Updated: Mar 27, 2026
Location and Projects
Address
PO BOX 24423, Seattle, WA, 98124
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Gravity Flow Systems Plumber
Gravity Flow Systems Inc, Seattle, Po Box 24423, Seattle, WA (Employees: Carl Miller, Gilman, Thomas L, and Harold Miller) holds a Construction Contractor, General license and 1 other license according to the Tukwila license board.
Their BuildZoom score of 108 ranks in the top 5% of 128,670 Washington licensed contractors.
Their license was verified as active when we last checked. If you are thinking of hiring Gravity Flow Systems Inc, we recommend double-checking their license status with the license board and using our bidding system to get competitive quotes.
Gravity Flow Systems Inc Services
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Gravity Flow Systems Inc Contact Information
Phone Number: (206) 723-9485
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Address: PO BOX 24423, Seattle, WA 98124
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Building Permits by Gravity Flow Systems Inc
This is a sample of this contractor's permits. Click here to access their complete permit history.
New sewer and draiange new 7-unit townhouse 6823492-cn: re-use the existing sanitary sewer connection to the sanitary sewer main in nw 60th st. pe eval/cert is required. new storm connection to the storm main in 26th ave nw. no footing drains. onsite stormwater management facilities are required. all work in the row requires a separate sdot permit. call spu at (206) 615-0511 to schedu... see more
Valuation:
N/A
Permit #:
7091618-SS
Status:
issued
Fee:
$750
Permit Type:
New
Building Type:
Single family/duplex
New sewer and draiange drainage to curb weep on nw 57th street. sanitary to the existing side sewer to the public sanitary sewer main in nw 57th street. no footing drains will be installed. per plan #6862279-cn for six (6) new townhouses. osm included. separate sdot row permit required. pe cert/eval will be required
Valuation:
N/A
Permit #:
7087376-SS
Status:
issued
Fee:
$825
Permit Type:
New
Building Type:
Single family/duplex
New sewer and drainage storm to infiltration facilities (2). no footing drains proposed. sanitary to the existing sanitary only side sewer. per plan #7020895-cn for new sfr+aadu+dadu. osm: permeable pavement facilities (2). pe eval/cert required. shares sanitary sewer connection to main with 12027 40th ave ne. 1 sanitary pump. revised ky 01/28/2025: added one sanitary pump. no change ... see more
Valuation:
N/A
Permit #:
7065441-SS
Status:
issued
Fee:
$969
Permit Type:
New
Building Type:
Single family/duplex
New sewer and drainage new 6-unit th: storm to alley and sanitary to existing side sewer to sanitary main per approved plan under 6896976-cn. pe eval. required. on-site stormwater management included. one drainage pump added
Valuation:
N/A
Permit #:
7078417-SS
Status:
issued
Fee:
$825
Permit Type:
New
Building Type:
Single family/duplex
New sewer and drainage storm to new connection to far side storm main. sanitary to existing side sewer to sanitary main. no footing drains. per plan 7070049-cn for new sfr/aadu. existing dadu to remain. pe eval/cert required. onsite stormwater management not required. separate sdot permit required for work in the right of way
Valuation:
N/A
Permit #:
7094824-SS
Status:
issued
Fee:
$750
Permit Type:
New
Building Type:
Single family/duplex
New sewer and drainage storm sanitary and footing drains to new connection to the combined main and existing combined sewer in 19th ave. per plan #6878466-cn for 9 new townhomes. osm: non-infiltrating bio retention planters (2) detention pipes. one drainage pump. pe eval/cert required. separate sdot row permit required. mdc received
Valuation:
N/A
Permit #:
7089599-SS
Status:
issued
Fee:
$825
Permit Type:
New
Building Type:
Single family/duplex
Addition alteration side sewer sanitary addition/alteration. side sewer only addition alter new connection from new basement plumbing to existing side sewer in driveway on property. no drainage. no work in right of way
Valuation:
N/A
Permit #:
7106630-SS
Status:
complete
Fee:
$375
Permit Type:
None
Building Type:
Single family/duplex
New sewer and drainage drainage and footing drains to drainage ditch (farside) on 26th avenue sw. includes one storm pump and force main in right-of-way. sanitary sewer to the existing shared side sewer to the king county sanitary sewer main in the alley to the east. per plan #6935406-cn for new single family residence attached accessory dwelling unit and detached accessory dwelling u... see more
Valuation:
N/A
Permit #:
7032559-SS
Status:
issued
Fee:
$825
Permit Type:
New
Building Type:
Single family/duplex
New sewer and drainage storm drains to new connection to culvert pipe. sanitary to existing sanitary lateral. per plan 6997291-cn for new single family residence aadu and dadu. project includes osm facilities pe eval cert required. separate sdot row permit required
Valuation:
N/A
Permit #:
7020330-SS
Status:
issued
Fee:
$814
Permit Type:
New
Building Type:
Single family/duplex
New sewer and drainage drainage and sanitary to existing side sewer to the public combined sewer main in ne 70th street. no footing drains will be installed. per plan #6842094-cn for new six (6) unit townhouses. osm included. pe eval/cert will be required. no work in row
Valuation:
N/A
Permit #:
7012512-SS
Status:
issued
Fee:
$750
Permit Type:
New
Building Type:
Single family/duplex
New sewer and drainage (7/6/23 vem: revision 6907735-cn-008 increased the amount of permeable pavement for the project.) storm to onsite infiltration. sanitary to existing side sewer to sanitary main. no footing drains. per plan 6907735-cn for new sfr/aadu and existing single family residence converted to dadu. pe eval/cert required. no work in right of way. includes onsite stormwater... see more
Valuation:
N/A
Permit #:
6949684-SS
Status:
complete
Fee:
$813
Permit Type:
New
Building Type:
Single family/duplex
New sewer and drainage new single family residence + aadu + dadu 6899798-cn: new sanitary sewer to the existing shared sanitary sewer connection to the combined sewer main. new sanitary sewer installed in 2004 under permit #6038494. no pe eval/cert required pending video verification by site inspector. new storm to the combined sewer. no footing drains. onsite stormwater management fa... see more
Valuation:
N/A
Permit #:
6960648-SS
Status:
issued
Fee:
$1,443
Permit Type:
New
Building Type:
Single family/duplex
New sewer and drainage new single family residence + aadu + dadu 6914255-cn: new sanitary sewer connection to the existing connection to the combined sewer main in 34th ave sw. pe eval/cert is required. new storm and footing drains to the combined sewer. onsite stormwater management facilities are required
Valuation:
N/A
Permit #:
6958329-SS
Status:
issued
Fee:
$750
Permit Type:
New
Building Type:
Single family/duplex
New sewer and drainage for dadu new dadu to connect to the existing shared sanitary sewer with the existing single family residence to the formerly combined sewer main. new storm to go to the existing connection to the formerly combined sewer. related construction permit 6749147-cn
Valuation:
N/A
Permit #:
6947043-SS
Status:
complete
Fee:
$1,077
Permit Type:
New
Building Type:
Single family/duplex
New sewer and drainage storm and sanitary to existing combined side sewer shared with 1704 n 47th st to the north (6821644-cn) no footing drain. per plan # 6821846-cn for 1 duplex osm required pe eval/cert required. no work in right of way
Valuation:
N/A
Permit #:
7043692-SS
Status:
issued
Fee:
$750
Permit Type:
New
Building Type:
Single family/duplex
New sewer and drainage for dadu 7/9/24 vem: addition one drainage pump. new dadu: storm to curb weep and sanitary to existing side sewer to sanitary main per approved plan under 6965290-cn. no osm required. separate sdot row permit required
Valuation:
N/A
Permit #:
7034297-SS
Status:
issued
Fee:
$825
Permit Type:
New
Building Type:
Single family/duplex
New sewer and drainage storm and footing drains to new combined sewer connection. sanitary to new connection to n.w. 83rd st. to combined. per plan 6781980-cn for townhomes. project includes osm facilities. separate sdot permit required
Valuation:
N/A
Permit #:
7028645-SS
Status:
issued
Fee:
$1,125
Permit Type:
New
Building Type:
Single family/duplex
New sewer and drainage storm drains to infiltration facility. no footing drains proposed. sanitary to the existing sanitary only side sewer. per plan #6967704-cn for new dadu and aadu. osm included. pe eval/cert required. no work in row
Valuation:
N/A
Permit #:
7004716-SS
Status:
issued
Fee:
$814
Permit Type:
New
Building Type:
Single family/duplex
New sewer anf drainge sanitary to existing side sewer and storm to new connection to drainage culvert in 30th ave ne per approved plans with building permit #7005912-cn. no osm required. separate sdot permit required for row work
Valuation:
N/A
Permit #:
7020327-SS
Status:
issued
Fee:
$750
Permit Type:
New
Building Type:
Single family/duplex
New sewer and drainage new 5-unit th: storm to curb weep and sanitary to existing side sewer to sanitary main per approved plan under 6894911-cn. pe eval. required. footings to onsite infiltration. separate sdot row permit required
Valuation:
N/A
Permit #:
6948425-SS
Status:
issued
Fee:
$813
Permit Type:
New
Building Type:
Single family/duplex
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Gravity Flow Systems Inc License info
License Not Verified
| License # | GRAVIFS013CA |
| Status | Active |
| City | Tukwila |
| Type | Construction Contractor, General |
| Class | Corporation |
| Business Type | Corporation |
- When BuildZoom last verified this license, it had an expiration date of February, 2026. Check the current license status of Gravity Flow Systems Inc with the The City of Tukwila, WA
This is a sample of licensing data; click here to access a complete history.
Verified License
| License # | GRAVIFS013CA |
| Status | Active |
| State | Washington |
| Type | Construction Contractor, Construction Contractor |
| Business Type | Corporation |
- BuildZoom verified this license was active as of February 2026.
Verify this license's status for Gravity Flow Systems Inc at the Washington State Department of Labor & Industries.
This is a sample of licensing data; click here to access a complete history.
108
BuildZoom Score
Insured
| Insurer | Liberty Northwest Ins Corp |
| Insured up to | $1,000,000 |
Bonded
| Bonded Agent | TRAVELERS CAS & SURETY |
| Bond Value | $12,000 |
901
Permits
- Building permit records show that Gravity Flow Systems Inc has worked on 901 permitted projects.
Gravity Flow Systems Inc Employees
CM
Carl Miller
President
GL
Gilman, Thomas L
Agent
HM
Harold Miller
President
MS
Miller, Harold S
President
MR
Miller, Paula R
Vice President
PM
Pamela Mitchell
Vice President
PM
Paula Miller
Vice President
TG
Thomas Gilman
Agent