Thailand: Tests prove ethanol plant leak killed giant stingrays

Thailand: Tests prove ethanol plant leak killed giant stingrays

The Pollution Control Department will sue Rajburi Ethanol Co for allowing
molasses wastewater to leak into the Mae Klong River, killing many giant
stingrays and other aquatic life.

Director-general Wijarn Simachaya said on Friday testing had shown that
molasses wastewater leaked from the plant into the river in Ban Pong
district of Ratchaburi, polluting it and killing aquatic life, including
many native giant stingrays, in Ratchaburi and Samut Songkhram provinces
from Oct 1 to 7.

He said Rajburi Ethanol earlier admitted there was a leak from its last pond
of treated molasses wastewater at 8.50am on Sept 30. Many agencies had
subsequently tested the water in the river.

Tests found that dissolved oxygen in the lower part of the river amounted to
1.0-2.8 milligrammes per litre from Oct 4 to 10. This was below the level
measured there in the same period last year.

Biochemical oxygen demand (BOD) in Samut Songkhram from Bang Khonthi
district down to the estuary ranged between 11 and 28 mg per litre on Oct 7.

Molasses wastewater leaked from Rajburi Ethanol on Sept 30 continued to
accumulate in the Mae Klong River at least until Sept 7. It took 6-8 hours
for the water mass in the river to flow from Ban Pong district, Ratchaburi,
to Bang Khonthi district, Samut Songkhram, and a high tide during the period
blocked the water mass from reaching the sea.

Consequently, some of the molasses wastewater settled in the riverbed and
high levels of free ammonia killed aquatic animals, including stingrays,
which were unable to discharge ammonia from their bodies during the time of
low dissolved oxygen, Mr Wijarn said.

Tests to simulate the condition of the river during the pollution period
showed that the level of free ammonia soared 18 times and caused the sudden
death of fish, he said.

The Pollution Control Department would take legal action against the plant,
he said.

A total of 45 giant stingrays were found dead in the area in early October.

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Ref:
http://www.bangkokpost.com/news/general/1116004/tests-prove-ethanol-plant-le
ak-killed-giant-stingrays

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John Diecker
APT Consulting Group Co., Ltd.

www.aptthailand.com