Environ Geol (2005) 47: 565–575 DOI 10.1007/s00254-004-1180-3
W.-J. Kang K. V. Kolasa M. W. Rials
Received: 27 May 2004 Accepted: 13 September 2004 Published online: 11 November 2004 Springer-Verlag 2004
W.-J. Kang (&) Æ K. V. Kolasa M. W. Rials Resource Management Department, Southwest Florida Water Management District, 2379 Broad Street, Brooksville FL 34604–6899, USA E-mail:
[email protected].fl.us Tel.: +1-352-796-7211 Ext 4494 Fax: +1-352-540-6027
ORIGINAL ARTICLE
Groundwater inflow and associated transport of phosphorus to a hypereutrophic lake
Abstract Hydrogeochemical data from lake, sediment pore, and well waters were used to quantify groundwater seepage and the associated transport of phosphorus to Lake Persimmon, Florida, USA. The data show that lake chloride concentrations vary as a function of lake elevations that are controlled by groundwater inflow. A whole-lake average seepage rate, estimated using a simple one dimensional advection-diffusion model fitted to the lake chloride profile, currently averages 2.3 ± 0.3 cm yr)1 and is in reasonable agreement with the rate of advective flow obtained from the pore water chloride profile. The ratios of nutrient regeneration versus sulfate consumption indicate that the phosphorus enrichment in deeper portions of sediment pore water
Introduction Groundwater flow is an important means for carrying nutrients to lake and coastal marine environments (Fellows and Brezonik 1981; Brock and others 1982; Belanger and Mikutel 1985; Shaw and others 1990; Reay and others 1992; Bussmann and others 1999; Corbett and others 1999). In some receiving waters, groundwater transport has been documented to be a significant source of nutrients (Belanger and Mikutel 1985; Shaw and others 1990; Simmons and Lyons 1994). For example, Simmons and Lyons (1994) found that the input of groundwater nitrogen to Bermuda coastal waters is
is most likely a result of groundwater phosphorus transport through sediment. Thus, the net inputs of groundwater phosphorus to the lake, calculated using the deep pore water phosphorus concentration, are about 7.4 ± 4.3 mg P m)2 yr)1 and comparable with recent in situ estimates from seepage meters. This study provides a simple hydrogeochemical method for estimating hydrologic and phosphorus inputs via groundwater to the lake, thereby supporting current efforts for lake management. Keywords Groundwater seepage Æ Groundwater phosphorus input Æ Pore water geochemistry Æ Bacterial sulfate reduction Æ Lake Persimmon Æ Florida Æ USA
about 1–4 times greater than that of sewage nitrogen. In such cases, surface eutrophication and algae blooms may be related to inputs of nutrients in groundwater. Due to the ecological and environmental significance of groundwater inflow, accurate estimates for inputs of nutrients via groundwater are important for appropriate scientific models as management tools. Previous investigations have determined a wide range of rates for groundwater seepage using chemical tracers (Lee and others 1980; Stauffer 1985; Cornett and others 1989; Corbett and others 1999; Kolak and others 1999), seepage meters (Lee 1977; Belanger and Mikutel 1985), chemical mass balance approaches (Sacks and others
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1998) and water balance models (Sutula and others 2001). Cornett and others (1989) successfully used pore water profiles for Cl) and 3H to estimate low rates (
