Water quality and productivity
Water, water, everywhere, And all the boards did shrink; Water, water, everywhere, Not any drop to drink. S. T. Coleridge
Water has become a strategic resource for the 21st century. With the decline in water productivity and quality, it is likely that water may catch fire, triggering social instability like hunger, civil unrest and wars over water. Below are some chilling facts :
- Every 3 seconds, a person dies of drinking contaminated water somewhere on earth.
- Everyday drinking water contamination claims 25 thousand human lives.
- Every one among five of us has no access to safe drinking water.
- Some 1.3 billion people worldwide are obliged to drink water, fouled by human and animal excreta.
- Some 120 million Europeans still do not have access to safe drinking water which claims untold number of lives.
- In spite of the piped water supply, the water made available to people is not fit for drinking purpose as there lacks proper treatment and regular maintenance.
- Drinking water contamination causes 80 percent of the human illnesses, mainly diarrhoeal diseases.
- Merely 1% of the water on earth, which in technical parlance called freshwater, are usable for drinking, agricultural and industrial purposes.
- Excessive withdrawal of freshwater (like overpumping of groundwater) for irrigation, drinking water and other uses to sustain a growing population are likely to pose a direct threat to the riverine ecosystems which in turn contaminates drinking water, reduces food productivity, and triggers famine as a result of salinization.
- Most of the river systems are heavily contaminated as the human excreta has been flushed into the rivers directly. Each person pollutes some 15,000 liters of freshwater to flush away some 400 liters of urine and 50 liters of faeces. Furthermore, draining the dilutes to rivers contaminates billions of liters of water. Dilution, as conventionally believed, is no solution to pollution.
What can you do?
Disinfect your drinking water with chlorine solution. Or, help others chlorinate drinking water. It takes as little as the cost of a toffee to help a 6-member family to ensure safe drinking water for a day. Go to One Dollar Revolution.
Safe Water for the Poor Movement demonstrated that chlorination also contributes to water conservation, women's empowerment and environmental protection. (Ask for detail literature from GIIS on technical aspects)
- In rural areas, promote drumstick tree paste as a cheaper and safer coagulant for water purification. Crush the seed kernel of the drumstick pods and form a paste by mixing with water. Add more water (1 gram paste to 100ml of water) and shake vigorously. Add the solution to the turbid water. Stir well and allow to stand. Within an hour, 90 per cent to 99.9 per cent of the bacteria in the water, some of them disease-causing, will be removed.
- Instead of flushing your sanitary water from bathrooms and toilets directly to the river systems, use them as an alternative to the compost by making a dehydrating safety tank. This has been practiced since time immemorial in the Kathmandu valley by the indigenous community, Jyapu—indulging in the farming profession without keeping animals. Thus, goes the proverb, Khetko petma, petko khetma (from farm to stomach and vice versa).
- Install a low-flow showerhead. Do not leave water running while brushing, shaving, washing vegetables and rinsing dishes. Put a bottle of water in the toilet tank to slash down the water use per flush.
In urban areas, encourage to adopt rooftop rainwater harvesting to recharge ground water withdrawal. This requires connecting the outlet pipe from rooftop to divert collected water to existing well/tubewell/borewell or a specially designed well.
Rainwater harvesting helps to hold the monsoon rainwater to flow directly into the sewers and then to the river systems. Thus, it mitigates the flood hazard.
Rain water is bacteriologically safe, free from organic matter and soft in nature, and could be directly used at the time of need. It improves the ground water quality through dilution, specially for fluoride and nitrate.
Below are simple, economical and eco-friendly ways how the rooftop rainwater could be recharged to the ground water reservoir (aquifer):
- Abandoned Dug Well
- This method is suitable for large buildings having the roof-area of more than 1000 sq. m. In this method, recharged water is guided through a pipe to the bottom of the dry/unused dug well or below the water level to avoid scouring of bottom and entrapment of air bubbles in the aquifer. Bottom of the dug well should be cleaned and all fine deposits should be removed before recharging. Recharge water should be silt-free. The well should be cleaned regularly. Periodic chlorination is required to prevent bacteriological contamination.
- Abandoned/Running Hand Pump
- This method is suitable for small buildings having roof area upto 150 sq. m. In this method, collected water is diverted from the rooftop to the hand pump through pipe of 50 to 100mm in diameter. For running hand pump, a closing valve is fitted in conveyance system near the hand pump to avoid entry of air in suction pipe. Recharge water should be silt-free. During the recharge, chlorination is necessary before drawing water from the pump.
- Recharge Pit
- This method is suitable for small buildings having the rooftop area of upto 100 sq. m. In this method, a recharge pit of 2 to 3 meter depth is dug to recharge the shallow aquifer. Recharge pit can be of any shape. If the pit is trapezoidal in shape, the side slopes should be steep enough to avoid silt deposition. After excavation, the pit is refilled with boulders and pebbles at the bottom followed by gravel and then sand on the top. Thus, Recharged water is filtered through the pit. Every year after the rainy season, the sand layer in the pit should be removed and replaced.
- Recharge Trench
- This method is suitable for buildings having rooftop area of 200-300 sq. m. Recharge trench is advised when permeable strata of adequate thickness is available at shallow depth. Trench is constructed across the land slope along the boundary walls. The trench may be 0.5 to 1 m wide, 1 to 1.5 m deep and 10 to 20 m long, depending upon the availability of land and rooftop area. The trench is filled with boulders at the bottom followed by pebbles and by sand on the top. The collected water from the roof is diverted through the drain pipe to the trench. The trench should be periodically cleaned.
- Gravity Head Recharge Well
- This method is most suitable in areas where ground water levels are very deep. This technique is appropriate where land availability is limited and aquifer is deep and overlain by impermeable strata. Borewells or tubewells can be used as recharge structures under this technique. The silt-free rooftop water is channelized to the well and recharged under gravity flow condition. The well can also be used for pumping. The number of recharge structures can be determined in limited area around the buildings depending upon the rooftop area and aquifer characteristics.
- Recharge Shaft
- This technique is suitable where shallow aquifer exists below clay layer. A recharge shaft is dug manually or drilled by the reverse/direct rotary drilling method some 10 to 15 meters away from the building for safety. Diameter of recharge shaft varies from 0.5 to 3m depending upon the availability of water to be recharged. Recharge shaft is back filled with boulders, gravel and coarse sand. The bottom the shaft would end in permeable strata i.e. sand. Recharge shaft should be cleaned regularly by scrapping the top sand layer and refilling it periodically.
- Defunct Borewell
- A defunct borewell can be used for recharging rooftop water. A circular pit of 1m diameter for a depth of 0.6 m below ground level is dug around the borewell. The bore and the pit are filled with broken bricks. The top 0.3m portion of the pit is filled with sand. The circular pit is covered with perforated slab at the top. The slab requires regular cleaning so as to keep its holes open to receive water.
Treat water with respect as a vulnerable resource with economic value. Spread the word about importance of domestic disinfection of drinking water, rainwater harvest and groundwater recharge to your family-members, friends and colleagues. Involve women in water management issues. Encourage farmers to use drip irrigation system which cuts down water use by 30 to 70 per cent and increase productivity by 20 to 90 per cent. Organize exhibitions, contests, public meeting or demonstrations on water issues, affecting you.
If your country has never seen a Safe Drinking Water Act, take initiatives to draft one and make efforts to endorse it as a private bill in the parliament. Your lawyer friends could help in this regard.