Abstract: A storm water management system includes a flow control device that includes a float in a storage chamber responsive to changes in water level and a valve disposed between the storage chamber and a discharge. The valve includes a relatively movable valving member connected to the float and a fixed valving member. Each valving member has a through opening that receives storm water flowing between the storage chamber and the discharge. The through-openings overlap one another whereby relative displacement of the valving members caused by float movement defines a variable-sized orifice between the storage chamber and the discharge that regulates the discharge rate of storm water from the system. The shapes of the overlapping openings enable the valve to closely follow the ideal output hydrograph and maximize the discharge rate as a function of storm intensity, thereby minimizing the required volume of the storage chamber.

Abstract: An underground stormwater management system includes a first-flush chamber that receives the first flush. The chamber removably holds filter cartridges that close the chamber and filter the first flush as the first flush drains out of the chamber and into an underlying porous substrate. When the filter cartridges are used up, they can be replaced with new filter cartridges.

Abstract: A liner system for detecting the presence or absence of water in soil includes a liner having opposite electrically conductive layers separated by an insulating layer, a number of electrodes embedded in the conductive layers, and a number of electric field detectors embedded in one of the conductive layers.

Abstract: A method for delaying the maximum rate of discharge of water from a stormwater retention basin includes varying the vertical distance of an intake opening from the waterline inversely with water depth. A flow control device for carrying out the method includes an intake pipe with an intake opening that is pivotally mounted to a float body, the pivot being spaced from the intake opening.

Abstract: A flow control device includes a float that moves vertically in response to changes in water level, a valve body that moves between extended and retracted positions, and a mechanism interconnecting the float and the valve body wherein changes of position of the float in response to changes in water level changes the position of the valve body. The valve body is placed adjacent a discharge pipe to change the effective intake area of the discharge pipe with changes in water level.

Abstract: A flow control device for a storm water management system includes a storage chamber and a number of discharge openings extending through the storage chamber. Associated with each opening is a valving mechanism that opens or closes the opening in response to changes in water level in the storage chamber.

Abstract: A coupler for coupling adjacent end portions of corrugated plastic pipe includes first and second arcuate members that cooperate with each other to surround and interfit with the corrugations of the plastic pipe. A stop member on one of the members enables the other member to be properly positioned over the other member when forming the coupler. Circumferentially aligned and spaced-apart attachment members resist relative movement of the two coupling members when backfilling the coupler and the pipes coupled by the coupler.

Abstract: A method for coupling corrugated pipe segments is disclosed. The method includes providing first and second thermoplastic corrugated pipe segments arranged to form a fluid flow path and aligning ends of the pipe segments adjacent one another to form a joint. The method further includes providing a coupling assembly having a thermoplastic sheet with a flexible weld rod of a thermoplastic material attached thereto and circumferentially contacting the coupling assembly with the first and second thermoplastic pipe segments. An electrical current is applied to the weld rod to cause the weld rod, sheet and pipe segments to fuse to one another and form a circumferential weld seam on each side of the joint.

Abstract: An underground stormwater management system includes a receiving tank connected to a source of non-first flush runoff and a storage chamber that accumulates stormwater runoff for discharge to a storm drain. The storage chamber includes a first inlet connected to a source of first flush runoff, a second inlet connected to receive overflow from the receiving tank, a first discharge and a second discharge above the first discharge. First flush is discharged from the first discharge and is filtered before reaching the storm drain. The receiving tank assists in delaying the receipt of non-first flush runoff into the storage chamber during a major rain event. During major rain events runoff is also discharged from the storage chamber directly to the surrounding media.

Abstract: A separator for stormwater includes a long, U-shaped sediment chamber and an oil chamber.