The information released yesterday by the EPA was limited to raw sampling data: The agency did not interpret the findings or make any attempt to identify the source of the pollution. From the start of its investigation, the EPA has been careful to consider all possible causes of the contamination and to distance its inquiry from the controversy around hydraulic fracturing.Still, the chemical compounds the EPA detected are consistent with those produced from drilling processes, including one -- a solvent called 2-Butoxyethanol (2-BE) -- widely used in the process of hydraulic fracturing. The agency said it had not found contaminants such as nitrates and fertilizers that would have signaled that agricultural activities were to blame.