Tainted wells that may be linked to discharge from Congin Elementary School are costing the city more than originally expected, and another could drive up costs even more.

After approving spending more than $9,000 in October to connect the Cumberland Avenue home of Jim Fahey, whose well tested positive for coliform bacteria, e-coli bacteria and arsenic, to public water, the City Council approved another $8,700 last week for unforeseen excavation costs incurred during the connection.

In addition, the Council approved up to $3,000 to connect the Cottage Place home of Councilor John O’Hara, who has gotten tests back showing similar contaminants in his well, to public water.

Though investigations are ongoing as to the source of the contamination, because Fahey discovered the problem when the city was looking into plumbing problems at the nearby Congin School, the City Council agreed to pay to have him connected to public water.

When the city discovered that sinks and a toilet at the school had been dumping into a brook that runs behind Cumberland Street and that Fahey’s well was contaminated, notices were delivered to residents in the area making them aware of the situation and asking them to contact the city if they have a well.

According to City Administrator Jerre Bryant, aside from Fahey and O’Hara, no other residents have come to the city.

The city and school department first became aware of the plumbing problem in March, when neighbors reported a nearby brook turning cloudy white. The Department of Environmental Protection discovered the discharge was coming from a sink at the Congin School and the white substance was from paintbrushes being washed in it.

Though school officials believed the problem was solved in March, neighbors called again in July to report that the brook, which runs from near the school on Bridge Street down into the Presumpscot River, was turning cloudy. More sinks and a toilet were discovered to be incorrectly plumbed.

For the second time in four months, the school department acknowledged that paint originating from a custodian’s sink at Congin School trickled into the brook.

Bryant said the city is not admitting guilt yet, but both the administration and the City Council agreed something had to be done for the Faheys before the winter, even if the investigation were not complete. If it turns out the city is not at fault for the contamination, Bryant said, it would likely not try to be reimbursed.