40 CFR § 57.504 - Continuing evaluation of fugitive emission control measures.

---
identifier: "/us/cfr/t40/s57.504"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 57.504 - Continuing evaluation of fugitive emission control measures."
title_number: 40
title_name: "Protection of Environment"
section_number: "57.504"
section_name: "Continuing evaluation of fugitive emission control measures."
chapter_name: "ENVIRONMENTAL PROTECTION AGENCY"
subchapter_number: "C"
subchapter_name: "AIR PROGRAMS"
part_number: "57"
part_name: "PRIMARY NONFERROUS SMELTER ORDERS"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "Secs. 110, 114, 119, 301, Clean Air Act, as amended (42 U.S.C. 7410, 7414, 7419, and 7601); sec. 406 of Pub. L. 95-95."
regulatory_source: "50 FR 6448, Feb. 15, 1985, unless otherwise noted."
cfr_part: "57"
---


# 57.504 Continuing evaluation of fugitive emission control measures.

Each NSO shall require the smelter owner to conduct an active program to continuously review the effectiveness of the fugitive emission control measures implemented pursuant to § 57.503 in maintaining the NAAQS and, if such measures are not sufficiently effective, to evaluate what additional measures should be taken to assure that the NAAQS will be maintained with a reasonably degree of reliability. The NSO shall also require submission of a semi-annual report to the issuing Agency detailing the results of this review and evaluation. Such a report may be submitted as part of the report required under § 57.402(f).