HOUSTON – A week after a chemical leak at an asphalt plant in Corpus Christi triggered a four-day water ban, the Texas attorney general's office has joined an investigation by state and federal environmental authorities and key questions remain unanswered.
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The ban was imposed the night of Dec. 14 out of concern that hydrochloric acid and Indulin AA-86, a corrosive asphalt-emulsifying agent, may have entered the water system. The ban was gradually eased as officials excluded outlying areas from being at risk.
Q: Was the water supply of Gulf Coast city of 320,000 residents contaminated? Was anyone sickened?
All of more than 100 water samples taken across the city and tested by the EPA for Indulin turned up negative so there is no evidence so far of contamination. The EPA and Texas Commission on Environmental Quality said Tuesday that included samples taken where 12 people reported illnesses possibly related to tainted water. Their symptoms could not immediately be determined. Contact with the chemical concentrate can blister skin and the respiratory system and damage internal organs, the manufacturer says.
The attorney general will decide whether to pursue legal action against the polluter, said TCEQ spokesman Terry Clawson. Several lawsuits have been filed and the mayor, Dan McQueen, has pledged to recover as-yet unspecified damages.
Q: How much of the chemical leaked, over what time period, who was responsible and when was the city notified?
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Employees of the oil refiner Valero Energy Corp. at an asphalt plant leased to Ergon Asphalt and Emulsions, Inc. first noticed rusty brown water coming from a faucet in the administration building on Nov. 23, Valero said in a timeline released Saturday.
Valero said its employees noticed "milky, sudsy water" at the faucet on Dec. 7 and notified the city and municipal workers flushed the water line. A day later, Valero said, Ergon officials were alerted and asked if their operations were the source of the tainted water.
On Dec. 12, Valero employees again noticed "milky, sudsy water" at the faucet and alerted the city. Municipal workers tried on Dec. 13 to locate the source of the tainted water and did not find a backflow protection device, said Assistant City Manager Mark Van Vleck. Such devices are required by the state at industrial sites to prevent chemicals from backing up into pipes that feed clean water when pressure reverses. The city cut off water to the plant on Dec. 13 , said Van Vleck, and notified the TCEQ the following afternoon of what the state agency described in an internal memo as a "backflow incident from a chemical tank impacting the public water system."
TCEQ and EPA officials say they are seeking to determine when the leak began, how much chemical was released and whether it entered the city water system. In its first detailed version of events, Ergon said Saturday that the "soap solution" it uses to make asphalt — which is 98 percent water — "back flowed" into a plant water line that is not directly connected to the city water supply. Ergon did not say how much or when but told city officials that each 3,300-gallon batch contains 24 gallons of Indulin and 10 gallons of hydrochloric acid.
Q. Was this the first hazardous chemical release at the Ergon asphalt plant?
No. A TCEQ report obtained from the agency by The Associated Press shows a March 24 spill of about 350 gallons of asphalt emulsion into the soil. The company cleaned up the spill, which it classified as nonhazardous waste, and disposed of it at a landfill. TCEQ did not issue a violation.
Q: Was Ergon in legal compliance and was Corpus Christi enforcing state regulations designed to protect the water supply?
Texas administrative code requires water providers to ensure that backflow prevention devices are installed at industrial sites, that certified testers do annual inspections and that records are kept. Corpus Christi's city ordinance requires annual inspections but the city does not perform them, leaving that to state-licensed testers. AP asked Ergon if a backflow device was installed at the asphalt plant. It did not respond. The city did not immediately respond to AP's question whether it has records on annual inspections at the plant.
Associated Press writer Paul J. Weber in Austin contributed to this report.