Bayou Plaquemine off 'impaired' list Grosse Tete, Maringouin declared safe for swimming

Deidre Cruse, Governmental Reporter

Government projects are making a difference for three Iberville Parish waterways, a state Department of Environmental Quality (DEQ) official told a public meeting here last week.

Bayou Plaquemine was listed on DEQ's list of impaired waterways in 2008 because it did not meet the standard for “dissolved oxygen,” a stagnation problem that affects fish, but was removed from the list as of 2010, Emilise Cormier, manager of DEQ's non-point source pollution program, told a meeting of the Upper Terrebonne Parish Water Quality Improvement Project.

The Bayou Plaquemine Freshwater Project, which reintroduced fresh water from the Mississippi River for the first time since the Plaquemine Lock closed, could have contributed to the renewed health of the local waterway she said.

“It definitely might have helped,” Cormier told the POST/SOUTH. “Anytime you increase the flow, more oxygen is added to it.”

Dissolved oxygen is the reason many bayous do not meet water quality standards, since by their nature, the streams are slow moving, she said.

Bayou Maringouin and Bayou Grosse Tete remain on the list of impaired streams in the Upper Terrebonne Basin – the area between the Mississippi and Atchafalaya levees in Iberville, West Baton Rouge and Pointe Coupee parishes – but are no longer contaminated with fecal coliform.

“They are now meeting the standard for swimming,” Cormier said.

Iberville Parish Environmental Manager John J. Clark credited sewerage improvements in North Iberville municipalities for the improvements in water quality in the two waterways.

“Any improvements in sewage treatment systems addresses that,” Cormier agreed.

Bayou Grosse Tete and Bayou Maringouin continued to be impaired because of dissolved oxygen and contamination with the nutrients nitrogen and phosphorus. Bayou Maringouin also is above the limit for “total dissolved solids.”

The Iberville Parish government joined with West Baton Rouge and Pointe Coupee several years ago to form the Upper Terrebonne Basin project to work to improve water quality in the three parishes, using parish funds as a match for a larger federal grant.

The current push is to identify and mitigate “non-point source pollution,” contamination that enters waterways from multiple and often unidentified sources, rather than from a single identifiable outlet, as perhaps from an industry, Clark and consultant Barton Rogers said.

They are interested in working with developers and property owners on solutions.

“A lot of this stuff can save you money,” Rogers said of the solutions.

Special guest Jose Barro of the Town of Grand Isle described the town's restoration of an area at a local park and its community center aimed at preventing non-point source pollution, improving conservation systems and providing recreation and beauty for the public.

The project recently won a DEQ Environmental Leadership Program Municipality Recognition Award in Pollution Prevention.

The project included installing permeable parking lots, cisterns for collecting rain water, and creating vegetative swales and rain gardens.

Further information on the Upper Terrebonne Basin project is available online at www.UTBwatershed.comor from Clark at 687-5190 or at, or from Rogers at (225) 612-4287 or