Petroleum's Poisonous Impact On Waterways

Oil spills are a major source of water pollution, with the Niger Delta being one of the most affected regions. Petroleum-contaminated water poses significant health risks, as seen in a Nigerian community where drinking water wells were found to contain high levels of benzene and other hydrocarbons. These pollutants can lead to neurological and hematological issues, irritation, and potentially cancer and birth defects. Other sources of petroleum water pollution include shipping accidents, tank washing, refinery run-offs, and pipeline failures, all contributing to the environmental and ecological damage caused by oil pollution.

Oil spills

The cleanup and recovery process after an oil spill is complex and challenging, depending on factors such as the type of oil, water temperature, and shoreline characteristics. Physical cleanups are expensive, and complete removal of the spilled oil is often impossible. In the case of the Exxon Valdez oil spill in 1989, it was found that the cleanup methods caused more damage than the oil itself. This incident led to the establishment of the Oil Pollution Act of 1990, which holds those responsible for oil spills accountable for the costs of cleanup and restoration.

Some notable examples of significant oil spills include the Deepwater Horizon spill in 2010, the Ixtoc I spill, and the Exxon Valdez spill in 1989. These incidents have received substantial remediation responses and media attention, highlighting the need for improved prevention measures and government responses to oil spills.

Hydrocarbons

Polycyclic Aromatic Hydrocarbons (PAHs) are a type of hydrocarbon commonly found in coal-tar, a pavement sealant ingredient. PAHs are associated with industrial processes like power generation, vehicle emissions, and manufacturing. They are toxic and have been linked to cancer and genetic mutations. PAHs accumulate in aquatic life, impacting ecosystems, and are classified as semi-volatile organic compounds due to their low solubility in water.

Petroleum hydrocarbons (PHCs) are another significant source of water pollution, particularly in groundwater systems near fuel stations. PHCs can contaminate soil and groundwater, and their chemical compounds can migrate through potential exposure pathways in the environment. Releases of fuels from leaking underground storage tanks (USTs) contribute to groundwater contamination. The proximity of USTs and fuel storage tanks influences the extent of groundwater contamination.

Benzene, a known human carcinogen, is often the primary concern at petroleum release sites due to its high toxicity and mobility. Other aromatic hydrocarbons like naphthalene and chrysene are also classified as priority pollutants. Petroleum hydrocarbon contamination is a prevalent issue, and remediation technologies have been developed to reduce PHC concentrations in soil and groundwater. However, complete restoration is challenging due to the complex behaviour of PHCs.

Industrial development

In addition to accidental spills, routine shipping activities, run-offs, and dumping also contribute to ocean pollution. Oil spills from tankers can be particularly detrimental due to the large volume of oil released in a specific location. The Niger Delta, a region rich in oil, has suffered extensive petroleum contamination, affecting the drinking water sources of communities such as Ogale. A 2011 study by the United Nations Environment Programme (UNEP) found high levels of benzene and other hydrocarbons in Ogale's drinking water wells, posing significant health risks to the residents.

Furthermore, operational discharges of oily tank washings from tankers are a frequent source of marine spills. This occurs when tankers fill their holding tanks with seawater ballast and later discharge the oily bilge water, containing hydrocarbon residues, into the sea. While the implementation of the load-on-top (LOT) process in the early 1970s significantly reduced this type of pollution, it still contributes to the overall problem.

The petroleum industry generates various toxic wastes during exploration and production, which can lead to water pollution if not properly managed. Improper disposal of drilling muds, shipping and traffic accidents, depot leakage, and pipeline failures or ruptures are all potential sources of water contamination. One of the most common forms of water pollution from the petroleum industry is the deliberate discharge of untreated wastewater, also known as formation water or produced water, into the local environment.

To address these issues, it is crucial to implement stringent regulations and waste control measures in the petroleum industry. Regular maintenance of oil-water separators, grease trap interceptors, and other waste management systems can help prevent accidental spills and discharges. Additionally, governments and industries should work together to promote sustainable practices, improve safety protocols, and invest in research and development for cleaner energy alternatives. By taking proactive measures, we can mitigate the impact of industrial development on water pollution from petroleum and protect our precious water resources for future generations.

Drilling mud disposal

Drilling mud, also known as drilling fluid, is a significant contributor to water pollution from the petroleum industry. Drilling mud is used to lubricate the drill bit, seal off porous geological strata, and stabilise shale layers during the drilling process. It also helps to bring drill cuttings, which are broken bits of solid material produced as the drill bit breaks the rock, to the surface.

Drilling mud typically consists of a water-based mud containing bentonite clay, with additives such as sodium hydroxide and barite to increase density and help float out rock cuttings. However, these additives can include toxic chemicals and heavy metals such as mercury, arsenic, chromium, and lead, which can contaminate soil and groundwater if not properly disposed of.

The disposal methods for drilling mud vary depending on the location and local regulations. In some cases, pit burial is used, where the waste is placed in a man-made or natural excavation. However, this method is not suitable for waste with high concentrations of oil and industrial chemicals, as they can easily leach into the soil and groundwater, causing pollution that can spread to other areas and persist for years or decades.

Land farming is another common disposal technique, where drilling fluid and produced water are repeatedly applied to the soil surface. This process can alter plant growth and soil chemical properties due to the addition of alkalinity, salinity, trace elements, and petroleum residue contained in the waste.

To reduce the environmental impact of drilling mud disposal, the US Environmental Protection Agency (EPA) regulates the discharge of contaminants, including drilling mud, into US waterways and offshore areas under the Clean Water Act. The EPA employs technology-based effluent standards when issuing discharge permits to onshore and offshore operators. Additionally, innovative approaches such as the Region X method, which includes collecting influent and effluent data and developing specific mud formulas, have been shown to reduce toxic discharges compared to standard command-and-control regulatory approaches.

Tanker washings

To comply with regulations and minimise pollution, tankers employ various systems for managing and treating wastewater. One such system is the segregated ballast tank (SBT), which is mandatory for certain tankers above a certain size and capacity. SBTs are completely separate from the cargo oil and fuel oil systems and are dedicated to carrying water ballast. By having sufficient segregated ballast tanks, the likelihood of oily ballast discharge is significantly reduced. Another system is the crude oil washing (COW) system, which uses the dissolving action of crude oil to clean cargo tanks, reducing the need for water washing and, consequently, reducing operational oil pollution.

Despite these regulations and systems, tanker washings continue to contribute to water pollution from petroleum. This is particularly true in cases of non-compliance, inadequate implementation, or accidental discharges. To address this issue, ongoing monitoring, research, and the implementation of proven methods for reducing nonpoint source discharges are essential. Additionally, there is a need for knowledge transfer and partnerships to better track and manage the release of petroleum and other pollutants into water bodies.

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