MODELLING AQUIFER VULNERABILITY TO NITRATES UNDER THE ASSUMPTION OF VARYING SPATIAL SUPPORT OF WATER WELL DISTRIBUTION

In the early 1980's the Italian scientific community, together with a number of institutional decision-makers, realized how urgent it was to protect natural and environmental resources. They agreed that an adequate level of scientifically organized knowledge allows the accurate planning and development of environmental systems through management and direction of the actual development process, without hindering it. Since the special project was first set up in 1984, as part of the GNDCI-CNR (National Group for the Defence against Hydrogeologic Disasters, of the Italian National Council of Research) scientific context, it has been the cardinal point of Research Line 4 “Assessment of Aquifer Vulnerability”. The problem of groundwater contamination was examined in this project for the very first time in Italy in an organic and extensive manner as a key for forecasting and prevention purposes. The Italian approaches to assessing and mapping groundwater vulnerability to contamination are essentially based on two main methodologies:- The GNDCI Basic Method a HCS (Hazard Contamination Source) type approach that can be used for any type of Italian hydrogeologic situation, even where there is a limited amount of data. A unified legend and symbols are also defined for each hydrogeologic level.- The SINTACS [Soggiacenza (depth to groundwater); Infiltrazione (effective infiltration); Non saturo (unsaturated zone attenuation capacity); Tipologia della copertura (soil/overburden attenuation capacity); Acquifero (saturated zone characteristics); Conducibilità (hydraulic conductivity); Superficie topografica (Slope)] method, a PCSM (Point Count System Model) developed for use prevalently in areas with good data base coverage. The methodological approaches described in this paper now make up the Italian standard which has been set in the recent very important Italian Law (152/99) and which has now been ratified in the national guidelines produced by ANPA, the Italian National Agency for Environment Protection. In this paper the structure of the Research Line, the progress obtained by the 21 Research units (over 100 researchers) in 20 years of activity, the results gained etc. are briefly highlighted.

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The Control of Iron Bacterial Plugging of a Well by Tyndallization Using Hot Water Recycling

Water Quality Research Journal ◽

10.2166/wqrj.1986.005 ◽

1986 ◽

Vol 21 (1) ◽

pp. 50-57 ◽

Cited By ~ 3

Author(s):

D. R. Cullimore ◽

N. Mansuy

Keyword(s):

Direct Injection ◽

Small Diameter ◽

Hot Water ◽

Water Recycling ◽

Water Heater ◽

Time Intervals ◽

Flow Rates ◽

Water Well ◽

Flow Loss ◽

The Town

Abstract A small diameter water well drilled in 1977 in the Town of Bulyea, Saskatchewan generated such a rapid plugging (biofouling) that by 1979 the flow rate was reduced by 59%. Heavy growths of non-specific iron bacteria were found in the water and biofouling projected to be the principal cause of the flow loss. Tyndallization (repeated pasteurizations) treatment was applied using a hot water recycling system installed above the well head. Using a displacement passive gravity direct injection of hot water at 82°C from a water heater into the well, a sequential elevation of water column temperatures occurred until bio-film dispersion occurred (pasteurization) at 45°C+. A recovery to original flow specifications was repeatedly obtained at time intervals ranging from 6 to 403 days. Between treatments, a recurrence of biofouling was noted with flow reductions of 0.06 – 0.07 1/min/day frequently being noted. The rate of plugging appeared to be affected by the previous sequence of pasteurization treatments. Tyndallization was found to satisfactorily control iron bacterial biofouling and maintain flow rates.

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COMPARISON OF WATER WELL SAMPLING METHODS FOR DISSOLVED GASES

10.1130/abs/2018am-322924 ◽

2018 ◽

Author(s):

Gus Wulsin ◽

◽

Colin Whyte ◽

Myles T. Moore ◽

Thomas H. Darrah

Keyword(s):

Sampling Methods ◽

Dissolved Gases ◽

Water Well

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Classification of Aquifer Vulnerability by Using the DRASTIC Index and Geo-Electrical Techniques

Water ◽

10.3390/w13162144 ◽

2021 ◽

Vol 13 (16) ◽

pp. 2144

Author(s):

Syed Hassan Iqbal Ahmad Shah ◽

Jianguo Yan ◽

Israr Ullah ◽

Bilal Aslam ◽

Aqil Tariq ◽

...

Keyword(s):

Land Use Planning ◽

Brackish Water ◽

Anthropogenic Pollution ◽

Aquifer Vulnerability ◽

Drastic Model ◽

Drastic Index ◽

Electrical Sounding ◽

Definition Of ◽

Treatment Policies

Vulnerability analysis in areas vulnerable to anthropogenic pollution has become a key element of sensible resource management and land use planning. This study is intended to estimate aquifer vulnerability using the DRASTIC model and using the vertical electrical sounding (VES) and electrical conductivity (EC) outcomes. The model allows for the identification of hydrogeological environments within the scope of the research, based on a composite definition of each environment’s main geological, geoelectrical, and hydrogeological factors. The results from the DRASTIC model were divided into four equal intervals, high, medium, low, and very low drastic index values. The SW area and NE area depict drastic index values from medium to very high, making it the most vulnerable zone in the study area, while the NW and SW areas show low to very low drastic index values. In addition, the results from the VES and EC the freshwater aquifer in the NE area and brackish water in the SE area, while the rest of the area falls into the category of brackish water. Overall, it can be concluded that areas having freshwater assemblages are on the verge of becoming contaminated in the future while the rest of the NW and SW areas constitute less vulnerable zones. The validation conducted for DRASTIC and EC shows a nearly positive correlation. Wastewater treatment policies must be developed throughout the studied region to prevent contamination of the remaining groundwater.

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