Oil's Impact: Understanding Water Pollution

Oil spills are a significant contributor to water pollution, with an estimated 706 million gallons of waste oil entering the ocean each year. While large oil spills from tankers are a severe problem, smaller spills from routine shipping, run-offs, and dumping also contribute significantly to water pollution. Oil spills can have catastrophic consequences for local marine wildlife, including fish, birds, and sea otters, and can also impact human activities and the economy. The clean-up and recovery process is challenging, and even with advanced technology and coordinated responses, it is difficult to remove 100% of the spilled oil.

Oil spills

The effects of oil spills on marine life are twofold. Firstly, oil can coat the feathers or fur of birds and marine mammals, impairing their ability to fly or swim, disrupting their insulating abilities, and causing hypothermia. Oil can also blind animals, leaving them defenceless, and impair their digestive processes when ingested. Secondly, oil spills can harm marine plants by blocking sunlight and inhibiting photosynthesis, leading to the death of plants growing in the water.

The cleanup and recovery process for oil spills is challenging and depends on factors such as the type of oil, water temperature, and shoreline characteristics. Physical cleanups are expensive, and chemical remediation methods are often employed. Bioremediation, controlled burning, dispersants, skimming, and solidification are some of the techniques used to address oil spills.

Oil toxicity

One of the main effects of oil toxicity is the destruction of the insulating ability of fur-bearing mammals and the water repellency of bird feathers. This loss of insulation and water repellency exposes these creatures to harsh weather conditions, leading to hypothermia and, in some cases, death. Oil spills can also directly poison birds and animals when they try to clean themselves or ingest contaminated food and water.

The toxicity of oil spills depends on various factors, including the type and volume of oil, the length of exposure, and the specific characteristics of the affected environment. Different types of oil have varying viscosities, volatilities, and toxicities, which play a crucial role in determining the impact on the environment. The length of exposure is also crucial, as both short-term and long-term effects can occur. Additionally, the specific ecological context, such as the presence of sensitive habitats or vulnerable species, will influence the severity and persistence of oil toxicity.

Oil spills can have both acute and chronic effects on marine life. Acute toxicity refers to the immediate short-term effects of high concentrations of oil, which can lead to direct damage or death. On the other hand, chronic toxicity results from long-term and continuous exposure to lower concentrations of oil, causing continuous effects on the affected organisms.

To mitigate the impacts of oil toxicity, it is essential to have effective response plans, clean-up strategies, and preventive measures in place. This includes the use of booms to contain oil spills, skimmers to remove oil from the water surface, and the implementation of regulations such as the Oil Pollution Act to prevent and prepare for oil spills.

Oil waste from offshore drilling

Offshore drilling produces waste every day, and this waste can be toxic to the environment. Oil drilling platforms, pipelines, and refineries create air pollution, which is harmful to human health and contributes to climate change.

Offshore drilling produces waste fluids, which are a major source of contaminants to continental shelf ecosystems. These waste fluids can be harmful to the workers tending them and nearby residents. Without proper disposal, the waste can contaminate people's drinking water.

The waste fluids from offshore drilling include drilling muds and produced water. Drilling muds are fluids used in the drilling process, which perform functions such as providing hydrostatic pressure, cooling and cleaning the drill, carrying drill cuttings, limiting corrosion, and lubrication. Produced water is contaminated water associated with oil and gas extraction, which is primarily composed of formation water extracted during oil and gas recovery.

The ecological effects of these waste fluids have been studied, and it has been found that they can disturb reproductive functions and affect several chemical, biochemical, and genetic biomarkers. The ecological effects are typically found within 200-300m of the well-head, but can occasionally extend to 1-2km for sensitive species.

The ecological effects of offshore drilling waste fluids are particularly harmful to cold-water corals, which are fragile and have low resilience to physical forces.

To mitigate the harmful effects of waste fluids from offshore drilling, certain practices are restricted or banned. For example, the use of drilling muds that used diesel oil as their base has been phased out, as these drilling fluids biodegrade very slowly and have high toxicity.

In addition, there are restrictions on the discharge of produced water, with produced water typically being expected to be re-injected into subsurface formations or cleaned to meet national oil-in-produced water discharge limits before being disposed into the sea.

Oil pollution prevention

Oil pollution in water is a pressing issue, with oceans being polluted by oil on a daily basis from oil spills, routine shipping, run-offs, and dumping. Oil spills can be highly detrimental to local marine wildlife and ecosystems, and they can contaminate drinking water sources. Oil pollution prevention is, therefore, crucial to minimizing the negative impacts on the environment and human health. Here are some measures that can be taken to prevent oil pollution:

Regulatory Measures:

• The Oil Pollution Act (OPA): Passed in 1990 in the US, the OPA amended the Clean Water Act, requiring oil storage facilities to prepare "Facility Response Plans" to prevent and prepare for emergency responses to oil spills. It also imposed liability for injuries, removal costs, and damages from oil discharges into navigable waters.
• Spill Prevention, Control, and Countermeasure (SPCC) Rule: This regulation helps facilities prevent oil discharges into navigable waters and adjoining shorelines. It requires facilities to develop and implement SPCC Plans, which include procedures, methods, and equipment requirements.
• Facility Response Plan (FRP) Rule: The FRP rule mandates certain facilities to prepare and submit response plans for a worst-case oil discharge scenario. This ensures that facility owners and operators are prepared and can minimize the impact of a potential spill.
• International Regulations: The United Nations treaty, MARPOL (Convention for the Prevention of Pollution from Ships), requires tankers and ships to use oil-pollution prevention equipment, such as double hulls, reliable navigation, and communication equipment.

Best Practices for Industries and Individuals:

• Proper Disposal of Oil: Educating individuals and industries about the proper disposal of oil, paint, and hazardous chemicals is essential. Promoting responsible practices can significantly reduce oil pollution in water sources.
• Safe Transportation and Storage: Oil transportation and storage facilities should implement safety measures to prevent spills and leaks. This includes regular maintenance, secure transfer procedures, and the use of advanced spill containment technologies.
• Routine Maintenance and Inspection: Industries that handle large amounts of oil, such as shipping companies and oil refineries, should conduct routine maintenance and inspections to identify and repair potential sources of oil leaks.
• Oil Spill Response Planning: Industries that are at high risk of oil spills, such as oil refineries and shipping companies, should have comprehensive response plans in place. These plans should include containment strategies, clean-up methods, and coordination with local authorities and environmental organizations.
• Promoting Recycling and Alternative Energy Sources: Encouraging the recycling of used oil and the adoption of alternative, cleaner energy sources can help reduce the overall demand for oil. This, in turn, can decrease the risk of oil spills and minimize environmental impacts.

Oil spill clean-up

Oil spills are a pressing issue that poses a serious threat to the marine ecosystem. They can inflict significant damage on the environment and have detrimental effects on marine life. Oil spills occur accidentally, so it is crucial to employ various clean-up methods to mitigate their impact. Here is a detailed guide on oil spill clean-up procedures:

Containment and Prevention of Spread:

The first step in oil spill clean-up is to contain the spill and prevent it from spreading further. This can be done using booms, which act as floating barriers to contain the oil and stop it from spreading or floating away. Booms have three parts: a 'freeboard' that rises above the water surface, a 'skirt' placed below the surface to stop oil from escaping, and a cable or chain to stabilise the boom.

Absorbing and Removing the Oil:

Once the spill is contained, the next step is to remove the oil from the water surface. This can be done through various methods such as:

• Skimming: Skimmers are machines that act like vacuum cleaners, sucking up the oil from the water surface. They are effective in recovering most of the spilled oil and are economically viable. However, they can get clogged by debris in the water.
• Sorbents: Sorbents are materials that absorb or adsorb the oil, making it easier to remove. Common sorbents include hay, peat moss, straw, and vermiculite. After absorption, sorbent materials must be retrieved carefully as they become heavier and may sink, posing a risk to aquatic life.
• Hot Water and High-Pressure Washing: This method is used when the oil is inaccessible to skimmers or booms. Water is heated to a high temperature and sprayed at high pressure to dislodge the oil, which can then be collected with skimmers or sorbents.
• Manual Labour: This involves using hand-held tools like rakes and shovels to clean up the oil and oily debris from the shoreline and place them in special containers for removal. While this method is cost-effective, it is labour-intensive and time-consuming.
• Mechanical Removal: Heavy machinery, such as backhoes or front-end loaders, can be used to remove oil from the shoreline when accessible. However, the use of heavy machinery may damage the shoreline.

Using Chemical Dispersants:

When oil cannot be contained by booms, chemical dispersants like Corexit 9500 can be used. These chemicals are sprayed onto the spill and help break down the oil components, allowing them to chemically bond with water. While this method is effective for large spills, it can create tarballs and negatively impact marine life, especially corals and seagrass.

Burning the Oil:

In some cases, the oil floating on the water surface may be ignited and burned off. This method can remove up to 98% of an oil spill but releases toxic fumes that can harm the environment and marine life. It is only effective for relatively fresh spills before the oil spreads too thinly.

Natural Recovery:

In remote or inaccessible areas, the oil spill may be left to natural recovery, allowing natural elements like the sun, wind, weather, and tides to evaporate or break down the oil. While this method is cost-effective, it is highly time-consuming and unreliable, requiring constant monitoring.

Bioremediation:

Bioremediation involves using specific microorganisms, such as bacteria, fungi, and algae, to break down petroleum products into simpler, non-toxic molecules. This process is typically used when the oil approaches the shoreline and may take a long time. Fertilisers may be added to aid the growth of microbes, but this can also encourage the growth of unwanted algae, negatively impacting marine life.

Chemical Stabilisation:

In recent years, experts have used compounds like 'Elastol' (poly iso-butylene) to solidify the oil on the water surface, preventing its spread. This method is quick and efficient, but the gelatinised oil may entangle or suffocate aquatic animals.

Reporting and Waste Disposal:

It is important to report oil spills to supervisors or local authorities, as required by legislation. Additionally, all waste absorbent materials and collected oil must be properly disposed of at registered hazardous waste disposal sites.

The choice of clean-up method depends on various factors, including the type and amount of oil spilled, the location of the spill, and weather conditions. A combination of these methods may be employed to effectively manage and clean up oil spills, protecting the environment and marine life.

Frequently asked questions