STUDY OF ALLUVIAL PROVIDES PROMISE

If the second phase of a study on alluvium wells is anything like preliminary reports on the first, Cape Girardeau Water Systems manager Tom Taggart will be switching to a better system.

Among the changes would be a more streamlined expansion design of the Cape Rock Water Treatment Plant, which is scheduled to be completed by late 1997 or early 1998. The Cape Rock plant has been renovated twice since it was built in 1931.

"If the results on the water are as promising as the preliminary tests on the rock formations, the city could save tens of thousands of dollars each year and as much as $1 million on the new plant," Taggart said.

Final results on the first phase are due in about a month. But based on data from early studies of the five sites being tested, Taggart feels there is a good chance the only doubt remaining is whether the water is free of contaminants.

The reason alluvium well water is a better source to tap is because the natural rock formations serve as a natural filter or sponge, blocking out animal waste and siltation.

The Cape Rock water plant currently treats water from the Mississippi River via a seven-phase process.

Kevin Priester, production superintendent for the Cape Rock No. 1 water treatment plant, said water from an alluvium well would make his job simpler in terms of treatment and control.

"It would eliminate much of the front part of the operation we use right now," he said. "It would also give us more consistency regardless of weather conditions."

Weather patterns can drastically alter the treatment and processing of the water. Heavy rain, severe heat or cold can change the way particles react to the chemicals used in treating the water.

If the source is ground water, weather wouldn't become as much of a factor.

The city has hired the engineering firm of Burns and McDonnell to test for ground-water development at a 30-acre site of alluvium immediately downstream on the Missouri side of the Mississippi River.

The initial phase of the tests included drilling to 150 feet to determine the nature of the alluvial materials at the site and to compile geophysical data.

Those tests revealed the rock formations are large enough to filter most of the particles and animal waste that come from the river and other areas along the flood plain.

After the 1993 flood, siltation in the existing surface-water intake and the down-river migration of the zebra mussels, which clog surface-water intakes, prompted consideration of a new water source. Taggart has also been concerned with how many peak months he has witnessed this year.

Together the two water treatment plants can produce 7.3 million gallons a day. Since May, Cape has used an average of slightly more than 6 million gallons a day.

"You would expect that average to go down, but the trend shows that we need to plan for additional water capacity by the year 2000," Taggart said.

Thus, the increasing demand for water in Cape Girardeau created a need to expand the plant.

If Taggart is able to rely solely on water from alluvium wells, he wouldn't be ordering such large quantities of the chemicals he now uses to treat water from the river. Even if he blended both sources together, there would be a significant savings.

The cost of the first phase of the alluvial well study is $65,000. The second phase will cost $100,000.

"The money you would save from using less of everything including chemicals would pay for the project in a few years," Priester said.

Alluvium wells aren't a new source of water.

"Alluvium wells have been used for some time," Taggart said. "The reason we started looking into it as a new source is because we knew we would be expanding our plant and we had the flood plain to draw from. Also, the EPA is probably going to be making stricter regulations on the treatment of water in the near future, which will make it even more expensive."