Sorting out the competing claims regarding fracking (hydraulic fracturing) for natural gas sure is challenging.

Many energy companies' management and their trade associations repeat the mantra that there are no documented incidents of water contamination from hydraulic fracturing for natural gas.

In contrast, numerous videos on community and environmental group websites document individuals setting fire to their homes' faucet and well water following fracturing operations.

The real story is obscured by the two sides frequently talking past one another.

For far too long, too many companies' management and trade associations have pursued a strategy of "circle the wagons and shoot the messengers," although some are finally wising up and recognizing that stonewalling is not a good strategy for building public trust.

As for the community videos, the water contamination episodes are more likely the result of either drilling activities disturbing gas pockets close to the surface or faulty well construction (poor cementing of pipes), rather than fracturing as it's technically defined.

Hydraulic fracturing uses millions of gallons of water injected under thousands of pounds of pressure to break apart gas-bearing shale formations many thousands of feet below the earth's surface. These shale formations are commonly separated by thousands of feet of impermeable rock strata from fresh groundwater supplies that typically are found only hundreds of feet below the earth's surface.

The shale itself usually is a few hundred feet thick. What happens at that depth is difficult to observe, but so far, using microseismic measurements during fracturing and on-going sampling of water wells, there is little accumulated evidence that fractures per se allow the chemicals to escape into the aquifers above.

The observed hazards are instead associated with transporting millions of gallons of water and thousands of gallons of chemicals to each well site; correctly placing pipes and protective cement in the drill hole; storing the water and chemicals that return to the surface during the fracturing process (including naturally occurring toxic chemicals in the formation that also surface during gas production); moving and treating waste waters; and managing air pollutants.

In the words of energy investors Tudor, Pickering, Holt & Company, "Simply put, [fracturing] chemicals and drilling waste are more hazardous above ground than several miles underground."

Explosions, contamination incidents, and millions of dollars in fines are clear evidence that many things can go wrong and have. Tudor, Pickering aptly characterizes the industry's "no documented incidents" defense this way: "That's useful in a lawsuit, but not in the court of public opinion."

The investors I work with bring a distinct point of view to this discussion separate from the battling armies of corporate managements and community activists. Investors look at the entire lifecycle of fracturing operations -- all the activities enabled by the availability of fracturing technology to access gas in shale formations. Investors want more information from corporate managers about fracturing's risks and rewards. Investors need assurance that company managers are reducing environmental health and business risks by addressing real operational hazards, and that they are capturing the very real business rewards flowing from sound environmental practices that lower costs and increase profits.