The use of water not intended for human consumption for domestic purposes must not, on any occasion, risk harming the population’s health. In addition, their use must remain highly regulated because of the potential presence of chemical and/or microbiological hazards.

To avoid health risks, the HCSP recommends the greatest precautions. Depending on the type of use, its statement specifies possible possibilities for using so-called "non-conventional" non-potable water such as rainwater, treated greywater from showers, baths and washbasins, but also, in certain cases, treated wastewater, as a replacement for water intended for human consumption (EDCH).

The HSCP recommends, subject to a prior global territorial diagnosis of water resource uses, that experiments be subject to authorisation after receiving the opinion of the regional health agency and be subject to permanent national feedback to contribute to the improvement of knowledge.

Whatever the type of non-conventional water used and its use, the distribution networks and indoor networks must be physically disconnected from any public EDCH network under conditions that can in no way induce health risks. In addition, their installation must be validated by a certified professional before they are put into service.

Any new owner or tenant must be informed by the person in charge of the dwelling or the establishment, receiving the public of the different types of water present and the associated risks.

Signs clearly differentiating between the water systems of the two types of water and their location in the premises must be provided. “Water diagnostics” at the time of the sale of property or change of tenant would make it possible to guarantee the traceability of information.