An order to boil drinking water remains in effect for residents in a local irrigation district, and the all-clear won't come until week's end at the soonest.
Carolyn Cox, a spokeswoman for the state Office of Drinking Water, said Friday afternoon a regional engineer and the Green Tank Irrigation District operator inspected the system but found no obvious sources of contamination.
"Because there weren't any smoking guns, so to speak, we're going to ask them to go through a weeklong process," Cox said. That process will attempt to nail down the source of the problem and culminate with five samples collected Thursday and five more Friday. If all 10 tests come back negative for contamination, the boil order will be lifted, Cox said.
"It is open ended. We still can't say when it is going to end, because if there is even one bad sample in those sets, we'll have to start over with that process."
The boil order was issued Wednesday afternoon after coliform bacteria and E. coli were found in samples of drinking water taken from the Green Tank Irrigation District, which serves 193 connections covering about 550 people in an area north of College Place and west of Walla Walla.
The irrigation district is bordered by Northeast Rose Street and North College and Wallula avenues.
No illnesses have been reported in connection with the contamination, Cox said. She added customers of the district will be notified when the coast is clear.
"We're not going to end this advisory until they get tests that show the water meets safe drinking standards," she said.
Alasdair Stewart can be reached at firstname.lastname@example.org or 526-8311.
For people affected by the boil order, the procedure is straightforward:
Place water in a clean metal or glass container and bring to a rolling boil that is sustained for at least one minute. Keep water covered while it cools and store it in containers intended for water, or in those that held juice, milk, pop or bottled water, but never in containers that have held substances such as cleaners, solvents or pesticides.
Coliform bacteria in general and E. coli in particular can cause health problems if ingested.
Symptoms can include stomach cramping and diarrhea - including bloody diarrhea - fever and occasionally more serious problems such as kidney failure.
For more information, call the Green Tank Irrigation District at 509-525-4608, or the Walla Walla County Health Department at 509-524-2662.