EPA records for Rapid City’s public water system, which serves over 72,000 people in Pennington County, indicate that 1,4-dioxane was not detected above the federal reporting threshold in monitoring from 2013 to 2015. This record provides a foundation for understanding local water quality regarding this cyclic ether but does not establish the specific presence or level in any individual household supply.
If You Understand the Difference Between UCMR3 Detection and Notification Levels
The EPA’s third Unregulated Contaminant Monitoring Rule (UCMR3) tracks contaminants like 1,4-dioxane in public water systems without enforcing a maximum contaminant level (MCL) for this compound. Rapid City’s data show no detections above the reporting threshold of 0.07 micrograms per liter (µg/L) or parts per billion (ppb) for 1,4-dioxane. Importantly, this is not a safety or notification limit—no state or federal notification level applies here. Detection in UCMR3 simply means the compound was measured at or above this threshold, while nondetection means levels were below it. This distinction matters because knowing whether 1,4-dioxane is present at very low concentrations requires specific household water testing, beyond the public system’s general survey.
If You Know How 1,4-Dioxane Moves Ahead of the Original Solvent Plume
1,4-Dioxane, a solvent stabilizer often found as a cyclic ether in water, has notable mobility in water systems. It tends to move faster than many other solvents it may accompany, advancing beyond initial plumes of contamination. This characteristic means that even if a solvent plume is stable or contained, 1,4-dioxane can spread further, potentially reaching areas downgradient. For households in Rapid City, this dynamic underscores why localized water testing is essential to determine actual exposure, as public records represent aggregated system results and not localized plumes.
If You Want to Understand What the Measured Range Means Against Federal Standards
The EPA cancer risk reference concentration for 1,4-dioxane is set at 0.35 µg/L. Rapid City’s public water monitoring from the UCMR3 program showed no detected samples above 0.07 µg/L, significantly below this risk benchmark. It is critical to interpret these figures correctly: nondetection at the reporting level does not mean absolute absence, only that concentrations were below measurement capability for this survey. Additionally, the absence of a federal maximum contaminant level (MCL) means there is no enforceable legal limit for this compound in the public water system, but the cancer risk concentration provides a guideline for risk assessment. For households concerned about 1,4-dioxane, private water testing will clarify individual water quality relative to these benchmarks.
If You Consider How Documented Equipment Maintains Household Water Quality
The Autotrol 1,4-Dioxane Filter ships ready to configure for household use, designed specifically for addressing 1,4-dioxane in residential water supplies. This equipment uses technology proven to treat cyclic ethers effectively when present. Regular maintenance, such as filter media replacement, typically follows a rhythm based on water usage and equipment specifications. Owners manage upkeep to maintain optimal performance, often needing media changes on an annual or biennial basis, depending on water conditions and usage volume. This routine ensures continued treatment efficacy against 1,4-dioxane and related contaminants.
If You Want to Know What Terms Like ‘Detected’, ‘Median’, and ‘Range’ Mean in This Context
- Detected: A measurement at or above the minimum reporting level; nondetection means levels are below this threshold.
- Median: The middle value of detected concentrations, if any; for Rapid City’s record, median is effectively below detection as no samples surpassed reporting limits.
- Range: The spread of detected results; with no detections above 0.07 µg/L during the survey, the range here indicates measurements below that threshold.
Together, these terms help interpret the water quality data, showing that while public water system testing found no measurable 1,4-dioxane above the reporting level, individual circumstances may vary.
In conclusion, Rapid City’s public water record for 1,4-dioxane shows no detections exceeding the EPA’s reporting limit, and no health-based violations exist for this contaminant. However, since this data pertains to the broader public water system and not individual household water, homeowners concerned about 1,4-dioxane concentration in their own supply should pursue specific water testing. If elevated levels are confirmed, documented equipment like the Autotrol 1,4-Dioxane Filter offers a practical option for managing this compound effectively at the residential scale. The public data provides reassurance about general water quality but cannot alone determine the exact condition of any single home’s water.
Where this information comes from
Source: EPA SDWIS public water system record. Sampled 2014-04-15. These figures describe the public water system's record, not the plumbing inside any individual building.
On record: EPA UCMR3 monitoring (2013-2015) for Rapid City (SD4600406), SD: 24 results across 1 listed contaminants, 0 detections above the reporting level; nothing detected above the method reporting level