From the Boulder Daily Camera (Heath Urie):
Officials say they don’t think the benzene and naphthalene — common industrial agents — are threatening the city’s drinking water, but they are investigating how and when the chemicals seeped into the groundwater at 1717 15th St. They are looking into whether the site’s history as a coal gasification plant in the early 1900s, or its more recent use as a dry cleaner business, are possible causes of the contamination. Most experts are already pointing to the old gas plant as the likely culprit, which could mean the chemicals have existed underground for decades. Regardless of the source of the potentially dangerous compounds, Xcel Energy and the city of Boulder have agreed to share the cost of a $30,000 study into the surrounding groundwater as well as the costs of a possible cleanup effort.
More water pollution coverage here.