All key types of water infrastructure in the US carry a strong risk of failure, according to the latest assessment by the American Society of Civil Engineers.

In the 2017 edition of its Infrastructure Report Card, the ASCE grades drinking water, dams, inland waterways and levees all at ‘D’, with wastewater scoring only slightly better at ‘D+’. The D grading denotes ‘poor, at risk’, and the ASCE’s explanation of this category states: ‘Condition and capacity are of serious concern with strong risk of failure’.

While the grades represent averages for the country, the D grading denotes that infrastructure is in a poor to fair condition and ‘mostly below standard, with many elements approaching the end of their service life’. According to ASCE, the grading also means ‘a large portion of the system exhibits significant deterioration’.

On drinking water, ASCE notes that the quality remains high, but adds that ‘legacy and emerging contaminants continue to require close attention’. It highlights that there are an estimated 240,000 water main breaks a year across the US, wasting over two trillion gallons of treated drinking water.

Investment in wastewater treatment means the condition of this infrastructure is seen as improving. However, ASCE cautions that more than 56 million new users are expected to be connected to centralised wastewater treatment plants over the next 20 years. The cost of meeting current and future demands is put at $261 billion.

In its assessment of dams, ASCE warns that around 15,500 have a high hazard potential, or 17% of the 90,580 dams in the country.

Last year ASCE warned that if the country’s infrastructure investment gap is not addressed by 2025, the economy would lose almost $4 trillion in GDP and this would result in a loss of 2.5 million jobs in 2025, according to its report ‘Failure to act: closing the infrastructure investment gap for America’s economic future’.