Just a note about rainwater as a non-potable irrigation source.
Read the following articles and do your own research before using rainwater as a non-potable irrigation source. Generally, using rainwater as an irrigation source for vegetable gardens through drip irrigation or sub-surface irrigation techniques is considered safe. Spraying non-potable water on leafy harvestable vegetables such as lettuce, broccoli, or cauliflower has risks, so read the following articles. If you do spray leafy harvestable vegetables with non-potable water they must be washed thoroughly with potable water prior to eating them. Non-potable water poses some hazards as spelled out in the articles below and care should be taken to insure your food is safe! Make sure you have done your homework so you know how to use non-potable water in a safe and healthy manner! If you are planning to use non-potable rainwater to water non edible flowers, shrubs, trees, and grass then it is perfectly safe for that purpose.