Contaminated soil in the former Orville Quarry in Longswamp Township should be capped, barrels from illegal dumping removed and access to that portion of the site restricted, Department of Environmental Protection officials said at a public hearing on Thursday.
The recommendations are part of a site clean-up plan proposed after a 10-year investigation into contaminated ground water near the site. The plan was presented for public comment Thursday night at the Longswamp Township Municipal Building. No one commented at the meeting but written comments will be accepted until Sept. 28.
The DEP has been monitoring chemical levels in the water of nearby properties since 2002 after perchloroethylne -- a cleaning solvent also known as PCE -- was detected in nearby well water. In addition to the PCE, officials found evidence of waste dumping on the grounds of the former quarry.
PCE in-home filtration systems were supplied to those residents affected. The DEP provided maintenance on these filters until 2010.
The PCE has filtered its way out of the groundwater due to its natural flow through the rock structure, said Project Manager Elise Juers. The ground in the area is primarily a mix of dolomite and limestone. When the water reached the limestone, it was naturally channeled away from and deeper below the properties.
Over the course of potable well-testing, officials saw the amount of PCE decrease from almost 20 parts per billion in some areas to non-detectable, with no sudden changes in other unaffected areas. DEP officials cited the relatively flat water tables in the area as another factor aiding in the resolution of the problem. Since many of the wells were drilled to the same level, it made it easy to determine the location of the PCE.
Now that the PCE problem has resolved itself, the state is allowing those residents with the filtration systems (called POET systems) to keep them, if they wish. If residents decide to keep their systems, it will be their responsibility to perform maintenance on them. It is recommended that the UV light be replaced every year, which can be done through hiring a company or buying a new bulb at a local hardware store. It is also suggested that the sediment filter should be monitored and replaced when needed. The filter, as it clogs, will begin to reduce water pressure in the building. Replacement filters can also be found at local hardware stores.
If residents do not wish to keep their systems, the state will remove them.
DEP officials discovered evidence of heavy metal dumping in an area of the Oreville Quarry when searching for the source of the PCE.
Old barrels and other debris dumped on a section of the property near Old Topton Road leaked heavy metals into the ground in that region. Tests detected metals such as arsenic, barium, lead, nickel and others on the ground in the quarry – some above “direct contact values” and to depths of 15 feet in some areas. Any level above direct contact values is dangerous to physical contact.
The DEP proposed removing the barrels and other physical debris from the area, covering the contaminated area with a soil cap and restricting access to that part of the property.
“A ridge that used to be a road running along the edge of the quarry, trucks would come in and simply dump their contents over the side. Whether they dumped the contents of the barrels, or the barrels themselves and they rusted through, we don’t know,” said Juers.
There was also evidence of dumping along Old Topton Road, likely due to the easy access.
The project crew is reasonably confident they have located all of the dump sites, but it is a difficult search, they said. Officials relied on aerial photographs of the area, land surveys to search for areas of disturbed earth and witness accounts. Normally a magnetic survey would be done to locate barrels but the location “is all iron ore.” said Juers, making a magnetic survey impractical.
Since no heavy metals reached the groundwater and the soil cap, expected to be about 2 feet deep, will be sufficient to prevent dangerous contact with the metals. DEP plans to block access to that section of the property by destroying much of the road and barring the entrance. In addition to the cap and entrance gate, DEP intends to pursue a restrictive environmental covenant for the property to ensure the cap remains undisturbed.
Questions, comments, and requests regarding POET systems should be addressed to PA DEP – South-Central Regional Office, Elise Juers Project Officer, firstname.lastname@example.org (717-705-4852).
The officials present also supplied information on other sites the DEP is involved with in the surrounding area including the Berks Sand Pit, Bali Groundwater Site, Crossley Farm and the Dorney Road Landfill superfund site in Lehigh County.