CNN  — 

As the Carolinas’ swollen rivers crest, their “polluted floodwaters” are dumping out into the Atlantic, visibly discoloring the water offshore, federal experts have noted.

It was estimated that Hurricane Florence would drop more than 10 trillion gallons in North Carolina alone. Now, that water is making its way through inland waterways and carrying sediment and debris slowly out into the Atlantic.

“Here you can see that the Pamlico Sound is particularly dirty,” the National Oceanic and Atmospheric Administration said Thursday in a tweet, citing satellite images. The water has grown noticeably darker in recent days.

Along with sediment, floodwaters also might pick up sewage and chemicals, along with livestock waste from breached hog lagoons. North Carolina officials have gotten reports of breaches.