“What kind of capacity and flow rate should my water well have?”
One of the most common questions people ask is, “how much water in a well is adequate for the average home?” It is an important factor when considering building or purchasing a home and the amount of water available in a well can be as important as the quality of the water. It is also important to consider flow rate when buying or building a new home. The Federal Housing Administration (FHA) requires 3 to 5 gallons per minute for older wells and a rate of 5 gallons per minute for new wells to pass inspection.
Calculating water capacity
There are a few different ways to look at the amount of water in the well. The first is water storage capacity. A standard 6-inch diameter drilled well can store 1.5 gallons of water per foot. If you know the depth of the well, the level of the water and pump depth, you can figure out the water storage capacity. Most people don’t know all of this information, but it can be figured out by consulting with a water system professional.
Calculating a water well's flow rate
When evaluating a well’s water supply, the first test done is typically a flow rate test. The flow refers to the amount of water coming from the well and the flow rate measures the gallons per minute coming out. The average American household needs 100 to 120 gallons per person per day, and a flow rate of about 6 to 12 gallons per minute. This requirement may be higher if it serves a home housing a large family or there are large water demands. This amount of water may be less than is needed for some families, especially if there is significant outdoor water use, which is why well professionals may recommend a minimum flow rate of 5 gallons per minute or more.
What to do if my well falls short?
If after conducting a flow rate test, the well does not meet the recommended standards, there are some options to increasing flow. If there is space on the property, another well can be dug. This is also costly, time consuming and may not get the results the homeowner needs. We recommend using a process called hydrofracking, which blasts water into an existing well bore to clear debris and open fissures allowing water to flow through the bedrock. Hydrofracking does not use chemicals and is different from the hydraulic fracking associated with the oil and gas industry.
Why is water sampling important?
Along with human activities, water quality is affected by a combination of natural processes. Most relate
to chemical compositions underground. However, other factors such as biological, physical, and
radiological conditions can affect water quality as well. Water contaminants include the following:
Bacteria, viruses, parasites and other microorganisms are sometimes found in water. Shallow wells, those with water close to ground level, are at most risk. Runoff, or water flowing over the land surface, may pick up pollutants from wildlife and soils. This is often the case after flooding. Some of these organisms can cause a variety of illnesses. Symptoms include nausea and diarrhea, and can occur shortly after drinking contaminated water. The effects could be short-term yet severe (similar to food poisoning) or might recur frequently or develop slowly over a long time.
The most common problem associated with ground water may be hardness, generally associated with
an abundance of calcium and/or magnesium dissolved in the water. Hard water has not been shown to
cause health problems, but can be a nuisance as it may cause soap curds and/or cause deposits to
form on pipes and other plumbing fixtures. Over time this can reduce the diameter of the pipes. Calcium and magnesium are found in ground water that has come in contact with certain rocks and
minerals, especially limestone and gypsum. When these materials are dissolved, they release calcium
and magnesium. Hard water is considered bad for your plumbing, but people with heart or circulatory
problems may want to consult their physician about drinking softened water, because the softening
process removes calcium and magnesium, and adds sodium to the water.
Iron and Manganese
A "rusty" or metallic taste in water is a result of iron, and sometimes manganese, in ground water. They not only create a bad taste, but they also can stain pipes and clothing. Iron and manganese are naturally occurring, and most ground water has some amount of dissolved iron
and manganese in it. It comes from contact with minerals that contain iron, such as pyrite. There are several treatment methods. Installing a water softener may help if iron and manganese are
present in low quantities and the softener is designed for their removal. Aeration (the addition of oxygen
to the water), chlorination, and feeding ozone or hydrogen peroxide can aid in the precipitation of iron,
which it is removed from the water by filtration. Potassium permanganate feed with manganese
greensand filters, and some recently designed synthetic media, will remove iron and manganese, as well.
Most nitrogen in ground water comes from the atmosphere. Some plants can "attach" nitrogen from the
atmosphere onto their roots. The nitrogen not used by the plants is then released into the soil. Nitrogen compounds also can work their way into ground water through fertilizers, manure, and urine
from farm animals, sewage, and landfills. The most common forms in ground water are ammonia,
nitrate, and nitrite. Nitrates can be especially toxic to children under six months of age. Exposure to
ammonia also presents a health risk. It is toxic to aquatic life such as fish, and it interferes with water
treatment. There are a variety of treatment methods to correct this problem, including reverse osmosis systems
with water softeners to remove nitrates and nitrites, and oxidation to remove small amounts of ammonia.
However, treatment should be a last resort. Removing the source of contamination is the first priority.
You should also be sure to protect the area around the wellhead from contamination by animals or
Sulfur can occur in ground water in two forms: sulfides and sulfates. Sulfides are naturally occurring in
much of the United States in limestone containing organic materials; ground water affected by oil, gas,
and coal deposits; in marshes and manure pits; and in the byproduct of well-established iron biofilms.
Sulfates often come from the dissolving of minerals, such as gypsum and anhydrite. A “rotten egg” smell coming from your water indicates the presence of hydrogen sulfide gas. Along with
creating an unpleasant odor and taste, sulfides cause corrosion to plumbing and darken water. There are several methods for treating sulfur. Aeration, ozone, hydrogen peroxide, and chlorine (best
followed by filtration) are effective against dissolved hydrogen sulfide or gas. A reverse osmosis system,
nanofiltration system, or a negative ion-exchanger also can be effective in reducing sulfates. Filtration is
necessary in combating sulfur formation as a mineral or in biofilms.
Total Dissolved Solids
TDS, as it is commonly known, is the concentration of all dissolved minerals in water. It is the direct measurement of the interaction between minerals and ground water. TDS levels above 1000 mg/L will usually yield poor tasting water. Levels above 2000 mg/L are
considered undrinkable due to taste, and levels more than 10,000 mg/L are defined as undrinkable. Water softeners with a reverse osmosis system are effective in lowering the TDS to satisfactory levels.
Radionuclides are radioactive elements such as uranium and radium. They may be present in
underlying rock and ground water.
Radon is a gas that is a natural product of the breakdown of uranium in the soil — can also pose a
threat. Radon is most dangerous when inhaled and contributes to lung cancer. Although soil is the
primary source, using household water containing Radon contributes to elevated indoor Radon levels.
Radon is less dangerous when consumed in water, but remains a risk to health.