By Michael Schnieders, PG, PH-GW
It’s just a hole in the ground. How complicated can it be?
While this may be the opinion of some of our customers, it is vital we do not slip into the same mind-set.
Today, we must look beyond the idea the well is a simple, singular entity. Each well is truly unique, and as such, is the sum of all its parts and influences; it is part of a dynamic system.
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Think for a moment: When construction begins on a new well, we are taking a bit and forcing it into the earth—through soil layers, multiple rock units, various aquifers, and mixing the energy with a variety of different water chemistries, microbial communities, and physical properties—regardless of surface casing or introduced fluids. This in and of itself is a lot to take into account.
Now, hopefully the well is developed properly to restore some stability, but even before that time, there are a lot of decisions to make with regards to materials selection and placement…all adding to the list or “mix.”
And that’s where we are left, a giant mixing bowl. The operation and maintenance of well systems has become an increasingly complicated business. Part of this has been an increase in the technology available to understand well problems as well as an increase in the regulatory scrutiny imposed on water systems. Don’t forget to add in extended drought conditions, shifting population centers, and an increased concern in the general public for water quality.
When we approach a well, we have to take in to account the way the well was constructed, the manner in which it has (or hasn’t) been maintained, the materials used in the operation, disinfection, and cleaning of the well, and any changes that have occurred to the well. We also have to consider the aquifer, fluctuations in the water table, area of recharge, immediate and regional surroundings, as well as the way it has or hasn’t been operated, and even the way the produced water is treated and utilized.
Corrosion, biofouling, bacterial occurrence, mineral scale, sediment infiltration, air entrainment, foul odor, discoloration—all of these are maintenance issues that are common to existing wells. However, rarely are they incorporated into the design of new wells.
In identifying a location and preparing a design, we should develop a plan that builds on available information of existing wells within the area but incorporates new, proven technology.
Removing reactive materials, limiting exposed perforations, isolating the structure from improper grounding and stray current, selection of the right gravel pack, and reducing the use of corrosive activities can all help reduce the potential for corrosion and limit iron production.
Maintaining a clean well site, properly developing the well, properly disinfecting the well and aquifer interface, and limiting static or idle behavior helps to reduce bacterial influence. Incorporating testing capabilities as well as access for maintenance efforts improves the ease of proactive maintenance. The knowledge is available, but it is up to us to both embrace it and educate our customers.
A lot of issues can influence a well system. When we look at a new well, we must take into account everything surrounding that decision and the decided location now as well as 75 years from now. Gone are the days of the shallow completion and the 25-year-old well of “reasonable water quality.”
Now we must take into account all the possible influences, predict the needs and challenges, and design for more active monitoring and maintenance. We must take the time to do it right the first time. And a big part of that is educating our customer, perhaps even while we educate ourselves.
Michael Schnieders, PG, PH-GW, is a professional geologist currently serving as the principal hydrogeologist and president of Water Systems Engineering Inc. in Ottawa, Kansas. Schnieders’ primary work involves water resource investigation and management, specializing in the diagnosis and treatment of fouled well systems. Schnieders was the 2017 McEllhiney Distinguished Lecturer in Water Well Technology. He can be reached at firstname.lastname@example.org.