The 2019 Gordon Research Conference entitled "Water Disinfection, By-Products, and Health: Finding Solutions to Emerging Issues Related to Disinfection Byproducts by Advanced Multidisciplinary Approaches" will be held at Mount Holyoke College in South Hadley, MA on July 27-August 2, 2019. The Conference will succeed a 1.5-day Gordon Research Seminar (GRS), organized by early career scientists. The GRS will feature presentations by graduate students and postdoctoral fellows, and a mentoring panel for young professionals. At the 2019 GRC/GRS, about 160 participants including academics, regulators, graduate students, postdoctoral fellows, industrial scientists, and water professionals from around world will present cutting-edge research to address challenges in providing sustainable safe drinking water. <br/> <br/>Disinfection of drinking water is one of the major public health achievements to prevent waterborne-diseases in the last century. Multiple global issues, including contaminated and diminishing water supplies, demand innovative technologies for effective treatment of new and existing water sources to provide safe drinking water to consumers. Different source waters (e.g., those impacted by domestic or industrial wastewater) require different disinfection strategies and therefore generate different types and amounts of disinfection byproducts (DBPs). When choosing disinfection treatment processes, many water utilities prioritize the reduction of specific DBPs to comply with regulatory guidelines. However, a treatment process that yields low levels of the regulated DBPs may produce higher concentrations of other more toxic DBPs. This raises new challenges in balancing microbial and chemical risks. Epidemiological studies have shown potential associations of DBP exposure with increased risk of bladder and colorectal cancers as well as adverse developmental effects. However, the DBPs responsible for the observed health effects remain unclear. Although hundreds of DBPs have been identified, the majority are still unknown and unclassified. These knowledge gaps present tremendous challenges in choosing treatment strategies, monitoring water quality, assessing health risks, and improving regulatory guidelines. The objectives of the 2019 GRC/GRS are (1) to fill the knowledge gap in identifying unknown DBPs of health relevance by integrating advanced analytical and toxicological testing technologies; (2) to get a better understanding of the mechanisms of DBP formation and transformation to engineer innovative disinfection schemes for better control of DBPs; (3) to discuss recent advances in exposure and epidemiological assessment for improving future guidelines. The cutting-edge research in the fields of engineering, chemistry, toxicology, epidemiology and regulatory policy will contribute to the central goal of protection of human health.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.