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The goals of wellfield management are simple, but lofty.
By Michael Schnieders, PG, PH-GW
The well industry, much like most of the water industry, is an often under-appreciated but vital part of our life. Sadly though, the “run to failure” attitude prevails, not just in the residential well arena, but also in the municipal realm.
Water wells are a true asset. Whether the owner is a family, rural water district, or large municipal entity, it is a vital part of planning and life, even if it is “out of sight, out of mind.” Well failure, be it a result of water quality, reduced efficiency, or a host of other issues, can significantly impact its owner. The costs associated with the run to failure mindset can be substantial for a family and for a municipality. As such, asset management, specifically well management, is vital.
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What’s the driving factor? Was there a contamination event? Dirty, stinky, or discolored water? Co
So what does wellfield management entail? Physical evaluation and maintenance of the well, pump, and distribution piping. Monitoring of the aquifer and area of recharge as well as neighboring water sheds, balancing needs, influence, and conservation. Regular evaluation of the produced water quality as well as any treatment methods. Monitoring of the property and any changing dynamics with regards to associated property, waterways and areas of potential influence. It’s not an easy or simple task, with the challenges increasing as the number of wells, contributing aquifers, and demand increases.
The goals of wellfield management are simple, but lofty:
- Eliminate run to failure
- Ensure water quality
- Ensure water quantity and well efficiency
- Reduce ownership costs
- Extend the life of the well system.
Let’s discuss the well, specifically evaluation and maintenance of the well and associated components. Although there are many similarities, each well is designed, constructed, and operated differently. Each well will have challenges that at times are similar to others but are unique to that well and reflect the way it was designed, completed, operated, and maintained (or not). As such problem resolution or maintenance should be well and problem specific.
Well maintenance begins with understanding what the problem is and where the problem is located. When conducting maintenance, we want to address the problem while not worsening the issue or causing new problems to occur. For example, chlorination of the well will have little effect on hard scale accumulations. Similarly, repeated disinfection of the well will do little to alleviate bacterial problems that are occurring as a result of problems in the distribution pipeline.
Some problems are tied to operation while others may be a symptom of the original construction, or changes in the aquifer. Oftentimes, multiple problems may be occurring and one particular issue, such as a coliform issue, may be masking larger problems downhole.
Periodic evaluation of the physical, chemical, and biological qualities of the well are useful mans of identifying problems early. Physical attributes of concern include changes in specific capacity, decreases in wire to water efficiency, corrosion or damage to the structure, and increases in sand or turbidity. Chemical changes outside of normal water quality concerns include total dissolved solids, calcium and magnesium, iron and manganese, as well as changes in the oxidation reduction potential. Biological concerns move beyond the typical coliform test to the tracking of the total population, level of anaerobic activity, and the rate of occurrence of iron oxidizing bacteria and sulfate reducing bacteria. How often a well is evaluated depends on its history and the role it plays in the owner’s water resources.
Moving the well owner’s mindset to a position of proactive, instead of reactive, can pay dividends over the life of the well—more so if it is the single resource or key component of their supply. Early identification of problems saves time and money while extending the operational life of the well.
