No abstract

Water quality in the Dalmatian waters of Southern Croatia was assessed using four different indices: an arithmetic index, arithmetic modified index, geometric modified index, and Solway-modified index. The waters were sampled 12 times during 1 year (from July 1998 to July 1999) at 50 sampling sites in Dalmatia. Nine water quality parameters were evaluated: temperature, mineralization, corrosion coefficient, dissolved oxygen, biochemical oxygen demand, total nitrogen, protein nitrogen, total phosphorus, and total coliform.A comparison of the indices showed that the arithmetic modified index and Solway modified index are relatively similar for high-quality water (i.e., they enable better discrimination between high-and low-quality water). Both indices, however, tend to yield a lower index number for low-quality waters. Water Environ. Res., 75, 388 (2003).

The purpose of this study was to evaluate the prevalence of Legionella spp. and compare the quality of hot water between four facilities for accommodation located in Southern Croatia (the Split-Dalmatian County). The research included data collection on the technical and technological characteristics in the period from 2009 to 2012. The survey included a type of construction material for the distribution and internal networks, heating system water heater type, and water consumption. Changes in water quality were monitored by determination of the physical and chemical parameters (temperature, pH, free chlorine residual concentrations, iron, zinc, copper and manganese) in the samples, as well as the presence and concentration of bacteria Legionella spp. The temperature is an important factor for the development of biofilms, and it is in negative correlation with the appearance of Legionella spp. Positive correlations between the Fe and Zn concentrations and Legionella spp. were established, while the inhibitory effect of a higher Cu concentration on the Legionella spp. concentration was proven. Legionella spp. were identified in 38/126 (30.2%) of the water samples from the heating system with zinc-coated pipes, as well as in 78/299 (26.1%) of the samples from systems with plastic pipes. A similar number of Legionella spp. positive samples were established regardless of the type of the water heating system (central or independent). The study confirms the necessity of regular microbial contamination monitoring of the drinking water distribution systems (DWDSs).

The purpose of this study was to monitor and record the specific characteristics and properties of most of the important water resources in Dalmatia located in Southern Croatia for a period of 5 years (1998-2002) according to established standards for drinking water. The paper presents a detailed account of their chemical content, the classification and the concentration of salts. The bacteriological pollution levels are indicated by the total coliform bacterial levels (MPN coli/100 mL). The water characteristics are expressed by coefficients, which represent the ratios between water ingredients. The Ca/Mg eq ratio, SO4/Cl eq ratio and K1, K2 for bicarbonate hardness were calculated. The hygienic characteristics of the water samples were expressed by the total coliform bacteria estimation (MPN coli/100 mL), the permanganate consumption (KMnO4) and biological oxygen demand (BOD5). Karst waters in Dalmatia are moderately hard, the SO4/Cl ratio is 0.38-1.6, non-corrosive (K1 lower than 0.2) and not significantly mineralised (< 500 mg/L minerals). Sulphate waters are generally hard, the SO4/Cl ratio is higher than 1.6, K1 is 0.2-0.65. Marine waters are quite hard or hard, particularly at the river estuaries, the SO4/Cl ratio is lower than 0.38, and K1 is higher than 0.65. The groundwater and springs in Dalmatia are less polluted than surface waters. A majority of these have a geometric average value of MPN coli < 150/100 mL of water observed in 24 of 42 locations studied. The highest bacteriological pollution was found in nine locations where MPN coli > 1000/100 mL and moderate pollution was found in nine locations where MPN coli is between 150 and 1000/100 mL of water. The physical and chemical parameters determined for the most sources in Dalmatia are safe below the international permissible limits.

The objective of this paper is to study the hydrological characteristics and origin of the hydrogen sulphide spring water from the Split spa in Southern Croatia in 1987, 1988 and 2003. This paper presents the results of monitoring the content of chlorides and hydrogen sulphide as well as the temperature of the hydrogen sulphide spring water. Since the hydrogen sulphide content during the dry periods significantly differs from the hydrogen sulphide content during rainy periods, this paper also compares the results obtained for those two periods. Under the influence of great quantities of rainfall during cold periods (winter and the beginning of spring) the ratio between seawater and surface water changes and thus the reduction of chlorides and other minerals occurs. The lowered temperature also reduces hydrogen sulphide which can disappear completely. The concentration of 12 per thousand chlorides (76-94.4% days/year) and 12 mg/L hydrogen sulphide (66.7-88.9% days/year) has been taken as a limit value between water with a normal typical content and water in cold rainy periods. According to the monitoring results it can be concluded that hydrogen sulphide spring water consists of seawater and hydrogencarbonate surface water with a fairly constant content during dry periods while the hydrogencarbonate content increases during rainy periods.