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Home My WebLink AboutDuke Energy Performance Standards_20170614Water Resources Environmental Quality June 14, 2017 Paul Draovitch Senior Vice President Environmental, Health & Safety Duke Energy 526 South Church Street Mail Code EC3XP Charlotte, North Carolina 28202 Subject: Permanent Alternate Water Supply Response Dear Mr. Draovitch, ROY COOPER Governor MICHAEL S. REGAN Secretary S. JAY ZIMMERMAN Director In the Proposed Permanent Alternate Water Supply Plans (Plans) for all fourteen (14) facilities submitted to DEQ in December 2016, Duke Energy proposed the following performance standards for the whole house filtration systems: "The performance standard for the water treatment system is also the Federal MCLs except for those constituents identified in 2015 as having potential health concerns: arsenic, hexavalent chromium, cobalt, iron, lead, manganese, sulfate and vanadium. For these constituents, the performance standard will be either one-half of the MCL, or the appropriate state standard, whichever is more protective. " The Coal Ash Management Act (CAMA) requires restoration of groundwater to conform with the requirements of 15A NCAC 02L. DEQ requests performance standards to be the 15A NCAC 02L groundwater standards (21- Standards). If there is not a 2L Standard, the proposed Interim Maximum Allowable Concentration (IMAC) shall be used (see Table 1: Performance Standards). In the case of hexavalent chromium where there is no specific 2L Standard or IMAC, the value for Total Chromium (10 micrograms per liter) shall be used. The following table shows the parameters and their associated 2L Standard or IMAC that shall be used as performance standards. State of North Carolina I Environmental Quality I Division of Water Resources Water Quality Regional operations Section 1636 Mail Service Center I Raleigh, North Carolina 27699-1636 919-707-9129 Table 1: Performance Standards Parameter 2L Standard IMAC Alkalinity Aluminum Antimony 1 µg/L Arsenic 10 µg/L Barium 700 µg/L Beryllium 4 µg/L Bicarbonate Boron 700 µg/L Cadmium 2 µg/L Calcium Carbonate Cobalt 1 µg/L Chromium (total) 10 µg/L ZChromium, (hexavalent) Copper 1 mg/L Iron 300 µg/L Parameter 2L Standard IMAC Lead 15 µg/L Magnesium Manganese 50 µg/L Molybdenum Mercury 1 µg/L Nickel 100 µg/L pH 6.5-8.5Su Potassium - Selenium 20 µg/L Sodium Strontium 'Thallium 2 µg/L Total Dissolved S01ids 500 mg/L 'Vanadium 10 µg/L Zinc I mg/L Chloride 250 mg/L mg/L = milligrams per liter Su = standard units µg/L = micrograms per liter 'These IMAC values are proposed and are currently under rule review. Previously approved Oct. 1, 2010 IMAC for Thallium = 0.2 ug/l, and for Vanadium = 0.3 ug/l 2This value corresponds to the 2L Standard for total chromium which was based on the assumption that all chromium present is in the hexavalent form. We recognize these values differ from the health advisory levels that are provided by the North Carolina Department of Health and Human Services (DHHS). It is DEQ's intent that when establishing future groundwater standards, DEQ will seek comment from the Science Advisory Board (SAB), where medical and scientific professionals will look at these standards in a more holistic manner before they are adopted. It is our hope that using this approach will further ensure that appropriate groundwater standards are established. Required Actions: Prior to installation, Duke Energy shall provide, at a minimum, whole house filtration system design specifications, manufacture specifications, location for sampling, frequency of monitoring, and maintenance and monitoring schedules based on the above required performance standards. It may be necessary for Duke Energy to notify all eligible households and provide them the opportunity to reevaluate which permanent alternate water system they prefer given the required performance standards. If you have any questions regarding any information provided, please feel free to contact Debra Watts at 919-807-6338. Sincerely, S. Zimmerman, P.G., Director Division of Water Resources cc: WQROS Regional Office Supervisors WQROS Central File Copy Mina Shehee (DHHS, Division of Public Health, Occupational and Environmental Epidemiology)