Containing the Slag

Selby Slag has been leaching heavy metals into the bay for more than a century, but some residents worry that a proposed cleanup may cause more harm than good.


There are suspicions that the cleanup of Selby Slag is related to Phillips 66’s refinery expansion plans.

Photo by Nancy Rieser

Selby, a small, unincorporated pocket of Contra Costa County, sits at the mouth of the Carquinez Strait, at the intersection where the Sacramento, San Joaquin, and Napa rivers drain into San Pablo Bay.

For a century, a smelting facility operated at this site, extracting metals such as lead and copper from rock through high-temperature melting. This produced a waste product called slag, which was left on the site and the surrounding tidelands. Although smelting operations ceased in 1971 and the slag was covered by asphalt, heavy metals have been leaching into the bay ever since. And while there have been remedial efforts over the years, there’s a new proposal to clean up the 66-acre Selby Slag site for good.

But some Crockett and Rodeo residents worry that the cleanup may cause more environmental harm than good. And they also question the motives for the effort, because the adjacent Phillips 66 refinery plans to greatly expand its oil-tanker traffic. A subsidiary of Phillips 66, C.S. Land, Inc., owns the Selby Slag site along with the California State Lands Commission. Now residents are mobilizing to fight what they see as two — possibly linked — threats to their community: the planned cleanup of Selby Slag and the expansion of oil-tanker traffic at the Phillips 66 refinery.

The multipronged cleanup plan includes removing part of the asphalt cap that now covers the slag. “When the cap is taken off, that portion of the slag is going to be exposed to bay winds, which will blow the dirt laced with carcinogenic metals into the kitchen and bedroom windows of the neighbors,” said Crockett resident Nancy Rieser of Crockett-Rodeo United to Defend the Environment, or CRUDE. In addition, Rieser fears, the planned dredging of the underwater portion of the slag will release more toxins into the bay.

Residents believe the cleanup may be linked to a Phillips 66 proposal to more than double the tanker traffic at its nearby wharf. Community and environmental groups have been opposing the plan due to concerns about pollution from the ships as well as the fact that the most likely cargo will be crude oil from Canadian tar sands. Refining tar sands oil causes especially high levels of air pollution and greenhouse-gas emissions.

C.S. Land, Inc., a Phillips 66 subsidiary, and the California State Lands Commission each own part of Selby Slag, and cleanup has been on the agenda since the early 1990s. Late last year, the California Department of Toxic Substances Control issued a Draft Environmental Impact Review of the proposed cleanup plan.

According to DTSC documents, the slag contaminates the bay when groundwater flows through it. Metals also leach into the bay from slag in the tidal and shoreline areas and underwater.

The plan includes building a steel wall at the shoreline and dredging up the underwater slag from the bay. About half of the existing asphalt cap will be removed to allow the dredged slag to be spread on top, and then the whole thing would be covered up again with new asphalt. In addition, a series of wells will be installed to draw up contaminated groundwater to be treated on-site.

The DEIR reviews possible hazards from this process. It dismisses some of these concerns as “less than significant” and describes safety measures that could successfully resolve others. But neighbors are not convinced by these assurances.

The newly formed Concerned Neighbors of Selby Slag wants the DEIR thrown out and a new one prepared. Members say the review underestimates the risks, fails to consider safer alternatives, and was prepared by firms with deep ties to Phillips 66.

They note that the DEIR is based partly on research by AECOM, an environmental consulting firm that has a joint venture with Tetra Tech, the contractor that was recently implicated in falsifying environmental reports in the Hunters Point Shipyard cleanup. In addition, the environmental impact report was prepared by Ascent, another environmental consulting firm that appears to have ties to AECOM. (AECOM has subcontracted with Ascent on several projects, and some senior staff at Ascent have also worked at AECOM.)

The report, said Rieser, underestimates the risk that air pollution from the uncovered slag will pose to nearby residents. She said it inaccurately states that the nearest residents live 2 miles away. In fact, “the first large Crockett neighborhood begins a half-mile away as the crow and dust fly,” according to a statement submitted to the California State Lands Commission by the Concerned Neighbors group.

Rieser also doubts the report’s assurances that dredging the slag will not increase pollution in the bay. The section on remediation states that stirring up the slag poses little risk because the metals are “bound in sediment” so they’re no longer harmful. But this seems to contradict the document’s earlier statement that cleanup is necessary partly because toxic metals leach from the underwater slag into the bay.

Neighbors also said the review dismisses alternatives they think might be safer. They want officials to consider either building a sea wall around the underwater slag or burying it in something like concrete.

Some neighbors speculate that the cleanup is underway now because Phillips 66 wants to use the site for its expansion. Rieser said the increase in tanker traffic will stir up the slag, so water coming into the plant’s cooling system will contain more corrosive material, endangering the pipes and therefore the whole refinery. Dredging out the slag, she speculates, is intended to safeguard the refinery from this danger.

Representatives from Phillips 66 did not respond to emails and phone calls requesting comments.

A spokesperson for the Department of Toxic Substances Control said it will respond to questions about the environmental impact review by the end of the summer.

Phillips 66 has made no public statements about why it purchased part of the Selby Slag. Ben Johnson, a lawyer at the California State Lands Commission, said as long as the site is contaminated, “they can only hold it in an undeveloped state.” He pointed out that “any future use would have to be approved by the [State Lands] Commission and evaluated under the California Environmental Quality Act.”

The danger of ships with tar sands oil is one of the reasons residents worry about the Phillips 66 proposal to start bringing in more than double the current number of oil tankers to its wharf adjoining Selby Slag.

The Bay Area Air Quality Management District is considering whether to grant a permit for this project. Community and environmental groups have mounted a campaign to stop it.

Contra Costa County Supervisor John Gioia, who sits on the board of the air district, along with air district staff, have asked Contra Costa County to review the proposed wharf expansion. A review by the air district is “more limited than what the county could do,” Gioia said, since the air district considers only air pollution. “I’m concerned about a number of facets of this project,” he said.

Phillips 66 has argued that it doesn’t need a new county land-use permit because it’s planning no new construction. But Leshun Cross, senior planner for Contra Costa County, said a new permit would be required if the project leads to increased risks. “A change of risk would be something like processing more hazardous material or expanding production, but Phillips 66 says there will be no change,” Cross said. “We intend to seek more information,” she added.

Environmental and community groups say that’s exactly what the wharf expansion will mean: processing more hazardous material and increasing production, thus increasing pollution. They are skeptical about the Phillips 66 claim that oil brought in by tanker will simply replace crude oil now coming in by pipeline.

Whether or not the Selby Slag cleanup and the Phillips 66 wharf expansion are related, neighborhood activists say, permitting agencies should consider the “cumulative impact” of these two projects, along with other sources of pollution, as state law requires.

“My porches are already filthy with soot from the refinery,” said Rodeo resident Maureen Brennan. “Rodeo is surrounded by pollution.”

Editor’s note: We incorrectly stated that AECOM is part of the same company as Tetra Tech. Instead, the two companies have a joint venture. This version has been corrected. We have also clarified the ties between AECOM and Ascent.

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