Chinese Premier Wen Jiabao has asked for strict enforcement of the law during the upcoming nationwide environmental inspection.
The inspection, which began on Wednesday under the supervision of the State Environmental Protection Administration, aims to prevent companies discharging waste illegally.
Wen ordered the "improvement of the legal system, clarification of which departments should be held accountable and the tightening of law enforcement" during the inspection.
China's top environmental official Zhou Shengxian called for the clearance of all the illegally constructed docks, stock farms and garbage storages.
The waste water discharging companies sitting along big rivers including the Yangtze River, Yellow River, Huaihe River and Songhua River that harbour potential pollution should be carefully dealt with, Zhou said.
"If illegal operations are discovered, the companies must be closed and punished," he ordered.
Zhou also pledged to block projects that cause serious pollution or harm the ecology. He said construction projects that have not passed environmental inspection should be strictly punished.
China has denied approval for 1,190 out of 55,000 construction projects evaluated over the last two years.
Last year, the environment agency ordered the suspension of 30 big construction projects for alleged violations of environmental laws.