Ground Water Monitoring Continues at Former Correctional Centre


Prior to the demolition of the Correctional Centre located at 706 County Rd 10 in Millbrook in 2015, Infrastructure Ontario (IO) conducted a series of tests to identify any potential contamination through a regulatory process provided by the Ministry of Environment and Climate Change (MOECC).

Despite repeated requests to receive the results of these studies, the township received limited information and in October 2014 was informed that detailed environmental studies conducted on the site had identified contamination on portions of the property resulting from previous activities at the Correctional Centre. They were advised by Adam Carr, the Director of Sales, Easements and Acquisitions for IO that independent experts had confirmed that the identified contamination contains no known threat to human health. Of concern was the impact of contaminants on local groundwater. Carr advised that the tests had revealed no groundwater impacts on the site, and that IO had decided to extend the testing to access the municipal drinking water aquifer to confirm these results.

In September 2015, the township received a report summarizing the results of those tests which indicated the presence of PCE, an industrial solvent degreaser. PCE is a chlorinated volatile organic compound that is slightly water soluble, and used as a solvent for removing organic material including oil and grease. Its toxicity is well documented, and because the substance is more dense than water, it sinks, making it difficult to locate.   The report prompted further drilling and sampling tests by the MOECC to assess the extent of the PCE contamination in the groundwater and to identify the source area of the contaminant.

The results of these tests were submitted in a June 2016 report entitled “Additional Deep Aquifer and Source Area Investigations, Former Millbrook Correctional Center”, prepared by BluMetric. The Township retained Cambium Inc., a local environmental engineering consulting firm to provide a peer review of the material from IO and MOECC and prepare technical comments on behalf of the Township to allow them to interpret the risks this contaminant presents, given the proximity of the compound to the Millbrook municipal drinking water supply wells.

In response to the report, the MOECC Drinking Water Inspector for the Township undertook an inspection of the Millbrook Drinking Water System in November 2016 and reported to the Township in January 2017. The report stated that studies will continue until enough data has been collected to allow the MOECC Hydrogeologist to perform a further review and provide analysis for PCE concentration in raw water from the Millbrook supply wells. It also stated that raw water samples taken from the Millbrook supply wells indicated that the contaminants were below acceptable limits and that volatile concentrations were below detectable limits.

Despite these results, the MOECC committed to continue sampling until enough information has been collected to allow the MOECC Hydro-geologist to perform a further review and provide recommendations for a sampling program moving forward, and that as operator of the Municipal Water supply, the township review the final Hydrological report prepared by MOECC and implement any recommendations. These recommendations have not yet been made available.

While no analysis to date indicates the presence of any PCE or related breakdown product in the Millbrook supply wells, the Township remains concerned about the potential impact on the Millbrook drinking water system. The MOECC must stay involved to ensure that off-site impacts are properly assessed and mitigated, where necessary.

The Township continues to be involved in the investigation process and is actively engaged in the protection of drinking water through increased water level monitoring of municipal and private wells and ongoing regulatory sampling of the Millbrook supply wells. Given the technical nature of the issue, staff and Council will continue to retain professionals to provide opinion and direction regarding any impact on groundwater identified at the Site to ensure the continued supply of safe, high quality drinking water for users of the Millbrook municipal water services. KG

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