Climate change is likely to result in substantial changes in autochthonous production of organic carbon. One important feature of this material is its relatively high abundance of proteins, polypeptides and amino acids. This could affect the quality of treated drinking water in significant ways. The common amino acids comprise 22 compounds, all of which may form disinfection by-products (DBPs) and TOX during disinfection with chlorine. This research focused on regulated DBP formation from the chlorination or chloramination of amino acids and related compounds. For chlorination, model compound solutions (2 mg∙C/L) were adjusted the desired pH and then dosed with chlorine at 20 mg Cl2/L. Samples were then incubated head space-free for 2 days at 20°C. After collecting the samples for DBP analysis, quench reagents were added to the bottles and the samples were stored at 4°C. Trihalomethanes (THMs) and haloacetic acids (HAAs) were analyzed using standard gas chromatographic methodology. Total organic halide (TOX) was determined and from this we calculated the unknown TOX. Asparagine, aspartic acid, proline, tryptophan and tyrosine were found to produce high TOX yields by chlorination. Some amino acids were major producers of haloacetonitriles. Tests with polypeptides and purified proteins revealed the role of peptide bonds on reactivity and byproduct formation. These data will be discussed and interpreted within the context of changing autochthonous carbon levels, drinking water quality and human health.