When reading online, or most other places as well, be selective in what you believe. Identify the state agency that regulates drilling activity in your state because their duties include protecting your groundwater.
http://oilandgas.ky.gov/Pages/Welcome.aspx Their regulations will most likely include a minimum depth for the surface casing - the most important factor. Most likely that state agency will also have a public information office that will help educate you.
If you get your well tested, consider using a professional to both take the sample and have it tested. Then you have an unbiased witness that can testify as to the quality of your water before the drilling activity started.
Be wary of getting all worked up over propaganda such as the film Gasland. Yes, accidents happen, and it is possible your groundwater will become contaminated from the drilling or production activity. But if you look at the huge number of wells drilled in Louisiana, Texas, Kansas and Oklahoma, that risk is minuscule. Probably a lot less than the risk of driving to the local market to buy eggs and milk.
Most of the groundwater contamination comes from leaking refineries, UST's, and pipelines carrying liquids, not from gas wells. If you are concerned about contamination and live near a gas station, read up on UST's (underground storage tanks). In the 60's the state inspector told me that almost all UST's in Oklahoma leaked fuel to one degree or another. Since then the feds have passed stringent regulations that have significantly reduced that problem.
