40 CFR § 63.9923 - How do I demonstrate continuous compliance with the emission limitations and work practice standards that apply to me?

---
identifier: "/us/cfr/t40/s63.9923"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 63.9923 - How do I demonstrate continuous compliance with the emission limitations and work practice standards that apply to me?"
title_number: 40
title_name: "Protection of Environment"
section_number: "63.9923"
section_name: "How do I demonstrate continuous compliance with the emission limitations and work practice standards that apply to me?"
chapter_name: "ENVIRONMENTAL PROTECTION AGENCY"
subchapter_number: "C"
subchapter_name: "AIR PROGRAMS"
part_number: "63"
part_name: "NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "42 U.S.C. 7401"
regulatory_source: "57 FR 61992, Dec. 29, 1992, unless otherwise noted."
cfr_part: "63"
---


# 63.9923 How do I demonstrate continuous compliance with the emission limitations and work practice standards that apply to me?

(a) For each affected source subject to an emission limit in Table 1 to this subpart, you must demonstrate continuous compliance according to the requirements in Table 4 to this subpart.

(b) For each wet scrubber subject to the operating limits for pressure drop and scrubber water flow rate in § 63.9890(b), you must demonstrate continuous compliance according to the requirements in paragraphs (b)(1) and (2) of this section.

(1) Collecting and reducing the monitoring data according to § 63.9921(b); and

(2) Maintaining the hourly average pressure drop and scrubber water flow rate at or above the minimum level established during the initial or subsequent performance.

(c) You must demonstrate continuous compliance with the work practice standards in § 63.9891 by operating according to the requirements in your fugitive dust emissions control plan and recording information needed to document conformance with the requirements.