Other water sources and conservation measures also should be tried to the extent practical, before turning to reclaimed waste water. Because regulations for safe drinking water were not developed with reclaimed water in mind, they may not be the best standard for testing its quality, the committee said. Reclaimed water may contain sources of contamination that cannot be determined through current testing or treatment processes. When considering reclaimed wastewater for public water supplies, the report distinguishes between direct and indirect use. Adding highly treated wastewater directly into a water supply without storing it first in a reservoir is not a viable option.
Indirect use is viable, however, and that approach was examined by the committee.
Indirect use augments the drinking-water supply by adding reclaimed treated water first to a lake, reservoir, or underground aquifer. The mixture of natural and reclaimed water is then subjected to normal water treatment before it is distributed as drinking water for the community. This mixture then is used as a source for drinking-water supplies. Since it is unclear whether or not highly treated wastewater contains harmful levels of byproducts from disinfection processes such as chlorination, this issue should be addressed by the research community. The Environmental Protection Agency should sponsor a study to develop methods for better detection of new pathogens, the National Research Council committee report recommends.