Persistent flooding caused by landfill subsidence and sea level rise has occurred at Oyster Point for the past decade or more. This week a five-day King Tide event will overtop the Oyster Point Landfill cap and flood Oyster Point Marina.
The Oyster Point Landfill is a closed, unlined Class III landfill in operation from 1956 to 1970. Prior to 1956, what would become the landfill primarily consisted of tidal wetlands.
Between 1956 and 1970, the city of South San Francisco leased the site (approximately 57 acres) to South San Francisco Scavenger Company.
In 1956, Scavenger began disposal operations at the landfill. Initially, municipal solid waste was burned. This activity ended in 1957 following the enactment of laws prohibiting open air burning of rubbish. To address Bay Area air quality regulations, South City and Scavenger established a solid waste disposal site on the submerged lands just east of the original Oyster Point.
The landfill was developed in three phases. Filling began in 1957 and was completed by late 1961. Scavenger placed waste directly into the wetlands and used a wire fence to control the discharge of solids into the Bay due to tidal action. Waste disposal operations eventually resulted in the relocation of the shoreline approximately 3,000 feet to the east of the pre-landfill shoreline.
The volume of waste in the landfill is approximately 2.5 million cubic yards and total tonnage of this material is approximately 1.4 million tons. This volume of waste would cover a football field almost to the height of the Empire State Building.
Beginning in 1961, the landfill received liquid industrial waste for disposal. The types of liquid waste included paints, thinners and coagulated solvent sludge. No records describing the construction of liquid waste sumps have been found. The total volume is estimated at nearly a million gallons.
Consistent with landfill practices at that time, no liner was installed at the site. Waste disposal design features such as liners, cellular division of waste and leachate collection systems were not installed. Instead, the waste materials were placed directly onto the Bay mud. To contain the solid waste from contact with state waters, Bay mud berms were constructed around portions of the waste disposal areas in 1961, 1962 and 1964. However, there is no data to suggest that the industrial waste sumps were ever constructed with additional berms or dikes to control the migration of liquid wastes.
In 1962, a small craft harbor was constructed along the north shore of the landfill. Upon completion of the disposal operations, various landfill closure activities took place through the late 1980s. The closed landfill then became the site for development of the Oyster Point Marina/Park.
The landfill is currently owned by the city of South San Francisco and is operated as a marina, ferry terminal, yacht club, hotel and open space that includes the Bay Trail. The city of South San Francisco is responsible for landfill maintenance; the San Mateo County Harbor District manages marina operations pursuant to a Joint Powers Agreement that terminates in 2026.
South San Francisco hopes to redevelop the site. The 2015 Semiannual Oyster Point Landfill Report states that a project would include excavation of landfill materials at the former Oyster Point Landfill and relocation of these materials off site. The landfill cap would be upgraded to meet the current requirements of Title 27 of the California Code of Regulations with the approval of the Regional Water Quality Control Board and San Mateo County Environmental Health Division.
Where is the wisdom in developing the site without first having a long-term solution for flooding? Health and safety concerns include flooding from landfill subsidence and sea level rise, saltwater breaching the landfill cap, water intrusion into underground electrical facilities, methane gas explosions and liquefaction.
On Dec. 9, 2015, Bruce H. Wolfe, executive officer of the San Francisco Bay Regional Water Quality Control Board sent the city of South San Francisco an enforcement letter regarding recurrent flooding overtopping the landfill cap. South City has until Jan. 30, 2016, to provide the water quality board with a short-term flood protection plan, and a long-term plan is due May 30, 2016.
A long-term management solution that is both fiscally and environmentally responsible should consider a proactive plan for managed retreat and bring the site up to current state regulatory standards.
Sabrina Brennan is a member of the San Mateo County Harbor District Board of Commissioners. The views expressed are her own and do not necessarily represent the views of the Harbor District board or its staff.