Using Vacuum Sewers as an Alternative Collection System

Water Law Resource
June 26, 2012 — 1,029 views  
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According to the Water Environment Federation, the cost of traditional wastewater collection systems began to get more expensive than the cost of treatment and disposal by the late 1960s. In fact, the cost to collect the water was about four times higher than the water treatment. This made it difficult and costly to provide rural communities with wastewater collection and treatment needs and these communities accounted for more than 80 percent of the country's wastewater services. It was at this time private and public sectors began trying to create alternative collection systems that would be more cost-effective.

These systems are usually referred to as alternative collection systems (ACS) and one of the systems is vacuum sewers. Government Engineering, a journal for public infrastructure, explains vacuum sewers were thought to only be a last resort for a long time until about thirty years ago. However, today vacuum sewers are considered to be an acceptable alternative for sewer services and have many advantages to traditional wastewater collection systems. For this reason, they provide reliable wastewater services to towns and communities worldwide.

Traditional sewers rely on gravity flow to dispose wastewater, whereas vacuum sewers use differential air pressure to move the sewage, notes the publication. Research has found that in order for vacuum systems to be cost effective, a minimum of approximately 75 to 100 customers have to be using the vacuum station, but in most cases, 200 to 500 people are using the wastewater service. Therefore, vacuum systems are now often the most inexpensive option.

Other advantages to using vacuum collection systems are aspects such as lower treatment and excavation expenses, decreased material costs and lower water use. Purdue University says one of the best features of alternative sewer systems is that they use much smaller plastic pipes than transition systems. Not only are these pipes less expensive, they are easier to install.

Furthermore, Government Engineering states manholes are not required for vacuum sewers, maintenance personnel are not as exposed to hazardous gases and only one source of power is required. Also, because it utilizes a completely closed system, any possible risk of contamination is virtually non-existent. 

Redivac, a vacuum sewage technology company based in the United Kingdom, explains vacuum sewers have multiple draining applications including roofs, new housing developments, hospitals, shopping centers, factories and coastal communities.

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