I can only consider that I think gas is best used up as it may leak away. Coal and oil are best left in the ground and to achieve this, I can only suggest that the government buys the old mines and oil reserves - except that gas can be produced by the odd oil reserve.
W G Treharne - Llanelli
Your statement above that "a drill is used to bore into the ground to about 50 -100m below the water table" is just plain wrong. Check the facts. Although the depth of the shale layer around the world varies, it is typically around between 5,000 and 15,000 feet below the surface.
The aquifer (water table) on the other hand is usually relatively close to the surface. Hence the zero chance of contaminating the aquifer through the fracking process - the only way it could happen is for the well casing to fail at the aquifer layer.
So there is an agreed need to properly regulate the drilling procedures to ensure this never happens. By the way, the Gasland film you refer to has been discredited in this respect - the 'gas from the water taps' episodes were happening in certain parts of the US before any fracking took place there. It's a known local natural phenomenon.
P.Rose - Lyndhurst, UK
The article is biased. Memorandum is only in France (probably nuclear energy lobby) and Romania (probably gas lobby). Other countries have little resources or no interest in the case, with exception to Poland, which indeed has potential reserves that could turn it from 90 per cent dependance from Russian gas to a producing and even exporting country. Such lobbying like 'Gasland' and fake or naive 'enviromentalists' are aiming to ban this turn for Poland on European level
Mark Lucas - Hannover
For all those who seem to not care about the major risk to the water supply. Before choosing to expose yourself to the many toxic outputs of fracking, consider this.
Fracking could be another boom and bust. The Energy Returned On Energy Invested (EROEI) for fracked shale gas is dramatically lower than for conventional supplies. In the US, shale gas production costs a multiple of the current selling price.
The Exxon CEO says low US natgas prices are not sustainable. Contrary to BP's prediction that shale gas exploration would make North America "energy independent by 2030", US gas production has already hit a production ceiling and is actually declining in major areas.
"Like the recent credit bubble, the boom and bust in gas were driven in large part by tens of billions of dollars in creative financing engineered by investment banks like Goldman Sachs, Barclays and Jefferies & Company." (New York Times, After the Boom in Natural Gas, 20 October 2012)
In many european countries, being able to excavate shale gas would make them more independent. I've read about polish hopes, now there are lot of researchers to find shale gas fields.
The process is massively flawed in a number of ways. The water table that the bore has to pass through is likely to become contaminated by the toxic chemicals pumped down the bore under pressure.
The aquifers are meant to be protected by cement pipes and lining of the bore, but as fracking can cause tremors and earthquakes when the fissures are triggered the lining can easily become compromised.
Huge volumes of clean water are trucked to the site to be combined with sand and a mixture of toxic chemicals. Once the fissures are created the gas leaches into the water. The contaminated water is then pumped out of the well and must be treated.
The water is in most cases untreatable and it is then trucked away to other dump sites and it is pumped into those mines. That water is never to be used again. It is taken out of the aquifers or from water sources above ground like lakes. The clean water is taken and contaminated water stored.
There is also a matter of gases being released from the operations. Methane gas is far more harmful to the atmosphere than almost any other gas. Maybe you have heard of cow farts - methane.
The common belief in the industry is that 3 per cent of the mined gas will escape into the atmosphere. There are studies that show it is likely as high as 7 or 8 per cent.
It will create jobs, sure, there will be pipelines - LNG storage, shipping terminals etc. But the cost of LNG is down to a average yearly price of less then 3$, down from double that price 5-10 years ago That has to do with the large number of wells drilled all over the place..
Methane, benzene, and other related chemicals from the fracking process have been proven to be associated with high risk of brain cancers, lymphoma and a range of other health problems. There have already been countless deaths related to the chemicals being released into the environment.
The companies claim there is no proof but there is proof these chemicals cause cancer and health issues, and the companies use those chemicals in their wells. Then nearby aquifers become contaminated, animals and people get sick and die, yet the companies claim there is no proof it was they that caused it. They will take the money they sucked out from under people's land. And they will let those people die. Gasland is not a hoax. It is real.
GeoEngineer77 - Groningen, Netherlands
Injecting chemicals in vast quantities into the earth is a bad idea all around no matter the purpose. Spill these same chemicals onto the surface of the earth and emergency response teams will descend on the scene to clean it up and remove the contaminated soil as well. How can anyone in their right mind condone this kind of activity for any cause?
Frank Pravda - Saratoga, NY, U.S.A.