Managing Emerging Compounds in Water

The N.C. Division of Water Resources is implementing several projects associated with compounds of concern, or emerging compounds. Studies were conducted in 2018, 2020 and 2021, and are ongoing in 2022, to characterize the presence of these compounds in various water supply reservoirs across the state. Efforts are underway to develop an overall management strategy to reduce the levels of these compounds in the Cape Fear River Basin. 

Emerging compounds, such as 1,4 dioxane and PFAS, do not currently have federal water quality standards. Data collected and reviewed as part of the U.S. Environmental Protection Agency (EPA) Safe Drinking Water Act (SDWA) Third Unregulated Contaminant Monitoring Rule has indicated elevated concentrations of these compounds in drinking water that originated from the Cape Fear River Basin. In addition, monitoring performed by DWR has confirmed the presence of these compounds in surface waters within the Cape Fear River Basin.

Recent Developments & Actions

January 2023:

June 2022:

December 2021: EPA Announces Nationwide Monitoring Effort to Better Understand Extent of PFAS in Drinking Water

Data & Test Results

Statewide 1,4 dioxane Sampling Results 

Tab/Accordion Items

Groundwater Standards

DWR continues to assess new information and stays updated on federal actions regarding standards development, including the establishment of national primary drinking water regulations for PFOA and PFOS as outlined in the EPA’s PFAS Strategic Roadmap. More information on North Carolina’s groundwater standards can be found at Groundwater Standards.

Surface Water Quality Standards

DWR has established 1,4-Dioxane in-stream target values (ITVs) of 0.35 ug/L in surface waters classified as water supplies and 80 ug/L in all other surface waters. ITVs provide numeric regulatory values for substances that do not have existing water quality standards in 15A NCAC 02B .0200. ITVs are developed based on the narrative standard for toxic substances in 15A NCAC 02B .0208 and are implemented as surface water quality standards.

DWR has proposed the codification of these ITVs into the 15A NCAC 02B .0200 Surface Water Quality Standards as part of the current 2020-2022 Surface Water Triennial Review. This triennial review is currently in progress.

More information about the 2020-2022 Surface Water Triennial Review, including an estimated rulemaking timeline, can be found at Surface Water Standards.

North Carolina Surface Water Quality Standards, In-Stream Target Values, Groundwater Standards, and IMACs for Protection of Health and the Environment

(Scroll to view all six columns in the table)



Current Concentration

Effective Date

Proposed Concentration




3 ug/L (ppb)


No change currently proposed

Groundwater Standard

15A NCAC 02L .0202



2 ug/L (ppb)



IMAC – NC DEQ plans to update IMAC after further investigation






NC DEQ plans to pursue IMAC after further investigation


Surface Water

0.35 ug/L (ppb) for water supply

80 ug/L for non- water supply

Cancer slope factor was posted in 2010 on US EPA IRIS database

Included in current triennial review. Moving from a narrative standard to a specific standard under 15A NCAC 02B .0211.

Currently in-stream target values per 15A NCAC 02B .0208. 


Surface Water



None.  Awaiting publication of toxicity endpoints and/or bioaccumulation information



Drinking Water

140 ng/L (ppt)



NC DHHS Health Goal

What is Surface Water Foam (SWF) or “PFAS Foam”

Since June 2020, DEQ’s Division of Water Resources (DWR) has responded to reports by residents and DWR staff who observed unusual surface water foam (SWF) appearing on streams and rivers following rain events. Some samples were found to contain elevated levels of per- and polyfluoroalkyl substances (PFAS). Surface water samples collected around and under the SWF contained considerably lower levels of PFAS.

The N.C. Department of Health and Human Services recommends avoiding contact with all SWF as a precaution, especially for children and pets, and to immediately wash with soap and water any skin or clothing that comes into contact with foam. Pets should be thoroughly rinsed off with clean water.

Recognizing Naturally Occurring Surface Water Foam

Foam on water is a common natural occurrence when rainfall and wind mix up fatty substances and gases from decomposing plants and aquatic animals. The concentration, or build up, of the organic compounds changes the physical nature of the water, enabling SWF to form. Wind turbulence and wave action at the shoreline pushes air into the water, which mixes with organic compounds and forms the bubbles to create in the foam. Currents and boats also churn the water and mix air with the organic compounds in the water to produce naturally occurring foam. Foam can appear year-round on lakes and streams and rivers.

Naturally occurring foam has the following typical characteristics:

  • is off-white and/or brown,
  • may have an earthy or fishy smell, and/or
  • often collects in bays, eddies or river blockages.

Identifying PFAS in Surface Water Foam

PFAS substances, environmental pollution and other harmful bacteria can intermingle within naturally occurring foams.

The only way to be certain a foam substance contains PFAS is to have it tested by a certified laboratory. However, there appears to be some distinguishing characteristics of SWF that contains PFAS:

  • it can be bright white
  • slippery to touch
  • piles up like shaving cream

Investigating Surface Water Foam

DWR completed a preliminary statewide survey on the presence of SWF at the State’s water quality monitoring stations from October and September of 2021.  Results of the survey found 14% of the stations had SWF present but only 3% of the stations had accumulations that could be potentially sampled.

N.C. Division of Marine Fisheries (DMF) completed a similar survey on the presence of foam occurring on coastal recreational beaches from July through September of 2022.  Results of the survey found foam present at 17% of the survey sites with only 3% that had accumulations large enough for potential sampling.

Testing SWF for PFAS

Lab analysis is the only way to determine if foam contains PFAS or any other harmful bacteria or pollutants. The U.S. EPA Office of Research and Development is developing approved new  sampling methods for PFAS in SWF called Method 1633.  DWR is collaborating with EPA and other states investigating SWF, including Minnesota, Wisconsin and Michigan, to assist in developing an effective collection and testing protocol. Presently there is no approved or certified method by the U.S. Environmental Protection Agency (EPA) for collecting or testing of SWF DWR is also expanding its Chemistry Lab PFAS analytical services and capabilities through laboratory renovations upgrades and developing capabilities to analyze samples following the EPA draft Method 1633.

As additional test methods, site monitoring and new scientific data become available at the federal and state levels, DEQ will provide updates on the occurrence of PFAS in SWF, and take appropriate actions to protect surface water, and ensure the recreational uses and the aquatic life and wildlife resources.

DWR required publicly owned utilities with pretreatment programs (POTWs) and industrial dischargers with state permits in the Cape Fear River Basin to screen for a set of emerging compounds in wastewater.  These permit holders were required to sample for 1,4 dioxane and per- and polyfluoroalkyl substances, known as PFAS, for three consecutive months. The monitoring effort is part of an ongoing management strategy to address some of these compounds in surface water and results for both rounds of sampling are included in the interactive map. 

View Map


The map shows each of the 28 Publicly Owned Treatment Works (POTWs) and the water supply intakes located in the Cape Fear River Basin. DWR required sampling of the influent (or incoming wastewater stream) at these facilities because they receive wastewater from industrial sources that may contain 1,4 dioxane or one or more of the per- and polyfluoroalkyl substances known as PFAS.  Sampling was performed over a three-month period starting in July 2019.

1,4 Dioxane

The 1,4 dioxane influent sampling results from all 28 POTWs indicated that there were three POTWs of primary concern belong to Greensboro, Reidsville, and Asheboro. The results from the remaining POTW samples were significantly lower and are not anticipated to cause levels at downstream water intakes to exceed the EPA drinking water health advisory of 35 micrograms per liter (ug/L), or parts per billion (ppb).

  • Notices of Violations have been issued to Greensboro and Reidsville and additional monitoring and enforcement actions are underway to limit and enforce reductions of 1,4 dioxane in their discharge.
  • Asheboro’s corrective action plan states that an industrial user in their pretreatment program is installing best available treatment technology to reduce 1,4 dioxane in its discharge to the wastewater treatment plant.  That treatment technology was installed in November 2020.  Asheboro’s POTW does not directly discharge to a water supply.
PFAS Compounds

The PFAS influent sampling results from the POTWs indicate that one facility is potentially affecting a downstream water intake. One sampling event at Sanford’s Big Buffalo POTW showed influent levels that may cause an instream concentration of PFOS, PFOA, or the sum of PFOS and PFOA to exceed EPA’s drinking water health advisory of 70 nanograms per liter (ng/L), or parts per trillion (ppt), at Sanford’s water supply intake.

  • DEQ has initiated ongoing monthly sampling and source identification measures with the city of Sanford.
  • Influent sampling results from the other 24 POTWs showed PFOS and PFOA at concentrations that would not cause a downstream water supply to exceed EPA’s drinking water health advisory of 70 ng/L at the intake.

Industrial Dischargers

The effluent sampling from the 20 Industries and Groundwater Remediation (GWR) Sites was performed over a three-month period starting in Oct. 2019. DWR required sampling at these facilities because they either had a history of discharging 1,4-dioxane indicator compounds or are industry types that are historically linked to the discharge of 1,4 dioxane or one or more of the PFAS compounds. Several facilities completed sampling in May and all results were submitted by the end of June 2020. The division reviewed all data and updated the map to include all the industrial facilities and data received.

DWR continues to investigate all potential sources of 1,4 dioxane and PFAS compounds in state waters and is using this information to help guide additional actions to protect downstream water supplies.

1,4-dioxane data collected from established DWR ambient water quality monitoring stations may be viewed on this Dashboard.

1,4-dioxane is a clear liquid that is highly miscible in water. It has historically been used as a solvent stabilizer and is currently used for a wide variety of industrial and manufacturing purposes. The compound can be found in industrial solvents, paint strippers and varnishes, and is often produced as a by-product of chemical processes to manufacture soaps, plastics, and other consumer products. PFAS compounds are most often associated with nonstick coatings, plating operations, firefighting foams, and stain- and water-resistant treatments for clothing, furniture and carpeting.

Since 2014, the Division of Water Resources has been sampling for 1, 4 dioxane in the Cape Fear River Basin, after seeing elevated concentrations reported as part of the Environmental Protection Agency’s Third Unregulated Contaminant Monitoring Rule (UCMR3).

Elevated levels of 1,4 dioxane were identified downstream of the Greensboro, Reidsville, and Asheboro wastewater treatment plants, and DWR has worked in collaboration with those facilities to reduce the discharge. To help facilitate the effort, DWR required all three cities to submit corrective action plans outlining steps to reduce the substance from their discharge. DWR also encouraged the pretreatment programs in the Cape Fear Basin to have the Division of Environmental Assistance and Customer Service’s Waste Reduction Partners work with their industry dischargers to reduce or eliminate their 1,4-dioxane effluent.  In addition, DEQ is working to determine and assess any additional sources of 1,4 dioxane contribution in the basin beyond the dischargers that may be causing contaminated groundwater to infiltrate into surface water. 

Monthly sampling for 1,4 dioxane has been collected by the permittees once per month since Dec. 2017 and submitted on the discharge monitoring reports. To see the discharge monitoring report data, go to the interactive map.

Weekly sampling for 1,4 dioxane at the Greensboro and Reidsville wastewater treatment plants was initiated when DWR learned about the elevated levels of 1,4 dioxane in Pittsboro’s drinking water in October 2019. In early November, staff also started sampling at the East Burlington wastewater treatment plant on the Haw River. That data will be released once it has been reviewed. 

On November 14, 2019 DEQ issued notices of violation to the wastewater pre-treatment programs for the cities of Greensboro and Reidsville for recent 1,4 dioxane discharges that violated water quality standards and the conditions of their wastewater permits.

Links to NPDES permit information for Greensboro, Reidsville and Asheboro

Greensboro NPDES permit documents

Reidsville NPDES permit documents 

Asheboro NPDES permit documents 

News Releases about the ongoing investigation

Nov. 15, 2019: DEQ issues violation notices to Greensboro and Reidsville for 1,4 dioxane discharges

Oct. 22, 2019: DEQ investigating 1,4 dioxane levels from Reidsville, notifying utilities

Oct. 15, 2019: DEQ Investigating 1,4 Dioxane Release

T.Z. Osborne WWTP - Special Order by Consent

EMC SOC WQ S19-010 - SOC between the EMC and the City of Greensboro (approved at the March 11, 2021 EMC meeting)

EMC Meeting March 11, 2021 Attachments:

The Groundwater Management Branch (GWMB) is evaluating PFAS occurrence and distribution in groundwater across North Carolina via DWR’s statewide Monitoring Well Network. The GWMB is currently sampling approximately 500 of the ~700 wells in the network, which encompasses all the state’s major aquifers and river basins. This project is expected to be completed around 2025-2026. PFAS data from this effort is being made publicly available here and is updated periodically as new data becomes available. To learn more about DWR’s monitoring well network and to view or download data, visit the GWMB’s home page and the groundwater quality and groundwater education and information pages.

Well Testing in New Hanover County

DEQ continues to investigate the presence of PFAS compounds in groundwater wells located in New Hanover County. Since May 2019, staff have performed multiple rounds of groundwater sampling in public water supply wells and DEQ ambient groundwater monitoring wells.

Detections of GenX to date in public water supply wells are below the provisional drinking water health goal set by DHHS in 2017. The 2019 public water supply well sampling results for PFOA and PFOS were below the lifetime health advisory level set by the EPA in 2016. Sampling results at one public water supply well in 2020 slightly exceeded the lifetime health advisory level for PFOA and PFOS. DEQ is preparing to resample this well and monitor any changes to groundwater quality results.

DEQ will continue to sample public water supply wells, groundwater monitoring wells, and surface water to further define the extent of the PFAS compounds in groundwater.  This page will be updated with the sampling results as they become available. The ongoing testing and assessment is being coordinated with New Hanover County Health Department and Cape Fear Public Utility Authority.

2019 - 2021 PFAS Sampling Results

Map of New Hanover County sampling locations
Please note: The yellow diamonds reference monitoring wells and the blue squares reference public water supply wells.



The Division of Water Resources conducted two studies in 2020 to provide baseline information on the presence of PFAS and 1,4-dioxane in public drinking water supply reservoirs.  These reports include the Study for the Ongoing Assessment of Water Quality in B. Everett Jordan Lake, Including Identification of Select Emerging Compounds: 2020 Results and Identification of Select Emerging Compounds in Public Water Supply Reservoirs of the Neuse River Basin.

In 2018, the Division performed three studies to characterize the presence and concentrations of select emerging compounds (EC) in B. Everett Jordan Reservoir and its immediate watershedFalls Lake and its immediate watershed and in various public water supply (PWS) reservoirs in the Cape Fear, New and Watauga River Basins.

Monitoring continues across the state to further evaluate potential source areas as the division establishes PFAS analytical capabilities. The division will also use the UNC Policy Collaboratory’s data from drinking water intakes when available to help identify future sampling locations.

Surface Water Sampling for PFAS in the Cape Fear River Basin

Industrial and Municipal WWTP PFAS Sampling in the Cape Fear River Basin 

Analytical Results for PFAS Screening of Select Public Water Supply Reservoir