Rochman ff, sheremet a, tamas i, saidimehrabad a, kim jj, dong x, sensen cw, gieg lm and dunfield pf 2017 benzene and naphthalene degrading bacterial communities in an oil sands tailings pond. Mar 30, 2017 a tailings pond near the syncrude tar sands operations near fort mcmurray, alberta, on sept. The solventfree tailings can then be stored in the tailings pond for future reclamation. Bitumen is primarily made up of polycyclic aromatic hydrocarbons pahs, sulfur, lead, mercury, and other heavy metals. Oil sand tailings or oil sands processaffected water ospw, have a highly variable composition and a complex mixture of compounds. Oil sands tailings ponds ostps currently cover 220 km 2 of the 142,200 km 2 aosr, and in 20, contained 1 billion m 3 of tailings alberta environment and parks, 2015. University of calgary characterization of oil sands. Oil sands tailings management and pond assessment mining sgs. Oilsands tailings ponds emit pollutants into the air, study. Oil sands produced 33 metric megatons mt of greenhouse gas emissions in 2006, he says. For years there has been growing evidence that toxic chemicals from albertas vast tar sands tailings ponds were leaching into groundwater and the nearby athabasca river.
Tailings are distinct from overburden, which is the waste rock or other material that overlies an ore or mineral body and is displaced during mining without being processed the extraction of minerals from ore can be done two ways. At an estimated 170 billion barrels of recoverable oil, the alberta oil sands are the third largest proven oil reserves in the world. As mining operations expanded, it became necessary to build more and larger settling ponds. Under this new directive, oil sands mining operators are required by law to commit to the reduction of fine fluid tailings and reduce any current inventories. Large volumes of tailings are a byproduct of bitumen extraction from. The accumulation of mature fine tailings mft in tailings ponds has been a concern of the oil sands industry for nearly four decades. Canadas most shameful environmental secret must not. The oil sands mining and extraction processes in canada produce large volumes of tailings that are a mixture of mainly water, clay, sand, chemicals and bitumen.
Federal study says oil sands toxins are leaching into. The oil sands are mined and produce substantial amounts of waste tailings needing to be stored in tailings ponds. Large enough to be seen from space, tailings ponds in albertas oil sands region are some of the biggest humanmade structures on earth. The problem of albertas growing oilsands tailings ponds is.
Geochemical interactions between processaffected water. Oil sands tailings ponds are engineered dam and dyke systems used to capture oil sand tailings. Oil sand tailings contain a mixture of salts, suspended solids and other dissolvable chemical compounds such as acids, benzene, hydrocarbons residual bitumen, fine silts and water. Physiology and molecular characterization of microbial. Management of oil sands tailings article in petroleum science and technology 20910. Utah oil sands are found in a different positionmuch of utahs oil sands deposits lie from surface to just 400 feet. A report cited the company for not meeting targets for the ponds. Exchanging oil sands expansion for renewable energy growth. You can just scoop up the oil sands with a front loader and then process. Department of the interior, one of these ponds the mildred lake settling basin is the worlds largest dam by volume of construction material. However, even when a few measures have been implemented, the. Alberta has a prosperous oil industry with large reserves of oil sands.
Tailings ponds of the athabasca oil sands region, alberta. Nafta scrutiny of oilsands tailings ponds opposed by canada. The company uses a proprietary citrusbased biosolvent to extract the bitumen, eliminating the need for large volumes of water or tailings ponds. The sheer size and scope of albertas some 20 oilsands tailings ponds is unprecedented for any industry in the world. Canadian oil sands northern alberta and saskatchewans oil sand reserves comprise 97% of canadas proven oil reserves, summing up to 170 billion barrels of recoverable bituminous oil. Processing oil sands to extract bitumen produces large volumes of a tailings slurry comprising water, silt, clays, unrecovered bitumen, and residual solvent used in the extraction process. In contrast, north dakota has zero abandoned wells the last one. Nov 27, 2014 oilsands study confirms link between tailings ponds and air pollution. The relatively dry oil sands deposit requires large volumes of water to produce an oil sands slurry that can be pumped and gravity separated throughout the process plant. Study shows oilsands tailings ponds releasing toxic. In proceedings of the 9th international conference on mine closure, johannesburg, south africa, october 2014. The particlesize distribution of oil sands tailings has always figured prominently in the mine planning and overall operations and closure strategy in surfacemined oil sands. Allen wrote that typically tailings ponds consist of c. Oil is a powerful and versatile source of canadian energy that will be a part of the global energy mix for decades to come.
The management of tailings ponds is one of the most difficult environmental challenges associated with oil sands and their existence is extremely controversial. Feb 02, 2014 the tailings ponds created by albertas oilsands mining have tripled in size since 2005 and are predicted to grow another 40 percent. Tailings are the materials left over after the process of separating the valuable fraction from the uneconomic fraction of an ore. Chris bourdeau, a spokesperson for alberta environment, says this is an unfair characterization of the impact of oil sands. Tailings solvent recovery units tsru used in the oil sands are modified versions of traditional flash columns, using temperature and pressure to recover the solvent.
It is aimed at standardizing sampling and measurement of fluid tailings including the. Sep 02, 2014 companies are scrambling to meet this target. While oil sands companies are expected to reclaim liquid tailings, there has been 40 years of poor performance in addressing this longterm liability. The trouble with tailings ponds mines generate a lot of waste. Although this article focuses on hardrock tailings, oil sands tailings can contain a similarly complex and toxic brew of minerals and chemicals, and pose a similar. The alberta in situ projects do not require tailings ponds. Alberta tailings ponds ii commission for environmental. Note that some of the mines have not been active during this entire period. These ponds are temporary storage facilities and need to be reclaimed when no longer in use. Oil sands firms warned on tailings ponds the globe and mail. Oilsands tailings ponds battle escalating calgary herald. Environmental consequences of oil production from oil sands. Toxic syncrude tailings pond kills hundreds more ducks.
This article originally appeared on the pembina institute website. Both scientists and aboriginals fear that a breached tailing pond could poison water for 40,000 people and travel all the way to the arctic ocean. Liquid tailings dry at a suncor oil sands operation. Oil sands extraction in alberta has attracted international attention for destroying tens of thousands of hectares of boreal forest and polluting nearby communities.
Second, the produced slurry is sent to the bitumen extraction plant, where more water is added to reach a density of 1400 kg m. Oil sands production also produces tailings, which are substantially different. May 10, 2018 in fact, canadas own socalled proactive inspectionsat six out of seven tar sands tailings ponds from 200920registered at least 15 samples with excessive levels of deleterious. Benzene and naphthalene degrading bacterial communities in. Dec 16, 2016 first, at the slurry preparation plant water is added to the mined oil sands ore to obtain a slurry with a density of 1500 kg m. Tailings ponds are massive earth structures used to store coarse and fine solids contained in the oil sands deposit and recover water back to the main processing plant. These tailings ponds made international headlines in 2008 when 1,600 ducks flew into.
Along with the 2030 wt% of solids sands and clays and slightly alkaline water ph7. Ostp are generally constructed overtop native ground lined with sand, and on occasion, some overburden mcneill and lothian, 2017. This guideline relies on the definitions included in those documents. Tar sands tailing ponds are leaking oil change international. Sep 04, 2015 the images of oil soaked, dying ducks flashed around the world and brought the size and scale of the land scarred by oilsands extraction and the deadly tailings ponds to international attention. The submitters assert that the government of canada is failing to effectively enforce subsection 363 of the canadian fisheries act with respect to the leaking of deleterious substances from oil sands tailings ponds into surface waters and the groundwater of northeast alberta.
The problem of albertas growing oilsands tailings ponds. B this article has been rated as bclass on the projects quality scale. Microbes indigenous to oil sands tailings ponds methanogenically biodegrade certain hydrocarbons, including nalkanes and monoaromatics, whereas other hydrocarbons such as isoand cycloalkanes are more recalcitrant. Large volumes of tailings are a byproduct of surface mining of the oil sands and managing these tailings is one of the most difficult environmental challenges facing the oil sands industry. There are several oil sands tailings ponds, each close to 4045 meters in height, covering a total area of 170 square kilometers. The oil sands to water ratio is typically about 1to1 or 50% water in t. Guidelines for determining oil sands fluid tailings volumes.
The athabasca oil sands first came to the attention of european fur traders in 1719 when wapasu, a cree trader, brought a sample of bituminous sands to the hudsons bay company post at york factory on hudson bay where henry kelsey was the manager. Fine solids from tailings streams tend to trap large volumes of water, making pond reclamation challenging at best. The government of alberta reported in 20 that tailings ponds in the alberta oil sands covered an area of about 77 square kilometres 30 sq mi. Because the barren process solutions were neutralised only to ph 78 instead of shifting ph to 10. A provincial directive forcing companies to capture and store 50 per cent of tailings by 20 came into effect last year, but mr. Tailings solvent recovery units oil sands magazine. This is part 2 of a series on the last 50 years of the oilsands industry. Canada has about six billion barrels of remaining oil reserves located outside the oil sands, found primarily in alberta, saskatchewan and offshore newfoundland and labrador. Currently microbes manifest as both beneficial and deleterious agents in the management and reclamation of oil sands mining wastes. David dodge, the pembina institute david dodge, the pembina institute we have a framework that measures the amount of tailings. Showdown looming for albertas oilsands over cleanup of.
The role of clays in the performance of oilsands tailings. Tailings ponds attract a lot of attention because there is currently about 77 square kilometres of oil sands tailings pond water in alberta, according to the government of alberta. These ponds hold 1 trillion litres of sludge that is unlike any other industrial byproduct in the world. To understand their roles in various aspects of oil sands tailings ponds ostps and reclamation practices, it is necessary to understand the processes that generate oil sands mining wastes and influence tailings management strategies. Oilsands tailing ponds ticking time bomb for canadians the tyee. Water management in oil sands mining facilities oil.
Dyer says just two of nine oil sands companies have submitted. Mark ralston via getty images a scarecrow lies in a tailings pond in front of the suncor oil sands extraction facility near the. According to the submitters, tailings ponds contain. Drilling in search of a basement reservoir of oil is the initial focus of development in albertas oil sands. Mature fine tailings from oil sands processing harbour. In northern alberta, the placement of outofpit oil sands tailings ponds atop natural buried sand channels is becoming increasingly common. The battle over when and how to clean up oilsands tailing ponds is escalating.
Oil sands tailings and directive 074 oil sands mining operations produce significant quantities of liquid waste materials called tailings. Tailings directive 074 explained oil sands magazine. Unlike oil sands deposits in the athabasca region, bitumen contained within utahs oil sands do not easily separate from the sand using just hot water. W aterfowl that land on oilsands tailings ponds can become coated in oil, causing them to sink to the bottom. In oil sands applications, the convention is to define the sand as the mineral components 44. It is estimated that every barrel of oil produced through surface mining generates one and a half barrels of fluid tailings. The tar sands leaking legacy from canadas environmental defence. So while most people have heard of tailings ponds and seen photos, few know what purpose they serve and what the ponds actually contain. The tailing ponds now cover a huge area some 176 square kilometres and given their size it is hardly surprising that some seepage may be occurring. Oilsands tailing ponds approved albertas energy watchdog has approved plans submitted by oilsands operators fort hills and syncrude to deal with waste from their projects. Closure option for oil sands fluid fine tailings ponds.
The oil sands tailings ponds are settling ponds that contain the waste byproduct of oil sands extraction and upgrading. Tailings ponds a toxic legacy of albertas oilsands the star. Oil sands mining facilities are fairly water intensive. In oil sands mining, every barrel of oil produces approximately 3 m 3 of tailings, which contain between 35% and 65% of solids, with fines content between 8% and 25% and approximately 1% of. Us oil sands enters into receivership oil sands magazine.
We tested the susceptibility of isoand cycloalkanes to methanogenic biodegradation by incubating them with mature fine tailings mft collected from two depths 6 and 31 m below. Some large tailings ponds are separated by earthen dikes from the. Jun 12, 20 oil sands firms warned on tailings ponds. A good deal of the controversy about oil sands development centers around those tailings ponds, which cover more than square kilometers in northern alberta, according to the 2008 report 11 million litres a day. In 2008, the former ercb alberta energy resources conservation board, now known as the alberta energy regulator introduced directive 074. The tailing ponds leach dangerous chemicals into the surrounding environment. The composition of oil sands oil sands albertas energy. This item is a table and graph of the area of the alberta oil sands mine tailings ponds from 1985 to 2016. A march 2012 handout photo of syncrude oil sands tailings pond. An industrial hellscape of openpit mines spreads across the land, giving way to 220 km2 of tailings ponds that drown the ruins of. In 20, oil sands mines owned by shell, suncor, and syncrude failed to meet targets. They are a mix of water, sand, silt, clay, unrecovered hydrocarbons, and other contaminants.
With a growing number of tailings ponds across the province, the possibility of a pond failure increases. A tailings pond near the syncrude tar sands operations near fort mcmurray, alberta, on sept. Oil sands tailings are the residue which remains after bitumen is separated from virgin oil sands. Geotechnical properties of polymeramended tailings. Preliminary modeling of such a site suggests that processaffected pa pond water will infiltrate through the underlying clay till aquitard, reaching the sand channel.
The influence of tailings composition on flocculation. Albertas oilsands could be heading for another showdown over tailings ponds after an. Mining oil sands tailings management and pond assessment sgs has been providing tailings management services to partners in the alberta oil sands industry for over 25 years. The most common design of a tailings pond is the raised embankment. Settling or tailings ponds are large engineered dam and dyke systems designed to contain and settle the water, sand, fine clays, silts, residual bitumen and other residual hydrocarbons of the oil sands mining and extraction process. Producing oil from tar sands is a resourceintensive process. Our highlyskilled, technical experts ensure that the tailings management at your operation is efficient and costeffective while meeting provincial safety regulations and. This mixture is transported to tailings ponds, where gravity segregation occurs. Oilsands study confirms link between tailings ponds and air. Canadas oil industry canadian oil and natural gas producers. The tailings ponds created by albertas oilsands mining have tripled in size since 2005 and are predicted to grow another 40 percent.
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