Oil and Grease
What is oil and grease?
Oil and grease refers to a combination of substances that do not readily mix with water and are commonly used in industry and daily activities. Examples include motor oils, lubricating oils, fuels, animal fats like bacon grease, and cooking oils. Components of oil and grease include total petroleum hydrocarbons (TPH), which may be more toxic than other components of oil and grease not derived from petroleum like vegetable oil.
How does oil and grease enter our environment?
Leaking machinery and vehicles, illegal dumping, spills, and disposal of cooking oils are some of the most common ways these substances enter the environment. Roadway runoff during heavy rains washes motor oil that has dripped from vehicles into rivers and lakes. The oil and grease components from cooking oils and animal fats that are poured down kitchen drains or washed off dishes are generally removed during sewage treatment. However, oil and grease may still be discharged from older sewer systems that use combined sewer overflows.
How are people exposed to oil and grease?
Public treatment systems remove oil and grease from our drinking water, although some oil and grease may be present in water from private wells. People can be exposed by swimming or wading in rivers and lakes that receive stormwater coming from outfalls, highways, or runoff.
Can oil and grease harm my health?
Oil and grease are primarily considered a threat to aquatic animals because it can deplete oxygen levels in water. In large quantities, oil and grease can even be deadly. Some petroleum hydrocarbons found in oil and grease can affect human kidneys, livers, and blood and increase the risk of cancer.