Final SW PFAS Proposed WQS Info Item

Implementation Strategy for Proposed PFAS Surface Water Quality Standards
Environmental Management Commission –Water Quality Committee, March 13, 2024
PFAS –
Emerging Compounds
“Chemicals of Emerging Concern” (CECs)
•PFAS are Mobile, persistent, bioaccumulate
•Unregulated; newly regulated
•Wide variety of chemical structures,
chemical and physical properties
•Differing fate, transport and toxicity
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Sources of Environmental PFAS
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1.Fire training & response
•AFFF
2. Industrial Sites
•Emissions to air and discharge to water
•Manufacturing, spills, disposal
3. Landfills
•Leachate →WWTPs
•Industrial & consumer waste
4. WWTPs & Biosolids
•Lagoons→air, soil, water
•Biosolids –
•Land application →plant, animal uptake
•Run-off, infiltration
5. Degradation of in-home consumer products
•Food packaging, stain-resistant products, etc.
How the Standards Are Derived
Proposed PFAS Numeric Standards Based 15A NCAC 02B .0208
❖Standards developed per the translation procedures & calculations
described in rule -02B .0208 (2)(A) & (2)(B)
❖Numeric criteria derived for fish consumption & water supply
designated uses
❖Carcinogenic & non-carcinogenic endpoints considered
❖Updated exposure factors proposed in the 2022-2024 Triennial
Review will be used
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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.
Updated Human Health Exposure Factors
Exposure Factor Current 02B Value1 2015 EPA Value2
Body Weight (kg)70 80
Drinking Water Intake Rate (L/day)2.0 2.4
Fish Consumption Rate (g/day)17.5 22.0
Footnotes:
1.Established in 02B .0208 in 1989 (Eff. 10/01/89); Fish consumption updated in 2007
(Eff. 05/01/07)
2.Updated based on CDC national health surveys
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PFAS
Compound
DRAFT 02B
Water Supply
Numeric Criterion
(ng/L)
DRAFT 02B
Non-Water Supply
Numeric Criterion
(ng/L)
EPA Limit of
Quantification
(ng/L)*
PFOS 0.04 0.05 4.0
PFOA 0.001 0.01 4.0
HPFO-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
Draft PFAS Surface Water Standards
*Proposed health-based standards for PFOA and PFOS are below detection limits. Permit effluent limits for PFOA and PFOS will be determined based
on 4 ng/L as reported by EPA as a Limit of Quantification from nation lab validation of the wastewater test method.
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NPDES Implementation of PFAS Standards
DWR considering measured implementation schedule for standards:
•Two years of PFAS Assessment Monitoring at EPA targeted Industry and major
POTWs and encourage source reduction, BMPs and minimization strategies
•EPA Certified Wastewater Test method promulgated needed for CWA permits
•Up to two years of certified monitoring allowing time for Permittees (and SIUs)
and conduct reasonable potential
•Anticipate by 2028 insert effluent limits and compliance schedules with
reasonable and feasible milestones in permits targeting facilities with higher
discharge concentrations first and all new dischargers to meet limits immediately
•Not looking to regulate discharges caused by raw water source (if that can be
determined)
•Effluent limits will not be set below detection
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NPDES Implementation of PFAS Standards
Stakeholder Feedback
Stakeholder meetings held on January 29 and January 30, 2024
Included representatives from: Industry, Large Municipalities (with Pretreatment
programs), Water Utilities, Landfill, NC League of Municipalities, NC Manufacturing
Alliance, and NC County Commissioners
Main Concerns:
•Costs
•Background and Uncontrolled Sources
•Application of Effluent Limits
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NPDES Implementation of PFAS Standards
Stakeholder Feedback
Costs
•Utilities are concerned about the cost of treatment at POTWs on top of Water Plants
having to meet MCLs -rate increases to customers could be cost prohibitive
Background and Uncontrolled Sources
•Source water (surface, municipal, or groundwater) may have PFAS levels above
standards
•Residential sources of PFAS that are uncontrollable could exceed standards (PFAS
found in consumer products)
•Priority should be on PFAS creators/generators not passive receivers
Application of Effluent Limits
•If standards are limit of quantification, who gets limits?
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Next Steps
•Consider how stakeholder feedback can be used to revise implementation plan with
enough detail to address concerns (where possible)
•Stakeholders asked for a follow-up meeting –present revised implementation plan to
stakeholders for feedback
•Hold a stakeholder meeting for concerned environmental organizations
•Fiscal analysis approach is being updated based on the implementation plan
adjustments, where applicable.
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Questions?
Julie Grzyb
Deputy Director
Division of Water Resources
NC DEQ
[e-mail]