Milano, January 15th 2016
CAP Holding, WATER SAFETY PLAN
Presentation of the research project:
Isotopic characterization of aquifers of
Milano and Monza/Brianza Provinces
Marco Petitta, Mariachiara Caschetto, Alessandro Lacchini, Valentina Marinelli
Dipartimento di Scienze della Terra– Università degli Studi di Roma "La Sapienza", Italy
Ramon Aravena
Department of Earth and Environmental Sciences, University of Waterloo, ON, Canada
AIM OF THE RESEARCH
Isotopic study of groundwater used for drinking waters by CAP Holding
- Use natural isotopes in groundwater as tracers, for analyze the origin, the flowpaths, the
ages of groundwater, but also interactions and processes driving water/rock exchanges,
including anthropic contribution of pollutants
- The acquired knowledge can be used for optimizing the water resource management,
previewing the future evolution of the aquifer, taking into account changes due to natural
events (climate changes, surface/groundwater interactions) or to human activities
(withdrawals, land use changes, etc.)
- Isotope approach has enormous potentiality, but it is mandatory that collected data are
placed in a correct “hydrogeological” framework, based on a groundwater conceptual model
generally known, to be verified and to be detailed thanks to isotope analysis
- Results can be enhanced by a multiisotope approach, including water and other dissolved
compounds, allowing the comparison of different groundwater flowpath hypotheses,
including flow and transport models, and taking into account not only physical and chemical
processes, but the biogeochemical ones too
Water availability and groundwater exploitation in Europe
90% of drinkable waters in Italy is
coming from groundwater
(but we are using most of the
renewable resources)
Trend- and Trend
reversal assessment
Criteria for Chemical
Status Assessment
Source: European Commission (2008),
Groundwater Protection in Europe, mod. J. Grath
European Commission vision (direttive GW e WFD)
RESEARCH PHASES
Environmental multisotope approach (CSIA FINGERPRINTING):
- Deuterium & Oxigen 18 in water (origin and flowpath of groundwater)
- Tritium in water (groundwater age)
- N15 e O18 in nitrates: origin, transport and fate of nitrogen in groundwater
-S34 e O18 in sulphates: origin and interaction between shallow groundwater and
deep aquifers
- C13 e Cl37 in chlorinated solvents, for evaluating origin, transport and fate
(degradation, natural attenuation) of pollutants of industrial origin showing
minimum concentration in groundwater
Three sampling phases:
- November 2015: characterization (about 80 wells for water isotopes, 20 wells for
nitrate and sulphate isotopes, 5 for chlorinated solvents) DONE
- Spring 2016: second sampling for seasonal changes and individuation of complex
situations
- Summer/Fall 2016: third sampling for examination of complex situations
THE CONCEPTUAL MODEL AS BASIS FOR RESEARCH
GROUNDWATER
MANAGEMENT
AVAILABLE DATA
AND REFERENCES
MONITORING
NETWORK AND
STRATEGY
CONCEPTUAL
MODEL REFINEMENT
POLICY,
Pic
modello
REGULATORY
ACTIONS AND
DECISIONS
FIELD
SURVEYS AND
MEASUREMENTS
COMMUNICATION
AND RESULT
TRANSFER
RESULT EVALUATION
DATA CHECK AND
ANALYSIS
FIRST
SAMPLING
NETWORK
FIRST
SAMPLING
NETWORK
PRELIMINARY
RESULTS FOR
WATER
ISOTOPES
(FIRST
SURVEY)
DISCUSSION AND PERSPECTIVES
Management of groundwater resource, for drinking and for different uses,
requires a detailed knowledge of aquifer and hydrodynamics
A conceptual model of groundwater flow is based on hydrogeological,
hydrodynamic and chemical information
This “basic” characterization is only a necessary starting point, but frequently it
is not sufficient for analizing in detail the processes that affect groundwater,
limiting the evaluation of future scenarios
The modern hydrogeology is adopting several different tools, primarly isotope
analysis (as natural tracers), not only related to the “classical” water isotopes,
but also several “new” compounds in water solution
Coupling a solid conceptual model with isotope results on different groundwater
compounds, allows the evaluation of the origines and of the processes
interesting flow and transport; by this way, the future evolution of the
“pumped” groundwater system can be previewed and the groundwater
management can be significantly improved