Source Pollution Management Research Articles

An integrated system for nonpoint source pollution modelling and management

Modelling the impact of nonpoint source pollution (NSP) is a complex problem that has troubled water resource managers for many years when trying to set up proper management practices in catchment areas. In this paper, an integrated decision support system, NPSDSS (nonpoint source decision support system), was introduced to resolve this problem in a relatively easy way. The system was developed in a unique platform and integrated with the IMPULSE (integrated model of nonpoint source pollution processes) model, a stand alone geographic information system (GIS) toolbox, a well-structured database, a measure screening model, and an expert system, as well. The system has been applied in the Dianchi Lake catchment area and shown to give a good perspective on providing useful recommendations for appropriate NSP management.

The Drama basin water: quality and peat/lignite interaction

The Drama basin is a typical intermontane basin (2,300 km2) in northern Greece filled with detrital and lacustrine sediments containing peat/lignite seams. In the southwestern part of the basin (Philippi sub-basin) peat accumulated practically until the present. Specific conductivity and pH, as well as contents of major ions and trace elements have been determined in 20 surface and shallow groundwater samples collected across the basin. Water composition reflects the dominance of carbonate rocks in the whole basin. Peat oxidation and mineralization contribute to poor element enrichment of the Philippi sub-basin surface water derived from both the organic and inorganic peat fractions. Anthropogenic activities (waste water effluents and rubbish dumps) increase Mn, P, B, and Br concentrations. Only Mn exceeds EC recommendations (50 µg/l) in some places. There is also a slight increase in Na+ and Cl– contents. Improving measures in the management of point pollution sources should be a priority to warrant the sustainable exploitation of water resources in the Drama basin.

A dimensionless analysis in the optimal management of groundwater pollutant sources

The impact of optimal waste disposal patterns upon the maximum assimilative capacity of groundwater systems is investigated in cases where the simultaneous utilization of the same aquifer for water supply as well as for waste disposal is required. A groundwater quality management model that combines analytic solutions off the dimensionless advective-dispersive transport equation with linear programming is developed. Three different patterns of waste disposal are considered: a constant rate, a pulsing-type, and a continuously varying rate. Optimal schedules for all the patterns are determined for a wide range of the problem's parameters, and a critical evaluation of their benefits leads, eventually, to a complete series of useful guidelines. These guidelines can serve as a-priori criteria for the selection of the most suitable waste disposal patterns.

Models for Ground-Water Pollution Management

Combined simulation-management models are being developed for determining optimal operating policies for ground-water pollution management subject to physical, chemical, economic or social constraints. In the hydraulic management approach, pollution is managed through control of ground-water gradients or of recharge and discharge as determined using the results from a ground-water simulation-management model. In the pollution source management approach, one manages concentrations, amounts or locations of pollution sources using the results from a solute-transport simulation-management model. Hypothetical examples are used to illustrate such models using both the embedding method and the response matrix method.

A model for managing sources of groundwater pollution

The waste disposal capacity of a groundwater system can be maximized while maintaining water quality at specified locations by using a groundwater pollutant source management model that is based upon linear programing and numerical simulation. The decision variables of the management model are solute waste disposal rates at various facilities distributed over space. A concentration response matrix is used in the management model to describe transient solute transport and is developed using the U.S. Geological Survey solute transport simulation model. The management model was applied to a complex hypothetical groundwater system. Large‐scale management models were formulated as dual linear programing problems to reduce numerical difficulties and computation time. Linear programing problems were solved using a numerically stable, available code. Optimal solutions to problems with successively longer management time horizons indicated that disposal schedules at some sites are relatively independent of the number of disposal periods. Optimal waste disposal schedules exhibited pulsing rather than constant disposal rates. Sensitivity analysis using parametric linear programing showed that a sharp reduction in total waste disposal potential occurs if disposal rates at any site are increased beyond their optimal values.

Optimal dynamic management of groundwater pollutant sources

The linear programing‐superposition method is presented for managing multiple sources of groundwater pollution over time. The method uses any linear solute transport simulation model to generate a unit source‐concentration response matrix that is incorporated into a management model. This series of constraints indicates local solute concentration histories that will result from any series of waste injection schedules. The linear program operates on the matrix to arrive at optimal disposal schedules. An example demonstrates application of the method to maximizing groundwater waste disposal while maintaining water quality of local water supplies within desired limits. Flow field variations associated with waste injection are ignored as an approximation. Parametric programing is shown to be an important tool in evaluating waste disposal trade‐offs at various injection sites over time. Mixed‐integer programing permits restrictions to be placed upon the number of injection wells which may operate during given management periods.

Land Use and Water Quality in New York Rivers

The Federal Water Pollution Control Act Amendments of 1972 require that land-use management and control of nonpoint pollution sources be included in areawide water quality planning. At the present time, few tested procedures are available to implement this policy. Statistical techniques, including correlation and regression analyses, offer a promising methodology for the study of land use and nonpoint source impacts on water quality. The methodology has been applied to water quality and land-use data from 20 river basins in New York State. The results indicated that river basin land uses could account for up to 89% of the observed variation in mean river nitrogen concentrations and 63% of the observed variation in mean total suspended solids concentrations. No relationships between phosphorus concentrations and land uses were found in the basins.