AbstractA process has been developed for removing nitrates and heavy metals from open ponds. Four ponds were treated using the developed process. The process steps involved neutralization of the ponds, followed by biological denitrification. The nitrate ions were reduced from 40,000 mg/L to<50 mg/L at an average denitrification decrease rate of 300 mg/L per day. The denitrified water was then flocculated and filtered to remove solids. The water quality met discharge water chemical limits as well as biological test requirements.