If you notice tea-colored water or staining at your faucets
Start by documenting where and when these changes appear. Note if the discoloration is continuous or intermittent, if it affects hot water, cold water, or both, and if it appears in all faucets or just some. Pay attention to any staining on plumbing fixtures, sinks, or laundry that corresponds with the color. This written record will be important for identifying if tannins or other causes may be involved before exploring treatment options.
If you observe a government sampling record listing 'detected', 'median', or 'range'
The Alderwood Water District in Snohomish County supplies water primarily from surface water sources. According to EPA Safe Drinking Water Information System records, this system has zero health-based violations, indicating regulatory compliance and no known health safety issues. However, there is no federal monitoring data reported for tannins specifically in this system. The terms 'detected', 'median', and 'range' refer to measured concentrations within samples collected but are not reported here for tannins. Without data, presence in your home water is not established by these records.
If you get a certified laboratory test for tannins on your water
A certified lab analyzes a water sample to quantify tannin levels, usually reported in milligrams per liter. The test distinguishes tannins from related organic substances that can also cause color or staining. Understanding the lab report helps confirm if tannins are contributing to discoloration seen at your taps and informs treatment decisions. Since government data do not provide tannin levels, direct testing is the reliable way to know your water’s condition.
If tannin levels are measured, what the results indicate versus federal standards
Currently, no federal health-based standards exist for tannins in drinking water because tannins are naturally occurring organic compounds that do not pose a health risk at typical environmental levels. Instead, tannins affect water aesthetics including taste and color, and can cause staining. The reported lab values help determine the severity of these aesthetic effects but are not a health violation or unsafe condition. Treatment is a quality-of-life improvement rather than a safety requirement.
If your water source is surface water like that serving Alderwood Water District
Surface water sources often contain higher natural organics like tannins derived from vegetation and soil runoff compared to groundwater. This is why tannins may be more common or noticeable in systems drawing directly from lakes, rivers, or reservoirs. The depth and treatment of source water influence tannin presence at the tap. Understanding your water source helps you anticipate potential discoloration and guides selection of appropriate treatment equipment.
If your household is large, a secondary residence, or a seasonal property
Water demand patterns affect the concentration and impact of tannins. Large households using greater volumes may see different tannin presence than small homes due to water turnover rates. Secondary or seasonal homes may experience tannin buildup during periods of low usage or system stagnation. Treatment equipment options for tannin removal can accommodate these varying household needs and usage patterns, ensuring effective performance year-round.
It is important not to conclude from area-wide government data that tannins are necessarily present or problematic in your home’s water. Since no tannin monitoring data is available for the Alderwood Water District, only direct testing of your water can confirm if tannins are affecting your water quality. When treatment is needed, the C-Series Yellow, Tea-Colored Tannin Water Filter ships ready to configure for residential use and is designed specifically to reduce tannin-related discoloration and staining. Understanding these factors will guide you to the most suitable treatment choice for your household’s water conditions.
Where this information comes from
Source: EPA SDWIS public water system record. Record retrieved 2026-09-10. These figures describe the public water system's record, not the plumbing inside any individual building.
On record: EPA SDWIS record for ALDERWOOD WATER DISTRICT (WA5301300), surface water supply, serving 245715 people: 0 health-based violations of 0 total