Two more wells near Dover Air Force Base found to be contaminated

DOVER — Two more wells near Dover Air Force Base have been found to have possible high levels of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), dangerous chemicals which are contained in firefighting foam.

The U.S. Air Force and Dover Air Force Base have notified Delaware’s Department of Natural Resources and Environmental Control (DNREC) that preliminary results show the pair of wells near the base were discovered to possibly have elevated levels of the synthetic chemicals.

The preliminary results indicate concentrations above the U.S. Environmental Protection Agency’s lifetime health advisory for these substances of 70 parts per trillion (ppt).

The Delaware Division of Public Health (DPH) said it is working with DNREC, USAF, Dover AFB and the owners of the affected wells to protect public health. The owners of the two wells, which both provide water to a single commercial business, have been notified and provided with bottled water by Dover AFB.

The unvalidated results of water samples recently collected by the USAF from 10 other wells reported PFOS and PFOA below the federal health advisory level. Although the recent test results are currently unvalidated, validation of the data is expected within 30 days.

The preliminary, unvalidated results for these two wells are in addition to validated detections of PFOS and PFOA for four wells announced in July 2019 along South Bay Road. The USAF continues to provide alternative water supply to those properties, which include a shopping center with five businesses, two residences and an office building.

The Air Force said it is committed to eliminating firefighting foam containing either PFOS or PFOA from its inventory and is finalizing a phased plan to replace existing firefighting foam inventories with recently approved PFOS/PFOA-free alternatives that still provide adequate fire protection for critical assets and infrastructure.

DAFB, in 2016, switched the foam in its emergency vehicles for another firefighting foam that is PFOS-free and contains trace amounts of PFOA.

In the wake of last year’s water detections of PFOS and PFOA, Lt. Col. Vhance V. Valencia wrote a letter dated Sept. 26, 2019, to Dover City Manager Donna Mitchell formally asking the city to prepare for an annexation so that a water project for the properties affected along South Bay Road could take place.

“The Air Force believes the best course of action for the affected properties is to connect them to the city of Dover public water supply,” Lt. Col. Valencia wrote last summer. “However, I am not authorized to obligate the Air Force to pay for the connection. At this time, the Air Force is reviewing whether it may design and pay for the construction of an extension to the existing city of Dover water main located on the east side of South Bay Road.

“Per preliminary discussions with your staff, the water main will need to be extended across South Bay Road and continue south along the west side of the road, to the southernmost affected property. There are many details that need to be worked out, including initiation of annexation activities, coordination with other agencies such as the Delaware Department of Transportation, and property owner involvement.”

The annexation into the city’s water supply has yet to take place as funding for the project continues to be sought. Dover’s Utility Committee voted Oct. 29 to waive an annexation requirement so the properties can get city water service.

Mrs. Mitchell said last October that requesting a waiver for the annexation requirement was a way to speed the process along should the base eventually request help for water service for the affected properties.

“The water is on the other side of the highway, so you’d have to come under the highway to get to these properties,” she said. “The base would be paying for that project as I understand it. We’re asking for the waiver to prepare for the base to come forward. They haven’t made the official request.

“They just told us that this was a problem and we’re just trying to make sure that we’ve got this matter taken care of so if they do come forward and they’re ready to pay for this project we can move forward because we’ve got council’s approval. So, we’re trying to be proactive with this waiver request.”

A USAF fact sheet about the Dover AFB PFOS and PFOA sampling published in spring 2019 indicated that groundwater samples collected in shallow monitoring wells on the base also showed levels of PFOS and PFOA above EPA’s 70 ppt health advisory.

No PFOS or PFOA have been detected in five nearby municipal water wells tested by Dover AFB’s water supplier, Tidewater Utilities. Tidewater sampled four on-base municipal supply wells and the off-base municipal supply well nearest the base. All these wells draw water from a deep, confined aquifer. There were no PFOS or PFOA detections in any of them.

There currently is no federal- or state-required standard for PFAS substances in drinking water supplies, so actions taken are based on the federal lifetime health advisory level.