Weston Water Treatment Plant

The Weston water treatment plant is a pre-War facility in the Commonwealth infested by Mirelurks and super mutants in 2287.

Background
Built in 2051, the Weston water treatment plant was part of a decade-long plan to modernize the city’s aging sanitation systems. The facility was equipped with advanced Mark IV flood control pumps, which Theodore Marks believes to be the only non-cheap equipment in the facility. Prior to the Great War, Saul Arenson was the plant's operations manager and was preparing a press event for their Weston WELLness press initiative. At the same time, Theodore Marks successfully water-proofed the facility's automated turrets, while Emmis was injured in a work accident. Decades after the Great War, rising sea levels overwhelmed and flooded the facility.

Layout
The facility is a water treatment plant with a series of ring-shaped open-air basins containing water on the eastward side. Around and across these basins, super mutants have constructed a series of walkways and are patrolling them. These mutants are armed with rocket launchers and sniper rifles. There is at least one suicider with a mini nuke. The trailers and shack in the very middle of the basin have floor traps in their entrances, including a tripwire-activated missile launcher.

Inside the facility, the player can check the entries of the Front Office terminal which will update the map. Around the corner is a toilet with first aid. Next to the stairs is a locked door (advanced) which has some goodies behind it. The player can go up to the roof via a ladder, and there is a cache of goodies behind a locked safe (expert) and a terminal (novice).

Down the elevator, the player character is led to a series of rooms with locked doors. These doors can only be opened by pressing a large red button beside them, and they can only be opened when the button is illuminated red. If the button is not lit, it means the section beyond is flooded. To traverse the level, the player character must activate a series of pumps to drain sections. This will expose the Sole Survivor to attacks from mirelurks that are living in the water treatment plant. The lower levels are also guarded by a series of turrets - a total of ten.

Upon exiting the elevator to the lower level, there is a turret to the left and a locked door (novice) with some ammo boxes behind it. To the right (the room with the Picket Fences skill book), there is a computer terminal and a locked safe (expert). This terminal gives the option to disable all automated turrets in the section. However, the auto turrets will target mirelurks as well as the Sole Survivor. This gives the player character the choice to fight the mirelurks unassisted, or to have the turrets help against the mirelurks, but have to fight turrets as well.

The third option is a mixture of both: Hack the terminal, deactivate the turrets, go downstairs, open the door, and corral all the already active mirelurks into the room with the turrets. Have your companion block the mirelurks at the bottom of the stairs, head back to the terminal and re-activate the turrets. If you want the XP for the turrets, you can then reactivate them and fight them once the mirelurks are gone.

Notable loot

 * Picket Fences issue #5 - In the metal office overlooking the generator room, before descending to the main treatment chamber.
 * Super mutant heavy gauntlets - Can be found in the shack to the right of the main entrance of the water plant.
 * Super mutant bladed helmet - Can be found on the floor of the highest shack.
 * A large repository of mirelurk eggs (at least 16).
 * Ironically, there is a significant number of dirty water items at this location.

Related quests

 * Troubled Waters

Appearances
The Weston water treatment plant appears in Fallout 4 and Fallout Shelter

Behind the scenes
Weston Reservoir is located west of this site in real life. The site itself is on top of an aqueduct from that reservoir and is the former site of Norumbega Park, an amusement park that fell out of popularity after World War II, and its namesake, Norumbega Tower.

Bugs

 * Be careful with the exit elevator that becomes available when the mission is over. It is possible to get stuck inside permanently, forcing one to reload a previous save.
 * If you're "stuck" (elevator or pump control switch won't work) open console ` and type "coc WestonWaterTreatmentExt" then "resetinterior 6fe2f" without quotes. The alternative is to reload a previous save, however, it seems the elevator and pump control switch won't work until you relaunch the game.
 * On approach it is possible that a Brotherhood of Steel Vertibird will attack the super mutants outside the facility, but the Vertibird will fly into the raised section of highway above the facility repeatedly and then crash.