ASSESSMENT OF SURFACE WATERS QUALITY IN THE UPPER PART OF THE RIVER BASIN

Zornitza Cholakova Assoc. Prof., PhD, University “St. Kliment Ohridski”, Faculty of Geology and Geography, Department of Landscape Ecology and Environmental Protection e-mail: [email protected]

• Current paper focuses on research of surface water in the upper Arda River basin (down to the Dam). Investigation area comprises the river basin and • the tributaries Cherna Reka, Byala Reka, Malka Arda, Davidkovska Arda, Madanska Reka, Elhovska Reka, Ribnitsa and two unnamed left and right tributaries. The main objective is to study the concentrations in the bottom sediments of specific and dangerous contaminants - heavy metals and metalloids such as As, Cd, Pb, Cu, Zn, as well as some physico-chemical parameters as pH, EC and TDS in waters.

The report presents and analyzes the indicated physico-chemical parameters of surface waters in the upper part of the Arda River basin. DATA

• Field sampling data, data from Executive Environment Agency and East Aegean River Basin Directorate are analyzed. • Legislation:  Regulation N-4/14.09.2012 for surface waters characterization;  Water Law (latest amendment SG No. 103/13.12.2018);  Regulation No. 6 of 9.11.2000 on emission standards for the permissible content of harmful and hazardous substances in wastewater discharged into water bodies (latest amendment SG No. 24/23.03.2004)  Regulation on environmental quality standards for priority substances and certain other pollutants (latest amendment SG No. 97/11.12.2015)

THE BASIN APPROACH

• The basin survey approach allows us to trace the effect of the tributaries of the main river and their share in the transfer of substances and pollutants to the selected 31 river sampling points in the Gorna Arda basin. • The spring, middle and mouth parts of the main rivers of this catchment are covered, as well as some sections with increased anthropogenic influence around the cities and Madan. UPPER ARDA RIVER WATERSHED

• Area ≈ 2000 km2 (down to the Kardzhali Dam) • 31 sampling points: – 12 p. on Arda River – 4 p. on Cherna River – 3 p. on Malka Arda River – 3 p. on Davidkovska River – 3 p. on Madanska River basin – 2 p. on Byala River – 1 p. on Elhovska River – 2 p. on Ribnitsa River – 1 p. on Malka River

MADAN

RUDOZEM

Golyama

r.

Electrical conductivity (EC) and acidity (pH) dynamic in Arda River waters 800 10

700 9.5 9 600 8.5 EC 500 8 pH 400 7.5 s/cm 410 420 μ 370 370 7 300 340 340 310 290 300 300 6.5 200 270 200 6 100 5.5 0 5 Electrical conductivity (EC) and acidity (pH) dynamic in Cherna River waters 350 9

300 8.8

250 8.6

200 8.4

S/cm EC μ 150 8.2 pH

100 8

50 7.8

0 7.6 Cherna reka Cherna reka before Cherna reka after Cherna before upstream Smolyan mouth in Arda Cherna river mouth into Arda

Electrical conductivity (EC) and acidity (pH) dynamic in Malka Arda River waters 280 8.34

8.32 270 8.3 260 8.28

250 8.26

EC S/cm μ 240 8.24 pH

8.22 230 8.2 220 8.18

210 8.16 Malka Arda before Vievo Malka Arda at Petkovo Malka Arda after Banite Electrical conductivity (EC) and acidity (pH) dynamic in Davidkovska River waters 400 8.4

8.3 350 8.2 300 8.1 250

8

200 7.9

S/cm EC μ 7.8 pH 150 7.7 100 7.6 50 7.5

0 7.4 Davidkovska at Starnitsa Davidkovska at Davidkovo Davidkovska before mouth village village - bridge Davidkovska river before mouth into Arda Electrical conductivity (EC) in Madanska River basin waters and status indicators (Regulation N-4, 2012) 800

750 700

600

500

400 EC S/cm

μ 390 Good 300 Excellent

200

160 100

0 Golyama reka before Right tributary building Madanska before mouth Madan Madanska before Madan • Madanska River waters before mouth exceed physicochemical quality indicator for EC 5 times in the period 1989-2003: • The water status is good in the years 1993 and 1994 (673-690 μS/cm). • The water status is excellent in the year 2019 (390 μS/cm). • After the Madanska River mouth into the Arda, the electrical conductivity of the waters of the main river decreases to 300 μS/cm. Golyama river before Madan Madanska river mouth into Arda Electrical conductivity (EC) in river waters from Rudozem area and status indicators (Regulation N-4, 2012) 800

700 670 600

560

500 540

400

S/cm EC μ Good 300 Excellent

200

100 120

0 Elhovska before Ribnitsa before Wastewaters Malka r. tailings Rudozem Rudozem flowing into Ribnitsa • The river system of Ribnitsa and Malka river (tailing dam outflow) have a major impact on the change in the electrical conductivity of the waters of the main Arda River. • EC rises from 270 (Smilyan downstream) to 420 μS/cm (Rudozem downstream).

Ribnitsa upstream Rudozem Statistical indicators

pH EC, μS/cm TDS, ppm Minimum 7.21 70 50 Median 8.33 310 220 Mean 8.27 320 226.5 Standard Deviation 0.41 150 106.9 Maximum 9.01 750 520 Coefficient of 5 48 47 variation, % Specific and hazardous contaminants – heavy metals (past periods) • Arda after Rudozem (1989-1997) – • Copper - 140 μg /l (1994) max; 10 μg /l min .; average 29.5 μg / l; Waste water emission standard – 500 μg/l ; Water quality standard – 1-22 μg/l; • Lead - 31,000 μg / l (1989) max; 9 μg/l min .; average of 1581.5 μg / l; Waste water emission standard – 200 μg/l • Cadmium - 180 μg /l (1989) max .; 1 μg /l min .; average - 12 μg / l; Waste water emission standard – 100 μg/l • Zinc - 49,500 μg /l (1989) max .; 7 μg /l min .; average over the period - 1752.9 μg / l; Water quality standard – 1-22 μg/l; Waste water emission standard – 2000 μg/l Specific and hazardous contaminants – heavy metals (past periods) • Arda at Vechtino (1981-2003) – • Copper 750 μg / l (1985) max; 1 μg / l min; average - 38.4 μg / l; Waste water emission standard – 500 μg/l ; Water quality standard – 1-22 μg/l; • Lead - 14000 μg / l (1985) max; 1 μg / l min; average - 771.3 μg / l; Waste water emission standard – 200 μg/l • Cadmium - 6300 μg / l (1986) max; 0.10 μg / l min; average - 167 μg / l; Waste water emission standard – 100 μg/l • Zinc - 33 300 μg / l (1985) max; 10 μg / l min; average - 1224.3 μg / l. Water quality standard – 1-22 μg/l; Waste water emission standard – 2000 μg/l Specific and hazardous contaminants – heavy metals (past periods) • Kardzhali dam lake after Arda mouth (1981-2003): • Copper - 500 μg/l max. (1985); 1 μg/l min; average over the period: 28 μg/l; Waste water emission standard – 500 μg/l ; Water quality standard – 1-22 μg/l; • Lead - 5000 μg/l (1982) max; 1 μg / l min .; average over the period: 225.7 μg / l; Waste water emission standard – 200 μg/l • Cadmium - 200 μg/l (1985) max; 0.2 μg/l min .; average over the period: 6.9 μg / l; Waste water emission standard – 100 μg/l • Zinc - 5100 μg/l (1982) max; 6 μg/l min .; average over the period: 365.8 μg/l. Water quality standard – 1-22 μg/l; Waste water emission standard – 2000 μg/l Specific and hazardous contaminants – heavy metals - 2019 • Madanska river: – exceedance of cadmium maximum permissible concentrations- environmental quality standards (MPC-EQS) 0.9 μg / l - up to 26,8 μg/l (approx. 26 times); – lead MPC-EQS 14 μg/l - up to 23,6 μg/l (approx. 1.7 times); – zinc MPC-EQS 75 μg/l - 5098 μg/l (approx. 68 times!) • Arda River at Vechtino: – Zinc MPC-EQS 40 μg/l - 75 μg/l (approx. 1.9 times).

CONCLUSIONS

• The electrical conductivity values of the Arda River waters gradually increase from the springs to the inflow into the Kardzhali Dam. • The valley after the town of Rudozem (after the confluence of the rivers Ribnitsa and Elhovska) and after the Malka river, which drains tailings in the area of the town, is distinguished with rapid growth. • This proves the continuing anthropogenic impact of mining sites and activities, combined with domestic wastewater. CONCLUSIONS

• The heavy metals content in the main stream waters and some of its tributaries show extreme concentrations and poor chemical status, both in past periods and in recent months and years. • This is expected to be confirmed by the concentrations of the same priority and hazardous pollutants (lead, cadmium, zinc, copper, arsenic) in the bottom sediments. THANK YOU FOR YOUR ATTENTION!

This work has been carried out in the framework of the National Science Program "Environmental Protection and Reduction of Risks of Adverse Events and Natural Disasters", approved by the Resolution of the Council of Ministers № 577/17.08.2018 and supported by the Ministry of Education and Science (MES) of (Agreement № D01-230/06.12.2018).