By Michael Saunders
Liquid-only sewers (also known as “effluent sewers”) have proven to be a cost-effective solution for municipalities, new subdivisions, and a variety of other areas in need of sewer. As opposed to the big pipes and deep excavations typically required by gravity sewers, liquid-only sewers use small-diameter, shallowly buried mainlines that follow the contour of the land and are easily installed with light-duty equipment, minimizing disturbance to the surrounding area. Because of their affordability, liquid-only sewers have been installed by hundreds of communities over the past several decades. Many of these sewers have now been providing reliable service for more than 35 years.