You can check it out here; short clips about rain water harvest devices, testing and urban waste of water.
The test results are in and they show that the water quality is not up to drinking standards as they show coliform bacteria which can cause some unpleasant bathroom centered problems when consumed. So in addition to storing that water the homeowner should make plans to treat this water before it is consumed. The two pictures below show rain water harvested from Costa Mesa and Tustin, California. One had a first flush device and the other had gutter glove as a first stage filtration. Both showed coliform bacteria after 27 hours. The brown color of the water from the first pix is because of the growth media which will blossom in the presence of fecal matter and turn the water black and poisonous. The black water in the second pix does not look appealing at all.
A view of the first flush device one one of the two systems tested.