---
kind: "section"
citation: "42 U.S.C. § 300j–13"
title: "42"
title_heading: "The Public Health and Welfare"
number: "300j–13"
heading: "Source water quality assessment"
release: "119-102"
date: "2026-07-12"
url: "https://uscodex.org/usc/42/300j-13"
units:
  - "Chapter 6A — Public Health Service"
  - "Subchapter XII — Safety of Public Water Systems"
  - "Part E — General Provisions"
---

# §300j–13. Source water quality assessment

- (a) **Source water assessment—**
  - (1) **Guidance—** Within 12 months after August 6, 1996, after notice and comment, the [Administrator](/usc/42/4005.md?p=1) shall publish guidance for [States](/usc/42/201.md?p=f) exercising primary enforcement responsibility for public water systems to carry out directly or through delegation (for the protection and benefit of public water systems and for the support of monitoring flexibility) a source water assessment [program](/usc/42/274l–1.md?p=4) within the [State](/usc/42/201.md?p=f)’s boundaries. Each [State](/usc/42/201.md?p=f) adopting modifications to monitoring requirements pursuant to [section 300g–7(b) of this title](/usc/42/300g–7.md?p=b) shall, prior to adopting such modifications, have an approved source water assessment [program](/usc/42/274l–1.md?p=4) under this section and shall carry out the [program](/usc/42/274l–1.md?p=4) either directly or through delegation.
  - (2) **Program requirements—** A source water assessment [program](/usc/42/274l–1.md?p=4) under this subsection shall—
    - (A) delineate the boundaries of the assessment areas in such [State](/usc/42/201.md?p=f) from which one or more public water systems in the [State](/usc/42/201.md?p=f) receive supplies of drinking water, using all reasonably available hydrogeologic information on the sources of the supply of drinking water in the [State](/usc/42/201.md?p=f) and the water flow, recharge, and discharge and any other reliable information as the [State](/usc/42/201.md?p=f) deems necessary to adequately determine such areas; and
    - (B) identify for contaminants regulated under this subchapter for which monitoring is required under this subchapter (or any unregulated contaminants selected by the [State](/usc/42/201.md?p=f), in its discretion, which the [State](/usc/42/201.md?p=f), for the purposes of this subsection, has determined may present a threat to public health), to the extent practical, the origins within each delineated area of such contaminants to determine the susceptibility of the public water systems in the delineated area to such contaminants.
  - (3) **Approval, implementation, and monitoring relief—** A [State](/usc/42/201.md?p=f) source water assessment [program](/usc/42/274l–1.md?p=4) under this subsection shall be submitted to the [Administrator](/usc/42/4005.md?p=1) within 18 months after the [Administrator](/usc/42/4005.md?p=1)’s guidance is issued under this subsection and shall be deemed approved 9 months after the date of such submittal unless the [Administrator](/usc/42/4005.md?p=1) disapproves the [program](/usc/42/274l–1.md?p=4) as provided in [section 300h–7(c) of this title](/usc/42/300h–7.md?p=c). [States](/usc/42/201.md?p=f) shall begin implementation of the [program](/usc/42/274l–1.md?p=4) immediately after its approval. The [Administrator](/usc/42/4005.md?p=1)’s approval of a [State](/usc/42/201.md?p=f) [program](/usc/42/274l–1.md?p=4) under this subsection shall include a timetable, established in consultation with the [State](/usc/42/201.md?p=f), allowing not more than 2 years for completion after approval of the [program](/usc/42/274l–1.md?p=4). Public water systems seeking monitoring relief in addition to the interim relief provided under [section 300g–7(a) of this title](/usc/42/300g–7.md?p=a) shall be eligible for monitoring relief, consistent with [section 300g–7(b) of this title](/usc/42/300g–7.md?p=b), upon completion of the assessment in the delineated source water assessment area or areas concerned.
  - (4) **Timetable—** The timetable referred to in [paragraph (3)](#a-3) shall take into consideration the availability to the [State](/usc/42/201.md?p=f) of funds under [section 300j–12 of this title](/usc/42/300j–12.md) (relating to [State](/usc/42/201.md?p=f) loan funds) for assessments and other relevant factors. The [Administrator](/usc/42/4005.md?p=1) may extend any timetable included in a [State](/usc/42/201.md?p=f) [program](/usc/42/274l–1.md?p=4) approved under [paragraph (3)](#a-3) to extend the period for completion by an additional 18 months.
  - (5) **Demonstration project—** The [Administrator](/usc/42/4005.md?p=1) shall, as soon as practicable, conduct a demonstration [project](/usc/42/13641.md?p=2), in consultation with other Federal [agencies](/usc/42/8262.md?p=1), to demonstrate the most effective and protective means of assessing and protecting source waters serving large metropolitan areas and located on Federal lands.
  - (6) **Use of other programs—** To avoid duplication and to encourage efficiency, the [program](/usc/42/274l–1.md?p=4) under this section may make use of any of the following:
    - (A) Vulnerability assessments, sanitary surveys, and monitoring [programs](/usc/42/274l–1.md?p=4).
    - (B) Delineations or assessments of ground water sources under a [State](/usc/42/201.md?p=f) wellhead protection [program](/usc/42/274l–1.md?p=4) developed pursuant to this section.
    - (C) Delineations or assessments of surface or ground water sources under a [State](/usc/42/201.md?p=f) pesticide management plan developed pursuant to the Pesticide and Ground Water [State](/usc/42/201.md?p=f) Management Plan Regulation (subparts I and J of part 152 of title 40, Code of Federal [Regulations](/usc/42/201.md?p=d)), promulgated under [section 136a(d) of title 7](/usc/7/136a.md?p=d).
    - (D) Delineations or assessments of surface water sources under a [State](/usc/42/201.md?p=f) watershed initiative or to satisfy the watershed criterion for determining if filtration is required under the Surface Water [Treatment](/usc/42/11851.md?p=11) Rule (section 141.70 of title 40, Code of Federal [Regulations](/usc/42/201.md?p=d)).
    - (E) Delineations or assessments of surface or ground water sources under [programs](/usc/42/274l–1.md?p=4) or plans pursuant to the Federal Water Pollution Control Act [[33 U.S.C. 1251](/usc/33/1251.md) et seq.].
  - (7) **Public availability—** The [State](/usc/42/201.md?p=f) shall make the results of the source water assessments conducted under this subsection available to the public.
- (b) **Approval and disapproval—** For provisions relating to [program](/usc/42/274l–1.md?p=4) approval and disapproval, see [section 300h–7(c) of this title](/usc/42/300h–7.md?p=c).

## Source credit

(July 1, 1944, ch. 373, title XIV, § 1453, as added Pub. L. 104–182, title I, § 132(a), Aug. 6, 1996, 110 Stat. 1673.)

## Notes

### Editorial Notes

### References in Text

The Federal Water Pollution Control Act, referred to in subsec. (a)(6)(E), is act June 30, 1948, ch. 758, as amended generally by Pub. L. 92–500, § 2, Oct. 18, 1972, 86 Stat. 816, which is classified generally to chapter 26 (§ 1251 et seq.) of Title 33, Navigation and Navigable Waters. For complete classification of this Act to the Code, see Short Title note set out under section 1251 of Title 33 and Tables.