The official report

The WC and the whole with the sewer are two errors of civilization, and particularly the conjugation of both.

Currently, one discusses together and in the same way, after having mixed them, of water of different origin and nature:
  water black, from the WC, charged out of nitrogen, phosphorus, organic matters and especially pathogenic fecal and chemical (antibiotics, hormones of synthesis…)
  #D0D17F water, resulting from the bathrooms and kitchens, whose polluting charge is quite less than that of #515200 water: three times less organic matter, very little nitrogen, very little phosphorus if one pays attention to the quality of the detergents employed, almost not of pathogenic fecal, not of medicamentous residues.

This domestic waste water (black and #D0D17F mixed) is discussed in individual cleansing (called not-collective now: pit + underground spreading on the spot), is collected by a sewerage system and is discussed in sewage treatment plants before being rejected into a permanent waterway.

In individual cleansing, the current regulation imposes in theory the recourse to heavy, expensive systems and sometimes not very effective (pollution, filling, odors…). These stresses and nuisances often push the private individuals to claim their connection with the sewerage system.

In addition, the WC with the disadvantage of making impossible, or intricate in any case, the agricultural re-use of the fertilizing potential contained in our excrements. In the case of connection with the sewer, part of this potential present in muds is turned over to the fields; but these muds are in charge of contaminants of various origins making their spreading debatable, even impossible. When with the individual cleansing, the system pit all water - underground spreading prevents any re-use.

The whole with the sewer is currently defended by the following postulates: the purification plants are effective and the surface water ready to cleanse what one throws there; however these two ideas are false. The sewage treatment plants retain the organic matter more or less, but they let pass a good part of phosphorus, almost all the nitrogen as well as the other soluble pollutants, and pathogenic finest (bacteria and virus). The ones can hardly but dilute and take along to far these pollutants. However all the water pick-ups of river (except the very first, upstream of the mining areas) are fatally downstream from the rejections of one or more stations.

The grounds are much ready to deal with the most varied pollution, its purifying capacity is infinitely higher than that of water.

The WC connected on a sewerage system is thus an ecological and medical calamity: multiplication and dissemination of pathogenic fecal, dissemination of the medicamentous residues (with negotiable instruments on the natural environments and the human health which start to be known and denounced), eutrophication of the rivers due to nitrogen and phosphorus, and indirectly impoverishment of the grounds by organic matter loss.

This stage, he is important to see that the planted filters, often forwarded like an ecological alternative to the conventional cleansing, are not more effective overall than the conventional purification plants. Construction in many rural communes of driving sewerage systems at a station with planted filters has as many disadvantages, in cost of installation and pollution for the river, that usual solution WC - sewerage system - conventional station.

This is why we think that the toilet with water is not a simple solution a priori, and especially which it is calamitous when it is connected to a sewerage system. It is the purpose of the proposals which we make within association ' Water).

Possible solutions

In other parts of the world, in North as in the South, an alternative to the WC develops: the toilet dries. It has as a merit to reduce considerably the polluting charge of the water rejected into the mediums, to allow a considerable organic matter contribution on the ground and to simplify management as well human metabolic waste as waste water.

As the WC and the whole with the sewer have linked party, the dry toilet returns the whole to the useless sewer, and reciprocally the choice not to extend the sewerage system more pushes with the adoption of the dry toilet.

By supposing the dry toilet adopted everywhere, it remains to deal with #D0D17F water. Everywhere where it is possible, one will privilege the processing on the spot, by planted filters or . In the urban areas, one will preserve the collecting systems for #D0D17F rain water and water which one will not have been able to discuss on the spot.

The dry toilet is an essential choice which allows:
  the reconquest of the water quality of surface, with for consequence simplified , bathe again possible…
  a conversation of the humus of the grounds, guarantor of their fertility, saving in industrial nitrate fertilizers and the recycling of phosphorus (mining reserves in process of exhaustion).
  a notable reduction in the financial expenses, for the households and the communities.

Catherine , Pierre , Didier . ' Water, 2008