Washington doesn't say anything about being CDL exempt if you are a private, non-farm user.
WA State Licensing (DOL) Official Site: Who needs a CDL?
Who needs a CDL?
Types of vehicles that require a CDL
You must have a commercial driver license (CDL) to drive any of the following vehicles:
All single vehicles with a manufacturer's weight rating of 26,001 pounds or more.
All trailers with a manufacturer's weight rating of 10,001 pounds or more, and a combined vehicles gross weight rating of 26,001 pounds or more.
All vehicles designed to transport 16 or more persons (including the driver). This includes private and church buses.
All school buses, regardless of size.
All vehicles used to transport any material that requires hazardous material placarding or any quantity of a material listed as a select agent or toxin in 42 CFR 73.
Who doesn't:
WA State Licensing (DOL) Official Site: Who doesn
Who doesn't need a CDL?
By law, the following types of drivers don't need a commercial driver license (CDL):
Farmers transporting farm equipment, supplies, or products* to or from a farm in a farm vehicle are exempt if the vehicle is:
Operated by the farmer or a farm employee.
Not used in the operation of a common or contract motor carrier.
Used within 150 miles of the farm (in an air-mile radius).
...
and others mentioned in previous posts.
Bruce