Dry Well System

The design of the dry well system consists of a treatment train of three components: a vegetated pretreatment feature, sedimentation well, and the dry well itself, as depicted in the diagram below. The vegetated pretreatment feature stored and filtered stormwater for a minimum of 7-minutes and reduced peak discharge rates and total runoff by using soil amendments to increase infiltration. The second stage of pretreatment, the sedimentation well, trapped and filtered additional sediment before runoff was discharged into the dry well. The dry well itself was designed to capture any remaining suspended solids by including both sand and gravel layers at the top of the well. While the pervious layers will facilitate a high infiltration rate, the clay layer in the vadose zone will cause stormwater to move horizontally to obtain further treatment of potential contaminants and will function as a final step of attenuation.

The project's dry well system to the left is composed of a (left to right) vegetated pre-treatment feature, sedimentation well and a dry well.