Tuesday, January 21, 2014

When soap and water are not a good thing

By Linda Kent, Southwest Regional Office and Lisa Copeland, Spills Program

Madge may soak in it and rubber ducks may get cleaned up with it, but soap isn’t the answer when there’s an oil spill.
We all use soap countless times a day, and that’s a good thing – keeping those hands clean helps us kill germs and avoid getting sick, after all.

Turns out soap's not so great when it comes to cleaning up oil spills.

Oil Sheen with soap bubbles in Westbay Marina, Olympia

Oil sheen in Westbay Marina, Olympia
In an incident that Ecology responded to at WestBay Marina in Olympia this weekend, someone had spilled diesel fuel as well as soap.

Complicating cleanup

The soap did not clean up the fuel spill. In fact, the soap (and the fact that the spill was not reported promptly) complicated things and made readily-available methods of picking up the oil ineffective. That's because detergent breaks up oil puddles into very small bits by surrounding it with molecules of water soluble compounds. When the water soluble compounds are dissolved in water they take the oil with them. That just spreads the oil around.

And that meant we had to rely on evaporation and natural degradation.

The "readily available methods" that were rendered ineffective include:
  •   Using absorbent materials like pads, sweep and boom that that attract oil and do not absorb water.
  •   Vacuuming up oil with a suction head on a hose connected to a tank truck.
  •   Skimming oil off the surface using mechanical means.
All of these methods — absorbents, vacuums and skimmers — require fairly thick layers or patches of thick oil for them to work.

In this case, the combination of time, which allowed the sheen to spread a greater distance, and soap dispersed the diesel fuel so it was too thin.
 Harming aquatic life
Soaps and detergents actually break up oil and send it lower into the water column, causing damage to more marine organisms.

And when spilled in our waterways, soaps and detergents in and of themselves are actually a pollutant that may be harmful.

They can have poisonous effects in all types of aquatic life:
  • All detergents destroy the external mucus layers that protect the fish from bacteria and parasites,
  • Detergents can cause severe damage to fish gills,
  • Soap and detergents can affect the critters fish eat, such as insects, by disrupting their cell membranes and by removing the protective waxes that cover the insects, causing them to die due to excess water loss.
Soaps and detergents cause other problems:
  • Detergents lower the surface tension of the water, making it hard for aquatic insects like water striders to float on the surface.
  • They can leave fish and other critters starved for air. Detergent binds up oxygen to form bubbles. Yes, the bubbles are bad for fish. Phosphates in detergents also can lead to freshwater algal blooms. These blooms reduce available oxygen that fish need in waterways because, when algae decompose, they use up the oxygen. Lower dissolved oxygen can also change the chemistry of the sediments under water, releasing toxins that harm aquatic life.

Report your spills

If you cause a spill, the best action you can take is to report it immediately by calling 1-800-OILS-911.

Prompt reporting of oil spills is important because the sooner responders are notified, the sooner they can work to minimize potential harm to the environment.

Some people fear that reporting a spill will cause them to receive a fine. However, failure to report a spill (if you are responsible for the spill) actually causes people to have more liability because:
  • It can delay response to the spill and increase the impact the spill has
  • Not notifying responders in a timely fashion increases your chances of receiving a penalty, or fine.

Soap? Nope!

The bottom line: Soap isn’t the solution when it comes to keeping our waterways clean.

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