We've all seen the ads touting the benefits of natural gas as a cleaner-burning alternative to other fossil fuels. And it's true that, compared to coal or oil, natural gas is much less harmful in terms of its effect on global warming when used to generate electricity or power vehicles.

"Natural gas produces 43 percent fewer carbon emissions than coal for each unit of energy delivered, and 30 percent fewer emissions than oil," according to the Union of Concerned Scientists.

Don't, however, be fooled into thinking that just because methane produces a lesser amount of greenhouse gases when it's burned means that it is necessarily a green-friendly fuel. Especially, as is increasingly the case, when that natural gas is extracted from the earth by means of a process known as hydraulic fracturing, or fracking.

Which is why a nonprofit group called Food & Water Watch had some of its folks holding a press conference down by the Detroit River on a sparkling morning earlier this week. They were there with copies of a just released report called "The Case for a Ban on Gas Fracking."

In case the subtlety of the report's title is lost on you, we can tell you that the group doesn't much like the process. Not here in Michigan. Not anywhere in the United States. It's also a safe bet that famed Texas oilman and relatively recent convert to the wonders of natural gas, T. Boone Pickens, isn't a big contributor to their cause.

Now, News Hits doesn't want to get all technical on you, but there is a fact we have to get cleared up at this point.

Fracking isn't new to Michigan. It has been going on here since the 1960s. According to the state's Department of Environmental Quality, "more than 12,000 wells have been hydraulically fractured since then." The process involves pumping water mixed with fracking chemicals and sand into the ground at high pressure. The shale is split apart, or fractured, allowing the gas to be extracted.

What's changed is that new techniques now enable drillers to go much deeper, past the Antrim shale formation that stretches across the northern part of the lower peninsula and into what's known as the Utica and Collingwood shale formations. Instead of boring down 1,000 or 2,000 feet, as is the case in the Antrim wells, the new type of drilling hits depths of as much as 10,000 feet. In addition, instead of just going straight down, these deeper wells curve and move horizontally once the shale formation is hit.

Currently, two such wells are operating in the state. But, based on the amount of acreage companies are buying the mineral rights to, the expectation is that horizontal drilling could take off here as it has in other parts of the country.

And along with that expectation is the concern that the same sorts of problems found in other states could occur here as well. For anyone really interested in the issue, News Hits highly recommends the documentary Gasland, which features Pennsylvania filmmaker Josh Fox visiting a variety of states and finding people who, among other things, can set their tap water on fire because of contamination from methane that has gotten into their wells due to problems associated with nearby fracking operations.

Aside from the depths, one big difference between the Antrim wells and its newer cousins is the amount of water used in the process.

"A fracture treatment of a typical Antrim gas well requires about 50,000 gallons of water," explains the DEQ. "In the emerging Utica/Collingwood Shale gas development, the amount of water needed to fracture a horizontal well may be up to 5 million gallons or more."

It's not just the fact that 100 times as much water is used that concerns activists such as Lynna Kaucheck, a senior organizer with Food & Water Watch. The process also uses 100 times as much chemicals.

And what exactly makes up the chemical recipe? Well, outside of the industry folks who are mixing up that stew, no one can say with absolute certainty. As the DEQ explains, "the details of some of the chemical compounds used in hydraulic fracturing are exempted from disclosure" under federal law.

However, a January 2011 report issued by the U.S. House Energy and Commerce Committee disclosed that various fracking fluids contained a total of 750 chemicals and other components, including carcinogens such as benzene and toluene. They can even pump diesel down there. There's also the issue of what happens to the chemically contaminated water once its been pumped down a well. Between 25 percent to 75 percent is initially recovered as what's called "flowback." That wastewater gets disposed of in deep injection wells.

As the people downriver in Romulus will tell you, these wells are themselves the subject of great controversy and concern.

And its not just chemicals in the water that have to be disposed of that are a problem. A February 2011 New York Times investigation found that three-quarters of the wells reviewed in Pennsylvania and West Virginia produced wastewater with high levels of radiation.

But if you believe our state officials, there's no need to worry about any of this. For one thing, they say, beefed-up regulations were issued last month. As a result: "Michigan's laws and rules effectively protect water and other natural resources as well as public health and safety from potential adverse effects of hydraulic fracturing."

Which just makes many environmentalists laugh. And it's not a happy laugh.

Some groups, such as Food & Water Watch and the Cheboygan County-based group Don't Frack Michigan are calling for an outright ban on horizontal fracturing.

Others aren't going quite that far. Instead of just saying "no," they are calling for a "whoa." In May, the Michigan Sierra Club and Clean Water Action issued a press release calling for a moratorium on fracking in the state.

> Email Curt Guyette