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,

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, 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), (105 dm3/per capita/ Directorates are engaged on river basin level. Six-year day - 110 dm3/per capita/day), (102 dm3/per river basin management plans (RBMPs) are the main tool capita/day-111 dm3/per capita/day), (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 coast and reducing pollution, promoting sustainable water ( - 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 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 , 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. The underground water body is accumu- points and levels (aquifers) on the basis of the average lated in Sarmatian deposits - organogenic limestone, annual values of the following key indices: рН, electro- sand and diversity of clays. The water is karst but is also conductivity, total hardness, permanganate, ammonium, precipitation influenced. The total number of catchments nitrate, sulfates, chlorides, Na, Mg, K, heavy metals, of Batovo water supplying system amounts to 40. The etc. The monitored indices are compared with the qual- average flow rate of the water supplying system is 95 ity standards (QS) of Ordinance 1/2007 and Directive dm3 s-1 - 100 dm3 s-1. The potential sources of contamina- 98/83/ЕО and threshold values (TV). tion refer to agricultural activities, wastewater, landfills, manure and livestock farms, as well as settlements of no Quality assessment of Varna region drinking sanitation located in the catchment area. The periodical water water pollution is caused by torrential rains and heavy The water intended for drinking is supplied to Varna snowmelt due to the shallow underground water and the region on the basis of special permits issued by the BSBD weak waterproof clay coating of the aquifer [21]. following the Water Act requirements. The permanent sanitary control is carried out by the WSSC-Varna and Quality assessment of the water resources in- RHI-Varna in accordance with the monitoring programs tended for water supply of Varna region and the water quality is evaluated according to the results The quality of the surface water intended for water of the following indices: organoleptic - colour, odour, supply and their categorization is determined in com- taste and turbidity; physico-chemical - temperature, pH, pliance with the national requirements of Ordinance total hardness, calcium and magnesium, conductivity, No1/2011 and Ordinance No 12/2002 [15, 12] on the manganese, fluoride, permanganate oxidizability (PO), 604 Anna Simeonova, Rozalina Chuturkova, Dora Slavcheva, Sofiya Kiryakova

nutrients, heavy metals, and bacteriological indices - the monitoring period. That is why the annual average Escherichia coli (E. coli) and enterococci, following values of the physico-chemical characteristics of the water the requirements of Ordinance 9/2001 and EU Directive bodies for 2014 year only [25] are listed in Table 2. Both 98/93/EC [10, 11]. water bodies showed high total hardness, high conduc- tivity, high Ca and Mg ions concentrations, which could RESULTS AND DISCUSSION be explained with the origin of the underground water. The latter comes from a limestone rock - Sarmatian Quality of the water resources intended for water limestone (Batovo springs) and Karst limestone (Devnya supply of Varna region springs). The sulphate and chloride concentrations were The results referring to the surface water (the Kam- considerably lower than those of TV and QS, typical for chiya dam) for 2011-2014 period (Table 1) showed that the fresh waters. most of the values are in compliance with the MV and The following results were recorded in 2014 (Table 2) GV for A1 category [20, 22 - 24]. The values of pH var- with reference to Devnya springs physico-chemical ied from 7,39 to 8,32 (GV for A1 category pH is in the characteristics: the water pH was stable, equal to 7,46; range of 6,5 - 8,5); nitrates varied from 1,20 mg dm-3 to the oxidisability value was 0,70 mg dm-3 (5 mg dm-3 -3 -3 2,27 mg dm (GV for A1 category NO3 is 25 mg dm ); QS for oxidisability); the nitrates highest concentra- -3 -3 -3 phosphates were within the range from 0,01 mg dm tion was 5,78 mg dm (50 mg dm QS for NO3); the -3 -3 to 0,032 mg dm (GV for A1 category PO4 is 0,4 mg ammonium concentration was equal to 0,05 mg dm -3 -3 -3 dm ); BOD5 was below 3 mg dm (GV for A1 category (50 mg dm QS for NH4). The average annual values -3 BOD5 is less than 3 mg dm ) and DO was within 71,87 did not show significant differences (P > 0.05). Casual % to 81,4 % (GV for A1 category DO is greater than ammonium concentrations above those of QS and TV 70 %). The heavy metals’ concentrations were consider- were registered. For example, ammonium concentrations ably below the GV for A1 category. The results of the of 0,78 ± 0.044 mg dm-3 were recorded at monitoring microbiological indices showed compliance with GV for point 2. This value is 1,56 times higher than that of QS A1 category varying from 8,88 total coliform/100cm3 to and 1,85 times higher than that of TV (0,4213 mg dm-3 3 45 total coliform/100cm (the corresponding GV value TV for NH4). The good quality of the water body of the is equal to 50 total coliforms/100 cm3). Devnya springs is determined by the perfect protection The ammonium concentrations values were above is provided by the Malm - Valanginian aquifer. those of GV for A1 category through the whole monitor- Regarding the Batovo springs the following results were ing period: 0,209 mg dm-3 in 2011 year; 0,324 mg dm-3 in recorded in 2014 for both monitoring points (Table 2): the 2012; 0,508 mg dm-3 in 2013 and 0,48 mg dm-3 in 2014 water pH value was in the range of 7,50 - 7,61; that of -3 -3 (GV for A1 category NH4 is equal to 0,05 mg dm ). The oxidisability was in the range of 0,50 mg dm - 0,70 mg annual average values were within the GV and MV range dm-3; the ammonium concentration value was equal to regarding A2 category (P > 0.05, Table 1). The Kamchiya dam water is found A2 category in correspondence with the quality requirements in respect to surface water intended for water supply. The monitoring results of the Devnya ground water body (obtained at two monitoring points) showed good water quality for the whole period. Most of the indices were in compliance with the TV and QS. Regarding the results of the Batovo underground water body for the same period (obtained at two points) - most of the indices except nitrates showed compliance with the national requirements. Considerable deviations of the values of most indices and changes of the Batovo and Fig. 2. Nitrate concentrations in Batovo underground Devnya water bodies’ status were not registered during water body for the period 2011 - 2014. 605 Journal of Chemical Technology and Metallurgy, 52, 3, 2017

Table 1. Annual average values of the physico - chemical characteristics of the Kamchiya dam, used for water supply to Varna region, 2011 - 2014.

Indices Year A1 - category A2 - category 2011 2012 2013 2014 GV MV GV MV pH - 7,39 7,95 8,32 8,03 6,5 - 8,5 - 5,5, -9,0 - Color, Pt mg dm-3 11,06 14,11 8,17 9,77 10 20 50 100 Non dissolved mg dm-3 2,28 3,36 1,65 1,5 25 - - - substances Temperature °С 8,5 9,68 11,49 11,92 22 25 22 25 Conductivity μS cm-1 335,37 309,19 228,33 316 1000 - 1000 -

Odor intensity 0 0 0 0 3 - 10 0

-3 NO3 mg dm 1,20 2,08 2,27 1,7 25 50 0 50

F mg dm-3 0,16 1,30 0,05 11,15 0,7 – 1,0 1,5 0,7 -1,7 - Fe mg dm-3 0,047 0,032 0,05 0,038 0,1 0,3 1 2 Mn mg dm-3 0,0053 0,0051 0,0033 0,0183 0,05 - 0,1 - Cu mg dm-3 0,00238 0,00138 0,00195 0,00278 0,03 0,05 0,05 - Zn mg dm-3 0,00245 0,0228 0,0044 0,02150 0,5 3 1 5 Ni mg dm-3 0,00229 <0,0001 0,02 - - - Cd mg dm-3 <0,00005 <0,0001 0,00005 0,0001 0,001 0,005 0,001 0,005 Cr total mg dm-3 0,00054 0,00023 0,00003 0,02710 - 0,05 - 0,05 Pb mg dm-3 <0,0001 <0,0001 0,00005 0,00005 - 0,05 - 0,05 Hg mg dm-3 <0,0003 <0,0003 0,000015 0,00005 0,0005 0,001 0,0005 0,001 CN mg dm-3 <0,006 <0,006 - - - 0,05 - 0,05

-3 SO4 mg dm 30,3 24,48 30,22 20,56 150 250 150 250 Cl mg dm-3 6,69 4,383 4,85 11,15 200 - 200 - Surface active mg dm-3 <0,0375 <0,05 - 1 0,2 - 0,2 - substances -3 PO4 mg dm 0,032 0,043 0,01 0,017 0,4 - 0,7 - Аs mg dm-3 <0,00042 <0,0001 0, 000753 0,0005 0,01 0,05 - 0,05

Dissolved О2 % 81,4 71,87 77,15 73,18 >70 - >50 -

-3 BOD5 mg dm <3 <3 1,5 1,5 <3 - <5 - N - Keldal mg dm-3 <0,7 <0,7 0,35 1,1 1 - 2 -

-3 NH4 mg dm 0,209 0,324 0,508 0,48 0,05 - 1 1,5 Total coliforms /100cm3 45 10 8,88 37,52 50 - 5000 - 37°C

606 Anna Simeonova, Rozalina Chuturkova, Dora Slavcheva, Sofiya Kiryakova

Table 2. Annual average values of the physico - chemical characteristics of the Devnya and Batovo under- ground water bodies, used for water supply to Varna region - 2014.

Indices Devnya undergroung Batova underground QS TV water body, ID water body, ID BG2G000J3К1041 BG2000000N018 Point 1 Point 2 Point 1 Point 2

pH - 7,46 7,48 7,61 7,50 6,5 - 9,5 -

NH4 mg dm-3 0,05 0,78 0,05 0,05 0,5 0,4213 Temperature °С 16,60 - 12,25 12,70 - - Conductivity μS cm-1 740,33 708,50 661,50 793,00 2000 1682,0000

K mg dm-3 3,84 - 3,76 3,86 - -

Ca mg dm-3 70,67 - 90,67 66,33 150 -

H2CO3 mg dm-3 16,52 - 16,52 16,52 - -

Mg mg dm-3 45,00 - 29,33 34,67 80 -

-3 NO3 mg dm 1,65 5,78 18,45 43,03 50 38,2500 Total dry mg dm-3 458,33 - 445,00 397,67 - - residue Total mgeq dm-3 7,23 - 6,93 6,17 12 - Hardness Oxidisability mg dm-3 0,70 - 0,50 0,70 5 - Dissolved mg dm-3 2,80 7,20 6,61 2,44 - - oxygen -3 SO4 mg dm 53,70 - 65,77 35,30 250 197,4875 Cl mg dm-3 22,20 - 8,33 28,27 250 191,8125 Hydro carbonate mg dm-3 405,00 - 311,00 358,00 - - ions

0,05 mg dm-3 (P > 0.05), i.e. it was in compliance with The values were equal to 44,7 mg dm-3 in 2011, 42,03 mg the standards. dm-3 in 2013 and 43,03 mg dm-3 in 2014 [26]. For that Nitrate concentrations above TV were recorded at reason Batovo spring was identified as a water body at both monitoring points of the Batovo springs (Fig. 2) risk from the point of view of fulfilling the main goals during the monitoring period of 2011 - 2014. The highest of environmental protection. The high nitrate concentra- value of 56,85 mg dm-3 was measured at point 1 in 2011. tions resulted most probably from nonpoint sources of

It was 1,49 times greater than that of TV (TV for NO3 pollution (land runoff, precipitation, agricultural activi- is 38,25 mg dm-3) and even higher than GS value (GS ties) favored by the geomorphology of the water body. -3 for NO3 is 50 mg dm ). Decrease of the nitrates values (below the TV) was registered during the following Quality of Varna region drinking water three years – the values found referred to 28,05 mg dm-3 The water intended for drinking is supplied to Varna in 2012, 16,73 mg dm-3 in 2013 and 18,45 mg dm-3 in region from three water supplying systems – the Devnya 2014. Nitrates concentrations above the standards were and Batovo springs network and the Kamchiya dam obtained at point 2 almost throughout the whole period. derivation. The results of the monitoring carried out

607 Journal of Chemical Technology and Metallurgy, 52, 3, 2017

Table 3. Physico - chemical and bacteriological indices of the drinking water in Varna, 2011 - 2014.

Maximum Varna Indices according to permissible Ordinance 9/2001 Devnya values Kamchiya Batovo supplying supplying derivation system system Temperature °C - 5 - 7 16 - 16,5 12 - 13 pH 6,5 - 9,5 7,5 - 7,8 7,3 - 7,4 7,1 - 7,3 Ammonium, mg dm-3 0,50 <0,01 <0,01 <0,01 Nitrite, mg dm-3 0,50 <0,01 <0,01 <0,01 Free residual chlorine, 0,3 - 0,4 0,3 - 0,4 0,3 - 0,4 0,3 - 0,4 mg dm-3 Sulphate, mg dm-3 250 25 - 30 60 - 65 30 - 40 Phosphate, mg dm-3 0,5 <0,03 <0,03 <0,03 Chloride, mg dm-3 250 9 - 12 18 - 20 20 - 25 Iron, mg dm-3 200 10 - 15 <5 <5 Manganese, mg dm-3 50 <10 <10 <10 Zink, mg dm-3 5,0 <0,05 <0,05 <0,05 Copper, mg dm-3 2,0 <0,02 <0,02 <0,02 Cyanide, mg dm-3 50 <2 <2 <2 Nickel, mg dm-3 20 <2 <2 <2 Chromium, mg dm-3 50 <10 <10 <10 Fluoride, mg dm-3 1,5 <0,10 <0,10 0,10 - 0,13 Cadmium, mg dm-3 5 <2 <2 <2 Selenium, mg dm-3 10 <4 <4 <4 Lead, mg dm-3 10 <10 <10 <10 Sodium, mg dm-3 200 <10 12 - 15 <10 Arsenic, mg dm-3 10 <5 <5 <5 Total coliforms and Е.coli , 0 0 0 0 number/100cm3 Enterococci, number/100 0 0 0 0 cm3 during 2011 - 2014 period showed a very good quality of the Devnya supplying system was 16°C - 16,5°C, that Varna region drinking water supplied by all water supply- of Batovo was 12°C - 13°C, while that of Kamchiya ing groups. Most of the values were in compliance with the dam was 5°C - 7°C. The active reaction of the water of national standards without significant variations(P > 0.05). the three supplying systems was neutral (pH range of The minimum and maximum concentrations of the key 7,1 - 7,8). It was not aggressive. indices are presented in Table 3. The total hardness (TH) of the drinking water varied The organoleptic indices - colour, odour, taste and considerably depending mostly on its origin (Fig. 3a, turbidity were in compliance with the Ordinance 9/2001 3b). The value of TH was higher for the water coming requirements [11]. The water was colourless, odourless, from Devnya and Batovo supplying systems due to the without an unpleasant taste, acceptable to consumers origin of the underground water - Karst limestone and with no abnormal changes. The water temperature of Sarmatian limestone, respectively. The TH varied from 608 Anna Simeonova, Rozalina Chuturkova, Dora Slavcheva, Sofiya Kiryakova

Batovo supplying system, 2,80 mgeq dm-3 - 3,45 mgeq dm-3 for Devnya and 0,33 mgeq dm-3 - 0,66 mgeq dm-3 for Kamchiya derivation (Fig. 3a, 3b). The different Ca to Mg ratio for both Devnya and Batovo supplying systems is due to the way the underground water reaches the surface (pressure outflow through the neck orifice of the Devnya springs and slow outflow of Batovo water) and the chemical composition of the limestone rocks of both water bodies. Water conductivity is an important electrochemical index presenting the anion and cation concentrations of the dissolved substances in the water. The lowest (see Fig. 4) was the water conductivity of Kamchiya dam (325 mS cm-1 - 345 mS cm-1), while the highest was that of Devnya supplying system (730 mS cm-1 - 750 mS cm-1). The high conductivity of Devnya and Batovo (670 mS cm-1 - 680 mS cm-1) supplying systems is determined by the high mineralization of both ground water bodies. The most common problem regarding the physico- chemical properties of the drinking water is the content

Fig. 3. Total hardness, calcium and magnesium ions of the drinking water in Varna for the period 2011 - 2014, (a) min. concentrations, (b) max. concentrations.

-3 -3 7,1 mgeq dm to 7,6 mgeq dm for Devnya supplying Fig. 4. Conductivity of the drinking water in Varna for -3 -3 system and from 6,2 mgeq dm to 6,8 mgeq dm for the period 2011 - 2014. Batovo. These values are closely related to those of TH of the underground water bodies. The water was classi- fied as hard regarding both supplying systems. Soft was the water coming from Kamchiya dam with TH varying from 3,0 mgeq dm-3 to 3,3 mgeq dm-3. The water TH depends mostly on the calcium and magnesium concentrations. The highest were the calcium concentrations of Batovo supplying system ranging from 4,99 mgeq/dm3 to 5,99 mgeq dm-3, fol- lowed by those of Devnya, which varied within 3,74 mgeq/dm3 - 3,99 mgeq dm-3 and those of Kamchiya dam, whose values were in the range of 2,50 mgeq dm-3 - 2,79 mgeq dm-3. The magnesium concentrations ranges Fig. 5. Nitrates of the drinking water in Varna for the -3 -3 were as follows: 0,82 mgeq dm - 1,23 mgeq dm for period 2011 - 2014.

609 Journal of Chemical Technology and Metallurgy, 52, 3, 2017

values (the fluoride permissible value is 1,5 mg dm-3). The manganese concentrations were below 10 mg dm-3 (Mn permissible values refer to 50 mg dm-3). The microbiological quality of drinking water is assessed by the parameters Escherichia coli (E. coli) and enterococci which are of paramount importance. E. coli has been used for many years as an indicator of contamination by faecal matter. The enterococci parameter comprises another group of faecal indicator organisms and its determination supplements that of E. coli. Regarding the microbiology of the drinking water supplied to Varna region from Kamchiya dam, Batovo Fig. 6. Permanganate oxidisability of the drinking water and Devnya springs E. coli and enterococci were not in Varna for the period 2011 - 2014. found during the whole monitoring period. of ions from the nitrogen group. Nitrate concentrations greater than 50 mg/dm3 could cause serious health CONCLUSIONS problems as methemoglobinemia in infants and young children [27]. Very low levels of nitrates ranging from The quality of the water resources intended for wa- 3 mg dm-3 to 5 mg dm-3 were registered in Devnya and ter supply to Varna region was in compliance with the Kamchiya water supplying systems (Fig. 5). Different national standards and safe for human health. Most of was the case with Batovo supplying system, where the physico-chemical and microbiological indices were nitrate concentrations of 35 mg dm-3 - 40 mg dm-3 were below the threshold values, which made the water in- -3 registered (NO3 permissible value is 50 mg dm ). The vestigated suitable for drinking purposes and household main reason refers to the high values of nitrates content needs. Problems were identified with some of the water of Batovo underground water body - they are well above resources intended for water supply - Kamchiya dam and the guide value. Ammonium and nitrites were not found Batovo springs. Kamchiya dam provides surface water in all water supplying systems. The phosphates concen- easily influenced by natural and anthropogenic impacts trations were also considerably below the permissible leading to some abnormalities of the water quality like values (Table 3). ammonium concentrations above the guide value for The PO is a very important indicator of the organic A1 category. Batovo is a shallow ground water source and mineral contamination of water. The results from contaminated by nitrates – the latter content is above the the monitoring showed values ranging from 0,4 mg threshold values and which is why the water body is at dm-3 to 0,6 mg dm-3 for Batovo supplying system and risk. The highest nitrate concentrations found could be from 0,5 mg dm-3 to 1,2 mg dm-3 for Devnya supplying referred to nonpoint sources of pollution generally from system (PO permissible value is equal to 5 mg dm-3). land runoff, precipitation and agricultural activities. Higher values were found for the drinking water from It was found that the drinking water supplied to Kamchiya dam derivation (ranging from 2,0 mg dm-3 to Varna region from Kamchiya dam, Devnya and Batovo 2,3 mg dm-3). In fact the latter tendency is expected in springs was of a good quality. The values of the key case of surface water bodies that are easily influenced indices were in compliance with the national standards by different natural and anthropogenic impacts and without significant variations. meteorological conditions (Fig. 6). The water quality of the water sources in Varna The content of the heavy metals Pb, Cd, As, Cr, Se, region can be further improved in case: Ni was below the permissible values (Table 3). Fluoride • The sanitary protection zones around Kamchiya concentrations lower than 0,10 mg dm-3 were recorded dam are revalidated according to Ordinance No 3/2000; for all water supplying systems. They are in compli- • Analytical methodologies referring some specific ance with the national and WHO guideline maximum chemical elements are introduced to provide data accu-

610 Anna Simeonova, Rozalina Chuturkova, Dora Slavcheva, Sofiya Kiryakova

racy in compliance with the standard set in Ordinance 5.12.1998, 1998. 12/2001 and Water Act; 11. MOEW, Ordinance No 9 on the quality of water • Good agricultural practices and serious control of intended for drinking and household purposes, SG the fertilizers and pesticide usage in the area of Batovo 30 of 2001, 2001, (in Bulgarian). ground water body are applied. 12. MOEW, Ordinance No 12/2002 on the quality re- quirements for surface water intended for drinking REFERENCES water supply, SG. 63 of 2002, 2002, (in Bulgarian). 13. MOEW, Ordinance No 3/2000 on the conditions 1. A.K. Biswasa, C. Tortajadab, Future Water Governance: and procedures for exploration, design validation, Problems and Perspectives, International Journal of and operation of sanitary protection zones around Water Resources Development, 26, 2, 2010, 129-139. water sources and facilities for drinking water sup- 2. G. Hlebarov, N. Kozarev, Dynamics of surface water ply and around the sources of mineral waters used pollution caused by open pit mining in copper concen- for therapeutic, prophylactic, drinking and hygiene trate, J. Chem. Technol. Metall., 51, 3, 2016, 350-356. purposes, SG. 88 of 2000, 2000, (in Bulgarian). 3. E. Beamonte, J.D. Bermudez, A. Casino, E. Veres, 14. MOEW, Ordinance No1/2007 on the exploration, A statistical study of the quality of surface water use and protection of groundwater, SG 87 of 2007, intended for human consumption near Valencia 2007, (in Bulgarian). (Spain), Journal of Environmental Management, 83, 15. MOEW, Ordinance No1/2011 on the monitoring of 2007, 307-314. water, SG 34 of 2011, 2011, (in Bulgarian). 4. M. El-Fadel, M. Zeinati, D. Jamali, Water Resources 16. MOEW, Ordinance No Н-4/2012 on the character- in Lebanon: Characterization, Water Balance and ization of surface water, SG 79 of 2014, 2014, (in Constraints, International Journal of Water Resources Bulgarian). Development, 16, 4, 2000, 615-638. 17. EC, Directive 2000/60/EC of the European 5. D. Cîrtînă, E. Traistă, Research on the influence Parlament and of the Council of 32 October 2000 of metallurgical industry waste on soil and ground establishing a framework for Community action in water quality, J. Chem. Technol. Metall., 49, 3, 2014, the field of water policy, Official Journal of the EU, 311-315. OJ L 327/1/22.12. 2000, 2000. 6. T. Todorov, D. Rabadjieva, S.Tepavitcharova, New 18. GWP, The post - 2015 development agenda, thermodynamic database for more precise simulation Bulgaria stakeholder perspective on water goal and of metal species in natural waters, J. Chem. Technol. its implementation, 2014, www.gwp.org. Metall., 41, 1, 2006, 97-102. 19. EEA, National report on the status and protection of 7. Iv. Boevski, N. Daskalova, A method for determina- the environment in Bulgaria, 2015. http://www.eea. tion of toxic and heavy metals in suspended matter europa.eu/soer-2015/countries/bulgaria. from natural waters by inductively coupled plasma 20. MOEW, MH, Annual report on the quality of the atomoc emission spectrometry (ICP-AES). Part I. surface water intended for water supply in the Black Determination of toxic and heavy metals in surface Sea River Basin District in 2014, 2015. www.bsbd. river water samples, J. Chem. Technol. Metall., 42, org, (in Bulgarian). 4, 2007, 419-426. 21. Varna Municipality, Development Plan of Varna 8. EUROSTAT, Water statistics, 2015. http://ec.europa. Municipality for the period 2014 - 2020, Varna, 2013, eu/eurostat/statistics-explained /index.php/ Water_ (in Bulgarian). statistics#Water_uses. 22. MOEW, MH, Annual report on the quality of the 9. MOEW, Water Act, State Gazette No. 67/27.07.1999, surface water intended for water supply in the Black 1999, (in Bulgarian). Sea River Basin District in 2011, 2012. www.bsbd. 10. EC, Council Directive 98/83/EC of 3 November org, (in Bulgarian). 1998 on the quality of water intended for human 23. MOEW, MH, Annual report on the quality of the consumption, Official Journal of the EU, OJ L 330, surface water intended for water supply in the Black

611 Journal of Chemical Technology and Metallurgy, 52, 3, 2017

Sea River Basin District in 2012, 2013. www.bsbd. vironmental status in 2014, 2015. www.riosv-varna. org, (in Bulgarian). org/, (in Bulgarian). 24. MOEW, MH, Annual report on the quality of the 26. RIEW - Varna, Regional report of the environmental sta- surface water intended for water supply in the Black tus in 2013, 2014. www.riosv-varna.org/, (in Bulgarian). Sea River Basin District in 2013, 2014. www.bsbd. 27. L. Fewtrell, Drinking - water nitrate, methe- org, (in Bulgarian). moglobinemia, and global burden of disease: A 25. RIEW - Varna, Regional report of Varna region en- Discussion,

612