Water Well Production

The amount of water produced by water wells varies greatly throughout Colorado and is dependent upon many factors, the most important being well location and water source. The amount of water needed by Coloradoans also varies greatly and there is no one well production rate considered “acceptable” for all situations.

The average person uses between 80 and 100 gallons of water per day. Outside irrigation usage is not considered in this figure - those with even small lawns will need significantly more water. Special consideration must also be taken by those frequently hosting gatherings or entertaining house guests.

Some lenders feel a well producing 2-3 gallons per minute provides an adequate water supply for a single family dwelling. A 3-gallon per minute well will produce approximately 4,320 gallons per day. There is also additional water stored in the well itself. For example, a 400-foot deep well with a static level of 60 feet (the distance from the surface to the water) would hold approximately 500 gallons of water. Thus, up to 500 gallons of the 4320 gallons produced but not used would then be stored for future use.

Wells producing less than 2-3 gallons per minute may easily provide an adequate water supply. The amount needed is entirely dependent upon each person’s water usage. If a well’s production is less than adequate, there are several methods that will increase the supply. Installation of a water cistern, either an underground concrete unit or an inside poly storage tank, will greatly increase the amount of available water. Residential cisterns usually hold between 200 and 4800 gallons of water and, once in place, will be continually filled by the well pump. Another option for increasing water supply would be to hydrofracture the well. This process involves using pressurized air or water to expand fissures in the well, allowing for greater water flow into the well. If neither of these options is feasible, it is possible to drill a new well.

A prospective home buyer should insist on a well flow production test performed by persons licensed by the State of Colorado as either water well drillers or pump installation contractors. Flow rates can fluctuate throughout the year and may even change significantly if large amounts of water are drawn from the well supply by surrounding developments. Natural events can also alter the amount of water entering the well. Therefore, we recommend that a buyer not use results from previous years as an indication of current flow.

While a well’s production rate is vital knowledge to a prospective home buyer, so is the quality of water produced. A portability test for coliform bacteria is essential. Coliform can cause severe gastrointestinal discomfort and may even be life threatening to young children and the elderly. Many other water analyses are also available, from simple hardness and iron tests to tests for VOCs, pesticides and heavy metals.


GNC Water Well Truck — Water Supply in Lafayette, CO


Water Well Terminology

  • Additional storage: Cisterns or other water storage tanks from which water is pumped into the house
  • Drawdown: The distance that the water level in the well is lowered by pumping. It is the difference between the static water level and the pumping level
  • Initial production: The maximum volume of water expressed in gallons per minute (gpm) which the pumping system discharges at the initial static level, demonstrating the satisfactory performance of the pumping system
  • Pumping level: The lowest water level reached during the pumping operation / cycle
  • Regeneration rate: The volume of water, expressed in gallons per minute (gpm), which the well produces independent of well storage or additional storage. This rate is established when a stabilizing pumping condition has been reached and the yield does not change by more than ten percent during the last hour of the test
  • Static level: The distance, in feet, from the ground surface to the level of water in the well prior to any pumping
  • Total production: The total volume of water, expressed in gallons, which the pumping system discharged during the duration of the test from well storage and regeneration
  • Well depth: The depth of the well from the ground surface to the well bottom. The depth could be reported by the owner, listed on the driller’s well log or estimated by the service person performing the well test
  • Well storage: The volume of water, expressed in gallons, which is available for immediate use within the well at the start of the test


Real Estate and Water Wells

The Safe Drinking Water Act passed in 1974 requires that state and local governments with public water systems must comply with maximum contaminant levels for the National Primary Drinking Water Regulations (NPDWR). Contaminant levels are determined for any ingredient of water which may adversely affect a person’s health. They are set with an adequate margin of safety. Water treatment techniques for each contaminant are also prescribed under the law. The NPDWR are enforced at the federal level unless a state has requested and obtained primary responsibility. Secondary regulations are recommended for aesthetic quality only and are not enforceable.

Prior to the purchase or sale of a home you should require proof that your drinking water is potable and of sufficient supply. The agreement you make when purchasing a home should be contingent upon written proof that the water supply is potable, sufficient in quality and palatable. If the water is not tested prior to closing, part of the purchase price should be held in escrow to cover a new water system or an upgrade of the existing system.

The owner of a residential property with its private system should supply you with the following information:

  • Location, type of well, and construction
  • Type of material used in the construction of the pipes leading to the house
  • Location, type, and age of the pump
  • Location of any septic systems in relation to the well

Determine what treatment systems are currently installed and why they are needed. Ask the following questions:

  • Is the water supply being softened and by what process?
  • Is the water supply bacteriologically safe?
  • Is the present method of treatment adequate for your needs?
  • Is the present method the best available for your specific water problems?
  • What is the age of the present water treatment system? Has it been checked by a licensed professional?

Most problems associated with poor water quality are treatable. The equipment needed to provide the most agreeable supply of clear, odorless and tasty water varies for each particular site. Below are common problems with residential water supply and acceptable methods of treatment:

  • Soap scum, bathtub rings, and / or spots on glassware can be treated with an ion exchange system such as a water softener, as can scaling and low-sudsing action of cleansers.
  • Unpleasant taste, smell, or color can be removed through distillation, reverse osmosis, or carbon filtration systems
  • Bacterial contamination can be eliminated using chlorination, ultraviolet systems, or microfiltration
  • Corrosion on pipes or water heaters can be treated with chemicals
  • Pesticide and / or industrial halogen contamination can be treated with an activated carbon filtration system

The maximum contaminant levels established by the NPDWR, the EPA or the Colorado State Health Department are listed below:

mg/l = milligrams per literppm = parts per million
ppm = mg/l
 pCi/l = picocuries per liter



Water Conditioning and Treatment Systems


Water quality is a concern for all homeowners. Unfortunately, not all of the water flowing from the tap is the pure, fresh water one’s body desires.

Water containing minerals and dissolved metals causes many problems – bath tub rings, shower scale and water spotting, along with residues left on skin, clothing and hair. Mineral-laden water is more expensive to heat, requires the use of additional soaps and cleansers and shortens the life of household appliances. Heavy metals, such as lead, cause very serious health problems; even minuscule amounts can accumulate in one’s body and will become a problem later in life. Colorado’s hard water, in general, also has higher levels of radon, uranium and other radioactive compounds than those found in other areas of the United States.

Water containing microorganisms pose many health problems. Most people are aware that coliform, cholera and hepatitis can be major health risks, but don’t understand to what extent they can damage the human body. Water from springs, lakes, improperly constructed wells and other untreated water sources should not be consumed unless first properly treated. Even residents drinking chlorinated city water will profit from the additional peace of mind provided by disinfection systems. In mid 1999, Greeley’s city water supply was accidentally infested with giardia. Chlorine-resistant cryptosporidium protozoa was discovered in Milwaukee’s water. Other microorganisms pose minimal health risks but can seriously damage the water system itself. Iron and manganese reducing bacteria produce a solid or slimy material that clogs pipes and tanks. Some bacteria produce a corrosive hydrogen sulfide gas, leaving the water smelling of rotten eggs. 

In 26 years of water treatment experience, Boulder GNC Water Well has developed water systems that provide homeowners with quality, drinkable water. The following list details several of the systems we provide:


Water Softeners

Most multi-media water conditioners feature standard cation exchange resin for the removal of hardness and low concentrations of iron. We offer water softeners that not only perform this function, but also utilize granular activated carbon media to treat or remove chlorine, some pesticides, herbicides and volatile organic chemicals. Other components can be incorporated to remove iron, excessive sulfides, and the offensive tastes and odors associated with these contaminants. We also provide our customers with a healthy alternative to the sodium chloride used in most water softeners – granular potassium chloride media. Your body will feel the benefits, your plants will thrive and your water will taste better. Potassium chloride also promotes the growth of important bacteria inside septic systems.


Hardness is classified as follows:

  • 0 to 1.0 gpg - Soft water
  • 1.1 to 3.5 gpg -  Slightly hard water
  • 3.6 to 7.0 gpg - Moderately hard water
  • 7.1 to 10.5 gpg - Hard water 
  • 10.6 or higher gpg - Extremely hard 


Reverse Osmosis Drinking Water Systems

Most R/O systems filter water to a bottled water quality level of purity. Water initially passes through a sediment filter which physically removes suspended particles. The reverse osmosis membrane then removes dissolved material in the water, which then enters a small storage tank prior to activated carbon filtration. The carbon filter removes any remaining tastes and odors from the water. To improve the R/O’s effectiveness, many water supplies may require other pre-conditioning units. We suggest a wide spectrum analysis of the water be performed prior to any treatment installation.


Ultraviolet Water Filtration and Sanitation

An effective ultraviolet system utilizes the “C” band of ultraviolet light to kill 99.99% of bacteria and viruses commonly found in drinking water. This treatment is preferred for several reasons: harmful bacteria and viruses are killed or rendered sterile to the point they are no longer damaging, and the harmful side effects of chemical agents on the septic system are negated. Installation of a staged filtration method prior to the ultraviolet unit provides a very effective treatment method.


Sterilight UV Disinfection — Water Supply in Lafayette, CO


Chlorination of Water Systems

Sometimes the demands placed upon a water system require chemical treatments, which can include injection of liquid chlorine or the addition of dry-pellet chlorine to the water. Either method adequately treats unsafe water and removes hydrogen sulfide from domestic water systems.


Keeping Your Well Water Safe

For rural residents, wells are the most important source of water for their family, animals, landscaping and crops. A turn of the tap brings water for drinking, cooking, livestock, irrigation and many other uses.  

Because water is so valuable, it’s critical that well owners make every effort to keep their well water free from contaminants. It is important to know state regulations for the construction of safe wells as well as the chemicals that may be used in the vicinity of the well. 

A combination of four major factors determines whether a chemical is likely to reach ground water: properties of the chemical, properties of the soil, conditions of the site and chemical use management practices. Runoff into nearby surface water is also affected by these factors. The potential for water contamination can vary greatly, depending upon the site and the effects of the factors listed above.

Chemical containers often contain information regarding the material’s potential to leach into ground water. If you can’t find the information you need, the Cooperative Extension Service, USDA’s Soil Conservation Service, EPA or manufacturer can provide information on the leaching potential of different chemicals.


Intelligent Landscaping and Gardening 

To protect your well water, carefully consider your choice of chemicals, cultivation practices and types of management for your garden, soil, land condition, weather patterns and topography. These decisions are especially important if you landscape in an environmentally sensitive area – one with highly vulnerable water supplies, wildlife or waterfowl. 


Managing chemicals doesn’t necessarily mean a greater burden for you. It just means everyone must use chemicals in a safe, environmentally conscious manner. Safe use of chemicals, fertilizers and lubrication fluids protects not only your drinking water, but your neighbor’s as well.