “Air Vacuum Relief Valve”, of these Specifications and must be installed in accordance with Standard Drawing L-10.

Air vacuum relief valve must be installed in-line with a subsurface dripperline at the highest point of the system.

20-4.05.C Flush Valve

Flush valve must conform to Section 50-43.32, “Flush Valve Assembly”, of these Specifications and must be installed in accordance with Standard Drawing L-9.

Flush valves must be installed at the end of a subsurface dripperline system as shown on the Plans and at a low point of planter, as recommended by the manufacturer. Install a minimum of one flush valve on each circuit for every 15 gallons per minute (GPM) of flow. Installation must include a plastic ball valve before the flush valve and a thirty-inch (30”) minimum length of flexible one-half inch (1/2”) polyethylene tubing coiled within the valve box, for the purpose of periodic maintenance.

Flush valves must be installed at the end of tubing and be able to be extended outside of valve box for manual flushing.

20-4.05.D Sprinklers and Emitters Sprinklers and emitters must conform to Section 50-43.20, “Sprinklers and Emitters”, of these

Specifications and must be installed in accordance with the corresponding details in the Standard Drawings.

Prior to installing sprinkler nozzles, irrigation heads for each valve shall be flushed to remove debris from the lateral lines. The Contractor shall strictly limit the flush time to the amount of water needed to clear the lateral lines and to minimize run-off.

The Contractor shall operate each valve zone and make adjustments to individual heads, nozzles, and/or valve pressure regulators in order to modify radii, arc, and patterns to minimize overspray and runoff onto pavement and existing native oak tree driplines.

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20-4.05.E Deep Watering Pipe

The Contractor shall furnish and install deep watering pipe with dripperline system at each tree location as shown on the Plans. Deep watering pipes shall be perforated Schedule 40 PVC in accordance with ASTM D2729 and Sections 50-43.17.B, “Plastic Pipe,” 50-16, “Clean Crushed Rock,” and Standard Detail L-20 of the these Specifications, and as shown on the Plans and as specified on the irrigation legend.

The Contractor shall install deep watering pipes with dripline on sides of tree root ball as shown on the Plans or as otherwise directed by the Engineer. The Contractor shall place deep watering pipes at edge of plant pit, and within the watering basin called for in the tree staking Standard Drawing L-1.

The Contractor shall wrap perforated pipe with an approved non-woven permeable filter fabric. The Contractor shall fill pipe with clean three-quarter inch (¾”) drain rock. The ends of PVC pipe shall be cut straight, and edges sanded smooth. The Contractor shall attach slotted PVC grate to top of deep watering pipe with two (2) three-sixteenth inch (3/16”) stainless steel screws drilled into opposite sides of pipe. Slotted grate shall be secured tight, flush and level with top of pipe. The top of grate shall not be visible through the top of mulch layer.

20-4.06 Valves

Irrigation control valves, master valves, and shut-off valves shall be of the type shown on the Plans and shall conform to Section 50-43.23, “Control Valves,” 50-43.30, “Gate Valves,” and Standard Drawings L-3, L-4, and L-7 of these Specifications.

The Contractor shall provide and install valves as shown on the Plans and as required for the proper control of the piping systems in which they are incorporated. Main line shut-off valves shall be gate valves.

The Contractor shall install pressure gauges for ease of view into a threaded PVC fitting with Teflon tape. Glue shall not be used. All adaptor fittings shall be Schedule 80.

Where a remote control valve is shown on the Plans at the edge of turf and shrub areas, it shall be placed in the shrub area. Valves shall be placed in groupings for ease of maintenance.

A control valve functioning as a master valve shall be installed downstream of the backflow preventer and wired to a dedicated master valve station on the controller. Follow the plan requirements to maintain a continuous pipe run between the master valve and the associated flow sensor.

20-4.06.A Valve Boxes Irrigation valve boxes shall by of the type shown on the Plans or as specified in the Special

Provisions and shall conform to Section 50-43.25, “Valve Boxes,” of these Specifications and installed in accordance with the corresponding valve detail in the Standard Drawings.

The top of valve boxes shall be placed slightly above finish grade and flush with the mulch layer in planter areas. Valve box edge shall be installed approximately 12-inches from adjacent sidewalks and not installed to conflict with trees, street light posts, or other utilities.

Valve boxes that contain remote control valves shall be identified on the top surface of the valve box covers with the appropriate letter and number of the corresponding controller station number as shown on the Plans.

Valve boxes shall be identified with labels attached to the covers that contain the appropriate abbreviation or station number. Quick coupling valves shall be labeled “QC,” gate valves shall be labeled “GV,” master valve shall be labeled “MV,” and flow sensor shall be labeled “FS.”

In addition to the box lid label, the Contractor shall secure a valve tag with the corresponding station number to each remote control valve assembly.

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20-4.06.B Quick Coupling Valve

Quick coupling valves must conform to Section 50-43.22, “Quick Coupling Valves”, of these Specifications and must be installed in accordance with Standard Drawing L-6. Quick coupling valves must be installed with Sch. 80 PVC fittings and swing joint assemblies.

20-4.07 Backflow Preventers

Backflow preventers must conform to Section 50-43.26, “Backflow Preventers”, of these Specifications and must be installed in accordance with Standard Drawing 8-8A or 8-8B, unless otherwise specified. Backflow preventer assemblies must consist of backflow preventer, wye strainer (when specified), gate valves, pipe fittings, portland cement concrete supports, and portland cement concrete pad for the assembly, and must conform to the details shown on the Plans, these Specifications, and the Special Provisions.

Installation of backflow preventer assemblies must conform to Agency codes and ordinances regarding cross connection control installation, must be UL listed and approved by the Research Foundation for Cross Connection Control, University of Southern California. Special attention must be given to the minimum and maximum heights of assemblies.

The bottom of backflow preventers must be installed twelve inches (12”) above finished grade or concrete pad. Exposed top surfaces of concrete foundations and pads must have a medium broom-finish applied parallel to the long dimension of foundations and pads. Backflow preventer assembly must be tested by a certified backflow device tester prior to initial usage and operation of the system.

Backflow preventer installations must include freeze protection in the form of a backflow device blanket cover or insulated enclosure, as indicated on the plans.

20-4.08 Flow Sensor

Flow sensor shall conform to Section 50-43.24, “Flow Sensor,” and Standard Drawing L-8 of these Specifications. Flow sensor work includes the installation of the sensor components downstream of the backflow preventer and master valve along a continuous length of pipe at a minimum distance shown on the Standard Drawing or as required by the manufacturer, whichever is longer.

Installation using conventional wiring shall include running three (3) #14 sensor wires: one red, one white (common), and one yellow spare, from the flow sensor to the controller. A two-wire path from the flow sensor to the controller shall be installed as recommended by the flow sensor and two-wire system manufacturers.

20-4.09 Pressure Testing Except for non-rigid pipelines and lateral irrigation lines, pressure testing for leakage must be performed on all supply lines installed by the Contractor. Pipelines must be tested in place and all open ends of the pipeline and fittings must be plugged or capped prior to testing.

The Contractor must notify the Agency at least twenty-four (24) hours prior to performing any pressure test. Pressure tests must be performed only between the hours of 8:00 a.m. and 5:00 p.m.

except that no pressure tests shall be made on Saturdays, Sundays, or legal holidays, unless otherwise approved in writing by the Agency. Each pressure test must be observed by the Agency.

Prior to pressure testing, pipes shall be flushed to remove all debris, rocks, and other deleterious particles.

Pipelines to be tested must be filled with water, and a pressure gauge must be connected to the pipeline. The pipe must then be placed under a pressure of one hundred twenty-five pounds per square inch (125 psi) (except as otherwise specified below) by air or water pressure, after which the source of pressure must be cut off, leaving the line under the required pressure.

The pressure gauge must be calibrated from zero (0) to two hundred (200) pounds per square inch (psi) in five (5) pound increments and must be accurate within a tolerance of two (2) pounds.

20.12

The Contractor must provide the necessary pump and equipment required for this test.

The pipeline must be tested under the required pressure for a period of one (1) hour. The pressure gauge must remain in place until each test period has been completed. Leaks that develop in the tested portion of the system must be located and repaired after each test period when a drop of more than two (2) pounds is indicated by the pressure gauge when testing pipe over one hundred feet (100’) in length. There must be no pressure drop permitted when testing pipe from one foot (1’) to one hundred feet (100’) in length. After such leaks have been repaired, the one-hour pressure test must be repeated and additional repairs made until there is no drop in pressure for pipe lengths up to one hundred feet (100’), or the drop in pressure is two pounds per square inch (2 psi) or less for pipe lengths over one hundred feet (100’). If testing by means of water pressure, air must be expelled from the pipe prior to testing.

Tests on pressure lines must be completed prior to backfilling; however, sufficient backfill must be placed in trenches between fittings to insure the stability of the line under pressure. In all cases, fittings and couplings must be open to visual inspection for the full period of the test.

No testing shall be done until the last solvent welded joint has had twenty-four (24) hours to cure.

Where any section of the pipe system is provided with a concrete thrust block, the test must not be made until at least five (5) Calendar Days have passed after the concrete thrust block was installed. If higher early-strength cement is used in the concrete thrust block, the test must not be made until at least two (2) Calendar Days have elapsed.

Contractor must disinfect potable water lines according to AWWA standards.

20-4.10 Repairs and Coverage All leaks that develop and all defective material in any portion of the irrigation system installed by the Contractor must be repaired or replaced by the Contractor.

The entire system must be checked and, if necessary, adjusted for uniform and complete coverage after installing the sprinklers. All emitters must be checked for proper operation and, if necessary, cleaned and replaced.

The risers for sprinklers on slopes must be set approximately perpendicular to the slope. Each series of sprinklers must be installed, and test operated. Nozzles of all sprinklers and bubblers must be adjusted for proper rate of flow and coverage.