Exposure to crude oil may irritate the eyes, skin, and respiratory system. It may cause dizziness, rapid heart rate, headaches, confusion, and anemia. Prolonged skin contact with crude oil may cause skin reddening, edema, and burning of the skin. Handling tarballs may cause an allergic skin reaction or skin rashes.
While most chemicals in crude oil have low toxicity in humans, a few of the chemicals can be quite toxic. Benzene and some of the polycyclic aromatic hydrocarbons (PAHs) are carcinogenic. Because of benzene’s characteristics, it does not persist in the environment. Benzene exposures are of most concern immediately after a spill when it can dissolve into the water or transfer to the air. Benzene rapidly goes away in water and air over time. For these reasons, potential exposures to people are short duration, acute exposures.
PAHs have different properties than benzene. PAHs do not easily dissolve in water or go into the air. In a creek like Red Butte, PAHs are typically found stuck to soil and sediment and can remain for several years. The most likely place to find PAHs is in the sediment. In addition to crude oil, PAHs come from many other sources in an urban environment like Red Butte Creek.
Crude oil is toxic to aquatic life, including: water birds, fish, and aquatic bugs (invertebrates). Waterfowl from Liberty Park pond were impacted by the crude oil. The majority of birds exposed were Canada Geese but the majority of birds that died were Mallard ducks.
- Captured—364 birds (this does not include 11 goose eggs, 12 duck eggs, and 5 ducklings)
- Washed/Cleaned—361 birds; released 328 birds
- Dead on Arrival—1 bird (this does not include 11 goose eggs, 12 duck eggs, and 5 ducklings)
- Euthanized—9 birds
- Died—27 birds
The oil appears to have little direct effects on fish because no dead fish were observed or reported in Red Butte Creek during the clean-up response. Ultimately, approximately 500 fish collected from Liberty Park pond were euthanized. Live fish were observed in Red Butte Creek after the spill.
The macroinvertebrates in Red Butte Creek were severely impacted by the oil and subsequent cleanup activities. As of April 2011, the bugs have not fully recovered. Get more information on the bug monitoring at Red Butte (34 KB).
Visual observations are often the most reliable guide. Oil is unequally dispersed through the environment. As a result, it’s difficult to get representative samples. See the attached maps for visual and chemical observations to date.
Our priority has been to monitor the spill. Quantifying the movement of the oil will help us determine its potential environmental impacts.
Once the spill has been contained and clean-up efforts are essentially complete, a more detailed sampling plan will be implemented. Over the next couple of days, we will place instruments which will allow us to continually measure the amount of Dissolved Oxygen in the waters. This information will help us determine the extent of the damage and will guide final clean-up actions. Future sampling will include collection of metals, total petroleum hydrocarbons, oil and grease, sediment, bugs, fish and other aquatic organisms.
Each oil spill is different and effects can be both short- and long-term. It is therefore important to make continued measurements of the amount of oil present in the environment and any ecological consequences that are observed. DEQ is just starting to obtain data now and will have a much better sense of environmental impacts once these data are evaluated.
In general, adverse affects can impact fish, birds, amphibians, bugs, algae, and even microbes. Because all of these animals are interrelated, oil spill effects on one group can potentially have indirect and longer lasting effects on others. Additionally, the susceptibility of species within each group also varies—further complicating data interpretation.
The severity of the any oil spill depends on the nature of the oil itself and characteristics of the environment. Water movement is a primary factor.
- In standing water, such as lakes and ponds, oil and tends to remain for a longer time than in flowing water. In extreme circumstances, oil can cover the entire surface of the water body.
- In flowing water, oil tends to move to the margins of streams or river, leaving some refuge for fish and other animals in the center of the stream.
While individual circumstances vary, oil spills have larger and longer lasting effects on the ecosystem of wetlands and lakes than they do for streams and rivers.
It is difficult to answer that question at this point. Adverse impacts from spills can last from weeks to decades. The most important step we can take now is to continue to collect data that will allow us to evaluate the extent of the problem and make informed decisions.
Red Butte Creek was physically cleaned over the course of several weeks after the spill. The Division of Water Quality (DWQ) reviewed all analytical results as they became available. In a few locations, known oil contamination was left where bank stability, structures, or trees could be damaged by additional clean-up. Unknown pockets of oil contamination likely remain in Red Butte Creek, but these are anticipated to be limited in extent. These pockets are evaluated for cleanup as they are discovered. Because of the time since the spill and the chemical properties of these contaminants, they are likely limited to the sediments, but can be in the water when the sediment is stirred-up.
Chemical concentrations were compared to concentrations that do not affect humans or aquatic organisms. Concentrations acceptable for drinking water were used for human health benchmarks. These are conservative benchmarks because they are based on a lifetime of exposure through drinking water and exposures to Red Butte Creek water are much less in both quantity and duration. Concentrations of benzene and naphthalene were occasionally detected above drinking water concentrations on June 12 through 15, 2010 when the creek was being actively remediated. Samples collected after this period were either “nondetect” or below drinking water benchmarks.
To evaluated potential effects to aquatic organisms, chemical concentrations were compared to no-effects concentrations. The detected concentrations are divided by the no-effects concentration resulting in a toxic effects ratio (TER). Figures XX compare the chemical concentrations measured in Red Butte Creek to known toxic concentrations. When the TER is less than one, no toxic effects are predicted. When the TER is greater than one, toxic effects are possible. Contaminant concentrations exceeded the benchmarks through the 3rd week of June when the creek was being remediated.
Sediment samples representative of general conditions in the creek detected trace amounts of oil-related compounds such as polycyclic aromatic hydrocarbons that were below human health benchmarks. Targeted samples from areas visually contaminated detected higher concentrations and were usually subsequently remediated.
Chevron was tasked to prepare comprehensive ecological and human health risk assessments for any residual oil-related contamination in Red Butte Creek. Water and sediment data will be collected in June 2011 to support these assessments. The data collected to date were reviewed and used to determine when access restrictions could be removed.
Red Butte Creek is designated as a Warm Water Fishery (3B) and for Waterfowl/Shorebirds (3D). The Jordan River is classified for Secondary Recreation (2B), as a Warm Water Fishery (3B), and for Agriculture (4). Utah’s Water Quality Act and the Federal Clean Water Act require that the Division of Water Quality protect and maintain the health of warm water fish and for waterfowl and shorebirds and all of the necessary organisms in their food chain.
Crude oil is a dark yellow-to-black oily liquid that is usually found in natural underground reservoirs. It was formed when the remains of animals and plants from millions of years ago were covered by layers of sand. Heat and pressure from these layers turned the remains into crude oil. Crude oil is extracted and used to make fuel and other petroleum products.
Crude oil is a mixture of a wide variety of constituents. It consists primarily of hydrocarbons, which are chemicals composed of hydrogen and carbon. Crude oil also contains hundreds of substances that include benzene, chromium, iron, mercury, nickel, nitrogen, oxygen, sulfur, toluene, and xylenes.
The exact composition of the oil spilled into Red Butte Creek in June, 2010 is unknown. However, based on the available data for oil from the Rangley, Colorado and Myton, Utah well field, the oil was most similar to a Class C. Class C: Heavy, Sticky Oils: These oils are brown or black and sticky or tarry, and include most crude oils. Their toxicity is low, but if spilled, their impacts on waterfowl and wildlife can be severe.
Analytical tests for crude oil are general or chemical-specific. The general tests quantify the several hundred chemical compounds that originally come from crude oil and report a single number that is useful to determine if oil contamination is present. These methods include total petroleum hydrocarbons (TPH), total recoverable petroleum hydrocarbons (TRPH), diesel range organics (DRO), and oil range organics. These tests are not chemical-specific and are primarily used to define the presence or absence of crude oil. The tests have limited usefulness for evaluating long term health effects of oil exposures.
Other analytical tests target specific chemicals found in crude oil. These tests are the most useful for identifying the potential toxic effects from crude oil. Crude oil is refined to produce gasoline, diesel fuel, jet fuel, residential fuel oil, kerosene, liquefied petroleum gases such as propane and other sources of energy to produce heat or electric power. It is also used to make lubricants, waxes, ink, crayons, eyeglasses, tires, CDs and DVDs, ammonia, dishwashing liquid, and some health and personal care products. The United States is the third top crude oil-producing country, after Russia and Saudi Arabia.