What Is The Difference Between A Dug Well And A Drilled Well?

Have you ever wondered which type of well will best serve your property and long-term water needs?

What Is The Difference Between A Dug Well And A Drilled Well?

You will find that dug wells and drilled wells differ in construction method, depth, vulnerability to contamination, cost, and suitability for different geologies. Understanding these differences helps you make an informed decision for your home, farm, or business.

What Is a Dug Well?

A dug well is created by excavating the ground from the surface downward using hand tools, backhoes, or excavators. These wells are typically wide and shallow, often lined with stone, brick, concrete rings, or other materials to prevent collapse.

What Is a Drilled Well?

A drilled well is formed using specialized drilling equipment that bores a narrow, deep hole into the ground and installs a steel or PVC casing and a screen at the intake. Drilled wells are designed to reach deeper aquifers and can provide more reliable yields and cleaner water in many geological settings.

Key Differences at a Glance

You will get a quick snapshot of the most important differences by reviewing a side-by-side comparison. This helps you see how construction, depth, cost, and risks contrast between the two types.

How Each Well Is Constructed

You should understand the construction steps so you can evaluate contractors, costs, and maintenance needs. Construction method influences durability, contamination risk, and regulatory requirements.

Construction of Dug Wells

Dug wells are usually excavated with shovels or machinery until water is encountered. After digging, you or a contractor will line the well with masonry or concrete rings to prevent collapse and install a basic well cap or cover to reduce contamination.

You often see dug wells near older properties because they were the easiest type of well to build before modern drilling rigs were common. Their large diameter makes them easier to service manually, but the open surface area increases contamination risk.

Construction of Drilled Wells

Drilled wells are installed by drilling rigs that use air or mud to remove cuttings and create a narrow borehole. The well is cased to isolate the borehole from overlying soils and then grouted to seal the annular space. Screens or slotted casing are installed at the intake zone to allow water into the well while keeping out sediment.

Drilled wells typically require specialized contractors and equipment but result in a deeper, narrower well that is easier to seal against surface contamination and better suited to reach confined aquifers.

Typical Depth and Diameter

You will find depth and diameter vary dramatically and affect water availability, pressure, and pump selection. These physical dimensions also influence maintenance and contamination risk.

Depth Ranges for Dug Wells

Dug wells are often shallow, commonly between 5 and 30 feet deep, although in rare cases they can be deeper depending on local water table conditions. Their shallow nature makes them sensitive to seasonal changes and droughts.

You’ll find that shallow depth contributes to lower hydraulic head, which usually requires a shallow well pump or hand pump capable of lifting water from a relatively short distance.

Depth Ranges for Drilled Wells

Drilled wells commonly range from 50 feet to several hundred or even a thousand feet, depending on local geology and regulatory practices. Because they access deeper aquifers, drilled wells often benefit from more consistent water supply and greater protection from surface contamination.

Your drilled well usually has a small diameter (commonly 4–10 inches), which helps maintain structural integrity and makes it easier to install submersible pumps inside the casing.

Water Source and Aquifer Types

You should consider which aquifer your well will use, as aquifer characteristics determine water quality, yield, and reliability. Different well types are better suited to specific aquifer conditions.

Aquifers Served by Dug Wells

Dug wells generally tap into the shallow water table or perched water bodies, which are unconfined and directly influenced by surface conditions. These aquifers can recharge quickly after rainfall but are more susceptible to contamination from surface activities.

When you rely on a dug well, seasonal variations and local land use (fertilizer application, septic systems, road runoff) will significantly affect water quality and quantity.

Aquifers Served by Drilled Wells

Drilled wells can reach confined or artesian aquifers, which are pressured and often isolated from the surface by impermeable layers. These deeper aquifers may have better protection from surface contamination and more stable yields.

Your drilled well may tap water that has been naturally filtered through geological materials, which can improve clarity and reduce certain contaminants, though it can also bring dissolved minerals that require treatment.

Water Quality and Contamination Risks

You will want to prioritize water safety, which requires understanding contamination pathways and mitigation options. Well type strongly influences exposure to contaminants and the required testing frequency.

Contamination Risks for Dug Wells

Because dug wells are shallow and often have larger openings near the surface, they are more vulnerable to contamination from surface runoff, animal waste, nearby septic systems, and agricultural chemicals. Direct infiltration after storms is a common pathway.

If you have a dug well, regular testing for bacteria (total coliform and E. coli), nitrates, and other local contaminants should be part of your maintenance plan. You will likely need more frequent testing than for a properly constructed drilled well.

Contamination Risks for Drilled Wells

Drilled wells are generally better protected because the casing and grout create a physical barrier against surface contaminants. Still, you are not immune to contamination—faulty casing, improper sealing, or cross-connections can introduce pollutants. Additionally, deeper aquifers can carry dissolved minerals like iron, manganese, or hardness-causing calcium and magnesium.

Even with a drilled well, you should test water at least annually for bacteria and check specific contaminants based on local geology and land uses (e.g., arsenic, radon, volatile organic compounds).

Pump Types and Water Delivery

You will choose a pump based on depth, flow requirements, and well type. Understanding pump options helps you size systems correctly and estimate energy costs.

Pumps for Dug Wells

Shallow wells typically use jet pumps (shallow or convertible) or suction-type pumps mounted above ground. You can also use hand pumps in remote or low-budget situations. These pumps are suitable when the static water level is within about 25 feet of the surface.

Your pump selection will consider lift capacity rather than submersible installation. Jet pumps may require priming and can be less efficient if they must lift water from deeper levels.

Pumps for Drilled Wells

Deep wells commonly require submersible pumps installed inside the casing or deep-well turbine pumps. These pumps operate submerged in the water column and can handle higher depths and pressures with greater efficiency.

If you use a drilled well, you can often achieve higher flow rates and consistent pressure with a properly selected submersible pump and pressure tank system. Pump installation, removal, and servicing require access to the wellhead and proper electrical connections.

Lifespan, Durability, and Maintenance

You should anticipate ongoing maintenance to protect both dug and drilled wells. Lifespan depends on construction quality, materials, environmental conditions, and upkeep.

Lifespan of Dug Wells

Dug wells may have shorter practical lifespans due to susceptibility to collapse, contamination, and degradation of masonry lining. If uncapped or poorly capped, these wells can quickly become unsafe.

Frequent inspections, capping, and periodic rehabilitation (re-lining or relining) are often necessary to maintain a dug well’s safety and functionality.

Lifespan of Drilled Wells

With proper construction, drilling, casing, and sealing, drilled wells can last several decades. Routine maintenance such as pump servicing, wellhead inspections, and occasional rehabilitation (e.g., pumping to remove sediment or acidizing to remove mineral encrustations) can extend functional life.

You will minimize problems by keeping accurate records (well log, pump make/model, depths) and scheduling periodic tests and inspections.

Costs and Budget Considerations

You will weigh upfront installation costs, operational expenses, and potential remediation costs. The right choice depends on your budget, water needs, and property geology.

Installation Costs for Dug Wells

Dug wells usually cost less upfront, especially if you do manual excavation or use modest equipment. However, because they are shallow and less reliable, you may face ongoing treatment, contamination mitigation, or replacement costs.

If you buy an older property with a dug well, plan for a thorough water test and potential upgrade to a drilled well if the dug well cannot reliably provide safe water.

Installation Costs for Drilled Wells

Drilled wells typically have higher initial costs due to rental of drilling rigs, specialized labor, casing materials, grouting, and sanitary well caps. However, their long-term reliability often reduces lifecycle costs and treatment needs.

You will find that cost depends heavily on drilling depth, rock hardness, required casing materials, and local labor rates. Deep drilling in hard rock is more expensive than drilling in unconsolidated sediments.

Legal, Regulatory, and Permitting Issues

You must follow local and state regulations for well construction, testing, and abandonment. Regulatory compliance protects your water supply and prevents environmental harm.

Permits and Regulations for Dug Wells

Some jurisdictions regulate all wells, including dug wells, and require permits or inspections. You will need to follow setback rules from septic systems, property lines, and surface hazards, and ensure proper wellhead protection.

Always check local health department or environmental authority requirements before constructing or refurbishing a dug well to avoid fines and future remediation.

Permits and Regulations for Drilled Wells

Drilled wells nearly always require permits, licensed drillers, and logging of the well record with the appropriate agency. Your contractor must follow standards for casing, grouting, and protective wellheads.

You should obtain a permit, ensure the contractor files the well log, and maintain records for future sale or refinancing of the property. Some regions also have minimum construction standards for setbacks and sealing.

Choosing the Right Type for Your Property

You will need to consider geology, water demand, budget, and long-term plans when choosing between a dug well and a drilled well. A professional site evaluation is often the best first step.

Factors Favoring a Dug Well

A dug well may be suitable if you have a shallow, reliable water table, low water needs, minimal contamination risk from neighboring land uses, and limited budget. It can be appropriate for small homesteads or historical structures where tradition or aesthetics matter.

If you choose a dug well, make sure it is properly lined and capped, and be prepared for frequent testing and possible upgrades.

Factors Favoring a Drilled Well

A drilled well is typically the better choice if you need a reliable supply, high yield, better protection from surface contamination, or if your local geology requires reaching deep aquifers. Drilled wells are more common for modern homes, farms with irrigation needs, and properties near potential contamination sources.

You should prioritize a drilled well if you plan long-term residence, have a higher water demand, or live in an area with variable seasonal water tables.

Advantages and Disadvantages

You will benefit from a clear, practical comparison of pros and cons to match your priorities with well type.

Advantages of Dug Wells

• Lower initial cost for construction in suitable conditions.
• Larger diameter can make manual repairs easier.
• Simpler technology (hand pumps possible) and less dependence on complex equipment.

You should remember the higher contamination risk and variable yields when considering a dug well.

Disadvantages of Dug Wells

• Vulnerable to surface contamination and flooding.
• Often shallow with seasonal fluctuations or low yields.
• Shorter lifespan and potentially higher long-term maintenance costs.

If contamination or reliability is a concern, a dug well may not be appropriate for your primary water source.

Advantages of Drilled Wells

• Better protection from surface contaminants due to casing and grouting.
• Greater depth and normally more stable yields.
• Compatible with modern submersible pumps and pressurized systems.

You will likely experience fewer water-quality surprises and more consistent supply with a drilled well.

Disadvantages of Drilled Wells

• Higher initial cost and need for specialized drilling contractors.
• Narrow diameter can make some types of repairs more complex.
• Possibility of dissolved mineral issues that require treatment.

Even with drilled wells, you must budget for testing, pump maintenance, and occasional rehabilitation.

Tables for Comparisons and Quick Reference

You will appreciate clear reference tables that summarize technical details and practical considerations. These tables help you compare at a glance.

Table: Depth, Diameter, and Typical Pump Type

Table: Common Contaminants and Treatment Options

Testing and Water Treatment

You will maintain safe water by establishing a testing and treatment plan tailored to your well type and local risks. Regular monitoring is essential.

Testing Frequency and Parameters

Test for bacteria (total coliform and E. coli) at least annually and after any well servicing or flooding event. Test for nitrates, pH, and locally relevant contaminants (e.g., arsenic, lead, VOCs) as recommended by your local health authority.

You should keep records of all test results and any treatment interventions for future reference and regulatory compliance.

Treatment Options Based on Issues

If bacterial contamination occurs, shock chlorination can be an immediate remedy that you can often perform yourself with guidance. For persistent chemical contaminants or mineral issues, install appropriate treatment systems such as activated carbon filters, reverse osmosis, or iron filters.

You will consult a water treatment professional to size, install, and maintain systems properly to ensure effective long-term treatment.

Common Problems and Troubleshooting

You will likely encounter occasional problems that can be resolved with systematic troubleshooting. Knowing common issues helps you respond quickly.

Low Yield or Dropping Water Levels

If your well yield drops, check for seasonal trends, increased local pumping, or declines in the water table. For dug wells, watch nearby land-use changes that may alter recharge. For drilled wells, consider pump drawdown tests and professional aquifer evaluation.

Proactive water conservation and monitoring can help you manage reduced yield issues before they become critical.

Contamination Events

If contamination is suspected (e.g., after heavy rainfall or septic failure), avoid using the water for drinking and call a professional to test and disinfect the well. Use an alternative safe water source until test results confirm safety.

You will prevent many contamination events by maintaining sanitary wellheads and keeping hazardous materials away from the well.

Pump Failure or Mechanical Issues

Signs of pump trouble include reduced flow, unusual noises, or electrical tripping. Check power supply, control switches, and pressure tanks. For submersible pumps, you will likely need a service professional to pull and repair or replace the pump.

Keep spare parts for common shallow-well pumps if you want to minimize downtime on a rural property where service calls may be delayed.

Decommissioning and Abandonment

You must properly decommission wells that are no longer in use to protect groundwater and comply with regulations. Improperly abandoned wells can be major contamination conduits.

Procedures for Safe Well Abandonment

You should contact your local environmental agency for required procedures and permitted contractors. Typical steps include removing pumps and equipment, filling the borehole with clean native material or approved grout, and sealing the top to prevent surface water entry.

Proper documentation of abandonment protects public health and eliminates liabilities when selling or developing property.

Risks of Improperly Abandoned Wells

Open or poorly sealed wells allow contaminants to bypass natural filtration and reach deep aquifers. Additionally, they present physical hazards (falling in) and legal risks if they affect neighboring properties.

You will avoid headaches and environmental harm by following official abandonment protocols and keeping records.

Frequently Asked Questions

You will find answers to common concerns about well choice, safety, and costs.

How often should I test my well water?

Test at least annually for bacteria and more often if you notice changes in taste, color, or odor, or after events like flooding. Test for other contaminants according to local guidance or known regional risks.

Can I convert a dug well to a drilled well?

You can decommission a dug well and install a drilled well nearby. In some cases, professional services may retrofit a shallow well with improved sealing or a narrower drilled bore, but conversion usually means abandoning the dug well and drilling a separate, deeper well.

Which well type provides better water pressure?

Pressure depends on pump type and system design more than well type. However, drilled wells with deeper intakes often allow submersible pumps that deliver consistent pressure and flow rates appropriate for household systems.

How much will a drilled well cost compared to a dug well?

Costs vary widely by location and geology. Drilled wells typically cost more upfront—often several thousand dollars or more—while dug wells can be less initially. Consider lifecycle costs: treatment, maintenance, and potential replacement for dug wells versus higher initial investment and longevity for drilled wells.

What should I do if my well is contaminated with bacteria?

Stop using the water for drinking and contact a professional for testing and shock chlorination. After disinfection, re-test to confirm the water is safe before resuming normal use. Investigate and fix the contamination source to prevent recurrence.

Final Recommendations and Next Steps

You will be best served by combining technical facts with local knowledge and professional advice. Before making decisions, have a hydrogeological assessment and consult licensed well contractors.

Start by obtaining local well logs, speaking with neighbors about their well performance, and contacting your local health department for guidelines and testing resources. If you decide on drilling, request multiple quotes, verify contractor licenses, and ask for detailed contracts specifying casing, grouting, and sanitary seals. If working with an existing dug well, test water comprehensively, inspect the wellhead, and consider upgrading the cap and lining for improved protection.

Your choice between a dug well and a drilled well should factor in water quality, reliability, long-term costs, and local regulations. With thoughtful planning and proper maintenance, you can secure a safe and dependable water source for your property.