What is required of the native soils along the bottom and sides of the permeable pavement system before placing the filter layer?

Before placing the filter layer in a permeable pavement system, it is essential that the native soils along the bottom and sides are scarified or tilled. This process helps to prepare the soil for proper drainage and water infiltration, which are critical for the effectiveness of the permeable pavement system. Scarification creates a rough surface by breaking up compacted soil, allowing for better water flow and preventing clogging of the filter layer. It also promotes the establishment of vegetation if necessary and enhances soil aeration, which is beneficial for the overall health of the system.

If the native soils were to be removed completely, it would eliminate any natural filtration benefits and could lead to structural issues. Similarly, packing the soils tightly could inhibit water movement, defeating the purpose of installing permeable pavement. Treating the soils with chemicals is generally unnecessary and may lead to adverse effects on soil health and surrounding ecosystems. Therefore, scarifying or tilling the soil is the optimal approach to ensure the permeable pavement system functions as intended.