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HomeMy WebLinkAboutAttachment A DRAFT_0208 (Sec. 8) Report - DWR DRAFT_2024.04.23 DRAFT for EMC Review and Consideration June 1, 2024 Report to the Joint Legislative Commission on Governmental Operations Study of Narrative Standards per SL 2023-137 (8) Session Law 2023-137 (8) directed the Environmental Management Commission (“EMC”) to review 15A NCAC 02B .0208 Standards for Toxic Substances and Temperature “to determine if the standards and methodologies for establishment of water quality criteria for specific pollutants included therein are scientifically sound, protective of human health and the environment, and result in water quality criteria that are technologically achievable without placing undue economic burdens on publicly owned treatment works and their ratepayers.” In its review, the EMC shall examine: (i) other states' narrative water quality standards and identify other states with more stringent and less stringent narrative standards and (ii) requirements established by the United States Environmental Protection Agency for development of narrative water quality standards and water quality criteria by states, as well as any discretion given to states to set standards and criteria. The EMC is providing its findings and recommendations for legislative action to the Joint Legislative Commission on Governmental Operations. DRAFT (4/23/24) Page 2 of 19 I. BACKGROUND Clean Water Act – Water Quality Standards The purpose of the Clean Water Act (CWA) is to restore and maintain the chemical, physical and biological integrity of the nation’s waters. Water quality standards (“standards”) are a keystone part of the CWA, providing a regulatory basis for water quality management1. Standards include: ❖ Designated Best Uses (“uses”), such as drinking water, aquatic life propagation, swimming, agriculture, etc.2 ❖ Water Quality Criteria (“criteria”) necessary to protect uses, which are expressed as numeric concentrations, levels or narrative statements. Numeric criteria are constituent concentrations or levels representing a quality of water that supports a particular use. Narrative criteria are statements that describe the desired conditions of a waterbody. A narrative criterion must be provided when a numeric criterion is not or cannot be established.3 ❖ Antidegradation, which is the framework for maintaining and protecting water quality that has been achieved and protecting the assimilative capacity of waters.4 Clean Water Act – Water Quality Criteria Under Section 303 of the CWA, states and authorized tribes (“states”) are responsible for adopting water quality standards necessary to protect designated best uses. States must conduct a review of its standards at least once every three years to comply with the CWA and the U. S. Environmental Protection Agency’s (EPA) regulations at 40 CFR Part 131.20, commonly referred to as the “Triennial Review.” EPA is required to review state water quality standards to ensure that the requirements of the CWA and applicable implementing regulations have been met. If EPA determines the state standard is consistent with the CWA and its implementing regulations (including 40 CFR Part 131 and 40 CFR 122.44), the standard is approved. However, if the state standard is not consistent with the CWA and its implementing regulations, EPA disapproves the standard. When EPA disapproves a state standard, the state may make appropriate corrections and resubmit. EPA may also promulgate a new or revised water quality standard for the state when necessary to meet the requirements of the CWA. EPA, under authority provided in Section 304 of the CWA, assists states by providing National Recommended Water Quality Criteria (“NRWQC”)5 established at values that are protective of human health and the environment. The NRWQC are developed using the latest scientific knowledge (e.g., toxicity data and risk analysis) and do not reflect considerations of economic 1 CWA Section 303 2 40 CFR 131.10 3 40 CFR 131.11 4 40 CFR 131.12 5 https://www.epa.gov/wqc/national-recommended-water-quality-criteria-tables DRAFT (4/23/24) Page 3 of 19 impacts or technological feasibility. As the scientific body of knowledge evolves and new toxicity data become available, EPA revises the NRWQC. These changes are peer reviewed and receive public comment before being published. States can adopt the NRWQC or adopt other criteria based on scientifically defensible methods. This allows states to address pollutants of concern within their state. Per 40 CFR 131.11, a CWA implementing regulation, state criteria must be based on scientific rationale, must contain parameters to protect designated uses, and must protect the most sensitive use. Figure 1: Requirements of State Criteria under 40 CFR 131.11(a)(1)6 No authority is given to states to consider economic impacts or technological feasibility when establishing criteria, though these may be considered on a site-specific basis, for example, in Special Orders by Consent, variances, or compliance schedules. Per Section 301(b)(1)(C) of the CWA, 40 CFR 122.44 (another CWA implementing regulation), and 15A NCAC 02H .0112(c), state narrative and numeric criteria must be used to set NPDES eftfuent limits that protect designated uses. North Carolina – Water Quality Criteria North Carolina has adopted numeric criteria as well as narrative criteria, both of which are used to set NPDES eftfuent limits to protect designated uses. An example of each is provided below: • Numeric: The numeric criterion for total residual chlorine in fresh surface waters in 17 ug/l. NPDES permit #NC0020460 was issued in January 2021 with a daily maximum eftfuent limit of 28 ug/l. • Narrative: The following narrative standard in 15A NCAC 02B .0211 states “… colored or other wastes: only such amounts as shall not render the waters injurious to public health, secondary recreation, or to aquatic life and wildlife, or adversely affect the palatability of fish, aesthetic quality, or impair the waters for any designated uses.” In the Pigeon River, this narrative color standard has been historically interpreted as an instream true color value of 50 Platinum-Cobalt Units (PCU). NPDES permit #NC0000272 was issued in March 2022 with an average annual discharge of true color 6 U.S. EPA. 2017. Water Quality Standards Handbook: Chapter 3: Water Quality Criteria. EPA-823-B-17-001. EPA Office of Water, Office of Science and Technology, Washington, DC. DRAFT (4/23/24) Page 4 of 19 not to exceed 36,000 pounds per day and a monthly average eftfuent true color loading not to exceed 52,000 pounds per day. Clean Water Act – Toxic and Priority Pollutants In the 1972 Amendments to the Federal Water Pollution Control Act, Congress stated, “it is the national policy that the discharge of toxic pollutants in toxic amounts be prohibited.” In 1987, an amendment to the CWA added Section 303(c)(2)(B), which required states to adopt criteria for certain toxic pollutants.7 EPA developed guidance8 for states to comply with this new effort in “scientifically and technically sound ways”, providing three options: 1. Adopt Statewide numeric criteria in State water quality standards for all section 307(a) toxic pollutants for which EPA has developed criteria guidance, regardless of whether the pollutants are known to be present; 2. Adopt specific numeric criteria in State water quality standards for Section 307(a) toxic pollutants as necessary to support designated uses where such pollutants are discharged or are present in the affected waters and could reasonably be expected to interfere with designated uses; 3. Adopt a procedure to be applied to a narrative water quality standard provision that prohibits toxicity in receiving waters. Such a procedure would be used by the State in calculating derived numeric criteria, which criteria should be used for all purposes under section 303(c) of the CWA. At a minimum, such criteria need to be developed for section 307(a) toxic pollutants, as necessary to support designated uses, where these pollutants are discharged or are present in the affected waters and could reasonably be expected to interfere with designated uses. EPA stated that it believed “option 2 above most directly satisfies the new Clean Water Act requirements and is the option recommended by the Agency. Option 3, while considered by EPA also to meet the requirements of the Act, is best suited for use as a supplement to option 2.” North Carolina – Toxic Substances In response to the 1987 amendment to the CWA, the EMC followed EPA guidance and proposed a combination of options 2 and 3 in the 1989 Triennial Review. Prior to adoption, the EMC formed a study committee to evaluate the appropriateness and economic impact of the proposed changes, how North Carolina’s proposed changes compared to other states, and what risk level should be used when setting health-based standards. 7 Section 307 of the Clean Water Act establishes a list of “toxic pollutants”. “Pollutants with toxic effects” are pollutants that may have toxic priorities not specifically regulated under Section 307. EPA also maintains a list of priority pollutants, which identifies individual chemical names as opposed to general classes of pollutants. 8 U.S. EPA. 1988. Guidance for State Implementation of Water Quality Standards for CWA Section 303(C)(2)(B). EPA-823-R-88-100. EPA Office of Water, Office of Water Regulations and Standards Criteria, Criteria and Standards Division, Washington DC. DRAFT (4/23/24) Page 5 of 19 The committee noted that EPA Region IV9 recommended that states adopt a risk level10 of 1x10- 6, as this level represents a negligible risk, and a negligible risk is required by law. EPA Region IV guidance also deemed consideration of economic impact in establishing standards unacceptable. The committee concluded that the proposed standards were not more stringent than the chemical characteristics of pristine streams and North Carolina’s proposed standards were generally in line with the proposals of other Region IV states, including a risk level of 1x10-6. The committee recommended North Carolina use mean annual flow11 in determining eftfuent limits for carcinogens, because the standards are based upon lifetime exposure to a pollutant. This flow criterion proposed by North Carolina was the least stringent of all the Region IV states for which flow criteria were known12 at the time. In addition to the study committee, the EMC requested guidance from the N.C. Attorney’s General Office on the responsibility and authority of the EMC to investigate the social and economic costs of the proposed standards. The Attorney’s General Office stated that the Clean Water Act does not provide for water quality standards to be set based on cost, but that pursuant to N.C.G.S. 143-214.1(d)(4), the EMC should consider the economic and social costs when revising existing or adopting new water quality standards. The Attorney’s General Office also stated that standards which are set contrary to the Clean Water Act requirements are subject to disapproval and promulgation by EPA if not corrected. Afler thorough investigation and public input, the EMC adopted individual numeric criteria for certain pollutants that were determined to be impairing the uses of the State’s waters and a narrative standard with procedures used to calculate appropriate derived numeric water quality criteria for substances for which no specific numeric water quality criteria are available. On February 7, 1991, EPA fully approved13 the numeric criteria and narrative criteria (with the associated translator mechanism and specified inputs) for toxic pollutants adopted by North Carolina as being consistent with options 2 and 3 of the 1988 EPA guidance document. II. FINDINGS Scientifically Sound As part of this report, the EMC reviewed 15A NCAC 02B .0208 to determine if the standards and methodologies for establishment of water quality criteria for specific pollutants included therein 9 EPA Region IV States: https://www.epa.gov/aboutepa/about-epa-region-4-southeast 10 A risk of 1x10-6 means that one person out of 1 million persons assumed to be exposed under similar conditions could develop cancer as a result of lifetime exposure to one or more potential carcinogens. 11 Mean annual flow means the average flow of a stream from measurements taken throughout the year. If available, flow data for the previous ten years are used in determining mean annual flow. This represents the long-term average flow of a stream. 12 Other Region IV states, for which flow criteria were known at the time, were proposing 30Q2 or 30Q5. 30Q2 means the minimum average flow for a period of 30 days that has an average recurrence of one in two years. 30Q5 means the minimum average flow for a period of 30 days that has an average recurrence of one in five years. 13 56 FR 58420 DRAFT (4/23/24) Page 6 of 19 are scientifically sound. The EMC concluded that the adopted specific numeric criteria for toxic pollutants and the narrative standard and translator mechanism that describes in detail the procedures used to calculate appropriate derived water quality criteria for other toxic pollutants are scientifically sound. This combination of specific numeric criteria for certain toxic pollutants (i.e., option 2) and a narrative standard and an approved translator mechanism with specified inputs (i.e., option 3) satisfies the requirements in Section 303(c)(2) of the federal CWA. Per 40 CFR 40 131.11(a)(1) (requiring that criteria be based on scientific rationale), EPA review and approval of the translator mechanisms with specified inputs ensured that they are of acceptable scientific quality. Additionally, for option 3, the EMC met the criteria set forth by EPA14: • The procedure must be used to calculate numeric water quality criteria. North Carolina uses the standards and methodologies outlined in 15A NCAC 02B .0208 to calculate derived numeric water quality criteria. • The state must demonstrate to EPA that the procedure results in numeric criteria that are sufficiently protective. The standards and methodologies outlined in 15A NCAC 02B .0208 were determined by EPA to be sufficiently protective of both aquatic life and human health. • The state must provide for full opportunity for public participation during the adoption of the procedure. The EMC complied with the North Carolina Administrative Procedures Act and federal rulemaking requirements, both of which require public notice and hearings. Additionally, the EMC formed a study committee to evaluate the appropriateness and economic impact during the 1989 adoption process. • The procedure must be formally adopted as a state rule and be mandatory in application. The procedure was formally adopted as a state rule effective October 1, 1989, codified in 15A NCAC 02B .0208 and creates a mandatory obligation to implement the derived numeric quality criteria in setting effluent limits in NPDES permits where necessary to protect designated uses. • The procedure must be submitted for review and approval by EPA. North Carolina’s methodologies were approved by EPA on February 7, 1991, satisfying the requirement in 40 CFR 131.11(a)(1) that the criteria be based on “sound scientific rationale.” 14 1991 EPA Amendments to Water Quality Standards Regulation, 56 FR 59420, 59425 (Nov. 19, 1991); see also 40 CFR 131.5 DRAFT (4/23/24) Page 7 of 19 Protective of Human Health and the Environment As part of this report, the EMC reviewed 15A NCAC 02B .0208 to determine if the standards and methodologies for establishment of water quality criteria for specific pollutants included therein are protective of human health and the environment. The EMC concluded that the rule is protective of the environment and the adoption, codification and EPA approval of the 2023- 2025 Surface Water Triennial Review will result in updated inputs that are protective of human health. Paragraph (a) of 15A NCAC 02B .0208 this rule states “… the concentration of toxic substances, either alone or in combination with other wastes, in surface waters shall not render waters injurious to aquatic life or wildlife, recreational activities, or public health, nor shall it impair the waters for any designated uses.” Specific numeric standards for toxic substances are listed in Rules 15A NCAC 02B .0211, .0212, .0214, .0215, .0216, .0218, .0219, .0220, .0221 and .0220. Procedures for interpreting the narrative standard for toxic substances is outlined in rule for both aquatic life criteria and human health criteria. Aquatic life criteria are developed to determine the highest concentration of a substance in water that will not present a significant risk to the aquatic organisms. Methods rely primarily on chronic15 and acute16 laboratory toxicity data for aquatic organisms in different taxonomic groups (e.g. Ceriodaphnia, minnows, etc.). Human health criteria are developed to protect human health from exposure routes, including fish and shellfish tissue consumption and water consumption. • Concentrations for non-carcinogens are calculated as follows: o For fish tissue consumption only, WQS = (RfD x RSC x BW) / (FCR x BAF) o For fish tissue consumption and water consumption, WQS = (RfD x RSC x BW) / [WCR + (FCR x BAF)] • Concentrations for carcinogens are calculated as follows: o For fish tissue consumption only, WQS = (RL x BW) / (CPF x FCR x BAF) o For fish tissue consumption and water consumption, WQS = (RL x BW) / (CPF x [WCR + (FCR x BAF)]) Where the following apply: 15 "Chronic toxicity to aquatic life" means any harmful effect sustained by either resident aquatic populations or indicator species used as test organisms in a controlled toxicity test due to long-term exposure (relative to the life cycle of the organism) or exposure during a substantial portion of the duration of a sensitive period of the life cycle to a specific chemical substance or mixture of chemicals. 16 "Acute toxicity to aquatic life" means lethality or other harmful effects sustained by either resident aquatic populations or indicator species used as test organisms in a controlled toxicity test due to a short-term exposure of 96 hours or less to a specific chemical or mixture of chemicals. DRAFT (4/23/24) Page 8 of 19 • WQS = water quality standard/criteria • RfD = reference dose, based on EPA published values • RSC = relative source contribution, based on EPA published values • BW = body weight, which was codified in 1989 at 70 kilograms17 (kg). • FCR = fish consumption rate, which was codified in 2007 at 17.5 grams/day18 (g/day). • BAF = bioaccumulation factor or bioconcentration factor, based on EPA published values. • WCR = water consumption rate, which was codified in 1989 at 2.0 Liters/day19 (L/day). • RL = risk level at 1x10-6. This means an unacceptable health risk for cancer shall be more than one additional case of cancer per one million people exposed20. • CPF = cancer potency factor, based on EPA published values. The EMC is completing the 2023-2025 Surface Water Triennial Review, with public notice and hearing scheduled during July and August 2024. As part of the review, the EMC will be incorporating the 2015 EPA updated National Recommended Water Quality Criteria for body weight (updating from 70 kg to 80 kg), fish consumption rate (updating from 17.5 g/day to 22.0 g/day) and water consumption rate (updating from 2.0 L/day to 2.4 L/day) to ensure the most current science is used when calculating water quality criteria for toxic substances. Consideration of Technologically Achievability of Water Quality Criteria As part of this report, the EMC reviewed the federal regulations to determine whether the state can consider technological achievability or undue economic burden on publicly owned treatment works and their ratepayers in the standards and methodologies for establishment of water quality criteria in 15A NCAC 02B .0208. The EMC concluded that these factors can be analyzed during rulemaking, but no authority is provided in the applicable federal regulations21 to incorporate these factors when calculating water quality criteria. In 1989, the EMC requested guidance from the N.C. Attorney General’s Office on the responsibility and authority of the EMC to investigate the social and economic costs of the proposed standards. The Attorney’s General Office stated that the Clean Water Act does not provide for water quality standards to be set based on cost, but that pursuant to N.C.G.S. 143- 214.1(d)(4), the EMC should consider the economic and social costs when revising existing or adopting new water quality standards. 17 In 2015, EPA updated the National Recommended Water Quality Criteria based on data from CDC National Health Surveys to 80 kg. 18 Fish consumption rate was established in 1989 as 6.5 grams (g)/day, then updated to 17.5 g/day in 2007. In 2015, EPA updated the National Recommended Water Quality Criteria based on data from CDC National Health Surveys to 22.0 g/day. 19 In 2015, EPA updated the National Recommended Water Quality Criteria based on data from CDC National Health Surveys to 2.4 L/day. 20 EPA publishes National Recommended Water Quality Criteria at a 1 x 10-6 risk level, which EPA considers appropriate for the general population. 21 Pursuant to 40 CFR 131.11(a)(1), “States must adopt those water quality criteria that protect the designated use. Such criteria must be based on sound scientific rationale [emphasis added] and must contain sufficient parameters or constituents to protect the designated use.” DRAFT (4/23/24) Page 9 of 19 “[W]ater quality standards must be set based on the scientific measurement of their necessity. However, the social and economic costs information is useful to the EMC and should not be kept from the record. Indeed, the knowledge of what the costs are and when standards will be achieved is consistent with informed and reasoned decision-making. In a contextual reading of both federal and State authorities, those costs should not be used to affect the adoption of standards otherwise required by the public health and welfare.” The Attorney’s General Office also stated that standards set contrary to the CWA requirements are subject to disapproval and promulgation by EPA if not corrected, and reminded the EMC that variances and compliance schedules are available tools where individual costs present a problem. In March 2024, EPA Region IV staff confirmed the 1989 Attorney’s General Office interpretation of the CWA is still accurate and added that an additional tool available where individual costs present a problem is a Use Attainability Analysis (UAA)22. A UAA is the process for reviewing and revising designated uses through a structured scientific assessment of the factors affecting the attainment of uses specified in Section 101 (a)(2) of the CWA23. The factors include the physical, chemical, biological and economic use removal criteria described in 40 CFR 131.10(g). In general, a UAA is required when revising designated uses related to protecting aquatic life, wildlife, or recreation (e.g., the City of Los Angeles completed a UAA24 to temporarily suspend recreational use in engineered channels during unsafe wet weather conditions). Other States Narrative Water Quality Standards – Region IV States As part of this report, the EMC examined other states codified narrative water quality standards using information compiled by EPA25. As required by the CWA, states have adopted a narrative water quality standard prohibiting toxic pollutants in toxic amounts to protect designated uses. Below is a detailed review of translator procedures used by EPA Region IV states and the Eastern Band of Cherokee Indians26 for calculating derived numeric water quality criteria from narrative water quality standards: • Alabama o Narrative water quality standard “State waters shall be free from substances attributable to sewage, industrial wastes or other wastes in concentrations or combinations which are toxic or harmful to human, animal or aquatic life to the extent commensurate with the designated usage of such waters.” 22 A Use Attainability Analysis (UAA) is a structured scientific assessment of the factors affecting the attainment of uses specified in Section 101 (a)(2) of the CWA. The factors include the physical, chemical, biological and economic use removal criteria described in 40 CFR 131.10(g). 23 Uses specified in Section 101 (a)(2) of the CWA include the protection and propagation of fish, shellfish, and wildlife, as well as recreation. These uses are also known as “fishable/swimmable”. 24 https://www.epa.gov/sites/default/files/2014-11/documents/la-channels-uaa.pdf 25 Staff reviewed EPA compiled information: https://www.epa.gov/wqs-tech/state-specific-water-quality-standards-effective-under-clean-water- act-cwa. This does not include policy or permitting information. 26 The Eastern Band of Cherokee Indians are located within North Carolina. DRAFT (4/23/24) Page 10 of 19 o Alabama uses option 1 and 3. For option 3, Alabama uses the same translator as North Carolina, except the fish consumption rate is higher 30 g/day rather than NC17.5 g/day. o Concentrations for non-carcinogens are calculated as follows: ▪ For fish tissue consumption only, conc. (mg/l) = (HBW x RfD x RSC) / (FCR x BCF) ▪ For fish tissue consumption and water consumption, conc. (mg/l) = (HBW x RfD x RSC) / [(FCR x BCF) + WCR] o Concentrations for carcinogens are calculated as follows: ▪ For fish tissue consumption only, conc. (mg/l) = (HBW x RL) / (CPF x FCR x BCF) ▪ For fish tissue consumption and water consumption, conc. (mg/l) = (HBW x RL) / (CPF x [(FCR x BCF) + WCR]) o Where the following apply: ▪ HBW = human body weight, set at 70 kg. ▪ RfD = reference dose, based on EPA published values. ▪ RSC = relative source contribution, based on EPA published values. ▪ FCR = fish consumption rate, set at 30 g/day. ▪ BCF = bioconcentration factor, based on EPA published values. ▪ WCR = water consumption rate, set at 2 L/day. ▪ RL = risk level, set at 1 x 10-6 (except for arsenic, which is set at 1 x 10-5). ▪ CPF = cancer potency factor, based on EPA published values. • Florida o Narrative water quality standard “All surface waters of the State shall at all places and at all times be free from… [d]omestic, industrial, agricultural, or other man- induced non-thermal components of discharges which, alone or in combination with other substances or in combination with other components of discharges (whether thermal or non-thermal)… are acutely toxic” and “Substances in concentrations which injure, are chronically toxic to, or produce adverse physiological or behavioral response in humans, plants, or animals… [n]one shall be present.” o Florida does not currently have a translator codified in their rules, rather they have an extensive list of numeric criteria for pollutants27. However, in December 2022, the EPA Administrator determined that new and revised human health criteria for Florida were necessary pursuant to CWA Section 303(c)(4)(B). Therefore, EPA is promulgating water quality standards to replace the values promulgated by Florida.28 EPA is using the following: ▪ Cancer risk level of 1x10-6. ▪ Body weight of 80 kg. ▪ Fish consumption rate of 22.0 g/day. 27 In 1992, Florida adopted “Option 2” from the 1988 EPA Guidance 28 88 FR 85530: https://www.federalregister.gov/documents/2023/12/08/2023-26734/water-quality-standards-to-protect-human-health-in- florida#footnote-14-p85532 DRAFT (4/23/24) Page 11 of 19 ▪ Drinking water intake of 2.4 L/day. ▪ Cancer Slope Factors based on EPA published values. ▪ Reference Doses based on EPA published values. ▪ Bioaccumulation bioconcentration factors based on EPA published values. ▪ Relative source contributions based on EPA published values. • Georgia o Narrative water quality standard “All waters shall be free from toxic, corrosive, acidic and caustic substances discharged from municipalities, industries or other sources, such as nonpoint sources, in amounts, concentrations or combinations which are harmful to humans, animals or aquatic life.” o Georgia does not have a translator codified in their rules, rather they have a list of numeric criteria for pollutants. Georgia’s toxics program was approved by EPA29 as consistent with option 1 in 1991. • Kentucky o Narrative water quality standard “Surface waters shall not be aesthetically or otherwise degraded by substances that… [i]njure or are chronically or acutely toxic to or produce adverse physiological or behavioral responses in humans, animals, fish, and other aquatic life.” o Kentucky does not have a translator codified in their rules, rather they have a list of numeric criteria for pollutants. Kentucky’s toxics program was approved by EPA30 as consistent with option 1 in 1991. • Mississippi o Narrative water quality standard “The concentration of toxic substances in Surface Waters of the State shall not result in chronic or acute toxicity or impairment of the uses of aquatic life… The concentration of toxic substances shall not exceed the level necessary to protect human health through exposure routes of fish (and shellfish) tissue consumption, water consumption, or other routes identified as appropriate for the waterbody.” o Mississippi’s toxics program was approved by EPA31 as consistent with options 1 and 3 in 1991. For option 3, Mississippi uses the same translator as NC. o Concentrations for non-carcinogens are calculated as follows: ▪ For fish tissue consumption only, WQC = (RfD x BW) / (FCR x BCF) ▪ For fish tissue consumption and water consumption, WQC = (RfD x BW) / [(FCR x BCF) + WCR] 29 56 FR at 59461 30 56 FR at 59462 31 56 FR at 59461 DRAFT (4/23/24) Page 12 of 19 o Concentrations for carcinogens are calculated as follows: ▪ For fish tissue consumption only, WQC = (Risk x BW) / [CPF x (FCR x BCF)] ▪ For fish tissue consumption and water consumption, WQC = (Risk x BW) / [CPF x ((FCR x BCF) + WCR)] o Where the following apply: ▪ WQC = water quality criterion. ▪ RfD = reference dose, based on EPA published values. ▪ BW = body weight, set at 70 kg. ▪ FCR = fish consumption rate, set at 17.5 gm/person-day. ▪ BCF = bioconcentration factor, based on EPA published values. ▪ WCR = water consumption rate, set at 2 L/day. ▪ Risk = risk factor, set at 1 x 10-6. ▪ CPF = cancer potency factor, based on EPA published values. • South Carolina o Narrative water quality standard “All ground waters and surface waters of the State shall at all times, regardless of flow, be free from… [h]igh temperature, toxic, corrosive, or deleterious substances attributable to sewage, industrial waste, or other waste in concentrations or combinations which interfere with classified water uses (except classified uses within mixing zones as described in this regulation), existing water uses, or which are harmful to human, animal, plant or aquatic life.” o South Carolina does not have a translator codified in their rules, rather they have a list of numeric criteria for pollutants. South Carolina’s toxics program was approved by EPA32 as consistent with option 1 in 1991. o South Carolina’s rules do specify “The human health criteria for the priority and non priority pollutants are based on carcinogenicity of 10-6 risk.” • Tennessee o Narrative water quality standard “The waters shall not contain toxic substances, whether alone or in combination with other substances, which will produce toxic conditions that materially affect the health and safety of man or animals, or impair the safety of conventionally treated water supplies.” o Tennessee does not have a translator codified in their rules, rather they have a list of numeric criteria for pollutants. Tennessee’s toxics program was approved by EPA33 as consistent with option 2 in 1991. o Tennessee’s rules do specify “10-5 risk level is used for all carcinogenic pollutants.” • Eastern Band of Cherokee Indians o Narrative water quality standard “The concentration of toxic substances shall not result in chronic or acute toxicity or impairment of the uses of aquatic life… The 32 56 FR at 59462-63 33 56 FR at 59463 DRAFT (4/23/24) Page 13 of 19 concentration of toxic substances shall not exceed the level necessary to protect human health through exposure routes of fish tissue consumption, water consumption, or other routes identified as appropriate for the particular body of water…” o For option 3, EBCI uses the same translator as North Carolina with updated 2015 EPA exposure factors. o Concentrations for non-carcinogens are calculated as follows: ▪ For fish tissue consumption only, WQS = (RfD x BW x RSC) / (FCR x BCF) ▪ For fish tissue consumption and water consumption, WQS = (RfD x BW x RSC) / [WCR + (FCR x BCF)] o Concentrations for carcinogens are calculated as follows: ▪ For fish tissue consumption only, WQS = (Risk x BW) / (CPF x FCR x BCF) ▪ For fish tissue consumption and water consumption, WQS = (Risk x BW) / [CPF x (WCR + (FCR x BCF))] o Where the following apply: ▪ WQS = water quality standard/criteria ▪ RfD = reference dose, based on EPA published values ▪ RSC = relative source contribution, based on EPA published values ▪ BW = body weight, set at 80 kg. ▪ FCR = fish consumption rate, set at 22.0 g/day. ▪ BAF = bioaccumulation factor, based on EPA published values. ▪ WCR = water consumption rate, set at 2.4 L/day. ▪ RL = risk level, set at 1 x 10-6. ▪ CPF = cancer potency factor, based on EPA published values. Other States Narrative Water Quality Standards – All States As part of this report, the EMC examined other states’ narrative water quality standards using information compiled by EPA34. • 44 states have a cancer risk level codified in their rules; o 28 states have a cancer risk level of 1x10-6; o 16 states have a cancer risk level of 1x10-5; • 40 states have an adult body weight codified in their rules; o 14 states have a body weight of 70 kg; o 6 states have a body weight of 80 kg; • 24 states have a fish consumption rate codified in their rules; o Varies from 6.5 g/day to 175 g/day; • 22 states have a water consumption rate codified in their rules; 34 Staff reviewed EPA compiled information: https://www.epa.gov/wqs-tech/state-specific-water-quality-standards-effective-under-clean-water- act-cwa. This does not include policy or permitting information. DRAFT (4/23/24) Page 14 of 19 o 15 states have a water consumption rate of 2.0 L/day; o 6 states have a water consumption rate of 2.4 L/day; o 1 state has a water consumption rate of 3.0 L/day. A summary of available information related to human health calculations for all 50 states is provided in the tables below. Table 1 – Summary of State Information18 Related to Human Health Calculations for States with Risk Factor and Body Weight, Fish Consumption and/or Water Consumption A Risk factor is 1x10-6 except for arsenic, which is 1 x 10-5 B Pending final promulgation by EPA C State does not have a translator codified in their rules18 D EPA promulgated criteria for the state of California EPA Region State Body Weight (kg) Fish Consumption Rate (grams/day) Water Consumption Rate (Liters/day) Risk Factor (cancer case per people exposed) I Maine 80 32.4 2.4 1x10-6 I Massachusetts 70 17.5 2.0 1x10-6 I Rhode Island 70 17.5 2.0 1x10-5 II New York 70 33 2.0 1x10-6 III Pennsylvania 80 22.0 2.4 1x10-6 IV Alabama A 70 30 2.0 1x10-6 IV Florida B 80 22.0 2.4 1x10-6 IV Mississippi 70 17.5 2.0 1x10-6 IV North Carolina 70 17.5 2.0 1x10-6 V Illinois 70 20 2.0 1x10-6 V Indiana 70 15 2.0 1x10-5 V Michigan 70 15 2.0 1x10-5 V Minnesota 70 30 3.0 1x10-5 V Ohio 70 15 2.0 1x10-5 V Wisconsin 70 20 2.0 1x10-5 VI Texas 70 17.5 2.0 1x10-5 VII Missouri N/A C 6.5 2.0 1x10-6 VIII Colorado 70 17.5 2.0 1x10-6 VIII Montana 80 22.0 2.4 1x10-5 VIII Wyoming N/A C 17.5 2.0 1x10-6 IX California D 80 22.0 2.4 1x10-6 X Idaho 80 66.5 2.4 1x10-5 X Oregon N/A C 175 N/A C 1x10-6 X Washington N/A C 175 N/A C 1x10-6 DRAFT (4/23/24) Page 15 of 19 Table 2 – Summary of State Information18 Related to Human Health Calculations for States with Risk Factor Only E EPA Region State Risk Factor (cancer case per people exposed) I Connecticut 1x10-6 I New Hampshire 1x10-6 I Vermont 1x10-6 II New Jersey 1x10-6 III Delaware 1x10-6 III Maryland 1x10-5 III Virginia 1x10-5 III West Virginia 1x10-6 IV South Carolina 1x10-6 IV Tennessee 1x10-6 VI Arkansas 1x10-5 VI Louisiana 1x10-6 VI New Mexico 1x10-5 VII Iowa 1x10-5 VII Kansas 1x10-6 VII Nebraska 1x10-5 VIII North Dakota 1x10-6 VIII South Dakota 1x10-6 VIII Utah 1x10-6 X Alaska 1x10-5 E States without a translator or risk level codified in their rules18 includes Georgia (Region IV), Kentucky (Region IV), Oklahoma (Region VI), Arizona (Region IX), Hawaii (Region IX), and Nevada (Region IX). Below is a detailed review35 of the translator procedures used by four states outside of EPA Region IV8 for calculating derived numeric water quality criteria from narrative water quality standards: • Maryland o Narrative water quality standard “The waters of this State may not be polluted by… [t]oxic substances attributable to sewage, industrial wastes, or other wastes in concentrations outside designated mixing zones, which… (a) [i]nterfere directly or indirectly with designated uses or (b) [a]re harmful to human, plant or aquatic life.” 35 Staff reviewed EPA compiled information: https://www.epa.gov/wqs-tech/state-specific-water-quality-standards-effective-under-clean-water- act-cwa. This does not include policy or permitting information. DRAFT (4/23/24) Page 16 of 19 o Maryland does not have a translator codified in their rules, rather they have a list of numeric criteria for pollutants. Maryland’s toxics program was approved by EPA36 as consistent with option 2 in 1990. o Maryland’s rules do specify “… a carcinogenic risk level of 10-5.” • Michigan o Narrative water quality standard “Toxic substances shall not be present in the surface waters of the state at levels that are or may become injurious to the public health, safety, or welfare, plant and animal life, or the designated uses of the waters.” o Michigan’s toxics program was approved by EPA37 as consistent with options 1 and 3 in 2000. o Concentrations for non-carcinogens are calculated as follows: ▪ HNV = (ADE x BW x RSC) / {WC + [(FCTL3 x BAF3) + (FCTL4 x BAF4)]} o Concentrations for carcinogens are calculated as follows: ▪ HCV = (RAD x BW) / {WC + [(FCTL3 x BAF3) + (FCTL4 x BAF4)]} o Where the following apply: ▪ HNV = human noncancer value in mg/L ▪ ADE = acceptable daily exposure in mg/kg/day ▪ BW = body weight, set at 70 kg ▪ RSC = relative source contribution factor of 0.8 ▪ WC = water consumption rate, set at 2 L/day for drinking and incidental exposure or 0.01 L/day for incidental ingestion only ▪ FCTL3 = fish consumption rate of trophic level 3 fish, set at 3.6 gm/person- day ▪ BAF3 = bioaccumulation factor for trophic level 3 fish, as derived using the methodology in rule ▪ FCTL4 = fish consumption rate of trophic level 4 fish, set at 11.4 gm/person-day ▪ BAF4 = bioaccumulation factor for trophic level 4 fish, as derived using the methodology in rule ▪ HCV = human cancer value in mg/L ▪ RAD = risk associated dose that is associated with a lifetime incremental cancer risk equal to 1 in 100,000 for individual chemicals divided by the slope factor (RAD = 0.00001/q1*, where q1* = slope factor) • Rhode Island o Narrative water quality standard “At a minimum, all waters shall be free of pollutants in concentrations or combinations or from anthropogenic activities subject to these regulations that: a. Adversely affect the composition of fish and wildlife; b. Adversely affect the physical, chemical, or biological integrity of the 36 56 FR at 58457-8 37 67 FR at 68039 DRAFT (4/23/24) Page 17 of 19 habitat; c. Interfere with the propagation of fish and wildlife; d. Adversely alter the life cycle functions, uses, processes and activities of fish and wildlife; or e. Adversely affect human health.” o Rhode Island’s toxics program was approved by EPA38 in 1999. o Rhode Island’s regulations reference “procedures for assessing health effects” but do not provide a calculation in rule. The regulations do specify the following: ▪ For carcinogens, criteria are established at: • Risk level of 10-5 • Body weight of 70 kg • Fish consumption rate 17.5 grams per day • Water consumption rate of 2.0 liters per day ▪ For non-carcinogens, criteria are established at: • Body weight of 70 kg • Fish consumption rate 17.5 grams per day • Water consumption rate of 2.0 liters per day • Minnesota o Narrative water quality standard “Toxic pollutants shall not be allowed in such quantities or concentrations that will impair the specified uses.” o Minnesota’s toxics program was approved by EPA39 in 1991. o Concentrations for non-carcinogens are calculated as follows: ▪ For fish tissue consumption and recreation, CCfr or CSfr = (RFD x RSC x 1,000) / {IWR + FCR x [(0.24 x BAFTL3) + (0.76 x BAFTL4)]} ▪ For fish tissue consumption, recreation and water consumption, CCdfr or CSdfr = (RFD x RSC x 1,000) / {DWIR + FCR x [(0.24 x BAFTL3) + (0.76 x BAFTL4)]} o Concentrations for carcinogens are calculated as follows: ▪ For fish tissue consumption and recreation, CCfr or CSfr = [CR/(CSF x AF)] x [1,000/{IWR + FCR x [(0.24 x BAFTL3) + (0.76 x BAFTL4)]}] ▪ For fish tissue consumption, recreation and water consumption, CCdfr or CSdfr = [CR/(CSF x AF)] x [1,000/{DWIR + FCR x [(0.24 x BAFTL3) + (0.76 x BAFTL4)]}] o Where the following apply: ▪ CC(d)fr or CS(d)fr = Chronic criterion or standard ▪ RFD = reference dose ▪ RSC = relative source contribution ▪ 1,000 = a factor used to convert milligram to microgram ▪ IWR = incidental water intake rate, set at 0.091 L/day 38 65 FR 47864 39 67 FR at 68039 DRAFT (4/23/24) Page 18 of 19 ▪ FCR = fish consumption rate, set at 30 g/day ▪ BAFTL3 = bioaccumulation factor for trophic level 3 fish ▪ BAFTL4 = bioaccumulation factor for trophic level 4 fish ▪ DWIR = drinking water intake rate, set at 3 L/day ▪ CR = cancer risk level, set at 1 x 10-5 ▪ CSF = cancer potency slope factor ▪ AF = adjustment factor Requirements by EPA for Narrative Standards The EMC examined the requirements established by the EPA for development of narrative water quality standards and water quality criteria by states, as well as any discretion given to states to set standards and criteria. The EMC concluded that North Carolina complies with those requirements and properly exercised its discretion. In response to the 1987 amendment to the CWA, which added Section 303(c)(2)(B), the EMC elected to comply with the requirements of this amendment through a combination of options 2 and 3 from EPA’s guidance7 in the 1989 Triennial Review. The EMC properly exercised its discretion in choosing these options afler significant study (including the input from an ad hoc committee) and extensive public outreach and comments. On February 7, 1991, EPA fully approved the criteria for toxic pollutants adopted by North Carolina as compliant with federal requirements. Since then, North Carolina has continued to operate under options 2 and 3, in accordance with 40 CFR § 131.11, and with EPA’s continued approval40 pursuant to 40 CFR § 131.5. 40 CFR § 131.11(a) requires the following: • States must adopt water quality criteria that protect designated uses. o North Carolina has adopted water quality criteria in 15A NCAC 02B .0200 that protect designated uses. • For waters with multiple use designations, the criteria shall support the most sensitive use. o Standards for different uses are specified in rules for different classifications. Looking at aldrin as an example, freshwaters classified for protection of aquatic life have a standard of 2 ng/L. For waters classified as a drinking water supplies, the more sensitive use is human health, therefore the standard is 0.05 ng/L. • Such criteria must be based on sound scientific rationale and must contain sufficient parameters to protect designated uses. o As stated above, North Carolina’s criteria are based on sound scientific rationale and protect designated uses. This has been reaffirmed each time EPA has approved North Carolina’s water quality standards. (note: Pursuant to 40 CFR § 131.5 (a)(2), EPA approval means EPA has determined “… the state has adopted 40 EPA’s most recent approval of 15A NCAC 02B .0208 was in April 2020. DRAFT (4/23/24) Page 19 of 19 criteria that protect the designated water uses based on sound scientific rationale consistent with § 131.11”.) • States must review water quality data and information on discharges to identify where toxic pollutants may be adversely affecting water quality or the levels of toxic pollutants are at a level to warrant concern. o North Carolina reviews water quality data from a variety of sources, including but not limited to Ambient Monitoring System data, Monitoring Coalition data, Unregulated Contaminant Monitoring Rule (UCMR) data, etc. • States must adopt criteria for such toxic pollutants sufficient to protect the designated use. o North Carolina adopted specific numeric criteria for Section 307(a) toxic pollutants where such pollutants are discharged or present in the state. North Carolina also adopted a narrative standard with a translator mechanism that describes in detail the procedures used to calculate derived water quality criteria for other toxic pollutants. • When a State adopts narrative criteria for toxic pollutants, it must provide information identifying the method. o North Carolina uses the standards and methodologies outlined in 15A NCAC 02B .0208 to calculate derived numeric water quality criteria. III. RECOMMENDATIONS FOR LEGISLATIVE ACTION The EMC does not recommend any legislative action at this time as sufficient authority has been provided to comply with the state’s obligations under the federal CWA to adopt, review and update water quality standards and criteria.