Around the time that Grassy Island became a disposal facility for the dredging of the nearby River Rouge in 1960, at least nine major industries (including the Ford River Rouge Complex) freely dumped their waste products into that river.
 This caused a huge buildup of toxic waste around the mouth of the river— the exact location where the sediments came from that were deposited on Grassy Island.
 The soil that was deposited on Grassy Island was highly contaminated from Detroit's unregulated industrialism for many decades.
 Grassy Island is now contaminated with polychlorinated biphenyl, polycyclic aromatic hydrocarbon, and lethal amounts of harmful heavy metals, such as mercury and lead.

While there is no imminent danger to human trespassers because of a thin layer of protective topsoil on Grassy Island, public access is prohibited but not often enforced.
 The island has become largely void of wildlife and vegetation, as 97% of the original wetlands around the Detroit River were depleted by 1982.
 The soil contains 28 different contaminants that exceed state and federal limits.
 While the site has not been declared a Superfund site, similar procedures are being used by the Environmental Protection Agency and other organizations to clean up Grassy Island.
 In 1994, the Department of the Interior began working on Grassy Island in order to find remedies for such hazardous sites.
 Currently, the island is still being evaluated to see if the many contaminants within the soil are leaking into the surrounding Detroit River.

In 2001, the Wyandotte National Wildlife Refuge, including Grassy Island, was absorbed into the newly created Detroit River International Wildlife Refuge, which allowed for more federal funds necessary to clean up the river.
 Large portions of land have been set aside for ecological restoration.
 Because of this, much of the Detroit River has been cleaned up, and a number of native animal and plant species have returned.
Around the time that Grassy Island became a disposal facility for the dredging of the nearby River Rouge in 1960, at least nine major industries (including the Ford River Rouge Complex) freely dumped their waste products into that river.  This caused a huge buildup of toxic waste around the mouth of the river— the exact location where the sediments came from that were deposited on Grassy Island.  The soil that was deposited on Grassy Island was highly contaminated from Detroit's unregulated industrialism for many decades.  Grassy Island is now contaminated with polychlorinated biphenyl, polycyclic aromatic hydrocarbon, and lethal amounts of harmful heavy metals, such as mercury and lead.
While there is no imminent danger to human trespassers because of a thin layer of protective topsoil on Grassy Island, public access is prohibited but not often enforced.  The island has become largely void of wildlife and vegetation, as 97% of the original wetlands around the Detroit River were depleted by 1982.  The soil contains 28 different contaminants that exceed state and federal limits.  While the site has not been declared a Superfund site, similar procedures are being used by the Environmental Protection Agency and other organizations to clean up Grassy Island.  In 1994, the Department of the Interior began working on Grassy Island in order to find remedies for such hazardous sites.  Currently, the island is still being evaluated to see if the many contaminants within the soil are leaking into the surrounding Detroit River.
In 2001, the Wyandotte National Wildlife Refuge, including Grassy Island, was absorbed into the newly created Detroit River International Wildlife Refuge, which allowed for more federal funds necessary to clean up the river.  Large portions of land have been set aside for ecological restoration.  Because of this, much of the Detroit River has been cleaned up, and a number of native animal and plant species have returned.
Grassy Island