One of the biggest discussion here in the state of Virginia as it pertains to the design of infiltration trenches, rain gardens, bio ponds, and dryswale, is should filter fabric be used to cover the tops & bottoms of the facility? Often times soil conditions lead to issues with water percolation and filter fabric in many discussions recently has been a focus of the problem being exacerbated. If water is ponding then even a high filtration rate fabric makes the issue considerably worse. As an installer, it is always interesting, and yet sometimes perplexing, when we work with the same engineer that changes the designs on the filter fabric installation from project to project. Take a closer look the next time you see us installing a BMP, as we would be happy to point out the variations in the plan as it pertains to filter fabric installation.
