Well & Septic ProsDarren J DerkowskiLicensed
| Name | Darren J Derkowski |
| License number | MP0001920, OS0031161, OS0033480 |
| License type | OSSF Installer II · OSSF Maintenance Provider · OSSF Site Evaluator |
| License status | Current — TCEQ OSSF licensing export (exported 2026-08-17) |
| License expires | 2029-09-30 |
| Location | Washington County, Texas |
Request a quote from Darren J Derkowski
What this license covers
- Site testing: licensed to run percolation tests and evaluate soils to determine what kind of system a site can support.
- Installation / repair: licensed to build and install septic tanks and drainfields, and to repair or replace failed ones.
- Maintenance: licensed to service and maintain aerobic and other advanced treatment systems on an ongoing contract, including the periodic checks those systems require.
How to verify this license
We publish this listing exactly as it appears in Texas's official licensing records; we do not vouch for the business itself. Before hiring, look up license #MP0001920, OS0031161, OS0033480 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.
Are you Darren J Derkowski? Claim this listing to set your business name and add your website, service area, hours, and photos. It's free.