Groundwater risk assessment in Regione Piemonte - Italy European Commission - DG Environment WORKING GROUP 2C WORKSHOP ON GROUNDWATER RISK ASSESSMENT Groundwater risk assessment in Regione Piemonte - Italy Stefano LO RUSSO Bruxelles 28th January 2004 Direzione Pianificazione delle Risorse Idriche E-mail: Direzione24@regione.piemonte.it

Activity and partnership Ministry of environment GNDCI Politecnico di Torino Università di Torino National Research Council

A L P S In the Po plain there are: 15 millions people living (density 375 inh/km2 ) 37 % of italian industrial activities 55 % of zootechnical activities 35 % of agricultural activities A L P S Milano Venezia Torino Po river Adriatic sea Bologna NORTHERN APENNINES Tyrrhenian sea Effects: strong groundwater abstraction (5.300 millions m3 per year) deterioration in groundwater quality (specially nitrate pollution)

Monitoring network for groundwater quality and quantity: Milano Torino Venezia Bologna Monitoring network for groundwater quality and quantity: 2.259 points (1 point /15 km2) two measures per year piezometric level measures started in 1978

Definitions VULNERABILITY CONTAMINATION RISK Specific characteristics of aquifers, related to different geometric and hydrodynamic conditions, to absorb and transport contaminants that degrade groundwater quality over space and time. It is an intrinsic property of aquifers. Regione Piemonte: G.O.D. CONTAMINATION Degradation of groundwater quality as result of human activity. Contamination, therefore, is not an intrinsic property of aquifers but it depends, mainly, on pollutant sources and characteristics. Regione Piemonte: groundwater monitoring network, N balance RISK Groundwater Risk: a measure of the probability that damage to environmental quality of groundwater will occur as a result of a given hazard. Regione Piemonte: …work in progress

Aquifer vulnerability G.O.D. (Foster, 1987; Foster and Hirata, 1988) INPUT PARAMETERS Groundwater hydraulic confinement in the aquifer under consideration; Overlying strata (vadose zone or confining beds); Depth to groundwater table; Method: Plain sector of the region is separated into hydrogeologic units. For each unit G.O.D. VULNERABILITY INDEX is computed.

Assessing nitrogen load deriving from agricultural activity the cultivated land was split into agronomically homogeneous areas (along boundaries of catastral “sheets”) data sources were selected in each area: technical advisors, leader farms, resellers... an interview was conducted for each area and crop: fertilization, management of residues, average yield crop management techniques were listed and a weight was assigned corresponding to its diffusion within the homogeneous area techniques were matched and joined with the crop extension data from the V Census of Agriculture (2000), miming a “sheet”-based detail which is not yet available N from manure was calculated by breeding data (V Census of Agriculture) supply, removal and balance of N at each cadastral “sheet” were calculated supply, removal and balance of N were calculated for agronomically homogeneous and for idrogeologically homogeneous areas

N supply (on agronomic units) Results - supply N supply (on agronomic units)

N removal (on agronomic units) Results - removal N removal (on agronomic units)

N balance (on agronomic units) Results - balance N balance (on agronomic units)

N balance (on hydrogeological units) Results - balance N balance (on hydrogeological units)

Conclusions and perspectives vulnerability of aquifer is an intrinsic property while contamination derives from anthropogenic sources; assessment of potential risk of groundwater contamination is based on overlapping of aquifer vulnerability and potential hazard, related to specific pollutant; there are several methods to evaluate vulnerability, potential hazard and therefore, the potential risk. We are testing some of them in test-sites; to reduce risk in the planning actions it’s only possible to limitate potential hazard by land uses regulations and identification of hazardous activities in high vulnerable zones;