Our Work

Dow Drainage

Dow Chemical USA
Taft, LA

SEMS was contracted by Dow Chemical USA to improve the drainage and storm water capacity of the main drainage ditch through the Taft, Louisiana facility.  Approximately 2,300 linear feet of ditch line had over time silted up to a level where water flow was severely restricted in the culverts (less than 10% capacity flow through), retention capacity was reduced by 75%, and flooding into the process units was a common occurrence during significant rain events.


Work performed:

  • Excavation and solidification, using portland cement, of in excess of 10,000 cubic yards of silt. (Once solidified in the ditch, the new ditch profile was excavated, and the excess material was used along the shoulders to increase flow through capacity)
  • Silt removal and cleaning of 426 linear feet of corrugated metal pipe ranging in diameter from 36” to 54”
  • Removal and replacement of 400 linear feet of 54” asphalt coated corrugated metal pipe and two 4’ x 6’ x 9’ prefabricated concrete cleanouts
  • Removal and reinstallation of a 100’ segment of railroad track
  • Installation of geotextile fabric throughout the ditch and banks (fabric secured in anchor trenches on both banks)
  • Placement of 3,800 tons of riprap throughout the entire ditch profile
  • Bypass pumping around the work area of all water entering the ditch from rain events and plant operations (non-storm related flow rates typically exceeded 400 gpm)
  • Site restoration activities including installation of new stone parking and laydown areas