lessons learned on the journey toward independence
Water System Example #5 - Dealing with Wells
The water source for the property is a well with a maximum static water level of 20 feet (Solution #1 ), 85 feet (Solution #2), 200 feet (Solutions #3 & #4), 300 feet (Solution #5), and 600 feet (Solution #6). Probably the most common water source one will encounter in the country is a well. While wells are generally the most protected type of water source from parasites, chemicals, etc, they have the disadvantage of necessitating a pump. But there are good ways to deal with this. Please be aware, though, the deeper the static water level of your well, the more expensive it will usually be to deliver pressurized water to your home.
The solutions below assume that you are not able to install a cistern at least 40 feet above the point of use (see picture to the left). If such an arrangement is possible, it would be a good idea for a few reasons:
- There would be a cistern full of water ready to “gravity flow” into your house as backup for mechanical problems
- With the solutions below that use a piston or booster pump (except solution #1), that expense would be eliminated.
- Low yield wells (less than 5 gallons per minute) may be made more workable by placing the pump on a timer and pumping water into a cistern on a regular basis. A slow well may run dry regularly while pumping, but if the pump has been cycling on and off throughout the day and night, collecting water in a large cistern, you now have a sizable amount of water at your disposal. This can make otherwise impossible tasks (like watering the garden) a possibility.
So, with many of the following solutions you might want to consider burying a cistern at least 40 feet (preferably 60) in elevation above the point of use (2nd floor if plumbing is there) and to pump the water from your well into the cistern when needed. In order to make sure your situation would qualify for this option, find out if the pump you intend to use has enough pumping power to handle the extra 40 or more feet of rise.
A Word about Wells: Static Water Level
As water from various underground water veins finds its way into a well, it starts filling the well up until it reaches a point at which it stabilizes and the water level will not go any higher or lower (unless water is pumped out too fast or a drought or change in the strata of the plates in your area makes other demands on the underground water supply). This point is known as the "static water level." One simplistic method to find the depth of your static water level is to tie a small piece of wood that has some weight to a long string. This piece of wood is then dropped into the well. Then the string is pulled lightly until tension is felt and the line is tight. Then pull the string out and measure it. This measurement is your approximate static water level.
With a static water level of only 20 feet or less, a piston or booster pump is used to pull water out of the well and then pump it to your house with pressure. A household diaphragm tank in your home keeps the household plumbing system pressurized until enough water has been used to deplete it, and then the piston or booster pump turns on to re-pressurize the system. Since the piston or booster pump is electric, it will be necessary to have an alternative energy system to run it. What makes the piston or booster pump more desirable than a regular submersible well pump for a shallow well? Much less electricity is required and it is possible to run certain models directly from your battery bank (making it even more efficient). Remember, though, it will only work with a well that has a static water level of 20 feet or less. We recommend that you look at the piston and booster pumps made by Dankoff. These are known for their durability.
In this solution, a 120 volt soft start submersible water pump is used to pump water directly from your well (with a static water level of 85 feet or less) to a household diaphragm tank inside your home. This tank keeps the household system pressurized until enough water is used to deplete the pressure. At that point, the pump turns on again to re-pressurize the system. Although the electric water pump will need an alternative energy system to run it, the soft start feature enables less expensive equipment to be used in the energy system (namely, a smaller inverter). The series of pumps we recommend for this purpose is the “SQ” series made by Grundfos (not to be confused with the "SQ Flex" series).
If the static water level in your well is 200 feet or less, a regular 120 volt submersible water pump may be used to pump water from the well to your home and into a household diaphragm tank with pressure. This tank keeps the household system pressurized until enough water is used to deplete the pressure. The pump then turns on and re-pressurizes the system. Even though this pump does not have the soft start feature mentioned above, there are models that will work with an alternative energy system, it just requires a larger inverter (due to the surge power requirements of a regular electric motor starting up). We recommend the 120 volt submersible water pumps made by Grundfos.
If your only water source is a well and you just cannot afford to install an alternative energy system, here is a backup option to make sure you have water when power is unavailable from the power company. A typical electric water pump is used in the well. It pumps to a household diaphragm tank, just like a typical setup. The difference is this: a hand pump is installed in the well also. This enables you to still at least pump water by hand. Although it will be a bit of work to pump by hand, it will surely be better than not having water at all. Please note: most hand pumps will only work properly with wells that have a static water level 200 feet deep or less (some models can only handle less than that). Before moving forward with this setup, contact the manufacturer or distributor of the hand pump to make sure the hand pump will work with your static water level and that it will be able to fit in the well with your electric water pump. The exceptions to the 200 foot rule would be the the Storm Pump and the Simple Pump, which are both capable of dealing with static water levels of 300 feet or more.
And while we are on this topic, one other option (probably not a very popular one with most) is the old “well bucket” setup. Drop the bucket down the well, a valve lets it fill up, pick it up, and the valve closes and holds water while you pull the bucket up. One big drawback to this backup system is that you would have to pull the well pump out of the well for this to work. That would be quite a job! There are options built out of PVC pipe or galvanized metal or you can build your own.
If the static water level in your well is down to 300 feet, things are going to get a little more expensive. First, we will use the same regular 120 volt submersible water pump that we did in Solution #3. But instead of making the pump pressurize a diaphragm tank, which would take around 92 feet away from the lifting capabilities of the pump (for a 40 PSI tank), we will use it to pump water to a cistern near the house. This means that no pressure tank will have to be pressurized by the pump. This enables the very same pump to now service wells with a static water level of 300 feet or less. But how do we pump the water from the cistern into the house with pressure? A 12, 24, or 48 volt DC piston or booster pump is used to do the task. It pressurizes a household diaphragm tank which keeps the household system pressurized until it is depleted of pressure by being used. The piston or booster pump then turns on to re-pressurize the system. And because this pump is DC and drawing straight from your battery bank, the inverter (which could be maxed out by a 120 volt submersible water pump) will not be tasked with supplying power to it. If you are unfamiliar with alternative energy systems and that didn’t make any sense, you can learn more about them here.
Up to 600 feet down to static water level? This is where you really have to spend some money. But it can certainly be done, and done independently from the power company. There are at least a couple of good options at the moment. The Sun Pumps SCS series csan reach down to 600 feet using DC power, and the SQFlex series made by Grundfos. is capable of reaching over 800 feet using AC or DC power. Both of these pumps are capable of being powered directly with solar panels or from a battery bank. Either way, the water may be pumped up to a cistern (in order to give the pump its maximum pumping depth) and a piston or booster pump is used to provide water to the household diaphragm tank with pressure. When the pressure is depleted by use, the piston or booster pump turns on to re-pressurize the system. If your static water level is not the maximum (600 feet) but is more like 400 feet, a Grundfos SQFlex series pump has enough flow (gallons per minute) to not only pump water out of the ground, but to also provide water with pressure to a household diaphragm tank. That would be a savings of money. Another option for those who are not on the bottom end of the static water level scale could be to pump water to a cistern at least 40 feet in elevation above the point of use (2nd floor if plumbing is present there). Then the water could “gravity flow” to your home (again, saving you money and providing emergency water in case of mechanical failures).
One solution we do not typically recommend, but which can be a viable option if certain precautions are taken, is a solar powered water pump/gravity flow system. Certain water pumps are available which may be powered directly by solar panels, without any need of batteries, etc (Dankoff makes a number of pumps like this, Grundfos makes the SQFlex series of pumps, and Sun Pumps produces a couple different types of solar pumps). They pump only when the panels are receiving enough solar energy to power the pump. These generally work slowly, so they may not be fast enough to keep up with the household diaphragm tank during high use times. You would need to bury a cistern at least 40 feet in elevation above the point of use (2nd floor if plumbing is there). Then the water pump has all day long (on days with sufficient sun) to fill the cistern up. The water “gravity flows” into your house with suitable pressure.
The reason we do not generally recommend this setup is the dependence it places upon having sunny weather. So a prerequisite is that you are in a very sunny climate and that your property has a good southern exposure. One option that would make this system much more desirable is to set up the pump in such a way that it could be connected to an alternative energy system when needed. That way, during cloudy weather, the pump could continue pumping with power from a source other than solar panels. But which ever way you go, at least 10 days supply of water is recommended in cloudy climates as a bare minimum. And it probably isn’t a bad idea in sunny areas either.
If an alternative energy system is not an option for you, this basic system could work well. Basically, we would install a large diaphragm tank and use a normal submersible water pump in our well to pressurize it. The pump is run by a generator which is only turned on when the diaphragm tank runs out. This is not an extremely desirable solution, but it is a simple one that could get you by in a pinch.
For those of you interested in the simplest option, or if your budget doesn’t permit an alternative energy system, consider this setup. The prerequisite is this - your well has a static water level that is very shallow (how deep it can be depends on the particular hand pump and how far above or below the well your house is). We will let the well be our cistern. But this time we rely on a hand pump as our main water pump. Certain models (such as the Simple Pump) are capable of pressurizing a diaphragm tank to a reasonable pressure (if the static water level of the well is very shallow). Provided a large diaphragm tank is used, this would allow you to pump your water pressure up a couple of times a day (depending on the amount of water use) and live normally the rest of the time. Because of the variables that exist with this system, ask a distributor or the manufacturer of the hand pump you intend to use about the feasibility of this setup for you.