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Excessive amounts of copper can be toxic to the Bay's ecosystem. Find out how you can reduce the amount of copper being released to the environment.

Plumbing Design and Installation
Corrosion from copper pipes is responsible for approximately 60% of copper reaching the Regional Water Quality Control Plant. Proper design, installation, and maintenance of copper pipes can decrease the amount of corrosion and loading to the Bay. For more information see our Plumbing Factsheets. We have one for designers (PDF) and one for plumbers and installers (PDF).

Copper in Plumbing
Sanitary sewer lines:

  • Copper
  • Copper Alloys
  • Lead
  • Lead alloys

All above noted are prohibited for use in sanitary sewer lines.

Prohibition of copper wastewater pipes
Potable water lines and other lines; when provided in the CA plumbing code, the City of Palo Alto will consider cross-linked polyethylene (PEX) as an alternative to copper.

Architectural Use of Copper
A copper roof on a new 2,500 sq ft home has been estimated to initially corrode at a rate of 2.5 pounds of copper per year. For more information see our report, Architectural Uses of Copper (2000) (PDF).

Architectural Copper Prohibition
The ordinance provision prohibits the installation of copper metal roofing, copper gutters, and copper granule containing asphalt shingles on new and existing buildings after January 1, 2003. Copper flashing for use under tiles and slates, and small copper ornaments would be exempted. Replacement roofs and gutters on designated historic buildings would also be exempted, but would be required to be prepatinated to reduce copper loading in storm water runoff. See New Palo Alto Ordinance Prohibits Copper Roofing Materials (PDF).

Brake pads
Many brake pads contain copper. They are designed to wear away little by little, each time you slow or stop. Brake pad dust is estimated to be the largest source of copper to the Bay! When it's time to replace your brake pads, inquire about pads made from materials that contain little or no copper. Some parts stores have information about brake pads' copper content, although manufacturers are not currently required to list ingredients. (PDF)