Part of Bath Charter Township’s wastewater collection system had limited downstream capacity. Hydrogen sulfide had corroded an aging concrete sewer, and it needed replacement. One of the Township’s main lift stations, Lift Station 203, had to be operated manually during significant rainfalls to avoid downstream overflows. This project solved these problems, eliminated an unnecessary lift station, and opened the door for a follow-up project to eliminate another lift station believed to be contributing to corrosion issues elsewhere in Bath’s collection system.
Prein&Newhof reviewed alternatives from Bath Charter Township’s 2016 State Revolving Fund Project Plan, which they produced using a 2013 S2 Grant. Prein&Newhof presented four modified alternatives to Bath and the Southern Clinton County Municipal Utilities Authority (SCCMUA), the wastewater operator for Bath, who chose the most cost-effective one.
The chosen alternative included installing an over-sized trunk sewer to serve as an equalization (EQ) basin and building a new Lift Station 203. The EQ basin creates enough storage volume for the sewer system upstream of Lift Station 203 to handle high flows without backing up into people’s homes.
The new Lift Station 203 communicates with the downstream lift station to coordinate operating conditions based on real-time flows. For example, in a high flow event, if the downstream station is overwhelmed, Lift Station 203’s pump speed decreases while the EQ basin fills. Once the downstream station is no longer overwhelmed, Lift Station 203’s pump speed will increase while the EQ basin drains.
The design chose a new lift station site 800 ft. away from the existing lift station location in order to eliminate another existing lift station only 1,500 ft. from the original lift station.The EQ basin was buried parallel to a corroding 18-in. concrete trunk sewer so it could be abandoned once the EQ basin was operational and to minimize bypass pumping operations during construction.
The project was designed to be built in two phases. The first phase was operational in late 2018. The first phase included:
- 2,200 ft. of 60-in. sewer serving as an in-line equalization (EQ) basin
- 35 ft. of 24-in., 160 ft. of 18-in., and 820 ft. of 8-in. sewer
- Installation of several large diameter polymer concrete manholes
- Installation of a triplex submersible lift station with a 30 ft.-deep polymer concrete wet well
- Demolition of two lift stations
- The scope of the second phase is:
- 2,300 ft. of 48-in. sewer serving as an in-line EQ basin
- Installation of several large diameter polymer concrete manholes
- 165 ft. of 12-in., 170 ft. of 8-in. sewer
- Demolition of one lift station
Weekly updates were published to Bath’s website during active construction, and Township Board members were regularly updated on project progress and construction challenges.