Our client was adding an ADU to her property in San Jose. Originally, we were contracted to connect the ADU to the sewer line in the front of the main home. This is a common configuration for an ADU and the home owner and her ADU builder assumed this would work. Once we started, we quickly realized that the sewer out from the ADU was lower than the connection point into the main home’s sewer line out. In California, the typical 4″ sewer pipe is required to maintain at least a 2% slope. In this case, we were not able to achieve this with the ADU being three feet lower than the main home.
Instead of the proposed sewer line from the ADU to the front, we came up with a new solution. A sewage pump is required whenever you need to elevate or “force” sewage up slope. We installed a dual pump station between the ADU and main home, then fed the discharge into the main home’s sewer line.
We installed a Liberty Pumps dual pump and basin solution. These were two 1 HP pumps inside a basin that captures the sewage and an external control panel that manages pump workload and provides redundancey in case one fails. This pump solution should provide many years of service.
We also installed a new two-way cleanout in front of the ADU and replace part of the sewer pipe in the front of the main home.
Our client was so pleased with our partnership that she left us a great review on Yelp. We hope she gets a lot of value out of her investment and we appreciate the opportunity to be part of her ADU project.