Full story on city well contamination

This article submitted by Linda Stelling on 2/17/98.

Paynesvilleís public works committee met with the Minnesota Pollution Control Agency (MPCA) and the Department of Health on Wednesday afternoon to learn more about the high levels of benzene found in well number three. The well is located near the city shop on Railroad Street.

The meeting Wednesday afternoon was to discuss various options and possible solutions available to the city.

In November 1997, the contaminant benzene was found in well number four behind city hall. In January, the same contaminant appeared in well number three. Benzene is a component of gasoline.

In a two-month span between testing, the parts per billion count went from 6.2 to 17 at well number three. Following treatment at the cityís water plant, the concentration dropped to 3.6 which is an acceptable level for the Department of Health. Anything over five is not acceptable.

The MPCA is looking at the four known leak sites in Paynesville: two are found a block apart on Garfield Avenue (MnDOT garage and Cenex), one is at the intersection of Lake Street and Mill Street and the fourth is between city hall and Vern Johnson Motors.

Jim MacArthur of MPCA said the leak sites have an impact on the shallow aquifer under the city but should not on the deeper aquifer in which the city pumps its water. The shallow aquifer is found anywhere from zero to 30 feet down and the deep aquifer is found 60 to 90 feet below the surface. A clay layer is found between the two aquifers.

MPCA has contacted contractors to drill monitoring wells near the leak sites to see if they are the cause of the problem. They also advised the city to pinpoint all the old gas stations in town which might have buried tanks containing gasoline yet.

MacArthur said it would be three to four months before they would have the test results back.

The city is concerned as to whether the contamination is moving toward their other water sources, wells five and six. MacArthur said they couldnít answer that question until they knew the extent of the contamination of the aquifer. However, he felt the other two wells were far enough away so they shouldnít be in danger for another five to six years or more. Wells five and six are are located south of Highway 23 on the east side of Paynesville.

Paynesville Public Works Director, Ron Mergen, questioned how fast the contaminant was moving. ďIn a matter of months we found contaminants in well number three where there had never been measurable levels before,Ē he said. ďIt seemed after we shut down well number four in November, the contaminant moved faster to the east.Ē

MacArthur said the increase level at well number three indicates a major contamination. He did not recommend shutting down the well until after the March test results are in. If the levels remain high, then the well will be required to be shut down as well.

Mergen also asked if other contaminants were found. The answer was no, according to the Department of Health records. The Department of Health, in partnership with the city of Paynesville, has a well protection monitoring plan in place. They have been monitoring the city wells for several years.

Mergen informed the group he has talked with AMPI about using their well as a back-up, if needed. ďAt present, wells five and six are adequate for winter usage. A lot will depend on the type of spring and summer we have and how soon people start watering lawns and gardens,Ē Mergen said.

The AMPI well has the capacity of pumping 200 gallons a minute. Wells five and six together, can produce up to 800 gallons per minute. The city is concerned that if they start pumping water out of the AMPI well, it will draw the contaminant in that direction.

Councilman Harlan Beek asked how successful MPCA has been in tracing sources of contamination. Walt Haas of MPCA said that sometimes they can. ďBut in the case of Paynesville, where the city has been in one spot for a long time, it will be hard to trace. There is not a lot we can do except locate all the old service station sites,Ē Haas said. ďThirty years ago people built on top of old tanks instead of removing them.Ē

Haas said he could set in motion a plan to design a carbon filtering system to clean a small portion of the cityís water supply from well number three. ďTo use this system over a long period of time could get very expensive for the city,Ē he cautioned. This is a short-term solution which will be used only if needed.

In the meantime, the city will try to locate all the old service station sites to check for abandoned tanks. The city will also check private wells close to town as it will be advantageous to use them for testing the aquifer instead of drilling test wells.

The city council was told not to panic. The water is safe to drink and not a threat to anyone. Test results from the monitoring wells should be known by April 1.

Paynesvilleís options:
Options presented to the city included:
• Look for an alternative aquifer.
• Explore different methods of treatment.
• Put a contingency plan into effect for wells number five and six before they show signs of contamination.
• New treatment plant for different methods of treatment.

Return to Archives