Nitrate in Polk County Groundwater: Multi-Year Variations and Household Effects

Government groundwater sampling in Polk County, MN's aquifer 112GSSG collected 284 nitrate results from 8 wells between July 2011 and September 2015, showing a median nitrate concentration of 4.9 mg/L with a range from 0.215 to 267.0 mg/L.

Seasonal and Multi-Year Variation in Polk County Nitrate Records

The sampling spanned over four years, capturing nitrate measurements from wells 10 to 69 feet deep. The results demonstrate significant variability over time and location within the aquifer; while many samples were well below the federal Maximum Contaminant Level (MCL) of 10.0 mg/L, 94 samples exceeded this health-based threshold. This range indicates nitrate concentrations fluctuate seasonally or due to local factors affecting groundwater.

Household Signs That May Indicate Elevated Nitrate

Elevated nitrate levels in a household water supply do not produce notable taste or odor changes, meaning typical sensory detection methods are unreliable. However, households relying on private wells may experience health concerns, especially for infants and pregnant women, if nitrate exceeds federal limits. Symptoms such as unexplained fatigue or respiratory distress in infants should prompt testing. It’s important to note that the presence of nitrate itself in the aquifer does not confirm the household water supply contains elevated nitrate without direct testing.

Fixtures and Processes First Affected by High Nitrate

Nitrate is dissolved in water and evenly distributed, so all water outlets and appliances using water from the well are exposed equally. Appliances like humidifiers, ice makers, and drinking water taps will all potentially reflect elevated nitrate levels simultaneously. Thus, household symptoms or appliance issues do not isolate particular fixtures but suggest the entire water source is impacted if nitrate is elevated.

Maintenance Rhythm of the C-Series Nitrate & Nitrite (Well) Filter

The C-Series Nitrate & Nitrite (Well) Filter ships ready to configure and is designed to reduce nitrate concentrations effectively for private household water systems. Maintenance involves routine monitoring and scheduled filter replacement based on usage and water quality but requires no specialized tools or external service. Regular monitoring of water quality ensures the filter continues to operate within its effectiveness range.

Impact of Sample and Well Depth on Expected Nitrate Levels

The Polk County aquifer samples ranged from 10 to 69 feet deep, which suggests nitrate levels may vary with well depth. Generally, shallower wells can be more susceptible to surface-related nitrate contamination from agriculture or septic systems. Deeper wells may show lower nitrate but are not immune to elevated concentrations. The specific depth and construction details of a household well greatly influence expected nitrate levels.

This briefing summarizes nitrate data from 284 samples collected within Polk County's aquifer 112GSSG between 2011 and 2015 as reported by the U.S. Geological Survey. For detailed information and updates, please consult the original groundwater data source directly.

Where this information comes from

Source: USGS groundwater sampling. Sampled 2015-09-10. 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 Nitrate in the 112GSSG aquifer (Polk County): 284 results from 8 wells, median 4.9 mg/L, range 0.215-267.0 mg/L; 94 above a health-based federal MCL (federal MCL 10.0 mg/L)