Editor’s note: Unless attributed otherwise, the information contained in this article was derived from the seven-volume Chemplex Superfund Draft Permit Administrative Record issued in June 2007. The administrative record and the Chemplex Superfund Draft Final Feasibility Study released Nov. 30, 2006 are available for review at the Clinton and Camanche public libraries.

This information is being provided as residents prepare for a July 10 meeting at the Camanche Fire Station, where officials will answer questions from residents from 6:30 to 8:30 p.m.

CLINTON — The purpose of the Focused Feasibility Report is to evaluate potential changes to the Chemplex groundwater remediation system.

According to an EPA Fact Sheet issued in May 2006, the draft FFS is based on cleanup technologies identified in the Technology Evaluation Report.

The draft final FFS contains three available options including taking no action, continuing the current pump and treat system, or performing exposure control including treating hot spots and extending the municipal water supply.

Under Alternative Three, localized chemical mass hot spots would be treated by introducing a strong oxidant such as potassium permanganate into designated monitoring wells. In another proposed approach, an electron donor such as molasses could be applied.

Hot spots would be identified on a case-by-case basis in cooperation with the EPA. For each hot spot, ACC/GCC would submit a workplan compiling available data, specifying the oxidant type and injection location and defining follow-up monitoring. The EPA, IDNR and ACC/GCC would discuss each year’s monitoring data during an annual meeting or conference call.

In addition, the city of Camanche water system would be extended westward to designated residences located potentially downgradient of the Chemplex groundwater plumes that currently draw water from private wells. Once arrangements have been made for design and construction of the water pipeline are in place, the existing pump and treat system would be shut down, but remain in a state of readiness for five years. After a “mothball” period, the system would be permanently shut down and demolished or abandoned.

Following the permanent shutdown, selected extraction wells would be converted to monitoring wells while others would be abandoned in accordance with state well abandonment procedures. Groundwater extraction and treatment equipment would be removed from service and buried piping and conduits would be abandoned in place. The existing treatment building, blower building and lift stations would be demolished or left in place as storage buildings.

In a letter to the EPA regarding comments on the draft FFS dated July 6, 2006, Iowa Department of Public Health Environmental Engineer Stuart Schmitz wrote, “The IDPH believes that the proposed alternative, Exposure Control, will be protective of human health.”

Schmitz goes on to explain the importance of connecting residents downgradiant of the contaminated area to an extended public water supply line.

“In order for the Exposure Control alternative to work, all potentially affected private residences must be connected to the extended public water supply... The IDNR does not see a problem with residents keeping their private wells, as long as the water from these wells is only used for livestock, watering of gardens or other non-potable uses.”

A response from the EPA states that residents would be encouraged to connect to the new water line, but would not be required to do so.

The letter states that the city of Camanche could enact an ordinance requiring connection to the public water supply for new residences or for existing homes in the event a private water well were to fail.

The pump and treat system shutdown would not occur until a written commitment by ACC/GCC is in place to design and construct the pipeline extension. While the city would be responsible for pipeline design, construction and operation, ACC/GCC would pay for the reasonable costs of water line hookups if they are completed during the construction of the pipeline. The company would not offer compensation for new residences built or to residents electing to connect to the pipeline after construction is complete. Any continued use and maintenance of existing wells following the availability of the extended water line would be the responsibility of the residents.

In addition to the exposure controls, institutional controls would be implemented including environmental covenants that would restrict the use of groundwater underlying the site and adjoining properties.

For some properties immediately downgradient of the plumes, restrictions would be negotiated with property owners on dewatering wells and the use of shallow groundwater for potable purposes.

Further, the Chemplex site could be listed in the Iowa Registry of Hazardous Waste Sites to provide notification that chemicals of concern remain onsite and that remedial action has been undertaken.

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