In cities and urban centres, most buildings are connected to a municipal wastewater treatment plant. Wastewater is conveyed through a sewer system to a central treatment plant which treats and discharges the wastewater. For buildings outside of the areas serviced by a municipal plant, an on site wastewater treatment system is required.
On site treatment systems generally consist of a collection system, a treatment system and an effluent discharge system. Specific details of each component are dependent on site specific requirements. The collection system carries the wastewater from the building or buildings to the treatment system. The treatment process will generally include primary treatment which occurs in the septic tank and involves settling of large solids. The wastewater can then be treated further through tertiary treatment equipment which consists of some form of media filter or aeration or a combination of both. Effluent discharge can be to a surface body of water or to groundwater. If discharge is to groundwater, the treated wastewater is sent into the ground through distribution piping within an absorption bed. The wastewater is further treated in the ground as it filters down through the bed material prior to reaching the groundwater table. Discharge to a surface body of water requires disinfection through ultraviolet radiation.
On site wastewater treatment systems that are designed for a flow of less than 10,000 L/day are regulated by the Ontario Building Code and require a building permit from the local municipality. Systems that are larger than 10,000 L/day are regulated by the Ontario Ministry of the Environment and require a Certificate of Approval.
Developments in rural areas can be difficult due to the lack of municipal services such as water supply and sewage treatment. K. Smart Associates Limited has been involved in the design of On-Site Wastewater Collection and Treatment Systems since 1985. We have designed a wide variety of sewage treatment systems for a variety of uses using a variety of treatment equipment.
K. Smart Associates Limited have completed projects for single family homes, nursing homes, restaurants, camp grounds, golf courses, highway service centres, churches, schools and resorts.
Size of projects range from 2,500 litres/day to 250,000 litres/day.
Our most notable wastewater treatment plant was designed to treat the wastewater and produce water quality suitable for reuse for toilet flushing. Reusing the water is environmentally sound practice that has been practiced in arid parts of the world and Europe for over 100 years. We implemented wastewater reuse in order to resolve the problem of disposal of treated wastewater and nitrate loading on a shallow ground water table and we reduced the demand for potable water from a deep aquifer which has limited supply potential.
Contact David Harsch, P.Eng. for more information regarding wastewater treatment systems.
