What Does ‘Not Detected’ Mean in Laboratory Testing for VOCs?
If your previous water treatment equipment failed and you wonder if VOCs (volatile organic compounds) are present in your water, the first step is understanding government water records. The EPA’s monitoring of the City of Riverton public water system from 2013 to 2015 shows no detections above the method detection limits for common VOCs such as 1,1-dichloroethane and chloromethane. When a compound is listed as 'not detected,' it means the laboratory's instruments did not measure the VOCs above a specific sensitivity level—variously 0.03 to 0.2 micrograms per liter (µg/L), or parts per billion (ppb). This is not a guarantee that no VOCs exist, but rather that concentrations, if present, were below this limit.
Seasonal Water Table Changes and Their Effect on VOC Plumes Near Your Well
In Fremont County, surface water is the source for Riverton’s supply, and shifts in the water table through seasons can move solvent plumes in groundwater. This means VOC levels around your well or local system may fluctuate depending on rainfall and groundwater flow patterns. Water-table rises can dilute solvents, while falls may concentrate them near well screens. Even if the municipal system consistently reports nondetection, your private well’s VOC levels could vary seasonally and should be individually tested.
Interpreting Median and Range VOC Results from the Riverton System
EPA sampling records offer median and range data to describe VOC presence. For Riverton’s public water, across 28 samples each for specific VOCs, none showed results above detection limits. Homeowners should note that median values of zero mean that, most of the time, VOCs were below detection, while the range confirms no sample measured above those thresholds. This suggests that current municipal water does not have measurable levels of these VOCs according to federal occurrence monitoring, but it does not establish individual household results.
Why the Design of a Granular Activated Carbon Filter Focuses on Contact Time
When VOCs or solvent compounds are a concern, treatment often involves granular activated carbon (GAC) filtration, which captures organics from water. The efficiency depends more on the water’s contact time with the carbon bed than simply flow rate. A longer contact time allows the carbon to adsorb more volatile organics effectively. This means that any replacement equipment you consider should be sized to provide sufficient filtration capacity to handle your household's water demand without rushing treatment time.
Sources of VOCs Detected in the Riverton Area’s Groundwater and Water Supply
Though no VOCs were detected above reporting limits in municipal monitoring, volatile organics can enter groundwater or surface water through historic or ongoing releases of solvents, degreasers, or industrial chemicals. Residential areas near industrial sites or transportation corridors might experience trace VOC presence in well water. In Riverton, the surface water supply is less prone to direct solvent contamination compared to groundwater wells, aligning with the EPA’s nondetection findings for common VOCs like bromomethane and HCFC-22.
Why Volatility Influences Exposure Risks Beyond Drinking Water
Volatile organic compounds are unique because they can evaporate during household uses—showering, dishwashing, or cooking—leading to inhalation exposure in addition to ingestion. Even if tap water tests low for VOCs, the volatility aspect means that air quality indoors can be affected if solvent compounds are present. Addressing VOCs with a treatment system designed for volatile organics reduces both ingestion and inhalation risks by removing these compounds before water reaches your taps.
Next Step: Testing Your Household Water for VOCs
Because municipal records reflect system-wide data rather than individual household water, the most certain way to confirm if VOCs are present after your previous equipment failure is to have your water tested by a qualified laboratory. Request analysis for volatile organic compounds at detection limits equal to or lower than those used by the EPA. Such testing will establish your specific concentrations and the treatment needs they create.
If VOCs are detected in your home’s water above the detection levels found in Riverton’s public supply records, a C-Series VOCs & Industrial Chemicals Filter ships ready to configure and can be added to your water system. It is designed to reduce a range of volatile organics and solvent compounds effectively, addressing the shortcomings of previous equipment and restoring water quality.
Where this information comes from
Source: EPA SDWIS public water system record. Sampled 2013-08-26. These figures describe the public water system's record, not the plumbing inside any individual building.
On record: EPA UCMR3 monitoring (2013-2015) for City of Riverton (WY5600047), WY: 168 results across 6 listed contaminants, 0 detections above the reporting level; nothing detected above the method reporting level