Compressor Stations

The progression of Marcellus Shale oil and gas development, processing, and export in western Pennsylvania has gone like this:

1. Seismic Surveys – Widespread exploration began with seismic surveys, that used “thumper trucks” and shot holes with explosive charges, to determine what the underground geology looked like for gas drilling and fracking. In our local area, spanning northern Washington County into southern Allegheny County, that survey was known as the BUNOLA 3D with the permitting activity and public meetings dating back 8 years, to May 2013, as shown in these pages from the Pennsylvania DEP’s Bureau of Mining and Reclamation:

Playlist of SEISMIC TESTING in western Pennsylvania featuring over a dozen videos:

2. Drilling wells and excavating pipelines from each well site. Alarmingly, these “gathering pipelines” were not required to be recorded and included in the ONE CALL system, the one that alerts companies and individuals who are digging, of underground hazards. ‘Stuck on Stupid’ there!

3. Building compressor stations to move the gas through pipelines. The compressor stations being built today are much larger than the original ones, having over 3- times more compression horsepower than the earlier ones. More horsepower equals more air pollution.

4. Installing aboveground pigging stations where “pigs” can be inserted to clean and inspect pipelines. These pigging sites have been known for their large releases of methane when opened up for servicing.

5. Building large cryogenic gas plants to separate gas liquids like ethane, propane and butane from the wet gas stream, for export through additional, larger pipeline networks.

6. Handling massive volumes of toxic drilling waste by way of huge, leaky, plastic- lined earthen impoundments, various tanks, tanker trucks, injection wells, and landfills. Marcellus Shale waste is known for its radionuclides, including water soluble Radium 226, which has a radioactive half life of 1600 years. How many future generations is that?

7. Enlarging and building new compressor stations, as more wells are drilled and fracked. More wells equals more compressor stations. And this brings us back to today’s topic, the McIntosh Compressor Station near Finleyville, Pennsylvania, which is undergoing some additional permitting, that can be extremely confusing to anyone who isn’t completely familiar with the terminology and air permitting process. Below is the latest example, dated 2 June 2021:

What are these six “MICROTURBINE GENSETS” being used for?

We see in an EPA bulletin: “Microturbines are a new, innovative technology based on jet engines (more specifically the turbo charger equipment found in jet engines) that use rotational energy to generate power. Most microturbines have four main components: compressor, combustion chamber, turbine blades, and drive shaft. The compressors operate by taking in the surrounding air at one end of the microturbine and then condensing the air by increasing the air’s pressure and density. This air is fed into the combustion chamber where it is mixed with fuel, and then burned. This combustion releases enormous amounts of heat energy and high-pressure exhaust gases. The exhaust gases are discharged through exhaust vents into a series of turbine fan blades that are attached to a central shaft. As the gases are discharged, they spin the turbine fans, which in turn spin the drive shaft at high speeds (100,000 revolutions per minute). The rotational energy produced by the shaft, spins copper coils, which excite the electrons in the wire, producing electricity.”

Reading further through the bulletin, we see this sentence, which will definitely be of concern to nearby residents: “One disadvantage of microturbines is a limit on the number of times they can be turned on. Microturbines also run at very high speeds and high temperatures, causing noise pollution for nearby residents and potential risks for operators and maintenance staff.”

Photo of the new McIntosh Compressor Station that was built right behind the older Hartson Compressor Station:

Compressor stations are already known for their vibration and noise, as seen in this graphic, “How loud is too loud?” The potential harmful decibel level is shown to be 85, while a natural gas compressor engine’s noise level is shown to be 70 to 90 decibels at 150 feet away. My question would be, what size compressor engine was used for the sound test, a small one, or a large one, like the four 5,350 horsepower compressors in the McIntosh?

Size matters. With some quick math, we see this compressor station has four CAT compressor engines that produce a total of 21,400 horsepower, making it slightly larger than the Three Brothers Compressor Station, with 19,800 horsepower, in another part of northern Washington County. It was the focus of a Post-Gazette story that focused on the air pollution produced by that facility, so pollution comparisons can be made. While the McIntosh looks smaller than the Three Brothers, keep in mind that its four compression engines are nearly three times larger than the ten smaller ones:

Quoting data from the Pennsylvania Department of Energy Emissions Inventory, the image in the Post Gazette clearly illustrated the huge volumes of air pollution from that one facility, over the 12 months of 2018:

  • Carbon dioxide: 68,715 tons
  • Methane: 23.75 tons
  • Volatile Organic Compounds or VOC’s: 20.76 tons
  • Carbon monoxide: 18.1 tons
  • Nitrogen Oxides or NOx: 12.81 tons
  • Particulate Matter PM 2.5: 5.27 tons
  • Formaldehyde: 1.53 tons
  • Benzene: 1.2 tons
  • Toluene: 1,060 pounds
  • Xylene: 440 pounds
  • Sulfur Oxides or SOx: 680 pounds

It’s interesting to note that our Pittsburgh region still gets failing grades for Particulate Matter air pollution, or PM 2.5, as our county and region continue to build more compressor stations. Washington County alone, has added over 50 compressor stations, as well as some huge gas processing plants that add even more air pollution, over just the past 15 years. It’s also worth noting that air testing doesn’t routinely test for all these polluting compounds, some of which are carcinogenic.

It’s also disturbing to note that the cumulative effect of all these air pollution sources isn’t being taken into consideration during the air permitting process by the Pennsylvania DEP. As one friend describes it, “They use egg- slicer permitting” where they look at each facility individually, instead of combined. Why?

Is there any limit on how many compressor stations we will end up with in western Pennsylvania over the next 50 years?

Drilling activity is likely to increase once the Shell Cracker Plant begins full operation next year, and there is still talk of a second new cracker plant being built, the PTT cracker plant further down the Ohio River Valley, in Belmont County, Ohio.

In the old days, when Pittsburgh had so many steel mills, they described the air as “Hell with the lid off.” It will be interesting to see what new term comes about if the petrochemical industry buildout in the Ohio River Valley ramps up, as so many politicians are hoping it will. What are they missing?
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