A SPILL demo case: The Songhua river, benzene spill
The massive benzene spill at Jilin on the Songhuajiang, China,
in November 2005 is used as a test case for the
SPILL dynamic water quality model.
Timeline of the accident
- Sunday, 13 November 2005: and explosion occured at a large petrochemical plant
in Jilin city (about 380 km) up the Songhua river from Harbin).
About 100 tons of hazardous chemicals (mainly benzene)
(about 10 tanker-truck loads) was spilled into the Songhua River.
Monday, 21 November 2005: Water to Harbin city is cut off;
the local government cites maintenance of water mains as the cause.
Tueday, 22 November 2005: State media say water could have been contaminated
after the blast;
Wednesday, 23 November 2005: Authorities admit very high levels of benzene
have been found in the water the contaminated river water was expected
to reach the city on Thursday morning and take two days to pass through.
- The toxic plume is expected to reach the city of Khabarovsk
with a population of 1,500,00 in a few days. Khabarovsk is situated
downstream of the confluence of the Songhua river and the Amur,
which should further dilute the toxic load.
Mitigations measure: Increasing the flow.
The photo taken on November 23, 2005 shows the dam of the Fengman Reservoir
on the Songhuajiang River in Jilin, a city in northeast China's Jilin Province.
The reservoir release has increased the river flow to 600 cubic meters per second,
about four times more than the usual, since November 15 to help dilute
the pollution and speed up the passage of the contaminant plume.
The photo taken on November 26, 2005 shows a section of the Songhuajiang River
in Harbin, capital of northeast China's Heilongjiang Province.
The density of nitrobenzene has lowered to only 0.99 times more
than the state standard in the Harbin section of the river,
implying that the most part of the contaminant plume
has passed the urban area of Harbin by 12:00 local time (0400 GMT)
on November 26, or 13 days after the accident.
The river: Songhuajiang
The Songhua river has a catchment of 390,526 km².
Average annual runoff is in the order of 1000 m³/s,
and varies from less than 500 to more than 1,700 m³'/s between years.
Low flows are observed between December to March, peak flows occur in
August and September. Average flow during November is 627.3 m³/s
with a standard deviation of 230.
The pollutant: BENZENE
Colourless, highly flammable liquid distilled from petroleum.
It is used as a cleaning agent, solvent, in dyes and paints.
Benzene is toxic, lethal to humans exposed to it in high levels.
Chronic exposure leads to progressive degeneration of bone marrow and leukaemia.
The city of Harbin
Harbin is located between 45o45' north latitude and 126o38'
east longitude in the the Southwest of Heilongjiang province,
at the bank of the Songhua River, in Southern Songnen Plain.
|Urban Population|| 3,370,000
|City Area|| 53,067|| km²
|Average annual temperature|| 4 ||degC
|Average annual rainfall|| 600|| mm
Impacts and Mitigation Measures
The water from the Songhua River used by the city's water supply will
be purified with active carbon after the polluted water has passed Harbin.
The purifying project demands a total of 1,400 tons of active carbon,
700 tons of which are available (by November 25) and another 700 tons
are still absent. The purification project is carried out by the
Peoples' Liberation Army of China.