SUVA (SPECFIC ULTRAVIOLET ABSORBANCE)

SUVA isn’t a chemical—it’s a water-quality indicator that reflects the type and amount of natural organic matter (NOM) in water and how likely disinfectants will create harmful byproducts. Utilities use SUVA254 to guide treatment and limit disinfection byproducts (DBPs) like trihalomethanes (THMs) and haloacetic acids (HAAs) [1][2].

Where It Comes From

Leaves, soils, and other decaying plant material that dissolve into rivers and lakes; SUVA254 is UV absorbance at 254 nm divided by dissolved organic carbon—higher SUVA means more aromatic NOM [1].

How You Are Exposed

You aren’t exposed to SUVA itself. High SUVA water, when chlorinated, can form DBPs that you can drink, inhale (e.g., shower steam), or absorb through skin [2][3].

Why It Matters

Some DBPs are linked with increased cancer risk and possible reproductive effects; EPA limits THMs/HAAs in tap water [2][3].

Who Is at Risk

People served by systems with elevated DBPs, heavy tap-water users, pregnant people, infants, and those taking long hot showers/baths [2][3].

How to Lower Your Exposure

Check your water system’s Consumer Confidence Report; consider an activated-carbon filter certified for organic chemicals/DBPs (NSF/ANSI 53 or 401); ventilate bathrooms and shorten hot showers; ask your utility about DBP control efforts [2][3][4].

References

[1]EPA. Enhanced Coagulation and Enhanced Precipitative Softening Guidance Manual. EPA 815-R-99-012 (1999).
[2]EPA. Disinfection Byproducts (DBPs) in Drinking Water: Basic Information.
[3]CDC. Disinfection By-Products (DBPs) in Drinking Water.
[4]EPA. Consumer Confidence Reports (CCR) for Community Water Systems.