WALLA WALLA - Public Works officials have backed off the pressure on their backflow prevention device testing program.
In recent years, the department tried to encourage residents with known underground irrigation lines to register their devices with the city and take part in annual testing.
Public Works Manager Mori Struve said the city has a databank of close to 2,500 residences with underground irrigation lines that are believed to have or need backflow prevention devices.
Last year, Public Works mailed notices to the 2,500 residences, informing them if they had a backflow prevention device, they needed to get their yearly test by a state-licensed technician.
The testing can cost anywhere from $40 to $100.
This year, the 2,500 property owners will not receive a testing notices, but they will one day.
"We are getting to the other 2,500, but we are not going to go there right now," Struve said, adding that the focus for now would be on education.
As for the 900 residences the city knows have underground irrigation and backflow prevention devices, Struve said they will still get yearly testing notices, but at least the notices will arrive during a more convenient time of year.
Last year, the Walla Walla Public Works Department was criticized for mailing testing notices out when lines had already been blown out for the winter.
"They sent them to people and in many cases, because of the winter, they had de-watered their systems ... we are going to wait a couple months and wait till May," Struve said.
Backflow prevention devices are safety valves design to keep contaminated water from entering the city's potable water system, which could happen if pressure in the city's water lines dropped.
While the possibility of contamination of city water through underground irrigation lines is a minimal risk, the results could be severe because lawn chemicals and fecal matter could enter through the irrigation lines.
The greater risk, however, is through commercial backflow prevention devices, especial with fire suppression systems in larger buildings and businesses with high volumes of water, like car washes and dry cleaners.
Public Works maintains a database of 300 high-risk commercial backflow devices and requires yearly testing of those devices.
Backflow prevention device monitoring is mandated by the Washington State Department of Health.