Tel Aviv’s Third Sewage Transmission Line: Going Where No Pipeline Has Gone Before

The Ayalon Sewage Transmission Project, known as the AY Line Project, was designed by Balasha-Jalon Infrastructure Systems Limited and built to enhance the sewage transmission system of the Dan Regional Association for Environmental Infrastructure (IGUDAN) and add redundancy. The project was designed to withstand future breakdowns and allow for major maintenance work without causing any sewer spills. This goal was achieved by creating two large transmission loops that interacted with each other, as with a water supply system. The project involved pipe jacking to install a 1,600 mm (64") diameter pipeline under one of the world’s most congested highways, using only the narrow shoulders and other small areas for work sites. The project also included a large pumping station with dry-installed submersible pumps and two rising mains. The AY Line Project was completed in 2021, and is fully operational, meeting or exceeding all of its design criteria. The successful completion of the AY Line Project demonstrated that large diameter sewage pipelines can be installed under major highways using microtunneling and other “no-dig” methods that work reliably, even under the most challenging conditions. It also demonstrated that water system design, using flow loops, can be applied to large sewage transmission system design, where sewage spills are unacceptable.