A Fracking Truck |
Assembly of Fracking Trucks; You can see the large engine and pump. |
Fracking involves adding high pressure water into the shale formations to crack them, and there are some chemicals in the water. People say the pressure used is 10,000 psi (7 MPa or 700 bar,) which is ridiculously high.
People get confused, and think that the shale formations are close to the surface. Some say that well could get contaminated with either chemical or oil.
Mines have had a terrible record with environmental contamination.
So what are the chemicals that are being used? That is well known, an industry consortium has a list on the internet, and the ratios are in this chart.
The chemicals in the fracking fluid. Source. |
Similarly some of the "friction reducers" could be problems, but at less than 0.1%, I can't get too excited about it. There is a lot of press on formaldehyde, and the industry says they are not using it. There is acetaldehyde, which is still not very nice, at about 0.002% or 20 ppm -- pretty low. Probably my biggest concern.
I would be more concerned about the fracking technique releasing naturally occurring minerals that were toxic.
For the fracking to work, the water must be delivered to the shale rock under pressure, and so there is a pipe running deep underground. The company can't let the water just bubble to the surface because it would be doing no good. If the equipment is used right, ground water is not at risk, but if there are mistakes or accidents, then the watery fracking solution might mix with surface water. Industry needs to install safeguards against accidents, and I expect they have some.
The industry and some governments want people to test their water to be sure there is no contamination, and not rely on the flavor. If you can taste a problem--you have a problem. If you can't taste something--there still might be a problem. It is important to run the lab tests.
Earthquakes
There has been speculation that earthquakes are increased in frequency due to fracking, including the recent Virginia earthquake. Looks to me like the Virginia earthquake was east of the main shale deposits, but it may be near the edge.
Some newspapers say there is a correlation and say that the solvents and the polyacrylamide which are so-called friction reducers might cause earthquakes. I tend to discount this based on my weak geology. Basically, earthquakes are caused by shifting the earth's crust, and fracking could at most make an earthquake occur earlier rather than later. If it occurs sooner, less stress will have built up, and the earthquake will be smaller. It is better to have small earthquakes not big ones. Nonetheless, I tend to think there is no effect.
Earthquakes are pretty emotional topics since there is nothing you can do about them.