Household Sulfur Smell in San Juan County: Understanding Aquifer 110AVMB Water Data

Government groundwater sampling in San Juan County’s aquifer 110AVMB found sulfide detected frequently but always below federal safety thresholds.

How often does maintenance keep the C-Series Rotten-Egg Sulfur Smell Filter working effectively?

The C-Series Rotten-Egg Sulfur Smell Filter ships ready to configure and is designed for periodic upkeep to maintain performance. Typically, filter media should be refreshed or replaced on a schedule based on household water usage and the extent of sulfur odor, commonly every 6 to 12 months. Routine checks of water clarity and smell guide this rhythm. Keeping to this schedule helps ensure the system’s ability to reduce sulfur smell remains consistent.

How do public water system records differ from private well testing in revealing sulfur smell causes?

The publicly available groundwater data for San Juan County represents samples from multiple wells ranging 35 to 68 feet deep, offering a regional picture of sulfide levels in aquifer 110AVMB. These figures do not reflect a specific household’s water quality. Private well testing is necessary to determine the actual sulfide concentration in your water supply, as local conditions and equipment issues can vary widely even within the same aquifer.

What does the range of sulfide measurements in San Juan County mean compared to federal standards, and what doesn’t it mean?

Measured sulfide levels range from 0.002 to 4.6 mg/L in these samples, with a median of 0.039 mg/L. All results stayed below federal thresholds for sulfide, meaning no health-based violations were identified. A detection or concentration below a federal limit does not indicate unsafe water but simply confirms presence in measurable amounts. It also does not predict the strength of sulfur smell experienced in each household’s water.

How does seasonal or multi-year variation appear in the sampling record for sulfide?

The dataset covers samples collected between April 6, 2021, and September 19, 2025. Over these years, sulfide was detected in 62 of 72 samples, and 9 were below reporting limits. The presence of sulfide fluctuates, demonstrating natural variability in groundwater chemistry over months and seasons. This variability means household water odor can change over time even without equipment issues.

How would a homeowner interpret the median and range of sulfide measurements from this record?

The median sulfide concentration of 0.039 mg/L suggests typical sulfide levels are modest in this part of aquifer 110AVMB. However, the upper range reaching 4.6 mg/L means some wells experience higher sulfide occasionally. If your household water matches this pattern, the sulfur smell could vary from barely noticeable to more pronounced, depending on well depth, age, and equipment condition.

What household symptoms indicate the sulfur smell problem detected in these aquifer samples, and what symptoms do not?

Persistent rotten-egg odors in tap water or showering water suggest sulfide presence, especially when accompanied by taste issues or corrosion. However, sulfur smell from plumbing materials or bacterial growth inside pipes can cause similar odors unrelated to groundwater sulfide. Equipment failure in water treatment units commonly causes a return or increase in sulfur smell symptoms.

The best way to determine if sulfide levels are contributing to your household’s sulfur smell problem is to order a private well water test specifically measuring sulfide. Results showing concentrations in the range of those detected in the San Juan County aquifer confirm the issue originates from the water source, guiding the choice to use a system like the C-Series Rotten-Egg Sulfur Smell Filter designed to reduce these odors reliably.

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