The purpose of the study was to generate laboratory data to support the development of wastewater discharge standards for ammonia in nonferrous metal winning processes. The objective was accomplished by studying ammonia removal from synthetically compounded 'wastewater' samples using a bench-scale steam stripping apparatus. Although no significant variation of mass transfer rate coefficient (K) was observed when SO4(-2) concentrations were varied from 5,000 to 20,000 mg/L, K was the highest for low SO4(-2) wastewaters when pH was adjusted using NaOH. Results of the steam stripping study indicated that varying chemical constituents such as SO4(-2) and the molal strength did not have a significant effect on the efficiency of ammonia removal.