RICHMOND -- State Attorney General Kamala Harris' office criticized Richmond's draft environmental impact report of the $1 billion proposal to expand and modernize Chevron's Richmond oil refinery. In a 10-page letter to the city, the office said the company needs to do more to reduce safety risks and air pollution.

The letter, dated June 6, also directly challenges the oft-stated claim by Chevron and city staff members that the 1,100-plus-page report is among the most comprehensive ever prepared involving an oil company seeking to modernize facilities.

"We urge the city of Richmond to revise the EIR so that it will fully inform the public and the City Council of the local and statewide impacts of this project," the letter concluded.

A spokesman for the Attorney General's Office said Tuesday that the office is in talks with the city and Chevron, and that he expects the concerns in the letter will be addressed before the city approves an EIR.

The letter immediately raised concerns by one city councilman that the city's review of the mammoth project could drag on for several more months, and that it could trigger a lawsuit similar to one that halted a similar project several years ago.

"I'm not sure where we go from here, but this is a major development that may thwart my objective to get the (final environmental impact report) certified and a permit issued before we go on August break," Councilman Tom Butt wrote in his online forum. "At this point, I would say we would be doing well to get it done before the end of 2014, and then it will likely become the target of a (California Environmental Quality Act) lawsuit like the last one."

The city released a final version of the environmental impact report on Monday, after Harris' letter was sent. City Manager Bill Lindsay said the EIR was complete before Harris' letter was received, but that her concerns will be addressed in supplemental documents.

"All comments are taken seriously and will be addressed," Lindsay said. Chevron spokeswoman Melissa Ritchie said Monday that the company had reviewed Harris' letter and that the issues she raised were already addressed in the final EIR, which she characterized as the "most comprehensive and thorough EIR ever developed for a refinery project."

The Attorney General's Office's letter, written by deputy attorneys general Rose Fua and David Zonana, comes amid building resistance to the project, which is under review by the city's Planning Commission. One day before Harris' letter, lawyers for a state environmental group sued the Bay Area Air Quality Management District in San Francisco Superior Court, demanding that the board rescind its permitting of the project until the city completes its environmental review.

Ritchie questioned the Attorney General's Office's complaints and its failure to mention other aspects of the project."Surprisingly, the letter fails to acknowledge the economic and environmental benefits of the project -- including the unprecedented commitment to no net increase in criteria air pollutants, greenhouse gas emissions and health risks -- as well as the scope and depth of work done," Ritchie wrote in an email.

The letter, addressed to city planner Lina Velasco, called on the city to address five main concerns: fuller evaluations of safety risks and air quality impacts; an explanation of how the project will meet state climate change goals; exploring more emission-mitigation measures; and providing a broader range of project alternatives.

Harris emphasized the central point of the project is that Chevron plans to process higher sulfur crude, which caused the corrosion that sparked a fire and explosion at the refinery in August 2012.

"There is an increased safety risk associated with the project's proposal to process higher sulfur crude and gas oils, and the EIR needs to adequately address at least three critical safety issues," Harris wrote, listing needs for a quantitative risk assessment, a risk-management plan and an explanation of its assumption that corrosion risks will not increase.

Facing a $10 to $20 million budget deficit, according to Lindsay, the City Council last week urged the Planning Commission to complete its review this month so that the council could weigh in on any appeals before its August recess. The modernization project promises around 1,000 jobs and could restore tax revenues, which plunged after the 2012 fire.

The Planning Commission is scheduled to hold a hearing on the EIR July 9.

In his e-forum newsletter, Butt said the letter arrived to city officials on Friday but that he didn't hear about it until he was informed by a Chevron official on Monday.

"I talked to a representative from the city's EIR and legal team last night who told me that they felt blindsided by (Harris' office)," Butt wrote. "They also believe that most, if not all, of the AG's concerns have been resolved in revisions to the (draft report) that are included in the (final report)."

Still, Butt expressed disappointment that the EIR now appears vulnerable to legal challenge.

"We charged our EIR and legal team with producing a bulletproof EIR, and I thought we were there. Obviously not," Butt wrote.