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HomeMy WebLinkAboutNC0089656_Fact Sheet_20210428DocuSign Envelope ID: 2FA56713-BCA3-4388-85EC-2F57769D032A DEQ / DWR /NPDES EXPEDITED FACT SHEET -NPDES PERMIT RENEWAL NPDES Permit NC0089656 Joe R. Co>fporon, P. G., Compliance & Expedited Permitting Unit 04Jan2021 i Table 1 - Facility Information Applicanti acility Name DC Charlotte Plaza LLLP - Dimensional Place Operations: Permanent Building Dewatering (construction now complete) Applicant Address: 191 Peachtree Street, Suite 500, Atlanta, GA 30303 Facility Address: 1515 South Tryon Street, Charlotte, NC 28203 Permitted Flow (MGD) 0.108 MGD Waste Character: 100% industrial, privately owned, <1.0 MGD Facility Class: PC-1 County: Mecklenburg Permit Status: Renewal Regional Office: MRO Stream Characteristics Receiving Stream: UT to Irwin Creek Stream Classification: C Stream Segment: 11-137-1 Drainage basin: Catawba Summer 7Q10 (cfs): 0 Subbasin [HUC]: 03-08-32 [030501030101] Winter 7Q10 (cfs): 0 Use Support: Impaired for Cu, Pb & Zn 30Q2 (cfs): 0 303(d) Listed: Average Flow (cfs): 0 State Grid: G15NE IWC (%): 100% USGS Topo Quad: Charlotte E, NC Draft Peer Reviewer: Brianna Young (NPDES) Facility Summary: Originally, this permit facilitated excavation dewatering since discontinued (March of 2019). Renewal therefore reflects a privately owned permanent dewatering treatment system [<1MGD] in support of a building's subterranean parking. This permanent system utilizes: • two (2) sumps [sub -slab dewatering drainage] • four (4) each 1,000-pound activated carbon tanks • one (1) bag filter • totalizing flow meter • effluent sample port In addition to the above treatment, captured effluent is further treated by anAquanomics system to produce potable water for consumption and building cooling. Considering the above bag and carbon filter system, and the absence of TSS in past effluent, both Turbidity and TSS monitoring have been discontinued for renewal. Stream and Outfall 001: The dewatering and treatment facility discharges via Outfall 001 [See site location map] discharging via storm sewer to an unnamed tributary (UT) to Irwin Creek under zero -flow receiving -stream conditions [7Q10/30Q2 = 0.0 cfs]. Effluent limitations therefore assume an instream waste concentration (IWC) of 100%. Irwin Creek [segment 11-137-1] is currently listed as impaired for Copper, Lead, Zinc [2018 Integrated Report 305(b)]. Fact Sheet Jan2021 NPDES Permit NC0089656 Page 1 DocuSign Envelope ID: 2FA56713-BCA3-4388-85EC-2F57769D032A Table 2 -- Discharge — Annual Flow Rate Summary (MGD I thru Au2020 YEAR n MAX MIN AVE Comments 2017 305 0.0.090 0.003 0.030 2018 359 0.195 0.0001 0.028 2019 363 0.068 0.004 0.025 2020 244 0.320 0.0031 0.031 Partial year *Flow considered for RPA = 0.040 MGD Aug2018 (highest monthly average). Renewal Parameters of Concern (POCs): See attached RPA spread sheets for Metals and Chlorinated hydrocarbons Table 3 — Summary of POC database Review (results in ug/L unless otherwise stated) [NOTE: these data in part reflect excavation dewatering discontinued in March 2019.] PERAMETER n MAX MIN AVE Detected Renew�Mmit RPA Results PCE 42 <1 <1 <1 No — No RP TCE 42 <1 <1 <1 No — No RP 1,1 DCE 42 2.9 0.53 1.03 3 — No RP 1,1 DCA 42 <1 0.31 0.98 6 100/100 RP = Yes 1,2 DCA 42 1.40 0.910 1.01 4 — No RP Chloroform 42 3.8 <1 1.18 9 — No RP TSS 42 1.4 2.5 3.07 5 30/45 mg/L Lead 42 10 <1 6.93 No — No RP Copper 42 20 5.1 14.22 3 — No RP Zinc 42 55 3.2 37.65 15 — No RP O&G 42 7.4 5 5.08 3 — — Total Hardness 42 190 77 136 — — — EPA 624 3 2.9 0.31 1.25 1 = (1,1 DCE) — No RP Epa 625 3 Semi-VOCs No WET Test (TAA6C) 25 — — — 1 Fail / retest Pass Discontinued as inappropriate for pennanent system — WET Test (TGE6C) 6 — — — All pass — — Fact Sheet Jan2021 NPDES Permit NC0089656 Page 2 DocuSign Envelope ID: 2FA56713-BCA3-4388-85EC-2F57769D032A Rationale for Renewal Limits As permitted, the treatment system anticipated serving during both building excavation/construction and long-term building dewatering. The system design addresses both physical and chemical contaminants of concern. The new structure's subterranean parking level was completed in March of 2019 in part finished below the local groundwater table. It is noteworthy that local groundwater influent to the treatment system appears stable now that construction has been completed for approximately 21 months, according to groundwater analyses. Data reported even during turbid excavation conditions indicate no reasonable potential for a list of contaminants of concern (see RPAs). Therefore, as recommended by the RPA (see Table 3), renewal permit limits of these parameters reflect "no further monitoring" [see permit section A. (1 .)]. Monitoring by broad -list tests EPA 624 and 625 are continued annually as a spot check for volatile and semi -volatile organic compounds, and Whole Effluent Toxicity (WET) testing, Acute, remains Quarterly. NPDES Implementation of Instream Dissolved Metals Standards — Freshwater Standards The NC 2007-2015 Water Quality Standard (WQS) Triennial Review was approved by the NC Environmental Management Commission (EMC) on November 13, 2014. The US EPA subsequently approved the WQS revisions on April 6, 2016, with some exceptions. Therefore, metal limits in draft permits out to public notice after April 6, 2016 must be calculated to protect the new standards - as approved. Table 1. NC Dissolved Metals Water Ouality Standards/Aquatic Life Protection Parameter Acute FW, µg/1 (Dissolved) Chronic FW, µg/1 (Dissolved) Acute SW, µg/1 (Dissolved) Chronic SW, µg/1 (Dissolved) Arsenic 340 150 69 36 Beryllium 65 6.5 --- --- Cadmium Calculation Calculation 40 8.8 Chromium III Calculation Calculation --- --- Chromium VI 16 11 1100 50 Copper Calculation Calculation 4.8 3.1 Lead Calculation Calculation 210 8.1 Nickel Calculation Calculation 74 8.2 Silver Calculation 0.06 1.9 0.1 Zinc Calculation Calculation 90 81 Table 1 Notes: 1. FW= Freshwater, SW= Saltwater 2. — = Hardness dependent standard 3. Only the aquatic life standards listed above are expressed in dissolved form. Aquatic life standards for Mercury and selenium are still expressed as Total Recoverable Metals due to bioaccumulative concerns (as are all human health standards for all metals). It is still necessary to evaluate total recoverable aquatic life and human health standards listed in 15A NCAC 2B.0200 (e.g., arsenic at 10 1.1g/1 for human health protection; cyanide at 5 µg/L and fluoride at 1.8 mg/L for aquatic life protection). Fact Sheet Jan2021 NPDES Permit NC0089656 Page 3 DocuSign Envelope ID: 2FA56713-BCA3-4388-85EC-2F57769D032A Table 2. Dissolved Freshwater Standards for Hardness -Dependent Metals The Water Effects Ratio (WER) is equal to one unless determined otherwise under 15A NCAC 02B .0211 Subparagraph (11 Xd) Metal NC Dissolved Standard, µg/1 Cadmium, Acute WER* {1.136672-[lnhardness](0.041838)} •e^{0.9151 [ln hardness] - 3.1485} Cadmium, Acute Trout waters WER* {1.136672-[lnhardness](0.041838)}•e^{0.9151[lnhardness]- 3.6236} Cadmium, Chronic WER* {1.101672-[ln hardness](0.041838)} • e^{0.7998 [ln hardness]- 4.4451 } Chromium III, Acute WER*0.3 16 • e^{0.8190[In hardness]+3.7256} Chromium III, Chronic WER*0.860 • e^ {0.8190 [ln hardness]+0.6848 } Copper, Acute WER*0.960 • e^{0.9422[ln hardness]-1.700} Copper, Chronic WER*0.960 • e^{0.8545[ln hardness]-1.702} Lead, Acute WER* {1.46203-[ln hardness](0.145712)} • e^{1.273[ln hardness]- 1.460} Lead, Chronic WER*{1.46203-[ln hardness](0.145712)} • e^{1.273[ln hardness]- 4.705 } Nickel, Acute WER*0.998 • e^{0.8460[In hardness]+2.255} Nickel, Chronic WER*0.997 • e^{0.8460[lnhardness]+0.0584} Silver, Acute WER*0. 85 • e^{1.72[lnhardness]-6.59} Silver, Chronic Not applicable Zinc, Acute WER*0.978 • e^{0.8473[lnhardness]+0.884} Zinc, Chronic WER*0.986 • e^ {0.8473 [ln hardness]+0.884} General Information on the Reasonable Potential Analysis (RPA) The RPA process itself did not change as the result of the new metals standards. However, application of the dissolved and hardness -dependent standards requires additional consideration in order to establish the numeric standard for each metal of concern of each individual discharge. The hardness -based standards require some knowledge of the effluent and instream (upstream) hardness and so must be calculated case -by -case for each discharge. Metals limits must be expressed as `total recoverable' metals in accordance with 40 CFR 122.45(c). The discharge -specific standards must be converted to the equivalent total values for use in the RPA calculations. We will generally rely on default translator values developed for each metal (more on that below), but it is also possible to consider case -specific translators developed in accordance with established methodology. RPA Permitting Guidance/WQBELs for Hardness -Dependent Metals - Freshwater Fact Sheet Jan2021 NPDES Permit NC0089656 Page 4 DocuSign Envelope ID: 2FA56713-BCA3-4388-85EC-2F57769D032A The RPA is designed to predict the maximum likely effluent concentrations for each metal of concern, based on recent effluent data, and calculate the allowable effluent concentrations, based on applicable standards and the critical low -flow values for the receiving stream. If the maximum predicted value is greater than the maximum allowed value (chronic or acute), the discharge has reasonable potential to exceed the standard, which warrants a permit limit in most cases. If monitoring for a particular pollutant indicates that the pollutant is not present (i.e. consistently below detection level), then the Division may remove the monitoring requirement in the reissued permit. 1. To perform a RPA on the Freshwater hardness -dependent metals the Permit Writer compiles the following information: • Critical low flow of the receiving stream, 7Q 10 (the spreadsheet automatically calculates the 1Q10 using the formula 1Q10 = 0.843 (s7Q10, cfs) 0.993 • Effluent hardness and upstream hardness, site -specific data is preferred • Permitted flow • Receiving stream classification 2. In order to establish the numeric standard for each hardness -dependent metal of concern and for each individual discharge, the Permit Writer must first determine what effluent and instream (upstream) hardness values to use in the equations. The permit writer reviews DMR's, Effluent Pollutant Scans, and Toxicity Test results for any hardness data and contacts the Permittee to see if any additional data is available for instream hardness values, upstream of the discharge. If no hardness data is available, the permit writer may choose to do an initial evaluation using a default hardness of 25 mg/L (CaCO3 or (Ca + Mg)). Minimum and maximum limits on the hardness value used for water quality calculations are 25 mg/L and 400 mg/L, respectively. If the use of a default hardness value results in a hardness -dependent metal showing reasonable potential, the permit writer contacts the Permittee and requests 5 site -specific effluent and upstream hardness samples over a period of one week. The RPA is rerun using the new data. The overall hardness value used in the water quality calculations is calculated as follows: Combined Hardness (chronic) = (Permitted Flow, cfs *Avg. Effluent Hardness, mg/L) x (s7Q1 0, cfs *Avg. Upstream Hardness, mg/L) (Permitted Flow, cfs + s7Q 10, cfs) The Combined Hardness for acute is the same but the calculation uses the 1Q10 flow. 3. The permit writer converts the numeric standard for each metal of concern to a total recoverable metal, using the EPA Default Partition Coefficients (DPCs) or site -specific translators, if any have been developed using federally approved methodology. Fact Sheet Jan2021 NPDES Permit NC0089656 Page 5 DocuSign Envelope ID: 2FA56713-BCA3-4388-85EC-2F57769D032A EPA default partition coefficients or the "Fraction Dissolved" converts the value for dissolved metal at laboratory conditions to totalrecoverable metal at in -stream ambient conditions. This factor is calculated using the linear partition coefficients found in The Metals Translator: Guidance for Calculating a Total Recoverable Permit Limit from a Dissolved Criterion (EPA 823-B-96-007, June 1996) and the equation: Cdjss = 1 Ctotal 1 + { [Kpo] [SS(l+a)] [10-6] } Where: ss = in -stream suspended solids concentration [mg/1], minimum of 10 mg/L used, and Kpo and a = constants that express the equilibrium relationship between dissolved and adsorbed forms of metals. A list of constants used for each hardness -dependent metal can also be found in the RPA program under a sheet labeled DPCs. 4. The numeric standard for each metal of concern is divided by the default partition coefficient (or site -specific translator) to obtain a Total Recoverable Metal at ambient conditions. In some cases, where an EPA default partition coefficient translator does not exist (ie. silver), the dissolved numeric standard for each metal of concern is divided by the EPA conversion factor to obtain a Total Recoverable Metal at ambient conditions. This method presumes that the metal is dissolved to the same extent as it was during EPA's criteria development for metals. For more information on conversion factors see the June 1996 EPA Translator Guidance Document. 5. The RPA spreadsheet uses a mass balance equation to determine the total allowable concentration (permit limits) for each pollutant using the following equation: Ca = (s7Q10 + Qw) (Cwqs) — (s7Q 10) (Cb) Qw Where: Ca = allowable effluent concentration (µg/L or mg/L) Cwqs =NC Water Quality Standard or federal criteria (µg/L or mg/L) Cb = background concentration: assume zero for all toxicants except NH3 * (µg/L or mg/L) Qw = permitted effluent flow (cfs, match s7Q10) s7Q 10 = summer low flow used to protect aquatic life from chronic toxicity and human health through the consumption of water, fish, and shellfish from noncarcinogens (cfs) * Discussions are on -going with EPA on how best to address background concentrations Flows other than s7Q 10 may be incorporated as applicable: 1 Q 10 = used in the equation to protect aquatic life from acute toxicity QA = used in the equation to protect human health through the consumption of water, fish, and shellfish from carcinogens 30Q2 =used in the equation to protect aesthetic quality 6. The permit writer enters the most recent 2-3 years of effluent data for each pollutant of concern. Data entered must have been taken within four and one-half years prior to the date of the permit application (40 CFR 122.21). The RPA spreadsheet estimates the 95th percentile upper concentration of each pollutant. The Predicted Max concentrations are compared to the Total allowable concentrations to determine if a permit limit is necessary. If the predicted max exceeds the acute or chronic Total allowable concentrations, the discharge is considered to show reasonable potential to violate the water quality standard, and a permit limit (Total allowable concentration) is Fact Sheet Jan2021 NPDES Permit NC0089656 Page 6 DocuSign Envelope ID: 2FA56713-BCA3-4388-85EC-2F57769D032A included in the permit in accordance with the U.S. EPA Technical Support Document for Water Quality -Based Toxics Control published in 1991. 7. When appropriate, permit writers develop facility specific compliance schedules in accordance with the EPA Headquarters Memo dated May 10, 2007 from James Hanlon to Alexis Strauss on 40 CFR 122.47 Compliance Schedule Requirements. 8. The Total Chromium NC WQS was removed and replaced with trivalent chromium and hexavalent chromium Water Quality Standards. As a cost savings measure, total chromium data results may be used as a conservative surrogate in cases where there are no analytical results based on chromium III or VI. In these cases, the projected maximum concentration (95th %) for total chromium will be compared against water quality standards for chromium III and chromium VI. 9. Effluent hardness sampling and instream hardness sampling, upstream of the discharge, are inserted into all permits with facilities monitoring for hardness -dependent metals to ensure the accuracy of the permit limits and to build a more robust hardness dataset. 10. Hardness and flow values used in the Reasonable Potential Analysis for this permit included: Parameter Value Comments (Data Source) Average Effluent Hardness (mg/L) [Total as, CaCO3 or (Ca + Mg)] - DMR data Average Upstream Hardness (mg/L) [Total as, CaCO3 or (Ca + Mg)] - DMR data 7Q10 summer (cfs) 0.0 BIMS 1 Q 10 (cfs) 0.0 RPA Permitted Flow (MGD) 0.040 Aug2018 (previous cycle highest monthly average). Fact Sheet Jan2021 NPDES Permit NC0089656 Page 7 DocuSign Envelope ID: 2FA56713-BCA3-4388-85EC-2F57769D032A 2016 Generic RPA (non -hardness dependent) - 95% Probability/95% Confidence MAXIMUM DATA POINTS = 58 REQUIRED DATA ENTRY Table 1. Project Information Facility Name WWTP/WTP Class NPDES Permit Outfall Flow, Qw (MGD) Receiving Stream Stream Class 7Q10s (cfs) 7Q1Ow (cfs) 30Q2 (cfs) QA (cfs) 1Q1Os (cfs) Data Source(s) ❑ CHECK TO APPLY MODEL ❑ CHECK IF HQW OR ORW Dimensional Place PC-1 NC0089656 001 0.040 UT to Irwin Creek C 0.00 0.00 0.00 0.00 0.00 0.040 MGD = highest Monthly Average flow (Aug2018) durning previous permit cycle [eDMRs]; used by RPA as conservative to protect the environment. Follow directions for data entry. In some cases a comment menu list the available choices or a dropdown menu will provide a list you may select from. Error message occur if data entry does not meet input criteria. Table 2. Parameters of Concern Par01 Par02 Par03 Par04 Par05 Par06 Par07 Par08 Par09 Par10 Par11 Par12 Par13 Par14 Par15 Par16 Par17 Par18 Par19 Par20 Par21 Par22 Name Type Chronic Modifier Acute PQL Units Chloroform C 2000 HH 1 pg/L 1,1-Dichloroethane C 100 HH 1 pg/L 1,2-Dichloroethane C 650 HH 1 pg/L 1,1-Dichloroethylene NC 3200 FW 1 pg/L 1,1-Dichloroethylene NC 20000 HH 1 pg/L Tetrachloroethylene C 3.3 HH 1 pg/L Trichloroethylene C 30 HH 1 pg/L 89656 Joe's RPA for Solvents final 12Mar2021, input 3/12/2021 DocuSign Envelope ID: 2FA56713-BCA3-4388-85EC-2F57769D032A REASONABLE POTENTIAL ANALYSIS Chloroform Values" then "COPY" . Maximum data points = 58 1,1-Dichloroethane Date Data BDL=1/2DL Results Date Data BDL=1/2DL Results 1 2017 < 1 0.5 Std Dev. 0.6490 1 2017 < 1000 500 Std Dev. 170.6497 2 2017 < 1 0.5 Mean 0.7857 2 2017 < 1000 500 Mean 465.1405 3 2017 < 1 0.5 C.V. 0.8261 3 2017 < 1000 500 C.V. 0.3669 4 2017 < 1 0.5 n 42 4 2017 1 1 n 42 5 2017 < 1 0.5 5 2017 < 1000 500 6 2017 < 1 0.5 Mult Factor = 1.1200 6 2017 1 1 Mult Factor = 1.0600 7 2017 < 1 0.5 Max. Value 3.8 pg/L 7 2017 < 1000 500 Max. Value 1000.0 Ng/L 8 2017 < 1 0.5 Max. Pred Cw 4.3 pg/L 8 2017 < 1000 500 Max. Pred Cw 1060.0 Ng/L 9 2017 < 1 0.5 9 2017 < 1000 500 10 2017 < 1 0.5 10 2017 < 1000 500 11 2018 < 1 0.5 11 2018 < 1000 500 12 2018 < 1 0.5 12 2018 < 1000 500 13 2018 < 1 0.5 13 2018 3 2.9 14 2018 < 1 0.5 14 2018 < 1000 500 15 2018 < 1 0.5 15 2018 < 1000 500 16 2018 < 1 0.5 16 2018 < 1000 500 17 2018 < 1 0.5 17 2018 < 1000 500 18 2018 < 1 0.5 18 2018 < 1000 500 19 2018 < 1 0.5 19 2018 < 1000 500 20 2018 < 1 0.5 20 2018 1 1 21 2018 < 1 0.5 21 2018 < 1000 500 22 2018 < 1 0.5 22 2018 < 1000 500 23 2019 3.8 3.8 23 2019 < 1000 500 24 2019 < 1 0.5 24 2019 < 1000 500 25 2019 1.3 1.3 25 2019 < 1000 500 26 2019 < 1 0.5 26 2019 < 1000 500 27 2019 < 1 0.5 27 2019 < 1000 500 28 2019 < 1 0.5 28 2019 < 1000 500 29 2019 < 1 0.5 29 2019 < 1000 500 30 2019 1.4 1.4 30 2019 < 1000 500 31 2019 1.9 1.9 31 2019 < 1000 500 32 2019 1.8 1.8 32 2019 < 1000 500 33 2019 1.6 1.6 33 2019 < 1000 500 34 2019 1.8 1.8 34 2019 530 530 35 2020 1.5 1.5 35 2020 < 1000 500 36 2020 < 1 0.5 36 2020 < 1000 500 37 2020 < 1 0.5 37 2020 < 1000 500 38 2020 < 1 0.5 38 2020 < 1000 500 39 2020 < 1 0.5 39 2020 < 1000 500 40 2020 1.4 1.4 40 2020 < 1000 500 41 2020 < 1 0.5 41 2020 < 1000 500 42 2020 < 1 0.5 42 2020 1000 1000 43 43 44 44 45 45 46 46 47 47 48 48 49 49 50 50 51 51 52 52 53 53 54 54 55 55 56 56 57 57 58 58 Values" then "COPY" . Maximum data points = 58 -1- 89656 Joe's RPA for Solvents final 12Mar2021, data 3/12/2021 DocuSign Envelope ID: 2FA56713-BCA3-4388-85EC-2F57769D032A REASONABLE POTENTIAL ANALYSIS 1,2-Dichloroethane Date Data BDL=1/2DL Results 1 2017 < 1 0.5 Std Dev. 0.1877 2 2017 < 1 0.5 Mean 0.5500 3 2017 < 1 0.5 C.V. 0.3413 4 2017 < 1 0.5 n 42 5 2017 < 1 0.5 6 2017 < 1 0.5 Mult Factor = 1.0500 7 2017 < 1 0.5 Max. Value 1.4 pg/L 8 2017 < 1 0.5 Max. Pred Cw 1.5 pg/L 9 2017 < 1 0.5 10 2017 < 1 0.5 11 2018 1.4 1.4 12 2018 < 1 0.5 13 2018 < 1 0.5 14 2018 < 1 0.5 15 2018 < 1 0.5 16 2018 < 1 0.5 17 2018 < 1 0.5 18 2018 < 1 0.5 19 2018 < 1 0.5 20 2018 < 1 0.5 21 2018 < 1 0.5 22 2018 < 1 0.5 23 2019 < 1 0.5 24 2019 < 1 0.5 25 2019 < 1 0.5 26 2019 < 1 0.5 27 2019 < 1 0.5 28 2019 < 1 0.5 29 2019 < 1 0.5 30 2019 < 1 0.5 31 2019 < 1 0.5 32 2019 1.2 1.2 33 2019 < 1 0.5 34 2019 0.91 0.5 35 2020 < 1 0.5 36 2020 < 1 0.5 37 2020 < 1 0.5 38 2020 < 1 0.5 39 2020 < 1 0.5 40 2020 < 1 0.5 41 2020 < 1 0.5 42 2020 1 1 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 Values" then "COPY" . Maximum data points = 58 1,1-Dichloroethylene Date Data BDL=1/2DL Results 1 2017 < 1 0.5 Std Dev. 0.3764 2 2017 < 1 0.5 Mean 0.5690 3 2017 < 1 0.5 C.V. 0.6615 4 2017 < 1 0.5 n 42 5 2017 < 1 0.5 6 2017 < 1 0.5 Mult Factor = 1.1000 7 2017 < 1 0.5 Max. Value 2.9 pg/L 8 2017 < 1 0.5 Max. Pred Cw 3.2 pg/L 9 2017 < 1 0.5 10 2017 < 1 0.5 11 2018 < 1 0.5 12 2018 < 1 0.5 13 2018 2.9 2.9 14 2018 < 1 0.5 15 2018 < 1 0.5 16 2018 < 1 0.5 17 2018 < 1 0.5 18 2018 < 1 0.5 19 2018 < 1 0.5 20 2018 < 1 0.5 21 2018 < 1 0.5 22 2018 < 1 0.5 23 2019 < 1 0.5 24 2019 < 1 0.5 25 2019 < 1 0.5 26 2019 < 1 0.5 27 2019 < 1 0.5 28 2019 < 1 0.5 29 2019 < 1 0.5 30 2019 < 1 0.5 31 2019 < 1 0.5 32 2019 < 1 0.5 33 2019 < 1 0.5 34 2019 0.53 0.5 35 2020 < 1 0.5 36 2020 < 1 0.5 37 2020 < 1 0.5 38 2020 < 1 0.5 39 2020 < 1 0.5 40 2020 < 1 0.5 41 2020 < 1 0.5 42 2020 1 1 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 Values" then "COPY" . Maximum data points = 58 89656 Joe's RPA for Solvents final 12Mar2021, data - 2 - 3/12/2021 DocuSign Envelope ID: 2FA56713-BCA3-4388-85EC-2F57769D032A REASONABLE POTENTIAL ANALYSIS 1,1-Dichloroethylene Date Data BDL=1/2DL Results 1 2017 < 1 0.5 Std Dev. 2 2017 < 1 0.5 Mean 3 2017 < 1 0.5 C.V. 4 2017 < 1 0.5 n 5 2017 < 1 0.5 6 2017 < 1 0.5 Mult Factor = 7 2017 < 1 0.5 Max. Value 8 2017 < 1 0.5 Max. Pred Cw 9 2017 < 1 0.5 10 2017 < 1 0.5 11 2018 < 1 0.5 12 2018 < 1 0.5 13 2018 2.9 2.9 14 2018 < 1 0.5 15 2018 < 1 0.5 16 2018 < 1 0.5 17 2018 < 1 0.5 18 2018 < 1 0.5 19 2018 < 1 0.5 20 2018 < 1 0.5 21 2018 < 1 0.5 22 2018 < 1 0.5 23 2019 < 1 0.5 24 2019 < 1 0.5 25 2019 < 1 0.5 26 2019 < 1 0.5 27 2019 < 1 0.5 28 2019 < 1 0.5 29 2019 < 1 0.5 30 2019 < 1 0.5 31 2019 < 1 0.5 32 2019 < 1 0.5 33 2019 < 1 0.5 34 2019 0.53 0.5 35 2020 < 1 0.5 36 2020 < 1 0.5 37 2020 < 1 0.5 38 2020 < 1 0.5 39 2020 < 1 0.5 40 2020 < 1 0.5 41 2020 < 1 0.5 42 2020 1 1 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 Values" then "COPY" . Maximum data points = 58 0.3764 0.5690 0.6615 42 1.1000 2.9 pg/L 3.2 Ng/L Tetrachloroethylene Date Data BDL=1/2DL Results 1 2017 < 1 0.5 Std Dev. 0.0000 2 2017 < 1 0.5 Mean 0.5000 3 2017 < 1 0.5 C.V. 0.0000 4 2017 < 1 0.5 n 42 5 2017 < 1 0.5 6 2017 < 1 0.5 Mult Factor = 1.0000 7 2017 < 1 0.5 Max. Value 0.5 pg/L 8 2017 < 1 0.5 Max. Pred Cw 0 DETECTS pg/L 9 2017 < 1 0.5 10 2017 < 1 0.5 11 2018 < 1 0.5 12 2018 < 1 0.5 13 2018 < 1 0.5 14 2018 < 1 0.5 15 2018 < 1 0.5 16 2018 < 1 0.5 17 2018 < 1 0.5 18 2018 < 1 0.5 19 2018 < 1 0.5 20 2018 < 1 0.5 21 2018 < 1 0.5 22 2018 < 1 0.5 23 2019 < 1 0.5 24 2019 < 1 0.5 25 2019 < 1 0.5 26 2019 < 1 0.5 27 2019 < 1 0.5 28 2019 < 1 0.5 29 2019 < 1 0.5 30 2019 < 1 0.5 31 2019 < 1 0.5 32 2019 < 1 0.5 33 2019 < 1 0.5 34 2019 < 1 0.5 35 2020 < 1 0.5 36 2020 < 1 0.5 37 2020 < 1 0.5 38 2020 < 1 0.5 39 2020 < 1 0.5 40 2020 < 1 0.5 41 2020 < 1 0.5 42 2020 < 1 0.5 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 Values" then "COPY" . Maximum data points = 58 89656 Joe's RPA for Solvents final 12Mar2021, data - 3 - 3/12/2021 DocuSign Envelope ID: 2FA56713-BCA3-4388-85EC-2F57769D032A REASONABLE POTENTIAL ANALYSIS Trichloroethylene Date Data BDL=1/2DL Results 1 2017 < 1 0.5 Std Dev. 0.0000 2 2017 < 1 0.5 Mean 0.5000 3 2017 < 1 0.5 C.V. 0.0000 4 2017 < 1 0.5 n 42 5 2017 < 1 0.5 6 2017 < 1 0.5 Mult Factor = 1.0000 7 2017 < 1 0.5 Max. Value 0.5 pg/L 8 2017 < 1 0.5 Max. Pred Cw 0 DETECTS pg/L 9 2017 < 1 0.5 10 2017 < 1 0.5 11 2018 < 1 0.5 12 2018 < 1 0.5 13 2018 < 1 0.5 14 2018 < 1 0.5 15 2018 < 1 0.5 16 2018 < 1 0.5 17 2018 < 1 0.5 18 2018 < 1 0.5 19 2018 < 1 0.5 20 2018 < 1 0.5 21 2018 < 1 0.5 22 2018 < 1 0.5 23 2019 < 1 0.5 24 2019 < 1 0.5 25 2019 < 1 0.5 26 2019 < 1 0.5 27 2019 < 1 0.5 28 2019 < 1 0.5 29 2019 < 1 0.5 30 2019 < 1 0.5 31 2019 < 1 0.5 32 2019 < 1 0.5 33 2019 < 1 0.5 34 2019 < 1 0.5 35 2020 < 1 0.5 36 2020 < 1 0.5 37 2020 < 1 0.5 38 2020 < 1 0.5 39 2020 < 1 0.5 40 2020 < 1 0.5 41 2020 < 1 0.5 42 2020 < 1 0.5 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 Values" then "COPY" . Maximum data points = 58 89656 Joe's RPA for Solvents final 12Mar2021, data - 4 - 3/12/2021 DocuSign Envelope ID: 2FA56713-BCA3-4388-85EC-2F57769D032A Dimensional Place REASONABLE POTENTIAL ANALYSIS NC0089656 Qw (MGD) = 0.04000 1Q10S (cfs) = 0.00 7Q1OS (cfs) = 0.00 7Q1OW (cfs) = 0.00 30Q2 (cfs) = 0.00 Avg. Stream Flow, QA (cfs) = 0.00 Receiving Stream: UT to Irwin Creek 2016 Generic RPA (non -hardness dependent) - 95% Probability/95% Confidence MAXIMUM DATA POINTS = 58 WWTP/WTP Class: PC-1 IWC @ 1Q10S = 100.0% IWC @ 7Q1OS = 100.0% IWC@7Q1OW= 100.0% IWC@30Q2= 100.0% IWC @ QA = 100.0% Stream Class: C Outfall 001 Qw = 0.04 MGD PARAMETER TYPE (q) STANDARDS & CRITERIA (2) J a n REASONABLE POTENTIAL RESULTS RECOMMENDED ACTION NC WQS / Applied Y2 FAV / Chronic Standard Acute n # Det. Max Pred Cw Allowable Cw Chloroform C 2000 HH 1 µg/L 42 9 4.3 Acute: NO WQS _ _ _ ---- _ _ -- Chronic:2,000 No value > Allowable Cw --------------------------- No RP; discontinue Monitoring 1,1-Dichloroethane C 100 HH 1 µg/L 42 6 1060 Acute: NO WQS _ Chronic 100 38 value(s) > Allowable Cw RP = Yes. apply Monthly Monitoring, Pollutant of concern 1,2-Dichloroethane C 650 HH 1 µg/L 42 4 1.5• Acute: NO WQS _ _ _ —650 ------------------------------ No value > Allowable Cw No RP; discontinue Monitoring 1,1-Dichloroethylene NC 3200 FW 1 µg/L 42 3 3.2 Acute: NO WQS _ _ _ ---- _ _ ----------------------------- Chronic:3,200 No value > Allowable Cw No RP; discontinue Monitoring 1,1-Dichloroethylene NC 20000 1111 1 µg/L 42 3 3.2 Acute: NO WQS _ _ _ ---- _ _ _ Chronic:20,000 No value > Allowable Cw ------ No RP; discontinue Monitoring Tetrachloroethylene C 3.3 HH 1 pg/L 42 0 NO DETECTS Acute: NO WQS _ Chronic 3.30 Max MDL = 1 No RP; discontinue Monitoring Trichloroethylene C 30 HH 1 pg/L 42 0 NO DETECTS Acute: NO WQS _ _ _ ___________ Chronic: 30 Max MDL = 1 _ _ _ _ _ _ ____________ No RP; discontinue Monitoring Page 1 of 1 89656 Joe's RPA for Solvents final 12Mar2021, rpa 3/12/2021 DocuSign Envelope ID: 2FA56713-BCA3-4388-85EC-2F57769D032A Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators MAXIMUM DATA POINTS = 58 REQUIRED DATA ENTRY Table 1. Project Information Facility Name WWTP/WTP Class NPDES Permit Outfall Flow, Qw (MGD) Receiving Stream HUC Number Stream Class ❑ CHECK IF HQW OR ORW WQS DC Charlotte Plaza LLLP - Dimensional Place PC-1 NC0089656 001 0.040 UT to Irwin Creek 030501030101 ❑ Apply WS Hardness WQC 7Q10s (cfs) 7Q10w (cfs) 30Q2 (cfs) QA (cfs) 1Q10s (cfs) 0.00 0.00 0.00 0.00 0.00 Effluent Hardness 136.12 mg/L (Avg) Upstream Hardness 25 mg/L (Avg) Combined Hardness Chronic Combined Hardness Acute 136.12 mg/L 136.12 mg/L Data Source(s) CHECK TO APPLY MODEL 0.040 MGD = highest Monthly Average flow (Aug2018) durning previous permit cycle [eDMRs]; conservative to protect the environment. Upsteam hardness assumed 25 mg/L [no data; zero -flow stream conditions] CHECK WQS Table 2. Parameters of Concern Par01 Par02 Par03 Par04 Par05 Par06 Par07 Par08 Par09 Par10 Par11 Par12 Par13 Par14 Par15 Par16 Par17 Par18 Par19 Par20 Par21 Par22 Par23 Par24 Name WQS Type Chronic Modifier Acute PQL Units 4 Copper Aquatic Life NC 33.5317 FW 51.6974 ug/L Lead Aquatic Life NC 19.1125 FW 490.4600 ug/L Zinc Aquatic Life NC 532.7044 FW 528.3822 ug/L 89656 Joe's RPA for metals final 12Mar2021, input 3/12/2021 DocuSign Envelope ID: 2FA56713-BCA3-4388-85EC-2F57769D032A 89656 Joe's RPA for metals final 12Mar2021, input 3/12/2021 DocuSign Envelope ID: 2FA56713-BCA3-4388-85EC-2F57769D032A REASONABLE POTENTIAL ANALYSIS H1 Effluent Hardness Date Data BDL=1/2DL Results 1 2017 130 130 Std Dev. 2 2017 130 130 Mean 3 2017 140 140 C.V. 4 2017 140 140 n 5 2017 120 120 10th Per value 6 2017 110 110 Average Value 7 2017 140 140 Max. Value 8 2017 77 77 9 2017 160 160 10 2017 150 150 11 2018 140 140 12 2018 150 150 13 2018 120 120 14 2018 140 140 15 2018 150 150 16 2018 150 150 17 2018 150 150 18 2018 140 140 19 2018 160 160 20 2018 150 150 21 2018 150 150 22 2018 190 190 23 2019 130 130 24 2019 100 100 25 2019 130 130 26 2019 130 130 27 2019 130 130 28 2019 140 140 29 2019 130 130 30 2019 150 150 31 2019 140 140 32 2019 120 120 33 2019 130 130 34 2019 130 130 35 2020 130 130 36 2020 130 130 37 2020 130 130 38 2020 130 130 39 2020 140 140 40 2020 140 140 41 2020 140 140 42 2020 130 130 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 Use"PASTE SPECIAL. values" then "COPY" . Maximum data points = 58 17.4862 136.1190 0.1285 42 120.00 mg/L 136.12 mg/L 190.00 mg/L H2 Upstream Hardness Date Data BDL=I/2DL Results 1 25 25 Std Dev. N/A 2 Mean 25.0000 3 C.V. 0.0000 4 n 1 5 10th Per value 25.00 mg/L 6 Average Value 25.00 mg/L 7 Max. Value 25.00 mg/L 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 Use "PASTE SPECIAL• Values" then "COPY" . Maximum data points = 58 -1- 89656 Joe's RPA for metals final 12Mar2021, data 3/12/2021 DocuSign Envelope ID: 2FA56713-BCA3-4388-85EC-2F57769D032A REASONABLE POTENTIAL ANALYSIS Pal Copper Date Data BDL=1/2DL Results 1 2017 < 10 5 Std Dev. 2 2017 < 10 5 Mean 3 2017 < 10 5 C.V. 4 2017 < 10 5 n 5 2017 < 10 5 6 2017 < 10 5 Mult Factor = 7 2017 < 10 5 Max. Value 8 2017 5.1 5.1 Max. Pred Cw 9 2017 < 10 5 10 2017 < 10 5 11 2018 < 10 5 12 2018 < 10 5 13 2018 < 10 5 14 2018 < 10 5 15 2018 < 10 5 16 2018 20 20 17 2018 < 10 5 18 2018 < 10 5 19 2018 < 10 5 20 2018 < 10 5 21 2018 < 10 5 22 2018 < 10 5 23 2019 12 12 24 2019 < 10 5 25 2019 < 10 5 26 2019 < 20 10 27 2019 < 20 10 28 2019 < 20 10 29 2019 < 20 10 30 2019 < 20 10 31 2019 < 20 10 32 2019 < 20 10 33 2019 < 20 10 34 2019 < 20 10 35 2020 < 20 10 36 2020 < 20 10 37 2020 < 20 10 38 2020 < 20 10 39 2020 < 20 10 40 2020 < 20 10 41 2020 < 20 10 42 2020 < 20 10 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 Use"PASTE SPECIAL. values" then "COPY" . Maximum data points = 58 Par14 Lead 3.2230 7.5500 0.4269 42 1.07 20.00 ug/L 21.40 ug/L Date BDL=I/2DL Results 1 2017 < 5 2.5 Std Dev. 2 2017 < 5 2.5 Mean 3 2017 < 5 2.5 C.V. 4 2017 < 5 2.5 n 5 2017 < 5 2.5 6 2017 < 5 2.5 7 2017 < 5 2.5 8 2017 < 1 0.5 9 2017 < 5 2.5 10 2017 < 5 2.5 11 2018 < 5 2.5 12 2018 < 5 2.5 13 2018 < 5 2.5 14 2018 < 5 2.5 15 2018 < 5 2.5 16 2018 < 5 2.5 17 2018 < 5 2.5 18 2018 < 5 2.5 19 2018 < 5 2.5 20 2018 < 5 2.5 21 2018 < 5 2.5 22 2018 < 5 2.5 23 2019 < 5 2.5 24 2019 < 5 2.5 25 2019 < 5 2.5 26 2019 < 10 5 27 2019 < 10 5 28 2019 < 10 5 29 2019 < 10 5 30 2019 < 10 5 31 2019 < 10 5 32 2019 < 10 5 33 2019 < 10 5 34 2019 < 10 5 35 2020 < 10 5 36 2020 < 10 5 37 2020 < 10 5 38 2020 < 10 5 39 2020 < 10 5 40 2020 < 10 5 41 2020 < 10 5 42 2020 < 10 5 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 Use "PASTE SPECIAL• Values" then "COPY" . Maximum data points = 58 1.3178 3.4643 0.3804 42 Mult Factor = 1.06 Max. Value 5.000 ug/L Max. Pred Cw 0 DETECTS ug/L -2- 89656 Joe's RPA for metals final 12Mar2021, data 3/12/2021 DocuSign Envelope ID: 2FA56713-BCA3-4388-85EC-2F57769D032A REASONABLE POTENTIAL ANALYSIS Par21 Zinc Date 1 2017 2 2017 3 2017 4 2017 5 2017 6 2017 7 2017 8 2017 9 2017 2017 2018 2018 2018 2018 2018 2018 2018 2018 2018 2018 2018 2018 2019 2019 2019 2019 2019 2019 2019 2019 2019 2019 2019 2019 2020 2020 2020 2020 2020 2020 2020 2020 Data 30 30 30 30 30 30 37 23 36 30 3.2 4.3 49 30 30 45 44 51 43 5.9 30 30 44 36 50 50 50 50 5 55 50 50 50 50 50 50 50 50 50 50 50 50 BDL=1/2DL 15 15 15 15 15 15 37 23 36 15 3.2 4.3 49 15 15 45 44 51 43 5.9 15 15 44 36 50 25 25 25 2.5 55 25 25 25 25 25 25 25 25 25 25 25 25 Results Std Dev. Mean C.V. n Mult Factor = Max. Value Max. Pred Cw Use"PASTE SPECIAL• values" then "COPY" . Maximum data points = 58 13.5064 25.4500 0.5307 42 1.08 55.0 ug/L 59.4 ug/L 89656 Joe's RPA for metals final 12Mar2021, data - 3 - 3/12/2021 DocuSign Envelope ID: 2FA56713-BCA3-4388-85EC-2F57769D032A DC Charlotte Plaza LLLP - Dimensional Place NC0089656 Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators MAXIMUM DATA POINTS = 58 Qw (MGD) = 0.04 1Q1OS (cfs) = 0.00 7Q1OS (cfs) = 0.00 7Q1OW (cfs) = 0.00 30Q2 (cfs) = 0.00 Avg. Stream Flow, QA (cfs) = 0.00 Receiving Stream: UT to Irwin Creek HUC 030501030101 WWTP/WTP Class: PC-1 IWC% @ 1Q1OS = 100 IWC% @ 7Q1OS = 100 IWC% @ 7Q1OW = 100 IWC% @ 30Q2 = 100 IW%C@QA= 100 Stream Class: C Outfall 001 Qw = 0.04 MGD COMBINED HARDNESS (mg/L) Acute =136.12 mg/L Chronic = 136.12 mg/L PARAMETER TYPE (1) NC STANDARDS OR EPA CRITERIAco Ci ° i_ D REASONABLE POTENTIAL RESULTS RECOMMENDED ACTION Chronic Applied Standard _ Acute n # Det. Max Pred Cw Allowable Cw Copper NC 33.5317 FW 51.6974 ug/L 42 3 21 Acute: 52 No RP -discontinue monitoring Chronic: 34 No value > Allowable Cw No RP - discontinue monitoring Lead NC 19.1125 FW 490.4600 ug/L 42 0 NO DETECTS Acute: 490 No RP - discontinue monitoring _ _ _ _ _ _ _ _ _ _ _ _ _ Chronic: 19 Max MDL = 10 No RP - discontinue monitoring Zinc NC 532.7044 FW 528.3822 ug/L 42 15 59 Acute: 528 No RP - discontinue monitoring _ _ _ _ _ _ _ _ _ _ _ _ _ Chronic: 533 No value > Allowable Cw No RP - discontinue monitoring Page 1 of 1 89656 Joe's RPA for metals final 12Mar2021, rpa 3/12/2021 DocuSign Envelope ID: 2FA56713-BCA3-4388-85EC-2F57769D032A NPDES Permit NC0089656 STATE OF NORTH CAROLINA DEPARTMENT OF ENVIRONMENTAL QUALITY DIVISION OF WATER RESOURCES PERMIT TO DISCHARGE WASTEWATER UNDER THE NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES) In compliance with the provisions of North Carolina General Statute 143-215.1, other lawful standards and regulations promulgated and adopted by the North Carolina Environmental Management Commission, and the Federal Water Pollution Control Act, as amended, DC Charlotte Plaza LLLP is hereby authorized to discharge wastewater from a facility located at the Dimensional Place - Groundwater Remediation (GW-REM) 1515 South Tryon Street, Charlotte 28203 Mecklenburg County to receiving waters designated as an unnamed tributary to Irwin Creek in the Catawba River Basin in accordance with effluent limitations, monitoring requirements, and other conditions set forth in Parts I, II, III, and IV hereof. The permit shall become effective March 1, 2017. This permit and the authorization to discharge shall expire at midnight on June 30, 2020. Signed this day March 1, 2017. S. Jay Zimmerman, P.G., Director Division of Water Resources By Authority of the Environmental Management Commission Page 1 of 11 DocuSign Envelope ID: 2FA56713-BCA3-4388-85EC-2F57769D032A NPDES PermitNC0089656 SUPPLEMENT TO PERMIT COVER SHEET All previous NPDES Permits issued to this facility, whether for operation or discharge are hereby revoked, and as of this issuance, any previously issued permit bearing this number is no longer effective. Therefore, the exclusive authority to operate and discharge from this facility arises under the permit conditions, requirements, terms, and provisions described herein. DC Charlotte Plaza LLLP is hereby authorized to: 1. begin operating a 0.108 MGD dewatering and groundwater remediation system consisting of, but not limited to; • a temporary dewatering and groundwater remediation system for during construction consisting of; o thirty-four (34) recovery wells o three (3) 1,000-gallon transfer tanks o a trailer -mounted treatment with two (2) 2,000-pound activated carbon tanks o a bag filter o a flow totalizer o an effluent sample port • a permanent dewatering and groundwater remediation system for post construction consisting of; o a sub -slab dewatering drainage system draining to two (2) sumps o sump pumps o four (4) 1,000-pound activated carbon tanks o a bag filter o flow totalizer o an effluent sample port located at Dimensional Place, 1515 South Tryon Street, Charlotte, Mecklenburg County; and 2. discharge from said treatment works via Outfall 001 at a location specified on the attached map, into an unnamed tributary to Irwin Creek [Stream Segment 11-137-1], currently a Class C waterbody within Subbasin 03-08-34 [HUC: 030501030101] of the Catawba River Basin. Page 2 of 11 DocuSign Envelope ID: 2FA56713-BCA3-4388-85EC-2F57769D032A NPDES PermitNC0089656 PART I A. (1.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS [15A NCAC 02B .0400 et seq., 02B .0500 et seq.] During the period beginning on the effective date of this permit and lasting until construction phase is completed, the Permittee is authorized to discharge via Outfall 001. Such discharges shall be limited, monitored and reported' by the Permittee as specified below: EFFLUENT CHARACTERISTICS [Parameter Code] LIMITS MONITORING REQUIREMENTS 1 Monthly Average Daily Maximum Measurement Frequency Sample Type Sample Locations 2'3 Flow (MGD) 50050 0.108 MGD Continuous Recording E Total Suspended Solids (TSS) C0530 30.0 mg/L 45.0 mg/L Per Batch 5 or Monthly Grab E Turbidity (NTU) 4 00070 50 NTU 50 NTU Per Batch 5 or Monthly Grab E pH (su) 00400 > 6.0 and < 9.0 standard units Per Batch 5 or Monthly Grab E 1,1 Dichloroethane (µg/L) 6 34496 100 µg/L 100 µg/L Per Batch 2'5 or Monthly Grab I & E 1,1 Dichloroethylene (mg/L) 6 34501 1.5 mg/L 1.5 mg/L Per Batch2'5 or Monthly Grab I & E 1,2 Dichloroethane (µg/L) 6 32103 37 µg/L 37 µg/L Per Batch2'5 or Monthly Grab I & E Chloroform (µg/L) 6 32106 170 µg/L 170 µg/L Per Batch 'S or Monthly Grab I & E Tetra chloroethylene (µg/L) 6 78389 3.3 µg/L 3.3 µg/L Per Batch's or Monthly Grab I & E Trichloroethylene (µg/L) 6 7839/ 3 µg/L 3 µg/L Per Batch2'5 or Monthly Grab I & E Oil and Grease (mg/L) [EPA Method 1664 SGT-HEM] 00556 Per Batch 5 or Monthly Grab E TotalCopper (µg/L) 6'7 01042 Per Batch 5'7 or Monthly Grab E TotalLead (µg/L) 6'7 01051 Per Batch 5'7 or Monthly Grab E Total Zinc (µg/L) 6'7 01092 Per Batch 5'7 or Monthly Grab E TotalHardness (as CaCO3)(mg/L)7 00900 Per Batch 5'7 or Monthly Grab E Acute Whole Effluent Toxicity 8 TAA6C Monthly Grab E Organics, TotalPurgeables (VOCs) (EPA Method 624) (µg/L) 6,9 76029 Annually Grab E Base Neutrals & Acids (Semi-VOCs) (EPA Method 625) (µg/L) 6'9 76028 Annually Grab E Footnotes: See next page Page 3of11 DocuSign Envelope ID: 2FA56713-BCA3-4388-85EC-2F57769D032A NPDES Permit NC0089656 Footnotes: 1. Effective December 21, 2016, begin submitting Discharge Monitoring Reports electronically using NC DWR's eDMR application system. See Condition A. (5.). 2. I = Internal Sampling, Location and Frequency: Prior to each carbon -filter change -out, the Permittee shall collect Internal samples immediately upstream of the final carbon -filter in order to document contaminant "break -through" of the next -to last carbon -filter. Internal samples shall be collected at minimum Monthly, or at a frequency matching or exceeding system -design expected filter saturation [break -through], herein defined as a Batch (see Treatment Batch), whichever is more frequent. 3. Sample Location: E = Effluent: In order to document that contaminants have not reached the environment; effluent samples shall be collected concurrently with break -through Internal samples. Effluent samples shall be collected immediately after the last carbon filter designated as final treatment before storm -drain discharge. 4. Turbidity: Effluent turbidity shall not cause receiving -stream turbidity to exceed 50 NTU. If background turbidity naturally exceeds 50 NTU, the effluent shall not cause background turbidity to increase. Any discharge exceeding this permit limit will require sufficient instream sampling (upstream and/or downstream) to verify compliance (effluent vs. background). [NCAC 02B. 0211(21)] 5. Treatment Batch - Batch Discharge Logs: A treatment Batch is defined as the useable life of a carbon filter, from the time of first installation to change -out. The permittee shall document total flow to each designated outfall; effluent discharge logs shall document Batch filter change -out to include, date, time, and total effluent flow. Copies of these logs shall be kept onsite for the duration of the project, at all times available for DWR inspection. 6. All practical quantitation limits (PQL) must be sufficiently sensitive to accommodate the respective water quality standard for each parameter [see Part II. Section D. (4.)]. 7. After securing a minimum of 12 sample analyses (sampling no more frequently than 2/month), the Permittee may submit a written request for the Division to reevaluate monitoring conditions and effluent limitations. 8. Whole Effluent Toxicity (WET): Acute, Monitor Only; Monthly (Pimephales promelas) 48-hour static test. [See Section A. (3)]. 9. For the eDMR application system, any detections shall be reported by entering "1" [Yes (Y) =1] and no detection shall be reported by entering "0" [NO (N) = 0]. Any detections for Total Purgeables Organics (EPA Method 624) or Base Neutrals & Acids (EPA Method 625) shall be noted in the comments section by noting the compound detected and reported concentration. Laboratory reports shall be kept on file in accordance with records retention requirements found in Part II. Section D. 6. Conditions: • There shall be no discharge of floating solids or visible foam in other than trace amounts. • Discharge shall show no evidence as a source for oily film or sheen on the receiving stream. Page 4of11 DocuSign Envelope ID: 2FA56713-BCA3-4388-85EC-2F57769D032A NPDES PermitNC0089656 A. (2.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS [15A NCAC 02B .0400 et seq., 02B .0500 et seq.] During the period beginning upon post construction and lasting until expiration, the Permittee is authorized to discharge via Outfa11001. Such discharges shall be limited, monitored and reported' by the Permittee as specified below: EFFLUENT CHARACTERISTICS [Parameter Code] LIMITS MONITORING REQUIREMENTS 1 Monthly Average Daily Maximum Measurement Frequency Sample Type Sample Locations 2'3 Flow (MGD) 50050 0.108 MGD Continuous Recording 1 E Total Suspended Solids (TSS) C0530 30.0 mg/L 45.0 mg/L Per Batch 5 or Monthly Grab E Turbidity (NTU) 4 00070 50 NTU 50 NTU Per Batch 5 or Monthly Grab E pH (su) 00400 > 6.0 and < 9.0 standard units Per Batch 5 or Monthly Grab E 1,1 Dichloroethane (µg/L) 6 34496 100 µg/L 100 µg/L Per Batch 2'5 or Monthly Grab I & E 1,1 Dichloroethylene (mg/L) 6 34501 1.5 mg/L 1.5 mg/L Per Batch2,5 or Monthly Grab I & E 1,2 Dichloroethane (µg/L) 6 32103 37 µg/L 37 µg/L Per Batch2'5 or Monthly Grab I & E Chloroform (µg/L) 6 32106 170 µg/L 170 µg/L Per Batch 'S or Monthly Grab I & E Tetrachloroethylene (µg/L) 6 78389 3.3 µg/L 3.3 µg/L Per Batch2'5 or Monthly Grab I & E Trichloroethylene (µg/L) 6 78391 3 µg/L 3 µg/L Per Batch2'5 or Monthly Grab I & E Oil and Grease (mg/L) [EPA Method 1664 SGT-HEM] 00556 Per Batch 5 or Monthly Grab E TotalCopper (µg/L) 6'7 01042 Per Batch 5'7 or Monthly Grab E TotalLead (µg/L) 6'7 01051 Per Batch 5'7 or Monthly Grab E TotalZinc (µg/L) 6'7 01092 Per Batch 5'7 or Monthly Grab E TotalHardness (as CaCO3)(mg/L)7 00900 Per Batch 5'7 or Monthly Grab E Acute Whole Effluent Toxicity 8 TGE6C Quarterly Grab E Organics, TotalPurgeables (VOCs) 6 9 (EPA Method 624) (µg/L) ' 76029 Annually Grab E Base Neutrals & Acids (Semi-VOCs) 6 9 (EPA Method 625) (µg/L) ' 76028 Annually Grab E Footnotes: 1. Effective December 21, 2016, begin submitting Discharge Monitoring Reports electronically using NC DWR's eDMR application system. See Condition A. (5.). Page 5 of 11 DocuSign Envelope ID: 2FA56713-BCA3-4388-85EC-2F57769D032A NPDES Permit NC0089656 2. I = Internal Sampling, Location and Frequency: Prior to each carbon -filter change -out, the Permittee shall collect Internal samples immediately upstream of the final carbon -filter in order to document contaminant "break -through" of the next -to last carbon -filter. Internal samples shall be collected at minimum Monthly, or at a frequency matching or exceeding system -design expected filter saturation [break -through], herein defined as a Batch (see Treatment Batch), whichever is more frequent. 3. Sample Location: E = Effluent: In order to document that contaminants have not reached the environment; effluent samples shall be collected concurrently with break -through Internal samples. Effluent samples shall be collected immediately after the last carbon filter designated as final treatment before storm -drain discharge. 4. Turbidity: Effluent turbidity shall not cause receiving -stream turbidity to exceed 50 NTU. If background turbidity naturally exceeds 50 NTU, the effluent shall not cause background turbidity to increase. Any discharge exceeding this permit limit will require sufficient instream sampling (upstream and/or downstream) to verify compliance (effluent vs. background). [NCAC 02B. 0211(21)] 5. Treatment Batch - Batch Discharge Logs: A treatment Batch is defined as the useable life of a carbon filter, from the time of first installation to change -out. The permittee shall document total flow to each designated outfall; effluent discharge logs shall document Batch filter change -out to include, date, time, and total effluent flow. Copies of these logs shall be kept onsite for the duration of the project, at all times available for DWR inspection. 6. All practical quantitation limits (PQL) must be sufficiently sensitive to accommodate the respective water quality standard for each parameter [see Part II. Section D. (4.)]. 7. After securing a minimum of 12 sample analyses (sampling no more frequently than 2/month), the Permittee may submit a written request for the Division to reevaluate monitoring conditions and effluent limitations. 8. Whole Effluent Toxicity (WET): Acute, pass/fail; Quarterly (Pimephales promelas) 24-hour static test at 90% effluent concentration, during January, April, July and October [See Section A. (4)]. 9. For the eDMR application system, any detections shall be reported by entering"1" [Yes (Y) =1] and no detection shall be reported by entering "0" [NO (N) = 0]. Any detections for Total Purgeables Organics (EPA Method 624) or Base Neutrals & Acids (EPA Method 625) shall be noted in the comments section by noting the compound detected and reported concentration. Laboratory reports shall be kept on file in accordance with records retention requirements found in Part II. Section D. 6. Conditions: • There shall be no discharge of floating solids or visible foam in other than trace amounts. • Discharge shall show no evidence as a source for oily film or sheen on the receiving stream. Page 6 of 11 DocuSign Envelope ID: 2FA56713-BCA3-4388-85EC-2F57769D032A NPDES PermitNC0089656 A. (3.) ACUTE TOXICITY MONTHLY - MONITOR ONLY [15ANCAC 02B .0200et seq.] The permittee shall conduct acute toxicity tests on a monthly basis using protocols defined as definitive in EPA Document EPA-821-R-02-012 entitled "Methods for Measuring the Acute Toxicity of Effluents and Receiving Waters to Freshwater and Marine Organisms." The monitoring shall be performed as a Fathead Minnow (Pimephalespromelas) 48-hour static test. Effluent samples for self -monitoring purposes must be obtained during representative effluent discharge and shall be performed at the NPDES permitted final effluent discharge below all waste treatment processes. The parameter code for Pimephalespromelas is TAA6C. All toxicity testing results required as part of this permit condition will be entered on the Effluent Discharge Form (MR-1) for the month in which it was performed, using the appropriate parameter code. Additionally, DWR Form AT-1 (original) is to be sent to the following address: Attention: North Carolina Division of Water Resources Water Sciences Section/Aquatic Toxicology Branch 1621 Mail Service Center Raleigh, North Carolina27699-1621 Completed Aquatic Toxicity Test Forms shall be filed with the Water Sciences Section no later than 30 days after the end of the reporting period for which the report is made. Test data shall be complete and accurate and include all supporting chemical/physical measurements performed in association with the toxicity tests, as well as all dose/response data. Total residual chlorine of the effluent toxicity sample must be measured and reported if chlorine is employed for disinfection of the waste stream. Should there be no discharge of flow from the facility during any month, the permittee will complete the information located at the top of the aquatic toxicity (AT) test form indicating the facility name, permit number, pipe number, county, and the month/year of the report with the notation of "No Flow" in the comment area of the form. The report shall be submitted to the Water Sciences Section at the address cited above. Should any test data from either these monitoring requirements or tests performed by the North Carolina Division of Water Resources indicate potential impacts to the receiving stream, this permit may be re -opened and modified to include alternate monitoring requirements or limits. NOTE: Failure to achieve test conditions as specified in the cited document, such as minimum control organism survival and appropriate environmental controls, shall constitute an invalid test and will require immediate follow-up testing to be completed no later than the last day of the month following the month of the initial monitoring. Page 7of11 DocuSign Envelope ID: 2FA56713-BCA3-4388-85EC-2F57769D032A NPDES PermitNC0089656 A. (4.) ACUTE TOXICITY PASS/FAIL MONITORING (QUARTERLY) [15ANCAC 02B .0200et seq.] The permittee shall conduct acute toxicity tests on a quarterly basis using protocols defined in the North Carolina Procedure Document entitled "Pass/Fail Methodology For Determining Acute Toxicity In A Single Effluent Concentration" (Revised December 2010 or subsequent versions). The monitoring shall be performed as a Fathead Minnow (Pimephales promelas) 24 hour static test. The effluent concentration at which there may be at no time significant acute mortality is 90% (defined as treatment two in the procedure document). The tests will be performed during the months of January, April, July and October. These months signify the first month of each three month toxicity testing quarter assigned to the facility. Effluent sampling for this testing must be obtained during representative effluent discharge and shall be performed at the NPDES permitted final effluent discharge below all treatment processes. Should any single quarterly monitoring indicate a failure to meet specified limits, then monthly monitoring will begin immediately until such time that a single test is passed. Upon passing, this monthly test requirement will revert to quarterly in the months specified above. All toxicity testing results required as part of this permit condition will be entered on the Effluent Discharge Monitoring Form (MR-1) for the month in which it was performed, using the parameter code TGE6C. Additionally, DWR Form AT-2 (original) is to be sent to the following address: Attention: North Carolina Division of Water Resources Water Sciences Section/Aquatic Toxicology Branch 1621 Mail Service Center Raleigh, North Carolina27699-1621 Completed Aquatic Toxicity Test Forms shall be filed with the Water Sciences Section no later than 30 days after the end of the reporting period for which the report is made. Test data shall be complete and accurate and include all supporting chemical/physical measurements performed in association with the toxicity tests, as well as all dose/response data. Total residual chlorine of the effluent toxicity sample must be measured and reported if chlorine is employed for disinfection of the waste stream. Should there be no discharge of flow from the facility during a month in which toxicity monitoring is required, the permittee will complete the information located at the top of the aquatic toxicity (AT) test form indicating the facility name, permit number, pipe number, county, and the month/year of the report with the notation of "No Flow" in the comment area of the form. The report shall be submitted to the Water Sciences Section at the address cited above. Should the permittee fail to monitor during a month in which toxicity monitoring is required, then monthly monitoring will begin immediately until such time that a single test is passed. Upon passing, this monthly test requirement will revert to quarterly in the months specified above. Assessment of toxicity compliance is based on the toxicity testing quarter, which is the three month time interval that begins on the first day of the month in which toxicity testing is required by this permit and continues until the final day of the third month. Should any test data from either these monitoring requirements or tests performed by the North Carolina Division of Water Resources indicate potential impacts to the receiving stream, this permit may b e re -opened and modified to include alternate monitoring requirements or limits. NOTE: Failure to achieve test conditions as specified in the cited document, such as minimum control organism survival and appropriate environmental controls, shall constitute an invalid test and will require immediate follow-up testing to be completed no later than the last day of the month following the month of the initial monitoring. Page 8of11 DocuSign Envelope ID: 2FA56713-BCA3-4388-85EC-2F57769D032A NPDES Permit NC0089656 A. (5.) ELECTRONIC REPORTING OF DISCHARGE MONITORING REPORTS [G.S. 143-215.1(b)] Federal regulations require electronic submittal of all discharge monitoring reports (DMRs) and program reports and specify that, if a state does not establish a system to receive such submittals, then permittees must submit monitoring data and reports electronically to the Environmental Protection Agency (EPA). The final NPDES Electronic Reporting Rule was adopted and became effective on December 21, 2015. NOTE: This special condition supplements or supersedes the following sections within Part II of this permit (Standard Conditions for NPDESPermits): • Section B. (11.) • Section D. (2.) • Section D. (6.) • Section E. (5.) Signatory Requirements Reporting Records Retention Monitoring Reports 1. Reporting Requirements [Supersedes Section D. (2.) and Section E. (5.) (a)1 Effective December 21, 2016, the permittee shall report discharge monitoring data electronically using the NC DWR's Electronic Discharge Monitoring Report (eDMR) internet application. Monitoring results obtained during the previous month(s) shall be summarized for each month and submitted electronically using eDMR. The eDMR system allows permitted facilities to enter monitoring data and submit DMRs electronically using the internet. Until such time that the state's eDMR application is compliant with EPA's Cross -Media Electronic Reporting Regulation (CROMERR), permittees will be required to submit all discharge monitoring data to the state electronically using eDMR and will be required to complete the eDMR submission by printing, signing, and submitting one signed original and a copy of the computer printed eDMR to the following address: NC DENR / Division of Water Resources / Water Quality Permitting Section A 11ENTION: Central Files 1617 Mail Service Center Raleigh, North Carolina 27699-1617 If a permittee is unable to use the eDMR system due to a demonstrated hardship or due to the facility being physically located in an area where less than 10 percent of the households have broadband access, then a temporary waiver from the NPDES electronic reporting requirements may be granted and discharge monitoring data may be submitted on paper DMR forms (MR 1, 1.1, 2, 3) or alternative forms approved by the Director. Duplicate signed copies shall be submitted to the mailing address above. See "How to Request a Waiver from Electronic Reporting" section below. Regardless of the submission method, the first DMR is due on the last day of the month following the issuance of the permit or in the case of a new facility, on the last day of the month following the commencement of discharge. Starting on December 21, 2020, the permittee must electronically report the following compliance monitoring data and reports, when applicable: Page 9 of 11 DocuSign Envelope ID: 2FA56713-BCA3-4388-85EC-2F57769D032A NPDES Permit NC0089656 • Sewer Overflow/Bypass Event Reports; • Pretreatment Program Annual Reports; and • Clean Water Act (CWA) Section 3 16(b) Annual Reports. The permittee may seek an electronic reporting waiver from the Division (see "How to Request a Waiver from Electronic Reporting" section below). 2. Electronic Submissions In accordance with 40 CFR 122.41(1)(9), the permittee must identify the initial recipient at the time of each electronic submission. The permittee should use the EPA's website resources to identify the initial recipient for the electronic submission. Initial recipient of electronic NPDES information from NPDES-regulated facilities means the entity (EPA or the state authorized by EPA to implement the NPDES program) that is the designated entity for receiving electronic NPDES data [see 40 CFR 127.2(b)]. EPA plans to establish a website that will also link to the appropriate electronic reporting tool for each type of electronic submission and for each state. Instructions on how to access and use the appropriate electronic reporting tool will be available as well. Information on EPA's NPDES Electronic Reporting Rule is found at: http://www2.epa.gov/compliance/final-national-pollutant- d ischarge-elimination-system-npd es -electronic -repo rting-rule. Electronic submissions must start by the dates listed in the "Reporting Requirements" section above. 3. How to Request a Waiver from Electronic Reporting The permittee may seek a temporary electronic reporting waiver from the Division. To obtain an electronic reporting waiver, a permittee must first submit an electronic reporting waiver request to the Division. Requests for temporary electronic reporting waivers must be submitted in writing to the Division for written approval at least sixty (60) days prior to the date the facility would be required under this permit to begin submitting monitoring data and reports. The duration of a temporary waiver shall not exceed 5 years and shall thereupon expire. At such time, monitoring data and reports shall be submitted electronically to the Division unless the permittee re -applies for and is granted a new temporary electronic reporting waiver by the Division. Approved electronic reporting waivers are not transferrable. Only permittees with an approved reporting waiver request may submit monitoring data and reports on paper to the Division for the period that the approved reporting waiver request is effective. Information on eDMR and the application for a temporary electronic reporting waiver are found on the following web page: http://deq.nc.gov/about/divisions/water-resources/edmr Page 10of11 DocuSign Envelope ID: 2FA56713-BCA3-4388-85EC-2F57769D032A NPDES PermitNC0089656 4. Signatory Requirements [Supplements Section B. (11.) (b) and Supersedes Section B. (11.) (d)1 All eDMRs submitted to the permit issuing authority shall be signed by a person described in Part II, Section B. (11.)(a) or by a duly authorized representative of that person as described in Part II, Section B. (11.)(b). A person, and not a position, must be delegated signatory authority for eDMR reporting purposes. For eDMR submissions, the person signing and submitting the DMR must obtain an eDMR user account and login credentials to access the eDMR system. For more information on North Carolina's eDMR system, registering for eDMR and obtaining an eDMR user account, please visit the following web page: http://deq.nc.gov/about/divisions/water-resources/edmr Certification. Any person submitting an electronic DMR using the state's eDMR system shall make the following certification [40 CFR 122.22]. NO OTHER STATEMENTS OF CERTIFICATION WILL BE ACCEPTED: "I certf, under penalty of law, that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fines and imprisonment for knowing violations." 5. Records Retention [Supplements Section D. (6.)1 The permittee shall retain records of all Discharge Monitoring Reports, including eDMR submissions. These records or copies shall be maintained for a period of at least 3 years from the date of the report. This period may be extended by request of the Director at any time [40 CFR 122.41]. Page 11 of 11