Guillermo Willie Sr Trevino, Licensed

License details

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

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 check this license

We publish the license details exactly as they appear in the public licensing records of the agency that issued the license; we do not vouch for the business itself. Before hiring, look up license #MP0000748, OS0007093, OS0010363 directly with the agency that issued it, 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. 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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