Health officials are well-versed in the dangers of arsenic in the water, especially in Hunterdon and Mercer counties in New Jersey which sit upon rich shale formations. Arsenic is unique in its ability to cause a wide range of physical disorders, and this range increases as studies continue. It is known that arsenic from “drinking water can cause severe skin diseases including skin cancer; lung, bladder, and kidney cancers, and perhaps other internal tumors; peripheral vascular disease; hypertension; and diabetes. It also seems to have a negative impact on reproductive processes (infant mortality and weight of newborn babies). The toxicology of arsenic involves mechanisms that are still not completely understood, but it is clear that a number of factors can affect both individual and population-level susceptibility to the toxic effects of arsenic-contaminated drinking water.”1

Several stakeholders presented substantial comments to the PennEast docket regarding arsenic contamination of the drinking water during the FERC scoping period in 2014 and 2015. Of particular note, Dr. Tullis Onstott of the Geosciences Department at Princeton University submitted an in-depth analysis of the concern to the docket, and testified to the issues at each of the two New Jersey scoping sessions in February 2015. He stated, “Several New Jersey Geological Survey reports document the high arsenic levels in the wells in Hunterdon and Mercer counties.

This belt of rocks – the Triassic shales of the Passaic and the Lockatong Formations – form an arsenic hot spot. The groundwater supply is known to be vulnerable in these counties, but Hunterdon County is uniquely vulnerable because the farms and rural homes all rely upon well water.

“These wells tap a surficial, unconfined, fractured rock aquifer in the Lockatong, Passaic and Stockton formations. The proposed PennEast pipeline cuts right through the arsenic hot spot where it can do the most damage to the drinking water supplies of the inhabitants. The soil cover is thin, so in order to bury the 36” diameter pipeline they have to trench or drill through this bedrock. This excavation will aerate the rock formation and expose the arsenic- bearing pyrite to oxidation which will release the arsenic as arsenate into the groundwater. This will occur on every ridge of every drainage divide the pipeline will cross… the proposed route crosses 87 drainage divides. These same drainage divides are the recharge zones for the groundwater used by the farmer and rural residences.”2

In their Response to Scoping3, PennEast brushed aside Dr. Onstott’s concerns, and those of all of the many stakeholders commenting on arsenic, by utilizing standard boilerplate platitudes regarding Best Management Practices in the construction of their pipeline through this area. They further claimed that “it will not impact groundwater”, although that statement seems to ignore the fact that the aquifer is surficial in the arsenic hotspot areas. If however, the construction renders the water unsafe for drinking due to arsenic release into the well waters, PennEast states that it will “replace or provide an alternate water source”. How PennEast proposes to do so is not discussed in its comment.

Dr. Onstott continued beyond construction issues in his comment to the docket: “This, however, is not the worst aspect of the pipeline. Once the pipeline is buried, its components and any methane that leaks from the pipeline provide reductants that will be consumed by anaerobic bacteria. These anaerobic bacteria will reduce the oxidized iron in the environment and will reduce the arsenate to arsenite, the highly mobile and toxic arsenic species. The pipeline will continue to do this throughout its operational lifetime and, if left in the ground, after its lifetime. In summary the construction phase will generate arsenic and the operational phase will mobilize arsenic.”2 In his testimony at the FERC scoping hearing on February 26, 2015 in Hunterdon County, New Jersey, he described how the effect of the anticorrosion electrodes on the exterior of the pipeline would create a galvanic corridor along which soil bacteria will mobilize arsenic. This testimony, which is available in the public record of the PennEast docket in the Transcript of the Scoping Sessions for February 25 and 26, 2015, as of March of 2016 has not been addressed by PennEast in their Response to Scoping filings.



  1. Hopenhayn, Claudia. Arsenic in drinking water: impact on human health. Elements, April 2006, v. 2(2): 103-107.
  2. Onstott, Tullis – comment to the PennEast docket
  3. PennEast Pipeline Company LLC Response to Scoping Comments. FERC Docket PF15-1, March 13, 2015.