Chinanews, Beijing, Nov. 22 – Zhou Shengxian, head of State Enviromental Protection Administration, said recently that water quality of the Huai River had improved in 10 years of management.Zhou said that the central government’s policy to improve Huai River’s water quality had been correct. He pointed out that stable and regular management could change the enviromental condition of the river.In response to foreign media’s doubt about improvement of the water quality of the river, and vice premier Zeng Peiyan pointed out that China had invested 19.3 billion yuan on improving Huai River’s water quality. Zhou Shengxian launched an investigation himself on Huai River’s tributaries in Henan Province.He stressed that a long period should be needed to make the water quality of the river become better.