Wastewater treatment is a process which removes and eliminates contaminants from wastewater. It thus converts it into an effluent that can be returned to the water cycle. Once back in the water cycle, the effluent creates an acceptable impact on the environment. It is also possible to reuse it. This process is called water reclamation. The treatment process takes place in a wastewater treatment plant. There are several kinds of wastewater which are treated at the appropriate type of wastewater treatment plant. For domestic wastewater the treatment plant is called a Sewage Treatment. Municipal wastewater or sewage are other names for domestic wastewater. For industrial wastewater, treatment takes place in a separate Industrial wastewater treatment, or in a sewage treatment plant. In the latter case it usually follows pre-treatment. Further types of wastewater treatment plants include Agricultural wastewater treatment and leachate treatment plants.
Water reclamation is the process of converting municipal wastewater or sewage and industrial wastewater into water that can be reused for a variety of purposes. It is also called wastewater reuse, water reuse or water recycling. There are many types of reuse. It is possible to reuse water in this way in cities or for irrigation in agriculture. Other types of reuse are environmental reuse, industrial reuse, and reuse for drinking water, whether planned or not. Reuse may include irrigation of gardens and agricultural fields or replenishing surface water and groundwater. This latter is also known as groundwater recharge. Reused water also serve various needs in residences such as toilet flushing, businesses, and industry. It is possible to treat wastewater to reach drinking water standards. Injecting reclaimed water into the water supply distribution system is known as direct potable reuse. Drinking reclaimed water is not typical. Reusing treated municipal wastewater for irrigation is a long-established practice. This is especially so in arid countries. Reusing wastewater as part of sustainable water management allows water to remain an alternative water source for human activities. This can reduce scarcity. It also eases pressures on groundwater and other natural water bodies.
A constructed wetland is an artificial wetland to treat sewage, greywater, stormwater runoff or industrial wastewater. It may also be designed for land reclamation after mining, or as a mitigation step for natural areas lost to land development. Constructed wetlands are engineered systems that use the natural functions of vegetation, soil, and organisms to provide secondary treatment to wastewater. The design of the constructed wetland has to be adjusted according to the type of wastewater to be treated. Constructed wetlands have been used in both centralized and decentralized wastewater systems. Primary treatment is recommended when there is a large amount of suspended solids or soluble organic matter.
Industrial wastewater treatment describes the processes used for treating wastewater that is produced by industries as an undesirable by-product. After treatment, the treated industrial wastewater may be reused or released to a sanitary sewer or to a surface water in the environment. Some industrial facilities generate wastewater that can be treated in sewage treatment plants. Most industrial processes, such as petroleum refineries, chemical and petrochemical plants have their own specialized facilities to treat their wastewaters so that the pollutant concentrations in the treated wastewater comply with the regulations regarding disposal of wastewaters into sewers or into rivers, lakes or oceans. This applies to industries that generate wastewater with high concentrations of organic matter, toxic pollutants or nutrients such as ammonia. Some industries install a pre-treatment system to remove some pollutants, and then discharge the partially treated wastewater to the municipal sewer system.
A fecal coliform is a facultatively anaerobic, rod-shaped, gram-negative, non-sporulating bacterium. Coliform bacteria generally originate in the intestines of warm-blooded animals. Fecal coliforms are capable of growth in the presence of bile salts or similar surface agents, are oxidase negative, and produce acid and gas from lactose within 48 hours at 44 ± 0.5°C. The term thermotolerant coliform is more correct and is gaining acceptance over "fecal coliform".
Effluent is wastewater from sewers or industrial outfalls that flows directly into surface waters, either untreated or after being treated at a facility. The term has slightly different meanings in certain contexts, and may contain various pollutants depending on the source.
The Hyperion Water Reclamation Plant is a sewage treatment plant in southwest Los Angeles, California, next to Dockweiler State Beach on Santa Monica Bay. The plant is the largest sewage treatment facility in the Los Angeles Metropolitan Area and one of the largest plants in the world. Hyperion is operated by the City of Los Angeles, Department of Public Works, and the Bureau of Sanitation. Hyperion is the largest sewage plant by volume west of the Mississippi River.
Robert A. (Bob) Gearheart is an emeritus professor of environmental engineering at Cal Poly Humboldt, in Arcata, California.
Secondary treatment is the removal of biodegradable organic matter from sewage or similar kinds of wastewater. The aim is to achieve a certain degree of effluent quality in a sewage treatment plant suitable for the intended disposal or reuse option. A "primary treatment" step often precedes secondary treatment, whereby physical phase separation is used to remove settleable solids. During secondary treatment, biological processes are used to remove dissolved and suspended organic matter measured as biochemical oxygen demand (BOD). These processes are performed by microorganisms in a managed aerobic or anaerobic process depending on the treatment technology. Bacteria and protozoa consume biodegradable soluble organic contaminants while reproducing to form cells of biological solids. Secondary treatment is widely used in sewage treatment and is also applicable to many agricultural and industrial wastewaters.
An aerobic treatment system (ATS), often called an aerobic septic system, is a small scale sewage treatment system similar to a septic tank system, but which uses an aerobic process for digestion rather than just the anaerobic process used in septic systems. These systems are commonly found in rural areas where public sewers are not available, and may be used for a single residence or for a small group of homes.
The Western Treatment Plant is a 110 km2 (42 sq mi) sewage treatment plant in Cocoroc, Victoria, Australia, 30 km (19 mi) west of Melbourne's central business district, on the coast of Port Phillip Bay. It was completed in 1897 by the Melbourne and Metropolitan Board of Works (MMBW), and is currently operated by Melbourne Water. The plant's land is bordered by the Werribee River to the east, the Princes Freeway to the north, and Avalon Airport to the west. It forms part of the Port Phillip Bay and Bellarine Peninsula Ramsar Site as a wetland of international importance. The Western Treatment Plant treats around fifty percent of Melbourne's sewage — about 485 megalitres or 393 acre-feet per day — and generates almost 40,000 megalitres or 32,000 acre-feet of recycled water a year.
Sewage treatment is a type of wastewater treatment which aims to remove contaminants from sewage to produce an effluent that is suitable to discharge to the surrounding environment or an intended reuse application, thereby preventing water pollution from raw sewage discharges. Sewage contains wastewater from households and businesses and possibly pre-treated industrial wastewater. There are a high number of sewage treatment processes to choose from. These can range from decentralized systems to large centralized systems involving a network of pipes and pump stations which convey the sewage to a treatment plant. For cities that have a combined sewer, the sewers will also carry urban runoff (stormwater) to the sewage treatment plant. Sewage treatment often involves two main stages, called primary and secondary treatment, while advanced treatment also incorporates a tertiary treatment stage with polishing processes and nutrient removal. Secondary treatment can reduce organic matter from sewage, using aerobic or anaerobic biological processes. A so-called quarternary treatment step can also be added for the removal of organic micropollutants, such as pharmaceuticals. This has been implemented in full-scale for example in Sweden.
A marine outfall is a pipeline or tunnel that discharges municipal or industrial wastewater, stormwater, combined sewer overflows (CSOs), cooling water, or brine effluents from water desalination plants to the sea. Usually they discharge under the sea's surface. In the case of municipal wastewater, effluent is often being discharged after having undergone no or only primary treatment, with the intention of using the assimilative capacity of the sea for further treatment. Submarine outfalls are common throughout the world and probably number in the thousands. The light intensity and salinity in natural sea water disinfects the wastewater to ocean outfall system significantly. More than 200 outfalls alone have been listed in a single international database maintained by the Institute for Hydromechanics at Karlsruhe University for the International Association of Hydraulic Engineering and Research (IAHR) / International Water Association (IWA) Committee on Marine Outfall Systems.
The San Joaquin Marsh Wildlife Sanctuary is a 300-acre constructed wetland in Irvine, California, in the flood plain of San Diego Creek just above its outlet into the Upper Newport Bay.
Duffin Creek Water Pollution Control Plant is on the north shore of Lake Ontario in the City of Pickering. It operates as a partnership between the Regional Municipality of York and the Regional Municipality of Durham. The Plant is capable of treating 630 million litres of wastewater each day and serves the communities of York Region, the Town of Ajax and the City of Pickering in Durham Region. Holding ISO 14001 certification, the Plant operates to ensure the environmentally responsible treatment of wastewater.
A vermifilter is an aerobic treatment system, consisting of a biological reactor containing media that filters organic material from wastewater. The media also provides a habitat for aerobic bacteria and composting earthworms that purify the wastewater by removing pathogens and oxygen demand. The "trickling action" of the wastewater through the media dissolves oxygen into the wastewater, ensuring the treatment environment is aerobic for rapid decomposition of organic substances.
The Sacramento Regional Wastewater Treatment Plant (SRWTP) is a wastewater treatment plant in Elk Grove, California, United States. It was built along the Interstate 5 during the 1970s and became fully operational in 1982. The plant was built to centralize wastewater treatment, instead of sending it to the 22 treatment plants that used to exist in the Sacramento Area. The SRWTP employs approximately 350 people, treats approximately 127 million gallons of effluent daily for over 1.4 million people in Elk Grove, Sacramento, Citrus Heights, Folsom, and Rancho Cordova. It was later renamed Regional Sanitation as it continues upgrades to meet new state standards.
George Herbert Allen was an American ichthyologist and fisheries scientist. His father was a US consul and they family moved to Calgary with his father's posting in 1927 and George remained there until he went to the University of Wyoming as an undergraduate where he graduated before entering the military during the Second World War. After the war he completed his master's and doctorate degrees at the University of Washington in 1956, where he met his wife, Beverly Robinson. He started a position at the Cal Poly Humboldt an association which was to last over 30 years, ending his career as a professor of fisheries. At Cal Poly Humboldt he played an important part in setting up the university's oceanography program and its graduate program in fisheries. He was awarded the President's Distinguished Service Award by the Cal Poly Humboldt and had a lab and part of the Arcata Wastewater Treatment Plant and Wildlife Sanctuary was named in his honor. Allen was nicknamed "Fishy" by the Arcata, California, city hall workers he co-operated with in the creation of its pioneering artificial marsh wastewater treatment facility. The toadfish genus Allenbatrachus was named in his honor by one of his former students, David W. Greenfield, for Allen's introduction of Greenfield to ichthyology. He was survived by his wife, Beverley, and their three daughters.
The San José–Santa Clara Regional Wastewater Facility is a wastewater treatment plant located in the Alviso neighborhood of San Jose, California. The facility treats 110 million U.S. gallons of wastewater per day, with a capacity of up to 167 million U.S. gal/d (630 ML/d), making it the largest tertiary treatment plant in the western United States. It serves 1.5 million residents and over 17,000 business facilities in eight cities. The 2,600-acre (1,100 ha) site is operated by the San Jose Environmental Services Department and jointly owned by the cities of San Jose and Santa Clara. It began operations in 1956 to address severe water pollution issues and played a key role in San Jose's aggressive annexation program during the 1950s and 1960s.
