If I'm reading your post correctly, you have a concentration of .03 parts per million (30 per 1,000,000,000 in your post). Is that correct?
The EPA standard used to be .05 ppm, but it was lowered to .01 ppm in 2006. You would have been within the EPA guidelines for human drinking water consumption up until the 2006 rules went into effect.
See this:
http://pubs.caes.uga.edu/caespubs/pubs/PDF/B1301.pdf
Looks like 1.0 ppm is a rule of thumb for poultry.
I'm guessing your birds would not live long enough to consume enough arsenic from your drinking water for it to be a health risk to them. As far as consuming your birds being a health risk to you, your birds may be getting less arsenic from your water than commercial birds get from their feed and litter. I have seen studies indicating impact to laying and reproductive levels, but it was at higher concentrations of arsenic, near the top end of the limit in the UGA link above. You're well under that.
Disclaimer: I'm not an environmental engineer!
To answer 3Good:
Arsenic can kill quickly, or over time, depending on the concentration and frequency of exposure. In high concentrations, it is immediately toxic. In moderate concentrations, it kills, and was used as a poison in the ol' days Europe because the poisoning symptoms looked similar to cholera. It was referred to as "inheritance powder" in its heyday as a murder weapon. In smaller doses over time, it leads to arsenicosis, and to increased risk of cancer and organ damage. Yes, accumlated exposure to dietary sources over time is a concern. Poultry consumption is of particular concern because of high levels of arsenic in some commercial poultry feeds and litter.