IncidentNews Home  >>  Incident  >>  Entry

Trajectory

Date: March 9, 2001
  To: NOAA SSC Charlie Henry
  
FROM: NOAA/Hazardous Materials Response Division
      Modeling and Simulation Studies
      Seattle, WA 98115
      
SUBJECT : Naphtha spill off Bolivar Peninsula

FOR ADDITIONAL INFORMATION, PLEASE CONTACT Glen Watabayashi 
MODELING AND SIMULATION STUDIES, NOAA, SEATTLE, WA 98115.
PHONE (206) 526-6317.
______________________________________________________
 The scenario as reported is as follows:

At about 05:30 CST on Friday, March 9, 2001, two barges collided at the intersection of
the Houston Ship Channel and the Intercoastal Waterway.


One of the barges is estimated to have lost between 600 and 1000 bbls of a "heavy straight
run naphtha.."  The specific gravity of the product is given as .788 (API about 48).  The
naphtha contains about 1% benzene and there is concern that the ferry terminal which is
about 1/4 miles for the accident site may be impacted by benzene fumes.


An overflight this morning reported seeing no sheens on the water but seas were choppy
with white caps.


If any of this initial information is incorrect, please let us know ASAP as it would
affect any trajectory implications.

______________________________________________________
1) 24-hour Wind Forecast
Winds are expected to be from the NNW this morning becoming N to NE 10 -15 knot this
afternoon.


2) TIDE CURRENTS
The accident occurred during a strong ebb which has been made even stronger due to a
frontal passage last night.  The ebb is expected to continue into this afternoon.


3) TRAJECTORY
We would expect the strong ebb tide and NNW to N winds to quickly move the oil out of
Galveston Bay.  By the end of the ebb tide sometime mid afternoon today, we would expect
most if not all of the floating product to be past the jetties and out into the Gulf.
With the persistent winds from the N, and weak flood this afternoon, very little if any
product will reenter Bolivar Roads.

Some of the naphtha may beach as it exits Bolivar Roads.  Possible beach impact areas are
the west end of Bolivar Peninsula, and the stretch of beach between Fort Pt and the south
jetty on the south side of Bolivar Roads.


4) OIL FATE
 ADIOS II model estimates are that about 90% of the product will be evaporated and
dispersed into the water column between 2 and 6 hours of the spill.


When spilled, the naphtha spreads quickly into thin films by forming patches of rainbow
and silver sheens.  If the sheens reach the shoreline in a few hours,  a slight staining,
or greasy film is common. Normally, this type of release does not become an involved
cleanup problem.


It should be noted that naphtha does have a relatively high concentration of light
aromatic compounds and tends to be more soluble and more toxic then heavier oils.  In high
energy environments, the naphtha will likely disperse as small droplets in the water
column.  Naphtha spills can result in an initial toxic shock to biota and result in a
local fish or shell fish kill.