Pollution Control Board, Assam Conservation of River Kolong, Nagaon Preparation of Detailed Project Report Project Feasibility Report for Sewerage Schemes December 2013 Joint Venture of THE Louis Berger Group, INC and DHI (India) Water & Environment Pvt. Ltd. Feasibility Report for Sewerage Schemes ii Feasibility Report for Sewerage Schemes CONTENTS Salient Features of the Project .................................................................................................. viii Executive Summary ..................................................................................................................... ix Check List for Feasibility Report ................................................................................................. xi 1 About the Project Area ............................................................................................... 1 1.1 Description of the Project Area ...................................................................................................... 1 1.1.1 Brief History of the Town................................................................................................................ 3 1.1.2 Geographical Location ................................................................................................................... 3 1.1.3 Climate ........................................................................................................................................... 3 1.1.4 Topography .................................................................................................................................... 5 1.1.5 Drainage Channels ........................................................................................................................ 5 1.1.6 Administrative Divisions ................................................................................................................. 6 1.1.7 Commercial Aspects ...................................................................................................................... 7 1.1.8 Industrial Activities ......................................................................................................................... 7 1.1.9 Educational Activities ..................................................................................................................... 8 1.1.10 Cultural Activities ........................................................................................................................... 9 1.1.11 Religious Activities ....................................................................................................................... 10 1.1.12 Socio-Economic Status ................................................................................................................ 10 1.1.13 Town Management ...................................................................................................................... 10 1.1.14 Land Cost in and around the Town .............................................................................................. 11 1.1.15 City Development Plan ................................................................................................................ 11 1.2 Population within the Project Area ............................................................................................... 11 1.2.1 Ward Wise Population ................................................................................................................. 11 1.2.2 Slum Wise Population of the last 5 Decades ............................................................................... 11 1.2.3 Population Projections as per the City Master Plan .................................................................... 12 1.3 Status of Water Supply ................................................................................................................ 13 1.3.1 Actual Water Supply from Different Sources ............................................................................... 14 1.3.2 Proposal for Augmentation of Water Supply System .................................................................. 15 1.4 Status of Existing Waste Water Disposal Works ......................................................................... 15 1.4.1 Existing Work ............................................................................................................................... 15 1.4.2 Work under Execution.................................................................................................................. 16 1.4.3 Work Sanctioned but not yet started ............................................................................................ 16 1.5 Status of Pollution of the River .................................................................................................... 16 1.5.1 Number and Details of Drainage Channel ................................................................................... 16 1.5.2 Waste Water Flow Carried by Drains .......................................................................................... 17 1.5.3 Measurement of Flows in Drains along with Copies of Test Report ............................................ 17 1.5.4 Waste Water Characteristics of Different Drains ......................................................................... 18 1.5.5 Measurement of Waste Water Characteristics along with Copies of Test Reports ..................... 18 1.5.6 Water Quality of the River U/S, D/S and at Outfall of Drain discharging into River..................... 19 1.5.7 Measurement of the Quality of River Water along with copies of Test Report ............................ 20 1.5.8 Methodology followed for Flow Measurement and Quality Characteristics ................................. 20 1.5.9 Water Quality Standards of River Water Quality ......................................................................... 20 1.6 Justification of the Project for Pollution abatement of the River .................................................. 21 2 Approach and Sewerage Districts ........................................................................... 22 2.1 Approach ...................................................................................................................................... 22 2.1.1 Design Criteria ............................................................................................................................. 23 2.1.1.1 System configuration .................................................................................................................................................... 24 2.1.1.2 Wastewater Generation Rate ........................................................................................................................................ 24 iii Feasibility Report for Sewerage Schemes 2.1.1.3 Groundwater Infiltration ................................................................................................................................................. 25 2.1.1.4 Depth of Flow ................................................................................................................................................................ 25 2.1.1.5 Peak Factor .................................................................................................................................................................. 26 2.1.1.6 Hydraulic Design Formula ............................................................................................................................................. 26 2.1.1.7 Flow Velocity and Gradient ........................................................................................................................................... 26 2.1.1.8 Maximum Depth to Invert .............................................................................................................................................. 27 2.1.1.9 Minimum Cover and Sewer Protection .......................................................................................................................... 27 2.1.1.10 Minimum Pipe Diameter ................................................................................................................................................ 27 2.1.1.11 Sewer Transition ........................................................................................................................................................... 27 2.1.1.12 Material of Sewer Line .................................................................................................................................................. 27 2.1.1.13 Structural Design of Sewer ........................................................................................................................................... 31 2.1.1.14 Manhole ........................................................................................................................................................................ 32 2.1.1.15 Sewer Crossing ............................................................................................................................................................ 33 2.1.1.16 Sewage Pumping Station .............................................................................................................................................. 33 2.1.1.17 Sewer Warning Tape ...................................................................................................................................................