plastic pipes with holes drilled through the bottom, installed on the bottom of an infiltration BMP to collect and remove excess runoff.
A perforated pipe, typically 4-6" in diameter placed longitudinally at the invert of a bioretention facility for the purposes of achieving a desired discharge rate.
The lower collection system in a filter which directs filtered water back towards the pool. It also distributes water in reverse during backwashing. See laterals.
A small diameter perforated pipe that allows the bottom of a detention basin, channel or swale to drain.
in drinking water treatment, a set of pipes placed below the sand and gravel in a filter to collect the treated water.
The bottom part of a filter that collects the filtered water and uniformly distributes the backwash water.
A drainage system installed under a slab or street to divert and channel away excess water.
Slotted tubes attached to the manifold of a sand filter. After water flows through the sand it continues on through the underdrain slots back to the pool.
1. Perforated pipe drain installed in crushed stone under a slab to intercept ground water and drain it away from the structure. 2. The distribution system at the bottom of a sand filter to collect the filtered water during a filter run and to distribute the backwash water during backwash.
Also call filter laterals or lower collection system - Slotted, finger-like tubes that are attached to a sand filter manifold. The slots are on the bottom side to prevent the sand from passing through. Water comes into the filter tank, through the sand, into the underdrain, and then back to the pool.
A drain that carries away water from prepared beds or agricultural fields to which water or wastewater has been applied.
The drainage piping arrangement to collect treated water at the bottom of the ion exchange or filter media beds.