This week’s episode of What’s Up With Water covers water shortages in Mexico and Italy. Plus, Circle of Blue reports on the U.S. government’s response to forever chemicals in drinking water.


Welcome to “What’s Up With Water” – your need-to-know news of the world’s water from Circle of Blue. I’m Eileen Wray-McCann.

Residents of one of Mexico’s most prosperous cities face water rationing and the prospect of no running water in their homes. It’s been a hot, dry spring and three reservoirs that supply the city of Monterrey are well below normal, according to the Associated Press. Two of the reservoirs have dwindled to less than 10 percent of their water capacity. Nearly 5 million people live in Monterrey, and city authorities are restricting water service to just a few hours each day. In some areas, taps have been dry for weeks. Authorities are responding by encouraging conservation and by looking to new sources of water, such as more wells and a fourth reservoir. Environmental groups, however, say the hasty response could have been improved by anticipating the consequences of a warming climate and planning for a drier future.

In northern Italy, residents of the Po Valley are facing similar struggles. The Guardian reports that over a hundred towns have been asked to suspend drinking water supplies at night in hopes of easing stress on local reservoirs. In recent months, the region has seen above-average temperatures and inadequate rainfall. The Po River is Italy’s longest river, and its water flows are the worst that they have been in 70 years. The low flow has prompted a national irrigation association to warn that saltwater from the Mediterranean may intrude upstream and damage crops.

This week Circle of Blue reports on the U.S. government’s response to forever chemicals in drinking water.

The U.S. Environmental Protection Agency has warned that even miniscule levels of PFAS in drinking water can pose health risks. On June 15, the agency substantially lowered existing health advisories for two of the so-called “forever” chemicals, PFOA and PFOS. And for the first time, the EPA also posted advisories for two additional chemicals, GenX and PFBS.

The new interim advisory levels for PFOA and PFOS are almost inconceivably small. They are are measured in fractions of a part per trillion. The amount of the contaminant that would trigger a health advisory is so tiny that it cannot be detected in drinking water by laboratory methods. The previous advisory level, set in 2016, was 70 parts per trillion for the two chemicals combined — that’s more than 10,000 times higher than the new level just for PFOA.

The new warnings about the danger of certain PFAS chemicals to human health are a stepping stone toward the agency’s development of national drinking water standards later this year. The warnings also test the limits of laboratory observation. Alan Roberson is the executive director of the Association of State Drinking Water Administrators, a group that represents state regulators. Roberson said there’s never been an EPA health advisory for something that’s below the level of detection.

This is raising concerns for those with an eye on drinking water contamination, according to John Lovie, the president of the Whidbey Island Water Systems Association. The association, in Washington state, has about 100 water systems as members. They range in size from several thousand customers to merely a handful. Lovie said that people on the island are already asking water systems what they plan to do about the health advisories. “The short answer,” said Lovie, is: “not very much at the moment.”

That’s because the EPA is using an advisory, not a standard. Federal drinking water standards are enforceable. Health advisories are not. If water utilities exceed the advisory limits, they don’t get punished. The advisories are intended as guidance for utilities, notifying them of chemical concentrations at which health damage can occur.

The EPA’s revision of the PFOA and PFOS health advisories has put a national spotlight on a class of chemicals known for their nonstick and water-repelling characteristics. PFAS chemicals number in the thousands. They are in cookware, clothes, carpets, firefighting foams, and even hamburger wrappers. They have been linked to a cluster of health problems, such as high cholesterol, kidney cancer, low birth weight, and damaged immune systems.

In developing the new advisory levels, the EPA looked at recent scientific findings that suggest that health damage occurs at miniscule concentrations. In large part, the revised health advisories for PFOA and PFOS are because the chemicals inhibit vaccine response in children. The advisories are based on a lifetime of tap water consumption.

As for the two PFAS chemicals that are new to the health advisory list, the advisory level for GenX was based on liver damage, and that threshold is 10 parts per trillion. The advisory level for PFBS was based on thyroid effects, and the threshold for that is 2,000 parts per trillion.

Health advisories are the EPA’s first step in dealing with drinking water contaminants. The next is creating a federal drinking water standard that can be enforced – officially called a maximum contaminant level. The EPA intends to publish draft maximum contaminant levels for PFOA and PFOS by the end of this year and finalize the rules next year.

And that’s “What’s Up With Water”  from Circle of Blue, where water speaks. More water news and analysis await you at This is Eileen Wray-McCann – thanks for being here.