The report by the volunteer group of shoreline water testers presented at a gathering Tuesday comes on the heels of a report for 20 South Maui sites in June. That report showed problems with turbidity and runoff nutrients, as well.

Turbidity is the biggest problem on the west side, followed by “really high nutrient levels,” the group reported. Water temperatures also are warming up to levels that could cause coral bleaching.

The hourlong presentation Tuesday night in Lahainaluna High School’s cafeteria included data collected from shorelines stretching from Honolua Bay to Papalaua. The goal of the Hui O Ka Wai Ola water sampling program is to reveal the true quality of the water and “accelerate positive change.”

“An incredible amount of interested volunteers have shown up for years now, and that is an integral part of gathering all that data,” said Alana Yurkanin of The Nature Conservancy, who’s also the communications and safety coordinator for the program. She noted that this is “the first citizen science-based water quality monitoring program like this in Hawaii.”