Engineering college of Brindavan, VTU, Bangalore, India
Email: [email protected]
Lecturer of Geodesy Department, Eshragh University, Bojnourd, Iran
Email: [email protected]
Water always contains dissolved and suspended matter of organic and mineral origin. When these minerals in water exceed the permissible limits, it is called as pollutants or contaminants. There are many reasons of groundwater contamination. Some of them include:
- Careless human attitude.
- Gasoline and other harmful liquids leak from underground storage tanks into the groundwater supply.
- Pollutants soak into groundwater from poorly constructed landfills or septic systems.
- Groundwater is polluted by runoff from fertilised fields, livestock areas, abandoned mines, salted roads and industrial areas.
- Homeowners contribute to groundwater contamination by dumping household chemicals down the drain or pouring them on the ground.
Groundwater moves slowly so the contamination is likely to remain concentrated and close to the point where the pollution occurred. Contaminated groundwater affects human health, water supply systems and environment. Groundwater contaminated with bacteria, chemicals, pesticides, gasoline or oil can result in serious human health problems. Those who drink it or come in contact with it can suffer bacterial diseases, nervous system disorders, liver or kidney failure, or cancer. Malfunctioning septic systems and the overuse of farm chemicals can pollute groundwater with bacteria and nitrates. The health of people and animals drinking contaminated groundwater can be jeopardised.
Table1: Effect of various parameters on human
Location (Study area)
Industrialisation areas including Bellandur, Kengery, Peenyaa, Tannery and Whitefield located at Bangalore City in Karnataka state, India.
Figure1: study area- Bangalore
Figure2: Flowchart showing the Methodology
Water Quality Index (WQI)
Meaning and significance of WQI: WQI is a system of ranking the quality of water in the environment by numerical means. The index assigns a number to a body of water to indicate its quality. The applications of WQI can be summarised as follows:
- It can provide a way to summarise overall water quality conditions in a manner that can be communicated to general public.
- It can tell us whether the overall quality of water bodies poses a potential threat to various uses of water.
- It can be used as a broad tool to indicate success in protection and remediation efforts.
Computation of water quality indices: The WQI can be calculated using the formula as shown here.
Table2: Water Quality Parameters, Standard and Unit Weightage
Table3: Water Quality Index Categories
“C” programme used to calculate the water quality indices of these years i.e. year 2003, 2006 (pre monsoon and post monsoon seasons). The results of WQI belong to Kengery; year 2003 and 2006 is mentioned in table 4, 5, 6.
Table 4: pre monsoon season- year 2006
Table 5: post monsoon seasons- year 2006
Table 6: year 2003
Researchers created maps for some areas in Bangalore including Bellandur, Kengery, Tannery, Peenyaa, White field. These maps indicate the concentration of Nitrate (NO3), Fluoride (F), and Sulphate (SO4), Chloride (Cl), and PH in these regions. In these maps the X axis indicates longitude and the Y axis indicates latitude. The red points in these maps indicate the well stations considered and the colour scale indicates the concentration of “Chloride” , “Fluoride”, “Nitrate”, “Sulphate” and “PH” in year 2003, 2006 in pre monsoon and post monsoon seasons.
In this study Contours define lines of equal “a certain chemical parameter” value across the map extents. . It also displays the distribution of that certain chemical parameter value.
In vector maps, small arrow represents “less pollution” and long arrow represents “large pollution”. And the direction of each arrow expresses whether or not either the concentration of a certain chemical parameter is coming to a well or either it goes out of well.
3D wireframe maps are three-dimensional representations of a grid file. “Z” axis on 3D wireframe maps shows the rate of concentration of a certain chemical parameter in the same area. In this paper, they represented contour maps and 3D maps belong to Kengery showing Nitrate levels in year 2003 and 2006.
Figure3: Nitrate levels- Kengery in year 2003
Figure4: Nitrate levels- Kengery in pre monsoon season in year 2006
Figure5: Nitrate levels- Kengery in post monsoon season in year 2006
Figure 6: 3D Map, Nitrate levels – Kengery in year 2003
Figure 7: 3D Map, Nitrate levels – Kengery in pre monsoon season in year 2006
Figure 8: 3D Map, Nitrate levels – Kengery in post monsoon season in year 2006
Thirty samples of groundwater taken from some areas in Bangalore including Bellandur, Kengery, Peenyaa, Tannery and White field for years 20003 and 2006 in pre monsoon season and post monsoon season and were tested for 10 physiochemical parameters. To study the influence of these 10 parameters on the quality of water they used WQI concept which helped categorise the water quality into ‘excellent, good, poor, very poor and unfit’ for drinking.
These maps were created using the Surfer 7.0 software. They pictorially depicted the areas with high concentration of Nitrate, PH, sulphate, Chloride and Fluoride. These five parameters were considered because they have no relaxation. Nitrate values should be less than 45 mg/L and PH should be between 6.5 and 8.5, Sulphate should be less than 400 mg/L and Fluoride should be less than 1.5 mg/L, Chloride value should be less than1000 mg/L any variance with these values will not be tolerated and it influences the quality of water.
During the span of years 2003 to 2006 the quality of water deteriorated. The PH values got further than the neutral value indicated that the water became more acidic or alkaline. Similarly, the nitrate values also moved higher with the years and as of 2006 it was higher than 300 mg/L. Likewise, the Sulphate value increased in year 2006 than year 2003.
Researchers observed the same result for Fluoride and chloride, which increased with the years. Hence these GIS maps made it possible to understand the area and spot of the problematic stations of groundwater. Now, knowing the polluted stations, they enabled concerning administration to apply remedial measures immediately and stop the spreading of the contaminants into other stations.
Communities generally protect groundwater and prevent pollution by carefully monitoring landuse, minimising hazards such as shallow injection wells, and making sure other practices, such as de-icing roads, use environmentally friendly materials. Restricting certain activities near the wellfield area and removing hazardous materials such as leaky tanks is also helpful. Individuals help protect groundwater by using and disposing of chemicals properly and getting directly involved in monitoring and education activities.
Individuals can do several things to protect groundwater which include:
- Dispose of chemicals properly.
- Take used motor oil to a recycling center.
- Limit the amount of fertilizer used on plants.
- Run full loads of dishes and laundry.
- Check for leaky faucets and have them fixed.
- Water plants only when necessary.
- Get involved in water education.
Communities generally protect groundwater and prevent pollution by carefully monitoring landuse, minimising hazards such as shallow injection wells, and making sure other practices, such as de-icing roads and use environmentally friendly materials.
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