TX-442-GS-1
LEPA Conversion
For Statewide Use
Natural Resources Conservation Service
CONSERVATION PRACTICE GENERAL SPECIFICATIONS
SPRINKLER SYSTEM
CONVERSION OF EXISTING SPRINKLER SYSTEM TO A LOW ENERGY, PRECISION APPLICATION (LEPA) SPRINKLER
(Ac.)
Code 442
for
Click here to enter Name of Owner/Operator & Contract Number
I.SCOPE
The work shall consist of furnishing and installing a Low Energy Precision Application (LEPA) sprinkler package on an existing linear or center-pivot sprinkler irrigation system.
II.LOCATION
The sprinkler system and its components shall be located as shown on furnished drawings/map or as staked in the field.
III.PUBLIC AND PRIVATE UTILITIES
A.Utilities are defined to be overhead and underground power or communication lines, and pipelines. The contractor should conduct their own search and discovery for utilities in order to lessen or avoid potential damages. Other buried infrastructure, such as landowner-installed drainage tile, private water lines, or electrical lines, are the responsibility of the landowner to locate. The owner/operator shall complete TX-ENG-80A, Utilities Inventory, during planning and return it to the NRCS representative.
B.The owner/operator shall also ensure that TX-ENG-80B, Cooperator Confirmation of the Utility Locator Service, is completed and returned to the NRCS representative prior to layout or any ground disturbance.
C.Cooperators, sponsoring organizations, and/or contractors shall be liable for damage to utilities and damage resulting from disruption of service caused by installation activities. The Natural Resources Conservation Service (NRCS) makes no representation on the existence or non-existence of any utilities. Absence of utilities on drawings is not assurance that no utilities are present at the site.
IV.ELECTRICAL WIRING, COMPONENTS AND PROTECTION
A.Extra care should be taken when working on or near electrical powered irrigation systems. Electric power shall be disconnected from the irrigation system prior to the installation of any sprinkler nozzle package.
B.ELECTRICAL COMPONENTS. All electrical components, including wiring, boxes, and connectors, shall meet the requirements of the National Electric Code for the location and type of installation. Additionally, all installation and components shall also meet any local electrical requirements and obtain permits if required.
C.ELECTRICAL INSTALLATION. This conservation practice includes an electrical component which can present a safety hazard to you and others if not installed and operated correctly. Therefore, it is highly recommended that you hire a licensed electrician to inspect and/or install the electrical elements. The licensed electrician would be able to determine if your installation meets the applicable state and local regulations, including National Electric Code. You as the landowner/operator are responsible for the installed practice meeting all the applicable state and local regulations, including National Electric Code.
D.USDA – Natural Resources Conservation Service will be performing a checkout/certification of the practice, but this checkout does not include any verification of the electrical components safetynor does it include any verification of compliance with NEC.
E.PROTECTION OF POWER SUPPLY. Power supply should be appropriately placed and protected to reduce the potential for accidental contact from machinery and personnel. If the power supply is located in an area that is reasonably accessible by machinery, it shall be protected by bollards or other appropriate measures.
I acknowledge the above Electrical Safety requirements and certify that they will be met.
Signature: ______Date: ______
V.INSTALLATION AND MATERIALS
A.All materials used in the installation of the LEPA system shall be new and free from defects. With the exception of weights, none of the existing sprinkler system shall remain as part of the new LEPA system below the existing furrow arms or goosenecks. The LEPA system shall be comprised of all new components including the flexible drop hose, any rigid pipe used on the drop, pressure regulators (if needed), isolation valves (if needed), nozzle bodies or bracket assemblies, sprinkler or bubbler-type nozzles and drag socks or surface hoses.
B.Existing weights, water outlets on the sprinkler mainline and furrow arms or goosenecks may be used provided they are not leaking and are in good condition. New mainline outlets to facilitate the location of the drops between crop rows shall be installed following the sprinkler system manufacturer’s recommendations.
C.Nozzle spacing shall not be greater than two times the row spacing of the crop. Water shall be discharged through a drag sock or hose on the soil surface, or through a bubble nozzle at uniform heights not to exceed 18 inches. All LEPA application device heights above the soil surface shall be uniform when the system is operating. After installation, the system shall be pressure tested at the system operating pressure. All leaks shall be repaired to insure a leak-free system.
VI.LEPA SYSTEM MANAGEMENT
LEPA systems are only applicable on crops planted with furrows or beds. Circular rows shall be used with center-pivot systems and straight rows shall be used with linear systems. For ease of farming operations, some straight rows will allowed near the center of center-pivot systems. The land slope for a LEPA system shall not exceed 1.0 percent on more than 50 percent of the field. LEPA systems shall employ some method of providing surface basin storage such as furrow diking or pitting or implanted reservoirs. Water shall not be applied in the tower wheel track of a LEPA system.
VII.CHEMIGATION SAFETY
All applicable Federal, state and local laws and regulations in regards to backflow prevention shall be followed in the installation of the system. All irrigation distribution systems into which any type of chemical (except disinfecting agents) or other foreign substances will be injected into the water pumped from water wells shall be equipped with an in-line, automatic quick-closing check valve capable of preventing pollution of the ground water in accordance with Texas Administrative Code, Title 16, Part 4, Chapter 76.1007,”Technical Requirements – Chemical Injection, Chemigation, and Foreign Substance Systems”.
VIII.CERTIFICATION
A.The installing contractor shall furnish the Natural Resources Conservation Service a copy of the sprinkler nozzle design printout, which will be made part of the supporting records for the LEPA sprinkler system. This sprinkler design printout is the installing contractor’s certification that the sprinkler conversion package was installed according to the design.
B.A field check of the installed LEPA sprinkler system will be made by NRCS personnel to compare the installed sprinkler nozzle package to the sprinkler nozzle design printout. The check will also insure that all new materials except weights, existing water outlets on sprinkler mainline and furrow arms or goosenecks were used in the installation of the LEPA sprinkler system conversion. The installed nozzle package will be checked with center pivot evaluation software to insure that a Coefficient of Uniformity (Cu) of 94 percent or better is achieved.
IX.MEASUREMENT
The amount of the LEPA sprinkler system conversion will be determined by counting the number of application devices (drops), that meet the LEPA standard and specification which is typically from the first converted sprinkler (drop) nozzle to the last converted sprinkler (drop) nozzle.
X.CONSTRUCTION DETAILS
A.Low Energy-Precision Application Sprinkler
B.Click here to enter Construction Details.
NRCS, Texas
January 2017