The whiffs of chlorine can still occasionally be detected with the sensitive nose in Rochester, but the Department of Environmental Protection says there is no risk. It has been three days since the former Pool Doctor-Beaver Alkail Products site on the Ohio River’s edge in Beaver County caught fire. Investigators believe the building’s collapsing roof caused a mixing of chemicals that erupted in flames. When firefighters realized what they were dealing with, “part of our fire fighting tactics were to contain it,” says Rochester VFD Chief Michael Mamone III. Mamone says the water from their hoses caused the formation of a chlorine plum that prompted a shelter in place recommendation in Rochester. But he says the alternative would have been a possible spread of the fire to the adjacent building which contains similar chemicals.