Original Notice.

Preproposal statement of inquiry was filed as WSR 00-03-076.

Title of Rule: Chapter 16-202 WAC, Application of pesticides and plant nutrients through irrigation systems -- Fertigation.

Purpose: To clarify rules and address issues and concerns raised since implementation of the original rules in 1998. These rule revisions address the proper operation and system configuration required to protect the environment and human health from chemigation applications.

Other Identifying Information: Fertigation is the distribution of pesticides through irrigation systems.

Statutory Authority for Adoption: Chapters 15.58 and 17.21 RCW.

Statute Being Implemented: Chapters 15.58 and 17.21 RCW.

Summary: The proposed rules contain significantly more explanatory provisions than the current rule. However, the actual numbers of additional provisions are few, and most of them are addressed in the small business economic impact statement. Intended to be as much of a reference document as a regulation, the proposed chemigation rule and fertigation rule incorporate or reference relevant provisions of chapters 16-200, 16-201, 16-228, 16-229 WAC, WAC 16-202-1000, and 16-202-2000 as well as chapters 15.54 and 17.21 RCW.

     Many of the supplementary provisions to current rule are addressed in the small business economic impact statement, and they follow:

     1. Manual shutoff valves must be placed on the main outlet of application tanks (WAC 16-202-1009 and 16-202-2005).

     2. Application tanks must contain "who to contact" information in a minimum of two-inch lettering on a contrasting background (WAC 16-202-1008 and 16-202-2004).

     3. Application tanks containing product must be periodically monitored (WAC 16-202-1010 and 16-202-2006).

     4. Chemigation and fertigation applications must be periodically monitored (WAC 16-202-1023 and 16-202-2019).

     5. For chemigation, a tank size limitation of 2,500 gallons and a cumulative application tank capacity of 3,000 gallons (with a soil fumigation exception of 6,500 gallons for a fourteen-day period) per injection site (WAC 16-202-1010).

     6. For fertigation, a tank size restriction of 6,500 gallons and a cumulative application tank capacity of 10,000 gallons per injection site (WAC 16-202-2006).

     7. An inspection port or other access point to assess the integrity and operation of irrigation mainline check valve and the low pressure drain, provided such devices are deemed necessary, must be installed (WAC 16-202-1002, 16-202-1013, 16-202-2002, and 16-202-2009).

     8. Department of Health approved backflow prevention devices must be installed on systems that are cross-connected to a public water supply (WAC 16-202-1013, 16-202-1024, 16-202-2009, and 16-202-2020).

     Presented below are proposed provisions not specifically addressed in the small business economic impact statement that may require a financial outlay by the system owner, lessee, or renter. However, a potential cost associated with a proposed provision may be nominal due to requirements of correlated rules, to conditions on the pesticide label, or to adherence with accepted industry practice.

     1. All system components must be compatible with injected materials, water containing injected materials, or system pressure (WAC 16-202-1003 and 16-202-2003).

     2. The application must be continuously observed whenever sensitive areas are at risk of being exposed to drift, runoff, or overspray (WAC 16-202-1003 and 16-202-2003).

     3. Overflow from an irrigation pond contaminated with product cannot enter a public waterway, off-farm irrigation supply ditch or conveyance system, or sensitive area (WAC 16-202-1009 and 16-202-2005).

     4. Barometric loops can only be used on systems pumping from a surface water source. The barometric pipe loop must be located in the main water line immediately downstream of the irrigation water pump. It must be designed with sufficient elevation differential to compensate for backflow. The bottom of the barometric loop apex must be at least thirty inches above the highest water-emitting device or of any portion of the irrigation application system. The chemical injection port must be located downstream of and at least thirty inches below the bottom of the pipe loop apex (WAC 16-202-1014, 16-202-1020, 16-202-2010, and 16-202-2016).

     5. Mixing or loading activities cannot occur within and an application tank cannot be placed closer than twenty feet of a sensitive area, wellhead, public waterway, off-farm irrigation supply ditch or conveyance system, and irrigation water source (WAC 16-202-1009 and 16-202-2005).

     6. For a chemigation operation (WAC 16-202-1010):

•	Product can remain in an application tank for a period not to exceed fourteen days between chemigation applications;
•	An application tank containing product must be inspected at least daily or monitored with remote access volumetric measuring devices; and
•	An application tank must be removed at the end of the irrigation or application season, whichever is shorter, but in no event, not to exceed nine months. At the end of this period, the application tank must be emptied, cleaned, visually inspected for integrity, and serviced. The tank must be removed from the site, or the tank must be decommissioned and clearly tagged with the words "Out-of-Service," or the tank must be managed as a permanent storage facility.

     7. For a fertigation operation (WAC 16-202-2006):

•	Product can remain in an application tank for a period not to exceed nine consecutive months during an irrigation or application season;
•	An application tank containing product during the nonapplication or nonirrigation season is subject to the secondary and operational area containment rules; and
•	The application tank must be removed at the end of the irrigation or application season, whichever is shorter but in no event, not to exceed nine months. At the end of this period, the application tank must be emptied, cleaned, visually inspected for integrity, and serviced. The tank must be removed from the site, or the tank must be decommissioned and clearly tagged with the words "Out-of-Service," or the tank must be managed as a permanent storage facility.

     8. For a fertigation operation, a person may function as a metering device with a nonpressurized irrigation delivery system. However, the individual must remain on-site to continuously monitor the application and be immediately available to terminate the application in the event of equipment malfunction (WAC 16-202-2014).

     For additional information, contact the WSDA Chemigation and Fertigation Technical Assistance Program at (509) 766-2574, or write Tom Hoffmann or Byron Fitch at WSDA Pesticide Management, 821 East Broadway, Suite 4, Moses Lake, WA 98837.

Reasons Supporting Proposal: The proposal is the result of numerous meetings with a technical advisory committee comprised of representatives of agricultural suppliers, producers, the United States Natural Resources Conservation Service, and the Washington State Department of Ecology. The revisions address a number of issues that have arisen since implementation of the chemigation rule in 1988.

Name of Agency Personnel Responsible for Drafting and Implementation: Ann Wick, 1111 Washington Street, Olympia, WA 98504, (360) 902-2051; and Enforcement: Cliff Weed, 1111 Washington Street, Olympia, WA 98504, (360) 902-2036.

Name of Proponent: Department of Agriculture, governmental.

Rule is not necessitated by federal law, federal or state court decision.

Explanation of Rule, its Purpose, and Anticipated Effects: The proposal contains backflow prevention requirements for the purpose of protecting the environment and ground water from contamination. These rules also address the proper operation and system configuration required to protect the environment and human health from chemigation applications. The rules went through a thorough review by a technical advisory committee described above. In addition, the department received input from the state departments of Health and Ecology during the rule revision process.

Proposal Changes the Following Existing Rules: See Summary above.

A small business economic impact statement has been prepared under chapter 19.85 RCW.

     1. Labeling requirements under chemigation (WAC 16-202-1008) and fertigation (WAC 16-202-2004) require tank contents and owner information to be visible and securely affixed to each application tank. Lettering that displays the contact name, telephone number, and tank identifier have to be a minimum of two inches in height and in a color contrasting to the background.

     Cost Analysis:

     &sqbul; Chemigation: Current rules require labeling of undiluted product in tanks with the EPA product label. Approximately 20% of all tanks in use for chemigation contain undiluted product and thus currently require labeling. This means approximately 80% of some 12,000 tanks used for chemigation could have a cost associated with the rule change or 9,600 tanks.

     Manufacturers usually provide product labels, however the tank owner would still need to affix his or her contact name, telephone number, and tank identifier. The average cost for materials to do this is $2.00. The cost for labor is estimated at $10 an hour with installation time taking approximately ten minutes per tank.

     The cost then to install needed information per tank is $3.67. If dealers own two-thirds of the tanks statewide, and 80% of those tanks require this information to be affixed, then their total cost would be 8,000 tanks *80% = 6,400 tanks *$3.67 = $23,488 statewide. These costs would primarily be incurred by large businesses. Growers represent the remaining 4,000 tanks requiring the identifying information to be installed; some of whom would be classified as small businesses. This would equal 4,000 tanks *80% = 3,200 tanks *$3.67 = $11,744 statewide.

     If there are sixty dealers, the cost per dealer is $391.15 per dealer.

     If growers have two tanks on average that need to meet this requirement, the cost per grower is $7.34.

     &sqbul; Fertigation: All tanks would require some work to meet these requirements.

     Per dealer this equals 8,000 tanks *$3.67 = $29,360/60 dealers = $489.33.

     Per grower this equals $7.34 for two tanks.

     Mitigation Factors: The Washington State Chemigation and Fertigation Technical Assistance Program staff based in Moses Lake would document tanks that require identification and would set up an agreement with growers as to when they would meet this requirement either through a solicited technical assistance audit or through the notice of correction process. If this requirement was not met after the agreed upon timeframe, then the grower could be cited.

     2. The proposed rules require system operators to monitor chemigation applications every four hours (WAC 16-202-1023), and fertigation applications daily (WAC 16-202-2019).

     Cost Analysis:

     &sqbul; Chemigation: The current chemigation rule requires "frequent monitoring." Agricultural representatives on the Technical Advisory Committee for this rule making indicated that the four-hour requirement is already standard practice. Therefore it is determined that there is no financial impact.

     &sqbul; Fertigation: The current fertigation rule has no requirements for monitoring daily. If the average wage per hour is estimated at $10 and the inspection takes two hours (including travel time), then the cost per day would be $20 to inspect each system. Due to the fact that monitoring systems daily is considered standard practice according to the Technical Advisory Committee, this requirement is considered a minimal impact. In addition, these costs would primarily be incurred by large businesses since they usually have more systems to inspect.

     Mitigation Factors: None.

     3. The fertigation rule requires secondary containment for all tanks larger than 6,500 gallons that are used during a fertigation operation (WAC 16-202-2006(2)). Currently, the WSDA secondary and operational area containment rules (chapter 16-201 WAC) require secondary containment for all fertilizer tanks 10,000 gallons or greater. The cost analysis is based on the difference between the new gallonage limitation of 6,500 gallons and the secondary containment requirement of 10,000 gallons.

     Cost Analysis:

     &sqbul; Chemigation: Not applicable.

     &sqbul; Fertigation: The average cost of a 6,500 gallon tank is $3,520. It is estimated that there are only a dozen 10,000 gallon tanks that would need to be replaced with smaller tanks and only one tank per dealer. Many of these tanks are typically rented or leased by the grower from dealers. This means the cost would primarily be borne by dealers and their cost is estimated at $3,520.

     Mitigation Factors: The Washington State Chemigation and Fertigation Technical Assistance Program staff based in Moses Lake would document tanks that need replacement and would set up an agreement with growers as to when they would meet this requirement through a solicited technical assistance audit or through the notice of correction process. If this requirement was not met after the agreed upon timeframe, then the grower could be cited.

     4. The proposed chemigation rule (WAC 16-202-1009(4)) and the fertigation rule (WAC 16-202-2005(4)) both require tank outlet ports to be fitted with manual shutoff valves. Although the current rules do not have this requirement, the current industry practice provides manual shutoff valves for all newer tanks. This means only the older tanks would need to be retrofitted. Less than 1% of tanks will require this retrofit, equaling about 80 tanks statewide.

     Cost Analysis:

     &sqbul; Chemigation: The cost of the valve is $20. The cost of labor is $10 per hour. This equals $30 per tank.

     &sqbul; Fertigation: Same as above.

     Mitigation Factors: The Washington State Chemigation and Fertigation Technical Assistance Program staff based in Moses Lake would document tanks that require this retrofit and would set up an agreement with growers as to when they would meet this requirement either through a solicited technical assistance audit or through the notice of correction process. If this requirement was not met after the agreed upon timeframe, then the grower could be cited.

     5. Both the chemigation rule (WAC 16-202-1013 (1)(b)) and the fertigation rule (WAC 16-202-2009 (1)(b)) require an inspection port or a direct access point to allow for visual and manual inspection of the check valve and the low pressure drain. The inspection port or access point has to be at least four inches in diameter. If this is not feasible, an alternative access system must be devised.

     Cost Analysis:

     &sqbul; Chemigation: The cost of installing an inspection port would be borne by the grower. The parts equal approximately $30 and the labor $10, costing the grower $40 per installation. On average, a grower might have six to eight systems requiring an inspection port to be installed equaling $320 per grower. These costs would primarily be incurred by large businesses because they may have more systems to retrofit.

     &sqbul; Fertigation: Same as above.

     Mitigation Factors: The Washington State Chemigation and Fertigation Technical Assistance Program staff based in Moses Lake would document systems that require inspection ports and would set up an agreement with growers as to when they would meet this requirement through either a solicited technical assistance audit or through the notice of correction process. If this requirement was not met after the agreed upon timeframe, then the grower could be cited.

A copy of the statement may be obtained by writing to Ann Wick, Pesticide Management Division, Washington State Department of Agriculture, P.O. Box 42589, Olympia, WA 98504-2589, phone (360) 902-2051, fax (360) 902-2093.

Section 201, chapter 403, Laws of 1995, does not apply to this rule adoption. The Washington State Department of Agriculture is not a listed agency in section 201.

Hearing Location: Natural Resources Building (NRB), 2nd Floor, Room 271, 1111 Washington Street S.E., Olympia, WA 98504-2589, on Tuesday, April 24, 2001, at 1:00 p.m.; at the Washington State Department of Agriculture Yakima, 21 North First Avenue, Conference Room 238, Yakima, WA 98902, on Tuesday, May 1, 2001, at 6:30 p.m.; at Columbia Basin College, Gjerde Multipurpose Center, Sections 1 and 4, 2600 North 20th Avenue, Pasco, WA 99301-3379, on Wednesday, May 2, 2001, at 6:30 p.m.; and at the Big Bend Community College Auditorium, Building 1400, 7662 Chanute Street, Moses Lake, WA 98837, on Thursday, May 3, 2001, at 6:30 p.m.

Assistance for Persons with Disabilities: Contact Laurie Mauerman by April 12, 2001, TDD (360) 902-1996.

Submit Written Comments to: Laurie Mauerman, Washington State Department of Agriculture, P.O. Box 42560, Olympia, WA 98504-2560, fax (360) 902-2093, by May 4, 2001.

Date of Intended Adoption: May 21, 2001.

March 7, 2001

Bob Arrington

Assistant Director

GENERAL PROVISIONS
NEW SECTION
WAC 16-202-2001   What is the purpose of this chapter?   The purpose of this chapter is to establish performance standards for fertigation that are protective of existing and future uses of surface water and ground water quality.

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     "Air gap" means an unobstructed physical separation between the free-flowing discharge end of a supply pipe and the overflow rim of an open or nonpressurized receiving vessel. The separation must be at least four times the diameter of the supply pipe measured vertically from the overflow rim of the receiving vessel, and in no case be less than 25 mm, or 1-inch.

     "Alternative technology" means any device or concept that meets the performance standards contained in this chapter.

     "Antipollution safety device" means any equipment or device effectively designed, constructed, and maintained that is used in the event of malfunction or shutdown to prevent backflow of a chemical or treated water into the water supply, or to reduce human exposure or hazard to the environment. Equipment or devices may include, but are not limited to, the irrigation line check valve, vacuum relief valve, low-pressure drain, inspection port, metering device, chemical injection closure device, and system interlock.

     "Application season" means the period during which product is injected into an irrigation system for crop protection, crop growth, or soil preparation.

     "Application tank" means a product container and appurtenances used for the storage of product that is dedicated for use with and functionally connected to an irrigation system.

     "Applicator" or "operator" means any individual who has assumed responsibility or is considered principally responsible to ensure that the fertigation system functions properly and conforms with the provisions of this chapter.

     "Approved backflow prevention assembly" means a reduced pressure backflow assembly, reduced pressure detector assembly, double check valve detector assembly, or double check valve assembly of a make and model that is approved by the Department of Health pursuant to WAC 246-290-490.

     "Approved reduced pressure backflow assembly or reduced pressure detector assembly" means backflow prevention assemblies of make and model approved by the Department of Health pursuant to WAC 246-290-490.

     "Aquaculture" means the cultivation of water-based plants or animals.

     "Backflow" means the reversal of fluid flow due to backpressure or backsiphonage.

     "Backflow prevention device" or "backflow safety device" means antipollution safety devices that prevent the flow of water from the water distribution system back to the water source or to the product source.

     "Barometric loop" or "gooseneck" means a raised section of pipe where the bottom of the loop is at least two feet above the highest water emitting device or any portion of the irrigation application system which has a vacuum relief valve installed on the top of the loop.

     "Check valve" means a certified device designed and constructed to provide automatic, quick-acting, and absolute closure that creates and maintains a watertight seal. The device prevents flow in the opposite direction of that desired when operation of the irrigation system or chemical injection unit fails or is shutdown.

     "Chemical" or "product" means a commercial fertilizer, soil amendment, system maintenance compound, or other materials such as reclaimed water or animal effluent.

     "Commercial fertilizer" means a substance containing one or more recognized plant nutrients and which is used for its plant nutrient content and/or which is designated for use or claimed to have value in promoting plant growth, and shall include limes, gypsum, and manipulated animal and vegetable manures. It shall not include unmanipulated animal and vegetable manures and other products exempted by the department by rule.

     "Contact name" means a person or company responsible for placement and operation of an application tank.

     "Decommissioned" means rendering an application tank unusable for product containment.

     "Deep percolation" means the movement of water downward through the soil profile below a plant's effective rooting zone.

     "Department" means the Washington State Department of Agriculture.

     "End gun" means an intermittent, high volume water-emitting device located at or near the end of an irrigation application system.

     "Environment" means any plant, animal, natural resource, surface water (including underlying sediments), ground water, drinking water supply, land surface or subsurface strata, or ambient air within the state of Washington or under the jurisdiction of the state of Washington.

     "Fertigation" means the application of any commercial fertilizer, nutrient, soil amendment, or reclaimed water with irrigation water intended for plant or soil biota growth and development or for soil conditioning or reclamation.

     "Fertigation operation" means all activities and equipment associated in preparing for, performing, and concluding a fertigation application, which includes, but is not limited to, calibrating, mixing, loading, starting up, operating, monitoring, or shutting down a fertigation system.

     "Fertigation system" means the chemical injection system as well as the water distribution and application system.

     "Homemade" means devices not otherwise commercially available for sale or not manufactured for the purpose of commercial sale.

     "Hydroponic" means the practice of growing plants in an aqueous solution, moist inert material, or otherwise in the absence of a mineral-based medium.

     "Imminent danger" means a threat to human health or the environment that is likely to happen during the current application.

     "Injection system" means all components used to supply, deliver, meter, and inject a substance into an irrigation system. This includes devices and components located between and inclusive of the application tank and the point of product discharge into the irrigation water, including components of the system interlock.

     "Inspection port" means an orifice or other viewing device from which the low pressure drain and irrigation line check valve may be assessed for proper operation.

     "Irrigation application system" means the physical components of an irrigation system that begins at the first water emitting device and ends with the last water emitting or purging device.

     "Irrigation season" means that period of time during which supplemental water is applied to aid in plant development, soil conditioning, temperature modification, or other such purposes.

     "Irrigation system" means all components used in diverting, supplying, distributing, and applying irrigation water.

     "Irrigation water supply system" means the water conveyance system, which begins at the point of diversion from the irrigation water source and ends with the first water emitting device.

     "Metering device" means a positive displacement injection pump, venturi device, or gravity feed device capable of being calibrated and used to gauge chemical placement into the irrigation distribution or application system.

     "Non-pressurized water delivery system" means a method of irrigation in which water is distributed over the soil surface by gravity flow, such as rill, border, gated pipe, or spigotted pipe.

     "Off-site application" means the application or movement of product from the target site.

     "Operator" means the individual who is performing a fertigation operation.

     "Outtake" means an opening that provides a source of untreated water.

     "Rinsate" means the liquid produced from the rinsing of any equipment or container that has come in direct contact with any fertilizer or soil amendment.

     "Runoff" means surface water leaving the target site.

     "Sensitive area(s)" mean schools, parks, dwellings, occupied buildings or structures, neighboring crops, public roadways, waters of the state, or other areas determined by the department to be vulnerable to environmental degradation or susceptible to injury or impairment.

     "Source water" or "water source" means an aquifer or surface water body, including a stream, stream system, lake, reservoir, or off-farm irrigation water ditch or conveyance system, and any spring water or underground water that is part of or tributary to the surface water body or aquifer.

     "System interlock" means the arrangement or interconnection of the irrigation pump or a pressure or flow sensing device with the chemical injection unit or other pumps in such a manner that shutdown of the fertigation injection system will occur in the event of any component malfunction or failure that substantially impacts the application rate.

     "Vacuum relief valve" means a device that automatically relieves or breaks a vacuum, thereby preventing backsiphoning.

     "Washwater" means the liquid produced from the rinsing of the exterior of any equipment or containers that have or may have come in direct contact with any fertilizer or soil amendment.

     "Waters of the state" means but is not limited to lakes, rivers, ponds, streams, inland waters, underground waters, salt waters, irrigation canals and reservoirs.

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GENERAL REQUIREMENTS FOR FERTIGATION OPERATIONS

[NEW SECTION]WAC 16-202-2003   What are the general requirements in performing a fertigation operation?   The applicator and fertigation system must comply with the following performance requirements to protect human health, source water, and the environment. The fertigation operator is responsible for safe application and for the proper operation of the fertigation equipment.

     (1) A fertigation system shall be operated in a manner that is consistent with the intent of this chapter and its provisions.

     (2) Substituted alternative technology not otherwise identified in this chapter must be evaluated by the department to determine if the provisions of this chapter have been fulfilled.

     (3) All fertilizers used for fertigation must be registered with the department and meet Washington's fertilizer standards. This does not prohibit fertigation systems from being used to apply other products such as reclaimed water, animal effluent or similar substances.

     (4) During a fertigation application, an irrigation system and injection system are considered one unit, and the applicator is responsible for their proper operation.

     (5) All applicable fertilizer laws, in addition to those contained in this chapter, pertain to fertigation.

     (6) A fertigation system cannot draw water from any water supply unless that supply is protected from contamination. The fertigation operator must verify that backflow cannot occur.

     (7) The application must be continuously monitored whenever sensitive areas are at risk of being exposed to drift, runoff, or overspray.

     (8) All fertigation systems and system components must allow for adequate visual, physical, and manual inspection.

     (9) A fertigation system must be flushed out and rinsed off after application.

     (10) All components must be chemically compatible with injected materials or water containing injected materials.

     (11) Equipment must be calibrated and maintained in a manner to prevent misapplication or off-site application of any product.

     (12) Safety devices and injection equipment must be installed, operated, and maintained in accordance with the manufacturer's specifications, established industry standards, and department rule.

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Reviser's note: The bracketed material preceding the section above was supplied by the code reviser's office.
NEW SECTION
WAC 16-202-2004   What are the identification requirements for the in-field placement of fertilizer application tanks?   The purpose of identification requirements is to minimize the potential for human exposure and to facilitate remediation in the event of component malfunction or a contamination event.

     (1) An application tank must:

     (a) Display a record of tank contents;

     (b) Display its maximum net capacity;

     (c) Display a contact name and telephone number; and

     (d) Display an owner-derived numeric or alphanumeric tank identifier.

     (2) This information must be visibly recorded and securely affixed to each application tank. The distinguishing information shall be designed to remain intact and legible throughout the active use of the container.

     (3) Lettering that displays the contact name, telephone number, and tank identifier shall be a minimum of two inches in height and in a color contrasting to the background.

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     (1) Application tanks should be positioned down gradient from wellheads, public waterways, off-farm irrigation supply ditches or conveyance systems, or sensitive areas.

     (a) If down gradient placement is not feasible, earthen berms or other structures of sufficient design must be constructed to divert spillage, leakage, or surface flow away from such areas.

     (b) An application tank cannot be placed closer than 20 feet from wellheads, public waterways, off-farm irrigation supply ditches or conveyance systems, or sensitive areas.

     (c) Mixing or loading activities cannot occur within 20 feet of a sensitive area, wellhead, public waterway, off-farm irrigation supply ditch or conveyance system, and irrigation water source.

     (d) Overflow from an irrigation pond contaminated with product cannot enter a public waterway, off-farm irrigation supply ditch or conveyance system, or sensitive area.

     (2) Application tanks must be positioned to prevent leaks, spills, or structural damage.

     (a) Application tanks must be placed on a rigid, sound understructure or on stable ground to prevent tippage, spillage, puncturing, or breakage.

     (b) Application tanks and the injection system must be protected against reasonably foreseeable risks of damage by implements, trucks or other moving vehicles, or objects.

     (3) Application tanks should be sited as close as reasonably possible to the injection point.

     (4) Tank outlet ports must be fitted with manual shutoff valves.

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     (1) Time-in-place

     (a) Product can remain in an application tank for a period not to exceed nine consecutive months during an irrigation or application season. If the nine month period is exceeded, the tank is deemed a storage facility and is therefore subject to the Secondary and Operational Area Containment Rules.

     (b) An application tank containing product during the non-application or non-irrigation season is subject to the Secondary and Operational Area Containment Rules.

     (c) The application tank must be removed at the end of the irrigation or application season, whichever is shorter but in no event, not to exceed nine months. At the end of this period, the application tank must be emptied, cleaned, visually inspected for integrity, and serviced. The tank must be removed from the site, or the tank must be decommissioned and clearly tagged with the words "Out-of-Service," or the tank must be managed as a permanent storage facility (WAC 16-201).

     (2) Tank size

     (a) An application tank must have a rated capacity of 6,500 gallons or less.

     (b) An application tank with a rated capacity exceeding 6,500 gallons is deemed a permanent storage facility.

     (c) Multiple tanks positioned at an injection site with a cumulative capacity exceeding 10,000 gallons are also deemed a permanent fertilizer storage facility.

     (d) Cumulative tank capacity cannot exceed 10,000 gallons per application system.

     (3) Monitoring

     (a) Tanks containing product must be inspected at least every seven days.

     (b) Tanks must be inspected each time a fertigation operation is performed.

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     (2) Contaminated backflush water from a filtration device cannot contaminate ground water or surface water, or adversely impact sensitive areas.

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SAFETY REQUIREMENTS FOR FERTIGATION SYSTEMS
NEW SECTION
WAC 16-202-2008   What are the general antipollution safety device requirements for a fertigation system?   All systems must have antipollution safety devices that include a backflow prevention system, a metering device, injection device, and system interlock to prevent backflow into the irrigation water source or chemical supply system.

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     (1) Pressurized irrigation system

     (a) At least one irrigation mainline check valve must be correctly installed, properly operated, and adequately maintained to prevent contamination of the water source. The check valve must be located upstream from the injection point. The check valve must be automatic, quick-closing, and capable of forming and maintaining a watertight seal.

     (b) An inspection port or a direct access point must be positioned immediately upstream of the check valve to allow visual and manual inspection of the check valve and the low pressure drain. The inspection port or access point must have a minimum diameter of four inches. If a four-inch inspection port or access point is not feasible, an alternative system must be devised.

     (c) An inspection port or access point is not required with an approved backflow prevention assembly.

     (d) A vacuum relief valve must be located upstream of the irrigation line check valve, installed at the top of the irrigation pipeline and adequately sized to prevent backsiphoning. The orifice size must comply with current American Society of Agricultural Engineers (ASAE) standards.

     (e) An automatic low pressure drain or similar mechanism must be placed upstream of the irrigation line check valve and at the lowest point in the bottom of the pipeline. The low pressure drain must be of adequate size and properly positioned to intercept and purge leakage away from the water source.

     (f) Product-treated water cannot be discharged through a water outtake.

     (2) Non-pressurized water delivery system

     (a) System design must prevent the introduction of treated water into the water source.

     (b) Backflow prevention may be achieved with a hydraulic discontinuity in source water flow or by a sufficient hydraulic gradient.

     (c) Backflow devices for non-pressurized systems may include a weir box, drop structure, ASAE approved air gap, batch tank, or similar device that can function to prevent backflow into the source water.

     (d) Injection must occur downstream from the water diversion point.

     (3) Cross-connection to municipal or public water system

     (a) Backflow prevention devices must be approved by the Washington State Department of Health in accordance with WAC 246-290-490.

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     (1) System design

     (a) If a system's configuration will provide substantially equal or greater protection due to the physical laws of gravity and water hydraulics, components of a backflow prevention system may be waived by the department.

     (2) Barometric pipe loop

     (a) Barometric loops can only be used on systems pumping from a surface water source.

     (b) The barometric pipe loop must be located in the main water line immediately downstream of the irrigation water pump.

     (c) A barometric pipe loop must be designed with sufficient elevation differential to compensate for backflow.

     (d) The bottom of the barometric loop apex must be at least 30 inches above the highest water-emitting device or of any portion of the irrigation application system.

     (e) The barometric loop must contain a vacuum relief device at the loop apex that allows air into the pipeline immediately upon loss of pressure. The orifice size must comply with current American Society of Agricultural Engineers (ASAE) standards.

     (f) The chemical injection port must be located downstream of and a least 30 inches below the bottom of the pipe loop apex.

     (3) The department will recognize alternative backflow devices, providing they are as restrictive as the provisions of this chapter.

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     (1) Injection into a pressurized section of an irrigation system must include:

     (a) An automatic, quick-acting injection line check valve must be used to prevent leakage from the application tank into irrigation water and to prevent irrigation water from entering the chemical injection line. The injection line check valve must maintain, at a minimum, 10 psi opening (cracking) pressure or adequate opening pressure to prevent gravity flow due to hydraulic head pressure from the application tank. The check valve must be located at the point of product injection into the irrigation water; and

     (b) Where siphon action induced by an irrigation system could compromise the cracking (opening) pressure of an injection line check valve, a vacuum relief valve must be installed in the irrigation line downstream of the injection point. The orifice size must comply with current American Society of Agricultural Engineers (ASAE) standards.

     (2) Injection into non-pressurized (e.g. open surface, gated pipe, or spigotted pipe) portion of irrigation system must include a hydraulic discontinuity in source water flow or a sufficient hydraulic gradient such that chemicals or treated water cannot contaminate the water source. Backflow devices for non-pressurized systems may include a weir box, drop structure, air gap, batch tank, or similar device whose intended function is to prevent backflow into the application tank.

     (3) Venturi or other passive injection systems

     (a) If backpressure or backsiphonage can occur, the chemical injection line must contain an automatic, quick-closing check valve. The valve must be located immediately adjacent to the chemical inlet side of the venturi.

     (b) If product can potentially siphon or seep into the water supply, the chemical injection line must contain a normally closed solenoid operative valve connected to the system interlock, or a normally closed hydraulically operated valve that opens only when the main water line is adequately pressurized. The valve must be installed adjacent to the product outlet on the application tank.

     (c) With a bypass system, as an alternative to (a) and (b) above, the automatic, quick-closing check valve may be installed in the bypass immediately upstream of the venturi water inlet. In addition, either the normally closed solenoid or the hydraulic solenoid may be installed immediately downstream of the venturi water outlet.

     (d) Bypass systems with a booster pump must have the normally closed solenoid interlocked with the source pump for the irrigation system.

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     (1) In lieu of a normally closed solenoid with the injection system

     (a) A normally open valve must be located in the chemical injection line between the application tank and a positive displacement injection pump. The normally open valve must be spring-loaded, and must close upon a vacuum and open at atmospheric pressure. It must be elevated at least 12-inches above the maximum fluid level in the application tank and must be the highest point in the injection line.

     (b) The mechanism described in (a) cannot be used in conjunction with a venturi injection system.

     (2) In lieu of a 10 psi opening (cracking) pressure check valve

     (a) An automatic, quick-acting, spring-loaded check valve must be attached at or positioned immediately adjacent to the injection point to prevent irrigation water from entering the chemical injection line.

     (b) A normally closed solenoid must be installed immediately adjacent to the product outlet on the application tank. If electric, it must be interlocked with the injection pump or, if hydraulic, with the irrigation system.

     (c) In place of (b), a normally open valve must be located in the chemical injection line between the application tank and a positive displacement injection pump as described in (1)(a). This alternative cannot be used with venturi injection systems.

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     (1) Injecting product with a pressurized metering pump

     (a) The metering pump must be of a positive displacement design.

     (b) Water-powered injection pumps can only be used when no other power source is available to operate the injection unit.

     (c) The metering pump must be interlocked to the irrigation system in the event of an irrigation system malfunction or failure.

     (2) Injection into non-pressurized section of an irrigation system

     (a) Application rate may be accomplished with an adjustable valve, flow control device, or other metering mechanism.

     (b) The metering device must also control application quantity by employing a slide metering device or by placing a predetermined quantity into a batch tank.

     (3) Venturi system as a metering device

     (a) A venturi system may be used as a metering device, except where variable pressure may contribute to a variable injection rate.

     (b) The chemical injection line must contain either a normally closed, solenoid-operated valve connected to the system interlock or a normally closed hydraulically operated valve that opens only when the main water line is adequately pressurized. The valve must be placed on the intake side of the injection pump, immediately adjacent to the application tank.

     (c) The chemical injection line between the application tank and the venturi must contain an automatic, quick-closing check valve to prevent the flow of liquid back toward the application tank. The check valve must be placed immediately adjacent to the venturi chemical inlet.

     (d) In bypass systems, the check valve may be installed immediately upstream of the venturi water inlet. Either the normally closed solenoid or hydraulically operated valve may be installed immediately downstream of the venturi water outlet.

     (e) If a booster or auxiliary pump is used in conjunction with a venturi system, the normally closed solenoid must be electrically interlocked with the source pump for the irrigation system.

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     A person may function as a metering device with a nonpressurized irrigation delivery system. However, the individual must remain on-site to continuously monitor the application and be immediately available to terminate the application in the event of equipment malfunction. The person must be knowledgeable about the operation of the irrigation and injection systems.

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     (1) Pressurized injection or injection into pressurized irrigation system

     (a) An injection line check valve must be used whenever injection occurs in a pressurized section of an irrigation system or with a pressurized injection system.

     (b) The injection line check valve must inject product directly into the irrigation water and must be installed downstream of the irrigation mainline check valve.

     (c) The point of injection into an irrigation system cannot be located within 10 feet of a wellhead, public waterway, off-farm irrigation supply ditch or conveyance system, or sensitive area.

     (d) The injection line check valve mechanism must prevent leakage due to hydraulic head pressure from the application tank and must prevent backflow from the irrigation water source into the supply tank. The injection line check valve must maintain, at a minimum, 10 psi opening (cracking) pressure or adequate opening pressure to prevent gravity flow from the application tank.

     (e) In instances where siphoning action induced by an irrigation system could compromise the opening (cracking) pressure of a injection line check valve, a vacuum relief valve must be installed in the irrigation line downstream of the injection point.

     (2) Injection into non-pressurized section of irrigation system

     (a) If injection occurs in a non-pressurized portion of the irrigation system, an air gap or other hydraulic discontinuity must exist between the pressurized or non-pressurized irrigation water source and the point of product injection.

     (b) When an air gap is used in conjunction with a public water supply, injection may only occur downstream of the air gap.

     (3) Venturi systems

     (a) The chemical injection line must contain either a normally closed solenoid-operated valve connected to the system interlock or a normally closed hydraulically operated valve that opens only when the main water line is adequately pressurized. The valve must be placed on the intake side of the injection pump, immediately adjacent to the application tank.

     (b) The chemical injection line between the application tank and the metering device must contain an automatic, quick-closing check valve. The check valve must be placed immediately adjacent to the venturi chemical inlet.

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     (1) Injection with barometric loops

     (a) Barometric loops can only be used on systems pumping from a surface water source.

     (b) The barometric loop must be located in the water line immediately downstream of the irrigation water pump.

     (c) A barometric pipe loop must be designed with sufficient elevation differential to compensate for backflow.

     (d) The bottom of the barometric loop apex must be at least 30 inches above the highest water-emitting device or of any portion of the irrigation application system.

     (e) The barometric loop must contain a vacuum relief device at the loop apex that allows air into the pipeline immediately upon loss of pressure. The orifice size must comply with current American Society of Agricultural Engineers (ASAE) standards.

     (f) The injection point on a barometric loop must be located downstream of and at least 30 inches below the bottom of the barometric pipe loop apex.

     (2) Solenoid and check valve

     (a) The chemical injection line must contain either a normally closed solenoid-operated valve connected to the system interlock or a normally closed hydraulically operated valve that opens only when the main water line is adequately pressurized. A normally closed, solenoid-operated valve must be placed on the intake side of the injection pump, immediately adjacent to the application tank.

     (b) The chemical injection line between the application tank and the metering device and the injection point must contain an automatic, quick-closing check valve to prevent the flow of liquid back toward the application tank. The check valve must be placed immediately adjacent to the venturi chemical inlet.

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     (1) Pressurized injection systems or injection into a pressurized portion of the irrigation system requires either an electrical, hydraulic, or mechanical system interlock device.

     (2) When the injection point is at a non-pressurized section of the irrigation application system, a slide metering scale or batch tank may function as the system interlock.

     (3) With venturi systems

     (a) Booster or auxiliary water pumps must be connected with the system interlock such that when pressure in the mainline changes to the point where product distribution is adversely affected automatic shutoff of product supply will occur.

     (b) The supply line must contain either a normally closed solenoid-operated valve connected to the system interlock or a normally closed hydraulically operated valve that opens only when the main water line is adequately pressurized. If a booster or auxiliary pump is used in conjunction with a venturi system, the normally closed solenoid must be electrically interlocked with the source pump for the irrigation system.

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     (1) Human interlock

     (a) In lieu of an automatic interlock, a person may serve as a system interlock. The individual must continuously monitor the application, be alert throughout the application process, be immediately available to terminate the application in the event of equipment malfunction, and be knowledgeable about the operation of the irrigation and injection systems.

     (2) Solenoid and check valve

     (a) The chemical injection line must contain either a normally closed solenoid-operated valve connected to the system interlock or a normally closed hydraulically operated valve that opens only when the main water line is adequately pressurized. A normally closed, solenoid-operated valve must be placed on the intake side of the injection pump, immediately adjacent to the application tank.

     (b) The chemical injection line between the application tank and the metering device must contain an automatic, quick-closing check valve to prevent the flow of liquid back toward the application tank. The check valve must be placed immediately adjacent to the venturi chemical inlet.

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     Cross-connections of a fertigation system to any potable water system intended for human use must have either a Department of Health-approved reduced pressure backflow assembly or reduced pressure detector assembly installed for backflow prevention. Otherwise, a physical separation in the form of an air gap may be used to protect the water source.

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PENALTIES AND PENALTY ASSIGNMENT SCHEDULE
NEW SECTION
WAC 16-202-2021   Penalties   (1) Any person who fails to comply with any provision of this chapter shall be subject to imposition of a civil penalty as provided in Chapter 15.54.474 RCW.

     (2) The director may bring an action to enjoin the violation or threatened violation of any provision of this chapter or any rule made pursuant to this chapter in a court of competent jurisdiction of the county in which such violation occurs or is about to occur.

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     The following section of the Washington Administrative Code is repealed:

WAC 16-202-2000

Fertigation.

© Washington State Code Reviser's Office