The MaxWell® Plus Drainage System is a dual-chambered infiltration BMP that pre-treats stormwater twice for constituent removal prior to infiltration. The product offers field-proven efficiency, and has become the standard of quality utilized by numerous municipalities in California and Arizona and the overwhelming choice of specifying civil engineers in the private sector. This popular model is best used in large paved areas when connected with underground storage tanks or where there is an abundance of silt, sediment and debris runoff.
During the pre-treatment process, this design traps out suspended solids and debris, and wicks away petroleum-based organic compounds from the inflow. Both chambers are equipped with hydrocarbon capture pillows filled with unique polymer beads, which capture a wide range of hydrocarbons and liquid organic compounds. The MaxWell Plus typically receives inflow through the grated opening on top of the primary settling chamber, although there may be direct piping connections into the inlet structure below the surface. The vented intake in the primary settling chamber incorporates a screen and reduction orifice. As the incoming water rises up in the primary chamber to the invert of a crossover pipe connected to the main drywell chamber, the initial removal of solids occurs in this chamber where silt, sediment and debris are dropped out by gravity separation. The accumulated material can then be conveniently hydrovactored during normal cleaning. The transfer of stormwater between the two chambers is metered by the installation of a reduction orifice. This restriction increases the efficiency of constituent removal by providing more residence time for the water in the primary settling chamber, thus enhancing the settlement of solids. Once in the main drywell, the pre-treatment cleaning of the inflow is repeated and further processed identical to the MaxWell IV single chamber drywell.