The Mill Valley School District is exploring other possible locations for its new middle school.

The expanded scope, prompted by community comments, means delaying the draft environmental impact report on the project, district officials said.

In October, officials said the draft report would be ready by February. The district now expects the draft will be available for public review this summer. A public hearing could be held in late July, said Elizabeth Kaufman, the district superintendent.

“We know the Mill Valley community is eager to see our proposed plans for the modernization of the Mill Valley Middle School,” Kaufman said. “However, we want to design the best possible project for our students, parents and the larger community — one that accounts for the environmental, sea-level rise and air quality concerns we have heard from our parents.”

In the earliest weeks of the project, parents and community members implored the district to find a new location for the school because of environmental concerns. The school sits on a former city burn dump, raising questions about soil or airborne contaminants, they said.Also, the campus at 425 Sycamore Ave. is adjacent to the Sewerage Agency of Southern Marin plant, which parents said emitted frequent odors. Sea-level rise also is a concern because the campus is subject to frequent flooding, parents said.

Keeping the school where it is remains an option, officials said. The district has not announced what the other prospective sites are.

Sharon Nakatani, the president of the district board, said the expanded review will provide more information on which sites are the best fit based on environmental conditions.

“While the current middle school site is the preferred site, the draft EIR will evaluate a variety of sites for interim and future use,” Nakatani said. “This information will allow the district to make an informed decision on how to proceed with the project.”

In addition to the draft report, the district is moving forward with an environmental investigation of the middle school campus under the oversight of the California Department of Toxic Substances Control and Marin County Environmental Health Services.

This work will evaluate the condition of the campus to ensure that historical environmental issues are safely addressed during a redevelopment. The district expects the findings of its investigation, called a preliminary endangerment assessment, to be available for public review and comment at the same time as the draft environmental impact report.

“We understand that the delays can be frustrating, but we want to make sure we take the time and necessary steps to ensure that we design a future middle school campus that is safe and meets the 21st century learning needs of our students,” Kaufman said.

The school project is expected to be funded by proceeds from Measure G, a $194 million facilities bond approved by district voters in 2022. The bond also includes some site improvements at the district’s five elementary schools, but the district plans to allocate at least $130 million of the bond proceeds to replace or upgrade the middle school.

Several other possible sites for the new school, including the Edna Maguire Elementary School campus, were explored early on but ruled out for various reasons. Friends Field, a site the district owns next to the middle school, was briefly considered last year, but the district quickly eliminated it after city leaders, athletic boosters and residents protested, with some threatening to sue.

The plan for environment review has been ongoing at the middle school campus. The district planned to hold classes in portable buildings during the two-year construction process after the current building was demolished.

However, parents in a group called MVMS Modernization Mess have continued to call for the district to explore new locations.

“This is not exactly what most of us envisioned for our children in this otherwise beautiful community,” the group’s website says. “We need an alternative site, and we need to take action now.”