ASSESSMENT OF THE CHEPINSKA RIVER WATERS QUALITY (BULGARIA) THROUGH THE COMBINED USE OF DIFFERENT INDICES

• Published in: International Multidisciplinary Scientific GeoConference : SGEM Vol. 23; no. 3.2; pp. 35 - 42
• Main Authors: Varbanov, Marian, Gartsiyanova, Kristina, Genchev, Stefan, Metodieva, Gergana
• Format: Conference Proceeding
• Language: English
• Published: Sofia Surveying Geology & Mining Ecology Management (SGEM) 01.01.2023
• Subjects: Agricultural wastes; Ammonium; Ammonium compounds; Ammonium nitrogen; Anthropogenic factors; Catchment area; Catchment areas; Chemical indicators; Dissolved oxygen; Electrical conductivity; Electrical resistivity; Human influences; Monitoring systems; Nitrates; Nitrogen; Oxygen balance; Pollutants; Pollution index; River water; Rivers; Sewage; Surface water; Tributaries; Urban agriculture; Wastewater; Water monitoring; Water pollution; Water quality; Bulgaria
• DOI: 10.5593/sgem2023V/3.2/sl2.05
• ISSN: 1314-2704

The article analyzes and evaluates the current status of the water quality of the Chepinska River. It is one of the main right-hand tributaries of the Maritsa River, and large settlements are located in its catchment area and active agricultural activity is carried out. They cause a strong anthropogenic impact and a significant change in water quality. The heterogeneous impact requires the assessment to be carried out by using a complex of indices that includes the Canadian Water Quality Index (CCME WQI), the Bavarian Pollution Index (CI) and the water oxygen balance index used in the BENILUX countries. The assessment was made according to more than 10 chemical indicators, such as dissolved oxygen, ammonium nitrogen, electrical conductivity, BOD5 and others. The data were obtained from the National Water Monitoring System, at 4 points along the main river and its tributaries, for the period 2015-2022. The reference values for the maximum permissible concentration of polluting substances are in accordance with Regulation N-4 of 2012. Significant water pollution is observed after the settlements, as a result of waste water from urban sewage and agricultural activity. Poor water quality is mainly observed in local sections of the river course. In the lower reaches of the river, the water quality improves significantly.