Current through Register Vol. XLI, No. 50, December 13, 2024
Section 47-2-8 - Specific Water Quality Criteria8.1. Charts of specific water quality criteria are included in Appendix E, Table 1. 8.1.a. Specific state (i.e. total, total recoverable, dissolved, valence, etc.) of any parameter to be analyzed shall follow 40 CFR 136, Guidelines Establishing Test Procedures for Analysis of Pollutants Under the Clean Water Act, as amended, June 15, 1990 and May 18, 2012, 47CSR10, and "National Pollutant Discharge Elimination System (NPDES) Program."8.1.b. Compliance with aquatic life water quality criteria expressed as dissolved metal shall be determined based on dissolved metals concentrations. 8.1.b.1. The aquatic life criteria for all metals listed in Appendix E, Table 2 shall be converted to a dissolved concentration by multiplying each numerical value or criterion equation from Appendix E, Table 1 by the appropriate conversion factor (CF) from Appendix E, Table 2.8.1.b.2. Permit limits based on dissolved metal water quality criteria shall be prepared in accordance with the U.S. EPA document "The Metals Translator: Guidance For Calculating A Total Recoverable Permit Limit From A Dissolved Criterion, EPA 823-B-96-007 June 1996.8.1.b.3. NPDES permit applicants may petition the secretary to develop a site-specific translator consistent with the provisions in this section. The secretary may, on a case-by-case basis, require an applicant applying for a translator to conduct appropriate sediment monitoring through SEM/AVS ratio, bioassay or other approved methods to evaluate effluent limits that prevent toxicity to aquatic life.8.1.c. An "X" or numerical value in the use columns of Appendix E, Table 1 shall represent the applicable criteria.8.1.d. Charts of water quality criteria in Appendix E, Table 1 shall be applied in accordance with major stream and use applications, sections 6 and 7, herein.8.2. Criteria for Toxicants 8.2.a. Toxicants which are carcinogenic have human health criteria (Water Use Categories A and C) based upon an estimated risk level of one additional cancer case per one million persons (10 -6) and are indicated in Appendix E, Table 1 with an endnote (b).8.2.b. The critical design flow for human health criteria effluent limits shall be the long-term harmonic mean flow.8.2.c. The components and other aspects of the human health criteria based on EPA's 2015 national recommended human health criteria were developed using available data, which in some cases may have been limited. The bioaccumulation factors, relative source contributions, and other relevant factors used in development of the human health criteria may be evaluated on a case-by-case basis as part of the NPDES permitting process or by petition to the Secretary. Permit limits based on revisions to the human health criteria made in accordance with this paragraph are subject to a 45-day public comment period and are subject to EPA review under CWA 303(c), but are not subject to review by the Legislative Rule-Making Review Committee in accordance with the rule-making procedures of the West Virginia Administrative Procedures Act.8.3. Criteria for Nutrients 8.3.a. Lakes 8.3.a.1. This subsection establishes nutrient criteria designed to protect Water Use Categories B and C. The following cool water nutrient criteria shall apply to cool water lakes. (See Appendix F for a representative list.) The following warm water nutrient criteria shall apply to all other lakes with a summer residence time greater than 14 days.8.3.a.2. Total phosphorus shall not exceed 40 [MICRO]g/l for warm water lakes and 30 [MICRO]g/l for cool water lakes based on an average of four or more samples collected during the period May 1 to October 31. Chlorophyll-a shall not exceed 20 µg/l for warm water lakes and 10 µg/l for cool water lakes based on an average of four or more samples collected during the period May 1 to October 31. In lieu of total phosphorus and/or chlorophyll-a sampling, impairment may be evidenced at any time by noncompliance with subsection 3.2 above, as determined by the secretary.8.4. Variances from Specific Water Quality Criteria. A variance from numeric criteria may be granted to a discharger if it can be demonstrated that the conditions outlined in paragraphs 6.1.b.1 through 6.1.b.6 herein limit the attainment of one or more specific water quality criteria. Variances shall apply only to the discharger to whom they are granted and shall be reviewed by the secretary at least every three years. In granting a variance, the secretary shall follow the requirements for revision of water quality standards in 46CSR6.8.5. Site-specific numeric criteria. The secretary may establish numeric criteria different from those set forth in Appendix E, Table 1 for a stream or stream segment upon a demonstration that existing numeric criteria are either over-protective or under-protective of the aquatic life residing in the stream or stream segment. A site-specific numeric criterion will be established only where the numeric criterion will be fully protective of the aquatic life and the existing and designated uses in the stream or stream segment. In adopting site-specific numeric criteria, the requirements for revision of water quality standards set forth in 46 CSR 6 shall be followed, unless developed pursuant to subdivision 8.5.a herein.8.5.a. A site-specific numeric criterion may be established as part of the NPDES permitting process using any of the following established methods: a Water Effect Ratio study pursuant to the procedures described in U.S. EPA's "Interim Guidance on the Determination and Use of Water-Effect Ratios for Metals" (February 1994); the Streamlined Water-Effect Ratio Procedure for Discharges of Copper (March 2001); a Biotic Ligand Model analysis pursuant to the procedures described in U.S. EPA's "Aquatic Life Ambient Freshwater Quality Criteria - Copper" (February 2007).