Key Istanbul drinking-water source faces pollution threat

Istanbul residents are facing concerns about the quality, not just the quantity, of the drinking water in the city’s dams following a report of dark, foul-smelling liquids flowing from a pipe into a key reservoir.

The origin of the pipe has not yet been identified, reporter Tahsin Aksu wrote in daily Milliyet on Thursday, noting that the body of a sea gull was found on the shores of the Alibeyköy reservoir near where the liquids were being discharged, and that white foam was observed on the water as well.

The reservoir is one of seven providing drinking water for the city of 15 million.

Experts from the Istanbul Chamber of Environmental Engineers, or İEEC, have formed an investigation team and are working to identify the causes of the reported water pollution in the Alibeyköy reservoir, İEEC member and Yıldız Technical University Professor Beyza Üstün told the Hürriyet Daily News & Economic Review in a phone interview Thursday.

“Should we find out that there are toxic substances being discarded in the reservoir, we will bring [all relevant authorities] to court and ask for the necessary measures to be taken,” she said. “We use this water to brush our teeth, wash our fruits and take a shower, thus its use affects people directly.”

The amount of water in Istanbul’s dams is always a source of concern for local residents, who face water cuts in the summer if levels drop too low, but the Milliyet report suggests the quality of the water may be as much of a potential problem as its quantity.

“About 1 million people live around drinking-water reservoirs, and industrial facilities are even constructed in such areas,” Ahmet Atalık, the chairman of Istanbul Chamber of Agricultural Engineers, told the Daily News on Thursday, adding that drinking-water areas are not being properly protected by the relevant authorities, as mandated by law. He added that authorities must also properly monitor the use of agricultural chemicals used on soils in the regions where reservoirs are situated.

Authorities from the Istanbul Waterworks Authority, or İSKİ, said the liquid being discharged into the reservoir is its own water, sent back from the Kağıthane water-purifying facility and having the characteristics of raw (non-purified) water, according to a report on NTVMSNBC’s official website.

Üstün told the Daily News, however, that the water taken from the reservoir was not discharged back directly, but first processed in the facility. “After the water is processed, the purified [stream] is transmitted for use by the city’s inhabitants while the remaining [liquids] are sent back to the reservoir,” she said, explaining that the water sent back from the purification facility has more concentrated levels of pollution than the water that was taken from the reservoir in the first place.

The unexpected and at times heavy rains this summer have also sent more mud and mineral salts into Istanbul’s drinking-water reservoirs, Serkan Bilgin, secretary-general of the Turkish Environmental and Woodlands Protection Society, or TÜRÇEK, told the Daily News in a written statement Thursday.

“This causes the remaining waters from the purifying facilities to be highly concentrated with mud, organic minerals and mineral salts,” he said, adding that this may contribute to the formation of swamps, as well as the dark color and bad smell of the water in the reservoir. Bilgin noted that such compounds can also change the water’s acidity level, killing some aquatic plants and animals.

The process known as water coagulation, which takes place in any water-purifying facility, uses potentially dangerous compounds such as aluminum sulphate or Fe3Cl (iron III chloride), Üstün said.

“One of these compounds has to be used for coagulation while purifying water; it is then mixed with the remaining concentrated water and discarded back into the Alibeyköy reservoir,” she said, suggesting that this could be the reason for the dark color and bad smell of the liquid being discharged into the reservoir.

According to Üstün, such compounds can be transmitted to the bodies of living creatures through drinking water.

“Once within animal or human bodies, metals such as aluminum are deposited there and not excreted out,” she said, adding that they can be very harmful to health when allowed to accumulate to certain levels, contributing to brain disorders such as Alzheimer’s disease, memory loss or hallucinations in humans, while potentially killing small birds or fish immediately.

The experts said İSKİ is obligated by law to protect drinking-water reservoirs, adding that it should not be allowed to discard highly concentrated and toxic-containing waters into the reservoirs, nor to make any other damaging intervention to such areas.

* Daily News reporter Erisa Dautaj Şenerdem contributed to this article.