Guy Laigast, director of the parish's Office of Homeland Security and Emergency Preparedness, insisted in mid-August, "The water's perfectly safe to drink. It's just got the elevated salt."
But for those on low-salt diets, drinking the water could cause big health problems -- hence a warning.
After the mighty Mississippi near its all-time low, the salty water crept in as a wedge, Laigast said. Because salty water is denser than fresh, it tends to collect at lower depths, he added. And pipes that pull drinking water from the river tend to draw from those same depths.
Sodium levels in the parish's drinking water ranged from 60 mg/L to 200 mg/L, far exceeding the EPA recommendation of no more than 20 mg/L for people on very low sodium diets.
What happened a few weeks later, though, shows that conditions can change, and fast, in southern Louisiana. Plaquemines Parish was among the areas hardest hit by what was once Hurricane Isaac, with scores of homes flooded by a powerful, expansive storm surge.
Nationwide and up above: American Farm Bureau asks people to turn to God to end drought
Farming practices has come a long way over the past several decades, especially since much of Texas, Oklahoma and Nebraska was devastated by a decade-long drought in the 1930s' Dust Bowl era. Soil preservation, irrigation and other developments make people who work the land better able to adapt and grow what Americans' eat.
But one thing hasn't changed, in the opinions of many: A higher authority is still in charge of the weather.
Desperate for rain and a respite from extreme heat, the American Farm Bureau called on people nationwide to join them Aug. 23 in a day of prayer. The request pointed to the need to support all those affected by the drought whether their crops withered away, their livestock were in desperate need of clean water, or their home regions were struck by prairie fires.
Everyone involved in agriculture has been affected, the bureau said in a blog post, as has every consumer.
"Let's pray for abundant rain to start nationwide and for those people are dealing with such hardship," the bureau said. "It is a great way to support everyone being challenged by this ongoing drought."