Septic permits and fees in Montgomery County, Texas

Which septic permit applies in Montgomery County?

The septic system permit, and it starts with the site evaluation. Texas requires a site evaluation before it issues a permit. The permit follows a passing evaluation. The building permit follows the septic permit.

A site evaluator or an engineer checks the soil in two pits or borings.

Texas Administrative Code, Title 30, Chapter 285, Section 285.30, Site Evaluation · checked 2026-09-23

What are the current septic fees in Montgomery County?

$295 for a septic system permit, on the county's own fee schedule.

Applies to a new residential septic system. It includes the fee the county collects for the Texas Commission on Environmental Quality.

A commercial system costs more. An add-on to an existing system costs less, and so does a subdivision review or a floodplain variance. A failed inspection carries its own fee.

Montgomery County Environmental Health Services — How to Obtain a Permit to Construct a Septic System · checked 2026-09-23

What state law fixes for every Texas system

• 750 gallons minimum septic tank capacity

  Applies to a design flow of 250 gallons a day or less. Most one- and two-bedroom homes fall under this flow.

  Table II scales the tank size up from this floor as design flow rises. A three- or four-bedroom home needs a bigger tank.

  Texas Administrative Code, Title 30, Chapter 285, Section 285.91(2), Table II · checked 2026-09-23

• 100 feet from a private well to the drainfield

  Applies to the drainfield's distance to an ordinary private well. A public well needs more room, and a sealed well needs less.

  This table sets a longer distance for a public well. It sets a shorter distance for a well that is properly sealed.

  Montgomery County Environmental Health Services — Minimum Required Separation Distances for On-Site Sewage Facilities · checked 2026-09-23

• 5 feet from any property line

  Applies to a septic tank or a drainfield, measured from a property line, a building, or a pool.

  State rules set the same five-foot distance for the tank and the drainfield alike.

  Texas Administrative Code, Title 30, Chapter 285, Section 285.91(10), Table X · checked 2026-09-23

What Montgomery County requires that the state does not

• No septic permit will issue for a site inside the floodway.

  Applies to a new system on a tract inside the floodway.

  State rules let an engineer design a system for a floodway site instead. The county allows no floodway system, engineered or not.

  Montgomery County Environmental Health Services — How to Obtain a Permit to Construct a Septic System · checked 2026-09-23

The steps, in the county's order

1. A registered site evaluator checks the soil and the site.
2. A sanitarian plans the system. An engineer may plan it instead.
3. The owner submits signed floor plans for the building.
4. The Permit Office states the floodplain status of the tract.
5. The owner turns in the application and pays the fee.
6. The county checks the system. This happens before backfill covers it.
7. The county issues a Notice of Approval. The owner may then use the system.

Montgomery County Environmental Health Services — How to Obtain a Permit to Construct a Septic System · checked 2026-09-23

Sources

Each figure on this page has a government source and a checked-on date.

1. Montgomery County Environmental Health Services — How to Obtain a Permit to Construct a Septic System · checked 2026-09-23
2. Texas Administrative Code, Title 30, Chapter 285, Section 285.30, Site Evaluation · checked 2026-09-23
3. USDA NRCS Soil Data Access (SSURGO) · checked 2026-09-22

Related pages

• Septic rules and requirements in Montgomery County, Texas
• Soil and perc tests in Montgomery County, Texas
• Septic rules and requirements in Texas
• Septic rules in Montgomery County