Trucks supply clean drinking water to Cipreses after their local water source was found to be contaminated with a fungicide used extensively by local farmers for decades. Photo: José Diaz

‘Water is sacred too’: How a pesticide banned in Europe robbed a Costa Rican town of its drinking water

Authorities have been trucking clean water to the mountain town of Cipreses after its tap water was found to be contaminated by chlorothalonil, a pesticide banned in Europe but still sold in Costa Rica by European companies. In a country without the means to test for this kind of pollution, Cipreses may be the tip of the iceberg.

Trucks supply clean drinking water to Cipreses after their local water source was found to be contaminated with a fungicide used extensively by local farmers for decades. Photo: José Diaz

‘Water is sacred too’: How a pesticide banned in Europe robbed a Costa Rican town of its drinking water

Authorities have been trucking clean water to the mountain town of Cipreses after its tap water was found to be contaminated by chlorothalonil, a pesticide banned in Europe but still sold in Costa Rica by European companies. In a country without the means to test for this kind of pollution, Cipreses may be the tip of the iceberg.

Trucks supply clean drinking water to Cipreses after their local water source was found to be contaminated with a fungicide used extensively by local farmers for decades. Photo: José Diaz


Álvaro Murillo

This is an Unearthed and Public Eye investigation

The news that the first tanker of clean water was on its way to Cipreses was proof to residents who had raised the alarm about pesticide contamination that the government was finally taking them seriously. The authorities decided to start delivering water to the small Costa Rican mountain town by truck after lab tests of local water sources found residues of the fungicide chlorothalonil, at levels up to 200 times greater than the legal limit. The substance is widely used on Costa Rica’s farms, but is banned in Europe after it was found to be a groundwater contaminant and “presumed human carcinogen”.

It was Saturday, 22 October 2022, two days after Costa Rica’s health ministry had issued an order that the more than 5,000 people who relied on the Cipreses water system should stop drinking the water or using it to prepare food. The tanker arrived at the entrance to the town at 08:50 am. The small activist group EcoCipreses was pleased to finally see some progress – eight years after a resident first raised concerns – but were also very aware that the problem was unlikely to be confined to their town.

Those fears were confirmed less than two weeks later. The authorities had been looking into the possibility of hooking Cipreses up to the water sources used by its neighbouring town of Santa Rosa, but lab tests found that most of these springs too were contaminated with breakdown products of chlorothalonil. On 4 November, the ministry of health issued another order, closing five of Santa Rosa’s springs. A later round of testing found the contamination present in another of Santa Rosa’s springs, and in March this year that too was closed for human consumption.

Residents of Cipreses fill containers from the back of the truck, which delivers clean water to the town. Photo: José Diaz

According to José Sánchez, president of the local authority responsible for administering Santa Rosa’s water system (known as an ASADA from its initials in Spanish), their problem is likely to be the tip of the iceberg. Cipreses and Santa Rosa both sit in an agricultural region in the north of Cartago province, close to the capital of San José, where farmers have been spraying huge amounts of chlorothalonil for decades. This area, on the fertile slopes of the Irazú volcano in Costa Rica’s central mountain range, produces 80% of the country’s vegetables and is home to tens of thousands of people. Sanchez believes the contamination is likely to be widespread throughout the region.

‘A regional emergency’

“Logic dictates that as more lab tests are done, we will continue to find that springs in this entire area are contaminated, because the type of agriculture and the type of soil are the same,” he told Unearthed and Public Eye in March, days after receiving the news that would mean another of his town’s water sources having to close. “This is no longer one town’s local problem, but a regional emergency.”

No one knows how many people in Costa Rica have been exposed to these contaminants, or for how long. The Costa Rican authorities have never systematically tested drinking water for the presence of one of the country’s most widely used pesticides. Nor do the national authorities even have the capability to test for metabolites of chlorothalonil. These are substances created when the pesticide starts to break down in the environment, which can also pose risks to health. 

It was metabolites of chlorothalonil that were found to have polluted the drinking water of Cipreses and Santa Rosa. But they may never have been discovered had it not been for the suspicions of a group of residents who organised themselves to call for the water to be tested, or for the work of specialists at the National University of Costa Rica’s Regional Institute for Studies on Toxic Substances (IRET, from its initials in Spanish), who agreed to do tests on the water free of charge. 

“We just trusted that the government was testing the water twice a year, and we never imagined this was happening,” says Sánchez. 

Sánchez is not the only one who fears that the contamination may be much more widespread than so far detected. In April, the Costa Rican health and environment ministries issued a joint report in response to the situation in Cipreses and Santa Rosa. The report noted that in the agricultural region immediately surrounding these communities, there were around 65,000 people who relied on similar water supplies. Many of these supplies, it added, were under “the same conditions”, with farming so close to water sources that it was “affecting the water quality of these sources” and leading to “a very high probability of pollution due to the use of chemical products”. The report concluded by recommending a national ban on the use of chlorothalonil.

But for now, farmers in this region – where nearly everyone’s livelihood depends on the production of potatoes, carrots, onions or cabbages – continue to spray chlorothalonil on their crops. And despite this pesticide now being banned across the European Union, Switzerland and the UK because of the dangers it poses to water sources and human health, European companies continue to sell it in large quantities in countries like Costa Rica.

Farmers harvest cabbages (above), and apply pesticides to their fields using backpack sprayers (below). Photos: José Diaz

According to official Costa Rican customs data analysed by Unearthed and Public Eye, the Swiss-headquartered pesticides giant Syngenta accounted for more than a quarter (26%) of all the chlorothalonil products imported into Costa Rica between 2020 and 2022. This represented a larger share of the market than that of any other manufacturer. Other European agrochemical companies, including Germany’s BASF, are also marketing chlorothalonil in Costa Rica. Some chlorothalonil products have even been sent to the country directly from Europe. Italy, Belgium, Denmark and the UK have all exported chlorothalonil to Costa Rica since passing domestic bans on the substance in 2019, customs data shows.

Syngenta declined to comment for this story. 

A spokesperson for BASF told Unearthed and Public Eye: “BASF is informed that traces of chlorothalonil metabolites have been observed in water systems in Cipreses, Costa Rica. Such reports are of great concern to us.”

The company is convinced that its products are safe “when they are used correctly following the label instructions and stewardship guidelines”, he added. “As an additional safety layer, we voluntarily assess all uses of products having potential health risks and only support them when the assessments confirm farmer safety under conditions of local use. Our employees live and work in the countries where we sell our products, and they are out in the fields with the local farmers.”

A clean water delivery is handed to a woman in Cipreses. The town has now been receiving water by truck for over eight months. Photo: José Diaz

It is now more than eight months since the tanker trucks began bringing water to Cipreses, and there is still no solution in sight. New building construction is currently prohibited in the town because of the lack of water pipe permits.  By mid-June, Costa Rica’s Water and Sanitation Institute, the central government body responsible for overseeing water supply services, had already paid out $200,000 for the truck deliveries.  

Nor is any quick or simple solution likely to be found. The evidence from studies in European countries where the chemical is already banned is that chlorothalonil metabolites are highly persistent in the environment, and are likely to “significantly impair groundwater for many years”. The technologies available for removing these contaminants from drinking water are prohibitively expensive and energy-intensive.

“We need to do more testing in the area, but we need resources and we need to know how to move forward with this problem. It’s not sustainable to keep taking water to the population by truck every day, nor is it an option to let people keep taking their chances with the tap water. We need to think about how to recover the springs, but it is not easy to solve, which is very sad,” says Clemens Ruepert, the IRET chemicals inspector whose tests proved the contamination in Cipreses and triggered  intervention by the national authorities. “The people are drinking water that undoubtedly contains breakdown products of certain pesticides which are widely used in the area,” he adds. “We have no doubt.”

Cipreses is situated on the fertile slopes of the Irazú volcano in Costa Rica’s central mountain range, in an agricultural region that supplies 80% of the country's vegetables. Photo: José Diaz

Our ‘daily bread’ 

“It’s like a drug,” says farmer Óscar Ruiz about the chlorothalonil he still sprays on his fields near Cipreses. Many of the estimated 9,400 inhabitants in Cipreses and Santa Rosa have carried on drinking the tap water despite the ministry of health order, but Ruiz is not one of them. He stopped drinking from the Cipreses water supply in October. Instead he takes advantage of the truck deliveries, or imports water from a property he owns in a nearby town called Pacayas, believing the Pacayas water to be uncontaminated. But he hasn’t stopped spraying chlorothalonil on his carrots and potatoes. 

“It is too good at killing fungi,” he tells Unearthed and Public Eye. Ruiz explains that the fungicide is effective and reasonably priced; people use it in huge quantities, and more frequently than the manufacturers recommend. He assures us that recently people have started to use less, because of advice from agricultural engineers working for the pesticide industry. The industry is huge in this rural area, where enormous billboards advertising pesticide products are visible all along the main highway.

Daconil and Bravonil are two of the best-known brands of chlorothalonil around here, both manufactured by Syngenta. They are sold widely in Costa Rica and are particularly popular to the north of the city of Cartago. For 14,000 colones (25 US dollars), we bought a bottle of Bravonil in one of the local Cipreses shops. “I sell lots of it,” the shopkeeper told us. 

Chlorothalonil was the fourth most-sold fungicide in Costa Rica between 2012 and 2020, according to data gathered by Elídier Vargas. Vargas researches the use of agrochemicals and is the author of studies sponsored by the local office for the United Nations Development Programme (UNDP). These studies show that per hectare, this Central American nation – known internationally  as the ‘greenest country in the world’ – is also one of the world’s largest consumers of pesticides. In the agricultural region near the Irazú volcano these chemicals are people’s “daily bread”, Ismael Serrano tells us. Serrano is a farmer who owns a factory in Cipreses that processes carrots for export, located just next to the spot where the first water truck parked last October.

Serrano was president of the Cipreses ASADA, the authority that administers the town’s water system, until almost nine years ago. He blames its current directors for allowing the water supply to be contaminated. He says that because the ASADA did not buy up the land surrounding the springs, farmers grow crops just a few metres from these water sources, even though the law requires a distance of at least 200 metres. Serrano says he always knew the concerns raised by EcoCipreses were not just the whims of activists. “They were right. Now there is proof that chlorothalonil particles are present in the water. Other countries have studied the serious effects they have on health,” he told Unearthed and Public Eye, in an interview at his factory.

A bottle of Bravonil purchased at a local store selling agricultural products (above). Óscar Ruiz mixes concentrated chlorothalonil with water in preparation for spraying crops (below). Photos: José Diaz

‘You live with the fear’

The potential health risks have raised concerns among some residents about the side effects of a substance which they have used for decades without control or limitations. “You live with the fear and often ask yourself at what point something strange will happen to your body,” Óscar Ruiz says, despite the fact that he and his son Jordi have always sprayed their carrot fields with chlorothalonil by hand, wearing no protective equipment.

“A week ago I lost a 45-year-old employee to stomach cancer,” says Ismael Serrano in his packaging plant. “He died, and now his dad has it too. You wonder if it’s connected.” Up the road in Santa Rosa, Unearthed and Public Eye meet Leonel Sánchez, 70, as he is on his way to get water from the truck. His wife has cancer, and his son has kidney failure, so they don’t want to “risk drinking contaminated water,” says the retired farmer, who used to use chlorothalonil himself and always drank the tap water without a second thought. But now he heeds the warnings. “We always used huge amounts of agrochemicals on our farms, and nobody ever warned us about them,” he says.

Doctors in Costa Rica who spoke to Unearthed and Public Eye said that the country’s monitoring of cancer rates in general and pesticide-related harms specifically was weak, and it was impossible to say whether the pesticides used around Cipreses were linked to observed diseases.

Scientists have not monitored the effects of chlorothalonil exposure on health in Costa Rica, according to Doctor Rebeca Alvarado, an epidemiologist researching the effects of pesticides for the UNDP. The only health effects of agrochemicals that are tracked at all are immediate crises, instances of acute poisoning;  there is little data about chronic diseases that can be caused by repeated pesticide exposure over time. “We have international literature that talks about the relationship of this substance to asthma, cancer, kidney damage, prostate and female reproductive systems and others,” says Alvarado. “What we know is that substances derived from chlorothalonil are present in the water, but we are unable to establish the relationship between that and the diseases found in the population. One thing, however, is clear: people are consuming traces of a substance whose side effects on health are proven in other countries.” 

A woman in Santa Rosa heads to collect water from the latest truck delivery. Photo: José Diaz

However, the local authority responsible for Cipreses’ water service does not accept that the water it provides is posing a risk to residents’ health. In fact – and in stark contrast with its counterparts in neighbouring Santa Rosa – the Cipreses ASADA does not even accept its water is contaminated. When the ministry of health issued its order to Cipreses ASADA president Virgilio Ulloa in October to close the springs for human consumption, he told the press that the water system would keep working as normal, that “no one here has died from this” and that people consume “more poison on their vegetables”.

In a two-hour interview with Unearthed and Public Eye, Ulloa pours scorn on the credentials of IRET, the university institute whose tests uncovered the contamination, despite the fact that his ASADA contracted IRET to run some of those tests. He now argues that the institute’s lab is not officially accredited to test  for chlorothalonil metabolites, and claims that IRET was under pressure from local activists to produce the results it gave. “This managing council made the mistake of hiring our enemies to do the tests,” says Ulloa, a local farmer who defends the area’s use of pesticides tooth and nail. During the interview, he wears a cap bearing the logo of the shop where we bought the Bravonil.

Cipreses ASADA president Virgilio Ulloa. Photo: José Diaz

Ulloa’s doubts are not shared by the director of Costa Rica’s National Water Laboratory, the lab of the national government authority that is responsible for rural water services like his own. This state-run lab is certified to test for chlorothalonil metabolites, but is now working with IRET to do so, because it does not have the resources to do the work itself. “You always have to apply the science, and if the IRET lab detected metabolites, we believe them,” says National Water Laboratory director Dárner Mora. He has no doubt that the spring waters all around the high zone of Cartago province are at high risk of contamination, due to the terrain and the type of agriculture in the region.

A second opinion

Rather than accept the counsel of these scientists, the Cipreses ASADA – with close support from representatives of Costa Rica’s pesticide lobby – has sought a “second opinion”. Earlier this year, the ASADA commissioned a new round of tests from a new lab, that of the University of Costa Rica (UCR)’s environmental pollution research centre. The only apparent purpose of these tests was to convince the town that there was no problem with drinking the tap water or continuing to spray the crops, because the UCR research centre had made clear from the outset that it could test for chlorothalonil, but it did not have the capability to test for metabolites. 

Nevertheless, the ASADA requested the tests, and on 2 February samples were taken at a Cipreses spring called Plantón, in a ceremony that was filmed for a post on the ASADA’s Facebook page. The spring sits within a small stand of trees surrounded by potato and cabbage fields, all much closer than the 200m gap required by law. Gathered for the event were members of the ASADA, its administrator Sonia Aguilar, a lawyer, and a businessman called Freddy Solís. The journalist paid to film the event introduced Solís as the president of the Costa Rican Association of Agrochemical Formulators and Marketers (ASOAGRO), a trade body for companies that mix and sell pesticides. He is also the director of a pesticide company called Distribuidora Inquisa, which sells chlorothalonil products. That day, Sonia Aguilar described Solís as “a businessman who supports us a lot here at the ASADA when it comes to agrochemicals.”

A water fountain in Cipreses. While some residents have been exclusively drinking delivered water, others have continued to drink the tap water. Photo: José Diaz

In an interview with Unearthed and Public Eye, Solís says he was present at the Plantón test as an industry representative, and that he is convinced the government closure of these water supplies was based on “mere presumptions.” He also denies chlorothalonil has any impact on health or the environment if it is used in doses recommended in the small print. “The use of agrochemicals in accordance with the manufacturer’s instructions, found on the label and in the instructions in the packet, has been shown not to cause side effects to health or the environment and is a tool to ensure the food security of the population, in accordance with national legislation,” the businessman assures us.

CropLife Latin America, the trade body representing pesticide multinationals in the region, issued a statement to Unearthed and Public Eye suggesting the problem was that the Costa Rican ministry of health had set an excessively strict limit for the amount of pesticides that can be present in drinking water. 

“What is relevant is not detecting whether or not pesticide residues appear in food products or water, but rather the level at which they are appearing, since, as long as the [maximum acceptable value] is not exceeded, there is no risk to the consumer; as long as the MAV have been established following internationally accepted scientific norms and standards, which is not the case in Costa Rica,” the statement read. 

It added that the Costa Rican regulations, which set a maximum acceptable limit for any pesticide in drinking water at 0.1 micrograms per litre, had been established “without any technical or scientific foundation.” 

This limit is exactly the same as the legal limit the European Union has set for the amount of any pesticide that can be present in drinking water or groundwater. Likewise, in the EU, this same limit applies to metabolites of chlorothalonil, because of the pesticide’s proposed classification as a chemical that may cause cancer.

The pesticide industry’s assurances have not proven reassuring to Costa Rica’s National Institute of Aqueducts, its health ministry, its ministry for the environment, or the constitutional chamber of its supreme court, all of which recognise the contamination is real and a problem.

A small statue of the Virgin Mary outside a home in Cipreses. Photo: José Diaz

‘Water is sacred too’ 

The contamination in Cipreses might never have come to light if it had not been for  the suspicions of resident Isabel Méndez, which arose when she visited the Plantón spring nine years ago. Cipreses is a staunchly Catholic town, and the community used to hold masses at this water source to ask the Virgin Mary to send rain for the crops. Méndez was working on the preparations for one of these ceremonies one Saturday in 2014 when she noticed a strong smell of pesticides. A white creamy substance had formed on the ground, possibly the result of heavy rain in the night washing the pesticides off the crops and running in channels from the farmland down towards the spring. “Later I asked the ASADA if the water was contaminated and they always told me it wasn’t,” the community leader says. “But I couldn’t stop thinking about it.”

Two years later, her daughter Fiorella, then only 16 years old, was diagnosed with paranasal sinus polyps, growths which line the nose or sinuses. These were operated on but soon grew back. “The doctors told me that in the absence of other factors, they could not discard the possibility that the polluted water had aggravated them,” says Fiorella. Now 23 years old, she has lost almost all sense of smell and taste. When she goes for a walk or a run down the streets between the farms, she can only recognise the irritating smell of the pesticides that rise in small clouds over the recently sprayed fields. For visitors, it is hard not to notice the chemical smell on the wind.

The Plantón spring, where Isabel Méndez's suspicions of contamination were first raised, supplies water to the town of Cipreses (above). An aerial view shows the spring, almost hidden by trees, surrounded by farmland (below). Photo: José Diaz

Isabel Méndez decided that for the sake of her family and her neighbourhood, she needed to do more than the community work she did for the church. “Water is sacred too,” she says. That was how she met the then-administrator of the ASADA, Ricardo Rivera, who had also raised concerns within the organisation about environmental problems caused by chlorothalonil. They got together with other neighbours, including a well-known ecologist called Fabián Pacheco who had recently moved to Cipreses to set up an organic farm, and they formed EcoCipreses. That was the start of a campaign that has not only uncovered heavy contamination in their own water supplies, but triggered support at a national level for a ban on this widely-used fungicide.

In April, Costa Rica’s ministries of health and the environment, alongside the Water and Sanitation Institute, issued a joint report recommending a national ban on the use of chlorothalonil. The report concluded that there was evidence that the chemical presented “significant risks for health and the environment” and in light of the contamination in Cipreses and Santa Rosa, it was “necessary to take measures to avoid the contamination of more water sources and to protect the health of the population.” In June, the constitutional chamber of Costa Rica’s supreme court issued a ruling giving the government six months to implement the report’s recommendations. 

However, in Costa Rica, the decision to ban a pesticide must be taken jointly by the ministries of the environment, health, and agriculture, and the ministry of agriculture did not add its name to the report. 

Beyond this, the fact that an official report recommends a ban does not necessarily mean the product will soon be banned. In the past, draft decrees to ban pesticides in Costa Rica have been “shelved” by the ministers responsible.

Isabel Méndez first raised concerns about Cipreses' drinking water eight years ago. Photo: José Diaz

The agrochemicals industry, for its part, appears unwilling to take chlorothalonil off the shelves. Solís says prohibition should be the last option, casts doubt on the evidence gathered so far, and insists that further tests are needed. “On matters of this kind, authorities must, in the first instance, request or gather real scientific proof that has been done using rigorous sample and analysis techniques, to prove that any presumption is really based on real facts,” he insists. 

“Mere presumption, without science or proper techniques, in this field or any other, should not lead us to discussion of prohibitions.” 

A mural in Cipreses shows a statue of the Virgin Mary overlooking a mountain spring. Photo: José Diaz

‘No one has an answer’

In the meantime, the people of Cipreses and Santa Rosa face an uncertain future. No one knows how long they were drinking contaminated water, or what the effects on their health will be. No one knows how widespread the contamination is across the country, and no one knows how the contamination can be removed from those springs already found to be tainted.

In Cipreses, this situation has caused deep divisions, with those who run the ASADA in open conflict with the residents who formed EcoCipreses. 

Among other residents, opinion is also divided. Many people still drink the tap water. 

Others drink only the truck water. Others still started off drinking the water from the trucks, but then grew tired of carrying it or waiting for the truck to arrive. “It’s not easy,” says José Miguel Quesada, a 76-year-old retired farm labourer, standing in the hallway of his home. Quesada now has cancer of the tongue, which his hospital doctor believes could be related to the water. “You don’t know for sure whether it is because of the water, but it is possible,” he says. 

At the town school, the children are only allowed to drink truck water. “I have no doubt that the water is contaminated, as tests have been done,” says the school’s director, Virginia Corrales. “What we don’t know is what the side effects are. However, we have the order from the ministry of health that we must use the truck water. I have the health of over 300 pupils to consider.” Meanwhile, in the school kitchen, cook Ana Lía Coto peels potatoes washed with truck water, but at home she uses water from the tap without worrying. “Nothing has happened to us,” she says, shrugging her shoulders.

Outside the school, Valeria Calderón was waiting for the bus to her job at a factory in another town. She lives with her husband and two children in a house lent to them by the farm where he works. She says she has been waiting five years for a house of her own in a social project for poor families, but the plans for this construction have come to a standstill because of the ban on new water connections, due to the contamination. “If they fire my husband, we have nowhere to go. We have been very affected by the problem of the contamination,” she says. She doesn’t know what will happen.

A sticker in a window bearing one of the slogans of the local activist group, EcoCipreses. Photo: José Diaz

She’s not the only one. It’s difficult to define when the problem will be solved, says Rafael Barboza, director of management of rural water services at the Water and Sanitation Institute. “Our interest is always in recovering the water source,” he adds. New tests are currently being done on water sources across the whole region of the Irazú volcano. This, of course, may simply reveal a much wider and more intractable problem. The “greatest concern”, admits Albin Badilla, coordinator of the drinking water quality control programme at the ministry of health, is that the contamination in Cipreses and Santa Rosa may turn out to extend across the entire region. Meanwhile, Sonia Aguiar, the administrator of the Cipreses ASADA, says they are looking into contracting filter systems for the contaminated springs, but she doesn’t know who should foot the bill. The evidence from Europe is that technology to remove chlorothalonil metabolites is prohibitively expensive. 

“Right now, we can’t bring the problem to an end, and if you ask me what the answer is, I have to tell you I have no answer,” says José Sanchez, president of the Santa Rosa ASADA. “I don’t have one and no ASADA in this zone has one.”