Karachay: The Deadliest Lake in the World

Who doesn’t love lakes?

For many people, a visit to a lake—especially somewhere isolated in the countryside, far away from the commotion of major cities—is a source of leisure, of rest-and-recuperation.

Lakes tend to be serene locations with fresh air, and spending time in their environs was—and remains—a ready source of treatment for individuals suffering from pulmonary illnesses throughout history, with the therapeutic value of the lakeside air seen as relief from many respiratory ailments and urban pollution.

Lakes are also a site of meditation for many people, and the serenity they provide has inspired many of the finest works of poetry and prose in various languages. The Lake District in England, for example, is seen as the inspiration for many of the most famous bodies of work in English, not least those of writers such as William Wordsworth, Samuel Coleridge, John Ruskin, Beatrix Potter, and John Cunliffe—creator of Postman Pat.

Aside from this, many people choose to visit lakes in their various localities to pursue various watersports, to go fishing, or simply to go swimming. The use of lakes for such physical activities is something which has remained consistently popular throughout history until this day, with lake activities alternating between older activities such as sailing and rowing to more modern pursuits such as zorbing and paddle-boarding. Swimming is an activity which has remained particularly present, and which remains a favoured pastime for people at lakes now as it did centuries ago.

But Lake Karachay in Russia—while no less beautiful than any other lake—is probably one of the few in which you would not go swimming under any circumstances.

That is because you would probably die.

Background: The Soviet Nuclear Arms Drive

Lake Karachay is located in the Ural Mountains in Russia’s Siberia. Admittedly, this likely already made it not really suited for swimming in the first place. The lake is located around 85 kilometres north east of the regional capital of Chelyabinsk, a city in which average temperatures in the winter are around -10 degrees celsius, and where the summer temperature has reached a record low of exactly 0 degrees—enough to cause water to freeze over entirely. The mean temperature of the water of nearby Lake Uvildy, one of the largest lakes in the Urals, is—at the height of the summer—only around 18 degrees, so significantly less than the minimum temperature of about 28 degrees recommended for immersion by the American Red Cross’s Water Safety Manual.

The much smaller Lake Karachay, for its part, has a year-round average temperature of around 14 degrees. But cold discomfort is not the primary reason why one would not saunter into it to go swimming. You see, the water is completely lethal.

That is because a legacy of nuclear waste dumping into the lake by Soviet authorities changed the picturesque waters into a kind of Biblical plague, unfit for marine life or human venture. While such a practice was not uncommon in the Soviet Union—and has even been observed in other places too—the sheer amount of garbage spewed into the lake stands it apart from any other, and leads it to rank comparably to its fellow Soviet-era disaster zone of Chernobyl in the volume of nuclear radioactivity generated.

Like Chernobyl, the area around Lake Karachay was a site of Soviet nuclear activity. While the world had stood appalled at the chaotic destruction meted out by the US’ bombing of Hiroshima and Nagasaki in 1945, the Soviet Union stood a little bit jealous. In its endeavour to build its own nuclear-grade weapons arsenal, it constructed a series of sites intended to nurture its nuclear aspirations.

One of these was a planned town codenamed City-40, alternately as Chelyabinsk-40, and today known as Ozyorsk. The town was built to house the workers of a nearby nuclear facility known as Mayak, or ‘Lighthouse’, and City-40 was effectively to Mayak what Pripyat was to Chernobyl.

Mayak was built in 1948 using the forced labour of some 70,000 gulag inmates. It soon became one of the Soviet Union’s most important nuclear development sites. City-40 became only the second city in the world to produce plutonium for use in atomic bombs, after Richland in the US, a town which housed workers contributing to the Manhattan Project at the nearby Hanford nuclear complex, which developed the polonium later used in the bombing of Nagasaki.

Like any nuclear power plant, Mayak produced a lot of nuclear waste. Unlike most nuclear power plants—in the West at least—the waste was not handled responsibly and was instead chucked into the rivers around City-40, exposing the inhabitants of nearby settlements to contend with it in whatever way their anatomy could. Eventually, it was decided to find a single repository in which to pool all this nuclear garbage.

That, fatefully, turned out to be the nearby reservoir of Lake Karachay.

Lake Karachay

The name “karachay” means “black water” or “black creek” in several Turkic languages, such as Tatar. Karachay was not a big lake, measuring only around 0.5 square kilometres or 15 hectares at its peak, and well hidden in the vast expanses of Siberia. It was really more like a natural bog, had a maximum depth of only 1.25 metres, and the total volume of water in the lake was about 400,000 metres cubed. Both Mayak and Lake Karachay were located not only in an isolated part of Russia but also close to the frontier with Kazakhstan— itself a key location in the Soviet nuclear arms project and where the USSR’s first nuclear bomb was successfully detonated—at the Semipalatinsk test site in August 1949.

Given its small size, Lake Karachay was not big enough to provide sufficient cooling water for Mayak’s reactors. It was, however, right on the doorstep of the site, and therefore conveniently close enough that it could be used as a dumping ground for nuclear waste, as was the case with other rivers nearby.

The lake rapidly became incredibly contaminated, but this would reach a whole new level in 1957, eight years after the successful test of the so-called First Lightning bomb at Semipalatinsk, and with the Soviet drive to develop more nuclear capabilities in full flow. That year, the already-high contamination level of the lake went absolutely supernova with what was retrospectively known as the Kyshtym Disaster.

The 1957 Kyshtym Disaster

The disaster took place at Mayak on the 29th of September, when unsafe and irresponsible storage of nuclear materials led to an explosion in an underground cooling tank. This sent huge amounts of nuclear waste such as ammonium nitrate and acetates skyrocketing into the air. The event is considered to be the third deadliest nuclear accident in history, after the 2011 Fukushima Disaster and the 1986 Chernobyl Disaster—which, if the disaster at Kyshtym had been responsibly investigated and learnt from, may have actually been avoided. Unfortunately, responsible oversight was exactly what wasn’t on the menu, and details of the event, as well as the vast scope of consequences, were obscured by the Soviet authorities for many years after.

As the toxic plume from the explosion rose into the atmosphere, it created a radioactive cloud which moved upwards of 300 kilometres from the site of the accident, and resulted in the contamination of an area that was up to 20,000 square kilometres in size. It also resulted in the transfer of 3 billion curies of high level nuclear waste into the wells at sites all around Mayak, much of which dived head-first into Lake Karachay.

After the disaster, nuclear waste was no longer dumped into the rivers around Mayak. But there was nothing to be done about Karachay, which was by now polluted to the gills.

Despite this, the Kyshtym disaster was kept secret by Soviet authorities right up until the end of the Soviet Union, almost certainly exposing the residents of surrounding districts to radioactive contamination for all that time. Details of the extent of the disaster saw light for the first time in the late 1970s, when Russian dissident and agronomist, Zhores Medvedev, published a detailed account of the accident after having defected to the West. He did so first with Hazards of Nuclear Power in 1977, and later in greater depth with The Nuclear Disaster in the Urals in 1979.

While rates of cancer and birth defects in the Chelyabinsk region rose dramatically, the reasons which lay behind this were not common knowledge. And why would they be? After all, City-40 didn’t officially exist: as a closed city, its purpose was kept hidden only to those working there—it didn’t appear on any maps, and non-residents were not allowed to set foot there. Ozyorsk remains a closed city until this day, with access granted only to visitors in possession of a special pass, and likewise even its residents are only permitted to leave with a special pass of their own.

And even the name of the Kyshtym disaster in some ways symbolises the great obscurity of the entire project. Kyshtym is a relatively large town about 20 kilometres west of the reactor at Mayak—no doubt affected in some way by the explosion, but not really the epicentre as the name would suggest.

Any local residents who did think to inquire why certain select population transfers were being carried out by large groups of soldiers in the years after 1957 were met with the information that rising health problems were the result of some vague special disease, and that they should rather swiftly hush their gums on the matter.

It’s generally thought that tens of thousands may have died from the health consequences of the disaster.

Modern Day

Today, Lake Karachay is so polluted that spending 30 minutes there would result in a lethal dose of radiation (around 300 roentgen). Recall how in the hit HBO series Chernobyl, what was believed to be a dose of 3.6 roentgen was enough to cause vomiting, dismissed as “not great, but not terrible”. Yeah, a 30 minute paddle in Lake Karachay would result in a dose of around 100 times more than that. Conclusion: you’d definitely die.

Even just standing next to the lake for an hour would produce the same effect. Although radiation levels are seemingly falling somewhat, it remains one of the most polluted places in the world.

Starting in the 1960s, the lake also began to dry out; its area dropped from 0.5 square kilometres to just 0.15 by the end of 1993. In 1968, a drought in the region caused radioactive dust to be carried away from the drying area of the lake, irradiating perhaps half a million people with 185 petabecquerels of radiation.

To account for its extreme pollution and volatility, between 1978 and 1986 the lake was filled with about 10,000 hollow concrete blocks to prevent sediments from shifting. The lake is now entirely covered by concrete, and inaccessible to the general public.

But even several generations later, children from the area continue to suffer health defects likely related to the mass contamination of the area. Moreover, an article by the International Atomic Energy Agency from the year 2000 stated that the risks posed by the toxic lake had not really subsided. The paper, written by Dr Aleksey Merkushkin of the Moscow Physical Engineering Institute faculty in Ozyorsk, described how a volume of polluted underground water had formed under the lake, swelling hourly.

It went on to mention that contaminated water migrated with a speed of about 100 metres per year, therefore risking approaching a nearby river called the Mishelyak. Dr Merkushkin concluded that if movement of the contaminated fluid continued, radionuclides would begin to penetrate into both the Mishelyak and Techa rivers, potentially leading to further disaster for nearby human populations.

By 2016, further work had been carried out to fill in the lake with even more special concrete blocks, rock, and dirt. The water was first backfilled in November 2015, then monitored before adding another layer of rock and dirt, effectively attempting to cancel the existence of the putrid lake out entirely.

Mayak, astonishingly, remains open and operational. It is Russia’s most important nuclear site to this day.

Frequently Asked Questions

Why is Lake Karachay considered the deadliest lake in the world?

Lake Karachay is considered the deadliest lake in the world due to the massive amounts of nuclear waste dumped into it by Soviet authorities, making the water completely lethal.

What is the origin of the name ‘Karachay’?

The name ‘Karachay’ means ‘black water’ or ‘black creek’ in several Turkic languages, such as Tatar.

What was the Kyshtym Disaster?

The Kyshtym Disaster was a nuclear accident that occurred at the Mayak nuclear facility in 1957, resulting in a massive release of nuclear waste into the environment, including Lake Karachay.

How did the Kyshtym Disaster affect Lake Karachay?

The Kyshtym Disaster significantly increased the contamination levels in Lake Karachay, making it one of the most polluted places in the world.

What measures have been taken to contain the pollution in Lake Karachay?

Between 1978 and 1986, the lake was filled with concrete blocks to prevent sediments from shifting. By 2016, further work was done to fill the lake with more concrete blocks, rock, and dirt to cancel its existence entirely.

What is the current status of Mayak, the nuclear facility near Lake Karachay?

Mayak remains open and operational, serving as Russia’s most important nuclear site to this day.

What are the health risks associated with Lake Karachay?

Spending 30 minutes in Lake Karachay would result in a lethal dose of radiation. Even standing next to the lake for an hour would produce the same effect.

How has the contamination from Lake Karachay affected nearby populations?

Children from the area continue to suffer health defects likely related to the mass contamination. There is also a risk of contaminated water migrating to nearby rivers, posing further disaster for human populations.

What was the initial purpose of Lake Karachay?

Lake Karachay was used as a dumping ground for nuclear waste produced by the Mayak nuclear facility due to its proximity to the site.

Why was City-40 (Ozyorsk) kept secret?

City-40 was kept secret because it was a closed city housing workers of the Mayak nuclear facility. Its purpose was hidden, and it didn’t appear on any maps, with access restricted to residents and authorized visitors only.

Sources

• Original Places video: Karachay: The Deadliest Lake in the World
• https://www.theguardian.com/tv-and-radio/2019/mar/12/how-postman-pat-changed-a-lake-district-village-archive-1994
• https://www.lakedistrict.gov.uk/learning/archaeologyhistory/famouswriters
• https://www.redcross.org/content/dam/redcross/docs/Water%20Temperature%20for%20Aquatics%E2%80%94ADVISORY.pdf
• https://wldb.ilec.or.jp/Display/html/3513
• https://www.bbc.com/reel/video/p095b019/the-huge-nuclear-disaster-hidden-by-the-soviets
• https://www.dw.com/en/germanys-leaking-nuclear-waste-dump/video-69502364
• https://www.worldatlas.com/articles/what-was-the-kyshtym-disaster.html
• https://inis.iaea.org/collection/NCLCollectionStore/_Public/32/015/32015191.pdf
• https://www.chemeurope.com/en/encyclopedia/Lake_Karachay.html#:~:text=History,with%20185%20petabecquerels%20of%20radiation
• https://www.theguardian.com/cities/2016/jul/20/graveyard-earth-inside-city-40-ozersk-russia-deadly-secret-nuclear
• https://www.telegraph.co.uk/travel/destinations/europe/russia/articles/russia-closed-cities/
• Hero image source by Christian Herrmann / openverse, by-sa.