Mercury Levels Low in Ramapo River Below Pompton Lake, Study Finds

By Omar Keita


Little evidence has been found of mercury flowing from Pompton Lake downstream into the Ramapo River, according to an article last August in The Record. A study was done by DuPont, the company that was responsible for putting mercury in the water. In the study sediment along the Ramapo River and Pompton River was sampled and the study concluded the mercury was not widespread. The study had to be done because the Federal Environmental Protection Agency said there had been concern that mercury was being pushed downstream, polluting a bigger area. When mercury is in the rivers it can be transformed into methylmercury, which is a more toxic form of mercury.  

“Mercury can accumulate in animal tissue as it moves up the food chain and affect humans who eat mercury-tainted fish, possibly damaging the nervous system and harming the brain, heart, kidneys, lungs and immune system,” The Record reported.

After hearing these reports, residents in the nearby neighborhoods were not happy about it because it just reassured their distrust of the company. For decades, the mercury migrated off DuPont's former munitions facility in Pompton Lakes from Acid Brook, which runs through a residential neighborhood below the 600-acre property and empties into the lake. The Ramapo River flows into the lake from the north and extends from the southern end of the lake and flows into the Pompton River in Wayne.

 Residents have been angered for many years because of this and do not trust anything the company says regarding the river situation. Local residents have been fighting to get an outside contractor to run the tests on the river instead of the company so they can feel more comfortable about the answer they are getting. One resident complained that they have been asking the Environmental Protection Agency to honor their request and get an outside contractor to run the tests but the agency always denies their requests.

DuPont hired their own contractor, AECOM. Earlier in 2015 a separate company called Chemours took on responsibility for most of the contaminated DuPont properties around the country, including the one in Pompton Lakes. AECOM took 34 samples from the river sediment and found fairly low mercury concentrations, with 25 of them showing less than 1 milligram per kilogram. The highest concentration was 23.5 milligrams, the report said. This was compared to Pompton Lake, where mercury levels in some of the sediment are more than 100 milligrams per kilogram.

Although the report concluded that the mercury levels in the river are fairly low, the U.S. Fish and Wildlife Service has stated that recent scientific studies show "lethal and sub-lethal effects in adult fish" even when mercury concentrations are well below 1 to 5 milligrams per kilogram, The Record reported.

Last May, the EPA approved a $43 million project to dredge the mercury-tainted sediment from Pompton Lake and add a layer of clean material to the lake bottom. Under this plan, Chemours is to dredge about 128,000 cubic yards of sediment and take it to a licensed disposal facility. 


For more information:
www.northjersey.com/news/environment/mercury-not-widespread-in-rivers-dupont-asserts-1.1388361?page=all