Reading a Certified Laboratory Test for Nitrate in Your Water
A certified laboratory test for inorganic nitrogen, which includes nitrate and nitrite, reports the concentration in milligrams per liter (mg/L). This figure helps you understand how much nitrate and nitrite are present in your household water. Since nitrate is a naturally occurring compound that can enter groundwater through natural processes and human activities, its levels fluctuate. A lab report will specify a number, but whether this number indicates a concern depends on federal recommendations. The federal maximum contaminant level (MCL) for nitrate is 10.0 mg/L; concentrations above this level are a threshold for health-based attention. Testing your own water is essential because area-wide data cannot confirm your home’s specific water quality.
Impact of Sample Depth, Well Depth, and Water Source Type
The nitrate data for Umatilla County comes from two wells within aquifer N100CMBPLB, sampled at depths between 40 and 170 feet. Depth influences nitrate presence because contamination sources mainly affect shallow groundwater more directly. Deeper wells often have different nitrate levels due to less surface influence, but this is not guaranteed. Additionally, the aquifer's characteristics and whether the water is from groundwater or surface sources will affect nitrate concentrations. These factors mean your home water nitrate levels might differ due to your well’s depth and source type.
Household Fixtures and Processes Most Sensitive to Nitrate Levels
Nitrate does not typically cause immediate taste or odor issues in water but is most significant for its health implications, particularly for infants and pregnant women. Plumbing fixtures and appliances such as kitchen faucets or drinking water dispensers are where nitrate exposure occurs, and these are the primary points of concern. Although nitrate itself does not corrode pipes or damage appliances, reducing its concentration in drinking water is important for safety. Water used for bathing or laundry is less affected by nitrate presence since ingestion is the main concern.
Seasonal and Multi-Year Variation in Nitrate Concentrations
The U.S. Geological Survey’s data for the Umatilla County aquifer from 2015 to 2019 shows a median nitrate level of 7.995 mg/L with results ranging from 2.94 to 15.4 mg/L. This range indicates nitrate can vary over time due to factors like precipitation and land use changes affecting groundwater recharge. The detection of nitrate was consistent in all 22 samples, suggesting a persistent presence in this aquifer. Three recorded results exceeded the federal MCL, indicating that high levels can periodically occur over several years. Understanding this variability is important for evaluating your water’s status over time.
Steps to Identify and Address Possible Nitrate Concerns
Start by visually checking water clarity and taste, although these rarely indicate nitrate issues. Next, test for nitrate specifically using a certified laboratory, as home test kits may lack reliability. Since area data cannot replace your own water test, this is crucial. If results approach or exceed recommended levels, consider treatment options designed for nitrate reduction. The Fleck Nitrate & Nitrite (Well) Filter is one such system that ships ready to configure and can help reduce nitrate levels in residential water systems. This equipment uses documented technology tailored to address nitrate and nitrite removal from well water.
Government data for Umatilla County's aquifer N100CMBPLB shows nitrate is detected in all sampled wells between 2015 and 2019, with levels sometimes surpassing the health-based federal threshold. These findings are from groundwater sampling of two wells between 40 and 170 feet deep and represent regional conditions, not your home's specific water quality. For further details, review the U.S. Geological Survey groundwater sampling data available at waterdata.usgs.gov.
Where this information comes from
Source: USGS groundwater sampling. Sampled 2019-04-16. 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 N100CMBPLB aquifer (Umatilla County): 22 results from 2 wells, median 7.995 mg/L, range 2.94-15.4 mg/L; 3 above a health-based federal MCL (federal MCL 10.0 mg/L)