General Water Quality Information

Mar 27th 2017

Why is water so unique and important?

Here are some basic facts about water:

  • Water is the most abundant compound on Earth.
  • It is the only substance that exists as a solid, liquid and gas at the same time at Earth's temperatures.
  • Water is used over and over and does not get degraded.
  • It is considered a universal solvent and will pick up a portion of everything it touches.
  • 97% of the Earth's water is in the form of undrinkable salt water, 2% is stored in ice caps and glaciers, leaving about 1% of all water on Earth suitable and accessible to drink.
  • Water is critical to human and animal life. The average human body is made up of a total of 50% to 55% water or 70% of the fat free mass. Lean muscle contains 75% water, blood is 83%, body fat is 25% and bone is 22% water.
  • Water carries nutrients to the body's cells and carries wastes away from the cells.
  • Water regulates body temperature and lubricates the joints.

Where does water come from?

The Earth's water is in constant movement above, below and at the Earth's surface. Nature created a water cycle in which water changes state from a liquid (or ice) to a vapor and back to a liquid (or ice) again. This natural water cycle phenomenon is driven by the sun and is called the Hydrologic Cycle. In the Hydrologic Cycle, water evaporates from oceans, lakes, rivers and through plant transpiration into water vapor and is carried by air currents into the atmosphere. The water vapor in the cooler upper atmosphere condenses into clouds and eventually falls as precipitation in a liquid or solid state (hail, snow) to replenish the oceans, rivers and lakes or to seep into the ground to create groundwater. This cycle is constant and has no beginning or end.

Water is held in various reservoirs within the Hydrologic Cycle and the amount of time water spends in that type of reservoir, called "Residence Time", has been estimated. For example, groundwater can spend over 10,000 years beneath the Earth's surface before leaving. The following chart created by Dr. Michael Pidwirny of the University of British Columbia provides typical Residence Times for various water reservoirs.

Reservoir Residence Time
Oceans 3,200 years
Glaciers 20 to 100 years
Seasonal Snow Cover 2 to 6 months
Soil Moisture 1 to 2 months
Shallow Groundwater 100 to 200 years
Deep Groundwater 10,000 years
Lakes 50 to 100 years
Rivers 2 to 6 months
Atmosphere 9 days

How does water become contaminated with undesirable substances?

Water is a universal solvent, meaning it will pick up a bit of everything it touches. Contaminants may come from direct discharges as point sources of pollution or they may come from non-point sources such as surface runoff or contaminated groundwater. Natural sources and human actions can both contribute to water contamination. Residential, municipal, commercial, industrial and agricultural activities can all affect surface and groundwater quality. Here are some examples of potential sources of water contaminants:

Storage Tank Leakage - underground and above ground storage tanks are common for storing heating oil, gasoline, diesel fuel and industrial chemicals. Until the mid-1980's, most underground storage tanks were made of bare steel that would corrode and leak over time. The following statistics represent the state of underground storage tanks that are used to store petroleum and certain hazardous substances. According to the EPA as of September 30, 2005:

    • Active Underground Storage Tanks - 653,621
    • Confirmed Releases - 452,041
    • Cleanups Completed - 332,799

Chemical Spills - tanker trucks and train cars carrying chemicals are another hazard. In 1990, the EPA indicated that 16,000 chemical spills from trucks, trains and storage tanks occur every year. Most often these spills occur when materials are being transferred.

Septic System Use - About 25% of all homes in the US utilize a septic system to dispose of human waste. Improperly sited, designed, constructed or maintained systems can contaminate groundwater with bacteria, viruses, nitrates, detergents, oils and chemicals. Dumping of toxic household chemicals down the drain also contributes to groundwater contamination through a septic system.

Naturally Occurring Substances - substances such as decaying organic matter, iron, manganese, chloride, fluoride, sulfates and radionuclides can become dissolved in water and move in streams and groundwater. They may become a health threat or create water quality problems when at undesirable levels.

Industrial Effluent - releases of toxic chemicals and manufacturing by-products into the environment can create water contamination. There is a vast amount of different types of chemicals used for industrial purposes. Active and abandoned mines can be another source of groundwater contamination with the release of heavy metals and other undesirable substances.

Landfills - chemicals that should be disposed of in hazardous waste landfills, which have special protective barriers, sometimes will end up in municipal non-protected landfills. Newer landfills have collection systems with clay or synthetic liners to capture the contaminant liquid. Most older landfills do not have safeguards and may be built over aquifers with very permeable soil to increase the risk of leaching into the groundwater.

Sewer Distribution Piping - the distribution piping in a municipal sewer system carrying wastes away from a building can leak fluids into the surrounding soil and groundwater. This sewage can contain bacteria, heavy metals, organic matter, inorganic salts, viruses and nitrogen.

Drinking Water Distribution Piping - the water quality leaving a municipal treatment plant may be acceptable, but there are a variety of physical, chemical and biological factors that can affect the water quality before it enters your home. Drinking water being transported from a municipal treatment system may pick up contaminants from breaks in the piping that can allow outside contaminants inside. Contaminants can also be picked up from the distribution piping itself. Much of the nation's distribution piping is aging and in 2002, there were 200,000 water main breaks nationwide. For example, some older distribution systems may still have lead pipe used for the service line to the home or there may be asbestos from the asbestos-cement pipe lines. Steel and iron pipes can corrode and leach zinc and iron into the water. In a 2002 EPA report titled "Health Risks from Microbial Growth and Biofilms in Drinking Water Distribution Systems", the EPA stated that biofilms, which protect microbes (possible disease causing pathogens) from disinfection, are likely to be present in all distribution systems and that "biofilms can act as a slow-release mechanism for persistent contamination of the water."

Land Use - millions of tons of fertilizers, pesticides and herbicides are applied to the land annually for crop production, residential and business lawn care and facility maintenance. These toxic substances can easily enter the ground or become part of surface runoff into other water bodies to contaminate surface and groundwater. In the EPA National Pesticide Survey conducted between 1985 and 1992 on 1,300 public drinking water wells, it was concluded that a significant percentage of wells contained pesticides at concentrations exceeding the Federal Maximum Contaminant Level (MCL) and almost 4% of the wells had nitrate concentrations above the MCL. In 1990, the EPA noted that more than 11 million tons of salt is applied annually to roads for ice removal. Precipitation can carry the salt into groundwater to create undesirable elevated levels. Storm water drains can also carry contaminants into the groundwater.

How is water treated?

Water service below 15 service connections or 25 persons that operate for at least 60 days per year are not regulated by the US Environmental Protection Agency as a Public Water System. If your drinking water is obtained through a private well or other non-Public Water System source, you are responsible for any necessary water treatment. If you have a community water service, the example below is a general guideline to the water treatment process. Follow a drop of water from the source through the treatment process. Water may be treated differently in different communities depending on the quality of the water which enters the treatment plant. Groundwater is located underground and typically requires less treatment than water from lakes, rivers and streams.

What if I have a water well for drinking water supply?

Approximately 15% of Americans obtain their drinking water from a private well. These wells are not subject to the EPA Safe Drinking Water Act (SDWA) and the Primary and Secondary Drinking Water Regulations. Some states and local governments may have established regulations to protect well owners. The quality of water from a private well is the responsibility of the well owner. Periodic testing is necessary to ensure safe and high quality drinking water and to identify the contaminants in your water that need to be reduced or the water conditions that need to be corrected. This is accomplished through water quality tests from a certified water testing laboratory. Dug and Driven wells have the greatest chance for changes to water quality because of the close proximity of the well water to the surface. Water quality in deep, drilled wells are generally stable and changes occur slowly, The US Environmental Protection Agency (EPA) has recommendations for testing private wells. Click here for more information on Well Water.

How do I find out about the quality of my drinking water?

As indicated above, if you are a well owner, you are responsible for testing the quality of the well water. If you are a municipal water service customer, you can obtain an annual report called the "Consumer Confidence Report" (CCR) from your municipal water service supplier. These reports indicate the source of the water supply, the levels of contaminants found in the water, the probable source f the contaminant, the EPA Maximum Contaminant Levels (MCLs) and any other mandatory info the EPA requires. These reports are based on water leaving the water treatment facility and will not determine the water condition at your faucet. Distribution piping and home plumbing systems can alter the water quality leaving the treatment facility. Click here for EPA Local Drinking Water Information to read local water quality reports and other local water quality information. Identifying the contaminants in your water that need to be reduced or the water conditions that need to be corrected is accomplished through a comprehensive water quality test from a certified water testing laboratory. Our mail in laboratory Water Test Kits are certified in all states as an out of state testing lab. Click here for the EPA list of State Offices that provide a directory of State certified Laboratories for water quality testing.

How can I protect my drinking water supply?

Protecting our drinking water is everyone's responsibility. The Environmental Protection Agency (EPA) performs a variety of activities such as setting drinking water standards and overseeing state efforts to enforce the standards. The EPA is also involved with a variety of programs to help reduce environmental pollutant exposure through landfills, storage tanks and pesticide use.

Septic System Owners

With 25% of US homes using septic systems, more than 4 billion gallons of wastewater is released below the ground’s surface each day. If you own a septic system, you must insure it is maintained according to design requirements. The septic tank holds the wastewater from the home long enough to allow solids (sludge) to settle out and oil and grease (scum) to float to the surface. Partial decomposition of the solid materials also occurs in the septic tank.

A failed or malfunctioning septic system is not only expensive to replace, but it can contaminate groundwater that might be a source of drinking water from water wells or contaminate surface waters that pose dangers to people and animals. Typical pollutants in household wastewater are nitrogen, phosphorus and disease causing bacteria and viruses. If a septic system is working properly, it will effectively remove most of these pollutants. Regular septic tank inspection and periodic pumping out of sludge and floating scum is necessary and the least expensive way to keep your septic system in good working order. Here are some recommended maintenance tips for septic systems from the US Environmental Protection Agency:

  • Have your septic system inspected at least every 3 years by a professional.
  • Have your septic tank pumped out as recommended by the inspector, usually every 3-5 years. A general rule for pumping is when the bottom of the scum layer is within 6 inches of the outlet tee and/or the top of the sludge layer is within 12 inches of the outlet tee.
  • Inspect all mechanical components if present, such as float switches and pumps.

It is very important to control what goes down your drains, whether you have a septic system or not. The septic system is a living collection of organisms that digest and treat waste. What goes down your drain can have a major impact on how well the septic system works and may also introduce toxic chemicals into the environment that can pollute groundwater resources. When the wastewater exits the septic tank, it is discharged into the drainfield for further treatment by the soil. Each time new wastewater enters the septic tank, more wastewater exits to the drainfield. Some recommendations:

  • Don’t use your septic system as a trash can to throw away dental floss, diapers, feminine hygiene products, cigarette buts, cat litter, coffee grounds, etc.
  • Don’t use throw hazardous chemicals and poisons down the drain such as toxic cleaners, caustic drain openers, pesticides, paints and other hazardous chemicals. Many natural ingredient based, safer and biodegradable Non-Toxic Household Cleaners are available that work effectively and local household hazardous waste collection centers are available to dispose of toxic chemicals appropriately.
  • Don’t use a garbage disposal with a septic tank. A garbage disposal grinds up kitchen scraps and mixes them in water and sends it to the septic tank. Some of the material is broken down, but most grindings have to be pumped out. Eliminating the garbage disposal reduces the amount of grease and solids entering the septic tank. Composting is a better way to handle kitchen scraps.
  • Use water efficiently in the home. When you limit the amount of water use through water conserving appliances and plumbing fixtures, you are reducing the amount of wastewater the septic system must treat. If you have high water use fixtures, make sure the septic system was designed for their use. For example, emptying water from a large hot tub into the household drainage system may stir up the solids in the septic tank and push them out to the drainfield where they can clog the distribution piping and cause system failure.

Well Owners

If you own a well, protecting your well head and maintenance of your well is your responsibility. Proper construction and continued maintenance are keys to a safe water supply. Click here for more information on Well Water.Some recommendations:

  • Install an animal or vermin proof cap to prevent rodents from entering your well that can become trapped and die.
  • Keeping the well cap above ground (18”) will help prevent unwanted substances from entering.
  • Locate your well away from possible sources of contamination.

  • Locate the well so rainwater flows away from it. Rainwater can pick up harmful bacteria and chemicals on the land’s surface and if the water pools near the well, it can seep into it.
  • Each month, check the visible parts of your well system for problems such as cracking or corrosion, settling or cracking of surface seals, broken or missing well cap.
  • Have your well tested periodically. The US EPA has these recommendations:

Before First Well Use - test for nitrates, coliform bacteria, total dissolved solids and pH levels. Consider testing your well for pesticides, organic chemicals and heavy metals.

Annually - test for nitrates, coliform bacteria, total dissolved solids and pH levels to detect contamination problems early.

More Frequent Testing - In some instances, more frequent testing than once a year may be necessary and recommended. Well water testing for bacteria should be done after any well construction activities or repairs. Here are some examples of when to consider additional well water testing:

  • If your well is located in a heavily developed area that handles hazardous chemicals
  • If your previously tested contaminant level was above state or federal standards
  • You notice a change in water quality such as taste, color or odor.
  • Someone in the household is pregnant or nursing or there are unexplained illnesses.
  • A neighbor finds a dangerous contaminant in their well water.
  • There has been a spill of chemicals or fuels near your well system.


The land area that catches precipitation (rain or snow) and drains it into a local water body and has an impact on flow and water level is the Watershed area. Stormwater runoff is one of the major concerns in protecting Watersheds. As water washes over the ground and other surfaces it can pick up fertilizer, pesticides and trash which can be deposited into drinking water resources. It is important to keep the Watershed area clean and free of contaminants that could wash into the water body that may be used as a source of drinking water. Participating in public hearings on water quality issues and volunteering in your community's containment monitoring activities.

How much water do we use each day?

The average American uses almost 90 gallons of water per day (gpd) in the home and each household uses approximately 107,000 gallons per year of water. We use water that has been treated to meet drinking water standards for a variety of non-drinking tasks such as flushing toilets, watering lawns, washing dishes and clothes and filling swimming pools. About 50%-70% of the water we use is for watering lawns and gardens and about 14% goes down the drain from leaky plumbing. We use much more water each day that other geographic areas such as Europe at 53 gallons per day and the Sub-Saharan area at 3-5 gallons per day. Our daily water use per person breaks down like this:

  • Bathing - 20 gpd
  • Toilet Flushing - 24 gpd
  • Laundry - 8.5 gpd
  • Lawn Watering and Pools - 25 gpd
  • Car Washing - 2.5 gpd
  • Garbage Disposal - 1 gpd
  • Dishwasher - 4 gpd
  • Drinking and Cooking - 2 gpd

Why can't we drink saltwater from the ocean?

To understand what happens when drinking sea water, you need to understand about the natural phenomenon called "Osmosis". In Osmosis, water with dissolved solids in a less concentrated solution will naturally move toward a more concentrated solution in an effort to dilute the more concentrated solution. All cells in our bodies operate this way to move substances in and out of our cell membranes. When a very highly concentrated salt water solution enters the body, the cells will lose their water and dissolved solids to the more concentrated solution. As a result, the cells become dehydrated due to the lack of water within them and the body begins to go into a dehydrated state. Extreme dehydration is a serious health problem and can lead to death.