Extraction of natural gas from a confined coal aquifer requires the pumping of large amounts of groundwater, commonly referred to as produced water. Produced water from the extraction of coalbed natural gas is typically disposed into nearby constructed discharge ponds. The objective of this study was to collect produced water samples at outfalls and corresponding discharge ponds and monitor pH, electrical conductivity (EC), calcium (Ca), magnesium (Mg), sodium (Na), and alkalinity. Outfalls and corresponding discharge ponds were sampled from five different watersheds including Cheyenne River (CHR), Belle Fourche River (BFR), Little Powder River (LPR), Powder River (PR), and Tongue River (TR) within the Powder River Basin (PRB), Wyoming from 2003 to 2005. From Na, Ca, and Mg measurements, sodium adsorption ratios (SAR) were calculated, and used in a regression model. Results suggest that outfalls are chemically different from corresponding discharge ponds. Sodium, alkalinity, and pH all tend to increase, possibly due to environmental factors such as evaporation, while Ca decreased from outfalls to associated discharge ponds due to calcite precipitation. Watersheds examined in this study were chemically different form each other and most discharge ponds with in individual watersheds tended to increase in Na and SAR from 2003 to 2005. Since discharge pond water was chemically changing as a function of watershed chemistry, we predicted SAR of discharge pond water using a regression model. The predicted discharge pond water results suggested a high correlation (R ² = 0.83) to discharge well SAR. Overall, results of this study will be useful for landowners, water quality managers, and industry in properly managing produced water from the natural gas extraction.

Trace metal levels in the otoliths of the juvenile chum salmon Oncorhynchus keta were examined by means of laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS). Life history transect analyses showed that all otoliths had a central region with low Zn/Ca ratios (mean, 0.35-0.68 x 10-⁴), and thereafter the ratios increased abruptly in the freshwater growth zone (mean: 1.72-1.90 x 10-⁴) toward the edge of otolith. In regard to otolith Sr/Ca ratios, all specimens showed slightly higher values in the otolith core region, and thereafter the ratios showed constant values or values that decreased gradually toward the edge of the otolith in the freshwater growth zone (mean, 3.33-4.58 x 10-³). An abrupt increase was found in some specimens to 5-7 x 10-³ in the maximum levels around the otolith edge. The relationship between Sr/Ca and Zn/Ca ratios at each ablation in otoliths in both juvenile and adult salmons showed a significant correlation. Otolith Zn/Ca and Sr/Ca ratio patterns were seen to reflect the levels in ambient water environment. Thus, these findings indicate that Zn, like Sr, in teleost otoliths is an excellent tracer for reconstructing the ambient aquatic environmental conditions which individual fish have experienced.

The sampling and analysis properties of 1-stage and 2-stage filter-pack methods were studied in detail in monitoring of sulphur and nitrogen containing inorganic gases and particles (sulphur dioxide, sulphate, sum of nitric acid and nitrate and total ammonium). The limit of detection and the limit of quantitation for 24-h samples were estimated using the results of a short-term field experiment completed with available data from long-term monitoring and internal quality assurance. Furthermore, the combined expanded measurement uncertainty including sampling and analysis (Uₜₒₜ) was estimated for filter-pack methods in order to give a tool for distinguishing long-term trends in air quality from the measurement variability. Uₜₒₜ was found to be very near the analytical uncertainty when measuring higher air concentration levels, being ± 4.0% for sulphur concentrations > 1.0 μg m⁻³, ± 3.0% for sulphate concentrations > 0.5 μg m⁻³, ± 3.5% for the sum of nitrate and nitric acid concentrations > 0.3 μg m⁻³ and ± 4.5% for total ammonium concentrations > 0.8 μg m⁻³. At the lower air concentration range Uₜₒₜ increases significantly due to the field blank values. The precision of the 24-h filter-pack sample results expressed by means of modified median absolute difference (M.MAD) and coefficient of variance (CoV) gave 8.3% for sulphur dioxide and 5.4% for particulate sulphate. For the sum of gaseous nitric acid and particulate nitrate the CoV was 5.5% and for total ammonium 4.3%. In addition the suitability of the 24-h filter-pack methods in weekly sampling was proved.

We simulate the market for emission permits by considering uncertainty in emission inventory reports. The approach taken in this analysis is to enhance the emissions reported in each region by a certain part of their uncertainty when compliance with the Kyoto targets is being proved. While this formulation is not new in the literature, we define the uncertainty component in a way that enables comparison with the approach of effective permits presented in Nahorski, Horabik, and Jonas (2007) Compliance and emissions trading under the Kyoto protocol: Rules for uncertain inventories, (this issue). We show and explain that the transformation to effective permits bears additional costs apart from those resulting from shifting the Kyoto targets.

The recovery from acidification has led to the demand for more precise criteria for classification of acidification. The Swedish Environmental Protection Agency has revised Sweden's Ecological Quality Criteria for acidification to improve the correlation between the chemical acidification criteria and biological effects. This paper summarises the most relevant findings from several of the studies commissioned for this revision. The studies included data on water chemistry in 74 reference lakes in southern Sweden with data on fish in 61 of the lakes, as well as data on littoral fauna in 48 lakes. We found that the acidity variable most strongly correlated to the biota was the median pH from the current year. Our results probably do not reflect the mechanisms behind the negative effects of acidity on the biota, but are fully relevant for evaluation of monitoring data. The biogeochemical models used for predicting acidification reference conditions generate a pre-industrial buffering capacity. In order to get an ecologically more relevant criteria for acidification based on pH, we transferred the estimated change in buffering capacity into a corresponding change in pH. A change of 0.4 units was defined as the threshold for acidification. With this criterion a considerably lower number of Swedish lakes were classified as acidified when compared with the present Ecological Quality Criteria.

Pollution of the atmosphere with cadmium (Cd), mercury (Hg), and lead (Pb) is a consequence of human activities. Natural archives are necessary to reconstruct the long-term history of metal deposition because accurate measurement of atmospheric deposition is a recent accomplishment. Reconstructions require: (1) accurate determination of concentrations of elements and isotopes, (2) accurate chronology of archives, and (3) archives that faithfully record atmosphere deposition. The most useful long-term archives are accumulations of ice and snow, peat, and lake sediment. Quantification of Cd deposition is uncommon because of its low concentration and substantial chemical mobility. Nonetheless, trends in peat and lake sediment are similar to those of Hg and Pb since ca. 1800 a.d. Both Hg and Pb are relatively chemically immobile and thus the peat and lake archives are believed to record historic trends of atmospheric deposition. Isotopic and concentration studies of Pb indicate a history of northern hemisphere atmospheric pollution extending back prior to 0 a.d. Although measurements of Hg concentration are now routine, isotopic measurements are in their infancy. Some Hg pollution sources have unique isotopic ratios, thereby contributing unique signals to the total Hg. Maximum accumulation rates of Hg and Pb occur up to 10 years later than for Cd (1970s versus 1960s in eastern North America, perhaps slightly later in Europe). By 2004, deposition of Cd, Hg, and Pb had declined from peak values in eastern North America more than 75, 75, and 90%, respectively.

The aim of presented study was to determine the influence of long-term inundation on the changes in the content of polycyclic aromatic hydrocarbons. Two soils (B, MS) with differentiated properties were selected for the presented study. The experiment was carried out in 5-l containers, irrigated with distilled or post-sewage water for seven days. The study samples were collected directly after the water had been drained and then after seven, 14, 28 and 50 days. In the material collected, the content of polycyclic aromatic hydrocarbons was determined by means of the HPLC-UV method. The soils used for the presented experiment were characterised by differentiated PAH content levels. However, in both soils 28 days after water had been drained, a gradual increase of the PAH sum was noted. This increase was in relation to beginning of the experiment significantly higher in soil MS characterised by a lower PAH content (43% and 86%, respectively in the experiment with distilled and post-sewage water). The range of the PAH sum increase in soil B was from 28% to 38%. After the 28th day of the experiment, a decreasing trend was noted. The trend persisted until the last experimental date. Only in soil B, a decrease in the PAH up to a level close to the PAH level on the onset of the experiment was observed. In soil MS, PAH content on the last experimental date was still 25% (distilled water) and 52% (post-sewage water) higher than at the beginning of the experiment. In control soils (non-flooded), PAH content did not undergo any significant changes during the whole experimental period. In the presented studies, significant relationships between the values of some PAH content levels and Ca²⁺ ions content was noted.

The objective of this study was to check the effect of the use of a physico-chemical treatment on the clogging process of horizontal subsurface flow constructed wetlands by means of dynamic modelling. The hydraulic submodel was based on series as well as parallel branched complete stirred tanks of equal volume. The model was validated with data obtained from 2 identical experimental wetlands, which had a surface area of 0.54 m² and a water depth of 0.30 m, and that were monitored over a period of 5 months. One of the wetlands was fed with settled urban wastewater, whereas the other with the same wastewater, but previously treated with a physico-chemical treatment. In the model, pore volume reduction depends on the growth of bacteria and on solids retained. The effluent concentrations of COD and ammonium in both experimental wetlands were very similar in all the conditions tested, and therefore the physico-chemical treatment did not improve the removal efficiency. The model indicated that after 120 days of operation in some regions of the wetland fed with settled wastewater the porosity decreased in a 17%, whereas in the other wetlands it only decreased as much as 6%. The use of a prior physico-chemical treatment is a good alternative for avoiding an anticipated clogging of subsurface flow constructed wetlands.