Acetochlor ESA
IUPAC Name: 2-[N-(ethoxymethyl)-2-ethyl-6-methylanilino]-2-oxoethanesulfonic acid
Source: Occurs as an environmental transformation product of acetochlor.
Water Treatment: https://tdb.epa.gov/tdb/contaminant?id=10660
Summary: Acetochlor ESA (ESA stands for ethanesulfonic acid) is an environmental transformation product of the herbicide acetochlor.