Page updated 10/06/2021 Go to PFAS Home Page
The Alaska Department of Transportation and Public Facilities (DOT&PF) was recently alerted to concentrations of per- and polyfluoroalkyl substances (PFAS) exceeding the former state action level for drinking water in the Holy Rosary Church well near the Dillingham Airport. The Alaska Department of Environmental Conservation (DEC) began initial sampling of private water wells near airport property in December 2018. They sampled nine wells on or near airport property, the others had concentrations well below the former action level of 70 parts per trillion (ppt) for the sum of five PFAS compounds.
DOT&PF has contracted with third-party independent contractor, Shannon & Wilson, Inc. to continue DEC’s preliminary investigation, which has included an in-depth well search and two sampling events.
PFAS are commonly used in products for fire suppression, resistance to wear, and repelling oil, stains, grease, and water. PFAS can be found in apparel, some consumer products, and firefighting aqueous film forming foams (AFFF). The use of AFFF during firefighting equipment testing at the Dillingham Airport is the presumed source of PFAS contamination in the affected wells. PFAS are considered emerging contaminants and the health effects are not yet well characterized.
Shannon & Wilson, Inc. sampled 65 drinking-water wells at residences and businesses near the airport for PFAS from Feb 26, 2019 through March 1, 2019. PFAS were found in 35 wells, seven of which had concentrations above the former DEC action level, including the Holy Rosary Church. Thirty wells had no detections of PFAS. DOT&PF and Shannon & Wilson, Inc. began contacting community members to notify them of their results April 4, 2019.
On February 14, 2019, the U.S. Environmental Protection Agency (EPA) published a PFAS action plan. This plan includes a commitment to propose a national drinking water regulatory determination for PFOS and PFOA for public comment in 2019, this is a critical step under the Safe Drinking Water Act for EPA to determine whether it will establish maximum contaminant levels. EPA also proposed to finalize toxicity assessments for five other PFAS. In order to align state actions to the recently announced EPA action plan, DEC will use the EPA lifetime health advisory (LHA) level of 70 ppt for the sum of two PFAS compounds, PFOS and PFOA, as the action level. Any new testing for PFAS will be for PFOS and PFOA only.
From June 9, 2019 through June 13, 2019 Shannon & Wilson conducted an additional well search and sampling event for private wells near the Dillingham airport. A total of 31 wells were sampled for PFOS and PFOA. There were no new exceedances above the EPA’s LHA of 70 ppt. To date, seven wells in Dillingham have exceeded actionable levels and have been provided an alternative drinking water source. Based on the results from this thorough well search, the sampling area does not need to be expanded further.
Shannon & Wilson, Inc. conducted a quarterly sampling event in November 2019. A total of five wells were sampled and one seasonal well was not sampled. Of the wells sampled, one new well was sampled. None of the samples collected exceeded actionable levels.
To date, DOT&PF’s priority in Dillingham has been to identify and provide safe drinking water to those who need it. Together with Shannon & Wilson, DEC, and engineering consultants, DOT&PF has begun to assess options for a long-term solution to provide clean drinking water.
In order to track PFAS movement in groundwater, DEC requires continued quarterly monitoring of wells with combined PFOS and PFOA sample results above ppt and annual monitoring of wells with sample results above 17.5 ppt.
During the quarterly sampling event in December 2019 Shannon & Wilson, Inc. completed property walk-throughs at six locations and sampled four impacted wells for various analytes. Shannon & Wilson, Inc. will utilize their finding from this effort to provide a feasibility study report to DOT&PF and the Division or Risk Management. The report will outline long-term solution options and is anticipated to be completed spring/summer 2020.
Those who participated in the sampling event have received a copy of their results at the mailing address they provided. If you have questions regarding sample results please email firstname.lastname@example.org.
Community members who utilized the Holy Rosary Church as a drinking water source may visit the Dillingham Senior Center, water is available on the north side of the building, between the hours of 7 a.m. – 7 p.m. to refill their jugs until an alternative permanent water solution has been established at the church.
Community members whose private wells exceeded the DEC action level have been provided an alternate water solution.
For more information, please contact us.
Shannon & Wilson, Inc.
Marcy Nadel, Project Manager
Alaska Department of Environmental Conservation,
Contaminated Site Program
Bill O’Connell, Environmental Program Manager
Alaska Department of Environmental Conservations,
Contaminated Site Program
Robert Burgess, Environmental Program Specialist III
Division of Spill Prevention and Response website:
Alaska Department of Health & Social Services
Sarah Yoder, Public Health Scientist
Division of Public Health Website:
Alaska Department of Administration
Division of Risk Management
Ken Simpson, Claims Administrator
PO Box 110218
Juneau, AK 99811-0218
Alaska Department of Transportation and Public Facilities
Sammy Cummings, PFAS Program Manager