Joliet's drinking water will soon contain safe levels of radium for the first time in more than two decades.

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Aside from the public health standpoint, the project is remarkable on other levels:

One, it employs an emerging technology for radium removal. Two, it is the city's largest public works endeavor yet and was segmented so that small local contractors could participate.

"Water will be safer for the people of Joliet and a lot more reliable," said Chris Ulm, co-project manager in Joliet for Madison, Wis.-based Strand Associates, the engineer and architect. Eleven general contractors are involved in the project.

Unsafe Radium Levels

Like many large municipal projects, this one has a long and convoluted history.

In 1985 the city's drinking water, which comes from underground wells, tested in violation of the federal Safe Drinking Water Act's standard for combined radium 226 and 228. The standard was 5 pCi/L, or picocuries per liter, and Joliet's water surpassed the standard by about three times.

Radium is a naturally occurring radioactive metal, commonly found in rock formations in the Midwest. Isotopes 226 and 228 may be carcinogenic when consumed over long periods of time and in amounts greater than prescribed levels.

By 1989, the city had plans to completely overhaul its water system, drawing from the nearby Kankakee River, instead of wells, and had raised $100 million through a bond issue to do it. About $50 million is being spent on the radium-removal project.

At the same time, the U.S. Environmental Protection Agency was considering raising the radium standards, which meant that Joliet would be in compliance after all. The overhaul project was put on hold.

But in 2002, the EPA maintained its tougher standard, at that was at the same time Joliet was undergoing a tremendous growth spurt, especially on the west end of town, and an increased demand for water and sewer service.

To cover all bases, a three-stage plan was implemented: a new wastewater treatment plant, which went into service in January; the radium removal project now in construction; and a sewer overflow system, which is in the design stages.

The original bond issue will cover the first two stages. Additional funding will be needed for the third, but the amount has yet to be determined.

"Just the wastewater treatment plant alone was the single largest capital project ever done," said Dennis Duffield, a civil engineer and director of Joliet's public works and utilities department. "When we wrap all three together, it will be massive."

After much research, pilot testing and cost analysis, the city chose to retain its system of wells-and add five more for increased capacity. Each well is being outfitted with radium removal equipment placed inside protective low-rise housing. Because some of the wells are clustered, the buildings service between one and eight wells on 11 sites.

Removing the radium from individual wells, rather than building a large centralized facility, enables the city to leverage the advantages of its existing distributed water supply, said Jim Groose, water treatment specialist for Aurora-based Layne-Western, the equipment supplier.

"By having wells scattered all over, the city can match demand with the well close to that demand," Groose added. "You have fewer line losses and less power consumption. And if one (radium removal treatment facility) has a problem, you have 10 other sites that will fill the void. That's a lot of backup."

Another point: only minimal new underground piping has to be laid, which helps keep the city's aesthetics intact, he said.

Getting Rid of Radium

Although various methods are known and approved by the EPA for radium removal, Joliet selected a relatively new process known as HMO, or hydrous manganese oxide co-filtration with iron.

It works by adding a blend of two chemical compounds, usually potassium permanganate and manganese sulfate, to the water. They form a fine slurry to which both radium and iron attach themselves. The slurry is filtered out and sent into the wastewater system, where it is less hazardous.

"You can stand next to radium. You can bathe in it," Ulm said. "It's only bad when ingested."

The HMO process is a simple one but can be tricky. The compounds must be kept agitated so they don't settle out. A bit of training is involved, but the process is typically more cost effective than other methods.

"We selected HMO because it is relatively easy to operate and deals just with the radium," Duffield said.

Other radium-removal methods, such as reverse osmosis and cation exchange softening, not only cost more but do more. They change the aesthetic qualities of water to make it look clearer and softer and taste better, but these were not problems in Joliet.

As for the design process, standardization of both equipment and building construction has been an important component. Sameness not only streamlines the current and future operations, but it creates more bidding opportunities.

The one-story, 2,000-sq.-ft. buildings are rectangular modules that can be mirrored according to how many wells are on a particular site. Their utilitarian facades are brick and block with concrete plank roofs, although the two located in residential neighborhoods will be slightly more adorned.

"It was a lot of copy-and-paste with just a few modifications for site orientation," said Mark Oleinik, co-project manager for Strand.

Duffield said the city's goal was to get the bid packages organized in a way so that contractors who "serviced us over the years could participate in the project. If we did it as one big bid packages, most of our local contractors couldn't compete because they would not have the bonding capability."

Last year's efforts went into the preliminary work such as drilling wells, building booster stations and a standpipe and putting in a couple hundred thousand feet of water main. It took a great deal of sequencing, Groose said.

"During last summer's drought, we had to be careful not to take critical facilities down at the wrong time," he said. "Other units of production had to be cut into the mix to keep the water supply running."

Now the treatment facilities are under way, with rolling completion dates to help pace the manufacture of the equipment. Layne-Western begins it deliveries this summer and will continue throughout the winter. From the time the equipment arrives at a site, it takes about four months to complete each facility. The first site should be online in November and the final one in spring 2007.

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