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HomeMy WebLinkAboutNC0000175_Correspondence_19990812NPDES DOCUHENT SCANNINO COVER SHEET NPDES Permit: NC0000175 Unimin Quartz Operation Document Type: Permit Issuance Wasteload Allocation Authorization to Construct (AtC) Permit Modification Complete File - Historical Engineering Alternatives (EAA) Correspondence ) ., .Yi^flW. liM�'�A7f.ii'i11!Rl'!�>3' n•c^. Owner Name Change Instream Assessment (67b) Speculative Limits Environmental Assessment (EA) Document Date: August 12, 1999 Thine docuxxsent its printed oa reuse paper. - ignore sixty cottent on the re'Srerse side urnmin Quartz Operation P. O. Box 588 Bakersville Hwy. Spruce Pine, NC 28777 (828) 765-4283 Fax: (828) 765-0912 August 12, 1999 Mr. David A. Goodrich N'PDE S Unit Supervisor NCDEHNR P. O. Box 29535 Raleigh, NC 27626-0535 Dear Mr. Goodrich: \I\ il^ i 7i..JJ P, AR - VIKI V R QII ALITI PUIST�'� This is to acknowledge receipt of the information on site specific standards for cyanide as developed for the Alcoa facility. That information is being reviewed by the three feldspar producing companies for applicability to the fluoride standard. Sincerely, Charles F. Stover Regional General Manager CC: Dennis Buchanan — K T Feldspar Tom Freeman — The Feldspar Corporation Cyanide Options for Alcoa L� 1 I- Site -specific standard. A. Eligibility per G.S. 143-2143(b) 1. Natural background conditions in the stream segment preclude the attainment of the applicable water quality standards; or 2. Irretrievable and uncontrollable man -induced conditions preclude the attainment of the applicable water quality standards; or 3. Application of effluent limitations for existing sources established or proposed pursuant to G.S. 143-215.1 which are more restrictive than those effluent standards and limitations determined or promulgated by the US EPA pursuant to section 301 of the Federal Water Pollution Control Act (CWA) in order to achieve and maintain applicable water quality standards would result in adverse social and economic impact, disproportionate to the benefits to the public health, safety or welfare as a result of maintaining the standards; and 4. There exists no reasonable relationship between the cost to the petitioner of achieving the effluent limitations necessary to comply with applicable water quality standards to the benefits, including the incremental benefits to the receiving waters, to be obtained from. the application of the said effluent limitations. B. Required Documentation 1. Compliance with all other NPDES permit requirements 2. Evaluation of sources and source reduction plan 3. Audit to assure proper function and management of facility 4. Pollution prevention plan & verification of implementation 5. Cost analysis of all available treatments 6. Understanding that the discharger will receive a lower permit limit, if, the site -specific standard is less than current state standard. C. Steps for Approval • 1. Approval ofsite-specific study results by Water Quality Staff 2. Compliance with G.S.143-214.3 and section 301 of the CWA. These regulations state that the new effluent limit nay not endanger human health and may not be less than either the current effluent guidelines for the discharger or the highest level of treatment which can reasonable be attained without economic hardship. 3. Compliance with state antidegradation policy (15A NCAC 2B .0201) must be determined prior to issuance or reissuance of any site -specific effluent limits. Existing uses must be protected by the site -specific water quality standard. 4. Approval by EMC through public hearing process. D. Study Plan 1. If one of the G.S.143-2143(b) requirements is judged by the EMC to be satisfactorily met, then the facility will provide Water Quality staff with a study plan demonstrating how sufficient data will be collected to develop a site -specific standard. 2. The discharger's permit limits will be based on the site -specific standard, even if the site -specific standard is lower than the applicable water quality standard. 3. Study plans must be approved by Water Quality Staff E. Methodologies 1. Recalculation Procedure - per 2nd Edition of EPA's Water Quality Standards Handbook. 2. Indicator Species Procedure - per 2nd Edition of EPA's Water Quality Standards Handbook. 3. Resident Species Procedure - per 2nd Edition of EPA's Water Quality Standards Handbook. II- We could change in standard to free cyanide. Could be added to Triennial Review and be final in summer of 1996. In the meantime, they could conduct biological studies to determine aquatic life effects and methodology studies to decrease variability in free cyanide determination. Would require WET testing of particulate and free cyanide to document protection of aquatic life. Fate of lead -cyanide compounds instream? Ohio has recalculated free cyanide standard for warm and cold water. warm water is 12 ug/1 and cold water is 5.2 net. Water Quality Standards Coordinator is not aware of any problems with standard or discharges has been on the books since 1989. He is checking with permitting folks to see number of dischargers and if they are aware of any problems. May 18, 1995 OUTLINE FOR ALCOA CYANIDE FATE & TRANSPORT STUDY ASSUMPTIONS -facility is seeking site specific standard based on recalculation and limited as Cyanide Amenable to Chlorination (CATC) -discharge 013 is legitimate effluent channel and not waters of state -discharge of 013 does not circumvent requirements of solid/hazardous waste -CN WQ standard is protective of primary human contact (Class B) -facility has demonstrated compliance with all other effluent parameters including whole effluent toxicity Treatment/Discharge Considerations -discussion of discharge alternatives •discussion of treatment alternatives • •discussion of diffuser alternatives and potential for discharge to existing diffuser •clarification that discharge permitting for. 013: will not circumvent intentions of groundwater or solid/ha7ardous waste regulations applicable to site. Characterization of CN discharge concentrations and factors that influence levels •flow variables including spring flow and rainfall and relationship of each to total flow. •concentration relative to rainfall •consideration of load issues relative to the above Cyanide Sampling •water samples of 013 cove including samples immediately within swimming area. •sediment samples within 013 cove including -samples immediately within swimming area. •water samples surrounding 012 discharge •sediment samples surrounding 012 discharge Characterization of species of cyanide and fate _ •Analysis of total cyanide vs. CATC and characterization of .the presence and percentage of cyanide as iron cyanides. •Evaluation of fate of cyanide including time and light dependent dissociation. (in situ vs. in vitro?) •Evaluation of light penetration at both discharges and influence on potential for photodecomposition •characterization of known interferences to CN analysis Biological sampling •demonstration that benthic macroinvertebrate populations are not impacted by either discharge through comparison with reference sites. •If existing benthic populations are insuff ceint for evaluation of impact AND sediment cyanide samples report positive values, demonstrate lack of sediment toxicity through sediment toxicity analyses using Chironomus tentans or Hyallella azteca per EP . •for use of site specific standard -demonstration that species removed from original criteria are not present in the receiving waters and that all EPA recalculation guidance is followed. Approval of Study Plan by DEM Evaluation of study results by Div. Health Services and County Health Dept. relative to swimming contact issues Conclusions that should be reached for site specific limit and standard to continue - Study plan has been approved by DEM, facility has completed study plan, and results are acceptable to DEM. - discharge to surface waters is the most ecologically/cost viable alternative LA/DMR Page 1 June 9,1995 • OUTL]NE FOR ALCOA CYANIDE FATE & TRANSPORT STUDY -alternatives analysis demonstrates that all treatment options are too costly. -diffusion at 013 or via 012 is not cost effective - discharge and permitting of this leachate from a hazardous waste site is appropriate - consideration of the lake as the receiving water vs. the streamflow from the spring is appropriate. -studies should show that levels of CN are not toxic and not likely to become toxic in the water column before dilution has reached the WQ std for total -concentrations in the sediment anre not accumulating to the point where dissociation from the sediment would exceed toxic levels - benthic macroinvert. communities are not being affected by either discharge -human health is not jeopardized by discharge of free or total cyanide levels (particularly fromexposure at the,swimming beach). -for site specific standard through recalculation- demonstration that species removed from criteria, for purposes of recalculation, are not present. LA/DMR Page 2 June 9,1995 CYANIDE INFO SHEET North Carolina Surface Water Quality Standard Development for Cyanide • Adopted in 1979 • Based on EPA "Red Book"' chronic value of 5.0 ug/1 for free cyanide. • Implemented as total cyanide due to lack of reliable analytical method for measuring free cyanide in wastewater. • Federal Cyanide Standard Development - 1976 "Red Book" chronic value of 5.0 ug/1 • - 1980 Criteria document2 chronic value of 3.5 ug/1 - 1985 Criteria document3 chronic value of 5.2 ug/1 • Reviewed in 1986. No changes made based on use of questionable acute/chronic ratio in 1980 and fact that there is verylittle difference between the 5.0 and 5.2 ug/L • 1994 EPA recommended the "Canide Amenable to Chlorine" (CATC) method for analysis of free cyanide in DRINKING WATER4. It should be noted that drinking water is not going to have the same interference potential as leachate, stormwater runoff and spring water. Standard-Methods5states that CATC is useful for natural_ and groundwaters and clean metal finishing, heat treating & sanitary effluents. Some unidentified organic chemicals may oxidize or form breakdown products during chlorination, giving higher results for CATC than before chlorination. CATC based on rapid dissociation of cyanide and complexing with chloramine-T. Chemistry6 • "Cyanide" refers to all the CN groups that can be determined as the cyanide ion, CN- • Ratio of CN- to HCN depends on pH & dissociation constant for HCN (pKa = 9.2) • HCN is most toxic form. • In natural waters HCN predominates. • Decreased pH = increased HCN = increased toxicity. • Simple metal cyanides vary in solubility but are highly soluble in complexes with alkali (sodium, potassium, ammonium) cyanides. • Synergistic toxic effects occur when zinc & copper ions combine with cyanide. _ • Iron cyanides do not dissociate easily. However, iron cyanides dissociation through photodecomposition. 10 mg/l iron cyanide =1 mg/1 HCN in strong sunlight, distilled water. • Dilution, mixing, clarity of the receiving waters & quantity of HCN released must be assessed. • ASTM recommends that total cyanide determination be used to ensure good waste treatment practices and states that there is a mistaken belief that the enumerated cyanide compounds are not "toxic". "The fact is that the toxicity is only of a lesser magnitude."7 Options for Cyanide Standard Implementation for Alcoa • Status Quo - Implement current standard as total cyanide. • Site -specific criteria development, see NC Site -specific criteria development guidance. Requires special study and rule -making. Discharge cannot be toxic at IWC. DMR/523/95 1 Quality Criteria for Water July 1976. US EPA. 2 Ambient Water Quality Criteria for Water. EPA 440/5-80-037. 3 Ambient Water Quality Criteria for Water. EPA 440/5-84-028. 4 57 FR 31776; July 17,1992 5 Standard Methods for the Examination of Water and Wastewater, l7th Edition . 1989. APHA, AWWA & WPCF. 6 1992 Annual Book of ASTM Standards Section 11, page 94 & Differential Toxicity of Forms of Cyanide, 1990, prepared for The Aluminum Association. 7 Ibid. page 97. Additional notes: The North Toe River is not listed on the 1998 303(d) impaired streams list. Biological info: Per the 1995 French Broad River Basin, indicated that biological monitoring in 1992 had improved from Poor in1989 to Good -Fair. Talked with Trish Macpherson on 5/4/99. Had sampled North Toe R. at three sites in 1997 with the following results: North Toe R. @ Ingalls (above the mines) - Excellent North Toe R. @ Penland (below the mines) - Good North Toe R. @ Loafers Glory (further downstream below the mines) - Good Told her instream compliance data showed instream values above the standard of 1.8 mg/l. Said that maybe the Fl instream was not in high enough concentrations to be toxic to the benthos. 5/5/99 - Made phone calls to Forrest and Matt Matthews to see whether they had any comments on the Unimin letter and if they wanted to incorporate them into the response. Permitted Qw Average Qw ('98= 99) Permitted Fluoride Average FI ('98-'99) Max. Fluoride ('98-'99) Monthly FI violations ('98-'99) Permitted Fluoride Average FI ('97-'98) Max. Fluoride ('97-'98) Monthly FI violations ('97-'98) Unimin Corp. NC0000175 3.6 MGD 0.904 MGD 109 Ibs/day 73 Ibs/day 413 Ibs/day none 109 Ibs/day 80 Ibs/day 216 Ibs/day none Active Fluoride Dischargers to the North Toe River Unimin Schoolhouse NC0000361 2.16 MGD 0.623 MGD 109 Ibs/day 53.2 Ibs/day 81 Ibs/day none 109 Ibs/day 39 Ibs/day 69 Ibs/day none Feldspar Corp. NC0000353 3.5 MGD 2.85 MGD 225 Ibs/day 217 Ibs/day 404 Ibs/day 3 247 Ibs/day 231.5 Ibs/day 230.3 Ibs/day (3,6,8/98) 225 Ibs/day 221 Ibs/day 506 Ibs/day 6 K-T Feldspar NC0000400 1.73 MGD 0.197 MGD 132 Ibs/day 45.5 Ibs/day 183 Ibs/day none 132 Ibs/day 65 Ibs/day 284 Ibs/day none Note: The Feldspar Corp. has had permit compliance issues for the past two years. March 1998 through Feb. 1999 there were violations for BOD5 (1), pH (2) and Fluoride (3). March 1997 through Feb. 1998, there were violations for BOD5 (2), TSS (2), pH (3), and Fluoride (6). Feldspar is also at 81% of their design flow. Note 2: Unimin Schoolhouse (NC0000361) started discharging fluoride in March 1997, at that time the fluoride limit for Unimin Corp (NC0000175) was decreased to 109 Ibs/day per previous permitting agreement.