ISSUES AT THE SITE GREATLY ADDED TO COMPLEXITY.
A lift station has a pump that lifts wastewater to a higher point so it can again flow by gravity to a treatment plant. In Plant City, these pumps and pipes are in a wet well. The wet well is where the wastewater is contained. Generators and electrical components sit on a concrete pad, above and around the lift station. Cellular antennas are attached to the above-ground components to transmit data to The City of Plant City’s Water Reclamation Facility control room so staff can monitor the system. Slatted, chain-link, privacy fence surrounds each lift station. There are more than 50 lift stations placed in strategic spots around the city.
In 2022, the city commission approved a project to construct a new lift station south of West Grant St, adjacent to Dr. Hal & Lynn Brewer Park. The plan was for the new station to replace the old lift station No. 7—which was built in the early 1960s. The replacement was intended to manage the current wastewater flows at the site and from the new Parkside Townhome Development. The project also involved extending the city’s sewer system to the new pump station and decommissioning the old Lift Station No. 7.
Grant Street was closed in May 2024 as a step to completing the project. However, during construction, workers discovered the soil at the planned location is muck. Geotechnical data confirmed that installing the sewer main there would end up with it sinking—therefore requiring the expense of doing the project again and again. Because of this, the project engineers had to change the plans for construction and installation of the new lift station No. 7—causing plans to have to be reconfigured, and causing delays.
Adding insult to injury, in June 2024, in the midst of the work on the new lift station, a sinkhole was discovered on the site. This required the plan to be revised again because the sinkhole had to be stabilized before the new lift station could be completed. With projects like this, engineers are largely flying blind because it is difficult to determine the volume of empty space that makes up a sinkhole. To stabilize a sinkhole, grout is injected into the hole, and the ground around it, until it is firm. Stabilizing this sinkhole took six injection points to a depth of 95 feet, 493 feet of grout castings, and 310 cubic yards of grout. Solving this problem caused more delays, and added an extra $96,553 to the project cost.
Now that the sinkhole has been stabilized, the work is in its next phase—dewatering the site down to a depth of 30 feet. “We are dealing with a combination of a wetland area there—basically a swamp—that was under the roadway, and, immediately adjacent to it, a sinkhole,” City Manager Bill McDaniel said. “Between the two it has created a very complex situation. The project was derailed and delayed by the combination of the wetland area and the existing sinkhole. So, we have had to stabilize the sinkhole. Then we have to dewater to put in the lift station, because lift stations go underground. A lift station has its own capacity to keep itself from flooding with the various pumps that are installed, as well as to provide the pressure to move the effluent along through the pipes in the sewer system. Lift stations are not a luxury. They are not an option if you want your toilets to work.”
Currently, the city has the revised lift station project design completed, and they have the contractor on board. “Sinkholes tend to have water in them, and when you are dealing with a swampy area—that has water,” McDaniel said. “So, we are dealing with quite a bit of saturation there. We have high capacity pumps on it, and they run, if not 24/7, most of the day. Currently, that water pumps off to the Brewer Park pond, and then drains out through the West Side Canal.”
The anticipated date Grant Street will be reopened is December, 2025.
