venerdì 13 gennaio 2017

Il problema dell'acqua negli USA

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At-risk and high-risk census tracts. Photo: MSU
A study from Michigan State University, published in PLOS ONE this week, states that the number of U.S. households unable to afford water could triple in five years, if water rates continue to rise at current projected amounts.
“Water is a fundamental right for all humans,” said Elizabeth Mack, assistant geography professor at MSU. “However, a growing number of people in the United States and globally face daily barriers to accessing clean, affordable water.”
The EPA recommends that households spend no more than 4.5 percent of their income on water and wastewater services, but the MSU study found that 13.8 million households, or nearly 12 percent of all households in the U.S., spend more than they can afford on these bills.
Since 2010, water rates have increased 41 percent. If this trend continues, the MSU researchers projected that 40.9 million, or 35.6 percent of households won’t be able to afford this necessity.
Households in Atlanta, Georgia and Seattle, Washington have some of the highest water rates in the country at $325.52 and $309.72 per month (based on a family of four), respectively. These rates were based on 100 gallons of water per person per day including water, sewer and storm water.
For water to be affordable at these rates, households must make at least $86,805, which is 1.6 times higher than the most recent estimates of U.S. median household income of $53,657.
The researchers highlight concerns in other cities throughout the country as well. In Philadelphia, four out of 10 water bills are past due, and 50,000 customers in Detroit, Michigan have had their services terminated due to payment delinquency since 2014.
The study points to a few main reasons behind the steady increase in water costs and the rising risk of unaffordability.
One of which is aging infrastructure. Many water systems are from the World War II era, but according to the MSU researchers’ estimates, updating these systems will cost $1 trillion over the next 25 years.
Significant costs like this are paid for at the expense of customers. Funds for water services are typically divided into two categories – operations and maintenance/capital improvements. Water companies set rates so that customers cover large fixed costs of building and maintaining infrastructure.
But in cities like Detroit and Philadelphia where population rates are decreasing, the customers that remain in these cities take on more of the cost burden. The monthly cost of water services jumps if the total number of customers in a specific location falls, or if the cost to update infrastructure and other maintenance needs increases.
Wastewater facilities are also sinking money into making improvements to better handle severe weather events as they become more frequent in a changing climate. Bigger storms and significant flooding put more pressure on water treatment facilities, while droughts tax water reserves.
The study states that implementing improvements to adapt to new weather patterns will cost a total of $36 billion by 2050.
The authors state that their projections are conservative, and could increase even more if cities refer to private water providers over public ones. They note that privatization of water services in Atlanta has contributed to the city’s high water costs.
The authors used a variety of metrics and benchmarks to determine affordability and other calculations in the study, although they also cited some limitations and challenges.
Water rates between different providers, particularly in metropolitan areas vary greatly and there is no national database on water prices at a community level. Another challenge was determining the perception of “essential” water use, and accurately analyzing water consumption levels. The perception of essential water uses varies dramatically based on climate lifestyle, diet and income.
For example, the study compared Uruguay, which uses 16.11 gallons per person per day, to Canada – which uses 203.15 gallons per person per day. In some geographic locations, gardening, pools, extra showers, etc. may be considered “essential” whereas in other locations simply flushing the toilet and running faucet water is all that’s needed. These factors contribute to overall affordability as well.
Despite these limitations, the study highlights that the need for clean, affordable water remains a challenge for people in developed countries, not just in the developing world.
“While research has highlighted issues with access to affordable water in developing countries and some developed countries, more work is needed in developed countries to better understand the extent of this issue in terms of the number of households and persons impacted,” write the authors.
“This assessment will create a benchmarking tool, based on EPA affordability standards, to provide a means of assessing the potential financial capacity of households to pay for water service.”

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