LITANI RIVER BASIN MANAGEMENT SUPPORT PROGRAM LITANI RIVER CONSTRUCTED TREATMENT WETLAND DESIGN REPORT June 2012 This report was produced for review by the United States Agency for International Development (USAID). It was prepared by International Resources Group (IRG) under Contract EPP-I-00-04-00024-00 order no 7. LITANI RIVER BASIN MANAGEMENT SUPPORT PROGRAM LITANI RIVER CONSTRUCTED TREATMENT WETLAND DESIGN REPORT Contract No.: EPP-I-00-04-00024-00 order no 7. JUNE 2012 DISCLAIMER The author’s views expressed in this publication do not necessarily reflect the views of the United States Agency for International Development or the United States Government TABLE OF CONTENTS 1. INTRODUCTION ················································································ 1 1.1. Summary of Feasibility Study ............................................................................................................. 1 1.2. Site Selection Justification ................................................................................................................... 2 2. SITE OVERVIEW ················································································· 3 2.1. Water Quality ....................................................................................................................................... 3 2.2. Hydrology ............................................................................................................................................... 5 2.3. Topography ............................................................................................................................................ 5 3. TREATMENT WETLAND PROCESS: BASIS AND FEATURES ················· 7 3.1. Pump Station .......................................................................................................................................... 7 3.1.1. Sizing ............................................................................................................................................................................. 7 3.1.2. Connection to Litani River ..................................................................................................................................... 7 3.2. Constructed Wetland ......................................................................................................................... 7 3.2.1. Sizing ............................................................................................................................................................................. 7 3.2.2. Location, Layout, and Features.............................................................................................................................. 8 3.3. Existing on-Site Drainage Canals .................................................................................................... 11 3.4. Discharge Channel ............................................................................................................................. 11 3.4.1. Sizing ........................................................................................................................................................................... 11 3.4.2. Layout and Features ............................................................................................................................................... 11 4. POTENTIAL PERFORMANCE OF WETLAND ······································ 13 4.1. Water Balance ..................................................................................................................................... 13 4.2. Treatment Performance Expectations........................................................................................... 13 4.3. Comparison to Lebanese Standards .............................................................................................. 14 5. VEGETATION AND HABITAT FEATURES ··········································· 16 5.1. Constructed Wetland ....................................................................................................................... 16 5.2. Discharge Channel ............................................................................................................................. 16 5.3. Litani River Banks ............................................................................................................................... 17 6. CONSTRUCTION AND STARTUP ······················································ 18 6.1. Earthmoving and Grading ................................................................................................................. 18 6.1.1. Constructed Wetland ............................................................................................................................................ 18 6.1.2. Discharge Channel .................................................................................................................................................. 19 6.2. Plants and Planting Specifications .................................................................................................... 20 6.2.1. Phragmites Australis .................................................................................................................................................. 20 6.2.2. Salix Species ............................................................................................................................................................... 20 6.2.3. Nymphaea alba .......................................................................................................................................................... 21 6.2.4. Other Species ........................................................................................................................................................... 21 6.3. Initial Filling of the Wetland ............................................................................................................. 21 6.4. Startup Requirements ........................................................................................................................ 22 6.5. Opportunities for Future Expansion .............................................................................................. 22 7. OPERATIONS AND MAINTENANCE GUIDANCE ································ 24 7.1. Operator Responsibilities ................................................................................................................. 24 7.2. Site Access ........................................................................................................................................... 24 7.3. Safety ..................................................................................................................................................... 25 7.4. Treatment Processes ......................................................................................................................... 25 7.5. Pump Station ........................................................................................................................................ 26 7.6. Constructed Wetland ....................................................................................................................... 26 7.6.1. Water Level Control ............................................................................................................................................. 27 7.6.2. Flow Control ............................................................................................................................................................ 27 7.6.3. Vegetation Management ........................................................................................................................................ 27 7.6.4. Berm Maintenance .................................................................................................................................................. 28 7.6.5. Control of Nuisance Animals .............................................................................................................................. 29 7.6.6. Mosquitoes ................................................................................................................................................................ 29 7.7. Discharge Channel ............................................................................................................................. 30 REFERENCES ······························································································ 31 FIGURES Figure 2.1: Summary of Water Quality Litani River Near Joub Jannine Bridge ......................... 4 Figure 2.2: Summary of Estimated Water Quality Litani River at Site ....................................... 4 Figure 2.3: Average Flow in the Litani River at Joub Jannine .................................................. 5 Figure 2.4: Digital Elevation Model of Wetlands Site .............................................................. 6 Figure 3.1: Site overview ............................................................................................................ 9 Figure 3.2: Wetland detail ....................................................................................................... 10 Figure 3.3: Results of hydraulic modeling in the Litani River at discharge channel outlet location .................................................................................................................................... 12 Figure