The municipality of Oropos, north of Athens, has instructed some of its residents to stop drinking tap water after tests found it to contain toxic substances, in the second case of dangerously contaminated water being detected recently.

Giorgos Gavriil, the mayor of Oropos, told Kathimerini he issued an urgent call to residents to stop drinking tap water in the areas of Halkoutsi, Pefkias and Nea Ekali.

«There is not just microbiologic contamination, but a contamination from heavy metals. The chromium is above allowable levels, while there are traces of depleted chromium. The water is unsuitable for drinking and cooking,» said Gavriel.

Samples were taken from three wells used to supply homes with water. Officials pointed out that water is only drawn from the wells - which have since been shut down - during the summer months.

Drinking water in the winter period is drawn from other reserves, according to officials.

Gavriil blamed the highly polluted area of Oinofyta nearby as being responsible for polluting his district.

«The Asopos River is not just the carrier (of pollution). Analysis shows there is extensive pollution in the water table,» he said referring to water collected underground in porous rocks.

«Depleted chromium does not just come from the river,» he added.

Tests showed in July that water from the Asopos River in Oinofyta is highly polluted due to untreated waste dumped in the river from the industrial plants in the area.

Since then government officials have decided to stop drawing drinking water from the Asopos but evidence now indicates that the broader area has been affected.

Water in the Oropos area has also been found in the past to be unfit for human consumption. According to tests held on other Oropos wells, the water was found to have very high concentrations of nitrates and iron and is only suitable for irrigation purposes.