U.S. public health officials today began investigating how civilians have been affected by the leakage of petroleum into Pearl Harbor’s tap water from a Navy fuel storage facility.

The Hawaii state Department of Health said it asked the Centers for Disease Control and Prevention and the Agency for Toxic Substances and Disease Registry to conduct the study.

The department said the officials will survey civilians living in homes served by the Joint Base Pearl Harbor-Hickam water distribution system. They will also try to reach people who may have been exposed to contaminated water at work or school.

The Navy’s water system serves some 93,000 people in residential homes, offices, elementary schools and businesses in and around Pearl Harbor.

Starting in late November, about 1,000 people complained that their tap water smelled like fuel or reported physical ailments like nausea and rashes after ingesting it.

Shortly after the Navy said it detected petroleum in a drinking well that serves its water system. Navy officials say they believe leaks from its Red Hill tank farm near Pearl Harbor polluted the well.

Dr. Diana Felton, the state toxicologist, said it’s vital that authorities track how the incident affected all Hawaii residents.

>> RELATED: Hawaii Department of Health upholds emergency order to drain Navy’s Red Hill fuel tanks

Meanwhile, Hawaii’s congressional delegation urged the Navy to comply with a Monday order from the Hawaii Department of Health to drain fuel from the tanks to protect Oahu’s drinking water.

“Defueling safely will require a coordinated effort, and the delegation will do everything possible to support this effort,” they said in a statement. “Clean drinking water is essential to our health and safety, and our future — we all agree this cannot be compromised for anything.”

The delegation consists of four members, all Democrats: U.S. Sens. Brian Schatz and Mazie Hirono and U.S. Reps. Ed Case and Kaiali’i Kahele.

So far only the Navy’s water system has been affected by the contamination. But Honolulu’s water utility draws from the same aquifer as the Navy, and Hawaii officials are concerned leaks will contaminate its water too.

The Red Hill facility holds 20 giant underground tanks built into the side of a mountain during World War II. Each tank is roughly the height of a 25-story building. Collectively, they can hold up to 250 million gallons (946 million liters) of fuel, though two of the tanks are now empty.

The tank farm sits just 100 feet (30 meters) above the aquifer shared by the Navy and the Honolulu Board of Water Supply. It supplies petroleum to all branches of the military.