Lake Lugano - Pollution

Pollution

Pollution has long been a problem in Lake Lugano. In the 1960s and 1970s it was officially forbidden to bathe in the lake

Despite the continued introduction of sewage treatment plants - e.g. in Gandria, factors such as lake retention time and lack of oxygen and increasing phosphor concentrations means it is unclear if the lake will recover.

The Federal Office for the Environment last published report on Lake Lugano dates from 1995. To summarise that report,

• at that time measurements indicated some improvement, but this was unlikely to continue at the same pace
• there were almost permanent polluted layers at the bottom of the very deep lake.
• oxygen was scarce and could not be found below 100m depth
• as a result phosphor levels were increasing at this depth
• phosphor levels in the northern basin were 6 and in the southern basin 2 times "too high".
• will take many decades to clean
• the Lake could be said to be "Chronically Sick".
• in the Italian part of the lake only 20% of the population were connected to sewage treatment plants with phosphor filters (not that all Swiss areas were connected either).

The Swiss/Italian organisation CIPAIS in its most recent published report says:

Considering the results obtained in 2009 it can be affirmed that, notwithstanding the observed improvement, Lake Lugano is still in a state of high eutrophy, the highest among Swiss lakes.

The Italian environmental group Legambiente in its 2007 study of all Northern Italian Lakes, found Lake Lugano to be the most polluted of all.

all water samples were even beyond the legal limits. At the polluted sites should not be bathed for health reasons. The bacteria can cause in the worst case, skin infections, diarrhea and vomiting.

According to Legambiente, the only reason swimming was not banned on the Italian Lakes was because the State of Lombardy changed the law. They state that pollution levels in the lakes do not conform to European rulings and the lack of sewage treatment is illegal.

Their 2010 measurements found samples taken at Ponte Tresa, Ostene and Port Ceresio to be "Heavily Polluted" (more than 1,000 UFC/100ml intestinal enterococci and / or greater than E.coli 2000 UFC/100ml).