Book excerpt: The objective of this paper is to provide a review of the characteristics of wastewater used for irrigation, and the reasoning behind the international guidelines presently used in regulating wastewater reuse for agriculture. This paper presents various systems of wastewater treatment available and discusses their benefits and shortcomings. A selective review of recent empirical studies identifies major impacts both positive and negative impacts of wastewater irrigation. Finally, the paper provides the review of environmental valuation techniques for analyzing impacts of wastewater uses in agriculture, and suggest a framework for application of some of these techniques. This framework will be applied to a developing country case study (Faisalabad area in Pakistan), in the ongoing IWMI research program.