Why Can’t You Drink Tap Water In Mexico? Plumbing & Filters

Clean water is one of the most important substances to maintain life. It is pretty common knowledge that you should not drink tap water in Mexico. However, we use water in a lot of different ways and acquire it from a myriad of different sources. This article is a deep dive into why you can’t drink unfiltered tap water in Mexico and what to do about it. 

Getting sick from water-borne illness is no fun. Traveler’s diarrhea is so common that there are names for it like Montezuma’s Revenge or Bali Belly depending on where you happen to be. 

I had an acquaintance in college who extrapolated that because water is the number 1 ingredient in beer he would not drink Mexican beer. There is a lot of misinformation out there that I hope to clarify in this article. 

Travelers need to be cautious when it comes to drinking water south of the border. Every building is going to have a different filtration system and a different maintenance record. Older buildings will have older systems that may have rusty pipes. Newer buildings will have a more efficient system that could include the best water filters. That is why the water quality can change substantially from one house to the next. As a general rule, it is a good idea to avoid drinking Mexican tap water until you have evaluated the public water systems and your own filtration systems.

Interestingly, Mexico is the country with the highest rate of bottled water consumption in the world. A large percentage of the population consumes water that has been filtered and purified by a private company, not the government. 

After watching the news, I have come to the conclusion that people in the United States need to take a more active role in monitoring their drinking water. Flint, Michigan was just the tip of the iceberg. We have seen contaminated water crises in Louisiana, West Virginia, and Ohio just to name a few. 

Water scarcity is only going to exacerbate these crises in the future. 

Every time I go home to San Diego, I am horrified by the taste of the water that comes out of the tap. In Mexico, I drink water that is purified by the Coca-Cola Company and delivered to my door for a fee. It tastes better than the tap water in most of California. 

Why Can’t You Drink The Water In Mexico?

You can not drink the tap water in Mexico because of contaminated regional water delivery systems, unmaintained household plumbing, and unsanitary water storage systems. Oftentimes water leaves the treatment facilities safe for human consumption but it is contaminated en route to the tap.

Any combination of minerals, bacteria, viruses, or heavy metals can contaminate that water and make you sick. 

Mexico is a much older country than the United States and many of the cities are using antiquated piping and delivery systems. Water does not arrive in houses with the same pressure that it has in the United States. 

A house’s plumbing system in Mexico is different from that of a house in the United States because of the lower pressure. In Mexico, houses typically have an underground cistern, a rooftop water tank, and pumps to move the water around. Homeowners and residents must apply regularly scheduled maintenance to the water system or else the water will grow mold or worse. 

I had an incident where the top of our rooftop tank (Tinaco) lost its top in a storm. Mosquitos quickly laid eggs and worms grew in the tank. In extreme cases, worms can get stuck in the old pipes or come out of the faucet. 

In Mexico, each house needs to take an active role in the delivery of its water system. 

Important Spanish World About Water

Agua Potable – Drinkable Water

Agua No-Patable – Not Drinkable

Household Water System Best Practices

Water comes into a house from the street at a trickle. This trickle of water is collected into an underground cistern that is usually made out of concrete and needs regular cleaning. A pump lifts water from the cistern to a water tank on the roof called a tinaco. 

Water filters are usually placed near the tinaco (rooftop water tank) and they need to be replaced every six months. Each house is different but the tinaco filtration system can be complex or it can be simple. The more complex the system the more expensive it is to replace the filters. 

Many houses will add a chlorine pill to the Tinaco every few months to kill any bacteria and or viruses that could find their way into the tank. Many times, the water coming out of the faucets in a house has just a hint of a chlorine smell. 

Do Local People Drink Tap Water?

No, most people who live in Mexico do not drink tap water. Mexico has the highest rate of private bottled water consumption in the world, and a good deal of plastic waste because of it. 

While there are some circumstances like living off the grid may have safe access to well water or natural springs, however, this isn’t common. Sometimes it is abject poverty that requires citizens to drink whatever water is available. The vast majority of the population does not trust the water coming out of the tap to be fit for human consumption.

Many parts of Mexico are notorious for hard water with a heavy mineral content. Limescale or hard water deposits collect on the faucets and stop up the showerheads. Those minerals can harm pet animals and cause kidney problems. Many people in Mexico won’t even give their pets water from the tap. 

In emergency situations, it is possible to boil water to make it safe for human consumption. It will still taste bad but the temperature kills the bacteria and viruses that could cause you harm. 

Most people who move to Mexico are surprised by the network of bottled water salespeople that distribute water throughout the city. They will set the heavy five-gallon jugs into a water dispenser and change it out a couple of times a week. 

Bottled water is relatively inexpensive and tastes so much better than the water that comes out of the tap. 

Do Mexican Houses Have Filtration Systems?

Yes, It is very common for houses to have basic filtration systems that remove some sediment. These filters need to be changed every six months or they get really dirty.

It is much less common for houses to install advanced filtration systems on the water they will drink. It is less common for all of the house’s water to pass through an expensive water filtration system. 

Filtration systems for drinking water need multiple (like six) stages of filtration, reverse osmosis, and UV light disinfection. They are complicated systems that require monthly maintenance by professionals. 

People installing water filtration systems do not want to use 5-gallon jugs because they are so heavy to lift. 

Professional water filtration systems start at around $500 pesos per month. 

In my opinion, the water doesn’t taste as good as Agua Ciel or Bonafont. One of the reasons that San Pellegrino tastes so good is its unique mineral content. If you strip out all the minerals without replacing the correct balance, the water tastes funny. 

Where Can You Buy A Bottle of Water In Mexico?

Bottled water is sold nearly everywhere in Mexico. There are tons of different-sized bottles but the most common is the returnable 5-gallon (20-liter) jug. 

5-gallon jugs can be returned to the Oxxo for a new one. There are usually at least two companies supplying each Oxxo with water. 

Supermarkets, grocery stores, pharmacies, convenience stores (abarotes), and tons of other retailers sell water. There are water kiosks set up all over my neighborhood where you can put some coins into a machine and fill up a jug with either normal water or alkaline water. There is a water kiosk behind my favorite taco shop so I can kill two birds with one stone (matar dos pajaros con un tiro). 

The best place to buy water is from the Waterman. In my neighborhood, we have at least four different companies that come by several days a week to sell water. 

I buy Agua Ciel (the best bottled water in my opinion) from the Coca-Cola Company. They sell soft drinks, sparkling water (Topo Chico and Agua Ciel), and Santa Clara milk. I tip them a few pesos each time they visit and they leave my 5-gallon jugs in the water dispenser. 

The water from the major companies tastes better than the tap water I grew up with back home and I have never gotten sick from it. If a 5-gallon jug is damaged in any way, they exchange it no questions asked. 

I have come to love my bottled water and the fact there is a milkman to deliver it. Every time we go back to San Diego, I have to buy purified water because the taste of the tap water discourages me from drinking the amount of water that is healthy. 

This is going to sound so yuppy, but I have even gotten in the habit of buying the gourmet ice. When it is hot, there is nothing more luxurious than a tumbler full of ice water. 

Will Ice Make Me Sick in Mexico?

This is where things get a little more complicated in Mexico. It is not common for restaurants to make their own ice. Successful restaurants almost exclusively purchase their ice from reputable ice makers that use purified water. 

I worked at a restaurant that would make its own oversized ice cubes for expensive spirits. Nobody behind the bar would ever consider using tap water to make those ice cubes. 

The best restaurants in Guadalajara would never consider using tap water in their ice or their drinks because people are going to get sick and they will not come back. The clearest sign that a restaurant is following basic sanitary standards is that there are a lot of people eating there. 

While I am sure that there are cases of restaurants using tap water when they should be using purified water but that is not common. No successful restaurant is going to cut corners on purified water in order to save money. Sick and unhappy customers are way more expensive in the long run. 

In 2022, there were images all over the news of a street vendor filling up buckets that made it look like he was going to use dirty water to make aguas frescas. There were no pictures of him actually mixing dirty water into food products the internet went mad. He could have been using that water to clean something but people didn’t want to take a chance. 

Be cautious about buying food from street vendors that do not take basic hygiene seriously. At a minimum, a street vendor should have access to a place to wash their hands. 

I eat street food all the time but I look for famous, busy street food stands that people return to often. I don’t want to buy aguas frescas from a dude who doesn’t have access to a bathroom or a place to wash his hands.

While it is not common to see dirty water used in food service it is important to always be on the lookout. In 2020 there was a story circulating around social media of a group of young women who found pills frozen into their ice cubes a a nightclub. Don’t let your guard down. 

Can I Make Coffee With Tap Water In Mexico?

No, don’t make coffee with tap water. Number 1, tap water tastes horrible and will ruin good coffee. Number 2, the ideal temperature for making coffee is way below boiling. If the water is contaminated, simply warming it will not kill all the bacteria. Water must reach boiling temperature and sustain that temperature for at least one minute to kill all the potential pathogens. 

Can I Brush My Teeth With Tap Water In Mexico?

Yes, as long as you do not swallow the water. Most adults are able to brush their teeth without swallowing the toothpaste water. Little kids find it a lot harder. 

If you are just arriving in Mexico or have little kids, try to use bottled water to brush your teeth. You honestly never know what the maintenance schedule looks like at the hotel or house you are staying at. 

Once you get your own place and have paid someone to scrub out the Tinaco you know that the water is clean. Until you have seen the Tinaco, you don’t know if the water is clean. 

Can I Drink Tap Water In A Hotel Room In Mexico?

No, do not drink the tap water in a hotel. Hotels provide at least a small amount of bottled water for each room. Additionally, the hotel will have 5-gallon jugs around somewhere. 

I always carry a reusable water bottle, an insulated tumbler with a top, that I can refill. I hate buying single-use plastic bottles of water because I can always fill up my water bottle at a hotel or restaurant. 

Do Restaurants In Mexico Serve Tap Water to Customers?

No, serving a glass of tap water to customers is a good way to go out of business. Sick customers do not return. 

It is common for waiters to try and upsell customers to purchase bottles of water. If a customer asks for a glass of water it will almost always come from a 5-gallon jug. Serving tap water is either malicious or ignorant. Restaurants do not want to get a reputation for making their customers sick. 

Final Thoughts On Why You Can’t Drink Tap Water In Mexico

Mexico’s tap water can be problematic. To be on the safe side, it is best to avoid drinking tap water until you have evaluated the local water supply, the city-wide water distribution system, and the local water storage system. Things like old pipes or a dirty storage tank can contaminate water sources. 

While some major cities like Puerto Vallarta have an improved water supply, you have no clue if smaller hotels are taking all the necessary precautions to keep that water clean and drinkable. 

The best way to make sure you are consuming safe water is to carry your own water bottle and fill it up from a 5-gallon jug of purified water. You can buy bottled water at every corner store but try to minimize the single-use plastics by using a refillable water bottle.