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HomeMy WebLinkAboutNC0090212_Correspondence_20240325 (3)Responses to the SELC Comments Permit NCO090212 Albemarle Kings Mountain Lithium Project March 25, 2024 1. First, as it has for many industrial NPDES permits, DEQ has ignored in this draft permit the mandatory requirement under the Clean Water Act to impose technology -based effluent limitations (TBELs). DEQ is well aware of this issue because we have raised it with the agency multiple times Response: During development of the permit DWR personnel reviewed all existing available data and required more data from the applicant, reviewed EPA documents and resources for relevant parameters of concern for established limits, conducted Reasonable Potential Analysis for each parameter of concern, assessed water quality impacts, evaluated other pertinent items, and as appropriate developed limits based upon Best Professional Judgement (BPJ) in accordance with applicable rules and regulations. Developing TBEL's is an extraordinarily complicated, difficult, and a time-consuming process as evidenced by the time and staff resource commitment expended by the EPA during the last time that agency developed TBELs. For example, the EPA spent 10 years to develop the latest update to the Power Plant Guidelines and then an additional 5 years to make subsequent adjustments to the Final Rule. This process involved the EPA Engineering and Analysis Division with a team of roughly 40 experts who do nothing but work on developing Effluent Guidelines, dozens of other EPA personnel, and outside contracted experts. DWR lacks capacity to develop BPJ Best Available Technology (BAT) limits.. Such an effort would be enormous in nature and would require full-time commitment from numerous existing staff members, expertise in economics beyond what exists at the DWR and likely securing significant outside resources (expert consultants). DWR past attempts to develop BPJ BAT taught us that DWR must strictly adhere to EPA guidance. 2. Second, water in the mine's existing pit extends to a depth of 165 feet below the mine's current surface. The draft permit proposes to authorize the discharge of that water. However, the proposed wastewater treatment design was developed based on removing water only up to 150 feet. Response: In accordance with established rules and practices the DWR conducted the EPA - recommended analyses to determine the reasonable potential for toxicants to be discharged at levels exceeding water quality standards/EPA criteria by this facility. For purposes of Page 1 of 3 the RPA background concentrations for all parameters were assumed to be below detection level. The RPA uses 95% probability level and 95% confidence basis in accordance with the EPA Guidance entitled "Technical Support Document for Water Quality -based Toxics Control." The Division used pollutant concentration data at a depth of 160 ft for the RPA because at this depth the pollutant concentrations are the highest. This analysis is conservative and considers the worst -case scenario. 3. 303(d) list. " Fact Sheet at 2. This is incorrect. Kings Creek (AU ID 12877) is listed as impaired for benthos on the 2022 303(d) list. Response: DWR personnel reviewed and assessed Kings Creek (AU ID 12877) 2022 303(d) list and determined that the basis of the listing is not associated with any parameter of concern associated with the proposed discharge. During the development of the permit, it was determined that the status of the waterbody is based upon other factors, such as poor habitat associated with periodic low flows during critical period. Specifically, the 2022 Assessment Report indicates the creek is impaired for macroinvertebrates which is typically associated with intermittent low flows which is common within this creek. The Assessment Report also indicates the creek meets the standards for fish community. Therefore, addition of the proposed flow is not going to contribute to the existing impairment. 4. We request that DEQ develop a monitoring regime to ensure discharges of effluent cause no increase in turbidity when background conditions in the receiving water already exceed 50 NTU. Response: Turbidity is a measure of water clarity and can be influenced by various factors, including natural processes and human activities. Permits may include turbidity monitoring requirements to ensure discharges do not cause excessive turbidity levels that could harm aquatic ecosystems or violate water quality standards. Thus, turbidity conditions and monitoring regimes for the permit were developed in accordance with existing rules, regulations and practices which have been approved by the EPA. The turbidity conditions have been consistently used by the DWR for the past 6 years. 5. Fifth, DEQ used a reasonable potential analysis to develop water quality based effluent limitations. That reasonable potential analysis assumed that "background concentrations for all parameters [are] below detection level" in Kings Creek. DEQ must rerun its reasonable potential analysis accounting for these background concentrations. Page 2 of 3 Similarly, DEQ completed its reasonable potential analysis for hardness -dependent metals "utilizing a default hardness value of25 mg/L CaCO3. "Fact Sheet at 2. But data in DEQ's position indicates hardness in Kings Creek is much higher. Response: DWR respects the concern raised and personnel re-evaluated the situation. Review of the background concentration data for Kings Creek indicates the majority of samples for all parameters of concern are below detection limit/practical quantitation limit. • Exceptions are As, Mo, and Chlorides. The limit for Chlorides is already in the permit and inclusion of the background concentration would have no impact on the RPA results. Two background samples for As are below practical quantitation limit, the remaining two are 0.54 µg/L and 1.72 µg/L. The allowable As concentration is 157.5 µg/L, and even if we consider the background concentrations and potential effluent concentration of 5.3 µg/L it would not change the RPA results. One background sample for Mo is below detection level, the remaining three have the following concentrations: 2.33 µg/L, 0.55 µg/L, and 0.76 µg/L. The allowable Mo concentration is 2,100.6 µg/L, and even if we consider the background concentrations and potential effluent concentration of <0.2 µg/L it would not change the RPA results. Employing a higher hardness value for the RPA analysis results in less strict permit limits. Thus, DWR is utilizing a default hardness value of 25 mg/L CaCO3 for hardness -dependent metals. This approach has been approved by the EPA, including the use of the default hardness value. The Division does not have statistically significant number of hardness data to change the conservative and environmentally protective default value. 6. Sixth, DEQ appears to be ignoring narrative water quality standards in calculating limits in this permit. See Memo from Sam Billin, Linkan Engineering, to Morgan Wallen, Albemarle, 5 (identifying sulfide and manganese as contaminants of concern). Response: While permitting authorities may not always be required to employ narrative water quality standards in calculating permit limits, they must ensure compliance with all applicable water quality standards, including both numeric and narrative criteria, to protect water quality and meet regulatory requirements under the CWA. With that said, DWR: • Specifically removed Mn standard on April 16, 2016 because this element is naturally present in high concentration in vast majority of North Carolina waters. • The RPA was conducted for Sulfide and the limit was added to the permit. Page 3 of 3