Water Quality of a Tectonic Lake: Hazar Lake

In this study, water quality parameters of Hazar Lake have been investigated and evaluated according to water quality regulations. Some water quality parameters, such as dissolved oxygen, water temperature pH, electrical conductivity salinity, transparency, (Sechii disc depth), Chlorophyll a, total alkalinity, BOD, chloride, calcium, magnesium, total phosphorus, sulfate, ammonium nitrogen, nitrite nitrogene, nitrate nitrogene, total nitrogen were examined between September 2019-August 2020. The results were evaluated according to the quality criteria of the In-Continental Water Resources Classes of The Water Pollution and Control Regulation. According to the regulation, the water quality of Hazar Lake is classified as the 1st class in terms of dissolved oxygen, water temperature, ammonium nitrogen, total phosphorus, nitrate-nitrogen, nitrate nitrogen, biological oxygen demand; as the 3rd class in terms of chloride ion; as 4th class in terms of pH. The average chlorophyll a value of 1.09 µg/L in Lake Hazar indicates that the lake shows oligotrophic lake category feature. Secchi disc depth was 3.8 m), which shows that Hazar Lake is at the oligotrophic level in terms of light transmittance. It is noticed that for total phosphorus less than 10 µg/L, the lake is oligotrophic, for 10-20 µg/L is called mesotrophic, and for more than 20 µg/L is so-called eutrophic. This value was measured 0.02 µg/L in the lake; therefore, it can be concluded that the lake is oligotrophic. In addition, the change in alkalinity values of the lake between 402-450 mg CaCO3/L indicates that the lake has very hard water characteristics. Precautions should be taken to protect ecological balances and prevent water pollution in Hazar Lake.