How Widespread & Dangerous Are Pesticides in U.S. Drinking Water?

As you probably know, most of the fruits and veggies we purchase at the supermarket are grown on farms. And on farms, you can find a range of insects, rodents, and weeds, many of which love to eat or attack plants and fresh produce. Of course, farmers cannot allow these pesky agents to destroy their crops, so some farmers apply pesticides to the plants and surrounding soil to keep pests at bay.

By controlling pests, pesticides help protect crops against disease, increase crop yield and quality, and improve food safety. However, despite these fantastic benefits, pesticides can be dangerous to your health, potentially causing a host of acute and chronic health effects, depending on the type and quantity of pesticide consumed and how a person is exposed.

But considering America’s long history with pesticides and the fact that these toxic chemicals can leach into groundwater and surface water and significantly degrade water quality, we can’t help but wonder if there are pesticides in our drinking water and how prevalent and dangerous they are.

Before addressing these concerns, let’s have a brief chat about pesticides: what they are, how they get into drinking water, and the best treatment method to remove them if they ever crop up in your home water supply.

What are Pesticides?

The National Institute of Environmental Health Sciences (NIEHS) defines a pesticide as “any substance used to kill, repel, or control certain forms of plant or animal life considered pests.” These potential pests include insects, unwanted plants (weeds), rodents, bacteria, fungi, viruses, etc. If left unchecked, weeds and other herbs can quickly out compete crops for essential light, water, and nutrients. Similarly, many insects feed on crops, damaging plants and limiting production.

Pesticide Use in America

According to the latest EPA data, the U.S. is the second-largest user of pesticides worldwide behind China, employing an estimated one billion pounds of conventional pesticides every year.

Today, America spends around $9 billion annually on pesticides for agricultural use alone, based on the most recent year of data. Pesticides are used on 900,000 farms and in 70 million households in the U.S. While 75% of pesticides are involved in agriculture, 85% of American households have at least one pesticide in storage, and 63% of families have one to five pesticides at home.

Pesticide use across the country has increased significantly over the decades to supply adequate food to the growing human population and meet export demands. The increased urbanization also played a role in the rising need for pesticides. However, the general increase in pesticide use was mainly due to the low price of pesticides compared to other pest control measures like tillage. However, it fluctuated over the past 30 years because of crop prices, weather, pesticide regulations, and inventions of new pest-resistant G.E. seed varieties.

The rising need for food resulted in more extensive crop plantings. So, farmers started spraying more pesticides on the growing production area to increase crop yields, improve the quality of crops, and increase the number of times a crop can be grown on the same land.

Pesticides Commonly Found in U.S. Drinking Water

Because there are many groups of potential pests, different classes of pesticides are made to combat specific target species.

During a 10-year program by the National Water-Quality Assessment (NAWQA), part of the U.S. Geological Survey (USGS), researchers discovered that pesticides exist in both streams and groundwater throughout the U.S. in urban and rural areas.

The pesticides most detected in stream water include:

  • agricultural herbicides, including atrazine, metolachlor, cyanazine, and acetochlor
  • non-agricultural herbicides in urban areas, including prometon, tebuthiuron, 2,4-d, and diuron
  • insecticides, namely diazinon, chlorpyrifos, and carbaryl

The most frequently detected pesticides in fish and streambed sediment were organochloride pesticides and degradation products. Organochlorides were used heavily in the 1950s and 1960s but were largely abandoned by the 1980s. Still, these compounds, including Dichlorodiphenyltrichloroethane (DDT), are very persistent in soils, sediments, and animals and were thus found at high levels in stream sources.

The pesticides present at these excessive concentrations include cyanazine, atrazine, dieldrin, and diazinon. notably, stream contamination was typically atrazine and cyanazine, and well contamination was Dieldrin, which is no longer used but is a known persistent pollutant. While the compounds listed above were frequently detected in the study period from 1992 to 2001, pesticide usage changed as scientists developed new pesticides.

A recent study of streams sampled in the U.S. in 2015 by the USGS indicates the existence of a relatively new class of pesticides – neonicotinoids, in U.S. water systems. The study found at least one neonicotinoid detected in 53% of all samples, with imidacloprid most detected (37%).

The use of chemicals for pest control dates back to the 20th century. However, applications took off in the mid-1940s after the advent of the insecticide DDT, and weed-killer 2,4-Dichlorophenoxyacetic acid, or 2,4-D. Popular herbicides like atrazine and glyphosate came onto the market in the following decades, along with hundreds of other pesticide formulations, with chemical applications increasing threefold between 1960 and 1981.

But for many years, the use of pesticides was largely unregulated in the U.S. While this has changed somewhat in the ensuing years, America is still lagging behind other agricultural nations in banning harmful pesticides. The country’s staggering pesticide usage continues to be a significant concern, not to mention the recent discoveries of detectable levels of pesticides in drinking water in some parts of the country.

How Do Pesticides Get into Drinking Water?

Every day, millions of Americans are likely exposed to toxic pesticides in their drinking water. A 2000 study by the USDA found that up to 50 million Americans could be drinking from groundwater potentially contaminated with pesticides. With the rapid increase in pesticide use since then, this number has likely increased significantly. Plus, it’s estimated that a percentage of the one billion pounds of pesticides used each year in the U.S. ends up as runoff in groundwater and streams, rivers, and lakes. But how do pesticides get into these water sources and, ultimately, our drinking water in the first place?

Pesticides can invade drinking water sources through different mediums. One way these toxic compounds can enter drinking water is through agricultural activities. Farmers often apply enormous amounts of pesticides to crops, plants, and soil to protect and increase crop yields. Once the pesticides are used, some of the chemical residues soak into the ground during rainfall or other forms of precipitation. The residues then travel downwards through cracks and other different pathways in the soil, eventually reaching underground water-bearing aquifers and contaminating groundwater.

Groundwater contamination with pesticides can be mild to severe based on several factors, such as the pesticide’s mobility in soil, the solubility of the pesticides in water, the mixing of additives and active ingredients in the pesticide itself, how long it takes for the pesticide to break down, soil temperature, microbial activity, and irrigation management.

Irrigation increases the risk of the pesticide migrating to groundwater and surface water. Irrigating at a speed exceeding the soil’s infiltration rate will result in runoff carrying the pesticide.

Because pesticides can easily make their way into groundwater, surface water systems that feed drinking water supplies most likely contain pesticides. This is very troubling because roughly half of the nation’s population relies on groundwater for drinking water, especially for people living in agricultural areas where pesticide use is much higher than in urban regions, and 99% of the rural demographic relies exclusively on groundwater for drinking water.

Another way pesticide can enter water is through spillage and improper disposal of pesticides from manufacturing plants, mixing-and-loading facilities, spills, wastewater recharge facilities (wells or basins), waste disposal sites, and sewage treatment plants.

There’s also the issue of pesticides seeping from golf courses, parks, home gardens, and residential lawns into groundwater and nearby surface sources. Sure, those lush green spaces are pleasing to the eyes. But collectively, many landscapers and homeowners use large amounts of pesticides to block out destructive pests and maintain the grass’s mesmerizing appearance. But like agricultural farms, rain or snowmelt can wash the chemicals through storm drains and deposit them into surface water sources.

Finally, wind may carry pesticides sprayed via aerial application away from target crops and deposit them into surface water sources.

What Are the Possible Health Effects of Pesticide Exposure in Adults and Children?

Many studies have linked pesticide exposure to various health complications in adults and children. However, according to the World Health Organization (WHO), “The toxicity of a pesticide depends on its function and other factors. For example, insecticides tend to be more toxic to humans than herbicides.”

The Possible Health Effects of Pesticide Exposure in Adults

An analysis of seven studies found that pesticide exposure could be linked to an increased risk of Alzheimer’s disease. Similarly, one review discovered that pesticide exposure may lead to a higher risk of Parkinson’s disease and could alter specific genes involved in its development.

The pesticide most notorious for causing Parkinson’s disease is paraquat, one of the most prevalent pesticides in the United States. Farmers all over the country use over eight million pounds of paraquat annually on crops such as peanuts, wheat, citrus, soy, corn, almonds, garlic, pears, grapes, and strawberries. Paraquat is soluble in water and is most likely to contaminate drinking water when used with atrazine or simazine. Still, it can end up in drinking water by itself as well.

Perhaps even more concerning: some research also shows that pesticide use may be associated with certain types of cancer. According to one study in over 30,000 female spouses of pesticide applicators, increased exposure to organophosphates was linked to a significantly higher risk for hormone-related cancers, such as breast, thyroid, and ovarian cancer.

Another review of human, animal and test-tube studies had similar findings, reporting that exposure to organophosphate pesticides like malathion, terbufos, and chlorpyrifos may be associated with a higher risk of developing breast cancer over time. Some studies have also found that pesticide use may be tied to an increased risk of several other types of cancer, including prostate, lung, and liver cancer.

The Possible Health Effects of Pesticide Exposure in Children

Pesticide exposure may also have several health effects on children. For example, studies show that accidental exposure to high pesticide levels in children is associated with autism, cancer (including leukemia, acute leukemia, and lymphoma, but not childhood brain tumors), and attention deficit hyperactivity disorder (ADHD).

Another study showed that even low levels of pesticide exposure could negatively affect neurological and behavioral development in children.

How Is Pesticide Contamination of Drinking Water Regulated in America?

The U.S. Environmental Protection Agency (EPA) has drinking water regulations for about 100 contaminants, including pesticides. The agency conducts ecological risk assessments to determine whether changes to the use or proposed use of a pesticide are necessary. Before allowing pesticide products to be sold on the market, they ensure that the pesticide will not pose any unreasonable risks to plants, wildlife, or the environment.

In addition, the Safe Drinking Water Act (SDWA) includes a process that the EPA must follow to identify and regulate new pollutants. SDWA requires the EPA to consider three criteria when deciding to regulate the chemicals:

  1. The contaminant may harm human health.
  2. The contaminant is known to occur, or there is a high chance that the contaminant will appear in public water systems often enough and at levels of public health concern.
  3. Control of the contaminant presents a meaningful opportunity for health risk reductions for people served by public water systems.

Unfortunately, while the EPA regulates maximum limits of some pesticides in drinking water, many remain unmonitored. Likewise, manufacturers must register all pesticides with the EPA, but inert ingredients are considered “trade secrets” and do not have to be disclosed.

Only 13 pesticides are regulated with maximum contaminant levels (MCLs) under the SDWA, such as glyphosate, atrazine, simazine, and 2,4-D. Not included are about 900 other pesticides registered for use in Northwest states, including those commonly found in Northwest streams, such as diuron (herbicide), metolachlor (herbicide), and imidacloprid (insecticide).

Due to the lack of adequate regulation of pesticide use and pesticides in drinking water, the U.S. continues to use several pesticides banned in the E.U. or other countries, including atrazine, glyphosate, 1,3-D, paraquat, and neonicotinoids.

Are There Pesticides in Your Drinking Water? (Here’s How to Find Out)

By now, you may be wondering if there are pesticides in your drinking water waiting to be ingested and wreak havoc on you and your family’s health. Thankfully, there are many ways to find out.

First off, the EPA requires local water companies to monitor water for pesticides. As a result, you can contact your local water company to request information on the quality of your tap water.

It is also common for water companies to send annual water reports to consumers. These documents typically contain vital information about the quality of your water supply, such as the specific contaminants detected, the level of contamination, etc.

In addition, you can find out more about the quality of your local drinking water by accessing the EPA consumer confidence reports. Click on the map or use the search box to narrow your search.

But what if your water comes from a private well? How do you know if it contains pesticides, given that the EPA and other similar public agencies don’t regulate private wells? You can send a water sample from your home to a certified laboratory in your area to have it tested. Typically, laboratory testing is more thorough and reliable than home water testing. Lab testing can detect a wider variety of contaminants, which maybe wouldn’t have been caught using a simple home water test kit.

How to Remove Pesticides from Your Drinking Water

So, you’ve had your drinking water tested, and the results determined that it is contaminated with pesticides and perhaps a range of other contaminants. What do you do next?

The best solution to remove pesticides and other contaminants from your drinking water is filtration. The most cost-effective and efficient way to filter your home’s water is to treat only the water you plan to consume. This can be done using a point-of-use water treatment system, such as an under-sink reverse osmosis drinking water filter. R.O. treatment that employs activated carbon filtration supposedly removes between 97% and 99% of all pesticides from drinking water.

Reverse osmosis utilizes normal household water pressure to force water through a selective semipermeable membrane that separates contaminants from the water. Treated water emerges from the other side of the membrane, and the accumulated impurities left behind are washed away.

But considering that you can be exposed to pesticides and other contaminants through the skin when you shower, you’ll need a solution that also filters the water coming from your shower head and everywhere else in your home. This is where an activated carbon whole house water filter system comes in.

While many activated carbon whole-house filters remove pesticides (in addition to chlorine, radon, trihalomethanes, and some inorganic chemicals), we recommend checking before buying to find out the exact contaminants they remove.

Final Thoughts

Pesticides play a vital role in agriculture – and helping homeowners maintain lush, healthy lawns. They are commonly used to control weeds, insects, and other threats to produce, thus increasing crop yield and quality, protecting crops and plants from diseases, increasing the number of times a crop can be planted on the same land, etc.

However, while incredibly useful, pesticides are linked to various health problems, including certain types of cancers, Alzheimer’s disease, Parkinson’s disease, etc. They can also be very harmful to children, potentially leading to autism, leukemia, and abnormal neurological and behavioral development.

Beyond that, pesticides from farmland, parks, golf courses, and residential properties can enter local waterways and contaminate surface and groundwater that serve public treatment plants and private wells. Thankfully, Springwell offers a variety of affordable, state-of-the-art water filtration systems to ensure your drinking water is pesticide-free. Our reverse osmosis water filter systems filter pesticides at specific taps, while our whole-house water filters treat all the water entering your household.

Contact Springwell today for help finding the best water filtration system to remove pesticides from your drinking water.