High levels of enterocci and fecal coliform reported on the south Kenai beach last week declined somewhat in testing done this week.
Results out Monday from testing done Sunday showed that the bacteria was back at lower levels.
“They came back below the standards,” said Tim Stevens from Alaska’s Department of Environmental Conservation.
The standard is based on two types of testing: a geometric mean, which looks at the values over time, and one that looks at just a single sample, Stevens said. The latter is the test the department is using to provide more immediate results this summer.
Sunday’s samples showed that both enterocci and fecal coliform were back below the standards considered safe for recreational use.
Testing last week showed that fecal coliform was above the standard, prompting the department to test again to verify the excedence. The next round showed that both types of bacteria were well above the standards, so the department notified the public, Stevens said. The official notice included a recommendation not to consume the water, and to thoroughly clean any fish caught in it. It also recommended cooking fish above 148 degrees for safe eating.
Those samples were taken on the south beach. There is also testing at the north beach, Stevens said, but the results came in below the standards. A site near the Warren Ames bridge is also being tested, to separate what is entering the river south of the bridge, and what is just traveling downstream.
Stevens cautioned that perfect trends can’t be found in the numbers yet.
Bacteria is funny, he said. It isn’t uniformly spread throughout the water.
Stevens said the department doesn’t plan to take any further action unless results come back quite a bit higher. It will continue testing the twice-weekly samples.
The department is also trying to figure out where the bacteria came from.
Stevens said they are doing microbial source testing, which looks for species markers in the bacteria. Humans, dogs, and gulls — among other animals — each imprint bacteria with their own signature. But the results won’t help pinpoint the source this summer.
“They won’t come in until this fall, unfortunately,” Stevens said.
For now, its too early to say what the cause is, he said.
“We are trying to keep our eye out for all potential sources out there and eliminate the human sources whenever possible,” he said.
Other possibilities include various wildlife in the area, including birds.
The department did similar testing last year, but did not include the markers. This summer’s testing will provide a more complete look at the numbers when all is said and done.