Naslov
Protection of Karst Aquifers in Istria

Autori
Bačani, Andrea ; Parlov, Jelena ; Posavec, Kristijan

Vrsta, podvrsta i kategorija rada
Radovi u zbornicima skupova, cjeloviti rad (in extenso), znanstveni

Izvornik
Second International Conference on Waters in Protected Areas / Nakić, Zoran - Zagreb : Hrvatsko društvo za zaštitu voda, 2007, 267-270

ISBN
978-953-96071-1-9

Skup
Second International Conference on Waters in Protected Areas

Mjesto i datum
Dubrovnik, Hrvatska, 24.04.2007. - 28.04.2007

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
protection zones; karst aquifers

Sažetak
With its population of 206, 344 inhabitants and at least three times more tourists during the summer period, Istria is supplied with potable water from the Istrian karst aquifers. Karst aquifers are highly susceptible to human impact because the water is retained in the underground for short periods of time and contact surfaces between water and rocks are small, and water generally streams through the underground by privileged routes - caverns so self-purification is highly improbable. Consequently, the water quality in Istrian well fields rapidly changes during rainy periods, particularly during intensive precipitation following dry periods, when the water turbidity and suspended matter contents increase by several times. The suspended matter increase is usually accompanied by an increase in concentration of organic oxidizing matter, nitrogen and phosphorus compounds, mineral oils, total fats and some heavy metals, particularly iron and manganese, and in smaller amounts zinc, copper and chromium in leachate from arable land, roads, landfills and, in general, by increased loading of wastewater from settlements either because of inefficient wastewater treatment facilities or leaking septic tanks. Most sources are permanently exposed to bacterial contamination with colliform bacteria, and fecal streptococcus and sulphitoreducing clostridia, which are indicators of permanent fecal contamination. The bacterial count increases by several times during the rainy periods and causes increase in quantity of sludge in spring waters. Only 48% of the Istrian County population is connected to sewerage systems, while the remaining population uses septic tanks or discharges the wastewater directly into the underground. About 500 km2 or almost 20% of the Istrian territory is under agricultural land, cultivated land, vineyards and orchards treated in one way or another with plant protection preparations (Istrian County Master Plan, 2002). Potential polluters registered amount to 216, including industrial facilities and craft workshops, and numerous illegal dumpsites frequently made in karst pits. The potential polluters also include roads, most of which are not fitted with an adequate drainage system. The present paper describes the most recent proposal for protection areas and measures for the Istrian wellheads (Bačani et.al, 2004) prepared in compliance with the applicable Regulation on Designation of Wellhead Protection Areas (OG 55/02). The proposal was promulgated into legislation by a decision of the County Assembly late in 2005. The Regulation envisages four areas for protection of karst aquifers. Pursuant to the Regulation, criteria for determination of the wellhead protection areas include wellhead replenishment time, flow rate and quantity depending on available data. The fourth area or area of limited protection includes the entire inflow area &#8211; the water particle travel time to the wellhead 10-50 days, flow rate <1 cm/s. The third area limitation and control assumes the travel time of 1-10 days, flow rate 1-3 cm/s, and generally encompasses the inflow area. The second protection area is an area of strict limitation with assumed travel time of up to 24 hours, flow rate >3 cm/s, and the first area of strict protection encompasses the narrow surface catchment area.

Izvorni jezik
Engleski

Znanstvena područja
Rudarstvo, nafta i geološko inženjerstvo

POVEZANOST RADA