Section 173-303-202. Special requirements for generators of between two hundred twenty and two thousand two hundred pounds per month that accumulate dangerous waste in tanks.

(1) This section applies to generators of more than two hundred twenty pounds but less than two thousand two hundred pounds of dangerous waste in a calendar month, that accumulate dangerous waste in tanks for less than one hundred eighty days (or two hundred seventy days if the generator must ship the waste greater than two hundred miles), and do not accumulate over two thousand two hundred pounds on-site at any time.

(2) Generators of between two hundred twenty and two thousand two hundred pounds per month of dangerous waste must comply with the following general operating requirements:

(a) Treatment or storage of dangerous waste in tanks must comply with WAC 173-303-395(1).

(b) Dangerous wastes or treatment reagents must not be placed in a tank if they could cause the tank or its inner liner to rupture, leak, corrode, or otherwise fail before the end of its intended life.

(c) Uncovered tanks must be operated to ensure at least sixty centimeters (two feet) of freeboard, unless the tank is equipped with a containment structure (e.g., dike or trench), a drainage control system, or a diversion structure (e.g., standby tank) with a capacity that equals or exceeds the volume of the top sixty centimeters (two feet) of the tank.

(d) Where dangerous waste is continuously fed into a tank, the tank must be equipped with a means to stop this inflow (e.g., waste feed cutoff system or by-pass system to a standby tank).

Note:	These systems are intended to be used in the event of a leak or overflow from the tank due to a system failure (e.g., a malfunction in the treatment process, a crack in the tank, etc.).

(3) Generators of between two hundred twenty and two thousand two hundred pounds per month accumulating dangerous waste in tanks must inspect, where present:

(a) Discharge control equipment (e.g., waste feed cutoff systems, by-pass systems, and drainage systems) at least once each operating day, to ensure that it is in good working order;

(b) Data gathered from monitoring equipment (e.g., pressure and temperature gauges) at least once each operating day to ensure that the tank is being operated according to its design;

(c) The level of waste in the tank at least once each operating day to ensure compliance with subsection (2)(c) of this section;

(d) The construction materials of the tank at least weekly to detect corrosion or leaking of fixtures or seams; and

(e) The construction materials of, and the area immediately surrounding, discharge confinement structures (e.g., dikes,) at least weekly to detect erosion or obvious signs of leakage (e.g., wet spots or dead vegetation).

Note:	As required by WAC 173-303-320(3), the owner or operator must remedy any deterioration or malfunction he finds.

(4) Generators of between two hundred twenty and two thousand two hundred pounds per month accumulating dangerous waste in tanks must, upon closure of the facility, remove all dangerous waste from tanks, discharge control equipment, and discharge confinement structures.

Note:	At closure, as throughout the operating period, unless the owner or operator can demonstrate, in accordance with WAC 173-303-070 (2)(a) or (b), that any solid waste removed from his tank is not a dangerous waste, the owner or operator becomes a generator of dangerous waste and must manage it in accordance with all applicable requirements of this chapter.

(5) Generators of between two hundred twenty and two thousand two hundred pounds per month must comply with the following special requirements for ignitable or reactive waste:

(a) Ignitable or reactive waste must not be placed in a tank, unless:

(i) The waste is treated, rendered, or mixed before or immediately after placement in a tank so that:

(A) The resulting waste, mixture, or dissolution of material no longer meets the definition of ignitable or reactive waste under WAC 173-303-090 (5) or (7) of this chapter; and

(B) WAC 173-303-395(1) is complied with; or

(ii) The waste is stored or treated in such a way that it is protected from any material or conditions that may cause the waste to ignite or react; or

(iii) The tank is used solely for emergencies.

(b) The owner or operator of a facility which treats or stores ignitable or reactive waste in covered tanks must comply with the buffer zone requirements for tanks contained in Tables 2-1 through 2-6 of the National Fire Protection Association's "Flammable and Combustible Liquids Code," (1977 or 1981).

(6) Generators of between two hundred twenty and two thousand two hundred pounds per month must comply with the following special requirements for incompatible wastes:

(a) Incompatible wastes, or incompatible wastes and materials, (see 40 C.F.R. Part 265 Appendix V for examples) must not be placed in the same tank, unless WAC 173-303-395(1) is complied with.

(b) Dangerous waste must not be placed in an unwashed tank which previously held an incompatible waste or material, unless WAC 173-303-395(1) is complied with.

[Statutory Authority: Chapters 70.105 and 70.105D RCW. WSR 94-01-060 (Order 92-33), § 173-303-202, filed 12/8/93, effective 1/8/94. Statutory Authority: Chapter 70.105 RCW. WSR 89-02-059 (Order 88-24), § 173-303-202, filed 1/4/89.]

Chapters 70.105 and 70.105D RCW. WSR 94-01-060 (Order 92-33), § 173-303-202, filed 12/8/93, effective 1/8/94. Statutory Authority: Chapter 70.105 RCW. WSR 89-02-059 (Order 88-24), § 173-303-202, filed 1/4/89.

Rules

173-303-395,173-303-320,173-303-070,173-303-090,173-303-395,173-303-395,173-303-395,