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The plan was to build a facility that could purify all the water in the Tidal Basin at once. No radiation, no muck, just clear water.Doctor Li

Project Purity was a water purification project in the Capital Wasteland circa 2278, located at the Jefferson Memorial.



"Fresh, clean water for everyone." Such a simple idea, and yet so impossible to realize. The plan was to build a facility that could purify all the water in the Tidal Basin at once. No radiation, no muck, just clean water.— Doctor Madison Li

The brainchild of James and Catherine, Project Purity was founded long[1] before 2257. Inspired by Catherine's favorite Bible passage, it was an ambitious attempt to create a water purifier capable of purifying water stored in the sealed-off Tidal Basin, providing millions of gallons of drinkable water to the wasteland. After years of work and preparation, the project team selected the Jefferson Memorial as the site of the purifier.[1][2]

However, building a large-scale water purifier capable of processing the basin and filtering out the pervasive radiation proved challenging. Small-scale tests yielded consistent successes, but James and his team were unable to scale it up to the desired output.[3] Coupled with the presence of large numbers of super mutants, the project nearly failed. However, the situation was salvaged by a contingent of Brotherhood of Steel soldiers established as a permanent garrison[4] at the memorial around December 2257, thanks to James' negotiations with newly-promoted Elder Owyn Lyons. Sentry guns maintained by the soldiers were essential to maintaining a safe perimeter. Madison Li was not fond of the military presence and refused to trust the Brotherhood.[5]

The situation was further improved by Catherine's pregnancy. She refused to slow down or reduce her workload, inspiring other members of the project to continue their work. The team quickly discovered a purification method that was horribly inefficient, but worked, as opposed to most they've tried before.[6] Despite that apparent breakthrough, progress halted quickly, while super mutant attacks intensified. The lack of concrete results, coupled with mounting losses to the super mutant attacks, two dead soldiers and three more injured was a regular weekly tally at this point, strained the team's relations with the Brotherhood.[7] The problems foreshadowed the collapse of the project following Catherine's death on July 13, 2258, while giving birth. James completely withdrew from the project, deciding to abandon it entirely and flee with his child to the safety of Vault 101, while super mutant attacks escalated to the point that the Brotherhood was fighting off several attacks each day.[8] As a token of appreciation, Elder Owyn Lyons permitted Star Paladin Cross to escort James and his child to the Vault,[4] then pulled all of his troops away from the memorial, leaving the scientists to fend for themselves.[8] Betrayed,[Non-game 1] Madison Li and what remained of the research team salvaged what they could, then moved their operations to Rivet City, focusing on hydroponics and purification in a safe, sheltered environment.[9]


The facilities were completely abandoned and left to the elements for the next nineteen years. Super Mutants would move in and take over the former Brotherhood site.

James continued to tinker with the principles of Project Purity after he was accepted into Vault 101 as its resident physician. His nightly routine included sneaking into restricted areas and poring over records, looking for a way to make his dream happen. During one semi-drunk excursion, he found records mentioning Stanislaus Braun and the Garden of Eden Creation Kit, which was the missing element of his puzzle.[10] After trying and failing to replicate results using Vault 101's technology (and Jonas Palmer), he realized that he would have to find either the GECK or Braun himself to make any actual progress.[11]

After his child reached adulthood, James decided on a last ditch attempt to achieve the goals of Project Purity. He escaped Vault 101, causing a brutal crackdown by the overseer and his security force that forced his child to abandon Vault 101 as well. He first visited the derelict facility,[12] rigging several fusion generators to activate emergency lighting and basic systems. Then he departed for Rivet City, to ask Li for help in powering the mainframe up and restarting the project.[13] Li told him in no uncertain terms that she's not interested, feeling James betrayed her nearly two decades earlier and came begging for her help without anything to show for his efforts.[14] This only strengthened James' resolve to find Braun and the GECK.[15] He left the facility again, this time to look for Vault 112.[16]

The Lone Wanderer followed in their father's footsteps, clearing the memorial of the Super Mutants, rescuing James, and aiding him in convincing Li to give the Project another chance. However, as the facility was brought back online and the team prepared to restart their work, the Enclave under Colonel Autumn deployed to the memorial in force. After subduing the team, Colonel Autumn confronted James and demanded that he turn over the facility to the Enclave, together with all existing documentation, and aid Enclave scientists in bringing it online. Defiant, James refused, which cost Janice Kaplinski her life. Afterwards, he pretended to comply, only to disable the radiation shielding and flooding the control chamber with lethal levels of radiation. Colonel Autumn survived, James did not, while the rest of the team safely made it to the Citadel through the Taft Tunnel.[17]

The Enclave set up a defensive perimeter around the purifier using forcefield generators and focused on repairing the purifier, waiting for the Lone Wanderer to clear the way into Vault 87 and procure the GECK. After Colonel Autumn and his strike team captured the Lone Wanderer at the Vault, the GECK was installed at the Jefferson Memorial and awaited the correct code.[18] While the Enclave hoped to activate the purifier and leverage the clean water supply to establish their dominion over the wasteland, Lyons' Brotherhood of Steel activated their trump card, Liberty Prime, and in a last-ditch attempt at victory attacked the purifier using it as the spearhead. The desperate plan worked, with Prime carving a swathe through the defensive lines around the memorial and scattering the rallying Enclave units, allowing the Lone Wanderer and Sarah Lyons to infiltrate the purifier, confront Autumn and activate it before it exploded.[19][20]

The Waters of Life[]

Activated Purifier

The activated purifier

With the purifier online and performing as expected, the Brotherhood received a powerful economic asset. However, Elder Lyons made the decision to provide water to all major settlements in the wasteland, completely free of charge.[21] Elder Lyons' insistence on providing water for free has made finding resources and funding for the operation extremely hard. So hard in fact, that it forced Scribe Bigsley, the man in charge of the entire venture, to go against his orders and sell water, in order to actually be able to accomplish what he's been ordered to do.[22][23] Another problem was that bottling water had to be accomplished manually, as the Brotherhood is too preoccupied with reverse-engineering Enclave tech to devise a bottling machine.[24] The entire operation was also severely hampered by a general lack of resources and planning.[25][26]

Despite this free clean water would continue be distributed by the Brotherhood throughout the Capital Wasteland by 2287.

Related quests[]


  • Project Purity coordinates are available when accessing Bradley-Hercules, but the site is unable to be targeted due to the satellite not being in the proper orbital path.[27]
  • Activating the purifier without inserting the FEV may cause certain plants to appear green during Broken Steel.[verification needed]
  • Inside the water container behind the password entry pad, the Lone Wanderer can see the statue of Thomas Jefferson that the lab was built around and named after.[28]
  • Canonically, it appears the Lone Wanderer does indeed purify the water, as characters such as Deacon in Fallout 4 comment on how the water is drinkable in the Capital Wasteland.[29]
  • After the decision is made, the water of the Capital Wasteland is purified at last, and life begins anew in the Capital Wasteland. The Lone Wanderer can also, if they choose, simply do nothing, allowing the purifier to self destruct, thus sacrificing the lives of everyone in the facility for no reason. The ending that follows is shorter than the normal ending.
  • In Broken Steel the purifier is activated, and the Brotherhood of Steel and the Rivet City Security Force begins distributing Aqua Pura (purified water) to the various settlements across Capital Wasteland. In addition, the small body of water directly in front of the Jefferson Memorial (the area before the bridge) known as the tidal basin is free of radiation.
  • Any water beyond the bridge is still irradiated as Project Purity will take some time to purify all the water in the Potomac River. If the modified FEV was inserted into the purifier, then the Aqua Pura will be infected with it.


Project Purity appears in Fallout 3, Broken Steel, and is briefly mentioned by Deacon in Fallout 4 as well as a raider in Fallout Shelter during the quest Game Show Gauntlet.


  • Playstation 3Playstation 3Playstation 3 Xbox 360Xbox 360 Occasionally, (after activating Project Purity) the tidal basin water will still be irradiated, even though it is supposedly "clean".[verified]
  • PCPC On some occasions a dead Mirelurk may appear to stand on water. If the bugged Mirelurk is shot with any weapon it will fall into the water. Requires the Broken Steel add-on.[verified]
  • Xbox 360Xbox 360 Sarah Lyons will continue to say "Let's get this place locked down before we do anything else." After speaking into the intercom and will continue to do this even though all enemies are dead.[verified]
  • PCPC Playstation 3Playstation 3Playstation 3 Xbox 360Xbox 360 Occasionally, the GNR announcement that Project Purity has been taken from the Enclave will go out before the player has started the related quests.[verified]
  • The player can actually access the Memorial grounds before Take It Back! by jumping onto the forcefield generator in the far-western portion of the area, then slide off of it inside. Enclave soldiers inside are coded as friendly, but the characters inside are not. Entering the rotunda will lock the player inside, as the player is only meant to go inside during Take It Back![verification needed]



  1. 1.0 1.1 The Lone Wanderer: ""Your responsibility"? What does that mean?"
    James: "Project Purity was underway long before you were born. There were many of us, including your mother, who devoted our lives to it. The idea of free, clean water for everyone drove us to succeed. So many sacrifices were made for that idea. My responsibility is to see it through to the end, to make sure those sacrifices mean something."
    (James' dialogue)
  2. The Lone Wanderer: "What exactly is this "Project Purity"?"
    James: "It started as an idea, really. Remember the Bible passage your mother loved so much? Free, clean water for everyone. What a difference it could make in the lives of everyone here in the Wastes. Over time, that idea took the form of a purifier. Not like the one in the Vault, though. This one was gigantic, capable of purifying millions of gallons of water at once. We used the old Jefferson Memorial for the location, right on DC's Tidal Basin. Someday soon, I hope you'll see it work."
    (James' dialogue)
  3. The Lone Wanderer: "Why didn't it work?"
    Madison Li: "We had the basic principles down; we understood most of the science behind it. But the radiation in the area is so pervasive... Small-scale tests were fine. But any time we tried to test the process on a larger scale, it was just too much. Maybe if we'd had more time, or better equipment..."
    (Madison Li's dialogue)
  4. 4.0 4.1 The Lone Wanderer: "You knew my father?"
    Cross: "I did. And you as well! Long ago, I helped guard the water purifier against the Super Mutant horde. When your father left, I escorted the two of you to Megaton. He was... a noble man. I was saddened to hear of his passing. But from what I've heard, he died with honor. He died for you. I only pray that my own death has such meaning."
    (Cross' dialogue)
  5. Project Purity Journal: Entry 1: "We're back at work after a full week of delays. The Brotherhood soldiers were able to repair the sentry guns, much to my relief. I know Madison isn't comfortable having them here, but there's no denying that we'd be lost without them. We're still waiting on the full analysis of the last three small-scale purification tests. Catherine hasn't been feeling well, and it's slowing down our research. I don't mind, but I can tell it's bothering some of the others."
  6. Project Purity Journal: Entry 3: "Well, there's no more mystery behind Catherine's health problems. The news of her pregnancy has lifted the spirits of everyone here, and given us a renewed interest in making the purifier work. We now have a future generation to provide for. The latest tests show that our methods are horribly inefficient, but I think we're on the right track. Catherine refuses to rest; she insists on spending all day in the lab. I've never seen her more driven. She's determined to resolve the power problems before the baby is born. I've tried to reason with her, but it's no use."
  7. Project Purity Journal: Entry 5: "The team has made plans to scale back our work once the baby is born. We're also trying to compensate for the increase in mutant attacks; no one is really talking about the implications of it. There are more of them than before. We know it, and the Brotherhood soldiers know it. Our relationship with the Brotherhood is straining. They're concerned by the lack of concrete results from the project, especially in light of the mutant attacks. They haven't come out and said it, but we all know what's going on. They're questioning whether their involvement in our project is worth the trouble it's causing them. They lost two good men this week, with three more injured."
  8. 8.0 8.1 The Lone Wanderer: "Why did you stop working on it? What happened?"
    Madison Li: "You happened. It wasn't just you; we had more problems than we could handle already, but your birth is what finally pushed it over the edge. Your father decided that you were more important than everything we'd been working for, and he left. He left all of us. Once he was gone, the Brotherhood decided we weren't worth their time anymore. Without their protection, we had to abandon the purifier."
    (Madison Li's dialogue)
  9. The Lone Wanderer: "So, you used to be in charge? How did you end up here?"
    Horace Pinkerton: "That lasted until 'bout 18 years ago, when those ambitious backbiters like Li and her little team showed up. She came in with her big "Purity Project" pipe dream, and my whole staff started working with her, those traitors! She even took my seat on the council. By then, I was glad to leave it behind. But hell if I'm leaving the city I made great!"
    (Horace Pinkerton's dialogue)
  10. Project Purity Personal Journal: Entry 5: "Even in Vault 101, my work on Project Purity never really stopped. Soon after we arrived, my nightly routine included sneaking into the restricted areas, searching for... I don't know. Whatever I could find. It was a Vault-Tec facility, after all. The place was built with some of the most advanced technology this country had ever developed. Those excursions never turned up anything particularly useful. So... one night, after half a bottle of scotch, I broke into the Overseer's office. It was easy enough to hack his console, gain access to the restricted files. Most of it was garbage. Propaganda, spy reports, just plain rambling bullshit, really. But there was one thing, one name that stood out amongst all the others -- Doctor Stanislaus Braun. I knew of Braun's work, of course. He was a celebrity in his day, Vault-Tec's "Sorcerer Scientist," leaving his peers in awe of his technological wizardry. But it was in Vault 101, that night in the Overseer's office... I first learned of Braun's involvement in Vault-Tec's Societal Preservation Program, and his work on something called the G.E.C.K. The Garden of Eden Creation Kit."
  11. Project Purity Personal Journal: Entry 8: "To be honest, the G.E.C.K. sounded like pure fantasy, even for someone of Braun's capabilities. It was nothing short of a miracle -- a terraforming module, capable of producing life from complete lifelessness. But not only was this thing a reality, it was actually distributed to several vaults, to be used after an atomic war. Vault 101 was, sadly, not on that list. I did some digging, and discovered Braun's name on the reservation list for a Vault 112. I'm no slouch, but this man... He could have easily succeeded where I failed. Does his collected knowledge remain within the halls of Vault 112? Journals, holotapes, computer records, maybe even experiments... If I could gain access to just a fraction of Braun's genius, Project Purity would become a reality."
  12. Project Purity Personal Journal: Entry 1: " So here I am, back where it all began. Project Purity. God, we wanted to change the world. We really thought the "waters of life" could be a reality. And that's why this is a momentous occasion. Because even after nineteen years, I still believe it. Project Purity can and will be operational. This is just the beginning."
  13. Project Purity Personal Journal: Entry 2: "This is day two of my attempt to resurrect this project. I've got one of the portable fusion generators up and running, but it's just enough to power the emergency lighting and a couple of other systems. That will serve for now, but I'll need help powering up the mainframe. Time to visit Madison at Rivet City."
  14. The Lone Wanderer: "If he was here, then do you know where he went?"
    Madison Li: "Yes, I do. I told him repeatedly that it's too late, that the project is too far gone to be revived. He insisted he can just pick up where we left off 20 years ago, and said he could prove it to me. So he headed off to the old lab. I advised against it, but he went anyway."
    (Madison Li's dialogue)
  15. Project Purity Personal Journal: Entry 3: "I spoke with Doctor Li... Madison... at Rivet City. It went about as well as I expected. That is to say, she thinks I'm completely mad. How can I blame her? She's got her own life, her own team, and is making real, tangible scientific progress. And here I come again, the very paragon of failure and false promises. But the reality is I need Madison, and whatever scientific team she may have assembled. I can't do this myself. Project Purity is bigger than me. It always was. And without Catherine... God, I can't let this die. Not again. Not like this."
  16. Project Purity Personal Journal: Entry 10: "I'm off to Vault 112 to search for anything of Braun's that might help me get this purifier up and running. All I know is that it's west of someplace called Evergreen Mills, and it's well-hidden in some sort of garage, but I'll find it. I have to. It's so close, but that's the story of Project Purity, isn't it? An eternity of "almost theres." Let's see if Braun has the missing puzzle piece."
  17. Waters of Life
  18. Finding the Garden of Eden
  19. Take it Back!
  20. Elder Owyn Lyons -- Personal Log 3: "I cannot -- I will not -- allow the Enclave to control the one thing that could bring even the slightest spark of hope to these people. Project Purity would mean millions of gallons of pure, clean water for the people of the Capital Wasteland. James never got the damned thing to run. Neither did we, for that matter. But the Enclave... If they controlled that much clean water... they would control the entire Capital Wasteland. I simply cannot allow that to happen."
  21. The Lone Wanderer: "Seems like a lot of trouble giving it away. Why don't you just sell the water?"
    Bigsley: "Many of us keep asking that same question. The Brotherhood isn't a postal service. We have IMPORTANT things to do, and we need caps and technology to do it! Lyons is on some kind of mission. Has he forgotten about the Enclave? That's our priority... But yeah. Things are being done to "offset" the cost of Lyons' little pet "Purity" project."
    (Bigsley's dialogue)
  22. The Lone Wanderer: "Griffon's up to something with the Aqua Pura. What do you know about it?"
    Bigsley: "Not that it's really any of your business, but we have an arrangement. He buys water, I send him some. I use the caps and tech he pays me to fund the other water deliveries. I send my men with the water to the Museum Authority in the Mall. Griffon sends the payment back with my men. So far, so good. Lyons wouldn't approve, but I don't really care anymore. I need the resources and there's certainly plenty of water to go around."
    (Bigsley's dialogue)
  23. Scribe: "They're a week late, sir. Should we send out a search party?"
    Bigsley: "For a couple of Wasteland hustlers and a pack Brahmin?"
    Scribe: "What about our men?"
    Bigsley: "I'm not wasting any more resources."
    Scribe: "Yessir."
    Bigsley: "If Lyons wants to chase after his deliveries, fine. Let HIM do it. But I'm done wasting resources and risking lives on this pet project of his."
    Scribe: "For what it's worth, you aren't the only one who feels that way."
    Bigsley: "Thank you. Now, kindly get the hell out of here. I need to think."
    (Scribes' and Bigsley's dialogue) Note: The following prompts and responses are selected randomly in DLC03WQBigsleyScribeConv07.
  24. The Lone Wanderer: "Is it hard bottling all that water? Or is it all done by machines?"
    Bigsley: "You take a bottle, you dunk it under water, and glug glug glug, it fills up. Amazing. But you're right a machine would help. But all the Scribes are busy reverse engineering Enclave gear. A machine that puts water in bottles just isn't on anyone's priority list at the moment."
    (Bigsley's dialogue)
  25. The Lone Wanderer: "Sounds like you have your hands full."
    Bigsley: "Everyone was so excited about that Purifier: "Project Purity this," and "Project Purity that." But did anyone stop to ask, "Hey, what are we going to DO with all that clean water?" Well, guess who gets to fill in that tiny detail. It'd be one thing if I had support, but that little war with the Enclave has depleted much of the Brotherhood's resources. And to top it off, I have to be mommy to a bunch of lab coats."
    (Bigsley's dialogue)
  26. The Lone Wanderer: "You're not the only one with problems."
    Bigsley: "Right. I heard about your dad. Sorry kid. I don't mean to sound unsympathetic, really. But, if you understood the pressure... You know the Wasteland. Imagine trying to get fresh water to every known settlement, without getting it stolen by Raiders or Mutants. Now imagine doing that without any trained soldiers or military resources because they've all been exhausted fighting a little war with the Enclave. Yeah. That's MY job. Not to mention the mountain of crap I get from all the lab coats running around underfoot."
    (Bigsley's dialogue)
  27. Adams Air Force Base terminal entries; satellite control tower, satellite uplink terminal, PAYLOAD COMMITED, Preset Target 02: Project Purity
  28. Statue of Jefferson inside the purifier
  29. Deacon: "I miss Capital Wasteland. You can actually drink the water there."
    "Capital Wasteland. Exports: purified water, some decent tech, oh, and an insane suicidal cult that worships radiation. Thanks, guys."
    (Deacon's dialogue)


  1. Fallout 3 Official Game Guide Game of the Year Edition p.69-70: "Doctor Madison Li
    Doctor Madison Li, 48, was a young, idealistic scientist who fully bought into the notion of Project Purity. She worked tirelessly with your father, and hid her growing romantic feelings while respecting his marriage to another scientist. When your mother was killed, Doctor Li was filled with remorse, but when the player's father decided to abandon Project Purity to keep his child safe, her sadness was replaced with a powerful sense of betrayal. Eighteen years later, she is older, wiser, and much more cynical."
    (Fallout 3 Official Game Guide Game of the Year Edition Wasteland Census)