BROOKINGS — A volunteer advisory against water contact at Harris Beach will remain in effect through the weekend because of elevated bacteria levels believed to come from bird waste on the beach, authorities said.
The Oregon Health Authority had hoped bacteria levels at the popular beach would drop enough that the advisory issued Monday would be lifted in time for Fourth of July visitors looking to beat the inland heat.
But water samples taken Monday and again Wednesday showed even higher levels of bacteria than water sampled June 26, prompting the extension, said David Farrar, a public-health toxicologist for the OHA's Beach Monitoring Program.
"That's definitely too bad," Farrar said Wednesday.
The likely cause stems from sea bird waste and not inland runoff as originally suspected, Farrar said. Harris Creek, which runs through the beach and through a large pond before spilling into the ocean, has changed course and now dumps into the surf very close to a measuring station, Farrar said.
"Unless the course of that stream changes, this could be a chronic problem for the beach," Farrar said.
Another rain storm is needed to flush that bacteria into the ocean, where it can dilute and dissipate, Farrar said.
That's the opposite of most cases of high bacteria levels at beaches in which fecal material is flushed from inland areas to the ocean during high runoff periods, he said.
Members of the beach-monitoring program will be back in town Monday for another test, Farrar said.
Fecal bacteria can cause anything from diarrhea and stomach cramps to skin rashes or no reaction at all, but it is the largest threat to the elderly, children and those more vulnerable to waterborne bacteria.
While the advisory against water-contact there is only voluntary, it includes nearby creeks as well as any discolored water.
People, especially children, should avoid wading in Harris Creek and the pond during the advisory, Farrar said.
Oregon Beach Monitoring Program monitors the waters along Oregon's coastline for the presence of fecal bacteria annually from Labor Day through Memorial Day.
Marine waters are tested for enterococcus, which is an indicator of the presence of other bacteria. Enterococcus is present in human and animal waste.
Harris Beach marked the third such advisory against water-contact at an Oregon beach this summer. Advisories were issued, then lifted, last month at Cannon Beach and Seaside beaches.
Reach reporter Mark Freeman at 541-776-4470 or firstname.lastname@example.org.