Heavy contamination of a subsurface aquifer and a stream by livestock wastewater in a stock farming area, Wonju, Korea

The impact of livestock activities and geochemical processes on groundwater quality of fractured volcanic rock aquifer: Lake Çıldır watershed (NE Turkey)

This paper presents the impact of livestock activities and geochemical processes on the water quality of a fractured volcanic rock aquifer in the Lake Çıldır watershed, located at the northeastern part of Turkey. The existence of a high livestock population and animal grazing activities in meadow and pasturelands of the watershed during the short summer period poses serious stress on both surface and groundwater resources being the only drinking water supply for the local communities. Therefore, understanding the effect of grazing and livestock breeding activities occurring in the recharge areas of the fractured volcanic rock aquifer is vital to take precautions in order to protect limited water supplies at the watershed and vulnerable lake ecosystem as well. The mean nitrate content of the groundwater was measured at 6.4 ± 6.6 (std. dev) mg/L in the wet (before grazing) period and 7.1 ± 5.9 mg/L in the dry (after grazing) period. Despite low nitrate concentration levels of groundwater, microbial contamination was observed in the spring waters at alarming levels especially after the animal grazing activities. 56%, 26%, and 11% of the groundwater samples showed bacterial contamination in terms of total coliform, fecal coliform, and fecal streptococci contents, respectively, prior to grazing activity, while in pursuit of intense livestock grazing at highland, these microbial indicators have been increased to 92%, 85%, and 77% in the dry period. A significant increase observed in fecal contamination indicates the negative impact of livestock activities on groundwater quality. Al (200-638 µg/L) and Fe (66-218 µg/L) enrichments locally observed in groundwater were related to advanced argillic alteration (kaolinization) and hematization zones in pyroclastic rocks.

Seasonal and Spatial Variability of Anthropogenic and Natural Factors Influencing Groundwater Quality Based on Source Apportionment

Globally, groundwater resources are being deteriorated by rapid social development. Thus, there is an urgent need to assess the combined impacts of natural and enhanced anthropogenic sources on groundwater chemistry. The aim of this study was to identify seasonal characteristics and spatial variations in anthropogenic and natural effects, to improve the understanding of major hydrogeochemical processes based on source apportionment. 34 groundwater points located in a riverside groundwater resource area in northeast China were sampled during the wet and dry seasons in 2015. Using principal component analysis and factor analysis, 4 principal components (PCs) were extracted from 16 groundwater parameters. Three of the PCs were water-rock interaction (PC₁), geogenic Fe and Mn (PC₂), and agricultural pollution (PC₃). A remarkable difference (PC₄) was organic pollution originating from negative anthropogenic effects during the wet season, and geogenic F enrichment during the dry season. Groundwater exploitation resulted in dramatic depression cone with higher hydraulic gradient around the water source area. It not only intensified dissolution of calcite, dolomite, gypsum, Fe, Mn and fluorine minerals, but also induced more surface water recharge for the water source area. The spatial distribution of the PCs also suggested the center of the study area was extremely vulnerable to contamination by Fe, Mn, COD, and F⁻.

Identification of hydrogeochemical processes in groundwater of Dawa River basin, southern Ethiopia

Dawa River basin in southern Ethiopia is covered by volcanic, basement, and sedimentary rocks. Locating good quality groundwater is a challenge in most parts of the basin. Statistical analysis and graphical plots of 94 hydrochemical data of groundwater were used as a main tool to acquire an insight into the major processes that control groundwater chemistry. In the volcanic terrain groundwater is dilute (mean total dissolved solids (TDS): 152 mg/l), while salinity is the highest in the sedimentary terrain (mean TDS: 1750 mg/l). NO3 (-) varies from below the detection limit to 433 mg/l NO3 (-). In 26 % of the water samples, nitrate concentration is above the human-affected value, 5 mg/l NO3 (-). In 6 % of the samples, NO3 (-) concentration is above the limit recommended in drinking water, 50 mg/l NO3 (-), by WHO. Concentration range of the other major ions is also high and hydrochemical water types are diverse, suggesting the effect of various hydrogeochemical processes on the water chemistry. Chemical data analysis revealed that in the volcanic and most parts of the basement terrains silicate hydrolysis is the dominant process. Gypsum dissolution is the main process in the sedimentary terrain. Dissolution of gypsum is also important at few locations along dry riverbeds in the semiarid area where the effect of evaporation on the water chemistry is considerable. Loading of factors with K(+) and SO4 (2-), K(+) and NO3 (-), and NO3 (-) and correlation of SO4 (2-) with Cl(-), along with the observed high nitrate concentration, indicate the effect of surface contamination sources on the water quality.

Multivariate Analysis of Confined Groundwater Hydrochemistry of a Long-Exploited Sedimentary Basin in Northwest China

A series of environmental and geological problems have been caused by overexploitation of confined aquifers (i.e., deep groundwater) in the Yinchuan region, northwest China. Accordingly, the characteristics of confined water were analyzed and collected from 33 sampling wells in spring of 2011, to determine the factors that influenced the composition and evolution of confined water, using principal component analysis (PCA), correlation analysis, groundwater evolution, and mineral dissolution/precipitation analysis. PCA showed that the hydrochemistry of confined water is controlled mainly by the dissolution of minerals, mixing between the confined aquifer and polluted phreatic water, and effects of ion exchange in the study area. The following management actions recommended were essential, in order to enable the sustainable exploitation of confined water: (1) gradually decreasing the amount of groundwater pumped from confined aquifer in the central part of the depression cone, (2) upgrading the quality of phreatic water, and (3) increasing artificial recharge of the groundwater system by flood waters in the Helan leaning pluvial plain.

Assessment of the microbiological quality of groundwater in three regions of the Valencian Community (Spain)

Urban groundwater development was traditionally constrained by concerns about its quality. This study was conducted in the regions of La Ribera Alta and Ribera Baja and La Plana de Requena-Utiel of the Valencian Community (Valencia, Spain) where population density, demand for drinking water and agricultural activities are high. Groundwater bodies (GWBs) are regarded as management areas within each territory, and were used to establish protection policies. This study analyzed eleven GWBs. We used two databases with microbiological measurements from 154 wells over a 7-year period (2004–2011), risk factors and groundwater information. Wells were grouped according to frequency of microbiological contamination using E. coli measurements, category <1, or wells with low-frequency microbiological contamination and high-frequency wells or category 1–100, according to World Health Organization (WHO) quality criteria of drinking water. Of all wells, 18.12% showed high-frequency microbiological contamination with a majority distribution in the Ribera Alta region (26.98%, p < 0.001). No significant differences were found between the two risk categories for flow, static level, well depth and distance from population centres. This paper reveals that the vulnerability classes established by the Geological and Mining Institute of Spain (IGME) do not match the microbiological results, and that only eight wells with high-frequency contamination coincide with the high vulnerability areas.

Comparison of compositional characteristics of amino acids between livestock wastewater and carcass leachate

This study was purposed to examine the use of amino acids as an indicator to determine whether groundwater around carcass burial sites is polluted by livestock wastewater (LW) or carcass leachate (CL). The analysis of samples showed that the average amino acid concentration of carcass leachate (531.897 mg/L; 4341.784 μmol/L) was about 300 times as high as that of livestock wastewater (1.755 mg/L; 16.283 μmol/L). To identify distinct characteristics between LW and CL, six amino acids were paired with one another to calculate their relative composition ratios, which were found to be Leu/Trp (CL 8.39∼98.6, LW 0.89∼4.77), Val/Trp (CL 11.95∼175.38, LW 0.73∼3.62), Lys/Leu (CL 0.01∼0.72, LW 0.96∼8.44), Lys/Ile (CL 0.02∼1.55, LW 1.64∼10.99), Met/Lys (CL 0.14∼0.45, LW 0.03∼0.14), and Ile/Val (CL 0.38∼0.73, LW 0.40∼0.97). The hierarchical clustering result showed that the similarity was 0.617 among the seven LW samples and 0.563 among the seven CL samples, while the similarity between LW and CL samples was 0.198, presenting that these two sources are distinct from each other. All these results indicate that amino acids can be used as a tracer to evaluate if the contamination source is livestock wastewater or carcass leachate. To apply amino acids to tracing pollutants more effectively, however, further studies are needed to understand whether the relative abundance ratios of amino acids are maintained as they are transporting through soils as a medium.

Removal of nitrate and ammonium ions from livestock wastewater by hybrid systems composed of zero-valent iron and adsorbents

The feasibility of hybrid systems for simultaneous removal of nitrate (NO3-) and ammonium ions (NH4+) from livestock wastewater was examined in batch experiments. As a part of efforts to remove nitrate and ammonium simultaneously, Fe0 and adsorbents including coconut-based granular activated carbon (GAC), sepiolite and filtralite were used. Various parameters such as adsorbent dosages and temperature were studied. Removal of NO3- increased with increase in temperature. Maximum NO3- removal (85.3%) was observed for the Fe0-filtralite hybrid system at 45 degrees C for a 24 h reaction time. Increase in GAC and sepiolite dosages had significant (P < 0.01) effect on the NH4+ removal efficiency, which was primarily due to the net negative surface charge of the adsorbents. The efficiency of hybrid systems for the removal of NO3- was in the order of filtralite > sepiolite > GAC, and the order of the removal of NH4+ was GAC > sepiolite > filtralite. The results of the present study suggest that the use of hybrid systems could be a promising innovative technology for achieving simultaneous removal of NO3- and NH4 from livestock wastewater.

Annual and nycthemeral studies of the survival and circulation of indicator bacteria in a schist aquifer

Escherichia coli and Enterococci are widely used as indicators of faecal contamination of groundwater while total coliforms, which are of environmental but also of faecal origin, are indicators of the overall quality of the water. The survival of bacteria in groundwater is dependent on many factors including temperature, competition with indigenous bacteria and entrapment in aquifer material. Previous studies showed two sources of faecal contamination of a schist aquifer: infiltration into the ground from nearby septic tank effluents and seepage of landfill leachate. Water samples for bacterial analysis were collected from a piezometer on a monthly basis (15 months) and every six hours over two non-consecutive days. The intermittent sampling showed relatively stable concentrations of bacteria over time after the removal of stagnant water. Therefore, a continuous bacterial contamination without significant daily variation exists. The ratio of E. coli densities to total coliforms densities (EC/TC) allowed differentiation between the sources of faecal pollution in groundwater by comparing the populations of faecal bacteria with those of environmental bacteria. Enumeration indicated that the densities of bacteria were much higher in this schist aquifer than those in alluvial aquifers contaminated by a septic tank reported in the literature.

Leaching of Mycobacterium avium Subsp paratuberculosis in Soil under In Vitro Conditions

Mycobacterium avium subsp paratuberculosis (Map), the causative agent of Johne's disease, has a robust ability to survive in the environment. However, the ability of Map to migrate through soil to drainage tiles or ground water, leave the farm, and leak into local watersheds is inadequately documented. In order to assess the ability of Map to leach through soil, two laboratory experiments were conducted. In the first study, 8 columns (30 cm long each) of a sandy loam soil were treated with pure cultures of Map. Two soil moisture levels and two Map concentrations were used. The columns were leached with 500 mL of water once a week for three weeks, the leachate was collected, and detection analysis was conducted. In the second experiment, manure from Map negative cows (control) and Map high shedder cows (treatment) were deposited on 8 similar columns and the columns were leached with 500 mL of water once a week for four weeks. Map detection and numeration in leachate samples were done with RT-PCR and culture techniques, respectively. Using RT-PCR, Map could be detected in the leachates in both experiments for several weeks but could only be recovered using culture techniques in experiment one. Combined, these experiments indicate the potential for Map to move through soil as a result of rainfall or irrigation following application.

Occurrence of steroid hormones and antibiotics in shallow groundwater impacted by livestock waste control facilities

Wastewater impoundments at concentrated animal feeding operations (CAFOs) represent a potential source of veterinary pharmaceuticals and steroid hormone contamination to shallow groundwater. This study investigates the occurrence of seventeen veterinary pharmaceuticals and thirteen steroid hormones and hormone metabolites in lagoons and adjacent groundwater at operating swine and beef cattle facilities. These sites were chosen because subsurface geology and previous monitoring of nitrate, ammonia and chloride levels in shallow ground water strongly indicated direct infiltration, and as such represent worst cases for ground water contamination by waste water. Pharmaceutical compounds detected in samples obtained from cattle facilities include sulfamerazine; sulfamethazine; erythromycin; monensin; tiamulin; and sulfathiazole. Lincomycin; ractopamine; sulfamethazine; sulfathiazole; erythromycin; tiamulin and sulfadimethoxine were detected in wastewater samples obtained from swine facilities. Steroid hormones were detected less frequently than veterinary pharmaceuticals in this study. Estrone, testosterone, 4-androstenedione, and androsterone were detected in wastewater impoundments at concentrations ranging from 30 to 3600ng/L, while only estrone and testosterone were detected in groundwater samples at concentrations up to 390ng/L. The co-occurrence of veterinary pharmaceutical and steroid hormone contamination in groundwater at these locations and the correlation between pharmaceutical occurrence in lagoon wastewater and hydraulically downgradient groundwater indicates that groundwater underlying some livestock wastewater impoundments is susceptible to contamination by veterinary pharmaceuticals and steroid hormones originating in wastewater lagoons.

Transport of testosterone and estrogen from dairy-farm waste lagoons to groundwater

Although concentrated animal feeding operations constantly generate physiologically active steroidal hormones, little is known of their environmental fate. Estrogen and testosterone concentrations in groundwater and their distribution in sediments below a dairy-farm wastewater lagoon were therefore determined and compared to a reference site located upgradient of the farm. Forward simulations of flow as well as estrogen and testosterone transport were conducted based on data from the sediment profile obtained during drilling of a monitoring well belowthe dairy-farm waste lagoon. Testosterone and estrogen were detected in sediments to depths of 45 and 32 m, respectively. Groundwater samples were directly impacted by the dairy farm, as evidenced by elevated concentrations of nitrate, chloride, testosterone, and estrogen as compared to the reference site. Modeling potential transport of hormones in the vadose zone via advection, dispersion, and sorption could not explain the depths at which estrogen and testosterone were found, suggesting that other transport mechanisms influence hormone transport under field conditions. These mechanisms may involve interactions between hormones and manure as well as preferential flow paths, leading to enhanced transport rates. These types of interactions should be further investigated to understand the processes regulating hormone transport in the subsurface environment and parametrized to forecast long-term fate and transport of steroidal hormones.

[Annual distribution of bacterial indicators generated by the domestic wastes from the landfill of Etueffont (France)]

We assessed over 15 months the distribution of total coliforms concentrations of Escherichia coli, Enterococci, Pseudomonas aeruginosa, Salmonella and Staphylococcus aureus in three monitoring points in the Etueffont landfill (Belfort, France). We selected the piezometer (PZ30) which is located downstream from the dump and two leachate collectors from the old dump and the new casing. The results showed that the leachate was free from both Salmonella and Staphylococcus aureus. The absence of Salmonella was most likely due to the small occupation of the landfill environment by vertebrates, especially rodents, birds and reptiles, which are known to be principal vectors of Salmonella. S. aureu, is generally hosted on skins and mucus of animals. The mean densities of E. coli and Enterococcus in the leachates were low. In contrast, P. aeruginosa abundance was high and closely related to precipitations. Coliform bacteria concentrations in the leachate averaged UFC.100 CFU x ml(-1). In the contaminated groundwaters, the coliforms, E. coli and Enterococci were always present at concentrations 10 to 100 fold higher than those reported from septic tank effluents. P. aeruginosa concentrations were low (mean: 11 CFU.100 ml(-1)) and inferior to those quoted in the leachate. This may be explained by the anoxic conditions which prevailed in the shistous aquifer. The absence of Salmonella in groundwaters may be due to its sensitivity to disinfectants and that of S. aureus linked to the fact that it is not a common host of the human intestine. Finally, our study clearly indicates the role played by E. coli and Enterococci as biomarkers of recent faecal contamination.

Estimating background and threshold nitrate concentrations using probability graphs

Because of the ubiquitous nature of anthropogenic nitrate (NO3(-)) in many parts of the world, determining background concentrations of NO3(-) in shallow ground water from natural sources is probably impossible in most environments. Present-day background must now include diffuse sources of NO3(-) such as disruption of soils and oxidation of organic matter, and atmospheric inputs from products of combustion and evaporation of ammonia from fertilizer and livestock waste. Anomalies can be defined as NO3(-) derived from nitrogen (N) inputs to the environment from anthropogenic activities, including synthetic fertilizers, livestock waste, and septic effluent. Cumulative probability graphs were used to identify threshold concentrations separating background and anomalous NO(3)-N concentrations and to assist in the determination of sources of N contamination for 232 spring water samples and 200 well water samples from karst aquifers. Thresholds were 0.4, 2.5, and 6.7 mg/L for spring water samples, and 0.1, 2.1, and 17 mg/L for well water samples. The 0.4 and 0.1 mg/L values are assumed to represent thresholds for present-day precipitation. Thresholds at 2.5 and 2.1 mg/L are interpreted to represent present-day background concentrations of NO(3)-N. The population of spring water samples with concentrations between 2.5 and 6.7 mg/L represents an amalgam of all sources of NO3(-) in the ground water basins that feed each spring; concentrations > 6.7 mg/L were typically samples collected soon after springtime application of synthetic fertilizer. The 17 mg/L threshold (adjusted to 15 mg/L) for well water samples is interpreted as the level above which livestock wastes dominate the N sources.

Increase in bacterial community diversity in subsurface aquifers receiving livestock wastewater input

Despite intensive studies of microbial-community diversity, the questions of which kinds of microbial populations are associated with changes in community diversity have not yet been fully solved by molecular approaches. In this study, to investigate the impact of livestock wastewater on changes in the bacterial communities in groundwater, bacterial communities in subsurface aquifers were analyzed by characterizing their 16S rDNA sequences. The similarity coefficients of restriction fragment length polymorphism (RFLP) patterns of the cloned 16S ribosomal DNAs showed that the bacterial communities in livestock wastewater samples were more closely related to those in contaminated aquifer samples. In addition, calculations of community diversity clearly showed that bacterial communities in the livestock wastewater and the contaminated aquifer were much more diverse than those in the uncontaminated aquifer. Thus, the increase in bacterial-community diversity in the contaminated aquifer was assumed to be due to the infiltration of livestock wastewater, containing high concentrations of diverse microbial flora, into the aquifer. Phylogenetic analysis of the sequences from a subset of the RFLP patterns showed that the Cytophaga-Flexibacter-Bacteroides and low-G+C gram-positive groups originating from livestock wastewater were responsible for the change in the bacterial community in groundwater. This was evidenced by the occurrence of rumen-related sequences not only in the livestock wastewater samples but also in the contaminated-groundwater samples. Rumen-related sequences, therefore, can be used as indicator sequences for fecal contamination of groundwater, particularly from livestock.