Mark C Nelson, Licensed

License details

"Based in" is the city and county of the address on the business's license record.

What this license covers

• Design: licensed to size and lay out a septic system for a specific site and soil condition.

How to check this license

License details are indexed from state and county licensing records as of 2026-08-17. We shorten or reword some labels. The agency's record controls, and we do not vouch for the business itself. Before hiring, look up license #5100338 directly with the agency that issued it, confirm it is still active, and ask for a current certificate of insurance.

Source: Washington State Dept. of Health - Credential Search, last checked 2026-08-17. Check current status at the state agency website.

GroundRoster is an independent publisher of public licensing records, not a government agency or licensing board. The business has not claimed this listing and is not affiliated with GroundRoster. Always confirm current license standing with the issuing state or county agency before hiring.

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