Description: The purpose of this project was to design and construct a passive treatment system to abate the iron and acidity loadings to the impacted UNT to Clearfield Creek. The pH of this discharge ranged from 5.7 to 6.5. Acidity ranged from 18 to 94 mg/L, and alkalinity ranged from 20 to 54 mg/L. The specific conductance ranged from 810 to 1470 umhos/cm. Aluminum ranged from 0.06 to 0.33 mg/L. Iron ranged from 12.9 to 54.5 mg/L, manganese ranged from 12.5 to 30.8 mg/L, and sulfates ranged from 397 to 904 mg/L. The average total discharge was 60 gpm and the average metal load was 252,000 g/day. This project was for the design and permitting of the passive treatment system to treat the Dimeling Discharge. The design consists of an equalization basin, sulfate reducing bioreactor, and settling basin as well as a relocated channel to route upslope runoff around the treatment system.