Article 1 — Description
Furnish and install an irrigation system as shown on the plans or as directed.
Article 2 — Materials
Unless otherwise shown on the plans, use materials that meet the following:
2.1 Irrigation Pipe . Use polyvinyl chloride (PVC) pipe meeting ASTM D2241, SDR 13.5, SDR 17, SDR 21; or
ASTM D1785, Sc hedule 40.
2.2 Fittings . Furnish fittings as shown on the plans. PVC fittings must be in accordance with ASTM D2466.
2.3 Encasement Pipe. Use PVC pipe in accordance with ASTM D1785, Schedule 40, with an inside diameter at
least 1 in. larger than the outside diameter of the irrigation pipe, unless otherwise shown on the plans.
2.4 Low-Voltage Wire . Use minimum 14- gauge UL- approved wire for direct burial.
2.5 Bentonite Slurry . Use a viscous mixture of commercial bentonite and fresh water containing 2– 8% bentonite
by weight.
2.6 Accessories. Use valves, sprinkler heads, and controllers that meet the requirements shown on the plans.
Use backflow preventers in conformance with the controlling water utility authority.
2.7 Electrical Service. Use materials meeting the requirements of Section 170.3. 2., “Electrical Service,” for
installations requiring over 100 V.
Article 3 — Construction
Perform irrigation system work under the supervision of a person possessing an irrigator’s license issued by TCEQ. Provide documentation of this license. Follow the codes of the utility service owner for irrigation system design, water and electrical connection, and service. Coordinate irrigation system installation with plant installation, when plant installation is specified, to ensure that watering requirements are met. Prevent damage to vegetation, slopes, utilities, structures, and other amenities. Repair any damage within the right of way caused by the Contractor. Perform the following activities as required.
3.1 Design . Provide an irrigation system designed by an irrigator licensed by TCEQ. Provide a system as shown
on the plans and in conformance with utility service owner and TCEQ requirements.
3.2 Electrical Service. Construct installations requiring more than 100V as shown on the plans and in
accordance with the following . Item 618, “Conduit” Item 620, “Electrical Conductors” Special Specification, “Duct Cable” Item 624, “Ground Boxes” Item 628, “Electrical Services .” 144 3.3. Water Service. Construct and maintain installations shown on the plans and in conformance with the utility service owner requirements.
3.4 Excavation and Trenching. Excavate and trench deep enough to provide for at least 12 in. of soil cover for
all lines , or as shown on the plans. Use common trenches for irrigation lines and wire runs where feasible. Protect trenches and boring pits less than 5 ft. deep using approved methods. Protect trenches and boring pits 5 ft. deep or deeper in accordance with Item 402, “Trench Excavation Protection,” and Item 403, “Temporary Special Shoring.”
3.5 Boring. Bore at the locations shown on the plans or as directed. Avoid weakening or damaging roadways or
other facilities. Bore the lengths in one direction only. Maintain horizontal and vertical alignment to an accuracy of 1 in. in 10 ft. Use water or other approved fluids for boring operations only to lubricate cuttings. Bentonite slurry may be used in unconsolidated soil formations to consolidate cuttings for the bit, seal the walls of the hole, and furnish lubrication for subsequent removal of cuttings and installation of the pipe immediately thereafter.
3.6 Water Jetting . Use water jetting only when shown on the plans or approved in writing. Water jet the lengths
in one direction only. Cease operations and complete all necessary work by boring when jetting operations fail to produce a smooth stable hole.
3.7 Encasement . Provide at least 12 in. of cover over encasement pipe. Cover is measured to the top of the
subgrade for roadways and paved areas and to the bottom of the structure for sidewalks , riprap, or non- load bearing slabs.
3.8 Pipe and Valve Assembly. Assemble pipe and fittings as rec ommended by the manufacturers. Clean pipe
and fittings of dust, dirt, and moisture before assembly. Make connections between plastic pipe and metal valves with threaded fittings and plastic adapters. Install backflow preventers as required by ordinances of the controlling water utility authority. Install pipe, valves, and valve boxes at least 12 in. from sidewalks, buildings, walls, and other objects .
3.9 Sprinkler Heads and Drip Tubing. Install sprinkler heads and drip tubing in conformance with the
manufactur er’s recommendations .
3.10 Controller . Install controllers in conformance with the manufacturer’s recommendations .
3.11 Low-Voltage Wire . Install wire in trenches below the pipe or in a minimum 1- in. PVC pipe with at least 12 in.
of cover over its entire run. Instal l wire in continuous lengths. Splice wire, if required, in valve boxes using waterproof materials.
3.12 Closing and Flushing of PVC Pipe . Cap or plug pipe after installation to prevent entry of foreign materials
that would obstruct the flow of water. Leave caps or plugs in place until removal is necessary for completion of the installation. Thoroughly flush all water lines.
3.13 Hydrostatic Tests. Notify the Engineer in writing at least 48 hr. before testing. Center -load all pipe with
enough backfill to prevent archi ng or slipping while under pressure. After all welded joints have cured for at least 24 hr., test the main lines from the meter to the valves, with all valves closed, for at least 2 consecutive hours by applying a continuous and static minimum 80- psi water pressure. Repair leaks if necessary , and retest. Maintain the lines under static pressure for 24 hr. without leaks before final approval.
3.14 Backfill and Compaction . Backfill trenches and other excavations with soil free of objectionable material
after the i rrigation system is fully operational, all tests and inspections have been performed, and the results are approved. Backfill and compact in 8- in. layers. Smooth and shape disturbed soil to final grade. 145 3.15. Performance Period . Operate and maintain each system f or 30 days after plant installation is complete. Repair and maintain in accordance with Section 193.3. 6., “Irrigation System Operation and Maintenance.” This period will extend until repairs are completed.
3.16 Operation . Begin operation of each system after plant installation has begun. Operate the system until work
is completed on the project. Inspect the system for proper operation, damage, and leaks every 3 mo. Adjust the irrigation schedule during inspection to provide proper soil moisture. Shut down the system and notify the Department if the system requires repairs.
Article 4 — Measurement
This Item will be measured by the lump sum or by each complete system.
Article 5 — Payment
For “lump sum ” measurement, the work performed and materials furnished in accordance with this Item and measured as provided under “Measurement” will be paid for at the unit price bid for “Irrigation System” and “Irrigation System Design.” For “each” measurement, the work performed and materials furnished in accor dance with this Item and measured as provided under “Measurement” will be paid for at the unit price bid for “Irrigation System” of the design specified. This price is full compensation for furnishing and installing all components; flushing and testing water lines; furnishing and operating equipment; and maintenance, repairs, design, labor, tools, and incidentals. Protection methods for excavations 5 ft. deep or deeper will be measured and paid for as required under Item 402 or Item 403. Water service work required will not be paid for directly but will be subsidiary to pertinent I tems. This includes all fees, testing, certifications, reoccurring test or certifications, permits, utility service owner inspections, connection or meter installation charges, and other costs; making arrangements with the utility service owner for all work, testing, certifications, and materials provided by the utility service owner; furnishing, installing, and connecting all components , including lines and service supports ; and materials, equipment, labor, tools, and incidentals. Applications for a utility service must designate the Department as the service owner , unless otherwise shown on the plans. Water service costs for utility- owned service line extensions and consumption charges will be paid for by the Department. The Department will reimburse the Contractor the amount billed by the utility service owner, and an additional 5% of the invoice cost will be paid for labor, equipment, administrative costs, superintendence, and profit. Electrical work, fees, and power consumption will be measured and paid for in accordance with Item 628. Payment for “Irrigation System” will be executed in the following manner.
5.1 Initial Payment . When the installation is completed, 95 % of the unit price bid for each system will be paid.
5.2 Final Payment . When performance period of the system is completed, the remaining portion of the unit price
bid for the system will be paid. Repair or replace system parts damaged by the Contractor’s operations at the Contractor’s expense. Upon completion of performance period and when Item 193, “Landscape Establishment,” is not included, repair or replacement of system parts not damaged by the Contractor’s operations will be paid for in accordance with Article 9.7., “Payment for Extra Work and Force Account Method.”