PCU Wastewater Treatment Plant
& Collection System
Upon site assessment and project evaluation, we wanted our design to address the crucial problem of bringing centralized wastewater service to a community previously relying on individual septic systems. Systems that are often past their life expectancy, in poor condition, and pose environmental risks. For this project, we designed a 20,000-gpd wastewater treatment plant and wastewater collection system consisting of over 8,000 LF of 12” and 15” gravity mains, a duplex lift station, and 4,800 LF of 8” force main. In 2021, we completed additional projects that significantly expanded this new wastewater system, including a 150,000-gpd
wastewater treatment plant expansion, another 7,000 LF of gravity main, two more lift stations, and over 11,000 LF of new force main. With this being a new system and on-going project, we were involved in a variety of tasks to get the system up and running. We also reviewed design plans for new subdivisions that would be connecting to this wastewater system for compliance with County Line SUD’s rules and regulations. The existing wastewater treatment plant serves a subdivision with 93 duplexes, so 186 living units, for about 500 people. Since we began work on this project, there have already been four new residential subdivisions and an elementary school constructed in the area, with more new developments expected. We are currently preparing a master plan for this wastewater treatment plant that could ultimately serve approximately 8,000 residents after additional expansions. Another goal is to eventually re-use all the effluent from the treatment plant for irrigation and other non-potable functions. Once the wastewater collection system has sufficient connections to generate enough reclaimed water, we will design a reclaimed water pump station and a purple pipe network.
Challenges and Solutions
"We encountered a great deal of groundwater that appeared suddenly halfway through construction. To help determine the source of the extra water, we arranged for several exploratory excavations. Eventually, we concluded that the flow came down the gravel bedding of the gravity wastewater pipe to the plant. We then tested the water quality to verify it was not wastewater and requested the water company confirm nearby water pipes were not leaking. Once we verified the water was naturally occurring groundwater, we designed a trench dam and gravel drain to re-direct this water to a nearby drainage low."
— SWE Project Manager
For us, the combination of legacy and eco-friendly design has made this project notable in our portfolio. Without a centralized wastewater treatment facility, future development in this community would have been limited due to the reliance on individual septic systems. Systems that can degrade and pollute the environment when not properly maintained. Conversely, this wastewater treatment facility produces a high-quality effluent that will be re-used for irrigation and other non-potable uses in the near future. This reduces the demand for valuable potable water while safeguarding the environment and community from pollution.