In contrast ASANO and LEVINE (1996) refer to the so called “Monterey Wastewater Reclamation Study for Agriculture”, which was a 10 years field study in the 1980s in California designed to evaluate the safety and feasibility of using reclaimed municipal wastewater to irrigate food crops that may be eaten raw (Engineering Science, 1987). This study as well as the Pomona Virus study (Sanitation Districts of Los Angeles County, 1977) provided conclusive evidence that effective virus removal can be accomplished through alternative tertiary treatment systems. A major benefit of these studies was the demonstration of lower cost alternatives for the production of reclaimed wastewater for irrigation processes. By comparison of the WHO guidelines and the criteria from California it is evident that the latter require less treatment and different monitoring conditions. The California criteria for example stipulate conventional biological wastewater treatment followed by tertiary treatment including filtration and chlorine disinfection to produce effluent that is virtually pathogen-free. In contrast the WHO guidelines emphasize that a series of stabilization ponds is necessary to meet microbiological water quality requirements.