REMEDIATION TECHNIQUES FOR DRINKING WATER CONTAMINATION AND FOR ELEVATION OF WATER TABLE, A CASE STUDY FROM KERALA, INDI

1. REMEDIATION TECHNIQUES FOR DRINKING WATER CONTAMINATION AND FOR ELEVATION OF WATER TABLE, A CASE STUDY FROM KERALA, INDIA Dr. V.R.Prakasam University of kerala INDIA

2. Scope of study • The aim of the present study : • to investigate the ground water (well wall) quality in one of the selected districts of the state viz. Kollam in India in relation to contamination sources, • and suggest remedies at household levelfor decontamination of water • and for augmentation of water availability.

3. Open dugwell used by villagers in a Panchayat

4. Another open dugwell of villagers

5. Methodology • The work consisted of a Survey among the households using a questionnaire in two panchayats viz. Mayyanad (Coastal land) and Edamulackkal (midland) in Kollam district and water quality analysis following APHA .

6. Methodology(contd.) • The survey was to find out : • The dependence of the households on well water, • The well protection measures adopted by villagers • The sources of contamination of well water. • FILTRATION AND BOILING • It was also attempted to solve issues such as high coliform contamination, low pH and high iron (Fe) content of well water using simple techniques such as filtration and boiling. • CONSTRUCTION OF PITS • Construction of two rain water recharging pits of 2 ft × 2ft × 2ft at a distance of 7 ft from the well was evaluated for elevation of water level in the wells of Mayyanad Panchayat.

7. Result • The survey showed that • In Mayyanad and Edamulakkal panchayats 91% and 95% of households were depending on dug well water. • Almost all the wells were of open type and did not have water tight casing or lining. • Wells were mostly protected by platform and net covering. • In Mayyanad panchayat majority of people used septic latrines whereas • In Edamulakkal panchayat majority used pit latrines. • The dugwells were found located at a distance less than 30 ft from latrines in 80-90% of cases. • Similarly in 75% to 87% of households, the distance between cattle waste pit and dug well was less than 30 ft. • The percentage of households disposing domestic waste in their backyard ranged from 45 to 51%.

8. RESULT(CONTD.) • Well water was found contaminated with coliforms and fecal coliforms in the range of 200 – 1200 MPN/100 ml and 40 to 150 MPN/100 mlrespectively. • pH of well water was always acidic, below the desirable limit of Bureau of Indian Standards (1991). The annual mean was 5.64 ± 0.69. • Similarly Fe fluctuated seasonally from 0.19 ± 0.18 mg/l to 0.51 ± 0.34 mg/l.

9. Water filtration unit The water filtration unit (as in figure) consists of the following materials from top to bottom 1.Crushed rock(gravel)-1.5 inch thick 2.Sand-1.75 inch thick 3.Charcoal-1.5 inch thick 4.Crushed rock(gravel)-1.5 inch thick When water is filtered through this unit the acidic pH of water turns to permissible limits of drinking water

10. Conclusions • Filtration of water using the simple filter unit- consisting of gravel, sand, coconut shell charcoal and gravel- resulted in elevation of low pH. • Excess iron could be removed through filtration of water through cotton cloth followed by boiling. • Bacterial contamination could be avoided by heating the water to roll boil. • Construction of rain pits (21 × 21 × 21) near dug wells increased the well water level during summer, by more than 2 ft. • The above simple techniques are valuable tools in purification of water as well as in improving water availability.