ALBERT

Beschreibung: The Ljubljansko polje and Ljubljansko barje aquifer system are the two most important groundwater sources for the Slovenia capital Ljubljana and its surroundings. The groundwater is pumped from 4 wellfields on Ljubljansko polje and one wellfield on Ljubljansko barje. In the central water distribution system some settlements are supplied with water from a single water plant, while some receive water from two or more facilities, depending on the volume of consumed water and pressure conditions. In Ljubljana, the water is prepared in a local water supply system without any technical water preparation procedures and is only chlorinated occasionally. Public Water Utility JP VODOVOD KANALIZACIJA SNAGA Ljubljana (JP VOKA SNAGA) monitors the microbiological and chemical parameters of drinking water at all stages. In 2018 started a new IAEA Coordinated Project F33024 "Use of Isotope Techniques for the Evaluation of Water Sources for Domestic Supply in Urban Areas" in which researchers from 16 countries worldwide participate. The Specific Slovenian Research Objectives in CRP are to improve the assessment of most important freshwater resources for domestic supply using environment isotopes, to select significant environmental isotopes for future monitoring that will enable better understanding and interpretation of water interactions important for water managers of JP VOKA SNAGA to predict the availability and quality of freshwater resources for Ljubljana domestic water supply and to develop together with JP VOKA SNAGA and CRP project partners guidelines on integrating environmental isotopes to assist water managers in the planning, designing, and management of freshwater resources for domestic supply in urban environments. Based on the synthesis of the results from previous investigations in the area and the experiences of JP VOKA SNAGA, 97 sampling sites in the Ljubljana water supply system were selected. Sampling sites were selected according to the water supply area and according to the type of sampling sites. Selection according to the type of sampling site in the water supply system includes 6 different types: wells (VD; 44 samples), joint exits from water pumping station (ZV; 7), reservoirs (VH; 23), water treatment locations (PV; 2), drinking water fountains (PIT; 13) and water tap in public buildings (PJ). Additionally, 10 sampling sites were selected including water taps in 2 public and 8 private buildings (PP) which are not included in regular monitoring of JP VOKA SNAGA. Selection according to the water supply area includes 8 different areas: 4 main water fields: Kleče (A), Hrastje (B), Brest (C), Jarški prod (D), Šentvid (E), and 4 areas where the water is mixed from two or three different supply areas: Hrastje/Jarški prod (F), Kleče/Brest (G), Kleče/Hrastje/Jarški prod (H) and Kleče/Hrastje/Brest (I2). Finally, sampling sites on River Sava (R: Brod, Črnuče, and Šentjakob) and at the outflow from wastewater treatment plant (CČN) were also selected. Sampling was performed between 06.09.2018 and 29.11.2018. This database is summarized results of in-situ measurements (water temperature and electrical conductivity) and laboratory analysis (pH, total alkalinity, the concentration of total arsenic in water, isotope composition of oxygen, hydrogen and carbon in dissolved inorganic carbon).

Beschreibung: The isotopic data was obtained to provide information on the temporal and spatial variability of surface water and groundwater in the Ljubljana basin. This dataset includes monthly hydrogen (δ²H) and oxygen (δ¹⁸O) sampling data for groundwater from the Ljubljansko polje (LP) and Ljubljansko barje (LB) aquifers, the primary sources of drinking water for the City of Ljubljana. Sampling was performed between January 2020 to December 2021. Groundwater samples were collected from the Kleče, Hrastje, Jarški prod, Šentvid wellfields (LP), and the Brest wellfield (LB). Groundwater sampling was performed at 13 preselected wells from all five wellfields. If the selected well was not operating, the closest well was sampled instead. Overall, 29 different wells were sampled, and 295 samples were collected monthly by the technical stuff of the water distribution company from a pipe directly connected to the specific well. The water was running for five minutes prior to the sampling. In-situ, temperature measurements were also recorded using a Superfast Thermapen 4 digital thermometer (Electronic Temperature Instruments Ltd). All water samples were collected in 60 ml HDPE bottles and stored at 5 °C until analysis. The isotope ratios of samples were performed at the Jožef Stefan Institute using a dual inlet isotope ratio mass spectrometer (DI IRMS, Finnigan MAT DELTA plus Finnigan MAT GmbH, Bremen, Germany) with an automated H₂-H₂O and CO₂-H₂O equilibrator HDOeq48 Equilibration Unit (custom built by M. Jaklitsch). The average sample repeatability was 0.3 ‰ for δ²H and 0.02 ‰ for δ¹⁸O. Deuterium excess (d−excess) was calculated as d−excess [‰] = δ²H − 8 x δ¹⁸O (Dansgaard, 1964). The obtained isotopic data provide information on the temporal and spatial variability of groundwater in the Ljubljana basin. The related surface water data is also archived at PANGAEA (Žagar et. al. 2022).

Beschreibung: The isotopic data was obtained to provide information on the temporal and spatial variability of surface water and groundwater in the Ljubljana basin. This dataset includes monthly hydrogen (δ²H) and oxygen (δ¹⁸O) sampling data for surface water from the Sava and Iška rivers. Sampling was performed between January 2020 to December 2021 using a polypropylene Burkle TM angular beaker attached to a BurkleTM telescopic rod (Bürkle GmbH, Bad Bellingen, DE). The Sava River sampling was performed at Sava Brod and Sava Šentjakob, while the Iška River samples were collected at Iška vas. Besides isotope data, physico-chemical parameters (water temperature and electrical conductivity) were measured on-site at each location using a calibrated UltrameterTM II 6PFCE (MYRON L Company, Carlsbad, CA, USA), with an accuracy of ±0.15 °C, ±1 μS/cm and ±0.02, respectively. In addition, water discharge and temperature data were obtained from the Slovenian Environment Agency (https://www.arso.gov.si/vode/podatki/amp/H3570_t_30.html, website accessed in 11/2022). Altogether, 56 samples of surface water were collected. All water samples were collected in 60 ml HDPE bottles and stored at 5 °C until analysis. The isotope ratios of samples were performed at the Jožef Stefan Institute using a dual inlet isotope ratio mass spectrometer (DI IRMS, Finnigan MAT DELTA plus Finnigan MAT GmbH, Bremen, Germany) with an automated H₂-H₂O and CO₂-H₂O equilibrator HDOeq48 Equilibration Unit (custom built by M. Jaklitsch). The average sample repeatability was 0.3 ‰ for δ²H and 0.02 ‰ for δ¹⁸O. Deuterium excess (d−excess) was calculated as d−excess [‰] = δ²H − 8 x δ¹⁸O (Dansgaard, 1964). The obtained isotopic data provide information on the temporal and spatial variability of surface water in the Ljubljana basin. The related groundwater data is also archived at PANGAEA (Žagar et. al. 2022).