SFO’s runway construction plans include up to two square miles of bay fill. The largest alternative calls for filling 1,332 acres of the bay. By comparison, only 400 acres of the bay have been lost to fill during the last 35 years. The largest runway configurations would also restrict the tidal flow to another 5-6 square miles of bay that would be bounded on three sides. An area of the bay that was similarly enclosed by the existing runways was transformed into mud flats. In all, 8 square miles of bay could be lost to fill, but the impacts on the circulation of the bay may be even worse.

The proposed runways extend far offshore and will impede the tidal flows that flush contaminants from the South Bay. SFO's Science Panel found that with the new runways, "changes in the tidal and sedimentation supply regimes could severely affect the form and ecological function of intertidal habitats throughout the subregion."¹² SFO's Runway Reconfiguration Study found that, "with poor tidal circulation in the South Bay, pollutants tend to build up and can be quite high during certain times of the year."¹³ During the summer months it takes an average of 5 months for a dissolved contaminant to be flushed out from the South Bay¹⁴ . The health of the South Bay depends on the unimpeded tidal action. New runways will trap contaminants and degrade the water quality in the South Bay.

Impacts on water quality will in turn have impacts on the fish and wildlife that inhabit the Bay. The area near SFO is a Pacific Herring spawning ground and is home to the endangered California Clapper Rail. Chinook Salmon and endangered Steelhead spawn in creeks to south of SFO. In the last few years Grey Whales have returned to the Bay and have recently been active well south of the airport. Species that feed in the Bay may absorb high levels of contaminants through the food chain. An advisory from the California Environmental Protection Agency warns, "adults should limit their consumption of San Francisco Bay sport fish to, at most, two meals per month."¹⁵

As it stands today, the health of the Bay is impaired, but San Francisco Mayor Willie Brown goes too far in stating that, "there is nothing natural about the bay."¹⁶ The fact is that the South Bay is a vital habitat that can continue to support many threatened species if it is protected and restored with care. Many government agencies and non-profit organizations are dedicated to both protection and the restoration of the South Bay. 

Extensive dredging will also add new contaminants and sediment to the bay waters. SFO’s status summary released in November 2000 indicates that the following amounts of dredging and fill could be required:

Bay mud to be dredged from runway sites 29 million cubic yards

Fill for runway construction 58 million cubic yards

Bay mud to be dredged to reach fill material 20 million cubic yards

Fill material removed from East Bay for use at SFO 58 million cubic yards

By way of comparison, the Port of Oakland's extensive new dredging program involves 13 million cubic yards. Maintenance dredging of the Bay's shipping channels runs between 4 million to 7 million cubic yards per year. The amount of mud SFO could dredge would cover the entire City of San Francisco a foot deep in mud. The amount of fill SFO could use for runway construction would cover the entire City another foot deep. If all of the dredge and fill were piled onto a football field, it would be over 12 miles high.

To see an image of the Bay before and after the "runway reconfiguration", please visit:
www.sfba.org/sfo/runways.htm

¹² Report of the San Francisco Airport Science Panel, October 19-20, 1999 - Page 17
¹³ URS Greiner Runway Reconfiguration Study (April 1999) - Page 2-17, Section 2.3.3.1
¹⁴ An Introduction to the San Francisco Estuary, Andrew Cohen (December 2000)
¹⁵ California EPA- Office of Environmental Health Hazard Assessment advisory updated 5/28/97
¹⁶ KGO- Channel 7 (12/4/00)

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