Government Sampling Overview for Joliet's Public Water System
Joliet's water system monitored 22 samples for 1,4-dioxane between March and November 2013
Two samples detected 1,4-dioxane above the reporting level of 0.07 micrograms per litre (ppb), with a highest measurement of 0.15 micrograms per litre
No sample exceeded any federal maximum contaminant level because none exists for 1,4-dioxane
Sources of 1,4-Dioxane in the Water Supply
Landfill leachate contributes solvents like the cyclic ether to groundwater supplies
Degreasing sites historically used industrial solvents, including 1,4-dioxane, entering aquifers
Consumer products such as detergents and cleaners can introduce trace amounts into water
Reading the Median and Range of Detected 1,4-Dioxane Levels
The median measurement of detected 1,4-dioxane was 0.13 micrograms per litre, indicating half the detected samples measured above this
The range of detected values extended from just over the reporting limit (0.07 micrograms per litre) to a maximum of 0.15 micrograms per litre
These low-level detections do not represent a violation or unsafe condition according to federal criteria
Distinctions Between Public System Records and Private Well Testing
Public system data represent averaged measurements from multiple sampling sites, not individual household results
Private well testing is necessary to determine a home's specific water quality regarding 1,4-dioxane
Public records provide a regional baseline but cannot substitute for personal water testing
How Sample Depth, Well Depth, and Source Type Influence Expectations
Joliet's groundwater source means 1,4-dioxane presence reflects subsurface conditions and historical use
Deeper wells may show different 1,4-dioxane levels than shallow monitoring points due to varied geochemistry
Sampling depth affects concentration measurements and must be considered when evaluating test results
Why 1,4-Dioxane Levels Are Reported to Three Decimal Places
Reporting micrograms per litre to three decimals conveys detection precision at trace levels
This level of precision helps distinguish between non-detects and low-level presence in monitoring
Precision does not imply a health threshold or regulatory limit
Sample Size and What It Means for Confidence in Data
The 22 samples represent a limited dataset for the public water system during the monitoring period
Limited samples can provide useful trends but should not be overinterpreted for individual exposure
Multiple wells and time points enhance the reliability of concentration estimates over a single reading
Summary: This page reviewed 1,4-dioxane data from the Joliet public water system, emphasizing how to interpret federal sampling results, distinctions from private well water testing, and the importance of precision and sample size. Determining your home's actual 1,4-dioxane level requires individual testing, and addressing it in your water uses equipment such as the C-Series 1,4-Dioxane Filter that ships ready to configure.
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: 22 results across 1 listed contaminants, 2 detections above the reporting level; no federal MCL; EPA cancer risk reference concentration 0.35 ug/L