Why is it Important to Monitor Drinking Water for Contaminants?
Drinking water is essential to life. In most part of the world, safety and accessibility of drinking water is a major concern, because it is vulnerable to contamination with what the World Health Organization categorizes as infectious agents, toxic chemicals, and radiological hazards. Thus, safe drinking water is defined as water lacking agents, chemicals, or hazards that are detrimental to our health.
In the United States, access to clean and safe drinking water is protected by the Safe Drinking Water Act (SDWA), a federal law that ensures potable water is accessible throughout the country. The Environmental Protection Agency (EPA) is the government entity responsible for setting the standards for quality drinking water.
The EPA distinguishes between “primary regulations” and “secondary regulations”. National Primary Drinking Water Regulations (NPDWRs) include a list of 80+ contaminants that must be monitored constantly based on Maximum Contaminant Levels (MCLs) to ensure drinking water sources are safe.
Additionally, the EPA has established secondary regulations, called National Secondary Drinking Water Regulations (NSDWRs). These measures are not mandatory, since they do not pose health risks, but they may have aesthetic effects, including odor, taste, and color, or may impact water tubing.
Common Drinking Water Contaminants
The Environmental Protection Agency has determined identified six different categories of contaminants: microorganisms, disinfectants, disinfection byproducts, inorganic chemicals, organic chemicals, and radionuclides. The complete EPA list contains almost 100 detectable primary and secondary water contaminants.
Below is a list of 14 of some of the most common or most troubling primary and secondary contaminants or analytes you can monitor to determine if water is safe to drink. For your ease of reference, we have organized the information in a table format, with the description of what is measured, the acceptable range, how the contaminant can get into your water, and potential health effects when the contaminant in drinking water is outside of the acceptable range.
|Analyte or Contaminant
||Cause or Source
||Potential health effects when outside of the acceptable limit/range
||Alkalinity measures the ability of water to neutralize acids.
||Normal values are usually between 75% and 100% of the total hardness value.
||Alkalinity is usually directly associated with total hardness because calcium and magnesium (minerals that determine hardness in water) also determine alkalinity.
||There are no health issues associated with alkalinity.
||pH measures the concentration of hydrogen ions in a solution or the acidity, neutrality, or alkalinity of your water. The lower the pH, the more acidic your water and, the more corrosive it will be.
||Typical pH levels are between 6.5-8.5.
||pH levels lower than 7 indicate that your water likely has higher levels of copper or lead, potentially from the household plumbing, and lower levels of minerals like calcium and magnesium.
||There is no health standard for pH, but water very low or very high pH levels typically will not taste very good.
||Hardness is a measure of the amount of calcium and magnesium in your water.
||Values near 150 mg/L are generally ideal
Values less than 150 mg/L: soft water
Values greater than 200 mg/L: hard water
|Hard water is caused by the ability of water to dissolve rocks that contain calcium magnesium over time.
||There are no health issues associated with hard water. In fact, both calcium and magnesium are important minerals for our diet. While our water usually doesn’t provide us with enough calcium and magnesium to meet our dietary needs, it is an issue in our drinking water because it can cause lime and soap scup buildup in your pipe system.
|Bacteria – Coliform
||Coliform-type bacteria are bacteria (or micro-organisms) that are naturally found in surface of untreated water and in the soil.
||ABSENT. No coliform bacteria should be present for water to be acceptable for drinking.
||Presence of coliform bacteria might mean that there is a leak of untreated water or sewage into the water system due to a loose cap, casing issue, structural defects, or others. For well water, contamination with coliform bacteria is one of the greatest contaminant risks.
||Coliform bacteria do not usually cause illness, but they may indicate that other disease-causing bacteria are present. Water contaminated with bacteria, like E. coli, can cause serious gastrointestinal diseases.
||Chlorine is a disinfectant that is added to water to control levels of microorganisms.
||The most common source of chlorine in drinking water is an additive used to control populations of microorganisms.
||Long-term exposure to drinking water high in chlorine can result in eye and nose irritation, stomach discomfort, and anemia.
||Fluoride is added to water intentionally in controlled amounts to promote strong teeth.
||Fluoride can come from an additive intentionally added to water, erosion of natural fluoride deposits, or from discharge from fertilizer and aluminum factories.
||Controlled fluoride levels are important to promote strong teeth. Prolonged exposure to high fluoride levels in drinking water may result in bone disease, and mottled teeth in children.
||Lead typically enters potable water from pipes, e.g. when pipes that contain lead corrode, especially where the water has high acidity or low mineral content.
||ABSENT. Action must be taken if levels surpass 0.015 mg/L.
||Most lead in water comes from corrosion of household plumbing and corrosion of natural deposits.
||Infants and children exposed to high levels of lead in water and in the environment can experience delays in physical and mental development, learning disabilities and attention disorders.
Adults with prolonged exposure to lead can experience kidney problems and high blood pressure.
||Copper is a metal found in natural deposits in the earth.
||Copper levels in drinking water may be due to corrosion of household plumbing systems, and erosion of natural copper deposits in the ground, soil, and rocks.
||Short-term exposure to copper may cause gastrointestinal issues. Long-term exposure to copper can cause liver or kidney damage. People with Wilson’s disease are particularly sensitive to copper levels.
||Mercury is a liquid metal found in natural deposits. It is used in electrical products like dry-cell batteries, fluorescent light bulbs, and control equipment, among others.
||Mercury in drinking water can come from erosion of natural deposits, discharge from refineries and factories, and runoff from agricultural land and landfills.
||Prolonged exposure or exposure in high amounts could lead to kidney damage.
|Nitrate/Nitrite – Nitrogen
||Nitrate is a chemical commonly found in fertilizers and animal wastes.
||For Nitrate: ≤10 mg/L is accepted.
Less than 2 mg/L is preferred.
For Nitrite: ≤1 mg/L
|High nitrate in water may mean that there is a leak of agricultural fertilizer, lawn fertilizer, manure, or other substances into the water source.
||Infants less than six months old who drink water with more than 10 mg/L of nitrate-nitrogen are at risk of being affected by the condition methemoglobinemia (also called blue baby disease) because nitrate can affect the ability of the body to transport oxygen. If not treated, this condition could be fatal. High nitrate water (over 10mg/L) may also be linked to birth defects and miscarriages.
|| Bromate forms when the disinfectant, ozone, reacts with naturally-occurring bromide in the water.
||ABSENT. 0 mg/L.
||Bromate can result from uncontrolled drinking water disinfection.
||Prolonged exposure or exposure in high quantities can result in an increased risk of cancer; liver, kidney, or central nervous system problems.
|Cyanide (as free cyanide)
||Cyanide is a chemical unit composed of carbon-nitrogen and many organic and inorganic compounds. It is mainly used to make compounds, synthetic fibers, and resins.
||Sources of cyanide in the water can include discharge from steel/metal, plastic, and fertilizer factories.
||Prolonged exposure or exposure in high quantities can result in nerve damage or thyroid problems.
||Chromium is a metallic element found naturally in rocks, plants and soil. One form of chromium (Chromium-3) is essential in the human diet.
||Chromium in water can come from discharge from steel and pulp mills, and/or erosion of natural deposits of chromium in the earth.
||Prolonged exposure or exposure in high quantities can result in allergic dermatitis.
||Arsenic is a toxic chemical found naturally in deposits the soil, rocks, and free minerals.
||Drinking water should not contain any arsenic, but a maximum of 0.010 mg/L is accepted.
||If there is arsenic present in water, potential sources could include: erosion of natural deposits of arsenic in the ground, runoff from fruit orchards and electronics production wastes.
||High-dose or prolonged exposure to arsenic could result in skin damage, problems with the circulatory system, and cancer.
Total dissolved solids (TDS)
|TDS is the sum of all of the inorganic salts (e.g. sodium, calcium, and magnesium ions), both soluble and insoluble, and organic matter in a liquid.
|≤500 mg/L (or ppm)
||TDS content in drinking water can come from natural and man-made sources. Man-made sources include urban run-off, sewage, industrial wastewater sources, water piping, and agricultural runoff. Natural sources include salt deposits, seawater intrusion, and carbonate deposits.
|Increased levels of total dissolved concentration (TDS) are not typically a health hazard. But, high TDS levels may present nuisance and aesthetic problems (e.g. distaste).
Table information sources: UWSP and EPA
A comprehensive chart of all of the contaminants (both regulated and unregulated) can also be found here.
Who is Responsible for Monitoring Water Safety?
In the United States, the Safe Drinking Water Act (SDWA) enforces your right to access safe drinking water at your home and in public safely and freely. The EPA is responsible for enforcing the contaminant limits by supporting local efforts and sources of water supply at wastewater treatment plants, which are either run by municipal governments or private entities.
Each year, the EPA provides funding and tools to states to ensure programs, like underground injection control and regulation compliance, are effectively carried out.
How Can I Monitor my Water at My Home or Business?
If you want to make sure that the drinking water that reaches your home or business is safe to drink, you can carry out your own monitoring activities. This could either be because you are wary of local compliance or worried about any contamination taking place in your home.
Here are two ways you can monitor water quality in your home:
Test Strips and Digital Meters
Test strips are an easy and budget-friendly way to monitor water safety and get immediate results. At-home test strips, like our HealthSnap Test Strips, will test the levels of 10 contaminants and analytes, including fluoride, lead, copper, pH, Chlorine, Nitrite, and more. Digital meters, like our hand-held HealthSnap 3-in-1 TDS, EC, and Temperature meter, also present an economical and precise way to monitor water quality.
The advantage of test strips is that they are easy to use and understand. After either submerging the test strip in a water sample or dripping a sample of water to the strips with a dropper, the test strip will change color within 30 seconds. You can then compare the color result on the test strip to the color chart provided (on the box, bottle, and/or instructions that come with the test strips), so you can determine whether your tap water or pool water is within safe levels. Digital meters are also easy to use and there is a wide range of digital water quality meters available on the market (depending on the type of product, digital meters can measure either single or multiple parameters in water).
If you are looking for high numerical accuracy, you can contract a third-party company to evaluate your water supply. You can contact private companies to take a sample of water on site, or you can send a sample of water to them to analyze. You can tell them exactly what you want them to analyze or request a comprehensive report. Costs are usually given per-analysis and can vary between $10.00-$40.00 per contaminant on the low end, and up to the hundreds (and even thousands) for high-quality in-depth lab analyses.
For analysis of your water by an EPA certified lab, simply browse the “Contact Information for Certification Programs and Certified Laboratories for Drinking Water” provided by the EPA.
Some contaminants are not regulated by the EPA. To have your water checked for these contaminants, you can view the EPA list of approved companies for testing unregulated contaminants.
Safe drinking water is essential for life, and access to it is your right. This article provides you with important information regarding the definition of safe drinking water, primary and secondary contaminants to monitor, and who is responsible for monitoring safe drinking water gets to your home and business.
However, contaminants may take place inside your home as well, or you might be wary of the effectiveness of local water treatment plants. That is why we also provide you with information on how to take control of monitoring your water so you can be confident that your water is safe and clean.
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