Oil and gas

Horse power

Coal may have fueled the industrial revolution, but the steam engine was a heavy and inefficient machine that mostly powered stationary machinery. Only very large forms of transport : railway locomotives and ships could support the large boilers and the reciprocating machinery on a platform that could actually move and carry passengers.  And you had to bring your own coal.

Passengers arriving at Paddington railway station in London in the mid-19th Century  would exit the station and hail a cab pulled by a horse.  Or maybe an omnibus—a horse-drawn carriage that seated about 20 passengers. In 1900, there were over 11,000 hansom cabs on the streets of London, and several thousand horse-drawn omnibuses each needing 12 horses a day. About 50,000 horses were transporting people around the city.  New York had even more horses—100,000 of them, producing over 1,000 tons of manure a day [1].  This was the real age of horsepower.

But all that changed with the invention of the internal  combustion engine. Its adoption was swift, and the subsequent growth of the automobile industry was phenomenal. In America, registrations for automobiles rose from 8000 in 1900 to 900,000 in 1912 [2].  By 1918 half of all cars in America were Ford Model Ts.  And they all ran on gasoline.

Oil was also powering ships—led in part by the British Navy, which famously converted their warships from coal to oil in 1912 under Winston Churchill when he was First Lord of the Admiralty.  The petroleum age was well and truly underway.

Oil on the move

But fossil fuels all have one irreparable and damaging drawback.  They have to be conveyed, often over very long distances, from where they are found and brought to the surface, to where they are processed and then distributed for sale. This is especially true in the case of oil and natural gas where a huge seemingly chaotic network of pipes and pipelines moves oil, petroleum products, and natural gas across countries and continents all around the globe.

This is in stark contrast to renewable energy where, if it’s not on your rooftop like photovoltaic energy, it’s generating electricity somewhere where that power is brought to you by electricity: a distribution network linked to high-voltage transmission lines. These transmission lines can also be very long, but unlike oil and gas pipelines, oil trains, and supertankers, they don’t leak, spill, crash, sink, or explode. Electricity is certainly dangerous—but its transmission doesn’t foul the environment, and if it’s generated from renewable energy, its use as a source of energy has the game-changing advantage that it doesn’t produce greenhouses gases.

Moving large quantities of oil, natural gas, and petroleum products across countries and around the globe is inherently risky. It is simply impossible to avoid accidents. Some accidents are minor—small quantities of petroleum products that leak slowly from a pipeline; others are large, spectacular, and catastrophic.

Petroleum also has more moving parts than coal.  There is first the production of crude oil, which if offshore is dangerous work and where there have been a number of horrific accidents and monumental spills. The Deepwater Horizon drilling platform explosion in 2010 that caused 210 million gallons of crude oil to pour into the Gulf of Mexica 66 km from the Louisiana coast being the worst of them.

Then there is the conveyance of the crude oil to a refinery where, if an oil train is employed, there have been several horrendous accidents—the catastrophic derailment and explosion in 2015 at Lac Megantic in Quebec in which 47 people were killed, being by far the worst.

If the oil is transported by sea in oil tankers, the risks are low but the impact of an accident is usually catastrophic. The worst disasters of tankers that broke apart and discharged over 100,000 tonnes of oil and petroleum products into the sea are shown in the table below.

These are just the big ones. During the last 60 years there have been at least 83 serious tanker accidents and shipwrecks that have spilled around 2.26 million tonnes of oil and petroleum liquids into the oceans [3].

On the north American mainland, Canada and the US are crisscrossed with an enormous network of pipelines that carry large quantities of a liquid petroleum products including crude oil and refined products such as gasoline, diesel fuel, and natural gas liquids. The US has the world’s largest pipeline network: more than 200,000 miles of pipelines carrying liquids, over 300,000 miles of gas transmission lines, and more than 2.1 million miles of gas distribution pipelines.

Pipelines ought to be a lot safer than tankers and trains, but accidents still happen—it’s inherent in a fossil fuel supply system that needs to constantly move large quantities of energy-intensive and flammable liquids and gases under pressure and over long distances.  The figure belwo shows the number of serious pipeline incidents that occurred in the US from 1997 to 2016.  Since 2002, when for some reason the number of accidents almost doubled, pipeline accidents have been running at about 600 a year.

                                                    Number of serious pipeline incidents from 1997 to 2016

Source:  US Pipeline and Hazardous Materials safety administration

Tucked away in the data for the year 2010 is the largest inland oil spill in US history. The spill occurred when a pipeline managed by the Canadian energy firm Enbridge carrying diluted bitumen from the Alberta oil sands ruptured, sending over 800,000 gallons of ‘dilbit’ into the Kalamazoo River near the town of Marshall, Indiana.  In 2016, it was reported that the cost of the cleanup of the 35-mile contaminated stretch of the Kalamazoo river was close to $1.21 billion.[4]

One part of the petroleum supply system that doesn’t always get looked at closely is the oil refinery itself—which is a complex petrochemical plant processing large quantities of crude oil. Accidents are rare in large petrochemical plants, but oil refineries produce considerable amounts of air pollutants and toxic waste.

Refined but not clean

Oil refineries are a major source of air and water pollution.  They are large and complex chemical plants processing a mix of liquid and gas-phase hydrocarbons at high temperatures and pressures. Leaks are inevitable—and frequent. In the US, Canada, and Europe, oil refineries are strictly regulated, but it is technically impossible to reduce emissions to zero. In the USA, in 2015 the petroleum industry, primarily the refineries, released more toxic emissions than the electric utilities sector [5].

A typical refinery generates approximately 10-15 gallons of wastewater for every barrel of oil processed.  This wastewater is treated on site so that the final effluent meets regulatory standards.  But removing the solids and suspended material from wastewater produces a secondary solid waste stream. Solid waste from refineries include tank bottoms, slop oil, spent catalysts, filter cake from water treatment, and numerous other solid or sludge wastes [6]. There is no other place to put them but in a holding pond on site.

But it’s the air pollution that most affects communities close to the refineries. In 2015, there were reportedly 142 large refineries in the US and about 6 million people living within 3 miles of them [7].  The main compounds released to the air from refineries are called Volatile Organic Compounds (VOCs)—consisting mostly of benzene, toluene, ethylbenzene, and xylene—all of which are considered to be carcinogenic to some degree, particularly benzene. Then there is particulate matter, nitrogen oxides, carbon monoxide, hydrogen sulfide, and sulfur dioxide—all of which are noxious air pollutants with a significant impact on human health.

Every refinery has a different emissions profile so precise data on individual refinery emissions are hard to come by. In Canada, the 17 refineries operating in 2013 reportedly emitted on average 430 tonnes of VOCs. But one refinery, the 130,000 barrels-a-day Co-op refinery in Regina released 4,229 tonnes of VOCs in the same year—almost 10 times more than the average [8].

In recent years there has been an increasing focus on environmental justice—the recognition that the health impacts of the pollution produced by chemical and petrochemical plants fall disproportionately on poor communities—which, in the USA, are very often communities of color.

As an example, take the case of the city of Port Arthur in Texas.  The city is home to two large oil refineries: the Motiva refinery in the northeast (the largest oil refinery in America), and the Valero refinery to the west, with a combined throughput capacity of more that 900,000 barrels a day. The Valero refinery borders west Port Arthur, a predominantly Afro-American community with several complexes of low-income public housing that are located right on the refinery fence. Like all oil refineries, the petrochemical plant pollutes the air with emissions of carcinogenic volatile organic compounds such as benzene; as well as carbon monoxide and sulfur dioxide. The EPA ranks Jefferson county among the worst nationally for emissions known to cause cancer, birth defects, and reproductive disorders, and Port Arthur is near the top of the list of offending cities.[9] The Manchester neighborhood adjacent to the Valero refinery has been called the most polluted community in the entire US.[10]

It is notoriously hard to prove cause (pollution) and effect (health impacts) in these circumstances. But anyone who has been in the vicinity of an oil refinery knows the smell. There’s no mistaking it. The smell comes from the vaporous organic chemicals tinged with a dash of sulfur; the burning sensation in the nose and throat comes from the sulfur dioxide; and the asthma attack is triggered by the ozone.

It’s not just the combustion of coal that releases mercury into the atmosphere and into the food chain.  Although petroleum contains less mercury than coal, it is still a fossil fuel, and all fossil fuels contain mercury.

EPA data shows that on-site air releases of mercury and mercury compounds has decreased by 55% since 2005—mainly as a result of a shift from coal to other fuel sources, and the installation of control technologies at coal-fired power plants.  In 2015, about 28 tonnes of mercury and mercury compounds was emitted into the air from point sources in the US.  Of this amount, coal fired and oil-fired power plants (mostly coal) accounted for almost half.


Perhaps unsurprisingly, complex chemical plants like oil refineries may have serious technical difficulties  when operations are disrupted by extreme weather. In August 2017, hurricane Harvey flooded several chemical plants and oil refineries in the Houston area, and as the refineries shut down or went to a standby status, one result was the emergency release of excess amounts of gaseous chemicals as engineers struggled to cope with the situation.  As the refinery switched to a circulation mode, Motiva was forced to flare refinery gases that could not be stored.[11]

At about the same time, the Arkema chemical plant in Crosby lost power and could not continue to refrigerate highly flammable chemicals that eventually exploded and caused a fire that burned for days. The town of Crosby was evacuated because of the risk of further explosions, but also because the smoke from the fire was extremely toxic—as it always is from any fire in a chemical plant or oil refinery.

During the same storm, the ExxonMobil refinery in Baytown was damaged and reportedly released pollutants, and two storage tanks holding crude oil burst into flames outside of Port Arthur after lightning struck the Karbuhn Oil Company facility [12]. Over in Manchester, the Valero refinery leaked benzene and other volatile hydrocarbons into the air when a storage tank’s roof failed.  According to one report, the power was out and the weather was sweltering hot, so many residents kept their windows and doors open increasing their exposure to the carcinogenic vapors.[13]

None of these incidents in the Houston area was particularly severe, and all were finally brought under control.  But these events highlight the fact that large chemical plants and oil refineries are highly vulnerable to extreme weather. Everyone knew that Harvey was coming. Torrential rain had been forecast and preparations made. But shutting down an oil refinery is complicated. It was unavoidable that some hydrocarbon liquids and gases would need to be released to the environment.

But by far the worst damage to petrochemical plants and oil refineries was caused by Hurricane Katrina in 2005. This hurricane was the most destructive natural disaster in US history.

The hurricane caused at least ten oil spills from refineries and other petrochemical plants, releasing the same quantity of oil as some of the worst oil spills in US history.  In total, more than 7.4 million gallons of oil and petroleum poured into local waterways [14].


For more information and data:

[1] See: http://www.historic-uk.com/HistoryUK/HistoryofBritain/Great-Horse-Manure-Crisis-of-1894/

[2] See: The Prize by Daniel Yergin, page 64.

[3] See the Wikipedia entry at : https://en.wikipedia.org/wiki/List_of_oil_spills/

[4] See: New price tag for Kalamazoo River oil spill cleanup: Enbridge says $1.21 billion. At: http://www.mlive.com/news/grand-rapids/index.ssf/2014/11/2010_oil_spill_cost_enbridge_1.html

[5] See the EPA toxic release Inventory (TRI) website at : https://www.epa.gov/trinationalanalysis/comparing-industry-sector-2015-tri-national-analysis

[6] EPA-600/R-01-066. Op.cit. page 17

[7] See: EPA cracks down on oil refinery pollution. At http://thehill.com/policy/energy-environment/255299-epa-cracks-down-on-oil-refinery-pollution

[8] See: Co-op refinery VOC emissions 10x higher than average of other refineries. http://www.cbc.ca/news/canada/saskatchewan/coo-op-refinery-voc-emissions-10x-higher-than-average-of-other-refineies-1.3122876

[9] See : Fumes across the fence-line: The health impacts of air pollution from oil & gas facilities on African American communities, a report by the Clean Air Task Force.  November 2017

[10] See: City in a swamp: Houstons flood problems are only getting worse. At https://inisideclimatenews.org/news/22012018/houston-flood-plain-development-hurricane-harvey-reservoirs-overflow

[11] See: Motiva shuts Port Arthur Texas refinery due to flooding.  At https://www.cnbc.com/2017/08/30/motiva-shuts-port-arthur-texas-refinery-due-to-flooding.html/

[12] See: Harvey shines a spotlight on a high-risk area of chemical plants in Texas. At https://www.theguardian.com/us-news/2017/sep/01/harvey-shines-a-spotlight-on-a-high-risk-area-of-chemical-plants-in-texas

[13] See: City in a swamp: Houstons flood problems are only getting worse. At : https://insideclimatenews.org/news/22012018/houston-flood-plain-development-hurricane-harvey-reservoirs-overflow and https://projets.propublica.org/graphics/harvey-manchester

[14] See the report on hurricane Katrina issued by the White House, at https://georgewbush-whitehouse.archives.gov/reports/katrina-lessons-learned/chapterr1.html