Don’t go drilling alone

Put experience and expertise on your side to avoid costly irrigation well drilling mistakes and failures.
BY GARY L. HIX, RG, CWD/PI
Well drilling mistakes
Drilling an irrigation well is a significant long-term investment.

Water well drilling services are a different form of contracting than almost any other form of contracting. Not only is the finished product sometimes difficult to build given natural geologic conditions, the outcome is often uncertain and the final product is nearly impossible to view. As much as 95% of a water well is out of sight below ground, and the quality of the work performed while building it, as well as its subsequent performance, are difficult to measure for someone without unique experience.

Gary Hix collects cuttings from a conventional mud rotary drill rig while the contractor drills the pilot borehole.

Irrigation wells are major capital expenses to build, and if not done properly, they can be even more expensive to operate during their producing years. If a well is not built with the proper materials, it can have a very short productive life.

Irrigation wells should never be purchased or contracted for based strictly on a lowest cost basis. An irrigation well is a significant purchase for a farmer or grower, and before making this investment it is important to get advice from a knowledgeable professional who has your best interest in mind. Even when done correctly, irrigation wells are subject to both mineral and microbial fouling that reduces performance and increases operating expenses. Well rehabilitations can restore some of the lost performance of a good well, but it can’t do much for a poorly drilled or constructed well.


Irrigation wells are major capital expenses to build, and if not done properly, they can be even more expensive to operate during their producing years.


Consider more than location

I have seen occasions when the location of an irrigation water well was chosen based strictly on it being an equal distance from the owner’s existing wells. This location made the installation of the electrical power and the piping of the water more convenient. The owner decided to just move down the road and put in a new irrigation well to the same depth and diameter as the closest existing well. The owner hired a local water well contractor to drill the new irrigation well. Although the owner got a completed irrigation well, it was far less productive than the nearby well due to differing subsurface geologic conditions. 

For situations like this where there is an expansion of existing fields with some known production results, it might seem logical to just contract directly with a well driller to drill a new production well. But in this case, it wasn’t. If the owner had asked for a small diameter test hole to be drilled first before bringing in the production rig, they would have saved money knowing of the poor geologic conditions at that site and drilled a production well at a better location. The lesson learned was that once a well has been drilled it cannot be moved.

Tap into regional experience

Water well contractors learn something new every time they drill another well in a given area. Their experience in a regional area is valuable knowledge. There are times when competent water well contractors are in short supply due to drought and other issues. In cases like these, growers have turned to out-of-state contractors trying to save a few months or a few dollars or to just get the job done. This kind of thinking has led to some poorly constructed wells that might not have turned out that way if they had used a hydrogeologist or a water well consultant with experience in the region. 

Localized collapse around an irrigation well (Image source: Gary L. Hix)

Some geologic conditions require the setting of a surface or conductor casing through unstable formations found at or just beneath the surface. Unfortunate and costly situations have resulted because of a contractor’s failure to appreciate the weakness of subsurface geologic conditions.

A California Central Valley nut grower entered into a contract with a well driller from outside his area without using a drilling consultant. This contractor did not anticipate the weak subsurface sandy conditions. The land surface collapsed while the well was still being drilled. Additional subsidence of the upper well casing collapsed the top of the well screen, necessitating lining it with a smaller diameter casing that significantly reduced its capability to pump enough water.

A pistachio grower in the California southern Central Valley contracted with a water well contractor for a 700-foot irrigation well to be equipped with a line shaft turbine pump. This grower also contracted without the help of a drilling consultant. The well was drilled and completed, but it was later found to be too crooked for the installation of a line shaft turbine pump. Both of the above cases ended up in court. 

Newly constructed irrigation well

Another unfortunate scenario can occur when drilling open borehole right from the land surface if the driller encounters an artesian formation with high head pressures. If there is not a surface casing or an intermediate string of conductor casing well cemented in place, a runaway flowing artesian well can cause a lot of collateral damage. When this happens, everyone loses something. 

These situations happen more often than one might expect, but only those active in the well drilling community are aware of these types of issues. A water well consultant would not let a well driller drill open borehole in unstable geologic formations. 

Cost vs. quality

It’s certainly not advisable to contract for well drilling services based solely upon the estimated costs made by three or even four water well contractors if you just ask them to give you a price for drilling a well. Chances are very good that the four contractors are not quoting costs for the same well that is built with the same materials and drilled using the same drilling method. How could they if they weren’t given identical detailed specifications and a specific contract to sign? 

A reverse circulation drill, such as this, is often used for deep and large diameter irrigation wells.

Contracting for an irrigation well should include a set of techni-cal specifications for the well at a defined location with the specific materials to be used. Unit prices multiplied by estimated quantities should be quoted for each step of the process and for materials provided. Contracting for an irrigation well should never be based on a bottom-line lump sum figure including everything.   

Searching out experienced water well professionals may sound like just another unnecessary expense to getting more groundwater for irrigation. But the cost is insignificant when compared to the costs resulting in a failure to get a productive well drilled with sufficient alignment for installing a turbine pump and producing enough water to justify the expense of drilling it. There are a number of unhappy well owners around the country who wish they had used a professional water well person to help them during locating, contracting, drilling and pump testing their newest water well. And the same is true for the work of reequipping or rehabilitating an existing well. Get professional advice before — not after — the job is done.

Hydrogeologists and well drilling consultants are there to give advice and protect their customers. They are the technical advisors between the landowner and the drilling contractor. These professionals have the knowledge necessary and are experienced with well drilling in your local area. They may have past experience with the local contractors and know which ones have the best experience and equipment to drill your well. Think about using one of them just as you would use an attorney or a licensed realtor if you were purchasing land or a new home.  

Unless you are sufficiently experienced in the nuances of well drilling, equipping and rehabilitations, find a hydrogeologist or a water well consultant to assist with your next irrigation well.    

Gary L. Hix, RG, CWD/PI, has been a fixture in the groundwater industry for nearly 40 years. He is the founder and owner of In2Wells.

Looking for a consultant or hydrogeologist in your region?

Go to www.ngwa.org. The Publication & News menu provides a directory to search for NGWA-certified professionals by state.

it-icon

RELATED NEWS

Optimizing irrigation water

Optimizing irrigation water

PAM optimizers are powerful tools for irrigation and are most effective when the application is customized for the circumstances.
Protect Colorado River

Keeping the Colorado flowing

What are we doing to safeguard the lifeblood of the American West?
California groundwater recharge

Drought & laws spark interest in groundwater recharge

Recent renewed interest in groundwater recharge in California brings new science, institutions, markets and investments.