The stretches of Lazios 361 km coast which are not fit for swimming have increased from 3,500 m in 2005 to 8,900 m this year, according to a survey by Arpa, the regional environment protection agency. The coast off-limits to bathers is divided into two categories depending on the strength of toxins in the waters. Areas which fall into the most toxic category around 5,000 m of coast will be closed for at least a year, since swimming bans cannot be lifted unless water samples are clean for the previous 12 months. The remaining coast falls into the second, less toxic category, and Arpa said the swimming ban could be lifted in May, depending on results of April surveys. Sewage pipes not connected to treatment plants and the reduced effectiveness of the treatment plants themselves were blamed for the changes. Local authorities are obliged by law to put up signs forbidding bathing in the affected areas.

The agency stressed that it is still safe to swim at Lazios main beaches, where toxicity levels have not changed greatly since 2004. Ostia has improved, while Fregene and Nettuno have remained stable, although S. Marinella, Civitavecchia and Cerveteri lost points this year. Sabaudia, S. Felice Circeo, Terracina, Sperlonga, Gaeta and the Isole Pontina remain the best bet for worry-free bathing.