Mineral water: A microbiological approach

The microbiological quality of bottled mineral water of various domestic brands sold in Brazil was investigated, with particular focus on the heterotrophic plate count (HPC). Neither total coliforms nor Escherichia coli were found in any 1.5 L bottle samples. Total coliforms were found in 2.9% of the small bottles, while in 20 L bottles the presence of total coliforms and E. coli was demonstrated in 15.5 and 2.4% of samples, respectively. Pseudomonas aeruginosa was detected in 4.3, 4.5 and 9.5% of small, 1.5 and 20 L bottles, respectively. In 36.4% of the samples of 1.5 L bottles, the HPC was above 500 cfu/mL. This percentage of samples with an HPC above 500 cfu/mL increased to 52.0 and 61.9% in small and 20 L bottles, respectively. Higher contamination by total coliforms, E. coli, P. aeruginosa and HPCs occurred in 20 L bottles. In conclusion, several samples in this study were outside the international quality standard for mineral water and the large number of samples with high HPCs shows that more work must be done on the use of HPC in mineral water and the damaging effects that these microorganisms may cause to humans. The bottled mineral water was confirmed as a particularly important public health problem, due to the poor microbiological quality of the products that are marketed. © IWA Publishing 2012.

Bacterially mediated iron cycling and associated biogeochemical processes in a subtropical shallow coastal aquifer: implications for groundwater quality

Bacterially mediated iron redox cycling exerts a strong influence on groundwater geochemistry, but few studies have investigated iron biogeochemical processes in coastal alluvial aquifers from a microbiological viewpoint. The shallow alluvial aquifer located adjacent to Poona estuary on the subtropical Southeast Queensland coast represents a redox-stratified system where iron biogeochemical cycling potentially affects water quality. Using a 300 m transect of monitoring wells perpendicular to the estuary, we examined groundwater physico-chemical conditions and the occurrence of cultivable bacterial populations involved in iron (and manganese, sulfur) redox reactions in this aquifer. Results showed slightly acidic and near-neutral pH, suboxic conditions and an abundance of dissolved iron consisting primarily of iron(II) in the majority of wells. The highest level of dissolved iron(III) was found in a well proximal to the estuary most likely a result of iron curtain effects due to tidal intrusion. A number of cultivable, (an)aerobic bacterial populations capable of diverse carbon, iron, or sulfur metabolism coexisted in groundwater redox transition zones. Our findings indicated aerobic, heterotrophic respiration and bacterially mediated iron/sulfur redox reactions were integral to carbon cycling in the aquifer. High abundances of dissolved iron and cultivable iron and sulfur bacterial populations in estuary-adjacent aquifers have implications for iron transport to marine waters. This study demonstrated bacterially mediated iron redox cycling and associated biogeochemical processes in subtropical coastal groundwaters using culture-based methods.

Evaluation of the Quality of Drinking Water in Kerala State, India

The quality of tap water from water supplies from 14 districts of Kerala state, India was studied. Parameters like pH, water temperature, total dissolved solids, salinity, nitrates, chloride, hardness, magnesium, calcium, sodium, potassium, fluoride, sulphate, phosphates, and coliform bacteria were enumerated. The results showed that all water samples were contaminated by coliform bacteria. About 20% of the tap water samples from Alappuzha and 15% samples from Palakkad district are above desirable limits prescribed by Bureau of Indian Standards. The contamination of the source water (due to lack of community hygiene) and insufficient treatment are the major cause for the coliform contamination in the state. Water samples from Alappuzha and Palakkad have high ionic and fluoride content which could be attributed to the geology of the region. Water supplied for drinking in rural areas are relatively free of any contamination than the water supplied in urban area by municipalities, which may be attributed higher chances of contamination in urban area due to mismanagement of solid and liquid wastes. The study highlights the need for regular bacteriological enumeration along with water quality in addition to setting up decentralised region specific improved treatment system.

Summary report on water quantity and quality studies of Vancouver Lake, Washington

Vancouver Lake, located adjacent to the Columbia River and just north of the Vancouver-Portland metropolitan area, is a "dying" lake. Although all lakes die naturally in geologic time through the process of eutrophication,* Vancouver Lake is dying more rapidly due to man's activities and due to the resultant increased accumulation of sediment, chemicals, and wastes. Natural eutrophication takes thousands of years, whereas man-made modifications can cause the death of a lake in decades. Vancouver Lake does, however, have the potential of becoming a valuable water resource asset for the area, due particularly to its location near the Columbia River which can be used as a source of "flushing" water to improve the quality of Vancouver Lake. (Document pdf contains 59 pages) Community interest in Vancouver Lake has waxed and waned. Prior to World War II, there were relatively few plans for discussions about the Lake and its surrounding land area. A plan to drain the Lake for farming was prohibited by the city council and county commissioners. Interest increased in 1945 when the federal government considered developing the Lake as a berthing harbor for deactivated ships at which time a preliminary proposal was prepared by the City. The only surface water connection between Vancouver Lake and the Columbia River, except during floods, is Lake River. The Lake now serves as a receiving body of water for Lake River tidal flow and surface flow from creeks and nearby land areas. Seasonally, these flows are heavily laden with sediment, septic tank drainage, fertilizers and drainage from cattle yards. Construction and gravel pit operations increase the sediment loads entering the Lake from Burnt Bridge Creek and Salmon Creek (via Lake River by tidal action). The tidal flats at the north end of Vancouver Lake are evidence of this accumulation. Since 1945, the buildup of sediment and nutrients created by man's activities has accelerated the growth of the large water plants and algae which contribute to the degeneration of the Lake. Flooding from the Columbia River, as in 1968, has added to the deposition in Vancouver Lake. The combined effect of these human and natural activities has changed Vancouver Lake into a relatively useless body of shallow water supporting some wildlife, rough fish, and shallow draft boats. It is still pleasant to view from the hills to the east. Because precipitation and streamflow are the lowest during the summer and early fall, water quantity and quality conditions are at their worst when the potential of the Lake for water-based recreation is the highest. Increased pollution of the Lake has caused a larger segment of the community to become concerned. Land use and planning studies were undertaken on the Columbia River lowlands and a wide variety of ideas were proposed for improving the quality of the water-land environment in order to enhance the usefulness of the area. In 1966, the College of Engineering Research Division at Washington State University (WSU0 in Pullman, Washington, was contacted by the Port of Vancouver to determine possible alternatives for restoring Vancouver Lake. Various proposals were prepared between 1966 and 1969. During the summer and fall of 1967, a study was made by WSU on the existing water quality in the Lake. In 1969, the current studies were funded to establish a data base for considering a broad range of alternative solutions for improving the quantity and quality of Vancouver Lake. Until these studies were undertaken, practically no data on a continuous nature were available on Vancouver Lake, Lake River, or their tributaries. (Document pdf contains 59 pages)

Temporal and spatial variations in the quality of water in El Gergal Reservior, Seville, Spain

It is often difficult to define ‘water quality’ with any degree of precision. One approach is that suggested by Battarbee (1997) and is based on the extent to which individual lakes have changed compared with their natural ‘baseline’ status. Defining the base-line status of artificial lakes and reservoirs however, is, very difficult. In ecological terms, the definition of quality must include some consideration of their functional characteristics and the extent to which these characteristics are self-sustaining. The challenge of managing lakes in a sustainable way is particularly acute in semi-arid, Mediterranean countries. Here the quality of the water is strongly influenced by the unpredictability of the rainfall as well as year-to-year variations in the seasonal averages. Wise management requires profound knowledge of how these systems function. Thus a holistic approach must be adopted and the factors influencing the seasonal dynamics of the lakes quantified over a range of spatial and temporal scales. In this article, the authors describe some of the ways in which both long-term and short-term changes in the weather have influenced the seasonal and spatial dynamics of phytoplankton in El Gergal, a water supply reservoir situated in the south of Spain. The quality of the water stored in this reservoir is typically very good but surface blooms of algae commonly appear during warm, calm periods when the water level is low. El Gergal reservoir is managed by the Empresa Municipal de Abastecimiento y Saneamiento (EMASESA) and supplies water for domestic, commercial and industrial use to an area which includes the city of Seville and twelve of its surrounding towns (ca. 1.3 million inhabitants). El Gergal is the last of two reservoirs in a chain of four situated in the Rivera de Huelva basin, a tributary of the Guadalquivir river. It was commissioned by EMASESA in 1979 and since then the company has monitored its main limnological parameters on, at least, a monthly basis and used this information to improve the management of the reservoir. As a consequence of these intensive studies the physical, chemical and biological information acquired during this period makes the El Gergal database one of the most complete in Spain. In this article the authors focus on three ‘weather-related’ effects that have had a significant impact on the composition and distribution of phytoplankton in El Gergal: (i) the changes associated with severe droughts; (ii) the spatial variations produced by short-term changes in the weather; (iii) the impact of water transfers on the seasonal dynamics of the dinoflagellate Ceratium.

Detection of specific bacteria in water: implications of survival strategy

It is widely recognised that conventional culture techniques may underestimate true viable bacterial numbers by several orders of magnitude. The basis of this discrepancy is that a culture in or on media of high nutrient concentration is highly selective (either through ”nutrient shock” or failure to provide vital co-factors) and decreases apparent diversity; thus it is unrepresentative of the natural community. In addition, the non-culturable but viable state (NCBV) is a strategy adopted by some bacteria as a response to environmental stress. The basis for the non-culturable state is that cells placed in conditions present in the environment cannot be recultured but can be shown to maintain their viability. Consequently, these cells would not be detected by standard water quality techniques that are based on culture. In the case of pathogens, it may explain outbreaks of disease in populations that have not come into contact with the pathogen. However, the NCBV state is difficult to attribute, due to the failure to distinguish between NCBV and non-viable cells. This article will describe experiences with the fish pathogen Aeromonas salmonicida subsp. salmonicida and the application of molecular techniques for its detection and physiological analysis.

Tastes and odours in potable water:perception versus reality

Tastes and odours are amongst the few water quality standards immediately apparent to a consumer and, as a result, account for most consumer complaints about water quality. Although taste and odour problems can arise from a great many sources, from an operational point of view they are either ”predictable” or ”unpredictable”. The former - which include problems related to actinomycete and algal growth - have a tendency to occur in certain types of water under certain combinations of conditions, whereas the latter - typically chemical spills - can occur anywhere. Long-term control is one option for predictable problems, although biomanipulation on a large scale has had utile success. Detection and avoidance is a more practicable option for both predictable and unpredictable problems, particularly if the distribution network can be serviced from other sources. Where these are not feasible, then water treatment, typically using activated carbon, is possible. In general there is a reasonable understanding of what compounds cause taste and odour problems, and how to treat these. An efficient taste and odour control programme therefore relies ultimately on good management of existing resources. However, a number of problems lie outside the remit of water supply companies and will require more fundamental regulation of activities in the catchment.

Integrated modelling of climate change impacts on water resources and quality in a lowland catchment: River Kennet, UK

An integrated approach to climate change impact assessment is explored by linking established models of regional climate (SDSM), water resources (CATCHMOD) and water quality (INCA) within a single framework. A case study of the River Kennet illustrates how the system can be used to investigate aspects of climate change uncertainty, deployable water resources, and water quality dynamics in upper and lower reaches of the drainage network. The results confirm the large uncertainty in climate change scenarios and freshwater impacts due to the choice of general circulation model (GCM). This uncertainty is shown to be greatest during summer months as evidenced by large variations between GCM-derived projections of future tow river flows, deployable yield from groundwater, severity of nutrient flushing episodes, and Long-term trends in surface water quality. Other impacts arising from agricultural land-use reform or delivery of EU Water Framework Directive objectives under climate change could be evaluated using the same framework. (c) 2006 Elsevier B.V. All rights reserved.

Using chemical and physical parameters to define the quality of Pardo River water (Botucatu-SP-Brazil)

This paper aims to study the ecological system of the Pardo River, at the source and lower-order passages, which are in the Botucatu area, São Paulo State, Brazil. This study was carried out to determine water quality with some chemical-physical indicators, coliforms, and chemical species of samples taken monthly, 1995/02-1996/01, from eight sampling stations sited along the Pardo River. The results in the river monitoring are discussed based on annual averages, analysis of variance, and compared to Tukey's Studentized Range-HSD, and principal component analysis (PCA) was applied to normalize data to assess association between variables. We can conclude that the variables used are very efficient for identifying and that the dry season shows the worst water quality. These were caused by organic matter, nutrients (originate) from anthropogenic sources (spatial sources) and mainly municipal wastewater, affecting the quality and hydrochemistry of the river water, which have been differentiated and assigned to polluting sources. Meanwhile, the degree of degradation of the Pardo River is low (sewage treatment carried out by the city of Pardinho is efficient), leaving the water of the river suitable for use by the population of Botucatu, after conventional treatment (Conama, Resolucao No. 20, CONAMA, Brazilia DF, 09-23, 1986-the water of the Pardo river is classified as level 03). (C) 2001 Elsevier B.V. Ltd. All rights reserved.

Laboratory essays on solid residues from an area of sand mining activities at Analandia, São Paulo, Brazil, and implications to the water resources quality

This investigation reports the results of tests performed in a laboratory with solid waste samples from an area belonging to Sibelco Mineracao Ltd., which is located around Analandia municipality, nearly in the center of São Paulo State, Brazil. Dissolution and leaching essays were realized under different experimental conditions in four samples collected from the mining front and decantation pool, with the aim of evaluating the possibility of release of several constituents to the liquid phase.

Quantitative variations in heterotrophic plate count and in the presence of indicator microorganisms in bottled mineral water

Quantitative variations in heterotrophic plate count (HPC) and in the presence of indicator microorganisms in 0.5, 1.5 and 20-L bottles of different brands of Brazilian mineral water were analyzed during their shelf life. No variations were identified in the presence of indicator microorganisms, but quantitative variations in HPC were observed in some brands, which suggests that changes may be occurring in the water quality during storage. The aim of this study was also to evaluate the quality of the bottled mineral waters and the presence of enterococci and Pseudomonas aeruginosa were verified in six and two bottles, respectively, which is in disagreement with the microbiological quality criteria established in the current legislation. Although no limit is set for HPC in mineral water, this study relies on the limit of 500 colony-forming units per mL of sample (CFU/mL). Seventy-two bottles presented levels above 500 CFU/mL and up to 560,000 CFU/mL. This study showed that the control of HPC (<500 CFU/mL) for non-returnable packaging seems to be adequate to ensure the quality of mineral water during storage. The high values of HPC and its variations detected during storage seem to fully justify the need for a reevaluation of the use of HPC in bottled mineral water quality management. More detailed studies on the potential health risk of HPC and its variations in mineral water are also needed. © 2012 Elsevier Ltd.

Quality of the effluents of bullfrog tadpole ponds

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Bacteriological quality of irrigation water from vegetable gardens in the municipalities of Araraquara, Boa Esperança do Sul and Ibitinga, SP

This work aimed to assess the bacteriological quality of water used in the irrigation of vegetable gardens in the municipalities of Araraquara, Boa Esperança do Sul and Ibitinga, São Paulo, Brazil. A total of 80 samples of water used in the irrigation of 40 vegetable gardens were analyzed, two samples coming from each vegetable garden. They were collected at the same site in different months, which resulted in two sample collection groups. The most probable number (MPN/100mL) of total coliforms, thermotolerant coliforms and enterococci was identifi ed by means of the multiple tube technique. The analysis of the fi rst group samples showed quantities of thermotolerant coliforms above the amount allowed by current law for irrigation water (CONAMA Resolution n. 357) in nine cases. The owners of those vegetable gardens were then instructed in water disinfection procedures. After the analysis of the second group samples, it was noticed that only one sample did not meet the quality standards, and it was collected at a site where no disinfection procedure had been carried out. According to the results, 77.5% of the vegetable gardens were using water whose samples meet the quality standards. After the owners were instructed with regard to disinfection procedures, that number changed to 97.5%, which confi rms the importance of controlling and supervising irrigation water quality

Spatial and temporal quality of water in the Itupararanga Reservoir, Alto Sorocaba basin (SP), Brazil

Considering the great importance of the Itupararanga Reservoir, Upper Alto Sorocaba basin/SP, this study aimed to report the variations of some parameters of water quality in the spatial and temporal gradients in this multipurpose res- ervoir. The eutrophication of this reservoir was checked using the Carlson Index Modified and the results indicate that the surface water were classified as eutrophic and mesotrophic in wet and dry periods, being characterized the better quality of water in wet period. In the vertical gradient the results showed a stratiphication in all parameters analyzed, except for the electrical conductivity, with good correlation between total phosphorous and chlorophyll-a, indicating that eutrophication of the reservoir changes the conditions of algal growth, mainly in its initial area. Immediate inter- ventions are needed, which must be directed to planning of land use, domestic effluents treatment, taking to an inte- grated management of this important watershed located in the São Paulo State.