Customers and service area |
| |
System |
West Point |
South |
Vashon |
Carnation |
|
34 local agencies
(includes 17 cities, 16 sewer districts, and the Muckleshoot Indian Tribe) |
-- |
-- |
1 sewer district |
City of Carnation |
Population Served |
1.5 million residents |
-- |
-- |
650 |
3,817
(by 2017) |
|
420 square miles |
-- |
-- |
620 acres
(by 2050) |
776 acres
(in city and surrounding Urban Growth Area) |
Sewage treated |
| |
System |
West Point |
South |
Vashon |
Carnation |
Sewage Treated
(Volume expected in Average Rainfall Year) |
About 206 million gallons a day (average) |
112 mgd |
94 mgd |
0.14 mgd |
0.10 mgd |
Sewage Treated
(2008 – low rainfall year is reflected in lower flows treated) |
161.5 mgd |
91.5 mgd |
70.0 mgd |
0.124 mgd |
--
(data not available yet, plant came online in May 2008) |
|
-- |
-- |
19.78 million gallons |
-- |
-- |
Facilities and Equipment |
| |
System |
West Point |
South |
Vashon |
Carnation |
Treatment plants |
4 |
West Point Treatment Plant,
Seattle |
South Treatment Plant,
Renton |
Vashon Treatment Plant,
Vashon Island |
Carnation Treatment Plant,
Carnation |
Treatment plants in construction |
1:
Brightwater |
-- |
-- |
-- |
-- |
Pump Stations |
42 |
-- |
-- |
4 |
-- |
Regulator Stations |
-- |
19 |
-- |
-- |
-- |
CSO treatment facilities |
4:
Alki, Carkeek, Mercer/Elliott West, Henderson/Norfolk |
-- |
-- |
-- |
-- |
King County sewer conveyance lines |
about 353 miles |
-- |
-- |
3.2 miles |
1.6 miles |
Sewer pipe diameter |
12 inches to 14 feet |
-- |
-- |
2 feet 5 inches HDPE |
12 inches |
Outfalls, length and depth |
-- |
3,600 ft long;
240 ft deep;
600 ft diffuser
(500 ft plus a 100-ft extension) |
10,000 ft long;
625 ft deep;
4 diffusers @ 500 ft L ea. |
2,850 ft long;
200 ft deep;
no diffuser |
Primary discharge: Chinook Bend Wetland Enhancement Project. Backup: Snoqualmie River at Carnation Farm Road Bridge. |
Design criteria |
| |
West Point |
South |
Vashon |
Carnation |
Average wet-weather flow (non-storm):
This number is often used to describe the size of the treatment plants. It is based on average wet-season flow (November through April) but does not include extraordinarily large storms in the average. It is based on an average that does not show the maximum flows that can be handled at a plant. |
133 mgd |
115 mgd |
-- |
.22 mgd |
Maximum monthly average flow |
215 mgd |
144 mgd |
0.52 mgd |
.27 mgd |
Average dry-weather flow |
110 mgd |
96 mgd |
-- |
.21 mgd |
Biological oxygen demand (BOD) influent loading (annual average) |
168,000 lbs/day |
220,000 lbs/day |
526 lbs/day |
314 mg/L |
Total suspended solids (TSS) influent loading (average annual) |
181,000 lbs/day |
201,000 lbs/day |
526 lbs/day |
314 mg/L |
Instantaneous maximum capacity:
Maximum flows that can be handled at the plants--often for short periods; some portions of these flows get minimal treatment. |
440 mgd |
325 mgd |
2.05 mgd |
1.4 mgd |
Permit information |
| |
System |
West Point |
South |
Vashon |
Carnation |
Permit (NPDES) renewal dates:
View permit limits (BOD, TSS, fecal coliform, chlorine residual) for each treatment plant. |
-- |
Pending |
10/1/09 |
9/1/11 |
River permit 4/15/13
Reuse permit 12/30/13 |
Resource recovery |
| |
System |
West Point |
South |
Vashon |
Carnation |
Electricity produced annually |
-- |
-- |
.23 million kilowatt hours |
-- |
-- |
Methane gas sold annually
(Both West Point & South Plant also use digester gas to power plant equipment, such as boilers and digesters) |
-- |
-- |
2.1 million therms |
-- |
-- |
|
About 116,066 wet tons
(or 28,434 dry tons @ 24.6% solids) |
51,701 wet tons (or 13,820 dry tons @ 26.81% solids) |
64,364 wet tons (or 14,614 dry tons @ 22.78% dryness) |
32.8 dry tons hauled to South Plant for further treatment |
Preliminary estimate of 19 dry tons/year to South Plant for further treatment.
7.3 dry tons produced in May-Dec 2008. |
|
About 293 million gallons used for landscape irrigation, industrial processes, heating/cooling |
195 million gallons |
98.4 million gallons |
-- |
All effluent reclaimed water to Chinook Bend wetland enhancement site |
Financial and budget information |
|
$31.90 per month (beginning 1/1/09) |
|
$47.64 per month (beginning 1/1/09)
($142.92 every three months for new hook ups as of 1/1/09) |
|
Operating: $103.6 million
Capital Improvement Program (CIP): $525.8 million |
|
About 563 full-time equivalents (FTEs),
32 term-limited temporary (TLT) employees, and 11 temps/interns. |
|
Cost: $1.802 billion (with inflation)
Will serve: South Snohomish and North King counties
Capacity: 36 mgd, 2010; 54 mgd, 2040 |
|
$3.5 billion (2008 dollars) |
Other |
Total Rainfall (measured at SeaTac) |
Total rainfall 2008, 34.05 inches;
Long-term average annual rainfall 37 to 38 inches |
|
Significant industrial users |
134 |
Industrial/Commercial facilities with discharge authorizations |
319 |
Approximate number of compliance samples taken |
2,258 |
Inspections conducted |
435 |
|
Baseline volume
(1980-83) |
2.3 billion gallons per year |
Current volume
(June 2006-May 2007) |
815 million gallons per year (view CSO reduction graph) |
Number of King County CSOs |
38; (view CSO location map) |
