Water Discharge Points Research Articles

The use of Radon (Rn222) isotopes to detect groundwater discharge in streams draining Table Mountain Group (TMG) aquifers

Environmental isotopes have been used for decades as natural tracers in studies aimed at understanding complex hydrogeological processes such as groundwater and surface water interactions. Radon (Rn222) is a naturally occurring, radioactive isotope which is produced from radium (Ra226) during the radioactive decay series of uranium (U238). Since U238 is present in most geological substrates, Rn222 is produced in various lithological structures and subsequently transported with groundwater through fractures and pore spaces in an aquifer towards surface water discharge points in rivers and springs. This study aimed to determine (i) the concentration of Rn222 within both surface water and groundwater in Table Mountain Group (TMG) aquifer systems, and (ii) the feasibility of using Rn222 isotopes as a natural tracer in groundwater-surface water interaction studies. This study was conducted in a highly fractured TMG aquifer system near Rawsonville, South Africa. Surface water from two perennial rivers (i.e. Gevonden and Molenaars), together with groundwater from a nearby borehole, were sampled and their corresponding Rn222 concentrations measured. Our study found median Rn222 concentrations in the Gevonden River of 76.4 Bq∙L-1 and 67.2 Bq∙L-1 in the dry and wet seasons, respectively. Nearly 12% of surface water samples exceeded 100 Bq∙L-1. These abnormally high Rn222 concentrations can only be attributed to the influx of groundwater with extremely high Rn222 concentrations. Under ambient (no pumping) conditions, Rn222 concentrations in groundwater range between 130–270 Bq∙L-1. However, when the borehole was pumped, and inflowing water from the surrounding aquifer was sampled, even higher Rn222 concentrations (391–593 Bq∙L-1) were measured. These extremely high Rn222 concentrations in groundwater are believed to be attributed to the underlying granitic geology and the prevalence of faults. The use of Rn222 isotopes as an environmental tracer in groundwater–surface water interaction studies is therefore regarded as a feasible option in similar highly fractured aquifer systems.

ОСОБЕННОСТИ ПОВЕДЕНИЯ ХИМИЧЕСКИХ ЭЛЕМЕНТОВ В СИСТЕМЕ ВОДА–ПОРОДА РАЙОНА РАЗРАБАТЫВАЕМОГО КАРЬЕРА БУТОВОГО КАМНЯ В ПИТКЯРАНТСКОМ РУДНОМ РАЙОНЕ (КАРЕЛИЯ)

Актуальность. Изучение особенностей перераспределения химических элементов в системе вода–порода в районах, где ведется активная разработка месторождений полезных ископаемых, актуально ввиду потенциального влияния этих процессов на экологическую обстановку и изменение геохимических условий природной среды. В частности, это важно для выбранного района, который входит в площадь водосбора крупнейшего природного резервуара пресной воды в Европе – Ладожского озера. Целью представленного исследования является изучение выноса химических элементов водой из гранитоидных пород, вскрытых карьером, и их дальнейшего поведения в природных водах и донных отложениях района. Объектом исследования являются природные воды и донные отложения района разрабатываемого карьера бутового камня (Питкярантский рудный район, республика Карелия). Авторы проследили изменения химического состава природных вод и связанных с ними донных отложений по мере движения воды от ее сброса из карьера до впадения в речную сеть. Методы. Анализ химического состава природных вод и донных отложений проведен стандартными методами: потенциометрия, титриметрия, ICP-AES, ICP-MS. Исследования минералов в составе пород карьера бутового камня проведено при помощи LA-ICP-MS, химический состав горных пород изучен методами XRF, ICP-MS и ICP-AES. Физико-химическое моделирование форм нахождения в природных водах и осаждения минералов проведено в программном комплексе HydroGeo. Верификация модели проведена на основе анализа химического состава донных отложений. Результаты. В изученных водных объектах в отдельных точках отмечены превышения ПДК Fe, Mn, Cu, Zn, Mo, V. При удалении от карьера бутового камня снижается величина общей минерализации природных вод и содержание макрокомпонетов, а также Sr, U, V, Mo, Zn, Cd. Концентрация железа, наоборот, увеличивается ввиду роста содержания органического вещества в воде. В донных отложениях пик концентрации многих элементов (Fe, Mn, Co, Cu, Zn, Cs, Ce, La, Y) наблюдается в точке сброса воды из карьера. Максимальное содержание U отмечается чуть ниже по потоку изучаемых вод, что согласуется с данными по составу донных отложений и моделирования, которые указывают на возможность выпадения уранинита из водного раствора в водоеме, сформировавшемся при сбросе воды из карьера бутового камня и истоке ручья, берущего начало в этом водоеме. Роль органического вещества в изученных водах высока для процесса накопления железа в воде за счет образования устойчивого гидроксо-фульватного комплекса железа, а также для редкоземельных элементов за счет образования комплекса с гуминовой кислотой. Анализ распространенности, форм нахождения и осаждения химических элементов позволили заключить, что эксплуатация карьера бутового камня вносит существенный вклад в перераспределение химических элементов в изучаемом районе.

Hydrometeorological factors determining the development of water table cave patterns in high alpine zones. The Ordesa and Monte Perdido National Park, NE Spain

This study is focussed on the geomorphological characterization and the processes driving the evolution of the highest karst system in Western Europe, which is located in the Ordesa and Monte Perdido National Park (PNOMP), in the central-southern Pyrenees. The karst system does not seem to have a well-developed epikarst. The studied area shows a karst network of polygenic branchwork type in the vadose zone. Additionally, the explored karst conduits in the epiphreatic zone show a water table cave pattern that is different to the looping one, which is the expected cave pattern development for a karst located in a mountain zone where a high irregular recharge is expected. We have designed a conceptual recharge model through a multidisciplinary approach, which has included the making of a new detailed geological and hydrogeological map of the study area, morphometric analysis of cavities, tests with fluorescent dye tracers and hydrometeorological monitoring of the karst system associated with the Garcés Spring. This spring, together with the Font Blanca Spring, constitutes the main water discharge point of the hydrogeological system. The conceptual recharge model explains how the observed unexpected cave pattern has developed in this karst.

Smart Sewers 1: Sewer Configuration at Rural Houses

The layout of houses and other buildings impacts the way in which foul sewer pipework is positioned internally and externally. Less water to waste through conservation measures reduces the distance that gross solids transfer in sewers and increases the number of sewer blockages. Dwelling houses are often laid out where the solids from faecal flushes are at the head of the sewer line with other flows entering downstream. Discharges from appliances such as washing machines, dishwashers, baths, showers and kitchen/utility sinks are often not utilised in the transfer of the gross solids when they enter downstream of the faecal flushes. At present, no recommendations or specific design guidance exist regarding the design of internal building layouts relating to sewer configuration requirements. Furthermore, to date, no specific research exists which examines pipeline configuration scenarios outside buildings in terms of the link between multiple grey water discharge points and solid transfer in a sewer system. The aim of this study was to investigate sewer layout at houses in terms of maximising greywater flow in relation to solid transfer. This study showed that smart sewers are needed which utilise all the foul water leaving a building as it was found that up to 100% of greywater in some instances is completely missed out in terms of solid transfer. Consequently, optimal sewer design is far from being realised and internal building layouts should be designed with consideration of the faecal flushes and greywater flows.

Prediction model for the water jet falling point in fire extinguishing based on a GA-BP neural network.

Past research on the process of extinguishing a fire typically used a traditional linear water jet falling point model and the results ignored external factors, such as environmental conditions and the status of the fire engine, even though the water jet falling point location prediction was often associated with these parameters and showed a nonlinear relationship. This paper constructed a BP (Back Propagation) neural network model. The fire gun nozzle characteristics were included as model inputs, and the water discharge point coordinates were the model outputs; thus, the model could precisely predict the water discharge point with small error and high precision to determine an accurate firing position and allow for the timely adjustment of the spray gun. To improve the slow convergence and local optimality problems of the BP neural network (BPNN), this paper further used a genetic algorithm to optimize the BPNN (GA-BPNN). The BPNN can be used to optimize the weights in the network to train them for global optimization. A genetic algorithm was introduced into the neural network approach, and the water jet landing prediction model was further improved. The simulation results showed that the prediction accuracy of the GA-BP model was better than that of the BPNN alone. The established model can accurately predict the location of the water jet, making the prediction results more useful for firefighters.

Current travertines precipitation related to artificial CO2 leakages from a natural reservoir (Gañuelas-Mazarrón Tertiary Basin, SE Spain)

In the framework of a natural CO2 reservoir with CO2 leakages as an analogue of a failed CO2 deep geological storage, the current precipitation of travertines and the associated upwelling of CO2-rich saline groundwater were analysed. This natural analogue is located in the Gañuelas-Mazarrón Tertiary Basin (SE Spain). The study comprises of the chemistry of both groundwater and travertines, including stable isotopes, mineralogy and petrography of the travertines, all this performed after a review of the geology of the basin. In this sense, the basin gathers the main features of a safe natural CO2 reservoir in a deep saline aquifer sealed by a thick marl formation. The aquifer was artificially perturbed by the drilling of wells, inducing the travertines precipitation at these water discharge points. Groundwater is saline, slightly acid, oversaturated in aragonite and calcite and with significant concentrations of heavy elements, some of them toxic. From an isotopic viewpoint, the relative constant δ13C-DIC values suggest that carbon is mainly inorganic in origin with minor organic and mantle contributions. Travertines are basically composed of aragonite or calcite, their precipitation being controlled by a sudden CO2 degassing and minor biological activity. Their δ13C signatures indicate that carbon mainly has an inorganic origin, although some contribution of organic carbon must be considered as well. Furthermore, these carbonate deposits did not precipitate in isotopic equilibrium, as determined by δ18O values. Finally, it is suggested that the appearance of travertines along with their carbon isotopic signatures represent efficient tools for detecting CO2 leakages from any CO2 storage site.

Mathematical calculation of additional cooling methods to achieve the established temperature regime at the reservoir-cooler of Zainskaya state district power plant

A natural and technical complex, including the industrial part - the turbine condenser and cooling system, and the natural part - the cooling reservoir with the surrounding atmosphere, is one of the options for the operation of the circulating system technical water supply of thermal power station and nuclear power station. For cooling equipment Zainskaya state district power plant as a pond-cooler is used Zainskoe reservoir. According to the available data on the reservoir-cooler of Zainskaya state district power plant, the average water temperature in comparison with the natural temperature of the water body in summer months exceeds the current requirements, which negatively affects the functioning of the reservoir and the operation of the power plant itself. The mathematical analysis of the reservoir cooling capacity and the technical justification for the introduction of additional methods for achieving the optimum temperature regime at the point of heat exchange water discharge of the Zainskaya state district power plant are carried out in the article. According to the obtained results, the expected water temperature in the hottest month of the year as a result of wastewater discharge will not exceed a critical temperature maximum of 28 ° C.

Assessment of water quality of Garmat Ali river for irrigation purposes

This study investigates the suitability of Garmat Ali river (Iraq) for irrigation uses. Two stations were chosen: station A; far from any polluted water discharge point, and station C; near to a very contaminated water discharge point). Water samples were picked up and tested for pH, electrical conductivity, total dissolved solids, sodium, potassium, calcium, magnesium, bicarbonate, sulfate, chlorine, and nitrate. Three samples were collected in January and March 2019 from each site, to reflect the wet season in Iraq. Besides the classification of water quality parameters of Garmat Ali river for watering, other parameters were also calculated, such as sodium adsorption ratio, soluble sodium percentage, exchangeable sodium percentage, magnesium hazard, kelly ratio, permeability index, and potential salinity. According to the Food and Agriculture Organization (FAO) guidelines, the overall results showed that the salinity and chlorine were within the range that causing severe problem to plants. In addition, sodium toxicity and hazard were classified the river water as unsuitable for irrigation. Potential salinity was under the class of unsuitable for irrigation. Bicarbonate hazard was under the category “slight to moderate”. However, the remaining parameters were within the accepted range. Most of the contaminants were higher in the polluted station.

Evaluation of River Water Quality and Indices for Fish Farm Development (Case study: Kabkian River)

Background: Fish farming requires proper water quality to increase productivity and reduce health risk exposures while they are emission sources in rivers themselves. The purpose of this research is to evaluate river water quality regarding physicochemical parameters coupling with water quality index (WQI) to study the viability of fish farming expansion. Methods: This study is carried out both as field survey and laboratory analysis. Samples were taken bimonthly in 6 periods (2016-2017) from 21 stations from Kabkian River, Iran, including the water body and discharge points. Afterwards, results were statistically analyzed by T-Test regarding the spatial and temporal specifications with SPSS. Results: Experimental results show that dissolved oxygen is over 7 mg/L and WQI is 70 which is classified as good. However, temporal variations of BOD, COD and nitrite concentrations are significant and their average are rather high about 10, 16 and 0.14 mg/L, respectively. Since, BOD is the only parameter with significant spatial variations, it is introduced as the main parameter for river water quality monitoring. Conclusion: Overally, Kabkian water quality is suitable for fish farming. However, due to the possibility of presence of malachite green, it is highly recommended that strict monitoring should be implemented upstream to control fish farm discharges and reduce health risk exposures.n n

Impact of coastal power plant cooling system on planktonic diversity of a polluted creek system

A tropical coastal power plant with a once-through cooling system that pumped sea water along with tiny marine phytoplankton and zooplankton for waste heat discharge recorded reduction in the population density of these organisms by 64% and 93%, respectively, at the discharge site. The depletion of organic carbon is 0.69 tons per annum with loss of 20 to 24 lakhs fish fecundity. The synergistic effect of tropical summer ambiance and waste heat discharge from the power plant considerably reduced the phytoplankton population in the coolant water discharge point during April, June, and July. This resulted in changes in the phytoplankton community structure from Bacillariophyceae > Dyanophyceae > Cyanophyceae to Bacillariophyceae > Cyanophyceae > Dyanophyceae in the Ennore creek system. A unique epibiotic assemblage of the diatoms Licmophora juergensii and Licmophora flabellata was observed on Phormidium sp., a mat-forming Cyanobacterium preharbored along the 4.5-km-long transport channel of the cooling tower blow out of the thermal power plant. These pedunculate fouling diatoms have a symbiotic association with Phormidium sp., which grows few microns high above the substrate, thus creating obstructive flow in cooling water channels of the power plant. Further, loss of fish larvae during zooplankton population reduction creates an impact on the local fishery. However, the emerging scenario of global warming predicts that the migration of fish population toward cooler regions shall further aggravate the fishery reduction near the power plant cooling operation along the tropical coasts. The marine organisms living in tropical coastal waters operated at upper limits of thermal tolerance produce a demand for the regulatory bodies in India to enforce a drop in discharge criteria for coolant water, with the pre-existing power stations permitted to discharge up to 10 °C above the ambient temperature and newer power stations permitted to discharge a maximum of 7 °C. It becomes a requisite for power stations to draw additional seawater along with the plankton. Therefore, an emerging technology of subsurface intake systems called beachwell that resolves the issue of coolant water intake without biota was advocated.

Особенности формирования и расчета обратных течений в Воткинском водохранилище (1d-постановка)

Issues of the contraflows formation in the Votkinsk Reservoir (the middle one in the sequence of the Kama reservoirs) have been studied. The water discharge regime through the Kama Hydro Power Plant determines the contraflow occurrence. The importance of the contraflow issues is caused by the risk of contaminated waters input to water intakes located upstream in respect of the waste water outlets. One of the major industrial agglomeration, namely the Perm-Krasnokamsk cluster with numerous water intakes and waste water discharge points, is located in the upstream part of the Votkinsk Reservoir with is the downstream reach of the Kama Reservoir. On the basis of assessment of the contraflows scale and the consequences for water users the water/economic and environmental limitations are set for the power plant operation regime including sanitary discharge volumes. The contraflows have been simulated as a result of digital solution of the Saint-Venant equation in 1D-definintion with input of the first type boundary conditions directly in the vicinity of the Votkinsk Power Station dam. We have assessed the reservoir morphometry role in the contraflows formation. Outputs of the comparative experiments performed at different schematic models of the Votkinsk Reservoir have shown that reflection of the level lowering straight wave from the Votkinsk Power Station dam is the determining factor of the contraflows formation rather than peculiarities of the morphometry. When decreasing the period of water discharge to the downstream reach the zone of contraflows formation is displacing towards the Votkins Power Plant dam.

Effect of thermal power plant effluent on the physico-chemical parameters of Thoothukudi coastal waters, South India

The coolant water discharge area of a thermal power plant in Thoothukudi, Tamil Nadu was investigated to elucidate the changes in the coastal water and sediment quality characteristics. Water and sediment samples were collected from three different stations namely station I (about 900 m away from coolant water discharge point), station II (about 1250 m away from discharge point) and station III (about 1600 m away from discharge point) and analysed for the various physico-chemical parameters. The dissolved oxygen level increased with increasing distance from the discharge point i.e., from station I to III, whereas the temperature values showed decreasing trend. Concentration of ammonia, nitrite, nitrate and phosphate were found in the decreasing order from station I, II and III. Accumulation of heavy metals was in the order of Al > Fe > Cu > Zn in the water samples and found slightly higher than the standards prescribed by European countries. The exchangeable phosphorus fraction appeared as the first major contributor among the different fractions of total sedimentary phosphorus. This study clearly explains that the effluent discharge in adjoining coastal waters affects the water and sediment quality.

Formation process and mechanism of seepage channels around grout curtain from microseismic monitoring: A case study of Zhangmatun iron mine, China

The grout curtain in Zhangmatun iron mine, China, suffers from the leakage of water due to the influence of multiple factors including inadequate grouting area, weak rock and mining disturbance. Water seepage through rock mass around the grout curtain further deteriorates the water plugging effect of the grout curtain and poses a potential hazard to workers underground. Thus, a microseismic (MS) monitoring system was established in the Zhangmatun iron mine. In the present paper, a MS monitoring analysis method for assessing a potential seepage channel is proposed. Using the proposed MS monitoring analysis method, the dip, dip angle and center depth of the potential seepage plane across the grout curtain in Zhangmatun iron mine are determined to be 126.1° E, 53.97° and 275m, respectively. The spatial and temporal behaviors of density distribution, source parameters and cracking type of the seismic source are analyzed to reveal the initiation, propagation, coalescence of seepage channel located at the southwest of the iron mine. Four types of local seepage channel formation processes are summarized by correlating the mechanism of microcracking. Two main weak areas around the grout curtain at the levels of −230m and −318m are identified and two seepage paths whose water discharge points are localized to the roof of stope 9, 10 and sidewall of stope 10 are determined, respectively. Our study helps to get a better understanding of damage and failure of rock mass around grout curtain and thus provides a basis for taking reinforcement measures to secure the stability of grout curtain in mines.

Comprehensive Groundwater Balance Development to Characterize Selenium Loading to Surface Water Channels in Orange County, California

Selenium concentrations are elevated above water quality criteria in several tributaries of Newport Bay. A watershed-scale hydrogeologic study was performed to identify processes driving selenium transport in the former “Swamp of the Frogs” area (cities of Santa Ana, Irvine, and Tustin). The former Swamp of the Frogs area was a depositional environment that historically received regional surface water runoff and accumulated naturally occurring selenium-bearing sediments from the larger watershed. Development beginning in the early 20th century included surface water channel installation that lowered the water table and drained the wetland, mobilizing selenium. A comprehensive groundwater/surface water balance was conducted in order to constrain hydrologic processes that continue to drive selenium mobilization into the surface water channels. The groundwater budget included precipitation and irrigation percolation modeling and groundwater flow mapping from thousands of publicly-available groundwater level measurements. Groundwater balance results indicated that lateral groundwater flow from upgradient alluvial-fan recharge areas accounts for most of the groundwater input to the former wetland area with additional input supplied by deep percolation of precipitation within the former wetland area itself, deep percolation of irrigation, and sewer/water line leakage. Overlaying selenium concentration data from groundwater wells and surface water sampling locations confirmed that selenium concentrations are similar in groundwater and nearby groundwater-to-surface water discharge points (e.g., weepholes). Results supported a Best Management Practice (BMP) Strategic Plan developed in compliance with a regulatory order prescribing numeric limitations on groundwater-related discharges of selenium in the watershed.

Lead isotope fingerprinting used as a tracer of lead pollution in marine sediments from Botany Bay and Port Hacking estuaries, southern Sydney, Australia

Anthropogenic lead has been released into environmental ecosystems via human activities; essentially from mining, smelting of lead, leaded gasoline and industrial activities. In order to explore the source apportionment and historic record of lead pollution in the marine sediments, concentration of lead was determined from the Botany Bay and Port Hacking estuaries, south of Sydney, Australia. Areas with the highest concentrations of lead in the sediment samples were analysed by inductively coupled plasma-mass spectrometry (ICP-MS) for lead isotopes to effectively identify the metal contamination source. In addition, other sediment samples were collected from cores at 40 cm depth to represent the natural background composition. The study found that the total lead in the tested marine sediments varied from 75.6 mg/kg to 582.2 mg/kg. The 206Pb/204Pb showed a decline towards the current surface sediment. Assuming that the natural background source of lead remains the same in terms of both isotopic signature and accumulation rate, the decline in 206Pb/204Pb indicated a rise in the contribution of old lead to the sediment, mainly from gasoline fumes (car and boat exhausts) and paint. This is because the samples came from close to water discharge points which have concentrated the catchment lead via stormwater runoff.

Исследование накопления радионуклидов озерной лягушкой (Pelophylax ridibundus Pall.) в водных экосистемах как индикатор антропогенного загрязнения

Accumulation of anthropogenic 90Sr and 137Cs radio nuclides in lake frog (Pelophylax ridibundus Pall.) in the subjected to anthropogenic pollution regions of Beloyarka and Verkhni Tagil reservoirs location, the Urals, has been investigated. Conduction of this research was caused by wide spreading of this amphibian species in water bodies, absence in literature any data on the lake frog radioecology, as well as by the fact that this research outcome can serve a good indicator of anthropogenic pollution. Levels of the radio nuclides accumulation by this frog in the Beloyarka nuclear power station industrial/storm water sewer characterized by the increased 90Sr and 137Cs discharge to the channel ecosystem have been determined. The Tagil River at the point of water discharge from the Verkhni Tagil reservoir (the Verkhni Tagil thermal power station basin cooler) was chosen as a reference point for comparison. Any reliable difference in radio nuclides accumulation depending on amphibian sex and age was not found. Comparative radio nuclides accumulation levels for lake frog in comparison with other species of aquatic ecosystem have been assessed. The industrial/storm water channel example has shown that 90Sr accumulation is decreasing in the following series: plankton > frogs, plants, ground > ichthyofauna, and for 137Cs: plankton > plants > frogs, ground > ichthyofauna. Содержание 137Cs content in animals from the channel appeared to be reliably lower than in the Tagil River. It was supposed that probably there was an unidentified source of amphibian radioactive contamination where from 137Cs was transferred to the Tagil River.

URBAN CITIES AND WASTE GENERATION IN DEVELOPING COUNTRIES: A GIS EVALUATION OF TWO CITIES IN BURKINA FASO

Cities in developing countries are faced waste management challenges in terms of quantity and quality. Most of the time, solid and liquid wastes are dumped on street and open spaces. Uncontrolled waste dumped has led to diverse kind of health problems. The purpose of this article is to characterize urban cities and evaluate their waste generation using the Geographical Information System (GIS). The focus is on two cities in Burkina Faso. Specific variables which were considered during the survey include urban fabric, grey water outlets and household garbage dumps sites/techniques. The study shows that in the two cities, the most dominant urban fabric is low standard of living (about 64% of housing in Fada and 62% of housing in Pouytenga). The urban fabric is also characterized by the existence of empty spaces. Overall, the average density of grey water discharge points is 0.85 points and 5.7 points per ha of street in Fada N’Gourma and Pouytenga respectively. The average density of solid waste dumps is 1.45 waste dumps per ha street and 7 waste dumps per ha street in Fada N'Gourma and Pouytenga respectively. In case of urgent waste management intervention, the priority areas for speedy intervention are area 10 in Fada N’Gourma, areas 2 and 5 in Pouytenga. GIS applied to waste management can be a decision making tool for urban planners in developing country.

URBAN CITIES AND WASTE GENERATION IN DEVELOPING COUNTRIES: A GIS EVALUATION OF TWO CITIES IN BURKINA FASO

Cities in developing countries are faced waste management challenges in terms of quantity and quality. Most of the time, solid and liquid wastes are dumped on street and open spaces. Uncontrolled waste dumped has led to diverse kind of health problems. The purpose of this article is to characterize urban cities and evaluate their waste generation using the Geographical Information System (GIS). The focus is on two cities in Burkina Faso. Specific variables which were considered during the survey include urban fabric, grey water outlets and household garbage dumps sites/techniques. The study shows that in the two cities, the most dominant urban fabric is low standard of living (about 64% of housing in Fada and 62% of housing in Pouytenga). The urban fabric is also characterized by the existence of empty spaces. Overall, the average density of grey water discharge points is 0.85 points and 5.7 points per ha of street in Fada N’Gourma and Pouytenga respectively. The average density of solid waste dumps is 1.45 waste dumps per ha street and 7 waste dumps per ha street in Fada N'Gourma and Pouytenga respectively. In case of urgent waste management intervention, the priority areas for speedy intervention are area 10 in Fada N’Gourma, areas 2 and 5 in Pouytenga. GIS applied to waste management can be a decision making tool for urban planners in developing country.

삼보광산 수계 하천수질 및 퇴적토의 오염도 평가

BACKGROUND: Mine drainage from metal mining districts is a well-recognized source of environmental contamination. Oxidation of metal sulfides in mines, mine dumps and tailing impoundments produces acidic, metal-rich waters that can contaminate the local surface water and soil. METHODS AND RESULTS: This experiment was carried out to investigate the pollution assessment of heavy metal on the water quality of mine drainage, paddy soils and sediment in lower watershed affected by mine drainage of the Sambo mine. The average concentrations of dissolved Cd (0.018∼0.035 mg/L) in mine drainage discharged from the main waste rock dumps(WRD) was higher than the water quality standards (0.01 mg/L) for agricultural water in Korea. Also, the average concentrations of dissolved Zn, Fe and Mn were higher than those of recommended maximum concentrations (Zn 2.0, Fe 5.0, Mn 0.2 mg/L) of trace metal in irrigation water proposed by FAO (1994). The average contents of Pb and Zn in paddy soils was higher than those of standard level for soil contamination(Pb 200, Zn 300 mg/kg) in agricultural soil by Soil Environmental Conservation Act in Korea. Also, the concentrations of Cd, Pb and Zn in sediment were higher than those of standard level for soil contamination (Cd 10, Pb 400, Zn 600 mg/L) in waterway soil by Soil Environmental Conservation Act in Korea. The enrichment factor (EFc) of heavy metals in stream sediments were in the order as Cd>Pb>Zn> As>Cu>Cr>Ni. Also, the geoaccumulation index (Igeo) of heavy metals in stream sediments were in the order as Zn>Cd>Pb>Cu>As>Cr>Ni, specially, the geoaccumulation index (Igeo) of Zn (Igeo 3.1∼6.2) were relatively higher than that of other metals in sediment. CONCLUSION(s): The results indicate that stream water and sediment were affected by mine drainage discharged from the Sambo mine at least to a distance of 1 km downstream (SN-1, SN-2) of the mine water discharge point.

Fecal coliforms, caffeine and carbamazepine in stormwater collection systems in a large urban area

Water samples from streams, brooks and storm sewer outfall pipes that collect storm waters across the Island of Montréal were analyzed for caffeine, carbamazepine and fecal coliforms. All samples contained various concentrations of these tracers, indicating a widespread sanitary contamination in urban environments. Fecal coliforms and caffeine levels ranged over several orders of magnitude with a modest correlation between caffeine and fecal coliforms ( R 2 value of 0.558). An arbitrary threshold of 400 ng caffeine L −1 allows us to identify samples with an elevated fecal contamination, as defined by more than 200 colony-forming units per 100 mL (cfu 100 mL −1) of fecal coliforms. Low caffeine levels were sporadically related to high fecal coliform counts. Lower levels of caffeine and fecal coliforms were observed in the brooks while the larger streams and storm water discharge points contained over ten times more. The carbamazepine data showed little or no apparent correlation to caffeine. These data suggest that this storm water collection system, located in a highly urbanized urban environment, is widely contaminated by domestic sewers as indicated by the ubiquitous presence of fecal contaminants as well as caffeine and carbamazepine. Caffeine concentrations were relatively well correlated to fecal coliforms, and could potentially be used as a chemical indicator of the level of contamination by sanitary sources. The carbamazepine data was not significantly correlated to fecal coliforms and of little use in this dataset.