Greece’s lakes and rivers are for the most part clean and comply with the strictest European standards, though they have some pollution caused by sewage and fertilizers, says an annual study that was released yesterday.

The government report showed that while in most cases Greece’s fresh water meets the strictest standards, sulfur and phosphate indicators stand at 98.8 percent and 71.4 percent, respectively, according to the European Environment Agency (EEA). This means that 1.2 percent and 28.6 percent of Greek waters are not up to EEA standards. As regards chemical oxygen demand (a measure of water quality that assesses the amount of oxygen needed to degrade the organic compounds in wastewater), 20 percent of fresh water is substandard, with lakes and rivers contaminated by organic waste from sewage systems and phosphate fertilizers. Toxic substances affect 3 percent of lakes and rivers.

Environment and Public Works Minister Vasso Papandreou presented the results as part of the national program called “Lakes and Rivers of Our Country.”

The longest rivers in Greece are the Aliakmonas, the Acheloos, the Pinios, the Strymon, the Evros and the Axios. The major lake areas are in western Greece, with 14 lakes having a surface area exceeding 8 square kilometers.

The program included a poll of the most popular rivers, selected by members of the public voting at www.thisavros.gr. The most popular rivers, in order of votes, were the Aoos, the Alpheios, the Axios, the Ardas, the Arachthos and the Acheron.

Papandreou said that 12 million euros will be spent on monitoring water quality and another 10.2 million euros on improving sewage systems. At least 600 million euros will go to regional programs for water resources and the management of 25 ecosystems.