This is a rendering of Alternative 3, which adds an express lane with the existing carpool lane to the San Diego (405) Freeway. The Springdale Street overpass in Westminster is pictured. (Courtesy OCTA / June 18, 2012)

The public has an extra 15 days to comment on the Orange County Transportation Authority's draft environmental impact report for a proposed widening of the San Diego (405) Freeway.

Orange County residents have until July 17 to send their comments to OCTA on the draft EIR, which outlines the potential effects on surrounding communities.

OCTA is working with the California Department of Transportation on a proposed $1.3-billion to $1.7-billion renovation that could add two to four lanes on the 405 between the San Gabriel (605) and Corona del Mar (73) freeways.

Two of the three options start at the 605 but end at Euclid Street in Fountain Valley and are on the lower end of the potential costs. The third option, the one most touted by the project's engineers and OCTA officials, stretches the widening to the 73.

Every freeway overpass within each proposal's area would have to be demolished, which in the third alternative's case would include the Fairview Road bridge. Costa Mesa finished a multi-million rebuild of that overpass three years ago.

The third choice would also turn the existing carpool lane into part of a two-lane toll road accessible only south of Bristol Street in Costa Mesa or north at Magnolia Street in Fountain Valley.

Some locals have come out against the third alternative at Costa Mesa City Council meetings and at OCTA's public hearings.

OCTA will likely determine which option it would prefer at its Aug. 13 board meeting, officials said. The agency would then make its recommendation to Sacramento, where the state would make the final decision.

A copy of the draft EIR is available on OCTA's website.

Comments on the draft EIR can be mailed to Smita Desphande of Caltrans at 2201 Dupont Drive, Suite 200, Irvine, CA 92612, or emailed to 405.dedcomments.parsons@parsons.com.

joseph.serna@latimes.com

Twitter: @JosephSerna