(a) Monitoring. (1) If you submitted an IDSE report, you must begin monitoring at the locations and months you have recommended in your IDSE report submitted under § 141.605 following the schedule in § 141.620(c), unless the State requires other locations or additional locations after its review. If you submitted a 40/30 certification under § 141.603 or you qualified for a very small system waiver under § 141.604 or you are a nontransient noncommunity water system serving <10,000, you must monitor at the location(s) and dates identified in your monitoring plan in § 141.132(f), updated as required by § 141.622.
(2) You must monitor at no fewer than the number of locations identified in this paragraph (a)(2).
Source water type
| Population size category
| Monitoring Frequency
1
| Distribution system monitoring location total per monitoring period
2
|
---|
Subpart H:
| | | |
| <500 | per year | 2
|
| 500-3,300 | per quarter | 2
|
| 3,301-9,999 | per quarter | 2
|
| 10,000-49,999 | per quarter | 4
|
| 50,000-249,999 | per quarter | 8
|
| 250,000-999,999 | per quarter | 12
|
| 1,000,000-4,999,999 | per quarter | 16
|
| ≥5,000,000 | per quarter | 20
|
Ground Water:
| | | |
| <500 | per year | 2
|
| 500-9,999 | per year | 2
|
| 10,000-99,999 | per quarter | 4
|
| 100,000-499,999 | per quarter | 6
|
| ≥500,000 | per quarter | 8
|
(3) If you are an undisinfected system that begins using a disinfectant other than UV light after the dates in subpart U of this part for complying with the Initial Distribution System Evaluation requirements, you must consult with the State to identify compliance monitoring locations for this subpart. You must then develop a monitoring plan under § 141.622 that includes those monitoring locations.
(b) Analytical methods. You must use an approved method listed in § 141.131 for TTHM and HAA5 analyses in this subpart. Analyses must be conducted by laboratories that have received certification by EPA or the State as specified in § 141.131.
[71 FR 488, Jan. 4, 2006, as amended at 74 FR 30958, June 29, 2009]