PFAS in Honolulu's Waipahu-Ewa-Waianae Water: What Regional Data Reveals About Your Household

Sources of Per- and Polyfluoroalkyl Substances (PFAS) in Waipahu-Ewa-Waianae

Firefighting foam use and potential legacy presence

The Waipahu-Ewa-Waianae water system, drawing from groundwater, serves over 217,000 residents. EPA records show no detections of several common PFAS compounds above laboratory reporting levels, indicating limited ongoing or localized source inputs such as firefighting foam in this region.

Textile finishing and manufacturing influence

The data for this public water system from 2023 monitoring reflects no measurable PFAS linked to industrial activities like textile treatment, suggesting minimal impact from such sources in this area.

Landfill leachate and environmental runoff as a factor

While landfills can contribute fluorinated compounds, the comprehensive monitoring of the Waipahu-Ewa-Waianae system has not detected PFAS above reporting limits, indicating these sources have not measurably affected the public water supply here.

Household Fixtures, Appliances, and Processes Most Sensitive to PFAS

Water dispensers and ice makers

PFAS compounds, even at very low levels, can accumulate in point-of-use fixtures like water dispensers and ice makers, as they rely on water with no additional fluorinated compound removal unless treated.

Cooking and drinking water taps

Fluorinated substances pass through typical plumbing systems; thus, kitchen taps used for drinking and cooking are the primary points where household water quality related to PFAS is experienced.

Home filtration and conditioning systems

Standard water filters often do not target PFAS compounds specifically, requiring dedicated solutions to address these persistent substances.

Considerations for Different Household Types in This Region

Large households and those with heavy water use

In homes with greater water consumption, even low-concentration PFAS exposure may accumulate more significantly over time, increasing interest in targeted treatment options.

Second homes or seasonal residences

Intermittent water use can affect how PFAS compounds persist in plumbing; periodic water quality testing is advisable to understand seasonal variations.

Properties with private wells versus municipal connection

This page summarizes the municipal system’s record only; private wells require individual testing to determine PFAS presence and concentrations.

Safely Comparing PFAS Data Between Honolulu and Neighboring Counties

Understanding system-wide monitoring versus individual household tests

The Waipahu-Ewa-Waianae system records reflect aggregated data for many connections; they do not predict levels in any single household without specific testing.

Reporting levels and health-based standards

None of the PFAS compounds detected showed concentrations above federal maximum contaminant levels (MCLs) set for 2024, affirming no official health-based violations in this system.

Regional differences in water source types and impacts

Neighboring areas using surface water or differing groundwater sources may show different PFAS profiles; comparing EPA data by system helps avoid overinterpretation.

Federal Maximum Contaminant Levels for Fluorinated Compounds in This Record

PFAS compounds with 2024 federal MCLs

• PFOA: MCL 4.0 ng/L (4 parts per trillion)
• PFOS: MCL 4.0 ng/L
• PFHxS: MCL 10 ng/L
• PFNA: MCL 10 ng/L
• HFPO-DA: MCL 10 ng/L

Compounds detected without assigned federal MCLs

• PFBS, PFHxA, PFPeA, PFBA, PFHpA — detected but no federal MCL as of the data period

The monitoring for Waipahu-Ewa-Waianae found only one detection above reporting level: PFPeA at 0.0033 µg/L (3.3 parts per trillion), well below any MCL because no such limit exists for PFPeA.

Addressing Homewater Quality Demands for PFAS in Honolulu

For households seeking to reduce PFAS exposure in their water, the Pentair PFAS Forever Chemicals Filter offers a proven solution. It is designed to configure directly for residential use to target a broad range of fluorinated compounds measured in this region. Assessing your household’s water use helps ensure the filter matches your demand efficiently.

Where this information comes from

Source: EPA SDWIS public water system record. Sampled 2023-11-09. These figures describe the public water system's record, not the plumbing inside any individual building.

On record: EPA UCMR5 monitoring (2023-2025) for WAIPAHU-EWA-WAIANAE (HI0000335), HI: 340 results across 10 listed contaminants, 1 detections above the reporting level; compared with the applicable federal MCL, none above