If you were to ask, the people in XXXX would say they need a centralized wastewater treatment system. But the way I think of it, due to its size, is more akin to a cluster or community system. While the plant will be “centralized”, the design concept will be decentralized and therefore, custom tailored to fit precisely the needs of the community.
The field of decentralized wastewater treatment is relatively new and continues to evolve. Perhaps the greatest challenge to the professional practicing in the field is that decentralized design requires a fluent command of numerous disciplines and areas of expertise. While a, large multi-disciplinary engineering firm may be able to assemble the appropriate expertise by employing many individuals, this strategy is not desirable because no one person is sufficiently experienced in all areas of expertise and leadership of the group will be lacking. The result is important tasks are handed off to personnel with little understanding of the goal and without a clear sense of direction or what the finished product should look like. The “Big Pipe” approach works this way. Ultimately, Big-Pipe design places little or no value on the actual needs and resources of the community but requires that the community force itself into compliance with the design. Big-pipe does not rely on creative thinking because every design has already been built and is explained in thousands of textbooks. This lack of creative thought leads to problems for the community however, because once the actual requirements deviate (and they always deviate) from the example presented in the textbook, the designer attempts to force compliance no matter how procrustean the fit. Big-Pipe can be described as a “brute force” approach to wastewater design where rather than the population being served by the treatment system, the treatment system is served by the population.
Decentralized, in contrast, begins with an understanding of the needs and resources of the humans being served by the wastewater treatment system. Assessing realistic growth patterns and growth potential is fundamental because an overdesigned system is, arguably, a more egregious design flaw than an under-designed one. Generally the problems associated with a smaller system may take years to develop and are easy to remedy. A typical grossly oversized big-pipe system will develop problems from the first day it is brought on line. Therefore, the decentralized approach will use realistic methods of flow prediction to arrive at a design that is congruous with the needs of the community. I am not suggesting that we under-design the wastewater treatment system, to the contrary, I suggest we develop a modular plan that allows the community to expand and contract according to its natural tendency and as driven by market forces. A decentralized approach demands an intimate understanding of the physical characteristics of potential sites and service areas so that many options and configurations can be considered before selecting the one best suited to the needs of the community.
An interesting aspect of the economic downturn is that classic big-pipe companies are now vying for much smaller projects than they typically manage. These firms generally, fail to offer due respect to the smaller systems and operate as though a system design for a community the size of XXXX is no more than a down-sized version of a large municipal plant. This thinking would lead one to believe that children are simply smaller versions of adults sharing the same needs ands concerns. Maybe I am stretching the analogy a little but the concept is intact; decentralized wastewater treatment is not simply a scaled-down version of municipal design but rather is a completely different way of thinking and approaching the task.
