Sanitary Sewer Exemption

The contamination of water resources is one of the most serious problems in environmental matters which Costa Rica is currently facing. For this reason, Costa Rican legislation has a series of regulations and legislations that must fulfill any activity, work or project.

To avoid contamination of surface and groundwater, it is expected that all developments have a wastewater treatment system as well as wastewater treatment plants. However, these are expensive and according to the geological environment, their location can be excessive because the transit of pollutants is long enough for pollutants to completely degrade before affecting aquifers or other bodies of water with cheaper measures, as is the use of septic tanks with drains.

There is a procedure which must be endorsed by the National Institute of Aqueducts and Sewers (AyA) to exempt the construction of a sanitary sewer system and to treat the waters through the use of septic tanks and individual drains, nevertheless, this procedure must be accompanied by a series of studies to examine the contamination vulnerability of the aquifers in the area to be developed.

In Geo Costa Rica we perform this type of studies which consist of studying the transit of pollutants where the risk and threat of present and future contamination for aquifers is detailed. If, as a conclusion of the analysis of the data, it is determined that the transit time of contaminants allows concluding that the project complies with the regulations it can give way to the exoneration of the obligation to build sanitary sewer for the project.

This will depend on the permeability of the soil calculated through infiltration tests performed in the field, soil porosity tests and the analysis of the hydrogeological study of the land from the elaboration of hydrogeological profiles and geological and hydrogeological cartography from data interpolation and interpretation of information such as that of nearby wells to determine the behavior and composition of the subsoil and groundwater in the project area.