IMAC Table January 2024

Effective Date: April 1, 2022 Table Updated November 4, 2022; January 18, 2024
Appendix: Groundwater Interim Maximum Allowable Concentrations (IMACs)
Substance Concentration (µg/L)
Ammonia 1,500
Bentazon 200
Benzaldehyde 700
Boscalid 2,000
tert-Butanol (tert-butyl alcohol) 10
Carbazole 2
Dibenzofuran 28
Dibromomethane 70
1,2-Dichloroethylene, mixed isomers 60
Ethanol (ethyl alcohol) 4,000
Ethyl tert-butyl ether (ETBE) 47
Fluometuron 90
Metolachlor 700
Perchlorate & Perchlorate Salts 2
Picramic Acid 0.7
Polychlorinated Biphenyls 0.09
Tert-Amyl Methyl Ether (TAME) 128
Tetrahydrofuran 2,000
p-Toluic Acid 35
Vinyl Acetate 88
Interim Maximum Allowable Concentrations (IMACs) shown in the table below are those established under 15A NCAC 02L .0202. For more information, visit: https://deq.nc.gov/about/divisions/water-resources/planning/classification-standards