Land: An adequate area of land should be used to ensure efficient treatment. Since land is limited, the key issue for constructed wetland construction is how to improve treatment efficiency while saving the land resource.

    Degradation of ammonia and nitrogen in the constructed wetlands: Due to the higher ammonia levels in the secondary effluent (8mg/L), compared with ordinarily wetlands being used for the treatment of the low BOD wastewater (less than 1-3mg/L), therefore, the challenge and issue will be to make the constructed wetlands more effective in nitrification of ammonia. Engineering/design will need to address this issue. Another issue is to reduce in the water of the constructed wetlands .

    Use of constructed wetlands to improve the ecological system along Hangzhou Bay : The constructed wetlands will substantially reduce land-based pollution to the Cixi coastal region. However, the constructed wetlands alone cannot counteract the ecological risks of sea reclamation. Sea reclamation will result in the loss of natural pollution removal processes by the tidal marshes. Therefore, an important opportunity for Cixi will be to implement an eco-friendly design to improve water quality of inland and coastal water bodies through ecological engineering approaches.