SAN RAMON (CBS SF) – Chevron announced Friday that has postponed its return to office plan for employees, the latest Bay Area company to change their plans amid rising COVID-19 cases.

According to Bloomberg, the petroleum giant planned for workers at its San Ramon headquarters to return in September but said in a statement that it is “monitoring regional case rates for improvement to determine a new return date.”

Earlier on Friday, Contra Costa County health officials said cases have risen in the county by 30% over the last two weeks as the Delta variant drives a surge in cases among the unvaccinated. COVID-19 hospitalizations in the county have also soared in the past month.

The company also said that employees at its largest office in Houston are not expected to return before October.

Texas has also been hard in the latest surge. According to the Texas Medical Center, more than 5,600 people tested positive in the Houston area for COVID-19 Thursday.

Chevron had planned to bring back office employees under a hybrid model of two remote days per week.

While most Chevron employees have been working from home, Bloomberg reported that about a third are working on site at service stations, oil fields, refineries, ships and offshore platforms.

Other Bay Area companies that have recently postponed their return to office plans include Facebook, Lyft and DoorDash.