Tag Archives: pollution control

Best Environmental Practices for the Main Sources of Air Pollution

Before we state each of the main sources of air pollution and list the respective best environmental practices for managing each of them, it is important to point out that prevention has to be pursued at all costs and with as much effort as possible, instead of allowing things to get out of hand and to such a point that we would have to employ best environmental practices to get things a bit or totally under control.

What is pollution prevention?

Pollution prevention is any practical method used to prevent or reduce the production or creation of wastes and eventually cut down air pollutants, solid wastes, hazardous wastes, and water pollutants.

Pollution prevention increases efficiency and enhances environmental protection; in addition, it helps reduce the toxicity and quantity of pollutants when:

  • spills and leakages are prevented from occurring.
  • reusable material is substituted for single-use material, where practicable.
  • less hazardous materials are substituted for more hazardous materials.
  • pollutants from leakages are captured, recycled, and treated before discharge into water or air.
  • solvents are cleaned and reused.
  • raw materials are efficiently utilized in a timely manner in order to avoid and reduce waste.
  • people and society are taught, properly trained, or directed on how to effectively tackle pollution.
  • materials are periodically inspected, serviced, or maintained, and unusable raw materials are rejected or returned.

The main sources of air pollution and the best environmental practices appropriate for each are as follows:

1. General pollutant sources of air pollution

The six criteria pollutants, hazardous air pollutants, and greenhouse gases originate from stationary sources, area sources, and mobile sources which are all different types of sources of air pollution.

Best environmental practices would be needed to manage the sources of air pollution and their respective pollutants which may mix or interact with each other and form completely new or complex pollutants that can be highly toxic at low concentrations and linger around for long periods of time.

The pollutants categorized under general pollutant sources may include the six criteria air pollutants, greenhouse gases, acid rain sources, and hazardous air pollutants.

Best environmental practices for general pollutant sources of air pollution

The best environmental practices for general pollutant sources—which are the same as the best environmental practices for all sources of air pollution—include the following:

  • Cleaning up all spills as quickly and thoroughly as possible.
  • Conducting surveillance on any part of the environment to determine where pollutants are being released into the air, the number and quantity of pollutants being released, and the exact times of their release.
  • Cleaning all HVAC (heating, ventilation, and air-conditioning) systems on rooftops and replacing all essential filters if they are incorporated to help prevent the growth and spread of Legionella organisms which cause Legionnaires disease.
  • Regularly replacing carbon absorbent materials and filters.
  • Searching for leaks using leak detectors, especially around vents, valves, sampling points, trainers, gaskets, ductwork, lint bags, seals, condensing coils, exhaust dampers, and pipe fittings.
  • Reusing and recycling substances, wherever or whenever possible.
  • Substituting less hazardous materials and chemicals for more hazardous materials and chemicals, whenever possible or appropriate.
  • Ensuring that general housekeeping, all operating equipment, sampling equipment, control devices, and storage vessels operate the right way and are maintained in a well-timed manner.
  • Keeping written records of all maintenance works carried out on facilities and equipment, and highlighting notable problems and the solutions that have been used to solve them.
  • Training employees to do their jobs properly, test their proficiency, continuously build their knowledge or education, and upgrade their skills on a periodic basis.

2. Stationary sources of air pollution

Stationary sources are point sources of air pollution, and some of the important information about them also applies to many aspects such as electric power plants, chemical plants, wastewater treatment plants, and a variety of industries.

Other examples of stationary sources of air pollution include areas or locations for mining of raw materials, storage points of raw materials, positions where fuel is stored for heating at industrial sites, etc.

Best environmental practices for stationary sources of air pollution

  • Ensuring that industrial operations are more efficient. Higher efficiency also generates greater profits.
  • Removing the sources of problems caused by the air pollution that is generated by industrial processes.
  • Altering industrial operations in order to reduce the number and quantity of air pollutants.
  • Ensuring that the industrial boilers that use fossil fuels are properly maintained and all leaks are eliminated and pipes are thoroughly insulated.
  • Adjusting various parts of equipment such as boiler doors and burners in order to reduce the amount of nitrogen oxides they discharge.
  • Controlling and properly handling gaseous emissions and employing the use of equipment such as absorbers, bio-filters, thermal oxidizers, boilers and process heaters, flares, catalytic reactors, flares, carbon absorbers, and condensers.
  • Using generated heat and power to distil much of the energy available in fuel.
  • Producing electric motors that are more efficient in various industrial applications: utilizing modern flat belts instead of V belts, and properly adjusting the components of motors—or replacing them with energy-efficient motors.
  • Using less-polluting materials in place of more-polluting materials.
  • Preventing pollutants from being carried downwind to other areas that may be easily affected by them, and using smokestacks that have appropriate sizes to dilute small quantities of pollutants.
  • Pre-treating raw materials before using them to reduce the concentrations of potential pollutants released during industrial processes.
  • Using fabric filters, cyclones, wet and dry electrostatic precipitators, venture scrubbers, and settling chambers to collect and control particulate matter.

3. Mobile sources of air pollution

Mobile sources of air pollution are categorized into on-road sources and off-road sources which discharge pollutants into the atmosphere after fuel evaporation and fuel combustion take place and produce hydrocarbons, carbon monoxide, nitrogen oxides, and particulate matter along with greenhouse gases and air toxics.

The mobile sources of air pollution that are regulated by the environmental protection agency (EPA) include: buses, cars, heavy-duty vehicles, commercial aircraft, recreational vehicles, minivans, semi-trailers, light-duty vehicles, SUVs, motorcycles, diesel-powered engines on locomotives, agricultural and construction equipment, lawn and garden equipment, propane and gasoline industrial equipment, snowmobiles, dirt bikes, a variety of boats and ships, etc.

Best environmental practices for mobile sources of air pollution

  • Using redeveloped gasoline to cut down emissions of toluene, benzene, and other toxic pollutants.
  • Ensuring that people who sell engines and vehicles prove they comply with any environmental laws that govern limits on emissions from fuel combustion.
  • Establishing standards for certain types of air pollutants emitted by mobile sources of air pollution, and combustible products such as on-road diesel fuel, off-road diesel fuel, and gasoline which are used to power mobile sources.
  • Ensuring that manufacturers design and implement efficient vapor recovery systems, combustion systems, and use computer technology to observe the performance of catalytic converters, engines, and use filters to efficiently remove pollutants from exhausts.
  • Establishing and enforcing limits for emissions from the tailpipe located at the rear end of cars.

4. Acid rain sources of air pollution

The wet forms of acid deposition/deposit such as acid rain, acid fog, acid snow, and acid mist, and the dry forms of acid deposition are all produced up in the atmosphere and fall down to the earth.

The wet and dry forms of acid deposition can change the chemistry of the soil and bodies of water, destroy or change alter ecosystems, cause health problems, create misty or foggy skies, damage property and goods, and affect the natural functioning of agricultural crops.

Acid precipitation is formed when nitrogen oxides and sulfur dioxide are discharged into the atmosphere and react with water vapor and other chemicals to form acids.

Best environmental practices for acid rain sources of air pollution

  • Carrying out adequate and appropriate maintenance on all motor vehicles and the diverse range of motorized tools and equipment.
  • Cutting down the quantity of emissions of nitrogen oxides and sulfur dioxide from automobiles and power plants.
  • Reducing thermostat usage during winter and economizing its usage during the summer. This helps to reduce fuel consumption and save money as well.
  • Purchasing and using only energy-efficient appliances and discarding those that aren’t energy-efficient.
  • Reducing the quantity of wasted electricity by switching off televisions, lights, computers, and appliances that aren’t being used or won’t be used for a certain time period.

Best Environmental Practices for the 6 Criteria Air Pollutants

Six of the most common air pollutants are popularly regarded as “the criteria air pollutants” or “the six criteria air pollutants”. By definition, the criteria air pollutants are air pollutants that are:

  • widely distributed across regions or countries and massively pollute the air in many cities around the world
  • regulated by environmental protection or regulatory bodies to control health and environmental effects or impacts of pollutants
  • useful indexes or indicators of the overall air quality.

Nations that are concerned about the atmosphere and environment have a set of standards in place for the following (six) criteria air pollutants—when they are in outdoor (or ambient) air:

  • Carbon monoxide
  • Ozone (ground-level)
  • Lead
  • Nitrogen oxides
  • Particulate matter or “particles”, and
  • Sulfur dioxide

The six air pollutants listed above are identified by the Environmental Protection Agency (EPA) as “criteria air pollutants” because the EPA itself regulates and uses them to formulate useful science-based guidelines and best environmental practices (BEPs).

The term “best environmental practice(s)” (BEP[s]) refers to the current most suitable professional environmental control or protection strategy/practical procedure that attracts the best or most effective results.

Because criteria air pollutants originate from various types of sources, the discussions concerning them put more emphasis on the criteria air pollutants themselves, instead of their sources. As a result, the best environmental practices for each criteria air pollutant are more general.

Research and experience have shown that the best environmental practices or procedures bring optimal results that can serve as standards appropriate for widespread adoption and application.

The BEPs, techniques, actions, or measures enable people and organizations to reduce the impact of waste generation on the environment which is under the direct control and influence of humans.

The following are the six criteria air pollutants and their respective best environmental practices:

1. Carbon Monoxide

Naturally, carbon monoxide is produced from the combustion of hydrocarbon fuels in homes, vehicular traffic, chemical plants, refineries, coke oven plants, power plants that use coal and gas, farming equipment, heavy equipment, etc.

People can knowingly or unknowingly become exposed to combustion or pollutants generated from the sources stated in the previous paragraph. Carbon monoxide can exasperate heart disease and cause headaches and chest pain and even result in death.

The best environmental practices for carbon monoxide are as follows:

  • Publicizing or calling attention to areas or regions that have or produce high concentrations of carbon monoxide, and encouraging people to live away from such areas.
  • Ensuring that gasoline power engines and tools are not operated in confined spaces.
  • Using motor vehicle inspection programs to assess whether or not fuel combustion is done thoroughly.
  • Employing motor vehicle inspection programs to achieve proper and maximum fuel combustion.
  • Halting the use of cold and rapid starts of motor vehicles in order to cut down carbon monoxide levels.
  • Innovating, initiating, adopting, and establishing programs to examine the level of efficiency of people in charge of fire-fighting and other types of emergency response, and providing efficient medical care when necessary.
  • Innovating, initiating, adopting, and establishing programs to supervise how wood-burning heaters and fireplaces are used and maintained while ensuring that fuel combustion is done properly.
  • Reducing the quantity of inhaled carbon monoxide by enforcing “no smoking” rules in public buildings or places that provide a more general or specific service.
  • Substituting less hazardous chemicals, products, or compounds for more hazardous ones.
  • Formulating or inventing programs that can use fuel more efficiently to reduce carbon monoxide, other pollutants, and pollution.
  • Utilizing continuous emission monitoring systems to record, report, and disseminate information about carbon monoxide emissions from stationary sources.

2. Ozone (ground-level)

Ozone is produced whenever a chemical reaction occurs in the atmosphere between a volatile organic compound (VOC) and nitrogen oxides and in the presence of sunlight.

Volatile organic compounds may be generated from fuel combustion, petroleum refineries, chemical manufacturing plants, cars that burn gasoline, and during use and storage of hydrocarbons, petroleum, and solvents, as well as landfills.

Children are at risk during summer when ozone levels in open/unconfined air are at their highest. Ozone can destroy agricultural crops, some types of plastic, rubber, and forests, especially in depressed/low-lying areas such as valleys or streets that exist between tall buildings. These types of topography could help pave a way for high concentrations of ground-level ozone.

The best environmental practices for ozone are as follows:

  • Using cleaner gasoline, adopting the use of low-emission cars and trucks, and increasing the efficiency of gasoline in order to increase the mileage covered per gallon of gasoline burned.
  • Reducing the amount of nitrogen oxide discharged from industrial combustion sources and power plants.
  • Using nuclear, solar, hydroelectric, and wind power—whenever or wherever possible—in place of fossil fuels.
  • Reclaiming or recovering vapor at service stations during refuelling of automobiles.
  • Reducing dependence on/use of automobiles by employing mass transit and carpooling, and making less use of automobiles for little trips or distances.
  • Using low-evaporation VOC solvents and paints instead of high-evaporation VOC solvents and paints.
  • Employing special gas cans to prevent spillage during refuelling of lawn equipment.
  • Inspecting emissions of nitrogen oxides, carbon monoxide, hydrocarbons, and sulfur oxides from automobiles on a yearly basis.

3. Lead

The most common sources of lead include industrial processes, mobile sources of pollution (buses, locomotives, trucks, passenger cars, construction equipment, etc.), resource recovery areas, battery manufacturing, waste incineration, piston-engine aircraft operation, and the deterioration of lead-based paint (indoors and outdoors).

Exposure (inhalation and ingestion) to lead in both indoor and outdoor environments can damage a children’s nervous system and the renal and cardiovascular systems in adults.

The best environmental practices for lead are as follows:

  • Employing bag-house filters during secondary lead production to get rid of debris from emissions that contain lead.
  • Using electrostatic filters, fabric filters, or wet scrubbers during the primary lead production process in order to remove dust that contains lead.
  • Efficiently controlling smelting operations and transportation of fugitive lead dust to and from a smelter.

4. Nitrogen oxides

Nitrogen oxides are mainly generated from fuel combustion, particularly in industrial boilers, electric utilities, and every kind of wood-burning appliance and fireplace.

Nitrogen oxides can lower one’s immunity or resistance to respiratory infections, induce irritation and damage in the lungs, and increase acute respiratory sickness in children; in addition, it can undergo reactions in the atmosphere to form acid rain and ozone.

The best environmental practices for nitrogen oxides are as follows:

  • Utilizing low nitrogen burners which can maintain high-efficiency combustion and recirculate combustion gases through flue pipes.
  • Recirculating the exhaust gases in automotive vehicles in order to reduce nitrogen oxides.
  • Modifying combustion systems to minimize peak temperatures and combustion time (i.e., time for complete fuel combustion) at peak temperatures in industrial processes.
  • Using catalytic converters to convert hydrocarbons into water and carbon dioxide, reduce nitrogen oxides to nitrogen and oxygen, and also convert carbon monoxide into carbon dioxide.
  • Employing energy conservation techniques in buildings in order to economize or use less fuel and save energy.
  • Properly maintaining automotive vehicles to ensure that gas compression ratios, spark timing, and air-fuel ratios are suitable.
  • Utilizing continuous emission monitoring systems to record, report, and disseminate information about nitrogen oxides emissions from stationary sources.

5. Particulate matter

Both the fine and respirable (breathable) types of particulate matter can increase lung damage and respiratory problems/diseases and may cause cancer, reduced visibility, surface soiling, and premature death.

Particulate matter causes various kinds of illnesses, especially in children, elderly people, and people who have asthma, lung diseases, and heart diseases.

The best environmental practices for particulate matter are as follows:

  • Applying water or chemical dust suppressants to dry bare soil and unpaved roads, especially in places that have high traffic and many ongoing construction activities.
  • Choosing and using cleaner fuels—for example, natural gas—which discharge little to no particulate matter—for example, natural gas.
  • Utilizing low-ash fossil fuels for burning or combustion.
  • Cleaning coal before burning it, in order to reduce ash.
  • Employing more effective technologies in industrial processes.
  • Using gasification products of coal as fuel, instead of using coal.
  • Using scrubbers, filters, electrostatic precipitators, and dust collectors to remove particulate matter (such as dust particles) from gas streams.
  • Applying appropriate dust collection systems to air emitted from industrial processes/production in order to reduce the quantity of dust generated in the cement industry.
  • Using a wet suppression system or dust collection system along with the principles of ventilation to reduce dust in coal processing.
  • Consistently utilizing appropriate pollution control tools and equipment.
  • Cutting down fuel combustion by upgrading various technologies tied to fuel products.
  • Using continuous emission monitoring systems to record, report, and disseminate information about particulate matter emissions from stationary sources.

6. Sulfur Dioxide

Ninety percent of all sulfur dioxide emissions originate from the activities of paper mills, iron and steel mills, power plants, fertilizer manufacturers, petroleum refineries, and copper smelters: sulfur dioxide is usually produced from and during fuel combustion in oil- or coal-burning industries, diesel engines, refineries, and electrical utilities.

But it comes with a problem: sulfur dioxide increases respiratory problems, exacerbates asthma, and reacts in air to produce acid rain which is also produced when nitrogen oxides combine with water.

The best environmental practices for sulfur dioxide are as follows:

  • Scouring sulfur dioxide from exhaust gases before discharging the gases into the atmosphere.
  • Using only low-sulfur coal as fuel.
  • Prewashing coal before using it as fuel.
  • Using natural gas in place of high sulfur coal.
  • Applying reactive lime in the removal of sulfur or sulfates.
  • Modifying industrial processes when possible in order to get rid of sulfur and sulfur compounds.
  • Using continuous emission monitoring systems to record, report, and disseminate information about sulfur dioxide emissions from stationary sources.

Best Practices for Managing Air Pollution Sources

They say “prevention is better than cure”. Definitely, it’s better and safer to prevent a problem, than allow it to grow and waste your time and effort which may end up not attracting any cure.

Before stating the best practices for managing air pollution, it is important to note that prevention should be pursued at all cost and with as much effort as one can exert.

Once the atmosphere/air is polluted beyond permissible limits, attention has to focus on reducing or managing pollutant or air pollution sources. However, pollution prevention in the environment (air, land, and water) should be the first goal.

What is pollution prevention?

Pollution prevention is any practical method used to prevent or reduce the production or creation of wastes and eventually cut down air pollutants, solid wastes, hazardous wastes, and water pollutants.

Pollution prevention increases efficiency and enhances environmental protection; in addition, it helps reduce the toxicity and quantity of pollutants when:

  • less hazardous materials are substituted for more hazardous materials.
  • reusable material is substituted for single-use material, where practicable.
  • spills and leakages are prevented from occurring.
  • pollutants from leakages are captured, recycled, and treated before discharge into water or air.
  • raw materials are efficiently utilized in a timely manner in order to avoid and reduce waste.
  • solvents are cleaned and reused.
  • materials are periodically inspected, serviced, or maintained, and unusable raw materials are rejected or returned.
  • people and society are taught, properly trained, or directed on how to effectively tackle pollution.

Best practices for managing air pollution sources

The following best practices can be used to manage air pollution sources, regardless of whether they are mobile sources, area sources, criteria pollutants, greenhouse gas sources, or major point sources of criteria pollutants and/or toxic air pollutants:

(1) Conducting surveillance on any part of the environment to determine where pollutants are being released into the air, the quantity of pollutants being released, and the exact times of their release.

(2) Searching or checking for leaks using leak detectors, especially around vents, valves, sampling points, trainers, gaskets, ductwork, lint bags, seals, condensing coils, exhaust dampers, and pipe fittings.

(3) Cleaning up all spills, as quickly and thoroughly as possible.

(4) Cleaning of all HVAC (heating, ventilation, and air-conditioning) systems on rooftops and replacing all essential filters if they have been incorporated to help prevent growth and spread of Legionella organisms which cause Legionnaires disease.

(5) Replacing carbon absorbent materials and filters, regularly.

(6) Substituting less hazardous materials and chemicals for more hazardous materials and chemicals, when possible or appropriate.

(7) Reusing and recycling substances, where or when possible.

(8) Ensuring that general housekeeping, all operating equipment, sampling equipment, control devices, and storage vessels operate the right way and are maintained in a well-timed manner.

(9) Training employees to do their jobs properly, test their proficiency, continuously build their knowledge or education, and upgrade their skills on a periodic basis.

(10) Keeping written records of all maintenance works carried out on facilities and equipment, and highlighting notable problems and the solutions that were used to solve them.

Point sources vs non-point sources of pollution; how non-point sources of pollution can be controlled

One of the problems environmental scientists have been addressing, and which is common in many environments, is pollution. Pollution is any condition (chemical, physical, dissonance (noise), heat, etc.) in an environment that is at a level which can harm the health of living organisms, and distort the composition of non-living organisms. Activities or substances that cause pollution (i.e., pollutants) enter an environment through natural activities such as eruption of volcanoes, etc., and man-made activities such as combustion of gasoline and discharge of chemicals or solid waste into rivers and oceans, etc.

Disposal of waste, which can be categorized into point source (PS) and non-point source (NPS) types, leads to point and non-point sources of pollution. Point and non-point sources of pollution exist in environments as a result of the disposal of various types of waste by nature, human beings and animals. If points/areas of waste disposal are concentrated, then they lead to point source pollution. On the other hand, if points of disposal are not concentrated, then they lead to non-point source pollution. In summary, pollution is broadly categorized into two types: point source (PS) pollution and non-point source (NPS) pollution.

Point source (PS) pollution

Point source pollution is any individual identifiable point or concentrated area that emits pollution, such as a hole on a septic tank, or the open end of a pipe discharging wastewater from a brewery. Point source pollutants and pollution can be noticed in various industries: mining, agricultural, pharmaceutical, manufacturing, oil and gas, etc.

Examples of PS pollution in the agricultural industry include (but are not limited to) areas/points for feeding, collection of animal waste, distribution of fertilizers, storage of insecticides/pesticides, etc. Examples of PS pollution in municipalities include (but are not limited to) landfills, wastewater treatment facilities, underground tanks in petroleum stations, etc. It can be notice in these examples that pollutants can be traced to particular points or areas.

One major problem associated with PS pollution is that, whenever pollutants are not handled properly, they end up in surface water (rivers, oceans, seas, etc.), underground water, or even potable water supplies. These instances occur when pipes discharge wastewater from industries into rivers or groundwater environment. Another instance is when there are leakages in pipe networks (for potable water distribution) that allow polluted groundwater to mix with potable water flowing through them.

Non-point source (NPS) pollution

Non-point source pollution is any dispersed area of pollution that emits pollution which can’t be traced to an identifiable point, a single source, or a concentrated area. Non-point sources of pollution are often called “diffuse” pollution, which means that they’re sources of pollution that cover a wide area and can’t be traced to a particular point or concentrated area.

Examples of instances when NPS pollution occur: whenever rainwater carries fertilizers away from agricultural farmlands into rivers or water bodies; whenever underground water flows and carries pollutants (bacteria, harmful microorganisms, etc.) from a polluted area and deposits them in other areas that are either not polluted, or are less polluted; etc. Water that conveys pollutants may originate from man-made sources like irrigation systems and leaking pipe networks, or from natural sources like rainfall.

It is much easier and cheaper to identify and control/prevent pollution from PSs than from NPSs.

Negative effects of pollutants

Pollutants have a lot of negative impacts on living organisms, just to name a few: they can reduce the quality of air, land and water; they can damage health, create irritations (such as noise), and unpleasant tastes, smells and sights; etc.

Reasons why point sources are preferable to non-point sources of pollution

Point sources and non-point sources of pollution are two negatives—which if not handle properly, can degrade environments and make them unsustainable. Non-point sources of pollution are more difficult to handle, and have been known to degrade environments much more than point sources. In order to sustain environments much better, individuals and governments have to provide structures and enforce legislations that promote the use of PSs of disposal, and discourage the use of NPSs of disposal.

The major reason why point sources are preferable (in comparison with NPS) is due to the environmental benefits that PSs provide when compared with NPSs. In summary, these are the following reasons why point sources of disposal are preferable:

  • Pollutants can be easily traced to PSs of disposal/pollution because PSs are usually noticeable, confined, and concentrations of pollutants are relatively easy to estimate. The point is this: appropriate technologies can be easily used to assess, control and abate pollution from PSs. On the hand, pollutants from NPSs are difficult to locate, and their concentrations are difficult to estimate because the pollutants are somewhat scattered and can’t be easily traced.
  • Pollutants from PSs are more controllable, while pollutants from NPSs are less controllable because they can be easily transported and dispersed. In parts of the world where there are high humidity, environments have more NPSs of pollution, and are more susceptible to NPSs of pollution because they have more runoff (water/wastewater flow)—which means more transportation and dispersal of pollutants.
  • It’s difficult to assess the origins and concentrations of pollutants transported from non-point sources into rivers and other bodies of water. Also, it’s a daunting task to conduct researches on NPSs of disposal/pollution than for PSs of disposal/pollution.

Generally, there are demanding challenges in studying different parameters associated with NPS disposal/pollution: determination of areas of selected sampling locations, determination of adequate runoff quality, determination of acceptable catchments, selection of the most acceptable test procedures, etc.

How to control non-point sources of pollution

In developing nations—particularly those that have low standards of living—prevention/control of NPSs of disposal and pollution has been quite difficult because it requires substantial amounts of money which are not always available. On the other hand, developed nations, which have higher standards of living, are able to control NPSs of disposal/pollution better by enforcing lawful regulations. For example, a regulation called “the Clean Water Act (1987)” was adopted in order to “establish a national program for controlling non-point source pollution and enhancing watershed protection”. Specifically, section 319 of the Clean Water Act adopts management programs for NPS pollution control.

Another control measure, as provided by Environmental Protection Agency (EPA), has been in place/practice since 1990. The EPA awards grants to states in order to assist in implementation of NPS control & management programs for reduction and prevention of NPSs of pollution.

Generally, non-point sources of pollution can be controlled by employing the following measures:

(1) Effective management of public lands

Public lands can be effectively managed in ways that reduce overflow of water, soil erosion, use of chemicals, etc. A lot of regulations (like erosion control laws) are in place, and people could be educated on watershed, conservation, and how to prevent NPSs of pollution in homes, offices, neighborhoods, industries, etc.

Homes are the smallest units in any society. A lot of activities that occur in (or around) homes require the use of best management practices (BMPs) for control/reduction of pollutants that contribute to NPS pollution. Each house contributes pollutants which can accumulate and create a significant impact on a neighborhood, city, state, nation, etc.

There are measures for pollution prevention that can be used to prevent NPS pollutants from littering around environments and mingling with storm water; such measures include: proper maintenance of sewerage systems; proper disposal of domestic animal waste; keeping food waste, cigarettes, etc., out of drainage systems so that clogging of can be prevented.

(2) Use of on-site technology in prevention or reduction of NPS pollution

Certain on-site technologies like stream-bank protection and channelization practices can be used to control or reduce NPSs of pollution which contain pollutants such as pesticides, fertilizers, animal dung washed away from farmlands, etc. These pollutants and similar types can be controlled by creating buffers consisting of vegetation, plants or trees between farmlands and banks of water bodies like rivers and lakes. Buffers help filter all types of pollutants—including sediments—and prevent them from entering receiving bodies of water, either completely, or, at least, to an appreciable extent.

Runoff from municipal and urban areas can be controlled using drainages, trenches and retention ponds to hold wastewater containing suspended solids and various types of pollutants.

(3) Use of watershed approach in management of NPSs of pollution

From available information, the watershed approach is proving to be the most effective technique for managing NPSs of pollution. A lot of literature has shown that every individual resides in a watershed or surface area in which water from many areas drains into. The watershed approach relies on input of information from local, state and federal agencies, and many stakeholders (political, social, and economic boundaries) who live in watersheds, and has been used to address serious environmental problems in watershed areas. The watershed approach has been successfully applied to a lot of watershed areas in the United States. According to the U.S. Geological Survey, U.S.A. can be divided into approximately 2,149 medium-sized watersheds, averaging about 1,700 square miles in each area.