The Water Efficiency category awards credits for strategies that minimize negative impacts to the environment and lessen the burden and demand on local water supplies and municipal water and wastewater treatment facilities. Reducing water usage also reduces operational expenses.
1. Indoor potable water use has been reduced by 76% compared to the conventional baseline use, through the following strategies:
• Installing low flow plumbing fixtures
• Groundwater from a shallow aquifer is collected in a building tile around the perimeter of the building, carried to a cistern and stored for non-potable usage. Filter cloth around the pipe helps to remove suspended sediments from the water. 100% of the water used to flush the toilets and urinals is from the cistern, completely eliminating the use of potable water for sewage conveyance. Water stored in the cistern is also used for outdoor irrigation, which will be minimal once the native plants become established. (Water from the roof is not used within the building because it would require treatment; instead, it is piped to the ground and outlets near the SWM pond.)
• Plants on the indoor green roofs are watered by drip irrigation, which uses less water than conventional watering methods.
• The landscaping around this building is comprised of native and adaptive species that do not require irrigation, saving water and minimizing maintenance.
2. The WCC is not connected to the municipal sewer system. All wastewater produced within the WCC is treated on-site by a septic tank and a tertiary system known as the Waterloo Biofilter, which uses bacteria to degrade, oxidize and consume contaminants found in the water.
Wastewater is first treated within the two chamber, 30,000 L septic tank (capacity of 15,330 L/day). In the septic tank, anaerobic bacteria/ microorganisms break down the wastewater/ effluent. The tank is designed so that heavier particles settle to the bottom and lighter particles float on the top. As the clearer effluent leaves the septic tank, it is further screened by an effluent filter to prevent solids from leaving the tank.
Effluent moves from the septic tank into a single compartment, 20,450 L pump chamber, where it is stored before being sprayed over the Waterloo Biolfilter treatment systems. This system consists of two above grade, open bottom biofilter treatment units (cedar sheds). A force main (pressurized pipe) carries effluent from the pump chamber to the sheds, where the effluent is sprayed evenly over a filter medium (foam biofilter cubes). As the effluent trickles over the absorbent biological medium, beneficial microbes consume organic pollutants, coliform bacteria, ammonium and contaminants present in the septic tank.
During the third and final treatment, the treated water is released back into an underlying Waterloo Biofilter area bed, which consists of a layer of stone over top of a layer of sand. The treated water is cleaner than that produced in a standard septic system, and there is no tile or perforated pipe which is typical in standard filter or leaching bed systems.