Runoff from fertilizer and manure application in agricultural regions has led to high levels of nitrate in groundwater, rivers, and coastal areas. These high nitrate levels can threaten drinking water safety and also lead to problems with algal blooms and degradation of aquatic ecosystems. Previous research has shown that wetlands improve water quality, but how much of an impact are wetlands having on nitrate removal now, and what improvements could wetland restoration deliver in the future?