Taiwanese company Vedan sent a scientist to a conference on Tuesday in Ba Ria-Vung Tau to claim less responsibility for the pollution of the Thi Vai River and therefore give out less compensation.
Ba Ria-Vung Tau is among three localities suffering from Vedan's untreated wastewater into the Thi Vai.
The others are Ho Chi Minh City and Dong Nai Province, where Vedan has its factory and which has reported the most damage.
Lee Ken, a Taiwanese professor representing the company that produces monosodium glutamate (MSG), said at the conference that the industrial zones along the Thi Vai and its tributaries such as Go Dau, Nhon Trach 2, Phu My 1 and My Xuan A are also responsible for the pollution.
Ken said Vedan should only be blamed for 8.8 77 percent of pollution in the river, depending on the area.
Vietnam's agencies and the affected localities have accused Vedan of causing 90 percent of the damage to the river.
Lee said Vedan's sewage had damaged 325 hectares of seafood farms in Ba Ria Vung Tau instead of 2,400 as the province had said earlier.
He said Vedan's discharge of fermented solutions didn't affect the local salt fields, and so that area could not be counted.
The company would therefore provide compensation amounting to more than VND2.1 billion instead of the VND53 billion agreed earlier by Vietnam's environmental authorities, the Taiwanese said.
He added Vedan will give the farmers in the province VND278 million for their time following the case over the past two years.
Tran Van Cuong, deputy director of Ba Ria Vung Tau Department of Agriculture and Rural Development, said the calculation was "surprising" as Vedan had paid VND4.7 billion for its pollution in 1995-1996, but was now only paying VND2.1 billion for the remaining time which totals over 10 years.
Vedan's untreated wastewater killed aquaculture and riverside crops from 1994 to 2008, when the illegal dumping was discovered by the environmental police.
Over the period, the company dumped 105 million liters of untreated wastewater into the river each month via a secret pipeline.
Cuong said agencies in the province saw the effects of Vedan's actions while monitoring 1,255 affected farmers and that they can provide proof if Vedan requires.
He said Vedan's wastewater polluted the water, so it must have affected the quality of local salt.
"Vedan should therefore consider compensating the salt farmers as well," he said.
The conference was attended by Vedan's general director Yang Kun Hsiang and officials from Vietnam's Environment General Department under the Ministry of Natural Resources and Environment.
Luong Duy Hanh, deputy chief inspector of the department, said Vedan and Vietnam's environmental officials should meet to agree on the final amount of compensation by the end of May.