What "Not Detected" Means: Understanding Laboratory Detection Limits
The official tests conducted by the EPA on the Joliet public water system found no detections of several volatile organic compounds (VOCs) above the laboratory’s method detection limits. For example, no 1,1-dichloroethane was detected above 0.03 micrograms per liter (µg/L), and no methyl tertiary-butyl ether (MTBE) was detected above 5.0 µg/L. When a compound is classified as "not detected," it means the laboratory’s instruments did not measure it above the smallest concentration their method can reliably identify. However, this does not guarantee the compound is entirely absent; it is just below this threshold. These thresholds vary with each VOC and the testing method used.
Why Volatility Matters: Showering, Dishwashing, and Inhalation Exposure
Volatile organic compounds are called "volatile" because they can readily evaporate into air from water. While ingestion through drinking is one exposure route, inhalation and skin contact often play a larger role for VOCs. Activities like showering or dishwashing release VOCs into indoor air, where household members may inhale them. This characteristic distinguishes VOCs from other water contaminants that primarily affect health through ingestion. Understanding this helps in considering treatment options that reduce VOC concentrations before these exposure pathways occur.
How Water Source and Depth Affect VOC Expectations
The Joliet public water system draws water from groundwater sources. Groundwater is generally less exposed to atmospheric contaminants than surface water but can be influenced by underground pollution sources like historic industrial sites or leaking underground storage tanks. Sampling depth and well construction also influence VOC results. The EPA’s data come from multiple wells and sources serving thousands of residents, but may not directly reflect conditions in any single home’s well or tap water. Individual households must test their own water to determine unique VOC levels.
Regular Maintenance Rhythm for a C-Series VOCs & Industrial Chemicals Filter
The C-Series System designed to reduce VOCs and industrial chemicals in water operates using a granular activated carbon bed that adsorbs these compounds. Its maintenance involves periodic replacement of the carbon media based on usage and water quality, which ensures continued effectiveness. This routine is straightforward: the filter ships ready to configure and requires monitoring to maintain optimal contact time for VOC reduction. Users should follow the product guidelines to schedule media renewal appropriate for their household water demand.
Contact Time Over Flow Rate: Granular Activated Carbon Bed Sizing
Effectively treating VOCs depends more on the contact time between water and the carbon bed than simply the flow rate. The carbon needs sufficient exposure time to adsorb volatile organics fully. Systems not appropriately sized for contact time may reduce flow but fail to achieve VOC reduction goals. The C-Series filter is designed with this principle, balancing flow demands with adequate contact to capture a wide range of VOCs and solvent compounds detected or potentially present.
Data Representation: Number of Samples and What a Limited Sample Size Means
The Joliet system data represent 22 sampling events per compound over a period from 2003 to 2013, covering a large population of about 160,000 people through nearly 49,000 connections. While this provides a broad overview of VOC presence in the municipal supply, it remains a relatively small sample compared to the total water used daily across households. This means it offers a general indication but cannot substitute for specific household water testing needed to confirm individual VOC status and guide treatment decisions.
In summary, the EPA data for Joliet’s groundwater-sourced public water system show no VOC detections above laboratory reporting levels for several key volatile organic compounds. These results reflect system-wide conditions over several years and thousands of connections but are not a substitute for household-specific testing to determine personal water quality and treatment needs. For full details and updates, refer to the EPA’s publicly available system records at their official site.
Where this information comes from
Source: EPA SDWIS public water system record. Sampled 2013-11-13. These figures describe the public water system's record, not the plumbing inside any individual building.
On record: EPA UCMR3 monitoring (2013-2015) for Joliet (IL1970450), IL: 154 results across 7 listed contaminants, 0 detections above the reporting level; nothing detected above the method reporting level