Lagoa de Pampulha, Brazil

Lagoa de Pampulha is a hyper-eutrophic, 190 hectare lake in the city of Belo Horizonte, Brazil

Lagoa da Pampulha is an artificial lake constructed for flood mitigation and water supply. The lake has become eutrophic in recent years, after receiving high organic loads from the catchment. After undertaking several measures to reduce external inputs of phosphorus in the lake, in 2015 the local government decided to implement measures aimed at improving water quality in the lake. 

A public tender was launched and won by a consortium consisting of PET’s Phoslock representative, Hydroscience, and two other companies. The restoration plan proposed by the winning consortium consisted of monthly applications of Phoslock and several other measures. Since the commencement of the treatment, nearly 2,000 tonnes of Phoslock have been applied to the lake. In addition, the original contract was extended to control new inputs of phosphorus from external sources entering the waterbody. 

Before applications commenced, the lake was classified as highly eutrophic with mean concentrations of total phosphorus of approximately 0.7 mg/L. Following the commencement of the treatment, total phosphorus concentrations decreased to 0.05 mg/L. After 10 months, the lake showed a significant reduction in all eutrophication indicator variables measured, being classified as Class 3 in accordance with the statutory law CONAMA 357/05.