Refined and improved over the decades, the MaxWell® IV Drainage System represents the state-of-the-art single chambered design for landscaped areas. This drywell is best described as a treatment BMP which utilizes infiltration to help replenish groundwater.
The drywell receives inflow through the grated opening on top of the chamber, although there may be direct piping connections into the drywell below the surface. The incoming water rises up inside the chamber, and is introduced into the overflow intake. The overflow inlet is equipped with an integral screen, which is in turn covered by a vented cylindrical shield. This feature blocks the passage of hydrocarbons and other floating constituents, and instead isolates and contains them inside the settling chamber. At the same time silt, sediment and debris are dropped out by gravity separation inside the deep settling chamber. This accumulated debris inside the chamber can be conveniently hydrovactored during normal cleaning.
The chamber is equipped with a floating hydrocarbon capture pillow filled with unique polymer beads, which attract a wide range of hydrocarbons and liquid organic compounds. Together, the shielded inlets and the hydrocarbon capture pillow provide an unequalled level of constituent removal. The pre-treated water then exits the system through the drainage screen at the end of the drainage pipe below the settling chamber, and is infiltrated into the subgrade. The water is then further polished by passage through the vadose zone soil envelope and eventually replenishes groundwater supplies.