Environmental Indicators
Environmental Indicators
6.2- Oxygen Consuming Substances in Rivers

The primary indicator of the oxygenation state in water bodies is biochemical oxygen demand (BOD) which expresses the demand of oxygen by the living creatures consuming oxidizable organic materials in a body of water. This indicator is a state indicator which shows the present situation and the tendency related with ammonium concentrations (NH4) and BOD in rivers.

Laboratory, Measuring and Monitoring Department of the Ministry of Environment and Urbanisation carried out Domestic and Industrial Pollution Monitoring Programmes in 2012, 2013, 2014, 2015, 2016 and 2017. Seasonal monitoring studies have been done in the basins: Ergene, Küçük Menderes, Gediz, North Aegean, Sakarya and Susurluk that have the highest pollution loads. As a result of the studies, Rivers in these basins were found out to be at the class IV quality (highly polluted) water according to the By-Law on Surface Water Quality Management for all these years of monitoring.

 

GRAPH 29- NORTH AEGEAN (BAKIRCAY) BASIN BOD (mg/L)

 

GRAPH 30- ERGENE BASIN BOD (mg/L)

Sources: Domestic and Industrial Pollution Monitoring Programme Monitoring Reports (2017)

 

GRAPH 31- GEDIZ BASIN BOD (mg/L)

 

GRAPH 32- KUCUK MENDERES BASIN BOD (mg/L)

Sources: Domestic and Industrial Pollution Monitoring Programme Monitoring Reports (2017)

 

GRAPH 33- SUSURLUK BASIN BOD (mg/L)

 

GRAPH 34- SAKARYA BASIN BOD (mg/L)

Sources: Domestic and Industrial Pollution Monitoring Programme Monitoring Reports (2017)

 

When the averages of all stations belonging to basins were compared in years, a decrease tendency was observed in BOD parameter in general.

In order to determine the pollution real-time and take rapid mitigation measures at source, the Ministry of Environment and Urbanisation is monitoring the pollutant emissions by installing online continuous monitoring stations at the discharge points of wastewater treatment units of installations with a capacity of 10,000 m3/day or higher. The system starts sampling automatically when triggered, measures are taken depending on the results of the analysis by authorised laboratories.

 

GRAPH 35- AVERAGE BOD IN THE HIGHEST POLLUTION LOADS BASINS ANNUALLY (mg/L)

Notes:

1) Basin averages are arithmetic mean of the values from the stations in the basin.

2) Values below detection limits have been asumed zero.

3) There is no measurement in Susurluk and Sakarya Basins for 2013.

 

Sources: Domestic and Industrial Pollution Monitoring Programme Monitoring Reports (2017)