In the first months after the Chernobyl disaster, all of the zone’s waterways were metaphorically bitter with radiation. It flowed through the entire aquatic cycle: falling with the rain; filtering through the radioactive cloud that meandered about the western Soviet Union for months; trickling across contaminated surfaces coated with fallout; washing out in the tons and tons of water and chemicals used to decontaminate towns, villages, and the nuclear plant’s grounds.

Winds, water currents, and waves spread the radioactive surface film on rivers and lakes to the banks, creating so-called riverbank anomalies—highly contaminated strips of soil that were at the level of the radionuclide-coated water at the time of the disaster. They were detected in all zone waterways and along the Dnieper basin, from Belarus to the Black Sea.

In the immediate aftermath, one liter of water in the nuclear plant’s cooling pond measured tens of thousands of becquerels of radioactivity, much of it from short-lived isotopes such as iodine-131, barium-140, and tellurium-132 that covered the surface and slowly sank into its depths. But the levels dropped quickly as these short-lived radionuclides decayed and longer-lived isotopes and fuel particles sank into the bottom sediments, although they spiked occasionally when radionuclides were washed out by cleanup works.

As time passed, 95 percent of the radioactivity ended up on the bottom. In closed aquatic systems such as the cooling pond, nuclides and fuel particles penetrated up to 10 centimeters (four inches) into the bottom sediments. Although fuel particles disintegrate more slowly in bottom sediments than in soil, they do cause continuous secondary contamination of water.

In the Pripyat River, bottom sediments nearest the reactor were so contaminated in 1988 that they were classified as solid radioactive waste. But flowing water systems such as rivers gradually dilute contaminants by transporting them downstream. In general, the higher the water flow, the greater the dilution and the lower the contamination. As one result, radioactivity levels in the zone’s rivers fell significantly. A decade after the disaster, most river bottoms in the 30-kilometer zone were virtually clean, measuring tens to hundreds of becquerels per kilogram and—in exceptional cases—in the thousands.

Yet the cleansing of some zone waterways by flowing water has a downside: nearly all of the radionuclides that get out of the zone, contaminating larger and larger regions, travel with water.

The deep crow’s feet around Marian Sikora’s pale blue eyes made him look about 50, though only a little gray sprinkled his brown hair and mustache. A hydrology technician by training, he was deputy director at the tongue-twisting Chernobylvodexpluatatsia agency. That translates roughly as Chernobyl Water Exploitation and reflects a still-Soviet habit of naming things by running the words and syllables together into single unwieldy neologisms. For the uninitiated, the results were slightly more informative than acronyms, but the ridiculously long words often didn’t even save much space on the signage. Chernobylvodexpluatatsia was too cumbersome for anyone to use regularly. The people who worked there referred to it as CheVE, as did I.

I was riding with Sikora in an old CheVE van on the left bank of the Pripyat River. Although it is a major river for Belarus, the 440-mile (710-kilometer) Pripyat is not very significant in Ukraine, which has much larger and economically significant rivers such as the Dnieper and Dniester. During more than a dozen trips to the Ukrainian zone, I had always stayed on the right bank of the river—except when I crossed it to go to Belarus, but that was very brief. The town of Chornobyl was

on the right bank as were the power plant, the town of Pripyat, the equipment graveyards, and just about anything of interest to most visitors. But on this trip I wanted to see something different and the only place to see it—indeed the only place to see anything remotely like it in the world—was across the river from the nuclear power plant.

The darkest colors on the radiation maps marred the spot, including a brown smudge near the village of Krasne that is one of the horns of dense debris from the April 26 explosion. But unlike the other horn, which killed the Red Forest but at least stays put, the right bank horn belonged to a mobile devil that is and will be a persistent threat to the Dnieper River. The reason is that the concentrated contamination lies directly on the Pripyat River’s floodplain. The entire eight-square-mile area contains an estimated total of 10,000 curies of cesium-137 and 6,500 curies of strontium-90. When it’s flooded, the radionuclides leach into the river, which spills them into the Kiev Sea, whence they gradually migrate down the cascade of Dnieper reservoirs that supply drinking water for 20 million people and irrigate nearly 2 million hectares of land in the arid southern steppe.

In 1991, when ice jams near the power plant caused intense flooding of the riverbanks in the 10-kilometer zone, strontium levels in the water reached as high as 12,000 becquerels in a cubic meter of water! Maximum allowable levels in Ukraine are 2,000 becquerels, though actual concentrations in the Kiev water supply are usually in double digits.

It took about 40 days for the contaminated water to travel from the northern part of the Kiev Sea closest to Chernobyl to the southern portion nearest the Ukrainian capital. By that time, the radioactivity had diluted to officially safe levels. But they were still four times higher than normal and caused a lot of anxiety—for me, too, because I had moved to Kiev a month or so earlier.

The ice jams lasted for more than a month and eventually had to be broken up by bombing. When the flooding ended, the river had carried more than 100 curies of strontium into the Dnieper system and the vast majority of it came from the Krasne floodplain.

Something clearly had to be done to keep the floodplain dry. So, after the floods ended, the Ukrainian government transformed the area into a polder. “Polder” is a Dutch word for a parcel of low-lying land reclaimed from the sea, a river, or another body of water and surrounded by dikes and canals that regulate water levels. More than a

third of Holland is below sea level, so polders make up a good portion of the country—including the biggest cities and best farmland.

The Chernobyl polder was, territorially, more modest, but its creation was the most important measure taken to keep radionuclides out of a major Ukrainian water supply. This, at least, was what I had read in numerous articles in Ukrainian scientific journals. The trouble was that none of them described the thing or explained how it worked. An Internet search for “Chernobyl polder” in English produced 129 results. The same search in Ukrainian produced only one result, and in Russian it produced zero. None of the results were useful. So, Sikora was taking me to see it firsthand.

Cleanup barges and ferries rusted in a bay of the Pripyat River under the bridge from Chornobyl. The river was gray under a steely and cool October sky. Some trees in Kiev were still green, but 50 miles to the north the foliage had already turned, though it lacked vibrancy under the dull clouds.

In a few minutes we were at the Paryshiv checkpoint. Actually, its official name was Paryshiv-2, and it was different from the Paryshiv-1 checkpoint I crossed on the border of the Ukrainian zone when traveling to Belarus. Paryshiv-2 was located less than two miles from Paryshiv-1 and was actually a very strange checkpoint because it wasn’t on any zone border and it was nowhere near the nuclear plant. In fact, it was impossible to tell what it controlled. But Paryshiv-2 was a multipurpose checkpoint that secured an intersection. The road we were on led to and from Chornobyl. A second road led southeast, towards the Kiev Sea. Another led northeast to Paryshiv-1 and Belarus.

We wanted to turn onto the fourth road that led northwest to the 10-kilometer zone. Because Paryshiv-2 controlled a four-way intersection, each arm of the intersection was blocked by a candy-striped gate. But the guardhouse stood quite a distance away from the actual crossroads, and the guard had to walk about five minutes to open any of the gates. Compared to the pretty flower-embroidered cottages at the checkpoints in the Belarusian radiological reserve, the Ukrainian post was an eyesore that looked as though it came from a prison camp.

It took more than an hour to drive 12 miles over the paved but potholed road leading past disintegrating villages that once tilled the Pripyat floodplains. Disrobing autumn trees revealed their ruins, dull and dark but for the occasional cottage sporting bright red creepers that flashed with brilliant color even under the gray skies. Flocks of

tree sparrows spilled out of abandoned orchards like brown autumn leaves.

The bright red apples ripening in the trees evidently reminded Sikora of a joke, which he proceeded to tell us:

A babushka at the market shouts: “Chernobyl apples! Get your Chernobyl apples!”

“Don’t say that they’re Chernobyl apples,” says a passerby. “No one will buy them.”

“Sure, people buy them,” says the babushka, “for their husband, their wife, their mother-in-law.”

There was no checkpoint at the border of the 10-kilometer zone itself and not even a sign of where it actually began. My homemade cartographical creation comprising three cellophane-taped pieces of Belarusian and Ukrainian topographical maps had a 10-kilometer circle that I drew with a compass. On the ground, though, the zones had very irregular borders. A length of the “ten’s” barbed wire fencing ran alongside the village of Koshivka, although that was outside the 10-kilometer zone’s borders on my map. Even my guides weren’t sure exactly where the inner zone began.

After passing the only other vehicle we would see on the left bank that day in more than three hours of driving—a CheVE truck in the village of Zymovyshche—our driver turned left onto a dirt path running alongside the railroad tracks that connect the town of Slavutich, built to replace Pripyat, with the nuclear plant. The path tilted down a bit towards the marshes that ran parallel to us, and a few times I had the feeling that we were going to tip over. But we just bumped and bounced along for half a mile and then turned onto a narrow sand dike.

“This old dike was built before the disaster to protect the riverside villages from spring floods,” Sikora said, pointing it out on my map with a stubby finger. “It forms the northern border of the polder.”

A canal on our right ran parallel to the dike’s northern slope and collected floodwaters that splashed up and seeped through its sand barrier. Known as MK-7, the canal followed the four-mile dike from the border with Belarus and drained into the Pripyat River. Some Belarus canals drained highly contaminated water into MK-7, too, and the Ukrainian side had come up with a plan to divert those canals in a

different direction so that they would spill their water much farther downstream, after the radionuclides settled out of the water and into the canal’s sediments.

The dike we were on was part of a land reclamation system that crisscrossed the left bank with channels and ditches for draining the peat swamps and bogs that had once dominated the area. Put into service in 1978, the system was declared unnecessary when the zone was evacuated and abandoned.

With time, however, the channels became clogged with contaminated silt and plants, eventually backing up and flooding nearly 5,000 acres of forest—far more than had been predicted. Highly contaminated with up to 100 curies of strontium and 200 curies of cesium per square kilometer, the re-created wetlands spilled radionuclides into the Pripyat and also impeded firefighting since fire trucks couldn’t get through the swamps. In 2001 the zone administration decided to renew the system, cleaning the radioactive muck out of miles of drainage ditches so that water levels on the floodplain could be controlled as needed. It was a balancing act. The forests had to be drained at the same time that the peat lands had to be kept relatively moist to reduce their risk of potentially long-lived and radioactive fires.

While my digital recorder captured Sikora’s words, I gazed out the van’s window and spotted a bull moose about 20 yards away, loping up the steep banks that led from the drainage channel into a copse of young birches, whose golden leaves trembled in a light breeze.

“Los!” I announced, using the Slavic word.

“What a beauty!” said Leonid, the driver. Like most drivers I’d met in the zone, I knew almost nothing about him and mostly saw only the back of his hair, which was blond. But I did learn that he was a hunter, skilled at spotting animals and birds.

Soon afterwards, he pointed out a black grouse that landed in a forest clearing near the road, and when a flock of partridges emerged from the brush and scurried on the path ahead of us, seemingly unworried and unhurried by our rattling van, Leonid obligingly slowed down and let them go at their own speed until they veered into a meadow.

“Hey, little fellows, take your time,” he said.

“We’re in no rush,” added Sikora.

Whether we were or weren’t in a rush was not up to me. Though I had, as always, planned what I called my “water trip” through

Chernobylinterinform, the agency had delivered me into CheVE’s care, with CheVE escorts and CheVE transportation. Although they were making a special trip for me—Sikora gave no indication that he had been planning to visit the polder that day—I felt as though I was tagging along. Knowing how underfunded all zone agencies are, I later tried to at least reimburse Sikora for gasoline, but he gallantly refused to even hear of it.

He asked Leonid to stop when we came to a lake on our left. Lake Hlyboke, meaning “deep,” was one of the most radioactively contaminated waterways in the zone. It was just across the river from the nuclear station, and the smokestack from the Sarcophagus rose above it on the horizon. The lake had a meandering edge bordered with reeds and rushes. Its still waters reflecting the gray skies looked like mercury.

After climbing out of the van, I turned on my dosimeter, which rapidly beeped out a reading of about 200 microroentgens an hour in the center of the dike. When I laid it down on the steep banks facing the lake, the reading shot up to 800.

“It’s high because this side was facing the reactor when it exploded,” Sikora explained. “Parts of the polder go even higher, into the milliroentgens.”

On the dike’s opposite slope, facing away from the plant, the liquid crystal display hovered around 300.

“The lake used to get flooded before the polder was built and spilled a lot of contamination,” said Sikora. “Although nearly all of the radionuclides are buried deeply in the bottom sediments, flooding can churn them up.”

Radioactivity in some lakes also gets stirred up by wind, circulating waters, and seasonal turnover of the warm and cool layers.

Like the Red Forest, Lake Hlyboke is not a place in which you want to spend too much time, so we piled back into the van after a few minutes and continued our drive along the dike until Leonid turned left onto what seemed a low and broad expanse of sand that hugged the Pripyat riverbank. The eponymous ghost town’s deserted apartment buildings rose from the other side of the river.

“This is the new dike completed in 1992,” said Sikora. “It runs along the riverbank to prevent floodwaters from entering the polder.”

The new dike was seven miles long and seemed lower than the old one, but this was because the latter was narrow, with steep slopes, while the new dike was so broad that I could barely see its gradient. Both

were the same height: about 23 feet above the river. But the new dike was wider to reduce seepage. A sand dike can prevent flooding, but it can’t stop some of the floodwaters from filtering through the pores and spaces between sand grains. The wider the dike, the farther the seeping water must travel and much of it loses power before it can get inside the polder. A canal ran alongside the dike inside the polder to collect whatever water did seep through and also to drain rainwater from the polder, carrying it to a collecting pond, where a pumping station kicked in automatically whenever the water exceeded a certain level. Instead of spilling into the polder and rinsing out radionuclides, the excess canal waters were pumped through pipes into an old channel of the Pripyat River near the village of Krasne.

The waters in the polder canal are far from clean. Rain drains through the contaminated territory, washing out radionuclides—though not all of them equally. Although plutonium will be around for many millennia, it is not very mobile in water. Once it sinks into soil and sediments, it tends to stay there. Cesium-137, which sticks to things in the sediments, also isn’t very mobile in water, although it can dissolve under acid conditions such as those in peat bogs. But in the waters of nonacidic closed lakes such as Hlyboke and the cooling pond, cesium levels have been falling over the years. The exception is the polder, where cesium levels increased in 2001 because mobile forms of the radioactive isotope were flushed into the water during earthworks on the drainage canals.

Strontium is by far the greatest concern, since it is much more mobile and its presence in water has been increasing. Indeed, strontium levels doubled between 1986 and 1994, and they were even higher during the 1991 ice jam. In 2002 the concentration of strontium in a cubic meter of the polder’s waterways averaged around 15,000 becquerels and went as high as 21,000. Strontium will continue to be released as the hot fuel particles dissolve with time.

Floodwaters can also carry radionuclides, especially when bottom sediments get churned. But the nuclides sink rather quickly into the canal’s bottom sediments, and only the upper layers of water, which are relatively clean, get pumped out.

The polder doesn’t completely prevent radionuclides from washing out of the floodplain. It merely reduces the amounts. If the 1991 ice jams flooded out 100 curies of strontium, comparable ice jams in 1999—when Pripyat waters levels were among the highest on record

and floods could have washed out as much as 400 curies—carried out only 50. Altogether, zone ecologists calculate that the polder prevented more than 540 curies of strontium from being carried out by ice jams and spring floods over the years.

Whether this is a lot or a little depends, like most aspects of Chernobyl, on your perspective. Since 1986 the river has swept more than 4,000 curies of strontium and 3,000 curies of cesium out of the zone. Most of this, however, happened in the year of the disaster, when about 1,800 curies of cesium and 750 curies of strontium were carried out. After 1988 the amount of strontium was usually double the amount of cesium because cesium started bonding to elements in the soil at the same time that disintegrating fuel particles started releasing strontium.

Moreover, although it is the largest, the Pripyat is not the zone’s only river. The Uzh is an important Pripyat tributary that flows along the south of the zone while the Braginka flows through Belarus. Both empty into the mouth of the Pripyat. Since 1986 these rivers have together washed a total of more than 12,000 curies of radionuclides out of the zone, but recent years have been contributing steadily reduced shares of that total. In 2001 the three rivers carried out 96 curies. In 2002 the total was 47, and in 2003 it was slightly more than 40—the lowest in the postdisaster period.

It would seem logical that the people who get the highest radiation exposures from consuming this water are the residents of Kiev, because the Kiev reservoir is directly in the path of water flowing from Chernobyl. But actually, only a few percent of an average Kiev resident’s radiation exposure comes from water. In contrast, water is responsible for 10 to 20 percent of the dose lower down the Dnieper basin because the river waters are used for irrigation and thus create a pathway for radionuclides to get into food. Nevertheless, in some country districts of Kiev, the dose from water may be much higher than average because small lakes, heavily used by the local population, were highly contaminated.

“So, this polder system has to be maintained for centuries,” I commented as we trundled along the dike directly across the river from the Sarcophagus.

“If they keep cutting our budget and laying off people, it will fall apart way before that,” said Sikora. “When I started at CheVE six years ago, 240 people worked there. Now there are 172.”

The new dike requires constant maintenance because the river current constantly erodes the sand. Sikora said that CheVE had reinforced parts of it with gravel and rocks but didn’t have enough money to complete the job. Lack of financing plagued all Chernobyl works.

As we drove off the dike, a small flock of cormorants flew out of the polder over the heads of three roe deer whose pelage was taking on its gray-brown winter cast.

Not long afterwards, Leonid spotting a wolf trotting up ahead on the road and gunned the gas with an excited whoop. It wasn’t clear if he was catching up to it or chasing it, but the distinction was lost on the wolf, which scrambled ahead of us, its thick reddish tail bouncing. Just when it seemed that we were about to run right over it, Leonid screeched to a stop that jolted us all and sent my bags flying to the floor. But the wolf was unharmed, and by the time we got our bearings, it had dashed into the thicket.

“After the disaster, there were wolf-dog hybrids because the wolf population was small and there were many stray dogs left behind after the evacuation,” said Leonid. “But when the wolf population stabilized, they pushed out and killed the hybrids. Wolves and dogs are competitors and don’t tolerate each other.”

It was the first time I had ever seen a wolf in the wild. Seeing it from inside a van suited me fine.

The next day was one of those beautiful autumn days when the air is crisp, the sun bright, and the foliage brilliant. Leonid was driving Sikora and me in the 10-kilometer zone on the way to the nuclear plant. The road from Chornobyl to Chernobyl runs roughly parallel to the plant’s artificial cooling pond, although it can’t be seen from the road. The first evidence of its existence comes when the Sarcophagus is in view and the road curves alongside the channel that once discharged hot water from the reactor at the rate of an Olympic-sized pool every 17 seconds. That hot water cooled as it diluted, but the artificial pond’s waters remained relatively warm and never froze in the winter. Many aquatic birds that normally migrated stayed there year-round. But since the last working reactor at the plant was shut down in 2000, most of the cooling pond freezes like the zone’s other waterways.

We stopped near the Chernobyl nuclear power plant’s parking lot, where a small bridge for its service railroad crossed the discharge channel. Since the waters had cooled, fish had started visiting the channel and the bridge was a favorite place for plant employees to toss them leftovers from lunch. Most famous were the giant Chernobyl catfish.

I carefully followed Sikora onto the bridge with the hopes of getting a glimpse of them. Between the tracks and the narrow pedestrian pavement that ran alongside, there were a lot of gaps through which I could see the murky waters below. It was not a very reassuring structure and I kept my eyes on my feet until reaching the middle of the bridge. A beam of sunlight illuminated the waters right beneath us, where dozens of normal-sized fish but no giants swam.

“There are swarms of them at lunchtime,” said a disappointed Sikora as he scanned the waters.

I don’t like heights or bridges—even bridges that were more solid than the one I was on—and I felt as though my glasses were in danger of slipping off when I looked straight down into the water. But when Sikora exclaimed that he saw one, I tightly clutched the handrail and looked down.

The other fish scattered when the predatory catfish entered the illuminated patch of water, its whiskers casting a shadow on the channel’s concrete bottom. It had a big, blunt head and must have been at least six feet long.

Though unsuspecting visitors can occasionally be fooled into thinking that the Chernobyl catfish were gargantuan mutants, they were actually known as wels catfish (Silurus glanis), Europe’s largest freshwater fish. Omnivorous and aggressive, wels catfish can grow to more than 18 feet in length.

As with mammals, no mutant or deformed fish have been discovered anywhere in zone waters. Scientists are stumped as to why, although it may be for the same reason that no mutant mammals have appeared either—if any mutants are born in the wild, they die. Also, the animals that received the worst genetic injuries from the disaster died before they could pass damaged genes to their offspring. Those that were born normal and survived may have been more resilient to radiation, a trait that their progeny inherited.

In fact, one study of 400 crucian carp in Chernobyl lakes found that although the fish showed many genetic changes, their appearance

was completely normal. Another study of channel catfish, which are much smaller than their wels cousins, also found that they looked perfectly normal but had genetic damage such as breaks in their DNA.

The channel catfish were probably descendants of farmed fish. In the early 1980s, the cooling pond was home to one of the Soviet Union’s largest industrial fish farms. Fed artificial clean feed, their radioactivity levels were actually lower than in wild fish, because wild fish eat food that still contains traces of fallout from atmospheric nuclear testing (as do we all). In fact, fish farming in the cooling pond has continued from 1987 to this day. It is experimental, and the fish can’t be eaten, but their young can be grown to maturity in radioactively clean waters.

“That’s a small one,” said Sikora, peering down at the wels catfish under the bridge. “There are much bigger ones in there.”

The catfishes’ size was, in part, a result of radiation—but not because they were mutants. Since fishing is banned in the zone, the catfish can grow to their maximum length undisturbed. Although wealthy businessmen and politicians pay hefty bribes or pull strings to poach some of the zone’s abundant fish or game for sport, few of them are dumb enough—or desperate enough—to catch fish in the cooling pond.

The cooling pond represents what is called a lentic aquatic system. Lentic systems, like lakes and ponds, have standing water or water with weak currents—as opposed to lotic systems, which have running water. Plants and animals in lentic systems are much more radioactive than those in lotic systems because there is no flowing water to dilute the radionuclide concentrations.

Though contamination levels in cooling pond fish have fallen well below the postdisaster high of more than 600,000 becquerels per kilogram, nearly all the fish continue to exceed radioactivity limits more than 18 years after the disaster. In contrast, less than 20 percent of Pripyat River fish are too contaminated to eat safely. But radioactivity levels in the same species of fish caught in the same place on the Pripyat River can differ from 10 to 140 times. In general, the closer fish are to the nuclear station, the higher are their radioactivity levels.

Fishes’ radioactivity levels depend on what they eat and their place in the food chain since they accumulate radionuclides with their food. Little contamination gets in through their skin or gills. As a rule, cesium concentrations increase up the aquatic food chain, with predators such as catfish and pike perch registering the highest levels. But

strontium levels decrease up the food chain. Herbivorous fish can contain a lot of strontium because the nuclide is bioavailable in plants, but nearly 90 percent of the strontium ends up in their bones, which don’t metabolize well. So, when herbivorous fish become food for predators, their radiostrontium is not bioavailable and is excreted rather than absorbed.

The main problem in the cooling pond, however, is not its fish. Other zone waterways, such as Lake Hlyboke, are more radioactive and have more radioactive fish. The problem is that the cooling pond is artificial. Money is needed to operate the pumping stations that maintain its water levels, but since the atomic station closed down, there’s no economic need to keep it going.

Back in the van, Leonid drove us around the back of the nuclear station and then turned right onto a narrow road bordered by a sandy shoulder and trees. It was the dike that surrounds the cooling pond and prevents it from spilling into the Pripyat River, since the former is about 21 feet higher than the latter. But the ever-alert Leonid had spotted what he thought was a snake on the road.

“They should already be hibernating,” he said and stopped the van to hop out for a look. But he didn’t actually put the hand brake on and I noticed that the landscape was moving in slow motion outside the window.

“We’re moving,” I said to Sikora.

“Don’t worry,” he assured me with an utter lack of concern. “We’ll stop eventually.”

We were probably moving at the pace of a slow shuffle, and the van did stop before Leonid got back in and announced that it was, indeed, a snake but a sluggish one. Still, the CheVE guys’ attitude towards auto safety made me wonder about their attitudes towards radiation safety. In general, after more than a decade of living in Kiev, I was still sometimes shocked by the lackadaisical attitudes that were inherited from Soviet times and quite obviously played a role in the Chernobyl disaster.

Soon we came to a control point at the pumping station on the cooling pond’s northern edge, with a view of the nuclear station’s fifth and sixth reactors looming above the opposite bank. Under construction when the disaster struck in 1986, and bristling with radioactive cranes to this day, the reactors were never completed.

The small cubic guardhouse was empty. In fact, there didn’t ap-

pear to be anyone around at all when we all climbed out of the van and walked past some tilted telephone poles and rusted metal structures that littered the grounds. Tall grasses grew from cracks in the concrete. Radiation levels at the center of the dike hovered around 50 microroentgens an hour.

Wind carried a light spray from the churning waters that the groaning pumps have had to pipe in from the Pripyat River since the nuclear plant was shut down and stopped discharging its hot waters into the cooling pond.

According to various estimates, the artificial pond’s nine square miles contain anywhere from 450 to 7,000 curies of radioactive cesium, strontium, and transuranic elements. Most of it is in the bottom silt and concentrated in about a third of its area, near the northern portion where we were standing, although the few hundred feet closest to the pumping station are the cleanest because of the uncontaminated river water flowing in. Fish caught there display a greater variety of radioactivity levels than in other parts of the cooling pond because they include clean specimens that reside there permanently as well as visitors from more contaminated sections.

The need to maintain water levels by pumping water from the Pripyat has also introduced some river species, such as Ukrainian brook lampreys, into the pond. If the pumps stop replenishing the cooling pond with river water, much of it will eventually either evaporate or filter through the sand dikes into the Pripyat River, leaving behind a series of small radioactive ponds and exposing up to six square miles of radioactive sediments. The risks of such a development were seen in the Soviet nuclear weapons complex in 1967, when a contaminated lake in the Urals dried out during a drought and winds blew radioactive cesium, strontium, and cerium up to 75 kilometers away.

A similar situation, though on a far smaller scale, occurred at the Savannah River nuclear site in the United States, where nuclear weapons reactors spilled some radioactivity into their cooling ponds in the mid-1960s. Radioactivity levels in the ponds’ flora and fauna have been declining steadily since then and were pretty much back to normal by the late 1980s. But in 1991, water levels in one of the ponds had to be lowered for repairs on a dam, temporarily exposing the contaminated sediments. As a result, some waterfowl such as coots showed high levels of radioactivity that had not been seen in decades.

The Chernobyl cooling pond is also a significant source for con-

tamination of groundwater that then flows into the Pripyat River, but cleaning up the pond is practicably impossible. The costs, in terms of finances and occupational radiation doses, would be too high and there is no place to put the radioactive waste that would be recovered.

So, what to do with a cooling pond that no one needs and costs money to maintain? One option is to keep replenishing the pond with water so that it doesn’t dry out. Another is to lower the water levels gradually and cover the exposed sediments with plants that will help prevent erosion.

Sediments aren’t the only problem. The cooling pond contains about 100,000 tons of radioactive organisms that will eventually die and decay if it is allowed to dry out. That prospect poses not only sanitary problems but also radiological issues since the radionuclides will get out of the aquatic ecosystem where the water keeps them relatively isolated from human populations.

For example, much of the cooling pond’s bottom is covered with zebra mussels. Named for the striped pattern on their shells, zebra mussels originated in Eastern Europe but expanded westward in the eighteenth and nineteenth centuries. Discovered in Canada in 1988, they have become a serious aquatic pest in North America, disrupting ecosystems and clogging water supply pipes of hydroelectric and nuclear power plants with their extremely high densities, which can reach as much as two to three kilograms per square meter.

Although each individual mussel is small—less than an inch in length—collectively they can play a decisive role in radionuclide cycles. Together, they filter six percent of the cooling pond’s water each day. Filter feeders that tend to the bottom of the cooling pond, they are in close proximity to the radioactive sediments and filter them whenever they get stirred up. Also, since they are near the bottom of the food chain, they pass on radionuclides to the fish that eat them. Even in 2002, a kilogram of zebra mussels in the zone’s most contaminated waterways contained as much as 27,000 becquerels of cesium and 62,000 becquerels of strontium. Strontium levels are especially high because about half of a normal mollusk’s shell is made of calcium which, in Chernobyl mollusks, gets replaced by radiostrontium. Moreover, dead mollusk shells continue to adsorb cesium and strontium from water. Radionuclide levels in dead shells can exceed those in live ones. Fish species such as roach whose diet consists almost exclusively of zebra mussels are especially radioactive.

Zebra mussels in the cooling pond are not leaders in radioactivity levels. But there are simply so many of them that their total population is estimated to contain about 400 billion becquerels of strontium, or 11 curies.

The problem of exposing radioactive bottom sediments is not limited to the cooling pond. The flow of radionuclides from the Pripyat River into the Dnieper has broader implications. Were the Dnieper still a natural river, those radionuclides would have largely washed out into the Black Sea. And some, in fact, did. Indeed, a research expedition to drill the Black Sea bottom for radionuclides ended up discovering that around 5000 B.C.E., the Black Sea, which was then a freshwater lake, was suddenly and catastrophically flooded by saltwater from the Mediterranean. Some scientists speculate that its transformation from a relatively shallow lake into a deep and brackish sea may be the real event behind the biblical flood story. But in Soviet times the Dnieper River was transformed into something called the Dnieper Cascade—a series of six giant reservoirs connected by small sections of the natural river. To flood the 350 square miles needed to create the Kiev reservoir, dozens of villages southwest of the town of Chornobyl had to be evacuated from the banks of a 50-mile stretch of the Dnieper River. One of those villages was Teremtsi, which is an evacuated village in the zone.

The reason it was in the zone instead of being under water was that it was right on the border of the area to be drowned. So when the villagers petitioned Soviet authorities to let them stay, they received a positive response. After the reservoir was filled and fishermen could see the bell towers and domes of drowned churches in its depths, some Teremtsi residents returned—until they were evacuated again in the wake of Chernobyl.

As with many Soviet schemes to change nature, the Dnieper Cascade is largely an environmental disaster. The reservoirs are shallow, too warm, and plagued by algal blooms, and periodically there have been calls to drain them. But even when such proposals are seriously entertained—and they usually aren’t—the bottom sediments of all the reservoirs are contaminated. Some predatory fish in the Kiev reservoir still exceed permissible radioactivity levels. But if the reservoirs are allowed to dry out without some kind of countermeasures to prevent their erosion, their radioactive sediments will eventually blow away in the wind.

Driving west on the cooling pond’s dike, we passed about a dozen camouflaged CheVE workers, and Sikora asked Leonid to stop the car so that he could check on them. He explained that they had put up a pumping station to drain a pond that formed when a protective dike was built on the right bank of the Pripyat River.

“The pond formed on a very contaminated area and when the water levels get high, they flood the nuclear station’s basements. So, we set this emergency pump to pipe the excess water into the cooling pond. Eventually, we’ll set up a permanent pumping station,” explained Sikora, lighting a filterless cigarette before heading off to give some epithet-laced orders to the crew.

Given the cooling pond’s uncertain future, it was not clear where exactly the permanent pumps would be placed or where they would drain the water. But the temporary pumping station was on a concrete platform built on an old canal. It ran parallel to the cooling pond’s dike to drain the water that filters through the sand. It was only partly successful. In high-water years, most of the radionuclides that the Pripyat carries out annually are from flooding the contaminated floodplains and the polder. But in low-water years, radionuclides are contributed by other sources such as groundwater and polder waters that filter through the dikes. A quarter of these “low-water” radionuclides filter in from the cooling pond.

Ducks swam amid the tall cattails, with their familiar brown pokers of seeds waiting to burst in the spring, and some of the pump operators amused themselves by making duck calls and chuckling in response to their quacks.

One side of the canal was ringed with yellow flag iris plants, their seed capsules looking like small green bananas ready to split and release their brown seeds. A young weeping willow was littering yellow leaves around them. But I was more interested in the water, which looked from a distance as though it was covered with pond scum. The green floating gook that is made up of blue-green algae, diatoms, and filamentous algae concentrates radionuclides. In the spring of 1987, some samples of pond scum in the cooling pond contained tens of millions of becquerels of cesium-137 per kilogram! By 1999, cesium levels had decreased significantly, but they still reached 200,000

becquerels at a time when most plants registered only a few tens of thousands.

When I clambered carefully down the uneven gravel that bordered the canal, instead of pond scum I saw what looked like a mat of green lima beans floating on the water. It was duckweed, one of the smallest and simplest of the flowering plants and a frequent resident of ponds, marshes, and quiet streams. The individual duckweed plants hang together in masses and often cover the surface of ponds.

My dosimeter rapidly squeaked a reading of about 200 microroentgens per hour when I crouched on the gravel by the canal’s edge for a closer look. This was quite high, given that the canal was surrounded by fresh cement and gravel. Although I was tempted to try to pick out some duckweed for a closer look, the rocks were slippery. I was game for taking some risks for a good story, but falling into such a contaminated canal was not one of them. A damsel fly buzzed lazily over the water’s surface, but there were few other insects given the early autumn temperatures.

Though each duckweed plant consists of a free-floating, oval frond less than three-eighths of an inch, the plants often appear to be in clusters of two to five. The clusters are actually duckweed reproducing asexually. Each duckweed plant is a single individual that produces buds from which new duckweed plants grow. For a time the offspring stay attached to the mom frond, forming temporary frond families.

Radiation seems to damage the plants’ spatial orientation in frond formation. Like the twisted pine bushes that can be used to identify radioactive waste dumps, twisted duckweeds are signs of high radioactivity levels in water. Duckweed is either right- or left-sided, depending on the direction in which its daughter fronds grow. Some studies show that radiation inverts the “sidedness.” Fronds in right-sided plants become left-sided and vice versa. The higher the radioactivity levels, the greater the percentage of inverted forms. Unlike twisted pine trees, however, these are forms that only scientists can see. If the duckweeds in the canal were inverted, I couldn’t tell by looking at them.

Back in the van, we drove down a deep sand trail that passed through colorful autumn woods towards the Pripyat River, but at some point the going got too rough for the van and we climbed out to walk across what looked like a wide beach but was actually an alluvial dike built to prevent spring flooding of a highly radioactive patch on the right bank

of the Pripyat River. Unlike the left-bank flood plain, which raised alarms in 1991, no one had worried too much about the right bank for much of the postdisaster period because it was at a relatively high elevation not vulnerable to flooding. But 1999 was a record year for spring flooding—the third-highest water levels in more than a century. The walls of CheVE’s offices in Chornobyl are decorated with aerial photographs depicting complete inundation of the contaminated right bank.

A short distance away, a lake mirrored the sky as I followed Sikora through deep and loose sand that displayed fresh moose prints. The alluvial sand, pumped up from uncontaminated layers of the Pripyat River bottom, was scattered here and there with fragments of shell from freshwater mollusks such as zebra mussels and snails. With a diet that consists of detritus—bits of matter from decomposing organisms—the snails had very high radioactivity levels in their muscle in the first two years after the disaster because the radionuclides stuck to the surfaces of things in the water, including detritus. And since very tiny things like detritus have higher surface areas compared to large ones, detritus-eating organisms accumulated a lot of radioactivity. The levels in the snails’ muscles went down in subsequent years when nearly all of the radionuclides washed off and sank deep into the bottom sediments. But like zebra mussels, the snails continued accumulating strontium-90 in their shells.

We were on the southeastern side of the highly contaminated patch, which did not itself have an official name. “Right-bank floodplain” was the only name I ever heard. Like the Red Forest and the polder, it suffered the heaviest fallout from the initial explosion and was colored brown on the radiation maps. Each of its five square kilometers was contaminated with as much as 1,600 curies of cesium and 450 curies of strontium.

On the edge of the lake, with the Sarcophagus looming over the horizon, Sikora showed me two shallow impressions that Chernobyl ecologists had experimentally planted with willow to see how it would prevent erosion if higher-ups in Kiev ever made a decision to drain the cooling pond. Grasses and a thick layer of thatch had also appeared.

“It keeps the wind from raising the radionuclides,” Sikora observed. “But look at all that dry grass. Heaven forbid there’s a fire.”

Cattails, rushes, and wind-burned reeds grew thickly around the edges of Lake Azbuchyn, which ranks up there with Lake Hlyboke in

the polder as one of the zone’s most contaminated bodies of water, although the ranking depends on which radionuclide is measured. Plants in Lake Hlyboke have the highest cesium-137 levels in the zone, running up to 36,000 becquerels per kilogram in 2003. But plants in Lake Azbuchyn have the highest strontium levels, with an average of 4,300 becquerels per kilo and a maximum of 24,000.

Actually, the average radioactivity levels are not very informative. If I collected a bunch of rushes from the same place on the edge of Lake Azbuchyn, there would be huge differences in their radioactivity. Indeed, the differences could be as high as 140 times because of the patchy contamination of the bottom sediments. Nevertheless, higher plants are more convenient for monitoring aquatic radioactivity than, say, fish. Fish move around, and therefore sampling always involves a certain randomness, while plants stay put.

As a rule, emergent plants such as sedges, reeds, and rushes—which are rooted in the underwater sediments where radionuclides are concentrated but emerge from water into the air—have the highest levels of cesium. The lowest levels are in plants that float on the surface of the water. But this is not true of strontium. Its highest levels are found in pondweed, some species of which have floating leaves that intensively absorb calcium—or its Chernobyl substitute, strontium—on their surfaces during photosynthesis. This makes them promising plants for radiation monitoring.

Unlike aquatic animals, which continue to accumulate radiostrontium in the course of their lifetime—and in Lake Azbuchyn the average strontium concentrations in a kilo of zebra mussels exceeded 50,000 becquerels in 2002—the aquatic plants were beginning to lose theirs as the growing season drew to a close. This could be because parts of the plants were dying and the oldest parts, with the highest accumulations of strontium, were falling to the bottom of the lake. The cooling waters were slowing biological processes, making strontium less soluble and affecting the plants’ ability to absorb it. The shortening days were also decreasing photosynthesis, which in turn was slowing the plants’ accumulation of nutrients and of the radionuclides that mimic them. The real reason could be all of the above or none. Because of budgetary shortfalls, there is barely enough money to monitor the radiological situation and almost none to study it.

My dosimeter displayed 1,000 microroentgens (or one milliroentgen) an hour when I followed Sikora up a moss-covered concrete stair-

case that climbed a steep, grassy incline. It was a hot spot indeed, although I had no idea of what he planned to show me until we reached the top and I saw that it was the railroad track of the Slavutich-Chernobyl line. The elevation provided a panoramic view of the Pripyat River’s floodplain. The track must have been decontaminated because the dosimeter calmed its excited squealing and dropped to a very normal 13 microroentgens.

Sikora pointed north of the tracks at a wide expanse of sand that peeked in and out of the vegetation on the Pripyat’s riverbanks. He explained that the sand was a new, two-and-a-half mile dike built to protect the right-bank floodplain. It connected with the cooling pond’s dike that was beyond the forest south of the tracks, enclosing the patch of contamination. Although the need to protect the patch was recognized in 1999, the dike wasn’t actually completed until 2004 because there was no financing.

Another problem is that the Pripyat is an active, young river. After the last Ice Age, glacial meltwaters turned Polissia into a huge freshwater lake known as the Polissia Sea that was eventually transformed into wetlands and the Pripyat River basin, with its numerous tributaries, enormous floodplain, complex and diverse landscape, and large number of floodplain lakes, bays, and tiny streams.

The river continues to actively dig its channel with the friction of flowing water on its banks and bed, but parts of those banks are contaminated with up to 100 curies of strontium per square kilometer and more. So, channel digging and the attendant erosion spill contamination into the river. A 4.7-kilometer section of the river between the railroad bridge and the village of Kosharovka had to be reinforced to prevent this.

“And that’s Lake Daleke,” Sikora said, pointing south of the tracks at another lake that was even closer to the plant than Lake Azbuchyn, though it was marginally less contaminated. In nearly all the radiological monitoring of cesium and strontium levels in the zone’s waterways, Lakes Azbuchyn and Hlyboke vie for first place, while Daleke is usually a close third.

Some strangely sexy things seem to happen in those lakes, too. In what may be an effort to resist the effects of radiation, aquatic worms that are capable of both sexual and asexual reproduction are more likely to have sex in Chernobyl than control worms outside the zone. Asexual reproduction means that each worm’s offspring is stuck with

whatever genes its parent had, while sexual reproduction causes genetic mixing that allows natural selection to promote genes and gene combinations that increase resistance.

The lakes reflected fall foliage under the brilliant blue of the October sky, and I thought it hard to believe that something so beautiful could be so deadly. Yet, as we walked back to the CheVE van, I wondered if it was correct to call them deadly at all—although “lethal,” “deadly,” and similar adjectives are often used to refer to radioactivity, whatever the amount or the source. But my body is radioactive, as is yours and that of every single person on the planet. And while I may, on occasion, get very angry, I am not deadly.

Yes, the lakes were radioactive, and no, I would not go swimming in them or drink their waters and I didn’t even want to be near them for very long. But they were not radioactive enough to kill with any certainty of time or place. The plants and animals in their waters were very much alive and, given the lack of human disturbance, might be even more plentiful than if the disaster had never happened. I was reminded of the restored—and very radioactive—peat mires in Belarus that had become beautiful and haunting magnets for aquatic birds.

As we drove past the decommissioned nuclear plant that had caused so much human heartache, I had mixed feelings about thinking something positive could have come of the disaster. But then I wasn’t sure if a radioactive nature preserve was a good thing or a bad thing. I wasn’t even sure if it could be called “natural” if it was radioactive, not because of the slight radioactivity with which creation endowed our planet and which is a part of us all, but because of the great (and truly deadly) amounts of the stuff produced by human effort and error. I was certain, however, that nature was refusing to abide by the absolute definitions we try to foist on it. Endangered species rebound in war zones, while grizzly bears struggle to maintain their numbers in protected areas such as Yellowstone Park. Chernobyl wildlife was thriving.

The van bounced and creaked over a paved, but rough, road that led from Chernobyl to a peninsula on the Pripyat that formed the Yaniv Zatok, or Yaniv Bay, named after the buried village of Yaniv just outside the nuclear station’s grounds. In nearly all the literature I had read about Chernobyl’s impact on aquatic systems, it was always mentioned as a significant danger. But like the articles about the left-bank polder, little of the literature about Yaniv Bay described the problem in a way

that was comprehensible to someone who wasn’t already an expert. All I knew was that it was a comma-shaped arm of the river, directly across from the polder, and stained the same shade of brown on the contamination maps.

The landscape on either side of the road was littered with sandy humps and bumps topped with triangular orange trefoil signs and Cyrillic letters that transliterate as PTLRW—the points for the temporary location of radioactive waste that were Valery Antropov’s biggest headaches in Chapter 1. Antropov had told me then that they used to think there were 800 of them, though in fact they had lost count and many had become flattened and thus invisible with time. Wherever they all were, they seemed to be everywhere alongside the road to Yaniv Bay. After more than a dozen trips to Chernobyl, I had never seen so many leaky radioactive waste dumps in one place.

Three tall cranes that used to unload ships in the Pripyat town port were silhouetted behind the deep crimson of some maple trees. A huge flock of migrating cormorants dotted their rusting and radioactive cables like musical notes. I asked Leonid to stop so that I could take a closer look with my binoculars and also measured out an hourly reading of 200 microroentgens on my dosimeter.

We went up a steep incline of deep sand, and Leonid parked the van near a small blue building with a gabled roof and white trim. Its cheerful colors looked incongruous on the desolate sands surrounding us when Sikora led me to the entrance and unlocked the metal door that announced the structure was paid for by the United Nations Development Agency in 2002. There was nothing inside except a simple little room, about 10 feet square, containing a wooden table, a chair, a broom, and a gauge on the wall.

Sikora explained that the system also included a metal plate attached to the riverbed and a sensor that regularly sends the plate an acoustic signal. The sensor determined the water level on the basis of how long it took the signal to bounce back.

“We send someone here once a week to download the data into a laptop,” said Sikora, leading me out and locking the door.

We crossed a broad expanse of sand that narrowed into a dike imprinted deeply with tractor treads. It was built right after the disaster, together with more than 130 other hydrological systems intended to prevent flooding and radioactive runoff. But they were built at a time when no one in the world had experience in cleaning up such a

disaster and nearly all of the systems quickly silted up, leading to even more flooding. Almost all of them were taken apart and replaced with new ones.

One of the few to stand the test of time was Dike No. 3—the one we were walking on. After walking for about five minutes through a forest of young (and normal-looking) pines, we came to the place where the dike cut off Yaniv Bay from the Pripyat River. Sikora explained that the purpose was to prevent spring floods from raising waters levels in the bay because the lands around it were littered with all the PTLRW we had passed on the way there. When water levels in the bay are high, they flood the radioactive waste, flushing radionuclides into the water. The dike was supposed to prevent them from ever getting that high.

“Why did they bury radioactive waste here, by the water?” I asked Sikora, although I knew what the answer would be.

He shrugged in response. “No one was thinking about the ramifications then.”

Although Dike No. 3 had served its purpose quite well, it didn’t completely prevent water from filtering through the sand, which was why, when we arrived, there was a confusing bustle of CheVE activity involving trucks, earth movers, and small mountains of alluvial sand. Diesel fumes clung to the air when I followed Sikora to a freshly dug trench containing a big black pipe that lay perpendicular to the dike’s length.

“This pipe will eventually link the river and the bay,” he told me as I followed him towards the bay across a temporary path of flat blocks covered with mosaic tile, as though they had come from a swimming pool. He showed me a large box with mysterious innards that he said would automatically drain water out of the bay whenever it exceeded a certain level.

Ringed with scarlet maples, yellow birches, and the beiges of beech trees, the bay was lovely in its autumn reflections. But through my binoculars, I could see some of the little triangular trefoil signs that dotted the woods around its shores. They had some elevation and weren’t right on the water.

For a time, at least, it seems that they won’t get flooded. But they do pose other dangers to the water.

Semykhody was a ghost village long before the Chernobyl reactor exploded. Although it is on all the topographical maps in a place that appears to be located right on top of the nuclear station, there is actually no evidence of its existence. The Chernobyl cultural expeditions that the Ukrainian Ministry of Emergencies sponsors to collect artifacts from abandoned villages have been looking for evidence of Semykhody’s existence for years, without success.

But place names are far more enduring than the memories of those who bestowed them, and even the memories about those who bestowed them, which is why another bay of the Pripyat River is named for Semykhody. Located about a mile upriver from Yaniv Bay, Semykhody Bay is much smaller but about equally contaminated. Like Yaniv Bay, it is also cut off from the river by a sandy dike.

We had to drive around the town of Pripyat to get there, passing the nuclear plant and a construction site on the road where a deep excavation clearly showed the new layers of roadway that were put down after the disaster to cover the contaminated surfaces. Actually, it was very rare to see any kind of roadwork in the zone except for patched potholes here and there on the main roads in Chornobyl and around the nuclear station. Even pothole patching was inconsistent.

But Sikora explained that the excavation was not to fix the road. It was to lay pipes to a new decontamination facility for the nuclear workers who would eventually work on decommissioning the shut-down reactors and dealing with the radioactive mess inside the Sarcophagus.

We were heading for a place informally called the Sandy Plateau, which does not appear on the topographical maps but ended up looking exactly as its name would suggest. To create new land for the town of Pripyat’s planned expansion, several acres of alluvial sand had been pumped out of the Pripyat River between Yaniv and Semykhody Bays. I forgot my dosimeter in the van when I trudged through the sand behind Sikora, so I didn’t know what the radioactivity levels were, but the area was colored the darkest shade of red on the radiation maps, meaning that the disaster dumped around 500 curies of cesium there in 1986. There was actually almost nothing interesting to see on the Sandy Plateau, but the reason I went there was not because of what could be seen but because of what was invisible—or at least invisible to the unaided eye.

For about 15 years after the Chernobyl reactor exploded, the zone was considered a kind of protective radiation sink that kept radionuclides relatively fixed in the layers of soil and sediments where their harm to the general population could be minimized. But this changed in 2002 when nuclides, especially strontium-90, started appearing in the groundwater. One of the places where such contamination was detected was the Sandy Plateau.

Probably like many people, I have always imagined groundwater to resemble vast underground lakes or rivers that are all interconnected and that we dip into with buckets and pipes. So, when I first read that strontium had penetrated the water table—which is the top of the groundwater—I imagined these subterranean flows of radioactivity that would spread into drinking water far beyond the zone, including my own faucet in Kiev. In fact, the groundwater is in layers of permeable rocks with fractures and pores that hold water from precipitation like sponges. When those waters are easily transferred to wells and springs, the water-bearing rocks are called aquifers.

The zone has three primary aquifers, all created by events that occurred many millions of years ago and containing water that can be hundreds and sometimes thousands of years old. The town of Chornobyl gets its water from rocks deposited during the Eocene period around 45 million years ago. The nuclear station’s water supply is from Cretaceous rocks deposited around 150 million years ago, during the age of dinosaurs. More than 18 years after the disaster, cesium and strontium levels in a cubic meter of these aquifers were less than 25 becquerels, which is so low as to be within the margin of error. But the quaternary rocks that were deposited in the last 2 million years and are therefore in the shallowest layers are a different matter. In some places, these quaternary layers are becoming contaminated.

Where exactly depends on the source of the radioactivity. There are two major sources in the zone and two ways that it can get into the groundwater. The “diffuse” source basically consists of the entire zone and all of the radionuclides that are now in virtually everything in the environment: the soil, plants, and animals. They contribute little to groundwater contamination. In nearly all places in the zone, strontium levels in a cubic meter of groundwater are usually double-digit becquerels and don’t exceed a few hundred. Cesium levels are even lower.

The problem is from so-called point sources: the leaky nuclear

waste dumps in the hundreds of PTLRW around the zone. Highly contaminated sediments in the radioactive lakes and bays such as Semykhody and Azbuchyn are also point sources, as are the Sarcophagus and the very grounds of the nuclear plant. Although the reactor debris that littered the grounds was bulldozed and the territory was covered with fresh asphalt and concrete during the cleanup, a good deal of radioactive material remains in the soil below, where drilling has revealed groundwater contamination.

After the turn of the third millennium, significant levels of radioactivity began appearing in quaternary groundwater deposits beneath all of these places. This is another reason Yaniv Bay is so dangerous, even if the new pumping station helps prevent flooding of the waste dumps. Rain trickling through the radioactive garbage washes radionuclides into the soil, and from there some travel into the groundwater. In 2000, test drills in Yaniv Bay found a maximum of 400,000 becquerels of strontium in a cubic meter of groundwater! Levels were lower in 2002—270,000—but this is still more than 100,000 times maximum permissible levels. Similar contamination levels are found in the groundwater beneath the Red Forest—where the buried trees that took the deadliest blow of radioactivity are gradually decomposing, releasing their vast stores of radionuclides into the soil. But Yaniv Bay is much more dangerous because of the Pripyat River’s proximity.

No other point sources of groundwater contamination have such high densities of radioactivity. The maximum strontium level measured under the cooling pond, for example, was 4,800 becquerels in a cubic meter. Another point source of radioactivity is the official waste disposal site in Burakivka, which I visited in Chapter 1. The clay seals there seem to be working quite well, and contamination of the ground beneath them is within safety limits. Some scientists nevertheless caution that the network of drills at the site doesn’t allow monitoring of groundwater under any of the trenches and there are no drills at all between some rows of trenches.

Most groundwater contamination remains localized, right under the point source. Yet although it is hard to generalize about groundwater, it does not always stay in one place. When it does move, it usually goes downwards because gravity pulls it towards the center of the Earth, but it can also move sideways. A particular aquifer’s qualities—its thickness, depth, the type of rock, and a multitude of other factors that make up what are very complex systems—determine how and

where the groundwater will move. In the zone, the groundwater’s lateral flow is generally towards the three main rivers—the Pripyat, Uzh, and Braginka—all of which drain into the Kiev reservoir. But all of the point sources of groundwater contamination are in the Pripyat River basin.

How much of the strontium in that water actually gets into the river and thus into the water supplies down the Dnieper Cascade is uncertain. Ukrainian geologists predict that radionuclide migration under the point sources will intensify 20 to 30 years after the disaster, creating a multitude of groundwater plumes that will constantly pour contamination into the Pripyat. However, some think that there will not be a great risk outside the zone because the radionuclide resides in the groundwater for a long time during which some of it decays. What doesn’t decay will dilute as it travels downriver.

When groundwater gets contaminated, however, it’s not always clear why. For example, one drill in the Sandy Plateau, not far from the Pripyat River, found 100,000 becquerels of strontium in a cubic meter of groundwater that was 15 meters (50 feet) deep. At a depth of four meters (13 feet), the level was 130,000! Anomalously high radioactivity levels have also been detected on the riverbank between the Sandy Plateau and the railroad bridge about a mile downstream. Scientists aren’t sure exactly why this should be so. Although it is highly contaminated, the Sandy Plateau is a diffuse rather than a point source of radioactivity and could not have been the origin of such high levels of radioactivity in groundwater.

One possible explanation I read was that the concentrated radionuclides may be from groundwater flowing to the river. But when I asked Sikora about this, he seemed dubious and dug into the sand with his heel. “There is an old sewage pipe underneath here that connects Yaniv and Semykhody Bays. It was laid before the accident when they were preparing to expand Pripyat. But it’s on the bottom of the bays where all the radionuclides settled. It’s probably leaking.”

It was hardly the first time that I had read something in a scientific journal, taken copious notes, and then traveled to Chernobyl to see it firsthand only to find out that what I read might be completely wrong. Or it might not be. The scientists who wrote the articles might not know about the sewage pipe. Or Sikora might not know the scientists or the results of their research. When I told him of the groundwater contamination under the Sandy Plateau, it was news to him.

I do not mention this to doubt Sikora’s word. Not once during any of my Chernobyl travels did I ever feel that he or anyone was deliberately lying or misleading me. Rather, I mention it to point out how much about Chernobyl remains unknown and disputed.

And perhaps one of the greatest mysteries is the disaster’s impact on people.

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