By Terri Harber
A slew of test results indicate municipal water is virtually free of cryptosporidium at several locations around Baker City - except for the discovery of one oocyst worth of the parasite at one location on the first day.
The city needed to complete two consecutive tests that have zero oocysts in the watershed at places where water is diverted from a stream into the city's pipeline, and at three locations in town.
The Oregon Drinking Water Services Program said the results would be more telling if tests at some of these locations were conducted within shorter spans of time, said City Manager Mike Kee.
There is a gap of about a week between tests at three of the locations and 10 days at another. That is why more samples have been collected and sent for testing.
If those results are clean then it's likely the state would allow consumption of water straight from the taps once again, Kee said.
"No one wants to see the boil order removed only to have it put right back on," Kee said Thursday.
The city expects to obtain results from this latest round
of sampling on Tuesday.
The total number of cryptosporidiosis cases in Baker City is estimated to be in the hundreds or possibly even "a four-digit" figure, said Dr. Bill Keene, senior state epidemiologist with the Oregon Health Division.
Most of those afflicted didn't seek treatment or testing. The number of confirmed cases had risen to 22 as of Thursday, Kee said.
A boil advisory for water users in Baker City began July 31 after some ill residents were found to have cryptosporidiosis.
The advisory was heightened to a boil order on Aug. 3 after water tests detected the presence of crypto in the city's water.
Only one of 16 water samples collected on Aug. 10 and Aug. 11 contained crypto. That sample was taken Aug. 10 from Little Mill Creek and it contained one oocyst.
Water experts say it takes at least 10 oocysts of crypto in water to make most people sick.
Two of the clean samples were taken at the city's reservoir. This is a location where water from several streams is mixed together.
Five other oocyst-free samples were taken from the distribution system inside the city: two from the Baker County Courthouse, two from a property on Lund Lane and one from a property on Birch Street.
The city hasn't tested more water from Elk Creek, the site where a sample taken Aug. 4 contained 913 oocysts. No water has been taken from the location since Aug. 7 - the day in which the results of that test came back.
That is why additional testing isn't necessary there right now. It's a seasonal water source usually out of use by this time of year, Kee said previously.
Little Mill Creek also isn't being used right now.
Once the boil order is lifted, the city will test the water for crypto twice a week, Kee said.
The state also will consider whether to change how the city should protect its water supply against crypto and other waterborne parasites long-term. The water is chlorinated but this treatment alone is considered insufficient to make crypto-tainted water safe for drinking, cooking, dish washing and tooth brushing.
andbull; Goodrich diversion (not Goodrich Reservoir): Aug. 10, no oocysts; Aug. 11, no oocysts
andbull; Mill Creek: Aug. 10, no oocysts; Aug. 11, no oocysts
andbull; Little Mill Creek: Aug. 10, one oocyst; Aug. 11, no oocysts
andbull; Salmon Creek: Aug. 10, no oocysts (also an Aug. 4 sample had no oocysts)
andbull; Marble Springs: Aug. 11, no oocysts (also an Aug. 4 sample had no oocysts)
andbull; Little Marble Creek: Aug. 11, no oocysts (also an Aug. 4 sample had no oocysts)
andbull; Combined sources at Goodrich Reservoir: Aug. 10, no oocysts; Aug. 11, no oocysts
andbull; Baker County Courthouse: Aug. 10, no oocysts; Aug. 11, no oocysts
andbull; 900 Lund Lane (northeast corner of city): Aug. 10, no oocysts; Aug. 11, no oocysts
andbull; 1605 Birch St.: Aug. 11, no oocysts (also an Aug. 1 sample had no oocysts).
The test results also can be found at bakercity.com.
Baker City Herald Editor Jayson Jacoby contributed to this report.