Unregulated Contaminant Monitoring

As part of the United States Environmental Protection Agency’s (U.S. EPA) Unregulated Contaminant Monitoring Rule 5 (UCMR5), the Joint Water Commission (JWC)’s four partners – including the Cities of Hillsboro, Forest Grove, Beaverton, and the Tualatin Valley Water District – will be collecting and testing water samples for 30 unregulated contaminants between 2023 and 2025.

Contaminants include 29 Per- and polyfluoroalkyl substances (PFAS) and Lithium. Testing will begin in July 2023.

 JWC Partner Test Results

Access UCMR 5 unregulated contaminant test results from the JWC partner’s links below OR contact each partner for individual results:

 Unregulated Contaminant Monitoring

As part of the Unregulated Contaminant Monitoring Rule (UCMR) program, the U.S. EPA identifies a list of unregulated contaminants to be monitored by public water systems once every five years.

Unregulated contaminants are those that may be present in drinking water but are not yet subject to U.S. EPA drinking water standards.

Information about e unregulated contaminants collected during the UCMR testing process is then used to support the U.S. EPA’s regulatory determinations.

So far, four UCMR cycles have been completed.

UCMR Cycle Timeframe Number of Unregulated
Contaminants to Monitor for the U.S. EPA
1 2001 to 2003 26
2 2008 to 2010 25
3 2013 to 2015 30
4 2018 to 2020 30

During the UCMR 5 cycle – which spans from 2023 to 2025 – public water systems are collecting information on 30 different unregulated contaminants for the U.S. EPA, which includes 29 Per- and polyfluoroalkyl substances (PFAS) and Lithium.

  • PFAS: A group of synthetic chemicals used in a wide range of consumer products and industrial applications including non-stick cookware, water-repellent clothing, stain-resistant fabrics and carpets, cosmetics, firefighting foams, electroplating, and products that resist grease, water, and oil.
  • Lithium: A naturally occurring metal that may concentrate in brine waters; lithium salts are used as pharmaceuticals, used in electrochemical cells, batteries, and in organic syntheses.

Learn more about PFAS and access tips to reduce risk.

Sampling Locations

The JWC partners will collect water samples at the entry points – or the location at which water enters their respective distribution systems – then test the samples for the 30 UCMR 5 unregulated contaminants. 

Sampling Frequency

During UCMR 5, JWC partners will collect water samples four times during a consecutive 12-month monitoring period, as decided by the U.S. EPA.

Test Results

JWC partner’s test results for UCMR 5 unregulated contaminants will be reported to the U.S. EPA to be included in the National Contaminant Occurrence Database for drinking water and can be accessed by contacting each partner for individual results.


If a JWC partner detects an UCMR 5 unregulated contaminant below, at, or above the U.S. EPA’s Minimum Reporting Level (MRL) or Oregon Health Authority’s Health Advisory Level (HAL), the JWC will take the below actions as outlined in the Safe Drinking Water Act.

Detection Level

Action by the JWC

No detection

No action required.


  • Below the U.S. EPA MRL (proposed)
  • Below the OHA HAL

No action required.


  • Above the U.S. EPA MRL (proposed)
  • Below the OHA HAL

Evaluate options to adjust drinking water treatment process to remove contaminants.


  • Above the U.S. EPA MRL (proposed)
  • Above the OHA HAL

Evaluate options to adjust drinking water treatment process to remove contaminants.

Any detections by the partners will also be reported in their respective annual Drinking Water Quality Reports.

Note: The MRL is the smallest concentration of a substance that can be reliably measured. The Oregon HAL is level that the State has determined as the minimum amount of a substance that can cause health effects. Access additional information on Oregon HALs for PFAS.


  • Call 503-615-6702
  • Email the JWC 
  • Visit or send mail to 150 East Main Street, Third Floor, Hillsboro, Oregon 97123