water quality

Pesticides and Water Quality


In modern agriculture, almost everything is grown with the help of pesticides. When these chemicals are sprayed on nearly everything we eat, we must ask: can they harm us?

Rachel Carson's book Silent Spring put the toxic and damaging effects of Dichloro-diphenyltrichloroethane (DDT) on the map in 1962, inciting a global conversation about the environmental and public health dangers of widespread pesticide use. 

The word “pesticides” refers to chemicals used to kill or deter pests. Different pesticides are used on different pests: herbicides for weeds and insecticides for insects, for example. Though some older, harmful pesticides (like DDT) are now banned, over 1,000 pesticides are still used globally, each with its own properties and human health effects.

So they kill weeds and pests, but what about humans? We help break down how pesticides can get in water and what their impacts could be on your health.

How Do Pesticides Get Into the Water Supply?

One of the primary ways that pesticides work their way into the water supply is by seeping through the soil to the groundwater. Around 50 percent of people in the US — and about 95 percent of those living in agricultural areas — rely on groundwater for drinking water.

Pesticides are most widely used in agricultural areas, so concentrations of pesticides are usually higher in those regions. Once in the environment, however, pesticides can easily spread, ending up in water through many paths: precipitation, leaching, runoff, and wind, for example.

This process can take years for chemicals to work their way through soil to the groundwater, creating a time lag between pesticide use and appearance in deeper water reserves. Once there, chemicals can stay in groundwater for decades, even if efforts are made to reduce pesticide use above ground.

Changing Pesticides, Changing Risk

Protecting crops and increasing yields has been a goal for decades now. Chemicals have been used to achieve that goal for as long, but the kinds of chemical used have changed.

Before the 1940s, compounds that included arsenic, mercury, or lead were common. Though these chemicals pose serious threats to human health, they are not very soluble, so they turned up in food more often than in water.

After World War II, pesticides shifted towards synthetic organic compounds, which were thought to be safer. These compounds, including chlorinated hydrocarbons such as DDT, are more attractedto soil than water, and so they tend to accumulate in soil and food chains as opposed to water.

When the toxic health effects of these chlorinated hydrocarbons were discovered, an effort began to replace them with safer, less toxic chemicals. One group of these new pesticides are called carbamates, and they are highly soluble in water.

Thus, while pesticides may be trending safer, they may also appear more frequently in our water sources. Long-term studies are still underway to figure out what the health effects are, but in the meantime, scientists are finding carbamates and their transformation products in our drinking water.

Environmental Protection Agency (or EPA) has health standards for pesticides before being released into the environment, but environmental groups have repeatedly identified chemicals (e.g. chlorpyrifos) that pass EPA’s requirements mark but are later found to be toxic.

What Are the Risks to Human Health?

The effects of pesticides on the human body are as varied as the chemicals themselves. Organophosphates and carbamates, for example, affect the nervous system, while others irritate the eyes or skin. They can be carcinogenic or disrupt the body’s endocrine system.

Scientists are studying both the acute and chronic effects of ingesting pesticides. Pesticides are being detected at low concentrations, and as such, acute toxic effects (like nausea or chemical burns) are of less concern for most people. Farmworkers and landscapers directly applying herbicides and pesticides are likely most at risk (consider the evolving case of glyphosate).

Many are concerned, though, that these chemicals can accumulate over time, leading to greater health effects.

Are Pesticides in My Drinking Water?

Only small quantities of pesticides have shown up in treated drinking water. There are two directions of research, however, that promise to illuminate more about how pesticides impact drinking water: 1) cumulative exposures and 2) transformation products.

So far we have been writing about one chemical at a time. In reality, there are multiple herbicides and insecticides present in the environment. Health impacts of cumulative exposure to these compounds are not well understood, which means that our general assessments of risk are likely under-estimating the potential health impacts of pesticide exposures.

As we noted above, scientists have found the transformation products of pesticides in drinking water. A pesticide transformation product is a new chemical formed when the “parent” compound (e.g. DDT) reacts under different conditions – e.g. sunlight or bacteria in the environment or UV treatment in a water treatment facility. Sometimes, these transformation products are even moretoxic than the parent compound. Until engineers and scientists identify the multiple transformation products formed when chemicals enter our treatment systems, we can’t be sure that we are adequately treating our water.

Check out our water testing packages to make an informed decision about your drinking water or get in touch with us here for more information!










Heavy Metals in Water & Soil: Methods for Treatment


The ultimate faceoff: Human engineering versus plant power

We’re back with Part 2 on heavy metals! If you haven’t read Part 1 yet, be sure to do so to ensure you’ve got all the background info down.

As discussed in Part 1, you can be exposed to heavy metals through bioaccumulation in food. Though bioaccumulation often starts with microorganisms in aquatic environments, contaminants can also enter agricultural crops through contaminated soil or irrigation water in crop fields. Similarly, humans can be directly exposed to heavy metals through drinking contaminated water.

There are many methods available for reducing heavy metals at their source–before they enter our food and bodies. Chemically engineered methods such as reverse osmosis, ion exchange, and chemical precipitation have been in use for a while, but there are also some emerging technologies that utilize the natural power of plants to absorb heavy metals directly from the environment. Some of these technologies can only be used at treatment plants, while some of them are more consumer friendly and can be used at home. We review them both, below.

Chemically Engineered Methods

Contamination Pathway: Water

Reverse Osmosis

Used For: At Home Water Treatment for City & Well Water; Water Treatment Plants

Reverse osmosis (RO) can be used to treat many heavy metals such as chromium, copper, lead, and arsenic. RO technology uses added pressure to push water through a semipermeable membrane, which blocks contaminants larger than 0.0001 micrometers from passing through.

Removal rates depend on several factors including the post- and pre-treatment steps, but RO removal efficiencies are high for metals, with upwards of 99.4% removal for metals like cadmium and copper. Though reverse osmosis is a very effective method, it is expensive (systems costanywhere from $150-$1000) and creates a high volume of wastewater. Not only will this likely increase your water bill (by about $50/month), but the wastewater stream contains a high concentration of contaminants can harm the environment if not properly disposed of.

Ion Exchange

Used For: At Home Water Treatment for City & Well Water; Water Treatment Plants

Ion exchange is another common heavy metal treatment method, which can reduce nickel, mercury, lead, cadmium, chromium, and copper in water. When water passes through an ion exchange resin, heavy metal ions are attracted to the resin surface and easily swap places with charged surface particles called ions. The swapped ions are harmless ions such as hydrogen, making the discharge water safe to drink and use for irrigation.

As with all technologies, ion exchange has some drawbacks, including: it requires diligent cleaning (through backwash and brine regeneration) of the resin to work properly, it cannot handle highly concentrated metal solutions, it is not selective to heavy metals, and it is sensitive to your water’s pH. Ion exchange resins being “non-selective” means that they can also filter out beneficial ions in water such as minerals, like calcium and iron, that your body needs.

Chemical Precipitation

Used For: Water Treatment Plants

Chemical precipitation is one of the most widely used methods for heavy metal removal. Contaminated water is mixed with a chemical solution, often containing lime, that reacts with the heavy metal ions. This causes the heavy metals to precipitate into solids. The precipitate is then large enough to filter out, and the heavy metal removal is complete!

Chemical precipitation is well established and low maintenance, but also creates concentrated wastewater sludge and can require complicated chemical dosing.

Ecologically Engineered Methods

Contamination Pathway: Soil & Water


Used For: Water Treatment Plants; Soil Remediation Projects

Phytoremediation enompasses any method that uses plants to uptake contaminants from soil or water.  It is more affordable than chemically engineered methods and more environmentally friendly, because it does not create concentrated wastewater sludge that can harm ecosystems.

Engineered wetlands are an example of phytoremediation in action: water passes through and sits in wetlands while contaminants collect on the floor of the wetland and get taken up by plants.

However, phytoremediation is time consuming, limited by the age of the plant, root depth, level of contamination, weather conditions, etc, and there still exists a concern for proper contaminated plant disposal.

A few phytoremediation methods include:

Phytoextraction & Phytovolatilization

Phytoextraction refers to plants’ ability to uptake/absorb heavy metals through their roots and transport them to the above ground parts of the plant, called shoots. The shoots can then be burned to both generate energy and extract heavy metals from the ash to be recycled. Or, in the case of phytovolatilization, the heavy metals are released into the atmosphere.


Certain plant species can immobilize heavy metals present in soil and groundwater by “adsorption and accumulation in plant tissues, adsorption onto roots, or precipitation within the root zone” (Tangahu).  Once the plant has latched onto the heavy metals, they can no longer move throughout the soil or be swept away by erosion.


Bio-sorption refers to the adsorption of contaminants onto modified agriculture such as hazelnut shells, pecan shells, maize cob or husk, rice husk, or jackfruit. The foods are heated into activated carbon, then used to adsorb heavy metals.

What about Contaminated Soil at Home?

Phytoremediation requires expertise to ensure that the correct plant species is being used and that contaminants are being removed effectively. At home, you’ll need a simpler approach–but you’ll want to know what’s in your soil first. Soil testing is an essential first step to understanding what is in your soil.

If you find you have contaminated soil with heavy metals, there are a few simple methods you can use to remediate the problem. You can create raised beds for your crops that are above the contaminated soil, or you can add a thick layer of organic material such as mulch or compost on top of your soil to create a physical barrier from the contamination.


Much water and soil treatment happens behind the scenes at treatment plants and soil remediation projects–but some of these methods are applicable at home. At Simple Water, we mostly focus on helping people protect themselves from heavy metals by providing advanced at-home tests for water and soil, so people can get a sense of what you’re dealing with and what type of treatment may be appropriate for their situation.

As always, if you have any questions, feel free to email us at hello@simplewater.us!
















Nitrites, Nitrates, and Your Health


If my water is contaminated, I will know, right? Unfortunately… if you’ve been reading Tips for Taps, you’ll probably know the answer. Some drinking water contaminants are completely impossible to see, smell, or taste.

Nitrite and nitrate are two such contaminants, but they are associated with serious health risks, especially for infants and pregnant women. A total of 2 million people were served water that exceeded public health guidelines for nitrite and nitrate in 2015.

There are many routes by which nitrite and nitrate can reach drinking water, and several options to prevent and treat contaminated water–Tap Score’s guide to understanding this stealthy pollutant covers the basics.

What are Nitrites and Nitrates?

Nitrite and nitrate are naturally produced in soil by nitrifying bacteria. A complex process called “nitrification” causes nitrites to form into nitrates, which is part of the complex but fascinating nitrogen cycle. Nitrites and nitrates have many other sources as well, including the atmosphere, agricultural runoff, and wastewater discharges.

As far as human activities, both compounds are important component of fertilizers. With the scale of today’s agricultural activity outpacing any other land use in the US, it is now even more abundant in soils all over the world. In industry, both nitrite and nitrate salts are used in meat-curing processes.

Although nitrite is a drinking water contaminant, most nitrite present in water is rapidly converted to nitrate. For this reason, we talk about “nitrate contamination”, which includes nitrite as a source.

How Do Nitrates Affect My Health?

The EPA deems nitrite and nitrate (measured as nitrogen) safe in water at levels below 1 and 10 parts per million, respectively. However, other countries have maximum levels for nitrate that are twice as strict as the EPA standards and some argue that the US should lower the maximum allowed levels. While there are several health risks from consuming too much nitrate–methemoglobinemia (also known as blue baby syndrome)–is one of the biggest risks.


After ingestion, the human body reduces nitrate to nitrite. Nitrite then converts normal hemoglobin (Hb), a protein in blood that transports oxygen to bodily tissues, to methemoglobin (metHb), which cannot transport oxygen. Thus, high concentrations of nitrates in drinking water can cause a condition called methemoglobinemia – leading to critical oxygen deficiency in the body.

Methemoglobinemia can lead to cyanosis, a skin discoloration, or even asphyxia - suffocation - at high concentrations.

In adults, a very high concentration of nitrate (unlikely to be consumed) is necessary to result in methemoglobinemia. Infants produce nitrite faster and are less resistant to its effects than adults. Methemoglobinemia is often referred to as “blue baby syndrome” because infants impacted by it can appear blue from lack of oxygen.

Blue baby syndrome is also a risk to fetuses in utero, so pregnant mothers are should test their water for nitrates especially if they live near agricultural lands and rely on private wells.

Other Health Risks:

There are several other health risks associated with nitrate in water, including thyroid issues, birth defects, and cancer.

How do Nitrates Get in My Drinking Water?

Nitrites and nitrates can enter your drinking water from a variety of sources. Your exposure pathway and solutions are different, as you might expect, if you get your water from a water system or a private well.

Public Water System

The highest risk of contamination is from nitrates in private wells, though hundreds of thousands of Americans are exposed to nitrates in public water systems. EPA found that water systems violating the 10 mg/L MCL for nitrates has actually been increasing. Water systems often rely on their own groundwater wells for source water, meaning nitrites and nitrates enter water treatment plants similarly to the way they might for a private well.

Private Well

If you rely on private well water, you are more at risk of nitrate contamination if your well is near the following areas commonly associated with nitrate contamination:

  1. Livestock or animal farms

  2. A septic system

  3. Agricultural land

  4. Neighbors overzealous with garden fertilizer

Nitrates and nitrites are readily mobilized in water. As excess levels are often applied to land for growing crops and livestock manure may not be properly managed, nitrates readily run into groundwater pumped up by wells.

What Should I Do About Nitrate in My Water?


Nitrate and nitrite are colorless, odorless, and tasteless compounds. That means they are impossible to detect without laboratory testing. The first step is to test your water. Tap Score’s well water and city water tests all include a nitrate screen. If you are in an at-risk environment (e.g. near agriculture), we recommend a higher-resolution test for nitrate (again, this is the most common form in your water and is measured as nitrogen). You might also consider testing for nitrifying and denitrifying bacteria.


If you find nitrates in your drinking water source, and you have an infant, do not feed your infant formula with the drinking water.

You will likely need to treat your water by installing an at-home treatment system such as those involving reverse osmosis, ion exchange, or distillation. Unless you are regularly testing the safety of your water treatment system, however, it is recommended that you do not use the water source with infants under six months old.

Though it is commonly believed that boiling water will remove contaminants, boiling water will not remove nitrite/nitrate and will actually increase their concentrations by evaporating some of the water around them.

If you have a private well, you should have it inspected and check the casings and fittings – any damage could enable seepage from shallow groundwater containing nitrates. Finally, remove any potential sources within close proximity to the well–e.g. improperly managed animal manure or fertilizer use.


Send any concerns or inquiry to Tap Score and you’ll be dispatched to a water quality expert in no time – hello@simplewater.us.




https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1071541/ https://www.ewg.org/research/pouring-it/health-effects-nitrate-exposure#.W2OD89JKg2x






https://www.epa.gov/sites/production/files/2015-09/documents/nitrification_1.pdf https://www.ewg.org/tapwater/contaminant.php?contamcode=1038#.W2oey9JKg2whttp://psep.cce.cornell.edu/facts-slides-self/facts/nit-heef-grw85.aspx 

What’s In Your Raw Water?


Nobody knows and that’s a problem...

A response on the Raw Water fad from the team at SimpleWater, the maker of Tap Score, a specialized environmental health testing company headquartered in Berkeley, CA.

Most people have a healthy skepticism of the latest marketing craze coming out of Silicon Valley: "Raw Water". While the region is known for its technological innovation, this latest fad would be quite literally the opposite of progress if millions of people switched over to pre-water treatment days.

Raw Water is marketed as a "health drink" that caught the headlines at the turn of the year. The hard truth is that neither bottled water, nor tap water, nor indeed raw water is perfect. There are minerals you want in your water, and chemicals you do not in your water.

We think this is a good time to remind folks about how far we've come in our understanding of environmental water and personal health. Here’s our take on Raw Water.

Raw Water, The Basics:

  • A company will bottled water from a groundwater well or a a surface water source
  • They will spend no money on treating it and, if they do test it, they aren't publishing the results
  • They will sell it at a 5x markup over regular bottled water and call it a health drink

Water Quality Matters

We don't live in a pristine world. Water runs downhill, so unless you're collecting rainwater in the High Sierra, you're also collecting whatever that water picked up on its way down through developed areas. Even deep wells near populated or industrialized regions are frequently contaminated. In many cases, the toxic chemicals are naturally occurring; most arsenic in groundwater comes from natural rock formations, and it's a deadly poison.

To our good fortune, water treatment plants and engineers exist to actively clean and monitor this water before it gets to your tap. While we think it’s important to test your water even if you have city water, our interest is to empower people to understand their water and identify potential problems–not to discredit water treatment operations like the conspiracy-theory approach of Raw Water sellers.

Untreated spring water promises a high risk of bacteria like Giardia or E. coli. They'll give you diarrhea, or worse. But these 'acute health risks', as we know them in the industry, are just the stuff that will make you sick in the very short term.

SimpleWater, the maker of Tap Score, exists because untreated water can also carry a number of long term health risks. Our job is to  quantify those risks using real science, making it simpler than ever to understand how what you drink every day could impact your long term health.

One of the biggest offenses of Raw Water marketing is that it's disingenuous to the people who rely on toxic wells because they've been left behind by public utilities. In many cases those same people have no choice but to drink from a contaminated well or spend their own money on treatment.

The Raw Water sales reps are in effect turning a blind eye to the contaminants that have caused cancers for millions worldwide, while mumbling something about probiotics. We love that every day more people are learning about the importance of the microflora in our intestines. But we're not talking about a carefully cultivated cup of yogurt here.

If You Have to Have it Raw, Test First

The water you drink will never be a meaningful source of nutrients versus the rest of your diet, but it could be a meaningful source of chronic poisons and bacteria. Some wells and springs produce really fantastic water– we know that because we've tested thousands of them. We've also tested hundreds of water samples that contain stuff you don't want to be putting in your body. The fact is: water quality is not a matter of “pure” versus “un-pure”. Bottled water is not necessarily better for you than tap water, and and untreated tap water is not necessarily better than treated tap water.

If you’re ever interested in testing your water (bottled water, tap water or even your “raw” water) then we invite you to run a water quality test with our Tap Score service.

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