Sanitation: regulatory framework
To date in Caledonia, there is no real common regulation applicable to the three provinces.
Within a few years, the territory should, in consultation with the various provinces, political actors and people in the sanitation profession, create regulations adapted to sanitation in Caledonia on the basis of metropolitan regulations.
In SOUTH Province
It is the DENV (Department of the Environment) which in its deliberation n ° 10277 of April 30, 2009 determines the discharge standards.
Each Town Hall takes care of itself to give the conformities with different rules according to the municipalities.
Above 50 W / H an ICPE file will be requested and the purification will have to be done using a purification station.
5.4 – Protection of the natural environment and requirements relating to the quality of the discharge
In the case of a discharge into a watercourse, the discharge point must be located in order to minimize the effect on the receiving waters and ensure optimal diffusion. The choice of its location must take into account the proximity of drinking water catchment, swimming, aquaculture, fish and shellfish areas. The discharge must be carried out in the minor bed of the watercourse with the exception of its backwaters. Discharges carried out on the public maritime domain must be done below the low water mark.
The discharge structure must not obstruct the flow of water and all measures must be taken to prevent erosion of the bottom or banks, ensure the cleaning of deposits and limit their formation.
The effluents are pretreated (screening, settling, etc.) then treated biologically; they can be treated by the physico-chemical route only if it is justified that the corresponding release is harmless to the natural environment and that there is no risk to public health.
Unless otherwise stipulated in the standard, the limit values for water discharges are checked on non-decanted and unfiltered treated effluent, without prior dilution or mixing with other effluents.
Biological treatment works must comply, at the outlet of the treatment installation, with the limit values for discharges of treated effluent, into the natural environment or into a collective sanitation network without a wastewater treatment plant, set as follows:
- pH between 6 and 8.5
- Temperature less than or equal to 30 ° C
- 5-day biochemical oxygen demand (BOD5) (NFT 90-103): the concentration should not
exceed 25 mg / l.
- Chemical oxygen demand (COD) (NFT 90-101): the concentration should not exceed 125
mg / l.
- Suspended matter (SS) (NFT 90-105): the concentration should not exceed 35 mg / l.
In the North Province
It is the DAN which sets the discharge standards and assigns compliance.
Article 3: Discharge standards
Domestic wastewater, black water and gray water, can only reach the natural environment after having undergone a treatment to meet the regulations in force and the following objectives:
1) Ensure the permanence of the infiltration of effluents by means of purification and evacuation by the ground;
2 °) Ensure the protection of underground water tables.
Discharge into the surface hydraulic environment can only be carried out in the event that the infiltration conditions or the characteristics of the effluent do not allow them to be dispersed in the ground, and subject to the provisions provided for in Articles 2 and 4. The minimum quality required for discharge to the surface hydraulic medium, observed at the outlet of the purification device on a representative sample of two hours not decanted, is 30 mg per liter for suspended solids (SS) and 40 mg per liter for the five-day biochemical oxygen demand (BOD5).
The health authority can make these thresholds more or less severe depending on the requirements of the receiving environment and, if necessary, impose the implementation of additional treatment.
If the discharge of treated effluents by infiltration into the ground or discharge to the surface hydraulic medium cannot be implemented, the discharge of effluents which have undergone complete treatment in an underlying permeable layer is authorized.