A: Groundwater can be anywhere from ten feet below the surface to thousands of feet below the surface. It’s just a matter of where you’re at geographically and the geology of the ground around you.
There’s different aquifers at different levels. Here in Houston, we’re really close to the ocean—the gulf and everything. So, in downtown Houston for example, you can dig down nine feet and hit water. In other parts of Texas—West Texas, North Texas, you may have to go a few thousand feet before you hit “good” water.
Now, there’s all different kinds of water as well. You can hit brackish water; you can hit water with a lot of iron and TDS’s. To find the correct, good quality water for municipal or human consumption—you have to have a water well driller that just knows that area.
Groundwater 101
Groundwater is the water that you find beneath the earth’s surface. It is found in rock and soil pore spaces as well as within fractures of rock formations. One common geological source of larger water deposits is an aquifer.
An aquifer is a water-bearing rock formation that can supply water to wells and natural springs. They are an important groundwater source for many municipalities. A famous example of an aquifer in Texas lies about two hours west of us in Austin. The Edwards Aquifer feeds the extremely popular Barton Springs where the water stays a cool 63-65° year-round. In fact, Texas is home to a significant part of the largest aquifer in the United States. The Ogallala Aquifer in the high-plains region spans 36,293 sq. miles in the Texas panhandle and over 174,000 sq. miles overall.
The depth at which water completely saturates, fractures, and voids in rock or soil pore spaces is referred to as the water table. The water table varies in depth with the topography. Groundwater sources are replenished by rainwater absorbed through the surface. The discharge of these sources can be natural via springs and seeps. However, it can also be extracted and used to irrigate crops, provide municipal water, and serve other agricultural uses. This extraction is achieved using extraction wells and groundwater pumps among other equipment.
Where Does Most Groundwater Come From?
When discussing groundwater, there are many sources including soil moisture, low permeability bedrock, geothermal springs, and of course, aquifers.
The groundwater that lies within aquifers is one of the most critical sources of water on the planet. A little over 30% of freshwater is sourced from aquifers. The remainder is sourced at the surface from lakes, rivers, reservoirs, and wetlands. However, the majority of the world’s freshwater—nearly 70%—isn’t even being tapped. That is because it is locked up in the ice caps and glaciers.
Groundwater can be found in a wide variety of rocks although the most bountiful aquifers are in porous, permeable rock. This includes varieties such as sandstone and limestone—quite common throughout Texas. Groundwater moves easier through these rock formations, so it allows for more efficient pumping.
Aquifer Characteristics
Aquifers can be found in multitudes of sizes and shapes, but all are essentially the same—underground water repositories. Concentrated, impermeable substances such as shale or clay are referred to as “aquitards.” An aquitard is a zone beneath the surface that restricts groundwater flow from one aquifer to another. Aquitards are usually comprised of clay or shale and while they restrict flow, they are not always completely impenetrable to water. If the water does flow, it does so very slowly.
The Importance Of Groundwater From Aquifers
Aquifers are like the world’s water wells. When rainwater penetrates the surface it absorbs and eventually, the excess makes its way to those aquifers. This is called “recharging” and it usually happens near mountain ranges, as water flows down from the slopes through rivers and such. How fast an aquifer recharges depends on the density of rock and soil the groundwater has to navigate.
It can move a few feet a day, or it can move as little as a few inches in a century—it all depends. However, the aquifers are in no rush or dire need. The water beneath the earth in these repositories can be held for vast periods. Scientists have estimated that some aquifers have water stored within that is over 10,000 years old. In fact, the oldest groundwater source ever discovered was two miles deep down a mine in Canada. It was estimated that the water within this aquifer was able to be dated as old as 1-2.5 billion years.
Depth Is Key
However, for drinking water, shallow aquifers are what we’re looking for. The deeper you dig for water, the more salt present. Groundwater can go thousands of feet deep but eventually, you get nothing but a salty brine.
Going back to the Ogallala Aquifer for example. It supplies almost a third of the water for agricultural use in America. Additionally, nearly 2 million people depend on that aquifer alone for their drinking water.
Here in Texas, roughly 60% of our water supply is sourced from groundwater—drinking, industrial, and agricultural usage. This is mainly since groundwater is typically much cheaper, easier to extract, and less susceptible to pollutants. That is why it’s so frequently used as a primary source for public water supplies, especially in rural areas. Even counting the Great Lakes, aquifers account for more freshwater than all of our lakes, reservoirs, and others combined.
Groundwater Pumps For Extraction
Of all resources that the nature provides to us, groundwater is the most important. All living things need water to survive. Animals, humans, plants—are comprised mostly of, you guessed it—water. Groundwater is extracted for drinking water, irrigation, and industrial uses by using groundwater pumps.
Before choosing a pump you need to know the application it’s being used for. What type of water are you extracting? Where are you moving it to? Also consider the change in elevation, distance, and flow. For example, take a look at the three most popular groundwater pump types we sell and what they’re good for.
- Electric Submersible Pumps— These pumps excel in deep groundwater applications.
- Well-Point Pumps— Great for groundwater depths less than 25 feet and are notably efficient. Mainly used in applications with long straight piping or when excavating a construction site.
- Centrifugal Pumps— Perfect for heavy-duty applications where there’s a mix of solids in the water.
Additional Considerations
Once you know your application and all its requirements and you know what type of pump you need, there’s more to think about. You need to consider some of the details like the specs, and components needed.
Size And Power: The main reason pumps experience failure on a job is choosing the wrong size and power. We’re not just talking about going too small, you can go too big as well—even in Texas. For example, too much power but not enough flow can blow a pump up. Too little power and you can burn up the motor. There’s a fine balance—find it.
Hose: Selecting the proper hose is just as important as pump selection. For example, HDPE will lower your losses from friction but only at a certain distance. Anything under 1,000 feet you want to use the same hose size as pump suction and discharge. Anything over that use the next size up. HDPE pipe is the one exception to this rule though.
Control Box: If your flow is going to be variable, you will need a full-featured control box. Honestly, there’s not really a reason to forego a full-featured box.
RPM’s: Just like you shouldn’t redline a car, you don’t want to do that with a pump or you’ll burn it up. Every pump has a perfect zone you want to be within. The more consistently you run the pump in the RPM zone the more efficient it will be. Also, running it within that zone extends the pump life.
Get The Right Pump With Gulf Coast
We aren’t just the top pump and supply company in the southwest, we also know the business you’re in. We specialize in knowing our client’s business and the challenges they face. So, when you need a pump for a job we can make sure you have the right setup. Contact us today and let us know what we can put together for you.