Water Well Rehabilitation and Maintenance - Cotey Chemical Corporation

Rehabilitate means to restore, reinstate, or put back in good condition.
When it comes to water wells, rehabilitation means one thing to every owner:

Getting your well producing water efficiently and affordably again.

At Cotey Chemical Corporation, our goal is to help you do just that — to bring your well back to life, save energy costs, and extend its service life using proven mechanical and chemical rehabilitation techniques.

Before (left) and after (right) pictures of a well screen on a well that has been rehabilitated.

As a water well ages, its ability to produce water efficiently tends to decrease. Whether by hard water deposits, biofouling, or physical plugging, all water wells develop performance issues over time. This guide explains how to identify well problems early and discusses effective rehabilitation methods to restore lost capacity, reduce energy costs, and extend the life of your well.

Understanding Well Performance and Specific Capacity

A common measure of water delivery is specific capacity, defined as the pumping rate (gallons per minute) divided by the drawdown or increased depth to water during pumping (measured in feet). Monitoring your well’s specific capacity annually provides early warning signs of deterioration.

To track well performance effectively, maintain records of:

Original flow rate and drawdown measurements
Annual specific capacity calculations
Energy costs for pumping operations
Water quality test results

Generally, a decrease of 25% or more in specific capacity indicates that rehabilitation is in order. Delaying rehabilitation can significantly increase costs and, in some cases, make restoration impossible.

Warning Signs Your Well Needs Rehabilitation

Watch for these indicators that suggest your well is experiencing problems:

Decreased pumping water level (increased drawdown)
Rising energy costs for the same pumping operations
Reduced water flow from the well
Declining water quality or appearance of sediment
Increased sand content in the water

Research shows that all water wells begin plugging, albeit in tiny amounts, from the day they first produce water. Early detection through annual monitoring allows for timely intervention before problems become severe.

Diagnose the problem using our quick reference table

Common Causes of Well Deterioration

Understanding what causes well performance to decline helps determine the most effective rehabilitation approach.

Mineral Deposits and Incrustation

Hard water deposits from calcium and magnesium salts create cement-like obstructions on well screens, in gravel packs, and throughout the water-bearing formation. These mineral deposits are often the most challenging to remove because:

Most mineral plugging occurs outside the well screen
Deposits can extend far into the formation
Hard minerals create extremely durable obstructions

Bio-Fouling and Bacterial Growth

Iron bacteria and other microorganisms create slimy biomasses that rapidly clog well screens and formation pores. While softer than mineral deposits, biological fouling can render a well virtually useless in months if left untreated.

Physical Plugging

Fine particles from the aquifer slowly migrate toward the well screen, causing:

Screen clogging
Reduced flow capacity
Sediment accumulation in the well

Additional Causes

Other factors contributing to well deterioration include:

Mud cake buildup
Oil film accumulation
Algae growth
Rust and corrosion of well components
Sand pumping from improperly developed wells

Methods for Water Well Rehabilitation

Successful well rehabilitation typically combines mechanical and chemical approaches. Each method has specific applications and limitations.

Mechanical Rehabilitation Methods

Mechanical solutions initiate energy in the well bore to break up obstructions and restore water pathways. Common techniques include:

Wire Brushing: Physical scrubbing of the well screen to remove soft deposits and biofilm.

Surging: Creating back-and-forth water movement to dislodge particles and stimulate the formation.

High-Pressure Jetting: Injecting water under extreme pressure to clean screen openings and formation pores.

Limitations of Mechanical Methods: The well screen, gravel pack, and formation all deflect mechanical energy from its intended targets. Mechanical solutions work best on soft materials inside the well bore but struggle with hard mineral deposits and materials far from the screen.

Chemical Rehabilitation Methods

Chemical treatments penetrate deeply into the formation because they travel with and similar to water. This provides thoroughness that mechanical energy alone cannot achieve.

Advantages of Chemical Treatment:

Penetrates screen, gravel pack, and formation
Completely dissolves hard mineral deposits
Holds dissolved materials in suspension for removal
Reaches plugging far beyond mechanical barriers
Particularly effective on calcium scale, rust, and mineral incrustation

Common Chemical Applications:

Acid treatments for dissolving mineral deposits and calcium scale
Chlorine solutions for treating iron bacteria and bio-fouling
Specialized formulations for mud-cake removal, oil film, and algae
Dispersing agents to break down and suspend particles

Important Safety Note: Chemicals affect only what they contact. Professional application ensures proper concentration, contact time, and agitation for maximum effectiveness.

For additional detail see:

Combined Approach for Best Results

The most effective rehabilitation programs utilize both mechanical and chemical methods:

Mechanical agitation breaks up soft materials and creates pathways
Chemical treatment dissolves hard deposits and penetrates deeply
Additional mechanical action removes dissolved materials from the well
Development procedures restore proper flow patterns

This combination addresses both immediate obstructions and deep formation plugging that mechanical methods alone cannot reach.

Real-World Results: Case Study

A farmer in West Texas noticed declining performance in his well serving a quarter-mile pivot (120 acres). After consultation with a professional contractor, he opted for combination mechanical and chemical rehabilitation.

Results of the rehabilitation:

Restored lost pumping capacity
Increased pumping water level by 50 feet (reduced drawdown)
Saved $1,036.80 annually in electricity costs
Improved water quality significantly
Extended overall well life

The reduced drawdown meant the pump didn’t have to lift water as far, directly translating to lower energy consumption and reduced wear on pump components.

The Value of Water Well Rehabilitation

Rehabilitation Planning and Execution

Step 1: Diagnose the Problem

Before beginning rehabilitation, conduct a thorough assessment:

Review well history and original specifications
Calculate current specific capacity
Compare to historical performance data
Inspect with downhole video camera if possible
Identify primary causes of performance loss

Note: Specific capacity drops don’t always directly correlate with the degree of plugging. Documented cases show wells with relatively small capacity drops that are nearly completely plugged upon video inspection. Professional assessment is crucial for accurate diagnosis.

Step 2: Select Appropriate Methods

Based on the assessment, determine whether to use:

Chemical treatment only (for mineral or biological issues)
Mechanical methods only (for loose sediment)
Combined approach (most common for established plugging)

Step 3: Proper Chemical Application

When using chemical treatments:

Calculate well volume accurately to determine chemical quantities
Select formulations appropriate for the specific plugging type
Ensure adequate contact time (often 12-24 hours)
Agitate the well to maximize chemical contact
Remove dissolved materials completely
Develop the well after treatment

Step 4: Well Development

Proper development after rehabilitation:

Removes all dislodged materials
Restores formation permeability
Stabilizes the aquifer around the screen
Establishes proper flow patterns

Step 5: Testing and Verification

After rehabilitation:

Measure new specific capacity
Compare to pre-rehabilitation performance
Document improvements for future reference
Establish new baseline for ongoing monitoring

Preventive Well Maintenance Best Practices

Regular maintenance prevents severe deterioration and reduces rehabilitation costs:

Annual Monitoring

Check specific capacity at the same time each year
Monitor energy costs for unusual increases
Test water quality
Inspect visible well components

Every Three Years

Conduct comprehensive water quality testing
Review pump performance metrics
Assess any changes in water clarity or taste

Every Ten Years

Professional well inspection
Video camera survey if warranted
Comprehensive performance evaluation

Record Keeping

Maintain detailed records including:

Well completion report with original specifications
Annual specific capacity calculations
Water quality test results
Inspection reports
Rehabilitation work performed
Equipment warranties and service records

Cost Considerations and Return on Investment

Well rehabilitation offers significant economic advantages over drilling new wells:

Typical Savings:

Restoration costs are 20-40% of new well drilling costs
Reduced energy consumption from improved hydraulics
Extended life of pump and well components
Avoided costs of temporary water supply during new well installation
Improved water quality reduces treatment needs

Calculating ROI: Track energy costs before and after rehabilitation. Many well owners see payback periods of 2-3 years from electricity savings alone, not counting extended equipment life and improved production capacity.

When to Call a Professional

Contact a licensed water well contractor when you notice:

Any decline in well performance
Changes in water quality
Increased pumping costs
Sediment or cloudiness in water
Unusual pump behavior or noises

Early professional intervention prevents minor issues from becoming major problems. Experienced contractors can:

Properly diagnose the cause of decline
Recommend appropriate rehabilitation methods
Apply chemicals safely and effectively
Use specialized equipment for mechanical cleaning
Ensure complete restoration of well performance

Treatment Products and Tools

Effective rehabilitation requires appropriate materials:

Chemical Treatment Products: Specialized formulations designed for specific well problems:

Acid-based products for mineral deposit removal
Bactericides for iron bacteria and bio-fouling control
Dispersing agents for mud cake and fine particles
Scale inhibitors for preventing future buildup

Mechanical Tools:

Well brushes sized for specific casing diameters
Surge blocks for agitation
Jetting equipment for high-pressure cleaning
Video inspection cameras for assessment

Volume Calculation: Use well dimension calculators to determine the precise volume of your well, ensuring accurate chemical dosing for effective treatment without waste.

Materials Compatibility

Well rehabilitation products must be compatible with well construction materials:

Plastic casing and components: Require pH-neutral or specially formulated products
Metal screens and casing: Can tolerate stronger acid solutions but require corrosion considerations
Rubber components: Need compatible chemical formulations

Always verify product compatibility with your well construction before application.

Summary: Restore, Don’t Replace

Water well rehabilitation offers a cost-effective alternative to drilling new wells. By combining mechanical and chemical methods, well owners can:

Restore lost capacity and return wells to original performance or better
Reduce operating costs through improved hydraulic efficiency
Extend equipment life by reducing pump strain and wear
Improve water quality by removing bio-fouling and contamination
Increase overall well longevity through proper maintenance

Regular monitoring of specific capacity and energy costs provides early warning of problems, allowing timely intervention before rehabilitation becomes difficult or impossible. Whether dealing with mineral deposits, bio-fouling, physical plugging, or combined issues, professional rehabilitation restores water production efficiently and economically.

For wells showing declining performance, prompt action with appropriate mechanical and chemical methods maximizes restoration success and minimizes costs. The investment in quality rehabilitation pays dividends through reduced energy consumption, restored capacity, and extended well life—helping ensure reliable water production for years to come.

For professional well rehabilitation services and treatment products, consult licensed water well contractors in your area who use proven mechanical and chemical rehabilitation techniques.

Water Well Rehabilitation: Restoring Performance and Extending Well Life