15 U.S.C. § 8911 — Monitoring and detection

(a) Monitoring program for unregulated contaminants
(1) The EPA Administrator^* must include the substances described below in the fifth version of the list of unregulated contaminants that public water systems must monitor for, under section 300j-4(a)(2)(B)(i) of title 42.
(2) Those substances are PFAS chemicals and groups of PFAS chemicals that (A) EPA has validated a way to measure in drinking water, and (B) are not already covered by a national drinking-water safety rule.
(3) These added PFAS chemicals do not count toward the normal limit of 30 unregulated contaminants that water systems must monitor under that section.

(b) Applicability
(1) The Administrator must: (A) require water systems serving more than 10,000 people to test for these PFAS chemicals; (B) require water systems serving 3,300 to 10,000 people to test too, subject to (2) below and if money is available; and (C) make sure only a representative sample of systems serving fewer than 3,300 people have to test, again subject to (2) below and available funding.
(2) If the Administrator decides labs do not have enough capacity to handle all the testing required under (1)(B) and (1)(C), the Administrator may waive those testing requirements.
(3) The Administrator must pay the reasonable cost of testing and lab analysis needed for the monitoring required under (1)(B) and (1)(C), using either money set aside under specific provisions of section 300j-4 of title 42, or any other available funds.