Used Oil is a useful and valuable petroleum resource in Colorado, however, if not handled properly it will pollute the state's water, land, air, and environment.  Water and soil contamination occur when any used oil is spilled, dumped or leaked on the ground. Used oil can seep through soil to pollute groundwater, and some used oil will "run off" into surface lakes and streams. Water pollution can damage fisheries, make swimming unsafe and affect culinary water. One misplaced gallon of used oil can affect the taste and quality of up to one million gallons of water. Used oil from cars, trucks, motorcycles, lawnmowers, tractors and other engines contains traces of heavy metals, arsenic and other chemicals. The chemicals can harm plants, humans or other animals when the chemicals are absorbed by plants and passed up the food chain. Because of these problems, it is illegal to dispose of used oil by dumping it on the ground or in water, and it is also illegal to place it in your trash.

Legislation was passed in 1994 to help solve the problem of improper disposal of used oil. The purpose of this legislation was to make oil collection centers more convenient, and promote oil recycling to the public.  Home mechanics now have the convenience of  Do - It - Yourselfer (DIY) Oil Collection Centers, making proper disposal even easier. Thanks to the State of Colorado's Department of Environmental Quality, Colorado now has over 270 used oil collection centers. These businesses provide a valuable community service by helping protect the local environment

Here are some tips for recycling your used oil:

Drain used oil from the engine. Then pour it into a seal able container so you can take it to a collection center. Plastic oil drain pans work well (available at most auto parts stores). Empty plastic milk bottles work well, too. They have screw-on lids, can be rinsed before use and don't cost anything. Farmers often use 55-gallon drums because they generate more oil than most households. Make certain the drum wasn't used for hazardous chemicals because these chemicals can contaminate the used oil.
· Do not mix antifreeze, gasoline or any other products or chemicals with used oil.
· Puncture the dome end of your oil filter with a screwdriver, and then drain the filter with the dome end down. Filters retain oil unless punctured because they have an anti-siphon valve.
· Take used oil to a collection center after each oil change. Storing oil can lead to leaks and spills.
· Please, only bring your oil to a used oil collection center during their normal business hours.
· Have an employee dump the used oil into the collection center's tank.
· Sign the used oil collection log sheet and indicate how much oil you deposited.
· Take your empty containers with you, so you can reuse them next time.

Recycling used oil is the smart and legal disposal method because recycling prevents soil and water pollution. This is especially important in Colorado with the dry climate and low water reserves.