1. (a) This section shall apply to owners and operators of elementary neutralization units and wastewater treatment units provided that, in the case of elementary neutralization units that are transport vehicles or vessels or containers otherwise used to transport the waste after neutralization, neutralization occurs in these units while they remain stationary and before transport of the neutralized waste begins.
2. (b) This section shall not apply to the owner or operator of an elementary neutralization unit or wastewater treatment unit if the owner or operator is a very small quantity generator as described in Env-Hw 503.02.
3. (c) A limited permit shall be granted only if the applicant meets the conditions specified in (d) through (i), below.
4. (d) The owner or operator shall not treat or store a hazardous waste in an elementary neutralization unit or a wastewater treatment unit without having received an EPA identification number in accordance with Env-Hw 504.

5. (e) The operator shall prevent the unknowing entry, and minimize the possibility for the unauthorized entry, of persons or livestock into or onto the elementary neutralization unit or wastewater treatment unit, unless:

   1. (1) Physical contact with the waste contained in the unit will not injure unknowing or unauthorized persons or livestock that might enter the unit; and
   2. (2) Disturbance of the waste or equipment by the unknowing or unauthorized entry of persons or livestock into or onto the unit will not cause a violation of the requirements of this section.
6. (f) The operator shall inspect the elementary neutralization unit or wastewater treatment unit in accordance with 40 CFR 265.15, except that the minimum inspection frequencies cited in 40 CFR 265.15(b)(4) shall not apply.

7. (g) The operator of an elementary neutralization unit or wastewater treatment unit shall ensure that:

   1. (1) The unit is constructed of sturdy, leak-proof material;
   2. (2) The unit is designed, constructed, and operated so as to prevent hazardous wastes from being spilled or leaked into or onto any land or water during the operating life of the unit; and

   3. (3) The treatment process conducted in the unit does not:

      1. a. Generate extreme heat or pressure, fire, explosion, or violent reaction;
      2. b. Produce uncontrolled toxic mists, fumes, or gases in sufficient quantities to threaten human health;
      3. c. Produce uncontrolled flammable fumes or gases in sufficient quantities to pose a risk of fire or explosion;
      4. d. Damage the structural integrity of the tank or equipment containing the waste;
      5. e. Otherwise threaten human health or the environment; or
      6. f. Include placement of hazardous wastes or treatment reagents if they could cause the unit or any of its equipment to rupture, leak, abnormally corrode, or otherwise fail before the end of its intended life.
8. (h) At closure, the operator of an elementary neutralization unit or wastewater treatment unit shall remove all hazardous waste and hazardous waste residues from the unit.

9. (i) Within 15 days after any spill or leakage of hazardous waste from an elementary neutralization unit or wastewater treatment unit, the operator of the unit shall submit a written report to the department that contains the following information:

   1. (1) Name, address, and telephone number of the owner or operator;
   2. (2) Name, address, and telephone number of the facility;
   3. (3) Date, time, and nature of the incident;
   4. (4) Name and quantity of materials involved;
   5. (5) The extent of injuries, if any;
   6. (6) An assessment of actual or potential hazards to human health or the environment, where this is applicable; and
   7. (7) Estimated quantity and disposition of spilled or leaked material recovered after the incident.

10. (j) A limited permit shall be granted only for an elementary neutralization unit or wastewater treatment unit that:

    1. (1) Meets the applicable definition for such a unit in Env-Hw 103 or Env-Hw 104;
    2. (2) Is subject to and in compliance with a National Pollution Discharge Elimination System (NPDES) permit if the unit discharges directly into surface waters;
    3. (3) Meets the best engineering practice for such units;
    4. (4) Has been assigned an EPA identification number, unless the unit is totally enclosed with no hazardous waste sludges produced;
    5. (5) Is in compliance with the manifesting requirements of Env-Hw 510; and
    6. (6) Is in compliance with the recordkeeping and reporting requirements of Env-Hw 512, for a generator, or Env-Hw 705, for an owner or operator of a hazardous waste facility.

11. (k) A limited permit shall be granted for a wastewater evaporation unit only if the applicant demonstrates that:

    1. (1) The facility uses an evaporation-type unit that removes wastewaters by an evaporation or heat process;
    2. (2) The unit is permitted for air emission discharges or demonstrates on documents that air emission discharges from the evaporation unit do not significantly impact ambient air quality; and
    3. (3) The facility complies with the requirements of (d) through (i), above.

12. (l) The operator of each unit subject to this section shall complete and submit:

    1. (1) Form HWM-1 “Hazardous Waste Limited Permit Application” as amended August 2025;

    2. (2) The following information:

       1. a. Process design drawings, plans, or flow diagrams;
       2. b. Engineering design plans or manufacturer technical specifications for the unit(s);
       3. c. A copy of the inspection schedule for the unit(s);

       4. d. Analytical results, from analyses conducted no more than 12 months prior to submittal of the application, for a representative sample of:

          1. 1. Wastewater, before and after treatment; and
          2. 2. Treatment sludge, if applicable;
       5. e. A copy of the related, current wastewater discharge permit, if any; and
       6. f. If seeking a permit for a wastewater evaporation unit, a copy of any related, current air resources division permits or documentation to demonstrate that the air emissions do not significantly impact air quality; and
    3. (3) The application fee specified in Env-Hw 304.07(d) or Env-Hw 304.07(e)(7), as applicable.
13. (m) A limited permit shall expire 5 years from the date of issuance.
14. (n) The permittee shall apply for a permit renewal by submitting an application as specified in (l), above, to the department before the limited permit expires.

Source. (See Revision Note at chapter heading for Env-Hw 300) #9362, eff 1-28-09; ss by #12345, eff 8-14-17; amd by #12922, eff 11-23-19; ss by #14279, eff 8-1-25, EXPIRES: 8-1-35