RA-6716_33873_CA_HRE_20221128_Determination WSW 28

November 28, 2022 TO: Mark Petermann NC UST Section
RE: Health Risk Evaluation Incident # 33873 Brenda Gregory Well Sampling Results 5813 Cheek Road
Durham, NC During this sampling event, one contaminant was 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 the contaminant concentration exceeds the applicable standard for using the water for drinking and cooking, the contaminant concentration is 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 concentration with the applicable standard: Sample ID Contaminant Concentration (µg/L) MCL (µg/L) 2L (µg/L)
22K1817-08 Methyl tert-Butyl Ether 0.20 20
µg/L – Stands for micrograms of contaminant per liter of water and is roughly equivalent to parts per
billion.
RECOMMENDATION: The detected contaminant did not exceed the applicable water standard. Therefore, no restrictions on the use of this water are recommended at this time.

David Lilley, Environmental Toxicologist Division of Waste Management, NCDEQ