1. What Does It Mean When a Compound Is 'Not Detected' in VOC Testing?
If a laboratory report shows 'not detected' for volatile organic compounds (VOCs) like 1,1-dichloroethane or bromomethane, it means the compound was not measured above the lab's method detection limit. This limit is the smallest amount the test can reliably identify. In the Bolling Water System record for Washington DC from 2013 to 2015, none of the listed VOCs were detected above their respective detection levels, indicating very low or undetectable concentrations in the public water supply during that period.
2. How to Read Median and Range Values Using the Bolling Water System Record
Government data present VOC measurements across multiple samples. The median is the middle value of all test results, while the range shows the lowest and highest detected levels. For Bolling Water System, all VOCs such as chloromethane and HCFC-22 recorded a median and range of zero since no samples exceeded detection limits. As a homeowner, this means the public supply had no detectable VOCs in these samples, but it does not speak for individual household plumbing or private wells.
3. What Do the Terms 'Detected', 'Median', and 'Range' Indicate in Your System's VOC Report?
'Detected' means the lab instrument measured a compound above its detection limit but does not indicate a violation or safety risk on its own. The Bolling Water System's EPA record shows zero detections above reporting levels for tested VOCs, and there are no health-based violations recorded. The median and range values confirm consistent non-detection across samples. Understanding these terms helps homeowners interpret what the data says and does not say about their water.
4. Differences Between Gasoline and Dry-Cleaning Chemical Releases Affecting Groundwater VOC Profiles
Solvent compounds classified as VOCs come from various sources such as gasoline spills or dry-cleaning solvents. Gasoline releases typically feature compounds like benzene, while dry-cleaning sites release chlorinated solvents. The Bolling Water System data lists no detections for VOCs associated with these sources, but VOC presence can vary widely with local contamination. Knowing the potential source helps homeowners decide what to test for in private water supplies.
5. What a Certified Laboratory Test for VOCs Reports and How to Read the Results
A certified lab test for volatile organics reports concentrations in micrograms per liter (µg/L), equivalent to parts per billion (ppb). Results below detection limits appear as 'not detected.' For homeowners with existing equipment that struggles to manage VOCs, confirming substance levels in their own water is critical. This test clarifies which solvent compounds, if any, are present and at what amounts to guide treatment decisions.
For households in the DC area served by the Bolling Water System, the documented solution to managing VOCs and solvent compounds that might challenge existing equipment is the C-Series VOCs & Industrial Chemicals Filter. It ships ready to configure and is designed to address VOC demands that your water test may reveal, complementing what your current system handles.
Where this information comes from
Source: EPA SDWIS public water system record. Sampled 2014-05-19. These figures describe the public water system's record, not the plumbing inside any individual building.
On record: EPA UCMR3 monitoring (2013-2015) for Bolling Water System - Jt. Base Anacostia-Bolling (DC0000007), DC: 24 results across 6 listed contaminants, 0 detections above the reporting level; nothing detected above the method reporting level