Rainwater is a key element in the Earth’s water cycle which is essential to life on Earth. But what happens when rain comes in contact with metal or shingled roofs before running off into the ground? Roof runoff can pick up contaminants from these roofs, including heavy metals used to discourage moss growth and then carry those contaminants to nearby waterways. In 2008, two talented port employees invented what is essentially a rain garden in a box to address the issues of roof runoff—and the results have been incredible. The Grattix (named for inventors Matt Graves and Mary Mattix) uses layered filtration materials and native plantings to remove unwanted contaminants in water runoff from roofs and downspouts. Although low-tech, low-cost, and low-maintenance, the Grattix system is extremely effective in lowering concentrations of heavy metals zinc (90-95%) and copper (85%) at project sites.

It has become the port’s mission to educate others about the benefits and provide resources and support so other organizations could build their own Grattix boxes. The port produced publicly available, step-by-step construction guide and partnered with both Washington State University and Washington Stormwater Center to create a how-to video for Grattix construction.

In the years following the invention of the Grattix, the project has inspired others across the country and even into Canada to build their own boxes.

The port’s Community Fund supported a Grattix project by Vancouver Public Schools’ iTech Preparatory students who built a Grattix box for use under a downspout on their building. The iTech Preparatory school is located on the Washington State University Vancouver campus. The teens also tested the runoff water to see what was captured in the runoff.

The port assisted the Lower Columbia Estuary Partnership (LCEP) as they applied for and received an Environmental Protection Agency (EPA) grant for more than $67,000 to build and deliver Grattix boxes to industrial areas with large concentrations of metal roofs along the Lower Columbia River. Oregon State University has donated 10 Grattix boxes built by grad students to LCEP for their efforts. These Grattix boxes will be built and delivered in 2023.

The port continues to be a source of information and support in stormwater treatment, making instructional materials readily available and partnering with various organizations in the pursuit of clean water. For more information about the port’s efforts, please visit our water quality page.