ROY COOPER Governor MICHAEL S. REGAN Sea-army MICHAEL SCOTT Director NORTH CAROLINA Environmental Quality May 15, 2019 Mr. Douglas Pierotti City of Charlotte Engineering and Property Management 600 East Fourth Street, 12th ?oor Charlotte, NC 28202-2844 Re: CDEQ Response to Annual GW Monitoring Receptor Sampling Reports Charlotte Police and Fire Training Academy 1770 Shopton Road, Charlotte, NC EPA ID NCD 991 278 623 Dear Mr. Pierotti: The North Carolina Department of Environmental Quality (NCDEQ) has reviewed the "Annual Groundwater Monitoring Report dated December 21, 2018 and the "Supply Well and Surface Water Sampling? Report, dated March 12, 2019, all prepared by Hart Hickman, for the CPFTA facility located at 1770 Stopton Road, North Carolina. Based upon the technical review of the reports NCDEQ has determined that the following actions need to be taken by the City of Charlotte: 1] 2) 3) A Plan must be submitted to NCDEQ within 45 days of receipt of this letter outlining how the facility will reduce or eliminate the current introduction of PFAS compounds to the site. A comprehensive assessment of on and offsite PFAS groundwater, soil and surface water contamination needs to be implemented according to the requirements of North Carolina 2 Rules, 15A NCAC 02L. Where a groundwater standard has not been established for a particular substance, the detection of that substance at or above the practical quantitation limit constitutes a violation of the standard. The assessment shall include an analysis of: i] the source and cause of contamination; ii] the horizontal and vertical extent of soil and groundwater contamination and all signi?cant factor affecting contaminant transport; and geological and hydrogeological features in?uencing the movement, chemical, and physical character of the contaminants. This assessment should also identify any groundwater seeps ADE 0:33 ?mwv NORTHM North Carolina Department of Environmental Quality I Division of Waste Management 217 West Jones Street I 1646 Mail Service Center Raleigh, North Carolina 27699-1646 919.707.8200 City of Charlotte Police Fire Site, Page 2 NCDEQ request for Assessment; May 15, 2019 contributing to surface water contamination at the site and areas with signi?cantly contaminated sediment. 4) Obtain Groundwater samples for PFAS and analyze them using EPA Method 537.1, including ?uorotelemers and 8:2 FTS. Please note that the following information was identi?ed in the ?Supply Well and Surface Water Sampling Report": 0 All ?eld blanks collected had PFAS with total concentrations ranging from 13.3-44.3 ng/ total PFAS. This is higher than normal. Typically, detections in blanks are infrequent and the detections of all PFAS summed rarely exceed 10ng/ total PFAS. 0 We suggest that the consultant?s sampling team review practices and make necessary adjustments to reduce sampling contamination. Consider that if the field blank is prepared at the highly contaminated site then there is more chance of cross contamination. It may be necessary to prepare separate field blanks for suspected low contamination sites and suspected high contamination sites. See the ?Clean Hands Dirty Hands" method for trace level sampling. 0 At this time, the drinking water samples were below the EPA Health Advisory Level [70 ppt) for PFOA and PFOS so the results are still usable. 5] A report identifying the ?ndings of the assessment activities should be submitted to our attention within 6 months of receipt of this letter, including updates via e-mail. 6) NCDEQ suggests that a meeting with the City of Charlotte be scheduled to discuss a planned assessment approach and any concerns or questions it may have regarding this comprehensive assessment request. We look forward to the successful completion of site activities and reviewing the subsequent report. Sincerely, Joe Ghiold, Project Manager Facility Management Branch Hazardous Waste Section Ec: Matt Bramblett, Hart 81 Hickman Andrew Martin, NCDEQ Bud McCarty, NCDEQ Joe Ghiold, NCDEQ