When evaluating the economic efficiency of policies to reduce nonpoint source pollution, administrative or transaction costs are usually not taken into account. While the importance of transaction costs has been recognized in the theoretical literature, the fact that they are not incorporated in empirical analyses means that, in effect, these costs are given a zero value. This issue is examined quantitatively using data collected by the National Resource Conservation Service (NRCS). Transaction costs are found to be a significant portion (38 percent) of overall conservation costs. This provides strong support for including these costs in economic evaluations of alternative policy instruments.