PROTECTING OUR AIR AND WATER WITH FLEXIBLE MEMBRANE
LINERS, COVERS, AND FABRICATIONS

Wastewater Plant Liners

Municipal wastewater plants treat raw wastewater in a series of steps, during which large volumes of liquids in various stages are slowed down by water tank baffles, or held, sometimes for weeks. Some of these steps are intended to allow solids to settle—sometimes unaided, sometimes aided by treatment with bacteria while being exposed to circulating air (aeration). Geomembrane waste lagoon liners and concrete holding tank liners are frequently installed to insure waste doesn’t seep into the ground and ultimately enter the water supply. Cleaning out the solids which have settled (sludge) can be hard in the liner, so it must be very abrasion, puncture, and tear resistant.

MPC installed a 40 mil PVC tank liner in this aeration basin which is part of a plant that treats wastewater for a number of communities in Indiana. Along with the requirement for the liner material to be tear and puncture resistant and chemically compatible with the waste being treated, it also had to be very stable dimensionally. If an extruded liner, such as HDPE had been used, the wide range of temperatures in the Midwest could cause deformation where the liner is fitted around outlets, inlets, etc., creating an opportunity for wastewater to escape into the environment.