The Porter-Cologne Water Quality Act is a California law that enforces compliancy to the Clean Water Act of 1972. The basic idea is to have all surface rainwater collected and purified before entering the City storm water systems. As Owners/Agents of commercial, industrial, or retail properties you currently will be expected to bring your properties up to current code if any of these (4) events occur: (By Nov. 2012 the EPA will mandate that all properties be brought up to code)

If a permit is pulled for any reason
If more than 50%of your parking lot is replaced
If more than 5,000 sf of area is re-graded
If any individual files a complaint with the City