Choose a barrel that doesn't add unwanted chemicals to the water you use on your garden.
Harvesting rain water is one means of reducing run-off in the garden and lawn. A typical 1,200-square-foot roof sheds 700 gallons of water during a storm, producing 1 inch of rain. Collecting rain provides a convenient source for gardeners, while saving money otherwise paid to the local water company. Choosing the right kind of barrel material eliminates the addition of toxic chemicals that can contaminate the contents of a water container. Does this Spark an idea?
Food-grade Plastic
Food-grade plastic barrels are preferable to those meant for holding chemicals. This type of barrel is available in 45- to 60-gallon capacities, and are often used to ship peppers and olives from foreign countries to the United States. Before using for water storage, these containers need to be thoroughly cleaned to remove any food residue. A mixture of chlorine bleach and water are most often used for this purpose.
Blue Plastic
These are food-grade barrels made of a medium-blue plastic. The color is attractive, but the real reason for its use is its ability to block light. Light encourages algae and bacterial growth in rain barrels. While not a leachable substance, water tainted in this way is undesirable for human consumption and watering plants. Rainwater harvested from roof run-off should never be used for human or animal consumption.
Wood
Wooden barrels that formerly contained wine, olives or other foodstuffs are safe for use as rain barrels. They are not recommended for collecting and storing drinking water because it is difficult, if not impossible, to remove all the food residue in the crevices and wood grain. Do not use barrels that contained chemicals or other toxic substances in the past.
Metal
Metal barrels are fine for collecting rain water, but tend to rust even when painted. Metal containers with an interior enamel coating are often used to ship foodstuffs. These can be used for garden rain water and for potable water in the short term. If the enamel is chipped or cracked, it no longer protects the metal, and the resulting rust will contaminate the water.
Collection, Filling and Storage
Shingled roofs contaminate the water that runs off them. Asphalt and treated-wood shingles leach chemicals and add undesirable solid particles to the run-off. Additionally, bird droppings may contaminate roof water. A hose made of food-grade plastic should be used, rather than a garden hose, to eliminate possible chemical leaching. The white potable-water hoses used to fill water tanks in recreational vehicles or boats are made of food-grade plastic. Store water barrels on a raised platform to reduce chemical leaching into the plastic from concrete or contaminated soil. Store water barrels away from substances that could introduce chemicals through absorption. For example; storing a plastic rain barrel near a lawn mower or gas cans allows gasoline vapors to leach into plastic storage containers.
Tags: often used, rain water, barrels that, chemical leaching, contaminate water, food residue, food-grade plastic