A year before the Madison Water Utility turned on well No. 29 last summer, the state warned that manganese problems at the well could prove troublesome.

Now, the utility has shut down what has been dubbed the "well from hell" on the far East Side because of manganese. Administrators plan to install a $2.5 million filter to remove the mineral, which discolors water and can cause health problems at high levels.

The well has already cost $2.8 million, half a million more than expected, because of production problems, said Al Larson, principal engineer for the utility.

Drinking water health advisories stemming from elevated manganese levels have been issued for residents served by two other wells - No. 3 serving the east side of the Isthmus and No. 10 in the Nakoma area.

The advisories say infants and people with liver ailments should not drink tap water to avoid possible neurological problems that could occur if manganese were ingested at high level over a long time.

In June 2004, after well No. 29 was constructed but before its pump station was built, the state Department of Natural Resources sent a letter to the utility.

The letter, from DNR engineer Norman Hahn, approved the pump station but expressed several points of concern, according to a copy obtained by the Wisconsin State Journal.

The letter noted that in samples from the well, the utility had found a manganese level of 158 parts per billion. The federal Environmental Protection Agency recommends levels below 50 ppb to avoid dirtied water and below 300 ppb to prevent health problems.

A level of iron more than two times the "aesthetic standard" had also been found, the letter said.

"This situation is of concern because significant customer complaints may occur if the concentrations are elevated," Hahn wrote of the manganese and iron levels.

The DNR "is concerned," he continued, "that the current pump station does not take into account any chemical and/or physical water treatment that may become necessary. . ."

The well, at North Thompson Drive and Mesta Lane, was put into service on July 1. After repeated manganese levels over several months of about 160 ppb to 170 ppb, the well was shut down for general use in late April, said David Denig- Chakroff, general manager of the utility.

The well is running a few hours a week to refresh the reservoir in case a fire or heat wave causes sudden demand, Denig-Chakroff said.

The utility is planning to add a $2.5 million filter to bring the well back to full use, Denig- Chakroff said. The filter could be ready by early 2008, Larson said.

With the filter, the cost of the well will be more than $5 million, about double what other wells have cost.

"It's embarrassing," said Jon Standridge, a member of the Madison Board of Water Commissioners.

Utility staff "might have given us the results" about the manganese and iron at the well before the pump station was built, "but they certainly didn't give us the context," Standridge said. "We have an expectation that the staff will educate us."

Larson said Monday the utility responded to the DNR concerns in 2004 by expanding the power of the pumps and the size of the pump station to accommodate a filter, if needed.

Administrators considered looking for an alternate site but decided it would be cheaper to continue pursuing the initial site, Larson said.

The well had already had other problems, he said. After the water volume was found to be too low, workers blasted the well with dynamite. That increased the water volume but clogged the well with sand, Larson said. A pump was installed to suck out the sand, he said.

It was only after those problems were solved that the manganese and iron problems surfaced, Larson said.

"We already had close to $1 million invested," he said. "Do you basically throw away $1 million and move to a second site?"

Purchasing other land and drilling a new well would have cost close to another $1 million, he said, with no guarantee the new site would be any cleaner.

The decision was made to keep well No. 29 in place.

"In hindsight, would we do it all over again?" Larson asked. "I don't know. Probably."