Early Friday morning, surfers walking to the ocean through Makalei Beach Park on the Ewa side of Diamond Head paused to read warning signs posted by the state Department of Health Clean Water Branch by the steps leading down to Kaluahole Beach.

“Caution: high bacteria levels found here on 10-7,” read the signs. ”Contact with water may cause illness.”

An advisory posted Thursday on the Clean Water Branch website stated that a count of 146 enterococci per 100 milliliters of beachwater, exceeding the risk threshold level of 130 ent/ 100 mL, had been found in samples taken during routine monitoring Wednesday.

The cause was undetermined, the advisory said, stating that enterococcus is a fecal indicator bacteria often found with pathogenic microorganisms that can cause gastroenteritis and ear, eye, nose and throat infections.

It warned that children, the elderly, and people with weakened immune systems are the most likely to develop illnesses after swimming in polluted water.

On the beach, a couple played in the brownish, high-tide shorebreak with two small children and an infant, their towels hung on a naupaka hedge near a bacteria warning sign.

The surfers paddled out to the break known as Suis, where, in between sets of smooth, 2-foot waves in the still, hazy air, they discussed the signs, which none of them could remember having seen there before.

“Where you enter the water, there were those floating bubbles that come with polluted water,” said Ron Iwami, a retired City and County firefighter.

“I think the water looked worse yesterday,” said bodyboarder Peter Ono, a.k.a. “Boogie Pete,” a bartender who was laid off when his Waikiki employer closed in March.

“The water doesn’t look that dirty,” said a non-regular.

“Bacteria are invisible,” someone else said.

“Just try not to swallow any water, I guess,” Ono said.

The surfers wondered what could have caused the bacterial spike, as the area hadn’t had heavy rains, which can cause pollution to be washed from land into overflowing streams, canals and storm drains and out to sea.

Two neighborhood moms paddled out with their school-age sons.

One mom said they’d hesitated when they saw the signs, but the waves were good, the kids had the day off from school, and “it’s probably less contagious than (a big box store).”

“It’s my birthday, I gotta surf,” said longboarder and public schoolteacher Andree Paradis.

Which didn’t mean the pollution wasn’t worrisome, she added.

Late Friday afternoon, the Clean Water Branch posted an advisory of a water quality exceedance of 254 ent/100 mL in beachwaters sampled at Laenani Neighborhood Park in Kaneohe.

To check on beachwater quality statewide, visit eha-cloud.doh.hawaii.gov/cwb/