I discovered a dead squirel in our cold water tank in our attic on return from a holiday. This resulted to smelly contaminated water running from cold taps supplied from this tank and also all hot water taps. I removed the animal from the water and let the system run through with a lots of fresh water but how can I disinfect the system to ensure safety? What should I do? How can this be done? Or do I need to replace both cold water storage cistern and hot water cylinder to be safe? Please help. Thank you.