QUALITY AND MAIN SOURCES OF URBAN WATER IN THE APULIAN REGION
Onofrio Lattarulo (°), Michele Maggiore (°°), Michele Vito Perrino (°), Franco Piracci (°) (°) A.R.P.A. Puglia - Agenzia Regionale per la Protezione Ambientale (°°) Dipartimento di Geologia e Geofisica – Università di Bari Abstract In the Apulian region urban water supply comes from various sources. The main ones are constituted by surface waters and spring waters, respectively about 50 % and 25 % of the total quantity (17.000 L/s). These resources are located in neighbouring regions and the water arrives in the cities and country of Apulia via pipelines. The remaining part, the other 25 %, comes from wells located in the Apulian region, which is particularly rich in groundwater. In the aqueduct of Apulia there flows about 17,000 L/s of water. Availability of drinking water for Apulian people is about 350 L/day per person, but about half of this quantity leaks out of water-pipes. Surface waters are collected by dams located prevalently in the Apenninic chain. Water, sufficiently pure and characterized by a low salt content, is subjected to treatment of potability. Spring waters outflow from mesozoic carbonatic aquifer located outside the Apulian region, at altitude of 1500 m. Average discharge is about 3500 L/s and the quality of the water is very good. Spring water show typical characteristics of cool water. The groundwater is affected by sea water intrusion phenomena and content of salt exceeds in some case the concentration of 1 g/L. The major risk related to sea water intrusion concerns the Salento Peninsula, where groundwater is the only resource for drinking use. In other areas of Apulia, urban water comes only from surface water, such as in the north part of Apulia (Foggia district), or is a mixture of surface water, groundwater and spring water such as in the central part (Bari district). Limitations to using groundwater for drinking purposes derive from contamination due to human activities with high vulnerability of aquifers in the karst areas of Gargano, Murge and Salento. The problem is very serious in several places and in particular in the Salento Peninsula where high values of ammonium and nitrate have been recorded in some wells constructed for the potable use of groundwater.