Introduction: Over recent years, environmental sustainability, agriculture and food security have been among the most important topics of global attention. Sustainability is based on economic, social and ecological factors. Sustainable agriculture requires a sustainable environment. Therefore, the main agricultural factors are soil, weather, water resources and nutrients, among which the protection of water and soil resources is more important than others for the efficiency of farmers. Although, water resources are essential for the functioning of any economy, they continue to be degraded at an unsustainable rate. This is true for the developed and developing countries due to the nature of their chosen path of economic growth and development. Both surface and underground water have characteristics of public goods, because the people who use them do not pay for their scarcity (whether in terms of quality or quantity) and only pay the cost of private extraction (private goods). When the cost of scarcity is not recognized, it leads to further extraction and pollution of resources and thus, inefficient use of them over time and space.
Materials and Methods: The choice experiment (CE) method has its theoretical basis in Lancaster's consumer choice model (Lancaster, 1966) and its econometric basis in random utility theory (Luce, 1959; McFadden 1973). Lancaster suggested that consumers get their satisfaction not only with simply goods and services but also with their attributes. According to Lancaster, demand is defined over the characteristics of goods, rather than goods themselves. In any CE exercise, respondents are thus asked to choose between the different bundles of goods- which could in fact be alternative designs of policy to provide such goods- described in terms of their characteristics (or attributes) and the levels these take. Offered choices defined in terms of these attributes, utility maximizing individuals will choose the alternative that gives the highest level of utility. According to the theory of random utility, the utility of a choice includes a deterministic component (V) and an error component (e), which is independent of the deterministic part and follows a predetermined distribution. This error component shows that predictions cannot be made with confidence. The choices that are made between alternatives are a function of the probability that the utility associated with a particular option J (for example, the groundwater pollution reduction program option) is greater than other options: 
 
Therefore, the desired data of this study were obtained through face-to-face interviews and the questionnaires filled out by 108 farmers of Dasht Abbas Plain aquifer in Ilam province of Iran in 2022.
Results and Discussion: The study results showed that the willingness to pay was influenced by socio-economic characteristics (including the level of education, age, household size, and environmental orientation) and other factors such as the use of well water. Therefore, to improve the efficiency and universality of the policy, the willingness and heterogeneity of public preferences should be fully considered in policy formulation. Also, based on the results obtained from the mixed logit model and hidden class, the compensatory surpluses of the aquifer improvement scenarios were specified and calculated. The willingness-to-pay values increased from the moderate improvement scenario of the aquifer environment to the optimal improvement scenario. The compensatory surpluses for the desired improvement of the features were estimated about 980 and 1380 thousand IRI rials per hectare per month, respectively. This research showed that the reduction of desertification, the reduction of reeds and the protection of water quality were all determinants of alternative policy plans.
Conclusion and Suggestions: This research showed that reducing desertification, protecting water quality, reducing reeds as well as the number of protected rural jobs were all important determinants of farmers' priorities for determining alternative policy. In this context, the results of this research can guide policy makers in improving the design and creation of agricultural environmental risk reduction policies with the social support of farmers; in addition, the evaluation of the heterogeneity of preferences provides a positive perspective for increasing the social adoption of such programs by farmers, especially that the adoption of such programs is of great importance for the study area. Social support for restoring ecosystems that are being destroyed can also be increased by extending the environmental behaviors by people. Increasing public awareness about the importance of environmental behavior increases social self-confidence and as a result, strengthens social support for improving the quality of environment. Based on the study results, the most important suggestion to be presented is to encourage farmers who use well water to continue using underground water and other farmers are also encouraged to use well water by granting them free well licenses or, if they have a well, by using the necessary incentives (purification device) in order to effectively contribute to the improvement of the environment of the Dasht Abbas Plain aquifer.