By Laura Sanicola

(Reuters] – Contra Costa County, California has stated that Phillips 66 (NYSE) and Marathon Petroleum (NYSE) might need to cut their capacity at proposed renewable plant sites by approximately 50% and 20% to offset environmental damage.

Two petroleum refiners plan to transform oil refineries located in San Francisco to make transportation fuel using feedstocks like soybean oil or animal fats, which produce less greenhouse gases.

Contra Costa must identify an alternative that is more environmentally friendly than the proposed projects as required by the California Environmental Quality Act.

According to the county, Marathon would have 23,000 barrels of fuel per day instead of 48,000 in Friday’s draft environmental impact report (EIR), which was released on Friday.

According to the county, public comments will be accepted on the draft EIR for at most 45 days.

The county determined that a refiner would be able to supply 102,000 bpd renewable fuels to the region market at Phillips 66 Rodeo in California. This is an improvement on 120,0000 bpd requiring only two pretreatment trains. It will also reduce the need for marine vessels.

Because Marathon uses less feedstock, the county claimed that Marathon would lower air emissions. It said that the plant’s emissions and those from nearby developments would continue to exceed regional air quality thresholds. This would mean that their cumulative impact on the environment would be significant.

The county must consider the impact on water quality, air quality, food prices and other environmental issues according to advocates.

Marathon announced Friday that the company is currently conducting research to see if “green hydrogen”, a form of hydrogen, would be possible at the facility in the future. It is essential to use hydrogen in order to make renewable fuels.