Wells and Groundwater

Wells provide one of the most reliable long-term water sources for emergency preparedness. Whether rehabilitating an existing well or planning a new one, understanding groundwater basics is essential for ensuring safe, sustainable water supply.

1. Types of wells

Different well types suit different conditions. The choice depends on depth to water table, soil composition, intended use, and available resources.

Key information

The depth of groundwater varies greatly by location and season. Before digging, research local water table levels and consult geological surveys if available.

Dug wells: Traditional hand-dug wells, typically 3-10m deep, lined with stone or concrete rings
Driven wells: Steel pipe with pointed screen driven into ground, best for sandy soil, 5-15m deep
Drilled wells: Machine-drilled to greater depths (30-300m+), most reliable but expensive
Bored wells: Hand-bored using auger, suitable for soft soils, 5-25m deep

Important Warning

Never dig a well near septic systems, fuel tanks, or areas where chemicals may have been used. Maintain minimum 30m distance from contamination sources.

2. Choosing well location

Proper well placement is crucial for both water quality and yield. Consider topography, distance from contamination sources, and accessibility.

Key Information

Wells on higher ground are less likely to be contaminated by surface runoff. Look for natural springs or vegetation indicating shallow water table.

Good indicators of groundwater:

Low-lying areas where water naturally collects
Presence of certain plants (willows, reeds, lush grass)
Valley floors and bases of slopes

Locations to avoid:

Within 30m of septic systems or latrines
Downhill from agricultural fields
Near old industrial sites or fuel storage

3. Well construction basics

Proper construction ensures well longevity and water safety. Key elements include adequate casing, proper sealing, and protection from surface contamination.

Key Information

A well apron (concrete pad around the well) is essential to prevent surface water from entering and contaminating the well.

Casing: Extends from surface into aquifer, prevents collapse and contamination
Grout seal: Fill space between casing and hole to prevent surface contamination
Well cap: Secure, watertight cover prevents debris and animals entering
Apron: 1-2m concrete pad sloping away from well head

4. Hand pumps and water extraction

For emergency preparedness, having a manual water extraction method is essential. Hand pumps work without electricity and can provide water indefinitely.

Key Information

Choose pump type based on well depth: suction pumps work to 7m, while lift pumps can draw from 25m or more.

Common hand pump types:

Pitcher pump: Simple, inexpensive, for shallow wells under 7m
Deep well pump: For depths 7-25m, uses cylinder below water line
Rope pump: Simple DIY design, effective for moderate depths
Lever-action pump: Efficient for medium depths, easier operation

5. Well maintenance

Regular maintenance ensures continued safe water supply. Neglected wells can become contaminated or lose their yield over time.

Key Information

Test well water annually for bacteria and contaminants. After floods or unusual events, disinfect the well before resuming use.

Regular maintenance tasks:

Inspect well cap and apron for cracks or damage
Clear vegetation within 2m of well head
Check pump operation and seals
Monitor water level and flow rate

Important Warning

If water becomes cloudy, develops odor, or tastes different, stop using immediately and test for contamination. Disinfect before returning to use.

6. Well disinfection

Periodic disinfection eliminates bacteria and ensures safe water. This is especially important for new wells, after repairs, or following contamination events.

Key Information

Shock chlorination uses high chlorine concentration to kill all bacteria. After treatment, pump water until chlorine smell disappears before drinking.

Shock chlorination steps:

1.
Calculate water volume in well (depth × diameter)
2.
Add appropriate amount of unscented bleach (typically 1L per 4000L water)
3.
Mix by pumping water back into well
4.
Let stand 12-24 hours
5.
Pump until chlorine smell gone, then test before use

Summary

A properly constructed and maintained well provides reliable, independent water access. Understanding groundwater principles and well care ensures long-term water security for your household.