rachel hunter
TRANSCRIPT
Wetland Assimilation of Treated Municipal Effluent: Wetland
Restoration & Improved Water Quality in Louisiana
Dr. Rachael Hunter 1,2, Dr. John W. Day1,2,
Dr. Robert R. Lane1,2, Joel Lindsey1.
Montgomery Hunter1 & Jason Day1
1Comite Resources, Inc., Zachary, LA2School of the Coast & Environment,
LSU, Baton Rouge, LA
Criteria for the use of Wetlands for Municipal Effluent Assimilation
• Effluent is treated, disinfected, and no toxic inputs.• Sheet-flow hydrology (minimal channels and no
short-circuits).• Appropriately sized wetlands: low nitrogen and
phosphorus loading rates.• Monitoring ecosystem response in receiving
wetlands, as well as non-impacted reference sites.
Monitoring
• Water level and hydrology.• Water quality: NOx, NHx, TN, PO4, TP, TSS,
D.O., salinity, BOD, and fecal coliform.• Vegetation species composition and productivity
– Stem growth (tree diameter)– Leaf fall (litter boxes)
• Soils: bulk density and heavy metal concentrations– Benthos is no longer monitored due to high seasonal
and spatial variability, and lack of statistically significant trends in past monitoring and research.
• Assimilation wetlands have typical benthic species composition found throughout coastal Louisiana.
ConclusionsWetland assimilation of municipal effluent is a
proven method of wetland restoration, as well as water quality improvement.
Municipal effluent positively effects wetlands by:• Increasing vegetative productivity• Increasing organic matter deposition• Increasing wetland surface elevation,
counteracting high regional subsidence