Nitrates in drinking water, which may come from nitrogen fertilizers applied to crops, are a potential health risk. This report evaluates the potential benefits of reducing human exposure to nitrates in the drinking water supply. In a survey, respondents were asked a series of questions about their willingness to pay for a hypothetical water filter, which would reduce their risk of nitrate exposure. If nitrates in the respondent's drinking water were to exceed the EPA minimum safety standard, they would be willing to pay $45 to $60, per household, per month, to reduce nitrates in their drinking water to the minimum safety standard. There are 2.9 million households in the four regions studied (White River area of Indiana, Central Nebraska, Lower Susquehanna, and Mid-Columbia Basin in Washington). If all households potentially at risk were protected from excessive nitrates in drinking water the estimated benefits would be $350 million.