PURPOSE: This rule establishes requirements for requesting exemptions to maximum contaminant levels and treatment techniques.

1. (1) Conditions of Exemption. The department may exempt a public water system from any maximum contaminant level (MCL) requirement, except for those MCL violations that present an acute, short-term risk to public health or any treatment technique requirement, or both, upon a finding that—

   1. (A) Due to compelling factors (which may include economic factors), the public water system is unable to comply with the contaminant level or treatment technique requirement;
   2. (B) The public water system was in operation on the effective date of the contaminant level or treatment technique requirement; and
   3. (C) The granting of the exemption will not result in an unreasonable risk to persons served by the system.

2. (2) Exemption Request. A supplier of water seeking an exemption shall submit a written request to the department. Suppliers of water may submit a joint request when they seek similar exemptions under similar circumstances. Any written request for an exemption shall include the following information:

   1. (A) The nature and duration of exemption requested;
   2. (B) Relevant analytical results of water quality sampling of the system;
   3. (C) Explanation of the compelling factors, such as time or economic factors, which prevent the system from achieving compliance;
   4. (D) A proposed compliance schedule including the date when each step toward compliance will be achieved;
   5. (E) Any other information the applicant believes to be pertinent; and
   6. (F) Other information the department may require.

3. (3) Consideration of an Exemption Request. In considering whether the public water system is unable to comply due to compelling factors, the department shall review the factors it determines relevant including the following:

   1. (A) Construction, installation or modification of treatment equipment or systems;
   2. (B) The time needed to put into operation a new treatment facility replacing an existing system which is not in compliance; and
   3. (C) Economic feasibility of compliance.

4. (4) Disposition of Exemption Request. If the department determines that a request for an exemption is inadequate or incomplete, it may deny the request.

   1. (A) If the department proposes to grant an exemption request submitted pursuant to sections (1)—(3) respectively, it shall notify the applicant of its decision in writing. The notice shall identify the exemption, the facility covered and shall specify, as appropriate, the termination date of the exemption.
   2. (B) The notice also shall provide that the exemption will be terminated when the system comes into compliance with the applicable regulation and may be terminated upon a finding by the department that the system has failed to comply with any requirements of a final schedule issued pursuant to 10 CSR 60- 6.030.

AUTHORITY: section 640.120, RSMo (Cum. Supp. 1989).* Original rule filed May 4, 1979, effective Sept. 14, 1979. Amended: Filed April 14, 1981, effective Oct. 11, 1981. Amended: Filed Dec. 4, 1990, effective July 8, 1991. *Original authority 1978, amended 1989.