GroundRosterMichael Gunnar CallisonLicensed
| Name | Michael Gunnar Callison |
| License number | OS0040858 |
| License type | OSSF Installer I |
| License status | Current — TCEQ OSSF licensing export (exported 2026-08-17) |
| License expires | 2029-02-28 |
| County | Brazoria County, Texas |
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What this license covers
- Installation / repair: licensed to build and install septic tanks and drainfields, and to repair or replace failed ones.
How to verify this license
We publish the license details exactly as they appear in Texas's official licensing records; we do not vouch for the business itself. Before hiring, look up license #OS0040858 directly with the state, confirm it is still active, and ask for a current certificate of insurance.
Source: Texas Commission on Environmental Quality (TCEQ) - OSSF occupational licensing, last checked 2026-08-17. Verify at the official source.
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