The quality of water coming off of a roof during a rain tends to improve as the rain continues.
Is it safe to collect rain water on a roof.
And also that a first flush diverter will remove a considerable number of the pathogens but not enough to be safe.
Roof runoff has many outdoor uses.
Unless the zinc content is particularly high it is safe to use on lawns and ornamental gardens.
The study has shown that water from a roof can contain about 60 cfu 100ml of coliform bacteria relatively harmless to 50 000 cfu 100ml very likely to contain harmful pathogens and not safe to use and that a slow sand filter will vary somewhat in its ability to remove pathogens.
Rain can wash different types of contaminants into the water you collect for example bird poop on your roof could end up in your water barrel or tank.
Germs and other contaminants while useful for many things rainwater is not as pure as you might think so you can t assume it s safe to drink.
Drinkable rainwater can be collected from most roof types including undamaged asbestos colorbond zincalume and galvanized steel.
Safe roofing materials for rainwater harvesting.
However still this water can be used if the first flush of water is diverted from the roof tops.
It is important to find out if the material or the paint used on your roof or in your gutters could contaminate your rainwater.
This is called the first wash and will be discussed in detail in the first filtering chapter.
Although it is the homeowner s responsibility to ensure drinking water is clean he says information on the safe collection and storage of roof collected rainwater seems not to be reaching many.