PURPOSE: This rule establishes waiver requirements from testing for asbestos, volatile organic chemicals, synthetic organic chemicals and inorganic chemicals.

1. (1) Waivers may be granted by the department in accordance with the criteria in sections (2) and (3) of this rule. The department may initiate the evaluation and issue a waiver based on its evaluation of the criteria in sections (2) and (3) of this rule. A public water system may submit a written request and supporting documentation for a waiver in accordance with sections (2) and (3) of this rule at any time if the department has not issued or denied a waiver.

2. (2) Use waivers may be granted if it is determined that there has been no previous use of a contaminant within a given boundary, and that the public water supply system is in no danger of contamination from the specified contaminant. Use waivers are based on the use, or absence of use, of a potentially harmful contaminant within a given boundary. The boundary size will be determined by the department and can range from a single water system to statewide. Use waivers obtained for asbestos and synthetic organic chemicals (SOCs) may relieve the system of any sampling requirements. Use waivers will not be granted for volatile organic chemicals listed in 10 CSR 60-4.100(2) or for inorganic chemicals listed in 10 CSR 60-4.030(1) other than asbestos.

   1. (A) Asbestos listed in 10 CSR 60- 4.030(1)—Waivers from analysis for asbestos in a water system will be based on the existence of asbestos-cement piping within the water system or asbestos contamination within the source water. If any asbestos-cement piping is present in any part of the treatment/distribution system, or if the source water is known to or suspected to contain asbestos, waivers will not be granted.
   2. (B) SOCs listed in 10 CSR 60-4.040— Waivers from analysis for SOCs in a water system will be based on knowledge of previous use (including transportation, storage, or previous disposal) within a given boundary. If a given SOC has been detected within a water system, a waiver will not be granted to that system.

3. (3) Susceptibility waivers may be granted in the form of reduced monitoring if all of the criteria in subsection (3)(A) are met. For assessing susceptibility and examining criteria in paragraphs (3)(A)2. and 3., the minimum boundary area will be a radius of one-quarter (1/4) of a mile about groundwater well head(s) or the watershed area(s) of a surface water source. Susceptibility waivers may be granted for SOCs listed in 10 CSR 60- 4.040(1) including polychlorinated biphenyls (PCBs), volatile organic chemicals (VOCs) listed in 10 CSR 60-4.100(2), and inorganic chemicals (IOCs) listed in 10 CSR 60- 4.030(1) except for nitrate and nitrite.

   1. (A) Criteria for Susceptibility Waivers.

      1. 1. Previous analytical results show no

detections.

1. 2. The proximity of the system to a

potential point or nonpoint source of contamination (that is, Superfund Amendments and Reauthorization Act (SARA) Title III hazardous waste site) is such that contamination is unlikely.

1. 3. The environmental persistence of the

contaminant is such that contamination is unlikely to occur due to the transport time, geographical, and geological characteristics.

1. 4. The water source is protected from

contamination by being constructed in a manner no less stringent than set forth for nonpublic wells in the Water Well Construction Code 10 CSR 23-3 promulgated pursuant to the Missouri Water Well Drillers Act, section 256.600–256.640, RSMo.

1. 5. The nitrate levels have been tested

and it has been found that elevated nitrate levels indicating surface water intrusion do not exist.

1. 6. The corrosive nature of the source

water and the effectiveness of the systems corrosion control program.

1. (B) PCBs—Susceptibility waivers may be granted for PCBs if the criteria in subsection (3)(A) are met and there has been no use of PCBs in the equipment used for production, storage or distribution of water, or sampling has not indicated the presence of PCBs. AUTHORITY: section 640.100, RSMo 2016.* Original rule filed March 31, 1992, effective Dec. 3, 1992. Amended: Filed May 4, 1993, effective Jan. 13, 1994. Amended: Filed June 13, 2018, effective Feb. 28, 2019.

*Original authority: 640.100, RSMo 1939, amended 1978, 1981, 1982, 1988, 1989, 1992, 1993, 1995, 1996, 1998, 1999, 2002, 2006, 2012, 2014.