Lab Report Basics: What Madison Water Utility’s VOCs Data Shows
Detection of 1,1-dichloroethane
Between 2013 and 2015, Madison Water Utility’s groundwater source was tested 44 times for 1,1-dichloroethane, a volatile organic compound linked to industrial use. Two samples showed presence above the reporting level of 0.03 micrograms per liter (µg/L), or parts per billion, with a highest level recorded at 0.08 µg/L and a median detection of 0.07 µg/L. No federal maximum contaminant level (MCL) applies to this compound, so these detections should be understood solely as measurements, not as violations or unsafe levels.
Other VOCs Monitored But Not Detected
Tests for chloromethane, bromomethane, HCFC-22, Halon 1011, 1,3-butadiene, and MTBE during the same period consistently fell below reporting thresholds, indicating these particular volatile organics were either absent or below detectable levels in the public supply.
How Gasoline and Dry-Cleaning Releases Differ in Groundwater VOC Profiles
Gasoline Releases: Complex Hydrocarbon Mixtures
Gasoline spills typically introduce a blend of hydrocarbons and fuel additives into groundwater, which can include compounds like MTBE. Madison’s data showed no detected MTBE, suggesting gasoline-related solvents are not currently present above detection limits in the system’s source.
Dry-Cleaning Solvents: Chlorinated Compounds More Common
Solvents such as 1,1-dichloroethane often originate from dry-cleaning operations or industrial degreasing. The occasional detection of this compound in the municipal supply reflects this type of contamination source rather than fuels.
How Seasonal Water-Table Changes Affect Solvent Plume Positions Relative to Well Screens
Rising Water Tables Can Expand Solvent Reach
Seasonal groundwater fluctuations may push a solvent plume vertically and horizontally, occasionally moving it closer to well intake zones. This dynamic means that VOC concentrations can vary over time even without new contamination events.
Lowered Water Tables May Reduce Immediate Exposure
Conversely, during drier seasons, a drop in the water table can lower solvent plumes beneath the screened well section, reducing the likelihood of detection or impact on supply.
The Role of Plumbing Material and Age, Separate From the Source Water
Older Plumbing Can Introduce VOCs
Materials such as certain plastics or rubber in aging plumbing systems can leach volatile organic compounds independently of source water quality. Diagnosing VOC presence thus requires testing water from the tap, not relying solely on municipal records.
Newer Fixtures May Reduce In-Home VOC Sources
Modern plumbing systems tend to use materials less prone to VOC leaching, helping to isolate source-related solvent presence from household-related contamination.
Consequences of Leaving VOCs Untreated in Household Water
Potential Taste and Odor Impacts
While detections in Madison’s system fall below health-based violation thresholds, prolonged exposure to VOCs can alter water taste or smell, affecting water enjoyment and use preferences.
Possible Equipment and Appliance Effects
Solvent compounds in water, even at low levels, may interact with household water heaters or ice makers, potentially causing operational issues or premature wear over extended periods.
Maintenance Rhythm for the Fleck VOCs & Industrial Chemicals Filter
Replacement Timing Based on Filter Contact Hours
The Fleck VOCs & Industrial Chemicals Filter uses a granular activated carbon bed sized for effective contact time with solvent compounds. Maintenance or media replacement should follow the manufacturer’s recommended schedule to maintain performance, typically assessed by water volume treated and system use intensity.
Monitoring Water Quality to Guide Filter Service
Periodic water testing can help confirm when VOC levels may be rising, signaling it is time to refresh the carbon media in the Fleck System to maintain effective removal.
This page describes the Madison Water Utility’s public water system record for volatile organic compounds, based on EPA sampling from 2013 to 2015. The data covers the municipal groundwater source serving over 270,000 people in Dane County, WI. For the original EPA data and more details, consult the agency’s public water system database.
Where this information comes from
Source: EPA SDWIS public water system record. Sampled 2015-12-29. These figures describe the public water system's record, not the plumbing inside any individual building.
On record: EPA UCMR3 monitoring (2013-2015) for Madison Water Utility (WI1130224), WI: 300 results across 7 listed contaminants, 2 detections above the reporting level; no federal MCL for these UCMR-listed VOCs