GLENBURN TWP. - Environmental Protection Agency (EPA) officials Nov. 20 demonstrated a new online database that displays chromium pollution levels in the area around the former Precision National Plating site on Ackerly Road.
This is a tool being used by the public to get a better understanding of the work we've done over the years, said David Polish, EPA community involvement coordinator.
The EPA database, which is one of only a few in the nation, represents a new chapter in the history of combating hexavalent chromium contamination around the site. The chromium leached into the environment during operations at the plant, which closed its doors in 1999.
Hexavalent chromium is a particularly toxic form of the element chromium. The chemical has various types of industrial applications, but is known to cause cancer in humans.
The new database, or data viewer, displays an aerial photograph of the region to show the location of each active testing well over time. Chromium concentration data for each public well—private wells results are excluded from the data—are rendered in a line graph and a table. The line graph, with time on the horizontal axis and contamination levels in micrograms per liter of water on the vertical axis, provides a picture of contamination levels over the life of each well.
The table provides more detailed data on the precise levels of contamination for each test.
A time slider feature allows a user to access data hundreds of tests at well locations for any time in the last 40 years, beginning with the first testing well constructed in 1970. The wells test surface water and groundwater at different levels of rock underground.
Some wells are nested, which means they are designed to test contamination at different levels underground in the same location. The viewer sorts data for each layer of rock under the site.
The geology of the region is unique, EPA onsite coordinator Ann DiDonato said, noting that the much of the rock is fractured, or cracked, and the underground layers are irregular. Despite the uneven geology of the site, EPA contractors have determined the dimensions of the contamination plume, which refers to the affected area.
They've done an amazing job tracking these areas down, DiDonato said, noting that the dimensions of the plume are fairly well-defined now.
EPA contractors, funded by Precision National Plating, have initiated several rounds of calcium polysulfide injections into the ground. Calcium polysulfide converts the hexavalent chromium into a trivalent form, which does not have the same toxic characteristics.
The injections have worked well, according to Ann DiDonato, the EPA's onsite coordinator for the Precision site.
Occasionally, the levels in a particular well will spike, a phenomenon that the officials call rebounds. DiDonato said the rebounds indicate that some of the chromium recently dislodged from within a rock fracture, or crack, and released into the aquifer.
Overall, however, concentrations are dropping. There is no timeline for ceasing the cleanup, which will continue for the foreseeable future. About half-a-dozen testing wells are added yearly, DiDonato said.
The viewer does not replace any other EPA website related to the site and is only meant to enhance public understanding, the EPA officials said.
Township Solicitor Malcolm MacGregor said the viewer is the result of the hard work of Glenburn residents and boards of supervisors over the years.
It's a pretty impressive thing, he said.
To access the viewer, visit https://gis2.westonproject.net/EPA_Precision_Viewer/