The Water Pump is a Rare recyclable item in ARC Raiders that drops from Mechanical and Industrial loot containers. It weighs 2.0, stacks up to 3, and sells for 1,000 Coins. You can recycle it or salvage it for crafting materials — but you probably shouldn't, at least not right away.
Quick answer: Keep at least 1× Water Pump in your stash. It's required for the Unexpected Initiative quest given by Tian Wen, and the quest must be completed in a single Buried City raid. Recycling every Water Pump you find before reaching that quest will force you to farm another one.

Water Pump stats and recycling output
| Property | Value |
|---|---|
| Rarity | Rare |
| Weight | 2.0 |
| Stack size | 3 |
| Sell value | 1,000 Coins |
| Found in | Mechanical, Industrial containers |
| Recycle result | 4× Metal Parts, 2× Oil |
| Salvage result | 2× Oil |
Recycling always yields more materials than salvaging. If you have extras beyond the one you need for the quest, recycling is the better choice over salvaging since you get the full 4× Metal Parts plus 2× Oil instead of just 2× Oil.
Where to find the Water Pump as general loot
Water Pumps commonly appear inside Metal Crates in industrial areas. Reliable spawn locations include the west tunnels of the Research and Administration section at Dam Battlegrounds, the Shipping Warehouse at Spaceport, and the Power Generation Complex at Dam Battlegrounds. You can also find them sitting on carts and shelves throughout industrial zones. Because the item spawns in Mechanical and Industrial container pools, any Metal Crate in those categories has a chance to contain one.

Unexpected Initiative quest — Water Pump location in Buried City
The Unexpected Initiative quest sends you to Buried City to collect both Fertilizer and a Water Pump for Tian Wen, who is setting up a greenhouse back in Speranza. Both objectives must be completed in a single raid, so plan your route before dropping in.
Step 1: Head to the Grandioso Apartments on the western side of the Buried City map. Take the inner zipline up the lift shaft, cross between the buildings, and climb the stairs to the rooftop. Look for soil-filled orange terracotta plant pots with a yellow interaction icon. Interact with one and pick up the Fertilizer that drops.

Step 2: Move northeast to Piazza Roma. You're heading for the rooftops of the large apartment buildings just north of the Grandioso Apartments, on the southern edge of the Piazza Roma area. Climb to the roof using the yellow ladder between the buildings or via zipline and stairs inside.
Step 3: On the rooftop, look for a large glass tank with a motor and hose attached, stuck into the soil of a planting bed. There are multiple spawn points — check both the northwest and southeast corners of the roof. Interact with the yellow icon on the tank and grab the Water Pump that drops.

Step 4: Extract from the nearest active metro station. Piazza Roma has one nearby. Return to Speranza and deliver both items to Tian Wen to complete the quest.
Should you recycle or keep the Water Pump?
The Water Pump is one of only seven recyclable items in ARC Raiders that are needed for quests. The full list of recyclables worth holding onto includes the Camera Lens (for Movie Night), Fireball Burner (for What Goes Around), Hornet Driver (for The Trifecta and Wasps and Hornets), Snitch Scanner (for The Trifecta), Tick Pod (for Small, But Sinister), Wasp Driver (for The Trifecta and Wasps and Hornets), and the Water Pump itself.
Everything else in the recyclable category — items like the Alarm Clock, Bicycle Pump, Frying Pan, Turbo Pump, and dozens more — can be safely recycled without worrying about future quest requirements or bench upgrades. Once you've turned in your Water Pump for Unexpected Initiative, any additional Water Pumps you find are free to recycle for Metal Parts and Oil.
The Water Pump sits in an awkward spot in ARC Raiders' item economy. It looks like just another piece of junk to break down, but recycling it before you reach the Unexpected Initiative quest means an extra trip to Buried City's rooftops. Hold one, recycle the rest, and you won't have to make that climb twice.