FAIVRE CONTRIBUTES TO THE FIGHT AGAINST CYANOBACTERIA IN LAKE ENGHIEN LES BAINS

Partly caused by a major outbreak of cyanobacteria, the fish kills on the Enghien-les-Bains lake in the summer of 2020 left a lasting impression. To prevent the same scenario from happening again, the SIARE (Syndicat Intégré Assainissement et Rivière de la Région d'Enghien-les-Bains) called on our expertise to supply surface aerators and hydro-ejectors to maintain a certain level of oxygen in the lake.

Cyanobacteria in a nutshell:

Cyanobacteria are micro-organisms which, when they proliferate, release toxins that are dangerous to wildlife and can also affect human health. Closely related to algae, cyanobacteria consume the oxygen available in bodies of water and are responsible for fish mortality through anoxia.
The main factors in the development of cyanobacteria are light, heat and nutrients. These three parameters are easily combined in the lake at Enghien-les-Bains.
Easily recognized, cyanobacteria form a green film on the surface of a body of water.

Several solutions were implemented, including FAIVRE aerators and hydro-ejectors:

Following the study carried out by the ID EAUX design office, the SIARE asked us to supply aerators, and a total of twelve machines were installed on the Enghien-les-Bains lake to provide the oxygen necessary for the survival of aquacultural life, particularly during the summer months.

The Flobull surface aerator is one of the ranges selected. Installed in a number of six, each Flobull - each with a 1.5 kW power rating - contributes to lake oxygenation by projecting a spray of water onto the surface, which then comes into contact with the atmosphere. The surface aerator helps to set water masses in motion, while bringing oxygen to the pond, creating a survival island for fish.

Water from a variety of sources:

Fed by several rivers, the water in Lac d'Enghien is no longer renewed during hot spells, resulting in water stagnation that can contribute to the development of cyanobacteria.

In summer, higher water temperatures generate significant evaporation, reducing the oxygen content of the water.

Finally, factors such as rainwater runoff from pavements and roofs, or poor sewage connections, are responsible for the discharge of organic matter and pollutants into the lake, providing nutrients on which cyanobacteria feed.

The other range selected for the Enghien-les-Bains lake is our Aquasub range of hydro-ejectors. Also installed in six units, these devices - each with a power of 1.5kW - promote mixing of the water mass at depth, while injecting oxygen into the lake's depths.

The devices have been positioned to create several oxygenation zones in the lake to prevent fish mortality during hot spells.

Find out more about the fight against cyanobacteria in Lake Enghien-les-Bains in the article written by the SIARE:
Read the SIARE online article