Summary

GiveWell is seeking a Senior Water Researcher to help direct tens of millions of dollars annually to the most cost-effective water interventions we can find. You will have an outsized influence on our funding decisions and help us save and improve lives on a global scale.

Our water grantmaking has historically focused on improving drinking water quality through chlorination — primarily chlorine dispensers and in-line chlorination — in low- and middle-income countries with a high burden of waterborne disease. In 2025, we ran a public Request for Information (RFI) that resulted in 18 pilot grants to 12 implementing partners across six African countries, totaling roughly $20 million. In 2026, we are beginning to pivot from a narrow focus on chlorination toward a broader exploration of the water sector. This includes investigating alternative water quality interventions (e.g., filtration, in-line ultraviolet disinfection, chemical contamination remediation), different clean water delivery models (e.g. diarrheal outbreak prevention and response, safe water enterprises), exploring water access and infrastructure layering with multilaterals such as the World Bank, market shaping for chlorine supply chains and measurement technology, and R&D for hardware and better service delivery models.

As a Senior Water Researcher, you'll create and lead ambitious research agendas related to our portfolios of work and answer complex questions that will inform GiveWell's grantmaking decisions. The researchers on our team combine rigorous evidence review, cost-effectiveness modeling, and thoughtful judgment.

We're open to a wide variety of professional development pathways depending on your preferences and our needs.

The role

You will be joining a small grantmaking team to contribute to our ambitious research agenda on water. You'll sift through the countless questions we could try to answer, and hone in on those that matter most. You'll also communicate externally about your work and mentor and advise other researchers on the team.

You will shape a research agenda that brings rigor and creativity to the thorniest questions the GiveWell water team faces. Your work will combine empirical evidence review and critical synthesis, cost-effectiveness modeling, discussions with subject matter experts, understanding of the broader context, and your own judgment.

What you might work on in your first year:

• How should we calibrate our cost-effectiveness estimates to real-world program performance?
• How does chlorination compare with alternative water quality methods — such as filtration, in-line UV, and chemical contamination remediation — across different settings? Where, if anywhere, are these alternatives more cost-effective?
• Can GiveWell unlock large amounts of cost-effective room for more funding by partnering with multilaterals (e.g. the World Bank) to layer water treatment onto large-scale piped water infrastructure projects? What are the practical and political constraints?
• To what extent should our portfolio shift between water quality (our current focus) and water access? Are there access-related grantmaking opportunities — for example, supporting direct delivery of clean water, water kiosks, or boreholes paired with treatment — that meet our cost-effectiveness bar?
• How do we improve our estimate of the all-cause mortality effect of chlorination on children under-5?
• How should we use new funding mechanisms — such as regranting, prizes, and a possible Water Incubator with implementing partners — to identify and scale promising interventions?

The Senior Water Researcher will help shape a major annual grantmaking portfolio, own grant investigations end-to-end (from research question through grant recommendation), and represent GiveWell to external counterparts. You'll have significant latitude to propose new areas of work.

Team structure

Our research department has over 60 people, and is currently organized into eight teams:

• Five of the teams (Livelihoods, Malaria, Nutrition, Vaccination, and Water) focus on specific areas of grantmaking.
• The New Areas team focuses on interventions in domains that are new to GiveWell.
• The Cross-Cutting team focuses on methodological issues, research quality, and other big-picture concerns that cut across all of our research work.
• The Commons team provides generalized research support to each of the other teams, including landscaping research, vetting, and publishing.

There are currently three people on our water team.

Team values

We think our research team has unique qualities:

• We care deeply and centrally about finding and sharing truth. Truth-seeking is one of our core values. We post our mistakes and we prize our team members who keep our culture of free-flowing feedback strong.
• We are independent. We focus 100% on finding the most cost-effective opportunities to save and improve lives. Our researchers assist in communicating our research findings to the public and our donors, and on occasion we provide tailored advice to ultra-high-net-worth donors who want to rely on our expertise to direct their giving—but we never ask our researchers to trade off against honesty, or to hide their real beliefs.
• We don’t waste time. Once it’s clear that a particular research question is unlikely to change our bottom-line funding recommendation, we drop it as quickly as possible. We encourage our research staff to constantly re-evaluate their portfolios and only work on the highest-priority questions.
• Lean research team = huge personal impact. In 2026,our research team of ~80 people is directing close to 1 billion dollars and we expect grantmaking dollars per research team member to increase in the future.
• We work well together. Our research team is lean because we’re able to attract top-tier people, all of whom complete skills-based assessments before joining our staff. We maintain a high-performing, collegial culture and pay our staff accordingly.

About you

We expect the Senior Water Researcher to have

• A quantitatively oriented advanced degree (e.g., in epidemiology, environmental engineering, environmental health, public health, economics, or related fields).
• Substantial professional experience in the water sector or an adjacent field (broadly defined). This could include experience in water quality, WASH, water infrastructure, environmental health modeling, or in program implementation, evaluation, or funding. We're especially interested in candidates with hands-on familiarity with water systems, epidemiology, or both. We don't expect any single candidate to have deep expertise across all of the areas we're exploring (chlorination, filtration, in-line UV, water access, market shaping, R&D), and we're happy to consider strong researchers whose expertise sits in any subset of these.

We expect that people with the soft qualities below will be the most successful and happy on our team. This isn’t a full list, but hopefully it conveys the gist of our team’s professional personality:

• GiveWell’s mission and methods are personally energizing—you like our approach to research and you find personal meaning in our story of impact.
• You’re abnormally curious—you ask lots of questions, and you’re willing to interrogate others’ work. Your curiosity also extends to your own work—you aren’t defensive when your research comes under scrutiny.
• You routinely think about and surface the value judgments, background knowledge, and strategic commitments that undergird your work. You understand the potential effects of mistaken mental models, so you strive to improve yours and your team’s.
• You dislike it when people express strong confidence in views that don’t seem to rely on commensurate evidence. You carefully and legibly communicate about your confidence levels.
• You appreciate the value of an excellent reputation and strong relationships. You can moderate your directness and intensity when you’re communicating with external folks.
• You love a gnarly problem. You figure out the most important questions to answer, go deep on the details where they matter (and move on where they don’t), and reassess your mental models based on what you’ve learned.
• You constantly assess whether you and the team are working on the most important things.

If you’re interested in working on GiveWell’s research team but don’t have water expertise, consider applying to our generalist Senior Researcher role, or our Researcher role if you have limited post-graduation experience.

The details

• Compensation: We set salaries using a location-based tier system. Our pay for this role:
• NYC or the San Francisco Bay Area: $308,000.
• All other U.S. locations: $280,000.
• International: Similar to the “all other U.S. locations” salary, based on historical exchange rates and delivered in locally-denominated currency. We can share a precise figure upon request after the first work trial stage.
• Benefits: Our benefits include:
• Fully funded health, dental, vision, and life insurance (we cover 100% of premiums within the US for you and any dependents)
• Four weeks of paid time off per year, plus a one week organization-wide summer break
• 16 weeks of fully paid parental leave
• Ergonomic home workstations or coworking space memberships
• Automatic contribution equal to 5% of your gross salary into your 403(b) retirement plan (for U.S. based staff)
• Location: GiveWell’s staff work primarily remotely within the U.S. and abroad. This position is eligible to work fully remotely. A successful candidate will need to commit to a work schedule that has some overlap with American working hours and the schedules of key coworkers.
• Offices: You are welcome but not required to work from our offices in Oakland, California; Brooklyn, NYC; or London, UK. We'll cover relocation expenses for candidates who wish to move to any of our physical office locations.
• International work: We are happy to employ staff internationally on a case-by-case basis.
• Flexibility: We support and encourage flexible working, including flexible hours, working remotely, and working from the office when you choose. The majority of our staff, including senior management, work flexibly in one way or another.
• Visa Sponsorship: If you want to work in the United States and need a work visa, we’ll do our best to sponsor it (and also cover up to 100% of relocation expenses on a case-by-case basis). Please note that government entities ultimately dictate our ability to sponsor visas.
• Travel: Research team members are sometimes required to attend international site visits and conferences (on average 1-2 per year), with additional travel for those interested in traveling more. Additionally, we strongly encourage staff members to attend quarterly whole-org and department retreats to bond with other team members and complete in-person work. We'll discuss travel obligations in more detail during late stages of the hiring process, and we’ll accommodate staff who have conflicting family or other obligations.
• Start date: We’d like a candidate to start as soon as possible after receiving an offer, but we’ll offer flexibility for candidates whose personal or professional circumstances require them to moderately delay their start date.

Miscellaneous details:

• Please apply to only one Senior Researcher posting. If you have deep expertise in this area, this pod-specific role is the right fit. If not, there's no need to apply here — our generalist Senior Researcher role is designed for strong researchers who don't have a single specialization, and you don't need to apply to both. Applying to the generalist role won't put you at any disadvantage!
• Please note that our hiring process consists of the same work trials for the following roles: Researcher, Senior Researcher, Senior Cross-Cutting Researcher, Senior Livelihoods Researcher, Senior Malaria Researcher, Senior New Areas Researcher, Senior Nutrition Researcher, Senior Vaccines Researcher, and Senior Water Researcher. If, within the last year, you applied and were rejected for one of these roles, you should hold off on applying to the other roles, unless explicitly asked to do so by a member of our team. If you're interested in all of these roles, please just apply once and note in your application that you'd like to be considered for the other roles, too.
• After application review, our hiring process consists of a short application exercise and up to 15 hours of compensated work trials. You can see more details about our hiring process on our FAQs page!
• We devote significant staff capacity to initial application review, and we respond to all applications as quickly as possible.
• We have a strong preference for full-time applicants, but we’ll consider applications for part-time work. We aren’t interested in reviewing applications for contract or project-based work at this time.
• If we settle on an application deadline, we’ll write it in bold here. If you’re on our website job posting and don’t see a deadline, there is no deadline. If you’re reading this on an external job board and don’t see a deadline, you should double-check on our website.
• You don't need to submit a cover letter—we rely mainly on your resume and answers to the application questions below when we're making early decisions.