The CACTUS Project's approach to Urban Sanitation

The Climate and Costs in Urban Sanitation (CACTUS) project is funded by the Bill & Melinda Gates Foundation (BMGF) and was launched in June 2017.

CACTUS aims to improve the quality of information available to decision makers who seek to make investment decisions relating to urban sanitation provision in cities and towns. Decisions about investments in sanitation infrastructure and services are complex and driven by a wide range of factors.

If you would like to contact the CACTUS team, please email Prof Barbara Evans at

CACTUS works on the principle that there is never a single ‘best’ solution to the question of how to provide effective, equitable and sustained sanitation – the decision will be driven by a variable number of factors, and that different cities and towns and indeed different stakeholders in a given city or town, would place different levels of emphasis on different factors. For example some decision makers would place a higher value on the mitigation of environmental impacts compared to financial costs, while others would have different priorities. CACTUS addresses this problem by generating data on three broad characteristics of different sanitation service delivery options, namely, cost (in the form of greenhouse gas emissions), climate and welfare effects.

Costing in the CACTUS Project

The CACTUS approach to costing is based on the observation that the urban sanitation sub-sector lacks two important tools to aid decision makers. Firstly a standardised metric for assessing the costs of sanitation delivery using different approaches and secondly, a database of real costs which could be used to generate globally-usable benchmark data.

CACTUS aims to address these two gaps by developing a standard metric for reporting on costs of service delivery using urban sanitation and the presentation of benchmark costs data for a range of sanitation delivery options.

A primary task therefore is to collect empirical data from real urban sanitation projects and to create a process for normalising this to enable the generation of meaningful comparable cost estimates for a range of sanitation service delivery options in a range of locations.

Currently the CACTUS database can report on normalised costs estimates based on reported expenditures from our empirical case studies.

Step 1

Component mapping of typical urban sanitation systems.

Step 2

Compilation of existing data of costing to deliver sanitation services.

Step 3

Standardised costing metrics, cost categorisations, data collection framework.

Step 4

Field research to collect cost data.

Step 5

Data compilation, database management, data analysis, visualisation in various media (website, publications, etc.).

Project's Timeline

  • 2016
    Project Initiated

    Climate and Costs in Urban Sanitation was shortened to acronym ‘C-CUS’, but later changed to ‘CACTUS’

  • 2017
    Recruitment Of 3 Post-Doctoral Researchers

    Tristano Sainati, Fiona Zakaria and Sally Cawood were recruited​

  • 1st Team Meeting

    Collaborated with Gunther Langergraber on CLARA costing tool

  • Fiona And Sally Joined In Leeds
  • BMGF MEDS Convening

    1st CACTUS poster

  • Work Plan Formulation, Technology Framework, Literature Reviews

    Technology framework, cost data from literatures

  • 2018
    Fiona And Sally’s Scoping Visit To India

    Visited BMGF funded FSTP in Dhenkhanal, Odisha – collaborated with Practical Action

  • Comparing Lifecycle Costs Of 4 Cases From Literature Search, Compilation Of Costs Of Sanitation Components

    Full system cases from Nonthaburi, Dakar and Cochabamba, ranges of sanitation components cases in USD 2016 (PPP&CPI)

  • Sally-MSc Student Mariam’s Field Research In Dhaka, Bangladesh

    Dhaka cost data (emptying and transport), manual emptying welfare case

  • Urban Sanitation Costing Workshop At WEDC Conference In Nakuru, Kenya
  • BMGF MEDS Convening

    2nd CACTUS Poster

  • Costing, Climate And Welfare Impact Workshop At UNC Water And Health Conference, Chapel Hill, US

    One-page CACTUS description

  • Climate Impact From Urban Sanitation, Recruited Researcher Jake Johnson

    Estimation of greenhouse gasses emissions from on-site sanitation, the case of Kampala City, Uganda

  • China Cost Data Literature Search, Researcher Zhe Zhan Was Recruited

    China cost data

  • Fiona Attended Aquaya’s Workshop In Nairobi And Field Research To Kisumu, Kenya

    Collaboration with WSUP and Aquaya, Kisumu cost data

  • 2019
    Fiona’s Field Research To Nakuru, Kenya

    Collaboration with WSUP, Nakuru cost data

  • Fiona’s Field Research To Accra And Kumasi, Ghana

    Ghana cost data (assisted by Water Aid, Clean Team, WSUP)

  • Sally-Mariam’s Field Research To Khulna, Kushtia, Jhenaidah – Bangladesh

    Collaboration with SNV, cost data from 3 cities

  • Literature Search For Sanitation Cost Data From Spanish Literatures, Interns Guillermo Was Recruited

    Contact and references

  • Development Of CACTUS Database And Website. Interns Anna (For Database And Website) And Valentina (For Database Programming) Were Recruited
  • 2020
    Fiona’s Field Research To Nakuru, Kenya

    Collaboration with WSUP, Nakuru cost data

  • 2021
    Fiona’s Field Research To Nakuru, Kenya

    Collaboration with WSUP, Nakuru cost data


We are a team of researchers at Leeds University led by Prof. Barbara Evans

Barbara Evans

Research leader

Areas of expertise: sanitation; water supply; public health; international development; political economy; international targets and monitoring faecal sludge management; economics and costing

Andy Sleigh

Leader, Database management and visualisation

Areas of expertise: computational fluid dynamics cfd; river flow; flood modelling; environmental risk analysis

Fiona Zakaria

Research fellow, Costing and climate impact and field researcher

Fiona's research has been in emergency sanitation and has working experiences as water-sanitation engineer in various humanitarian agencies includes International Committee of The Red Cross (ICRC) and United Nations Children[s Funds (UNICEF) in Indonesia and Sudan

Tristano Sainati

Research fellow, Project management approach in sanitation costing and Database management

Tristano's research is focused on contracting and project management in the field of project financing, the research was cross-sectorial but focused prevalently on energy, oil & gas, and nuclear.

Sally Cawood

Research fellow, Welfare effect in urban sanitation and Cost field researcher

Sally's main research interests include: inclusive Water, Sanitation and Hygiene (WASH); community-led urban development; collective action (e.g. CBOs, cooperatives and urban social movements); gender and WASH; climate change impacts and adaptations in low-income settlements

Giorgio Locatelli

Adviser and Co-investigator in project management

Areas of expertise: project management; infrastructure economics & financing; complex and large projects, cost estimation, cost-benefit analysis

Miller Alonso Camargo Valero

Adviser and Co-investigator in waste water treatment and climate impact

Areas of expertise: wastewater treatment systems; the recovery of resources from human and animal excreta, wastewater and sewage sludge; and associated environmental impacts

Ruthie Rosenberg

Cost Data contributor

Ruthie leads Citywise advisory services at Sanergy. Her areas of expertise include sanitation, public health, product and service design, sales and marketing strategy, and business model development. She has worked in sanitation provision, water service delivery, health education, and behavior change communication in Dominican Republic, Peru and Kenya, and has supported this work in Ghana and India.

Lauren Trondsen

Data collection interface design

Lauren works at Citywise

Valentina Sleigh Muñoz

Database structure, programing and visualisation

Data Scientist / Engineering

Anna Sevillano Evans

Database structure, management and website design

Multimedia student

Guillermo Domínguez Peláez

Literature search for cost data in spanish speaking countries

Civil Engineering student

Contact Us

Contact by e-mail can be made to Prof Barbara Evans at
CACTUS Project

WASH Research Group
School of Civil Engineering, University of Leeds
Leeds LS2 9JT, United Kingdom

Leeds University

WASH Research Group, School of Civil Engineering, University of Leeds |
© 2022 CACTU$ Costing