Scio Township Pump Station Oxygen Injection System

Award-Winning, Innovative Wastewater Solution Improves Quality of Life for Two Communities

Scio Township partnered with OHM Advisors to address hydrogen sulfide (H2S) odors emanating from their sanitary system’s force main outfall which had permeated into a neighboring major city. The odor was a noxious problem for the communities’ residents and was causing the Township an infrastructure corrosion issue. Our team of experts investigated and discovered that the odors resulted from excessive H2S gas created due to the extended residence time of the flows through the Township’s oversized force main.

Since the Township contracts with the neighboring city to receive the Township’s sanitary flows, it was important to not just create a solution for the Township, but for that solution to positively impact the residents of both communities to foster continued successful relationships. Our team performed an odor control study to assess the best long-term solution to accomplish that goal. The solution needed to significantly lower H2S concentration, deter continuing infrastructure corrosion and require only minor maintenance and oversight by the Township. The design team considered several alternatives before ultimately choosing an oxygen injection solution, as it met the design goals at the lowest present worth cost.

Oxygen injection is an innovative and environmentally-conscious approach to H2S control. Its goal is to increase the dissolved oxygen (DO) concentration in the force main’s wastewater, to overcome both pre-existing dissolved sulfides at the wet well and the oxygen uptake due to biological conditions in the force main piping. The system that deploys it is a new technology to the Midwest, so our team consulted with out-of-state communities who used it for similar-level H2S concentrations to inform the Township’s decision-making process. With the Township’s decision to implement it, the oxygen injection solution became only the second of its kind in Michigan.

OHM Advisors’ collaborative, multidisciplinary design team also completed the design for a pump station building addition that was required to accommodate the new system. Since the building’s completion, the new system has become fully operational and H2S concentrations have been reduced to below-nuisance levels, improving the quality of life for and the relationship between the Township and its community neighbors.

Project Highlights: wastewater, pump station, oxygen injection system, infrastructure