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Latest NMI News Recent Documents

GW Treatment System Vanox Unit Installed

Visit GW NTCRA Progress Photos for more photo updates.

GW Treatment System Vanox Unit with persulfate tank, January 2019.

GW Treatment System Building, January 2019.


Treatment System Building Completely Erected; 100% Remedial Design for Treatment System Approved by EPA 12DEC18

To date, the Groundwater Treatment System building has been completely erected and minor interior work continues. During the coming weeks, it is anticipated that the electrical and plumbing services will be completed, finishing the construction phase of the building.

Concurrent with completion of the building, work has begun to install and assemble the treatment system. The system will be constructed as designed in the 100% Removal Design-Treatment System, approved by the EPA on December 12, 2018. This system will include a metals pre-treatment process prior to treating the groundwater through the Vanox™ Advanced Oxidation Process. This final step in the treatment process is a destructive technology, and it is anticipated that 1,4-dioxane will be treated to nearly non-detectable concentrations.

The Temporary Groundwater Treatment System continues operations. The Demonstration of Compliance Report through September 2018 can be found here.

Installation of the Treatment System is anticipated to last through February, 2019.

Temporary Groundwater Treatment System Continues Operations; Construction of Treatment Building Begins

During the treatment system design process, the Temporary Groundwater Treatment System has been operating since May 2017. Continued hydraulic monitoring and routine sampling of the system and surrounding groundwater monitoring wells indicate the system continues to achieve the three performance objectives required by design: maintaining a hydraulic capture zone, decreasing concentrations of 1,4-dioxane in groundwater, and maintaining acceptable treatment system effluent concentrations. The Demonstration of Compliance Report through June 2018 can be found here.

Work during the spring and summer of 2018 has been focused on completing the final design of the permanent treatment system and continued operations of the Temporary Groundwater Treatment system.

A site specific treatability study was completed in 2017 to identify the best ex-situ treatment option for the 1,4-dioxane and VOCs in the groundwater plume. Based on this study, an Advanced Oxidation Process (AOP) was selected as the most effective treatment option due to its ability to degrade 1,4-dioxane. A 100% Design Report for the system was submitted to the EPA in July 2018. Construction of the Treatment Building began in September and the final treatment system is expected to be installed and operational before the end of 2018.

Temporary Groundwater Treatment System on the Knox Trail Property, operating since May 2017 and maintaining the hydraulic containment.

Community Involvement  Recent Documents

Site Meeting on Building and Groundwater NTCRAs

On 31 AUG 2016, representatives from EPA, MassDEP and de maximis met with members of the 2229 Main Street Committee, CREW, and Green Acton, as well as representatives of the Town of Acton and Acton Water District to present an update on the Building and Groundwater Non-Time-Critical Removal Actions (NTCRAs).

The Groundwater NTCRA AOC became effective in July 2016. Between October 2015 and July 2016, significant further delineation of the extent of groundwater contamination was completed. The next steps under the Groundwater NTCRA will be installation of pumping and monitoring wells, hydraulic testing, and design and construction of an ex-situ groundwater treatment system.

EPA Issues Fact Sheet on NMI Activities Update

In light of building demolition resuming on 19 APR 16, EPA issued a fact sheet to update on the status of activities on site and the various winter activities performed for the test of the Assabet 1A and 2A production wells to define the “capture zone,” which will assist in determining an effective location to install and test a pumping well.

Last updated on January 23, 2019