In recent years, problems related to the adequacy of existing water resources have arisen due to issues such as population growth, rapid urbanization, industrialization, and climate change. Especially in agricultural production where water is used the most, the use of wastewater has become widespread as a solution to this problem. Considering that wastewater may harm the environment due to the substances it contains, it is aimed to make an environmental valuation in this study. In this context, by using the travel cost method used in the valuation of goods without a market, a different approach was brought to this method, as agricultural production is concerned, and an evaluation was made based on producer surplus. In the study, by comparing the agricultural productions with wastewater and well water, 2 hypotheses have been developed about the environmental valuation of wastewater; First, if the producer surplus of agricultural production with wastewater is lower than that of production with well water, there is environmental pollution, and its value is the difference between the two rents. The second hypothesis is that if the producer's surplus with wastewater is high, positive externality will occur as a hypothesis against the negative effects of environmental pollution. By conducting a survey with 125 producers in the research area, the data of 314 parcels in total were included in the analysis, and the producer surplus was calculated by creating the supply function with the regression analysis. As a result of the research, the producer surplus (584.40$) obtained from the agricultural production made by irrigating with wastewater was found to be higher than the producer surplus (553.44$) of the production made by irrigating with well water. In this case, it was concluded that the wastewater irrigated did not affect the environmental pollution, but the positive externality. Although the use of wastewater in agricultural production has made a positive contribution to the economy, it will be beneficial to use it after the necessary treatment processes, considering its harmful effects on human health.