Wastewater System Infrastructure Retrofit

The residents of the City of Seabrook are currently served by a single wastewater treatment plant located on a small island that stretches into Clear Lake, approximately 500 feet from Galveston Bay on the south side of town. Due to the low elevation, the plant is at risk of flooding during a natural disaster such as a hurricane. During Hurricane Ike in 2008, the storm surge overtopped the walls of the plant causing sewage to be washed out creating an environmental hazard for the surrounding area. High flood waters also damage the plant’s electrical and mechanical equipment, as well as structural components, even during smaller flood events. The proposed system retrofit will include a new plant near Pine Gully which is at a higher elevation and further inland. The project will also include an additional lift station and upgrades to three existing lift stations in order to redirect approximately 22,000 linear feet of sanitary sewer lines.

CobbFendley helped the City of Seabrook obtain a grant for the project which was awarded to the City by the Texas Division of Emergency Management (TDEM) through the Federal Emergency Management Administration’s (FEMA) Hazard Mitigation Grant Program (HMGP). CobbFendley was the prime consultant and was responsible for coordinating with 5 subconsultants for geotechnical, environmental, electrical, construction materials testing, and construction inspection services. Our team also coordinated with CenterPoint Energy to add power to the new wastewater treatment plant and lift station sites. CobbFendley’s Municipal Department was responsible for the design of the new wastewater treatment plant facility, lift station design, sanitary sewer system design, and overall project coordination.  CobbFendley’s Survey department provided topographic survey for the entire corridor of proposed sanitary sewer line, topographic survey of the new wastewater treatment plant location and lift stations, and metes and bounds for utility easements. Our structural department assisted with the design of the new wastewater treatment plant facility and lift station facilities.

This project required an analysis of the sewer system flows of the entire City of Seabrook and what improvements would be required to send flow to the new plant site on the opposite side of town. The calculations indicated which lift stations would need modifications due to increased or reduced flow, the need and location of a new lift station, and sizing both force main and gravity sewer pipes. At the plant site, CobbFendley obtained a new permit through the Texas Commission on Environmental Quality (TCEQ).

Once the project is complete, the residents of Seabrook will enjoy an upgraded sanitary sewer system with a wastewater treatment plant that is far less likely to lose its ability to service the City during future storm events due to its higher elevation and inland location.