Analytical requirements for microbiological contaminants

Analytical requirements for microbiological contaminants. (1) Analytical methods. Analyses conducted to determine compliance with s. NR 809.31 shall be made in accordance with methods listed in Table F. (2) Sample volume. The standard sample volume required for total coliform analysis, regardless of analytical method used, is 100 ml. (3) Sample collection preservation and holding time. (a) Sample collection for microbiological contaminants under s. NR 809.30 shall be conducted using the sample preservation, containers and maximum holding time procedures specified in par. (b) . (b) Sample preservation requirements and holding times for microbiological samples are specified in subds. 1. and 2. In all cases, samples shall be analyzed as soon after collection as possible. 1. Total Coliform and E. coli samples are not required to be preserved by cooling to 10 ° C, however it is encouraged during transit. Sodium thiosulfate shall be added to the sample container prior to adding water containing chlorine and the holding time shall be 30 hours. 2. Heterotrophs may be either held at room temperature with a holding time of 6 hours or preserved by cooling to 4 ° C with a holding time of 24 hours. (4) Laboratory certification. Analyses under this section shall only be conducted by laboratories that have received certification under ch. ATCP 77 or approval by EPA. (5) Presence or absence. Water suppliers need only determine the presence or absence of total coliforms; a determination of total coliform density is not required. (6) Required methods. Samples collected to determine compliance with s. NR 809.30 (1) shall be analyzed by enzyme substrate test methods. (7) Other methods. The department may approve, on a case-by-case basis, other methods for use in determining compliance with s. NR 809.30 (1) if they have been approved by EPA. (8) Sample integrity. If chlorine odor is present in a drinking water sample the laboratory shall test the sample for the presence of chlorine. If chlorine is detected in the sample, the laboratory shall reject the sample for analysis, based on the improper preservation. The water supplier shall submit a new sample for analysis to replace the rejected sample.