The Opequon watershed is located in northern Virginia (VA) and the eastern panhandle of West Virginia (WV). In both states, Opequon Creek is classified as impaired based on violations of bacteria, benthic and biologic standards. Both VA and WV are using Total Maximum Daily Load (TMDL) plans to improve water quality within Opequon Creek. However, these TMDL plans are at different stages with VA being completed and WV still in progress. As part of the TMDL process in VA, this research is based on a contingent valuation survey which was developed to measure the expected monetary benefits of TMDL implementation throughout the Opequon watershed. On the basis of log-likelihood tests of grouped tobit models to explain willingness-to-pay (WTP) for watershed clean-up, VA, WV, and VA riparian landowner respondents were found to consist of different populations. Riparian landowners had the highest median annual WTP at $64, VA respondents the next highest ($49), and WV the lowest ($32). These medians were found to be statistically different from each other. When valuing out-of-state clean-up, however, VA and WV respondents were found to be similar populations with a one-time median WTP of $28. Results show that the TMDL process did impact VA respondent WTP for in-state clean-up.