The Royal Decree 1620/2007 for the reuse of treated wastewater complies with the provisions of the Water Law, which urges the Government to develop the basic conditions for reuse. Annex I.A includes the quality criteria required according to each of the possible uses.
The main parameters that should be always controlled are microbiological and physical-chemical indicators
The parameters that should always be controlled are: intestinal nematodes, Escherichia coli, suspended solids and turbidity. The first two are microbiological indicators and the other two are physical-chemical indicators.
In addition, and depending on the type of use or purpose of the water reclaimed, the Royal Decree for the reuse of treated wastewater requires the control of other types of parameters, such as, Legionella spp. in the event that there is aerosolization, or nitrogen and total phosphorus in the case of aquifer recharge or filling of ponds at risk of eutrophication.
Depending on the discharge authorisation, it will be necessary to control the other parameters that are specified in said authorisation. In the case of dangerous substances, environmental quality standards must be observed.
To sum up, there are six kinds of qualities depending on the uses of reclaimed water
To sum up, Table 1 shows six kinds of qualities depending on the uses of reclaimed waters and those limits with regard to Escherichia coli, intestinal nematodes and Legionella spp. required in the Royal Decree for the reuse of water.