The report concludes that there is a critical need to evaluate reused water chemically, microbiologically, and toxicologically, and that the most practical way to make judgments about the potential health hazards of reused water is to compare it with conventional supplies with risks, if any, that are presumed to be acceptable. The initial comparisons of conventional with reused water should be done on the basis of identifiable individual compounds and microbiological organisms. The results of these tests would determine the need to proceed with additional testing and would indicate whether or not the reused water was 'as safe as' a generally accepted conventional supply.