IS THERE ARSENIC IN THE WATER? IS IT A PROBLEM? EXPLAINING RISK TO THE PUBLIC IN THE WALLKILL RIVER WATERSHED, NEW JERSEY

The NJ 303d list of impaired waters identified segments within the Wallkill River Watershed as exceeding the surface water quality standard for arsenic (0.017ppb). The New Jersey Department of Environmental Protection (NJDEP) developed total maximum daily loads (TMDLs)to address impairments. The NJDEP engaged the US Geological Survey to identify and assess the relative contribution of various sources of arsenic. The study looked at the concentration of natural arsenic in the rock formations in the Watershed and the ability of the arsenic to be leached into the water column.

A component of the TMDL process is public participation. At the onset, the NJDEP was concerned whether arsenic levels were high enough to impact public health. In January 2006, The NJ Drinking Water Standard was changed from 50 ppb to 5 ppb. The public are sensitive to environmental issues due to previous incidents of contamination. The majority of the Watershed is ground water dependant. Care was needed by NJDEP to present the information found from the study to the public to minimize alarm, misinformation and distrust. The public was asked for help in identifying possible sources of arsenic including dumps and slag piles, uses of creosote timbers for mine construction, railroad ties and docks and agricultural uses including orchards and golf courses and septic system clusters.

The arsenic data revealed that levels tend to be higher in the headwaters at Lake Mohawk a private lake community and at the town of Franklin. Franklin Borough is known as the “Fluorescent Capital of the World” having over 70 fluorescent minerals. Concentrations of arsenic varied from 1-6 ppb. Sediment concentrations were the highest at Franklin. Ground water samples were documented in the shale formations and highest in the precambian gneiss at 4 times the new drinking water standards. Arsenic mobilization is sensitive to pH and oxidation-reduction (redox) reactions.

By informing the public prior to the study, allowing their input at milestone steps and the fact that the NJDEP and USGS were receptive to their input at each step, public concern regarding the impairment have been managed to date. The study will continue to look at ground water and drinking water impacts. The NJDEP and USGS will continue to not only communicate to the citizens affected but also to regulatory groups within NJDEP to formulate an action plan.