Bathing waters closely monitored in Monaco
This must be the first reflex before taking a dip in the Big Blue: visualize the color of the flag floating above the lifeguard station or take note of the water analysis results, which must be displayed at each place. of bathing. If the Principality has already advised against bathing due to imponderables, such as weather conditions or the presence of jellyfish, it remains very little exposed to health threats to its bathers. We will explain to you what safeguards exist upstream and how the Monegasque authorities monitor its bathing waters on a weekly basis.
Wastewater at 97%
“In the Principality, wastewater, normally loaded with faecal germs, is not discharged directly into the sea. Before that, it is treated by the residual water treatment plant (UTER)”, says Valérie Davenet, Director of the Environment. Nearly 98% of these waters are occupied by this recently modernized underground infrastructure. “Around the Mediterranean, this type of factory does not always exist. In some places, there are still industrial discharges, septic tanks or individual houses which discharge wastewater into the valley before it ends up at sea. In Monaco, all the buildings are associated with the network.”
Weekly checks
Every Monday morning, from 1uh May to September 30, the Department of the Environment takes samples from six sites in the Principality: the two coves of Larvotto, the Solarium, the fishermen’s beach and the bathing areas near the Monte-Carlo Bay and the Méridien Square of the beach. A regulatory obligation of the Monegasque Code of the Sea.
During the year, at least once a month, other checks are carried out on the coast to improve knowledge of the marine environment.
What are they looking for?
The first part concerns the presence of any bacteria: streptococci and faecal coliforms or total coliforms.
“These faeces can contaminate the water and have a health impact on swimmers, explains Valérie Davenet. Below the guide values, the water is of good sanitary quality. Above, it is considered average. When we are above the so-called imperative values, we are talking about poor water quality.
The physico-chemical parameters are also monitored very closely and must comply with the regulations in force. “These are transparency, coloring, surface-active substances such as foam, the presence of mineral oils, tarry residues or floating materials”she lists.
Where are the samples analyzed?
The samples are analyzed in Monaco, in the premises of the Department of the Environment, by biologists. The delays in results can vary between a few hours, for the physico-chemical aspect, to 48 hours for bacteriology, the time to grow the germs in the appropriate media. “But in 24 hours, on one already of the first indications on the quality of the water”specifies the director of the environment.
Have there ever been bathing bans for health reasons?
Yes, but this is still extremely rare. 1uh July 2019, the Monegasque authorities are waving the red flag on Larvotto beach and the Solarium de la Digue following accidental organic pollution.
That day, a human handling error led to the overflow of a sewage drain into the Larvotto’s storm drain. Two days later, everything was back to normal.
A few days earlier, as a precaution, swimming had been prohibited after 80 liters of organic hydraulic oil leaked into the body of water at the offshore extension site, on the Grimaldi Forum side. A crisis cell had been activated but the pollution had been quickly contained by various equipment.
15,000 m3 of treated wastewater discharged into the sea every day
The residual water treatment plant (UTER) treats up to 98% of the so-called “carbon” pollution and part of the “nitrogen” pollution retained in the waste water. “We do not deal with so-called phosphorus pollution because this is reserved for sectors placed in sensitive areas, of which the Mediterranean is not partexplains Manuel Nardi, Managing Director of the Monegasque Water Company (SMEAUX). As for bacteriological pollution, it is not treated within the purification plant. The micro-organisms present in wastewater are accustomed to fresh water, so as soon as they encounter the marine environment, they are literally destroyed by the presence of salt.”
In addition to Monegasque wastewater, the infrastructure buried under Le Triton, rue du Gabian, treats that of Beausoleil and part of that of Cap-d’Ail and La Turbie. With 27 million euros invested for the extension of the UTER, the Principality has thus acquired its capacity to handle the daily flow – from 100,000 to 130,000 inhabitants – for the future.
The discharge into the sea of this depolluted water, at a rate of 15,000 m3 per day, takes place 800 meters from the Monegasque coast from an outfall placed 100 meters deep. “In terms of discharge, Monaco does much better than European requirements. Even with 2% of pollution discharged after treatment, discharge from the UTER does not degrade the quality of seawater.assures Manuel Nardi. Analyzes are regularly carried out at the right of the emissary to check its proper functioning, the conformity of the ambient environment and identify any anomalies.
The only risks of uncontrolled waste water discharges into the sea occur during heavy storms, causing the collection network to be naturally overloaded. “But the State has developed storm basins which retain and prevent the network from being under tension. The last, at the level of the Portier roundabout, is a few years old”, he explains.