A wastewater treatment plant flooded during Hurricane Harvey in Houston, Texas.

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At a Glance

A new study found sea level rise will have a far greater impact on Americans through comprised infrastructure than through direct flooding.A 1-foot rise in sea levels would leave 1.5 million Americans without services.A 6-foot rise would leave 27.8 million in the lurch.

Rising seas will inundate dozens of coastal wastewater treatment centers, leaving an estimated 1.5 million Americans without service by 2030when levels are expected to rise at least a foot, a new study says.

According to a study by the University of California, Berkeley, published Monday in the journal AGU, researchers say the study shows the ""

The study highlights the notion that sea level rise will have a far greater impact on Americans through compromised infrastructure than through direct flooding.

Wastewater treatment facilities are particularly vulnerable because they aretypically located at low elevations near the coastlines to minimize the cost of collecting water and discharging treated water.

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Using a national database of wastewater treatment facilities, the researchers looked at the number of plants that would be underwater or compromised at various levels of sea rise, including the 1.5 million impacted by a 1-foot rise.

“We found that almost all coastal cities in the U.S. will experience some impact ,” environmental engineer and lead researcherMichelle HummeltoldEos.

The number of Americans impacted would increase considerably as sea levels rise. Hummelnoted that at a 3-foot rise, 8.4 million would lose wastewater treatment services. At 6 feet, the number jumps to27.8 million.

While permanent inundation is still a few years away, increased storm surge amid rising seas is creating an increased number of temporary but challenging problems for coastal communities. During Hurricane Harvey, some 40 wastewater treatment centers in the Houston area were shut down, while 10 billion gallons of sewage were dumped into New York City's East River, Hudson Riverand New York Harbor during Superstorm Sandy in 2012.

The researchers note that identifying critical infrastructure components exposed to sea level rise is "an important first step in developing targeted investment in protective actions and enhancing the overall resilience of coastal communities."