Reduced Water Flow or Well Yield? Consider Well Rehabilitation
If you've lived in your home for a long time, you may notice that your well isn't producing the water that it did when you first moved in. This is not uncommon. As a water well ages, the rate that water may be pumped, also known as well yield or flow, tends to decrease especially if your well did not properly develop when it was first drilled.
Water production can fluctuate due to some naturally occurring reasons. This can even happen in relatively new wells due to drought or over-pumping, which can dewater water bearing zones. Often reduced yield can be related to natural changes in the water itself for example:
- Mineral deposits
- Bio-fouling due to microorganism growth
- Physical plugging of the aquifer (the sand, gravel or rock water flows through) by sediment
- Sand pumping
- Casing or well screen corrosion
- Pump damage
The situation is not always bleak. Instead of incurring the expense of abandoning the well and drilling a new one a qualified well water contractor can often “rehabilitate” your existing well, restoring the flow to the level needed to meet your family's needs.
What is Water Well Rehabilitation?
Well, rehabilitation or restoration refers to the measures taken to correct the problem of low or no flow. A successful well rehabilitation can maximize the water flow from your well. The results of any restoration efforts are dependent upon the cause (or causes) of failure and how far these problems have progressed.
As soon as you notice any deviation from a normal performance the best course of action is to contact your well water professional and schedule an inspection. Tell them the problem is reduced flow and they will come prepared with a downhole camera to assess the situation and diagnose the problem.
The common measure of delivery of water is known as “specific capacity.” Specific capacity is defined as the pumping rate (gallons per minute) divided by the drawdown of your well measured in feet during pumping.
As a general rule, a decrease of 25% of more in yield is an indicator that well rehabilitation is in order. Delaying treatment can significantly increase costs. To detect a drop, you will need a point of reference. When you purchased your home, or if you had a well drilled on your property you should have the original well construction and well pump data. However, if you don't have this information, any significant changes in your well should be considered a warning sign. Here are some of the characteristics to watch for:
- Decreased pumping rate
- Decreased water level
- Decreased specific capacity
- Increased cloudiness, sand or sediment at the tap
- Decreased total well depth
If you notice any of these conditions or are notified of any of these issues during your annual inspection and testing, contact your well water professional immediately!
Well Rehabilitation Methods
There are two standard methods for rehabilitating a well: physically cleaning the well, or using chemicals to dissolve any encrusted materials or kill any biological elements that are clogging the well.
Physical methods include using a brush attached to a drilling rig, which is lowered into the well and scrubs the sides of the casement and shaft. Three other common physical methods involve injecting water into the well, and sometimes chemicals.
They include high pressure jetting, hydrofracturing (or hydrofracking) and well surging. In these three methods water is injected into the well under extreme pressure. Often contractors will use a combination of these methods depending on the reason for the decrease in performance.
Chemical treatment may be necessary for certain types of issues. Chemical and biological incrustation are common causes of well failure. Incrustations are physical blockages, for example, mineral deposits or slime developing on the screens or within the rock fractures that deliver water to the screen or borehole.
In these instances, a strong acid is used to dissolve the blockage. Once the acid has loosened the encrustation, the materials are pumped from the well along with the acid solution for disposal. Acid treatments are effective, but may also be used in conjunction with mechanical methods like brushing to improve results.
Biological incrustation is often treated using a bleach solution. The advantages of this form of treatment are the cost involved (it is a relatively inexpensive solution) and are usually allowed by most municipalities.
In other instances, hydrofracturing may be necessary. This method uses water sent into the entire well through a multi-head water jet at extremely high pressure to reopen and clear debris from clogged perforations and open new fissures to create new sources of water.
If your well is not producing the way it used to, contact Skillings & Sons. We are experts at well rehabilitation and have been restoring flows to wells for our clients throughout New Hampshire and Massachusetts. We will come to your home, assess your well's condition and recommend the proper treatment to restore your well to its original flow whenever possible. Don't let a compromised well put your water supply at risk. Contact Skillings & Sons today!