Sediment and Erosion Control Laboratory (SEC Lab)

The Texas A&M Transportation Institute’s (TTI’s) Sediment and Erosion Control Laboratory (SEC Lab) provides the transportation industry with a research and performance evaluation program for roadside environmental management. The program includes:

• stormwater quality improvement,
• erosion and sediment control, and
• vegetation establishment and management.

TTI’s Environment Group operates this 19-acre, full-scale, indoor/outdoor facility. The SEC Lab includes a rainfall simulator building with three 8-by-40-feet variable slope soil fill test beds accommodating any slope up to 2:1 (50%). Adjacent to the rainfall simulator building is a 1,500-feet covered sediment bed preparation area, which creates a dry work space for storing large test beds during inclement weather.

Equipment

Rainfall Simulators

The five-bay, full-scale indoor rainfall simulators are capable of producing rainfall intensities from 0 to 12 inches per hour. Variable slope, soil-filled test beds allow for testing of any soil type. They are American Society for Testing and Materials (ASTM) D6459 and ASTM D8297 test protocol compliant.

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.

Index/Physical Properties Testing

The physical property tests conducted include, but are not limited to, the following test methods:

• ASTM D6818
• ASTM D5199/6525
• ASTM D6818 (modified)
• ASTM D6475/6566
• ASTM D6567
• ASTM D7986
• ASTM D7560
• ASTM D7367

Sediment Retention Device Test Flume

The sediment retention device testing flume has a 12-feet upper flume and a 2-feet lower flume. A 4-feet wide soil-filled area is used to install the material according to the 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 1 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 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 for precise capture and water release in the structure.

Soil Embankment

The 25-feet-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-feet 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 maximum stress flow of 12 psf (575 Pa).