If you’re looking for a well contractor in Minnesota, then you may wonder whether you will need a deep well in order to secure a steady supply of clean water. That is a reasonable question – but the answer to it is too complicated to be summarized by “yes” or “no.” A shallow well can in fact provide sufficiently clean water, which alongside its lower installation cost may make it your best bet!
What Makes a Well “Deep?”
First off, “deep” and “shallow” are relative terms as far as well depth is concerned. For example, a deep well for a home in Utah would extend to around 300 feet, but that depth is on the lower side of average for many residential wells in Colorado. This is because groundwater’s distance from the ground’s surface varies dramatically depending on geography.
When we refer to a “deep” well, we’re speaking in terms that are relative to the surrounding area. Even the world’s deepest hand-dug well – which is an impressive 1,280 feet deep – is probably deeper than any normal residential property in the country requires.
Why Does Well Depth Matter?
In order to be effective, a well has to access groundwater. Groundwater in the Midwest typically originates as rain and snowmelt, which gravity forces through the soil until it reaches the zone of saturation. The water table separates the saturated zone from the appropriately named unsaturated zone. In essence, a well shaft must penetrate the water table in order to access groundwater.
A well which just barely penetrates the water table will produce water, although that water may not necessarily be clean. If the land immediately surrounding a well is frequently exposed to substances such as pesticides, fertilizer and human waste, those contaminants can easily access the groundwater that well draws from.
In contrast, a deeper well draws groundwater which gravity has spent more time driving through the soil. It is entirely possible for deep groundwater to contain contaminants, but if that groundwater originated from faraway grassland, woodland or other virgin land, it is nearly certain to contain zero (or negligible) contaminants.
Is Well Depth the Only Thing That Matters?
Not at all! Like any other water, groundwater flows across a gradient. That’s why it is crucial to consider the nature of any land which lies uphill from a new well. If it is used for industrial or agricultural concerns, then a deeper well may be necessary to avoid the upgradient land’s runoff.
Its casing also affects the quality of the water a well can supply. For example, consider a 100-foot well. If its casing is 97 feet deep, then the well should only draw groundwater positioned around the final three feet of its depth. But if its casing spans only half of its length, then the 100-foot well is essentially yielding the same quality of water that a 50-foot well would have.
Time is another factor to take into account. While a shallow well is likely to get contaminated by recent spills in the immediate surrounding area, a deep well can get contaminated by spills that occurred far away and several years ago. Furthermore, some contaminants (such as pesticides) gradually break down. Even if a deeper well does draw water that ran off of a farm, that water’s contaminants may have spent so much time degrading that they have become significantly less harmful.
Are Deep Wells Always Better?
Shallow wells are always more economical. They require less time and fewer materials to create, so they are naturally preferable in circumstances where they are appropriate. But when land has an unusually deep water table or is immediately surrounded by one or more sources of contaminants, a deeper (and regrettably more expensive well) is typically warranted.
Choosing the best well depth requires a deep understanding of geography and groundwater dynamics. When you want to ensure that your new well will provide your home, farm or commercial property with clean, potable water for decades to come, you can count on Geo-Tech of Minnesota. We welcome you to contact us today for professional well installation, maintenance, repair or abandonment in Western Minnesota or Eastern North Dakota.