Step 1: How Manganese Enters Groundwater in San Juan County's Aquifer 110AVMB
San Juan County's groundwater, particularly from aquifer 110AVMB, supplies many residential wells drawing water typically between 35 and 68 feet deep. Manganese naturally occurs in soils and rocks underlying this region and dissolves into groundwater over time through geological processes. This elemental presence in the aquifer contributes to measurable manganese concentrations in sampled wells. While manganese itself is not hazardous at the levels documented here, it is known to cause a metallic taste in water which some households may find unpleasant.
Step 2: Understanding 'Detected', 'Median', and 'Range' in Local Manganese Sampling Data
The U.S. Geological Survey has collected 285 manganese measurements from nine wells within this aquifer area from 2010 through 2025. Out of these, manganese was detected in 271 samples, with a median concentration of 81 micrograms per liter (ug/L) and observed values ranging from 0 to 29,000 ug/L. 'Detected' means an instrument measured manganese present, not that any health or safety standard has been exceeded. Indeed, none of these results surpassed federal thresholds. The median indicates the middle value where half samples are lower and half are higher, reflecting typical regional levels. The range shows variability among wells and times sampled.
Step 3: The Testing Sequence to Identify the Metallic Taste Cause in Your Home
To determine the source of metallic taste in household water, start with simpler checks such as flushing taps or changing faucet aerators to rule out localized equipment effects. If taste persists, homeowners should conduct a certified laboratory test for manganese and other metals specific to their water supply, as regional data do not establish individual well conditions. These lab results provide the precise information needed to decide on treatment. Understanding the exact manganese concentration helps to distinguish if the metallic flavor arises from this element or other possible contributors not covered in regional sampling.
Step 4: Comparing San Juan County’s Water Quality Record with Neighboring Areas
When comparing manganese data from San Juan County with neighboring counties, recognize that sampling depth, frequency, and local geology affect reported concentrations. Differences in median and range values reflect distinct aquifer characteristics rather than uniform water quality. Thus, while one area may show higher median manganese, that does not imply a widespread issue or a direct correlation to individual wells in another county. Such regional comparisons serve to contextualize but not substitute for testing your own water.
Step 5: Additional Considerations for Commercial or Industrial Water Users
Commercial and industrial operations often have stricter water quality requirements and may monitor multiple constituents beyond manganese, including those affecting equipment longevity or processes. They might require more frequent or varied testing and tailored treatment solutions. In contrast, typical residential water users focus primarily on aesthetic effects like metallic taste and rely on periodic testing to confirm if manganese concentrations justify treatment.
Summary: This guide has outlined how manganese from aquifer 110AVMB contributes to metallic taste in San Juan County water, emphasizing the importance of understanding regional sampling data and following a logical testing sequence. Ultimately, household users deciding between technical treatment options can rely on precise laboratory testing to confirm manganese levels and then consider solutions such as the C-Series Metallic-Tasting Water Filter that ships ready to configure for effective taste improvement.
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 Manganese in the 110AVMB aquifer (San Juan County): 285 results from 9 wells, median 81.0 ug/L, range 0.0-29000.0 ug/L; none above any federal threshold