Sugar Land police say the incident happened around 8:30 a.m. and had the freeway closed until noon while TxDOT crews worked to clean up the mess.
The driver of the 18-wheeler did not stop.
According to witnesses, the 18-wheeler's trailer was secured at the top, but there may have been structural problems, allowing the waste to get out.
Police say they have called the company out of Franklin, Texas, that owns the 18-wheeler.
It may face a fine for an unsecured load.
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