Michigan Seamless Tube, LLC (South Lyon, Oakland County)

Joe Rogers, RogersJ5@Michigan.gov or 517-599-5312.

Michigan Seamless Tube, LLC (MST), manufactures specialty metal tube products at a manufacturing facility at 400 McMunn Street in South Lyon. Remedial Actions at MST are being conducted under a Corrective Action Consent Order. Given the historic manufacturing and waste management activities that have occurred at the site, including plating, EGLE, in a letter dated December 21, 2018, requested MST conduct PFAS sampling. A work plan to conduct the sampling was approved by EGLE in March 2019, and the sampling was conducted in the spring and summer of 2019.

The hydrogeology at the site is mainly sand about 100 feet thick, with some discontinuous silt and clay layers present. Groundwater flow at the site is to the south or southwest toward an ephemeral stream called Yerkes Drain, which is located just south of the southern border of the MST facility. Depending on the time of year and the amount of recent precipitation, Yerkes Drain may be a “gaining” (i.e., receiving or gaining flow from groundwater) or a “losing” (losing flow to groundwater) stream. Yerkes Drain then flows westerly, and then flows into, or is connected to, several small lakes west of the facility (Limekiln Lake, Nichwagh Lake, etc.). The site is in the Huron River watershed. There is a City of South Lyon Municipal pumping well located approximately 1 half mile upgradient of the highest PFOS concentration on site. Data from this well collected in 2018 did not identify detectable levels of PFOS and PFOA. EGLE has worked with local public health to previously identify potential downgradient residential wells as part of the ongoing corrective action process and is the process of evaluating the PFAS data to see if additional sampling needs to be completed. This work will be completed in conjunction with Oakland County Public Health and Michigan Department of Health and Human Services (MDHHS).

Content posted August 2020.

EGLE has worked with local public health to previously identify potential downgradient residential wells as part of the ongoing corrective action process and is the process of evaluating the PFAS data to see if additional sampling needs to be completed. This work will be completed in conjunction with Oakland County Public Health and MDHHS.

Both of the above reports are under review by EGLE, and formal comments have not yet been provided to MST. Due to several of the groundwater concentrations being above the proposed new criteria, it is anticipated that additional investigation will be required at the facility to better define the source(s) of the PFAS, as well the extent and fate of the contamination. It is anticipated the additional investigation will be initiated later in 2020.