The results from this study indicate that polyacrylamide polymers used for water and wastewater treatment strongly absorb light in the 191.5–230 nm wavelength range, and the peak absorbance was measured at 191.5 nm for all of the seven polymers tested in this study. The detection limits in distilled water were different for different polymers and depended on polymer type and chemistry. In addition, presence of organic and inorganic impurities in water samples impacted the detection limits. In distilled water samples, the detection limits were below 0.1 mg / L for all polymers at 191.5 nm. The lowest detection limit measured was 0.05 mg / L. For raw and clarified water and centrate samples collected from treatment plants, the detection limits varied between 0.07 and 1.35 mg / L depending on the polymer type and impurities in the sample. Choosing the right dilution range also improved the sensitivity of the method and lowered the detection limits. The in-line UV–vis spectrophotometer used in this study provided a powerful tool for accurate and sensitive measurement of polymer concentration. The method has strong potential for research and industrial applications where the process flow characteristics do not change significantly. For water and wastewater treatment applications, it needs to be tested at fullscale treatment plants to determine whether it can successfully be used to measure and adjust the polymer dose under varying water quality parameters and operational conditions.