Compressor stations, sometimes called pumping stations, are the “engine” that powers a pipeline. Transmission pipeline companies typically install compressor stations every 40 to 100 miles. The size and number of compressors varies, based on the diameter of the pipe and the volume of gas to be moved. Most compressor facilities are completely automated, so the equipment can be started and stopped from a pipeline’s central control room.
Not all compressor facilities are the same. The design and operation of interstate transmission pipeline compressor facilities is overseen by the Federal Energy Regulatory Commission, as well as the U.S. Department of Transportation. Compressor facilities which support gathering or intrastate pipelines are not subject to many of the same strict design and operating requirements.
The criteria used to identify potential facility locations included property availability, access to electric power, pipeline hydraulics, compatibility with local zoning, land use and land development, site terrain, water table and storm water management, and site accessibility. Williams also evaluates a number of environmental factors, including potential impacts to nearby residences. As part of the FERC application process, Williams will develop a detailed analysis of the project’s effect on wildlife, vegetation, wetlands, water bodies and groundwater, geology, soils, land use, air and noise quality.
Potential Facility Locations
The location of the Somerset County compressor station facility has not yet been finalized. Williams initially identified four potential locations that appeared to meet the facility’s design requirements, but after further investigation has narrowed its focus to two potential sites (Alternate Sites 2 & 3). Both sites are located in an industrial-zoned area located within Franklin Township along the existing Transco pipeline in Somerset County.
- Site Alternative 2 (35.9 acres) located off Route 27, near Promenade Boulevard
- Site Alternative 3 (52.2 acres) located, north of site alterative 2 between County Road 518 and Highway 27.
The facility would be situated on about six acres. The current design would require clearing approximately 15 acres, while the remaining acreage will be left wooded.
The compressor station proposed as part of the Northeast Supply Enhancement project will feature two Mars 100 natural gas-fired turbine compressor units to ensure maximum reliability. The units will be located inside of an enclosed, sound-attenuating building, situated on approximately six acres.
The station will include the following facilities:
- A 80 x 120 compressor building to house the compressors;
- A power control room building;
- An office/warehouse building;
- A small drum-storage building;
- A telecommunications building;
- A communications tower;
The facility will be designed, constructed and commissioned strictly in accordance with all applicable codes, standards and specifications. It will be equipped with federally-required and industry-recognized safety features such as pressure relief valves, emergency shutdown systems, and gas/ fire detection devices. It is planned to be manned during normal business hours and monitored around the clock by our Operations Control Center. In addition, the facility will also be designed for remote operation and will include computerized controls for automatic shut down in the event of an emergency.
Venting / Blowdowns
A station “blowdown” refers to a controlled release of natural gas that is vented to the atmosphere. Natural gas, which is mostly composed of methane, is colorless, odorless, and lighter than air. When released into the air it rapidly rises and dissipates. “Mercaptan” is the odorant that is added to natural gas to give it the rotten eggs smell. In an emergency situation, or in anticipation of planning system maintenance, Transco may conduct a controlled venting of gas from the facility. While blowdowns are a standard operational practice, they do not occur at regular intervals and would occur infrequently (possibly once per year) at this location. Prior to a blowdown taking place, local emergency officials and nearby residents are alerted. Gas is directed through a filter to remove the odorant and through a silencer to reduce the noise.
The facility will be designed in such a way that it is not noticeable to nearby residents. Per federal regulation, the sound emitted from our operation cannot exceed 55 dBA at the nearest noise sensitive area (station fence line). The facility enclosure will include approximately nine inches of sound-buffering insulation. Transco will conduct a pre-construction study to measure existing noise levels at the location of the proposed station. A post-construction noise survey will be completed after construction is complete to demonstrate that the compressor station complies with sound requirements
The facility would not create vibration at levels perceptible to the human body.
Transco plans to install Dark Sky compliant LED lighting at the compressor station. This lighting directs light downward to reduce the light visible from neighboring properties. Nighttime lighting will be minimized to provide only enough light for station security under normal operations.
The new station will be classified as a minor source of air emissions for permitting purposes and will feature state of the art emission control technology. This includes Selective Catalytic Reduction (SCR) technology, which is used to significantly reduce the emission of NOx. This technology is similar to the catalytic converter used on cars and trucks to reduce motor vehicle emissions.
The Transco pipeline has safely operated in Somerset County since 1950s. According to U.S. Department of Transportation (USDOT) statistics, pipelines are the safest method for transporting energy. As this Project is designed, constructed and operated, Transco is committed to maintaining the highest standards of safety, utilizing construction and operational procedures that exceed already stringent industry regulations.
- Station monitored 24 / 7 by centralized operations control center.
- Facility will feature state-of-the-art automatic emergency shutdown systems.
- Design requirements based on its area classification, which are based on population density in the vicinity of the proposed facility
- Facility will be equipped with federally-required and industry-recognized safety features such as pressure relief valves, emergency shutdown systems, and gas/ fire detection devices.
- Computerized controls designed for remote operation.
- Site specific emergency response plans will be prepared in consultation with local responders.