This is a complicated ...

This is a complicated subject, and there have been some very good comments, reuses a huge need in many geographic areas. We have created about eighty-five thousand chemicals mostly new to the environment, to put into products we have been using, these products are dispersed around the world to eventually degrade often becoming pollution. Very few have had adequate toxicity testing done. Water is a solvent and transporter of most of these chemicals. Grey water is contaminated by a huge number of these chemicals, but highly variably. We have not even developed test protocols for identifying multiple thousands of these contaminants. Extremely low doses of many chemicals can have adverse biologic, and pathogenic, effects that we are unaware of of even having, let alone ascribing causation to. Some of these chemicals are accumulative in our bodies. They can be additive in adverse effects, and even synergistic in subtle-but-persistent low dose effects as mixtures. Science is able to look at many toxic effects of many of these chemicals, but does not do a very good job of identifying toxic effects of mixtures of them. There are huge gaps in our knowledge of the toxicologic effects potentials and our ability to tease out the risks in grey water that is highly variable. Anything we can do to gain additional knowledge about these very real health risks is going to become even more essential as clean freshwater becomes increasingly contaminated by our products. The science is critical, we are harming ourselves and others, but often it is very subtle to determine adequately.... we are not very good at this yet... but we must keep getting better at it rapidly IMHO