OSS Designer Professional List

The State of Washington requires that designers of septic systems be licensed by the State. This list represents licensed Wastewater System Designers and Professional Engineers (PE) who are qualified to perform design work in Washington, and have requested their names be added to our list. This list is not a recommendation, endorsement, or guaranty of workmanship by Cowlitz County. Questions, concerns, or comments concerning designers or engineers designing wastewater systems may be directed to the Washington State Department of Licensing (DOL) at 360-664-1568, or by accessing the DOL website at: https://www.dol.wa.gov/

Do Your Homework

As with any professional you hire, do your homework. The County is not able to give suggestions or references.

Business Name
Name
Mail AddressCity, State, Zip
Phone
ABC SEPTIC DESIGNS & MAINTENANCE
HAVILAND, DONALD L.
664 DEEP CREEK RD.
CHEHALIS, WA 98532
360-520-1390
ADVANCED ENGINEERING
ELSTROTT, CHRISTOPHER
128 N RIVER ST
MONTESANO, WA 98563
360-249-8447
ADVANCED SEPTIC CONSULTINGBUCK, TRAVIS220 HANSON RDKALAMA, WA 98625360-433-5476
ASD2 INC - COLLIER SEPTIC CONSULTING & DESIGN
COLLIER, MARK
PO BOX 1476
BRUSH PRAIRIE, WA 98606
360-798-6456
BRIAN L. HEWITT ENGINEERING
HEWITT, BRIAN L.
1928 BETHANY ST.LONGVIEW, WA 98632
360-751-3751
BRIAN L. HEWITT ENGINEERING
HEWITT, MARC
1928 BETHANY  ST.LONGVIEW, WA 98632360-751-3751
EK ENGINEERING
EK, CHANE
PO BOX 3097BATTLE GROUND, WA 98604360-687-7668
EK ENGINEERING
EK, NATHAN
PO BOX 3097
BATTLE GROUND, WA 98604
360-687-7668
ENVIRONMENTAL DESIGN LLC
RIEGER, BECKY
901 L ST
CENTRALIA, WA 98531
360-219-3343
ENVIRONMENTAL MANAGEMENT SYSTEMS
SWEENEY, ROBERT
4080 SE INTERNATIONAL WY
 #B112
MILWAUKIE, OR 97222
360-735-1109
EVERGREEN SEPTIC DESIGN INC.
WILLIAMS, MIKE
7503 NE 219TH ST
BATTLE GROUND, WA 98604
360-687-9919
H&H ENGINEERING, PLLCBROWN, MATTPO BOX 1220RAINIER, WA 98576253-320-5397
MCNAIR SEPTIC DESIGNMCNAIR, CORY S18915 NE 164TH STBRUSH PRAIRIE, WA 98606360-907-1576
SWANCO CONSULTANTSSWANSON, MATT1603 LARCH ST. #2603LONGVIEW, WA 98632360-430-4965
WHORTON ENGINEERING
WHORTON, DEAN
426 SEARS RD
WINLOCK, WA 98596
360-785-4329