Water quality studies, also known as self-purification studies or carrying capacity studies, aim to quantify the pollutant load that a water body can receive without compromising its predominant uses and ecosystem functions.
When applied to rivers and canals, this study involves evaluating their self-purification potential — that is, their natural capacity to assimilate, dilute, and transform pollutant loads.
Studying water quality is essential for environmental planning and water resource management. Failure to understand this limit can result in water quality degradation, compromised multiple uses, eutrophication, and ecological imbalance.
The discharge of effluents into water bodies is subject to environmental licensing. Therefore, capacity assessments inform decision-making in licensing processes, granting effluent discharge permits, and establishing progressive targets for classifying water bodies as required by CONAMA Resolution No. 357/2005.
At Rhama Analysis, the methodology used involves mathematical or numerical modeling, depending on the environment being assessed. For rivers, we use models such as QUAL-2K and HEC-RAS; for lagoon systems, we use DELFT3D. We prioritize the use of primary data, our own monitoring, or validated databases to ensure the reliability of our simulations. The main results involve defining sustainable discharge standards and verifying compliance with environmental legislation, state regulations, and local environmental agency guidelines.
Example of water quality modeling in HEC-RAS
Main benefits
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Technical support for environmental licensing and granting processes;
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Reduction of contamination risks and water use conflicts;
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Identification of sustainable effluent discharge limits;
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Subsidies for public policies on sanitation, drainage and environmental management;
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Support for the recovery of degraded water bodies;
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Verification of location alternatives, if the location is previously unfeasible.