Test Results: No Detections

UCMR 5 contaminants were not present at detectable levels in recent water samples. 

UCMR 5

During the UCMR 5 cycle – which spans from 2023 to 2025 – public water systems collected information on 30 different unregulated contaminants, including 29 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.
  

Detection Levels

No Detection (Green Label)

• No action required.

Detection (Yellow Label)

• Detected below U.S. EPA's Minimum Action Level.
• Detected below Oregon Health Authority's Health Advisory Level.
• No action required.

Detection (Orange Label)

• Detected below U.S. EPA's Minimum Action Level.
• Detected above Oregon Health Authority's Health Advisory Level.
• Action: Evaluate options to adjust drinking water treatment process to remove contaminants.

Detection (Red Label)

• Detected above U.S. EPA's Minimum Action Level.
• Detected above Oregon Health Authority's Health Advisory Level.
• Action: Evaluate options to adjust drinking water treatment process to remove contaminants.

UCMR 5 Unregulated Contaminants

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

• Sampling Locations: Hillsboro Water collects water samples at entry points – locations at which water enters Hillsboro’s distribution system – then test the samples the unregulated contaminants. 
• Sampling Frequency: Hillsboro Water collects water samples four times during a consecutive 12-month monitoring period, as determined by the U.S. EPA for UCMR testing.
• Test Results: Hillsboro Water’s test results for UCMR 5 are reported to the U.S. EPA to be included in the National Contaminant Occurrence Database for drinking water. Test results are available by request at WaterQuality@Hillsboro-Oregon.gov. 
• Detections: If an unregulated contaminant is detected below, at, or above the U.S. EPA’s Minimum (proposed) Reporting Level (MRL) or Oregon Health Authority’s (OHA) Health Advisory Level (HAL), Hillsboro Water will take action as outlined in the Safe Drinking Water Act. Detections will also be reported in Hillsboro Water’s annual Drinking Water Quality Report.

Note: The MRL is the smallest measured 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.

• Fifth Unregulated Contaminant Monitoring Rule


• The Fifth Unregulated Contaminant Monitoring Rule (UCMR 5) Fact Sheet


• La Quinta Regla de Monitoreo de Contaminantes No Regulados (UCMR 5) Hoja informativa del programa


• Oregon Health Authority: Emerging Contaminants in Drinking Water