§ 141.620 General requirements.
(a) General. The requirements of subpart V of this part constitute national primary drinking water regulations. The regulations in this subpart establish monitoring and other requirements for achieving compliance with maximum contaminant levels based on locational running annual averages (LRAA) for total trihalomethanes (TTHM) and haloacetic acids (five)(HAA5), and for achieving compliance with maximum residual disinfectant residuals for chlorine and chloramine for certain consecutive systems.
(b) Applicability. You are subject to these requirements if your system is a community water system or a nontransient noncommunity water system that uses a primary or residual disinfectant other than ultraviolet light or delivers water that has been treated with a primary or residual disinfectant other than ultraviolet light.
(c) Schedule. You must comply with the requirements in this subpart on the schedule in the following table based on your system type.
| If you are this type of system | You must comply with subpart V monitoring by: 1 |
|---|---|
| Systems that are not part of a combined distribution system and systems that serve the largest population in the combined distribution system | |
| (1) System serving ≥100,000 | April 1, 2012. |
| (2) System serving 50,000–99,999 | October 1, 2012. |
| (3) System serving 10,000–49,999 | October 1, 2013. |
| (4) System serving <10,000 | October 1, 2013 if no Cryptosporidium monitoring is required under § 141.701(a)(4) or October 1, 2014 if Cryptosporidium monitoring is required under § 141.701(a)(4) or (a)(6) |
| Other systems that are part of a combined distribution system | |
| (5) Consecutive system or wholesale system | —at the same time as the system with the earliest compliance date in the combined distribution system. |