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The Ultimate Guide To Home Water Testing

Home Water testing

Are you getting weird odors and taste in your drinking water? Don’t ignore this, as your water can be dangerously contaminated by hydrogen sulfide, excess chlorine, or harmful organic compounds.

The worst part?

Some dangerous contaminants like lead and arsenic don’t have any taste or odor, and you can’t detect them unless you get your water tested using water testing kits.  

Knowing about different water contaminants and proper testing methods through a water test kit can save you from serious health effects. 

And that’s why we present you with a detailed home water testing guide in 2024 based on CDC recommendations. Let’s dive in!

What Are The Most Common Contaminants In Drinking Water?

Drinking Water SourceThe Most Common Contaminants Found 
Well Water Iron & Manganese, Sodium, Chlorine & chloramine, Hydrogen sulfide, Lead, VOCs, Nitrate, Radon, Coliform Bacteria, and others.
City Water Lead, Fluoride, Cryptosporidium, Arsenic, Copper, Nitrate, Radon, and others.

EPA generally maintains a Contaminant Candidate List (CCL) to classify different contaminants found in wells and city water. The list is as follows:

Physical Contaminants Chemical Contaminants Biological Contaminants Radiological Contaminants 
SedimentIron & Manganese
Chlorine & chloramine
Hydrogen sulfide
Lead Fluoride
Pharmaceuticals, Herbicides, VOCs, and others.
Coliform bacteria
Legionella and other microbes
Uranium along with others

Physical Contaminants


Sediment is a collective name for soil particles, dead animal & plant matter, loose sand, clay, or silt. They get into the surface or groundwater from soil erosion, surface runoff carried by rain or snowfall, and wind and can be detected through water testing kits.  

EPA categorizes them as one of the most predominant pollutants that degrade your home water’s quality. 

Excess sediment deposition in water or water bodies, as detected through the water test kit, results in

  • Cloudy or murky water (bad for drinking and watering plants)
  • Unusual smell and taste in the water.
  • Blue-green algae activation (that releases toxins into the water)

Besides, they disturb the food chain, reduce fish population, alter river water flow, and affect river depth. 

Chemical Contaminants

Iron and Manganese: 

Both iron and manganese are frequently found in groundwater. However, the concentration of iron is usually much higher than that of manganese. 

You can detect the presence of these heavy metals through their strong metallic taste or the stains they cause to the vessels. However, it’s necessary to confirm their exact concentration in water through home water test kits or at a professional lab. 

If the test results come positive, you must install an iron/manganese filtration system to prevent the harmful effects of more than 0.3 mg/L of iron+manganese, which include:

  • Stain your laundry or plumbing fixtures,
  • Hair fall, wrinkles, or skin infections,
  • Reduced memory, awareness, and motor skills in children, 
  • Learning and behavioral crisis in infants.

Chlorine & Chloramine: 

Chlorine, a potent oxidant used in treating various microbes in water (in diluted form), and chloramine, a secondary disinfectant, are usually used by multiple municipal water systems to fight the microbes present in the local water supply.

  • Since chlorine has the property of being absorbed in one’s body through the skin, it can get into your body while bathing or through drinking and can severely dry your hair and skin or cause irritation in your eyes/nose. 
  • Besides, chloramines and chlorine can react with various naturally occurring materials in your drinking water to produce disinfectant byproducts or DBPs, that may cause cancer in your body. 

To avoid these issues caused by chloramines and chlorine, you should perform your home water test using a water testing kit. 

Hydrogen sulfide:

It originates from decaying plants or other decomposing underground deposits. It is brought in water by sulfur-reducing bacteria that chemically transform the natural sulfates into it. 

The presence of hydrogen sulfide in water as detected by water quality test:

  • Causes a rotten egg smell and bad taste in water. 
  • Corrodes iron, copper, brass, and steel metal equipment.
  • Results in black/yellow stains on your bathroom fixtures or kitchen.
  • Affects the taste and composition of cooked food and beverages.


Lead is a highly toxic metal that can cause coma and even death if ingested in small doses. 

It enters your drinking water from your old lead pipes and plumbing fixtures. Old houses used lead faucets because it was the miracle metal everyone used for 5000 years until we found its serious health effects. 

The following factors determine the lead amount in your home water:

  • Duration for which your water remained in touch with lead pipes.
  • Level of corrosion in fixtures.  
  • How acidic the water is.
  • The water’s temperature.

The lead attacks your central nervous system, and children can suffer from behavioral disorders and impaired brain development.


Whether fluoride in water is safe or not is debatable. 

It commonly occurs in the ground and may lead to severe illnesses such as cancer and skeletal fluorosis if consumed excessively for an extended period.

However, considering its benefits, it is used (kept within a limit of 0.7 mg/l) for treating contaminated water and preventing tooth decay. 


Sodium and chloride are formed as a byproduct when you dissolve salt in water. The sources of sodium in water include:

  • Natural salt deposits in groundwater
  • The flow of salty water from sewage
  • Fertilizer runoff
  • Malfunctioning of water softeners 

Sodium in drinking water might not be suitable for people on low-sodium diets or who have high BP, heart disorders, liver issues, or any kidney condition.


Though sodium as such has no drinking water standard, SFA (State And Federal Agencies) has recommended a 20 mg/L limit for people on extremely low sodium diets and 270 mg/L for others.

Excess sodium can lead to several health issues:

  • Nausea
  • Convulsions
  • Cerebral & pulmonary edema
  • Vomiting
  • Muscular twitching


Arsenic is a toxic and tasteless element in various midwest US regions like Michigan. Even a small dose of arsenic in your drinking water may turn fatal for your health. Its harmful health effects include:

  • Neurological crises
  • Elevated blood pressure
  • Heart ailments
  • Cancer


Copper enters drinking water from copper pipes & fixtures and can cause various complications if present over 1300 ug/L:

  • Kidney problems
  • Liver problems
  • Stomach cramps
  • Vomiting


Nitrate usually comes in water from:

  • Various fertilizers,
  • Animal feedlots
  • Food processing waste, septic systems, and industrial waste 

If present over 10 ppm in water can cause:

  • Blood pressure fall
  • Rapid heartbeat
  • Headaches
  • Vomiting
  • Stomach cramps
  • Fatigue 

If you have an infant below six months, they are at a higher risk of nitrate poisoning. 


Mercury, a liquid metal, mainly arises from natural deposits and gets into the water by either erosion or landfill and cropland runoff.

In addition, it can enter your drinking water through the factories’ discharge of mercuric waste into various water bodies. 

The EPA safe limit for mercury in water is 2 ppb or 0.002 mg/L. Exposure to inorganic mercury can cause:

  • Kidney damage
  • Muscle weakness
  • Skin rashes
  • Memory loss

Infants and toddlers are most vulnerable to its adverse health effects.  

Pharmaceuticals, Herbicides, VOCs, and others:

Pharmaceuticals (like antacids, antidepressants, anti-inflammatories, steroids, antibiotics, therapeutic medicines, and veterinary medications), herbicides (like Atrazine), and Volatile Organic Compounds are all synthetic chemicals that enter the drinking water supply from:

  • Improper waste disposal
  • Incorrectly governed manufacturing faculties
  • Aggregation in public soil, etc. 
  • Oil spills
  • Leakage of fuel manufacturing plants

They can cause:

  • Irritation in your eyes, nose, or throat  
  • Nausea
  • Headaches
  • Liver damage
  • Loss of coordination
  • CNS (Central Nervous System) damage
  • Damage of Kidneys 
  • Cancer (some VOCs are only carcinogens, not all) 

Biological Contaminants

Coliform Bacteria: 

EPA classifies coliform bacteria as non-risky to public health. However, its presence in drinking water may indicate the presence of harmful pathogens, which in turn can cause diseases. 

The primary source of coliform bacteria is the surface runoff of animal or human feces into water sources.


Like coliform bacteria, EPA doesn’t recognize Cryptosporidium (“Crypto” for short) as a health hazard. However, its long-term exposure can lead to:

  • Vomiting
  • Diarrhea
  • Cramps


Better known as Giardia Iamblia, this microscopic parasite can cause giardiasis, a small intestinal infection that is characterized by:

  • Diarrhea 
  • Fatigue 
  • Cramps 
  • Belching gas

It usually travels into your home water through fecal waste. However, EPA classifies Giardia as zero MLC (meaning no health risk), just like coliform bacteria and Cryptosporidium. 


It enters your drinking water from:

  • Cattle farms (remains in various healthy cattle’s intestines)
  • Sewage overflows comprising an infected human or animal’s stool
  • Contaminated stormwater flow 
  • Agricultural runoff

If you consume E. coli bacteria along with water, you will face:

  • Severe stomach cramps
  • Vomiting or nauseous feeling
  • Bloody diarrhea  

Boiling your water before drinking for 1 – 3 minutes, disinfecting it through the spread of chemicals, or installing filters saves you from E.coli. 

Legionella and Other Microbes:

Another zero MLC, Legionella, is found naturally in water and thrives in water heater tanks below 120o F with nutrients like sediment, scale, sludge, and some water organisms. 

Its long-term exposure can cause:

  • A severe type of lung infection, Legionnaires’ disease.
  • A less-serious flu-like disease, Pontiac fever.


The lung disease affects seniors above 40, heavy drinkers, and smokers. 1 out of 10 people die out of complications from Legionnaires’ disease. Boiling water above 160o F instantly kills Legionella.  

Radiological Contaminants


Radium naturally occurs from rocks and soil in the earth’s crust. 

When you drill a well into bedrock, it causes dissolved radium to mix in your water supply. In addition, dumped industrial wastes may also contain radium which contaminates your drinking water. This radioactive contaminant is harmful even as little as five picoCuries per liter (pCi/L). 

80% of radium ingested through drinking water is passed off as feces, whereas the remaining 20% can get absorbed in bones, which can lead to:

  • Immune system depression
  • Fractured Teeth
  • Cataracts
  • Anemia


Radon is an odorless and colorless radioactive element that emerges naturally in the atmosphere and exists in various rocks or soil within the earth’s crust. This inert gas has many isotopes and can spread rapidly outdoors. 

Showering or washing laundry in radon-contaminated water is more dangerous than drinking it. It is because these activities trap radon within the indoor atmosphere and make you prone to lung cancer (through its long-term exposure).  


It is another radioactive element that arises naturally in groundwater and through human activities. High levels of uranium in water result from nitrate pollution and undue groundwater table deterioration. 

EPA prescribes 30 ug/L as the safe limit for uranium in drinking water. Its long-term exposure beyond the safety limit can lead to serious kidney diseases.  

Read: How To Remove Uranium From Well Water

When Should You Do a Home Water Test?

If you use city water, we recommend going through CCR to check the water quality in your area. 

Contact state-certified labs for the water test if you find anything unusual in CCR or your water supply, like the weird taste, smell, lather soaps not producing lather, etc.


For well water users, EPA doesn’t regulate well water quality. So, regularly testing well water is solely the owner’s responsibility. You should test your drinking water once a year for biological contaminants and 3-5 years for other pollutants listed above.

Also, consider water testing if:

  • Your well runs dry
  • Well was flooded recently
  • After well or plumbing repairs
  • Change in water taste and odor
  • If pregnant women, infants, or seniors joined your family recently

Home Water Testing FAQs

What are the symptoms of drinking water with bacteria?

Drinking water contaminated with bacteria may cause various fatal illnesses. Some of their symptoms are:

-Abdominal cramps,
-Extremely watery diarrhea or loose stool
-Nauseous feeling,
-Rapid running of pulse,
-Flu-like symptoms
-Temperature rise
-Hypovolemic shock (it happens in extreme cases and may lead to a person to death within twelve to eighteen hours).

What is TDS in water?

TDS stands for Total Dissolved Solids and represents the total of organic and inorganic substances that remain in the dissolved form, including various metals, salts, ions, minerals and practically anything that is dissolved in water except H2O molecules.

How often should you test drinking water?

EPA recommends testing drinking water at least once a year. However, the testing rate depends on factors like the water source and the presence of contaminants. 

You must test your water even if you’ve installed a water treatment system. It’ll confirm the efficacy of your filtration system and will ensure that your tap water is safe to drink.

Does the EPA regulate well water?

No, EPA doesn’t regulate or recommend standards for either of the 23 million plus US households that rely on private wells for their water needs. 

The well’s owner is fully responsible for the safety of his home water. Therefore, he has to test his water periodically and, if necessary, install an efficient water filtration system to eliminate unwanted contaminants.

Is tap water safe to drink in the USA?

Yes, technically, tap water in the United States is safe to drink. It is because US public water systems follow EPA regulations to appropriately treat surface water before supplying them to various households. 

However, recent studies have indicated that nearly 9 million American households have received water supply that violated the Safe Drinking Water Act (SDWA) norms. Therefore, installing water filters to remove specific contaminants has become a necessity rather than simply for water taste.

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