The first step is keeping liquids and solids separated at the very beginning. Keep materials such as rags out of oil containers. Don't pour oil into solid waste containers. The cost of disposal for liquid oily waste will increase dramatically if rags or other solids are in it. Since most liquid oily waste will be pumped through an oil recycling system, any rags will have to be removed before waste oil can be recycled, and this unnecessary separation Process will add to your cost.
Hazardous waste made up of liquids containing oil and water are very common.
The oil may still be recoverable but very contaminated. Oil may not wear out but it does pick up metals and dirt when used as a lubricant. Depending on the current market, this oil may be sold or its disposal cost may be reduced because it has a resale value. Contaminating this oil with other waste such as paint, acids or caustics will increase the disposal cost and may render it unacceptable for recycling. The same is true about solid, oily hazardous waste.