Radiological testing conducted today at the site of a sediment collapse into the Detroit River shows levels of radiation below background levels throughout the site, the Michigan Department of Environment, Great Lakes and Energy (EGLE) announced this afternoon.
EGLE staff tested for radiation on the property in numerous locations away from the shore, both near the area that collapsed and in the area that is intact. EGLE also tested the soil in the collapsed shore area along the riverfront.
Background radiation levels at the site farthest away from the river were at 4 microroentgen per hour (μR/hr). Naturally-occurring radiation levels in Michigan are typically between 5 and 8 (μR/hr). Testing closer to the water, including tests from inside the crevasses opened by the sediment collapse, ranged between 3 and 5 μR/hr. More than 1,000 data points were recorded during the testing.
EGLE staff also took water samples from the Detroit River upstream and downstream from the site of the limestone pile collapse, as well as in front of the site. The three water samples will be tested for material including suspended solids, metals (including uranium), PCBs, and industrial contaminants. The samples will be processed at EGLE’s lab in Lansing on an expedited timeframe.
The riverfront site, commonly referred to as the Revere Copper & Brass site or Detroit Bulk Storage site, was remediated in the 1980s and 1990s. Tests at that time by federal agencies – as well as sediment tests conducted earlier this year by EGLE -- showed radiation levels at or below typical background levels. Today’s testing confirmed there is no elevated radiation risk to health or the environment associated with the collapse.
The limestone aggregate spill was first noticed by the company Nov. 26. EGLE was notified on Wednesday, Dec. 4, and sent staff to the site Thursday. A larger EGLE crew returned on Friday to do the testing and assess the damage from the spill. EGLE worked with a variety of federal, state and local partners in the site assessment.