Pentair Perchlorate Filter

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What Detected, Median, and Range Mean in the Perchlorate Sampling Record

Detected Level Does Not Mean Problem

The public water system record for Waipahu-Ewa-Waianae shows 70 perchlorate sampling results from 2001 to 2005. None were detected above the reporting level of 4.0 micrograms per liter. A detection means a laboratory measurement above the reporting threshold; here, that threshold was never exceeded.

Median and Range Inform Variation

Because no results in this sampling were reported above the detection limit, median perchlorate concentration and measured range are effectively below 4.0 micrograms per liter. This indicates that perchlorate has not been measurable at significant levels across the sampling events.

How Seasonal and Multi-Year Variation Reflects in the Monitoring Results

Sampling Taken Over Several Years

The EPA’s Unregulated Contaminant Monitoring Rule data was collected from May 2001 through June 2005. Sampling over multiple years helps capture seasonal differences, yet no detectable perchlorate was found. This suggests stable low perchlorate presence in the water system over time.

Seasonal Fluctuations Not Evident

Despite groundwater sources being susceptible to seasonal influences, the perchlorate record here shows no change crossing the detection threshold, indicating minimal seasonal impact on perchlorate levels in the source water.

Separating Plumbing Materials and Age Effects From Source Water Quality

Source Data Reflects System Supply, Not Individual Plumbing

The perchlorate monitoring data applies to the public water system as a whole, based on groundwater sources. It does not measure any specific home’s tap water or plumbing impact. Variations in household plumbing materials or age can affect other water qualities but have no bearing on the perchlorate levels measured at the system scale.

Household Equipment May Affect Perceived Treatment Capacity

If existing household water treatment cannot keep up with perchlorate removal demand, this is due to equipment capacity, not a sudden change in source water quality, as recorded by the public system data.

Differences Between Aesthetic Secondary Standards and Health-Based Limits for Perchlorate

No Federal Maximum Contaminant Level for Perchlorate

The EPA has not set a federal MCL (maximum contaminant level) for perchlorate. Therefore, detections below reporting levels are not violations or health-based concerns.

Secondary Standards Address Taste or Appearance, Not Health

Where aesthetic secondary standards apply, they govern factors like taste, staining, or corrosion potential. These are separate from health-based limits and do not indicate safety issues for perchlorate in this water system.

What the Measured Range Means Relative to Federal Standards—and What It Does Not

Measured Range Shows Perchlorate Below Detection Threshold

The set of 70 samples showed no perchlorate above 4.0 micrograms per liter. This means all recordings were below this detection limit but does not prove perchlorate is absent — only that it was not quantifiable by this method at these times.

No Health-Based Violations Recorded

The system has zero EPA health-based violations on record for perchlorate or any other contaminants. This confirms compliance with federal requirements but does not replace testing your own water supply if you have specific concerns.

Understanding Sample Size and Its Impact on Data Reliability

Seventy Samples From Multiple Wells

The data represents 70 samples collected across groundwater wells serving over 217,000 people through more than 40,000 connections. This broad sampling helps ensure the data reflects overall source water conditions rather than a particular well or home.

Limitations of the Small Detection Threshold

While no perchlorate exceeded 4.0 micrograms per liter, newer, more sensitive testing might reveal lower levels. Current data indicates perchlorate is not present at levels measurable by this survey method.

A Documented Solution for Meeting Household Perchlorate Treatment Demand

For households whose current equipment struggles to keep up with perchlorate removal, the Pentair Perchlorate Filter ships ready to configure and can address your demand. It is designed to reduce perchlorate effectively when properly sized for your household’s water use, supplementing existing treatment where capacity no longer suffices.

Where this information comes from

Source: EPA SDWIS public water system record. Sampled 2004-06-01. These figures describe the public water system's record, not the plumbing inside any individual building.

On record: EPA UCMR1 monitoring (2001-2005) for WAIPAHU-EWA-WAIANAE (HI0000335), HI: 70 results across 1 listed contaminants, 0 detections above the reporting level; nothing detected above the method reporting level