Noise Abatement Study

Noise Abatement Studies for Natural Gas Operations

Natural gas exploration in Fredville, whether drilling, hydraulic fracturing or ongoing production, has to stay within set noise limits, and the operator must show ahead of time that the proposed work will meet the city's noise standards. That showing is made through a noise abatement study, performed by a qualified noise consultant or engineer whom the Director of Health and Environment has approved in advance.

Every proposed gas drilling operation must include a noise abatement study with its permit application. Before the study starts, the approved consultant must arrange a meeting with designated Health and Environment staff to go over the study plan. The consultant should come ready to explain in detail how ambient noise data will be gathered and how the study will be developed from it.

Minimum Contents of the Study

1. A description of the proposed facility and operation.
2. The ambient (background) noise level, set by a noise survey lasting at least 72 hours, with at least 24 of those hours falling on a weekend.
3. An analysis of every significant noise source during the drilling, fracturing and production phases at the site, compared with the applicable noise standards. The consultant must state either that the activity will meet the standards or what changes are needed to bring it into compliance.
4. An analysis of the abatement measures needed to bring the facility in line with the city's noise standards. If measures are needed, the applicant must submit a detailed plan describing them, with product information and a diagram showing where each one goes. Soundproofing must follow accepted industry standards, and every abatement measure must be in place before drilling starts.
5. Any information needed to satisfy the special requirements for sites near protected uses, described below.
6. Any other items the Director of Health and Environment requires.

The noise standards for gas drilling operations are found in the gas well drilling provisions of the City's Code of Ordinances, which can be read online. This page is a general guide only; the ordinance itself sets the binding requirements.

Special Noise Requirements for Protected Use Adjacency

Drilling sites located less than 1,000 feet from a protected use must also meet these added requirements:

1. Noise blankets at least 30 feet tall must line every edge of the drill pad that faces a protected use within 1,000 feet.
2. Noise blankets must also cover:
   • the substructure and floor area of the rig
   • the mud pumps
   • pumps and brake drum housings
   • generators and diesel engines
3. Every internal combustion engine or compressor, fixed or wheel-mounted, needs a hospital-grade muffler or an equivalent control device.
4. Noise outside the site must be monitored continuously. Readings go to the inspector every day, electronically or in another format the inspector chooses.
5. The study must include a detailed site plan showing where the boundary noise blankets will stand, along with a rig layout diagram locating all other noise blankets, hospital-grade mufflers and noise-control equipment. The plan must also mark each protected use within 1,000 feet, the points where ambient noise was measured and the planned spots for the continuous monitors.
6. At night, audible vehicle back-up alarms are not allowed and must be replaced by approved silent methods such as spotters or flaggers. Pipe, casing and other heavy loads may be delivered only in daytime, except in an emergency. While the derrick hand is up in the derrick, the derrick hand and driller may talk only by walkie-talkie or another quiet method. Horns may not be used to signal connections or call the crew, only for emergencies. The operator must hold on-site meetings so every worker understands the nighttime noise rules.

Allowed Increase Over Ambient Noise

These limits apply to all natural gas drilling operations. Compliance is measured at the property line of the nearest protected use or at a point 100 feet out from the closest protected use structure, using whichever location sits nearer to that receptor.

Note 1: Where a site lies inside the 1,000-foot protected use zone and the nighttime ambient level plus 3 dB(A) would top 58 dB(A), the limit becomes the ambient level itself.

Note 2: At night, flowback operations may not exceed ambient noise by more than 5 dB(A).

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