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109-558: The site sits on more than 2,600 acres (1,100 ha) on the southern end of the San Francisco Bay , adjacent to the Don Edwards San Francisco Bay National Wildlife Refuge . It consists of a 175-acre (71 ha) processing area, a 750-acre (300 ha) sludge-drying area, a 850-acre (340 ha) former salt evaporation pond , and open buffer space. About 200 acres (81 ha) is set aside for

218-451: A CHP gas engine , where the waste heat from the engine is conveniently used for heating the digester; cooking; space heating; water heating ; and process heating. If compressed, it can replace compressed natural gas for use in vehicles, where it can fuel an internal combustion engine or fuel cells and is a much more effective displacer of carbon dioxide than the normal use in on-site CHP plants. Raw biogas produced from digestion

327-567: A fuel ; it can be used in fuel cells and for heating purpose, such as in cooking. It can also be used in a gas engine to convert the energy in the gas into electricity and heat. After removal of carbon dioxide and hydrogen sulfide it can be compressed in the same way as natural gas and used to power motor vehicles . In the United Kingdom, for example, biogas is estimated to have the potential to replace around 17% of vehicle fuel. It qualifies for renewable energy subsidies in some parts of

436-592: A joint powers agreement , "Agreement between San Jose and Santa Clara Respecting Sewage Treatment Plant", giving Santa Clara 20% ownership in exchange for helping to fund upgrades at the plant, which was renamed the San Jose/Santa Clara Water Pollution Control Plant. In 1964, the plant added secondary treatment capabilities to meet state requirements. In the 1960s and 1970s, Milpitas, the Cupertino Sanitary District, and

545-449: A 1000-litre digester using psychrophiles harvested from "mud from a frozen lake in Alaska" has produced 200–300 liters of methane per day, about 20–30% of the output from digesters in warmer climates. The air pollution produced by biogas is similar to that of natural gas as when methane (a major constituent of biogas) is ignited for its usage as an energy source, Carbon dioxide

654-622: A 12,000-square-foot (1,100 m) laboratory to monitor performance. In 1998, the South Bay Water Recycling facility began providing water reclamation service. In early 2013, the wastewater treatment plant was renamed the San José–Santa Clara Regional Wastewater Facility, though it retained its former name for legal purposes. A $ 114 million cogeneration facility was completed in August 2020, featuring

763-457: A Nut detailed the biogas production process from pig manure and showed how it fueled a custom-adapted combustion engine. In 2007, an estimated 12,000 vehicles were being fueled with upgraded biogas worldwide, mostly in Europe. Biogas is part of the wet gas and condensing gas (or air) category that includes mist or fog in the gas stream. The mist or fog is predominately water vapor that condenses on

872-537: A deep red color to these ponds from the pigment within the algae protoplasm. The salt marsh harvest mouse is an endangered species endemic to the wetlands of the San Francisco Bay with a high salt tolerance. It needs native pickleweed , which is often displaced by invasive cordgrass, for its habitat. The seasonal range of water temperature in the bay is from January's 53 °F (12 °C) to September's 60 °F (16 °C) when measured at Fort Point , which

981-513: A faecal sludge treatment plant. Faecal sludge can also be co-treated with organic solid waste in composting or in an anaerobic digestion system. Biogas can be generated through anaerobic digestion in the treatment of faecal sludge. The appropriate management of excreta and its valorisation through the production of biogas from faecal sludge helps mitigate the effects of poorly managed excreta such as waterborne diseases and water and environmental pollution. The Resource Recovery and Reuse (RRR) )

1090-403: A façade by Buster Simpson that is illuminated at night. As of 2020, the facility treats 110 million U.S. gallons (420 megaliters) of wastewater per day, with a capacity of up to 167 million U.S. gal/d (630 ML/d). Most effluent is discharged into Artesian Slough. However, an average 14 million U.S. gal/d (53 ML/d) of treated wastewater is diverted to

1199-1003: A hotspot for polybrominated diphenyl ether ( PBDE ) flame retardants used to make upholstered furniture and infant care items less flammable. PBDEs have been largely phased out and replaced with alternative phosphate flame retardants. A 2019 San Francisco Estuary Institute (SFEI) study assayed a wide range of these newer flame retardant chemicals in Bay waters, bivalve California mussels ( Mytilus californianus ), and harbor seals ( Phoca vitulina ) which haul out in Corkscrew Slough on Bair Island in San Mateo County , with phosphate flame retardant contaminants such as tris(1,3-dichloro-2-propyl)phosphate (TDCPP) and triphenyl phosphate (TPhP) found at levels comparable to thresholds for aquatic toxicity. Thousands of man-made chemicals are found in Bay water, sediment, and organisms. For many of these, there

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1308-650: A major seaport . The Port of Oakland is one of the largest cargo ports in the United States, while the Port of Richmond and the Port of San Francisco provide smaller services. An additional crossing south of the Bay Bridge has long been proposed. San Francisco Bay is popular for sailors (boats, as well as windsurfing and kitesurfing ), due to consistent strong westerly/northwesterly thermally-generated winds – Beaufort force 6 (15–25 knots; 17–29 mph; 8–13 m/s)

1417-459: A new wastewater treatment facility. In 1954, the city purchased land near Alviso for a wastewater treatment plant. The plant began operations in 1956. Despite having only primary treatment capabilities designed for cannery effluent, it was the first and largest treatment plant in the South Bay, giving it outsized importance in the region's development. In 1951, the city council banned connections to

1526-716: A popular source of energy and is starting to be used in the United States more. In 2003, the United States consumed 43 TWh (147 trillion BTU) of energy from "landfill gas", about 0.6% of the total U.S. natural gas consumption. Methane biogas derived from cow manure is being tested in the U.S. According to a 2008 study, collected by the Science and Children magazine, methane biogas from cow manure would be sufficient to produce 100 billion kilowatt hours enough to power millions of homes across America. Furthermore, methane biogas has been tested to prove that it can reduce 99 million metric tons of greenhouse gas emissions or about 4% of

1635-472: A population under 15,000, in order to discharge organic waste from the city's many fruit canneries. By the 1930s, the canneries along with indoor plumbing increasingly contributed to pollution in the bay. However, voters rejected bonds to fund upgrades to the sewage system. By 1948, the state declared San Jose to be in violation of state water pollution regulations, risking a moratorium on building permits. In 1950, San Jose voters finally passed bonds to construct

1744-421: A pressure gauge. Frequent smell checks must be performed on a biogas system. If biogas is smelled anywhere windows and doors should be opened immediately. If there is a fire the gas should be shut off at the gate valve of the biogas system. Landfill gas is produced by wet organic waste decomposing under anaerobic conditions in a similar way to biogas. The waste is covered and mechanically compressed by

1853-468: A report stating that if current infill trends continued, the bay would be as big as a shipping channel by 2020. This news created the Save the Bay movement in 1960, which mobilized to stop the infill of wetlands and the bay in general, which had shrunk to two-thirds of its size in the century before 1961. The San Francisco Bay continues to support some of the densest industrial production and urban settlement in

1962-462: A safe eating advisory for fish caught in the San Francisco Bay based on levels of mercury or PCBs found in local species. The San Francisco Bay Area Water Trail is a planned system of designated trailheads designed to improve non-motorized small boat access to the bay. The California Coastal Conservancy approved funding in March 2011 to begin implementation of the water trail. Biogas Biogas

2071-454: A waterway and harbor , many thousands of acres of marshy wetlands at the edges of the bay were, for many years, considered wasted space. As a result, soil excavated for building projects or dredged from channels was often dumped onto the wetlands and other parts of the bay as landfill. From the mid-19th century through the late 20th century, more than a third of the original bay was filled and often built on. The deep, damp soil in these areas

2180-560: A widespread distribution in the bay, with uptake in the bay's phytoplankton and contamination of its sportfish. In January 1971, two Standard Oil tankers collided in the bay, creating an 800,000-U.S.-gallon (3,000,000-liter) oil spill disaster , which spurred environmental protection of the bay. In November 2007, a ship named COSCO Busan collided with the San Francisco–Oakland Bay Bridge and spilled over 58,000 U.S. gallons (220,000 liters) of bunker fuel , creating

2289-421: Is 5% methane and the upper is 15% methane. The methane in biogas is 28 times more potent a greenhouse gas than carbon dioxide. Therefore, uncontained landfill gas, which escapes into the atmosphere may significantly contribute to the effects of global warming . In addition, volatile organic compounds (VOCs) in landfill gas contribute to the formation of photochemical smog . Biochemical oxygen demand (BOD)

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2398-407: Is a function of biogas temperature; correction of measured gas volume for water vapour content and thermal expansion is easily done via simple mathematics which yields the standardized volume of dry biogas. For 1000 kg (wet weight) of input to a typical biodigester, total solids may be 30% of the wet weight while volatile suspended solids may be 90% of the total solids. Protein would be 20% of

2507-642: Is a gaseous renewable energy source produced from raw materials such as agricultural waste , manure , municipal waste , plant material , sewage , green waste , wastewater , and food waste . Biogas is produced by anaerobic digestion with anaerobic organisms or methanogens inside an anaerobic digester , biodigester or a bioreactor . The gas composition is primarily methane ( CH 4 ) and carbon dioxide ( CO 2 ) and may have small amounts of hydrogen sulfide ( H 2 S ), moisture and siloxanes . The methane can be combusted or oxidized with oxygen. This energy release allows biogas to be used as

2616-806: Is a measure of the amount of oxygen required by aerobic micro-organisms to decompose the organic matter in a sample of material being used in the biodigester as well as the BOD for the liquid discharge allows for the calculation of the daily energy output from a biodigester. Another term related to biodigesters is effluent dirtiness, which tells how much organic material there is per unit of biogas source. Typical units for this measure are in mg BOD/litre. As an example, effluent dirtiness can range between 800 and 1200 mg BOD/litre in Panama. From 1 kg of decommissioned kitchen bio-waste, 0.45 m of biogas can be obtained. The price for collecting biological waste from households

2725-491: Is a subprogram of the CGIAR Research Program on Water, Land and Ecosystems (WLE) dedicated to applied research on the safe recovery of water, nutrients and energy from domestic and agro-industrial waste streams. They believe using waste as energy would be good financially and would tackle sanitation, health and environmental issues. The European Union has legislation regarding waste management and landfill sites called

2834-551: Is approximately €70 per ton. The composition of biogas varies depending upon the substrate composition, as well as the conditions within the anaerobic reactor (temperature, pH, and substrate concentration). Landfill gas typically has methane concentrations around 50%. Advanced waste treatment technologies can produce biogas with 55–75% methane, which for reactors with free liquids can be increased to 80–90% methane using in-situ gas purification techniques. As produced, biogas contains water vapor. The fractional volume of water vapor

2943-543: Is common on summer afternoons – and protection from large open ocean swells. Yachting and yacht racing are popular pastimes and the San Francisco Bay Area is home to many of the world's top sailors. A shoreline bicycle and pedestrian trail known as the San Francisco Bay Trail encircles the edge of the bay. The San Francisco Bay Area Water Trail , a growing network of launching and landing sites around

3052-456: Is likely N. de Morena who was left at New Albion at Drakes Bay in Marin County, California , by Sir Francis Drake in 1579 and then walked to Mexico. The first recorded European discovery of San Francisco Bay was on November 4, 1769, when Spanish explorer Gaspar de Portolá , unable to find the Port of Monterey , continued north close to what is now Pacifica and reached the summit of

3161-433: Is little or no data on their impacts on the environment or human health, and they are not regulated by state or federal law. These are often referred to as "contaminants of emerging concern." The San Francisco Estuary Institute has studied these chemicals in the Bay since 2001. Scientists have identified the following most likely to have a negative impact on Bay wildlife: San Francisco Bay's profile changed dramatically in

3270-432: Is made as a product which is a greenhouse gas ( as described by this equation: CH 4 + 2 O 2 → CO 2 + 2 H 2 O ). The content of toxic hydrogen sulfide presents additional risks and has been responsible for serious accidents. Leaks of unburned methane are an additional risk, because methane is a potent greenhouse gas . A facility may leak 2% of the methane. Biogas can be explosive when mixed in

3379-476: Is near the southern end of the Golden Gate Bridge and at the entrance to San Francisco Bay. For the first time in 65 years, Pacific Harbor Porpoise ( Phocoena phocoena ) returned to the bay in 2009. Golden Gate Cetacean Research, a non-profit organization focused on research on cetaceans , has developed a photo-identification database enabling the scientists to identify specific porpoise individuals and

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3488-635: Is now the GMP Cow Power Program. Customers can elect to pay a premium on their electric bill, and that premium is passed directly to the farms in the program. In Sheldon, Vermont , Green Mountain Dairy has provided renewable energy as part of the Cow Power program. It started when the brothers who own the farm, Bill and Brian Rowell, wanted to address some of the manure management challenges faced by dairy farms, including manure odor, and nutrient availability for

3597-615: Is powered by biogas and natural gas from the plant's cogeneration facility and digester tanks. A diesel generator provides emergency backup power for the plant. Discharges are monitored by the San Francisco Bay Regional Water Quality Control Board , and emissions are regulated by the Bay Area Air Quality Management District . As of 2020, the facility serves 1.5 million residents and over 17,000 business facilities in

3706-552: Is produced by microorganisms, such as methanogens and sulfate-reducing bacteria , performing anaerobic respiration. Biogas can refer to gas produced naturally and industrially. In soil, methane is produced in anaerobic environments by methanogens, but is mostly consumed in aerobic zones by methanotrophs . Methane emissions result when the balance favors methanogens. Wetland soils are the main natural source of methane. Other sources include oceans, forest soils, termites, and wild ruminants. The purpose of industrial biogas production

3815-499: Is produced from organic compounds containing nitrogen, such as the amino acids in proteins . If not separated from the biogas, combustion results in NO x emissions. In some cases, biogas contains siloxanes . They are formed from the anaerobic decomposition of materials commonly found in soaps and detergents. During combustion of biogas containing siloxanes, silicon is released and can combine with free oxygen or other elements in

3924-418: Is roughly 60% methane and 39% CO 2 with trace elements of H 2 S : inadequate for use in machinery. The corrosive nature of H 2 S alone is enough to destroy the mechanisms. Methane in biogas can be concentrated via a biogas upgrader to the same standards as fossil natural gas , which itself has to go through a cleaning process, and becomes biomethane . If the local gas network allows,

4033-424: Is stored under anaerobic conditions. During storage and when manure has been applied to the land, nitrous oxide is also produced as a byproduct of the denitrification process. Nitrous oxide ( N 2 O ) is 320 times more aggressive as a greenhouse gas than carbon dioxide and methane 25 times more than carbon dioxide. By converting cow manure into methane biogas via anaerobic digestion , the millions of cattle in

4142-541: Is subject to soil liquefaction during earthquakes, and most of the major damage close to the bay in the Loma Prieta earthquake of 1989 occurred to structures on these areas. The Marina District of San Francisco, hard hit by the 1989 earthquake, was built on fill that had been placed there for the Panama-Pacific International Exposition , although liquefaction did not occur on a large scale. In

4251-431: Is the collection of biomethane, usually for fuel. Industrial biogas is produced either; A biogas plant is the name often given to an anaerobic digester that treats farm wastes or energy crops. It can be produced using anaerobic digesters (air-tight tanks with different configurations). These plants can be fed with energy crops such as maize silage or biodegradable wastes including sewage sludge and food waste. During

4360-474: Is the remaining inorganic matter that was not transformed into biogas. It can be used as an agricultural fertiliser. Biogas can be used as the fuel in the system of producing biogas from agricultural wastes and co-generating heat and electricity in a combined heat and power ( CHP ) plant. Unlike the other green energy such as wind and solar, the biogas can be quickly accessed on demand. The global warming potential can also be greatly reduced when using biogas as

4469-631: Is trying to ascertain whether a healthier bay has brought their return. Pacific harbor porpoise range from Point Conception , California, to Alaska and across to the Kamchatka Peninsula and Japan. Recent genetic studies show that there is a local stock from San Francisco to the Russian River and that eastern Pacific coastal populations rarely migrate far, unlike western Atlantic Harbor porpoise. The common bottlenose dolphin ( Tursiops truncatus ) has been extending its current range northwards from

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4578-754: The Carquinez Bridge in May 1927, the San Francisco–Oakland Bay Bridge in 1936, the Golden Gate Bridge in 1937, the Richmond–San Rafael Bridge in 1956, and the San Mateo–Hayward Bridge in 1967. During the 20th century, the bay was subject to the 1940s Reber Plan , which would have filled in parts of the bay in order to increase industrial activity along the waterfront. In 1959, the United States Army Corps of Engineers released

4687-575: The Carquinez Strait , carving out sediment and forming canyons in what is now the northern part of the San Francisco Bay and Golden Gate strait . San Francisco Bay has been filled and emptied of sea water many times during the Pleistocene in accordance with sea level changes caused by glacial advances and retreats. During the Wisconsin Glaciation , between 15,000 and about 10,000 years ago,

4796-917: The Landfill Directive . Countries such as the United Kingdom and Germany now have legislation in force that provides farmers with long-term revenue and energy security. The EU mandates that internal combustion engines with biogas have ample gas pressure to optimize combustion, and within the European Union ATEX centrifugal fan units built in accordance with the European directive 2014–34/EU (previously 94/9/EG) are obligatory. These centrifugal fan units, for example Combimac , Meidinger AG or Witt & Sohn AG are suitable for use in Zone 1 and 2 . The United States legislates against landfill gas as it contains VOCs . The United States Clean Air Act and Title 40 of

4905-617: The Pacific Ocean via the Golden Gate strait. However, this entire group of interconnected bays is often called the San Francisco Bay . The bay was designated a Ramsar Wetland of International Importance on February 2, 2013, and the Port of Oakland on the bay is one of the busiest cargo ports on the west coast. The bay covers somewhere between 400 and 1,600 square miles (1,000–4,000 km ), depending on which sub-bays (such as San Pablo Bay), estuaries, wetlands , and so on are included in

5014-674: The Southern California Bight . The first coastal bottlenose dolphin in the Bay Area in recent times was spotted in 1983 off the San Mateo County coast in 1983. In 2001, bottlenose dolphins were first spotted east of the Golden Gate Bridge and confirmed by photographic evidence in 2007. Zooarcheological remains of bottlenose dolphins indicated that bottlenose dolphins inhabited San Francisco Bay in prehistoric times until at least 700 years before present, and dolphin skulls dredged from

5123-491: The combustion gas . Deposits are formed containing mostly silica ( SiO 2 ) or silicates ( Si x O y ) and can contain calcium , sulfur , zinc , phosphorus . Such white mineral deposits accumulate to a surface thickness of several millimeters and must be removed by chemical or mechanical means. Practical and cost-effective technologies to remove siloxanes and other biogas contaminants are available. High levels of methane are produced when manure

5232-752: The first transcontinental railroad was connected to its western terminus at Alameda on September 6, 1869. The terminus was switched to the Oakland Long Wharf two months later on November 8, 1869. In 1910, the Southern Pacific railroad company built the Dumbarton Rail Bridge , the first bridge crossing San Francisco Bay. The first automobile crossing was the Dumbarton Bridge , completed in January 1927. More crossings were later constructed –

5341-458: The 1,200-foot-high (370 m) Sweeney Ridge , now marked as the place where he first sighted San Francisco Bay. Portolá and his party did not realize what they had discovered, thinking they had arrived at a large arm of what is now called Drakes Bay . At the time, Drakes Bay went by the name Bahia de San Francisco and thus both bodies of water became associated with the name. Eventually, the larger, more important body of water fully appropriated

5450-411: The 1850s, when hydraulic mining released massive amounts of sediment from the rivers that settled in those parts of the bay that had little or no current. Later, wetlands and inlets were deliberately filled in, reducing the bay's size since the mid-19th century by as much as one third. Recently, large areas of wetlands have been restored, further confusing the issue of the bay's size. Despite its value as

5559-405: The 1990s, San Francisco International Airport proposed filling in hundreds more acres to extend its overcrowded international runways in exchange for purchasing other parts of the bay and converting them back to wetlands. The idea was, and remains, controversial. ( For further details, see the " Bay fill and depth profile " section. ) There are five large islands in San Francisco Bay. Alameda ,

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5668-485: The Code of Federal Regulations (CFR) requires landfill owners to estimate the quantity of non-methane organic compounds (NMOCs) emitted. If the estimated NMOC emissions exceeds 50 tonnes per year, the landfill owner is required to collect the gas and treat it to remove the entrained NMOCs. That usually means burning it. Because of the remoteness of landfill sites, it is sometimes not economically feasible to produce electricity from

5777-742: The Historic Landmarks committee, Native Sons of the Golden West , 1921." The bay became the center of American settlement and commerce in the Far West through most of the remainder of the 19th century. During the California Gold Rush (1848–1855), San Francisco Bay suddenly became one of the world's great seaports, dominating shipping in the American West until the last years of the 19th century. The bay's regional importance increased further when

5886-472: The Port of Oakland. Some six million cubic yards (160 million cubic feet; 4.6 million cubic meters) of mud from the dredging was deposited at the western edge of Middle Harbor Shoreline Park to become a 188-acre (0.294 sq mi; 0.76 km ) shallow-water wetlands habitat for marine and shore life. Further dredging followed in 2011, to maintain the navigation channel. This dredging enabled

5995-534: The United States on December 3, 1849, and was accepted as the 31st State of the Union on September 9, 1850. In 1921, a tablet was dedicated by a group of men in downtown San Francisco, marking the site of the original shoreline. The tablet reads: "This tablet marks the shore line of San Francisco Bay at the time of the discovery of gold in California, January 24, 1848. Map reproduced above delineates old shore line. Placed by

6104-471: The United States would be able to produce 100 billion kilowatt hours of electricity, enough to power millions of homes across the United States. One cow can produce enough manure in one day to generate 3 kilowatt hours of electricity. Furthermore, by converting cattle manure into methane biogas instead of letting it decompose, global warming gases could be reduced by 99 million metric tons or 4%. Biogas can be used for electricity production on sewage works, in

6213-487: The United States. The San Francisco Bay Area is the American West's second-largest urban area, with approximately seven million residents. Despite its urban and industrial character, San Francisco Bay and the Sacramento–San Joaquin River Delta remain perhaps California's most important ecological habitats . California's Dungeness crab , California halibut , and Pacific salmon fisheries rely on

6322-475: The West Valley Sanitation District began contracting with the plant. In 1979, the plant added tertiary treatment. From September 4 to September 29, 1979, 4 billion U.S. gallons (15 gigaliters) of partially treated sewage flowed into Artesian Slough, much of it reaching the southernmost portion of the San Francisco Bay, where massive wildlife die-offs were reported. In 1996, the plant opened

6431-473: The Western burrowing owl , a California species of special concern . The plant's outfall channel is Artesian Slough, which flows into the San Francisco Bay via Coyote Creek . In the 1880s, San Jose built a simple sewage disposal system that discharged untreated wastewater directly into the San Francisco Bay. It was the largest sewage disposal system in the South Bay, with enough capacity for 250,000 people despite

6540-621: The adjacent South Bay Water Recycling (SBWR) plant and distributed as reclaimed water to about 750 customers in San Jose, Santa Clara, and Milpitas . Solids removed from the effluent are processed into class A biosolids , which are used as daily cover at Newby Island landfill . The plant's laboratory analyzes about 70,000 samples per year. The facility has an annual operating budget of about $ 80 million, funded by rate revenue from contracting agencies. It has about 200 employees. It consumes 11 megawatts (15,000 hp) per day, about 60% of which

6649-431: The arrival of Europeans. Indigenous peoples used canoes to fish and clam along the shoreline. Sailing ships enabled transportation between the bay and other parts of the world—and served as ferries and freighters within the bay and between the bay and inland ports, such as Sacramento and Stockton. These were gradually replaced by steam-powered vessels starting in the late 19th century. Several shipyards were established around

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6758-605: The arrival of the largest container ship ever to enter the San Francisco Bay, the MSC Fabiola . Bay pilots trained for the visit on a simulator at the California Maritime Academy for over a year. The ship arrived drawing less than its full draft of 50 feet 10 inches (15.5 m) because it held only three-quarters of a load after its stop in Long Beach. San Francisco Bay was traversed by watercraft before

6867-401: The average depth of the bay is only as deep as a swimming pool—approximately 12 to 15 ft (4–5 m). Between Hayward and San Mateo to San Jose it is 12 to 36 in (30–90 cm). The deepest part of the bay is under and out of the Golden Gate Bridge, at 372 ft (113 m). In the late 1990s, a 12-year harbor-deepening project for the Port of Oakland began; it

6976-675: The basin which is now filled by the San Francisco Bay was a large river valley with small hills, channeling the Sacramento River through the Golden Gate Strait into the ocean. When the great ice sheets began to melt, around 11,000 years ago, the sea level started to rise rapidly, by about 1 inch per year. Melting glaciers in the Sierra Nevada washed huge amounts of sediment down the Sacramento and San Joaquin rivers, which accumulated on

7085-568: The bay as a nursery. The few remaining salt marshes now represent most of California's remaining salt marsh, supporting a number of endangered species and providing key ecosystem services such as filtering pollutants and sediments from the rivers. San Francisco Bay is recognized for protection by the California Bays and Estuaries Policy , with oversight provided by the San Francisco Estuary Partnership . Most famously,

7194-533: The bay for non-motorized small boat users (such as kayakers) is being developed. Parks and protected areas around the bay include Eden Landing Ecological Reserve , Hayward Regional Shoreline , Don Edwards San Francisco Bay National Wildlife Refuge , Hayward Shoreline Interpretive Center , Crown Memorial State Beach , Eastshore State Park , Point Isabel Regional Shoreline , Brooks Island Regional Preserve , and César Chávez Park . The California Office of Environmental Health Hazard Assessment (OEHHA) has developed

7303-580: The bay is a key link in the Pacific Flyway . Millions of waterfowl annually use the bay shallows as a refuge. Two endangered species of birds are found here: the California least tern and the Ridgway's Rail . Exposed bay muds provide important feeding areas for shorebirds , but underlying layers of bay mud pose geological hazards for structures near many parts of the bay perimeter. San Francisco Bay provided

7412-417: The bay suggest occasional visitors in historic times. San Francisco Bay faces many of the same water quality issues as other urban waterways in industrialized countries, or downstream of intensive agriculture. According to state water quality regulators, San Francisco Bay waters do not meet water quality standards for the following pollutants: Industrial, mining, and other uses of mercury have resulted in

7521-473: The bay, augmented during wartime (e.g., the Kaiser Shipyards , Richmond Shipyards ) near Richmond in 1940 for World War II for construction of mass-produced, assembly line Liberty and Victory cargo ships . San Francisco Bay is spanned by nine bridges, eight of which carry cars . The Transbay Tube , an underwater rail tunnel, carries BART services between Oakland and San Francisco. Prior to

7630-523: The bay, with the Leslie Salt Company the largest private land owner in the Bay Area in the 1940s. Low-salinity salt ponds mirror the ecosystem of the bay, with fish and fish-eating birds in abundance. Mid-salinity ponds support dense populations of brine shrimp , which provide a rich food source for millions of shorebirds. Only salt-tolerant micro-algae survive in the high salinity ponds, and impart

7739-591: The bay. Thousands of sea otter skins were taken to Sitka, then Guangzhou (Canton), China, where they commanded a high price. The United States seized the region from Mexico during the Mexican–American War (1846–1848). On February 2, 1848, the Mexican province of Alta California was annexed to the United States with the signing of the Treaty of Guadalupe Hidalgo . A year and a half later, California requested to join

7848-420: The biogas produced by wastewater from the brewery only. Manufacturing of biogas from intentionally planted maize has been described as being unsustainable and harmful due to very concentrated, intense and soil eroding character of these plantations. There are two key processes: mesophilic and thermophilic digestion which is dependent on temperature. In experimental work at University of Alaska Fairbanks ,

7957-645: The bridges and, later, the Transbay Tube, transbay transportation was dominated by fleets of ferryboats operated by the Southern Pacific Railroad and the Key System transit company. However, in recent decades, ferries have returned, primarily serving commuters from Marin County, relieving the traffic bottleneck of the Golden Gate Bridge (see Ferries of San Francisco Bay ). The bay also continues to serve as

8066-531: The center of the bay, following the ancient drowned river valley. In the 1860s and continuing into the early 20th century, miners dumped staggering quantities of mud and gravel from hydraulic mining operations into the upper Sacramento and San Joaquin Rivers. GK Gilbert's estimates of debris total more than eight times the amount of rock and dirt moved during construction of the Panama Canal. This material flowed down

8175-602: The cities of San Francisco , San Jose , and Oakland . San Francisco Bay drains water from approximately 40 percent of California. Water from the Sacramento and San Joaquin rivers, and from the Sierra Nevada mountains, flow into Suisun Bay , which then travels through the Carquinez Strait to meet with the Napa River at the entrance to San Pablo Bay , which connects at its south end to San Francisco Bay. It then connects to

8284-552: The crops they need to grow to feed the animals. They installed an anaerobic digester to process the cow and milking center waste from their 950 cows to produce renewable energy, a bedding to replace sawdust, and a plant-friendly fertilizer. The energy and environmental attributes are sold to the GMP Cow Power program. On average, the system run by the Rowells produces enough electricity to power 300 to 350 other homes. The generator capacity

8393-400: The decades surrounding 1900, at the behest of local political officials and following Congressional orders, the U.S. Army Corps began dredging the Sacramento and San Joaquin Rivers and the deep channels of San Francisco Bay. This work has continued without interruption ever since. Some of the dredge spoils were initially dumped in the bay shallows (including helping to create Treasure Island on

8502-434: The energy can be used for on-site generation , resulting in a reduction of losses in the transportation of energy. Typical energy losses in natural gas transmission systems range from 1% to 2%; in electricity transmission they range from 5% to 8%. Before being injected in the gas grid, biogas passes a cleaning process, during which it is upgraded to natural gas quality. During the cleaning process trace components harmful to

8611-590: The first map of the area. A number of place names survive (anglicized) from that first map, including Point Reyes , Angel Island , Farallon Islands , and Alcatraz Island . Alaskan Native sea otter hunters using Aleutian kayaks and working for the Russian–American Company entered San Francisco Bay in 1807 and again over 1810–1811. Led by the Russian Timofei Nikitich Tarakanov , these hunting raids probably wiped out sea otters in

8720-468: The flow stream because of daily and seasonal temperature fluctuations, and account for the moisture in the flow stream to produce a dry gas value. Biogas can be used in different types of internal combustion engines, such as the Jenbacher or Caterpillar gas engines. Other internal combustion engines such as gas turbines are suitable for the conversion of biogas into both electricity and heat. The digestate

8829-404: The following Santa Clara County jurisdictions, which maintain separate collection infrastructure: 37°25′52″N 121°57′6″W  /  37.43111°N 121.95167°W  / 37.43111; -121.95167 San Francisco Bay San Francisco Bay is a large tidal estuary in the U.S. state of California , and gives its name to the San Francisco Bay Area . It is dominated by

8938-549: The former shoals to the north of Yerba Buena Island ) and used to raise islands in the Sacramento-San Joaquin Delta. The net effect of dredging has been to maintain a narrow deep channel—deeper perhaps than the original bay channel—through a much shallower bay. At the same time, most of the marsh areas have been filled or blocked off from the bay by dikes . Large ships transiting the bay must follow deep underwater channels that are maintained by frequent dredging as

9047-605: The fuel instead of fossil fuel . However, the acidification and eutrophication potentials produced by biogas are 25 and 12 times higher respectively than fossil fuel alternatives. This impact can be reduced by using correct combination of feedstocks, covered storage for digesters and improved techniques for retrieving escaped material. Overall, the results still suggest that using biogas can lead to significant reduction in most impacts compared to fossil fuel alternative. The balance between environmental damage and green house gas emission should still be considered while implicating

9156-499: The gas grid and the final users are removed. If concentrated and compressed, it can be used in vehicle transportation. Compressed biogas is becoming widely used in Sweden, Switzerland, and Germany. A biogas-powered train, named Biogaståget Amanda (The Biogas Train Amanda), has been in service in Sweden since 2005. Biogas powers automobiles. In 1974, a British documentary film titled Sweet as

9265-481: The gas. There are a variety of grants and loans the support the development of anaerobic digestor systems. The Rural Energy for American Program provides loan financing and grant funding for biogas systems, as does the Environmental Quality Incentives Program , Conservation Stewardship Program , and Conservation Loan Program . With the many benefits of biogas, it is starting to become

9374-573: The greenhouse gases produced by the United States. The number of farm-based digesters increased by 21% in 2021 according to the American Biogas Council. In Vermont biogas generated on dairy farms was included in the CVPS Cow Power program. The program was originally offered by Central Vermont Public Service Corporation as a voluntary tariff and now with a recent merger with Green Mountain Power

9483-482: The largest oil spill in the region since 1996. The bay also has some of the highest levels of dissolved inorganic nitrogen known from any coastal water body, mostly originating from treated wastewater from Publicly owned treatment works . In other bays, such nutrient levels would likely lead to eutrophication , but historically, the bay has had less harmful algal blooms than other water bodies with similar nutrient concentrations. Potential explanations have included

9592-438: The largest island, was created when a shipping lane was cut to form the Port of Oakland in 1901. It is now a suburban community. Angel Island was known as " Ellis Island West" because it served as the entry point for immigrants from East Asia. It is now a state park accessible by ferry. Mountainous Yerba Buena Island is pierced by a tunnel linking the east and west spans of the San Francisco–Oakland Bay Bridge . Attached to

9701-546: The late 19th century and again with the initiation of dredging by the US Army Corps of Engineers in the 20th century. Before about 1860, most bay shores (with the exception of rocky shores, such as those in Carquinez Strait; along Marin shoreline; Point Richmond; Golden Gate area) contained extensive wetlands that graded nearly invisibly from freshwater wetlands to salt marsh and then tidal mudflat. A deep channel ran through

9810-636: The measurement. The main part of the bay measures three to twelve miles (5–19 km) wide east-to-west and somewhere between 48 miles (77 km) and 60 miles (97 km) north-to-south. San Francisco Bay is the second-largest estuary on the Pacific coast of the Americas, following the Salish Sea in Washington State and British Columbia, Canada. The bay was navigable as far south as San Jose until

9919-537: The name San Francisco Bay . The first European to enter the bay is believed to have been the Spanish explorer Juan de Ayala , who passed through the Golden Gate on August 5, 1775, in his ship the San Carlos and moored in a bay of Angel Island now known as Ayala Cove. Ayala continued to explore the San Francisco Bay Area and the expedition's cartographer, José de Cañizares, gathered the information necessary to produce

10028-698: The nation's first wildlife refuge, Oakland's artificial Lake Merritt , constructed in the 1860s, and America's first urban National Wildlife Refuge, the Don Edwards San Francisco Bay National Wildlife Refuge (SFBNWR) in 1972. The bay is also plagued by non-native species. Salt produced from San Francisco Bay is produced in salt evaporation ponds and is shipped throughout the Western United States to bakeries, canneries, fisheries, cheese makers and other food industries and used to de-ice winter highways, clean kidney dialysis machines, for animal nutrition, and in many industries. Many companies have produced salt in

10137-516: The north is the artificial and flat Treasure Island , site of the 1939 Golden Gate International Exposition . From the Second World War until the 1990s, both islands served as military bases and are now being redeveloped. Isolated in the center of the bay is Alcatraz , the site of the famous federal penitentiary. The federal prison on Alcatraz Island no longer functions, but the complex is a popular tourist site. Despite its name, Mare Island in

10246-575: The northern part of the bay is a peninsula rather than an island. San Francisco Bay is thought to represent a down-warping of the Earth's crust between the San Andreas Fault to the west and the Hayward Fault to the east, though the precise nature of this remains under study. About 560,000 years ago, a tectonic shift caused the large inland Lake Corcoran to spill out the central valley and through

10355-416: The presence of intensive "top-down control" from grazing clams like Potamocorbula , high sediment supply limiting light availability for the algae, and intensive tidal mixing. The occurrence of an unprecedented harmful algal bloom of Heterosigma akashiwo in 2022, resulting in mass fish deaths and anoxia, suggests that the mechanisms of control on algal growth may be eroding. The bay was once considered

10464-428: The process, the micro-organisms transform biomass waste into biogas (mainly methane and carbon dioxide) and digestate . Higher quantities of biogas can be produced when the wastewater is co-digested with other residuals from the dairy industry, sugar industry, or brewery industry. For example, while mixing 90% of wastewater from beer factory with 10% cow whey, the production of biogas was increased by 2.5 times compared to

10573-441: The producer of the biogas may use their distribution networks. Gas must be very clean to reach pipeline quality and must be of the correct composition for the distribution network to accept. Carbon dioxide , water , hydrogen sulfide , and particulates must be removed if present. There are four main methods of upgrading: water washing, pressure swing absorption, selexol absorption, and amine gas treating . In addition to these,

10682-419: The ratio of one part biogas to 8–20 parts air. Special safety precautions have to be taken for entering an empty biogas digester for maintenance work. It is important that a biogas system never has negative pressure as this could cause an explosion. Negative gas pressure can occur if too much gas is removed or leaked; Because of this biogas should not be used at pressures below one column inch of water, measured by

10791-457: The rivers, progressively eroding into finer and finer sediment, until it reached the bay system. Here some of it settled, eventually filling in Suisun Bay, San Pablo Bay, and San Francisco Bay, in decreasing order of severity. By the end of the 19th century, these " slickens " had filled in much of the shallow bay flats, raising the entire bay profile. New marshes were created in some areas. In

10900-537: The sewage system from outside the city limits, giving San Jose City Manager Dutch Hamann leverage against neighboring cities and landowners in his annexation campaigns. Hamann's agents instigated local campaigns in Alviso and Milpitas to agree to annexation and give San Jose more control over its sewer infrastructure. San Jose succeeded in annexing Alviso in 1968. On May 6, 1959, the City of San José and City of Santa Clara signed

11009-457: The shores of the bay, forming huge mudflats and marshes that supported local wildlife. By 5000 BC the sea level rose 300 feet (90 m), filling the valley with water from the Pacific. The Farallon Islands are what used to be hills along the old coastline, and Potato Patch Shoal is an area of sand dunes now covered by the ocean. The indigenous inhabitants of the San Francisco Bay are Ohlone . The first European to see San Francisco Bay

11118-608: The sides of pipes or stacks throughout the gas flow. Biogas environments include wastewater digesters, landfills, and animal feeding operations (covered livestock lagoons). Ultrasonic flow meters are one of the few devices capable of measuring in a biogas atmosphere. Most of thermal flow meters are unable to provide reliable data because the moisture causes steady high flow readings and continuous flow spiking, although there are single-point insertion thermal mass flow meters capable of accurately monitoring biogas flows with minimal pressure drop. They can handle moisture variations that occur in

11227-460: The system. Projects such as NANOCLEAN are nowadays developing new ways to produce biogas more efficiently, using iron oxide nanoparticles in the processes of organic waste treatment. This process can triple the production of biogas. Faecal Sludge is a product of onsite sanitation systems. Post collection and transportation, Faecal sludge can be treated with sewage in a conventional treatment plant, or otherwise it can be treated independently in

11336-399: The system. It takes roughly between 3% and 6% of the total energy output in gas to run a biogas upgrading system. Gas-grid injection is the injection of biogas into the methane grid ( natural gas grid ). Until the breakthrough of micro combined heat and power two-thirds of all the energy produced by biogas power plants was lost (as heat). Using the grid to transport the gas to consumers,

11445-451: The use of membrane separation technology for biogas upgrading is increasing, and there are already several plants operating in Europe and USA. The most prevalent method is water washing where high pressure gas flows into a column where the carbon dioxide and other trace elements are scrubbed by cascading water running counter-flow to the gas. This arrangement could deliver 98% methane with manufacturers guaranteeing maximum 2% methane loss in

11554-548: The volatile solids, carbohydrates would be 70% of the volatile solids, and finally fats would be 10% of the volatile solids. Toxic and foul smelling Hydrogen sulfide ( H 2 S ) is the most common contaminant in biogas, but other sulfur-containing compounds, such as thiols may be present. Left in the biogas stream, hydrogen sulfide is corrosive and when combusted yields sulfur dioxide ( SO 2 ) and sulfuric acid ( H 2 SO 4 ), also corrosive and environmentally hazardous compounds. Ammonia ( NH 3 )

11663-426: The weight of the material that is deposited above. This material prevents oxygen exposure thus allowing anaerobic microbes to thrive. Biogas builds up and is slowly released into the atmosphere if the site has not been engineered to capture the gas. Landfill gas released in an uncontrolled way can be hazardous since it can become explosive when it escapes from the landfill and mixes with oxygen. The lower explosive limit

11772-442: The world. Biogas can be cleaned and upgraded to natural gas standards, when it becomes bio-methane. Biogas is considered to be a renewable resource because its production-and-use cycle is continuous, and it generates no net carbon dioxide. From a carbon perspective, as much carbon dioxide is absorbed from the atmosphere in the growth of the primary bio-resource as is released, when the material is ultimately converted to energy. Biogas

11881-630: Was largely completed by September 2009. Previously, the bay waters and harbor facilities only allowed for ships with a draft of 46 ft (14 m), but dredging activities undertaken by the United States Army Corps of Engineers in partnership with the Port of Oakland succeeded in providing access for vessels with a 50-foot (15 m) draft. Four dredging companies were employed in the US$ 432 ;million project, with $ 244 million paid for with federal funds and $ 188 million supplied by

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