Applicable Noise Statutes, Regulations, and Standards
Domain 4: Applicable Noise Statutes, Regulations, and Standards
This domain tests your ability to identify the governing instrument and the correct limit for a project. Community noise in the United States is largely regulated by state and local ordinances, while federal statutes control federal actions and specific sources.
Core rules
- The Noise Control Act of 1972 established a federal role in noise research and source regulation; the Quiet Communities Act of 1978 extended EPA's noise program. There is no single federal community noise limit that applies to all projects.
- Federal actions are reviewed under NEPA (40 CFR 1500-1508). Highway projects use 23 CFR 772 and the FHWA Traffic Noise Model; transit and aviation have their own procedures, including FAA 14 CFR Part 150.
- State and local ordinances commonly set property-line or receptor limits by zoning class and time of day. Read the permit or ordinance for the exact metric, averaging time, and measurement location.
- Technical standards include ISO 1996 for environmental noise description and measurement, IEC 61672 for meters, and ANSI S1.4 for legacy meter specifications.
- OSHA 29 CFR 1910.95 is an occupational standard, not a community limit. It uses an 8-hour 90 dBA permissible exposure limit, an 85 dBA action level, and a 5 dB exchange rate.
Worked example
A highway project is predicted to produce 69 dBA Leq(1h) at a residential receptor. Under the FHWA noise abatement criteria, the activity category may use 67 dBA Leq(1h) as the approach level. The predicted level is 2 dB above the criterion, so the analysis must consider abatement and document feasibility. Applying OSHA's 90 dBA limit here would be the wrong framework.
Traps
Treating OSHA as a community standard; citing a federal limit that does not exist; ignoring state preemption; and comparing a modeled Lmax to a Leq criterion.