OCCURRENCE OF ALUMINUM, LEAD, AND TRIHALOMETHANES IN DRINKING-WATER FROM THE GREAT-LAKES

Existing data on the concentrations of aluminum, lead, and total triha lomethanes in raw lake/river water and treated drinking waters were co llected for six cities in the Great Lakes basin. These values are comp ared to existing goals and standards for drinking water quality. Two c ommunities have often exceeded the WHO drinking water guideline for al uminum of 200 mug/L, and all communities exceed 10 mug/L most of the t ime, even in the raw water. Raw water lead concentrations for five of the communities studied were <1 mug/L or below the method detection li mits. One U.S. community has exceeded the current WHO standard of 50 m ug/L for lead in drinking water about 7% of the time, although the dat a collected were from the distribution system and not the treatment pl ant effluent. Occurrences of lead above the current Canadian drinking water guideline of 10 mug/L are rare except for the community mentione d above. Trihalomethane concentrations in raw water are below detectio n limits and in treated waters do not exceed the Canadian guideline of 350 and the U.S. standard of 100 mug/L for drinking water. However, t wo Ontario communities exceeded the proposed Canadian standard of 50 m ug/L at least 20% of the time. The three communities studied which add ed ammonia during water treatment had the lowest THM levels in their d rinking water.