§ 141.602 System specific studies.
(a) System specific study plan. Your system specific study plan must be based on either existing monitoring results as required under paragraph (a)(1) of this section or modeling as required under paragraph (a)(2) of this section. You must prepare and submit your system specific study plan to the State according to the schedule in § 141.600(c).
(1) Existing monitoring results. You may comply by submitting monitoring results collected before you are required to begin monitoring under § 141.600(c). The monitoring results and analysis must meet the criteria in paragraphs (a)(1)(i) and (a)(1)(ii) of this section.
(i) Minimum requirements. (A) TTHM and HAA5 results must be based on samples collected and analyzed in accordance with § 141.131. Samples must be collected no earlier than five years prior to the study plan submission date.
(B) The monitoring locations and frequency must meet the conditions identified in this paragraph (a)(1)(i)(B). Each location must be sampled once during the peak historical month for TTHM levels or HAA5 levels or the month of warmest water temperature for every 12 months of data submitted for that location. Monitoring results must include all subpart L compliance monitoring results plus additional monitoring results as necessary to meet minimum sample requirements.
| System Type | Population size category | Number of monitoring locations | Number of samples | |
|---|---|---|---|---|
| TTHM | HAA5 | |||
| Subpart H: | ||||
| <500 | 3 | 3 | 3 | |
| 500–3,300 | 3 | 9 | 9 | |
| 3,301–9,999 | 6 | 36 | 36 | |
| 10,000–49,999 | 12 | 72 | 72 | |
| 50,000–249,999 | 24 | 144 | 144 | |
| 250,000–999,999 | 36 | 216 | 216 | |
| 1,000,000–4,999,999 | 48 | 288 | 288 | |
| ≥5,000,000 | 60 | 360 | 360 | |
| Ground Water: | ||||
| <500 | 3 | 3 | 3 | |
| 500–9,999 | 3 | 9 | 9 | |
| 10,000–99,999 | 12 | 48 | 48 | |
| 100,000–499,999 | 18 | 72 | 72 | |
| ≥500,000 | 24 | 96 | 96 | |
(ii) Reporting monitoring results. You must report the information in this paragraph (a)(1)(ii).
(A) You must report previously collected monitoring results and certify that the reported monitoring results include all compliance and non-compliance results generated during the time period beginning with the first reported result and ending with the most recent subpart L results.