LIHUE — A monthly analysis of streams, rivers and surf spots around the island found high concentrations of enterococcus bacterium at more than a dozen locations with Nawiliwili Stream easily being the nastiest in September.
Volunteers with the Surfrider Foundation’s Blue Water Task Force gathered water samples from 21 sites across Kauai, and then tested the water for the bacterium, which is a federally recognized indicator of fecal presence in the water.
The samples, which were collected on Saturday, Sept. 14, showed seven sites produced results below Hawaii’s single-day sample standard of 130 enterococci per 100 milliliters of water.
The sites with acceptable readings were Waiohai Surf, Kealia Surf, Waikoko Surf, Davidsons Surf, Anini Boat Ramp, Rock Quarry Surf and Waimea River Mouth.
The sites with subpar readings, from bad to worse, were The Bowl Surf (Hanalei), Anahola Bay Surf, Wainiha Stream, Middles Surf, Pakala Surf, Hanamaulu Bay Beach, Wailua River Park, Koloa Landing (Waikomo), Moloaa Stream, Kalapaki Bay Surf, Hanalei River, Hanamaulu Stream and Nawiliwili Stream.
Kalihiwai Surf tested between acceptable and subpar.
The task force uses the same test as the Hawaii Department of Health (HDOH), but compliments its water quality program by testing surf sites and streams, not the mainly popular beaches the HDOH tests.
“With very little rain in recent weeks you may be surprised that some of the stream values are still high. While with little or no rain there is likely no surface runoff of animal wastes, there is still groundwater contamination from cesspools and malfunctioning septic systems,” said Surfrider Kauai senior scientist Carl Berg in a note that accompanied the findings.
“These contaminated groundwater wastes do not get diluted by rainwater if there is very low stream flow. By looking at salinity (saltiness) of the sampled water we can tell if there is input of contaminated fresh water or if the sample contains just oceanic saltwater. Koloa Landing, Pakala, The Bowl and Middles surf sites all show decreased salinity, which correlates with their high bacteria concentrations.”
The task force’s year-to-date geomean — essentially a site’s average bacterial concentration in 2024 — found nine sites tested above the mean bacteria concentration mark of 35 enterococci per 100 milliliters of water.
The nine sites were, from bad to worse, Wailua River Park, Hanamaulu Bay Beach, Waimea River Mouth, Hanalei River, Wainiha Stream, Koloa Landing (Waikomo), Moloaa Stream, Nawiliwili Stream and Hanamaulu Stream.
“Looking at the yearly averages (geomeans), Nawiliwili Stream is nearly 35 times more polluted than the state standard,” Berg said.
While Surfrider has made some progress in getting signs posted at certain locations, such as Hanamaulu Stream and Moloaa Stream, there are other spots that need signage as well.
“Koloa Landing is the (fourth) most polluted area that desperately needs a sign. It can be on county property or on land owned by adjoining resorts. Wainiha Stream is the (fifth) most chronically polluted stream and Surfrider will be posting that area this month,” Berg said.
“Hanalei River, at Black Pot County Beach Park, is the (sixth) most chronically polluted stream and (the) Hawaii Department of Health (HDOH) has posted “caution” signs there for more than a decade! HDOH had posted signs at Hanamaulu Beach Park and Niumalu Beach Park, but they are no longer there.”
In the meantime, Berg said if people are surfing or playing in the water, it is best to rinse off with clean water as soon as getting out of a river, stream or the ocean.