Choosing the appropriate water treatment for volatile organic compounds (VOCs) is an important step for any household. This week, you face the decision of which class of VOC water treatment best fits your home’s needs based on the public water record in GU.
What 'Not Detected' Means in VOC Laboratory Methods
When a laboratory test reports a VOC as 'not detected,' it means the compound’s concentration was below the method detection limit—essentially the smallest amount the test can reliably measure. For example, in GU, the EPA monitoring of the EARTH TECH, INC. system found no detections of MTBE above 5 micrograms per liter (µg/L), or 5 parts per billion (ppb). This does not confirm absence but rather that any presence is below the test’s detection threshold.
How Seasonal Water-Table Changes Affect Solvent Plume Position
Volatile organics such as solvents often enter groundwater in localized plumes that can shift with seasonal changes in the water table. During wetter seasons, plumes may rise or spread differently near well screens, potentially affecting local concentrations at a given time. The public system sampling captures some of this variability but does not represent a singular household’s water at all times.
Interpreting Measured Ranges Against Federal Standards
The EPA's federal Unregulated Contaminant Monitoring Rule 3 (UCMR3) study for EARTH TECH, INC. recorded MTBE at zero above the 5 µg/L reporting level; there are no federal maximum contaminant levels (MCLs) for these VOCs currently. This means detected values are measurements, not safety exceedances. Absence of detection above the reporting level indicates VOC concentrations are below levels that require federal action.
Sampling Scope and Its Implications for Household Water Safety
The data represents 20 samples collected from the public water system between 2013 and 2015. While this supports a broad regional picture, it does not directly measure any particular household’s water. A limited sample size and system-wide focus mean home-specific testing is necessary for definitive decisions.
The Impact of Plumbing Material and Age Separate from Source VOCs
Household plumbing materials and the age of pipes can influence VOC concentrations or presence in tap water separately from the source water. Some volatile organics may originate from plumbing components or be affected by water’s contact time with these materials. Public system records do not capture this variability.
Working Through GU Public Water VOC Data as a Homeowner
Consider the median and range for any detected VOCs in the public system record as an overall benchmark, not a direct prediction for your home. For example, detecting no MTBE above 5 µg/L in all samples implies your water likely has very low or undetectable MTBE concentrations by that standard, but only specific home water testing confirms this.
To address VOC concerns tailored to your household’s demand and confirmed concentrations, the documented solution is the Pentair VOCs & Industrial Chemicals Filter. This system ships ready to configure and is designed specifically to reduce volatile organic compounds and solvent chemicals in residential water supplies. Consider testing your home water to determine the VOC levels before selecting this targeted treatment option.
Where this information comes from
Source: EPA SDWIS public water system record. Sampled 2003-10-07. These figures describe the public water system's record, not the plumbing inside any individual building.
On record: EPA UCMR3 monitoring (2013-2015) for EARTH TECH, INC. (GU0000016), GU: 20 results across 1 listed contaminants, 0 detections above the reporting level; nothing detected above the method reporting level