Sediment and Erosion Control Laboratory (SEC Lab)

The Environment and Planning Program operates the Sediment and Erosion Control Laboratory, a full-scale, indoor/outdoor facility with testing capabilities and research programs for technology, products and devices used for storm water quality improvement, erosion and sediment control, and vegetation establishment and management.

The 19-acre SEC Lab provides the transportation industry a uniform and timely testing and research program for technologies, products and devices used for storm water quality improvement. Request for Testing Services Through a research program with the Texas Department of Transportation (TxDOT), the SEC Lab currently tests erosion control technologies, products and devices to produce and maintain a defensible "Approved Products List" for all sediment and erosion control products used by TxDOT on Texas roadsides. All erosion controls used on TxDOT construction and maintenance projects must first be tested for their performance effectiveness and be certified as an approved product.

At-Grade Channels

These 10 soil channels are 85 ft long with a trapezoidal shape and 1:1 side slopes - four with a centerline gradient of 3% and six with a 7% gradient.

Bench Scale Testing Equipment

Bench scale capabilities of the lab include bench scale slope testing and bench scale channel erosion testing equipment. This bench scale equipment is useful to evaluate performance of erosion control materials and compare bench scale results to full scale and large scale testing data.

Climate Controlled Greenhouse

A 2,800-square-foot climate-controlled greenhouse is used for growing approved seed mixes free from outside contaminants such as weeds. The climate control characteristics of the greenhouse also provide the SEC lab with the ability to test vegetation establishment on a year-round basis. The erosion and sediment control materials are tested in the greenhouse to determine their ability to establish perennial vegetative cover. The purpose is to understand how materials foster establishment of vegetative cover and how vegetation contributes to the control of surface erosion on slopes and in channels.

Indoor Rainfall Simulator

The indoor rainfall simulator has two adjustable soil beds to match any desired slope up to 2:1 (50%). It provides water drop size distribution and impact velocity that are typical of storms common to Texas and the Gulf Coast regions of the country. The rainfall simulator is designed to subject test beds of selected soils to very destructive rainfall characteristics and high rainfall rates. Rain drops are dropped from a height of 14 ft above the test bed which allows them to reach 85-90% terminal velocity before they hit the soil surface. A large 4.4 mm average drop size also simulates large drop sizes commonly found in severe storms. This state-of-the art facility has dramatically expanded the research capabilities of the lab.

Mobile Rainfall Simulator

The mobile rainfall simulator can be used to simulate natural rainfall and control rainfall rates at any remote location. This is useful when testing plots of existing vegetation for erosion control characteristics or monitoring planted or bare soil outdoor test plots.

Overland/Sheet Flow Test Flume

The 65 ft concrete channel has a potable water reservoir and weir designed to simulate overland sheet flow for water quality testing. The channel can be filled with specified soil type and gradient.

Potable Water Tank

This 5000 gallon potable water tank can be used for water quality testing.

Sediment Retention Device Test Flume

The sediment retention device testing flume has a 12 ft upper flume and a 2 ft lower flume. A 4 ft wide soil-filled area is used to install the material according to manufacturer's specifications. The reservoir continually mixes a slurry of well-graded artificial sediment. Turbidity meters monitor influent and effluent concentrations. Flowmeters are also used to monitor influent and effluent flow rates.

Small Footprint Stormwater Quality Structure

This concrete structure is designed to hold one acre inch of water and is designed to capture and treat sediment laden water for various time periods. Samplers and flowmeters used in conjunction with this device, monitor settlement rates of sediment and also allow water to be slowly released, skimmed off the surface, or held for a designated time period and then released. One key feature of this device is a solar powered electronic butterfly valve that allows for precise capture and release of water in the structure.

Soil Embankment

The 25-foot-tall, L-shaped embankment of 1,000 linear feet has both clay and sand soil sections built with 2:1 and 3:1 slopes per highway specifications.

Variable Slope Channel Flume

The 30 ft outdoor, variable slope channel flume is used for testing the performance capabilities of flexible channel liner materials at a range of stress flows. The current protocol tests products and materials up to a maximun stress flow of 12 psf (575 Pa).

For More Information

Jett McFalls
TTI/Environment and Planning
Texas A&M Transportation Institute
Texas A&M University System
3135 TAMU
College Station, TX  77843-3135
ph. (979) 847-8709 · fax (979) 862-1759
j-mcfalls1@tamu.edu