Rusty Metal Roof Poison Water?

[Sahlin Farm]

I am building my chicken coop and run and I'm using an old rusty metal roof for both. I was hoping to catch the rain water into a water barrel and use this for the chickens water supply but I'm concerned that the water may be contaminated from the rust particles/residue that may get into the water. Does anyone have knowledge about this and is there a way to ensure the water is safe?

 

[HopefulAcres]

Never use rain run off for drinking water. Between chemicals in the roofing material, dirt and wild bird poop on the roof washing into the water it is always contaminated. Watering plants or general clean up outdoors is the best way to use collected rain water.