Middle Chickahominy PFAS Study
A Collaborative Effort of the Virginia Department of Environmental Quality, Virginia Department of Health, and Henrico County
The Middle Chickahominy River watershed is located in central Virginia within the boundaries of the city of Richmond and the counties of Henrico, Hanover, New Kent, and Charles City. The Chickahominy River is a major tributary of the James River, the largest river in the Commonwealth of Virginia.
The Middle Chickahominy PFAS Study is a multi-agency effort to investigate the presence of PFAS in the Middle Chickahominy River watershed.
What is PFAS?
Per- and polyfluoroalkyl substances (PFAS) are a group of human-made chemicals that were created for a variety of household and industrial uses. PFAS can repel oil, grease, and water, and they have been used in protective coatings for many different products including food packaging, nonstick cookware, carpets and upholstery (stain-protectants), mattresses and clothing (water-proofing), and have also been used in fire-fighting foams. Some of the more commonly known PFAS are perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA).
Most PFAS (including PFOA and PFOS) do not readily break down, so they remain in the environment for a very long time. This is why PFAS are termed "forever chemicals." Because of their widespread use and their persistence in the environment, PFAS can be found in water, soil, air, and human blood all over the world. Some PFAS can accumulate in people and animals with repeated exposure.
Health effects from exposure to low levels of PFAS are not well known, but may include elevated cholesterol levels, interference with thyroid function, preeclampsia, and decreased fertility. PFAS may also affect the immune system and cause developmental effects in fetuses, infants, and children. Some studies have found increases in prostate, kidney, and testicular cancers in workers exposed to PFAS and people living near a PFAS production facility. However, other studies focused on cancer effects present less definitive results. More research is needed to better understand the health effects of PFAS exposure.
The United States Environmental Protection Agency (EPA) has issued drinking water health advisory levels for four PFAS compounds: PFOA, PFOS, perfluorobutane sulfonic acid (PFBS), and hexafluoropropylene oxide-dimer acid and its ammonium salt (HFPO-DA or GenX). These thresholds are considered protective of lifetime exposure. The health advisory levels for PFOA and PFOS are considered interim, while the advisories for PFBS and HFPO-DA/GenX have been finalized.
What is the Middle Chickahominy PFAS Study?
In October of 2021, Newport News Waterworks alerted the Virginia Department of Environmental Quality (DEQ) to elevated PFAS concentrations in the Middle Chickahominy River watershed and pinpointed the White Oak Swamp watershed as the possible origin of the PFAS. DEQ, the Virginia Department of Health (VDH), and Henrico County immediately formed a team effort process--a Unified Command--to develop a joint response focused on identifying any potential risks to public health.
Click here to read the initial press release.
White Oak Swamp just upstream from Route 156
Redear sunfish caught in Chickahominy Lake
Environmental Monitoring
Henrico County sampled the White Oak Swamp watershed to verify Newport News Waterworks' initial findings. Henrico's findings were consistent with what Newport News Waterworks found.
DEQ contracted with the United States Geological Survey (USGS) to complete a study of PFAS in the Middle Chickahominy River watershed. Fish tissue, sediment and surface water samples were collected at locations throughout the watershed, including in Chickahominy Lake, to understand the possible exposure pathways for human health.
Interpreting the Results
Using toxicity information published by the EPA, DEQ and VDH established provisional screening thresholds for four PFAS compounds--PFOA, PFOS, PFBS, and GenX. These thresholds are compared to sample concentrations to identify sites that may be contaminated and thus in need of additional investigation. Exceedances of screening thresholds do not necessarily indicate that human health has been or will be negatively impacted. These thresholds are considered provisional because they may be adjusted when more information becomes available. The technical document describing these thresholds can be found here .
The dashboard below shows environmental sample results from Newport News Waterworks, Henrico County Department of Public Utilities (DPU), and DEQ/USGS. Use the tools on the left side of the dashboard to explore the data.
PFAS concentrations are typically expressed in parts per trillion (ppt). One ppt is equivalent to one drop in 20 Olympic-sized swimming pools.
The upper portion of White Oak Swamp has shown consistently elevated levels of PFAS, with PFOA and PFOS concentrations exceeding recreational surface water thresholds. It is recommended that sensitive populations (e.g. children and pregnant women) avoid eating fish from the Middle Chickahominy River watershed until EPA finalizes recommendations to protect human health from exposure through fish ingestion. Further investigation is needed to identify the potential source(s) of the contamination in White Oak Swamp.
Private Drinking Well Monitoring
Henrico County has reached out to residents in close proximity to the White Oak Swamp who obtain drinking water through private wells. The county sampled approximately 280 private drinking wells to determine whether there are elevated PFAS concentrations in groundwater. Both shallow and deep wells were sampled. PFAS were not detected in 80% of the wells tested. Sample concentrations from 26 wells were greater than the interim EPA Lifetime Health Advisory Levels for PFOA, PFOS, or both.
Click on a grid cell in the dashboard to the right to see a summary of the private drinking well results for that area.
Henrico County has notified all testing recipients of their well sampling results by mail. Granulated Activated Carbon (GAC) filter systems have been installed at two locations with elevated PFOS/PFAS detections. Upon resample and retesting, the PFOS/PFAS compounds are non-detect. A third system will be installed in the coming months.
Public Drinking Water Systems Monitoring
The Virginia Department of Health Office of Drinking Water (ODW) identified and tested three public water systems within a 1-mile radius of White Oak Swamp. PFAS concentrations in these systems ranged from single digit to mid-30 ppt. ODW staff reached out to all three waterworks owner/operators and provided additional technical assistance. Efforts are underway to connect the one waterworks with elevated PFAS concentrations to the Henrico County water system. Additional PFAS sampling at the public waterworks along the Chickahominy River will be conducted in the next phase of monitoring.
Next Steps
The Virginia Department of Health is working with USGS to determine if the elevated PFAS concentrations found in private well water are due to elevated concentrations in the White Oak Swamp watershed.
The Virginia Department of Environmental Quality is investigating sources and identifying responsible entities of PFAS in the watershed. Additional sampling may be conducted to better understand the nature and extent of the occurrence of PFAS in the area.
DEQ and VDH will be tracking EPA's technical and policy recommendations regarding PFAS as they develop and will use this information, along with additional monitoring datasets, to inform management decisions, as appropriate.
This page will be updated with additional information as it becomes available.
Resources
More Information about PFAS
Reports
Datasets
Technical Memo
Special thanks goes to the Newport News Waterworks and the United States Geological Survey for their work on this project.
