Incident Name: San Jacinto River Spill
Subject: Report - Final
Incident Date: 10/20/1994
Incident Location: Channelview, Texas
Author: Ilene Byron and Ken Barton
Latitude: 29°48.5' N
Longitude: 95°04.0' W
USCG District: 8
Product: gasoline, home heating oil, Arabian crude, and natural gas
Type: 1, 2
Volume: 64,000 barrels of gasoline
196,000 barrels of crude oil
146,000 barrels fuel oil
Source:pipeline
RAR: Marine Mammals: bottlenose dolphins
Birds: waterfowl, bald eagle
Fish: Gulf menhaden, spotted seatrout, black drum, red drum, striped mullet, and southern flounder
Mollusks: oysters
Crustaceans: brown shrimp, white shrimp, and blue crabs
Recreation: state park, marinas, boat ramps
Dispersants: No
Bioremediation: Yes
In-Situ Burning: Yes
Special Interest Topic(s): marshes, exposed tidal flats, sheltered fine-grained sand beaches, sheltered tidal flats, mixed sand and shell beaches, salt marsh, riprap, piers, spoil bank, grass lawns
Summary: Between October 18 and 20, a strong low-pressure system stalled over the Houston area producing more than 30 inches of rain. The San Jacinto River rose from its normal height of 2.5 feet to 24.3 feet. The river overtopped its banks, cutoff a meandering loop, and scoured a new channel through a normally dry area containing pipelines. As a result of the flooding, Houston had been declared a National Disaster Area and the estuarine environments of Galveston Bay were stressed because of the influx of fresh floodwaters. As the flood waters began to recede, pipelines began to rupture.
It was surmised that large debris or some barges had broken free and were caught in the high-river currents and collided with the pipelines, causing four of them to rupture. It is also possible that the new channel cut by the flooded river may have undercut the pipeline supports, which were not designed for water crossing.
The ruptured pipelines contained gasoline, crude oil, heating oil, and natural gas. Within hours of the ruptures, the spilled products ignited and, already caught up in the flood waters, become a burning mass moving downstream. The fires destroyed many homes along the river banks. However, as a result of the fire much of the spilled products were consumed. After some time, the fire continued only at the source of the leaks. The natural gas leak stopped, but a combination of the remaining products continued to leak.
Behavior: Initially, all the gasoline, diesel, and crude oil pipelines were burning and remained burning at the rupture point for seven days. The combustion was incomplete and when the flames died out, flowing bands of black oil were seen. The thick, black oil was seen at the release point and immediately downstream from the fires. The diesel diluted the crude oil between 20 and 80 percent as shown by gas chromatography-mass spectrometry (GC-MS) test results. The separate source oils were emulsified by the rapid current of the San Jacinto River and decaying organic matter absorbed much of the oil. The products flowed downstream and pooled along some shorelines and, as the water level dropped, the oil stranded on these shorelines. Because of the unusually high water, some oil was found on the lawns of private homes and in the tops of small trees along the rivers.
The reliability of calculations of mass balance in the San Jacinto River spill is questionable. While it is possible to estimate the amount recovered or evaporated, the fraction of the oil burned or dispersed in the river cannot be determined. There were 8,500 barrels of product decanted from the recovered oil-water mixture.
Countermeasures/Mitigation: A Unified Command Center was established in Baytown, Texas at the Exxon facility. About 1,000 people were involved in the cleanup, including contract workers and Federal, state, and local government employees. A section of Interstate 10 was closed for two days to make a staging area for helicopters and equipment. There were 18 skimmers used and 40,000 feet of hard boom were deployed. The affected area was divided into five divisions, each with a field division leader and contractors. The northernmost division, at the site of the pipeline break, was particularly difficult to clean. In a heavily wooded area, the rain mixed with the sand to form a shallow quicksand. Cleanup proved easier as the water level dropped and the area began to dry out.
The uncontrolled in-situ burning of the spilled products lasted seven days and reduced the amount of product released onto the water. The Unified Command decided to let the fire burn because it was consuming some of the spilled oi,l minimizing the chance of creating an explosive atmosphere from the leaking gasoline. Dispersants were considered; however, no easily accessible freshwater dispersants were available. The shoreline cleaning agent Corexit 9580 was used at the request of land owners and was very effective on riprap.
Other Special Interest(s): Except for emergency operations, much of Houston was shut down because of the floods before the pipelines ruptured. Emergency operations included evacuating residences and closing the Houston Ship Canal and sections of Interstate 10. The USCG spearheaded flood rescue efforts by directly assisting and rescuing over 500 victims.
Initially all the pipelines were burning. The gasoline and crude and diesel oils were burning at the pipe source and the gasoline was pooling in the lee of shoreline where it continued to burn. Fire boom was deployed at the pooled gasoline to contain it for burning. At one point the gasoline fire at the shoreline was extinguished; however, it was re-lit to remove the threat of an explosive situation and protect life and property.
The RRT approved a proposal to use Corexit 9580 to clean the riprap along the shoreline of the Exxon facility. A test to monitor the effectiveness of the Corexit was observed and a follow-up study is planned.
RRT approval was also given to conduct a bioremediation treatment and study in Upper San Jacinto Bay. This is an ongoing study by Texas A & M University.
NOAA Activities: NOAA was notified of the incident on October 20, 1994, by the USCG MSO Houston, who requested on-scene support. The NOAA Scientific Support Team was assembled early in the response. State of Texas biologists, RP representatives, and USFWS personnel were also members of this team. NOAA personnel conducted overflights to track the oil in the river and determined whether any oil could be seen in Galveston Bay, determined the chemical fate of the oil, and led a team considering the applicability and biological feasibility of using bioremediation products. NOAA also provided information management support to the Unified Command Planning Section and produced twice-daily overflight, sector, shoreline oiling, and cleanup status maps. NOAA personnel led the shoreline oiling assessment teams.
The SSC provided twice-daily weather and river-stage briefings and attended and spoke at daily press briefings. The SSC also attended two townhall-type meetings to address the local communitys concerns as a result of the spill, fire, and flood. NOAA worked closely with state and federal trustees to facilitate the consensus of what cleanup methods were to be used and "how clean is clean." NOAA also provided guidance to the FOSC on the use of shoreline cleaning agents and facilitated a test and an RRT-approved application to help remove oil from private shorelines.
NOAA provided the FOSC with on-scene scientific support from October 20 through November 3, 1994.
References: Genwest Systems. 1994, Information Management Report
for the San Jacinto River Spill. November 14, 1994. Seattle: Genwest
Systems for Hazardous Materials Response and Assessment Division,
NOAA. NOAA. 1995. Hotline 165. Seattle: Hazardous Materials Response
and Assessment Division, Office of Ocean Resources Conservation and
Assessment. 50 Reports
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