A team of about 1,600 firefighters and professionals has been sent out to stop an oil leak that was discovered on Aug. 28 in Yulin, Northwest China’s Shaanxi province. Photo: Ding Gang/Caixin

Firefighters participate in the cleanup Thursday. Local authorities said that about 62 barrels of an oil and water mixture has leaked from the pipeline. Photo: Ding Gang/Caixin

A temporary dam has been built to filter the water polluted by the leak. Photo: Ding Gang/Caixin

The temporary dam prevents polluted water from flowing into the Yanhe River, which supplies water to more than 2 million residents in the city of Yanan. Photo: Ding Gang/Caixin

Leaked oil floats on the water’s surface. It was reportedly the second time this month that a leak had been discovered at China’s largest oil and gas field. Photo: Ding Gang/Caixin

Firefighters work near the site of the leak. As of Thursday, most of the leaked oil had been cleaned up, according to local authorities. Photo: Ding Gang/Caixin