WS-8622_37884_CA_HRE_20230110_SW1

January 10, 2023

TO: Ashley Dinkins
Guilford County Department of Health and Human Services for
Winston-Salem Regional Office
NC UST Section
RE: Health Risk Evaluation
Incident # 37884
Stop & Shop, Inc. Well Sampling Results
801 NC Highway 62 West
Greensboro, NC

During this sampling event, eight contaminants were detected in the well water. The standards
used to determine if the water is suitable for drinking and cooking are the United States Environmental
Protection Agency’s Maximum Contaminant Levels (MCLs) or, if no MCLs exist, North Carolina
Groundwater Standards (2L).

If contaminant concentrations exceed the applicable standards for using the water for drinking
and cooking, the contaminant concentrations are further analyzed to determine if the water is suitable for
other household uses, such as showering, bathing, washing dishes, flushing toilets, and hand washing.
The chart below compares the detected contaminant concentrations with the applicable standard:

Sample ID Contaminant Concentration (µg/L) MCL (µg/L) 2L (µg/L)
95180 Benzene 10.7 5
Chloroform 4.11 80*
Methylene Chloride 0.538 5
Methyl-tert-butyl ether 2.88 20
Naphthalene 4.48 6
n-Propylbenzene 0.220 70
tert-Butyl Alcohol 7.16 10**
tert-Amyl Alcohol 54.7 NA NA
Shaded boxes indicate a standard has been exceeded.
NA – Not Available
µg/L – Stands for micrograms of contaminant per liter of water and is roughly equivalent to parts per
billion.

* As total trihalomethanes.

** This value is an Interim Maximum Allowable Concentration (IMAC).

RECOMMENDATION: The benzene concentration exceeds the applicable standard, and the
total risk exceeds the level that would be considered safe for other household uses. Therefore, this water
is not recommended for any residential use at this time.
David Lilley, Environmental Toxicologist
Division of Waste Management, NCDEQ