How Many Samples and Wells Stand Behind the Figures, and What a Small Sample Means
Extensive Sampling Across Multiple Wells
The U.S. Geological Survey collected 229 hardness measurements from 9 wells in San Juan County’s aquifer 110AVMB between 2010 and 2025. These wells were 35 to 68 feet deep, offering a broad perspective of the aquifer’s general water quality rather than any single residential well.
Area-Wide Data Does Not Define Your Water
Though the data set is large and collected over many years, it does not establish the specific condition of your household’s water. The aquifer is sampled in different locations and depths, so your water may vary. This means government results provide context, not exact personal measurements.
How to Judge Treatment Capacity Against the Household's Daily Demand
Matching Capacity to Household Needs
Your household’s water use should guide the treatment system's required capacity. The Autotrol Acidic Water + Hard Water System offers a grain capacity of 32,000 grains, which handles substantial hardness loads in typical residential demands. Evaluate your daily water consumption against this capacity to decide if this system suits your needs.
Why Capacity Matters After Equipment Failure
When existing treatment equipment fails, it is crucial to select a replacement system that adequately covers hardness levels without frequent regeneration or maintenance interruptions. Calculating your household’s hardness load based on usage helps ensure uninterrupted benefit.
Why Aesthetic Secondary Standards Differ from Health-Based Limits, Applied to This Constituent
Hardness and Acidic Water Affect Taste and Fixtures, Not Health
The sampled hardness levels in the San Juan County aquifer ranged from 644 to 1750 mg/L, with a median of 1190 mg/L, all below federal health-based thresholds. These concentrations can influence water taste, cause scaling, and affect plumbing longevity but do not indicate health risks under regulatory standards.
Understanding What ‘Detected’ Means
All samples showed hardness was detected, but detection simply means it was measured, not that it violates any regulation. These are aesthetic or operational concerns rather than safety violations.
How the Constituent Enters Groundwater or the Distribution System in This Region
Origin of Hardness in San Juan County
Calcium and magnesium, the minerals responsible for hardness, naturally dissolve into the groundwater as it moves through mineral-rich soils and rock formations in the San Juan County area. This is typical for regional aquifers and explains the measured hardness range.
Acidic Water Factors
Acidity can arise from natural processes or interaction with soils and organic materials in the aquifer. Its presence alongside hardness complicates treatment, requiring systems designed to balance both conditions effectively.
What ‘Detected’, ‘Median’, and ‘Range’ Mean in the Sampling Record on This Page
Median and Range Explain the Spread of Measurements
The median hardness value (1190 mg/L) represents the middle value of all 229 samples, giving an idea of central tendency. The range from 644 to 1750 mg/L shows variability, highlighting that some wells have lower or higher hardness within the aquifer.
‘Detected’ Reflects Measurement, Not Severity
Detection indicates that calcium and magnesium were found in every tested sample—it does not imply a problem or violation by itself.
How Sample Depth, Well Depth or Source Type Changes What a Reader Should Expect
Depth Influences Water Composition
Samples were taken from wells 35 to 68 feet deep, a moderate depth range. Wells deeper or shallower than this may exhibit different hardness or acidity characteristics, as water chemistry can change with depth.
Source Variation Means Personal Testing Is Key
Since the sampled wells might differ from your household’s actual source depth or location, only a dedicated water test of your own well or connection can confirm your water’s precise hardness and acidity levels.
Next Step: The Single Test That Settles Your Water Quality Question
To move forward confidently after equipment failure, order a comprehensive water analysis focusing on acidity (pH) and hardness (calcium and magnesium content). This test will provide the specific figures needed to select an effective replacement system.
Once you have your test results, the Autotrol Acidic Water + Hard Water System, designed with a 32,000 grain capacity, is a documented solution for managing acid and hardness issues commonly found in this region’s water. The system ships ready to configure to your household demand and water chemistry.
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 Hardness, Ca, Mg in the 110AVMB aquifer (San Juan County): 229 results from 9 wells, median 1190.0 mg/L, range 644.0-1750.0 mg/L; none above any federal threshold
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