When heavy rains hit San Mateo, the wastewater collection system is overwhelmed by the extra rainwater entering the system, causing 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 even San Francisco Bay.
The Dale Avenue Pump Station Upgrade will help fix 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 capacity, or the 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 by “lifting” wastewater from lower elevations to higher elevations so gravity can take over, sending the City’s wastewater to the plant.
More About the Upgrade
The Dale Avenue Pump Station Upgrade encompasses several capital improvement projects, including upgrades to and rehabilitation of the pump station and its associated piping. Did you know the City owns and operates 26 pump stations throughout San Mateo? The Dale Avenue Pump Station is one of the busiest, with 80 percent of San Mateo’s wastewater passing through the pump station before reaching the treatment plant.
The pump station has a capacity of up to 56 million gallons a day, which is a lot! But when the heavy rain falls, even more water enters the system, putting the pump station over its capacity. And that’s when overflows happen.
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 (check out the picture of 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 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
Like to swim?
If you built a swimming pool to hold a million gallons, you would need a big yard for sure. Your pool would be about 267 feet long (almost as long as a football field), 50 feet wide, and 10 feet deep. Now imagine 56 of those pools!
What Does this Mean for You?
The City and those working on the upgrade are committed to completing this work while reducing inconveniences, such as noise, dust, and extra traffic, to you and our community. All work will be self-contained at the pump station, with most the work happening inside the building. Two projects, the surge tank and the force main, will happen outside the pump station property, but again, our contractors will work hard to keep noise, dust, odors, and traffic inconveniences to a minimum. Work will be done in the daytime; you may notice an increased amount of traffic in the neighboring streets, but it will not be significant. Any activities that could cause dust will be mitigated by watering down loose soil to prevent dust from spreading. And odors will be kept to a minimum during the work.
What’s Been Done So Far?
The construction team has shutdown half of the pump station while still pumping wastewater through the station in the other half. This will continue through this summer and fall 2020 during the dry months while flows are low. Thus far, crews have demolished old materials and equipment and have been replacing pumps, valves and piping. They have also excavated down to the first force main that is currently shutdown at various locations for access to line the interior of the pipe.
What’s Coming Up?
Upcoming work includes:
- Continuing with the replacement of the pump piping and valves and general upgrading of the overall pump station
- Upgrading the electrical, instrumentation, and other equipment
- Improving access
- Lining the force mains
- Replacing surge tanks
- Performing another shutdown of the other half of the pump station in the summer of 2021 to upgrade equipment in that half
Residents near the project area will receive additional notices before this work begins.
Environmental and Permitting Documents:
Bay Area Air Quality Management District Permit. Programmatic Environmental Impact Report.
Engineer Firm Name: