Fact Sheet 2

McHenry, Illinois

Background

Soil contamination on the Elm Street site is located mainly underneath and near the building foundation. Groundwater contamination appears to extend beyond the property boundaries to the west towards the Fox River, which is approximately 1100 feet west of the site. The groundwater contamination is located in a mixed industrial, commercial and residential area. It is not clear at this point whether there may be multiple sources of contamination in the area. Currently, the public water supply is only available to some properties along Route 120, where there is a water main in place. Most of the homes and businesses in the area use private wells for their water source.

What were the results of the additional sampling that was done on nearby wells?

Additional testing performed in February 2007 by the McHenry County Health Department confirmed the results from the January 2007 well testing and identified two wells contaminated with vinyl chloride. The well owners were advised by county and state health agencies not to drink the well water. Both of these wells were west of the Inverse Investments site. Five other wells had detections of vinyl chloride or cis-1,2-Dichloroethene (cis-1,2-DCE), which are breakdown products of solvents. Two private wells showed gasoline-related contamination at low levels, and nine wells showed no VOC contamination.

What did the previous sampling reveal about the location of contamination?

Sampling done in association with the investigation at the Inverse Investments property found a plume of VOC contamination in groundwater west and northwest of the Inverse Investments site between the site and the River (see map on page 4). At this time, Illinois EPA has not determined whether the groundwater contamination is from multiple sources.

Are any public water wells affected by the contamination?

No. The closest public water supply well, which is northeast of the site, was tested for possible VOC contamination, and none was detected.

How will I know whether my well water safe to drink?

The best way to know that your well water is safe to drink is to have it tested. A list of VOCs for which Illinois EPA and the Illinois Department of Public Health recommend private well owners test is available here.

Did any part of the area that is shown on the  site map on  Fact Sheet 1 test clean?

Yes. The area where sampling was recommended has been evaluated for the presence of VOCs - vinyl chloride and cis-1,2-DCE in particular ( see revised site map; the area within the yellow line). Wells in much of the area did not have detections of any VOCs and have been eliminated from consideration for the purpose of the Illinois EPA investigation. However, well users in this area may still want to test their well water in the future, since this is an area of mixed commercial/industrial development. There could be other contamination issues from various sources.

The shaded area on the revised site map shows where contamination was found (Revised Area of Concern) - west and northwest of the Inverse Investments property. (A sewer along Riverside Road may be affecting the direction of groundwater flow near the river).

Have any well owners been contacted?

Yes. The county and state health departments have notified well users about their results.

Will my private well be tested?

Illinois EPA is not planning on conducting any private well testing. Since the soil type in this area is favorable to the movement of water through it, and the contamination is in groundwater, the Illinois EPA and the Illinois Department of Public Health recommend that anyone who lives near this site (within the boundaries of the contamination plume on the revised site map) and uses a well for their source of drinking water have their well tested. Please see the list of VOCs for which Illinois EPA and the Illinois Department of Public Health recommend private well owners test.

What are the next steps that are going to be taken?

Illinois EPA is working to identify the nature and extent of the existing contamination and is evaluating other potential sources of VOC contamination. Illinois EPA staff will conduct a physical survey of the area, including door-to-door interviews with businesses regarding waste handling and other issues.

Illinois EPA is requesting that the Inverse Investments property owner provide definitive locations of all area private wells in use.

Have cleanup plans been approved so treatment can begin for the VOC contamination in the soil?

Yes. Illinois EPA sent a letter to the site owner on August 8, 2007 approving the proposed cleanup plans with the comment that the well survey near the site should be completed as soon as possible.

How will this treatment protect private wells now and in the future?

The proposed cleanup method will make use of injection of an oxygen-rich compound into the contaminated area around the existing building. This will speed up the degradation (breakdown) of the chemicals. Illinois EPA is requesting quarterly monitoring of downgradient water quality at the edge of the site to watch for the potential movement of contaminants.

Have there been any additional sources of contamination identified?

No. Illinois EPA is currently investigating whether additional sources may exist in the immediate area.

Are rules in place now to prevent this type of groundwater contamination?

Yes. Federal laws put into place in the 1980s addressed hazardous chemicals and require generators of hazardous waste to properly identify, store and dispose of it properly. Under the Resource Conservation and Recovery Act (RCRA), Illinois EPA inspectors have the right to make routine inspections of facilities that generate this type of chemical waste. Most of these facilities today are in compliance with the RCRA laws. In the years prior to the law taking effect, businesses routinely dumped out used solvent chemicals on their own property or elsewhere. Those past practices led to the groundwater contamination we are seeing today.

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