PFAS Rules and Regulations Spotlight: North Carolina
- By: Lindsay Boone, M.Sc.
- Tags: PFAS
North Carolina has become a focal point in the national conversation on PFAS regulation, driven by high‑profile contamination events and active community engagement. Over the past several years, the North Carolina Department of Environmental Quality (DEQ) and the Environmental Management Commission (EMC) have advanced a series of actions focused on addressing PFAS contamination at the source. This post highlights several of the most important developments, including enacted PFAS groundwater standards, emerging monitoring and minimization requirements for wastewater dischargers, and key findings from the state’s PFAS biosolids study.
North Carolina PFAS Ground Water Standards
North Carolina’s 2L groundwater standards are health‑based limits that apply anywhere groundwater could reasonably be used as a current or future drinking‑water source. These standards set enforceable concentration limits for contaminants. When levels are exceeded, regulators generally expect investigation, remediation, or other mitigation to protect public health.
In late 2025, as concerns about PFAS contamination grew, DEQ proposed adding several PFAS compounds to the 2L standards table, extending these regulations for the first time to this class of emerging contaminants. These compounds included PFOA, PFOS, HFPODA (GenX), PFBA, PFHxA, PFNA, PFBS, and PFHxS. From this group, DEQ adopted final groundwater standards for three compounds: PFOA, PFOS, and Gen X.
North Carolina Final Groundwater Standards for PFOA, PFOS and GenX
02L Standard (ng/L) | Current PQL* (ng/L) | Current Compliance Levels (ng/L) | |
|---|---|---|---|
PFOA | 0.001 | 4 | PQL |
PFOS | 0.7 | 4 | PQL |
HFPO DA (GenX) | 10 | 5 | 10 |
For GenX, DEQ set the standard at 10 ppt, but the ultra‑low standards set for PFOA and PFOS reflect the prevailing view that no level of these compounds in drinking water is truly safe. The challenge for regulators is that these levels fall below the Practical Quantitation Limit (PQL) for EPA Method 1633, the method used for groundwater analysis in North Carolina and in most other states. The PQL represents the lowest concentration that a laboratory can reliably and consistently measure with acceptable accuracy and precision using a defined analytical method.
To address this challenge, DEQ tied compliance to the PQL for PFOA and PFOS, meaning that any detection above the PQL would be considered an exceedance. As the science of PFAS analysis evolves, the PQL may drop, which would result in a corresponding drop in the compliance level for these compounds.
It is essential to discuss your data quality objectives with your laboratory partner, especially when dealing with challenging matrices such as groundwater. Groundwater has the potential to contain elevated levels of total suspended solids (TSS) that can interfere with PFAS quantitation via EPA 1633. Method 1633 is a performance-based method, so laboratories are allowed to modify aspects of the method in order to meet specific program needs, such as the lower limits of 4 ppt associated with both PFOA and PFOS.
The PQL values for PFOA and PFOS, in particular, can be impacted by the inability of the laboratory to utilize the full sample volume for analysis. However, the lab can implement steps during sample preparation that will aid in the mitigation of solids impacts and the need for sub sampling. These steps aid in maintaining the lower PQLs needed for the 2L limits. Therefore, it is of the utmost importance to have a discussion with your laboratory partner about specific program needs prior to submitting samples. The laboratory should be treated as part of your overall team when scoping out studies associated with programs like the 2L limits in North Carolina.
New Testing Requirements for Significant Dischargers
Although we’ve increasingly seen PFAS included in North Carolina NPDES permits, the state is advancing rulemaking that would, for the first time, impose formal PFAS monitoring requirements on selected wastewater dischargers. This monitoring program specifically call out PFOA, PFOS, and GenX. The same three compounds with associated 2L standards. The proposed rules focus on two main groups:
- Direct NPDES permit holders with a reasonable potential to discharge PFAS
- Significant Industrial Users (SIUs) that send wastewater to Publicly Owned Treatment Works (POTWs).
DEQ and the EMC have also requested comment on whether it is appropriate to focus applicability on SIC/NAICS codes associated with PFAS use and discharge, which signals an intent to prioritize sectors with known PFAS connections. If your operations fall into one of these focus groups, it’s critical to establish a PFAS monitoring strategy if you have not already done so. Pace® can help you evaluate potential PFAS risks, design a monitoring program aligned with the proposed rules, and navigate evolving analytical and regulatory requirements. Reach out to us if you’d like to discuss how we can support your PFAS risk assessment and monitoring program.
The North Carolina PFAS Biosolids Study
To better understand how PFAS behave in real-world wastewater and biosolids systems, North Carolina undertook a statewide PFAS biosolids and wastewater study in 2023. In this study, the state sampled multiple components at dozens of facilities across North Carolina, including:
- Influent, primary effluent, and final effluent at municipal wastewater treatment plants
- Biosolids destined for land application
- Soils on fields where biosolids had been applied
- In some cases, groundwater near land-application sites
The objective of the study was to build a robust dataset to inform future policy decisions, and several themes emerged from the research:
PFAS are widespread in biosolids. PFAS, especially PFOS, were detected in biosolids at nearly all participating facilities, although levels varied widely depending on industrial contributions, treatment processes, and historical practices.
Most PFAS pass through plants into effluent. For many facilities, the mass balance showed that the majority of PFAS entering the plant left in treated effluent rather than in biosolids. That reinforces the focus on minimizing PFAS at the source and in wastewater discharge, with biosolids management as a secondary priority.
Soils at land‑applied sites contained PFAS, but patterns varied. Fields with a long history of biosolids application often showed higher PFAS levels than reference fields, though the degree of accumulation and vertical migration in the soil profile varied by site, soil type, and application history.
Drinking water risk depends on site conditions. While PFAS were present in soils and sometimes in shallow groundwater near application areas, the risk to drinking water sources depends on hydrogeology, proximity of wells, and the specific PFAS and concentrations involved.
Webinar: Biosolids Analysis for PFAS: Challenges, Considerations, and Options
Partnering With Pace® on Your PFAS Strategy
North Carolina’s PFAS landscape is moving quickly, and it can be challenging to translate emerging rules, studies, and public expectations into a clear action plan. If you are looking to strengthen your PFAS strategy, we invite you to reach out to us to get a conversation started.
