Susan M. Doerr

Chloride model for polluted onondaga lake

Abstract The validation of a mass balance chloride (Cl) model for enriched Onondaga Lake is documented for the period 1973–1991. The history of loading of Cl to the lake, extending from the mining of NaCl brines adjoining the lake in the late 1700s, through the 102 year period of operation and discharges of an adjoining soda ash/chlor-alkali facility, is reviewed. Loads are estimated for the 1973–1991 interval based on a program of continuous flow measurements and bi-weekly monitoring of Cl concentration for the major inflows. The model performs well in matching the substantial seasonal variations in lake Cl concentration and the major reduction in concentration observed since closure of the facility in 1986 (from about 1585 to 430 mg l −1 ). Projections with the validated model demonstrate the Cl concentration in the lake would be about 230 mg l −1 , nearly 50% lower than the present concentration, without the continuing waste input from the soda ash/chlor-alkali facility.

Supply of phosphorus to the water column of a productive hardwater lake: controlling mechanisms and management considerations

Onondaga Lake is a hypereutrophic, industrially polluted lake located in Syracuse, NY. High hypolimnetic concentrations of H2S that develop after anoxia restrict the accumulation of total Fe2+ due to the formation of FeS, and may limit Fe-PO4 interactions. High water column concentrations of Ca2+ and high rates of CaCO3 deposition occur due to inputs of Ca2+ from an adjacent soda ash manufacturing facility. Patterns of P concentration and other water chemistry parameters in the lower waters, and results from chemical equilibrium calculations, suggest that Ca-PO4 minerals may regulate the supply of P from sediments to the water column in Onondaga Lake. These findings have important management implications for Onondaga Lake. First, declines in water column Ca2+ concentrations due to reductions in industrial CaCl2 input may result in conditions of undersaturation with respect to Ca-PO4 mineral solubility and increases in the release of P from sediments to the water column. Second, introduction of O2 from hypolimnetic oxygenation, as a lake remediation initiative, may enhance P supply from sediments, because of increased solubility of Ca-PO4 minerals at lower pH.

Changes in inorganic carbon chemistry and deposition of Onondaga Lake, New York

Changes in Ca 2+ , alkalinity, dissolved inorganic carbon (DIC) and pH have occurred in the epilimnion of Onondaga Lake over a 10-yr period, in response to a major reduction in erternal Ca 2+ loading that resulted from the closure of an adjoining soda ash manufacturer. These changes included reduced Ca 2+ concentrations, diminished depletion of DIC and alkalinity in the upper waters in the summer, and a shift to higher pH values. Results of analyses from sediment trap collections before and after closure of the facility indicate approrimately 3-fold reductions in particulate inorganic carbon (PIC), and suspended solids deposition have occurred as a result of the closure

Development and Testing of a Nutrient-Phytoplankto Model for Cannonsville Reservoir

ABSTRACT A dynamic multi-layer one-dimensional mass balance nutrient-phytoplankton (eutrophication) model is developed and tested for the lacustrine zone of eutrophic Cannonsville Reservoir. The model simulates concentrations of chlorophyll (Chl), zooplankton biomass, various forms of phosphorus (P) and nitrogen (N), and dissolved oxygen (DO). Model development was integrated with, and supported by, limnological analysis of detailed monitoring data and findings of various system-specific process/kinetic studies. Model testing is supported by comprehensive monitoring data of in-reservoir concentrations and important environmental and operational forcing conditions. Model credibility is enhanced by the independent determination of a number of important model coefficients from the process/kinetic studies, which greatly constrains the role of calibration. The model performed well in simulating observations of seasonal average Chl concentration, the progressive depletions of nitrate plus nitrite from the epili...

Development and Testing of a Total Phosphorus Model for Onondaga Lake

ABSTRACT Adynamic two-layer mass balance model for total phosphorus (TP) is developed for culturally eutrophic Onondaga Lake, NY, and tested for the May 1987 through 1990 period. The model accommodates key processes in the lakes phosphorus cycle, including settling of the particulate fraction of TP, sediment release, and vertical mass transport Model development and testing were supported by a comprehensive program of field and laboratory measurements and experiments, to determine model coefficients and external loads, and to establish temporal and vertical distributions of lake TP concentrations. The model performs well in tracking documented interannual, seasonal, and vertical distributions of TP in the lake, and thus is appropriate as a management tool to evaluate management scenarios aimed at abating the lakes cultural eutrophication problem.

A Strategy for Reservoir Model Forecasting Based on Historic Meteorological Conditions

ABSTRACT A strategy for the application of linked watershed and reservoir models in the analysis of water quality management proposals for a water supply reservoir is presented. This strategy is based on the use of a long-term historical record of meteorological data, so that die predicted changes in water quality may be evaluated by considering the variations in streamflow, material loading, reservoir heat transfer and mixing associated with natural variations in meteorological conditions. Model simulations for a baseline condition and for several management proposals involving point source nutrient control, nonpoint source nutrient reduction, and reservoir operations are presented. The predictions are presented as distributions of the frequency of occurrence of selected annual statistics of nutrient loading, reservoir stratification, and reservoir water quality. Simulations for Cannonsville Reservoir indicate that reductions in phosphorus loading from wastewater treatment plants in the watershed would h...

Pollutant loadings from solvay waste beds to lower Ninemile Creek, New York

Concentrations of Cl, total ammonia (TNH3), NO3 plus NO2, total P (TP), and soluble reactive P (SRP) were measured at two sites, located 5 km apart, on Ninemile Creek, New York, for a period of more than 8 mo. The sites bound the most recently formed Solvay waste beds, associated with the production of soda ash, that adjoin the creek. Concentrations of Cl and T-NH3 increased on average by factors of 16.1 and 7.6, respectively, over the monitored stream reach. The estimated average loadings of these materials to the stream over this reach were 2.3 × 105 and 1.2 × 102 kg d−1, respectively. These inputs are attributable to the Solvay waste beds. The loading of Cl from this source has not changed significantly over a 4 yr period since the closure of the soda ash manufacturing facility. This is the single largest source of Cl, and the second largest source of T-NH3, to polluted Onondaga Lake. Profiles of Cl in the lake indicated that at times the creek inflow plunges to subsurface layers as a result of its elevated density. This is at least in part a result of the creeks ionic enrichment. The concentration of SRP decreased by a factor of 2.0 on average over the study reach, probably due to adsorption to the CaCO3 deposits that cover the stream bed in this area. However, the TP load from the creek to the lake is not significantly affected by this phenomenon.

Water Quality Model Evaluations For Scenarios Of Loading Reductions And Diversion Of Domestic Waste Effluent Around Onondaga Lake

ABSTRACT Management models for total phosphorus (TP), various nitrogen (N) species, and dissolved oxygen (DO), for polluted culturally eutrophic Onondaga Lake are developed from models presented and tested earlier in this issue (Doerr et al. 1996a, Canale et al. 1996, Gelda and Auer 1996). The management models are applied to test a wide range of remediation alternatives, corresponding to a wide range of reductions in pollutant loading. The analysis focuses primarily on the effluent (3.5 m3/s(80 MGD)) received from an adjoining domestic wastewater plant (METRO), though a reasonable upper bound of reductions in tributary TP load also is considered. The decreases in lake TP and total ammonia (T-NH3) concentrations that could be achieved by partial diversion of METRO, increased treatment at METRO, and reductions in tributary loading, would not be adequate to meet the established in-lake TP goal of 20 μg/L (as a summer average in the upper waters), the T-NH3 standard for the lake (0.77 mgN/L for the upper wat...

A Zero Degree of Freedom Total Phosphorus Model: 1. Development for Onondaga Lake, New York

ABSTRACT A seasonal, two-layer, variable volume, mass balance model for total phosphorus in a stratifying eutrophic lake is developed and tested for a single spring to fall interval. The model recognizes settling, sediment release, and vertical mass transport as key in-lake processes mediating phosphorus dynamics. The application presented is termed a “zero degree of freedom” model, as all inputs are determined independently through field and laboratory studies conducted on a test system. The model is considered validated for the test system because simulation results closely match field observations with no calibration (adjustment of model coefficients). Loading reductions at an adjoining wastewater treatment plant, the lakes major phosphorus source, provided an opportunity for model verification. The model framework has utility for other eutrophic stratifying lakes and the “zero degree of freedom” approach will find application where opportunities for both calibration and verification do not exist.

Forecasting Impacts of a Hypolimnetic Wastewater Discharge on Lake Water Quality

ABSTRACT Water quality impacts of shifting the shoreline discharge of a major (3.5m3/s) domestic wastewater treatment faclity (METRO) on polluted, eutrophic Onondaga Lake, NY, to a deep-water location are evaluated with three mechanistic water quality models. Transport and mixing inputs for the simulations are specified from the output of a separate hydrothermal model (Owens and Effler 1996). Model simulations indicate, that by trapping enriched effluent in the lower layers, summertime concentrations of total phosphorus (TP) and total ammonia (T-NH3) would decrease in the upper mixed layer (0 to 4.5 m depth interval). Further reductions in the concentrations of those constituents would be realized by reducing sediment release, through maintenance of oxia in the hypolimnion. However, the decreases that could be achieved with the prevailing METRO effluent characteristics would not result in substantial reductions in phytoplankton growth nor prevent violation of the T-NH3 standard. An extremely high degree o...