If we think back to our school days, most of us can remember studying the "hydrological cycle". You remember the process of how water vapor condenses in the atmosphere and falls to earth as precipitation. Once on the surface of the earth, most of the water evaporates back into the atmosphere, where it will again condense and fall back to earth as precipitation. About 30% of the precipitation, however, does not evaporate. Instead, it seeps into the ground or runs off into streams, rivers, or lakes. As the water seeps into the ground or as it flows over the surface, it dissolves minerals and other substances contained in the ground. Under the surface, the water tends to collect in porous portions called 'aquifers.' These aquifers are the source of our well water.
HARDNESS (Calcium and Magnesium)
The term hardness refers to the quantity of dissolved calcium and magnesium in water. These minerals, which come primarily from limestone type rock formations, are found to some degree in almost all natural waters. Calcium and magnesium cause problems for two principal reasons:
Water which contains excess acidity tends to act aggressively towards plumbing and fixtures, causing corrosion and staining (i.e.-blue green stains on fixtures from copper pipes). Relative acidity/alkalinity is measured on the pH scale, ranging from 0- 1 4, where 7 is neutral, numbers lower than 7 are progressively more acidic, and numbers higher than seven are increasingly alkaline (basic). The pH value refers not to the quantity of acidity, but rather to the relative acidity/alkalinity of a particular sample.
Alkalinity acts as a buffer to deactivate the acidity, a process called neutralization. For example, limestone (calcium carbonate) is often applied to soil to offset the acidity which comes from acid rain and decaying organic material. The acceptable range for water is 6.5-8.5.
Acidity cannot be removed from water. However, it can be neutralized by raising the pH with alkalinity. This can be done by injecting a highly basic (alkaline) solution with a feed pump or by passing the water through a bed of processed limestone or similar material.
The presence of Iron is a very common water quality problem, particularly in water from deep wells. Water containing even a significant quantity of iron may appear clear when drawn, but will rapidly turn red upon exposure to air. This process is called oxidation, and involves the conversion of ferrous (dissolved) iron, which is highly soluble, to ferric (precipitated) iron, which is largely insoluble. The ferric iron then causes red/brown staining on clothes, fixtures, etc.
Iron concentration is measured in ppm or mg/l (milligrams per liter, where 1 ppm = 1 mg/l). Staining usually becomes a problem at concentrations greater than 0.3 ppm. Removal is through ion exchange (water softener) or oxidation/filtration (APIR).
Manganese is a metal similar to iron which causes a grey/black stain. It can cause staining in concentrations as low as 0.05 ppm. Manganese is removed in a manner similar to iron, although oxidation is more difficult, requiring a pH of at least 8.5.
Hydrogen Sulphide is a gas which smells strongly like rotten eggs. It results from the decay of organic matter with organic sulphur and the presence of certain types of bacteria. Even very low concentrations are offensive as well as highly corrosive (silver tarnishes almost immediately upon contact with H2S).
Because it is in a gaseous form, H2S cannot be collected in a sample bottle for laboratory analysis. Therefore, its presence must be reported when a sample is submitted for a treatment recommendation. It can be removed by oxidation/filtration, aeration, or well sanitization.
Turbidity is a measure of suspended particles in water and can range from large particles which settle out of solution rapidly (such as sand), to extremely fine sediment which may stay suspended in solution even after standing for hours. Treatment depends upon size, which is measured in microns.
Most tastes and odors are caused by the presence of organic matter and chlorine. The vast majority of these can be removed with activated carbon.
The presence of toxic chemicals at various concentrations has been widely documented in many water supplies. Detection can be difficult as these contaminants often have no taste or odor. Treatment depends on type and concentration. These chemicals may be industrial solvents or agricultural pesticides and herbicides. One of the most common is Trihalomethane (THM) which is formed when chlorine in the water reacts with natural organic matter.
TDS is the sum of the mineral salts in water and if too high can result in objectionable taste, cloudy ice, interference with the flavor of foods and beverages and scale left behind in cookware. Generally speaking, the lower the TDS the more acceptable the drinking water. TDS of 1,000 ppm or more is unacceptable for drinking water. Reverse Osmosis (R0) process has proven itself as the most practical and cost effective method of correcting problems caused by high TDS.
Nitrates are inorganic chemicals dissolved in some water supplies as a result of feedlot and agricultural activities. Nitrate levels over 45 mg/L as actual NO3 (or 10 mg/L as Nitrogen, N) can be a serious health risk to infants and children. Reverse Osmosis has proven itself as an effective method of reducing Nitrates to safe levels.
The so-called heavy metals are toxic elemental metals such as Lead, Cadmium, Mercury, and Arsenic that find their way into water supplies from natural and industrial sources as well as home plumbing. These metals, especially Lead, can seriously affect the mental and neurological development of infants and children. Reverse Osmosis (R0) is recognized as the most practical method of reducing Lead to insignificant levels in drinking water. Carbon Block technology that incorporates ceramic ion exchange media is also an effective method of reducing lead.
Radium occurs in ground water due to the radioactive decay of Uranium in geologic formation. There is a health risk if the Radium level exceeds 20 pecocuries per liter (pCi/L). Cation exchange water softeners using proper regeneration procedures are effective in reducing Radium for POE applications. Reverse Osmosis systems are effective for reducing Radium for POU applications.
Molds are fungi. Molds grow throughout the natural and built environment. Tiny particles of mold are present in indoor and outdoor air. In nature, molds help break down dead materials and can be found growing on soil, foods, plant matter, and other items. Molds produce microscopic cells called "spores" which are very tiny and spread easily through the air. Live spores act like seeds, forming new mold growths (colonies) when they find the right conditions.
Mold only needs a few simple things to grow and multiply:
Mold should not be permitted to grow and multiply indoors. When this happens, health problems can occur and building materials, goods and furnishings may be damaged.
Mold can affect the health of people who are exposed to it. People are mainly exposed to mold by breathing spores or other tiny fragments. People can also be exposed through skin contact with mold contaminants (for example, by touching moldy surfaces) and by swallowing it.
The type and severity of health effects that mold may produce are usually difficult to predict. The risks can vary greatly from one location to another, over time, and from person to person.
The most common health problems caused by indoor mold are allergy symptoms. Although other and more serious problems can occur, people exposed to mold commonly report problems such as:
There is wide variability in how different people are affected by indoor mold. However, the long term presence of indoor mold growth may eventually become unhealthy for anyone. The following types of people may be affected more severely and sooner than others:
Investigate, don't test. The most practical way to find a mold problem is by using your eyes to look for mold growth and by using your nose to locate the source of a suspicious odor. If you see mold or if there is an earthy or musty smell, you should assume a mold problem exists. Other clues are signs of excess moisture or the worsening of allergy-like symptoms.
Look for visible mold growth (may appear cottony, velvety, granular, or leathery and have varied colors of white, gray, brown, black, yellow, green). Mold often appears as discoloration, staining, or fuzzy growth on the surface of building materials or furnishings. When mold is visible, testing is not recommended.
We do not recommend testing for mold yourself. Instead, you should simply assume there is a problem whenever you see mold or smell mold odors. Testing should never take the place of visual inspection and it should never use up resources that are needed to correct moisture problems and remove all visible growth.
Sometimes, mold growth is hidden and difficult to locate. In such cases, a combination of air (outdoor and indoor air samples) and bulk (material) samples may help determine the extent of contamination and where cleaning is needed. However, mold testing is rarely useful for trying to answer questions about health concerns.
To clean up and remove indoor mold growth, follow steps 1-6 as they apply to your home.
1-Identify and Fix the Moisture Problem - the most important step in solving a mold problem is to identify and correct the moisture sources that allowed the growth in the first place. Common indoor moisture sources include:
Rebuilding and refurnishing must wait until all affected materials have dried completely. Be patient it takes time to dry out wet building materials.
To properly kill mold, bleach may not be the answer. We recommend consulting a qualified professional mold mitigator to properly disinfect the areas of concern. Simply cleaning the areas with mold have proven NOT EFFECTIVE in killing the mold.
This Guide answers important questions about radon and lung cancer risk. It also answers questions about testing and fixing for anyone buying or selling a home.
You cannot see, smell, or taste radon. But it still may be a problem in your home. When you breathe air containing radon, you increase your risk of getting lung cancer. In fact, the Surgeon General of the United States has warned that radon is the second leading cause of lung cancer in the United States today. If you smoke and your home has high radon levels, your risk of lung cancer is especially high.
Testing is the only way to find out your home's radon levels. EPA and the Surgeon General recommend testing all homes below the third floor for radon.
If you find that you have high radon levels, there are ways to fix a radon problem. Even very high levels can be reduced to acceptable levels.
EPA recommends that you test your home before putting it on the market and, if necessary, lower your radon levels. Save the test results and all information you have about steps that were taken to fix any problems. This could be a positive selling point.
EPA recommends that you know what the indoor radon level is in any home you consider buying. Ask the seller for their radon test results. If the home has a radon-reduction system, ask the seller for information they have about the system.
If the home has not yet been tested, you should have the housed tested.
If you are having a new home built, there are features that can be incorporated into your home during construction to reduce radon levels.
The radon testing guidelines in this Guide have been developed specifically to deal with the time-sensitive nature of home purchases and sales, and the potential for radon device interference. These guidelines are slightly different from the guidelines in other EPA publications which provide radon testing and reduction information for non-real estate situations.
This Guide recommends three short-term testing options for real estate transactions. EPA also recommends testing a home in the lowest level which is currently suitable for occupancy, since a buyer may choose to live in a lower area of the home than that used by the seller.
Radon is a radioactive gas that has been found in homes all over the United States. It comes from the natural breakdown of uranium in soil, rock and water and gets into the air you breathe. Radon typically moves up through the ground to the air above and into your home through cracks and other holes in the foundation. Radon can also enter your home through well water. Your home can trap radon inside.
Any home can have a radon problem. This means new and old homes, well-sealed and drafty homes, and homes with or without basements. In fact, you and your family are most likely to get your greatest radiation exposure at home. That is where you spend most of your time.
Nearly 1 out of every 15 homes in the United States is estimated to have an elevated radon level (4 pCi/L or more). Elevated levels of radon gas have been found in homes in your state. Contact your state radon office for information about radon in your area.
Testing is the only way to know if you and your family are at risk from radon. EPA and the Surgeon General recommend testing all homes below the third floor for radon.
You cannot predict radon levels based on state, local, and neighborhood radon measurements. Do not rely on radon test results taken in other homes in the neighborhood to estimate the radon level in your home. Homes which are next to each other can have different radon levels. Testing is the only way to find out what your home's radon level is.
In some areas, companies may offer different types of radon service agreements. Some agreements let you pay a one-time fee that covers both testing and radon mitigation, if needed. Contact your state radon office to find out if these are available in your state.
If you are thinking of selling your home and you have already tested your home for radon, review the Radon Testing Checklist to make sure that the test was done correctly. If so, provide your test results to the buyer.
No matter what kind of test you took, a potential buyer may ask for a new test especially if:
Have a test taken as soon as possible. If you can, test your home before putting it on the market. You should test in the lowest level of the home which is suitable for occupancy. This means testing in the lowest level that you currently live in or a lower level not currently used, but which a buyer could use for living space without renovations.
The radon test result is important information about your home's radon level. Some states require radon measurement testers to follow a specific testing protocol. If you do the test yourself, you should carefully follow the testing protocol for your area or EPA's Radon Testing Checklist. If you hire a contractor to test your residence, protect yourself by hiring a qualified individual or company.
You can determine a service provider's qualifications to perform radon measurements or to mitigate your home in several ways. Check with your state radon office. Many states require radon professionals to be licensed, certified, or registered. Most states can provide you with a list of knowledgeable radon service providers doing business in the state. In states that don't regulate radon services, ask the contractor if they hold a professional proficiency or certification credential. Such programs usually provide members with a photo-ID card, which indicates their qualification(s) and its expiration date. If in doubt, you should check with their credentialing organization. Alternatively, ask the contractor if they've successfully completed formal training appropriate for testing or mitigation, e.g., a course in radon measurement or radon mitigation.
If you are thinking of buying a home, you may decide to accept an earlier test result from the seller, or ask the seller for a new test to be conducted by a qualified radon tester. Before you accept the seller's test, you should determine:
Make sure that a radon test is done as soon as possible. Consider including provisions in the contract specifying:
Radon-resistant techniques work. When installed properly and completely, these simple and inexpensive passive techniques can help to reduce radon levels. In addition, installing them at the time of construction makes it easier to reduce radon levels further if the passive techniques don't reduce radon levels below 4 pCi/L. Radon-resistant techniques may also help to lower moisture levels and those of other soil-gases. Radon-resistant techniques:
Radon-resistant techniques (features) may vary for different foundations and site requirements. If you're having a house built, you can learn about EPA's Model Standards (and architectural drawings) and explain the techniques to your builder. If your new house was built (or will be built) to be radon-resistant, it will include these basic elements:
Radon testing is easy and the only way to find out if you have a radon problem in your home.
Since you cannot see or smell radon, special equipment is needed to detect it. When you're ready to test your home, you can order a radon test kit by mail from a qualified radon measurement services provider or laboratory. You can also hire a qualified radon tester, very often a home inspector, who will use a radon device(s) suitable to your situation. The most common types of radon testing devices are listed below. As new testing devices are developed, you may want to check with your state radon office before you test to get the most up-to-date information.
Passive radon testing devices do not need power to function. These include charcoal canisters, alpha-track detectors, charcoal liquid scintillation devices, and electret ion chamber detectors which are available in hardware, drug, and other stores; they can also be ordered by mail or phone. These devices are exposed to the air in the home for a specified period of time and then sent to a laboratory for analysis. Both short-term and long-term passive devices are generally inexpensive. Some of these devices may have features that offer more resistance to test interference or disturbance than other passive devices. Qualified radon testers may use any of these devices to measure the home's radon level.
Active radon testing devices require power to function. These include continuous radon monitors and continuous working level monitors. They continuously measure and record the amount of radon or its decay products in the air. Many of these devices provide a report of this information which can reveal any unusual or abnormal swings in the radon level during the test period. A qualified tester can explain this report to you. In addition, some of these devices are specifically designed to deter and detect test interference. Some technically advanced active devices offer anti-interference features. Although these tests may cost more, they may ensure a more reliable result.
A state or local radon official can explain the differences between devices and recommend the ones which are most appropriate for your needs and expected testing conditions.
Make sure to use a radon measurement device from a qualified laboratory. Certain precautions should be followed to avoid interference during the test period. See the Radon Testing Checklist for more information on how to get a reliable test result.
There is a potential for test interference in real estate transactions. There are several ways to prevent or detect test interference:
There Are Two General Ways To Test Your Home for Radon:
Because radon levels vary from day to day and season to season, a short-term test is less likely than a long-term test to tell you your year-round average radon level. However, if you need results quickly, a short-term test may be used to decide whether to fix the home.
The quickest way to test is with short-term tests. Short-term tests remain in your home from two days to 90 days, depending on the device. There are two groups of devices which are more commonly used for short-term testing. The passive device group includes alpha track detectors, charcoal canisters, charcoal liquid scintillation detectors, and electret ion chambers. The active device group consists of different types of continuous monitors.
If you are testing in a real estate transaction and you need results quickly, any of the following three options for short-term Tests are acceptable in determining whether the home should be fixed. Any real estate test for radon should include steps to prevent or detect device interference with the test device.
If You Do the Test Yourself
When you are taking a short-term test, close windows and doors and keep them closed, except for normal entry and exit. If you are taking a short-term test lasting less than four days, be sure to:
The average indoor radon level is estimated to be about 1.3 pCi/L; roughly 0.4 pCi/L of radon is normally found in the outside air. The U.S. Congress has set a long-term goal that indoor radon levels be no more than outdoor levels. While this goal is not yet technologically achievable for all homes, radon levels in many homes can be reduced to 2 pCi/L or below.
For reliable test results, follow this Radon Testing Checklist carefully. Testing for radon is not complicated. Improper testing may yield inaccurate results and require another test. Disturbing or interfering with the test device, or with closed-house conditions, may invalidate the test results and is illegal in some states. If the seller or qualified tester cannot confirm that all items have been completed, take another test.
Before Conducting a Radon Test:
EPA recommends that you take action to reduce your home's indoor radon levels if your radon test result is 4 pCi/L or higher. It is better to correct a radon problem before placing your home on the market because then you have more time to address a radon problem.
If elevated levels are found during the real estate transaction, the buyer and seller should discuss the timing and costs of the radon reduction. The cost of making repairs to reduce radon levels depends on how your home was built and other factors. Most homes can be fixed for about the same cost as other common home repairs, like painting or having a new hot water heater installed. The average cost for a contractor to lower radon levels in a home can range from $800 to about $2,500.
A variety of methods can be used to reduce radon in homes. Sealing cracks and other openings in the foundation is a basic part of most approaches to radon reduction. EPA does not recommend the use of sealing alone to limit radon entry. Sealing alone has not been shown to lower radon levels significantly or consistently.
In most cases, a system with a vent pipe(s) and fan(s) is used to reduce radon. These "sub-slab depressurization" systems do not require major changes to your home. Similar systems can also be installed in homes with crawl space. These systems prevent radon gas from entering the home from below the concrete floor and from outside the foundation. Radon mitigation contractors may use other methods that may also work in your home. The right system depends on the design of your home and other factors.
Techniques for reducing radon are discussed in EPA's "Consumer's Guide to Radon Reduction." As with any other household appliance, there are costs associated with the operation of the radon-reduction system.
Select a qualified radon-reduction contractor to reduce the radon levels in your home. Any mitigation measures taken or system installed in your home must conform to your state's regulations. In states without regulations covering mitigation, the system should conform to EPA's Radon Mitigation Standards.
EPA recommends that the mitigation contractor review the radon measurement results before beginning and radon-reduction work. Test again after the radon mitigation work has been completed to confirm that previous elevated levels have been reduced. EPA recommends that the test be conducted by an independent qualified radon tester.
A qualified radon-reduction (mitigation) contractor should be able to:
The radon in your home's indoor air can come from two sources, the soil or your water supply. Compared to radon entering your home through water, radon entering your home through soil is a much larger risk. If you've tested for radon in air and have elevated radon levels and your water comes from a private well, have your water tested. The devices and procedures for testing your home's water supply are different from those used for measuring radon in air.
The radon in your water supply poses an inhalation risk and an ingestion risk. Research has shown that your risk of lung cancer from breathing radon in air is much larger than your risk of stomach cancer from swallowing water with radon in it. Most of your risk from radon in water comes from radon released into the air when water is used for showering and other household purposes.
Radon in your home's water in not usually a problem when its source is surface water. A radon in water problem is more likely when its source is ground water, e.g., a private well or a public water supply system that uses ground water. Some public water systems treat their water to reduce radon levels before it is delivered to your home. If you are concerned that radon may be entering your home through the water and your water comes from a public water supply, contact your water supplier.
If you've tested your private well and have a radon in water problem, it can be fixed. Your home's water supply can be treated in one of two ways. Point-of-entry treatment can effectively remove radon from the water before it enters your home. Point-of-entry treatment usually employs either granular activated carbon (GAC) filters or aeration devices. While GAC filters usually cost less than aeration devices, filters can collect radioactivity and may require a special method of disposal. Point-of-use treatment devices remove radon from your water at the tap, but only treat a small portion of the water you use, e.g., the water you drink. Point-of-use devices are not effective in reducing the risk from breathing radon released into the air from all water used in the home.
For information on radon in water, testing and treatment, and existing or planned radon in drinking water standards, or for general help, call EPA's Drinking Water Hotline at (800) 426-4791 or visit www.epa.gov/safewater/radon.html. If your water comes from a private well, you can also contact your state radon office.
EPA supports the following hotlines to best serve consumers with radon-related questions and concerns.
Radon Hotline, operated by the National Safety Council (NSC) in partnership with EPA. Order radon test kits by phone.
For live help with your radon questions. Operated by the National Safety Council (NSC) in partnership with EPA.
Radon Fix-it Hotline, operated by the Consumer Federation of America Foundation (CFAF) in partnership with EPA. For help with your radon mitigation questions.
A Spanish (Español) language radon hotline, operated by the National Alliance for Hispanic Health (the Alliance) in partnership with EPA. For general help with radon, testing, and mitigation questions, and free test kits.
The Indoor Air Quality (IAQ) Information Clearinghouse is privately operated under contract to EPA. You can order copies of EPA consumer-oriented radon publications and get general information on radon and indoor air quality issues.
Safe Drinking Water Hotline, privately operated under contract to EPA. For general information on drinking water, radon in water, testing and treatment, and radon drinking water standards.
SURGEON GENERAL HEALTH ADVISORY"Indoor radon gas is a national health problem. Radon causes thousands of deaths each year. Millions of homes have elevated radon levels. Homes should be tested for radon. When elevated levels are confirmed, the problem should be corrected."