The rain submerged hundreds of cars, as well as water pumps and tanks. Nine deaths and exposed power lines triggered panic across neighbourhoods. Residents were left wondering whether it was safe to use electrical appliances or drink tap water without confirmation of its safety.
Metro spoke to engineers and officials to answer some of the pressing questions troubling Calcuttans.
Q: My car was submerged in water in the parking lot. How to bring it back to life?
A: The car’s engine should not be turned on if the water reaches the window. “Do not turn on the engine till the water is drained completely. Even after that, look for moisture traces and carry out a thorough inspection. Use a dry cloth or a blower for drying. Only after that, turn the engine on,” an electrical engineer said. Even after drying or even when the ignition is off, it is unsafe to touch the car’s battery in the bonnet.
It is also advisable not to use keyless entry before the car is dried.
Q: My car’s wheels are half submerged in water. Should I be concerned?
A: No. The problem starts when the water level crosses 70% of the wheel height.
Q: My bike was parked in the open and was partially submerged. Is it safe to use it?
A: A two-wheeler, too, needs to be dried completely before starting. “One has to be careful of damaged insulation and, in case of any fault in the wires, it could be dangerous to switch on the battery. It is always advisable to thoroughly dry the two-wheeler, before switching it on,” said an electrical engineer.
Q: Rainwater has flooded my underground reservoir. How to clean or decontaminate it?
A: Drain out the water from the underground reservoir. Cleaning it with bleaching powder and scrubbing the floor and walls of the tank is a safe practice to restore hygiene before allowing fresh water to enter, said an official of the civic body.
The official said that 250-300gm of bleaching powder should be added for every 1,000 litres of water to sanitise it. The person going down into the tank must clean her/his hands and feet with soap before entering.
Q: Rainwater has flooded my water pump. Is it safe to operate it even after draining the water?
A: No. It is unsafe if it is an overground pump and has got submerged in water. Ideally, an insulation resistance testing device should be used to check the IR value before making the pump operational again. “Sometimes using the primitive method of heating the pump with a halogen lamp comes in handy to increase the IR value and make it fit to start,” said an official of West Bengal State Electricity Distribution Company.
Q: What precautions should I take while operating the pump?
A: It has to be ensured that the pump is completely dry and the IR value is over the permissible limit. It is best to consult a licensed electrician before operating a damp pump.
Q: The water has seeped into my room and some of the electrical switchboards are close to the water. How to ensure safety before re-operating the switches?
A: The power supply to the house should be turned off before trying to handle a wet switchboard. “If there is no puncture in the insulation wiring, it should be safe to handle. But it is difficult to ensure or detect if there is a fault in the insulation. So it is advisable to switch off the power supply before handling a wet switchboard,” said an official of the state power department.
Q: Is it safe to step out of home?
A: Only if one does not step into a waterlogged street or come in contact with a lamp post or pole. All of these could cause electrocution.
Q: How do I know if a waterlogged stretch is electrified?
A: Practically, it is not possible to determine if a water body is electrified. There are instruments that can determine this.
Q: What precautions should I take if I’m forced to step out?
A: It is best to stay only on dry surfaces and refrain from touching any metal object like an iron railing, a lamp post or a trident which is exposed to rain.
Reporting by Monalisa Chaudhuri and Subhajoy Roy