OAR 690-215-0017: Down Well Continuous Water Treatment and Back-Siphon Prevention Devices

(1) The following definitions apply solely to OAR 690-215-0017: (a) “Backflow” means the flow of a mixture of water, fertilizer and/or chemicals in the opposite direction of that intended. (b) “Backpressure” means an elevation of pressure downstream of the distribution system that would cause, or tend to cause, water to flow opposite of its intended direction. (c) “Back-siphonage” means a drop in distribution system pressure below atmospheric pressure (partial vacuum), that would cause, or tend to cause, water to flow opposite of its intended direction. (d) “Reduced Pressure Principle Backflow Prevention Assembly (RP)” means an assembly containing two independently acting approved check valves, together with a hydraulically operating, mechanically independent pressure differential relief valve located between the check valves and at the same time below the first check valve. The unit shall include properly located resilient seated test cocks and tightly closing resilient seated shutoff valves at each end of the assembly. This assembly is designed to protect against a non-health hazard or a health hazard. (e) “University of Southern California, Foundation for Cross-Connection Control and Hydraulic Research (USC FCCCHR)" is an agency that conducts laboratory and field tests to evaluate and grant "Certificates of Approval" to backflow prevention assemblies meeting approved standards. (2) If a chemical is used to treat well water, it shall not be allowed to come into contact with the inside of the well casing above the water level. Down well treatment of well water will only be allowed if a commercial water treatment system is used. Delivery pipes or tubes designed for use with the treatment chemicals shall be used to place the chemicals into the water in the well. This rule does not apply when disinfecting the well and the pumping equipment. (3) Only chemicals approved by the National Sanitation Foundation to treat drinking water may be allowed to enter a well. In no event shall agricultural chemicals or fertilizers be allowed to enter a well. (4) Back-siphon prevention devices shall be installed on any irrigation system connected to a groundwater source when chemicals or fertilizers are applied through the system. The landowner or other responsible party shall ensure that back-siphon prevention devices are installed and function properly prior to the irrigation system being used for the application of chemicals or fertilizers. (See Figure 215-1 and Figure 215-2.) The landowner or other responsible party shall test the devices at the time of installation and prior to the first use of each calendar year to ensure that the devices are installed and function properly. The Department may require the landowner or other responsible party to submit a copy of the back-siphon prevention device test results for review. The installation of chemical or fertilizer injection equipment into an irrigation system connected to a groundwater source shall not result in contamination of the groundwater resource. (a) Irrigation systems with a mainline diameter 4-inches or greater shall contain: (A) An automatic low-pressure drain or similar device approved by the Water Resources Department which shall: (i) Be installed between the irrigation pump and the irrigation mainline check valve at the lowest point of the horizontal water supply mainline; (ii) Be designed to drain all incidental leakage from the check valve out of the irrigation mainline before that leakage enters the groundwater supply; (iii) Be at least 3/4 inch in diameter with a closing pressure of not less than 5 psi; (iv) Use a corrosion-resistant tube, pipe, or similar conduit that is sloped to discharge the solution a distance of at least 20 feet away and down-gradient from the irrigation groundwater source and any other water sources. At the discharge point there shall be an air gap between the discharge pipe and the discharged solution. The air gap shall be a minimum of six inches; (v) Not have any valves located on the outlet side of the drain tube; and (vi) Have a dam, collection reservoir or similar means to prevent the discharged solution from pooling and draining back toward the groundwater source. (B) An inspection port or direct access point which shall: (i) Be located on top of the mainline between the irrigation pump and the irrigation mainline check valve, directly overhead of the low-pressure drain; and (ii) Have a minimum diameter opening of four inches from which the check valves and low-pressure drain shall be visible. If a four-inch inspection port or direct access point is not possible, a proposed alternative access system may be submitted for review and approval by the Department. (C) An irrigation mainline check valve which shall: (i) Consist of at least a single check valve; (ii) Be located in the irrigation mainline between the irrigation pump and the point of chemical or fertilizer injection into the irrigation mainline, and downstream from the vacuum relief valve and automatic low-pressure drain; (iii) Be of heavy-duty construction with all materials being compatible with and resistant to any chemicals or fluids that it is expected to come into contact with; (iv) Be resistant to corrosion or protected to resist corrosion; (v) Be spring-loaded and provide and maintain a watertight seal against backflow; (vi) Be labeled with the following information: manufacturer's name and model number, working pressure in pounds per square inch (psi), maximum flow rate, and direction of flow; (vii) Not consist of metal-to-metal seal surfaces; and (viii) Be designed and rated for pressures expected to be encountered, including those caused by pumping, water hammers, back-pressure, or other sources. Installation, operation, maintenance and testing shall be according to design and manufacturer's specifications and recommendations. (D) An air/vacuum relief valve which shall: (i) Be located on top of the horizontal irrigation mainline between the irrigation pump and the irrigation mainline check valve; and (ii) Have a total (individually or combined) orifice size of at least 3/4-inch diameter for a 4-inch pipe, a 1-inch diameter for a 5- to 8-inch pipe, a 2-inch diameter for 9- to 18-inch pipe, and a 3-inch diameter for a 19-inch and greater pipe. (E) An automatic, quick-closing chemical injection line check valve which shall: (i) Be attached to the irrigation mainline or located between the chemical injection unit and the point of chemical or other fluid injection into the irrigation mainline; (ii) Be made of material that is compatible with and resistant to any chemicals or fluids to be injected; (iii) Prevent backflow of irrigation water into the chemical injection line; and (iv) Prevent siphoning or seepage from the chemical supply tank when the irrigation system is either automatically or manually shut down. (F) A system interlock which shall: mechanically or electrically connect the water supply pump and the chemical injection unit for the purpose of automatically shutting down the chemical injection unit in the event of water supply pump shutdown or failure. The landowner or other responsible party shall demonstrate system interlock operation if requested by the Department. (G) An emergency shut-off that can be operated manually by the landowner or other responsible party so that the irrigation system or the chemical injection unit can be shut down in the event it becomes necessary. (H) A pressure switch that will stop the chemical injection unit when the water pressure decreases to the point where chemical or fertilizer distribution is adversely affected. (b) Irrigation systems with a mainline diameter less than 4-inches shall contain: (A) A lead free reduced pressure principle backflow prevention assembly (RP) which shall: (i) Be approved by the University of Southern California, Foundation for Cross-Connection Control and Hydraulic Research, or other equivalent testing laboratory; (ii) Be installed horizontal unless they are specifically approved for vertical installation; (iii) Be located in the irrigation mainline between the irrigation pump and the point of chemical or fertilizer injection into the irrigation mainline; (iv) Be of heavy-duty construction with all materials compatible with and resistant to any chemicals or fluids that it is expected to come into contact with; (v) Be resistant to corrosion or protected to resist corrosion; (vi) Provide and maintain a watertight seal against reverse flow; (vii) Be labeled with the following information: manufacturer's name and model number, working pressure in pounds per square inch (psi), maximum flow rate, and direction of flow; (viii) Not consist of metal-to-metal seal surfaces; (ix) Be designed and rated for pressures expected to be encountered, including those caused by pumping, water hammers, back-pressure, or other sources. Installation, operation, maintenance and testing shall be according to design and manufacturer's specifications and recommendations; and (x) Include an approved air gap and drain line. The diameter of the drain line shall be at least as large as the mainline diameter. The drain line shall be sloped in such a manner as to drain all incidental leakage a distance of at least 20 feet away and down-gradient from the irrigation groundwater source and the RP assembly. The air gap shall be a minimum of one and one-half times the diameter of the mainline. The outlet side of the drain line shall have a dam, collection reservoir or similar means to prevent the discharged solution from pooling and draining back toward the groundwater source. (B) An automatic, quick-closing chemical injection line check valve which shall: (i) Be attached to the irrigation mainline or located between the chemical injection unit and the point of chemical or fertilizer injection into the irrigation mainline; (ii) Be made of material that is compatible with and resistant to any chemicals or fluids to be injected; (iii) Prevent backflow of irrigation water into the chemical injection line; and (iv) Prevent siphoning or seepage from the chemical supply tank when the irrigation system is either automatically or manually shut down. (C) A system interlock which shall: mechanically or electrically connect the water supply pump and the chemical injection unit for the purpose of automatically shutting down the chemical injection unit in the event of water supply pump shutdown or failure. The landowner or other responsible party shall demonstrate system interlock operation if requested by the Department. (D) An emergency shut-off that can be operated manually by the landowner or other responsible party so that the irrigation system or the chemical injection unit can be shut down in the event it becomes necessary. (E) A pressure switch that will stop the chemical injection unit when the water pressure decreases to the point where chemical or fertilizer distribution is adversely affected. (c) The Director may allow modifications or changes in materials, design, or technology in lieu of that specified herein. Requests for modifications or changes shall be in writing, detailing the current or proposed system and the desired changes, and shall include component specifications, a detailed drawing of the proposed system, and the system’s uses. Once installed, the modified system shall provide at least as much protection to the groundwater resource as that provided by the devices required in this regulation; (d) The injection of chemicals or fertilizers into an irrigation system connected to a groundwater source shall not occur within ten feet from a wellhead. (e) An additional vacuum relief valve may be installed downstream of the irrigation mainline check valve to prevent potential collapse of the irrigation mainline in the event of rapid mainline drainage. (f) The landowner or other responsible party shall ensure that additional inspections and testing of approved back-siphon prevention devices are conducted: (A) At the time of any repair or relocation; (B) More frequently than annually for back-siphon prevention devices that repeatedly fail; or (C) After a backflow incident. (g) These regulations are in addition to equipment requirements for chemical application under the Federal Insecticide, Fungicide and Rodenticide Act, and are not intended to replace those regulations; (h) Irrigation systems that are subject to OAR 690-215-0017(4) and are connected to: (A) A public water system, shall also comply with Oregon Health Authority cross-connection control requirements in OAR Chapter 333 and backflow prevention requirements in the Oregon Plumbing Specialty Code. Contact the Oregon Health Authority and the Oregon Building Codes Division for more information; (B) A private water system, shall also meet the backflow prevention requirements in the Oregon Plumbing Specialty Code. Contact the Oregon Building Codes Division for more information. Before each chemical application, the treatment site and surrounding area should be assessed to determine if the application will endanger or be a potential hazard to workers, bystanders, domestic animals, fish or wildlife, ground or surface water, or neighboring crops. (5) Back-siphon prevention devices found not to be functioning properly shall be either repaired or replaced. Repair or replacement shall take place prior to the irrigation system being used for the application of chemicals or fertilizers. (6) Bypass piping installed around approved back-siphon prevention devices must be equipped with approved back-siphon prevention devices and must: (a) Afford at least the same level of protection as the approved back-siphon prevention devices being bypassed; and (b) Comply with all other requirements. (7) The landowner or other responsible party shall provide access and clearance for required operation, testing, maintenance, and repair of back-siphon prevention devices. (8) In cold climate areas, back-siphon prevention devices shall be protected from freezing. (9) Back-siphon prevention devices shall: (a) Not be located in any area containing fumes that are toxic, poisonous, or corrosive; (b) Be installed in a manner that precludes the possibility of continuous submersion of back-siphon prevention devices; and (c) Be installed in a manner that precludes the possibility of any submersion of the air/vacuum relief valve. (10) The Director may require a landowner or other responsible party to install a back-siphon prevention device on any water supply well, including wells which are exempted by ORS 537.545. The Director also may require a landowner or other responsible party to install a back-siphon prevention device as a condition of a water right permit. When required to be installed: (a) Back-siphon prevention devices shall be specifically designed and manufactured to prevent backflow, back-siphonage, backpressure, siphoning, seepage, suction, or leakage and shall prevent used, unclean, polluted, or contaminated water, mixtures, or substances from entering the groundwater resource; (b) The landowner or other responsible party shall test the back-siphon prevention devices at the time of installation and once per calendar year to ensure that they are functioning properly; (c) The Department may require the landowner or other responsible party to test the back-siphon prevention devices more frequently than annually to ensure that they are functioning properly; and (d) The Department may require the landowner or other responsible party to submit a copy of the back-siphon prevention device test results for review. (11) Whenever the Director deems it appropriate, the Department may investigate alleged violation of statutes, standards or rules governing back-siphon prevention devices to determine whether a violation has occurred. Violations of OAR 690-215-0017 may be administered under ORS 536.900(1)(b), 537.990(3), or OAR Chapter 690, Division 260, as appropriate to gain compliance. (12) Additional Oregon Health Authority standards apply to wells used for public water systems. See OAR Chapter 333 or contact the Oregon Health Authority for more information. (13) Additional requirements in the Oregon Plumbing Specialty Code apply to wells used for public or private water systems. Contact the Oregon Building Codes Division for more information. [ED. NOTE: To view attachments referenced in rule text, click here to view rule.]