The City has been constructing sewer infrastructure improvements at the pump station, and will now need to install an emergency standby generator. The pump station is vital for the operation of the City’s sewer system and must remain operational 24/7. The purpose of the new emergency standby generator is to provide a power supply to the pump station in the event of a power outage. The existing generator requires replacement to be compliant with air quality requirements. It will be installed east of the pump station building, as shown in the image below.
The upcoming emergency standby generator installation will consist of site preparation, excavation, foundation piles, concrete pours, generator placement, wiring, and piping installation. Construction of the generator is anticipated to start in Spring 2023 and last a few months. The proposed site plan and equipment elevations can be seen here.
On September 20, at 6 p.m. we had a virtual neighborhood meeting to learn the details of upcoming work associated with the emergency standby generator for the Dale Avenue Pump Station project. The virtual meeting provided details of the work related to the emergency standby generator and included construction schedules and what the community can expect. You can view a recording of the meeting here, or view the presentation by clicking here.
The construction notices below highlight recent construction updates related to the DAPS project.
Heavy rains overwhelm the San Mateo wastewater collection system. The extra rainwater causes sewer overflows at some manholes and at the wastewater treatment plant. These sewer overflows pose a danger to human health and the environment by contaminating our streets, creeks, lagoons, and beaches, and the San Francisco Bay.
The Dale Avenue Pump Station Upgrade will alleviate this problem by improving the wastewater collection system’s ability to manage heavy rainfall, reducing overflows, and helping the City meet important regulatory requirements. By increasing Dale Avenue Pump Station’s amount of wastewater the pump station can handle, we can reduce the risk of sewer overflows, which is better for all of us and our environment.
Pump stations are a critical component of the wastewater treatment process. They help move wastewater from homes, businesses, and other facilities to the wastewater treatment plant (WWTP) by “lifting” wastewater from lower elevations to higher elevations so gravity can take over, sending the City’s wastewater to the treatment plant.
Upgrading the Dale Avenue Pump Station is a high priority for the City. Overall, the project includes:
- Replacing pumps, piping, valves, and other associated elements in the well
- Lining the existing force mains that convey wastewater from the pump station to the wastewater treatment plant
- Process improvements to the well
- Replacing the emergency standby generator
- Improving the electrical and instrumentation systems and heating, ventilation, and air conditioning system
- Making some safety and accessibility improvements
- Replacing a portion of the pipe in the pump station yard
More About the Upgrade
Construction began in 2020 and will continue until 2022. Work along Dale Avenue will repair the existing force mains that carry wastewater from the Dale Avenue Pump Station to the City’s treatment plant. Two pipelines run the length of Dale Avenue between both facilities that need to be repaired. Instead of excavating trenches along Dale Ave to repair the full length of the pipeline, the City chose a less impactful method to repair the pipes: plastic liner material will be inserted into the pipe and filled with water to push it along the pipeline. Water expands the liner to take the shape of the inside of the existing pipe; then the water is heated and the resins in the liner harden into place. The rehabilitation of the first pipeline completed in 2020; the second pipeline is being rehabilitated in 2021.
For 2021, the City adjusted the rehabilitation method to reduce community inconveniences experienced in 2020. The lining system used in 2020 required the hot water be heated and circulated non-stop until the resin materials hardened. The duration of the heating lasts as long as needed to reach a specific temperature to make the resin cure; boilers were required to operate overnight. This year, we are using a material that does not require constant heating to reach the curing point. The contractor can install the liner and operate the boilers during the day and shut them down at the end of the workday. Overnight noise near the pit locations will be reduced. Switching the pipe lining material also allows for longer distances between lining pits, which allows the number of access pits on Dale Ave to be reduced.
In 2020, the Dale Avenue roadway had three access pit locations and two additional pits off the roadway (at the two ends of the force main rehabilitation limits). The 2021 work removed one of the access lining pit locations in the Dale Avenue roadway (See the map). At each pit location, the contractor will dewater groundwater from the excavation to install fittings and gain access to line the pipe. The generators used to power the dewatering pumps will be located near the pit locations and enclosed in sound reducing blankets, similar to the method used in 2020. These pumps will operate while the access pits are open.
In 2020, the contractor encountered a layer of concrete below the road surface that required breaking and removal. This year, the contractor anticipates this material and will saw cut the material before removal, thus helping to reduce vibrations and noise.
What Does this Mean for You?
The City and those working on the upgrade are committed to reducing impacts and inconveniences, such as noise, dust, and extra traffic, to our community while completing this project. All work will be self-contained at the pump station.
Billy Robowski of Anvil Builders at 408.410.6068