---
kind: "section"
citation: "40 C.F.R. § 141.605"
title: "40"
number: "141.605"
heading: "Subpart V compliance monitoring location recommendations."
url: "https://uscodex.org/cfr/40/141.605"
---

# §141.605. Subpart V compliance monitoring location recommendations.

- (a) Your IDSE report must include your recommendations and justification for where and during what month(s) TTHM and HAA5 monitoring for [subpart V](/cfr/40/subpartV.md) of this part should be conducted. You must base your recommendations on the criteria in [paragraphs (b) through (e)](#b..e) of this section.
- (b) You must select the number of monitoring locations specified in the table in this [paragraph (b)](#b). You will use these recommended locations as [subpart V](/cfr/40/subpartV.md) routine compliance monitoring locations, unless State requires different or additional locations. You should distribute locations throughout the distribution system to the extent possible.
- (c) You must recommend [subpart V](/cfr/40/subpartV.md) compliance monitoring locations based on standard monitoring results, system specific study results, and [subpart L](/cfr/40/subpartL.md) compliance monitoring results. You must follow the protocol in [paragraphs (c)(1) through (c)(8)](#c-1..c-8) of this section. If required to monitor at more than eight locations, you must repeat the protocol as necessary. If you do not have existing [subpart L](/cfr/40/subpartL.md) compliance monitoring results or if you do not have enough existing [subpart L](/cfr/40/subpartL.md) compliance monitoring results, you must repeat the protocol, skipping the provisions of paragraphs [(c)(3)](#c-3) and [(c)(7)](#c-7) of this section as necessary, until you have identified the required total number of monitoring locations.
  - (1) **Location with the highest TTHM LRAA not previously selected as a subpart V monitoring location.**
  - (2) **Location with the highest HAA5 LRAA not previously selected as a subpart V monitoring location.**
  - (3) Existing [subpart L](/cfr/40/subpartL.md) average residence time compliance monitoring location (maximum residence time compliance monitoring location for ground water systems) with the highest HAA5 LRAA not previously selected as a [subpart V](/cfr/40/subpartV.md) monitoring location.
  - (4) **Location with the highest TTHM LRAA not previously selected as a subpart V monitoring location.**
  - (5) **Location with the highest TTHM LRAA not previously selected as a subpart V monitoring location.**
  - (6) **Location with the highest HAA5 LRAA not previously selected as a subpart V monitoring location.**
  - (7) Existing [subpart L](/cfr/40/subpartL.md) average residence time compliance monitoring location (maximum residence time compliance monitoring location for ground water systems) with the highest TTHM LRAA not previously selected as a [subpart V](/cfr/40/subpartV.md) monitoring location.
  - (8) **Location with the highest HAA5 LRAA not previously selected as a subpart V monitoring location.**
- (d) You may recommend locations other than those specified in [paragraph (c)](#c) of this section if you include a rationale for selecting other locations. If the State approves the alternate locations, you must monitor at these locations to determine compliance under [subpart V](/cfr/40/subpartV.md) of this part.
- (e) Your recommended schedule must include [subpart V](/cfr/40/subpartV.md) monitoring during the peak historical month for TTHM and HAA5 concentration, unless the State approves another month. Once you have identified the peak historical month, and if you are required to conduct routine monitoring at least quarterly, you must schedule [subpart V](/cfr/40/subpartV.md) compliance monitoring at a regular frequency of every 90 days or fewer.

## Notes

### Amendments

[71 FR 483, Jan. 4, 2006, as amended at 74 FR 30958, June 29, 2009]

### Source

Source: 71 FR 483, Jan. 4, 2006, unless otherwise noted.

### Authority

Authority: 42 U.S.C. 300f, 300g-1, 300g-2, 300g-3, 300g-4, 300g-5, 300g-6, 300j-4, 300j-9, and 300j-11.

### Source

Source: 40 FR 59570, Dec. 24, 1975, unless otherwise noted.

### Amendments

[71 FR 483, Jan. 4, 2006, as amended at 74 FR 30958, June 29, 2009]