Frequently Asked Questions
There are no guarantees of hitting water, and much of the drilling that occurs in the third world is trial and error. Even with an experienced driller, there is still no practical way of determining what is actually under the ground once you choose a location and start drilling. However, there are things you can look for to increase your success. First, look at vegetation – is the area generally green, or barren? Next, ask if there are any wells in the area – if so, where and how deep are they? Also, look at the lay of the land – are you on a mountain, or in a valley? Finally, make sure you are drilling uphill away from any latrines or waste runoff. Those are just a few of the specifics, but you should rely on the information given to you by the locals – they live there, and they usually know where the water is. Personally, we like to drill under the shade of a big tree at high noon. No great mystery here – trees have to have water and they tend to seek it out (part of God’s amazing creation). We know that we only need about a 6 inch hole, so if we run into a root, we just move over a foot – eventually, we will get through the root “fingers”. True, the tree branches make pulling the rig in and out slightly more difficult, but by drilling in the shade at noon, we avoid blazing hot sun (and once the well is finished, the people don’t have to stand in that blazing hot sun to get water either). The biggest thing to remember is that physical water is only the second goal of water missions. The first goal is sharing the living water of Jesus Christ. Some of the best opportunities to present the gospel come from not hitting water, so don’t be discouraged if and when that happens – just use the opportunity.
We discourage the practice for several reasons. Dowsing (also known as ‘divining’ or ‘water witching’) has little if any scientific basis, and is only about 30% accurate according to studies (better odds flipping a coin). Bad science, coupled with the fact that terms like “divining” and “witching” carry strongly negative spiritual connotations, the practice is best left alone. There are many geologic and other indicators that can help direct you to potentially favorable sites. Click here for more information on knowing where to drill.
The water production of a well depends on the volume and flow rate of the water table. This will vary from well to well, and typically increases with the diameter of the well casing (the tube that goes down the hole). The rate will also depend upon the person using the pump. At its greatest rate (for example, a healthy adult male pumping the well as fast as he can), a hand pump will pump about 5 gallons of water per minute. This rate is typical for all hand pumps. As long as the water can keep up with the pace of the pump, you’ve established a good well. If you run into a slow recharge rate, and you do not have enough water to pump, you may want to consider the lowest-tech approach, the Hydromissions® BB-01 “Bailer Bucket”.
The safety and quality of the water depends on where you drill. In most rural areas, well water is safe to drink as long as you are careful to drill uphill from human or livestock sewage, and far enough away from a river to provide some degree of filtration. Typically, the local river is used for everything from bathing, to sewage treatment, to irrigation, to drinking – a deadly combination. Our view is that even if your well is not of the best quality, you can at least get the people to drink from a cleaner source than the river. If water quality does become an issue, you can always add low-tech, low-cost biosand filters to clean the water, or you can use a chlorinator to disinfect standing water (see Safe Water International Ministries (SWIM) on the “Links” page). In areas where brackish (salty) water is encountered, you may want to consider a desalinator in conjunction with the well (we are working on that one as fast as we can!). Even in this situation, the water may be useful for other things besides drinking – such as irrigation, livestock, or washing. The U.S. Environmental Protection Agency gives the following helpful information on water quality and uses:
- The earth’s crust is saturated with water, like a wet sponge. The surface of the earth is either wet (oceans, lakes, swamps) or dry (terra firma, dry land). On land, water exists at some depth below land surface, from 2 inches (south Louisiana) to 600 feet (Mojave desert). Water that exists beneath the land surface is called ground water. At some point below the surface, the pores of the rocks are completely saturated with water (the “water table”). A permeable layer whose pores are saturated with water is called an aquifer.
- Water contains dissolved minerals, especially salt. The salinity of water is expressed as Total Dissolved Solids (TDS), measured as parts per million (ppm) or the equivalent milligrams per liter (mg/L). The salinity of drinking-quality water ranges from 0 to 3,000 mg/L TDS. Humans prefer water containing less than 500 mg/L, but many water supplies contain as much as 1,000 mg/L TDS. Water containing up to 3,000 mg/L can be consumed by livestock or used for crop irrigation. Because water that has a higher salinity than drinking water may be used for many other purposes (i.e., agricultural and industrial uses), we designate usable quality water as that containing from 3,000 to 10,000 mg/L TDS. Water containing in excess of 10,000 TDS is called brine, or simply salt water.
- Ground water increases in salinity with depth. On the Gulf Coast, drinking water exists from 5 feet to about 1,500 feet below land surface, usable quality water from about 1,500 feet to about 3,500 feet, and brine at about 7,000 feet contains about the same salinity as sea water (about 26,000 mg/L TDS). Below 20,000 feet, the water can be ten times as saline as sea water (over 200,000 mg/L TDS). In West Texas, drinking water exists in the interval from 150 to 350 feet below ground surface, and usable quality water extends to only about 500 feet. The depth to the water table, ground water salinity profile, and depth to the base of usable quality water are unique to each geologic region.
The following (edited) information was given by the Straight Dope Science Advisory Board
We need water to live, and we need salt to live, so what’s the big deal about not being able to drink saltwater? The answer is that we only need a small amount of salt to live. The recommended daily dose is around 500 mg/day–around a quarter of a teaspoonful. “Salt” is a “chemical term for a substance produced by the reaction of an acid with a base – in this case, sodium and chlorine. Sodium chloride is essential for digestion and respiration. Without sodium, which the body cannot manufacture, the body would be unable to transport nutrients or oxygen, transmit nerve impulses, or move muscles, including the heart. But when we’re talking about seawater, we’re not just talking about common salt. Other compounds and elements and minerals called salts are found in ocean water, such as epsom salts, potassium salts, iodine salts, and so forth.
The composition of ocean salt is very complex. According to the U.S. government, salinity is measured by the concentration of dissolved salts. That is, we take the amount (by weight) of the salt in water, expressed as “parts per million” (ppm.) The government defines fresh water as having less than 1,000 ppm of dissolved salts–in other words, less than 0.1% of the weight of the water comes from dissolved salts. By contrast, human blood is around 0.9% salt, and about 0.25% of our total body weight is salt. On this scale, the ocean is classified as “highly saline” (over 1.0% dissolved salts.) In fact, seawater is around 3.5% dissolved salts by weight. That’s about three times as salty as human blood. That’s way more salt than we can safely metabolize. Interestingly, the proportion of minerals and salts in human tissue is very similar to the composition of seawater. The adult human body contains enough salt to fill about three salt shakers, but the salt is constantly lost through bodily functions like sweating, crying, urinating, etc. It is essential to replace this lost salt, but not to over-replace. We can’t tolerate seawater consumption. Our cells can’t take it and our kidneys can’t take it.
So, what happens if you drink seawater?
Take a lot of salt into your body and your metabolism very quickly goes into crisis. From every cell, water molecules rush off like so many voluntary firemen to try to dilute and carry off the sudden intake of salt. This leaves the cells dangerously short of the water they need to carry out their normal functions. They become, in a word, dehydrated. In extreme situations, dehydration will lead to seizures, unconsciousness, and brain damage. Meanwhile, the overworked blood cells carry the salt to the kidneys, which eventually become overwhelmed and shut down. Without functioning kidneys you die. That is why we don’t drink seawater.
There have been significant efforts at desalinizing seawater. The cost is high, around five times the cost of processing water from normal supply sources. Technology is improving and costs are dropping, though, and there is even speculation that desalinization techniques could be used to bring water to irrigate the deserts of the Middle East.
The “Explorer” is designed to be used for shallow well drilling (up to 100 feet). As packaged, the EXP-50 will go down 50 feet. The system can go much deeper, but this distance was based on field reports and drilling logs from missionaries around the world. We determined that in most of those wells water was hit at far less than 50 feet, which allowed us to concentrate on the portability issue (how to meet the 50 pound per bag airline restrictions). We offer extension rods if you need to go deeper, or you can build your own extensions in-country with local materials. Most portable drilling rigs cannot go through solid rock, and the EXP-50 is no exception. However, we do include a cracking bit that gives the “Explorer” some advantages over other systems with regards to drilling through difficult soils. The cracking bit can be used to break up compacted gravels, small rocks, and sandstone, making it more likely that you can keep drilling when you encounter these obstacles. In addition, the EXP-100 Percussion Kit is designed to be used in conjunction with the “Explorer” system to go through some harder formations if necessary.
The “Explorer” is manufactured to very high quality standards, and there are no engines or moving parts to break. If properly used and maintained, your “Explorer” system should last for an indefinite number of wells. We hope that you will only have to buy one Explorer,” but if a part does break, you can always purchase individual replacement parts directly from Hydromissions, or you can repair or replace the part in-country with local materials.
This depends on what kind of soil you encounter while drilling. These are rough estimates, but if conditions are favorable, a comfortable drilling rate is about 10 feet per hour for the first 20 feet, and between 5 and 10 feet per hour thereafter. In our experience, a typical 50ft well, drilling through average soil, takes a total of about 10-15 hours spanned over 2 days to complete. One great thing about hand drilling is that you only drill once for a completed hole (you do not have to drill an exploratory pilot hole). Another advantage to hand drilling is that you always know when you hit water because it is a dry drilling system (when the bit is wet, you’re there). You won’t waste time and effort drilling beyond where you need to drill. Although it is possible to complete a well in 2 or 3 days, we suggest that you plan on drilling one well per week for a short-term trip as this will give you more time to build relationships and share Christ in the process (plus, you never know how difficult logistics can be in developing countries – trust us, things almost never go as smoothly as you plan).
The “Explorer” can be operated by one person, but we recommend that you have at least 2 people to drill. The ideal number on a drilling team is 4. This number allows you to share the workload, while providing enough people to interact with the locals. The big thing to remember is to include the local people in the drilling process. Not only does this give you extra help, it also gives the locals a sense of ownership for the well, and this is very important for the long-term. You will find that most locals are willing and eager to help, so don’t hesitate to take them up on the offer.
Assuming that it does not run dry from drought or other fluctuations in the water table, a well should last indefinitely. It is a good idea to drill during the dry season to ensure the most viable well. The more common question is ‘how long does a pump last’? Most hand pumps do run into mechanical problems in about 6 months, so it is important to use a pump that the locals can repair for themselves. It is also vital to train the locals in pump repair techniques, and it has been proven by experience that they will be more likely to take ownership of the well and its maintenance if they had a hand in drilling the well. Our VK-01 pump was field tested in Venezuela and was reported to have lasted a year before needing repair. However, the VK-01 is only intended to be a backup system if you can’t find anything locally made. Our BB-01 “Bailer Bucket” should last almost indefinitely.
This all depends on the cost of the pvc and the hand pump. In most developing countries, pvc is relatively cheap, but be careful – schedule 40 or other high-grade pvc costs a lot (most of that type is imported). We always go with the cheap stuff that is made locally. If you plan to use our BB-01 “Bailer Bucket” and Hydromissions® Bicycle Windlass (download), the total cost is estimated around $75 or less for everything (pvc, cement, bucket, windlass).