Why Decentralized Sanitation Systems?

by Larry Losoncy, PhD

Centralized sanitation systems are those that collect sanitation waste, pipe it to central treatment plants or lagoons and treat it. Most cities run sewer mains from homes and offices to a central collecting line for this purpose. Just over half of the United States structures are on centralized sanitation systems.

On-site systems include septic systems and also other types of treatment systems, often referred to as “alternative on-site treatment systems”. These would include composting toilets, aeration systems, mini-treatment systems and evaporative systems as well as a variety of cluster systems designed to service a group of structures.

There are strong reasons to consider moving away from centralized systems and towards on-site treatment systems. The first reason is economic and the second reason is environmental.

Reason one: cheaper. The cost of running sewer mains and of building a central plant or lagoon system is staggering. The cost of operating the system, maintaining the system, repairing the system and eventually replacing the system is also staggering. In the end the users pay these costs through taxes and monthly fees.

In order to have a centralized system the first cost is land. Then, either a plant must be constructed or treatment lagoons with lining against leakage, must be constructed. Lagoons require substantial acreage. Collecting lines from each home and commercial structure using water must be laid in order to get the sanitation and other wastewater to the treatment place. Each of these steps involves materials and labor. Inevitably there are leaks or breaks in the lines. These require excavation in order to repair or replace sections of the line.

Once the centralized treatment is accomplished the treated waste needs to go somewhere: a great deal of water and treated material in one place. In the case of lagoons there is a buildup of sludge at the bottom of the lagoon to be removed every few years, another costly process. In the case of treatment plants what comes out must be treated to a very high standard of water quality if it is to be discharged into a body of water. If it is discharged into the ground, care must be taken that what is discharged, primarily nutrients and metals, not become an environmental hazard. This requires once again a great deal of land or a high standard of treatment that is costly. The technology and science involved with centralized sanitation treatment is good and getting better. The problem is cost.

The cost, generally speaking, increases with each technological improvement. These costs are passed along to the landowners, homeowners, business owners, ratepayers and taxpayers. These costs become one of the built-in fixed costs of operating towns and cities, a permanent expense. As the area served by centralized treatment plants increases the systems eventually reach capacity and must be expanded or replaced. When anything in the system breaks it must be repaired or replaced. Floods, earthquakes and accidents are always costly to these systems.

Reason two: environmental. When centralized treatment plants and lagoons operate properly they are environmentally safe these days, due to increased protections and treatment methodologies. The environmental concerns increasingly revolve not around what happens when the system works properly but what happens when the system does not work properly or shuts down completely. Flooding and system malfunctions are the big concerns.

When centralized treatment systems shut down or get overloaded or get flooded, raw sewage simply flows away untreated. As the flooded townspeople of Oklahoma, Ohio, Wisconsin, Illinois, Texas and other states can attest to the Spring and Summer floods of 2007, this means raw sewage flowing through their homes and businesses, their front yards and their intersections, into their automobiles and classrooms, their hospitals and clinics, pastures, barns and vegetable gardens. The health hazards and destruction of soil conditions are frightful.

There is no easy or quick solution but it is safe to say that the merits of centralized waste treatment are being reconsidered as the quality of on-site treatment systems continues to improve.


Larry Losoncy is the president of Clean Up America, Inc. The company manufactures and markets  The Sanitizer™ non-discharge, evaporative toilet.  To learn more about The Sanitizer™ please go to http://www.cuaproducts.com.