Occurrence of aminopolycarboxylates in the aquatic environment of Germany

Aminopolycarboxylic acids, such as ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA), diethylenetriaminepentaacetic acid (DTPA), 1,3-propylenediaminetetraacetic acid (1,3-PDTA), beta-alaninediacetic acid (beta-ADA), and methylglycinediacetic acid (MGDA), are used in large quantities in a broad range of industrial applications and domestic products in order to solubilize or inactivate various metal ions by complex formation. Due to the wide field of their application, their high polarity and partly low degradability, these substances reach the aquatic environment at considerable concentrations (in the microg/L-range) and have also been detected in drinking water. This review evaluates and summarizes the results of long-term research projects, monitoring programs, and published papers concerning the pollution of the aquatic environment by aminopolycarboxylates in Germany. Concentrations and loads of aminopolycarboxylates are presented for various types of water including industrial and domestic waste waters, surface waters (rivers and lakes), raw waters, and drinking waters.     

Nitrate Leaching From a Mountain Forest Ecosystem with Gleysols Subjected to Experimentally Increased N Deposition

Nitrate leaching was measured over seven years of nitrogen (N) addition in a paired-catchment experiment in Alptal, central Switzerland (altitude: 1200 m, bulk N deposition: 12 kg ha^-1 a^-1). Two forested catchments (1500 m² each) dominated by Picea abies) were delimited by trenches in the Gleysols. NH₄NO₃ was added to one of the catchments using sprinklers. During the first year, the N addition was labelled with ¹⁵N. Additionally, soil N transformationswere studied in replicated plots. Pre-treatment NO₃ ^--N leaching was 4 kg ha^-1 a^-1 from both catchments, and remained between 2.5 and 4.8 kg ha^-1 a^-1 in the control catchment. The first year of treatment induced an additional leaching of 3.1 kg ha^-1, almost 90% of which was labelled with ¹⁵N, indicating that it did not cycle through the large N pools of the ecosystem (soil organic matter and plants). These losses partly correspond to NO₃ ^- from precipitation bypassing the soil due to preferential flow. During rain or snowmelt events, NO₃ ^- concentration peaks as the water table is rising, indicating flushing from the soil. Nitrification occurs temporarily along the water flow paths in the soil and can be the source of NO₃ ^- flushing. Its isotopic signature however, shows that this release mainly affects recently applied N, stored only between runoff events or up to a few weeks. At first, the ecosystem retained 90% of the added N (2/3 in the soil), but NO₃ ^- losses increased from 10 to 30% within 7 yr, indicating that the ecosystem became progressively N saturated.     

LAKE ONTARIO REGULATION UNDER TRANSPOSED CLIMATES1

ABSTRACT: The implications of Lake Ontario regulation under transposed climates with changed means and variability are presented for seasonal and annual time scales. The current regulation plan is evaluated with climates other than the climate for which it was developed and tested. This provides insight into potential conflicts and management issues, development of regulation criteria for extreme conditions, and potential modification of the regulation plan. Transposed climates from the southeastern and south central continental United States are applied to thermodynamic models of the Great Lakes and hydrologic models of their watersheds; these climates provide four alternative scenarios of water supplies to Lake Ontario. The scenarios are analyzed with reference to the present Great Lakes climate. The responses of the Lake Ontario regulation plan to the transposed climate scenarios illustrate several key issues: (1) historical water supplies should no longer be the sole basis for testing and developing lake regulation plans; (2) during extreme supply conditions, none of the regulation criteria can be met simultaneously, priority of interests may change, and new interests may need to be considered, potentially requiring substantial revision to the Boundary Waters Treaty of 1909; (3) revised regulation criteria should be based on ecosystem health and socio-economic benefits for a wider spectrum of interests and not on frequencies and ranges of levels and flows of the historical climate; and (4) operational management of the lake should be improved under the present climate, and under any future climate with more variability, through the use of improved water supply forecasts and monitoring of current hydrologic conditions.     

400 YEARS OF CENTRAL CALIFORNIA PRECIPITATION VARIABILITY RECONSTRUCTED FROM TREE-RINGS1

ABSTRACT: Coastal central California is a region that has never been the subject of tree-ring studies. New tree-ring chronologies developed from cores of big cone spruce (Pseudotusuga macrocarpa (Torr.) Mayr.) growing in the Transverse Ranges of central Santa Barbara county were used to reconstruct precipitation fluctuations for this region. To verify the new reconstructions, calibration with recorded rainfall using cross-validation, comparison with other reconstructions, and documentary evidence from historical sources were utilized. The precipitation reconstructions show that there have not been fluctuations in mean precipitation on time scales longer than 30 years, but there have been major fluctuations in precipitation variability including changes in the frequency of extremes and rare events that have not occurred in the modern record.     

The MYSound Project: building an estuary-wide monitoring network for Long Island Sound,USA

A network of five water quality monitoring stations has been established in Long Island Sound, measuring temperature, salinity, and dissolved oxygen since 1999. The stations are located in areas of extreme water quality degradation (western Long Island Sound) as well as in pristine areas (eastern Long Island Sound). The data from these stations are collected every 15 minutes and posted to the project web site in real time as provisional data. After subsequent quality assurance procedures, the data are archived to the project File Transfer Protocol (FSP) site for downloading by the user community. The network of stations is in part supported logistically by a number of partners, including state and local agencies, schools, and non-governmental organizations. Data from the monitoring programs of some of these partners are also published to the project website providing a more comprehensive and complete picture of the status of the Sound than can be provided independently. This repository of information is used by marine educators, resource managers, scientists, and the general public, each with a different end purpose. We use the data from two of the stations to show that these high frequency time series measurements can be used to complement and enhance other monitoring programs within the Sound, documenting in greater detail the occurrence and duration of hypoxic events.