Why Your Tap Water May Taste Earthy In Fall

Fall is my favorite time of year, but it’s also when I usually notice changes in the way our water tastes and smells.

Is it possible for water quality to change throughout the year? Well, as temperatures cool, algae in our local reservoir die and release a non-toxic organic compound, known as “MIB” (2-Methylisoborneol), which can make water taste and smell unpleasant.

“MIB” generally doesn’t pose any direct hazards to your health. But, when algae interact with chlorine, a disinfectant commonly used in water treatment, harmful byproducts may form in your drinking water.

How Can Algae Impact the Quality of Your Drinking Water?

Blue-green algae are microscopic organisms that thrive in reservoirs, and other calm bodies of water warmed by direct sunlight. They can produce blooms in a range of colors, including bright green, blue-green, yellow, brown, and even red. These blooms can make algae relatively easy to identify.

Some species of blue-green algae release toxins called cyanotoxins into the surrounding water. These toxins may be harmful to humans and other animals, so stay out of any body of water that contains noticeable algae growth.

Many water companies, like the Beaver Water District in Northwest Arkansas, monitor algae populations so they can make adjustments to water sourcing and treatment when necessary. Fortunately, conventional water treatment processes have proven effective at removing cyanotoxins from drinking water.

How algae can cause problems in treated water

As part of the water treatment process, many water companies add chlorine to the water supply. While this is great for ridding the water of any remaining parasites, bacteria, or viruses, it can also result in the formation of harmful byproducts known as Trihalomethanes (THMs). 

THMs can form when chlorine interacts with algae or other organic matter contained in the water. Prolonged exposure to THMs can cause kidney, liver, or thyroid problems, and pose an increased risk of cancer.

What can you do to reduce algae in your local water source?

Phosphorus and nitrogen, two common fertilizers that can make your grass greener and your flowers more vibrant, can also spur on the growth of algae. So, if you’d like to do your part to control algae populations in your area, try limiting the amount of fertilizer you use on your lawn and garden.

Other Things That Can Give Your Water an Unusual Taste or Smell

Have you ever been traveling and noticed the water in certain areas tastes or smells differently than water from your tap at home? Well, several things, some naturally occurring and some human-made, can affect water’s taste, smell, or appearance.

Last month, when my wife and I visited Boise, Idaho, we noticed a very distinctive flavor in the tap water at a restaurant outside the city. The water tasted so strongly of iron that it was almost as if we were drinking blood. 

Sometimes the pipes in older buildings can give water a metallic taste. So, we weren’t sure if the iron flavor was from the local water supply or the plumbing in the restaurant itself.

Out of curiosity, while we waited for our food, I decided to take a quick look at the latest annual water report for the Boise area. Sure enough, iron levels were reportedly as high as 1,680 ppb or more than five times the level suggested by the EPA.

To help public water companies manage the taste, smell, and appearance of the drinking water they deliver to their customers, the EPA established guidelines for 15 contaminants, including iron. While these contaminants do not carry any associated health risks at the levels recommended by the EPA, they can certainly have undesirable effects on your water.

Four of these contaminants (aluminum, color, fluoride, and silver) are only known to affect the appearance of drinking water. The 11 remaining contaminants, however, can negatively impact the way water tastes or smells.

11 contaminants that can affect drinking water odor or flavor:

ContaminantPotential Affects on Water Quality
Chloridesalty taste
Coppermetallic taste; blue-green staining
Corrosivitymetallic taste; corroded pipes/ fixtures staining
Foaming agentsfrothy, cloudy; bitter taste; odor
Ironrusty color; sediment; metallic taste; reddish or orange staining
Manganeseblack to brown color; black staining; bitter metallic taste
Odor“rotten-egg”, musty or chemical smell
pHlow pH: bitter metallic taste; corrosion
high pH: slippery feel; soda taste; deposits
Sulfatesalty taste
Total Dissolved Solids (TDS)hardness; deposits; colored water; staining; salty taste
Zincmetallic taste

Source: epa.gov

What to Do If You Notice a Change in Drinking Water Taste or Smell

While a sudden change in your drinking water’s flavor or odor does not necessarily signal a health concern, you should always take it seriously.   

You see, even treated water can become contaminated before it reaches your home. If just one underground pipe is compromised, hazardous substances can leach into your drinking water supply, and potentially make it unsafe for consumption.

If your water comes from a public water system:

If you notice a sudden change in your drinking water, you should contact your water provider to report your concerns and request additional information. You should be able to find your water company’s contact information on your latest water bill or on the company’s website.

If you get your water from a private well:

If you notice your well water tastes or smells unusual, you should have it tested by certified professionals.

In fact, even if you don’t notice any changes in the quality of your well water, it’s wise to have it tested periodically.

How to Improve the Flavor and Odor of Your Drinking Water

Once you confirm your tap water is safe to drink, is there anything you can do to make it more palatable?

Well, fortunately, there are several simple and inexpensive things you can do to improve the taste and smell of your water.

Here are three things you can try today:

1. Use an activated carbon water filter

Even after being treated, your local drinking water may contain residual contaminants. So, I recommend everyone use a filtration device of some kind. In addition to reducing the amounts of select contaminants from your tap water, filters containing activated carbon can also effectively eliminate unpleasant flavors or odors.

2. Allow your water to breathe

If you’re unhappy with the amount of chlorine in your tap water, fill your glass and allow the water to sit out, or “breathe” for a while before you take a drink. When I lived in Houston, Texas, my tap water was heavily chlorinated. But, I found if I filled a pitcher, and allowed it to stand overnight, the chlorine was not as apparent.

3. Add a twist of lemon to your water

If your local water source is known to be affected by algae, consider adding a little lemon to your water. It can help neutralize seasonal odors or flavors.

Related Questions

Does the EPA restrict levels of Trihalomethanes (THMs) allowed in drinking water? The four THMs most commonly found in public water systems include Bromodichloromethane, Bromoform, Chloroform, and Dibromochloromethane. The EPA requires drinking water to be treated to contain total THMs of no more than 0.08 mg/L.

Your water doesn’t have a noticeable odor. Does that mean it’s safe to drink? While smell and taste can be useful indicators of water quality, it’s worth mentioning that some harmful contaminants may not produce a significant odor. So, even if your water is odor-free, it may not be safe to drink.

Will your water company notify you if your water is found to be unsafe? When regulated contaminants exceed allowable limits, water providers are required to inform the public. If your water company sends you any information regarding the quality of your drinking water, read it carefully, and be sure to follow any instructions closely.


I’ve moved several times over the years, so I know just how stressful it can be to relocate. I want to help put your mind at ease. That’s why I research and write about all the things I think you should consider when moving to a new town.

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