How Seasonal or Multi-Year Variation Shows in the Record (2010–2025) in Washington County
The U.S. Geological Survey sampled manganese in 17 wells across Washington County’s 220NVJO aquifer with 77 results spanning from March 2010 to April 2025. These results show a range from 0.18 to 25.4 micrograms per liter (µg/L), with a median of 0.42 µg/L. Some samples were below the reporting limit, showing manganese was not detected at measurable levels in about one-third of results.
The data reflect fluctuations over time and between wells of varying depths, from 61 to 1140 feet. Seasonal shifts or changes in groundwater flow could influence these variations, but the sampling frequency and well diversity give a general picture rather than exact predictions for any one household.
What Happens When Manganese Is Left Untreated for Years
In Washington County, manganese concentrations measured have not exceeded federal health-based thresholds. However, manganese can cause aesthetic issues if untreated: it may leave dark stains on fixtures and laundry and cause minor taste or odor changes. Over time, these effects might become more noticeable if manganese accumulates in plumbing or appliances. While manganese is not a health threat at these levels, managing it can improve water clarity and household maintenance.
What 'Detected', 'Median', and 'Range' Mean in This Sampling Record
In these samples, 'detected' means the instrument measured some manganese content, not that it exceeded any limits. The 'median' of 0.42 µg/L shows the middle value where half the readings were above and half below this point. The 'range' describes the span from the lowest detected concentration (0.18 µg/L) to the highest (25.4 µg/L) in the sampled wells over 15 years.
Importantly, detection does not imply that the manganese presents a violation or unsafe condition under federal standards. This dataset summarizes area-wide groundwater manganese presence but does not define the exact concentration in an individual household’s water.
What Changes for a Large Household, a Second Home, or a Seasonal Property
Larger households or properties with higher water use may notice manganese causing staining or aesthetic effects more quickly as water passes through more fixtures and appliances. Conversely, seasonal or second homes with intermittent use might see manganese deposits accumulate during periods of inactivity, potentially causing sudden visible stains or taste changes upon return.
Because manganese presence varies even within the same aquifer, homes with different usage patterns can experience these effects differently. Regular water testing tailored to the home’s water use pattern is essential to understand specific conditions.
How Public-System Records Differ from Private-Well Testing in What They Establish
Public water system records in Washington County cover compliance with federal health standards and provide general water-quality data but may not reflect manganese fluctuations at each household tap. These records often show manganese below health-based thresholds without aesthetic secondary standards details.
Private well testing focuses on the individual well and tap water quality, providing specific manganese levels to guide treatment or management decisions. Because manganese varies in groundwater, only a private well test can confirm the actual concentration at one’s home.
What You Should Not Conclude From Area Data Alone
Area-wide manganese data describe general conditions in Washington County’s 220NVJO aquifer but cannot determine the manganese concentration in your household water. Detection in the area does not mean your water contains the same levels. Samples below reporting limits show manganese is sometimes not measurable in local wells. No federal health-based violations were found in this data set.
To know your home’s manganese level and whether your current equipment needs assistance, an individual water test is necessary. For households with equipment that cannot keep pace with manganese effects, the C-Series Black Manganese Stains Filter system ships ready to configure and is designed to reduce manganese-related staining and discoloration, improving water appearance and quality at the tap.
Where this information comes from
Source: USGS groundwater sampling. Sampled 2025-04-23. 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 220NVJO aquifer (Washington County): 77 results from 17 wells, median 0.42 ug/L, range 0.18-25.4 ug/L; none above any federal threshold