R 325.10705 Collection and analysis of samples for coliform bacteria; community water systems.

Rule 705. (1) A supplier of water of a community water system shall collect samples of water to be analyzed for the presence of coliform bacteria at sites which are representative of water throughout the distribution system according to a written sample siting plan that is subject to department review and revision. (2) The monitoring frequency for total coliforms for a community water system is based on the population served by the system as set forth in table 1 of this rule: Table 1 Total Coliform Monitoring Frequency for Community Water Supplies Population Served Minimum Number of Samples Per Month 25 to 1,000 * 1 1,001 to 2,500 2 2,501 to 3,300 3 3,301 to 4,100 4 4,101 to 4,900 5 4,901 to 5,800 6 5,801 to 6,700 7 6,701 to 7,600 8 7,601 to 8,500 9 8,501 to 12,900 10 12,901 to 17,200 15 17,201 to 21,500 20 21,501 to 25,000 25 25,001 to 33,000 30 33,001 to 41,000 40 41,001 to 50,000 50 50,001 to 59,000 60 59,001 to 70,000 70 70,001 to 83,000 80 83,001 to 96,000 90 96,001 to 130,000 100 130,001 to 220,000 120 220,001 to 320,000 150 320,001 to 450,000 180 450,001 to 600,000 210 600,001 to 780,000 240 780,001 to 970,000 270 970,001 to 1,230,000 300 1,230,001 to 1,520,000 330 1,520,001 to 1,850,000 360 1,850,001 to 2,270,000 390 2,270,001 to 3,020,000 420 3,020,001 to 3,960,000 450 3,960,001 or more 480 * Includes public water supplies which have not less than 15 service connections, but which serve fewer than 25 persons. (3) If a community water system that serves 25 to 1,000 persons does not have a history of total coliform contamination in its current configuration and a sanitary survey conducted in the past 5 years shows that the system is supplied solely by a protected groundwater source and is free of sanitary defects, the department may reduce the monitoring frequency specified in table 1 of this rule, except that the department shall not reduce the monitoring frequency to less than 1 sample per quarter. To be valid, the reduced monitoring frequency shall be approved, in writing, by the department. (4) Suppliers of water for all community water systems and noncommunity water systems shall collect samples at regular time intervals throughout the monitoring period, except for those groundwater supplies which serve fewer than 4,901 persons and which are not influenced by surface water. Groundwater suppliers that serve fewer than 4,901 persons may collect all required samples on a single day if the samples are taken from different sites.