«Streams of pollution» are gushing into the Thermaic Gulf daily due to the inadequate operation of biological wastewater treatment plants in the Thessaloniki area, a study by the northern city’s Aristotle University has revealed. According to the 600-page study, which took experts at the university’s pollution-monitoring laboratory two years to complete, the Thermaic Gulf is being polluted by seven key sources. Among the main offenders are local wastewater treatment plants, whose purpose, ironically, is to cleanse water. The results of the study, commissioned by the government, were made public at a joint press conference yesterday by Macedonia-Thrace Minister Margaritis Tzimas and by Constantinos Fytianos, the chemist who led the research project. The study mentions more than 30 proposals for improving the operation of local wastewater management and cleansing the polluted gulf. According to Fytianos and his fellow researchers, action must be taken immediately to upgrade the operation of processing plants in Angelohori, on the east coast, and the city’s main sewage processing plant, on the west coast near the Gallikos River. The sewage unit alone processes some 160,000 cubic meters of waste every day. This is «theoretically a full second-stage biological processing procedure,» according to the report, which noted concern «at the presence of phosphoric acid in the processed sewage as well as high levels of bacteria.» This toxic waste was found to be particularly concentrated around the area of Kalohori. Tests revealed high traces of heavy metals, including lead, chromium and copper. They also discovered traces of pesticides that have been banned in Greece for years. Last month, the Environment and Public Works Ministry heralded a project for the reuse of hundreds of tons of wastewater that is discharged daily from a sewage processing unit on the islet of Psyttaleia, off Piraeus. The water would be purified before being used for irrigation, the ministry said.