To improve water quality, focus on the source!

Posted in: Water


grate in pavement with leaves and sidewalk curbOn my way to work recently, I saw a transit worker blowing debris and trash out of a sheltered bus stop into the street. I thought their next step would be to collect that waste from the street, but no such luck—instead, it was left to be picked up with the next rain event and runoff into the stormwater drainage system. As this was an older part of the city with little to no runoff treatment, I knew it would eventually end up unfiltered in an already-impaired waterway. This incident got me thinking about the importance of source control.

As stormwater engineers, we analyze and design various treatment Best Management Practices (BMPs) to filter stormwater runoff before it’s discharged from the project site. We typically select BMPs based on the most cost-effective measure to achieve the most water quality benefit. And the most cost-effective measures are source control: keeping pollutants out of stormwater to begin with.

Source control measures are typically divided into two categories: operational and structural. Operational source control measures include:

  • Controlling the type, storage and use of substances like deicers, cleaners, and fertilizers to reduce nutrients and chemicals
  • Keeping vehicles and equipment in good working condition to reduce oil, grease, and heavy metals
  • Maintaining vegetated areas to reduce sediment
  • Using proper sanitation facilities and picking up pet waste to reduce bacteria
  • Providing waste receptacles for trash
  • Disconnecting impervious surfaces and routing to vegetated areas to reduce thermal impacts and direct runoff of pollutants to the stormwater drainage system

These operational source control measures do rely on implementation and maintenance by other people, so as I observed with the bus stop cleaning, they are not as fool-proof as structural treatment BMPs. Yet their value and importance should not be dismissed.

Water Environment Federation made a recent announcement that stormwater infrastructure will soon receive a national report card. This holds promise of an increased awareness of the needed maintenance and upgrades to our stormwater infrastructure. Infrastructure age and lack of construction and maintenance funds are the two greatest concerns for municipalities. As source control is the most cost-effective measure for stormwater management, focusing efforts there takes the most advantage of limited funds.

Source control is the critical front line to water quality; if we can increase public training and awareness, I am hopeful I will never have to see such blatant disregard for our waterways on my morning commute again.


Kari Nichols, PE

About the Author

If a raindrop falls on the project, Kari Nichols, P.E., gets involved to find a stormwater management solution. “I believe in dedication and follow-through,” she says. “Deciphering regulatory language and developing workable design solutions helps me connect with clients and colleagues.” Kari has a taste for adventure and a passion for sustainability, which she satisfies by exploring natural and urban environments.

Read more posts by Kari Nichols, PE

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