Did I get your attention? Late last year I read a report on a study trying to identify sources of copper in run-off into the San Francisco Bay. Copper pipes are named as a source. I was surprised to see copper roofs and raingutters also named in the report. Why is this a problem, you might ask? Apparently it's the effect on salmonids. It doesn't kill them, but impairs their immune systems, weakens their eggshells, and makes them more susceptible to stress. Around here that's salmon and steelhead. Here's the report: http://www.swrcb.ca.gov/rwqcb2/basinplan/amend/copper/Cu_SSO_BPA_project_description_11-30-06.pdf Here's more about specifics for reducing copper in wastewater: http://www.sanjoseca.gov/ESD/PDFs/cu_designers_05_03.pdf So, how does this effect us? Not sure yet, but it was interesting about clean cuts on the copper reducing turbulence, and using less flux. Obviously, irrigation water doesn't usually end up in the sewer. And most of the water we apply that comes from copper pipe ends up soaking into the soil and not running off into storm drains, right? And the plumbing and homebuilding industries probably won't be forced to switch to any other pipe because a viable alternative just isn't available. But I just thought I'd bring it up in case anyone else is running into this, especially in other sensitive watershed areas like, I dunno, maybe Chesapeake Bay.