Greek environment experts have complained to the European Commission (EC) that Bulgaria has polluted the Maritsa and Mesta Rivers. Both these rivers begin in Bulgaria but eventually flow to its southern neighbour Greece. The pollution meant that the level of chemicals, pesticides and refuse in the water had increased, Bulgarian-language Netinfo.bg reported on August 19.

Environment experts from several Greek universities pinpointed the excessive quantity of harmful substances. The Greek TV channel Sky reported on the high level of metals and nitrates in Maritsa and Mesta, while Athens newspaper Kathimerini called the situation "a deadly cocktail in Greek rivers". It claimed that Vardar River is also polluted with fertilizers as well as household and industrial rubbish. According to Greek environmentalists, the situation with Vardar River was the worst because it also carried industrial refuse from 14 cities in Macedonia.

Scientists would evaluate the river quality with "black flags". Greek seawater, on the other hand, was deemed to one of the cleanest and was evaluated with "blue flags" by the EC, Kathimerini reported.

Mayors from the area of the Greek town of Drama and members of local environmental organisations said that on many occasions they had insisted that the Greek environmental ministry sign an agreement with Bulgaria to abide by European environmental requirements.

On August 19, the Bulgarian Ministry of Environment and Water Affairs said in a media statement that during the past several months no pollution was detected in Mesta and Maritsa rivers. The constant monitoring of the Environment Executive Agency showed these results.

Pollution in another Bulgarian water basin caused the death of about 4000 fish on August 19, in Shirokolushka River in Rhodopi Mountain near Pamporovo winter resort. Experts from the Smolian regional inspectorate on environment and waters established that the deaths were caused by pollution in the river from canal waters in the village of Shiroka Luka. The lack of water in the river during the summer led to inadequate dilution of the refuse waters. This, reported Focus news agency, caused the deaths.