A constructed wetland in Pocatello, Idaho is being used to clean up urban stormwater before it reaches the Portneuf River. The wetland is expected to reduce runoff by 37 to 105 meters per day through infiltration. Evaporation in the summer can account for 30% to 84% of the infiltration rates. Over time, infiltration rates are expected to decrease due to sediment buildup. All water infiltrating the wetland is likely to recharge the groundwater. Water samples collected show high levels of copper, zinc, and lead, which exceed EPA freshwater toxic criteria.