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Wastewater Treatment

King County, Washington

For questions about the Wastewater Treatment Division website, please send an e-mail message or contact us at:

King Street Center
201 S. Jackson St., Suite 500
Seattle, WA 98104-3855
Phone: 206-477-5371
Fax: 206-684-1741
Telecommunication device for the deaf (TTY): 711

Get Directions to our office location in Seattle, Washington.

Staff Contacts

Directions to King County WTD's administration offices and treatment plants

Administration offices

King Street Center (division headquarters)

King Street Center

201 S. Jackson St.
Seattle WA 98104-3855
206-477-5371; fax 206-684-1741

5th floor -- Wastewater Treatment Division
View map and directions and GoogleMaps.

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King County Industrial Waste Program office -

These offices will relocate to King St. Center (above) in mid-November 2014

Canalplmap_150

Canal Place Office Park
130 Nickerson Street, Suite 200
Seattle, WA 98109-1658
206-263-3000; fax: 206-263-3001
View larger verson of map, GoogleMaps, and Industrial Waste Program home page

From I-5 Southbound

1. Take Exit 169 (NE 50th St.)
2. Turn right (westbound), follow 50th St past Woodland Park playfields.
3. After driving under the Aurora Avenue overpass, take the first left (southbound) onto Fremont Avenue North.
4. After crossing Fremont Bridge, turn right (northwesterly) onto Nickerson St.
5. Look for 130 Nickerson St. building on your right, in the Canal Place Office Park. Park in the adjacent parking lot.

From I-5 Northbound

1. Take Exit 167 (Mercer St.) westbound.
2. Turn right on Fairview Avenue North going northbound.
3. Turn left on Valley Street (westbound).
4. Turn Right on Westlake Avenue North (northbound). Westlake will turn into Nickerson Street after passing the Fremont Bridge.
5. Look for 130 Nickerson St. building on your right, in the Canal Place Office Park. Park in the adjacent parking lot.

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Treatment Plants

Brightwater Treatment Plant

Brightwater Project Office map

22505 State Route 9 SE
Woodinville, WA 98072-6010
Receptionist: 206-263-9465
View larger version of map, GoogleMaps, and Brightwater Treatment Plant home page

View directions to Brightwater Center - education & community center and park

Note: Visitors must check in at the Brightwater office front desk.

From Interstate 405
1. From N or S I-405, take State Route 522 N. (Woodinville/Monroe freeway).
2. About 1 mile after the Woodinville exit, take the State Route 9 exit.
3. Turn left onto State Route 9 (Snohomish Woodinville Rd).
4. Turn right at the light at 228th St. S.E.228th St. S.E.
5. On the site turn left (north) at the 'T' and stop sign.
6. Drive about 75 yards and you will come to another stop sign, then, for plant and plant operations, turn right to the entry gate. The main office entry is at south-west corner of the building near flag poles.

Note: the above directions are for the treatment plant. You can view directions to Brightwater Center - education & community center and park here.

From Lake City/Bothell Rd
1. Drive eastbound until the road turns into State Route 522 N (this occurs at the I-405 interchange).
2. Follow Steps 2-6 listed above under From Interstate 405.

Coming from Everett and points north
1. Take I-5 S
2. Take the I-405 S exit
3. Proceed to exit 23A and head towards WA-522 E
4. Keep left at the fork and merge onto WA-522 E
5. Take the WA-9 N exit toward Snohomish/Arlington
6. Turn left onto WA-9 N/Snohomish Woodinville Rd
Brightwater will be on the right.
7. Follow steps 4-6 above.

From Monroe:
1. Turn left to merge onto WA-522 W toward Seattle
2. Take the WA-9 N exit toward Snohomish/Arlington
3. Turn left onto WA-9 N
Brightwater will be on the right
4. Follow steps 4-6, above.

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Carnation Treatment Plant

Vicinity map for Carnation Treatment Plant

4405 Larson Ave.
Carnation, WA 98041
Administration (Main Control at South Treatment Plant, Renton): 206-684-2400
View larger version of map, GoogleMaps, and Carnation Treatment Plant home page

From Interstate 405
1. Go north on I-405 toward Renton/Everett.
2. Take exit #14 onto 520 east, go 5.8 miles.
3. Take the Redmond Way exit toward Fall City/North Bend, go 1.7 miles.
4. Continue on NE Redmond-Fall City Rd., go 6.4 miles.
5. Turn on NE Tolt Hill Rd., go 3.2 miles.
6. Turn on Fall City-Carnation Rd. NE, go 0.1 mile.
7. Continue on Tolt Ave., go 0.7 mile.
8. Turn on E Entwistle St., go 0.2 mile.
9. Arrive at 4405 Larson Ave.

From Interstate 90 through Issaquah
1. Go east on I-90 toward Issaquah
2. Take exit 17/Front St. toward E Lk Sammamish Parkway SE, go 0.3 mile.
3. Turn on Front St. N., go 0.1 mile.
4. Front St. N. becomes E. Lake Sammamish Parkway SE, go 0.2 mile.
5. Turn on SE Issaquah-Fall City Rd., go 3.0 mi
6. Continue on SE Duthie Hill Rd., go 2.2 mi
7. Continue on 292nd Ave. SE, go 0.1 mile.
8. Turn on Redmond-Fall City Rd., go 2.6 mi
9. Bear on NE Tolt Hill Rd., go 3.2 mi
10. Turn on Fall City-Carnation Rd. NE, go 0.1 mile.
11. Fall City-Carnation Rd. NE becomes Tolt Ave., go 0.7 mile.
12. Turn on E Entwistle St., go 0.2 mile.
13. Arrive at 4405 Larson Ave.

From Interstate 90 through Preston
1. Go east on I-90
2. Take exit 22 Fall City/Preston, go 0.3 miles.
3. Turn on SE 82nd St., go 0.2 mile.
4. Turn on SE High Point Way, go 0.5 miles.
5. Continue on Preston-Fall City Rd. SE, go 4.0 miles.
6. Fall City Preston-Fall City Rd. SE becomes Fall City-Carnation Rd., go 5.3 miles.
7. Fall City-Carnation Rd. becomes Tolt Ave., go 0.7 mile.
8. Turn on E Entwistle St., go 0.2 mile.
9. Arrive at 4405 Larson Ave.

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South Treatment Plant and Waterworks Gardens0

South Treatment Plant vicinity map

South Treatment Plant - site map

1200 Monster Road S.W.
Renton WA 98057
206-684-2400; fax 206-684-2448
View larger version of map, GoogleMaps, and South Treatment Plant home page

From King Street Center (in Seattle's Pioneer Square) via southbound Interstate 5
1. Go east on S. Jackson Street.
2. Turn right onto Fourth Avenue S.
3. Turn right onto I-90 entrance.
4. Take the I-5 South exit.
5. Take Exit 157: East Martin Luther King Junior Way (I-900).
6. Stay to the left off I-5 and follow MLK for approximately 1.5 miles.
7. At the second stop light turn right onto 68th Ave.
8. Follow this road for 1 mile, and turn right onto Monster Road SW
9. The entrance to the treatment plant is on the left just after the old train tracks at the bottom of the hill about a half of a mile from the turn onto Monster Rd.
10. Turn left at the entrance and follow to the parking area on your right. Follow the signs to the administration building and check in.

From northbound Interstate 5
1. Take Exit 154 to I-405 North (Burien/Renton exit).
2. Move to right lane and proceed about 1/2 mile.
3. Take Exit 1 (West Valley Highway).
4. Turn left onto Interurban Avenue S.
5. At light, turn right onto S.W. Grady Way.
6. See South Plant entrance or Waterworks Gardens below.

From southbound Interstate 405
1. Take Exit 1 (Tukwila/West Valley).
2. At light, turn right onto Interurban Avenue S.
3. At light, turn left onto S.W. Grady Way.
4. See South Plant entrance or Waterworks Gardens below.

From Highway 167/Rainier Avenue S
1. Turn left (west) onto SW Grady Way.
2. See South Plant entrance or Waterworks Gardens below.

From Sea-Tac Airport
1. Go north on Highway 99.
2. Take the I-5/405 exit (on the right side).
3. Continue straight to I-405 North.
4. Take Exit 1 (Tukwila/West Valley).
5. At light, turn left onto Interurban Avenue S.
6. Turn right onto S.W. Grady Way.
7. See South Plant entrance or Waterworks Gardens below.

South Plant Entrance:

Main Entrance/Monster Rd

1. Continue on S.W. Grady Way and turn onto Longacres Drive S.W.
2. Turn right onto Jackson Place S.W./Monster Road S.W.
3. The Gate 1 entrance into the plant is on the right, just before the railroad tracks. Follow signs to the Administration Building and check in.

7th Ave/Dewatering Building Entrance
1. Continue on S.W. Grady Way and turn onto Oaksdale Ave.
2. Turn left onto 7th Ave.
3. Enter the gate 3 entrance.
4. Parking is to the right.

For Waterworks Gardens
Instead of turning into the plant main entrance, continue on Monster Road S.W., go around the corner and up the hill. As you come down the incline, Waterworks will be on the right, just before you get to "T" intersection at Oakdale Avenue S.W.

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Vashon Treatment Plant

The Vashon Treatment Plant is located on Vashon Island, located southwest of Seattle, Washington.

9615 SW 171st Street
Vashon, WA 98070
206-463-7318
View larger version of map, GoogleMaps, and Vashon Treatment Plant home page

From Seattle
1. Take the West Seattle Bridge to West Seattle.
2. Stay straight to go on to Fauntleroy Way SW
3. Stay on Fauntleroy until you get to the Fauntleroy-Vashon Ferry (external link)
4. At the end of the ferry driveway, turn left onto Vashon Highway SW
5. Proceed 4.4 miles and turn left onto SW 171 st Street.
6. Turn right into the driveway at the Vashon Treatment Plant at 9621 SW 171 st St
7. Parking is available at the administrative building at the top of the driveway.

From Tacoma
1. Take the Point Definace-Tahlequah Ferry (external link)
2. Exit the ferry driveway and turn left onto Vashon Highway SW
3. Proceed 9.2 miles
4. Turn right on SW 171 st Street
5. Turn right into the driveway at the Vashon Treatment Plant at 9621 SW 171 st St
6. Parking is available at the administrative building at the top of the driveway.

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West Point Treatment Plant

West Point Treatment Plant vicinity map

West Point Treatment Plant - site map

1400 Discovery Park Blvd 
Seattle WA 98199
206-263-3800; fax 206-263-3850
View larger version of map, GoogleMaps, and West Point Treatment Plant home page


From King Street Center (in Seattle's Pioneer Square)
1. Go east on S. Jackson Street.
2. Turn right on Fourth Avenue S.
3. Turn right on S. Royal Brougham Way.
4. Turn right on Alaskan Way S.
5. Continue north to Elliott Avenue W., which becomes 15th Avenue W.
6. Take the West Emerson/Fisherman's Terminal exit and continue west.
7. See West Point entrance below.

From northbound Interstate 5
1. Take W. Mercer Street exit and head west.
2. Turn right on Westlake Avenue N.
3. Continue on Westlake Avenue N., which becomes W. Nickerson Street.
4. Continue to W. Emerson Street.
5. See West Point entrance below.

From southbound Interstate 5
1. Take Exit 173.
2. Turn right on N.E. Northgate Way, which becomes N. 105th Street.
3. Turn left on Holman Road N.W., which becomes 15th Avenue N.W.
4. Cross the Ballard Bridge.
5. Take the W. Emerson Street exit.
6. See West Point entrance below.

From Sea-Tac Airport
1. Go west on Highway 518.
2. Take Highway 509 North exit.
3. Continue on Highway 509, which becomes Highway 99.
4. Take Western Avenue exit.
5. Continue north on Western Avenue, which becomes Elliott Avenue W., then becomes 15th Avenue W.
6. Take West Emerson/Fisherman's Terminal exit and head west.
7. See West Point entrance below.

West Point Entrance
1. Turn right onto Gilman Avenue W.
2. Continue on Gilman Avenue W., which becomes Government Way and leads to Discovery Park.
3. Continue up the hill into the park.
4. Take the second left at Discovery Park Blvd.
5. Drive past the Authorized Vehicles Only sign, through the military housing.
6. At the bottom of the hill, turn right.
7. Continue under the overpass to the Administration Building parking lot on the right.

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