This study, managed by the Water Environment Research Foundation (WERF) and funded by the U.S. EPA, identified the principal barriers that prevent engineers from giving equitable consideration to decentralized wastewater treatment options. The barriers were prioritized to determine which were the most influential and solvable, then strategies and actions were identified through which engineers can overcome the most influential barriers. While the barriers can seem daunting, it is important to keep in mind how much progress has been made. The decentralized wastewater treatment industry has become significantly more professional, many great examples of success exist, and knowledgeable champions of the decentralized field are sharing what they know in an effort to encourage the use of decentralized systems. With funding becoming more constrained nationally, and the funding gap for necessary wastewater infrastructure continually growing under the old centralized paradigm, the time may be right for new alternatives to gain traction. It will take hard and persistent work by many; however, that is the call of this study. If we each take on what we can and particularly if we each become champions for others, then the barriers will tumble and the wastewater issues faced by our communities will be solved by the best overall available solutions. This title belongs to WERF Research Report Series ISBN: 9781843395218 (eBook)

In the case of the decentralized wastewater sector, very little research has been done to establish the long-term performance of onsite or cluster systems, or the effect that various management approaches may have on that performance. These approaches could include, for example, high quality design and equipment requirements; preventive maintenance, repair, or replacement; residuals management needs; inspections; remote monitoring; education and training of installers, operators, inspectors and maintenance specialists; certification and licensing for all practitioners; and homeowner education. With greater understanding of reliability analysis and life-cycle costing, the potential exists for substantial improvement in the performance and cost-effectiveness of the decentralized wastewater sector.

In response to heightening stormwater standards, increasingly intensive stormwater management has been applied to increasingly smaller catchments and development activities. To achieve these higher standards a host of structural and non-structural stormwater best management practices (BMPs) are being developed, recommended, and applied prescriptively with little regard to their net environmental performance. Even where BMP treatment performance and design is defined by removal rates of criteria pollutants within a watershed context, the direct impacts of construction, the indirect impacts of embodied materials and energy, the fate of pollutants captured, and changes in performance over the life of the system, are typically ignored. This is likely due to a lack of information regarding such impacts. A life cycle assessment (LCA) methodology has previously been developed to systematically evaluate the long-term, indirect, and cumulative non-monetary impacts of human activities, by accounting for all of the materials and energy consumed and substances emitted to air, water, and soil, from the initial extraction of raw materials needed through the decommissioning and disposal of the system at the end of its life. As such, LCA may provide a truer quantification of the net or total environmental benefit of employing specific stormwater BMPs or general policies. In this paper LCA is used to compare four conventional and low-impact designs under evaluation at a BMP performance verification center in New England. The impacts of the life cycle inventories of design and construction (cradle to gate) are assessed using the US EPA TRACI model.

This paper describes the findings of the initial stages of a project that aims to review and develop tools for asset management of decentralized wastewater systems. The work is being conducted for the NDWRCDP (National Decentralized wastewater Research and Capacity Development Project) in the United States. Here we provide a description of what reliability analysis and an asset management approach mean for decentralized wastewater. The key facets of centralized urban water asset management are first summarized. Strong parallels can be drawn from these, however important differences exist between centralized and decentralized systems and their management. These differences stem from the distinctive characteristics of decentralized wastewater assets and the large spectrum of management, regulatory, and policy scenarios confronting decentralized asset managers. In addition, for decentralized wastewater, we argue that system reliability must be interpreted broadly, and include the analysis and evaluation of technical, ecological, public health, and socio-economic risks. Such differences mean that an adapted asset management framework is necessary for decentralized wastewater. Finally, although some of the necessary tools already exist, our framework and outline of tool groupings shows that potential remains for development of further reliability analysis and life-cycle costing tools to aid asset management of decentralized wastewater systems.