Port Commission receives update on Pier 70 environmental investigation; consultants report contaminants but no showstoppers

The Port Commission on an open-session agenda item heard an update on the environmental investigation underway at Pier 70, east of Illinois Street between Mariposa and 20th Street. Carol Bach, the port's Environmental and Regulatory Affairs Manager, and consultants reported that initial field work has identified metals and polycyclic aromatic hydrocarbons (PAHs) in fill material across the site but that the conditions seen to date do not make the project "nonviable."

"We have a pretty good significant set of data," Mark Johnson of the Regional Water Quality Control Board said, adding, "I see no real red flags that are gonna kill the project." Johnson said the findings and approach are comparable to prior bayshore redevelopment efforts such as Mission Bay, where a risk-management plan guided safe redevelopment.

Dorinda Shipman, the project manager with Treadwell and Rollo, summarized field results: Phase 1 and Phase 2 work has collected just under 200 soil samples at roughly 90 locations, more than 30 soil-gas samples and a set of groundwater grab samples, and installed eight monitoring wells. Shipman said analysts found elevated concentrations of metals including arsenic, cadmium, chromium, copper, lead, nickel, mercury, vanadium and zinc above preliminary screening levels, and PAHs in fill and in shallow soils near the former power plant area. Volatile organic compounds in soil and groundwater were generally low, though soil-gas benzene exceedances were detected near Building 36 and the eastern end of Building 105.

"We're assessing that in the human health risk assessment right now," Shipman said, explaining the team will use a risk assessment and a feasibility study to determine whether and where remedial work or engineered and institutional controls are required. She noted that, because contaminants are widespread in fill, complete excavation would likely be cost-prohibitive; cover systems, deed restrictions and other controls are among the likely tools.

Shipman and Johnson described a localized dense non-aqueous phase liquid (DNAPL) observed in the BAE shipyard area that appears viscous and immobile; additional targeted sampling and monitoring wells have been placed to determine whether that material poses a migration risk. In the southeast portion of the site adjacent to the power plant consultants, Shipman said investigators found evidence consistent with manufactured gas plant waste at depth that appears to have migrated onto Pier 70 property; the port will follow up with the power plant owners about next steps.

Commissioners questioned the team about whether previously removed tanks could explain benzene hits. Shipman said the sampling program targeted known former tank areas and that some tanks had been removed; she acknowledged undocumented tanks are possible but said the benzene exceedances are limited and that surrounding samples were below screening levels. A commissioner noted the team had 23 soil-gas samples in an exchange during the discussion.

Shipman said the combined site investigation and risk assessment report is anticipated in roughly May, after which the team will begin a feasibility study and develop a risk-management plan, expected in draft form by the fall. The port will present draft findings to advisory groups and the public for comment before returning to the commission with a final document.

The presentation emphasized that next steps will include hazardous building materials assessments for prioritized buildings and potential abatement planning; the port intends to request authorization to issue an RFP for that work at a future meeting.

The commission did not take a formal action on the investigation at this meeting; the item was informational and staff said they would bring future authorization requests (such as consultant contracts) back to the commission when appropriate.