01.969.934.0558 info@foodbankchicxulub.com

Thanks to YucaLandia/Surviving Yucatan. © Steven M. Fry

The issue of drinking water quality keeps coming up over & over on Expat web-boards, webpages, and Expat FB pages, for at least the past 14 years.

The common ~lurid rumor~ that many newbies propose is that our Merida City tap-water is somehow ~magically~ “bad” …

Fortunately, the opposite is true. … Merida City tap water consistently tests clean roughly 97% of the time, when tested before the water enters the home. … Sadly, so many Merida homes have contamination in their tinacos** and cisterns** that just 75% of Merida homes test clean at the kitchen sink tap. *  (See below for instructions on inspecting your home water system quality.)

Continuing… Why is Merida tap water so clean, but SO HARD??

Our Merida City Water (JAPAY) comes from 360 ft deep wells … and it’s from 10 million years ago. … Were there pesticides & herbicides 10 million years ago?

Since there is 330 feet of limestone between modern surface water and our 360 ft deep Merida City drinking water wells, there really is no way for surface contamination to get down 360 ft to our drinking water supply. … Merida is not New Orleans whose Mississippi River contains the effluents & sewage & feed-lot & farm run-off from the Rocky Mountains to the Appalachians…

USA water?? One of the earth’s most polluted rivers

That’s the USA …  Not Merida … ?

Fortunately, here in Merida … We have no tar-sands oil… We have no fracking .. We have no mega-hog farms or Mega-chicken farms … No big chemical plants nor refineries …  and there’s NOBODY “upstream” from our drinking water …

Remember … USA-nians are justified to fear the over 5,000 USA water districts** who have been failing US EPA standards for years … But those fears simply do not fit Merida. … Seriously … It’s US drinking water that people should fear.

Fortunately, Merida City JAPAY water is proven clean at 97% of the homes tested***, when it enters our homes.

**The water for Merida City wells at 360 ft depths is very clean … but it is very hard (High calcium carbonate levels – which are NOT a health risk – but just taste a bit “off”)…   Why is Merida city water so clean? …. because that water is 10 million yrs old … and there were no pesticides 10 MILLION years ago.

*       *       *       *        *
***Past independent studies show clean Merida city water 97% of the time, ~ENTERING~ the house … but that water entering the house … is not the same as water at the kitchen faucet … That means that roughly 25% of the water tested in Merida kitchen sinks had microbial contamination (fecal coliforms) FROM INSIDE THE HOUSE’s plumbing.


No dead birds … no dead ‘possums … no accumulated leaf litter … SERIOUSLY … people leaving the tops of their cisterns & tinacos open is THE REAL ISSUE, per 20 yrs of test results.

and yes, Virginia … You can test your own water!
~ Note that if you test the water coming into your Merida home  for free-Chlorine (swimming pool test kit) … and if you measure chlorine present – then your water is FINE !

= = = = = = =
Next:  Are you unsure about the quality of your Merida City water in your tinaco or cistern ?

*Tinaco~Cistern Inspection & Maintenance:
For people on Merida City water (JAPAY) … Basically … LOOK in your tinaco~cistern    and  ~sniff~  it. ?

If you see organic detritus (dead leaves, dead rotting vegetation, dead birds, dead iguanas, or roots) … then REMOVE all the detritus, rinse it out … and disinfect it with normal laundry bleach**.

If the tinaco~cistern water looks clear, and smells OK, then it’s 97% likely OK … To ENSURE it’s OK, add enough ordinary laundry bleach** to disinfect it: … ¼ cup of bleach per 1,100 liter tinaco (300 gal) … completely eliminates bacteria, viruses, microbes. … This free-chlorine concentration is equal to a US public swimming pool … (for about the next 2 days). ?

After adding the bleach, mix the water gently … and wait 15 minutes. … Then flush the toilets, run the sinks & showers … etc to fill your all of your home’s pipes with the nice free-Chlorine disinfectant (bleach) …
Image result for glass of clean water
Allow that water to stand for about 15 minutes … to kill everything that may have accumulated in the pipes.

Then …. use the water as normal.  … Note that there will be a light chlorine smell (like a swimming pool) for the next 2-3 days => thoroughly disinfecting your home’s plumbing !

*       *       *       *        *
As long as you have a good top on your tinaco~cistern, this bleach treatment is likely needed only about twice a year. … If you get dead birds, dead possums, dead iguanas or dead leaves in your tinaco~cistern, in the meantime … then start over. ?

*       *       *       *        *
What if you are not on Merida City JAPAY water?

If you are drinking private well water from TOO SHALLOW wells across Yucatan – or drinking cenote water … then all bets are off. ?

If you are drinking well water from a TOO SHALLOW well, dump a bottle of blue food dye into the toilet … flush the toilet … and turn on all the faucets in the house for about 10 minutes … collecting the water into white containers (like a white bowl) …  then wait 30 minutes,  and run your kitchen sink water again into a white bowl  (and flush the toilet) … and look for blue …

The first 30 ft of water here ACROSS YUCATAN is often contaminated … most often by private homes septic systems.   … That means shallow wells are a problem, but GOOD wells drilled to 18m – 20m almost always have hard, but clean  water …    Why?? … Note that our BIG hard limestone aquatard between 30 ft to 60 ft (20m) ~blocks~ surface contamination from reaching even private wells drilled to 18 – 20m.

Final note … A literal 47 years of scientific measurements show there is very little horizontal (sideways) movement of ground water in Yucatan, with 2 exceptions.*   … Notice that there are NO mythical “underground rivers” flowing in almost all of Yucatan. … 47 years of measurements shows that most (95%?)  of our surface water moves vertically through our limestone.

Notice that if there was lateral-horizontal movement of water in the caves that connect cenotes … then the sediment in this channel would be stirred up by the flow of the mythical “underground river” …

No flowing river here.

*The 2 exceptions to “no under-ground rivers”:  

Near the coasts, the rainwater in the first 10 km – 15 km of rainwater does slowly move out towards the sea.   and … In the hilly areas of Yucatan – like Campeche & Bacalar – the rain water does move downhill underground …

But notice how slow the flow is … from how clear the happy diving-girl image is. ?

Don’t worry …. Be happy …

You’re in Yucatan! ….. Enjoy!