A small pontoon bridge from Zemun shores to Lido beach offered a safe passage for many citizens and tourists searching for a cool relief on the beach last summer. Unlike the passage, the safety of the water stays unclear. The green algal cover spreads along  Zemun shores accompanied with the sewage smell contaminating the area.

For a summer afternoon, with only a few swimmers in the water, the beach looks abandoned. Although the press informed the public that the water quality is changeable, meaning sometimes not recommended for swimming, they forgot to mention the sewage leak ‘across the street’.

An independent research gives a hint on how dirty Danube in Belgrade is 

During the summer of 2013 an international team of 20 scientists travelled for along more than 2.000 km down the river through 10 countries in the Danube Delta sampling and analysing the water components. The world’s biggest river research expedition, as they call it, was conducted by the International Commission for the Protection of the Danube River (ICPDR).

In the Belgrade area, water was analysed on four locations, and the results showed higher concentration of nitrates – a sign of untreated wastewater leaking into the river.

Momir Paunovic, one of the scientist from the ICPDR expedition explains high levels of pollution  in Pancevo could be linked to heavy chemical industry in this city or wastewater coming from Belgrade.

‘Pancevo is known for the canal where the chemical plant – HIP-Azotara and Oil Refinery discharge their wastewaters, this could be one of the causes of the pollution. Other cause might be the influence of Belgrade city and the wastewaters discharged.’  

Data published in the The International Commission for the Protection of the Danube River database  and analyzed for this article, evidence how the amount of nitrates in Serbian waters varies from moderate ecological state near Ada Medjica, island in Sava river, to low ecological state in Pancevo, a suburban town east of Belgrade.

High levels of nitrates in ground waters are usually linked to wastewater pollution and might occur from sewage, agriculture and livestock farms.

Mr. Paunovic explains that Danube is rich in water, so catching the level of pollution might be a difficult task. ‘Large amounts of water flows through the Danube, which contributes to dilution of wastewater. In the significant number of cases the influence of the collector could be detected only locally.’

Mr. Paunovic adds that ICPDR chooses measuring locations carefully through a collaboration with local experts and institutions, paying attention to endangering factors such as pollution.

Water is life … or not

Although it is still possible to swim and fish in second and third class water, drinking and swimming in untreated water is health damaging, triggering diseases affecting the digestive system, most commonly accompanied with diarrhea, stomach ache and skin disease.

But more than for humans, this river is the most dangerous for its inhabitants – fish and aquatic life. Waters with high levels of organic contaminants become overpopulated with algae. This leads to low levels of oxygen for fish and creates dead zones as blocks the sun light. This is evidence of damaging human influence changing the natural balance of the river.

Apart from a bright green cover and unpleasant smell, which do not invite for a swim, algal blossom areas are flourishing with a variety of bacteria. Most dangerous of them are cyanobacteria – toxic bacteria that is linked to liver cancer when found in drinking waters.

Serbia itself is not concerned about its dirty waters

However, the official picture is much brighter and cleaner. Environment protection Agency of Serbia measures monthly the level of nitrates as part of the annual water quality report in two spots in Belgrade.

During September 2013, the same month as the independent measurements were taken, the level of nitrates in Danube and Sava suited the good ecological state. In theory this kind of water could be used for swimming, fishing and drinking after filtration.

Same river, different results – why?

Although both agencies were measuring the same compounds within the same city during the same month, locations were different. Exact locations where the samples were taken show that official Agency measures the quality of the water before the sewage leaks, showing brighter picture of the river state. In Zemun, pollution was measured 700 m upstream of the leak, showing the level of nitrates at acceptable levels.

The Head of the Department for monitoring of water quality and sediment in the Serbian Environmental Protection Agency, Nebojša Veljković explains that by the Serbian water law, sources of pollution should conduct its own monitoring. ‘The one who pollutes is in charge for the source of the pollution, and that are PUC Waterworks and Sewage and the Industry. They are obliged to measure water quality upstream, downstream and at the source of the pollution.’

When asked about the Agency’s capacity to conduct control measurements, Mr. Veljkovic raised concerns about the budgetary decrease.  Despite the fact that 400 measuring places are required to meet the EU standards, water quality is measured only at 80 at the time, one fifth of the standard. ‘Since 2012 there have been less money in the budget for the purpose of measurements and accordingly there have been less people and stations. In the 80 places where the monitoring is conducted only  30 experts are working.’

On the other hand, ICPDR’s samples were taken after the sewage leak, downstream Ada Huja – where is discharged the biggest amount of wastewater in Belgrade and close to the industrial area of Pancevo.

Measuring station in Pancevo was once in the program of monitoring, but cut off due to lack of funding. ‘In the inner city of Belgrade quality of Danube was measured only in Zemun. Number of measuring stations is shrinking every year. For example, quality of water is no longer measured in Pancevo, next measuring station after Zemun is Smederevo.’, Mr. Veljkovic explains.

Wastewater problem

The bigger problem is not the measurements – it is the dirty sewage water that flows unnoticed and untreated directly into Danube river. Even though Belgrade is the largest city in Serbia, home of 2 million inhabitants, it doesn’t have a wastewater treatment plant.

For every citizen living in Belgrade there are 100 m3 of wastewater discharged every year, nearly a quarter of Olympic pool. For comparison, Novi Sad and Kragujevac produce only half as much, although Nis produces the most  – 133 cubic meters a year. But among all these cities only Kragujevac has treatment facilities, which treats 84% of the wastewater generated in the city.

A typical wastewater treatment plant includes primary treatment to remove solid material, secondary treatment to digest dissolved and suspended organic material as well as the nutrients nitrogen and phosphorus.

Without any wastewater treatment facilities in Belgrade, Novi Sad and Nis produce endless amounts of dirty water, polluting the rivers around. This situation is repeated across the whole country. To meet the EU standards required in the chapter 27, Serbia would be required to treat 90% of the wastewater.

According to Eurostat, 9 in 10 citizens in Serbia are not connected to wastewater treatment  at all. For every person that is connected to urban wastewater sewage network with at least secondary treatment in Serbia, there are 6 in Bulgaria and 4 in Croatia. Secondary treatment of water implies both mechanical and biological treatment is conducted.

According to the government plans Belgrade’s would have its first water treatment plant in 2031. While waiting to put an end to pollution, citizens would have to pay attention where to go for a swim or fishing avoiding sewage leaks along Danube and Sava.