MADISON, Wis. -- Two troubled Madison water wells, one old and one new, would be permanently shut down under new plans from Madison Water officials.

High levels of a potential carcinogen and a new cost analysis prompted the proposals, WISC-TV reported.

An Isthmus-area well plagued periodically with high levels of a cancer-causing manufacturing solvent is headed for shut down, as is an almost brand new $3 million well that's had manganese problems.

Water Utility officials are doing an about-face, and now looking at abandoning the new well altogether.

Madison Water Utility officials previously proposed an expensive filter for Well 29 to deal with its manganese issues. But a tentative plan being embraced by the Water Utility's top engineer, Al Larson, is calls for closing Well 29 and building a new well that taps the current pump station.

Larson and other officials have said the best and cheapest way to eliminate high manganese levels at Well 29 off Thompson Drive is to install a $2.4 million filter.

But no one figured in the cost to maintain and operate it, until recently when a city alderman asked for it. Those costs were calculated at $100,000, which is more expensive in the long run than drilling a new well that gets good water.

"It's a valid point. So in the future, obviously, we'll consider operation costs much more closely in total cost of the project," said Larson, principal engineer at the Madison Water Utility.

But Alderman Zach Brandon said it begs the question of why the cost analysis wasn't done to begin with.

"The real question for me is, I'm not an engineer; I'm not a water quality specialist. (So) why is that an alder at a finance committee meeting asked the question that should have been answered by engineers months ago? And we were told that this is the only answer -- that you have to put a filter on," Brandon said.

"It was a learning experience obviously to look at the whole cost over the life of the project," Larson said.

Larson and the Water Board now aim to amend a capital budget proposal to use money set aside for a Well 29 filter to drill a new well, should plans pan out the way engineers hope.

Drilling a new well there would cost more than $2 million. Putting a new well on the near East Side would likely cost more than $3 million, WISC-TV reported.

Under another new proposal, Water Utility officials are looking to permanently shut down Well 3 on the Isthmus due to higher-than-desirable levels of the industrial solvent carbon tetrachloride, which has been shown to cause cancer.

Well 3 feeds tens of thousands of homes and schools like East High School, WISC-TV reported.

But officials said the Environmental Protection Agency voluntary goal for that solvent is zero, and even though no standards are being broken, the well should be shut down.

"The goal is zero and I think as a utility our goal is basically to have carbon tetrachloride free water as well," Larson said.

Officials said replacing Well 3 will take at least $3 million and likely years to find a spot on the Isthmus.

In the meantime, three other wells will be able to feed the area unless a drought were to occur, in which case those homes could see some water restrictions.