E coli bacteria in Kakkanad flat's drinking water: How to stay safe?

Around 338 people suffered from vomiting and constipation at the DLF flat in Kochi's Kakkanad recently, and the health department has confirmed that it was due to the contamination of their drinking water. Manorama News reported that the water was polluted due to E coli (Escherichia coli) bacteria, which is generally found in animal and human intestines. Most of its strains are harmless, but some can harm your health, say experts. It can cause mild to severe diarrhoea, nausea, abdominal cramps, dehydration and in rare cases, kidney and other organ failure. To ensure that the water you use is safe, here are a few preventive measures and hygiene practices you can follow:
1)Boil the water for at least three minutes before drinking it. 
2) Once boiled well, ensure the water is stored in a clean, covered container to avoid re-contamination.

3) You can use water testing kits available in markets to check the quality of your water if you suspect contamination.
4) Install a water filter that removes bacteria, with filters of the size 1 micron or smaller. Make sure you specifically check this feature during the time of purchase. The filter should have a 'purification' feature rather than just filtration.
5) Use hot water to wash dishes as well, to avoid contamination through food.
6) Make sure that the appliances for water distribution (refrigerators, filters, dispensers, ice makers and more) undergo regular maintenance.
7) Disinfection tablets like iodine and chlorine balls are also used in certain households to kill bacteria including E coli.