NJDEP Lead Investigation Update 8/20/2024
As NJDEP continues to investigate materials observed on a section of Raritan Bay beach in Keyport, Monmouth County, geologists from the NJDEP and the New Jersey Geological and Water Survey have preliminarily indicated that the material may be a naturally occurring part of the Merchantville geological formation underlying the area and may have become naturally exposed along a roughly 200-foot section of the beach due to erosion.
Additional investigation is necessary before the NJDEP can confirm whether the material is naturally occurring. NJDEP’s evaluation to confirm the nature of the material will include reviews of aerial imagery, further mineralogical analysis and digging of test pits that is anticipated to be conducted the week of Aug. 26.
The DEP, in consultation with the New Jersey Department of Health, continues to advise the public to refrain from touching the materials as they may contain elevated levels of arsenic. The route of potential exposure for arsenic is ingestion, which can occur when people touch the rocks and then eat food or touch their mouths without having washed their hands. To protect yourself and your family, it is recommended that you avoid contact with these materials if seen on the beach.
Durable metal advisory signs in both English and Spanish have been placed on the beach.
Background:
The DEP was informed of the presence of the material by the New York/New Jersey Baykeeper on July 16. The rocks were initially thought to be slag or a byproduct of metallurgical processing, possibly containing lead. The Geological Survey team noted that the presence of loose bricks, pieces of concrete, metal, glass and other manmade items on the beach may have contributed to speculation that the rocks were slag. Slag is a stony waste material that separates from metals during the smelting or refining of ore and may contain harmful levels of heavy metals.
Since the week of July 29, a contractor for the DEP has removed nearly 23 drums of material from the beach. Investigators continue to observe additional materials during varied tide conditions.
Ten samples of the material were analyzed for metals. While tests have found very small concentrations of lead that are well below direct contact standards, most of the samples were found to have elevated concentrations of arsenic.
Arsenic levels ranged from 12.7 parts per million to 128 parts per million. Arsenic can be naturally occurring in New Jersey’s geology, therefore the residential and non-residential soil remediation standards for arsenic is set at 19 parts per million. There were no exceedances of residential soil remediation standards for any metals in sand that was analyzed.