4903_IredellCoMSWLF_April2024_14_DayExceedanceNotification_FID1834255_20240416

April 15, 2024

Mr. Erin Lane Solid Waste Section (SWS) Division of Waste Management North Carolina Department of Environmental Quality (NCDEQ) 217 W. Jones St. Raleigh, NC 27699
Re: 14-Day Notification of an Exceedance of Vinyl Chloride in MW-17 Iredell County Lined Landfill, Phase 3&4 Sample Date: March 20, 2024 Lab Results Date:April 4, 2024 Permit No. 49-03
Dear Mr. Lane:
During the latest semi-annual water quality monitoring event performed at the Iredell County Lined Landfill Phase 3&4 a concentration of vinyl chloride was found in sample MW-17 (1 ug/L) which is above the 2L groundwater protection standard (0.03 μg/L). Since this is the first time that vinyl chloride has been detected in MW-17 above the reporting limit and 2L Standard a 14-Day notification form with a detections table is attached. MW-17 is located hydraulically upgradient of the landfill and serves as a background well. The preliminary transport mechanism of vinyl chloride is believed to be landfill gas. The active Gas Control & Collection System
(GCCS) proximal to MW-17 will be evaluated in an effort to reduce fugitive emissions. The full Semi-Annual Water Quality Monitoring Report for this Spring 2024 event is planned to be submitted prior to the 120-day deadline. The site was in assessment monitoring in August 2017 and 2018 in response to VOC violations in MW-21S. Assessment monitoring is not planned to be reinstituted in response to this premier violation and water will be tested again in September 2024. If you have any questions or concerns regarding this project, please contact us by phone at [phone] or by email at [e-mail].
Sincerely, MUNICIPAL ENGINEERING INC.
Jonathan Pfohl Environmental Specialist
cc: Mr. Teddy Boller Iredell County Solid Waste Director

Shipwash Drive ● Garner, NC 27529 ● ph: 919-772-5393 ● fx: 919-772-1176 ● www.mesco.com
Table 1
Groundwater, Leachate and Quality Control Sample Detections
March 20 & 22, 2024
2L STANDARD MW-17 MW-18 MW-19SR MW-19D MW-21S MW-21D MW-27S MW-27D MW-28 MW-29 MW-30 FORCEMAIN EB FB
Antimony, total 1 2 1 6 8.9 --Arsenic, total 0.5 1 10 10 1.1 1.1 1.8 1.3 39.9 --Barium, total 0.5 1 700 2000 51.2 35.8 192 1.2 135 9.4 145 43.9 10.6 32.2 57.8 599 --Beryllium, total 0.033 0.1 4 4 0.21 0.074 J 0.074 J 0.5 0.17 0.53 0.04 J --Cadmium, total 0.067 0.1 6*5 0.078 J 0.34 0.21 0.16 0.38 0.41 0.13 0.096 J --Chromium, total 0.5 1 66*100 3.5 2.3 1.9 3.9 8.5 2 2.7 58.7 --Cobalt, total 0.24 1 22*NE 0.95 J 0.27 J 1.4 3.3 1.5 0.25 J 2.7 13.1 --
Copper, total 0.42 1 1000 1300 1.4 5.9 1.2 0.77 J 5.6 0.95 J 0.5 J 2.1 116 --
Lead, total 0.22 1 15 15 1.1 0.43 J 2.4 6.6 --
Nickel, total 0.26 1 100 NE 2.2 1.3 7.1 2.5 0.45 J 3.8 0.38 J 0.81 J 4.6 94.8 --
Selenium, total 0.2 2 20 50 0.58 J 0.77 J 0.24 J 0.72 J --
Thallium, total 0.11 1 2 2 0.18 J 0.72 J --
Vanadium, total 0.91 1 89*NE 2.3 14.6 1.5 2.1 7 1.9 1.5 14 --
Zinc, total 6.7 10 1000 NE 10 7.2 J 8.6 J 7.7 J 102 --
1,1-Dichloroethane 0.37 1 6 NE 0.98 J
1,4-Dichlorobenzene 0.33 1 6 75 0.66 J
1,4-Dioxane 8.6/38.7 20/150 3 NE <38.7 <38.7 <38.7 <38.7 <38.7 <38.7 <38.7 <38.7 <38.7 <38.7 <38.7 1182-Butanone (MEK)39.6 50 4000 NE 1140
4-Methyl-2-pentanone 2.7 5
1.6 8.4
1.3
1
PH (Field) (SU)0.1 0.1
Notes:
Bold Above RL and Established 2L/SMAC recognized by NC SWS as regulatory groundwater compliance value
Highlighted Above Established MCL Drinking Water Std. (No regulatory significance)
U= Well Upgradient, D = Well Downgradient, QC = Quality Control Sample
MDL = Adjusted Method Detection Limit established by the laboratory via a statistical calculation.
Since the MDL is below the point of calibration, results reported down to the MDL are not reliable and must be qualified as estimated values and, as such, carry a "J" qualifier designation.
2L = NC 2L Groundater Standard 15A NCAC 02L .0202
*SMAC = Site Maximum Allowable Concentration (Approved by NCDEQ via ASD in 2020)
MCL = Maximum Contaminant Level for drinking water established by the USEPA.
J = "J-qualified". Defined by the lab as "estimated concentration above the adjusted method detection limit and below the adjusted reporting limit".
Preliminary source of standard violations is believed to be anthropogenic with Landfill Gas as suspected transport mechanism. A definitive source of the detections was not determined as part of this report.
Leachate Parameters
Outside Historically Observed Range
Parameter Name MDL RL MCL
Iredell County Lined Landfill, Phases 3 & 4 Page 1 of 1