BY TIM BONFIELD
The Cincinnati Enquirer

The floodwaters are receding, but more than 140,000 Kentucky residents and about 64,000 Ohio residents were still living under boil-water advisories Monday.

Raw sewage coursing along the muddy Ohio River and contaminating wells remains the largest health threat posed by the Flood of '97.

At its peak, the flood caused 43 sewer treatment plants in Ohio and Kentucky to either shut down or allow some raw sewage to reach the river untreated. To reduce the risk of bacterial contamination, more than 75 water systems last week advised customers to boil drinking water.

Now the number of boil advisories is down to 50 water systems. However, the full extent of the flood damage to drinking water and wastewater treatment plants has not been fully assessed.

The boil advisories are issued for any of several reasons, including low water pressure, bacterial contamination and high ''turbidity,'' which means a higher-than-normal amount of solids suspended in the water. High turbidity indicates a risk of parasites, such as cryptosporidium.

In Kentucky, water treatment plants in Butler and Brandenburg are out of service. Three systems - Falmouth, Brandenburg and Beaver-Elkhorn - have boil ''notices,'' which means contamination has been confirmed. Thirty four water systems have boil advisories, indicating possible contamination.

In Ohio, 13 drinking water systems still have boil advisories in effect.

Meanwhile, sewer treatment plants in Aberdeen and Ripley, both in Ohio, have been damaged and remain offline. The full extent of damages and estimates of repair times have not been determined.

Several other Ohio plants are still discharging raw sewage into the river, including the Nine Mile Plant in Clermont County, and the Little Miami, Mill Creek and Muddy Creek plants in Hamilton County, according to the Ohio Environmental Protection Agency.

Untreated sewage can carry a wide variety of bacteria, viruses and parasites that can cause illnesses ranging from diarrhea and vomiting to hepatitis and meningitis.

Water-quality experts test for sewage contamination by measuring the amount of coliform bacteria in river water samples. Tests completed last week in Cincinnati revealed coliform counts running 10 times higher than normal, creating ''unhealthful'' conditions, according to the Cincinnati Health Department.

New coliform tests were not complete Monday, but were expected to be completed later this week.

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