Arquivo da tag: Infraestrutura

Texas Blackouts Point to Coast-to-Coast Crises Waiting to Happen (New York Times)

nytimes.com

Christopher Flavelle, Brad Plumer, Hiroko Tabuchi – Feb 20, 2021


Traffic at a standstill on Interstate 35 in Kileen, Texas, on Thursday.
Traffic at a standstill on Interstate 35 in Kileen, Texas, on Thursday. Credit: Joe Raedle/Getty Images
Continent-spanning storms triggered blackouts in Oklahoma and Mississippi, halted one-third of U.S. oil production and disrupted vaccinations in 20 states.

Even as Texas struggled to restore electricity and water over the past week, signs of the risks posed by increasingly extreme weather to America’s aging infrastructure were cropping up across the country.

The week’s continent-spanning winter storms triggered blackouts in Texas, Oklahoma, Mississippi and several other states. One-third of oil production in the nation was halted. Drinking-water systems in Ohio were knocked offline. Road networks nationwide were paralyzed and vaccination efforts in 20 states were disrupted.

The crisis carries a profound warning. As climate change brings more frequent and intense storms, floods, heat waves, wildfires and other extreme events, it is placing growing stress on the foundations of the country’s economy: Its network of roads and railways, drinking-water systems, power plants, electrical grids, industrial waste sites and even homes. Failures in just one sector can set off a domino effect of breakdowns in hard-to-predict ways.

Much of this infrastructure was built decades ago, under the expectation that the environment around it would remain stable, or at least fluctuate within predictable bounds. Now climate change is upending that assumption.

“We are colliding with a future of extremes,” said Alice Hill, who oversaw planning for climate risks on the National Security Council during the Obama administration. “We base all our choices about risk management on what’s occurred in the past, and that is no longer a safe guide.”

While it’s not always possible to say precisely how global warming influenced any one particular storm, scientists said, an overall rise in extreme weather creates sweeping new risks.

Sewer systems are overflowing more often as powerful rainstorms exceed their design capacity. Coastal homes and highways are collapsing as intensified runoff erodes cliffs. Coal ash, the toxic residue produced by coal-burning plants, is spilling into rivers as floods overwhelm barriers meant to hold it back. Homes once beyond the reach of wildfires are burning in blazes they were never designed to withstand.

A broken water main in McComb., Miss. on Thursday.
Credit: Matt Williamson/The Enterprise-Journal, via Associated Press

Problems like these often reflect an inclination of governments to spend as little money as possible, said Shalini Vajjhala, a former Obama administration official who now advises cities on meeting climate threats. She said it’s hard to persuade taxpayers to spend extra money to guard against disasters that seem unlikely.

But climate change flips that logic, making inaction far costlier. “The argument I would make is, we can’t afford not to, because we’re absorbing the costs” later, Ms. Vajjhala said, after disasters strike. “We’re spending poorly.”

The Biden administration has talked extensively about climate change, particularly the need to reduce greenhouse gas emissions and create jobs in renewable energy. But it has spent less time discussing how to manage the growing effects of climate change, facing criticism from experts for not appointing more people who focus on climate resilience.

“I am extremely concerned by the lack of emergency-management expertise reflected in Biden’s climate team,” said Samantha Montano, an assistant professor at the Massachusetts Maritime Academy who focuses on disaster policy. “There’s an urgency here that still is not being reflected.”

A White House spokesman, Vedant Patel, said in a statement, “Building resilient and sustainable infrastructure that can withstand extreme weather and a changing climate will play an integral role in creating millions of good paying, union jobs” while cutting greenhouse gas emissions.

And while President Biden has called for a major push to refurbish and upgrade the nation’s infrastructure, getting a closely divided Congress to spend hundreds of billions, if not trillions of dollars, will be a major challenge.

Heightening the cost to society, disruptions can disproportionately affect lower-income households and other vulnerable groups, including older people or those with limited English.

“All these issues are converging,” said Robert D. Bullard, a professor at Texas Southern University who studies wealth and racial disparities related to the environment. “And there’s simply no place in this country that’s not going to have to deal with climate change.”

Flooding around Edenville Township, Mich., last year swept away a bridge over the Tittabawassee River.
Credit: Matthew Hatcher/Getty Images

In September, when a sudden storm dumped a record of more than two inches of water on Washington in less than 75 minutes, the result wasn’t just widespread flooding, but also raw sewage rushing into hundreds of homes.

Washington, like many other cities in the Northeast and Midwest, relies on what’s called a combined sewer overflow system: If a downpour overwhelms storm drains along the street, they are built to overflow into the pipes that carry raw sewage. But if there’s too much pressure, sewage can be pushed backward, into people’s homes — where the forces can send it erupting from toilets and shower drains.

This is what happened in Washington. The city’s system was built in the late 1800s. Now, climate change is straining an already outdated design.

DC Water, the local utility, is spending billions of dollars so that the system can hold more sewage. “We’re sort of in uncharted territory,” said Vincent Morris, a utility spokesman.

The challenge of managing and taming the nation’s water supplies — whether in streets and homes, or in vast rivers and watersheds — is growing increasingly complex as storms intensify. Last May, rain-swollen flooding breached two dams in Central Michigan, forcing thousands of residents to flee their homes and threatening a chemical complex and toxic waste cleanup site. Experts warned it was unlikely to be the last such failure.

Many of the country’s 90,000 dams were built decades ago and were already in dire need of repairs. Now climate change poses an additional threat, bringing heavier downpours to parts of the country and raising the odds that some dams could be overwhelmed by more water than they were designed to handle. One recent study found that most of California’s biggest dams were at increased risk of failure as global warming advances.

In recent years, dam-safety officials have begun grappling with the dangers. Colorado, for instance, now requires dam builders to take into account the risk of increased atmospheric moisture driven by climate change as they plan for worst-case flooding scenarios.

But nationwide, there remains a backlog of thousands of older dams that still need to be rehabilitated or upgraded. The price tag could ultimately stretch to more than $70 billion.

“Whenever we study dam failures, we often find there was a lot of complacency beforehand,” said Bill McCormick, president of the Association of State Dam Safety Officials. But given that failures can have catastrophic consequences, “we really can’t afford to be complacent.”

Crews repaired switches on utility poles damaged by the storms in Texas.
Credit: Tamir Kalifa for The New York Times

If the Texas blackouts exposed one state’s poor planning, they also provide a warning for the nation: Climate change threatens virtually every aspect of electricity grids that aren’t always designed to handle increasingly severe weather. The vulnerabilities show up in power lines, natural-gas plants, nuclear reactors and myriad other systems.

Higher storm surges can knock out coastal power infrastructure. Deeper droughts can reduce water supplies for hydroelectric dams. Severe heat waves can reduce the efficiency of fossil-fuel generators, transmission lines and even solar panels at precisely the moment that demand soars because everyone cranks up their air-conditioners.

Climate hazards can also combine in new and unforeseen ways.

In California recently, Pacific Gas & Electric has had to shut off electricity to thousands of people during exceptionally dangerous fire seasons. The reason: Downed power lines can spark huge wildfires in dry vegetation. Then, during a record-hot August last year, several of the state’s natural gas plants malfunctioned in the heat, just as demand was spiking, contributing to blackouts.

“We have to get better at understanding these compound impacts,” said Michael Craig, an expert in energy systems at the University of Michigan who recently led a study looking at how rising summer temperatures in Texas could strain the grid in unexpected ways. “It’s an incredibly complex problem to plan for.”

Some utilities are taking notice. After Superstorm Sandy in 2012 knocked out power for 8.7 million customers, utilities in New York and New Jersey invested billions in flood walls, submersible equipment and other technology to reduce the risk of failures. Last month, New York’s Con Edison said it would incorporate climate projections into its planning.

As freezing temperatures struck Texas, a glitch at one of two reactors at a South Texas nuclear plant, which serves 2 million homes, triggered a shutdown. The cause: Sensing lines connected to the plant’s water pumps had frozen, said Victor Dricks, a spokesman for the federal Nuclear Regulatory Agency.

It’s also common for extreme heat to disrupt nuclear power. The issue is that the water used to cool reactors can become too warm to use, forcing shutdowns.

Flooding is another risk.

After a tsunami led to several meltdowns at Japan’s Fukushima Daiichi power plant in 2011, the U.S. Nuclear Regulatory Commission told the 60 or so working nuclear plants in the United States, many decades old, to evaluate their flood risk to account for climate change. Ninety percent showed at least one type of flood risk that exceeded what the plant was designed to handle.

The greatest risk came from heavy rain and snowfall exceeding the design parameters at 53 plants.

Scott Burnell, an Nuclear Regulatory Commission spokesman, said in a statement, “The NRC continues to conclude, based on the staff’s review of detailed analyses, that all U.S. nuclear power plants can appropriately deal with potential flooding events, including the effects of climate change, and remain safe.”

A section of Highway 1 along the California coastline collapsed in January amid heavy rains.
Credit: Josh Edelson/Agence France-Presse — Getty Images

The collapse of a portion of California’s Highway 1 into the Pacific Ocean after heavy rains last month was a reminder of the fragility of the nation’s roads.

Several climate-related risks appeared to have converged to heighten the danger. Rising seas and higher storm surges have intensified coastal erosion, while more extreme bouts of precipitation have increased the landslide risk.

Add to that the effects of devastating wildfires, which can damage the vegetation holding hillside soil in place, and “things that wouldn’t have slid without the wildfires, start sliding,” said Jennifer M. Jacobs, a professor of civil and environmental engineering at the University of New Hampshire. “I think we’re going to see more of that.”

The United States depends on highways, railroads and bridges as economic arteries for commerce, travel and simply getting to work. But many of the country’s most important links face mounting climate threats. More than 60,000 miles of roads and bridges in coastal floodplains are already vulnerable to extreme storms and hurricanes, government estimates show. And inland flooding could also threaten at least 2,500 bridges across the country by 2050, a federal climate report warned in 2018.

Sometimes even small changes can trigger catastrophic failures. Engineers modeling the collapse of bridges over Escambia Bay in Florida during Hurricane Ivan in 2004 found that the extra three inches of sea-level rise since the bridge was built in 1968 very likely contributed to the collapse, because of the added height of the storm surge and force of the waves.

“A lot of our infrastructure systems have a tipping point. And when you hit the tipping point, that’s when a failure occurs,” Dr. Jacobs said. “And the tipping point could be an inch.”

Crucial rail networks are at risk, too. In 2017, Amtrak consultants found that along parts of the Northeast corridor, which runs from Boston to Washington and carries 12 million people a year, flooding and storm surge could erode the track bed, disable the signals and eventually put the tracks underwater.

And there is no easy fix. Elevating the tracks would require also raising bridges, electrical wires and lots of other infrastructure, and moving them would mean buying new land in a densely packed part of the country. So the report recommended flood barriers, costing $24 million per mile, that must be moved into place whenever floods threaten.

A worker checked efforts to prevent coal ash from escaping into the Waccamaw River in South Carolina after Hurricane Florence in 2018.
Credit: Randall Hill/Reuters

A series of explosions at a flood-damaged chemical plant outside Houston after Hurricane Harvey in 2017 highlighted a danger lurking in a world beset by increasingly extreme weather.

The blasts at the plant came after flooding knocked out the site’s electrical supply, shutting down refrigeration systems that kept volatile chemicals stable. Almost two dozen people, many of them emergency workers, were treated for exposure to the toxic fumes, and some 200 nearby residents were evacuated from their homes.

More than 2,500 facilities that handle toxic chemicals lie in federal flood-prone areas across the country, about 1,400 of them in areas at the highest risk of flooding, a New York Times analysis showed in 2018.

Leaks from toxic cleanup sites, left behind by past industry, pose another threat.

Almost two-thirds of some 1,500 superfund cleanup sites across the country are in areas with an elevated risk of flooding, storm surge, wildfires or sea level rise, a government audit warned in 2019. Coal ash, a toxic substance produced by coal power plants that is often stored as sludge in special ponds, have been particularly exposed. After Hurricane Florence in 2018, for example, a dam breach at the site of a power plant in Wilmington, N.C., released the hazardous ash into a nearby river.

“We should be evaluating whether these facilities or sites actually have to be moved or re-secured,” said Lisa Evans, senior counsel at Earthjustice, an environmental law organization. Places that “may have been OK in 1990,” she said, “may be a disaster waiting to happen in 2021.”

East Austin, Texas, during a blackout on Wednesday.  
Credit: Bronte Wittpenn/Austin American-Statesman, via Associated Press

Sabesp admite que rodízio pode contaminar água (Estadão)

Pedro Venceslau e Fabio Leite – O Estado de S. Paulo

26 Fevereiro 2015 | 03h 00

Diretor disse em CPI que problema não colocaria usuário em risco; empresa também afirmou que pressão está fora da norma

SÃO PAULO – O risco de contaminação da água admitido nesta quarta-feira, 25, pelo diretor metropolitano da Companhia de Saneamento Básico do Estado de São Paulo (Sabesp), Paulo Massato, em caso de rodízio oficial já é realidade em algumas regiões altas da Grande São Paulo. São locais onde a rede fica despressurizada após o fechamento manual dos registros na rua, conforme um alto dirigente da empresa admitiu ao Estado no início do mês.

“Se implementado o rodízio, a rede fica despressurizada, principalmente em regiões de topografia acidentada, nos pontos em que a tubulação está em declive. Se o lençol freático está contaminado, isso aumenta o risco de contaminação (da água na rede)”, afirmou Massato, nesta quarta, durante sessão da CPI da Sabesp na Câmara Municipal.

O resultado desse contágio, segundo ele, não colocaria a vida dos consumidores em risco, mas poderia causar disenteria, por exemplo. “Nós temos hoje medicina suficiente para minimizar risco de vida para a população. Uma disenteria pode ser mais grave ou menos grave, mas é um risco (implementar o rodízio) que nós queremos evitar ”, completou. Apesar do alerta, ele disse que a estatal poderia “descontaminar” rapidamente a água afetada.

Hélvio Romero/Estadão

‘Estamos em uma situação de anormalidade. Nós não conseguiríamos abastecer 6 milhões de habitantes se mantivéssemos a normalidade’, disse Massato

No início do mês, um dirigente da Sabesp admitiu ao Estado que em 40% da rede onde não há válvulas redutoras de pressão (VRPs) instaladas, o racionamento de água é feito por meio do fechamento manual, flagrado pela reportagem na Vila Brasilândia, zona norte da capital. Segundo ele, a manobra “não esvazia totalmente” a rede, mas “despressuriza pontos mais altos”.

“A zona baixa fica com água. Se não houver consumo excessivo, a maior parte da rede fica com água. Acaba despressurizando zonas altas, isso acontece mesmo. Tanto é que quando abre (o registro) para encher de novo, as zonas mais altas e distantes acabam sofrendo mais, ficando mais tempo sem água”, afirmou.

Para o engenheiro Antonio Giansante, professor de Engenharia Hídrica do Mackenzie, é grande o risco de contaminação em caso de fechamento da rede. “Em uma eventualidade de o tubo estar seco, pode ser que entre água de qualidade não controlada, em geral, contaminada por causa das redes coletoras de esgoto, para dentro da rede da Sabesp.”

Segundo interlocutores do governador Geraldo Alckmin (PSDB), a declaração desagradou o tucano, uma vez que o rodízio não está descartado. Massato já havia causado constrangimento ao governo ao dizer, em 27 de janeiro, que São Paulo poderia ficar até cinco dias sem água por semana em caso de racionamento.

Fora da norma. Massato e o presidente da Sabesp, Jerson Kelman, que também prestou depoimento à CPI, admitiram aos vereadores que a empresa mantém a pressão da água na rede abaixo do recomendado pela Associação Brasileira de Normas Técnicas (ABNT), conforme o Estado revelou no início do mês. Segundo o órgão, são necessários ao menos 10 metros de coluna de água para encher todas as caixas.

“Nós estamos garantindo 1 metro da coluna de água, preservando a rede de distribuição. Mas não tem pressão suficiente para chegar na caixa d’água”, admitiu Massato. “Estamos abaixo dos 10 metros de coluna de água, principalmente nas zonas mais altas e mais distantes dos reservatórios.”

“Essa é uma medida mitigadora para evitar algo muito pior para a população, que é o rodízio”, afirmou Kelman. “São poucos pontos na rede em que não se tem a pressão exigida pela ABNT para condições normais. Isso não é uma opção da Sabesp. Não estamos em condições normais”, completou.

Em dezembro, Alckmin disse que a Sabesp cumpria “rigorosamente” a norma técnica. A Sabesp foi notificada pela Agência Reguladora de Saneamento e Energia do Estado de São Paulo (Arsesp) e respondeu na terça-feira aos questionamentos feitos sobre as manobras na rede. O órgão fiscalizador, contudo, ainda não se pronunciou.

Ar encanado. Questionados sobre a investigação do Ministério Público Estadual que apura suposta cobrança por “ar encanado” pela Sabesp, revelada pelo Estado, os dirigentes da empresa disseram que a prática atingiu apenas 2% dos clientes. Das 22 mil reclamações registradas em fevereiro sobre aumento indevido da conta, 500 culpavam o ar encanado. O problema ocorre quando a água retorna na rede e empurra o ar de volta para as ligações das casas, podendo adulterar a medição do hidrômetro. / COLABOROU RICARDO CHAPOLA