TRA Experiencing Outflows Due to Heavy Snow Melt Runoff 

Grand Prairie – A Trinity River Authority manhole began overflowing wastewater on Thursday, February 18, 2010 at 8:00 a.m. after heavy runoff from recent snowfall caused hydraulic overloading in the Authority’s East Mountain Creek pipeline resulting in outflows. 

During periods of heavy snow melt runoff or rainfall, it is common for water to cover manholes and underground wastewater pipes. When this occurs, unwanted water gains access to the pipeline system through openings in the manholes and cracks in the pipelines. The pipelines can become hydraulically over loaded and wastewater spills result. 

No public drinking water supplies were threatened or contaminated by this overflow. The Texas Commission on Environmental Quality (TCEQ) requires all wastewater overflows in excess of 100,000 gallons to be reported to TCEQ, the public, and other designated public officials.  

TRA estimates that by 4:30 p.m. on February 21, 2010, 100,000 gallons of wastewater outflowed from the manhole, located ¼ mile west of Mountain Creek Parkway, and ½ mile south of I-20, discharging into a low lying area of the Mountain Creek drainage basin. 

The overflowing manhole is part of TRA’s East Mountain Creek interceptor system and carries flows from the Cities of Grand Prairie and Cedar Hill. The final volume that overflows will be reported to TCEQ. 

The impact of this inadvertent spill was minimized by large quantities of floodwater which served to dilute the wastewater in the East Mountain Creek Interceptor and Mountain Creek drainage basin. 

All required city, county and state officials have been notified of this event by TRA. 

For more information please contact John Jadrosich, (817) 467-4343

Texas Commission on Environmental Quality
Chapter 319 – General Regulations Incorporated Into Permits
Rule Log No. 99031-319-WT

Figure: 30 TAC §319.303

NOTICE OF SPILL FROM A WASTEWATER FACILITY

A spill from a wastewater treatment or collection facility has occurred. 

INFORMATION ABOUT THE SPILL 

Facility Name: Trinity River Authority’s Central Regional Wastewater System, East Mountain Creek 

Contact for further information John Jadrosich - Public Information (817) 467-4343  

Location of the spill:    ¼ mile west of Mountain Creek Parkway and ½ mile south of I-20 

Estimated time and date of spill:         Started at 8:00 a.m. on February 18, 2010 and exceeded 100,000 gallons by 4:30 p.m. on February 21, 2010 

Estimated volume of the spill (number of gallons): Exceeded 100,000 gallons at 4:30 p.m. on February 21, 2010.  The final volume released will be reported to TCEQ.                                     

Type of spill: (domestic) (industrial) (other) Explain other      Domestic                                              

Area potentially affected:        Mountain Creek drainage area in Grand Prairie                                 

Suspected cause of spill:        Hydraulic overload due to heavy snow melt runoff                                      

THE FOLLOWING ACTIONS HAVE BEEN TAKEN:

x  Appropriate local governmental officials have been notified

x TCEQ regional office has been notified

      The spill has been contained

      Increased monitoring of water supply systems has been initiated 

      The cause of the spill has been corrected 

      Clean-up activities are underway/completed

   Other                                                                                                              

As listed in the Sanitary Sewer Overflow (SSO) Outreach Initiative Final Corrective Action Plan, submitted by the Authority and approved by the Texas Commission on Environmental Quality (TCEQ), the Authority annually performs internal line video inspection and line cleaning activities.  Problem areas identified are scheduled for corrective action.  Construction of a relief project is underway for the Mountain Creek Interceptor, Mountain Creek Sections 5 & 6 Phase 1A is complete, Phase 1B is under construction and is anticipated to be completed December 2010.  Phase 2 is designed and is scheduled to be bid in August 2010.  Construction will begin approximately October 2010 and is expected to be complete by late 2011.  This will increase the diameter of the pipe from 72 to 96 inches, resulting in additional line capacity.  In addition, preliminary design activities are underway to increase the East Mountain Creek Interceptor from 33 and 36 inches to 60 inches in diameter, which will result in increased hydraulic capacity.  Construction is expected to begin in
early 2011.