How stormwater can be the enemy of industrial permits

23rd October 2020

Stormwater management is often a low priority for industrial businesses—but it can seriously affect their ability to remain compliant with permits and regulations. Here’s what they can do about it.

Here’s a statement that should surprise nobody: industrial businesses use water in a lot of different ways.

We’re all aware of water being used to wash grit and solids off things like grapes and olives, to clean hides in tanneries, to transport carrots, to blast paper labels from recycled drinks bottles. You may even have seen the vast amounts of water that are apparently required to produce a single kilo of beef or a single almond.

You’re probably also aware that almost all that water needs to be treated before it can either be recycled and reused, or discharged into a sewer or waterway (and that better water treatment can be a way to save money).

Here’s a statement that might surprise some of you, however: industrial businesses also have to deal with stormwater.

And that can be a costly problem when it comes to compliance.

Surface water can harm your ability to meet regulations

While companies spend time and money on recycling their process water and improving their water treatment to reduce the cost of effluent surcharges, most do little or nothing to improve runoff reduction or stormwater treatment on site.

Yet surface water carries pollutants, and surface water that finds its way into the drainage system can harm your ability to meet regulations and operate within the parameters of a discharge permit.

Industrial facilities are rich in potential sources of pollution: storage areas for various materials, particularly liquids, are a risk for spills and leaks, while vehicles are a source of fuel and oil, as well as dust and particulates deposited by wheels.

All of these can put a site in breach of its discharge regulations.


Surface water carries pollutants, and can harm your ability to meet regulations and operate within the parameters of a discharge permit.

Sources of surface water

The most obvious way that surface water will present itself will be simply as rainfall. Or, more accurately, as precipitation—because when it melts, snow, hail and ice will also carry pollutant materials to the nearest drainage outlet.

Small amounts of rain and snow will not present a significant problem, but heavier or prolonged rainfall and storm events increase the volume of water and also, if strong winds are also a factor, the risk of spills and leaks. In the worst case you might even have to deal with flooding.

Another source of surface water is from cleaning, particularly vehicles. The simple act of hosing down a truck will dislodge whatever particulates, oils and liquids are on the vehicle and carry them into the sewer…carrying whatever else it picks up from the ground along the way.

The impacts of surface water pollution

Industrial companies have to operate within set parameters in terms of the effluent that they discharge, with permits that specify surcharges that must be paid based on the water quality that they put into the external water network.

If a facility discharges in excess of its permitted levels and a significant breach of compliance occurs, that business might have to pay fines, legal fees and cleanup costs. And that’s not to mention the often deep and lasting cost of bad publicity.

Process water and wastewater are relatively predictable, and relatively straightforward to manage and control. And while stormwater is unpredictable in the sense that we can’t foresee the weather, it is reliably predictable in terms of how it behaves on a site.

Under this misapprehension many businesses treat stormwater as though it’s inevitable and unmanageable, and simply cross their fingers and hope that they won’t be hit by a compliance breach. But this doesn’t have to be the case.

What you can do

1. Review your site

Look for potential sources of pollution (storage areas, cleaning areas) as well as potential sources of significant water flow (rooftops, slopes). Look at the ground—are there patches of oil? Is there standing water? Is sediment building up around any drains? Water behaves predictably on surfaces: examine your yards, walkways and drainage sites and identify the likely routes that rainwater, cleaning water and firefighting water will take. During the next significant rainfall, observe how and where your surface water moves.

2. Review your processes

Look at where you’re conducting activities that generate a lot of surface water. Where does the water go? Look at where you’re storing items that generate ground-based pollutant materials. Can you move these to places where the pollutants are less susceptible to surface water? Your objective should be that either the surface water has no pollutants to pick up, or that the pollutants in the surface water go where you want them to.

3. Build in safety measures

Eliminating surface water pollution is almost impossible—there will always be a risk of stormwater runoff carrying something down into the drain—so put down a safety measure: put in place passive, “always on” systems that can catch damaging materials before they get to the water network.

For example, screens, separators and filters will capture trash and gross solids, TSS (total suspended solids) and BOD (biochemical oxygen demand), as well as oils and hydrocarbons, while bioinfiltration systems can help return rainwater to the soil, filtering out pollutants (and even brightening up the place) at the same time.


Put in place passive, “always on” systems that can catch damaging materials before they get to the water network.

In summary

View water on your site as being part of a single holistic system. Industrial permits and effluent surcharges don’t make a distinction—it’s all effluent, whether it comes from your processes, your wastewater treatment system or from the roof of your building. The same is true of costly spills and compliance breaches.

The businesses that do well at lowering their surcharge costs and preventing damaging breaches are the ones that that take a big-picture view and use that to make sure that they have all their bases covered.