Changsha Xianghu Sewage Treatment Plant is a state-owned enterprise?

No. Changsha Xianghu Sewage Treatment Plant is an enterprise under Changsha City Urban Construction Development Group Co., Ltd, which is a municipal enterprise, not a state-owned enterprise. Changsha City Urban Construction Development Group Co., Ltd. is a large comprehensive urban investment and construction group company authorized by the Changsha Municipal Government, which is mainly responsible for the investment, construction and operation management of municipal infrastructure construction and urban utility projects in Changsha City.