Phytoremediation of dissolved phase organic compounds: Optimal site considerations relative to field case studies

The United States Environmental Protection Agency/Environmental Response Team (EPA/ERT) has been supporting and implementing the use of phytoremediation to remediate dissolved phase organic compounds at Superfund sites since March 1996. Since then, ERT has applied phytoremediation field plots, both pilot and full scale, to a variety of field conditions. These active sites vary considerably as to depth to groundwater, groundwater transmissivity, contaminant concentrations, contaminant hydrophobicity, climate, planting design, plant selection, planting technique, and type of monitoring. Here we compare the literature and discuss lessons learned at five Superfund sites. Current maintenance and monitoring techniques at these sites are also discussed with recommendations for the maintenance and monitoring of similar sites in the future. © 2003 Wiley Periodicals, Inc.     

The Application of the Ecological Footprint: a case of passenger transport in Merseyside

The release of carbon dioxide from the burning of fossil fuels is believed to be responsible for climate change. In the UK, road transport emits 22% of the total output of carbon dioxide. This study applies the ecological footprint to Merseyside to ascertain the global environmental impact of passenger transport (expressed in hectares). Results show that car travel has a footprint of 704 000 hectares, which is 87% of the total footprint. It is demonstrated in scenarios that Policy initiatives involving the Local Transport Plan will cause the footprint to increase. It is also shown that individual behaviour could be influenced when highlighting the impacts of different modes of transport along the same route. By using the ecological footprint in educational programmes, the effect can be shown of carbon emissions and land appropriation on the 'school run'; these issues could be promoted alongside others such as health, safety, congestion, global equity and fairness.     

HISTORICAL AND ESTIMATED GROUND WATER LEVELS NEAR WINNIPEG,CANADA, AND THEIR SENSITIVITY TO CLIMATIC VARIABILITY1

ABSTRACT: Long term well hydrographs and estimated ground water levels derived from hydroclimatic and biological data were used to evaluate trends within the Upper Carbonate Aquifer (UCA) near Winnipeg, Canada, during the 20th Century. Ground water records from instruments have been kept since the early 1960s and are derived from piezometers in the overlying sediments and in open boreholes in the UCA. Some boreholes extend into an underlying Paleozoic carbonate sequence. Shallow well hydrographs show no obvious long term trends but do exhibit variations on the order of three to four years that are correlated with changes in annual temperature and precipitation at lags up to 24 months. Trends observed in deeper wells appear to be largely related to ground water usage patterns and show little correlation with climate over the past 35 years. Stepwise multiple regression modeled average annual hydraulic head in the shallow wells as a function of regional temperature, precipitation, and tree ring variables. Estimated hydraulic heads had a slightly greater range prior to the 1960s, most prominently during an interval of lowered ground water levels between 1930 and 1942. Regression results demonstrate that moisture sensitive tree ring data are viable predictors of past ground water levels and may be useful for studies of aquifers in regions that lack long, high quality precipitation records.     

Shoreline erosion in a reef-beach system

Beach erosion on Cinnamon Bay in the U.S. Virgin Islands results from storm waves in the North Atlantic. The net trend of erosion, however, is due to local environmental degradation. Reef die-back, initiated during the period of high sedimentation associated with 18th and 19th century sugar cane cropping, has reduced the rate of generation of new coral sands. Sand losses to deep water during periods of storm waves are not replenished. Engineering measures designed to check erosion at Cinnamon Bay have had little effect in this environment of low wave energies, but sand deficiency. The appropriate environmental focus for management of reef-beach systems is reef health and thus, water quality.     

Variation and evaluation of coastal salt marshes

Ten intertidal salt marshes along the Rhode Island coast were sampled and compared in terms of the relative standing crop and height of tallSpartina alterniflora, density of shoots, seed production and size, fish populations, and the abundance of grass shrimp, fiddler crabs, insects, and birds. The marshes ranged from 0.49 to 52.61 hectares (1.2 to 130 acres) and included fringe marsh in dense urban developments as well as unspoiled waterfowl preserves in rural isolation. Large variation in most parameters made it impossible to separate the sites with statistical significance using either univariate or multivariate techniques. Moreover, there was little meaningful intercorrelation among the parameters. Although more intensive sampling might make it possible to separate individual marshes with statistical rigor, these results suggest that the necessary effort may be too great to allow comparative field sampling to play a practical part in wetlands evaluation programs. The results also indicate that there is little, if any, correlation between visual esthetic perceptions of a marsh and its ecological characteristics. This work suggests that the development of ecological rating systems will not provide a reliable tool for the management of coastal wetlands.     

Self-organization theories and environmental management: The case of South Moresby,Canada

This article presents a new approach to the analysis and management of large-scale societal problems with complex ecological, economic, and social dimensions. The approach is based on the theory of self-organizing systems—complex, open, far-from-equilibrium systems with nonlinear dynamics. A brief overview and comparison of different self-organization theories (synergetics, self-organization theory, hypercycles, and autopoiesis) is presented in order to isolate the key characteristics of such systems.The approach is used to develop an analysis of the landuse controversy in the South Moresby area of the Queen Charlotte Islands, British Columbia, Canada. Critical variables are identified for each subsystem and classified by spatial and temporal scale, and discussed in terms of information content and internal/external origin. Eradication of sea otters, introduction of black-tailed deer, impacts of large-scale clearcut logging, sustainability of the coastal forest industry, and changing relations between native peoples and governments are discussed in detail to illustrate the system dynamics of the South Moresby sociobiophysical system. Finally, implications of the self-organizing sociobiophysical system view for regional analysis and management are identified.     

Regional Lake Trophic Patterns in the Northeastern United States: Three Approaches

N   = 11,076). Results were compared to a large, nonrandomly sampled data set for the same area compiled by Rohm and others and contrasted with lake trophic state information published in the National Water Quality Inventory: 1994 Report to Congress [305(b) report. Lakes across the entire Northeast were identified by EMAP data as 37.9% (±8.4%) oligotrophic, 40.1% (±9.7%) mesotrophic, 12.6% (±7.9%) eutrophic, and 9.3% (±6.3%) hypereutrophic. Lakes in the ADI and NEU generally are at a low, nearly identical trophic state (96% oligotrophic/mesotrophic), while those in the CLP are much richer (45% eutrophic). EMAP results are similar to results of the Rohm data set across the entire region. In the CLP, however, EMAP identified approximately 45% of the lakes as eutrophic/hypereutrophic, while the Rohm data set identified only 21% in these categories. Across the entire Northeast, the 305(b) report identified a much higher proportion (32.2%) of lakes in eutrophic condition and a much smaller proportion (19.8%) in oligotrophic condition than did the EMAP survey data (12.5% ± 7.9% and 37.9% ± 8.5%, respectively). Probability sampling has several advantages over nonrandom sampling when regional resource condition assessment is the goal.     

ESTIMATION OF WATER TEMPERATURE EXCEEDANCE PROBABILITIES USING THERMO-HYDRODYNAMIC MODELING1

ABSTRACT: A continuous simulation approach is proposed for estimating water temperature exceedance probabilities using thermo-hydrodynamic modeling. The approach uses (1) a deterministic unsteady flow and heat transport model, (2) continuous hydrological and meteorological data for a long historical period, and (3) synthetic records of tributary water temperatures and other model inputs. Representative historical records of streamflow, air temperatures, and other hydrometeorological variables are obtained from nearby gages. Stochastic modeling methods are used to construct synthetic records for other model inputs, including inflow water temperatures. An application of this deterministic-stochastic approach is presented for a complex waterway in northeastern Illinois with heat discharges from several power plants and wastewater treatment plants. Statistical results from the continuous simulations are compared to results obtained from traditional event simulations. The application illustrates the information that engineers and biologists can obtain for (1) evaluating compliance with water temperature standards, and (2) assessing the effect of water temperatures on aquatic habitat.     

Application of a scenario-based modeling system to evaluate the air quality impacts of future growth

The structure and design of future urban development can have significant adverse effects on air pollutant emissions as well as other environmental factors. When considering the future impact of growth on mobile source emissions, we generally model the increase in vehicle kilometers traveled (VKT) as a function of population growth. However, diverse and poorly planned urban development (i.e., urban sprawl) can force higher rates of motor vehicle use and in return increase levels of pollutant emissions than alternative land-use scenarios. The objective of this study is to develop and implement an air quality assessment tool that takes into account the influence of alternative growth and development scenarios on air quality.The use of scenario-based techniques in land use planning has been around since the late 1940s and been tested in many different applications to aid in decision-making. In this study, we introduce the development of an advanced interactive scenario-based land use and atmospheric chemistry modeling system coupled with a GIS (Geographical Information System) framework. The modeling system is designed to be modular and includes land use/land cover information, transportation, meteorological, emissions, and photochemical modeling components. The methods and modularity of the developed system allow its application to both broad areas and applications.To investigate the impact of possible land use change and urbanization, we evaluated a set of alternative future patterns of land use developed for a study area in Southwest California. Four land use and two population variants (increases of 500k and 1M) were considered. Overall, a Regional Low-Density Future was seen to have the highest pollutant emissions, largest increase in VKT, and the greatest impact on air quality. On the other hand, a Three-Centers Future appeared to be the most beneficial alternative future land-use scenario in terms of air quality. For all cases, the increase in population was the main factor leading to the change on predicted pollutant levels.