Soil and Site Evaluation for On-Site Sewage Facilities

Septic system failure due to presence of shallow groundwater in Harris County, Texas.

Over 50,000 on-site sewage systems are permitted every year in Texas. Improperly installed or maintained systems are a major cause of runoff pollution in this state. The first step to a functioning on-site sewage system is a soil and site evaluation. When the site is properly evaluated, a system adequate to the limitations of the site can be engineered

Web-based Soil and Site Evaluation Course
This course provides 8 hours continuing education for the OSSF program. Register online and take the course online!

Water Table Map of Galveston County (PDF File - 724 K) *
This map shows the minimum soil water table depths for Galveston County. This is the default level for designing an on-site system. Only examination by a professional soil scientist can over-ride this value.

The following two documents deal with an on-going project with the Texas On-Site Wastewater Treatement Research Council to deal with the issues of shallow groundwater and on-site septic systems.

Synoptic Literature Review of Shallow Groundwater (short version) (PDF File - 145 K) *

Synoptic Literature Review of Shallow Groundwater (full version) (PDF file - 441 K)*
(fully annotated bibliography and review of pathogen survival in soils)

Pilot Study for Shallow Groundwater Maps for On-Site Evaluation (PDF File - 1.45 MB) *

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* (PDF files require Adobe Acrobat reader)