OHA Drinking Water Services
OR41
PWS ID: 00379 ---- JOINT WATER COMMISSION

See also: Coliform Schedules  ::  LT2 Schedules

Chemical Sampling Schedule Status
Facility
ID		 Analyte or Group   Sampling
Interval		 Monitoring Period Days
Until
End		 Samples
Required		 Samples
Received		 Last
Sample
Date
Start End
CH-A  COMMON HEADER FOR WTP-A TOC & ALKALINITY notesQuarterly10/01/2025 - 12/31/2025 47 1 done 10/08/2025
DIST-A  DISTRIBUTION SYSTEM STAGE 2 DBP notesYearly01/01/2025 - 12/31/2025 47 1 done 07/09/2025
 Seasonal sampling period:  07/01  thru  07/31
EP-A  EP FOR TUALATIN RIVERHEXACHLOROCYCLOPENTADIENE notesYearly01/01/2025 - 12/31/2025 47 1 done 04/02/2025
EP-A  EP FOR TUALATIN RIVER ARSENIC notes9 Years01/01/2020 - 12/31/2028 1,143 1 done 04/02/2025
EP-A  EP FOR TUALATIN RIVER IOC notes9 Years01/01/2020 - 12/31/2028 1,143 1 done 04/02/2025
EP-A  EP FOR TUALATIN RIVER NITRATE  Yearly01/01/2025 - 12/31/2025 47 1 done 04/02/2025
EP-A  EP FOR TUALATIN RIVER NITRITE notes9 Years01/01/2020 - 12/31/2028 1,143 1 done 04/02/2025
EP-A  EP FOR TUALATIN RIVER RAD - GROSS ALPHA notes9 Years01/01/2017 - 12/31/2025 47 1 done 04/07/2021
EP-A  EP FOR TUALATIN RIVER RAD - RADIUM 226/228 9 Years 01/01/2023 - 12/31/2031 2,238 1 incomplete04/07/2021
EP-A  EP FOR TUALATIN RIVER RAD - URANIUM notes9 Years01/01/2017 - 12/31/2025 47 1 done 04/07/2021
EP-A  EP FOR TUALATIN RIVER SOC notes3 Years01/01/2023 - 12/31/2025 47 2 done 04/02/2025
EP-A  EP FOR TUALATIN RIVER VOLATILE ORGANICS  Yearly01/01/2025 - 12/31/2025 47 1 done 04/02/2025
SRC-AA  TUALATIN RIVER CYANOTOXINS  2 Weeks-- -- -- -- --10/20/2025
 Seasonal sampling period:  05/01  thru  10/31
WTP-A  TP FOR TUALATIN RIVERTOTAL ORGANIC CARBONnotesMonthly11/01/2025 - 11/30/2025 16 1 incomplete 10/08/2025

14  secs
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Expired Schedules
Facility
ID		 Analyte or Group    Sampling
Interval		 Start End Samples
Required		    Notes
CH-A  COMMON HEADER FOR WTP-ATOC & ALKALINITY  Monthly01/01/200212/31/20051Raw and filtered TOC and alkalinity
DIST-A  DISTRIBUTION SYSTEMHAA5 & TTHM  Quarterly01/01/200206/30/20084Reflects 4 RT Samples Per QT Per WTP
EP-A  EP FOR TUALATIN RIVERARSENIC  Yearly01/01/200212/31/20101
EP-A  EP FOR TUALATIN RIVERHEXACHLOROCYCLOPENTADIENE   Quarterly01/01/201912/31/20191
EP-A  EP FOR TUALATIN RIVERHEXACHLOROCYCLOPENTADIENE   Quarterly01/01/202212/31/20221
EP-A  EP FOR TUALATIN RIVERHEXACHLOROCYCLOPENTADIENE   Yearly01/01/202012/31/20211Collect sample between October 1 and December 31.
EP-A  EP FOR TUALATIN RIVERRAD - RADIUM 226/228  6 Years01/01/200812/31/20131
WTP-A  TP FOR TUALATIN RIVERTOTAL ORGANIC CARBON  Monthly01/01/200212/31/20051Post Filtration TOC
WTP-A  TP FOR TUALATIN RIVERTOTAL ORGANIC CARBON  Quarterly01/01/200612/31/20191Post Filtration TOC

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More information for this water system: SDWIS ID 3889
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