What is on-site sewage treatment or on-site sewage facility?
On-site wastewater treatment is commonly utilised in areas where housing density is low enough that centralised wastewater treatment is not economically feasible. It is also employed in places where technological and resource constraints prevent the installation of centralised wastewater treatment plants. The goal of on-site wastewater treatment systems is to reduce pollutant concentrations to acceptable levels before the treated waste enters water sources or comes into contact with humans. Organic compounds (e.g., oil and grease), inorganic chemicals (e.g., heavy metals), nutrients (e.g., nitrogen and phosphorus), and disease-causing microbes (pathogens) are all contaminants in home wastewater.
Onsite wastewater treatment systems (OWTS):
Onsite (or decentralised) wastewater treatment systems treat wastewater from a house or company and return it to the receiving environment. They are commonly referred to as septic systems since the majority of them have a septic tank for partial treatment.
In the World today, a septic tank and drain field combination is a very popular form of on-site sewage infrastructure. Small-scale aerobic and biofilter units, membrane bioreactors, or sequencing batch reactors can also be used for on-site sewage treatment. These can be regarded of as scaled down versions of municipal sewage treatment plants, and are also known as package plants.
Traditional septic systems include a septic tank that gravity drains to a soil adsorption area for ultimate treatment and dispersion. The septic tank permits particle matter to settle to the tank's bottom, preventing big solids from clogging the drain field. An effluent screen, which is installed at the septic tanks exit, is used to filter suspended particles from the effluent. The wastewater is finally treated and dispersed in the soil adsorption field.
The main functions of a non-traditional system are the same as those of conventional septic systems. When location, space, laws and regulations, soil type, and/or the quantity of wastewater being treated become limiting factors, differences arise. In this situation, a non-traditional system is any OWTS that employs pumps or sophisticated therapy. These systems employ technologies that need more frequent operation and maintenance.
Performance standards can be expressed as numerical criteria (e.g., pollutant concentration or mass loading limits) or narrative criteria (e.g., no odours or visible sheen) and are based on regional ground water or surface water assimilation capacity, water quality objectives, and public health goals.
Wastewater flow and pollutant content aid in the definition of system design and size, and may be calculated by comparing the size and type of facility to observed effluent outputs from similar, existing facilities. To further define system design requirements and determine the physical placement of system components, site evaluations combine detailed analyses of regional hydrology, geology, and water resources with site-specific characterization of soils, slopes, structures, property lines, and other site features.
The majority of alternative treatment systems used today treat wastes after they have exited the septic tank; the tank stores settleable solids, grease, and oils and offers an environment for partial digestion of settled organic wastes. Aerobic (with oxygen) or anaerobic (with no or low oxygen) biological treatment in suspended or fixed-film reactors, physical/chemical treatment, soil infiltration, fixed-media filtration, and/or disinfection are all options for post-tank treatment. Performance requirements, wastewater characteristics, and site circumstances all influence the use and sizing of treatment units based on these technologies.
For more details, contact Netsol Water.