Heavy Metals in Motor Oil Have Heavy Consequences

Tanker source flow from tree line. Photograph from Flickr Creative Commons

By: Annie Reisewitz and Sarah Martin

We’ve all heard the old adage, “Oil and water don’t mix.” Yet we are constantly mixing the two, it seems, hoping that one day they will indeed mix. Add in drought and pollution and the potential environmental problems grow even larger.

Every year 10 billion gallons of liquid petroleum, in the form of motor oil and other industrial lubricants, are released into the environment due to human activity. But how does that oil affect the quality of our water supply, especially in severe drought regions like California?

Tanker source flow from tree line. Photograph from Flickr Creative Commons

As motor oil circulates through a car’s engine it picks up heavy metals such as arsenic, lead, cadmium, copper and zinc, as well as other toxins. The U.S. EPA considers all of these to be priority pollutants, toxins that, according to the Clean Water Act, are a high priority for development of water quality control measures and discharge limitations because they are frequently found in wastewater.

As the drought shrinks useable freshwater supplies, heavy metal contaminates in motor oil concentrate, further jeopardizing our drinking water supply. Another concern is that, as these toxic pollutants enter our waterways, they are consumed by smaller fish, eventually cascading up the food chain in larger concentrations before entering our bodies from the fish we eat.

The extent by which these toxins are entering stormwater runoff and polluting lakes, rivers and oceans downstream are largely unknown. However, we do know that one gallon of motor oil can pollute one million gallons of water. The average car loses two gallons of oil a year from normal use, and one gallon is lost through improper disposal. This means we are potentially polluting three million gallons of water per year, per car, and there are 253 million —> Read More