Though much of a civil engineer’s work is not glamorous by any means, that doesn’t mean that it isn’t often significant or impactful. One example of this is our recent work designing the largest low-pressure sewer system owned and operated by the City of Fort Worth. Also the largest such system designed by BHB in the past 29 years, it serves over 110 homes and businesses spanning roughly five miles of frontage along Lake Worth.
The community located North of Lake Worth along Watercress was originally developed decades ago as land leases by the City of Fort Worth. The homes were originally built as fishing cabins with minimal utility service, including individual septic tank systems. Over the years the development became more dense as permanent homes were built, but still without a public sanitary sewer system. As the septic system began to age the threat of system failures and lake contamination began to grow.
In 2018, the City of Fort Worth brought in Baird, Hampton & Brown civil engineers to design a public sanitary sewer system to serve the community and resolve the looming threat of lake contamination, funded by royalties from oil and gas sales. For this project, we had two options for the system: a traditional gravity system or a low-pressure system. Because of the area’s proximity to the lake, and therefore relatively flat elevation, a traditional gravity system would require numerous lift stations. A low-pressure system on the other hand would rely on individual home pump stations throughout the community served by small diameter force mains and was chosen.
A low-pressure system is somewhat unique as opposed to the more commonly used gravity system. Instead of relying on gravity to move waste through the system, everything is pressure forced by private grinder pump stations at each property. The sewer lines are also significantly smaller (individual structures are served by one and half inch services with public mains ranging from two to four inches, as opposed to the more traditional gravity mains with an eight-inch minimum sewer lines) and are appropriately pressure rated. In the design process, our engineers focused on sewer line capacity to help ensure that each home could be served and would also contribute to the pressure needed to keep the system functioning.
In addition to the utility improvements included during the course of the project, we discovered several sections of public streets that didn’t follow the right-of-way, cutting into private property. The scope was expanded to include realignment of those sections of roadway.
Although the vast majority of this project is now hidden underground, the effects of this work will benefit the Watercress community for years to come.