R 325.10604b MCLs for volatile organic chemicals other than total trihalomethanes.

Rule 604b. (1) The maximum contaminant levels and effective dates for volatile organic chemicals in table 1 of this rule apply to community and nontransient noncommunity water supplies. Table 1 MCLs for volatile organic chemicals Contaminant Maximum Contaminant Level in mg/l Effective Date Benzene 0.005 January 9, 1989. Vinyl chloride 0.002 January 9, 1989. Carbon tetrachloride 0.005 January 9, 1989. 1,2-dichloroethane 0.005 January 9, 1989. Trichloroethylene 0.005 January 9, 1989. 1,1-dichloroethylene 0.007 January 9, 1989. 1,1,1-trichloroethane 0.20 January 9, 1989. para-dichlorobenzene 0.075 January 9, 1989. cis-1,2-dichloroethylene 0.07 July 30, 1992. 1,2-dichloropropane 0.005 July 30, 1992. Ethylbenzene 0.7 July 30, 1992. Monochlorobenzene 0.1 July 30, 1992. 0-dichlorobenzene 0.6 July 30, 1992. Contaminant Maximum Contaminant Level in mg/l Effective Date Styrene 0.1 July 30, 1992. Tetrachloroethylene 0.005 July 30, 1992. Toluene 1 July 30, 1992. trans-1, 2-dichloroethylene 0.1 July 30, 1992. Xylenes (total) 10 July 30, 1992. Dichloromethane 0.005 January 17, 1994. 1,2,4-Trichlorobenzene 0.07 January 17, 1994. 1,1,2-Trichloroethane 0.005 January 17, 1994. (2) Compliance with the MCLs in table 1 of this rule shall be determined based on the analytical results obtained at each sampling point. If 1 sampling point is in violation of the MCL, then the supply is in violation of the MCL. All of the following provisions apply: (a) For supplies monitoring more than once per year, compliance with the MCL is determined by a running annual average at each sampling point. (b) Supplies monitoring annually or less frequently whose sample result exceeds the MCL shall begin quarterly sampling. Compliance with the MCL shall be based on the running annual average. For the purpose of calculating the running annual average, the initial exceedance shall be considered the result for the first quarter. If the department requires a confirmation sample under R 325.10716(15), then the average of the initial exceedance and the confirmation sample shall be considered the result for the first quarter. The supply shall not be considered in violation of the MCL until it has completed 1 year of quarterly sampling. (c) If any sample result causes the running annual average to exceed the MCL at any sampling point, then the supply is out of compliance with the MCL immediately. (d) If a supply fails to collect the required number of samples, then compliance shall be based on the total number of samples collected. (e) If a sample result is less than the detection limit, then zero shall be used to calculate the annual average.