Operational Costs Of Two Pressure Sewer Technologies: Effluent (STEP) Sewers And Grinder Sewers

By Tyler J. Molatore, P.E., Orenco Systems®, Inc.

Alternative wastewater collection systems, such as pressure sewers, can save small communities millions of dollars in capital costs when compared with conventional gravity sewers. Pressure sewers can affordably serve small, spread-out communities, largely because they use small-diameter, shallowly-buried PVC or HDPE mainlines along variable grades to convey wastewater to a treatment facility rather than using large diameter, deeply excavated conveyance mains laid at a constant slope.

Because of their affordability, pressure sewers have been installed by thousands of communities over the past several decades, a number of which are more than 30 years old. Two of these technologies, effluent sewers and grinder sewers, are being proposed in an ever increasing number of small communities.