1. (1) Application tanks shall not be located in an area or placed in such a manner to contaminate water, the environment, sensitive areas, or to endanger human health.

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

   1. (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.
   2. (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.
   3. (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.
   4. (d) Alternative technology that provides substantially equal protection such as a secondary containment facility that complies with the structural design requirements in the secondary and operational area containment rules found in chapter 16-201 WAC (commercial fertilizers) and chapter 16-229 WAC (pesticides) will fulfill the requirements in (a), (b), and (c) of this subsection.
   5. (e) Overflow from an irrigation pond contaminated with product cannot enter a public waterway, off-farm irrigation supply ditch or conveyance system, or sensitive area.

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

   1. (a) Application tanks must be placed on a rigid, sound understructure or on stable ground to prevent tippage, spillage, puncturing, or breakage.
   2. (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.
4. (4) Application tanks should be sited as close as reasonably possible to the injection point.
5. (5) Tank outlet ports must be fitted with manual shutoff valves.

[Statutory Authority: RCW 17.21.030, 15.58.040(2), and 15.54.800(2). WSR 25-22-066, s 16-202-250, filed 10/31/25, effective 12/1/25.]