PURPOSE: This rule sets forth requirements for the removal of lead service lines if lead action levels are exceeded, and corrosion control efforts and source water treatment are unsuccessful in lowering the lead concentration levels in tap samples.

1. (1) Systems that fail to meet the lead action level in tap samples taken pursuant to 10 CSR 60-15.070(4)(B), after installing corrosion control, source water treatment, or both (whichever sampling occurs later), shall replace lead service lines in accordance with the requirements of this section. If a system is in violation of 10 CSR 60-15.020 or 10 CSR 60-15.040 for failure to install source water or corrosion control treatment, the department may require the system to commence lead service line replacement under this section after the date by which the system was required to conduct monitoring under 10 CSR 60-15.070(4)(B) has passed.
2. (2) A system annually shall replace at least seven percent (7%) of the initial number of lead service lines in its distribution system. The initial number of lead service lines is the number of lead lines in place at the time the replacement program begins. The system shall identify the initial number of lead service lines in its distribution system based upon a materials evaluation, including the evaluation required under 10 CSR 60- 15.070(1). The first year of lead service line replacement shall begin on the date the action level was exceeded in tap sampling referenced in section (1) of this rule.
3. (3) A system is not required to replace an individual lead service line if the lead concentration in all service line samples from that line, taken pursuant to 10 CSR 60- 15.070(2)(C), is less than or equal to 0.015 milligrams per liter (mg/l).
4. (4) A water system shall replace the entire service line (up to the building inlet) unless it demonstrates to the satisfaction of the department under section (5) of this rule that it controls less than the entire service line. In those cases, the system shall replace the portion of the line which the department determines is under the system’s control. The system shall notify the user served by the line that the system will replace the portion of the service line under its control and shall offer to replace the building owner’s portion of the line, but is not required to bear the cost of replacing the building owner’s portion of the line. For buildings where only a portion of the lead service line is replaced, the water system shall inform the resident(s) that the system will collect a first flush tap water sample after partial replacement of the service line is completed if the resident(s) so desires. In cases where the resident(s) accepts the offer, the system shall collect the sample and report the results to the resident(s) within fourteen (14) days following partial lead service line replacement.
5. (5) A water system is presumed to control the entire lead service line (up to the building inlet) unless the system demonstrates to the satisfaction of the department, in a letter submitted under 10 CSR 60-7.020(5)(D), that it does not have any of the following forms of control over the entire line (as defined by Missouri statutes, municipal ordinances, public service contracts or other applicable legal authority): authority to set standards for construction, repair or maintenance of the line; authority to replace, repair or maintain the service line; or ownership of the service line. The department shall review the information supplied by the system and determine whether the system controls less than the entire service line and, in those cases, shall determine the extent of the system’s control. The department’s determination shall be in writing and explain the basis for its decision.
6. (6) The department shall require a system to replace lead service lines on a shorter time schedule than that required by this section, taking into account the number of lead service lines in the system, where such a shorter replacement schedule is feasible. The department shall make this determination in writing and notify the system of its finding 10 CSR 60-15

within six (6) months after the system is triggered into lead service line replacement based on monitoring referenced in section (1) of this rule.

1. (7) Any system may cease replacing lead service lines whenever first-draw tap samples collected pursuant to 10 CSR 60- 15.070(4)(C) meet the lead action level during each of two (2) consecutive monitoring periods and the system submits the results to the department. If the first-draw tap samples in any such water system after that exceed the lead action level, the system shall recommence replacing lead service lines, pursuant to section (2) of this rule.
2. (8) To demonstrate compliance with sections (1)—(4) of this rule, a system shall report to the department the information specified in 10 CSR 60-7.020(5).

AUTHORITY: section 640.100, RSMo (Cum. Supp. 1989).* Original rule filed Aug. 4, 1992, effective May 6, 1993.

*Original authority 1939, amended 1978, 1981, 1982, 1988, 1989.