Groundwater drawn from aquifer 110QRNR in McLean County, Illinois, supplies many residential wells. Water from this aquifer is sourced from depths ranging approximately 12 to 320 feet, where nitrate and nitrite—forms of inorganic nitrogen—have been periodically measured by the U.S. Geological Survey across multiple wells in the area. Understanding these regional measurements can help household water users begin to assess their own water situation.
What Does the Measured Nitrate Range Mean Compared to the Federal Standard, and What Does It Not Mean?
Government sampling in this area, conducted from 2010 to 2018, found nitrate and nitrite concentrations ranging from as low as 0.01 mg/L to as high as 10.2 mg/L, with a median value near 2.69 mg/L. Among 58 samples taken from 11 different wells, only one result exceeded the federal Maximum Contaminant Level (MCL) for nitrate/nitrite, which is set at 10.0 mg/L. The MCL is a health-based threshold intended to limit potential risks from prolonged exposure. However, it is important to clarify that a detection above or below this level in these sampled wells does not automatically apply to your household’s specific well water. The data reflect regional averages and variability rather than individual well conditions.
What Additional Questions Do Commercial or Industrial Operators Ask Compared to Households?
Commercial and industrial water users often require more detailed information about nitrate levels due to larger volumes and diverse applications. They may examine seasonal fluctuations, cumulative nitrate loading, and interactions with other water constituents not typically prioritized in residential settings. For households, the key concern is whether nitrate concentrations might pose a health risk or cause operational issues. Larger usage scales or regulatory compliance bring a broader scope of inquiry in commercial contexts, which generally exceeds household priorities.
What Do Terms Like ‘Detected,’ ‘Median,’ and ‘Range’ Mean in This Sampling Record?
- Detected: Indicates the nitrate compound was present at a measurable level in the sample. Detection does not imply a violation or unsafe condition.
- Median: The middle value when all samples are ordered; half the measurements were above 2.69 mg/L and half below, signifying typical concentrations in the sampled wells.
- Range: The span between the lowest and highest nitrate levels found (0.01 to 10.2 mg/L), illustrating variability among wells and sampling events.
These terms provide context to the dataset but do not define your well’s specific nitrate level. To know your water’s nitrate content, a certified laboratory test of your household water is necessary.
How Does Treated Water Differ at the Tap Once the Autotrol Nitrate & Nitrite Filter Is in Place?
Water treated with the Autotrol Nitrate & Nitrite (Well) Filter can have significantly reduced nitrate and nitrite concentrations at the household tap. This system uses proven filtration technology designed to remove these inorganic nitrogen compounds effectively, helping ensure water meets health-based standards. While results vary by source quality and system configuration, the filter ships ready to configure for use with residential well water and works to alleviate concerns related to elevated nitrate levels.
How Do Sample Depth, Well Depth, or Source Type Change What a Reader Should Expect?
In aquifer 110QRNR, well depths sampled ranged from 12 feet to 320 feet, which can influence the nitrate concentration encountered since shallower groundwater may be more susceptible to surface contamination sources such as fertilizer runoff or septic systems. Deeper wells might show different nitrate profiles due to geologic and hydrologic factors. The type of water source—whether a private well, public supply, or other—also affects expected nitrate levels. Understanding the depth and source characteristics can guide what nitrate concentrations a household might anticipate and inform water testing priorities.
What Changes for a Large Household, a Second Home, or a Seasonal Property?
Households with larger water demands might need to monitor nitrate levels more frequently, as water quality can impact both health and appliance longevity. Second homes or seasonal properties may experience different water quality dynamics due to periods of inactivity or seasonal recharge patterns that affect nitrate presence. In these cases, testing at the start of use periods and after dormancy can be particularly valuable. The Autotrol system remains a valid option across these scenarios, providing adaptable filtration tailored to household needs.
What Should You Not Conclude From Area Nitrate Measurements? It is essential not to assume that your own well water contains nitrate at the same concentration as reported in these regional samples. Only direct laboratory testing of your household water can determine your specific nitrate level. Furthermore, a detection of nitrate in nearby wells does not constitute a violation or inherently unsafe condition. Regional data inform general expectations and encourage appropriate testing but do not replace individualized water quality assessment.
Where this information comes from
Source: USGS groundwater sampling. Sampled 2018-08-01. 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 Inorganic nitrogen (nitrate and nitrite) in the 110QRNR aquifer (McLean County): 58 results from 11 wells, median 2.69 mg/L, range 0.01-10.2 mg/L; 1 above a health-based federal MCL (federal MCL 10.0 mg/L)