The Puget Sound
Harmful Substances
How Does Washing Cars Cause Pollution?
The Effects of Pollution on Salmon and Other Wildlife
How Do I Prevent Pollution?

In Washington State, there is no law banning people from washing their cars in their driveways, but there are laws that specify what can and cannot be released into storm drains. Regulations on residential car washing are clearly for the benefit of the citizens of Washington State, the condition of the Puget Sound, and the marine life living there.

The Puget Sound

It is estimated that more than $5.5 billion is gained during the fishing season every year in the Northwest, and with that comes thousands of jobs for Washington State residents. Stormwater pollution is a leading contributor in the death of the very salmon that provide this great economic foundation.

The Puget Sound is also a major source of amusement and provides citizens with a plethora of recreational choices such as boating, fishing, and playing on the beaches.

It is also an excellent resource for scientists, especially marine biologists, to do research. This work would be thwarted if the water were polluted.

How Does Washing Cars Cause Pollution?

The amount of pollution caused by one car being washed in a driveway may be minor, but when thousands upon thousands are doing the same thing, it becomes a huge problem. The journey of pollution from your car to the Puget Sound is actually a simple process:

1. You wash your car on your driveway.
2. Little bits of oils, metals, soap, and other harmful substances travel down the street and into the storm drain.
3. The contaminated liquid goes without treatment or filtering and directly into the streams and rivers which lead it to the Puget Sound.

Normally, when these substances seep down into soil, microorganisms break them down and no damage is done. However, on paved surfaces, the water cannot seep through the concrete and into the earth, and the buildup of those chemicals goes into the storm drains.

Harmful Substances

Cars are the biggest contributor of stormwater pollution. Research has shown that 33.8% of stormwater pollution is from automotive fluid. That is more pollution in our storm drains and streams than that of washwater, food waste, yard waste, sewage, and solvents combined. Cars contain several substances that are harmful to the environment such as:

• Oil
• Brake dust
• Tire fragments
• Antifreeze
• Other liquids

These contaminants all appear on the roads, highways, and driveways, and when it rains or snows, they have no place to go but into the storm drains. In fact, in King County Washington, where it rains about 40 inches a year, water washing over one square mile will carry 20,000 gallons of oil into the Puget Sound each year. As you can imagine, this number is dramatically increased by thousands of citizens washing their cars and forcing additional contaminants into the stormwater systems.

The Effects of Pollution on Salmon and Other Wildlife

Every time you hit the brakes in your car, a metal dust is produced which contains tiny flakes of copper. When water comes in contact with this dust, it washes from roads and driveways into the storm drains and eventually into the Puget Sound. Although it is not usually harmful to humans, copper, even in very small amounts, can be lethal for marine plant and animal life. For example, in salmon copper:

• Inhibits the sense of smell they use to avoid predators
• Hinders growth and development
• Causes migration patterns to be thwarted
• Harms them with disorientation and confusion

So if the copper toxicity does not kill them, the salmon do not have the senses they need to avoid other predators, and they are more likely to be killed by them.

Like copper, zinc is not usually harmful to humans but even in extremely small amounts such as the amount produced by cars, it can be deadly to the salmon in the Puget Sound. It causes problems with the blood of salmon, as well as their rates of reproduction and growth, resulting in the death of many salmon.

A study showed that in the past three years while female Coho salmon were returning to the Seattle area, almost 90% of them died before spawning, most likely due to pollution problems.

How Do I Prevent Pollution?

There are several ways to prevent stormwater pollution and still keep your car clean. The right education and implementing advice from the Department of Ecology will improve the condition of the Puget Sound. For example:

• Wash your car on your lawn or gravel instead of your paved driveway
• Use a shut-off valve on your hose when washing your car
• Place something on the ground to divert the water away from the storm drain
• Use a professional car wash facility