Behavior of Metals Under Different Seasonal Conditions: Effects on the Quality of a Mexico–USA Border River

Spatial and seasonal mobilization trends of metals in surface water were evaluated in the US–Mexico San Pedro River (SPR). Water samples were collected at five sampling stations for the analysis of dissolved oxygen, pH, electric conductivity, sulfates, and metals (Cd, Cu, Fe, Mn, Pb, and Zn). Quality of the water was characterized through Ecological Criteria of Water Quality (ECWQ) established in Mexico and Water Quality Criteria (Environmental Protection Agency (EPA)). High total metal concentrations were detected as follows: Fe?>?Cu?>?Mn?>?Zn?>?Pb?>?Cd. Metal concentrations were slightly higher in dry season than in rainy season: Cd (below detection limit (BDL)–0.21 mg L^?1), Cu (BDL–13 mg L^?1), Fe (0.16–345 mg L^?1), Mn (0.12–52 mg L^?1), Pb (BDL–0.48 mg L^?1), and Zn (0.03–17.8 mg L^?1). Low pH and dissolved oxygen values as well as high sulfate content were detected in both seasons. High values of metals (Cd, Cu, Fe, Mn, Pb, Zn) were detected at station E1 representing pollution source, as well as at stations E2 (Cd, Cu, Fe, Mn), E3 (Fe, Mn, Pb), and E4 and E5 (Fe, Mn). Detected concentrations exceeded maximum permissible established in ECWQ and Water Quality Criteria (EPA). Efflorescence salts on sediments in the dry season could increase levels of metals in water column. This study provides valuable information on the potential mobility of metals in surface water of SPR located in an arid environment where transport processes are strongly linked to climate. The information derived from this study should help the regional and national authorities to address present environmental regulations.     

Metal concentrations in the ground water of the Ouachita Mountains,Arkansas, U.S.A.

Ninety-one ground water samples (predominantly from springs) in two mineralized areas of the Ouachita Mountains in west-central Arkansas, were analyzed for Fe, Mn, Zn, Cu, Co, Ni, Pb, Hg, Sb, Sr, Ba, Ca, and Li. These areas contain Mn, barite, strontianite, cinnabar, stibnite and scattered Pb-Zn mineralization, Cumulative frequency curves were used to determine the threshold and anomalous concentrations for each element in the two areas. These values were, in general, higher in the ground water from the more mineralized area for several of the base metals, but most notably for Mn and Fe, the principal metals in the Mn oxide minerals. The United States Environmental Protection Agency (EPA, 1976) criteria for Fe (300 μg L ^?1) and Mn (50 μg L^?1) in drinking water were exceeded, respectively, in 34% and 30% of the springs in Area I, and 13% and 23% in Area II. One spring exceeded the EPA Hg criterion (2 μg L^?1) and 3 springs exceeded the 50 μg L^?1 criterion for Pb. In spite of the large number of anomalous Ba concentrations, the highest concentration of Ba was 930 μg L^?1 (EPA criterion 1000 μg L ^?1).     

Indicator bacteria in water and stream sediments near the snowy range in Southern Wyoming

Water samples were taken at eight pools in streams in the Nash Fork watershed after snowmelt in the summer of I980. The watershed is below the Snowy Range escarpment, and principal land uses include skiing and other winter sports, sheep and cattle grazing, camping and fishing, and summer homes. Water samples taken before and after disturbing streambottom sediment were analyzed for fecal coliforms and fecal streptococci. The levels of these indicator bacteria were low, except where sheep and cattle had recently grazed. Recreation use had little effect on bacterial densities. Disruption of streambottom sediment increased the mean concentration of fecal coliforms 1.7 times and fecal streptococci 2.7 times. Stream sediment was not a significant secondary source of fecal coliforms but appeared to harbor residual fecal streptococci that had survived and multiplied.     

Recovery,survival and dissemination of human enteric viruses in ocean waters receiving sewage in Hawaii

A commercial model of a portable virus concentrator operating on the principle of the membrane virus adsorption-elution technique was used to examine the recovery and distribution of human enteropathogenic viruses in Hawaiian waters receiving sewage wastes. Although operating at an efficiency of 20%, a variety of human enteric viruses was isolated, including polioviruses, Coxsackievirus and Echoviruses. Positive virus isolations were consistently made and at high concentrations at sampling stations closest to the sewage outfall. The frequency of virus isolations decreased with increasing distance from the discharge site. viruses were recovered in all directions from the outfall and even as far as 3.2 km east but not 6.4 km away from the discharge site. Tidal conditions to some degree were found to influence the dissemination of viruses. However, since sampling was generally performed at the surface of the water (0.3 to 0.6 m depth), the influence of winds and surface currents was more difficult to assess. Although a positive correlation was found between the presence of high concentrations of indicator coliforms and viruses in waters closest to the discharge site, this relationship was not seen at sampling stations farther away. At these latter stations, positive virus isolations with corresponding low to negligible coliform counts were made which reaffirmed previous published observations that human enteric viruses are relatively more stable in ocean water than coliform bacteria. Furthermore, the instability of the coliform bacteria consequently affected the fecal coliform/fecal streptococci ratios which thus invalidated the use of such ratios to indicate contamination by human wastes.     

Environmental fecal pollution and concentration power of the clam Chamelea gallina

This study is aimed to verify hygienic conditions of a commercially-important clam: Chamelea (Venus) gallina, widely distributed along the Italian coasts. Five mussel beds have been simultaneously surveyed, collecting samples of water, sediment and molluscs. Total coliforms, fecal coliforms, and fecal streptococci have been analyzed. Results show that this shellfish does not seem to accumulate enteric bacteria in spite of the microbial contamination of water and sediment.     

Coliforms,fecal coliforms,and fecal streptococci as indicators of water pollution

The presence and survival of coliforms, fecal coliforms, and fecal streptococci were studied in sewage treatment plants, heavily polluted rivers, a lake, and other drinking water sources. In all cases the fecal streptococci were generally more resistant to the natural water environment and to purification processes than the other indicator organisms and, at points distant from the original source of pollution were often the only indicators of the fecal nature of the pollution. In two of the systems studied the survival of the fecal streptococci paralleled the survival of enteric viruses better than the coliforms. The fecal streptococci may thus in certain cases provide a better estimate of the probable virus content in lightly contaminated water than the other two indicators.     

Fecal streptococci recoveries in different marine areas

The usual media and procedures were followed to measure the concentration of fecal streptococci (MPN on Azide Dextrose and Ethyl Violet Azide broths, membrane filtration on m-Enterococcus, KF and Pfizer Selective Enterococcus agars and according to the mE procedure) in samples collected along two different marine areas. The results were evaluated on the basis of three parameters: total concentrations, number of enterococci-like colonies (namely colonies gram positive, catalase negative, coccus shaped) and rate of strictly named fecal streptococci. From the results it appears that the various media and procedures employed gave different yields and their capacity to measure fecal streptococci varies according to the origin of samples. The accompanying bacterial flora may play an important role on the selectivity of each technique to measure the fecal streptococci.     

Heavy metal-antibiotic resistant bacteria in a lake recreational area

We undertook this study to determine the impact of urbanization on the microbial content of waters of a major recreational area of Lake Champlain. We followed changes in the numbers of total coliforms, fecal coliforms, fecal streptococci, and ascertained resistance of coliforms to heavy metals and antibiotics. We determined the distribution of these bacterial indicators of pollution by examining water and sediment samples. We also surveyed changes in physical parameters such as pH, temperature, turbidity, and wind direction to evaluate their effect on the examined aquatic microbial population. The level of all standard microbial indices of pollution frequently exceeded acceptable levels for recreational waters. Sediment samples indicated prolonged deposition of microbial pollutants, but efforts to demonstrate their release from sediment by dislocation and resuspension were inconclusive. We confirmed the presence of a population of heavy-metal and antibiotic-resistant coliforms isolated from harbor waters. Eighty-four percent of the total coliforms isolated from harbor water samples were resistant to one or more antibiotics and 96% were resistant to two or more heavy metals. The presence of these antibiotic resistant properties in coliforms, as well as elevated fecal coliform and fecal streptococci counts in both water and sediment samples, suggests to us that the bay is polluted by human fecal matter. This pollution probably emanates from south harbor sources and affects the shores of the major northern bathing area. It constitutes a potential hazard to public health because of the geophysical nature of the harbor and the location of the pollution source.     

Fecal contamination of marine sediments in a stretch of the Gulf of Naples

In the summer of 1980, 78 sediment samples were collected in the gulf of Naples. Samples were analyzed for total and fecal coliforms, fecal streptococci, sulfite reducer clostridia and total plate count. Over almost all of the area surveyed fecal pollution was widespread, but different indicators exhibited different distribution patterns. The presence of fecal streptococci was found prevalent with the respect to that of fecal coliforms.     

Effect of cooking on levels of ethylene dibromide residues in rice

Two studies were conducted to determine the effect that cooking has on the level of residues of ethylene dibromide (EDB) in rice. In the first study, 4 samples of long and medium grain polished white rice containing 113, 295, 956, and 1568 ppb EDB were cooked according to typical label directions. Three batches of cooked rice were prepared from each sample of polished rice and frozen until analysis; each batch was analyzed in duplicate. EDB levels in all cooked rice samples were less than 10 ppb. In the second study, conducted jointly by the Food and Drug Administration (FDA) and the Environmental Protection Agency (EPA), a sample of medium grain polished white rice containing about 1600 ppb EDB was cooked by each laboratory. Overall average EDB levels in rice analyzed immediately after cooking were 16 and 37 ppb for FDA and EPA, respectively. The corresponding frozen samples contained 8 and 39 ppb EDB. The 2 laboratories exchanged these frozen samples and reanalyzed them to check variability in the analytical procedure. FDA found 49 ppb EDB in the sample cooked by EPA and EPA found 8 ppb EDB in the sample cooked by FDA, thus indicating that analytical methodology was not a major source of variability. The range of EDB levels was therefore attributed to minor differences in the way the rice was cooked or handled immediately after cooking.     

Microbiological Quality Assessment of Watershed Associated with Animal-Based Agriculture in Santa Catarina, Brazil

Environmental problems many times could evolve when manure-containing pathogens are distributed into an open environment with no effort made to reduce the content of pathogens or limit their movement in the environment. Wind, surface flow, and subsurface flow can all carry enough pathogens to receiving waters to exceed water quality standards. This study was conducted to assess the microbiological quality of water associated with animal-based agriculture in the sub-basin of Pinhal River located in the rural area of Concordia, Santa Catarina, Brazil. Six sampling points representing different agricultural land uses (LU1—dairy cattle; LU2—without animals; LU3—dairy + pigs + poultry + crops; LU4—pigs + poultry + crops; LU5—dairy + pigs + poultry + crops + human; and LU6—dairy+pigs+crops) along the Pinhal River sub-basin (north to south) were sampled biweekly from August 2006 to December 2008. Concentrations of fecal coliforms and Escherichia coli varied significantly (p?≤?0.05) with land use (LU), but there was no interaction effect of LU, season, and time. Water samples from the catchment area of LU1 had the highest concentration of fecal coliforms (4,479?±?597 CFU ml^?1) when compared with other catchment areas. Catchment area associated with LU2 (no animal) had the lowest concentrations of fecal coliforms (39.2?±?5.2 CFU ml^?1). With the exception of LU2 (control site), all the maximum concentrations of E. coli exceeded the single maximum allowable concentration for E. coli (100 CFU ml^?1). When LU1 was compared with other catchment areas (LU3, 50%; LU4, 67%; LU5, 58%; and LU6, 44%), it had the lowest counts (39%) of Salmonella sp. Our results suggest that spatial pattern of bacterial water quality is evident, which can be linked to the different land uses and associated practices (present or absent of animal activities). Therefore, varying responses associated with the different land uses would be critical in identifying the importance of different sources of bacteria in the catchment area and the mechanisms transferring them.     

Depth transfer of fecal indicator organisms in an arable clayey soil

In clayey soils, shrinking cracks formed during dry periods in the summer are the most important form of macropores. They may contribute under disadvantageous conditions to the movement of fecal microorganisms and therefore to the contamination of groundwater. For this reason, a field experiment was carried out on a highly clayey arable soil to investigate the effect of the factors slurry addition, sampling date, depth, and season. Under worst case conditions, i.e. a soil at field capacity, irrigated directly after application of fresh cattle slurry with high rates of water, the numbers of spores, total coliforms, fecal coliforms and fecal streptococci were not significantly increased at depths of 15 cm, 45 cm and 75 cm in spring (with less shrinking cracks) or in autumn (with more shrinking cracks). The close correlations between the numbers of spores, total coliforms, aerobic bacteria and microbial biomass C indicate that spore forming organisms and most total coliforms belong to the autochthonous soil microflora and cannot indicate fecal pollution.     

Remarks for Stanford Research Institute Conference April 17, 1973

The Noise Control Act of 1972 establishes the first Federal regulatory program to control noise pollution in the U.S. It mandates a three-pronged approach dealing with new products (including motor vehicles), aircraft, and interstate rail and motor carriers. The key challenge now is proper implementation of the legislation by the Environmental Protection Agency. Although the EPA working agenda contains promising implementation plans, and the initial signs were encouraging, recent developments give: cause for concern. Among these are indications of inadequacies in the new product noise criteria being developed, reliance on DOT and FAA personnel to evaluate the performance of their own agencies, and the Administration's hiring ‘freeze’, which hinders the expansion of the EPA's Office of Noise Abatement to a size equal to the task ahead. These and other developments are interpreted in light of the provisions and intent of the Noise Control Act to form the basis of a ‘score card’ for the EPA.     

Fecal pollution in llobregat river: Interrelationships of viral,bacterial, and physico-chemical parameters

A 19-mo survey of enterovirus in the Llobregat river, located south of Barcelona was conducted. Total coliforms, fecal coliforms, and fecal streptococci counts, as well as several physico-chemical parameters were also measured at two sampling sites. The data show a very high level of fecal and chemical pollution caused by untreated wastewater effluents from several suburbs of Barcelona.     

Bacterial air pollution from an activated sludge tank

Concentrations of air-borne coliforms and ‘other’ bacteria (defined as total bacteria minus coliforms) were measured. downwind of a sewage treatment plant activated sludge tank. The Gaussian plume diffusion equation adequately predicts concentrations of the ‘other’ bacteria; the diffusion equation must be modified by an extinction coefficient, equivalent to a half-life of about 7.4 s, to predict coliform concentrations. Coliform concentrations downwind of this tank did not present a significant health hazard, but the method is applicable to treatment plants of higher capacity and possibly greater emissions.     

Intercomparison of stack gas mercury measurement methods

The Electric Power Research Institute (EPRI) and the United States Environmental Protection Agency (EPA) have carried out joint tests for validation of EPA (Draft) Method 29 (“multi-metals method”) for measurement of mercury (Hg) and other selected metals in the stack gas of a coal-fired electric utility. The tests were performed according to the “analyte spiking” procedure of EPA Method 301 protocol for the field validation of stationary source emission measurements. Several other Hg measurement methods were also employed during the tests to provide a comparison to the Method 29 measurements; these included EPA Method 101A, the Hazardous Element Sampling Train (HEST), and two solid sorbent methods, one using activated charcoal and the other using iodated carbon traps in series with soda lime traps. Results indicate reasonably good agreement between the total Hg measurements by the different methods.     

Identification of an Assemblage of Indicator Organisms to Assess Timing and Source of Bacterial Contamination in Groundwater

Bacterial contamination of drinking water wells is a commonproblem in many rural areas. Some of this contamination may berelated to manure spreading or housing of livestock; another source is on-site septic systems. Current indicator organisms are able to detect the presence of fecal contamination, but where there may be more than one potential source of fecal material, the current indicators are unable to ascertain the origin. This laboratory investigation was undertaken to determine the longevity and reliability of a selected suite of indicator organisms. Total coliform, fecal coliform, fecal streptococci and Clostridium perfringens were monitoredin a simulated contaminated groundwater environment for 6 months. All four indicator organisms were present at the end of6 months. The number of fecal streptococi bacteria decreased most noticeably, allowing assessment of relative age of contamination. C. perfringens was found to be a reliableindicator of contamination from animal manure. Fecal material from 28 different animals and three septic systems were assessed for the presence of the indicator organisms. Totalcoliform, fecal coliform and fecal streptococci were present in the fecal material of all animals tested including reptiles.C. perfringens was detected in feces from all but two of the animals assessed. Using an assemblage of indicator organisms provides more information regarding source and timingof contamination than just testing for total coliform and fecalcoliform bacteria.     

Effects of 15-year application of municipal wastewater on microbial biomass,fecal pollution indicators,and heavy metals in a Tunisian calcareous soil

Purpose

Water shortage in most countries of the southern Mediterranean basin has led to the reuse of municipal wastewater for irrigation. Despite numerous advantages for soil fertility and crop productivity, recycling wastewater in the soil also has several ecotoxicological and sanitary problems. To evaluate the chronic soil contamination and the cumulative impact of wastewater, we compared seven plot sites irrigated with treated wastewater 1, 2, 7, 9, 13, and 15 years and one nonirrigated taken as control, and these were sampled for soil analysis.

Materials and methods

Soil samples were analyzed for pH, electrical conductivity (EC), total Kjeldahl nitrogen (TKN), total organic matter, and total concentrations of Cu, Zn, Fe, Ni, Pb, and Cd. Microbial biomass and enteric bacteria (fecal coliforms and fecal streptococci) were determined in all soil samples.

Results and discussion

The soil pH values were not consistently affected. Soil salinity, measured as EC, appeared significantly high and proportional to the duration of wastewater irrigation. Also, concentrations of total Ni, Zn, Cu, Pb, and Cd increased significantly (P?≤?0.05) according to the number of irrigation years but are usually under Tunisian standards. The concentration of heavy metals (Ni, Zn, Cu, Pb, and Cd) showed a significant decrease in the soil profile. The microbial biomass carbon (MB_C) is 1.5 times larger in the soil irrigated for 15 years with treated wastewater as compared to the one taken as control. The growth of microorganisms might be explained by the ready source of easily degradable compounds in the oligotrophic soil environment brought about by wastewater irrigation. Soil bacteriological analysis showed that the number of fecal coliforms (FC) and that of fecal streptococci (FS) were affected appreciably (P?≤?0.05) by the duration of wastewater application (number of years) and by the soil depth (0–20, 20–40, and 40–60 cm).

Conclusions

Treated wastewater irrigation led to changes in physicochemical and microbiological soil properties. The magnitude and specificity of these changes significantly correlated with the duration of such practice. It can be concluded, based on these results, that the proper management of wastewater irrigation and periodic monitoring of soil fertility and quality parameters are required to ensure successful, safe, and long-term reuse of wastewater irrigation.     

Evaluation of microbial indicators for the determination of bacterial groundwater contamination sources

Several different Microbial source tracking methods (MSTs) can be used to distinguish human from animal fecal contamination in water; In this study, experiments were carried out to test the effectiveness and reliability of three bacteria based approaches (the fecal coliforms to fecal streptococci ratio, antibiotic-resistant Clostridium perfringens, and human bifidobacteria) in a simulated groundwater micro-environment. The methods were evaluated in three phases: initially, the specificity of each indicator was validated on groundwater samples affected by known pollution source; then the variation of performance with time of each method was determined, and finally, the die-off coefficients for pure species of Clostridium perfringens and Bifidobacterium adolescentis were measured. The results indicate that only the determination of human bifidobacteria concentration can be considered reliable in distinguishing human from animal pollution in groundwater at the conditions applied. Nevertheless, human bifidobacteria were detectable only for two weeks after the contamination event. This study also shows that antibiotic resistant Clostridium perfringens detected using the Shahidi-Ferguson medium is not source specific, whereas it confirms that this species can be useful for timing general fecal contamination events.