It's called Kapakahi Stream and there's definitely something out of sorts with the Waipahu stream's water quality.
"It smells like sewage, there was white material floating in the water that turned the water milky," said environmental activist Carroll Cox.
"I see degraded water, the quality of the water is degraded and it's been this way since last Friday."
Cox said he first noticed the problem of milky sediment last week and reported it the state and city.
But he said he got no answers about what's causing it and said there's been little action to clean it up.
"It's still the same situation. Nothing has changed. It's about the same consistency when I originally came," he said.
State and city officials have no idea what the milky substance is but said there have been no reported sewage spills in the area.
The Department of Land and Natural Resources said it's monitoring the situation but said it has seen no impact on wildlife.
The Kapakahi Stream in Waipahu is a mile-long stream running the Hawaii Plantation Village to West Loch.
It also feeds into the Pouhala Marsh, which is a critical wetland habitat and is home threatened bird species such as the Hawaiian Stilt, the Hawaiian Coot and the Gallinule.
"The bigger concern is the endangered species that are found here that inhabit this area," Cox said.