Category: Case Study

Read article on Onsite Installer: Case Studies: System Repair/Drainfield Rejuvenation

On a constrained 3-bedroom lakefront property in Ashland, Wisconsin, limited space made a conventional onsite wastewater system unworkable. The only viable location for treatment was a narrow area between an existing driveway and a retaining wall, leaving no flexibility for traditional designs.

An in-ground Eljen GSF Bed system provided the ideal solution. The system was installed as a two-row gravity bed using sixteen (16) B43 modules, fitting into a compact drainfield measuring just 10 feet by 33 feet. The small footprint and adaptable layout of the Eljen GSF system allowed the drainfield to be placed precisely where no other system would fit.

The gravity configuration simplified installation, minimized site disturbance, and helped protect the sensitive lakefront environment. This project showcases how the Eljen GSF system delivers reliable performance, regulatory compliance, and unmatched flexibility for challenging, space-limited sites.

Pinnacles National Park, located in central California, is renowned for its striking spires, canyons, and as a refuge for the endangered California Condor. Protecting the pristine landscape and delicate ecosystems is a top priority, especially when it comes to wastewater treatment. When the park sought a sustainable solution to meet nitrogen reduction goals, the Eljen Geotextile Sand Filter (GSF) was selected and installed in its nitrogen reduction configuration.

The site’s conditions, low groundwater, rocky terrain, and a high-value natural habitat—made Pinnacles an ideal candidate for the GSF’s passive denitrification capabilities. Unlike mechanical treatment systems, the GSF requires minimal maintenance and no power, which reduces operating costs and environmental impact. The layered geotextile and sand filtration process ensures advanced treatment, significantly lowering nitrogen, BOD, and TSS levels while protecting surrounding water resources.

Since its installation, the GSF has provided reliable performance with a small footprint, aligning with the National Park Service’s mission to conserve natural resources for future generations. This project illustrates how innovative, low-maintenance technologies like the GSF can serve sensitive sites where both performance and sustainability are critical. By helping Pinnacles safeguard water quality while reducing operational demands, the GSF stands as a model for wastewater treatment in national parks and beyond.