water to be fit for drinking even though thousands of the dead animal were found floating across a stretch flowing through the city, officials said.
Official figures said 5916 dead pigs were fished out the river but many more remain.
The city's water quality has not been affected and is safe for human consumption, a local water supply company said.
"The dead pigs will float to the area near the Songpu Bridge, one of the major water intakes of the Huangpu River, if they are not collected in time," said Chen Zhenlou, a deputy to the National People's Congress and a professor with the College of Resources and Environmental Science, East China Normal University told state media.
An automatic water quality monitoring network should be built to constantly check for changes in relevant indicators, Chen added
Qian Huizhong, deputy director of the Xiaokunshan water plant in Shanghai, said: "If the water is contaminated, we will put more the disinfectants and activated carbon to purify the water."
According to reports, tags pinned to the ears of the pigs for tracing purposes indicate that they may have come from the upper reaches of the Huangpu River in Jiaxing City, east China's Zhejiang Province
Meanwhile, authorities were checking the on rumours of a diseased dead pig dumping scandal that is circulating in Zhejiang province.
Porcine circovirus was detected in one water sample taken from the Huangpu River, according to the local agricultural commission.
It was not immediately whether the dumping of the dead pigs was related to a case in which 46 people were handed prison sentences for selling meat from diseased pigs.
"A court in east China's Zhejiang Province on Wednesday issued prison sentences ranging from six months to six-and-a-half years to 46 people involved in processing and selling meat from diseased pigs," state-run Xinhua news agency reported.
Zhang Xingbing, the principal offender who illegally purchased, slaughtered the diseased pigs and sold the meat, was sentenced to six-and-a-half years in prison and fined 800,000 yuan (128,687 U.S. dollars), according to the Wenling People's Court.