Chemical Industry: Red Muddy Waters
January 9, 2018
To celebrate Exponent's 50th Anniversary, we created a book featuring our most notable projects from the last decade. Below is an example of our work in the Chemical Industry.

Red Muddy Waters: Opinions differed as to the potential impact of process waste waters on marine resources in St. Croix of the U.S. Virgin Islands.


Red mud, a common byproduct of alumina refining, originated at the industrial site. Exponent sought to evaluate all potential environmental stressors in the marine waters and to determine whether exposure of marine natural resources to hazardous substances allegedly released at the site could be observed.

In 2005, the U.S. Virgin Islands sued a number of companies over process wastes that allegedly had seeped from evaporation ponds at a St. Croix industrial site owned at one time by each of the defendants. For years, a refinery producing alumina (the common name of aluminum oxide) had operated at the site, which borders and drains into an industrial shipping channel, the Alucroix Channel. Alumina process waste, a byproduct of alumina refining known as red mud, contains heavy metals and has a potentially damaging high pH.

Over the years, heavy metal components of red mud allegedly had seeped into the groundwater and into the Alucroix Channel, which in turn discharges into the Caribbean Sea.

To identify potential pathways of contaminant transport and possible adverse environmental effects, Exponent marine biology, hydrogeology, environmental, and forensic chemistry experts surveyed seeps of groundwater and nearshore marine waters to obtain and evaluate onshore and offshore samples. Transport of hazardous metals to the waterway and sensitive coastal areas was not detected at levels that adversely affected the marine environment. Exponent therefore found that no linkage of site activities to marine or natural resource damage was established.

Red muddy waters

The flora and fauna of offshore habitats adjacent to 
the facility were examined by Exponent to document
any damage. 
The reef and seagrass communities 
south of the facility did not show any indication of
adverse health-related effects from activities or
chemicals used at the site.