Money pours into water

The new water treatment plant in Scott City was seen as a blessing when it began service last July, replacing the five deep wells the city used for its water.

At the time, the wells just weren't doing enough to provide water to the residents of the city.

"The main problem they caused was they couldn't keep up with consumption, especially in dry seasons," city administrator Ron Eskew said. "In the last drought, they were running very close to full capacity and just barely keeping up."

That was sometimes accompanied by boil-water orders, as the wells would pump out murky water when they were running too close to capacity.

But the switch to the city's new water treatment plant, which cost about $3 million to construct, hasn't been easy. Working out the bugs of converting from the old system to the new system is a process that was just completed, as the city's public works department tried to figure out the right mix of chemicals to properly treat the water and worked on fixing valves that weren't working properly.

Now there's a new challenge the city will face in operating the plant. The cost of the chemicals used to treat the water has exceeded estimates given by plant engineers, Waters Engineering out of Sikeston, Mo. -- the chemical treatment cost is running at about $32,000 per year, twice what Eskew said estimates indicated.

Eskew said the engineers gave a projected cost based on other plants in the area, but the cost was low, in part because the city has used extra chemicals to ensure the best water quality.

To get that highest possible quality, the plant uses a polymer to remove iron from the water. As the polymer is added to the water, it oxidizes any iron in the supply, which then allows the iron to be separated from the water using a special tank called a "cone."

The results can be seen when water superintendent John Smith pours water from the cone -- in some areas of the cone it's clear, like at the top, but in other areas it comes out a rusty brown.

"That iron would be clear if it wasn't oxidized," Smith said.

The polymer used in the process is a big expense. The city's public works director, Jack Rasnic, said the plant is going through about seven pounds of the chemical every day at a cost of $5.50 per pound.

With those kinds of costs adding up, the city will now have to re-evaluate the way it treats its water and try to find the most cost-efficient way to do so.

"We've got everything running good," Rasnic said. "Now it's time to start tweaking it."

Eskew said the city is now ready to go through a six- to nine-month period of operating the plant at its maximum efficiency -- a time in which Rasnic and Smith will test their options for treating the municipal water supply.

One option being discussed is to limit the use of chemicals and increase the use of filters. Currently about 98 percent of the iron is removed from the water by means of chemical treatment, while the rest is taken care of by filters using sand and charcoal.

Eskew said the amount of particulate matter removed from the water by chemical means could be scaled back to 85 percent or 90 percent, with the filters handling the rest. That could save $5,000 to $10,000 a year in chemical costs.

Using the filters more could come with its own increased cost. Currently the plant spends about $1,800 in electric costs a month, Rasnic said. As the use of filters goes higher, those electric costs will go up, because more water has to be backwashed through the filters so they can continue to clean out the sediment. Using them more could also shorten the 20-year lifespan of the filters.

The city council has expressed the possibility that water rates might have to be raised if a more cost-effective way of treatment can't be found.

Regardless of how the city treats its water, Rasnic said, it still must be treated.

"The end result is the same," Rasnic said. "We cannot let bad water out of here."

After six to nine months, the city will evaluate its options. The results may show that a rate increase is needed, said Eskew, and the city will have no choice but to pursue one. Either way, there is no guarantee yet how the water will be treated, or what it will cost.

msanders@semissourian.com

335-6611, extension 182