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Every time there is a storm, stormwater makes its way across the land, and as it travels, it picks up all sorts of chemicals and pollution – some of which can be harmful. In the absence of any stormwater treatment, this pollution ends up in our waterways, and our oceans.

Stormwater treatment is the process of removing those pollutants from stormwater before they discharge to our waterways and ocean. Here’s what you need to know.

What is stormwater?

A simple definition of stormwater is that it is rainwater – filled with whatever that water comes into contact with. If you’ve ever seen a flood, you’ll likely remember how dirty that water was – that’s stormwater and it’s filled with contaminants. This could include anything from oil the water has picked up on driveways before it’s made its way into the drains in your street, to exposed soil, chemicals, and more.

All of this water has to go somewhere … and it usually ends up in creeks and rivers, which lead to the ocean.

Why we need stormwater treatment?

As a business or property owner, if you don’t treat stormwater, you’re putting your health, your property, and your employees’ health, at risk. In addition, if local councils don’t treat stormwater, they’re putting communities, as well as ocean and river life, and natural habitats at risk.

The pollutants caused by stormwater are harmful and reducing those can enhance the health of not only people, but the planet in general.

Stormwater Treatment Methods

Stormwater must be effectively treated to adhere to government guidelines for Urban stormwater management and there are a few ways this can be done.

  • Retention is where stormwater runoff is stored to allow the contents to settle and lower the risk of flooding.
  • Separation is the use of hydrodynamic separators to separate materials from surface water runoff. This process uses a vortex to separate grit, sand, and silt from the stormwater, while catching nutrients, pollutants, or heavy metals attached to the solids.
  • Screening is where stormwater screens are used as physical barriers to prevent garbage, gross solids, and other large particles from entering a drainage network.
  • Infiltration systems replicate the soil’s natural impact, providing a surface for runoff to soak through, such as engineered soils to trap certain contaminants.
  • Filtration is the use of a filter to remove contaminants from surface water. The water goes through the filter, which catches any contaminants. These can be modified to target specific pollutants as well, including zinc, lead and copper.
Ocean Protect’s Stormwater Management StormFilter® is an example of filtration. It has been designed to clean stormwater through passive filtration. It removes pollutants, using rechargeable, self-cleaning, media-filled cartridges that absorb pollutants from stormwater runoff. This includes hydrocarbons, suspended solids, nutrients, soluble heavy metals, and more.