Locations and Materials Reward (in no particular order)

1. Name: Wastewater Treatment Facilities
Location: S7
Materials: 500 Instrument Parts, 150 Mechanism Parts

2. Name: Office Center
Location: P - 7
Materials: 500 Iron, 50 Iron Plates

3. Name: University
Location: P - 11
Materials: 500 Wood, 50 Boards

4. Name: School
Location: R - 17
Materials: 150 Weapon Parts, 10 Boarding Kits

5. Name: Max Shopping Center
Location: L - 18
Materials: 500 Rags, 75 Cloth

6. Name: Museum
Location: G - 16
Materials: 600 Fiber, 50 Rope

7. Name: Tumbledown Skyscraper
Location: I - 13
Materials: 500 Plastic, 50 Plastic Plates

8. Name: Unfinished Business Center
Location: E - 10
Materials: 500 Copper, 50 Copper Plates

9. Name: Stranded Barge
Location: E - 2
Materials: 400 Ammunition Fragments, 40 Dynamite

10. Name: Observatory
Location: V - 11
Materials: 300 Chemical Waste, 50 Reagents

11. Name: Helipad
Location: 5/6 - T/U (this one is on the lines that intersect on the grid)
Materials: 5000 Medallions, 10 of each consumable)

Note: You complete the foot zone by picking up the resources and bringing them back to your boat. When you complete the foot zone it says "Recovering from plunder" on it, a few seconds later it starts to recharge the materials and they slowly recharge back to full. It takes 1 hour and 40 minutes to fully recharge. Also, the recharge only applies to you, meaning anyone can get the resources at any time without affecting the materials or timers of anyone else.

A few tips:

It is easier to complete them when you try to kill everyone first in most cases, but there are a few of them that I am able to grab the resources and run back to the boat while only killing a few enemies.

The more times you do each foot zone, the better you will get at them. The scene in each one plays out exactly the same each time you do it, so you will learn your best way to do them.

The Helipad was particularly more difficult than the rest of them, at least for me.