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What can I do if I don’t have enough water?
This article was written by Jeff Twitchell on July 25, 1999
Jeff is the V.P. Air & Water Quality Inc.
Wells drilled directly into bedrock tend to be low yield wells. Peak demands can require more water than the well
can provide. This article describes possible options and issues to consider when choosing a solution to a low yield
well. You have three options if you don’t have enough water. The options are as follows:
- Drill the well deeper to provide more storage and perhaps
hit a fissure that produces more water.
- Hydrofracture the well.
- Provide auxiliary storage below or above ground.
Drilling Deeper
If you decide to drill the well deeper, you will need to
consider the following:
· The new source of water may be of poorer quality
than what you have so you will need to retest the water.
· Increasing the size of your systems pump
· Salt water intrusion along coastal areas
· Expense (often as much as a new well- $4000 or more)
· NO GUARANTEE OF SUCCESS.
Hydrofracturing
Hydrofracturing is the process of placing hydraulic pressure
on the bedrock surrounding the well for the purpose of enhancing the yield of water. A packer is lowered into the
hole and inflated below the well casing to seal the top of the well. Water is then pumped at 25-60 gpm through
the packer and into the well. The pressure created blows water into the fractures cleaning out obstructions.
If you decide to hydrofracture the well, you will need to
consider the following:
· The new source of water may be of poorer quality
than what you have so you will need to retest the water.
· Expense ( $2,000 or more)
· NO GUARANTEE OF SUCCESS.
Storage
Most wells yield water at a rate that would be adequate if
the demand could be spread evenly throughout the day. This can best done by providing storage for periods of high
demands.
In a storage system water is pumped to an atmospheric tank
and then re-pumped by a second pump to the house. The storage can be provide in the form of an above or below ground
storage system. The simplest system consists of a polyethylene storage tank above ground.
The size of the storage tank will depend on the volume of
water required during peak demands. Generally, a design of a system assumes that the total amount of water used
in the typical residence occurs during a 4 hr period (2 hours in the morning and 2 hours later in the afternoon
or evening. The storage is sized to only handle one of these two hour peaks because the system will have time to
refill the tank before the next peak.
Example-
A family of 4 uses 75 gallons per day per person. This total
use for the day is 300 gallons. If we assume half of this is in the morning and half of this is later in the day,
the storage required will be 150 gallons.
If you decide to use auxiliary storage for the well, you
will need to consider the following:
The cost of these systems can be estimated using the following:
A basic system with 165 gallon tank, repressurization pump, pump protection, solenoid valve,
flow control, electrical controls, piping, fittings, wiring, and installation is $2,000.
Options to consider-
Back up float and solenoid safety- $150
Remote low water level indicator for storage tank - $150
UV light for continuous disinfection- $1295
Extra storage - $350 per 165 gallons
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