1. PERMEABLE REACTIVE WEIR (PRW)
Patent pending 2014
Inventors: Erick McWayne and Howard Sprouse
Intracep Engineering, LLC
emcwayne@intracep.com
Phone: (800) 684-6634
Contaminants in streams, rivers, and other waterways adversely affect aquatic
ecosystems by destabilizing the food chain and directly harming aquatic life. Permeable
reactive weirs (PRWs) can improve aquatic habitats by removing pollutants from water,
and creating upstream pools that allow suspended solids to settle and downstream
cascades that increase dissolved oxygen. Engineered streambeds (engineered hyporheic
zones) designed to treat surface water can also improve aquatic habitats by removing
pollutants from water and reducing temperatures. PRWs are one of the only methods for
reducing thermal pollution in surface water, which is the primary cause of surface water
impairment in western states. Below is an example configuration of the PRW with
openings for fish passage.

2. BRIEF DESCRIPTION OF INVENTION
The permeable reactive weir is comprised of an outer wall, which defines a
chamber that holds reactive filter media or replaceable media cartridges. The filter media
removes contaminants from stormwater runoff or surface water and may be renewed or
changed to increase the functional lifespan of the permeable reactive weir. The filter
media is chosen to address site-specific water quality concerns such as: metals, nutrients,
petroleum, polycyclic aromatic hydrocarbons, glycols, pesticides, surfactants, and other
toxic organics. Below are two example configurations, one with upper and lower fish
bypass, and the other showing the removable media cartridge.
Flow through the permeable reactive weir is controlled by ports on the influent and
effluent sides, baffles, valves, and conduits. The permeable reactive weir is completely
scalable and configurable to site conditions. It may be installed at stormwater outfalls,
within storm sewer systems, surface water canals, ditches, small streams, and rivers.
Construction is similar to a concrete weir with optional fish passage measures where
necessary. Permeable reactive weirs may be used in series or parallel. Engineered
streambeds (i.e., engineered hyporheic zones) may be installed below the permeable
reactive weir. Water flow is driven into the streambed by the head difference between the
upstream and downstream sides of the device.
For more information or to suggest demonstration project sites, please contact Erick
McWayne at (800) 684-6634 or emcwayne@intracep.com.
For the fish!