EPA will test 2 options to address toxic water in Ringwood Mines Superfund site in 2023
After a year of consolidating and capping contaminated soil at the Ringwood Mines Superfund site, cleanup work is set to go deep underground in 2023.
A work plan released this month by the Environmental Protection Agency and Ford Motor Company set a new timeline to address the toxic water flooding the 19th century mining complex. It also set the stage for a late-winter analysis of two tactics designed to treat the benzene, chloroethane and 1,4-dioxane contamination under a 50-home neighborhood.
The options — aerobic biodegradation and chemical oxidation — will be studied for effectiveness, particularly against 1,4 dioxane. The chemical compound 1,4 dioxane is a probable carcinogen that remains under investigation by the EPA. So far it has proven to be resistant or fully unresponsive to air stripping, activated carbon treatment or biodegradation in subsurface environments, according to a report from In-Situ Oxidative Technologies, Inc.
Plan critics, ranging from members of the Ramapough Lenape tribe to officials at the North Jersey District Water Supply Commission, asked for the water to be pumped above ground, treated and filtered at greater expense. However, federal officials have defended the practicality of the selected plan. The underground workings in the Peter's Mine and Cannon Mine areas are thought to store a combined 262 million gallons of groundwater, records show.
The water contains benzene, arsenic and 1,4-dioxane at levels above state groundwater standards. One well sample in 2017 exceeded the standard for 1,4 dioxane by a factor of over 200.
Most of the contamination has been tied to paint sludge and other pollutants dumped by contractors for Ford Motor Co. a half-century ago in the low-income neighborhood surrounding the abandoned iron mines.
Previous projects have tried to remove the contaminants. Some were deemed successful enough to have the site's Superfund status removed. However, all have since been deemed inadequate, and the site bears the odd distinction of having been relisted as a Superfund.
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The plan would close permanently the air shaft for the now flooded Peter's Mine. The 17-level, 1,500-foot-deep mining complex is where scientists have identified the highest loads of groundwater contaminants on site. First, however, the plywood that now covers the shaft will be removed to allow further study, according to the plan.
Sediment sampling and a visual inspection using an underwater camera are proposed. Moreover, in March 2023, 121 pounds of sodium bromide are expected to be mixed into the shaft's groundwater to determine the travel time and direction of the water flowing from the shaft. The tracer study will include monitoring at nearby bedrock wells.
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In February, new bedrock wells and overburden wells are expected to be drilled to aid in monitoring. At these so-called sentinel wells, soil cores would be collected and screened for contaminants. Field sampling ahead of that project is due to start in January.
Unveiled in late 2020, the $3.4 million plan will treat the 500-acre Superfund site's groundwater by pumping compounds underground.
Work to clean up lingering surface contaminants, including rotting drums of paint sludge and assorted waste from Ford's former Mahwah plant, started in November 2021. By mid-April 2022, workers had excavated more than 42 cubic yards of paint waste and 42 drum carcasses, federal records show. Since then, geotextile caps have been installed to contain any lingering soil contamination in the main contamination zones.
The groundwater on the site is not connected to any drinking wells or used for potable water. Still, the Wanaque Reservoir roughly one mile away supplies water to more than 3 million people through the North Jersey District Water Supply Commission. Most critics say the proximity is reason enough to take more precautions.
Studies released by the EPA have shown that the toxins migrating off site, including 1,4-dioxane and benzene, dissipate before they reach the reservoir. EPA officials have said they have a good idea of how the groundwater moves and have no indication that site contaminants are migrating into town drinking water wells or the reservoir.
As with the soil cleanup, Ford and the Borough of Ringwood are responsible to pay for site groundwater projects.
This article originally appeared on NorthJersey.com: EPA to test 2 water cleanup options at Ringwood Superfund site
