Kitsap streams getting generally cleaner, but storms have an effect

Kitsap County’s streams are getting generally cleaner when it comes to bacterial levels, according to an annual water-quality report issued by the Kitsap Public Health District. But streams can have good years and bad years — and 2017 was not so good.

Let’s compare the annual report for 2016 to the newly released report for 2017, both found on the health district’s website. Reporter Tad Sooter offered a nice overview of the new report in a Kitsap Sun story on Friday.

Graph: Kitsap Public Health District

Before getting to the findings, it’s important to understand that there are two bacterial water-quality standards that must be met for a stream to get a clean bill of health. The first part calls for an average of no more than 100 bacteria per 100 milliliters of water (or no more than 50 bacteria if the water body has been designated “extraordinary”). The second part states that, regardless of the average, no more than 10 percent of the samples taken can exceed 200 bacteria per 100 milliliters of water (or 100 bacteria for “extraordinary” water).

It came as a surprise to me that in water year 2017 a total of 23 streams — or 35 percent of the 66 streams sampled — failed both water-quality standards. That’s worse than in water year 2016, when 25 percent of the 64 streams on the list failed both standards. (A water year goes from Oct. 1 to Sept. 30 of the next year.)

One reason that water quality got worse in 2017 was that rainy weather at times was more conducive to washing bacteria into the streams, according to Shawn Ultican, a water-quality expert with the health district.

“Bacterial levels were higher in general than we have seen them in the past few years,” Shawn said of the 2017 data. “We had more intense rainfall at times. We don’t think that suddenly more pollution sources have become a problem.”

Similar patterns also were seen in 2009 and 2010, he said.

More streams were deemed clean in 2016 than 2017. In 2017, 21 streams — 32 percent — met both of the water-quality standards, compared to 30 streams — 47 percent — the year before.

For discussion, I took a look at reports in 2008, when 38 percent met both standards, and 2013, when 29 percent met both standards. So it really does vary from year to year. And whether a stream is considered clean or polluted depends on recent rainfall and other fleeting factors. Consequently, much depends on when a water sample is taken, which is why health officials choose their sampling dates randomly.

Because weather plays an important factor in the bacterial counts, health officials tend to focus on long-term trends rather than on the results of individual water samples. Trends result from a statistical exercise using data collected each month over many years. For most streams, sampling has been going on for 22 years.

If the bacterial counts stay relatively the same over many years, the health of the stream is listed as “stationary.” If the numbers show a statistical trend, a stream will be listed as “worsening” or “improving.”

In 2017, five streams were listed as worsening: Coulter Creek in South Kitsap; Lofall and Kinman creeks in North Kitsap; and Stavis Creek and the Tahuya River, which drain into Hood Canal. You might consider Stavis Creek and Tahuya River to be statistical anomalies, because they are so clean that it takes only a few additional bacteria to result in an unwelcome trend.

Stavis Creek met both part 1 and 2 of the water quality standards in 2017, while the Tahuya River failed part 2 because of a few high counts. In 2016, both streams met both water-quality standards, so health officials aren’t worried about either stream at this point.

In 2016, 21 streams were listed as improving, compared to 18 streams in 2017. Olalla, Wilson, Barker and Chico creeks are among those that went from improving to stationary. Barker and Chico creeks are pretty clean, meeting both parts of the water-quality standards.

Tad’s story in the Kitsap Sun includes an interactive map that provides the status of each stream in Kitsap County monitored by the health district.

Lofall Creek, which includes drainage from the community of Lofall as well as upstream areas, has been giving health officials fits for years. Bacterial counts are high and getting worse, despite successful efforts to eliminate sources of pollution, such as failing septic systems and pet wastes.

Special tests are planned to see whether pollution in the stream is coming from pets, birds or ruminants, such as cows and deer, according to Ian Rork, an environmental health specialist with the health district who is assigned the cleanup of Lofall Creek and nearby Kinman Creek.

Health officials have long suspected that raccoons may be a source of the pollution, but they have no strong evidence. Raccoons are known to deposit their wastes in communal areas. As new development takes over uplands, these small animals may be pushed into remaining vegetated areas along the streams.

Last year, Ian began a new effort to work closely with residents of the community to see if they could take steps to discourage raccoons and other wildlife from congregating near Lofall. Steps people can take include making sure animals don’t have access to garbage, keeping barbecue grills clean and avoiding the intentional feeding of raccoons.

“The local residents have been so gracious and good to work with,” Ian told me, adding that most people are committed to solving the problem if only there were a clear answer.

For the 2017 report, Lofall Creek remains the most polluted stream in the county, followed by Ostrich Bay Creek in Bremerton; Olalla Creek and Burley Creek, both in South Kitsap; and Kinman Creek and Vinland Creek, both in North Kitsap.

The cleanest streams are Dewatto Creek, followed by Anderson Creek, Stavis Creek, Seabeck Creek, Salmonberry Creek, Big Beef Creek and Wright Creek. All drain into Hood Canal, except Anderson and Wright creeks, which drain into Sinclair Inlet, and South Kitsap’s Salmonberry Creek.

Climate change is expected to bring more intensive rainstorms, but how that will affect long-term trends in water quality is yet to be seen.

One thought on “Kitsap streams getting generally cleaner, but storms have an effect

  1. First – it is good when these kinds of reports and stories are provided.
    But –

    Sample, sample, sample, sample. Explain, explain, explain. explain.

    It really helps, when water quality in a stream is improving, to have some words about who did what to actually fix something.

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