Excavation permits and rules in Washington

Anyone digging in Washington has to notify Washington 811 before work starts. The notice period under Chapter 19.122 RCW (Underground utilities), notice duty in RCW 19.122.030: Not less than two full business days and not more than 10 full business days before the scheduled work-to-begin date, unless otherwise agreed by the excavator and facility operators in writing.^{1, 2}

Washington licenses contractors through the Washington State Department of Labor and Industries (L&I), contractor registration. Who needs a license: All construction contractors must register with L&I (no dollar threshold stated). Registration with bond and insurance, no exam; the specialty "Excavation, grading and land clearing" covers excavation, or a general contractor registration.^{3, 4}

A stormwater permit is needed at 1 acre, or less than 1 acre if part of a larger common plan of development that will ultimately disturb 1 acre or more and discharges stormwater to surface waters. Coverage is under the Construction Stormwater General Permit (CSWGP), 2026 permit effective Jan. 1, 2026 to Dec. 31, 2030.⁵