Rainwater harvesting tanks are used by many people as either their only source of water for their horses/livestock or as a way to supplement mains water.

Every system is different, you may just have water barrels or IBC’s with the gutter directly into them, or larger collection tanks with a filter at the top to prevent debris entering the tank.

We would always recommend having a filter to collect stop debris entering the container.

The problem with rainwater collection is not the rainwater, but what it is running off and exposed to, on the way to the tank, as well as the biofilm built up inside the collection tank. If you’re using an IBC then you will also have algae. 

Rainwater is generally collected from roofs. The roof material, the age of the roof and whether it is surrounded by trees or in direct sunlight will also have an effect, on the quality of the water collected. As will whether the gutters are kept clear or not.  

We would advise you to have your water sent for testing, for Equine/livestock water, we would advise that you test for Salmonella, E Coli and Total Coliforms.

Total coliforms is the collective term for the different kinds of bacteria found in water, this includes faecal coliforms, which in this case would be the faeces of birds on the roof of buildings. You can send your water for testing to companies such as Kingshay or the Irish Equine Center.