Development of Conceptual Design and Cost Estimation for Decentralized Sanitation and Wastewater Treatment Solutions & Management plan in Korail Settlement…

Title of the assignment

Development of Conceptual Design and Cost Estimation for

Decentralized Sanitation and Wastewater Treatment Solutions & Management plan in Korail Settlement, Dhaka

Purpose

To develop conceptual decentralized wastewater treatment solutions and indicative cost estimates for Korail Settlement through an evidence-based planning process that supports improved wastewater and fecal sludge management and provides a pathway toward sustainable municipal service integration

Location

Karail Slum, Dhaka, Bangladesh

Estimated Duration

3 Months

Reporting to Technical Supervisor of this assignment

WASH Specialist, WASH Section, UNICEF, Bangladesh

1.Background

Korail is the largest informal settlement in Dhaka, covering approximately 100 acres and accommodating an estimated 250,000 residents. The settlement is characterized by very high population density, inadequate housing conditions, limited public infrastructure, and insufficient water and sanitation services.

The sanitation situation remains critical. Most households rely on shared or informal sanitation facilities, with wastewater and fecal sludge frequently discharged into the surrounding environment. Formal fecal sludge management services are almost non-existent, contributing significantly to environmental pollution, particularly in Banani Lake.

Water quality is also a major concern. Widespread contamination of municipal piped water due to leaking distribution systems, illegal connections, and unsafe storage practices exposes

residents to significant public health risks, including diarrheal diseases and typhoid. Children are particularly vulnerable.

UNICEF, in partnership with Dhaka North City Corporation (DNCC), the Government of Denmark, the Gates Foundation and other stakeholders, has been supporting innovative sanitation interventions within Korail. However, a comprehensive Karail low-income community sanitation and wastewater management framework, including a clear pathway for integration into Dhaka city-wide inclusive sanitation planning and DWASA/DNCC investment planning, is still lacking.

Given the complexity of the settlement, land tenure challenges, and limited municipal service provision, there is a need to develop technically feasible, climate-resilient and scalable decentralized wastewater treatment solutions accompanied by indicative cost estimates and implementation strategies.

2.Objectives, Purpose and Expected Results Purpose:

To develop a settlement-level conceptual sanitation and wastewater management plan/ solutions

for Karail including, conceptual decentralized/hybrid wastewater management solutions, indicative investment and O&M costing, t through an evidence-based planning process that supports improved wastewater and fecal sludge management and provides a practical pathway for sustainable integration of the settlement into city wide sanitation planning process.

Objectives

Assess the existing sanitation, wastewater, fecal sludge management, environmental, and institutional and social inclusion and service delivery contexts in Karail.

Develop technically feasible, climate resilient and financially realistic decentralized and/or hybrid sanitation and wastewater management scenarios suitable for Karail and comparable high-density low-income settlements.

Prepare conceptual engineering designs, indicative layouts, service-zone maps and technology option for clustered and hybrid decentralized wastewater treatment systems.

Define potential service zones and infrastructure requirements.

Estimate indicative CAPEX, OPEX, lifecycle costs, investment requirements, O&M responsibilities, cost recovery options, and phased investment/deployment options.

Provide recommendations for institutional arrangements, service delivery mechanisms, community engagement, gender/disability inclusion, safeguards long-term O&M and integration of Karail into DWASA/DNCC master planning and CWIS processes.

Expected Results

Output 1: Baseline Assessment, Service-Zone Mapping and Strategic Projection

A comprehensive assessment synthesizing existing information on wastewater, fecal sludge management, water quality, socio-economic conditions, environmental contamination pathways and institutional challenges in Korail.

Output 2: Decentralized/Hybrid Sanitation and Wastewater Treatment Options and Concept Design

Conceptual designs of decentralized and hybrid wastewater treatment solutions suitable for high-density informal settlements, including phased implementation strategies.

Output 3: Karail Sanitation and Wastewater Management Plan, Service Zone Modelling and Investment Framework

Service zone delineation, wastewater demand projections, indicative engineering requirements, land requirements, and cost estimates to support future investment decisions.

Major Activities

Task 1: Inception and Baseline Assessment

Task 2: Institutional and Service Delivery Assessment

Task 3: Development of Wastewater Management Scenarios Task 4: Conceptual Engineering Design

Task 5: Service Zone Planning and Cost Estimation Task 6: Final Reporting and Presentation

3.Description of Assignment

Details of these tasks are described in the table below

Timeline

Name of Activity

Description of tasks

Locations/ quantity

Deliverables

Week 2

Inception and Baseline Assessment

reports, plans and datasets related to water, sanitation, wastewater and fecal sludge management in Korail.

environmental and topographical conditions.

contamination pathways and wastewater leakage points.

consultations with relevant government agencies, service

Karail Slum, Dhaka

Inception Report including methodology, workplan and stakeholder engagement strategy

Timeline

Name of Activity

Description of tasks

Locations/ quantity

Deliverables

providers, community representatives and development partners.

with methodology and workplan.

Week 6

Institutional and Service Delivery Assessment

institutional arrangements and service provision mechanisms.

with land tenure, service mandates and public sector engagement.

integration into future

municipal wastewater management systems.

Karail Slum, Dhaka

Baseline Assessment, service-zone mapping, and Institutional Analysis Report

Week 8

Development of Wastewater Management Scenarios

decentralized wastewater treatment technologies.

nature-based, mechanical and hybrid treatment options.

delivery scenarios integrating sewered and non-sewered systems.

technical, environmental, social and financial criteria.

Karail Slum, Dhaka

Wastewater Management Scenarios and Technology Assessment Report

Week 10

Conceptual Engineering Design

for decentralized wastewater treatment facilities.

and conveyance systems, including condominial or shallow sewer alternatives.

and technology options.

flooding risks and resource recovery opportunities.

Karail Slum, Dhaka

Scenario Assessment, Conceptual Design Package, Costing and Investment Roadmap and Service Zone Plan

Timeline

Name of Activity

Description of tasks

Locations/ quantity

Deliverables

Week 11

Service Zone Planning and Cost Estimation

service zones.

generation and treatment demand.

requirements.

and operational cost estimates.

implementation and investment scenarios.

Karail Slum, Dhaka

Cost Estimation and Investment Roadmap

Week 12

Final Reporting and Presentation

reports.

recommendations to UNICEF and key stakeholders.

finalize deliverables.

Karail Slum, Dhaka

Final Karail sanitation and wastewater management plan, CWIS integration note, capacity building completion report and

Presentation

5.Reporting requirements

The consultant will work under the overall guidance of the UNICEF Bangladesh WASH Section and in close coordination with Dhaka North City Corporation (DNCC), community representative and other relevant stakeholders.

All reports, datasets, drawings and outputs developed under this assignment shall become the property of UNICEF and shall be submitted in editable and PDF