Posted: 5/26/05
Contamination found at site while exploring for new well
By Joel Stottrup
The Princeton Public Utility Commission's exploration for a new well last week ended abruptly when sand being pumped out of a hole with pressurized water showed diesel fuel contamination.
The drilling took place on the former Princeton Feed Mill site along Second Street South, behind the PUC's maintenance shop.
Tanks with petroleum products once sat along Eleventh Street, about a block away near the former train depot, now a museum. Trains also used to run along the railroad tracks that once sat just west of the old mill site.
Traut Wells, Waite Park, was doing the drilling, which began about 8:30 a.m. last Thursday and ended about 15 minutes later.
Mark Traut, owner of Traut Wells, confirmed what PUC general manager Dave Thompson said Friday about the problem.
Tony Traut was doing the drilling and when the drill bit was about 16.5 feet into the ground, the sand coming up from the water pumped into the hole, went from the normal tan to brown color, to "pure black," in Thompson's words. The odor of diesel fuel was also in the air, he said.
Thompson had the well driller go down about another five feet to see if the contamination continued and it did. The wet sand was not as black but the diesel fuel odor was still there, said Thompson.
By Monday Thompson was working with the PUC's consulting engineering firm, SEH, to try to come up with another site to explore for an additional well for the city.
The main well the city has, and is using now for its water supply, just barely keeps up with the maximum demand of about 800 gallons per minute during peak summer usage, according to Thompson. If that well went out, the city would have a major problem, he said.
Contamination
If the problem was not bad enough of not finding an additional well site the city needs, now the city must deal with the contamination, Thompson said.
He explained that when contamination is found in groundwater, the involved entities must notify the Minnesota Pollution Control Agency within 24 hours. The city made the notification within five hours and now the MPCA and the Minnesota Department of Health know about the situation, according to Thompson.
Mark Traut and Thompson both said the water table at the location where the test drilling began last Thursday is at about 16 feet.
Thompson called the contamination a "serious, serious concern." The site where the drilling began is on tax- forfeited property.
Mille Lacs County Auditor-Treasurer Phil Thompson, asked Monday how tax-forfeited property is disposed of, said such property belongs to the state, and the county administers the sale of it by auction. Wredberg Princeton Mill was the former owner, according to Auditor-Treasurer Thompson.
PUC manager Thompson, meanwhile, has been pondering where the contamination is in the ground. He noted that the area typically has a layer of clay. That clay layer could be keeping the contamination from going lower into a deep aquifer, Dave Thompson added.
If someone should puncture a hole through the clay layer, however, it could allow the contaminants to seep through and that "could be trouble," Thompson said. "We're hoping it's trapped," he said.
He said the PUC has to look at the possibility of applying for a grant to clean up the contamination so it doesn't get into the aquifer supplying water to the city.
"It could be a $50,000 cleanup project or a $5 million project," PUC manager Thompson said. "It could take one month to 20 years."
Shortly after Traut Wells pulled its drill out of the ground at the exploratory well site, it sealed the hole with a natural substance called bentonite.
Both Dave Thompson and Mark Traut have mentioned a way of drilling in such a way that a large casing is run from the surface to the impervious layer. Then any contaminants are kept from going down the well casing hole through the clay layer and on to the aquifer.
But both noted that it would mean a lot larger set of casings than would otherwise be used had there been no contaminants, and Traut said that would be quite a bit more costly.
Thompson is trying to find another site for exploring for an additional well. There is already a disadvantage of going far away from the city's water-treatment plant that removes iron and manganese from water once it comes out of a city well. That treatment plant is not far from the exploratory site that had to be abandoned.
PUC commissioners meet today (Thursday) and the problem with the contamination and the need for a new well site will be discussed, said Thompson.
"It's something that we will continue to stay on top of," he said, "and try to figure out what we're going to do. We've done everything we're supposed to do."
Thompson was asked what residents should be told concerning possible contamination of their drinking water.
"If I had a shallow well in this area, I'd have it tested," Thompson advised.
Princeton Union-Eagle
P.O. Box 278
Princeton, MN 55371
Telephone: 763-389-1222
Fax: 763-389-1728