Abstract

Onsite, or decentralized wastewater systems make up a large and critical portion of the world's wastewater systems, with approximately 1/4 of the U.S. population served by them. These systems are sometimes considered temporary solutions for wastewater service, but are increasingly recognized as a necessary element of long-term sustainable development and infrastructure. Property developers and systems owners frequently arrange for wastewater systems having the least short-term investment, rather than the lowest life-cycle costs with consideration to important long term sustainability issues. Such choices are often largely based on the absence of readily available information that could help with that decision-making.<p> This U.S. nationwide 2-year study was conducted by the author for the Water Environment Research Foundation (WERF) in Alexandria, Virginia. U.S. nationwide performance, cost and operational data was gathered and analyzed for systems with flows between 5,000 gallons (19,000 litres) and 50,000 gallons (190,000 litres) per day, and with at least 5 years of operational history. Those findings and recommendations, as related to long-term sustainability are discussed. Study findings discussed include reliability of performance for specific system types; capital and operational costs; energy consumption; sludge production; and useful service lives.</p>