Nonpoint source pollution in the context of "Debris"

Pollution is the introduction of contaminants into the natural environment that cause harm. Pollution can take the form of any substance (solid, liquid, or gas) or energy (such as radioactivity, heat, sound, or light). Pollutants, the components of pollution, can be either foreign substances/energies or naturally occurring contaminants.

Although environmental pollution can be caused by natural events, the word pollution generally implies that the contaminants have a human source, such as manufacturing, extractive industries, poor waste management, transportation or agriculture. Pollution is often classed as point source (coming from a highly concentrated specific site, such as a factory, mine, construction site), or nonpoint source pollution (coming from widespread distributed sources, such as microplastics or agricultural runoff).

A pollutant or novel entity is a substance or energy introduced into the environment that has undesired effect, or adversely affects the usefulness of a resource. These can be both naturally forming (i.e. minerals or extracted compounds like oil) or anthropogenic in origin (i.e. manufactured materials or byproducts). Pollutants result in environmental pollution or become of public health concern when they reach a concentration high enough to have significant negative impacts.

A pollutant may cause long- or short-term damage by changing the growth rate of plant or animal species, or by interfering with resources used by humans, human health or wellbeing, or property values. Some pollutants are biodegradable and therefore will not persist in the environment in a long term. However, the degradation products of some pollutants are themselves pollutants such as DDE and DDD produced from the degradation of DDT.

A point source of pollution is a single identifiable source of air, water, thermal, noise or light pollution. A point source has negligible extent, distinguishing it from other pollution source geometrics (such as nonpoint source or area source). The sources are called point sources because in mathematical modeling, they can be approximated as a mathematical point to simplify analysis. Pollution point sources are identical to other physics, engineering, optics, and chemistry point sources and include:

• Air pollution from an industrial source (rather than an airport or a road, considered a line source, or a forest fire, which is considered an area source, or volume source)
• Water pollution from factories, power plants, municipal sewage treatment plants and some farms (see concentrated animal feeding operation). The U.S. Clean Water Act also defines municipal separate storm sewer systems and industrial stormwater discharges (such as construction sites) as point sources.
  • Man-made, natural, and groundwater reservoirs can all be contaminated by point source pollution which can threaten human health and safety.
• Noise pollution from a jet engine
• Disruptive seismic vibration from a localized seismic study
• Light pollution from an intrusive street light
• Radio emissions from an interference-producing electrical device

Eutrophication is a general term describing a process in which nutrients accumulate in a body of water, resulting in an increased growth of organisms that may deplete the oxygen in the water; ie. the process of too many plants growing on the surface of a river, lake, etc., often because chemicals that are used to help crops grow have been carried there by rain. Eutrophication may occur naturally or as a result of human actions. Manmade, or cultural, eutrophication occurs when sewage, industrial wastewater, fertilizer runoff, and other nutrient sources are released into the environment. Such nutrient pollution usually causes algal blooms and bacterial growth, resulting in the depletion of dissolved oxygen in water and causing substantial environmental degradation. Many policies have been introduced to combat eutrophication, including the United Nations Development Program (UNDP)'s sustainability development goals.

Approaches for prevention and reversal of eutrophication include minimizing point source pollution from sewage and agriculture as well as other nonpoint pollution sources. Additionally, the introduction of bacteria and algae-inhibiting organisms such as shellfish and seaweed can also help reduce nitrogen pollution, which in turn controls the growth of cyanobacteria, the main source of harmful algae blooms.

Marine pollution occurs when substances used or spread by humans, such as industrial, agricultural, and residential waste; particles; noise; excess carbon dioxide; or invasive organisms enter the ocean and cause harmful effects there. The majority of this waste (80%) comes from land-based activity, although marine transportation significantly contributes as well. It is a combination of chemicals and trash, most of which comes from land sources and is washed or blown into the ocean. This pollution results in damage to the environment, to the health of all organisms, and to economic structures worldwide. Since most inputs come from land, via rivers, sewage, or the atmosphere, it means that continental shelves are more vulnerable to pollution. Air pollution is also a contributing factor, as it carries iron, carbonic acid, nitrogen, silicon, sulfur, pesticides, and dust particles into the ocean. The pollution often comes from nonpoint sources such as agricultural runoff, wind-blown debris, and dust. These nonpoint sources are largely due to runoff that enters the ocean through rivers, but wind-blown debris and dust can also play a role, as these pollutants can settle into waterways and oceans. Pathways of pollution include direct discharge, land runoff, ship pollution, bilge pollution, dredging (which can create dredge plumes), atmospheric pollution and, potentially, deep sea mining.

Different types of marine pollution can be grouped as pollution from marine debris, plastic pollution, including microplastics, ocean acidification, nutrient pollution, toxins, and underwater noise. Plastic pollution in the ocean is a type of marine pollution by plastics, ranging in size from large original material such as bottles and bags, down to microplastics formed from the fragmentation of plastic materials. Marine debris is mainly discarded human rubbish which floats on, or is suspended in the ocean. Plastic pollution is harmful to marine life.

A street gutter is a depression that runs parallel to a road and is designed to collect rainwater that flows along the street diverting it into a storm drain. A gutter alleviates water buildup on a street, allows pedestrians to pass without walking through puddles, and reduces the risk of hydroplaning by road vehicles. When a curbstone is present, a gutter may be formed by the convergence of the road surface and the vertical face of the sidewalk; otherwise, a dedicated gutter surface made of concrete may be present. Depending on local regulations, a gutter usually discharges, as a nonpoint pollution source in a storm drain whose final discharge falls into a detention pond (in order to remove some pollutants by sedimentation) or into a body of water. Street gutters are most often found in areas of a city which have high pedestrian traffic. In rural areas, gutters are seldom used and are frequently replaced by a borrow ditch.

When urban streets do not have sanitary sewers, street gutters are made deep enough to serve that purpose as well; responsibility for operation and maintenance of the dual-purpose street gutter was cooperatively shared between the local government and the inhabitants.