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HomeMy WebLinkAboutAllen BTVs Comparison 03-06-2020 (003)Fnl_20200306Table 1a Comparison Between June 2019 and NCDEQ October 2019 Groundwater Background Threshold Values ARC'ADIS o�ll,assar, Allen Steam Station Duke Energy Carolinas, LLC 15A NCAC Constituent Reporting 02L Unit Standard or IMAC CCRAl III or IV Constituent Standard Maximum Regional Background Concentrations4 2018 BNs1 2019 Uptlatetl gNs' Shallow Flow 2019 Proposed Primary Reason NCDEQ BNsa for Difference" Zone -I I Background Wells 2018 BNs1 2019 Updated gNs' DeepFlow 2019 Proposed Primary Reason NCDEQ BNsd for Difference" Zone -11 Background Wells 2018 BNs1 2019 Updated BNs' Bedrock Flow 2019 NCDEQ BNsa Zone -4 Proposed Primary Reason for Difference" Background Wells MENSee OEM 'Additional notes tedos, f, sidditionill reason. for potential differsoose Nor, 0 id= ._. moon • MR IMMEMOMEMI ■00 MMM� es .. S..'Addidonal not. bell differences sort for potential d,ff=asons EEE=000 00. Net. potential .00for nN6 000in t in di •.... ®®®®©©© ©®® EMAINCE, . 2019 arl ..INC... ..rnso MEN diff" ... Vt1u,of20S, NCD EQ..lud.d--Iu..f17.3, Q—ludenlon-1-ofl-I ENEENSWINMEQi—ludlid Id'" "fl-alfiliA• no ENNINCE, ®®®®®®®® MEE MMM... . General Notes: a. June 2019 background thresbdo values dai h—beenr rdl toslinibrlevelsofpreclSlon as 15A NoM Carolina Adminldrdlve Code(NCAC)02LStandard or Inkrlm M—in Allowable Goncentrolbn(IMAG). In —tee a difference betwaen the June 2019 BN and the NCDEQ October 201913-Pro dprimary ree-r far differerce namded. 4 CCR Appendx IV con Duke Energy-ncure wtlh BN. Energy belkm this value Is In-necl due to BN cdwlalkn mdM1atlokgy usetl. 501 BNtnet—Idk tee Value shownis groJndwater pnnectim ne-nd(GAPS). CCR Appendix lV conatlNenta conoerations are alsocompered to their BN. IndkaCCR Appendix 111 r—fluent. CCR App.dix 111 constituent c rtrodons are cMp"d to their BN. AntimonyIndicates SitaspecedAific constituent of interest(COI). Boron Indkaks Slkepc COI cametl MviaN Mcamd- action. Footnotes: - t e CAC 02L SlendaM, Append. 1, Apol 1, 2013. -BNs were-Icukted using darn flan background grourdwder samples cdledW June 2015 W September 201). lldll ulded using dies son, background groundwdersamples —del Me,h 2011 to December 2018. s NCDEQ BN values ham Octgber 11,2.191erahan Linda Cukepper,NCDEQ, to Peul Dreavitch. Duke Enemv.13—inclutle dete ham Q12019. in June 2109 Background —nerdtl Vdue Update repots for Allen Steam Station, BNews Greek Steam Station, Clinside Steam Ss lon, Marshall steam Stdion, Mayo Steam Eleclrk Plam, antl RoNroro steam ElsrW Plant. D p y tdnetl han Ubks providetl on NCDEQ webslks kr NCDEQ grountlwder researoM1 SUtkns In Me Pletlmont region. ' Additional notes regarding potential reasons for differences between Duke Energy 2019 Ill antl NCDEQ October 2019 BNs: Date set evaluated The cutoff dais M-I-Iding BNs presented in the Duke Energy Are 2019 W.rts wu December 31. 2018. NCDEQ used a cutoff dale d April 30, 2019 as daletl in the Octgber 17, 20191ererham Lind. Culpepper, NCDEQ, to Paul DraoMlch, Duks Energy. How non-0eteUs are handled. NCDEQ uaetl incorrect nanencleture in haedere d-lumps that identify con as detected gr ngt detected In their PrgUCL input tlde sets. PrWCL requires the cdumn header to star vAth io e.g., D Aa faarsmic. NCDEQ hea column heatlen tlesignated with _D eflerthe-nd8umt name, a.g. As rD. Th e will cause PmUCL to in -redly reed the ddecled I It. ddecled -it;o don for each non -dated date paint. Whatsinir ins $tllyare assumedMa.Howdahareevaluated wither QOU krIfiwithatliIMWR-r motlel tlepentlsm M1ow non-0deck were M1antlletl. A5 ndetl in Me ride above, NGOEQ incmeclly-tletl the column M1eatlem krdte proUGL Input files kr tlelecl/non-0eled tlesgnauons. ThIs may kid to a tllrt¢rence between June 2019 and NCDEQ October2019 cdaldm BNs. Whet typed upper tderen-limit (UR) is-kuleted. The type d UTL calculated is a Mnctim d haw ngndetec[ values ere hantlled antl the diaMbutim d Me tle1a. As noted In Me previous taa rotes. NCDEQ Incareclly coded the column heed— la the ProUCL input files far ddedln.nEeteddesgnadgns.Thismayi.d Wadifferen-in thedatedistribution-I.ultdby NCDEQw,lhIntommayekedthe UTLcalculatedbypWCL. Thismayleadbad'Meren-beM June2019and NCDEQOcl r2019-Iculeded BNs. Reasons Ell may Ile higher than the mazlmum detected cons/ltuent concentration for groundwater flow zone: The detaset is heavily skewed to the right (alenderd dinenof In-trenahmed ddeaet is greeter Man 1). The dL . k wed small in c 15), skeantl he, a not, valance (dantlara tlekdipnl. The ddea-n ines ofdda ham mudpls—the ere p—d together, end their meenalmedlenaare sigrti ly different flan one another(Ls., distil mtly vary over speci). Acronyms and Abbevlations: ,rd-- micrograms per f er g-- micrograms per milllllter ­11L irriffir— In, it s —0,- Ir .1 re—cabonde NA Ls - p Lter ae nitrogen nat aPPll-bee m NE-nIX estebliahed pCl/L-III_ per Ider S.U. - stsndl units Most constituents had additional data from 2019 samples that were added by NCDEQ. There is uncertainty regarding which constituents NCDEQ ran for their updated BNs since most constituents had additional data from 2019, yet the June 2019 and NCDEQ October 2019 BTVs are the same for many constituents for the three flow zones. Table lb Detailed Comparison Between June 2019 and NCDEQ October 2019 Groundwater Background Threshold Values - Shallow Flow Zone P ARCADIS flesign&Consultancy f---ral and quilt assets Allen Steam Station Duke Energy Carolinas, LLC Well ID Sample Date Constituent RepoM=&VMaII..Below) Reason for Difference GWA-21 S 03/07/2019 pH S.U. 5.1 2019 Sample date added by NCDEQ R-BG-01S 03/11/2019 pH S.U. 5.3 2019 Sample date added by NCDEQ GWA-21 S 03/07/2019 Alkalinity mg-CaCO3/L 4.4 2019 Sample date added by NCDEQ BG-02S 02/28/2018 Aluminum µg/L 2030 Value excluded by NCDEQ, no rationale provided by NCDEQ GWA-19S 03/29/2017 Aluminum µg/L 1870 Value excluded by NCDEQ, no rationale provided by NCDEQ BG-01 S 12/10/2015 Antimony µg/L 3.4 Value excluded from June 2019 data set, but included by NCDEQ BG-03S 12/10/2015 Antimony µg/L 3 Value excluded from June 2019 data set, but included by NCDEQ GWA-21 S 03/07/2019 Antimony µg/L 0.5 2019 Sample date added by NCDEQ GWA-23S 02/03/2016 Antimony µg/L 1.4 Value excluded from June 2019 data set, but included by NCDEQ R-BG-01S 03/11/2019 Antimony µg/L 0.5 2019 Sample date added by NCDEQ AB-12S 03/01/2011 Arsenic µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 07/07/2011 Arsenic µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 11/01/2011 Arsenic µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 03/05/2012 Arsenic µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 07/05/2012 Arsenic µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 11/05/2012 Arsenic µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 03/05/2013 Arsenic µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 07/02/2013 Arsenic µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 11/06/2013 Arsenic µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 03/05/2014 Arsenic µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 11/04/2014 Arsenic µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 03/02/2015 Arsenic µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 11/06/2015 Arsenic µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 07/07/2016 Arsenic µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 03/07/2017 Arsenic µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 11/08/2017 Arsenic µg/L 1 Elevated reporting limit, not included in June 2019 data set BG-01 S 03/14/2016 Arsenic µg/L 2.7 Value excluded from June 2019 data set, but included by NCDEQ GWA-21 S 03/07/2019 Arsenic µg/L 0.1 2019 Sample date added by NCDEQ R-BG-01S 03/11/2019 Arsenic µg/L 0.1 2019 Sample date added by NCDEQ GWA-21 S 03/07/2019 Barium µg/L 35.5 2019 Sample date added by NCDEQ R-BG-01S 03/11/2019 Barium µg/L 24.4 2019 Sample date added by NCDEQ AB-12S 11/06/2015 Beryllium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 07/07/2016 Beryllium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 03/07/2017 Beryllium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 11/08/2017 Beryllium µg/L 1 Elevated reporting limit, not included in June 2019 data set GWA-21 S 03/07/2019 Beryllium µg/L 0.11 2019 Sample date added by NCDEQ R-BG-01S 03/11/2019 Beryllium µg/L 0.1 2019 Sample date added by NCDEQ GWA-21 S 03/07/2019 Boron µg/L 3 2019 Sample date added by NCDEQ R-BG-01S 03/11/2019 Boron µg/L 5.2 2019 Sample date added by NCDEQ AB-12S 03/01/2011 Cadmium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 07/07/2011 Cadmium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 11/01/2011 Cadmium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 03/05/2012 Cadmium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 07/05/2012 Cadmium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 11/05/2012 Cadmium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 03/05/2013 Cadmium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 07/02/2013 Cadmium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 11/06/2013 Cadmium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 03/05/2014 Cadmium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 11/04/2014 Cadmium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 03/02/2015 Cadmium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 11/06/2015 Cadmium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 07/07/2016 Cadmium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 03/07/2017 Cadmium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 11/08/2017 Cadmium µg/L 1 Elevated reporting limit, not included in June 2019 data set GWA-21 S 03/07/2019 Cadmium µg/L 0.08 2019 Sample date added by NCDEQ R-BG-01S 03/11/2019 Cadmium µg/L 0.08 2019 Sample date added by NCDEQ GWA-21 S 03/07/2019 Calcium mg/L 0.425 2019 Sample date added by NCDEQ R-BG-01S 03/11/2019 Calcium mg/L 0.917 2019 Sample date added by NCDEQ GWA-21 S 03/07/2019 Chloride mg/L 3.6 2019 Sample date added by NCDEQ R-BG-01S 03/11/2019 Chloride mg/L 1.4 2019 Sample date added by NCDEQ GWA-21 S 03/07/2019 Chromium (Total) µg/L 0.5 2019 Sample date added by NCDEQ R-BG-01S 03/11/2019 Chromium (Total) µg/L 1.3 2019 Sample date added by NCDEQ GWA-21 S 03/07/2019 Cobalt µg/L 2.1 2019 Sample date added by NCDEQ R-BG-01S 03/11/2019 Cobalt µg/L 0.64 2019 Sample date added by NCDEQ BG-01 S 09/23/2015 Copper µg/L 8.9 Value excluded from June 2019 data set, but included by NCDEQ BG-01 S 12/10/2015 Copper µg/L 13.4 Value excluded from June 2019 data set, but included by NCDEQ GWA-21 S 03/07/2019 Fluoride mg/L 0.1 2019 Sample date added by NCDEQ R-BG-01S 03/11/2019 Fluoride mg/L 0.1 2019 Sample date added by NCDEQ GWA-21 S 03/07/2019 Lead µg/L 0.087 2019 Sample date added by NCDEQ R-BG-01S 03/11/2019 Lead µg/L 0.1 2019 Sample date added by NCDEQ GWA-21 S 03/07/2019 Lithium µg/L 1.4 2019 Sample date added by NCDEQ R-BG-01S 03/11/2019 Lithium µg/L 0.67 2019 Sample date added by NCDEQ GWA-21 S 03/07/2019 Magnesium mg/L 0.854 2019 Sample date added by NCDEQ R-BG-01S 03/11/2019 Magnesium mg/L 0.456 2019 Sample date added by NCDEQ GWA-16S 12/13/2016 Manganese µg/L 1620 Value excluded by NCDEQ, no rationale provided by NCDEQ GWA-21 S 03/07/2019 Mercury µg/L 0.2 2019 Sample date added by NCDEQ R-BG-01S 03/11/2019 Mercury µg/L 0.2 2019 Sample date added by NCDEQ BG-04S 02/04/2016 Molybdenum µg/L 3.3 Value excluded from June 2019 data set, but included by NCDEQ GWA-21 S 03/07/2019 Molybdenum µg/L 0.5 2019 Sample date added by NCDEQ R-BG-01S 03/11/2019 Molybdenum µg/L 0.5 12019 Sample date added by NCDEQ GWA-21 S 08/12/2016 Potassium mg/L 18 Value excluded from June 2019 data set, but included by NCDEQ GWA-21 S 1 03/07/2019 1 Potassium mg/L 5 2019 Sample date added by NCDEQ R-BG-01S 03/11/2019 Potassium mg/L 5 2019 Sample date added by NCDEQ 3/6/2020 2 of 6 Table lb Detailed Comparison Between June 2019 and NCDEQ October 2019 Groundwater Background Threshold Values - Shallow Flow Zone P ARCAD I S f ufta &Consultancy f---ral and quilt assets Allen Steam Station Duke Energy Carolinas, LLC Well ID AB-12S Sample Date 03/01/2011 Constituent Selenium Reporting..Below) µg/L 1 Reason for Difference Elevated reporting limit, not included in June 2019 data set AB-12S 07/07/2011 Selenium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 11/01/2011 Selenium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 03/05/2012 Selenium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 07/05/2012 Selenium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 11/05/2012 Selenium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 03/05/2013 Selenium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 07/02/2013 Selenium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 11/06/2013 Selenium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 03/05/2014 Selenium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 11/04/2014 Selenium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 03/02/2015 Selenium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 11/06/2015 Selenium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 07/07/2016 Selenium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 03/07/2017 Selenium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12S 11/08/2017 Selenium µg/L 1 Elevated reporting limit, not included in June 2019 data set BG-02S 09/15/2017 Selenium µg/L 1.8 Value excluded from June 2019 data set, but included by NCDEQ GWA-21 S 03/07/2019 Selenium µg/L 0.5 2019 Sample date added by NCDEQ R-BG-01S 03/11/2019 Selenium µg/L 0.5 2019 Sample date added by NCDEQ GWA-21 S 03/07/2019 Sodium mg/L 2.8 2019 Sample date added by NCDEQ R-BG-01S 03/11/2019 Sodium mg/L 2.54 2019 Sample date added by NCDEQ BG-04S 02/04/2016 Sulfate mg/L 43.9 Value excluded from June 2019 data set, but included by NCDEQ GWA-21 S 03/08/2016 Sulfate mg/L 3.2 Value excluded from June 2019 data set, but included by NCDEQ GWA-21 S 03/07/2019 Sulfate mg/L 1 2019 Sample date added by NCDEQ R-BG-01S 03/11/2019 Sulfate mg/L 1.3 2019 Sample date added by NCDEQ GWA-21 S 03/07/2019 Total Dissolved Solids mg/L 30 2019 Sample date added by NCDEQ R-BG-01S 03/11/2019 Total Dissolved Solids mg/L 25 2019 Sample date added by NCDEQ AB-12S 03/01/2011 Thallium µg/L 0.2 Elevated reporting limit, not included in June 2019 data set AB-12S 07/07/2011 Thallium µg/L 0.2 Elevated reporting limit, not included in June 2019 data set AB-12S 11/01/2011 Thallium µg/L 0.2 Elevated reporting limit, not included in June 2019 data set AB-12S 03/05/2012 Thallium µg/L 0.2 Elevated reporting limit, not included in June 2019 data set AB-12S 07/05/2012 Thallium µg/L 0.2 Elevated reporting limit, not included in June 2019 data set AB-12S 11/05/2012 Thallium µg/L 0.2 Elevated reporting limit, not included in June 2019 data set AB-12S 03/05/2013 Thallium µg/L 0.2 Elevated reporting limit, not included in June 2019 data set AB-12S 07/02/2013 Thallium µg/L 0.2 Elevated reporting limit, not included in June 2019 data set AB-12S 11/06/2013 Thallium µg/L 0.2 Elevated reporting limit, not included in June 2019 data set AB-12S 03/05/2014 Thallium µg/L 0.2 Elevated reporting limit, not included in June 2019 data set AB-12S 11/04/2014 Thallium µg/L 0.2 Elevated reporting limit, not included in June 2019 data set AB-12S 03/02/2015 Thallium µg/L 0.2 Elevated reporting limit, not included in June 2019 data set AB-12S 11/06/2015 Thallium µg/L 0.2 Elevated reporting limit, not included in June 2019 data set AB-12S 07/07/2016 Thallium µg/L 0.2 Elevated reporting limit, not included in June 2019 data set AB-12S 03/07/2017 Thallium µg/L 0.2 Elevated reporting limit, not included in June 2019 data set AB-12S 11/08/2017 Thallium µg/L 0.2 Elevated reporting limit, not included in June 2019 data set GWA-21 S 03/07/2019 Thallium µg/L 0.1 2019 Sample date added by NCDEQ R-BG-01S 03/11/2019 Thallium µg/L 0.1 2019 Sample date added by NCDEQ BG-02S 11/13/2015 Total Organic Carbon mg/L 20.8 Value excluded by NCDEQ, no rationale provided by NCDEQ GWA-21 S 03/07/2019 Total Radium pCi/L 0.824 2019 Sample date added by NCDEQ R-BG-01S 03/11/2019 Total Radium pCi/L 1.05 2019 Sample date added by NCDEQ BG-02Stt 09/15/2017 Vanadium µg/L 7.5 Value excluded from June 2019 data set, but included by NCDEQ GWA-21 S 1 03/08/2016 Zinc µ9 43 Value excluded from June 2019 data set, but included by NCDEQ General Notes: Elevated reporting limit, not included in June 2019 BTV data set, but included in NCDEQ October 2019 BTV data set. Reporting limit was higher than majority of reporting limits and most, if not all, detected concentrations; therefore, not representative of background concentrations. The cutoff date for calculating BTVs presented in the June 2019 reports was December 31, 2018. NCDEQ used a cutoff date of April 30, 2019 as stated in the October 17, 2019 letter from Linda Culpepper, NCDEQ, to Paul Draovitch, Duke Energy. Therefore, NCDEQ added some 2019 samples to their background data set. Value excluded by NCDEQ. No rationale provided by NCDEQ. Excluded value is typically a high concentration relative to remainder of data set. Value excluded from June 2019 data set, but included by NCDEQ. Concentration was not included in the calculation of BTVs because data validation and detailed evaluation of Site - specific geochemical conditions indicated that the concentration was a result of field error or laboratory analytical error. Acronyms and Abbreviations: BTVs- below threshold values dig/L - micrograms per liter mg/L - milligrams per liter mg-CaCO3/L - milligrams per liter as calcium carbonate NCDEQ - North Carolina Department of Environmental Quality pCi/L - picocuries per liter S.U. - standard units 3/6/2020 3 of 6 Table 1 c Detailed Comparison Between June 2019 and NCDEQ October 2019 Groundwater Background Threshold Values - Deep Flow Zone POARCAD I S I designs Consultancy f- nu -1 and built assets Allen Steam Station Duke Energy Carolinas, LLC Well ID AB-12D Sample Date 03/01/2011 Constituent pH Reporting..Below) S.U. 6.1 Reason for Difference (See Notes Section for More Sample date for well excluded from NCDEQ data set GWA-21 DA 03/07/2019 Alkalinity mg-CaCO3/L 68.2 2019 Sample date added by NCDEQ GWA-21DA 08/31/2018 Aluminum µg/L 980 Value excluded by NCDEQ, no rationale provided by NCDEQ AB-12D 07/07/2011 Antimony µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 11/01/2011 Antimony µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 03/05/2012 Antimony µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 07/05/2012 Antimony µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 11/05/2012 Antimony µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 03/05/2013 Antimony µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 07/02/2013 Antimony µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 11/06/2013 Antimony µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 03/05/2014 Antimony µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 07/07/2014 Antimony µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 11/04/2014 Antimony µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 03/02/2015 Antimony µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 11/06/2015 Antimony µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 07/07/2016 Antimony µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 03/07/2017 Antimony µg/L 1 Elevated reporting limit, not included in June 2019 data set GWA-21 DA 03/07/2019 Antimony µg/L 0.5 2019 Sample date added by NCDEQ R-BG-01 DA 03/11/2019 Antimony µg/L 0.2 2019 Sample date added by NCDEQ AB-12D 03/01/2011 Arsenic µg/L 1 Sample date for well excluded from NCDEQ data set GWA-21 DA 03/07/2019 Arsenic µg/L 0.097 2019 Sample date added by NCDEQ R-BG-01 DA 03/11/2019 Arsenic µg/L 0.31 2019 Sample date added by NCDEQ AB-12D 03/01/2011 Barium µg/L 57 Sample date for well excluded from NCDEQ data set GWA-21 DA 03/07/2019 Barium µg/L 5.3 2019 Sample date added by NCDEQ R-BG-01 DA 03/11/2019 Barium µg/L 18.6 2019 Sample date added by NCDEQ AB-12D 06/20/2015 Beryllium µg/L 0.2 Elevated reporting limit, not included in June 2019 data set BG-02D 12/10/2015 Beryllium µg/L 0.2 Elevated reporting limit, not included in June 2019 data set BG-03D 06/26/2015 Beryllium µg/L 0.2 Elevated reporting limit, not included in June 2019 data set BG-03D 11/11/2015 Beryllium µg/L 0.2 Elevated reporting limit, not included in June 2019 data set GWA-21 DA 03/07/2019 Beryllium µg/L 0.1 2019 Sample date added by NCDEQ GWA-26D 03/27/2017 Beryllium µg/L 0.2 Elevated reporting limit, not included in June 2019 data set R-BG-01 DA 03/11/2019 Beryllium µg/L 0.1 2019 Sample date added by NCDEQ AB-12D 03/01/2011 Boron µg/L 50 Sample date for well excluded from NCDEQ data set GWA-21 DA 03/07/2019 Boron µg/L 3.8 2019 Sample date added by NCDEQ R-BG-01 DA 03/11/2019 Boron µg/L 5.4 2019 Sample date added by NCDEQ AB-12D 03/01/2011 Cadmium µg/L 1 Sample date for well excluded from NCDEQ data set GWA-21 DA 03/07/2019 Cadmium µg/L 0.08 2019 Sample date added by NCDEQ R-BG-01 DA 03/11/2019 Cadmium µg/L 0.08 2019 Sample date added by NCDEQ GWA-21 DA 03/07/2019 Calcium m /L 10.6 2019 Sample date added by NCDEQ R-BG-01 DA 03/11/2019 Calcium m /L 13.7 2019 Sample date added by NCDEQ AB-12D 03/01/2011 Chloride m /L 4.7 Sample date for well excluded from NCDEQ data set GWA-21 DA 03/07/2019 Chloride m /L 3.9 2019 Sample date added by NCDEQ R-BG-01 DA 03/11/2019 Chloride m /L 3 2019 Sample date added by NCDEQ BG-01DA 06/21/2017 Chromium Total µg/L 93.2 Value excluded by NCDEQ, no rationale provided by NCDEQ GWA-21 DA 03/07/2019 Chromium Total µg/L 1.4 2019 Sample date added by NCDEQ R-BG-01 DA 03/11/2019 Chromium Total µg/L 0.49 2019 Sample date added by NCDEQ AB-12D 03/01/2011 Chromium Total µg/L 5 Sample date for well excluded from NCDEQ data set GWA-21 DA 03/07/2019 Cobalt µg/L 0.073 2019 Sample date added by NCDEQ R-BG-01 DA 03/11/2019 Cobalt µg/L 0.13 2019 Sample date added by NCDEQ AB-12D 03/01/2011 Copper µg/L 5 Sample date for well excluded from NCDEQ data set GWA-26D 03/27/2017 Copper µg/L 358 Value excluded from June 2019 data set, but included by NCDEQ GWA-21 DA 03/07/2019 Fluoride m /L 0.077 2019 Sample date added by NCDEQ R-BG-01 DA 03/11/2019 Fluoride m /L 0.098 2019 Sample date added by NCDEQ AB-12D 03/01/2011 Iron µg/L 498 Sample date for well excluded from NCDEQ data set AB-12D 07/07/2011 Lead µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 11/01/2011 Lead µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 03/05/2012 Lead µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 07/05/2012 Lead µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 11/05/2012 Lead µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 03/05/2013 Lead µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 07/02/2013 Lead µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 11/06/2013 Lead µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 03/05/2014 Lead µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 07/07/2014 Lead µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 11/04/2014 Lead µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 03/02/2015 Lead µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 11/06/2015 Lead µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 03/03/2016 Lead µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 07/07/2016 Lead µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 03/07/2017 Lead µg/L 1 Elevated reporting limit, not included in June 2019 data set GWA-21 DA 03/07/2019 Lead µg/L 0.12 2019 Sample date added by NCDEQ R-BG-01 DA 03/11/2019 Lead µg/L 0.08 2019 Sample date added by NCDEQ BG-02D 02/28/2018 Lithium µg/L 23.7 Value excluded from June 2019 data set, but included by NCDEQ GWA-21 DA 03/07/2019 Lithium µg/L 2.2 2019 Sample date added by NCDEQ R-BG-01 DA 03/11/2019 Lithium µg/L 21.4 2019 Sample date added by NCDEQ GWA-21 DA 03/07/2019 Magnesium m /L 5.77 2019 Sample date added by NCDEQ R-BG-01 DA 03/11/2019 Magnesium m /L 2.66 2019 Sample date added by NCDEQ AB-12D 03/01/2011 Manganese µg/L 31 Sample date for well excluded from NCDEQ data set GWA-23D 12/12/2018 Manganese µg/L 900 Value excluded by NCDEQ, no rationale provided by NCDEQ AB-12D 03/01/2011 Mercury µg/L 0.05 Sample date for well excluded from NCDEQ data set BG-02D 12/13/2016 Mercury µg/l- 2.4 Value excluded from June 2019 data set, but included by NCDEQ GWA-16D 12/13/2016 Mercury µg/L 1.2 Value excluded from June 2019 data set, but included by NCDEQ GWA-21 DA 03/07/2019 Mercury µg/L 0.2 2019 Sample date added by NCDEQ R-BG-01 DA 03/11/2019 Mercury µg/L 0.2 2019 Sample date added by NCDEQ GWA-26D 09/23/2016 Methane µg/L 125 Value excluded by NCDEQ, no rationale provided by NCDEQ GWA-26D 06/21/2017 Methane µg/L 451 Value excluded by NCDEQ, no rationale provided by NCDEQ GWA-21 DA 03/07/2019 Molybdenum µg/L 0.59 2019 Sam le date added by NCDEQ GWA-26D 03/27/2017 Molybdenum µg/L 55.4 Value excluded from June 2019 data set, but included by NCDEQ R-BG-01 DA 03/11/2019 Molybdenum µg/L 6.8 2019 Sample date added by NCDEQ AB-12D 1 03/01/2011 1 Nickel I µg/l- 1 5 1 Sample date for well excluded from NCDEQ data set 3/6/2020 4 of 6 Table 1 c Detailed Comparison Between June 2019 and NCDEQ October 2019 Groundwater Background Threshold Values - Deep Flow Zone F'1 ARCADIS I luilta s Consultancy f- natural and built assets Allen Steam Station Duke Energy Carolinas, LLC Well ID BG-01DA Sample Date 06/21/2017 Constituent Reporting.. Nickel µg/L Reason for Difference - 52.6 Value excluded by NCDEQ, no rationale provided by NCDEQ GWA-21 DA 03/07/2019 Potassium m /L 5 2019 Sample date added by NCDEQ R-BG-01 DA 03/11/2019 Potassium m /L 12.4 2019 Sample date added by NCDEQ AB-12D 07/07/2011 Selenium µ9/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 11/01/2011 Selenium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 03/05/2012 Selenium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 07/05/2012 Selenium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 11/05/2012 Selenium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 03/05/2013 Selenium µg/L 1.13 Value excluded from June 2019 data set, but included by NCDEQ AB-12D 07/02/2013 Selenium µ9/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 11/06/2013 Selenium µ9/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 03/05/2014 Selenium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 07/07/2014 Selenium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 11/04/2014 Selenium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 03/02/2015 Selenium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 11/06/2015 Selenium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 03/03/2016 Selenium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 07/07/2016 Selenium µg/L 1 Elevated reporting limit, not included in June 2019 data set AB-12D 03/07/2017 Selenium µg/L 1 Elevated reporting limit, not included in June 2019 data set GWA-21 DA 03/07/2019 Selenium µg/L 0.5 2019 Sample date added by NCDEQ R-BG-01DA 03/11/2019 Selenium µ9/L 0.5 2019 Sample date added by NCDEQ GWA-21 DA 03/07/2019 Sodium m /L 8.24 2019 Sample date added by NCDEQ R-BG-01 DA 09/13/2016 Sodium m /L 78 Value excluded by NCDEQ, no rationale provided by NCDEQ R-BG-01DA 03/11/2019 Sodium m /L 11.9 2019 Sample date added by NCDEQ AB-12D 03/01/2011 Sulfate m /L 5.4 Sample date for well excluded from NCDEQ data set GWA-21 DA 03/07/2019 Sulfate m /L 1.2 2019 Sample date added by NCDEQ R-BG-01DA 03/11/2019 Sulfate m /L 1.4 2019 Sample date added by NCDEQ AB-12D 03/01/2011 Total Dissolved Solids mg/L 120 Sample date for well excluded from NCDEQ data set AB-12D 07/05/2012 Total Dissolved Solids m /L 250 Elevated reporting limit, not included in June 2019 data set AB-12D 12/07/2018 Total Dissolved Solids m /L 25 Elevated reporting limit, not included in June 2019 data set GWA-21 DA 03/07/2019 Total Dissolved Solids m /L 150 2019 Sample date added by NCDEQ R-BG-01DA 03/11/2019 Total Dissolved Solids m /L 129 2019 Sample date added by NCDEQ AB-12D 07/07/2011 Thallium µ9/L 0.2 Elevated reporting limit, not included in June 2019 data set AB-12D 11/01/2011 Thallium µ9/L 0.2 Elevated reporting limit, not included in June 2019 data set AB-12D 03/05/2012 Thallium µg/L 0.2 Elevated reporting limit, not included in June 2019 data set AB-12D 07/05/2012 Thallium µ9/L 0.2 Elevated reporting limit, not included in June 2019 data set AB-12D 11/05/2012 Thallium µ9/L 0.2 Elevated reporting limit, not included in June 2019 data set AB-12D 03/05/2013 Thallium µ9/L 0.2 Elevated reporting limit, not included in June 2019 data set AB-12D 07/02/2013 Thallium µ9/L 0.2 Elevated reporting limit, not included in June 2019 data set AB-12D 11/06/2013 Thallium µ9/L 0.2 Elevated reporting limit, not included in June 2019 data set AB-12D 03/05/2014 Thallium µ9/L 0.2 Elevated reporting limit, not included in June 2019 data set AB-12D 07/07/2014 Thallium µ9/L 0.2 Elevated reporting limit, not included in June 2019 data set AB-12D 11/04/2014 Thallium µ9/L 0.2 Elevated reporting limit, not included in June 2019 data set AB-12D 03/02/2015 Thallium µ9/L 0.2 Elevated reporting limit, not included in June 2019 data set AB-12D 11/06/2015 Thallium µ9/L 0.2 Elevated reporting limit, not included in June 2019 data set AB-12D 03/03/2016 Thallium µ9/L 0.2 Elevated reporting limit, not included in June 2019 data set AB-12D 07/07/2016 Thallium µ9/L 0.2 Elevated reporting limit, not included in June 2019 data set AB-12D 03/07/2017 Thallium µ9/L 0.2 Elevated reporting limit, not included in June 2019 data set GWA-21 DA 03/07/2019 Thallium µ9/L 0.1 2019 Sample date added by NCDEQ R-BG-01DA 03/11/2019 Thallium µg/L 0.1 2019 Sample date added by NCDEQ BG-03D 11/11/2015 Total Organic Carbon mg/L 17.3 Value excluded by NCDEQ, no rationale provided by NCDEQ GWA-26D 06/21/2017 Total Organic Carbon mg/L 1.6 Value excluded from June 2019 data set, but included by NCDEQ AB-12D 03/01/2011 Zinc µ9/L 5 Sample date for well excluded from NCDEQ data set BG-02D 11/08/2017 Zinc µ9/L 622 Value excluded from June 2019 data set, but included by NCDEQ BG-03D 11/11/2015 Zinc µ9/L 36 Value excluded from June 2019 data set, but included by NCDEQ GWA-26D 1 03/27/2017 1 Zinc I µg 86.9 lValue excluded from June 2019 data set, but included by NCDEQ General Notes: Elevated reporting limit, not included in June 2019 BTV data set, but included in NCDEQ October 2019 BTV data set. Reporting limit was higher than majority of reporting limits and most, if not all, detected concentrations; therefore, not representative of background concentrations. The cutoff date for calculating BTVs presented in the June 2019 reports was December 31, 2018. NCDEQ used a cutoff date of April 30, 2019 and some samples were added to the background data set by NCDEQ. Value excluded by NCDEQ. No rationale provided by NCDEQ. Excluded value is typically a high concentration relative to remainder of data set. Value excluded from June 2019 data set, but included by NCDEQ. Concentration was not included in the calculation of BTVs because data validation and detailed evaluation of Site -specific geochemical conditions indicated that the concentration was a result of field error or laboratory analytical error. Sample date for well exclduded from NCDEQ data set. No rationale provided by NCDEQ for excluding this sample date. Acronyms and Abbreviations: BTVs- below threshold values pg/L - micrograms per liter mg/L - milligrams per liter mg-CaCO3/L - milligrams per liter as calcium carbonate NCDEQ - North Carolina Department of Environmental Quality pCi/L - picocuries per liter 3/6/2020 5 of 6 Table 1 d Detailed Comparison Between June 2019 and NCDEQ October 2019 Groundwater Background Threshold Values - Bedrock Flow Zone P ARCAD I S f uilta s Consultancy fornaturaland built assets Allen Steam Station Duke Energy Carolinas, LLC Well ID Sample.. for Difference Reason AIL I - - - BG-01 BR 03/04/2019 pH S.U. 7.9 2019 Sample date added by NCDEQ BG-01 BR 03/11/2019 pH S.U. 7.6 2019 Sample date added by NCDEQ, autocorrelated sample date BG-01 BR 03/04/2019 Alkalinity mg-CaCO3/L 103 2019 Sample date added by NCDEQ BG-01 BR 03/04/2019 Aluminum µg/L 95.3 2019 Sample date added by NCDEQ BG-01 BR 03/04/2019 Antimony µg/L 0.41 2019 Sample date added by NCDEQ BG-01 BR 03/11/2019 Antimony µg/L 0.79 2019 Sample date added by NCDEQ, autocorrelated sample date BG-01 BR 03/04/2019 Arsenic µg/L 1.2 2019 Sample date added by NCDEQ BG-01 BR 03/11/2019 Arsenic µg/L 0.45 2019 Sample date added by NCDEQ, autocorrelated sample date BG-01 BR 03/04/2019 Barium µg/L 15.1 2019 Sample date added by NCDEQ BG-01 BR 03/11/2019 Barium µg/L 10.2 2019 Sample date added by NCDEQ, autocorrelated sample date BG-01 BR 03/04/2019 Beryllium µg/L 0.1 2019 Sample date added by NCDEQ BG-01 BR 03/11/2019 Beryllium µg/L 0.1 2019 Sample date added by NCDEQ, autocorrelated sample date BG-01 BR 03/04/2019 Bicarbonate Alkalinity mg-CaCO3/L 103 2019 Sample date added by NCDEQ BG-01 BR 03/04/2019 Boron µg/L 39.8 2019 Sample date added by NCDEQ BG-01 BR 03/11/2019 Boron µg/L 29 2019 Sample date added by NCDEQ, autocorrelated sample date BG-01 BR 03/04/2019 Cadmium µg/L 0.08 2019 Sample date added by NCDEQ BG-01 BR 03/11/2019 Cadmium µg/L 0.08 2019 Sample date added by NCDEQ, autocorrelated sample date BG-01 BR 03/04/2019 Calcium µg/L 25.9 2019 Sample date added by NCDEQ BG-01 BR 03/11/2019 Calcium µg/L 27.3 2019 Sample date added by NCDEQ, autocorrelated sample date BG-01 BR 03/04/2019 Carbonate Alkalinity mg-CaCO3/L 5 2019 Sample date added by NCDEQ BG-01 BR 03/04/2019 Chloride m /L 9.3 2019 Sample date added by NCDEQ BG-01 BR 03/11/2019 Chloride m /L 9.1 2019 Sample date added by NCDEQ, autocorrelated sample date BG-01 BR 03/04/2019 Chromium Total µg/L 0.64 2019 Sample date added by NCDEQ BG-01 BR 03/11/2019 Chromium Total µg/L 1.6 2019 Sample date added by NCDEQ, autocorrelated sample date BG-01 BR 03/11/2019 Chromium Hexavalent µg/L 0.39 2019 Sample date added by NCDEQ, autocorrelated sample date BG-01 BR 03/04/2019 Cobalt µg/L 0.059 2019 Sample date added by NCDEQ BG-01 BR 03/11/2019 Cobalt µg/L 0.077 2019 Sample date added by NCDEQ, autocorrelated sample date BG-01 BR 03/11/2019 Copper µg/L 1.3 2019 Sample date added by NCDEQ, autocorrelated sample date BG-01 BR 03/04/2019 Fluoride m /L 0.087 2019 Sample date added by NCDEQ BG-01 BR 03/11/2019 Fluoride m /L 0.065 2019 Sample date added by NCDEQ, autocorrelated sample date BG-01 BR 03/04/2019 Iron µg/L 75.5 2019 Sample date added by NCDEQ BG-01 BR 03/04/2019 Lead µg/L 0.1 2019 Sample date added by NCDEQ BG-01 BR 03/11/2019 Lead µg/L 0.18 2019 Sample date added by NCDEQ, autocorrelated sample date BG-01 BR 03/04/2019 Lithium µg/L 2.5 2019 Sample date added by NCDEQ BG-01 BR 03/11/2019 Lithium µg/L 1.3 2019 Sample date added by NCDEQ, autocorrelated sample date BG-01 BR 03/04/2019 Magnesium m /L 4.93 2019 Sample date added by NCDEQ BG-01 BR 03/11/2019 Magnesium m /L 5.45 2019 Sample date added by NCDEQ, autocorrelated sample date BG-01 BR 03/04/2019 Manganese µg/L 14.3 2019 Sample date added by NCDEQ BG-01 BR 03/04/2019 Mercury µg/L 0.2 2019 Sample date added by NCDEQ BG-01 BR 03/11/2019 Mercury µg/L 0.2 2019 Sample date added by NCDEQ, autocorrelated sample date GWA-21 BR 06/20/2017 Methane µg/L 89.6 Value excluded by NCDEQ, no rationale provided by NCDEQ BG-01 BR 03/04/2019 Molybdenum µg/L 8.8 2019 Sample date added by NCDEQ BG-01 BR 03/11/2019 Molybdenum µg/L 2.6 2019 Sample date added by NCDEQ, autocorrelated sample date BG-01 BR 03/04/2019 Nickel µg/L 0.6 2019 Sample date added by NCDEQ BG-01 BR 03/04/2019 Nitrate+Nitrite m /L-N 1.2 2019 Sample date added by NCDEQ BG-01 BR 03/04/2019 Potassium m /L 5.77 2019 Sample date added by NCDEQ BG-01 BR 03/11/2019 Potassium m /L 3.7 2019 Sample date added by NCDEQ, autocorrelated sample date BG-01 BR 03/04/2019 Selenium µg/L 0.5 2019 Sample date added by NCDEQ BG-01 BR 03/11/2019 Selenium µg/L 0.5 2019 Sample date added by NCDEQ, autocorrelated sample date BG-01 BR 03/04/2019 Sodium m /L 15.3 2019 Sample date added by NCDEQ BG-01 BR 03/11/2019 Sodium m /L 9.46 2019 Sample date added by NCDEQ, autocorrelated sample date BG-01 BR 03/04/2019 Strontium µg/L 166 2019 Sample date added by NCDEQ BG-01 BR 03/04/2019 Sulfate m /L 7.5 2019 Sample date added by NCDEQ BG-01 BR 03/11/2019 Sulfate m /L 4.2 2019 Sample date added by NCDEQ, autocorrelated sample date BG-02BRA-2 12/07/2018 Sulfate m /L 33.3 Value excluded by NCDEQ, no rationale provided by NCDEQ BG-01 BR 03/04/2019 Sulfide m /L 0.1 2019 Sample date added by NCDEQ BG-01 BR 03/04/2019 Total Dissolved Solids m /L 166 2019 Sample date added by NCDEQ BG-01 BR 03/11/2019 Total Dissolved Solids m /L 159 2019 Sample date added by NCDEQ, autocorrelated sample date BG-01 BR 03/04/2019 Thallium µg/L 0.1 2019 Sample date added by NCDEQ BG-01 BR 03/11/2019 Thallium µg/L 0.1 2019 Sample date added by NCDEQ, autocorrelated sample date BG-01 BR 03/04/2019 Total Organic Carbon m /L 1 2019 Sample date added by NCDEQ BG-04BR 03/30/2017 Total Organic Carbon m /L 5.6 Value excluded by NCDEQ, no rationale provided by NCDEQ BG-01 BR 03/11/2019 Total Radium Ci/L 0.734 2019 Sample date added by NCDEQ, autocorrelated sample date BG-01 BR 03/04/2019 Vanadium µg/L 7.8 2019 Sample date added by NCDEQ BG-01 BR 1 03/04/2019 Zinc µg 10 12019 Sample date added by NCDEQ General Notes: The cutoff date for calculating BTVs presented in the June 2019 reports was December 31, 2018. NCDEQ used a cutoff date of April 30, 2019 and some samples were added to the background data set by NCDEQ. Autocorrelated sample dates are samples that were collected less than 60 days since previous sample was collected. Autocorrelated sample dates were not used in the June 2019 background groundwater data sets. Value excluded by NCDEQ. No rationale provided by NCDEQ. Excluded value is typically a high concentration relative to remainder of data set. Acronyms and Abbreviations: BTVs- below threshold values mg/L - micrograms per liter mg/L - milligrams per liter mg-CaCO3/L - milligrams per liter as calcium carbonate mg/L-N - milligrams per liter as nitrogen NCDEQ - North Carolina Department of Environmental Quality pCi/L - picocuries per liter S.U. - standard units 3/6/2020 6 of 6