If you notice a sulfur smell—often described as rotten egg odor—coming from your household water in San Juan County, especially where your water source taps into aquifer 110AVMB, several aspects are important to consider before choosing the right treatment equipment.
Fixtures and Water Uses Most Affected by Sulfur Smell
Kitchen Faucets
Cold and hot water taps in the kitchen often reveal sulfur odor first, as people detect smell while filling drinking glasses or cooking.
Bathroom Showers and Sinks
Showering or washing hands may highlight the sulfur smell due to warm water releasing more sulfur odor.
Water Heater Vessels
Residences using water heaters may find that the smell intensifies after water passes through them, as heat can accelerate sulfide gas release.
Sample Size and Well Depth Underpinning Sulfide Data
Number of Samples and Wells
The U.S. Geological Survey collected 72 sulfide measurements from 8 wells in San Juan County’s aquifer 110AVMB between April 2021 and September 2025.
Depth of Sampled Wells
Wells sampled ranged from 35 to 68 feet in depth, providing a focused but geographically limited view of sulfide levels in this area.
Interpreting Small Sample Data
While these samples establish a reliable regional pattern, they do not determine sulfide levels in any individual household water source; specific testing is required for personal water quality.
Maintenance Rhythm of the Fleck Rotten-Egg Sulfur Smell Filter
Filter Media Replacement
The Fleck System’s filter media should be refreshed on a schedule recommended by its operational guidelines to maintain odor reduction effectiveness.
System Backwash and Regeneration
The system periodically cycles to cleanse itself, supporting continuous sulfur odor control without manual intervention.
Simple Monitoring
Households can check performance regularly by smelling water output and following prompts for maintenance steps to sustain the filtration quality.
Understanding Certified Laboratory Sulfide Testing
What the Test Measures
A certified lab analysis quantifies dissolved sulfide concentrations in milligrams per liter (mg/L), a numeric value reflecting sulfur compounds responsible for odor.
Results Interpretation
Detection of sulfide does not imply safety concerns; in the San Juan County data, no measured level exceeded any federal health threshold.
Usefulness of Testing
Testing clarifies if sulfur odor stems from sulfide levels needing treatment and guides the selection of appropriate filtration technology.
Differentiating Sulfur Smell from Similar Water Issues
Hydrogen Sulfide Versus Iron Bacteria
Sulfur smell primarily arises from hydrogen sulfide gas; iron bacteria, which may cause staining and slime, rarely emit this odor.
Sulfide Odor Versus Hardness Effects
Hard water can cause scaling but does not produce sulfur smell; these issues require different treatment approaches.
Aligning Treatment Capacity with Household Water Demand
Estimate Daily Household Usage
Calculate typical water consumption to ensure the system's filtration can handle peak and average daily flow without odor breakthrough.
System Sizing Considerations
Select equipment capacity based on the number of users, water usage patterns, and sulfide concentration estimates from testing.
Planning for Future Variations
Account for potential seasonal or operational changes in sulfide levels that may affect treatment requirements over time.
This overview relies on U.S. Geological Survey sampling in San Juan County’s aquifer 110AVMB, where sulfide was detected in most samples but remained below federal thresholds. For detailed data, visit the government source at waterdata.usgs.gov.
Where this information comes from
Source: USGS groundwater sampling. Sampled 2025-09-19. These figures describe groundwater sampled in this area. They are not a test of any individual private well - only a test of that well can establish its own water.
On record: U.S. Geological Survey sampling of Sulfide in the 110AVMB aquifer (San Juan County): 72 results from 8 wells, median 0.039 mg/L, range 0.002-4.6 mg/L; none above any federal threshold
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