Testing mandated: Added water quality constituents of concern

Posted in: Environmental, Water


tear gas can harm water quality

In August, we celebrate Water Quality Month to bring awareness to the importance of water. This year, Water Quality Month comes at a time when many have been calling for awareness and change on other issues throughout the country. Demonstrations against racial injustice continue throughout the city of Portland—mainly concentrated in our city center, where the Willamette River quietly flows nearby. During the demonstrations, there was repeated use of tear gas to disperse crowds. These gases contain heavy metals and chemicals which linger in the environment, collecting on pavements, buildings and vegetation. Just like other pollutants commonly found in an urban environment, these pollutants can make their way into storm drains and our receiving waters, creating water quality concerns.

The City routinely monitors their stormwater outfalls for various water quality parameters as part of their National Pollutant Discharge Elimination System (NPDES) Municipal Separate Storm Sewer System (MS4) Discharge Permit (Permit) requirements. However, on July 30, 2020, the City received a new requirement from the state to conduct additional monitoring of the outfalls to the Willamette River in and around the area of heavy tear gas usage in the central city. Specifically, the City must monitor seven different heavy metals and chemicals known to be associated with CS gas, a form of tear gas used here in Portland. Of the specified parameters to be monitored, the City typically tests many of these as part of their Permit.

After receipt of the notice and in advance of a pending rainfall, the City cleaned six storm drains within the area of concern. Samples of the material were taken before being disposed of in a landfill. The City also established a monitoring plan to sample at the outfalls to the Willamette River which is about three city blocks to the east after the next significant rainfall.

The use of tear gas is not unique to Portland, nor are environmental concerns from widespread usage. In 2019, a significant amount of tear gas was deployed in Hong Kong during months of protesting. Air and water quality concerns were raised at that time as well.

While many impacts of tear gas exposure have been well-documented, water quality impacts from these heavy metals and chemicals on the environment are still largely unknown. Because most of us live our lives within a built environment, we may lose sight of how our actions directly affect our natural environment. Buildings and roads separate us from our waterways, and we can’t always see a clear connection between cause and effect. As a culture, we are sharing our thoughts and letting our voices be heard about issues that matter to us. Let’s also champion the importance and value clean water holds for our health.


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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