China - Ningbo Water Management (GEF) Project : environmental assessment (Vol. 2 of 3)

El 302 Volume 2 Constructed Wetland Study Of the Proposed GEF Ningbo-Cixi Wetland Project r = South China Institute of Environmental Sciences, SEPA of China March. 2006  Constructed Wetland Study Of the Proposed GEF Ningbo-Cixi Wetland Project Contents Chapter One Outline ........................................1 1.1 Project Name ........................................1 1.2 Study Object ........................................1 1.3 Construction Institution ........................................1 1.4 Construction Site ........................................1 1.5 Main Construction and Scale ........................................1 1.6 Construction Period ........................................2 1.7 Investment Estimate ........................................2 1.8 Compilation Base ........................................2 Chapter Two Project Background ........................................3 2.1 General Situation of the Area ........................................3 2.2 Natural Conditions ........................................3 2.2.1 Topography and Physiognomy ........................................ 3 2.2.2 Geology ........................................3 2.2.3 Soil ........................................4 2.2.2 Rivers and Hydrology ........................................4 2.2.4 Climate ........................................4 Chapter Three Project Construction Scheme ........................................6 3.1 Design Object ........................................6 3.2 Project Content ........................................6 3.3 Technological Route and Construction Scheme .............................6 3.3.1 Technological Route ........................................7 3.3.2 Construction Scheme ........................................8 3.4 Design Principle ........................................8 3.5 Design Water Quality ........................................9 3.6 Construction Scale and Scheme Selection .................................... 10 3.6.1 Construction Scale ....................................... 10 3.6.2 Scheme Selection ....................................... 10 3.7 North Wetland Design ....................................... 15  Constructed Wetland Study Of the Proposed GEF Ningbo-Cixi Wetland Project 3.7.1 Technique Design ................................................... 15 3.7.2 Layout ................................................... 19 3.7.3 unit design ................................................... 20 3.8 East Wetland Design ................................................... 24 3.8.1 Technique Design ................................................... 24 3.8.2 Layout ................................................... 25 3.8.3 unit design ................................................... 26 3.9 Characters of the wetland ................................................... 28 Chapter Four Predict of Constructed wetland treatment effect ........... 29 4.1 Design Improvement of the Constructed Wetland ........................ 29 4.1.1 Enhancement of the removal rate of N and P ...................... 29 4.1.2 Design Improvement of Constructed Wetland .................... 30 4.2 Performance Prediction of Constructed Wetland ......................... 31 4.2.1 Minimal Requirement of Constructed Wetland Performance ....................................................................................................... 3......................... 31 4.2.2 Prediction of Wetland Treatment ......................................... 32 4.3 Ammonia ( non-ion ammonia) and Involved Public Health ........ 38 4.4 Issue of Nitrates ................................................... 40 Chapter Five Estimated Engineering Investment ................................ 42 5.1 Estimated Investment of North Constructed Wetland .................. 42 5.2 Estimated Investment of East Constructed Wetland ..................... 43 5.3 Operational Fee ................................................... 43 5.3.1 Operational Fee of North Constructed Wetland .................. 43 5.3.2 Operational Fee of East Constructed Wetland ..................... 43  ChapterOne Outline Chapter One Outline 1.1 Project Name Constructed Wetland Study of Ningo-Cixi Wetland Project 1.2 Study Object The project studies the associated constructed wetland system of the two Cixi City's Wastewater Treatment Plants, and prepares for World Bank and GEF's approval of the proposed Ningbo-Cixi Wetland Project. The research will reach the extent of Feasibility Study, including demonstration, design and cost estimate of detail wetland schemes. 1.3 Construction Institution Cixi City Drainage Co., Ltd. 1.4 Construction Site Cici city, Zhejiang province. The construction site is shown in figl-l. 1.5 Main Construction and Scale The associated constructed wetland of Cixi City Wastewater Treatment Engineering will be constructed in two stages: for the North Wastewater Treatment Plant, the scale of year 2010 is 100,000 m3/d, and that of year 2020 is 320,000 m3/d; for the East Wastewater Treatment Plant, the scale of year 2010 is 50,000 m3/d, and that of year 2020 is 100,000 m3/d. Now only consider the scale of year 2010. (1) North Constructed Wetland: its scale is 100,000 m3/d, which technique is Vegetated Submerged Beds + Free Water System; (2) East Constructed Wetland: its scale is 50,000 m3/d, which technique is Vegetated Submerged Beds + Free Water System. I  ChapterOne Outline 1.6 Construction Period The constructed wetlands will be constructed and used with the secondary wastewater treatment plants synchronously. 1.7 Investment Estimate Total construction investment of North Constructed Wetland: RMB Y57,964,500, including: Part I Engineering Cost: 42,141,800+6,191,300= RMB Y48,333,100; Part 2 Other Cost: 5,970,800+900,400= RMB Y6,871,200; Basic Contingent Cost: 2,405,600+354,600= RMB Y2,760,200. Total Construction Investment of East Constructed Wetland: RMB Y 12,776,400,including: Part 1 Engineering Cost: RMB Y 10,668,000 Part 2 Other Cost: RMB Y 1,500,200; Basic Contingent Cost: RMB Y608,400. 1.8 Compilation Base 1.8.1 State Laws and Regulations 1.8.2 Local Regulations and other documents 1.8.3 Standards and Criteria 2  Chapter Three Project Construction Scheme Chapter Two Project Background 2.1 General Situation of the Area Cixi is located on the side of East Sea, 60 km away to the west of Ningbo, 148 km away to the south of Shanghai, 138 km away to the west of Hangzhou. It is the center of the Three Cosmopolitan Golden Economic Triangle - Shanghai, Hangzhou and Ningbo, which is located at Hangzhou Bay Area of the South Loop of Yangtze River Delta Economic Circle. Its regional and transportation advantage is quite significant. Cixi City is in charge of Ningbo City. Its administrative area is 1,154 km2, and its population is 1,015,400. 2.2 Natural Conditions 2.2.1 Topography and Physiognomy Cixi City is located at the Seashore Plain, north of Ningshao Plain, which position is longitude 121