The use of decentralized/distributed sewering is an emerging trend intended to bridge the gap between both central sewer and residential septic systems. Upgrading and improving a city’s wastewater-treatment infrastructure is one of the most important public policy issues and the most costly. Often not an environmental benefit, there is conclusive evidence that centralized sewer collection systems are leaking and causing treatment-plant overflows during strong, wet-weather events. Leakage into streams and ground water are a common occurrence in many places and a significant problem in many communities across the U.S. A study in Albuquerque, New Mexico concluded that 10 percent of average expected daily flow or [approximately] five million gallons per day at their wastewater treatment plant was lost due to leakage. With infrastructure costs rising and these types of overflow issues, alternative ways of providing wastewater service in suburban areas are gaining increasing attention.
In many situations, a decentralized/distributed system is the better way to go. Frequently seen as only a suitable choice in low-density/rural situations or for temporary solutions, the decentralized-wastewater-treatment system is not the usual choice as an option for a community – until now. With proper design, installation and operation, the advantages of decentralized systems are many. By collecting, treating, and reusing or disposing of wastewater from the homes, buildings, and/or cluster systems onsite or near the point of generation, decentralized/distributed systems can reduce the time, amount of water, and energy involved in treating wastewater with a higher pollutant removal rate. This takes the strain off an overloaded plant and provides the community with highly treated water available for reuse.
Benefits for Developers
Developers who look into alternatives to traditional sewer or center-collection systems actually see plenty of reasons to choose decentralized/distributed systems for their homes. For example, a developer who is looking to build 50 suburban homes can have his project delayed up to five years while the city extends the existing sewer lines to the homes. Plus, the developer is likely to pay significant sewer-tap fees as well as substantial fees for the cost of extending sewer lines so that current sewer customers will not have to see their rates increase. If the developer is charged more, chances are the cost increases will be passed along to the new residents. Additionally, especially in places like coastal areas, small lots and heavy regulation can tie the developer’s hands when trying to put in a sewer connection, which will further delay the development’s completion.
Because decentralized/distributed systems are typically composed of modular, interconnected, and easily replaceable parts, installation and maintenance is simple. It only takes a matter of days or weeks to install and start-up a decentralized system. The savvy developer does not have to plan as extensively in comparison to building a neighborhood with a central-sewer connection. The developer may also decide to use these decentralized systems instead of building out from the central infrastructure because they require less time and money to obtain permits. But one of the major benefits of these systems is the developer can build out slowly and add to the treatment system as needed to maintain treatment meaning the upfront costs are significantly lower.
An onsite wastewater treatment option is the small, quick-to-install, MicroFAST® wastewater-treatment unit from Bio-Microbics, Inc., based in Shawnee, KS. These modular units can treat 500 gallons per day or significantly more by using a cluster system treating from 3,000 up to 160,000+ gallons/day—enough to accommodate an entire community. These advanced systems treat the water to considerably higher standards for subsurface irrigation or other reuse method. These units are easily upgradable, scalable, and take up considerably less space than centralized treatment options.
Moreover, these advanced treatment systems offer a water-reuse opportunity for community parks, schools, golf courses and reduce potable water consumption for non-potable uses. The developer also has more options in terms of the topography and/or type of land available, which not only increases property value but can lead to a decrease in urban sprawl.