Foul Waters from Russia: How Ukraine Prepares for a Second Wave of Desna Pollution

We meet Leonid Myslyvets, the mayor of Oster, on the banks of the Desna, near the rescue station. He spreads a map of the community over the car hood to show the length of the riverbed—from the village of Bilyky in the north to Krekhaiv in the south, covering over 50 kilometers. Almost every day, rescuers go out on the water here to check if any dead fish have appeared along the shores.

Black Water

Oster lies on the Desna, halfway between Kyiv and Chernihiv. By car, it takes about 1.5 to 2 hours to reach from either city. Just south of the town is the Beremytske Nature Park, where green tourism had been promoted before the full-scale war. However, the russian invasion, followed by russia’s poisoning of the Seym and Desna rivers, significantly reduced the flow of visitors.

The pollution of the Seym in the Sumy region began around August 14, when the first reports of deteriorating water quality emerged. By September, it had reached the Chernihiv region. Social media was flooded with photos and videos showing hundreds, if not thousands, of dead fish along the riverbanks. There were fears that the contaminated water could even reach Kyiv.

From mid-August to mid-September, local authorities and volunteers in the Sumy and Chernihiv regions collected nearly 40 tons of dead fish.

“The poisoned water reached us on September 12. At that time, we set up two small aeration stations along the shore, and from them, we placed tubes into the water—one 40 meters long, the other 70. We punched holes in the tubes, following advice from the department [Desna Basin Water Resources Management],” Leonid explains. “The water is gradually getting oxygenated: our divers went down there and said that fish gather near the oxygen sources to survive.”

We head down to the pier, where we can hear a buzzing sound. These aren’t russian Shahed drones that fly along the Desna at night. Near the water, there are two small pumps, each providing a flow of 400–450 liters [100-120 gallons] per minute. Tubes extend from the pumps into the water, and from the middle of the river, you can see bubbles being carried along by the current.

“The water still isn’t bright and clear enough, but on September 13, let’s say, it was like tar, and there was a dark residue along the banks. Now there’s much less of it. But if the situation worsens, we’ll install more aeration stations—we’ve already arranged with local businesses to add four more of varying capacities,” the mayor of Oster states.

While chatting, we put on life vests brought by Oleksiy, a rescuer. He helps us settle into a boat, starts the engine, and steers us to the middle of the river. We speed upstream. Both banks are empty. Occasionally, a solitary gull soars above the water, or a kite circles high in the sky.

“Fortunately, it didn’t come to a fish die-off in Oster. There’s a key indicator—the level of dissolved oxygen in the water. The normal value is 7 milligrams per cubic decimeter or higher. Ours dropped to 5, and below 4, fish begins to die. Another indicator is chemical oxygen demand, also measured in milligrams per cubic decimeter. The normal level is around 30, but ours reached 50 or more. I know that upstream, it could reach more than 100,” Leonid explains.

A drop in the first indicator and an increase in the second shows that a chemical reaction is consuming oxygen from the water. When fish start dying, they begin to decompose, which also requires oxygen.

“If there’s a fish die-off, they need to be collected quickly. We were prepared for this and are still ready because we read reports of more pollution being dumped into the Seym. The rescue station has six boats and nets to retrieve the dead fish. Even some locals have offered to help. So, I hope we’re ready if it comes to that,” says Leonid.

We approach the boundary of the community along the river. No dead fish are visible along the shores. Currently, in Oster and throughout the Desna and Seym, there is a ban on using the water for any purpose, swimming or fishing. But this doesn’t stop the locals. As we moved upstream, we saw several fishermen: one casting from a boat and two others from the shore. When they noticed us, they pretended they were just relaxing and that the rods and reels weren’t theirs.

“What can you do about them?” Oleksiy chuckles. “Some people just don’t care about bans. I hope they don’t get poisoned. At least at the market, they try to control the sale of dead fish. But how do you control it on the river? Sure, we go out every day, travel upstream. But we can’t be going back and forth all day,” the rescuer complains.

Oleksiy steers our boat into an old part of the riverbed—the natural course of the Desna. The one we had traveled earlier was dug during Soviet times. The Desna, though navigable, was too winding, so they decided to dig a straighter course. During the fish die-off, the old channel became a refuge.

“The fish sought refuge in the old riverbed, these backwaters, to survive. The water here was cleaner—people noticed that. You won’t see it now, though, because the water quality has improved,” explains Oleksiy, peering into the water. “Oh, beaver dens. I hope we haven’t disturbed them too much because beavers are the real masters here,” he adds as we turn back into the newer river channel.

On our way back, we spot tourists with a tent on one of the banks. Leonid remarks that these are the first he’s seen since the river pollution began. Before the full-scale war, up to 300-500 cars would pass through Beremytske Park, that is, its parking lot, every day.

“Usually, from late May to October, people would come to the Desna for camping. In the Oster area alone, there could be as many as 5,000 visitors during the season. Now, the shore is empty. As soon as the news of river contamination broke, people stopped coming,” Leonid explains.

We dock at the shore. The aeration stations are humming. The rescuers tell us that they keep running even during power outages, thanks to a dedicated generator.

How They Dispose of the Fish

The village of Slabyn, located 60 kilometers from Oster, is part of the neighboring Honcharivka community. We meet with the local elder, Serhiy Kraskov, also near the Desna. He’s currently giving an interview to British journalists.

Even though we’re standing on the steep right bank, the wind still carries the heavy, cloying stench of decay from the water. As soon as we descend, the smell hits us with full force. Dark patches are visible on the water, and along the shore, there are black streaks left by residue. However, there are almost no dead fish on the shore—they were mostly collected the day before. Nevertheless, among the shoreline vegetation, some dead crucian carp can still be seen, and a pike about a meter long lies nearby.

“The banks here are overgrown, so a lot of dead fish got stuck there. On Sunday, September 15, we walked along the shore and pulled them out with nets. We had people from the village council, the cultural center, and the medical outpost helping. There were also a few volunteers with boats—they took care of the opposite shore. That day, we gathered almost one and a half tons,” Serhiy recalls.

Simply discarding or burying the collected fish isn’t an option: the decomposition products could contaminate the soil and groundwater. Therefore, a special burial site is needed—a deep pit lined with concrete wells with a concrete bottom. These burial sites are sealed with a similar concrete cover and placed far from water sources and residential areas.

“In our community, there’s still a burial pit left from Soviet times, but it hasn’t been used since the 1980s. I remember talking about it with Chernihiv [the State Environmental Inspectorate in the Chernihiv region] when the foul water reached them, and they were also gathering dead fish,” says Serhiy.

We head out to see this burial pit. It’s a few dozen kilometers of driving along rough field roads. As the car bounces over the bumps, Serhiy continues talking about the die-off: many large fish perished. The biggest one he saw was a catfish about a meter long. They collected bream, crucian carp, and zander, and the most numerous were pikes.

“I don’t know how all this will recover. If both the large and small fish have died, who will lay the eggs? Unless we artificially restock. Plus, maybe something will come down from the upper Desna, where the poisoned water didn’t reach. But even if that happens, who can guarantee that this won’t happen again in a year or two? russia isn’t going anywhere,” Serhiy says in frustration.

We cross the highway connecting Kyiv and Chernihiv and head into dense wooded plantations between fields. In one of these plantations, we stop and get out. From there, we continue on foot along a packed dirt road leading to a deep pit. The closer we get, the stronger the stench becomes. The pit is about four meters deep, roughly the same width, and about ten meters long. If it weren’t for the two concrete wells, it could easily pass for a dugout for armored vehicles.

“Since September 13, I’ve been dealing with this burial pit. We urgently ordered concrete rings from a local business to line the wells. It turned out that in the forty years since it was last used, the burial pit had completely grown over with trees. There was no access, so we had to cut down some of them. Now, we need to lay an asphalt road here,” says Serhiy.

We approach the wells. One is empty, while the other is nearly full of bags sprinkled with chlorine. Despite the concrete lining, puddles are starting to form at the bottom of the pit—a result of the decomposition of the dead fish. The buzzing of green flies, seemingly thousands of them, is unbearable.

“Since we’re a starostat [an administrative unit headed by a starosta—a village elder], bureaucracy moves slowly here: we can’t make quick payments, especially on a Friday evening. But I’m grateful to the local businessmen who delivered the first three concrete rings already on Saturday. And on Monday, September 16, they brought three more. It was all based on trust—they trusted that we’d pay them later. But we needed to bury the fish immediately,” Serhiy explains.

The community ordered a second well just in case, anticipating a larger die-off. However, by September 17, the number of dead fish had decreased, so it wasn’t needed for now.

The filled well will eventually be sealed with a concrete cover and buried. A fence and warning signs will be placed around the perimeter of the burial site so that locals won’t accidentally unearth it a decade or two from now.

New Pollution Incident

On September 17, Serhiy Zhuk, the head of the Environmental Inspection in the Chernihiv region, told UAnimals media that the situation in the rivers of the Chernihiv region had finally improved: “The fish are no longer dying. I can say this because I personally walked along the banks. We still find dead fish, but these are ones that died 3-5 days ago, surfacing from the bottom or from under the roots. Of course, the Seym and Desna waters are still unsafe for swimming. Almost all life there has perished, and an unpleasant odor persists. However, the levels of oxygen, ammonium, and iron are normalizing.”

The Chernihiv and Sumy regions are still calculating the damages, which are currently estimated to be around 450 million hryvnias.

This environmental crime has clear russian involvement. The Department of Environmental Protection and Natural Resources of the Sumy Regional State Administration believes that wastewater from a sugar factory in the village of Tyotkino, in russia’s Kursk region, entered Ukrainian rivers. This conclusion was drawn after analyzing satellite images: they show that in early August, the wastewater accumulation basin at the factory was full, but by the second half of August (when reports of pollution in Ukrainian rivers emerged), it had emptied. Moreover, laboratory analysis of the water found substances “specific to sugar production.”

This is not the first time that russian activities have polluted Ukrainian rivers with wastewater. Oleksandr Yemets, a research associate at the Seymskiy Regional Landscape Park, recalled that this had happened at least twice before: in 2011, when an accident occurred at the treatment facilities in Kursk, and the dam near Tyotkino deliberately released polluted water into Ukraine, and again this year at the end of May. On those occasions, fish and crustaceans also perished. Each time, the incidents increased the risk of extinction for a unique species of the region, the Desman, which is on the Red List of endangered animals.

Unfortunately, this might not be the last such environmental crime. On September 16, the Ministry of Environmental Protection and Natural Resources reported further deterioration of water quality in the Seym. Samples taken in the village of Manukhivka (about three kilometers from the russian border) indicated a drop in oxygen levels. Once again, russia is the most likely source of this pollution. However, identifying the exact origin and cause of the contamination is difficult due to ongoing hostilities in the Kursk region, which borders Sumy.

As of September 25, polluted water reached Baturyn in the Chernihiv region. The dissolved oxygen level, as mentioned earlier, was less than one—ranging between 0.3 and 0.8 milligrams per cubic decimeter. In the Sumy region, between the villages of Mutyn and Ozarichi, the oxygen in the water was completely depleted. The next day, the situation in the Seym in the Chernihiv region worsened further.

The Ministry of Environmental Protection assures that this pollution incident is not as severe as the one in August, and the rivers should be able to recover more quickly. However, if a fish die-off occurs again, the border communities will once again have to collect the dead fish from the banks.

This publication was compiled with the support of the European Union and the International Renaissance Foundation within the framework «European Renaissance of Ukraine» project. Its content is the exclusive responsibility of the authors and does not necessarily reflect the views of the European Union and the International Renaissance Foundation.