Phosph. Acid Spill; Houston Ship Channel, TX

Houston Ship Channel, TX | 2001-Jan-12

Initial Notification: The NOAA SSC was notified by MSO Houston of a chemical spill at approximately 1830 hours last evening (11 Jan.). The spill was the result of heavy rains and a "weak" containment dike (this is a simplified characterization of the problem). One report estimated 35,000 lbs of phosphoric acid diluted into a "million" gallons of water was released into a small ditch which eventually emptied into the Houston Ship Channel. A verbal assessment of the behavior of the chemical and possible risks was provided after contacting Dr. Ed Overton at LSU for his chemistry prospective and a review of the CAMEO data. Water monitoring had already began using a pH meter. The verbal results passed to the SSC indicated that the ditch was at pH 2 (bottom of the acid scale). However, within 40 feet of entering the ship channel, the values were neutral or background. These may have only been surface readings, so a recommendation was made that a bottom pH profile be taken. This is because concentrated solutions of phosphoric acid are more dense than water and would initially sink. Source control had reduced addition drainage from the site to a "trickle." A fish kill is possible (probable). A similar release in the same location, but of a much larger volume (45,000,000 gallons), was reported to have caused a major fish kill in 1992. A cleanup contractor is on-scene and neutralizing the ditch water with lime. John Kern, NOAA DAC, has been in contact with the state resource managers who are conducting a survey this AM. USCG district 8.