Occurrence of DDA in DDT-contaminated sediments of the Southern California Bight

► DDA, a water-soluble DDT metabolite, occurs in DDT-contaminated sediments. ► DDA levels occurred only at wastewater outfalls where DDT levels were present. ► DDA is missed by usual environmental monitoring procedures for DDT contamination. ► DDA may occur naturally in the recovery of DDT-contaminated sediments.