Mole (architecture)
A mole is a massive structure of stone, used as a pier, breakwater, or a causeway between places separated by water. The word comes from Middle French mole from Latin mōlēs, meaning a large mass of rock. A mole may have a wooden structure built on top of it; the defining feature of a mole, however, is that water cannot flow underneath it, unlike a true pier. The oldest known mole is at an ancient Egyptian harbor complex on the Red Sea. In the San Francisco Bay Area in California, there were several moles, combined causeways and wooden piers or trestles extending out from the eastern shore and utilized by various railroads, such as the Key System, Southern Pacific Railroad, Western Pacific Railroad: the Alameda Mole, the Oakland Mole, the Western Pacific Mole. By extending the tracks the railroads could get beyond the shallow mud flats and reach the deeper waters of the Bay that could be navigated by the Bay Ferries. A train fell off the Alameda Mole through an open drawbridge in 1890 killing several people.
None of the four Bay Area moles survive today, although the causeway portions of each were incorporated into the filling in of large tracts of marshland for harbor and industrial development. A large mole was completed in 1947 at the San Francisco Naval Shipyard in the Bayview-Hunters Point neighborhood of San Francisco to accommodate the large Hunters Point gantry crane; the mole required 3,000,000 cubic yards of fill. The two concrete moles protecting the outer harbour at Dunkirk played a significant part in the evacuation of British and French troops during World War II in May/June 1940; the harbour had been made unusable by German bombing and it was clear that troops were not going to be taken directly off the beaches fast enough. Naval captain W. G. Tennant had been placed ashore to take charge of the navy shore parties and organise the evacuation. Tennant had what proved to be the successful idea of using the East Mole to take off troops; the moles had never been designed to dock ships, but despite this, the majority of troops rescued from Dunkirk were taken off in this way.
The Churchill Barriers are a series of four causeways in the Orkney Islands with a total length of 1.5 miles. They link the Orkney Mainland in the north to the island of South Ronaldsay via Burray and the two smaller islands of Lamb Holm and Glimps Holm; the barriers were built in the 1940s as naval defences to protect the anchorage at Scapa Flow. They were commissioned following the sinking of HMS Royal Oak in 1939 by German U-boat U-47 which had penetrated the existing defences of sunken blockships and anti-submarine nets; the barriers now serve as road links. Notable in antiquity was the Heptastadion, a giant mole built in the 3rd century BC in the city of Alexandria, Egypt to join the city to Pharos Island where the Pharos lighthouse stood; the causeway formed a barrier separating Alexandria's oceanfront into two distinct harbours, an arrangement which had the advantage of protecting the harbours from the force of the strong westerly coastal current. The Heptastadion is believed to have served as an aqueduct while Pharos was inhabited, geophysical research indicates that it was part of the road network of the ancient city.
Silting over the years resulted in the former dyke disappearing under several metres of accumulated silt and soil upon which the Ottomans built a town from 1517 onwards. Part of the modern city of Alexandria is now built on the site; when England acquired the north African city of Tangier as English Tangier in 1661, the English began building a mole to improve the harbour. The mole was planned to be 1,436 feet long and cost £340,000, the improved harbour was to be 600 yd long, 30 ft deep at low tide, capable of keeping out the roughest of seas. Work continued for some years under a succession of Governors. With an improved harbour the town would have played the same role that Gibraltar played in British naval strategy. However, Parliament expressed concern about the cost of maintaining the Tangier garrison, by 1680 King Charles II had threatened to give up Tangier unless the supplies were voted for its sea defences. A crippling blockade by the Jaysh al-Rifi forced the English to withdraw from Tangier in 1683.
The King gave secret orders to abandon the city, level the fortifications, destroy the harbour, evacuate the troops. Samuel Pepys wrote an account of it. Stone quaysides are sometimes called moles. A well-known example is the Molo in Venice, it is two pillars which form a gateway to the sea. It has been depicted numerous times by artists such as Canaletto. Breakwater Groyne Jetty Media related to Moles at Wikimedia Commons The dictionary definition of mole at Wiktionary
Montgomery County, Maryland
Montgomery County is the most populous county in the U. S. state of Maryland, located adjacent to Washington, D. C; as of the 2010 census, the county's population was 971,777, increasing by 9.0% to an estimated 1,058,810 in 2017. The county seat and largest municipality is Rockville, although the census-designated place of Germantown is the most populous place. Montgomery County is included in the Washington–Arlington–Alexandria, DC–VA–MD–WV Metropolitan Statistical Area, which in turn forms part of the Baltimore–Washington Combined Statistical Area. Most of the county's residents live in unincorporated locales, of which the most built up are Silver Spring and Bethesda, although the incorporated cities of Rockville and Gaithersburg are large population centers, as are many smaller but significant places; as one of the most affluent counties in the United States, Montgomery County has the highest percentage of residents over 25 years of age who hold post-graduate degrees. The county has been ranked as the one of the wealthiest in the United States.
Like other inner-suburban Washington, D. C. counties, Montgomery County contains many major U. S. government offices, scientific research and learning centers, business campuses, which provide a significant amount of revenue for the county. The Maryland state legislature named Montgomery County after Richard Montgomery. On September 6, 1776, Thomas Sprigg Wootton from Rockville, introduced legislation, while serving at the Maryland Constitutional Convention, to create lower Frederick County as Montgomery County; the name, Montgomery County, along with the founding of Washington County, after George Washington, was the first time in American history that counties and provinces in the thirteen colonies were not named after British referents. The name use of Montgomery and Washington County were seen as further defiance to Great Britain during the American Revolutionary War; the county's nickname of "MoCo" is derived from "Montgomery County". The county's motto, adopted in 1976, is "Gardez Bien", a phrase meaning "Watch Well".
The county's motto is the motto of its namesake's family. Before European immigration, the land now known as Montgomery County was covered in a vast swath of forest crossed by the creeks and small streams that feed the Potomac and Patuxent rivers. A few small villages of the Piscataway, members of the Algonquian people, were scattered across the southern portions of the county. North of the Great Falls of the Potomac, there were few permanent settlements, the Piscataway shared hunting camps and foot paths with members of rival peoples like the Susquehannocks and the Senecas. Captain John Smith of the English settlement at Jamestown was the first European to explore the area, during his travels along the Potomac River and throughout the Chesapeake region; these lands were claimed by Europeans for the first time when George Calvert, 1st Baron Baltimore was granted the charter for the colony of Maryland by Charles I of England. However, it was not until 1688 that the first tract of land in what is now Montgomery County was granted by the Calvert family to an individual colonist, a wealthy and prominent early Marylander named Henry Darnall.
He and other early claimants had no intention of settling their families. They were little more than speculators, securing grants from the colonial leadership and selling their lands in pieces to settlers. Thus, it was not until 1715 that the first British settlers began building farms and plantations in the area; these earliest settlers were English or Scottish immigrants from other portions of Maryland, German settlers moving down from Pennsylvania, or Quakers who came to settle on land granted to a convert named James Brooke in what is now Brookeville. Most of these early settlers were small farmers, growing wheat and a variety of other subsistence crops in addition to the region's main cash crop, tobacco. Many of the farmers owned slaves, they transported the tobacco. Sparsely settled, the area's farms and taverns were nonetheless of strategic importance as access to the interior. General Edward Braddock's army traveled through the county on the way to its disastrous defeat at Fort Duquesne during the French and Indian War.
Like other regions of the American colonies, the region, now Montgomery County saw protests against British taxation in the years before the American Revolution. In 1774, local residents met at Hungerford's Tavern and agreed to break off commerce with Great Britain. Following the signing of the Declaration of Independence, representatives of the area helped to draft the new state constitution and began to build a Maryland free of proprietary control. By 1776, there was a growing movement to form a new, strong federal government, with each colony retaining the authority to govern its local affairs. Member of the Maryland Constitutional Convention Thomas S. Wootton thought that dividing large Frederick County into three counties, each governed by elected representatives, would result in greater self-government; when Wootton discussed his idea with the residents of southern Frederick County, the residents supported his idea for a different reason. At some point everyone had needed to traveling to the courthouse in Frederick Town, the travel cost and time was prohibitive.
The residents wanted a county courthouse to be located closer to the residents. On August 31, 1776, Wootton introduced a measure to form a new county from the southern portion of Frederick County. Resolved, That after the first day of October, such part of the said county of Frederick as is contained within the bounds and limits following, to wit: beginn
United States Environmental Protection Agency
The Environmental Protection Agency is an independent agency of the United States federal government for environmental protection. President Richard Nixon proposed the establishment of EPA on July 9, 1970 and it began operation on December 2, 1970, after Nixon signed an executive order; the order establishing the EPA was ratified by committee hearings in the Senate. The agency is led by its Administrator, appointed by the President and approved by Congress; the current Administrator is former Deputy Administrator Andrew R. Wheeler, acting administrator since July 2018; the EPA is not a Cabinet department, but the Administrator is given cabinet rank. The EPA has its headquarters in Washington, D. C. regional offices for each of the agency's ten regions, 27 laboratories. The agency conducts environmental assessment and education, it has the responsibility of maintaining and enforcing national standards under a variety of environmental laws, in consultation with state and local governments. It delegates some permitting and enforcement responsibility to U.
S. states and the federally recognized tribes. EPA enforcement powers include fines and other measures; the agency works with industries and all levels of government in a wide variety of voluntary pollution prevention programs and energy conservation efforts. In 2018, the agency had 14,172 full-time employees. More than half of EPA's employees are engineers and environmental protection specialists; the Environmental Protection Agency can only act under statutes, which are the authority of laws passed by Congress. Congress must approve the statute and they have the power to authorize or prohibit certain actions, which the EPA has to implement and enforce. Appropriations statutes authorize how much money the agency can spend each year to carry out the approved statutes; the Environmental Protection Agency has the power to issue regulations. A regulation is a standard or rule written by the agency to interpret the statute, apply it in situations and enforce it. Congress allows the EPA to write regulations in order to solve a problem, but the agency must include a rationale of why the regulations need to be implemented.
The regulations can be challenged by the Courts, where the regulation is confirmed. Many public health and environmental groups advocate for the agency and believe that it is creating a better world. Other critics believe that the agency commits government overreach by adding unnecessary regulations on business and property owners. Beginning in the late 1950s and through the 1960s, Congress reacted to increasing public concern about the impact that human activity could have on the environment. Senator James E. Murray introduced a bill, the Resources and Conservation Act of 1959, in the 86th Congress; the 1962 publication of Silent Spring by Rachel Carson alerted the public about the detrimental effects on the environment of the indiscriminate use of pesticides. In the years following, similar bills were introduced and hearings were held to discuss the state of the environment and Congress's potential responses. In 1968, a joint House–Senate colloquium was convened by the chairmen of the Senate Committee on Interior and Insular Affairs, Senator Henry M. Jackson, the House Committee on Science and Astronautics, Representative George P. Miller, to discuss the need for and means of implementing a national environmental policy.
In the colloquium, some members of Congress expressed a continuing concern over federal agency actions affecting the environment. The National Environmental Policy Act of 1969 was modeled on the Resources and Conservation Act of 1959. RCA would have established a Council on Environmental Quality in the office of the President, declared a national environmental policy, required the preparation of an annual environmental report. President Nixon signed NEPA into law on January 1, 1970; the law created the Council on Environmental Quality in the Executive Office of the President. NEPA required that a detailed statement of environmental impacts be prepared for all major federal actions affecting the environment; the "detailed statement" would be referred to as an environmental impact statement. On July 9, 1970, Nixon proposed an executive reorganization that consolidated many environmental responsibilities of the federal government under one agency, a new Environmental Protection Agency; this proposal included merging antipollution programs from a number of departments, such as the combination of pesticide programs from the United States Department of Agriculture, Department of Interior, U.
S. Department of Interior. After conducting hearings during that summer, the House and Senate approved the proposal; the EPA was created 90 days before it had to operate, opened its doors on December 2, 1970. The agency's first Administrator, William Ruckelshaus, took the oath of office on December 4, 1970. In its first year, the EPA had 5,800 employees. At its start, the EPA was a technical assistance agency that set goals and standards. Soon, new acts and amendments passed by Congress gave the agency its regulatory authority. EPA staff recall that in the early days there was "an enormous sense of purpose and excitement" and the expectation that "there was this agency, going to do something about a problem, on the minds of a lot of people in this country," leading to tens of thousands of resumes from those eager to participate in the mighty effort to clean up America's environment; when EPA first began operation, members of the private sector felt that the environ
Waste weir
A waste weir on a navigable canal is a slatted gate on each canal level or pound, to remove excess water and to drain the canal for repairs or for the winter shutdown. This differs for a dam or reservoir, for which a waste weir is another name for a spillway, i.e. not having the boards to adjust the water height nor the paddles to drain all the water as on a canal, only to drain the excess. A canal will need some means to maintain a water level. A canal consumes water due to leakage and the operation of lift locks. Excess water from storms or emptying locks could cause problems eroding the banks of a canal, causing washouts, flooding buildings or adjacent properties. Waste weirs were one of several items used to remove surplus water; the waste weir functioned as an opening to drain the entire canal prism of water for repairs, or for winter, or in anticipation of flooding. In some cases when a creek was used to feed the canal, a waste weir was necessary for excess water from the creek. For instance on the Morris Canal, the Lopatcong creek went into the canal to feed it, but it had a tendency to flood, hence the need for a couple of waste weirs in the area around the bottom of Plane 9 West.
Reservoirs and tanks use a waste weir for flood discharges. The maximum flow output Q in cubic meters/sec over the top of the waste weir with a length L and height of water H above the crest can be calculated by the formulas: Q = K L H 3 / 2 and K = 2 3 C d 2 g where g=gravitational constant of 9.8 m / s e c 2 and Cd is the coefficient of discharge over the weir. Various values of Cd can be given. On the Erie Canal and the Chesapeake and Ohio Canal, waste weirs were constructed from masonry or from concrete. Since a waste weir was part of canal property, it would sometimes be explicitly protected by law. On the Morris Canal, New Jersey Statue 136 section 61 stated for willfully and maliciously opening the gates of waste weirs the penalty was $25
Storm drain
A storm drain, storm sewer, surface water drain/sewer, or stormwater drain is infrastructure designed to drain excess rain and ground water from impervious surfaces such as paved streets, car parks, parking lots, footpaths and roofs. Storm drains vary in design from small residential dry wells to large municipal systems. Drains receive water from street gutters on most motorways and other busy roads, as well as towns in areas with heavy rainfall that leads to flooding, coastal towns with regular storms. Gutters from houses and buildings can connect to the storm drain. Many storm drainage systems are gravity sewers that drain untreated storm water into rivers or streams—so it is unacceptable to pour hazardous substances into the drains. Storm drains cannot manage the quantity of rain that falls in heavy rains or storms. Inundated drains can cause street flooding. In many areas require detention tanks inside a property that temporarily hold runoff in heavy rains and restrict outlet flow to the public sewer.
This reduces the risk of overwhelming the public sewer. Some storm drains mix stormwater with sewage, either intentionally in the case of combined sewers, or unintentionally. Several related terms are used differently in American and British English: There are two main types of stormwater drain inlets: side inlets and grated inlets. Side inlets are located adjacent to the curb and rely on the ability of the opening under the back stone or lintel to capture flow, they are depressed at the invert of the channel to improve capture capacity. Many inlets have gratings or grids to prevent people, large objects or debris from falling into the storm drain. Grate bars are spaced so that the flow of water is not impeded, but sediment and many small objects can fall through. However, if grate bars are too far apart, the openings may present a risk to pedestrians and others in the vicinity. Grates with long narrow slots parallel to traffic flow are of particular concern to cyclists, as the front tire of a bicycle may become stuck, causing the cyclist to go over the handlebars or lose control and fall.
Storm drains in streets and parking areas must be strong enough to support the weight of vehicles, are made of cast iron or reinforced concrete. Some of the heavier sediment and small objects may settle in a catch basin, or sump, which lies below the outlet, where water from the top of the catch basin reservoir overflows into the sewer proper; the catchbasin serves much the same function as the "trap" in household wastewater plumbing in trapping objects. In the United States, unlike the plumbing trap, the catch basin does not prevent sewer gases such as hydrogen sulfide and methane from escaping. However, in the United Kingdom, where they are called gully pots, they are designed as true water-filled traps and do block the egress of gases and rodents. Most catchbasins contain stagnant water during drier parts of the year and can, in warm countries, become mosquito breeding grounds. Larvicides or disruptive larval hormones, sometimes released from "mosquito biscuits", have been used to control mosquito breeding in catch basins.
Mosquitoes may be physically prevented from reaching the standing water or migrating into the sewer proper by the use of an "inverted cone filter". Another method of mosquito control is to spread a thin layer of oil on the surface of stagnant water, interfering with the breathing tubes of mosquito larvae; the performance of catch basins at removing sediment and other pollutants depends on the design of the catchbasin, on routine maintenance to retain the storage available in the sump to capture sediment. Municipalities have large vacuum trucks that perform this task. Catch basins act as the first-line pretreatment for other treatment practices, such as retention basins, by capturing large sediments and street litter from urban runoff before it enters the storm drainage pipes. Pipes can come in many different cross-sectional shapes. Drainage systems may have many different features including waterfalls, stairways and pits for catching rubbish, sometimes called Gross Pollutant Traps. Pipes made of different materials can be used, such as brick, high-density polyethylene or galvanized steel.
Fibre reinforced plastic is being used more for drain pipes and fittings. Most drains have a single large exit at their point of discharge into a canal, lake, sea or ocean. Other than catchbasins there are no treatment facilities in the piping system. Small storm drains may discharge into individual dry wells. Storm drains may be interconnected to make a larger dry well system. Storm drains may discharge into man-made excavations known as recharge basins or retention ponds. Storm drains are unable to manage the quantity of rain that falls during heavy rains and/or storms; when storm drains are inundated and street flooding can occur. Unlike catastrophic flooding events, this type of urban flooding occurs in built-up areas where man-made drainage systems are prevalent. Urban flooding is the primary cause of sewer backups and basement flooding, which can affect properties repeatedly. Clogged drains contribute to flooding by the obstruction of storm drains. Communities or cities can help reduce this by cleaning leaves from the storm drains to stop ponding or flooding into yards.
Snow in the winter can clog drains when there is an unusual amount of rain in the w
Bacteria
Bacteria are a type of biological cell. They constitute a large domain of prokaryotic microorganisms. A few micrometres in length, bacteria have a number of shapes, ranging from spheres to rods and spirals. Bacteria were among the first life forms to appear on Earth, are present in most of its habitats. Bacteria inhabit soil, acidic hot springs, radioactive waste, the deep portions of Earth's crust. Bacteria live in symbiotic and parasitic relationships with plants and animals. Most bacteria have not been characterised, only about half of the bacterial phyla have species that can be grown in the laboratory; the study of bacteria is known as a branch of microbiology. There are 40 million bacterial cells in a gram of soil and a million bacterial cells in a millilitre of fresh water. There are 5×1030 bacteria on Earth, forming a biomass which exceeds that of all plants and animals. Bacteria are vital in many stages of the nutrient cycle by recycling nutrients such as the fixation of nitrogen from the atmosphere.
The nutrient cycle includes the decomposition of dead bodies. In the biological communities surrounding hydrothermal vents and cold seeps, extremophile bacteria provide the nutrients needed to sustain life by converting dissolved compounds, such as hydrogen sulphide and methane, to energy. Data reported by researchers in October 2012 and published in March 2013 suggested that bacteria thrive in the Mariana Trench, with a depth of up to 11 kilometres, is the deepest known part of the oceans. Other researchers reported related studies that microbes thrive inside rocks up to 580 metres below the sea floor under 2.6 kilometres of ocean off the coast of the northwestern United States. According to one of the researchers, "You can find microbes everywhere—they're adaptable to conditions, survive wherever they are."The famous notion that bacterial cells in the human body outnumber human cells by a factor of 10:1 has been debunked. There are 39 trillion bacterial cells in the human microbiota as personified by a "reference" 70 kg male 170 cm tall, whereas there are 30 trillion human cells in the body.
This means that although they do have the upper hand in actual numbers, it is only by 30%, not 900%. The largest number exist in the gut flora, a large number on the skin; the vast majority of the bacteria in the body are rendered harmless by the protective effects of the immune system, though many are beneficial in the gut flora. However several species of bacteria are pathogenic and cause infectious diseases, including cholera, anthrax and bubonic plague; the most common fatal bacterial diseases are respiratory infections, with tuberculosis alone killing about 2 million people per year in sub-Saharan Africa. In developed countries, antibiotics are used to treat bacterial infections and are used in farming, making antibiotic resistance a growing problem. In industry, bacteria are important in sewage treatment and the breakdown of oil spills, the production of cheese and yogurt through fermentation, the recovery of gold, palladium and other metals in the mining sector, as well as in biotechnology, the manufacture of antibiotics and other chemicals.
Once regarded as plants constituting the class Schizomycetes, bacteria are now classified as prokaryotes. Unlike cells of animals and other eukaryotes, bacterial cells do not contain a nucleus and harbour membrane-bound organelles. Although the term bacteria traditionally included all prokaryotes, the scientific classification changed after the discovery in the 1990s that prokaryotes consist of two different groups of organisms that evolved from an ancient common ancestor; these evolutionary domains are called Archaea. The word bacteria is the plural of the New Latin bacterium, the latinisation of the Greek βακτήριον, the diminutive of βακτηρία, meaning "staff, cane", because the first ones to be discovered were rod-shaped; the ancestors of modern bacteria were unicellular microorganisms that were the first forms of life to appear on Earth, about 4 billion years ago. For about 3 billion years, most organisms were microscopic, bacteria and archaea were the dominant forms of life. Although bacterial fossils exist, such as stromatolites, their lack of distinctive morphology prevents them from being used to examine the history of bacterial evolution, or to date the time of origin of a particular bacterial species.
However, gene sequences can be used to reconstruct the bacterial phylogeny, these studies indicate that bacteria diverged first from the archaeal/eukaryotic lineage. The most recent common ancestor of bacteria and archaea was a hyperthermophile that lived about 2.5 billion–3.2 billion years ago. Bacteria were involved in the second great evolutionary divergence, that of the archaea and eukaryotes. Here, eukaryotes resulted from the entering of ancient bacteria into endosymbiotic associations with the ancestors of eukaryotic cells, which were themselves related to the Archaea; this involved the engulfment by proto-eukaryotic cells of alphaproteobacterial symbionts to form either mitochondria or hydrogenosomes, which are still found in all known Eukarya. Some eukaryotes that contained mitochondria engulfed cyanobacteria-like organisms, leading to the formation of chloroplasts in algae and plants; this is known as primary endosymbiosis. Bacteria display a wide diversity of sizes, called morphologies.
Bacterial cells are about one-tenth the size of eukaryotic cells
Water pollution
Water pollution is the contamination of water bodies as a result of human activities. Water bodies include for example lakes, oceans and groundwater. Water pollution results. For example, releasing inadequately treated wastewater into natural water bodies can lead to degradation of aquatic ecosystems. In turn, this can lead to public health problems for people living downstream, they may use the same polluted river water for bathing or irrigation. Water pollution is the leading worldwide cause of death and disease, e.g. due to water-borne diseases. Water pollution can be grouped into surface water pollution. Marine pollution and nutrient pollution are subsets of water pollution. Sources of water pollution are either non-point sources. Point sources have one identifiable cause of the pollution, such as a storm drain, wastewater treatment plant or stream. Non-point sources are more diffuse, such as agricultural runoff. Pollution is the result of the cumulative effect over time. All plants and organisms living in or being exposed to polluted water bodies can be impacted.
The effects can damage individual species and impact the natural biological communities they are part of. The causes of water pollution include a wide range of chemicals and pathogens as well as physical parameters. Contaminants may include inorganic substances. Elevated temperatures can lead to polluted water. A common cause of thermal pollution is the use of water as a coolant by power plants and industrial manufacturers. Elevated water temperatures decrease oxygen levels, which can kill fish and alter food chain composition, reduce species biodiversity, foster invasion by new thermophilic species. Water pollution is measured by analysing water samples. Physical and biological tests can be done. Control of water pollution requires appropriate management plans; the infrastructure may include wastewater treatment plants. Sewage treatment plants and industrial wastewater treatment plants are required to protect water bodies from untreated wastewater. Agricultural wastewater treatment for farms, erosion control from construction sites can help prevent water pollution.
Nature-based solutions are another approach to prevent water pollution. Effective control of urban runoff includes reducing quantity of flow. In the United States, best management practices for water pollution include approaches to reduce the quantity of water and improve water quality. Water is referred to as polluted when it is impaired by anthropogenic contaminants. Due to these contaminants it either does not support a human use, such as drinking water, or undergoes a marked shift in its ability to support its biotic communities, such as fish. Natural phenomena such as volcanoes, algae blooms and earthquakes cause major changes in water quality and the ecological status of water. Water pollution is a major global problem, it requires ongoing revision of water resource policy at all levels. It has been suggested. Water pollution accounted for the deaths of 1.8 million people in 2015. India and China are two countries with high levels of water pollution: An estimated 580 people in India die of water pollution related illness every day.
About 90 percent of the water in the cities of China is polluted. As of 2007, half a billion Chinese had no access to safe drinking water. In addition to the acute problems of water pollution in developing countries, developed countries continue to struggle with pollution problems. For example, in a report on water quality in the United States in 2009, 44 percent of assessed stream miles, 64 percent of assessed lake acres, 30 percent of assessed bays and estuarine square miles were classified as polluted. Surface water pollution includes pollution of rivers and oceans. A subset of surface water pollution is marine pollution. One common path of entry by contaminants to the sea are rivers. An example is directly discharging sewage and industrial waste into the ocean. Pollution such as this occurs in developing nations. In fact, the 10 largest emitters of oceanic plastic pollution worldwide are, from the most to the least, Indonesia, Vietnam, Sri Lanka, Egypt, Malaysia and Bangladesh through the rivers Yangtze, Yellow, Nile, Pearl, Amur and the Mekong, accounting for "90 percent of all the plastic that reaches the world's oceans."Large gyres in the oceans trap floating plastic debris.
Plastic debris can absorb toxic chemicals from ocean pollution poisoning any creature that eats it. Many of these long-lasting pieces end up in the stomachs of marine animals; this results in obstruction of digestive pathways, which leads to reduced appetite or starvation. There are a variety of secondary effects stemming not from the original pollutant, but a derivative condition. An example is silt-bearing surface runoff, which can inhibit the penetration of sunlight through the water column, hampering photosynthesis in aquatic plants. Interactions between groundwater and surface water are complex. Groundwater pollution referred to as groundwater contamination, is not as classified as surface water pollution. By its nature, groundwater aquifers are susceptible to contamination from sources that may not directly affect surface water bodies; the distinction of point vs. non-point source may be irrelevant. Analysis of groundwater contamination may focus on soil characteristics and site
