Sewage Lagoon with Aerator.The ugly underbelly of any town includes its sewer plant: hidden from view near a river or creek, with most residents oblivious to where and how their waste is treated. Sewer plant maintenance is not glamorous, but it is very important to do the work well. Plant workers must regularly maintain filter screens, tanks, pumps, sediment traps and lagoons full of varying states of human waste and everything else that can be flushed down a toilet or washed down a drain. Almost every sewer plant sends treated waste back to a local stream. The plant’s discharge point on the stream usually begins a zone of impairment that extends a great distance downstream. These stream reaches have discolored water, mucky bottoms, and a depleted community of fish, aquatic insect and invertebrate species. Only the tough species can live downstream of a sewer plant. Unfortunately, our natural streams serve as the final treatment stage for wastewater. All over the U.S. and especially in the humid south, cities have used their rivers for decades for the basic function of diluting treated sewage with fresh water.Two Mississippi Delta towns, Clarksdale and Indianola, with underperforming sewage treatment plants are renewing their permits to discharge treated water into the Big Sunflower River. This river drains the northwestern quarter of the vast, flat agricultural region of Mississippi. Typical sewage permits last five years in Mississippi, and before each renewal, the draft permit goes out for public comment. In the Mississippi Department of Environmental Quality’s (MDEQ) regulatory system, due process takes the form of public notice and the opportunity to comment. Individuals and groups like GRN can get access to DEQ files with a public records request in order to examine a city sewer plant’s files and compliance record and provide comments. Written comments can be part of the justification to appeal the granting or renewal of a permit.Summing up the Delta as land-rich and city-poor is an oversimplification, but the last twenty years have not been kind to this region’s cities and towns. Large scale commodity farming has done fine. Cities have scraped by while losing industries, jobs, people and tax base. The basic services of cities, like sewage treatment, go along with the trend. This was apparent when I examined the records of inspections, complaints, monitoring and enforcement in the Clarksdale and Indianola files for the last five years. For example, Clarksdale’s ultraviolet light (UV) sterilizer that is supposed to kill fecal coliform bacteria was performing at less than half capacity from July to November of 2012. The effluent going back into the Big Sunflower violated the fecal coliform standard by as much as 100% in some months. Inspectors also found that maintenance at the Clarksdale plant was awful. The inspector’s photos showed basic neglect – weeds growing on clumps of accumulated solid waste on screens and baffles that should have received daily or weekly cleaning. The plant at Indianola has an ongoing problem removing suspended solids, with many months of violation notice letters in the files. Water passing through the plant’s 50 acre lagoon seemed to be gaining suspended solids by the end of treatment. These are particles, such as algae, animal matter, industrial wastes and silt that don’t readily settle but should be reduced through treatment. The city’s consulting engineer explained it away instead of organizing repairs.MDEQ responds to comments submitted on the various permits, so it will be interesting to see the permit engineer’s answers to questions raised about these two plants. Click here to read our Clarksdale comments and here to read our Indianola comments. The Big Sunflower River joins the Yazoo River north of Vicksburg where it empties into the Mississippi. The degree and quality of sewage treatment in each Delta town makes a difference in the water quality of the Mississippi River and later in the Gulf of Mexico. Sewer plants like these have significant amounts of dissolved nitrogen and phosphorous compounds in their discharges to the Big Sunflower. These nutrients move downstream, contribute to algae growth in surface waters of the Gulf, and feed the cycles of algal growth and decay that contribute to the dead zone. Making that connection is GRN’s challenge – sewer plant by sewer plant.Andrew Whitehurst is GRN’s Assistant Director of Science and Water Policy.