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HomeMy WebLinkAboutWI0400198_Monitoring (Report)_20180502ARCADIS Design sr Consultancy fornaturaland built assets Mr. Michael Rogers UIC Program Manager NCDEQ — DWR 1636 Mail Service Center Raleigh, North Carolina 27699 Subject: 1st Semi -Annual Groundwater Monitoring Report — 2018 Former BP Facility #24163 381 Knollwood Street Winston-Salem, North Carolina 27103 Incident Number: 6400 (Closed) Risk Classification: Low (No Further Action) Dear Mr. Rogers: On behalf of Atlantic Richfield Company (ARCO), a BP Products North America, Inc. (BP) affiliated company, Arcadis G&M of North Carolina is submitting the attached 1 st Semi -Annual Groundwater Monitoring Report — 2018 for the above referenced site. An electronic copy of this report including the associated laboratory analytical report is included with the attached CD. Please contact me at (919) 415-2327 with any questions or concerns related to the Report or this incident number. Sincerely, Arcadis G&M of North Carolina, Inc. r Paul Goodell, E.I. AFS Project Manager 5 Copies: File — BP #24163 Arcadis U.S., Inc. 111-D Sanders Lane Bluefield, VA 24605 Tel 276 322 3879 Fax 276 322 3946 www.arcadis.com A019Ide7►1tIIA0II Date: May 2, 2018 Contact: Paul Goodell Phone: 919.415.2327 Email: Paul.Goodell@arcadis.com Our ref: GP16BPNA.NC10 Page: 1/1 ARCADIS ')',sign&Consultancy far naturaand Built assetls Atlantic Richfield Company c/o BP Products North America, Inc. SEMI-ANNUAL MONITORING REPORT - 2018 Former BP Facility #24163 381 Knollwood Street Winston-Salem, Forsyth County, North Carolina NCDEQ Incident #6400 (Closed) Injection Permit #W10400198 May 2018 1$1 Semi -Annual Monitoring Report - 2018 A'X Alexandra M. Simpson AFS Task Manager 3 ��Lt;tll Paul Goodell, E.I. AFS Project Manager 5 IST SEMI-ANNUAL MONITORING REPORT !J'*H*-3 Prepared for: Atlantic Richfield Company c/o BP Products North America, Inc. Mr. Greg Frisch — Project Manager 4850 E. 491' Street MBC-3 Room 155C Cuyahoga Heights, Dhio 44125 Tel 216.416.1232 Prepared by: Arcadis G&M of North Carolina, Inc. 801 Corporate Center Drive Suite 300 Raleigh, North Carolina 27607 Tel 919.854-1282 Fax 919.854,5448 www.arcadis-us.curii Environmental Our Ref.: GP16BPNA.NC10 Date: April 30, 2018 This document is intended only for the use of the individual or entity for which it was prepared and may contain information that is privileged, confidential and exempt from disclosure under applicable law. Any dissemination, distribution or copying of this document is strictly prohibited. srcadis.-Com 1=' Semi -Annual Monitoring Report - 2018 1 sc Semi -Annual Monitoring Report - 2018 Former BP Facility #24163 381 Knollwood St Winston-Salem, Forsyth County, North Carolina Latitude 36115' 25.94' N Longitude 80° 17' 11.79"W (Reference Figure 1) Groundwater Incident #: 6400 (Closed) Risk Classification: Reason for Risk Classification - Land Use Category: Source of Release: Date of Release Discovery: Estimated Quantity of Release: Cause of Release; Responsible Party: Property Owner Low (No Further Action) Dissolved -phase Sulfate concentrations above groundwater quality standards (2L) Ind ustrial/Com mercial Former gasoline LIST system(s) 1983 Unknown Former UST System Atlantic Richfield Company c!o BP Products North America, Inc- Attn: Greg Frisch 4850 East 49tr' Street MBC-3 Room 155C Cuyahoga Heights, Ohio 44125 (216) 416-1232 Mr. Charles Sherren Thruway Shopping Center, LLC. 7501 Wisconsin Ave., Suite 1500 Bethesda, Maryland, 20814 (301) 986-2925 ext. 215 !N 10r'r I, �• a Professional Engineer for Areadis G&M of North Carolina, IncSdoc 4r16 that tq':ir�.arrnation contained in this report is correct and accurate to the best of my knowled f Arcad -36-A i of North'Carolina, Inc. is licensed to practice geology and engineering in North Carol 14-CThe c9i;iWt tion,; u'ers of the company are C-155 (geology) and C-1869 (engineering), 1st Semi -Annual Monitoring Report - 2018 CONTENTS 1.0 Site History and Characterization .... 2.0 Groundwater Monitoring ................... 2.1 Groundwater Gauging ................ 2.2 Groundwater Sampling .............. 2.3 Groundwater Analytical Results. 3.0 Site Remediation .............................. 3.1 Remediation Activities to Date... 4.0 Conclusions and Recommendations TABLES Table 1. Monitoring Well Construction Data Table 2. Groundwater Elevation Data Table 3. Summary of Groundwater Analytical Data FIGURES Figure 1. Site Location Map Figure 2. Site Map Figure 3. Potentiometric Surface Map - March 1, 2018 Figure 4. Groundwater Analytical Data - March 2017 - March 2018 Figure 5. Sulfate Isoconcentration Map - March 1, 2018 APPENDICES A- Historical Groundwater Elevation Data B- Laboratory Analytical Report and Chain -of -Custody Record — March 1, 2018 C- Historical Groundwater Analytical Data 3 5 5 5 5 6 7 8 arcadis.com 15t Semi -Annual Monitoring Report - 2018 EXECUTIVE SUMMARY On behalf of Atlantic Richfield Company (ARCO), a BP Products North America, Inc. (BP) affiliated company, Arcadis G&M of North Carolina, Inc. (Arcadis) personnel performed the semi- annual groundwater sampling of groundwater monitoring wells associated with Former BP Facility #24163 located at 381 Knollwood Street, in Winston-Salem, Forsyth County, North Carolina (the Site) on March 1, 2018. All groundwater monitoring activities were conducted in response to the final project evaluation requirement specified in Part VII, Item 5 of the Renewal Issuance of Injection Permit W10400198 from the North Carolina Department of Environmental Quality (NCDEQ) Division of Water Quality — Aquifer Protection Section in April 2013. On March 1, 2018, Arcadis completed a semi-annual groundwater monitoring and sampling event at the Site. Four (4) groundwater monitoring wells (MW-5R, MW-8R, MW-18, and MW-19) were gauged to determine the depth to water (DTW). DTW ranged from 13.42 feet below top of casing (btoc) in groundwater monitoring well MW-19 to 13.63 feet btoc in groundwater monitoring well MW-8R. The historical groundwater flow direction for the Site is towards the southeast. On March 1, 2018, groundwater samples were collected from groundwater monitoring wells MW- 5R, MW-8R, MW-18, and MW-19. The maximum concentrations of selected dissolved -phase COCs found during the March 1, 2018 sampling events are summarized in the table below: Maximum Groundwater Concentrations (March 1, 2018) Chemical of Monitoring Well Concentration North Carolina Concern ID (mg/L) Groundwater (COC) Quality (2L) Standards Sulfate MW-19 745 250 Note: Concentration in Bold exceeds the applicable North Carolina GCL Standard mg/L: milligrams per liter Dissolved phase sulfate concentrations decreased compared to historical groundwater analytical data. Dissolved phase sulfate was detected above the applicable North Carolina Groundwater Quality (2L) Standard at groundwater monitoring wells MW-8R, MW-18, and MW-19. Arcadis recommends discontinuing semi-annual sampling of groundwater monitoring well MW-5R as dissolved -phase sulfate concentrations at this location do not currently exceed the applicable North Carolina 2L Standards. Arcadis recommends continuing the semi-annual groundwater monitoring and sampling program at the Site to document the natural attenuation of sulfate. The next semi-annual groundwater monitoring and sampling event is scheduled for September 2018. Groundwater monitoring wells MW-8R, MW-18, and MW-19 will be gauged to evaluate the potentiometric surface at the Site. Groundwater samples will be collected from MW-8R, MW-18, and MW-19 for analysis of sulfate by Standard Method 9056A. A Semi -Annual Groundwater Monitoring Report documenting the arcadis.com ES-1 15t Semi -Annual Monitoring Report - 2018 proposed activities for 2018 will be submitted to the NCDEQ for review and approval within 45- days of receipt of the laboratory analytical report. arcadis.com ES-2 15t Semi -Annual Monitoring Report - 2018 1.0 SITE HISTORY AND CHARACTERIZATION Former BP Facility #24163 is located at 381 Knollwood Street, Winston-Salem, Forsyth County, North Carolina (the Site). The Site is currently owned by Thruway Shopping Center, LLC. and serves as a parking lot adjacent to surrounding retail stores. The site property is approximately 0.5 acres, covered by asphalt and concrete, and was formerly developed as a retail fueling station which housed gasoline, diesel, waste oil, and kerosene Underground Storage Tanks (USTs). A site location map is presented as Figure 1 and a site map is shown as Figure 2. The North Carolina Department of Environmental Quality (NCDEQ) issued groundwater incident number 6400 due to a subsurface release of gasoline that occurred on or before September 14, 1983 from a ruptured product line associated with the UST system. The quantity of the release remains unknown. One (1) 10,000-gallon steel gasoline UST, three (3) 6,000-gallon steel gasoline USTs, and one (1) 10,000-gallon steel diesel UST were removed from the site in 1990. Three (3) 10,000-gallon gasoline USTs, one (1) 10,000-gallon diesel UST, and one (1) 550-gallon waste oil UST were subsequently installed at the site and the site was purchased by M. M. Fowler, Inc. in January 1994 and continued operation until 2004. The remaining five USTs were removed before 2005 and the site was razed. Site geology and hydrogeology include surficial deposits immediately underlying the site are described generally as sandy silts that grade upward to clayey silts and silty clays. Bedrock beneath the site is mapped as a strongly foliated biotite gneiss and schist. The maximum depth of investigation at the site has been approximately 55 feet below ground surface (bgs); bedrock has not been encountered during site investigation work. Historically, the range for shallow groundwater beneath the site is approximately 11 to 14 feet bgs, and groundwater flow direction is toward the southeast with an apparent horizontal gradient of approximately 0.012 feet per foot (ft/ft). The calculated groundwater seepage velocity for shallow groundwater beneath the site is approximately 2.8 feet per year. Two activated sodium persulfate injections were performed at the Site on June 4 — 9, 2012 and June 3 — 6, 2013 under Underground Injection Control (UIC) Permit #W10400198 which was issued by the NCDEQ Division of Water Quality on August 9, 2011. Approximately 11,237-gallons of sodium persulfate and 6,826-gallons of sodium persulfate were injected at the Site on June 4 — 9, 2012 and June 3 — 6, 2013, respectively. The NCDEQ Risk Classification for this site was reduced to "Low" on January 23, 2015 after issuing a request for Notice of Residual Petroleum (NORP). The NORP was recorded with the Forsyth County Register of Deeds on March 18, 2015 and imposed the following perpetual restriction on the Site property: • Groundwater: Groundwater from the site is prohibited from use as a water supply. Water supply wells of any kind shall not be installed or operated on the site. No Further Action (NFA) status was granted for the subject incident number by the NCDEQ on April 28, 2015. In accordance with UIC Permit #W10400198, dissolved -phase concentrations of sulfate are being monitored on a semi-annual basis at the Site. Closure of UIC Permit #W10400198 will be requested once arcadis.com 15t Semi -Annual Monitoring Report - 2018 dissolved -phase sulfate concentrations are no longer detected above the North Carolina Groundwater Quality (2L) Standards. arcadis.com 15t Semi -Annual Monitoring Report - 2018 2.0 GROUNDWATER MONITORING 2.1 Groundwater Gauging On March 1, 2018, Arcadis G&M of North Carolina, Inc. (Arcadis) personnel gauged groundwater monitoring wells MW-5R, MW-8R, MW-18, and MW-19. Gauging was conducted with a water interface probe (IP) prior to purging and sampling to determine DTB and DTW. The IP and attached tape, marked in 0.01-foot increments, were properly decontaminated before each use with Alconox soap and rinsed with distilled water. The DTW was measured from the marked survey point on the top of well casing (TOC). All measurements were recorded to the nearest 0.01-foot increment. The DTW ranged from 13.42 btoc in groundwater monitoring well MW-19 to 13.63 feet btoc in groundwater monitoring well MW-8R. Groundwater monitoring well construction details are included in Table 1. Current groundwater elevations are summarized in Table 2. Historical groundwater gauging data is provided in Appendix A. A potentiometric surface map depicting historical groundwater flow direction is provided as Figure 3. 2.2 Groundwater Sampling On March 1, 2018, groundwater monitoring wells MW-5R, MW-8R, MW-18, and MW-19 were purged of stagnant water to prepare for groundwater sampling. Prior to purging, the amount of water to be removed was calculated using the following formula: 3.1415 x rz x (TD-DTW) x 7.481 = gallons of water (1 well volume) Where: r = radius of well (in feet) TD = total depth of well (in feet) DTW = depth to water (in feet) In order to ensure that the water in the wells after purging is representative of the water in the aquifer, a minimum of three well volumes were removed. Groundwater samples obtained from the groundwater monitoring well were collected from disposable polyethylene bailers using new nylon rope. Groundwater samples were placed in laboratory supplied containers and shipped on wet ice to TestAmerica Inc. in Nashville, Tennessee, for analysis of Sulfate (SO4) by Standard Method 9056A. Groundwater samples submitted for sulfate analysis were collected in 250-milliliter plastic bottles. The laboratory analytical report and chain -of -custody record for the March 1, 2018 groundwater sampling event is included as Appendix B. 2.3 Groundwater Analytical Results Groundwater analytical data from the March 1, 2018 groundwater sampling event indicated the following: arcadis.com 15t Semi -Annual Monitoring Report - 2018 • Dissolved -phase concentrations of sulfate were detected in concentrations exceeding the applicable North Carolina 2L Standard of 250 milligrams per liter (mg/L) in groundwater monitoring wells MW-8R (677 mg/L), MW-18 (253 mg/L), and MW-19 (745 mg/L). Current groundwater analytical results are presented in Table 3. Historical groundwater analytical data can be found in Appendix C. A dissolved phase concentration map is presented as Figure 4. A sulfate isoconcentration map depicting the dissolved -phase extent of sulfate exceeding the applicable 2L groundwater quality standard is presented in Figure 5. arcadis.com 6 15t Semi -Annual Monitoring Report - 2018 3.0 SITE REMEDIATION 3.1 Remediation Activities to Date Summarized in the table below is a chronology of remediation activities performed at the site to date: Date Activity September 14, 1983 Subsurface release of gasoline from a ruptured product line associated with the UST system December 1990 UST systems associated with release removed; 500 tons of contaminated soil removed during UST closure 1992 Vacuum Extraction System Installed 1992 - 1994 Vacuum Extraction System Operation 1994 - 2011 Monitoring of site June 4 — 9, 2012 Activated Sodium Persulfate (ASP) injection event. Approximately 11,237-gallons of sodium persulfate injected. June 3 — 6, 2013 ASP injection event. Approximately 6,826-gallons of sodium persulfate injected. 2013 - Present Monitored Natural Attenuation arcadis.com 15t Semi -Annual Monitoring Report - 2018 4.0 CONCLUSIONS AND RECOMMENDATIONS Dissolved -phase sulfate was detected above the applicable 2L groundwater quality standard for sulfate of 250 mg/L in groundwater monitoring wells MW-8R, MW-18, and MW-19 on March 1, 2018. Arcadis recommends discontinuing semi-annual sampling of groundwater monitoring well MW-5R as dissolved -phase sulfate concentrations at this location do not currently exceed the applicable North Carolina 2L Standards. Arcadis recommends continuing the semi-annual groundwater monitoring and sampling program at the Site to document the natural attenuation of sulfate. The next semi-annual groundwater monitoring and sampling event is scheduled for September 2018. Groundwater monitoring wells MW-8R, MW-18, and MW-19 will be gauged to evaluate the potentiometric surface at the Site. Groundwater samples will be collected from MW-8R, MW18, and MW-19 for analysis of sulfate by Standard Method 9056A. A Semi -Annual Groundwater Monitoring Report documenting the proposed activities for 2018 will be submitted to the NCDEQ for review and approval within 45- days of receipt of the laboratory analytical report. arcadis.com 8 TABLES Table 1 Monitoring Well Construction Data Former BP Service Station No. 24163 381 Knollwood Street Winston-Salem, Forsyth County, North Carolina Design b iat�c � 04ARCADISIfor ltancy MW-3 In Use Type II 99.03 20 2 NA - NA NA MW-5 Abandoned Type II 99.39 25.5 4 10.5 - 25.5 81.4 MW-5R In Use Type II NS 20 2 10 - 20 NA MW-6 In Use Type II 98.68 25.5 4 10.5 - 25.5 80.7 MW-6i In Use Type III 99.26 55 2 50 - 55 46.8 MW-8 Abandoned Type II 97.84 24 6 NA - NA NA MW-8R In Use Type II NS 20 2 10 - 20 NA MW-14 In Use Type II 100.44 22 4 7 - 22 85.9 MW-15 In Use Type II 99.91 22 4 7 - 22 85.4 MW-16 In Use Type II 97.42 25 2 10 - 25 79.9 MW-17 In Use Type II 100.00 22 4 7 - 22 85.5 MW-18 In Use Type II NS 20 2 10 - 20 NA MW-19 In Use Type II NS 20 2 10 - 20 NA Notes: 1. Reported in feet below grade 2. Measured in feet relative to site datum 3. Conestoga Rover and Associates, a former consultant for this Site, previously reported that no reference was found to the following wells: MW-1, MW-9, MW-10, MW-11, MW-12 or MW-13. These wells are presumed to be abandoned. 4. Monitoring wells MW-5 and MW-8 were abandoned on 5/19/2010 and replaced with monitoring wells MW-5R and MW-8R the same day. 5. Monitoring wells MW-18 and MW-19 were installated on October 25, 2011. NA = Not Applicable / Available NS = Not Surveyed TOC = Top of Casing Page 1 of 1 Table 2 Groundwater Elevation Data Former BP Service Station No. 24163 381 Knollwood Street Winston-Salem, Forsyth County, North Carolina A ARC AU S Wft. B Consaltgncy fornatu and hum assets MW-5R 3/1/2018 NS ND 13.62 0.00 NM MW-8R 3/1/2018 NS ND 13.63 0.00 NM MW-18 3/1/2018 NS ND 13.60 0.00 NM MW-19 3/1/2018 NS ND 13.42 0.00 NM Notes: 1. Measured in feet relative to site datum 2. Corr. GW Elev. _ (ref. point elevation) - (depth to groundwater) + (LNAPL thickness)(LNAPL specific gravity) 3. LNAPL specific gravity assumed to be 0.73 LNAPL = Light non -aqueous phase liquid ND = Not Detected NM = Not Measured NS = Not Surveyed TOC = Top of casing btoc = below top of casing Page 1 of 1 Table 3 Summary of Groundwater Analytical Data Former BP Service Station No. 24163 381 Knollwood Street Winston-Salem, Forsyth County, NC Date Sampled 3/1/2018 Units mg/L Sulfate 163 PARCADIS' � t � 3/1/2018 3/1/2018 3/1/2018 mg/L mg/L mg/L 677 253 745 Notes: mg/L - milligrams per liter BOLD text indicates exceendance of NC groundwater standard 2L for sulfate (250 mg/L). Page 1 of 1 FIGURES z zo W z o� �a m c7 d °aa U y zg w� a� 0 a E ❑ g zo a- M W N z z U U 44 RO I z� RO � Buena RO@INHRO ,y1�yv x DDiNGTON LN paD x 3 Vista a x r- 4 4 ti� z ul'i 3 Y o SUSSEx G7ON tN NW� RD NN o gUFta SST z -- ul., GREENBRIER.RD ti4Q i¢MONT Fp A PQ d 3 VJRGINIA RD 85D r 93 FIEtDALE AVE ?�� -• 2 r y.. 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FORMER BP STATION 24163 W a 381 KNOLLWOOD ST., WINSTON-SALEM, NORTH CAROLINA &� 1st SEMI-ANNUAL MONITORING REPORT-2018 a E l a AREA LOCATION SITE LOCATION MAP vi FIGURE Dwi Itancy ARCAD I S Mil@aasssets nd " NORTH CAROLINA U Z Z a wm w�Q �o Z ON ou oLL . a m —z o �< a0 0 nU Op U < w � om� it a rcox ohm M= mm _ m� �5a x oaS adm U > w0a ON �N o� E M L£0 U m F �?O UUd O M.H. LEGEND: UP is�q�o - - PROPERTY LINE • U.P.• • U.P. 00- f ABANDONED GROUNDWATER MONITORING WELL ONCRETE FORMER PRODUCT LINE GRASS EL METER IC g QC.B. CATCH BASIN PARKING M-17 Q M.H. MAN HOLE AREA LIGHT ` • U.P. UTILITY POLE ' F.H. FIRE HYDRANT TELEPHONE ASPHALT TRASH LARGE MANHOLE COVER PARKING ENCLOSURE ` GROUNDWATER MONITORING WELL MW-3 METAL SHED N 2 O W' F — — — — — — I METAL SHED I • ����Lu/ I FORMUSFORMER GASOLINE ` T AREAI BP SERVICE V/ I_____ J STATION ` NOTE: Q CONCRETE MW-18 PAD 1. MONITORING WELL LOCATIONS ARE APPROXIMATE. O 40. 0 0 2. THE SITE PARKING IS A VACANT PARKING LOT. ALL SITE FEATURES EXCEPT LOT CURBS AND ROADWAYS REPRESENT FORMER SITE MW-5_ _ MW-5R MW-14 CHARACTERISTICS. J W J M 8 - - - MW-16 p F.H. F FORMER PUMP MW-8R ISLAND(( YP) I FORMER ` �Q Z MW-6i I CANOPY PARKING MW-1I -_ J FORMER DIESEL UST AREA I I MW-6 1 — FORMERPUMP ' ISLAND(TYP) I CONCRETE FO ER TAN OLD 'Fb• ' 0 0 o T 0 30 60 FORMER o 0 o UO CANOPY aaaaaaaal I GRAPHIC SCALE ❑ - I FORMER VENT RISERS 00 ATLANTIC RICHFIELD COMPANY C/O BP PRODUCTS NORTH AMERICA, INC. ODp FORMER BP STATION 24163 381 KNOLLWOOD ST., WINSTON-SALEM, NORTH CAROLINA 1st SEMI-ANNUAL MONITORING REPORT - 2018 MW-15 FORMER OG0 VENT RISERS SITE MAP O M.H. FIGURE /� /� for natural. A I `VADIS 0 O M.H. LEGEND: UP is�q�o - - PROPERTY LINE • U.P.• • U.P. 00- f ABANDONED GROUNDWATER MONITORING WELL ONCRETE FORMER PRODUCT LINE GRASS EL METER IC g QC.B. CATCH BASIN PARKING M-17 Q M.H. MAN HOLE AREA LIGHT ` • U.P. UTILITY POLE ' b- F.H. FIRE HYDRANT TELEPHONE ASPHALT TRASH LARGE MANHOLE COVER PARKING ENCLOSURE ` GROUNDWATER MONITORING WELL MW-3 METAL y (NSVD) NOT SURVEYED TO VERTICAL DATUM 20 HISTMETAL L DEPICTED GROUNDWATER FLOW (FT W F------� SHE AMSO DI IC Lu I • FT AMSL FEET ABOVE MEAN SEA LEVEL ����Lu/ FORMUSFORMER GASOLINE ` T AREAI BP SERVICE I_____ STATION MW-18 CONCRETE NOTE: 0 TTT (NSVD) PAD 1. MONITORING WELL LOCATIONS ARE APPROXIMATE. 0 40 0 0 2. THE SITE PARKING IS A VACANT PARKING LOT. ALL SITE FEATURES EXCEPT LOT CURBS AND ROADWAYS REPRESENT FORMER SITE MW-5_ _ MW-5R MW-14 CHARACTERISTICS. J I (NSVD) M W-8 MW-16 0 F.H. r FORMER MP ' - PUISLAND(TYP) I FORMER ` �Q Z MW-6i MW-8R CANOPY (NSVD) PARKING MW-19 (NSVD)— -_ J FORMER DIESEL UST AREA I I I MW-6 — FORMER PUMP ' ISLAND(TYP) CONCRETE FOF AER TAN OLD 0 0 0 0 T 0 30 60 FORMER • o 0 0 o CANOPY I GRAPHIC SCALE ❑ - I FORMER VENT RISERS ATLANTIC RICHFIELD COMPANY C/O BP PRODUCTS NORTH AMERICA, INC. ODp FORMER BP STATION 24163 381 KNOLLWOOD ST., WINSTON-SALEM, NORTH CAROLINA 1st SEMI-ANNUAL MONITORING REPORT - 2018 Mw-15 00 FORMER 0°0 VENT RISERS POTENTIOMETRIC SURFACE MAP MARCH 1, 2018 O M.H. FIGURE fa�/� /� A Imilt�aswtsnd._ I `VADIS MW-1 W W 0 0 J J 0 Z MW-8R Date 3/3/2017 9/20/2017 3/1/2018 SO4 1,720 797 677 MW-18 Date 3/3/2017 9/20/2017 3/1/2018 SO4 295 1 257 253 MW-5R Date 3/3/2017 9/20/2017 3/1/2018 SO4 1 3,570 1 1,060 163 MW-19 Date 3/3/2017 9/20/2017 3/1/2018 SO4 941 1,020 745 LEGEND: — — — PROPERTY LINE ABANDONED GROUNDWATER MONITORING WELL FORMER PRODUCT LINE C.B. CATCH BASIN O M.H. MAN HOLE AREA LIGHT • U.P. UTILITY POLE F.H. FIRE HYDRANT TELEPHONE LARGE MANHOLE COVER GROUNDWATER MONITORING WELL mg/L MILLIGRAMS PER LITER LEGEND Abbreviation Constituent 2 L SO4 Sulfate 250 NOTE: 1. THE NORTH CAROLINA 2L STANDARD FOR SULFATE IS 250 mg/L 2. VALUES IN BOLD EXCEED NORTH CAROLINA 2L STANDARDS. 0 30' 60' GRAPHIC SCALE 0 U Z Z a m w�Q �o Oo Z oN OZ oLL . a m —z o �< a0 0 nU 00 U < w � om� it Q rcox ohm M= mm _ m� �5a x oaS adm U > w�Q 0 o 0 �2 o� E M Lew F U m �?O UUd O M.H. O U.P. U.P. /S<ANO U.P. ONCRETE GRASS EL ECTRIC MITER PARKING I MW-17 LEGEND: PROPERTY LINE ` f ABANDONED GROUNDWATER MONITORING WELL FORMER PRODUCT LINE ' QC.B. CATCH BASIN ASPHALT TRASH O M.H. MAN HOLE PARKING ENCLOSURE ` AREA LIGHT MW-3 METAL SHED r • U.P. UTILITY POLE F — — — — — — METAL SHED v2o F.H. FIRE HYDRANT W I TELEPHONE W I LARGE MANHOLE COVER w I I FORMER GASOLINE FORMER ` GROUNDWATER MONITORING WELL UST AREA I 14% BP SERVICE STATION (745) SULPHATE CONCENTRATION (mg/L) 0 ,00r _ _ _ j AMW-18 ` 250 ESTIMATED SULFATE CONCENTRATION CONTOUR O CONCRETE / (253) PAD 2L STANDARD (mg/L) O h� � 40. a O (mg/L) MILLIGRAMS PER LITER MW-(_ MW-5R MW-14 J I (163) �s MW-16 J O Z _ _ PU F.H. MW L ` FORMER MP ISLAND (TYP) MW-6i I FORMER CANOPY ` I9yO NOTE: 1. THE NORTH SHADED CAROLINA 2L STANDARD FOR SULFATE IS 250 mg/L CAROLINA STANDARDS. `Mw_gR -�(677) I I ` PARKING 2. VALUES EXCEED NORTH 2L MW-19 �(745) FC DIESEL J UST AREA I I MW-6 FORMER PUMP ' ISLAND(TYP) I CONCRETE FO ER TAN OLD 0 0 o 'Fb• FORMER T 0 30 60 ' o 0 o UO CANOPY aaaaaaaal I GRAPHIC SCALE ❑ - I FORMER 00 VENT RISERS ATLANTIC RICHFIELD COMPANY C/O BP PRODUCTS NORTH AMERICA, INC. ODp FORMER BP STATION 24163 381 KNOLLWOOD ST., WINSTON-SALEM, NORTH CAROLINA 1st SEMI-ANNUAL MONITORING REPORT - 2018 Mw-15 FORMER 0°0 VENT RISERS SULFATE ISOCONCENTRATION MAP MARCH 1, 2018 O M.H. FIGURE /� /� A`VADIS for natural. builtaassets�dI APPENDIX A Historical Groundwater Elevation Data Appendix A Historical Groundwater Elevation Data Former BP Service Station No. 24163 381 Knollwood Street Winston-Salem, Forsyth County, North Carolina A ARCADIS hoift"-r,,, * 06/24/93 ND 13.89 0.00 85.14 * 08/23/94 ND 14.36 0.00 84.67 * 03/21/95 ND 13.58 0.00 85.45 * 08/05/96 ND 13.54 0.00 85.49 * 11/17/98 ND 14.09 0.00 84.94 * 06/19/01 ND 14.11 0.00 84.92 * 09/12/01 ND 14.41 0.00 84.62 * 12/27/01 ND 14.51 0.00 84.52 * 03/05/02 ND 14.29 0.00 84.74 05/13/03 ND 14.35 0.00 84.68 12/09/03 ND 13.63 0.00 85.40 03/23/06 ND 13.64 0.00 85.39 05/08/07 ND 13.40 0.00 85.63 05/14/08 ND 13.42 0.00 85.61 05/28/09 ND 13.31 0.00 85.72 05/27/10 ND 13.07 0.00 85.96 10/31/11 ND 13.87 0.00 85.16 MW-3 99.03 05/22/12 ND 13.55 0.00 85.48 06/14/12 ND 13.53 0.00 85.50 07/09/12 ND 13.98 0.00 85.05 08/14/12 ND 14.24 0.00 84.79 09/19/12 ND 14.08 0.00 84.95 12/05/12 ND 14.42 0.00 84.61 02/26/13 ND 13.55 0.00 85.48 05/31/13 ND 13.58 0.00 85.45 08/28/13 ND 13.57 0.00 85.46 11/07/13 ND 14.30 0.00 84.73 02/27/14 ND 13.28 0.00 85.75 06/02/14 ND 13.34 0.00 85.69 10/16/14 ND 14.18 0.00 84.85 04/23/15 ND 13.54 0.00 85.49 04/28/16 ND 13.51 0.00 85.52 09/19/16 ND 13.92 0.00 85.11 03/03/17 ND NM 0.00 NM 06/24/93 ND 13.51 0.00 85.88 08/23/94 ND 13.82 0.00 85.57 _ 03/21/95 ND 13.71 0.00 85.68 _ 08/05/96 ND 13.54 0.00 85.85 11/17/98 ND 14.08 0.00 85.31 06/19/01 NM NM NM NM 09/12/01 ND 14.46 0.00 84.93 MW-5 12/27/01 99.39 14.51 15.07 0.56 84.73 03/05/02 14.45 14.88 0.43 84.82 05/12/03 NM NM NM NM 12/09/03 13.18 13.60 0.42 86.10 03/23/06 ND 13.67 0.00 85.72 05/08/07 ND 13.45 0.00 85.94 05/14/08 ND 13.51 0.00 85.88 05/28/09 ND 13.39 0.00 86.00 Page 1 of 5 Appendix A Historical Groundwater Elevation Data Former BP Service Station No. 24163 381 Knollwood Street Winston-Salem, Forsyth County, North Carolina A ARCADIS Llesivn&r nsun "'' forneturel and 05/27/10 ND 13.70 0.00 NM 10/31/11 ND 13.97 0.00 NM 05/22/12 ND 13.66 0.00 NM 06/14/12 ND 13.73 0.00 NM 07/09/12 ND 14.18 0.00 NM 08/14/12 ND 14.45 0.00 NM 09/19/12 ND 14.35 0.00 NM 12/05/12 ND 14.68 0.00 NM 02/26/13 ND 13.89 0.00 NM 05/31/13 ND 13.77 0.00 NM 08/28/13 ND 13.83 0.00 NM MW-5R NS 11/07/13 ND 14.53 0.00 NM 02/27/14 ND 13.39 0.00 NM 06/02/14 ND 13.47 0.00 NM 10/16/14 ND 14.32 0.00 NM 04/23/15 ND 13.69 0.00 NM 10/13/15 ND 14.19 0.00 NM 04/28/16 ND 13.61 0.00 NM 09/19/16 ND 13.99 0.00 NM 03/03/17 ND 14.01 0.00 NM 09/20/17 ND 13.67 1.00 NM 03/01/18 ND 13.62 0.00 NM 06/24/93 ND 12.31 0.00 86.37 08/23/94 ND 12.61 0.00 86.07 03/21/95 ND 13.15 0.00 85.53 08/05/96 ND 12.39 0.00 86.29 11/17/98 ND 13.16 0.00 85.52 06/19/01 NM NM NM NM 09/12/01 ND 13.51 0.00 85.17 12/27/01 ND 13.61 0.00 85.07 03/05/02 ND 11.02 0.00 87.66 MW-6 98.68 05/12/03 ND 11.10 0.00 87.58 12/09/03 ND 13.49 0.00 85.19 03/23/06 ND 11.79 0.00 86.89 05/08/07 ND 12.50 0.00 86.18 05/14/08 ND 12.16 0.00 86.52 05/28/09 ND 10.64 0.00 88.04 05/27/10 ND 11.84 0.00 86.84 10/31/11 ND 12.95 0.00 85.73 06/02/14 ND 12.38 0.00 86.30 06/24/93 ND NM 0.00 NM 08/23/94 ND NM 0.00 NM 03/21/95 ND 14.75 0.00 84.51 08/05/96 ND 14.13 0.00 85.13 11/17/98 ND 14.09 0.00 85.17 06/19/01 ND 18.07 0.00 81.19 09/12/01 ND 16.60 0.00 82.66 12/27/01 ND 14.61 0.00 84.65 03/05/02 ND 14.96 0.00 84.30 MW-6i 05/12/03 99.26 ND 15.17 0.00 84.09 12/09/03 ND 13.55 0.00 85.71 03/23/06 ND 13.55 0.00 85.71 05/08/07 ND 12.93 0.00 86.33 05/14/08 ND 13.22 0.00 86.04 05/28/09 ND 13.39 0.00 85.87 05/27/10 ND 13.23 0.00 86.03 10/31/11 ND 13.90 0.00 85.36 06/02/14 ND 13.35 0.00 85.91 04/28/16 ND 13.55 0.00 85.71 Page 2 of 5 Appendix A Historical Groundwater Elevation Data Former BP Service Station No. 24163 381 Knollwood Street Winston-Salem, Forsyth County, North Carolina A ARCADIS Llesivn&r nsun "'' forneturel and * 08/23/94 ND 12.14 0.00 85.70 03/21/95 ND 12.02 0.00 85.82 08/05/96 ND 11.99 0.00 85.85 11/17/98 ND 12.53 0.00 85.31 06/19/01 NM NM NM NM 09/12/01 ND 12.67 0.00 85.17 12/27/01 14.47 15.03 0.56 83.26 MW 8 97.84 03/05/02 12.42 12.60 0.18 85.38 05/12/03 NM NM NM NM 12/09/03 13.32 13.56 0.24 84.47 03/23/06 ND 12.15 0.00 85.69 05/08/07 ND 11.90 0.00 85.94 05/14/08 ND 11.95 0.00 85.89 05/28/09 ND 11.70 0.00 86.14 05/27/10 ND 12.97 0.00 NM 10/31/11 ND 13.34 0.00 NM 05/22/12 ND 13.69 0.00 NM 06/14/12 ND 14.94 0.00 NM 07/09/12 ND 14.08 0.00 NM 08/14/12 ND 14.29 0.00 NM 09/19/12 ND 14.08 0.00 NM 12/05/12 ND 14.53 0.00 NM 02/26/13 ND 13.80 0.00 NM 05/31/13 ND 13.61 0.00 NM 08/28/13 ND 13.74 0.00 NM MW-8R NS 11/07/13 ND 14.42 0.00 NM 02/27/14 ND 13.33 0.00 NM 06/02/14 ND 13.34 0.00 NM 10/16/14 ND 14.18 0.00 NM 04/23/15 ND 13.57 0.00 NM 10/13/15 ND 14.08 0.00 NM 04/28/16 ND 13.53 0.00 NM 09/19/16 ND 13.91 0.00 NM 03/03/17 ND 13.92 0.00 NM 09/20/17 ND 13.61 0.00 NM 03/01/18 ND 13.63 0.00 NM 06/24/93 NM NM NM NM 08/23/94 NM NM NM NM 03/21/95 ND 13.55 0.00 86.89 08/05/96 ND 13.64 0.00 86.80 11/17/98 ND 14.26 0.00 86.18 06/19/01 ND 14.55 0.00 85.89 09/12/01 ND 14.81 0.00 85.63 12/27/01 ND 14.85 0.00 85.59 03/05/02 ND 14.64 0.00 85.80 MW-14 05/12/03 100.44 ND 13.41 0.00 87.03 12/09/03 ND 13.51 0.00 86.93 03/23/06 ND 13.82 0.00 86.62 05/08/07 ND 13.54 0.00 86.90 05/14/08 ND 13.64 0.00 86.80 05/28/09 ND 13.47 0.00 86.97 05/27/10 ND 13.00 0.00 87.44 10/13/11 ND 14.14 0.00 86.30 06/02/14 ND 13.42 0.00 87.02 04/28/16 ND 13.65 0.00 86.79 Page 3 of 5 Appendix A Historical Groundwater Elevation Data Former BP Service Station No. 24163 381 Knollwood Street Winston-Salem, Forsyth County, North Carolina A ARCADIS Llesivn&r nsun "'' forneturel and 06/24/93 NM NM NM NM 08/23/94 NM NM NM NM 03/21/95 ND 12.83 0.00 87.08 08/05/96 ND 12.77 0.00 87.14 11/17/98 ND 13.58 0.00 86.33 06/19/01 ND 13.80 0.00 86.11 09/12/01 ND 14.18 0.00 85.73 12/27/01 ND 14.29 0.00 85.62 03/05/02 ND 13.98 0.00 85.93 05/12/03 NM 12.75 NM 87.16 MW-15 99.91 12/09/03 ND 12.89 0.00 87.02 03/23/06 ND 13.14 0.00 86.77 05/08/07 ND 12.90 0.00 87.01 05/14/08 ND 13.12 0.00 86.79 05/28/09 ND 12.90 0.00 87.01 05/27/10 ND 12.25 0.00 87.66 10/31/11 ND 13.61 0.00 86.30 06/02/14 ND 12.82 0.00 87.09 10/16/14 ND 13.91 0.00 86.00 04/28/16 ND 13.15 0.00 86.76 06/24/93 NM NM NM NM 08/23/94 NM NM NM NM 03/21/95 ND 12.06 0.00 85.36 08/05/96 ND 12.09 0.00 85.33 11/17/98 ND 12.60 0.00 84.82 06/19/01 ND 12.74 0.00 84.68 09/12/01 ND 12.98 0.00 84.44 12/27/01 NM NM NM NM 03/05/02 ND 12.83 0.00 84.59 MW-16 05/12/03 97.42 NM NM NM NM 12/09/03 ND 12.13 0.00 85.29 03/23/06 ND 12.18 0.00 85.24 05/08/07 NM NM NM NM 05/14/08 ND 12.03 0.00 85.39 05/28/09 ND 11.96 0.00 85.46 05/27/10 ND 11.69 0.00 85.73 10/31/11 ND 12.45 0.00 84.97 11/07/13 ND 12.88 0.00 84.54 06/02/14 ND 11.97 0.00 85.45 06/24/93 NM NM NM NM 08/23/94 NM NM NM NM 03/21/95 ND 14.42 0.00 85.58 08/05/96 ND 14.46 0.00 85.54 11/17/98 ND 14.91 0.00 85.09 06/19/01 ND 15.03 0.00 84.97 09/12/01 ND 15.28 0.00 84.72 12/27/01 ND 15.37 0.00 84.63 03/05/02 ND 15.15 0.00 84.85 05/12/03 NM 14.15 NM 85.85 MW-17 100.00 12/09/03 ND 14.50 0.00 85.50 03/23/06 ND 14.45 0.00 85.55 05/08/07 ND 14.22 0.00 85.78 05/14/08 ND 14.22 0.00 85.78 05/28/09 ND 14.12 0.00 85.88 05/27/10 ND 13.90 0.00 86.10 10/31/11 ND 14.72 0.00 85.28 06/02/14 ND 14.14 0.00 85.86 04/28/16 ND 14.36 0.00 85.64 Page 4 of 5 Appendix A Historical Groundwater Elevation Data Former BP Service Station No. 24163 381 Knollwood Street Winston-Salem, Forsyth County, North Carolina MW-18 MW-19 10/31 /11 05/22/12 06/14/12 07/09/12 08/14/12 09/19/12 12/05/12 02/26/13 05/31 /13 08/28/13 11/07/13 02/27/14 06/02/14 10/16/14 04/23/15 10/13/15 04/28/16 09/19/16 03/03/17 09/20/17 03/01 /18 10/31 /11 05/22/12 06/14/12 07/09/12 08/14/12 09/19/12 12/05/12 02/26/13 05/31 /13 08/28/13 11 /07/13 02/27/14 UbIUL/l4 10/16/14 04/23/15 10/13/15 04/28/16 09/19/16 03/03/17 09/20/17 03/01 /18 NS 0t.9 h.ift"_.rI., A ARCADIS ND 13.95 0.00 NM ND 14.10 0.00 NM ND 13.61 0.00 NM ND 14.05 0.00 NM ND 14.43 0.00 NM ND 14.34 0.00 NM ND 14.62 0.00 NM ND 14.67 0.00 NM ND 14.57 0.00 NM ND 14.33 0.00 NM ND 14.51 0.00 NM ND 13.76 0.00 NM ND 13.55 0.00 NM ND 14.37 0.00 NM ND 13.84 0.00 NM ND 14.81 0.00 NM ND 13.62 0.00 NM ND 14.04 0.00 NM ND 14.08 0.00 NM ND 13.21 0.00 NM ND 13.60 0.00 NM ND 13.75 0.00 NM ND 13.37 0.00 NM ND 13.39 0.00 NM ND 13.89 0.00 NM ND 14.13 0.00 NM ND 14.02 0.00 NM ND 14.39 0.00 NM ND 13.62 0.00 NM ND 13.47 0.00 NM ND 13.56 0.00 NM ND 14.25 0.00 NM ND 13.17 0.00 NM ND 13.14 0.00 NM ND 14.03 0.00 NM ND 13.46 0.00 NM ND 14.01 0.00 NM ND 13.38 0.00 NM ND 13.75 0.00 NM ND 13.79 0.00 NM ND 13.48 0.00 NM ND 13.42 0.00 NM Notes: 1. Measured in feet relative to site datum 2. Corr. GW Elev. _ (ref. point elevation) - (depth to groundwater) + (LNAPL thickness)(LNAPL specific gravity) 3. LNAPL specific gravity assumed to be 0.73 - Prior to URS' work at this Site, monitoring well MW-3 has previously been reported as MW-2, monitoring well MW-6 has previously been reported as MW-8, and monitoring well MW-8 has previously been reported as MW-6. LNAPL = Light non -aqueous phase liquid ND = Not detected NM = Not measured NS = Not Surveyed TOC = Top of casing btoc = below top of casing - During the May 2003 sampling event LNAPL was observed in MW-5. Depth to groundwater and thickness of LNAPL were not measured. Page 5 of 5 APPENDIX B Laboratory Analytical Report and Chain -of -Custody Record — March 1, 2018 TestAmerica ° THE LEADER IN ENVIRONMENTAL TESTING ANALYTICAL REPORT TestAmerica Laboratories, Inc. TestAmerica Nashville 2960 Foster Creighton Drive Nashville, TN 37204 Tel: (615)726-0177 TestAmerica Job ID: 490-147334-1 TestAmerica SDG: 381 Knollwood Street, Winston-Salem, NC Client Project/Site: BP # 24163 - Winston-Salem, NC ror: ARCADIS U.S., Inc. 801 Corporate Center Drive Suite 300 Raleigh, North Carolina 27607-5073 Attn: Paul Goodell Authorized for release by. 311312018 10:44:38 AM Leah Klingensmith, Senior Project Manager (615)301-5038 leah.klingensmith@testamericainc.com Designee for Jennifer Huckaba, Project Manager II (615)301-5042 jennifer.huckaba@testamericainc.com The test results in this report meet all 2003 NELAC and 2009 TNI requirements for accredited parameters, exceptions are noted in this report. This report may not be reproduced except in full, and with written approval from the laboratory. For questions please contact the Project Manager at the e-mail address or telephone number listed on this page. This report has been electronically signed and authorized by the signatory. Electronic signature is intended to be the legally binding equivalent of a traditionally handwritten signature. Results relate only to the items tested and the sample(s) as received by the laboratory. Client: ARCADIS U.S., Inc. TestAmerica Job ID: 490-147334-1 Project/Site: BP # 24163 - Winston-Salem, NC SDG: 381 Knollwood Street, Winston-Salem, NC Table of Contents CoverPage .............................................. 1 Table of Contents ......................................... 2 Sample Summary ......................................... 3 Case Narrative ........................................... 4 Definitions............................................... 5 Client Sample Results ...................................... 6 QC Sample Results ........................................ 10 QC Association ........................................... 11 Chronicle................................................ 12 Method Summary ......................................... 13 Certification Summary ...................................... 14 Chain of Custody .......................................... 15 TestAmerica Nashville Page 2 of 16 3/13/2018 Sample Summary Client: ARCADIS U.S., Inc. TestAmerica Job ID: 490-147334-1 Project/Site: BP # 24163 - Winston-Salem, NC SDG: 381 Knollwood Street, Winston-Salem, NC Lab Sample ID Client Sample ID Matrix Collected Received 490-147334-1 MW-19 Water 03/01/18 10:15 03/02/18 09:25 490-147334-2 MW-5R Water 03/01/18 10:25 03/02/18 09:25 490-147334-3 MW-18 Water 03/01/18 10:35 03/02/18 09:25 490-147334-4 MW-8R Water 03/01/18 10:45 03/02/18 09:25 TestAmerica Nashville Page 3 of 16 3/13/2018 Case Narrative Client: ARCADIS U.S., Inc. Project/Site: BP # 24163 - Winston-Salem, NC Job ID: 490-147334-1 Laboratory: TestAmerica Nashville Narrative TestAmerica Job ID: 490-147334-1 SDG: 381 Knollwood Street, Winston-Salem, NC 0 Job Narrative 490-147334-1 Comments No additional comments. Receipt The samples were received on 3/2/2018 9:25 AM; the samples arrived in good condition, properly preserved and, where required, on ice. The temperature of the cooler at receipt was 1.91 C. HPLC/IC Method(s) 9056A: The matrix spike / matrix spike duplicate (MS/MSD) recoveries for analytical batch 490-499940 were outside control limits. Sample matrix interference and/or non -homogeneity are suspected because the associated laboratory control sample (LCS) recovery was within acceptance limits. Method(s) 9056A: Due to the nature of the sample matrix, a matrix spike / matrix spike duplicate (MS/MSD) was not analyzed with 490-500159. However, the laboratory control sample / laboratory control sample duplicate (LCS/LCSD) recoveries were within the acceptance limits. No additional analytical or quality issues were noted, other than those described above or in the Definitions/Glossary page. TestAmerica Nashville Page 4 of 16 3/13/2018 Definitions/Glossary Client: ARCADIS U.S., Inc. Project/Site: BP # 24163 - Winston-Salem, NC Glossary Abbreviation a % R CFL CNF DER Dil Fac DL DL, RA, RE, IN DLC EDL LOD LOQ MDA MDC MDL ML NC ND PQL QC RER RL RPD TEF TEQ TestAmerica Job ID: 490-147334-1 SDG: 381 Knollwood Street, Winston-Salem, NC These commonly used abbreviations may or may not be present in this report. Listed under the "D" column to designate that the result is reported on a dry weight basis Percent Recovery Contains Free Liquid Contains No Free Liquid Duplicate Error Ratio (normalized absolute difference) Dilution Factor Detection Limit (DoD/DOE) Indicates a Dilution, Re -analysis, Re -extraction, or additional Initial metals/anion analysis of the sample Decision Level Concentration (Radiochemistry) Estimated Detection Limit (Dioxin) Limit of Detection (DoD/DOE) Limit of Quantitation (DoD/DOE) Minimum Detectable Activity (Radiochemistry) Minimum Detectable Concentration (Radiochemistry) Method Detection Limit Minimum Level (Dioxin) Not Calculated Not Detected at the reporting limit (or MDL or EDL if shown) Practical Quantitation Limit Quality Control Relative Error Ratio (Radiochemistry) Reporting Limit or Requested Limit (Radiochemistry) Relative Percent Difference, a measure of the relative difference between two points Toxicity Equivalent Factor (Dioxin) Toxicity Equivalent Quotient (Dioxin) TestAmerica Nashville Page 5 of 16 3/13/2018 Client Sample Results Client: ARCADIS U.S., Inc. Project/Site: BP # 24163 - Winston-Salem, NC Client Sample ID: MW-19 Date Collected: 03/01/18 10:15 Date Received: 03/02/18 09:25 Method: 9056A - Anions, Ion Chromatography Analyte Result Qualifier RL Sulfate 745 200 TestAmerica Job ID: 490-147334-1 SDG: 381 Knollwood Street, Winston-Salem, NC Lab Sample ID: 490-147334-1 Matrix: Water MDL Unit D Prepared mg/L Analyzed Dil Fac 03/08/1813:46 200 TestAmerica Nashville Page 6 of 16 3/13/2018 Client Sample Results C Client: ARCADIS U.S., Inc. TestAmerica Job ID: 490-147334-1 Project/Site: BP # 24163 - Winston-Salem, NC SDG: 381 Knollwood Street, Winston-Salem, NC Client Sample ID: MW-5R Lab Sample ID: 490-147334-2 Date Collected: 03/01/18 10:25 Matrix: Water Date Received: 03/02/18 09:25 Method: 9056A - Anions, Ion Chromatography Analyte Result Qualifier Sulfate 163 RL MDL Unit D Prepared Analyzed Dil Fac 20.0 mg/L 03/07/1816:29 20 TestAmerica Nashville Page 7 of 16 3/13/2018 Client Sample Results Client: ARCADIS U.S., Inc. Project/Site: BP # 24163 - Winston-Salem, NC Client Sample ID: MW-18 Date Collected: 03/01/18 10:35 Date Received: 03/02/18 09:25 Method: 9056A - Anions, Ion Chromatography Analyte Result Qualifier RL Sulfate 253 50.0 TestAmerica Job ID: 490-147334-1 SDG: 381 Knollwood Street, Winston-Salem, NC Lab Sample ID: 490-147334-3 Matrix: Water MDL Unit D Prepared mg/L Analyzed Dil Fac 03/08/1814:05 50 TestAmerica Nashville Page 8 of 16 3/13/2018 Client Sample Results Client: ARCADIS U.S., Inc. Project/Site: BP # 24163 - Winston-Salem, NC Client Sample ID: MW-8R Date Collected: 03/01/18 10:45 Date Received: 03/02/18 09:25 Method: 9056A - Anions, Ion Chromatography Analyte Result Qualifier RL Sulfate 677 200 TestAmerica Job ID: 490-147334-1 SDG: 381 Knollwood Street, Winston-Salem, NC Lab Sample ID: 490-147334-4 Matrix: Water MDL Unit D Prepared mg/L Analyzed Dil Fac 03/08/1814:24 200 TestAmerica Nashville Page 9 of 16 3/13/2018 QC Sample Results Client: ARCADIS U.S., Inc. Project/Site: BP # 24163 - Winston-Salem, NC Method: 9056A - Anions, Ion Chromatography Lab Sample ID: MB 490-499940/3 Matrix: Water Analysis Batch: 499940 MB MB Analyte Result Qualifier Sulfate ND Lab Sample ID: LCS 490-499940/4 Matrix: Water Analysis Batch: 499940 Analyte Sulfate Lab Sample ID: LCSD 490-499940/5 Matrix: Water Analysis Batch: 499940 Spike Added 5.01 TestAmerica Job ID: 490-147334-1 SDG: 381 Knollwood Street, Winston-Salem, NC Client Sample ID: Method Blank Prep Type: Total/NA RL MDL Unit D Prepared Analyzed Dil Fac 1.00 mg/L 03/07/1814:04 1 Client Sample ID: Lab Control Sample Prep Type: Total/NA LCS LCS %Rec. Result Qualifier Unit D %Rec Limits - - - 5.080 mg/L 101 EM-120 Client Sample ID: Lab Control Sample Dup Prep Type: Total/NA Spike LCSD LCSD %Rec. RPD Analyte Added Result Qualifier Unit D %Rec Limits RPD Limit Sulfate 5.01 4.852 mg/L 97 80 -120 5 20 Lab Sample ID: MB 490-500159/3 Client Sample ID: Method Blank Matrix: Water Prep Type: Total/NA Analysis Batch: 500159 MB MB Analyte Result Qualifier RL MDL Unit D Prepared Analyzed Dil Fac Sulfate ND 1.00 mg/L 03/08/1812:48 1 Lab Sample ID: LCS 490-500159/4 Client Sample ID: Lab Control Sample Matrix: Water Prep Type: Total/NA Analysis Batch: 500159 Analyte Sulfate Lab Sample ID: LCSD 490-50015915 Matrix: Water Analysis Batch: 500159 Analyte Sulfate Spike LCS LCS %Rec. Added Result Qualifier Unit D %Rec Limits 5.01 5.061 mg/L 101 80 -120 Client Sample ID: Lab Control Sample Dup Prep Type: Total/NA Spike LCSD LCSD %Rec. RPD Added Result Qualifier Unit D %Rec Limits RPD Limit 5.01 4.987 mg/L 100 80 -120 1 20 TestAmerica Nashville Page 10 of 16 3/13/2018 QC Association Summary Client: ARCADIS U.S., Inc. Project/Site: BP # 24163 - Winston-Salem, NC HPLC/IC Analysis Batch: 499940 Lab Sample ID Client Sample ID 490-147334-2 MW-5R MB 490-499940/3 Method Blank LCS 490-499940/4 Lab Control Sample LCSD 490-499940/5 Lab Control Sample Dup Analysis Batch: 500159 Lab Sample ID Client Sample ID 490-147334-1 MW-19 490-147334-3 MW-18 490-147334-4 MW-8R MB 490-500159/3 Method Blank LCS 490-500159/4 Lab Control Sample LCSD 490-500159/5 Lab Control Sample Dup TestAmerica Job ID: 490-147334-1 SDG: 381 Knollwood Street, Winston-Salem, NC Prep Type Matrix Method Prep Batch Total/NA Water 9056A Total/NA Water 9056A Total/NA Water 9056A Total/NA Water 9056A Prep Type Matrix Method Prep Batch Total/NA Water _ 9056A ' Total/NA Water 9056A Total/NA Water 9056A Total/NA Water 9056A Total/NA Water 9056A Total/NA Water 9056A TestAmerica Nashville Page 11 of 16 3/13/2018 Client: ARCADIS U.S., Inc. Project/Site: BP # 24163 - Winston-Salem, NC Client Sample ID: MW-19 Date Collected: 03/01/18 10:15 Date Received: 03/02/18 09:25 Lab Chronicle C TestAmerica Job ID: 490-147334-1 SDG: 381 Knollwood Street, Winston-Salem, NC Batch Batch Dil Initial Prep Type Type Method Run Factor Amount Total/NA Analysis 9056A 200 Client Sample ID: MW-5R Date Collected: 03/01/18 10:25 Date Received: 03/02/18 09:25 Batch Batch Dil Initial Prep Type Type Method Run Factor Amount Total/NA Analysis 9056A 20 Client Sample ID: MW-18 Date Collected: 03/01/18 10:35 Date Received: 03/02/18 09:25 Lab Sample ID: 490-147334-1 Matrix: Water Final Batch Prepared Amount Number or Analyzed Analyst Lab 500159 03/08/18 13:46 T1C TAL NSH Lab Sample ID: 490-147334-2 Matrix: Water Final Batch Prepared Amount Number or Analyzed Analyst Lab 499940 03/07/18 16:29 SW1 TAL NSH Lab Sample ID: 490-147334-3 Matrix: Water Batch Batch Dil Initial Final Batch Prepared Prep Type Type Method Run Factor Amount Amount Number or Analyzed Analyst Lab Total/NA Analysis 9056A 50 500159 03/08/18 14:05 T1C TAL NSH Client Sample ID: MW-8R Date Collected: 03/01/18 10:45 Date Received: 03/02/18 09:25 Lab Sample ID: 490-147334-4 Matrix: Water Batch Batch Dil Initial Final Batch Prepared Prep Type Type Method Run Factor Amount Amount Number or Analyzed Analyst Lab Total/NA Analysis 9056A 200 500159 03/08/18 14:24 T1C TAL NSH Laboratory References: TAL NSH = TestAmerica Nashville, 2960 Foster Creighton Drive, Nashville, TN 37204, TEL (615)726-0177 Page 12 of 16 TestAmerica Nashville 3/13/2018 Method Summary C Client: ARCADIS U.S., Inc. TestAmerica Job ID: 490-147334-1 Project/Site: BP # 24163 - Winston-Salem, NC SDG: 381 Knollwood Street, Winston-Salem, NC Method Method Description Protocol Laboratory 9056A Anions, Ion Chromatography SW846 TAL NSH Protocol References: SW846 = "Test Methods For Evaluating Solid Waste, Physical/Chemical Methods", Third Edition, November 1986 And Its Updates. Laboratory References: TAL NSH = TestAmerica Nashville, 2960 Foster Creighton Drive, Nashville, TN 37204, TEL (615)726-0177 TestAmerica Nashville Page 13 of 16 3/13/2018 Accreditation/Certification Summary C Client: ARCADIS U.S., Inc. TestAmerica Job ID: 490-147334-1 Project/Site: BP # 24163 - Winston-Salem, NC SDG: 381 Knollwood Street, Winston-Salem, NC Laboratory: TestAmerica Nashville Unless otherwise noted, all analytes for this laboratory were covered under each accreditation/certification below. Authority Program EPA Region Identification Number Expiration Date North Carolina (WW/SW) State Program 4 387 12-31-18 The following analytes are included in this report, but are not accredited/certified under this accreditation/certification: Analysis Method Prep Method Matrix Analyte 9056A Water Sulfate TestAmerica Nashville Page 14 of 16 3/13/2018 ffw-T� M �W THE LEADER IN ENVIRONMENTAL TESTING 1111111111111111111111 fill 1111111I111111111111111111 IIIIIII11p Nashville, TN COOLER RECEIPT FORM 490-147334 Chain off Custod 11 Cooler Received/Opened On 3/2/2018 @09225 Time Samples Removed From Cooler : �J� Time Samples Placed In Storage (2 Hour Window) 1. Tracking # 1 L C:5 T (last 4 digits, FedEx) Courier: FedEx IR Gun ID_17610176 pH Strip Lot__ Chlorine Strip Lot ) l ° 2. Temperature of rep. sample or temp blank when opened: Degrees Celsius 3. If Item #2 temperature is 0°C or less, was the representative sample or temp blank frozen? YES NO ... NO 4. Were custody seals on outside of cooler? lf�..NOO..'..NA 1 If yes, how many and where: 5. Were the seals intact, signed, and dated correctly? ...NO ... NA 6. Were custody papers inside cooler? ..NO ... NA I certify that I opened the cooler and answered questions 1-6 (intial)✓"' 7. Were custody seals on containers: YES NO and Intact YES ... NO... 16A Were these signed and dated correctly? YES ... NO...e 8. Packing mat'I used? Dle-ra Plastic bag Peanuts Vermiculite Foam Insert Paper Other None 9. Cooling process: Ice Ice -pack Ice (direct contact) Dry ice Other None 10. Did all containers arrive in good condition (unbroken)?GE ... NO ... NA 11. Were all container labels complete (#, date, signed, pres., etc)? IQ ... NO...NA 12. Did all container labels and tags agree with custody papers? YE ...NO...NA 13a. Were VOA vials received? YES.. NO ..NA b. Was there any observable headspace present in any VOA vial? YES ... NO.. NA ® 40 Larger than this. 14. Was there a Trip Blank in this cooler? YES .9..NA If multiple coolers, sequence # 1 certify that I unloaded the cooler and answered questions 7-14 (intial) O'r� 15a. On pres'd bottles, did pH test strips suggest preservation reached the correct pH level? YES ... NO.-Q b. Did the bottle labels indicate that the correct preservatives were used 'E ...NO...NA 16. Was residual chlorine present? YES... NO. N® 1 certify that 1 checked for chlorine and pH as per SOP and answered questions 15-16 (intial) ,r_6r 17. Were custody papers properly filled out (ink, signed, etc)? YES...NO...NA 18. Did you sign the custody papers in the appropriate place? )0 ... NO...NA 19. Were correct containers used for the analysis requested? 1�E ... NO ... NA 20. Was sufficient amount of sample sent in each container? (�E ... NO ... NA I certify that I entered this project into LIMS and answered questions 17-20 (intial) certify that I attached a label with the unique LIMS number to each container (intial) r-,4 -'Lf- 21. Were there Non -Conformance issues at login? YES. 0 Was a NCM generated? YES... ...# BIS = Broken in shipment Cooler Receipt Form.doc LF-I Revised 8/23/17 End of Fonn Page 15 of 16 3/13/2018 1 w W N O TestAmerica Nashville Loc: 490 2960 Foster Creighton Drive 147334 NashvillE, TN 37204 Phone (615) 726-0177 Fax (615) 726-3404 Chain of Custody Record Test medca THE 6 @ADER IN FNVIRONMFYTA„ T65nING mpler: '/V' C.tL Lab PM: Carrier Tracking No(s): COC No: Client Information 2�s (r Huckaba, Jennifer 490-81073-18478.1 Client Contact: ine: p 04, 3aa 3 e E-Mail: Page: Alex Sim oson o 7 ( )ennifer.huckaba@testamericainc.com Page 1 of 1 Company: Job #: ARCADIS U.S., Inc. Analysis Requested Address: Due Date Requested: (� a Preservation Codes: 801 Corporate Center Drive Suite 300 S t(3171( a. r� A- HCL M-Hexane B - NaOH N -None City: TAT Requested (days):" Raleigh /E O C - Zn Acetate O - AsNa02 d DE- State, Zip: / �I 2y„ NarHSO4ic NC, 27667-5073 J ' '.'• . '' 0 - Na204S F - McOH R - Na2S203 G - Amchlor S - H2SO4 Phone. PO #: 919-415-2299(Tel) Purchase Order not required a; ? o' 'mi"`.. Y m o � - P•` ,- ;; B � Q j' H- Ascorbic Acid T- TSPDodecahydrate I -Ice U -Acetone J-DlWater v-MCAA K -EDTA W - pH 4-5 L - EDA Z -other (specify) Uther: Email: alexandra.simpson@arcadis-us.com WO #: Project Name: BP # 24163 - Winston-Salem, NC Project #: 49011104 Site: SSOW#: 381 Knollwood Street, Winston-Salem, NC ::' M �t Q Sample Matrix Type o Sample,t'. (w wa�,s olm. ,i'-' Sample Identification Sample Date Time G=grab) aT=rls:�e,ha. um.`'' Special Instructions/Note: ;:; Preselatronodri ., : �, 0i-/tS joI.] 9 Water 1N:/ /Q 1bh /g L� Watai- 9v Water N Vo Water f{,a 'P: Water Water Possible Hazard Identification Sample Disposal (A fee maybe ssessed if samples are retained longer than f month) 0 Flammable Skin irritant O Poison B 0 Unknown Non 'Z -Hazard Radiological Return To Client isposal By Lab Archive For Nonths Deliverable Requested: I, II, III, IV, Other (specify) Special Instructions/QC Requirements: Empty Kit Relinquished by: Date- Time: Method of Shipment: Relinquishec by: fb IJ Date/Time, ®3_nl' i a� Company , e'eci, � t�ceiv�e�i yJ:� I ` 7�0 S3 8� t � ©� Date/Time: ; �,�1.1 � %� �s Company FcJ FA Relinquishec by: DateRme: Company R eived by: _ Date i Company � 0021� (1q<25 -rA -WAS Relinquishec by: Date/rime: Company Received by: Date/Tme: Company Custody Seals Intact: Custody Seal No.: Cooler Temperature(s) `C and Other Remarks: j /1 "l A Yes A No ` , 00 Ver: 08/04/2016 APPENDIX C Historical Groundwater Analytical Data Appendix C Historical Groundwater Analytical Summary Former BP Service Station No. 24163 381 Knollwood Street Winston-Salem, Forsyth County, North Carolina end �i/aRCJaDIS prsign&Cansi[ancy Poriiahirel auiltasSeK NC GCL: NC 2L Units: 5,000 1 Ng/I 84,500 600 Ng/I 260,000 600 Ng/I 85,500 500 Ng/I 20,000 20 Ng/I NE 250 mg/I NE NE mg/I 5/13/2003 8.5 0.98 J 0.61 J 1.7 J 8 12/9/2003 47.4 14.3 1.9 8.1 37.3 3/23/2006 4.5 J < 0.5 < 0.5 UJ < 1 UJ 5.5 5/8/2007 40.4 3.7 1.4 2 J 13.1 5/14/2008 4.3 J < 0.8 < 0.7 < 0.8 14 5/28/2009 5.4 0.44 J 0.14 J 0.49 J 5.6 5/27/2010 0.44 J < 0.11 0.3 J < 0.32 4.8 10/31 /2011 5.5 0.76 < 0.17 U 0.38 J 19.1 8.4 405 5/22/2012 < 0.43 U < 0.2 < 0.2 < 0.52 4.6 15.3 378 6/14/2012 12.1 6.7 0.72 4.7 15.4 6.6 J 344 7/9/2012 2.2 1.6 2.6 3 14.7 9.9 393 MW-3 8/14/2012 2 2.1 < 0.13 0.4 J 17.9 3.6 303 9/19/2012 2.7 0.66 < 0.13 0.33 J 19.8 2.8 459 12/5/2012 11.3 1.2 0.43 J 1.11 19.3 0.78 J 377 2/26/2013 0.23 J < 0.1 < 0.1 < 0.22 5.4 32.6 338 5/31 /2013 0.32 J < 0.1 < 0.1 < 0.22 10.5 17.9 334 8/28/2013 3.6 0.53 0.12 J 0.31 J 10.3 21.9 457 11 /7/2013 4.3 0.27 J 0.13 J < 0.22 10 21.7 536 2/27/2014 < 0.1 < 0.1 < 0.1 < 0.2 1.3 42.2 198 6/3/2014 0.48 J 0.15 J < 0.1 < 0.2 3.1 10/16/2014 18.0 372 4/23/2015 22.8 296 9/19/2016 21.3 3/23/2006 11,700 2,440 32,000 13,500 16,100 3/23/2006 (1) 11,000 2,370 30,700 13,200 15,400 5/8/2007 7,410 1,590 21,100 8,920 8,830 5/8/2007 (1) 7,400 1,680 20,100 9,290 9,360 MW-5 5/14/2008 10,000 2,100 29,000 12,000 18,000 5/14/2008 (1) 10,000 2,100 30,000 12,000 18,000 5/28/2009 7,390 2,330 25,700 13,400 6,920 5/28/2009 (1) 6,510 2,240 22,100 12,900 6,510 5/27/2010 6,610 2,810 24,300 J 15,700 4,330 5/27/2010 (1) 6,090 4 2,380 30,100 J 13,300 4,250 10/31/2611 7,960 2,660 28,000 13,800 3,830 < 1 < 5 10/31/2011 (1) 8,360 2,870 24,600 14,800 4,070 5/22/2012 7,980 3,470 32,200 19,200 3,820 < 5 179 6/15/2012 (2) i 244 227 1,190 1,120 36.9 6,070 1,820 7/9/2012 336 J 481 J 2,010 J 2,400 J 48.4 J 6,470 2,620 MW-5R 8/14/2012 201 283 1,050 1,300 48.5 14,700 4,190 9/19/2012 158 181 650 883 114 19,000 3,280 12/5/2012 754 505 2,220 2,380 1,160 13,600 1,840 2/26/2013 1,360 878 3,520 3,940 1,660 8,520 1,530 5/31/2013 1,410 1,380 5,930 6,220 1,150 J 4,680 1,560 8/28/2013 165 178 489 1,380 417 13,900 1,590 11/7/2013 214 131 331 969 651 14,400 1,570 2/27/2014 142 177 328 1.060 240 2,990 807 Page 1 of 4 Appendix C Historical Groundwater Analytical Summary Former BP Service Station No. 24163 381 Knollwood Street Winston-Salem, Forsyth County, North Carolina end �i/aRCJaDIS prsign&Cansi[ancy Poriiahirel auiltasSeK NC GCL: NC 2L Units: 5,000 1 Ng/I 84,500 600 Ng/I 260,000 600 Ng/I 85,500 500 Ng/I 20,000 20 Ng/I NE 250 mg/I NE NE mg/I 6/2/2014 256 436 1040 2520 519 J 10/16/2014 9,950 1,390 4/23/2015 5,980 1,510 10/13/2015 5,790 MW-5R 4/28/2016 2,980 9/19/2016 2,880 3/3/2017 3,570 9/20/2017 1,060 3/1 /2018 163 5/12/2003 < 0.5 0.52 J < 0.5 < 1 3 12/9/2003 2.3 0.64 J 1.1 3.6 17.6 12/9/2003 2.4 0.68 J 1.1 3.8 18 3/23/2006 0.76 J 0.59 J 3.6 2.8 J 1.1 5/8/2007 < 0.5 < 0.5 < 0.5 < 1 < 0.5 MW-6 5/14/2008 < 0.5 < 0.8 < 0.7 < 0.8 < 0.5 5/28/2009 < 0.06 < 0.05 < 0.06 < 0.14 0.17 J 5/27/2010 < 0.11 0.13 J 0.38 J 0.46 J < 0.12 10/31/2011 8.7 J 11.7 J 27.5 J 132 J < 0.26 UJ 131 2,130 6/2/2014 17.6 J 59.4 J 31.6 J 99.4 J 783 J 5/12/2003 < 0.5 < 0.5 < 0.5 1.1 J < 0.5 12/9/2003 < 2.5 < 2.5 < 2.5 < 5 < 2.5 3/23/2006 49.7 18.9 48.7 443 3,560 5/8/2007 < 25 < 25 < 25 < 50 6,910 MW-61 5/14/2008 5.2 J < 2 < 1.8 < 2 3,400 5/28/2009 2.5 < 0.05 < 0.06 < 0.14 1,150 5/27/2010 1.6 J < 1.1 < 1.1 < 3.2 492 10/31/2011 0.41 J < 0.36 < 0.32 < 0.75 122 < 1 76.1 6/2/2014 < 0.1 < 0.1 < 0.1 < 0.2 3.3 3/23/2006 671 1,340 1,230 8,100 124 5/8/2007 1,160 799 196 2,990 1,440 MW 8 5/14/2008 600 1,800 700 3,000 190 5/28/2009 1,390 2,050 357 3,310 1,560 5/27/2010 8,570 2,870 31,700 15,700 6,260 10/31/2011 8,000 3,180 32,100 17,200 3,170 < 1 < 5 5/22/2012 8,270 3,360 36,400 J 17,800 3,920 < 5 119 6/15/2012 (2) 726 47 J 760 242 J 96.3 J 4,760 22,200 7/9/2012 4,540 J 1,870 J 17,100 J 10,800 J 1,530 J 6,570 4,500 8/14/2012 4,370 1,610 19,300 8,780 2,000 7,010 1,560 9/19/2012 4,780 1,800 20,900 10,400 2,600 6,700 1,100 12/5/2012 7,760 2,440 31,900 13,800 4,560 2,410 635 2/26/2013 7,310 2,480 30,500 13,400 4,530 959 590 5/31/2013 6,540 ' 3,040 30,500 12,500 4,200 439 437 8/26/2013 1,600 628 5,390 3,990 1,380 4,770 703 MW-8R 11/7/2013 1,130 329 2,440 1,830 1,770 7,460 766 2/27/2014 1,020 603 3,200 3,430 1,190 7,670 940 6/2/2014 1,360 J 680 J 3,510 J 3,330 J 2,110 J 6/2/2014 (1) 1,540 556 J 3,650 2,630 J 2,640 J 10/16/2014 3,310 883 9,070 4,940 3,910 3,560 842 4/23/2015 2,050 812 10/13/2015 _ 1,600 4/29/2016 _ 1,640 9/19/2016 1,330 3/3/2017 1,720 9/20/2017 - 797 3/1/2018 677 5/12/2003 < 0.5 < 0.5 < 0.5 < 1 0.52 J 12/9/2003 < 0.5 < 0.5 < 0.5 < 1 5.9 3/23/2006 < 0.5 < 0.5 < 0.5 < 1 < 0.5 5/8/2007 < 0.5 < 0.5 < 0.5 < 1 < 0.5 MW-14 5/14/2008 < 0.5 < 0.8 < 0.7 < 0.8 < 0.5 5/28/2009 < 0.06 < 0.05 0.077 J < 0.14 < 0.06 5/27/2010 < 0.11 < 0.11 < 0.11 < 0.32 < 0.12 10/31/2011 <0.13 <0.15 <0.42U <0.3 <0.13 43.2 <5 6/3/2014 < 0.1 < 0.1 < 0.1 < 0.2 < 0.1 Page 2 of 4 Appendix C Historical Groundwater Analytical Summary Former BP Service Station No. 24163 381 Knollwood Street Winston-Salem, Forsyth County, North Carolina end �i/aRCJaDIS prsign&Cansi[ancy Poriiahirel auiltasSeK NC GCL: 5,000 84,500 260,000 85,500 20,000 NE NE NC 2L 1 600 600 500 20 250 NE Units: Ng/I Ng/I Ng/I Ng/I Ng/I mg/I mg/I 3/23/2006 0.63 J 2.1 < 0.5 18.6 1.6 5/8/2007 < 0.5 < 0.5 < 0.5 2.2 J < 0.5 5/14/2008 <0.5 <0.8 <0.7 3.7J <0.5 MW-15 5/27/2010 < 0.11 < 0.11 < 0.11 < 0.32 < 0.12 10/31/2011 <0.13 <0.15 <0.13 <0.3 <0.13 <1 <5 6/3/2014 <0.1 <0.1 <0.1 <0.2 <0.1 10/16/2014 <0.1 <0.1 <0.1 <0.2 <0.1 3/23/2006 < 2.5 90.8 15.8 836 2.8 J 5/14/2008 < 0.5 160 15 1,600 4.1 J 5/27/2010 3.6 54.7 J 5.1 525 J 1.3 MW-16 10/31/2011 < 0.65 17.2 < 1.4 U 321 < 0.65 194 < 5 11 /7/2013 -- -- -- -- 55.4 < 5 6/3/2014 < 0.1 25 0.92 417 J < 0.1 5/13/2003 57.7 < 0.5 < 0.5 < 1 69 5/13/2003 40.8 < 0.5 < 0.5 < 1 63.3 12/9/2003 6.6 0.65 J < 0.5 < 1 80.6 3/23/2006 1 < 0.5 < 0.5 < 1 58.9 5/8/2007 < 0.5 < 0.5 < 0.5 < 1 17.4 MW-17 5/14/2008 3.7 J < 0.8 < 0.7 < 0.8 19 5/28/2009 7 < 0.05 0.076 J < 0.14 14.5 5/27/2010 5.7 < 0.11 < 0.11 < 0.32 12.4 10/31/2011 0.51 0.16 J < 0.81 U 0.57 J 8.9 < 1 422 6/3/2014 < 0.1 < 0.1 < 0.1 < 0.2 4.1 10/31/2011 3,140 998 11,100 8,950 1,140 8.2 446 5/22/2012 2,280 2,790 18,200 12,000 789 < 5 307 6/15/2012 (2) 373 910 4,800 3,910 114 10,600 3,410 7/9/2012 1,730 J 2,170 J 15,000 J 9,750 J 676 J 2,300 835 8/14/2012 3,020 2,990 24,400 12,800 1,090 758 580 9/19/2012 3,190 3,090 22,600 14,000 1,240 322 542 12/5/2012 3,370 2,970 20,100 12,800 1,380 32 436 2126I2013 2,510 2,970 10,100 8,690 1,140 13.8 500 5/31/2013 2,780 3,070 8,210 5,740 1,000 83.3 475 8/28/2013 182 368 730 1,660 139 7,850 2,230 MW-18 11/7/2013 1,140 727 4,910 3,250 694 2,640 1,370 2/27/2014 16.6 109 20.2 45.8 18.5 4,310 1,270 6/2/2014 26.2 J 125 J 37.5 J 31.6 J 37.4 J 10/16/2014 359 388 244 138 364 1,540 513 4/23/2015 780 1,100 10/13/2015 516 4/29/2016 79.4 9/19/2016 377 3/3/2017 295 9/20/2017 _ -- 257 3/1/2018 _-- 253 Page 3 of 4 Appendix C Historical Groundwater Analytical Summary Former BP Service Station No. 24163 381 Knollwood Street Winston-Salem, Forsyth County, North Carolina �i/aRCJaDIS prsign&Cansi[ancy Poriiahirelend auiltasSeK NC GCL: NC 2L Units: 5,000 1 pg/I 84,500 600 pg/I 260,000 600 pg/I 85,500 500 pg/I 20,000 20 pg/I NE 250 mg/I NE NE mg/I 10/31/2011 2,390 1,380 8,790 7,040 5,160 3.7 425 5/22/2012 2,700 1,560 14,200 7,940 4,880 <5 310 6/15/2012 (2) 4,020 1,440 18,200 7,940 3,290 1,090 6,520 7/9/2012 2,910 30,400 J 16,300 5,330 232 991 8/14/2012 2,420 1,650 14,200 8,370 4,090 469 1,080 9/19/2012 2,090 1,630 12,900 8,640 3,960 260 690 12/5/2012 2,320 1,810 15,200 10,400 4,010 58.8 588 2/26/2013 2,210 1,110 10,600 6,990 3,890 169 503 5/31/2013 1,830 894 8,820 5,250 3,120 1,530 606 8/28/2013 2,710 J 1,190 J 13,100 7,420 J 3,240 J 2,660 525 MW-19 11/7/2013 2,020 984 9,850 5,620 2,260 2,890 255 2/27/2014 2,550 1,400 10,900 7,880 3,320 2,790 322 6/2/2014 2,370 1,260 11,900 7,260 2,830 10/16/2014 2,340 632 4/23/2015 2,540 514 10/13/2015 1,960 4/28/2016 1,780 9/19/2016 1,270 3/3/2017 941 9/20/2017 1,020 3/1/2018 745 Notes: (1) Field duplicate (�)Alkalinity, sulfate, and carbon dioxide samples were collected 6/14/2012 and volatile organic analysis samples were collected 6/15/12. - Not sampled or analyzed < - Not detected at the specified detection limit pg/I - Micrograms per Liter GCL - Gross Contamination Level 2L - North Carolina Groundwater Quality (2L) Standard J - Estimated value mg/I - Milligrams per Liter MTBE - Methyl tert-Butyl Ether NE - Not established U - Not present above the associated level; blank contamination exists UJ - Not detected and the detection limit is estimated BOLD text indicates 2L exceedance ]Bold cell with green highlight indicates GCL exceedence Activated sodium persulfate injections were performed at the site from June 4, 2012, to June 9, 2012, and from June 3, 2013, to June 6, 2013. Page 4 of 4 04ARCADIS5deign&Consultancy for naturaland built assets Arcadis U.S., Inc. 111-D Sanders Lane Bluefield, Virginia 24605 Tel 276 322 3879 Fax 276 322 3946 www.arcadis.com