Since I've been planning on buying a rain barrel for a while now and I have it listed as one of my action items for Low Impact Week, I decided to do some more research on them before I buy.
One thing I ran across, for those of you out there that want to make your own, is this super nifty set of instructions that even I could do myself (with some additional tools). But, just when I was all ready to start planning my rain barrel production line, I ran across something that stopped me in my tracks.
According to this guide from Seattle Rain Barrel (see page 3), if you have an asphalt roof, you shouldn't use the water you collect for watering vegetable or herb gardens. Of course, that is what I was planning on doing with all this fabulous Seattle rain.
Apparently, a lot of modern asphalt shingles contain zinc, which produces toxic chemicals. Since our roof was replaced by the previous owner, I don't know whether or not it is safe.
Does anyone have any clue as to how to test whether my shingles will kill me if I use the collected water on my vegetable plants?