2B PFAS Rulemaking Update EMC May 2024

May 2024 Water Quality Committee Informational Item
May 8, 2024
Julie A. Grzyb, Deputy Director – Division of Water Resources
Environmental Management Committee
Background - Previous Surface Water Quality Standard
WQC and EMC Presentations
•November 2023 EMC Meeting
•Information Items - Proposed PFAS Toxicological Summaries and Potential
Affected Sources
•January 2024 WQC Meeting
•Information Items - Implementation Strategy for Proposed PFAS Surface
Water Quality Standards; Cost and Benefits Analysis Approach
•March 2024 WQC Meeting
•Information Item - Implementation Plan Timeline; DWR Stakeholder Meetings
Overview and Feedback
•May 2024 WQC Meeting
•Information Item – Proposed surface water standards, implementation plan
update and cost benefit analysis
2
Presentation Overview
•Surface Water Standards Overview
•Proposed 2B PFAS Standards
•NPDES Implementation Update
•Fiscal Analysis Snapshot
•Next Steps
3
Surface Water Standards Basics
4
Types of North Carolina Water Quality Standards
Federal and State Rules
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Groundwater Standards
(protect resource)
Surface Water Standards
(protect resource)
Drinking Water Standards
(treatment)
Clean Water Act
Safe Drinking Water Act
Surface Water in North Carolina
What is surface water?
•Surface Water is considered any body of water above ground, including streams, rivers, and
lakes. It is a key component of the hydrologic cycle and provides various societal and
ecosystem services, including drinking water, agricultural irrigation, and habitat for aquatic
plants and wildlife.
Example uses of surface water in NC
•22% of community drinking water systems use surface water as source water (~444 systems)
•41% of large public water supply (PWS) (>10,000 people) exceed EPA maximum contaminant
levels (MCLs).
•Approximately 3,268,000 residents are impacted by drinking water quality that exceeds EPA
MCLs.
Permitted discharges to surface waters NC (maximum permitted flow)
•Publicly owned treatment works (POTWs) with pretreatment programs: ~1,188 million gallons
per day
•Industrial Dischargers (Majors): ~305 million gallons per day
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Upstream Impacts on Surface Water Intakes and
Drinking Water Treatment Burden
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Pretreatment
Controls NC Surface Water Standards
Federal
Drinking
Water
Standards
Surface Water Human Health Criteria
•Human health criteria protect for fish consumption & water supply uses
•Standards determined using human health criteria calculations
•Calculations consider current toxicological information and exposure factors
•Calculation per 15A NCAC 02B .0208 (a)(2):
WQS = Water Quality Standard
RfD = Reference Dose
RSC = Relative Source Contribution
BW = Body Weight
WCR = Water Consumption Rate
FCR = Fish Consumption Rate
BCF = Bioconcentration Factor
𝑊𝑄𝑆=𝑅𝑓𝐷×𝑅𝑆𝐶× 𝐁𝐖
𝐖𝐂𝐑+(𝐅𝐂𝐑 𝑥 𝐵𝐶𝐹)
Full toxicity summary was given at November 2023 EMC meeting
Exposure factors highlighted in red are being updated
during the 2023-2025 triennial review
Toxicological Values for Standards Calculations
1.Reference Dose (RfD)
An estimate of a daily exposure to the human population that is likely to
be without an appreciable risk of deleterious effects during a lifetime
2.Cancer Slope/Potency Factor (CSF or CPF)
The cancer risk (proportion affected) per unit of dose and can be used to
compare the relative potency of different chemical substances.
3.Bioaccumulation Factor (BAF)(Surface Water Standards Only)
The amount of a chemical taken up from water plus the
contribution of chemical in the diet of the organism.
Proposed PFAS Compounds for Surface Water Standards
Development
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PFAS Compound Acronym
1 Perfluorooctane sulfonic acid PFOS
2 Perfluorooctanoic acid PFOA
3 Hexafluoropropylene oxide dimer acid HFPO-DA (GenX)
4 Perfluorobutanesulfonic acid PFBS
5 Perfluorobutanoic acid PFBA
6 Perfluorohexanoic acid PFHxA
7 Perfluorononanoic acid PFNA
8 Perfluorohexanesulfonic acid PFHxS
Standards Proposed to be Added to 02B
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PFAS Compound
DRAFT 02B
Water Supply
Numeric Criterion
(ng/L)
DRAFT 02B
Non-Water Supply
(Class C Waters)
Numeric Criterion
(ng/L)
EPA Limit of
Quantitation
(ng/L)*
PFOS 0.04 0.05 4.0
PFOA 0.001 0.01 4.0
HFPO-DA (GenX)20 500 5.0
PFBS 2,000 10,000 3.0
PFBA 6,000 200,000 5.0
PFHxA 3,000 200,000 3.0
PFNA 9 20 4.0
PFHxS 10 70 3.0
* Proposed health-based standards for PFOA and PFOS are below Limit of Quantitation. Permit effluent limit compliance for PFOA and PFOS will be
determined based on 4 ng/L as reported by EPA as a Limit of Quantitation from national lab validation of the wastewater test method (1633).
How are Water Quality Standards Used to Determine Effluent
Limits?
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Effluent Limit Calculation
PFAS Surface Water Standards Rulemaking
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PFAS Water Quality Standards Rulemaking
Guiding Principles
•Protect drinking water sources from upstream dischargers and other sources of
contaminants into surface water.
•Reduce treatment cost burden by addressing upstream dischargers.
•Propose surface water quality standards for all PFAS that also have Federal Primary
Drinking Water Standards.
•Propose surface water and ground water quality standards for remaining PFAS chemicals
where toxicity and human health data are published.
•Provide transparency to regulated sources and reasonable time for monitoring and taking
actions to meet effluent limits (if applicable).
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How are Standards Used to Determine the Impact on
Regulatory Programs?
•Identification of affected sources/permittees
•Development of an implementation plan
•Use implementation plan to determine the fiscal impacts on a regulated
entity
•Conduct a cost-benefit analysis
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Identification of Potentially Affected Sources and Permittees
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Industrial Dischargers (Direct)Publicly Owned Treatment Works with
Pretreatment Programs
~450+ SIUs suspected to be
associated with PFAS
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2025
EMC adopts NC PFAS
2B Standards
2029
Compliance with EPA
MCLs in effect
NPDES Implementation of PFAS Standards
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Effluent limits will not
be set below the Limit of
Quantitation (4 ng/L)
Development of a Tier Approach to Roll Out Effluent Limits
Goals of Tiered Approach
•Prioritize facilities that are the highest discharges of PFAS.
•Focus on facilities that are creators of PFAS or are a pass through from facilities that create PFAS and
discharge to a POTW.
•Address stakeholder feedback that identified the concern over treating what is considered the
uncontrolled sources of PFAS (e.g., residential homes) vs. controllable sources (e.g., significant
industrial users).
Development of Tiered Approach
•Based on the currently available site-specific influent data in NC
•Compiled influent data from studies on non-industrial impacted POTWs to understand what the
“uncontrollable” concentration ranges are for each of the 8 PFAS.
•Practical and systematic staged approach to roll out effluent limits
•Allows time for source reductions at SIUs and reductions through treatment at higher dischargers
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2029
Compliance with EPA MCLs in effect for PWS
~10 permits ~15-20 permits
2036
Reductions or treatment systems for significant PFAS
dischargers (Tiers 1 & 2) should be operational
Cost-Benefit Analysis Approach
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Benefits
•Estimate the anticipated benefits of the
proposed PFAS regulatory alternatives
relative to the baseline, including
quantification and monetization.
Costs
•What are the costs associated
with the proposed PFAS
regulatory changes?
2B Status Update
•Results of stakeholder discussions are being incorporated into permitting implementation
strategy
•Completing the analysis of anticipated costs for POTW with pretreatment programs
(including significant industrial users) and industrial dischargers
•Benefits analysis will be completed in the coming weeks
•Hold additional stakeholder meetings
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Questions?
Julie A. Grzyb
Deputy Director
Division of Water Resources
NC DEQ
[e-mail]