UN-Habitat’s vision is “a better quality of life for all in an urbanizing world”. UN-Habitat works with partners to build inclusive, safe, resilient, and sustainable cities and communities. UN-Habitat promotes urbanization as a positive transformative force for people and communities, reducing inequality, discrimination, and poverty.

In line with the New Urban Agenda, UN-Habitat seeks to contribute to increased equitable access to safe and affordable drinking water, improved sanitation, and sustainable management of water resources, including wastewater treatment, recycling and safe reuse. It does so by facilitating policy dialogue, sharing good practices, by providing technical assistance for the development and implementation of field demonstration projects, and by supporting local, national, and global data collection and monitoring in order to strengthen advocacy, policy, and decision-making.


The Sustainable Development Goals (SDG) set by the United Nations aim to address global challenges and ensure a sustainable future. SDG 6.3.1 focuses on improving water quality by reducing pollution, eliminating dumping, and minimizing the release of hazardous chemicals and materials. It also aims to halve the proportion of untreated wastewater and substantially increase recycling and safe reuse globally. 

In line with this goal, UNHABITAT seeking a partner to perform a study in Thailand to assess the current state of Greenhouse Gas (GHG) emissions from residential wastewater treatment plants. In addition, estimation of wastewater treated from industrial sources is also requested. 

This study relies on secondary data, utilize secondary data from the Pollution Control Department and other relevant agencies in Thailand, which offers a valuable starting point but may have limitations for detailed GHG emissions estimation. Different agencies might use varying methodologies to collect and report data, potentially leading to inconsistencies. Secondary data might not capture the specific processes within wastewater treatment plants that contribute the most to GHG emissions. Consultation with experts can help fill data gaps and refine estimates.

The findings from this study will not only contribute to the global discourse on sustainable development but also guide policy decisions and interventions in Thailand for improved wastewater management and GHG emission control.


The objective of the study is to quantify the total Greenhouse Gas (GHG) emissions associated with domestic wastewater treatments at country scale, covering wastewater treatment, wastewater discharge, and sludge disposal. The GHG emissions are calculated based on the current operational status, and off-site GHG emissions associated with energy consumption and chemical usage are also estimated.

GHG emission estimation can be conducted by: 

  1.  data collection, analysis and verification of secondary data on treatment processes, treated wastewater volumes, pollutants load, wastewater discharge and sludge disposal from existing centralized wastewater treatment plants. In addition, data will be gathered on key parameters required for emissions estimation, including: 
    • Industrial and domestic wastewater flows as needed for monitoring the SDG indicator 6.3.1 on the proportion of wastewater (safely) treated.

    • Characteristics of influent and effluent wastewater (e.g., biochemical oxygen demand, chemical oxygen demand)

    • Operational parameters of treatment processes (e.g., temperature, retention time)

    • Energy consumption data for treatment operations

  2. Quantification of GHG emissions according to globally recognized estimation methods.

    • Estimate emissions of methane (CH4) and nitrous oxide (N2O) from different treatment processes using the following IPCC Tier 2 methodologies:

For CH4:

  1. Anaerobic digestion: Calculate CH4 emissions based on the organic carbon content of influent wastewater and treatment efficiency.

  2. Sludge treatment and disposal: Estimate CH4 emissions from sludge storage, treatment, and disposal based on IPCC default emission factors.

For N2O:

  1. Nitrification and denitrification processes: Estimate N2O emissions based on nitrogen loading rates, temperature, and pH conditions, using IPCC default emission factors.

  2. Calculate total GHG emissions by summing the emissions of CH4 and N2O from all relevant treatment processes.


The Activities

Activities expected to produce the deliverables includes:

  1. Research Design: Define the scope, objectives, and methodology of the study. Determine the specific metrics and parameters that will be used for estimating.

  2. Data Collection: Gather data on industrial and domestic wastewater treatment facilities across Thailand. This may involve collaborating with government agencies. In order to collect secondary data, validate emissions estimates, and identify factors influencing emissions variability.

  3. Emissions Measurement: Develop protocols for quantifying domestic GHG emissions from different types of wastewater treatment processes, including aerobic and anaerobic treatment methods. Use established methodologies such as the Intergovernmental Panel on Climate Change (IPCC) guidelines to calculate emissions of methane (CH4) and nitrous oxide (N2O).

  4. Data Analysis: Analyze the collected data to estimate the country-scale GHG emissions from domestic wastewater treatment in Thailand.

  5. Reporting and Communication: Prepare reports detailing the findings of the study, including the methodology, and results. 

The Deliverables

Expected deliverables are:

  1. Detailed Methodology for quantifying GHG emission from wastewater treatment plants in Thailand. 

  2. A comprehensive document outlining the step-by-step procedure for quantifying GHG emissions from WWTPs in Thailand. This document should serve as a guide for researchers, practitioners, and policymakers involved in emissions quantification efforts.

  3. A draft quantification report of the GHG emissions from wastewater treatments and contribute to Thailand’s GHGs inventory report.

  4. Final report.

  5.  Online presentation of the methodology and the results in international fora.

This call invites Expression of Interest from international organizations, nonprofit organizations, NGOs, and research and academic institutions, to lead the activities. Selected institution(s) will be expected to work under the overall guidance of UN-Habitat and in collaboration with other partners in developing the structure and scope of the process, including the reports development. 

Selected institution(s) will prepare an Inception report to detail the proposed process. Prior to the completion of the activities, the institution(s) will develop activities report with the overall activities including the outcomes expected and agreed during the inception report. All materials and raw data, if any, shall be handed over to the UN Habitat as part of acceptance of final deliverables. 

Institutions interested in complementing their expertise through collaboration are encouraged to submit joint expressions of interest. Such partnerships should appoint a lead entity responsible for subsequently subcontracting the other partner(s). 

Short-listed candidates may be requested to submit detailed proposals or provide clarifications. 

The Expression of Interest

The Expression of Interest (EOI) should contain, but may not be limited to, the following: 

  1. A concept note including background information and the approach that will be applied by the institution’s contribution towards the dissemination, including the staff/expert, time frame and work plan of each activity proposed; 

  2. Experience of the institution in wastewater management and treatment, SDG 6.3.1 and related topic on GHG emission. The institution should be able to perform data collection, verify and analyse the data. This should include a portfolio of projects undertaken in similar areas (references); 

  3. Institution should specify their intended support, detailing cash and in-kind contributions, which may include staff time, office space, equipment, and other resources, quantified in monetary terms;

  4. Details on governance and organizational structure, along with resumes highlighting the experience and qualifications of key staff and descriptions of the organization's infrastructure facilities, should be provided; 

  5. Certified true copies of original Audited Account Statements for the last two years 

  6. Latest annual report.

UN-Habitat Financial Contribution

The estimated UN Habitat Financial contribution, detailing cost breakdown of each proposed activities.

Upon selection, UN-Habitat will enter into an Agreement of Cooperation with the selected entity with a value of US$ 15,000 for the successful deliverables.  

Overall Timeframe

The work outlined in this EOI will commence in July 2024 and be completed within 6 months.  

Submission Requirements and Guidelines

The EOI must be delivered in electronic format no later than Wednesday 10 July 2024, 23.59 EAT (Nairobi Time), to cc-ed to florian.thevenon@un.orgwith the reference “Country-Scale Quantification of GHG Emissions from Domestic WWTP in Thailand” indicated in the subject. 

Contact information  

Dewi Rimayani Hanoum, 

Programme Management Officer, Urban Basic Services Section, UN Habitat


Please note that this EOI notice does not constitute a solicitation. UN-Habitat reserves the right to change or cancel this requirement at any time in the EOI/or solicitation process. Submitting a reply to an EOI does not guarantee that a Cooperation Partner will be considered for receipt of the solicitation when issued and only Cooperation Partners who are deemed qualified by UN-Habitat upon completion of evaluation of submission will receive the final solicitation document.