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Wastewater Treatment Trails: These Hikes Don't Stink

Want to visit one of the most underrated destinations for year-round hiking? Check out your local wastewater-treatment plant. No, really.

If you haven’t hiked near a wastewater-treatment plant, you’re missing out. Here’s why you should go:

    • They are often located near estuaries, which are beautiful and full of life.
    • They are an excellent spot to watch birds, particularly migrating ducks.
    • They are usually in low-elevation areas that are hikeable year-round.
    • They often include interpretive signs that can give you a better understand of how wastewater is treated.
    • They remind you of your impact as a human. And it never hurts to be reminded of the bigger picture of the world around you.

If we’ve convinced you, and we hope we have, here are eight hikes where you can explore the natural world — and learn about people’s place in it at the same time.


Location: Puget Sounds and Islands — Seattle/Tacoma area
Mileage: 3.2 miles, roundtrip
Elevation Gain: Minimal

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The Ebey Waterfront Trail is paved, making it easy for hikers of all levels to enjoy. It's also a good spot to look for eagles. Photo by Muledeer. 

This paved trail, which is open to walkers and bikers, is an easy stroll along the Snohomish River in Marysville. The area has an interesting history. The Qwuloolt Estuary was restored in 2015 after levees were breached, allowing a return to more natural habitat.

It passes directly past Marysville’s water treatment plant, where you’re likely to see a variety of ducks in the holding ponds. The trail then passes the estuary, where you’re likely to see waterbirds and raptors. It’s fun to visit more than once to see how the river looks different at high and low tide. 

> Plan your trip to the Ebey Waterfront Trail using WTA's Hiking Guide

Spencer Island

Location: Puget Sounds and Islands — Seattle/Tacoma area
Mileage: Up to 6.6 miles, roundtrip
Elevation Gain: None

Spencer Island. By LZhang.
Spencer Island is an excellent spot to look for birds, including raptors. Photo by LZhang. 

This hike begins in the midst of Everett’s water treatment facilities. But don’t let this deter you. In fact, if you like birds, it’s a benefit. The large holding ponds are always full of ducks. Be sure to bring your binoculars.

The trail mostly follows along old levees, some of which have been breached, allowing for a more natural saltwater/freshwater estuary. You’ll often spot hawks, herons, shorebirds, ducks and songbirds. Visit at different times of year to see different species. On calm days, the view is also spectacular, with the mountains and sky reflected on wide swaths of flat water.

> Plan your trip to Spencer Island using WTA's Hiking Guide

Brightwater Center

Location: Puget Sounds and Islands — Seattle/Tacoma area
Mileage: 3 miles of trails
Elevation Gain: 120 feet

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Brightwater Center has a number of small ponds and wetlands for hikers to explore. Photo by Heather DeGraw.

The Brighwater Treatment Plant, which treats waste and storm waters for King County, opened in 2011. It’s a very modern treatment plant, and there’s not a whiff of odor from the operations, which are all indoors.

The campus is between Woodinville and Maltby and includes wetlands, woodlands and open meadow areas. There are interpretive signs along the trails. Be sure to check out the visitor’s center and admire the beautiful and fascinating public art, both at the center and around the campus. There are also a number of public environmental education events at the center. 

> Plan your trip to Brightwater Center using WTA's Hiking Guide

Waterworks Garden

Location: Puget Sounds and Islands — Seattle/Tacoma area
Mileage: 0.7 mile, roundtrip
Elevation Gain: minimal

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Hikers will wander by several small ponds on a trip through Waterworks Garden. Photo by austineats. 

This short trail in Renton provides a pretty stroll through an interesting park that is adjacent to one of King County’s water treatment plants.

The parkland features ponds and marshes that help treat the stormwater that runs off from the treatment plant’s roads and other hard surfaces. A series of garden “rooms” make up the park, including leaf-shaped ponds, a mosaic grotto and wetlands.

> Plan your trip to Waterworks Garden using WTA's Hiking Guide

Hawks Prairie Reclaimed Water Ponds

Location: Puget Sounds and Islands — Seattle/Tacoma area
Mileage: About a mile of trails
Elevation Gain: Minimal

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Hawks Prairie Reclaimed Water Ponds are an interesting leg-stretcher near Olympia. Photo by Bob and Barb. 

This casual stroll is an interesting up-close look at the ways reclaimed water can be, and is managed at this site near Olympia. It’s a great walk for young children. A number of holding ponds cover the site, which is near Olympia, and trails wrap around some of ponds.

Informational kiosks provide more information about water management and feature rain gardens. Look for ducks and other wildlife and admire the native vegetation.

> Plan your trip to Hawks Prairie Reclaimed Water Ponds using WTA's Hiking Guide

Chehalis River Discovery Trail

Location: Southwest Washington — Lewis River region
Mileage: 3.6 miles, roundtrip
Elevation Gain: 210 feet

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The Chehalis River Discovery Trail has views of farmland and river beaches. Photo by Will-Jolene.

Walk along the Chehalis River, past farmland and recently restored riparian areas near Centralia. The trail ends at the river. You’re likely to spot birds, including swallows and eagles.

The trail is on property purchased for Centralia’s wastewater treatment plant. Large agricultural fields along the way act as a final filter for treated water before it reaches the river.

> Plan your trip to the Chehalis River Discovery Trail using WTA's Hiking Guide

Riverside State Park

Location: Eastern Washington — Spokane Area/Coeur d'Alene
Mileage: 2.1 miles, roundtrip
Elevation Gain: 166 feet

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Riverside State Park offers excellent views of interesting rock formations — made even prettier with a bit of snow. Photo by adowling.

Spokane’s waste-water treatment facility is just upriver of the Bowl & Pitcher area of Riverside State Park. Trail 100, which is just across the river from the facility, offers great views of the river and cool basalt formations. There are many options for loops or outs and backs to make your trip as long or as short as you’d like.

> Plan your trip to Riverside State Park using WTA's Hiking Guide

Discovery Park

Location: Puget Sounds and Islands — Seattle/Tacoma area
Mileage: 5.1 miles, roundtrip
Elevation Gain: 380 feet

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Discovery Park offer water views, as well as access to the beach. Photo by AKorn. 

Discovery Park is Seattle’s largest city park and it’s a great destination for a good hike close to a big city. This loop has meadows, forest, beaches and views. A highlight of the hike is the West Point Lighthouse. And on the same point of land is King County’s West Point water treatment plant.

When up high on the trail, watch for eagles and other wildlife. Down by the beach, keep an eye out for seals and waterbirds. It's possible to loop multiple trails and walk right by the plant, but be warned; this one can be a little smelly when you get close. 

> Plan your trip to Discovery Park using WTA's Hiking Guide