In June 2019, JET Filter System partnered with the Michigan DOT and LS Engineering in a field demonstration program of maintainable weep hole filters. The units were installed in a box culvert under US-31 at the north branch of the Macatawa River.
The program was sponsored by AASHTO TSP-2 Bridge Preservation Partnership.
The demonstration program, officially called Innovative Technology Demonstrations (ITD), is designed to introduce new and innovative preservation materials and technologies to owners of the nation’s highway systems.(TSP 2 Bridge Preservation )


Built in 1964, this twin box culvert is 176 feet long. It was originally designed with 3″ weep holes for drainage. Over time, the weep holes failed and backfill material escaped through the hole.
Many of the failed weep holes were plugged to stop soil loss. This resulted in constant high water levels and high pressure behind the walls. With no formal place to drain, the water found other paths through seams and cracks.
