As a child growing up in Nanakuli in the 1960s, Tammy Mahuka remembers swimming in the waters mauka of the Ulehawa Channel. Her companion, Kenneth Silva, recalls fishing and crabbing there as well.

"It was fun," she says. "The water was clean back then."

Today, Mahuka shivers at the thought of swimming in Ulehawa Stream. Illegal dumping upstream has contaminated the waters, she says. The last time Silva went crabbing in the stream, he said, his legs glowed in the dark after he climbed out.

"Seriously," he says. "When we came out the mud, the sludge that settles on the bottom actually glows on your feet. It's from all the phosphates they dump directly into the canal."

"Everything they throw in there," adds Mahuka. "People upstream don't realize what they're doing when they throw stuff in the water."

What sort of stuff?

Name it, she says — dead dogs, wild pigs, animal entrails, hypodermic needles, motor oil, car batteries, household chemicals, industrial effluents, fertilizer runoff — just about any awful thing you can think of gets hurled in the stream.

Periodically, Mahuka says, city crews come in to "remove the gunk," because it would be too hazardous to allow it to enter the ocean.

"If the people just realized if they stopped doing that, then the water wouldn't glow at night," she says.

Mahuka points out a historical marker planted only a few yards from the tent where she and Silva live at Ulehawa Beach Park.

"Beneath your feet are the remains of traditional Hawaiian settlement dating to A.D. 1500 to 1800," it reads. "This site has been preserved by the City and County of Honolulu for future research and education purposes. Few such coastal sites survive along this part of the Wai'anae shoreline, so please kokua and do not disturb this cultural resource."

"This place is historic," says Mahuka, who tells a stranger she remembers when the old Ulehawa bridge was torn out in the mid-1990s. "You know where that bridge is today? You're standing on it!"

It has been covered with sands removed from the Ulehawa Channel, she says.