---
title: "Requirements for selecting borrow areas"
subject: "Engineering Geology II"
chapter: 7
key: "semester_4/engineering_geology_ii:borrow-area-requirements"
source: https://www.bctengineer.com/q/semester_4/engineering_geology_ii/borrow-area-requirements
site: BCT Engineering
---

# Requirements for selecting borrow areas

Engineering Geology II · Chapter 7: Geology and Construction Materials

- Asked in: 2072 Magh, 3 marks; 2075 Baisakh, 1 marks; 2068 Bhadra, 2.5 marks (asked 3 times)
- Video: [Regulations governing the excavation of ordinary earth from a borrow areas |  EC | Corpbiz](https://www.youtube.com/watch?v=69JpnZJWX5s) — Corpbiz
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_4/engineering_geology_ii/borrow-area-requirements
- Whole chapter: https://www.bctengineer.com/md/semester_4/engineering_geology_ii/chapter-7

## Question

What are the requirements for selection of a borrow area for construction material exploration? Describe the types of resource.

## Short answer

Borrow area must have acceptable quality and adequate quantity, be close to the site with easy access, require minimal overburden and dewatering, and be stable, safe, legally permissible, and environmentally acceptable. Resource types: identified (measured, indicated, inferred) and undiscovered (hypothetical, speculative).

## Answer

A **borrow area** is a place from which soil, sand, gravel or rock is excavated for use in construction (embankments, concrete, road base).

#### Requirements for selection
1. **Quality:** suitable grading, strength, durability and soundness; free of organic matter, excess clay, salts and harmful minerals; passes the tests required for its use (embankment fill, concrete aggregate, etc.).
2. **Quantity:** adequate volume (usually 1.5 to 2 times the requirement) after deducting overburden, waste and the portion under water.
3. **Location:** close to the site (short haul distance), with easy road access and low transport cost.
4. **Ease of excavation:** thin overburden, workable slopes, little blasting, and above the water table.
5. **Stability and safety:** away from landslide, flood and other hazard zones; stable excavated slopes.
6. **Legal and social:** land ownership and clearance, government permission, compensation, and acceptance by the community.
7. **Environment:** little damage to forests, farmland, water sources and scenery; the area can be rehabilitated; no effect on river morphology or on structures such as bridges.
8. **Drainage and water:** no waterlogging, and water available for processing.
9. **Economics:** low cost of excavation, processing and royalty.

#### Types of resource
| Type | Meaning |
|---|---|
| **Identified: demonstrated (measured + indicated)** | Location, grade, quality and quantity known from measurements and sampling |
| **Identified: inferred** | Estimated from geological evidence and assumed continuity, with less certainty |
| **Undiscovered: hypothetical** | Not yet found, but expected in known districts |
| **Undiscovered: speculative** | Not yet found, but expected in unexplored areas |

Identified resources thus include the demonstrated and inferred categories, while undiscovered resources are hypothetical or speculative. Each can be economic (reserve) or sub-economic. For construction materials, the sources are also grouped as rock quarries (bedrock aggregate), river-bed and terrace deposits (sand and gravel), and soil borrow pits.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. What quantity rule applies to a borrow area?
   A. Exactly the requirement
   B. Half the requirement
   C. Volume usually 1.5 to 2 times the requirement after deducting overburden, waste and the part under water
   D. Quantity does not matter if the quality is good
   Answer: C. A margin allows for losses; overburden and underwater parts are unusable. (Key point: Quantity)

2. Which site is preferable?
   A. Close to the project with easy access, thin overburden and above the water table
   B. Far away, to avoid disturbance
   C. Under the water table for easy dredging
   D. Under thick overburden, for protection
   Answer: A. Short haul, easy access and easy excavation keep cost low. (Key point: Location and excavation)

3. Which resource types are undiscovered?
   A. Measured and indicated
   B. Demonstrated and identified
   C. Hypothetical and speculative
   D. Inferred only
   Answer: C. Identified/demonstrated (measured + indicated) and inferred are known; hypothetical (known districts) and speculative (unexplored areas) are undiscovered. (Key point: Resource types)

## Related in Engineering Geology II

- [Define reserve and estimate construction material](https://www.bctengineer.com/question.md?key=semester_4%2Fengineering_geology_ii%3Adefine-reserve-estimation) — Engineering Geology II, chapter 7, asked 10×
- [Geology in road alignment selection](https://www.bctengineer.com/question.md?key=semester_4%2Fengineering_geology_ii%3Aroad-alignment-geology) — Engineering Geology II, chapter 4, asked 5×

## Related in other subjects

- [Foundation selection factors, excavation in wet areas](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Aexcavation-selection-wet-080c) — Building Technology, chapter 2
- [Requirements of a good pipe material](https://www.bctengineer.com/question.md?key=semester_5%2Fwater_supply_engineering%3Arequirements-good-pipe-material) — Water Supply Engineering, chapter 8, asked 2×
- [Factors for selecting construction materials](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Afactors-selection-construction-material) — Civil Engineering Materials, chapter 1, asked 9×
- [Factors in selecting construction equipment](https://www.bctengineer.com/question.md?key=semester_8%2Fconstruction_management%3Aequipment-selection-factors) — Construction Management, chapter 4, asked 6×