Current Open Coliform Sample Schedule
(subject to change based upon future test results)
(A begin date of 01/01/1991 indicates the year the Total Coliform Rule was established)
Public water systems that use chlorine or chloramines must measure the
residual disinfectant level at the same points in the distribution system and at the same time when total coliforms are sampled.
Repeat, Temporary Routine, and Prior Coliform Sample Schedules
(Schedules in bold reflect current schedules)
--No schedules--
Show schedules prior to 2021
Instructions and Notes
- If no prior sample schedules appear, then no prior schedules exist within the database.
- Schedules for Oregon very small systems might not appear. If the system is active, samples must be collected for the presence of coliform bacteria once per month or once per quarter depending on water type, seasonal operating cycle, or previous sampling results.
- If a sample tests positive for total coliform or E. coli, a minimum of 3 repeat samples must be collected. At water systems where quarterly monitoring takes place, 3 routine samples must be collected the month following one in which a routine sample tested positive for the presence of total coliform or E. coli.
Any time a sample tests positive for the presence of coliform bacteria, the system's operator should contact their regulator. For this water system, that is:
WASHINGTON CO HEALTH DEPT
Larry Fenster/Ashley Davis
(503) 846-3866
