The chemical, used to eradicate hydrilla, was used by Dow Chemical, which reported to the water authority it had inadvertently sprayed it too close to the area where water is taken in from the waterway.
Test results, according to the Brazosport Water Authority and the city's public works director, came back last night after 11pm and showed the water samples were all within acceptable levels for any contamination.
Restrictions which urged customers to avoid watering lawns or washing cars were cancelled at midnight. The city's water reserve was never affected, according to the water authority.
Samples were tested twice at the Dow Chemical lab. A backup test is also being performed.