1. CURRENT STATUS OF
THE POTABLE WATER
SECTOR IN BULGARIA
PROBLEMS AND FUTURE
DEVELOPMENT
Prof. Dr. Eng. Petar Kalinkov

2. Water resources in Bulgaria
 Surface water
1961-1998 (50% probability)
River basin Total flow BG territory neighbouring countries
106 m3 % 106 m3 % 106 m3 %
Danube basin 6017 30,96 5996 31,63 20,6 4,3
Black sea basin 2243 11,55 1976 10,43 267 56
East Belomorski 7184 36,97 7183 37,90 - -
West Belomorski 3988 20,52 3799 20,04 189 39,7
Total: 19433 100 18956 100 476.9 100
82% formed in the mountains 18% formed in the plains
2430 m3 per capita per annum available surface water

3. Water resources in Bulgaria
 Underground water
1961-1998
Operational Underground Water Resources
River Basin
Potential Utilized Non utilized
m3/s 106 m3/a m3/s 106 m3/a m3/a 106 m3/a %
Danube basin 90 2838 13.5 426 76.5 2412 85
Black sea basin 22 662 11.8 372 10.2 322 48
East Belomorski 37 1167 19.7 621 17.5 552 47
West Belomorski 9 284 5 158 4 126 44
Total (1998) 158 4953 50 1577 108 3376 68
 Underground water is the only possible solution for potable water supply
in many regions of the country.
612 m3 per capita per annum potential underground water

4. WAI & WSI
WATER AVAILABILITY WATER STRESS INDEX
INDEX
WAI = available fresh water WSI = consumed water
population available water
 WAI < 1000 m3/cap/a  WSI = 0,0 - 0,1 no stress;
water deficit  WSI = 0,1 - 0,2 low stress;
 WSI = 0,2 - 0,4 average stress;
 WSI = 0,4 - 0,8 high stress;
 WSI = 0,8 - 1,0 very high
stress;

5. WAI & WSI in Bulgaria
Indices 1991 1995 2001 2004 2005 2010
Population 8 669 269 8 384 715 7 891 095 7 761 049 7 718 750 7 504 868
WAI
2 238 2314 2 458 2 500 2 513 3250
m3/cap./day
Abstracted water,
5199 2464 2 403 2 891 2 657 3 330
10 6 m3
WSI m3/cap./day) 0.268 0.127 0.124 0.149 0.137 0.136

6. Water supply service
At 1998
 4510 (75.8%) settlements are served by the National
Water Supply System;
 98 % of the population is water supplied;
At 2010
 5031 (84.6%) settlements are served by the National
Water Supply System;
 98.8 % of the population is water supplied;

7. the facilities
 11+5 reservoirs with 1 505,000,000 m3 storage capacity;
 42 WTPs with 480,506,000 m3/a capacity, providing 42% of the
supplied water;
 3560 pump stations with 768,378,000 m3/a capacity
 6 087 water tanks with total capacity 2615879 m3;
 70620 km water distribution network.
others
PVC+PEHD
Cast iron
Steel
Asbestos cement
0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

8. Water supplied by WSS
2010
Companies
1998
1994
1986

9. Population (un)growth
2010
1998
1994
1986

10. …which results in
500
450
400
Liters per capita per day
350
300
250
200
150
100
50
0
1986 1994 1998 2010

11. …however
 in 2010
 929,410,000 m3 - supplied water; 340 l/cap/d
 Only 371,400,000 m3(40%) are accounted; 135 l/ca/d
 And 558,000,000 m3 (60%) are not accounted;
70% are 30% are
pure physical consumed but 205 l/cap/d
losses not accounted

12. …and the problems
 Great water losses in the transport trunks, the
distribution networks and the building connections;
 Water shortage during the summer months and
during droughty conditions, due to lack of equalizing
water reservoirs;
 Many not completed facilities of the water supply
infrastructure;

13. Potable water abstraction
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
reservoirs underground rivers
water

14. The water quality
Water Quality Unit River water Res.water Und. water
pH - 7.0-7.8 7.0-8.0 7.0-7.5
0,0÷12,0~330 d 0,0÷10,0
Turbidity NTU 0,0÷0,01
10÷300~40 d 12,0÷20,0
Colour (Pt. Co.) ° 5,0÷30,0 5,0÷45,0 -
Alkalinity mg/l 0,2÷1,0 1,0÷4,0 -
Oxidizability mg.O2 /l 1,0÷6,0 1,0÷12,0 -
Temperature ºC 0,2÷16,0 4,0÷15,0 6,0÷12,0
Fe mg/l 0,0÷1,0 0,0÷0,5 0,0÷0,12
Mn mg/l 0,0 0,0÷2,5 0,0÷0,5
NH3 mg/l 0,0÷1,2 0,0÷0,5 -
NO3 mg/l 0,0÷10,0 0,0÷5,0 0,0÷12,0
NO2 mg/l 0,0÷0,1 0,0÷0,35 -
Microb. Indices above the norm above the norm above the norm

15. 2-stage water treatment scheme

16. 1-stage water treatment scheme

17. Removal of Manganese

18. What are the main WTPs’
problems?
 The equipment is physically and technically out dated;
 Necessity of re-evaluation of the treatment technologies due to
deterioration of the raw water quality;
 The preparation of projects for many WTPs is preceding the
construction and filling in of the reservoirs, which results in
utilization of prognostic, not real water quality data;
 The treatment of technical waters is either not developed at all or
has not been solved good in many WTPs;
 Some water abstraction by reservoirs are not secured by sanitary
protection zones, which creates problems to the raw water quality;
 Lack of research institute that should develop technologies based
on real, not prognostic water quality.

19. THANK YOU FOR YOUR
ATTENTION