title: Effects of a constructed wetland and pond system upon shallow groundwater quality.
abstract: Constructed wetland (CW) and constructed pond (CP) are commonly utilized for removal of excess nutrients and certain pollutants from stormwater. This study characterized shallow groundwater quality for pre- and post-CW and CP system conditions using data from monitoring wells. Results showed that the average concentrations of groundwater phosphorus (P) decreased from pre-CW to post-CW but increased from pre-CP to post-CP. The average concentrations of groundwater total Kjeldahl nitrogen and ammonium (NH(4)(+)) increased from pre-CW (or CP) to post-CW (or CP), whereas the average concentrations of groundwater arsenic (As), chromium, nickel, and zinc (Zn) decreased from pre-CW to post-CW regardless of the well locations. Variations of groundwater cadmium, copper, and Zn concentrations were larger in pre-CP than in post-CP and had a tendency to decrease from pre-CP to post-CP. In general, the average concentrations of groundwater aluminum and manganese decreased and of groundwater calcium, iron, magnesium, and sodium increased from pre-CP to post-CP. The average values of water levels (depth from the ground surface), redox potential, and conductance decreased and of chloride and sulfate (SO(4)(-2)) increased after the wetland and pond were constructed regardless of the well locations. Results further revealed that there were significant differences (α = 0.05) between the pre- and post-CW (or CP) for redox potential, water level, and As. This study suggests that the CW-CP system had discernible effects on some of the shallow groundwater quality constituents. This information is very useful for fully estimating overall performance of stormwater treatment with the CW-CP system.
authors.affiliation: USDA Forest Service, Center for Bottomland Hardwoods Research, 100 Stone Blvd, Thompson Hall, Room 309, Mississippi State, MS 39762, USA. youyang@fs.fed.us
authors.forename: Ying
authors.initials: Y
authors.lastname: Ouyang
mesh_terms: D001151:Arsenic / Q000032:analysis; D004784:Environmental Monitoring; D052918:Environmental Restoration and Remediation / Q000379:methods*; D060587:Groundwater / Q000737:chemistry*; D008670:Metals / Q000032:analysis; D009584:Nitrogen / Q000032:analysis; D010758:Phosphorus / Q000032:analysis; D061005:Ponds / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*; D053833:Wetlands
chemical_list: D008670:Metals; D014874:Water Pollutants, Chemical; D010758:Phosphorus; D001151:Arsenic; D009584:Nitrogen