Volatile organic compounds (VOCs) are a group of organic chemicals that can evaporate and turn into gases at normal air temperatures. Concerns about VOCs in water are becoming more and more prevalent as people become aware of the health risks associated with these chemicals.
This guide will provide everything you need to know about VOCs in water, including what they are, how they get into our water supply, their potential health effects, and how to test for and remove them from drinking water.
- VOCs are additives in many common products including gasoline, carpets, paints, varnishes, adhesives, perfumes, and pharmaceuticals.
- Many volatile organic compounds in drinking water are cancer-causing carcinogens and pose a danger to human health with effects like nausea, skin irritation, and nervous system damage.
- The best way to detect VOCs in water is with a certified lab test to scan for common VOCs and provide the exact amount present.
- The best water filter technology to treat VOCs in water is an activated carbon filter or reverse osmosis system that is certified by third parties for VOC reduction.
What Are Volatile Organic Compounds (VOCs) In Water?
Volatile Organic Compounds (VOCs) are chemicals that have high vapor pressure, meaning they can quickly turn into gases and enter the air we breathe. When these organic chemicals are released into the air, they can react with other pollutants and form ozone, which harms human health. Similarly, VOCs can also enter the water supply and contaminate our drinking water.
According to the Environmental Protection Agency (EPA), Volatile Organic Compounds contamination is one of the US’s most widespread water quality problems.
VOCs can contaminate ground and surface water, posing a risk to the drinking water supply. Private wells are particularly susceptible to VOC contamination, including heavy metals. Fortunately, there are methods for removing VOCs from drinking water.
How Do VOCs Get Into Water Supplies?
Once Volatile Organic Compounds (VOCs) are dissolved into groundwater, they are more persistent and can travel very long distances into our water supplies. They can enter water supplies in several ways, but the most common sources of VOCs are the following:
- Petroleum-based products
- Adhesives and glue
- Personal care products (deodorant, perfume, lotion)
- Rubber products and plastic
- Paint and paint thinners
- Dry cleaning
The sources of VOCs in water can be classified into point sources and non-point sources.
Point sources are locations where VOCs are released into the environment, such as human activity in factories, wastewater treatment plants, and hazardous waste sites.
Non-point sources, such as runoff from roads, parking lots, and agricultural activities, are diffuse and scattered.
City Water vs. Well Water
City water is treated and disinfected before it is distributed to households and regulated by the Environmental Protection Agency (EPA). However, even treated city water can be contaminated with Volatile Organic Compounds. Whether from disinfection byproducts, industrial runoff, or chemical spills, public water supplies frequently carry varying amounts of VOCs.
On the other hand, well water is not treated, and it is the homeowners’ responsibility to ensure their well water is safe for consumption. Well water is also at a higher risk of contamination from nearby agricultural practices or improper disposal of chemicals.
List Of Common VOCs In Drinking Water
The EPA has set maximum contaminant levels (MCLs) for several Volatile Organic Compounds (VOCs) in drinking water. Here are some of the most common VOCs found in drinking water and their EPA limits:
- Trihalomethanes (THMs): Trihalomethane is a disinfection byproduct that is the most common VOC found in water. The EPA set a maximum allowable average level of 80 PPB for total THMs.
- Benzene. Benzene is a byproduct of petroleum refining and combustion and a known carcinogen. The EPA limit is 0.005 milligrams per liter (mg/L).
- Toluene. An organic chemical commonly found in gasoline, solvents, and paints. The EPA limit is 1 mg/L.
- Xylene. A solvent used in printing, rubber, and leather industries. EPA limit is 10 mg/L.
- Ethylbenzene. A component of gasoline and used in the production of styrene. EPA limit is 0.7 mg/L.
- Trichloroethylene. An organic chemical commonly used as a solvent to remove grease from metal parts. The EPA limit for trichloroethylene is 0.005 mg/L.
- Perchloroethylene (PCE). Used in dry cleaning, shoe polish, and degreasing applications. The EPA limit for PCE is 0.005 mg/L.
- Dichloromethane (methylene chloride). Used in paint strippers, degreasers, and as a solvent. EPA limit is 0.005 mg/L.
- Vinyl Chloride. Used in the production of PVC pipes and vinyl products. The EPA limit is 0.002 mg/L for vinyl chloride.
- MTBE (Methyl Tertiary-Butyl Ether or Methyl Tert-Butyl Ether). A gasoline additive that is used to increase oxygen content and reduce air pollution. The EPA limit for MTBE is 0.005 mg/L. Studies conducted on animals have shown that MTBE can lead to the formation of kidney and liver tumors.
What Are The Health Effects Of VOCs In Drinking Water?
Exposure to VOCs in drinking water can cause various health problems, depending on the type and concentration of the VOC.
Some VOCs can cause short-term health effects such as nausea, headache, and dizziness. Long-term exposure to some VOCs can cause liver and kidney damage, nervous system damage, and an increased risk of cancer.
The EPA has enforceable chemical limits for only 21 VOCs in public water systems. Furthermore, these regulations were last updated in 1992 and are not reflective of the current effects known on human health.
It’s essential to note that the actual concentration of VOCs in the water supply is crucial in determining the severity of health risks. Most VOCs in drinking water are typically found at low concentrations that are not harmful. However, long-term exposure to even low levels of VOCs can pose significant health risks.
What Is My Risk Of Volatile Organic Compounds Exposure?
In a recent US Geological Survey (USGS) study, VOCs are present in one-fifth of the United States’ water supplies. This means that many of the population may be exposed to potentially harmful chemicals in their drinking water.
The risk of exposure to VOCs in drinking water varies depending on several factors, including the water source, geographic location, and the type of VOCs present. Public water systems must regularly monitor the levels of VOCs in the water supply. Routine monitoring ensures that the levels are within the EPA’s maximum contaminant level set for each VOC.
However, there are many VOCs that are not tested for or regulated by the EPA. This means you are your own advocate in protecting your water supply – even if you have municipal water!
Individuals with private wells are responsible for their own testing and monitoring. The best way to determine your risk of exposure to VOCs in drinking water is to have your water tested by a certified laboratory.
Note that some people may be more vulnerable to VOC exposure due to genetic factors or pre-existing medical conditions. However, the risk of VOC exposure can be reduced by taking measures such as testing your water and treating it with the appropriate filtration.
How To Detect VOCs In Water?
Volatile organic compounds (VOCs) are composed of carbon and other elements which are too small to be visible to the naked eye. They can be as small as a few atoms and range up to several hundred atoms in size.
The presence of VOCs in water can sometimes be detectable by undesirable tastes or odors. For example, Benzene, which is a common petroleum chemical, can have a sweet odor or taste that is detectable at concentrations between 0.5 – 4.5 mg/L. Trihalomethanes, which is the most common disinfection byproduct, can have a chlorine smell at elevated levels above 2 mg/L.
However, it is important to note that the absence of these indications does not mean that VOCs are not present. Many VOCs do not have a strong odor, or their odor threshold may be higher than the level that poses a health risk. The only way to know for sure if VOCs are present in your water is to test for them.
How To Test For VOCs In Water?
VOC testing water is important to ensure drinking water is safe and free from harmful contaminants. There are several methods to test for VOCs in water, including certified laboratory tests, EPA water quality reports, and NAWQA data.
Certified Laboratory Test
Certified laboratory tests are the most accurate and reliable way to detect the presence of VOCs in water. These tests involve collecting and sending a water sample to a certified laboratory for analysis.
I recommend using the Freshnss Labs Ultimate Water Test Kit that screens for over 50 VOCs in drinking water. The kit includes everything you need to properly collect a sample and send it to a certified lab to be analyzed. You will receive a report within 3 business days indicating the exact level of VOCs detected in the sample, health or plumbing alerts, and the best treatment methods based on your data.
EPA Water Quality Reports
Another way to identify VOCs in water is through EPA water quality reports. The EPA requires public water systems to provide their customers with an annual water quality report. These reports include information about the quality of the water, including any contaminants that have been detected, including VOCs. If you receive your water from a public water system, you can request a copy of the report to see if any VOCs have been detected in your water.
It is important to remember that the Consumer Confidence Reports do not test for all VOCs known in public water sources. Additionally, the reports do not account for contamination throughout the distribution system and in your home. As such, the surest way to get accurate results is to test your home’s tap water.
The National Water Quality Assessment (NAWQA) program is another resource to see potential contamination for VOCs in groundwater. This program conducts assessments of water quality across the United States and provides information about contaminants, including VOCs. The data is publicly available and can be accessed through their website.
How To Remove VOCs From Drinking Water
Exposure to high VOC levels in drinking water can have adverse health effects. Fortunately, there are ways to remove VOCs from drinking water. These are:
Activated Carbon Filters
Activated carbon filters are one of the most common methods for removing VOCs from drinking water. These filters are highly effective in removing organic compounds from water due to their chemical properties.
The activated carbon filter is a highly porous form of carbon treated with oxygen to open millions of tiny pores between the carbon atoms. These pores increase the surface area of the carbon, allowing it to attract and absorb a wide range of organic and inorganic compounds, including VOCs, from water. The activated carbon has a negatively charged surface, which attracts positively charged VOC molecules, making it highly effective in removing them from water.
The effectiveness of activated carbon filters in removing VOCs from drinking water depends on the type of carbon used and the contact time between the water and the carbon. Granular activated carbon (GAC) is commonly used in drinking water treatment as it provides a larger surface area for adsorption and allows longer contact time between the water and the carbon. GAC filters effectively remove many VOCs, including vinyl chloride, petroleum products, and heavy metals.
However, it is important to note that activated carbon filters have limitations in removing certain VOCs, such as those with low molecular weight or highly soluble in water. Additionally, the filters must be replaced regularly to maintain their effectiveness in removing VOCs from drinking water.
Reverse Osmosis Remove
Reverse osmosis is a highly effective water treatment process that can remove many contaminants from water, including heavy metals, minerals, and salts. However, reverse osmosis alone is not enough when it comes to removing VOCs from drinking water. This is because some VOCs can be too small to be filtered out by the reverse osmosis membrane.
To effectively remove VOCs from drinking water with reverse osmosis, the system must include an activated carbon filter specifically designed to attract and trap organic compounds like VOCs. When the water passes through the activated carbon filter, the VOCs get trapped in the filter’s porous structure, preventing them from passing through to the final stage of the reverse osmosis process.
Frequently Asked Questions
Does boiling water remove VOCs?
Boiling water will not remove VOCs from drinking water. In fact, boiling water may increase the concentration of VOCs in the water by evaporating some of the water and leaving the VOCs behind.
What is the VOC limit in water?
The EPA has set maximum contaminant levels (MCLs) for some VOCs in drinking water. For example, the MCL for benzene is 0.005 mg/L, while the MCL for carbon tetrachloride is 0.005 mg/L. However, not all VOCs have MCLs set by the EPA.
What is the most toxic VOC in drinking water?
Benzene is the most toxic of the VOC fuel components and high levels can seriously affect white blood cells and is a known carcinogen that increases the risk of cancer.
Do water filters remove VOCs?
Activated carbon filters and reverse osmosis systems are two filtration technologies that are highly effective at removing VOCs from drinking water. Activated carbon filters attract and trap organic compounds, including VOCs, as water passes through the filter. Reverse osmosis systems, on the other hand, work by forcing water through a semi-permeable membrane that removes contaminants, including VOCs.
Is VOC harmful in drinking water?
Exposure to VOCs in drinking water can pose serious health risks. Some VOCs, such as benzene, perchloroethylene (PCE), and trichloroethylene (TCE), have been identified as carcinogens and can increase the risk of cancer if ingested over a long period. When present in high concentrations, VOCs can also cause damage to the nervous and immune systems, as well as to the kidneys and liver.
Can bottled water contain VOCs?
Yes, bottled water can contain VOCs. The sources of VOCs in bottled water are similar to those in tap water, such as surface and groundwater contamination, or leaching from plastic packaging.