GroundRosterMark C NelsonLicensed
| Name | Mark C Nelson |
| License number | 5100338 |
| License type | On-Site Wastewater Designer |
| License status | Active — Washington DOH credential |
| Location | Ellensburg, Washington |
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What this license covers
- Design: licensed to size and lay out a septic system for a specific site and soil condition.
How to verify this license
We publish this listing exactly as it appears in Washington's official licensing records; we do not vouch for the business itself. Before hiring, look up license #5100338 directly with the state, 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. Verify at the official source.
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