JournalJournal of Chemical of Chemical Technology Technology and Metallurgy,and Metallurgy, 52, 3, 52, 2017, 3, 2017 602-612 QUALITY ASSESSMENT OF THE WATER RESOURCES INTENDED FOR WATER SUPPLY OF VARNA REGION, BULGARIA Anna Simeonova1, Rozalina Chuturkova1, Dora Slavcheva2, Sofiya Kiryakova2 1 Department of Ecology and Environmental Protection Received 13 September 2016 Technical University - Varna, 1 Studentska str. Accepted 20 December 2016 9010 Varna, Bulgaria E - mail: [email protected] 2 Water Supply and Drainage Sytems Co. Ltd, 33, Prilep str., 9000 Varna, Bulgaria ABSTRACT Quality of the main water resources intended for water supply to Varna region was assessed for the period 2011 - 2014. Kamchiya dam, Devnya and Batovo underground water bodies were subjected to investigation. Key physico-chemical and bacteriological indices were analyzed following the EU and national standards. Some abnormalities like ammonium con- centrations above the guide value were registered for the Kamchiya dam - the highest value of 0,508 mg dm-3 was registered in 2013. Nitrates contamination above the standards was established for the Batovo water body, probably from nonpoint sources of pollution. The highest nitrate value of 56,85 mg dm-3, 1,49 times above the threshold value, was measured at one of the monitoring points during 2011. Most of the values obtained were below the threshold limits through the whole period and the water was classified as suitable for drinking purposes and household needs. Keywords: water resources, drinking water quality, physico-chemical indices, pollution, Varna, Bulgaria. INTRODUCTION latter refers to the water resources balance. It is worth noting that the water sources are scarce - 20 billion m3/y, The challenges faced by all countries in their strug- excluding Danube river, and besides they are unevenly gle for economic and social development are largely distributed throughout the country. The average annual related to water. Fresh water resources are essential amount of water per capita is about 2300 m3/y - 2500 for every human activity and must always be of qual- m3/y which ranks the country among the five poorest ity appropriate to their intended use. The problems of countries in Europe, i.e. Poland, Czech Republic, Bel- fresh water referring to pollution, over-exploitation, gium and Cyprus (the average annual amount of water shortages, improper treatment are identical worldwide. per capita for Europe is 5300 m3/y) [8]. On the other Fresh water resources are not inexhaustible and they hand, almost all water resources are formed on the ter- must be conserved, controlled and, if possible, increased ritory of Bulgaria providing the country’s independence or sustainably used [1 - 7]. in this respect. The water resources on the territory of Bulgaria The water resources within the territory of Repub- (110912 sq. km.) depend on numerous factors: climate, lic of Bulgaria are exclusive state property and their topography, geology and geomorphology, hydrographi- management is carried out on a national and basin level cal characteristics of the river basins and anthropogenic regulated by the Water Act [9] and many national regu- impacts. The geographical position of the country, the lations, fully harmonized with EU directives [10 - 16]. specific atmospheric circulation and diverse landscape The Ministry of Environment and Waters (MOEW) is structure are the main reason for unfavorable water. The the responsible authority for the quality of the water 602 Anna Simeonova, Rozalina Chuturkova, Dora Slavcheva, Sofiya Kiryakova resources on a national level, while the four River Basin dm3/per capita/day), Blagoevgrad (105 dm3/per capita/ Directorates are engaged on river basin level. Six-year day - 110 dm3/per capita/day), Pernik (102 dm3/per river basin management plans (RBMPs) are the main tool capita/day-111 dm3/per capita/day), Plovdiv (94 dm3/ for ensuring the required amount and quality of water with- per capita/day - 101 dm3/per capita/day). Some of these out any to human health and no environmental damages. districts are less populated than Varna. However there are The Ministry of Health and its regional structures many Bulgarian districts of water consumption similar (28 regional health inspectorates, RHI) are the competent to that of Varna or even lower (Fig. 1b). authority in the field of drinking water. The water supply and sewerage companies (WSSC), in their capacity as Characterization of water resources intended for entities, are responsible for implementing the require- water supply of Varna region ments of drinking water legislation. They are active in The water supply of Varna region is carried out by two complete drinking water quality monitoring. types of water resources - surface and underground water. Following the UN proposed global goals concerning The region is water provided by three different in size and water and the EU Water Framework Directive goal [17] origin water supplying systems situated outside the terri- of reaching “sustainable water use based on a long-term torial boundaries of the municipality: the Kamchiya dam, protection of available water resources” for all Commu- the Devnya Springs group and the Batovo Springs group. nity waters by 2015, Bulgaria needs to make great efforts The Kamchiya dam is the main surface water source in fulfilling a number of objectives such as preventing used for water supply of the central Black Sea coast and reducing pollution, promoting sustainable water (Burgas - Varna) and the only one which supplies Varna use, timely and adequate provision of clean water and sanitation services, preventing, controlling and reducing water-related diseases, etc. [18]. The present study aims to investigate the quality of the available water resources intended for human con- sumption and household needs in Varna region as well as the quality of the drinking water for 2011 - 2014 period. EXPERIMENTAL Study area Varna is the third largest city in Bulgaria with population of 335,949 and the largest seaside resort on the Bulgarian Black Sea coast, often referred to as the marine (or summer) capital of Bulgaria (Fig. 1a). The hydrogeological conditions of Varna municipality are a prerequisite of the insufficient water resources to meet its needs for drinking water supply. The water consumption varies through the seasons and strongly increases during the summer period due to the large number of tourist and recreational users visiting the resort areas. The drink- ing water from the public water supply to Varna district varied from 90 dm3/per capita/day to 95 dm3/per capita/ day (2011 - 2014) [19], which is considerably lower than that of several Bulgarian districts such as Sofia, the capital of the country (128 dm3/per capita/day-136 dm3/ Fig. 1. Map of Bulgaria (a) and drinking water consump- per capita/day), Burgas (108 dm3/per capita/day - 112 tion of the Bulgarian population by districts, average per dm3/per capita/day), Ruse (99 dm3/per capita/day - 113 capita (b). 603 Journal of Chemical Technology and Metallurgy, 52, 3, 2017 region. The dam is built on the Luda Kamchiya river, basis of monitoring programs approved by the MOEW. about 120 km south-west of Varna city with capacity of The Black Sea Basin Directorate (BSBD) and RHI - 228 million m3. It collects mostly surface water from Varna are the responsible authorities for the quality of snowmelt and rainfall. The water is fed to Varna with a the surface water intended for drinking on the territory flow rate of1800 dm3 s-1 through “Kitka-Varna” deriva- of Varna region. On yearly based monitoring programs tion. Bearing in mind that the dam is an open reservoir, BSBD and RHI organize the sampling of the surface there is a potential risk for direct and indirect water water. The water quality is analyzed by selected key contamination caused by anthropogenic activities and indices as dissolved oxygen (DO), biochemical oxygen unfavorable weather conditions [20]. demand (BOD5), ammonium (NH4 - N) and nitrate (NO3 The Devnya Springs are located in Devnya river val- - N) nitrogen, phosphate (PO4 - P), heavy metals, total ley, about 28 km to the west of Varna. They are the big- coliforms, streptococci, etc. The project category of gest karst springs in Bulgaria. They are approximately the surface water intended for drinking (A1, A2 and A3 30 in number and are combined in seven spring groups. category) is determined on the basis of average annual The geological horizon is exclusively represented by values of physico-chemical and bacteriological indices the karst limestone rocks of Malm-Valanginian aquifer compared with guide (GV) and mandatory values (MV). forming a water-bearing layer. The underground water A1 category is given to water of best quality which could body is directly fed by rain and surface streams’ infiltra- be used for water supply after preliminary treatment and tion. The Devnya Springs are the only place where the disinfection only. A2 water category requires preliminary underground water comes out naturally to the surface. treatment as well as physico-chemical treatment and dis- The average delivery rate of the springs is about 3400 infection. Water determined as A3 category needs more dm3 s-1, while 1600 dm3 s-1 are used for Varna water precise treatment including several stages of preliminary supply. A lot of potential sources of contamination are and physico-chemical treatment and disinfection [12]. situated in the area of the Devnya Springs but the Malm- The quality of the underground water in Varna is Valanginian aquifer (powerful coated waterproof marl) determined in compliance with the requirements of provides good natural protection of the springs from Directive 98/83/ЕО and Ordinance No1/2007 [10, 14] deterioration [21]. The Batovo springs group is located under the responsibility of BSBD and WSSC-Varna. about 10 km north of Varna city along the terrace of The water quality is assessed at different monitoring Batovo river.