# Quality Assurance Requirements for Continuous Opacity Monitoring Systems at Stationary Sources
> **Rule** · Withdrawal of direct final rule. · Published 2012-03-28 · 77 FR 18709
## Document
- **Document number:** 2012-7487
- **Category:** other
- **Federal Register citation:** 77 FR 18709
- **CFR reference:** 40 CFR 60
- **Publication date:** 2012-03-28
- **EPA docket:** EPA-HQ-OAR-2010-0873
## Abstract

The EPA published a direct final rule titled "Quality Assurance Requirements for Continuous Opacity Monitoring Systems at Stationary Sources" in the Federal Register on February 14, 2012. Because we received adverse comments to the parallel proposed rule issued under the same name on February 14, 2012, we are withdrawing the direct final rule.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/2012/03/28/2012-7487/quality-assurance-requirements-for-continuous-opacity-monitoring-systems-at-stationary-sources)
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