A filtration system is being installed in response to the discovery of contaminants in water supplies close to the Luke Air Force Base near Phoenix. Lab tests detected high levels of chemicals from a fire extinguisher foam that has long been used on the military base. Customers of the water utility company in the area have been provided bottled water since February while the Air Force installs treatment facilities to reduce the presence of the chemicals. Fulton Schools Professor Paul Westerhoff, an environmental engineer whose research focuses on water, says the levels of the chemicals are not yet dangerously high. There are places where water with similar levels of these chemical compounds has been consumed for many years without resulting in significant health problems, Westerhoff says. The Air Force plans to have the filtration system operating by the end of this month. (Access to the Daily Independent online is for subscribers only.)