Sinking water table and stinking drainages
June 16, 2010 Leave a comment
MADURAI: Rows of colourful plastic pots, waiting to be filled up with water from hand pumps. Worn out water tankers racing ahead of schoolgoing children. These scenes are very common in residential areas along the banks of the now bone-dry Vaigai. The frequent power shutdowns notwithstanding, people residing so near, yet so far from the city are not able to pump groundwater to their overhead tanks. The water is too meagre and too hard.
The groundwater table has shown a progressive decline over the years in Madurai due to various factors. The major factor is the demise of its water bodies, from where concrete structures have sprouted. The disappearance of water carriers and encroachment of the surviving water bodies have ensured that there is inadequate percolation of rainwater.
According to a City Development Plan prepared by the National Institute of Urban Affairs, the city’s population is expected to touch 12.82 lakh in 2011. The city can take pride in having one of the oldest underground drainage systems in the State that came into existence between 1925 and 1948. But much water has flowed down the Vaigai since then and the flow has now stopped. At present, an estimated 50 to 60 million litres of waste water is generated in the city daily. A major portion of this water is either let into the ground or the Vaigai or subjected to improper treatment at inadequate facilities. There are even reports of sewage water getting mixed up with drinking water in areas like Karpaga Nagar in K. Pudur. Till the ongoing underground drainage work is completed and the water treatment plants start functioning, the quality of groundwater is going to be abysmally low.
The groundwater available at several places in the city and suburbs does not conform to Indian Standard Specifications for Drinking Water (IS: 10500), according to a study made by Madurai-based Enviro Care India. In many places, the hardness and total dissolved solids (TDS) are more than two times the desirable levels. The worst affected places are residential areas not properly served by underground drainage. The hardness of water around the many urinals dotting Madurai is very high.
Absence of flow in the Vaigai, discharge of waste water into the ground and failure to recharge and replenish groundwater are the main reasons for the current state of affairs, according to S. Rajmohan, Managing Director, Enviro Care India, who conducted the study in association with the Confederation of Indian Industry in March 2010.
The steps required to improve the quality of ground water, which remains unfit for human consumption now, are a proper sewage treatment system and improvement of rainwater harvesting system. The Koodal Alagar Perumal Temple tank on Town Hall Road is an example of neglect. After putting a rain water harvesting system in place, the tank is always filled with garbage and rainwater. Dr. Rajmohan insists that properly treated waste water can be re-used productively.
It is estimated that 14,000 litres of water can irrigate one acre of land. The recycled water can be used to develop a green belt around the city, water plants in gardens and even to raise crops, he points out.
According to the study, the highest level of TDS (against the desirable level of 500 milligrams per litre) is in Industrial Estate, Kappalur (4,400), followed by K. K. Nagar (2,970), Avaniapuram (2,580), Villapuram Housing Board (2,430), Tirupparankundram (2,060) and New Vilangudi (2,010). Beyond 500 milligrams, water can cause gastro-intestinal irritation.