Horticultural products irrigated with treated sewage: are they acceptable?

Public acceptance of treated sewage (TS) reuse in agriculture is a key element in successful implementation of TS reuse projects, but relevant research on the topic is limited. This study examined public willingness to accept (WTA) and willingness to pay (WTP) for agricultural products derived by irrigation with TS in Lorestan province, Iran, applying the contingent valuation (CV) method. The agricultural products determined for the study included corn, peaches, apricots, and plums, while TS was introduced in three qualities [Q1, complete TS treatment (i.e., physical treatment, aeration, and chemical treatment); Q2, partial TS treatment (i.e., physical treatment and aeration); and Q3, no TS treatment]. With reference to WTA, products irrigated with Q1 TS received 62.7% positive responses, while products irrigated with Q2 TS and Q3 TS received 21.3% and 17.0% positive responses, respectively. With reference to WTP, data showed that if the price of products derived by irrigation with TS was less than that of products irrigated with fresh water, some people would be willing to pay for these products (52.0% positive responses versus 48.0% negative responses). Awareness had a significantly positive impact on WTA1 and WTA2 (products irrigated with Q1 TS and Q2 TS, respectively) as well as on WTP1, WTP2, and WTP3 (products irrigated with Q1 TS, Q2 TS, and Q3 TS, respectively). Similarly, information sources had a significantly positive effect on WTP1, WTP2, and WTP3. Overall, individuals with high levels of health risk perception and high awareness showed high WTA, while non-processed corn and men were associated with low WTA. Concerning WTP, individuals with high awareness and those who had access to information sources showed high WTP, while men were associated with low WTP. Information about the importance of TS reuse, reduction of prices of products derived by irrigation with TS, and promotion of public confidence in TS are essential to increase public WTA and WTP.