Vehicles lined up early Wednesday afternoon at Baker High School for a free COVID-19 testing clinic.

Jason Yencopal concedes that it seems a bit unusual for Baker County officials to urge residents who feel fine to be tested for COVID-19.

But more tests could be the key to the county remaining at the lowest risk level, with the least stringent restrictions on businesses and gatherings.

It’s a matter of math, said Yencopal, the county’s emergency management director.

Specifically, it’s a matter of what percentage of COVID-19 tests are positive in the county.

The positivity rate is one of two criteria the Oregon Health Authority (OHA) uses to determine the county’s risk level (the other is the number of COVID-19 cases).

The county returned to the lowest risk level on Thursday, May 27. To stay there, the county needs to have a positivity rate below 5%, based on two-week periods (the current measuring period is May 16-29).

The problem, Yencopal said, is that although the county’s number of new cases has plummeted during May, so has the number of tests.

And that means even a moderate increase in cases could push the positivity rate above 5%.

To cite a recent example, for the period May 23-27, the county had five new cases, an increase from two new cases from May 16-22.

But because the total tests dropped from 133 (May 16-22) to 113 (May 23-27), the positivity rate rose from 1.5% to 4.4%.

Had the county conducted just 30 more negative tests during the latter period, the positivity rate would have been almost one percentage point lower, at 3.5%.

In response to the declining test totals, the county plans to have free drive-thru testing clinics each Thursday in June. The first event is set for June 3 from 10 a.m. to 2 p.m. in the parking lot at the Baker County Health Department, 2200 Fourth St.

Although pre-registration isn’t required, residents can do so at the county’s website, www.bakercountycovid19.com.