Blackwater (coal)

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Not to be confused with Blackwater (waste).

Blackwater is the pollution produced from coal preparation.[1] [2]

It contains copious amounts of hazardous substances, including carcinogenic compounds and heavy metals. Blackwater is permanently impounded in toxic waste facilities, as it cannot be processed into a form that can be returned to the natural environment. The aftermath of coal's preparation method results in the formation of blackwater. The more coal is filtered and screened from rocks and minerals, the higher its efficiency and value.

Coal slurry[edit]

Coal slurry is a fluid produced by washing coal with water and chemicals prior to shipping the coal to market. This waste product cannot be recycled, or broken down into usable substances, and is a major cause of concern, because storage procedures may not be environmentally sound over a long period of time. Coal slurry harms the marine life and aquatic animals, as well as causes air pollution. Components of coal slurry like carcinogenic compounds and heavy metals are permanently stored in toxic waste facilities because they are hardly transformed into a biodegradable natural form. Mankind acts of dumping the hazardous substance into a body of water or attempting to destroy the waste by incinerating it, all come on the account of harming the natural state of the environment, and the health of humans.


In order for coal to be ready to use, it has to go through a coal preparation plant. The extracted coal from underground or mountain formations goes through a process of screening. It is washed off from rocks, residues and sediments. The coal preparation plants are designed to yield a manageable quality of coal to meet the contract specifications and requirements that are set out by the standards and quality control commissions. A considerably clean lump of coal is tested for ash content, sulfuric level, calorific value and moisturization content. Coal goes through different circuit levels depending on the quality yielded. The main objective is to decrease the ash content and improve the maceral composition of the final clean product. Coal that is used for heating and energy is usually not thoroughly assessed, while coal that is used for electricity goes through an intensified line of purification. Despite the coal’s contribution as a rich source of energy and electricity, the accumulation of coal slurry pursues long-term harmful effects on the environment. It is a byproduct of coal mining and preparation that is in a form of solid waste, typically composed of dirt, sludge, and rocks. The composition of coal slurry makes it almost impossible to decompose or biodegrade. Because the nature of the waste is ineffective as a reusable form of energy, it is used to mold a dam between two mountains, and then the slurry is placed behind the dam and impounded in the ground. The mixture of coal slurry and water creates liquid, solid and hazardous wastes that seep into the ground, evaporate into the air or are dumped into bodies of water. Coal slurry contains a large number of highly abrasive and corrosive minerals that have been washed and leached out of coal and rocks. The slurry also includes the infused chemicals that were used in the preparation cycle making it a viscous form of hazardous compounds. Some of these chemicals are acrylamide, butyl benzyl phthalate, hexachlorobenzene, naphthalene, chlorophenyl phenyl ether, and dichlorobenzidine. Heavy metals that are included in coal slurry are mercury, arsenic, lead, and nickel.

Since coal slurry is difficult to store, or dissociate, it is dumped into water systems by pipelines and progressive cavity pumps. The lethal coal slurry turns the water into blackwater, causing discoloration and low dissolved oxygen levels (Hypoxia), which drastically damages animal life. Blackwater changes the natural temperature of the water and the carbon levels, making it difficult for aquatic life to flourish. Aquatic animals rely on oxygen to breathe (aerobic); a low level of dissolved oxygen or state of hypoxia kills fish and sea life. A large number of native fish die, and Murray crayfish, shrimps, and yabbies are observed to go near the surface or the shore to gasp any form of oxygen causing them to die. Blackwater also causes fish to leave their natural habitat and migrate to areas where oxygen is readily available, affecting the temporary food chain of that part of the water system. Migration can also make it hard for fish to find their food and nutrition niche causing them to slowly die. Increased levels of carbon in the water can also cause the formation of radioactive chemicals in the water causing a dysfunction in the reproductive system of fish, which results into mutant fish. Fish can also lose the ability to feed because of visual impairment or the ability to reproduce and lay eggs. The change in water temperature can cause the water to easily evaporate in warm seasons, which decreases the water level and affects the sea life of aquatic animals and water plants that are always near the surface. High temperatures of water can make the environment favorable for bacterial growth like Escherichia coli, which can be found in fish and later affect humans who consume that fish. Blackwater in water bodies is also considered as a large threat to the irrigation and agricultural systems, as water used for irrigation can be used to water fruits, vegetables, and wheat. Blackwater can also seep into the soil, reducing soil nutrients that are an essential key for living organisms. The secondary effect happens when humans consume those blackwater-affected products, and get sick.

Coal power plants are a leading pollutant of carbon dioxide; they also contribute to the existence of smog, acid rain and toxic air pollution. Some of the most hazardous air toxins emitted from a coal power plant are sulfur dioxide, nitric oxide, particulate matter, and mercury. The emissions created from Coal plants create acidic particulates that damage the human health by penetrating the lung and circulating the blood stream, which causes the blood to acidify and oxidize, leading to death in very short periods of time. Other health aftermaths include chronic respiratory diseases, chronic bronchitis and aggravated asthma. The chemicals are also emitted into the air by the evaporation of blackwater in water and river systems. Once the water is evaporated, all the chemical compounds within the coal slurry are invited into the air, causing air pollution and putting risk on those who inhale it or live by the water system. It also pollutes the water, making it unsafe and hazardous for humans.

One of the riskiest components of blackwater to human health is carcinogens. Being exposed to coal slurry or blackwater can be deadly. Whether you are in close contact with a water system that is victimized by blackwater or drank water from your tap coming from a blackwater-contaminated resource; there is a high possibility of being exposed to carcinogen. Carcinogen is a radioactive agent that directly causes cancer, kidney failure, high blood pressure, miscarriages, and birth defects. One of the critical diseases that carcinogens create is the damaging of tissue cells, which damages the genome structure of the cellular metabolic process. Carcinogens are also reducing safe drinking water stains, which make it harder for humans to obtain a safe-drinking source.

It is often difficult to find alternative solutions for blackwater, because it results from coal slurry, which is non-biodegradable and hard to break its components into ones that can be used in their natural form in the environment. One of the possible alternatives will be using a semi-permeable membrane that filters the coal from rocks and residues without letting blackwater pass through the membranes and into the pipelines. Another alternative would be to manage the water systems, and use water turbines to circulate the streams of water, so blackwater does not concentrate in a certain area to the extent it leaves a damaging aftermath. An additional alternative might be adding chemical additives to reduce the hazardous effects of blackwater but that will also come on the account of marine life. The best alternative would be applying government tradable permits on the amount of blackwater that a coal preparation power plant can create, which will act as an incentive for mining sites to reduce any form of pollution, in fear of paying pollution taxes. Funding research on preventing blackwater spills and blackwater pollution is significant in order to take practical, preventative measures with a relatively low cost and the potential of being highly effective. And as always, the most important aspect is to advocate humanitarians and environmentalists on raising awareness for the current generation and the ones to come.

See also[edit]


  • Australia. Primary Industries. Fishing and Aquaculture. Black Water Events Causing Fish Kills in the Murray and Murrumbidgee River Catchments. NSW Government, 2010. Web. 27 Jan. 2013.
  • Department for Natural Resources. Report Of The Black Water Task Force. Rep. Environmental and Public Protection Cabinet, 2005. Web. 27 Jan. 2013.
  • Hales, Simon, J. Gohlke, A. Pruess-Ustun, D. Campbell-Lendrum, and A. Woodward. "Mitigation of Climate Change and the Potential Reduction in Global Health Impact of Particulate Air Pollution from Coal Fired Power Station." IOP Conference Series: Earth and Environmental Science 6.58 (2009): 582014. Print.
  • King, A. J., Tonkin, Z., and Lieshcke, J. (2012). Short-term effects of a prolonged blackwater event on aquatic fauna in the Murray River, Australia: considerations for future events. Marine and Freshwater Research 63, 576–586.
  • Orem, Williams. Research Geochemist, USGS. Coal Slurry: Geochemistry and Impact on Human Health and Environmental Quality.
  • Ryan, Barry, Ross Leeder, John T. Price, and John F. Gransden. "The Effect Of Coal Preparation On The Quality Of Clean Coal And Coke." British Columbia Geological Survey, n.d. Web. 27 Jan. 2013.
  • "Uses of Coal." World Coal Association. N.p., n.d. Web. 28 Jan. 2013.