By Cate White, MPA Earth Systems Science, Policy & Management & Coordinating Council Member, Sustainable West Seattle
Puget Sound is sick. Polluted runoff from sealed surfaces like paved streets, sidewalks and rooftops is the number one source of toxics entering Puget Sound each year. This toxic mix threatens human health, the economic vitality of the region, and the survivability of the Sound’s most emblematic species: salmon and orcas.
The good news is that local community members can adopt behaviors that will reverse the damage to Puget Sound and restore it to health. Our citizens are the stewards of the same streets, sidewalks and rooftops that convey 14 million pounds of pollutants into Puget Sound each year. Pollutants include motor oil, pesticides, fertilizers, grease, paint, heavy metals, and bacteria.
There are simple actions people can take to become stewards of Puget Sound. Among the most important are:
- Keeping water on-site with rain barrels, rain gardens, and porous surfaces,
- Practicing natural yard care,
- Picking up pet waste,
- Walking, biking, or riding public transit instead of driving,
- Planting and protecting native evergreens, and
- Using car wash facilities instead of washing cars on driveways.
1. Keep water on-site with rain barrels, rain gardens, and permeable surfaces
A big part of the problem with polluted runoff is that it runs quickly over hard surfaces and collects toxics that flow directly into our streams, rivers and Puget Sound. Rainwater retained onsite that percolates through soil can cleanse many of the toxins.
Keeping water on-site may sound counter-intuitive. One might think “if the polluted rainwater runoff is bad for Puget Sound, then it must be bad for my yard.” But that isn’t exactly true. A healthy soil profile with lots of microbes and fungi can help degrade many of the pollutants like hydrocarbons that wash off our streets and driveways. Some mushrooms can absorb heavy metals too, although they do require proper hazardous waste disposal. So filtering rainwater through healthy soils is a first step toward cleaning the water that goes into Puget Sound.
There are many ways to retain water on one’s property. You can use rain barrels to collect water that is later used to water gardens. Or, you can build a special kind of garden called a rain garden to absorb rainwater. Or, you can replace cement surface with permeable surfaces that absorb water. Learn more about each of these alternatives at https://rainwise.seattle.gov/
2. Practicing natural yard care
Directing rainwater into porous surfaces for absorption is half the solution. The other half is making sure that those surfaces have the ability to break down pollutants. Soils rich in organic matter that have lots of microbes are critical to solving polluted runoff because those microbes can start metabolizing and degrading many pollutants. Soils that have chemicals added like synthetic fertilizers, pesticides (herbicides, fungicides or insecticides) and other unnatural chemicals don’t develop the microbial populations that are necessary to break down pollutants. So any garden made to absorb rainwater should be organic.
The best things to add to your soil are organic compost and woodchips. You can work compost into your annual/vegetable beds, but topdressing soil with two inches of compost works fine. Raking a one- to two-inch compost/sand mix into your lawn can help absorb more rainwater as well. Woodchips in perennial beds and natural areas help create an environment similar to a forest floor in the Pacific Northwest, encouraging beneficial fungi. Soils in need of nitrogen can benefit from a “mulch sandwich: two inches of compost with three to six inches of woodchips on top. Avoid bark. It repels water and resists breakdown, suppressing the fungal populations that plants need. Woodchips can be obtained from tree trimming crews working in your area.
- To learn more about natural yard care, visit http://your.kingcounty.gov/solidwaste/naturalyardcare/index.asp
- The Dirt Exchange in Ballard is a good source of compost, wood chips, and bio retention soil mix
- Mariposa Naturescapes is a West-Seattle business that focuses on natural yard care: http://www.mariposanaturescapes.com/
3. Picking up pet waste
Creating a poop-free Puget Sound is more important than you might think. According to King County, there are more than 200 tons of pet waste deposited in the Puget Sound region every day, and water runoff flushes it into streams, rivers and Puget Sound. Dog poop contains things like E. coli, Giardia and Roundworms – nasty stuff that we don’t want in Puget Sound. The very best thing you can do when walking your dog outside is to bring plastic bags, pick up the poop, and dispose of it in a trash can. Do not contaminate your compost with pet waste. This is one of those rare cases where throwing something away is the best option. Or, if you have trouble managing your dog’s mess in a dog-run, you can line it with arborist woodchips 1-foot deep to allow beneficial fungi to filter pollutants.
4. Walking, biking, or riding public transit instead of driving
Each year, one-half of an Exxon Valdez oil spill worth of oil flows into Puget Sound. It’s rather hard to fathom. Leaks from cars and hydrocarbons from exhaust are responsible for a significant amount of pollution. Also, the copper in brake pads can have toxic impacts. Copper is also being linked to the disruption of salmon olfactory (smell) senses and may be disorienting them, impeding their ability to spawn. Furthermore, car tires contain zinc, another toxic heavy metal. We can all drive less to reduce pollution. When you have the option, choose to walk, bike, or ride the bus instead of driving a car.
5. Planting and protecting native evergreens
Our native forests are integral to our success in reducing polluted runoff. Native evergreen trees are stormwater-holding tanks. For example, a mature evergreen can absorb as much as 250 gallons of rainwater a day – more than a 12-foot square rain garden built to SPU specifications to mitigate a 400 square foot roof. However, we are losing our native forests not only to development, but also to invasive species like English Ivy, Holly, Laurel, Knotweed and Himalayan Blackberry.
You have a lot of options to help plant and protect our native evergreens. If you have a large yard, you may consider planting evergreen trees. If you have an evergreen that has been taken over by English Ivy or Wild Clematis, you can periodically cut the vines at the ground and at chest level to keep if from fruiting and re-infecting forest restoration work elsewhere. If you prefer getting some social time in while saving the Sound, consider joining restoration efforts.
- Groups that run forest restoration projects include: The Nature Consortium, the Duwamish River Cleanup Coalition, EarthCorps, or Green Seattle Partnership.
- Good trees and shrubs to plant include Madrona, Doug Fir, Western Hemlock, Western Red Cedar, Evergreen Huckleberry, Shore Pine, Pacific Rhododendron, Salal and Sword Fern. Non-native plants (Rosemary, Thyme, fruit trees) for food or ornament are fine, as long as they’re not invasive.
- Garden Cycles is a West-Seattle based business that removes invasive species: http://gardencycles.com/
- The West Seattle Nursery has a good selection of native plants: http://www.westseattlenursery.com/
6. Using car wash facilities instead of washing cars on driveways
Finally, there is the car wash. Soaps can include phosphates, which can lead to low oxygen levels in our waterways, thereby killing fish through oxygen depletion. Soaps can also include phthalates that have been linked to reproductive problems and obesity. So, it’s best not to wash your car on your driveway and let soap wash down the storm drains. Going to a carwash is a much better alternative because the soapy water doesn’t go untreated into storm drains. If you are considering a high school fundraiser, ask your local carwash if they will give you discounted gift certificates for resale instead of washing cars in a school parking lot.
Why we should become stewards of Puget Sound
There is a lot at stake. Citizens are losing their rights to fish and swim in the Sound’s waters or to make their livelihoods from local fisheries and ecotourism. Warnings are posted around the Sound alerting people to the dangers of eating fish and shellfish. Over the past decade the gross revenue earned by Washington’s shellfish industry fell by two-thirds to $55 million in 2008 due in large part to pollution-related harvest closures.
We are also losing the salmon and orcas that underpin the identity of Pacific Northwest residents and help to drive tourism to our region. Puget Sound’s Coho Salmon are classified as a “Species of Concern.” Our orcas are the most PCB-contaminated marine mammals in the world and our Southern Resident Killer Whales are a federally listed “Endangered Species.”
We can reverse these trends. Exciting efforts are being implemented throughout the region to staunch the flow of polluted runoff using rain gardens. Seattle’s Street Edge Alternative Project (SEA Streets) used rain gardens and evergreen trees and shrubs to effectively reduce stormwater pollution by 99 percent. This creative use of “green stormwater infrastructure” actually beautified the community, increased its carbon sequestration capacity with lots of vegetation, and is promoting natural drainage. King County Wastewater Treatment Division now plans to implement similar “green stormwater infrastructure” in the Sunrise Heights and Westwood neighborhoods of West Seattle to reduce combined sewer overflows (CSO) at the Barton Pump Station.
Together, the citizens of Puget Sound can take small steps, like picking up dog poop, volunteering in a forest restoration effort, and going to the carwash – and large steps like building rain gardens – to restore Puget Sound to health. Through collective effort, we can hope to see robust salmon and orca populations once again.