Across the United States, water suppliers and managers are finding dangerous levels of 1,4-dioxane in water. This compound has been used for decades in a wide range of applications including as (1) a solvent in paints, varnishes, and prints; (2) treatment agent in artificial leather; (3) ingredient in pesticides and fumigants; (4) purifying agent in pharmaceuticals; and (5) solvent in resins, oils, plastics, adhesives, waxes, and cement. 1,4-dioxane is a probable human carcinogen at extremely low levels in water (parts-per-billion). It is highly soluble and thus travels extensively in water. Most importantly, ew conventional water treatment technologies can remove 1,4-dioxane from water. There are only two current routes of eliminating 1,4-dioxane in water: UV or hydrogen peroxide coupled with ozone oxidation (i.e. advanced oxidation), and biological degradation. The energy and chemical costs of UV and chemical oxidation processes are often prohibitively high. There is also a significant risk of producing harmful by-products (such as carcinogenic bromate) and these technologies have limited applicability in certain circumstances such as high levels of inorganic salts. Biological degradation alternatively suffers from a number of drawbacks, including process stability, the need to induce degradation, limited performance, clogging, performance sensitivity, and the production of sludge or secondary waste streams. If these problems can be overcome, however, biological treatment offers a promising method of completely degrading 1,4-dioxane into harmless products and protecting public health. This Phase II demonstration proposal is based on successful Phase I results showing the feasibility of a new biological approach. In Phase I, a technology was designed and tested for 1,4-dioxane degradation that does not require pre-induction and can be applied using a new high performance bioprocess. The prototype developed in the Phase I work will be scaled and piloted at an actual contaminated site. The pilot will seek to establish performance and operational parameters of the new technology, evaluate long-term and sustainable operation, and address parameters informing a technoeconomic analysis. The major outcome of this Phase II effort will be the demonstration and full characterization of a first-of-its-kind high performance bioprocess for eliminating 1,4-dioxane in water resources. The technology's intended value proposition includes simple operation, rapid and effective degradation, wide applicability to a range of water sources, reliable performance, and lower overall costs compared to existing methods, especially chemical oxidation. Most importantly, the Phase II funding will provide a valuable tool for protecting and remediating drinking water supplies, thus safeguarding public and safety, and environmental sustainability for generations to come.