Indiana Administrative Code
Title 327 - WATER POLLUTION CONTROL DIVISION
Article 8 - PUBLIC WATER SUPPLY
Rule 2 - Drinking Water Standards
Section 2-8.8 - Monitoring requirements; PWSs that provide filtration treatment
Current through September 18, 2024
Authority: IC 13-13-5; IC 13-14-8-2; IC 13-14-8-7; IC 13-18-3-1; IC 13-18-3-2; IC 13-18-16-8; IC 13-18-16-9
Affected: IC 13-18-2; IC 13-18-16
Sec. 8.8.
(a) A PWS that:
(b) Turbidity measurements as required by section 8.5 of this rule must be performed on representative samples of the PWS's filtered water every four (4) hours (or more frequently) that the PWS serves water to the public. A PWS may substitute continuous turbidity monitoring for grab sample monitoring if the PWS validates the continuous measurement for accuracy on a regular basis and obtains approval from the commissioner. The commissioner may reduce the turbidity sampling frequency to once per day if the commissioner determines that less frequent monitoring is sufficient to indicate effective filtration performance for the following:
(c) The residual disinfectant concentration of the water entering the distribution system must meet the following:
PWS size by population | Samples per day* |
[LESS THAN]500 | 1 |
501-1,000 | 2 |
1,001-2,500 | 3 |
2,501-3,300 | 4 |
*The day's samples cannot be taken at the same time. The sampling intervals are subject to review and approval by the commissioner.
(d) The residual disinfectant concentration must be measured according to the following:
if the commissioner determines that the sampling points other than those under subdivision (1) are more representative of treated (disinfected) water quality within the distribution system.
Heterotrophic bacteria, measured as heterotrophic plate count (HPC), as specified in section 8.7(3) of this rule, may be measured in lieu of residual disinfectant concentration.
(e) If the commissioner determines, based on site-specific considerations, that a PWS:
*These documents are incorporated by reference. Copies may be obtained from the Government Publishing Office, www.gpo.gov, or are available for review at the Indiana Department of Environmental Management, Office of Legal Counsel, Indiana Government Center North, 100 North Senate Avenue, Thirteenth Floor, Indianapolis, Indiana 46204.