A disgusting odor has been permeating the city of Hattiesburg, MS lately. For awhile, the city public works department claimed it didn’t know the cause, but most everyone who smelled it knew that it smelled a lot like sewage. It turns out that the city’s sewage lagoons are to blame.There is more to the story, though. The lagoons, which are a very basic type of sewage treatment most commonly used by very small towns, are in violation of the Clean Water Act, polluting the nearby Leaf and Bowie Rivers. Sewage lagoons are basically a series of ponds which, under ideal circumstances, treat sewage using bacteria that live in the ponds. The Hattiesburg lagoons are truly massive as you can see from the satellite photo I included (the four polygons make up the south lagoon). In fact, by my estimate, the total size of the lagoon is about 330 acres, or roughly half a square mile.As I argue in the letter I wrote in the Hattiesburg American, the city has not properly planned for growth and is sticking with its outdated sewage treatment lagoons rather than upgrading them to a modern treatment system. Why is this important? What Hattiesburg puts into the Leaf River, ultimately flows into the Pascagoula River and the Gulf of Mexico. In order to protect the Gulf of Mexico, we have to look upstream.If you live in Hattiesburg, it is time to let your local leaders know they need to do better and should start by raising the money to replace the smelly lagoons. In the meantime, if you use the Leaf or Bowie Rivers, you may want to think twice about swimming or fishing near where the lagoons empty into the rivers.Jeff Grimes is Assistant Director of Water Resources.