US: Irish cement maker Ecocem's proposed manufacturing plant in San Francisco Bay faces a potential planning setback after receiving almost 500 submissions challenging its environmental impact report.

Ecocem is seeking permission for a US$50m grinding plant in Vallejo, close to San Francisco, in the group's first venture in the US, but the town's residents are objecting to the proposal on environmental grounds. According to local reports, some 400 - 500 people and organisations have questioned the company's assessment of the plant's likely impact on the environment, which could force Vallejo's council to delay a decision on planning permission until 2016. The council was hoping to have cleared all planning hurdles by December 2015, but local sources have said that the volume of questions posed during a 60-day public consultation period means the deadline could be pushed back to March 2016.

California law requires Ecocem's subsidiary, Orcem Americas, which is directly responsible for the project, to answer the questions before preparing a final environmental impact report. The city's Architectural Heritage and Landmarks Commission will have to decide whether the buildings that would be knocked to make way for the plant are historic, which is likely to happen in December 2015. The proposal will then have to pass both the Vallejo Planning Commission and then get the support of a majority of councillors before it can get the go ahead.

According to local activist Peter Brooks, a group of citizens recently began a petition to remove four council members said to favour Ecocem's project. He also said that influential US environmental group, the Sierra Club, wrote to the city's authorities expressing concerns about the plans.

Ecocem wants to build the plant on the site of an old flour mill in the city's harbour. It would grind furnace slag from iron smelting that is then used as a component in cement. The process cuts greenhouse gas emissions from normal cement manufacture by 90%.