Li studying how to lower pollution from
TxDOT construction stormwater runoff

A Texas A&M landscape architecture professor is looking for technologies to help transportation agencies meet new federal guidelines restricting the content of stormwater runoff from road construction sites.

The three-year, $736,293 study funded by the Texas Department of Transportation, pairs Ming-Han Li, associate professor of landscape architecture, with researchers from the Texas A&M University System's Texas Transportation Institute, the University of Texas and Texas Tech University. Li is a co-principal investigator on the project.

"Under current regulations, dirty stormwater discharged from construction sites must be treated to meet stormwater quality standards," said Li. "With appropriate management, constituents in stormwater such as nutrients, heavy metals and suspended solids can be substantially removed."

However, the U.S. Environmental Protection Agency has drawn up new, tighter regulations calling for the discharges to be clear. The new rules take effect in 2013 at all construction sites disturbing 20 or more acres of land at a time. In 2014, the limits will apply to construction sites disturbing 10 or more acres of land.

Since TxDOT's construction activities are considered a source of pollution in terms of stormwater quality, its sites must also be compliant with EPA regulations, said Li.

"Because turbidity, or opacity, has never been a concern for stormwater before, TxDOT is seeking research-based solutions for meeting this soon-to-be-implemented rule," he said.

The research team conduct experiments to:

• determine typical turbidity of runoff collected by TxDOT's drainage structures at construction sites,
• collect performance data on innovative erosion and sediment control measures that might be expected to achieve the discharge standard, and
• produce guidance measures and sampling protocols for TxDOT to negotiate with the Texas Commission on Environmental Quality in the development of statewide monitoring/sampling procedures.

- Posted: Sept. 30, 2010 -

Contact:   Phillip Rollfing, prollfing@archone.tamu.edu or 979.458.0442.