Source Of Public Water Supply Research Articles

Preliminary groundwater modelling by considering the interaction with superficial water: Aosta plain case (northern Italy)

The study is developed through scientific cooperation between the University of Milano-Bicocca and the Regional Agency for Environmental Protection (ARPA) of the Valle d’Aosta Region. Its aim is to produce a decision-support tool to help the Public Administration’manage groundwater and public water supply. The study area is the plain of Aosta, between the cities of Aymavilles and Brissogne; in this area groundwater represents the main source of public water supply. The valley is oriented east-west, along the Baltea for a length of 13.1 km and a width of 4.6 km. The textural and hydrogeological properties of the deposits are strictly connected to glacial deposition and to the subsequent sedimentary processes which took place in glacial, lacustrine and fluvial systems. The study is based on available well information in the Aosta plain - including water wells (133) and piezometers (121) - which have been coded and stored in the well database TANGRAM,. The database facilitates interpretation of the well data, and it allows three-dimensional mapping of subsurface hydrogeological characteristics through database codification and ordinary kriging interpolation. The study is designed to achieve two objectives. The first is to provide the Aosta Public Authorities with a well database in order to simplify groundwater management. The second is to provide Public Authorities with a groundwater flow model of the local aquifer. The model integrates surface and subsurface flows in order to fully account for all important stresses, both natural and anthropogenic, on the groundwater system. It provides a tool for testing hypotheses (such as the impact of new wells) and thereby allows science-based management of the aquifer resource.

A basin-scale approach for assessing water resources in a semiarid environment: San Diego region, California and Mexico

Abstract. Many basins throughout the world have sparse hydrologic and geologic data, but have increasing demands for water and a commensurate need for integrated understanding of surface and groundwater resources. This paper demonstrates a methodology for using a distributed parameter water-balance model, gaged surface-water flow, and a reconnaissance-level groundwater flow model to develop a first-order water balance. Flow amounts are rounded to the nearest 5 million cubic meters per year. The San Diego River basin is 1 of 5 major drainage basins that drain to the San Diego coastal plain, the source of public water supply for the San Diego area. The distributed parameter water-balance model (Basin Characterization Model) was run at a monthly timestep for 1940–2009 to determine a median annual total water inflow of 120 million cubic meters per year for the San Diego region. The model was also run specifically for the San Diego River basin for 1982–2009 to provide constraints to model calibration and to evaluate the proportion of inflow that becomes groundwater discharge, resulting in a median annual total water inflow of 50 million cubic meters per year. On the basis of flow records for the San Diego River at Fashion Valley (US Geological Survey gaging station 11023000), when corrected for upper basin reservoir storage and imported water, the total is 30 million cubic meters per year. The difference between these two flow quantities defines the annual groundwater outflow from the San Diego River basin at 20 million cubic meters per year. These three flow components constitute a first-order water budget estimate for the San Diego River basin. The ratio of surface-water outflow and groundwater outflow to total water inflow are 0.6 and 0.4, respectively. Using total water inflow determined using the Basin Characterization Model for the entire San Diego region and the 0.4 partitioning factor, groundwater outflow from the San Diego region, through the coastal plain aquifer to the Pacific Ocean, is calculated to be approximately 50 million cubic meters per year. The area-scale assessment of water resources highlights several hydrologic features of the San Diego region. Groundwater recharge is episodic; the Basin Characterization Model output shows that 90 percent of simulated recharge occurred during 3 percent of the 1982–2009 period. The groundwater aquifer may also be quite permeable. A reconnaissance-level groundwater flow model for the San Diego River basin was used to check the water budget estimates, and the basic interaction of the surface-water and groundwater system, and the flow values, were found to be reasonable. Horizontal hydraulic conductivity values of the volcanic and metavolcanic bedrock in San Diego region range from 1 to 10 m per day. Overall, results establish an initial hydrologic assessment formulated on the basis of sparse hydrologic data. The described flow variability, extrapolation, and unique characteristics represent a realistic view of current (2012) hydrologic understanding for the San Diego region.

Handling of Astyanax sp. for biomonitoring in Cangüiri Farm within a fountainhead (Iraí River Environment Preservation Area) through the use of genetic biomarkers

Aquatic environmental pollution may cause biodiversity loss. Thus, monitoring studies are very important because fish health reflects both quality and sustainability of the environment, as well as of the individuals that live there. In the present report, genetic biomarkers (piscine micronucleus test; comet assay with blood, liver, and kidney cells) were used in specimens of Astyanax sp. to analyze the contamination level of the Cangüiri Farm through biomonitoring. The Cangüiri Farm, the old school farm of the Federal University of Paraná, is inside the Iraí River Environment Preservation Area, created in 1996 to preserve the sources of public water supply in Curitiba and metropolitan area. We verified that the fishes collected within the Cangüiri Farm area presented high damage levels, showing more environment contamination when compared to the specimens collected in the Costa Ecologic Park, used as reference in the present report. The results indicate that the Cangüiri Farm, which is inside an environment protection area, created especially for the protection of the fountainhead for water supply, may be contaminated. These toxic residues, which were remarkably persistent in the environment, are possibly derived from agricultural activities in the wider area. Thus, we suggest the analysis of the area with other biomarkers and for a longer time period.

An Evaluation of Demand for and Supply of Potable Water in an Urban Centre of Abeokuta and Environs, Southwestern Nigeria

The current and future demand for potable water supply to Abeokuta city and environs in southwestern Nigeria were estimated in this study. The estimated water demands, up to the year 2030, were based on population growth and per capita water consumption. The study also investigated whether the present source of public water supply to the city and environs could meet the estimated demand. The consumption standards of 120 and 60 l per capita per day for urban and semi-urban water supplies respectively, recommended in the Nigerian Water Supply and Sanitation Policy, were used for domestic demand estimates. The institutional, industrial, fire service, horticulture and animal husbandry water requirements were based on reasonable percentages of the total domestic demand. The flow of Ogun River, which is the source of raw water for the Abeokuta Water Supply scheme serving Abeokuta city and environs, was assessed and found sufficient to meet the estimated future potable water requirements of the study area. The study indicated that the estimated current annual potable water demand of Abeokuta city and environs (in 2011) is 5.52 × 107 m3 (1.51 × 105 m3/day) and the projected annual potable water demand for the year 2030 is 7.67 × 107 m3 (2.10 × 105 m3/day). At a design capacity of 1.62 × 105 m3/day, the total water supply from the Abeokuta Water Supply Scheme at full capacity will just be about the total required in 2014. By 2015, the scheme will no longer be adequate to meet the total water required, even if it is run at full capacity. It is therefore imperative that the current scheme is expanded within the next 4 years in order to meet the potable water demand of the intended population.

Effect of Size and Surface Ligands of Silver (Ag) Nanoparticles on Waterborne Bacteria

Clean drinking water is a matter of concern for all countries, more so for many developing countries and consequently various methods of producing clean drinking water are being practiced for provision of such water to the consumers. At the same time an attempt is always made to adopt any new technique or technology to use it for commercially feasible production of such water. In recent years, with the advent of fast developing technologies, nanotechnology has also come into operation for economic and commercial production of clean drinking water. With a view to produce clean drinking water free from pathogens by the use of nanotechnology, we have investigated the antibacterial properties of silver (Ag) nanoparticles against waterborne bacteria in the public water supply sources in Islamabad, the capital of Pakistan. Water samples from over 50 water supply sources were collected and bacterial strains were identified by API20E method. Different silver nanoparticles were tested against 8 different bacterial isolates at concentrations varying from 26 to about 77 μg/mL. Nanoparticles of size ranging from 3-8 nm prepared by casein stabilization method showed the best activity against all isolated strains, E. coli being the most effectively inhibited with an average 14.9 mm zone of inhibition. C. sakazakii (12.6 mm) was most sensitive to citrate stabilized particles, followed by E. coli (12.3 mm), K. pneumoniae (12 mm) and P. aeruginosa (11.6 mm). These results provide a useful picture for the development of water filters incorporated with silver nanoparticles. We believe that this study is important for the public, particularly in the developing countries and also for others working in the area of antibacterial effects of nanoparticles.

Evaluating Bank Filtration as an Alternative to the Current Water Supply from Deeper Aquifer: A Case Study from the Pannonian Basin, Serbia

Groundwater from a depth of 100–200 m is the main source of public water supply in most municipalities in the Pannonian basin in central and southeastern Europe. Even though its quality does not always meet EU standards for drinking water—including those regarding arsenic—in many villages and even in some major cities no treatment except chlorination takes place. Of the several alternatives to improve the water supply situation in the Autonomous Province of Vojvodina in the northern part of the Republic of Serbia, re-orientation towards more centralized systems combined with river bank filtration as an additional and sustainable raw water resource was evaluated as the best. A hydrogeological and hydrochemical survey of the Tisa (or Tisza) River alluvium in the Padej test field confirmed the aptness of this approach. A good connection between the Tisa River bed and the alluvial aquifer consisting of fine-grained sand was found (average hydraulic conductivity of 5 × 10−5 m/s). With appropriately designed and managed wells, 80–100 l/s bank filtrate per km of river bank can be produced for water supply. Comprehensive analysis of the river water and river bank filtrate as well as a pilot treatment of the bank filtrate suggest that aeration-oxidation-flocculation-filtration-disinfection is a suitable technology for the Tisa River bank filtrate.

Applying gross alpha and beta measurements as an estimate to the total indicative dose of Cambrian-Vendian ground water in Estonia

Gross alpha and beta measurements are common procedures for screening water samples in order to estimate the level of total indicative dose (TID) from the radionuclides in water. However, it has been pointed out that gross alpha and beta measurements are not suitable for waters containing high concentrations of natural radionuclides, especially Ra-226 and Ra-228. Cambrian-Vendian aquifer system is the major source of public water supply in northern and north-eastern Estonia. The aquifer is known for its high radionuclide concentrations. The main sources of TID are Ra-226 and Ra-228, but the water also contains K-40. Other nuclides from uranium and thorium series may be present as well. A set of Ra-226, Ra-228 and K-40 activity concentrations measured by gammaspectrometry are studied to analyze the applicability of gross alpha and beta measurements in case of Cambrian-Vendian ground water. The calculations indicate that the levels suggested by WHO guidelines are not suitable for the Cambrian-Vendian ground water. Results on the applicability analysis are given.

Concentration of222rn in drinking water along coastal kerala and evaluation of ingestion doses

In this study, the result of systematic measurement of activity concentration of 222 Rn in drinking water from sources of public water supply along the coastal regions of Kerala is discussed. The 222 Rn concentrations in water were measured using the emanometry method and it was found to vary from 0.03 to 1.31Bq l −1 . The associated effective doses were computed for the population of the region.

Assessment of spring water quality and quantity, and health implications in Tongaren division, Nzoia River catchment, Kenya

AbstractSpring water is the common source of public water supply in most rural communities of developing countries such as Kenya. The water quality and quantity may be altered due to catchments degradation. This study was carried out in Tongaren division, Nzoia River catchment. The aim of this study was to investigate and map the occurrence and distribution of springs and to determine their water quality and quantity. This study determined the spring water discharge, conductivity, turbidity, total and thermotolerant (faecal) coliforms to assess suitability and sustainability of spring water for safe drinking. Twenty‐eight springs were identified and their locations mapped using Global Positioning System (GPS) geo‐reference data. Discharge ranged from 0.1 to 3 l s−1, with some drying up during dry season. Total coliform was innumerable in most of the studied springs while thermotolerant (faecal) coliform counts occurred in eight springs, including four protected springs. This poses high risks of water‐borne diseases. The water should be filtered and boiled prior to use for drinking. Facilitation of communities enabled development of seven springs to enhance water yield and quality. This study established high potential in the communities to develop springs and utilize the spring water as alternative source of livelihoods.

Population dynamics of Cylindrospermopsis raciborskii (Woloszynska) Seenayya & Subba Raju, a Cyanobacteria toxic species, in watersupply reservoirs in São Paulo, Brazil

The Guarapiranga and Billings reservoirs are main sources of public water supply to millions of people in the city of São Paulo, Brazil. They have been under intense antropic action as a result of domestic, industrial, farm and livestock waste being dumped in the reservoirs. Cyanobacteria develop very well in such an environment, producing blooms that are most often toxic. Cylindrospermopsis raciborskii(Woloszynska) Seenayya & Subba Raju is a toxic species which is rapidly spreading all over the world and is abundant in the studied reservoirs. The goal of the study was to follow the year-round variation of the C. raciborskii population density and to correlate it with selected environmental factors. Samples were collected monthly on the surface of the water column and studied under a binocular optic microscope, whereas quantitative studies were carried out under an inverted microscope, according to the Utermöhl method. Among the phytoplankton community, organisms of the Cyanobacteria Class were represented by the greatest population density (cells mL-1). Cylindrospermopsis raciborskii was one of the abundant species in the Billings reservoir, both in the dry and rainy season. The principal environmental factors that influenced C. raciborskii population dynamics were water temperature, high pH values and low euphotic zone values

Airborne and waterborne radon concentrations in areas with use of groundwater supplies

A preliminary survey of airborne and waterborne radon concentrations was given for an area where groundwater is used as a source of public water supply. The average of the waterborne radon concentrations was 77 Bq/l for 36 samples and that of airborne radon concentrations was 18 Bq/m3for ten houses. It is concluded that the exposure dose due to radon-in-water is likely to be much smaller than the total dose from natural radiation.

Effectiveness of the Nitrate Sensitive Areas Scheme in reducing groundwater concentrations in England

The Nitrates Sensitive Areas (NSA) Scheme in England was a voluntary, compensated measure from 1990 to 2003 which aimed to reduce nitrate leaching from agricultural land to vulnerable groundwaters by modifying land use management. Measurements from 22 NSAs introduced in 1994/5 show an overall 34% decrease in the nitrate concentration of water leaching from the soils from 115 mg/l (1994/5-1995/6) to 76 mg/l (1998/9-1999/2000). This study looks at two NSAs in depth. The Old Chalford NSA consists of a small (81 km 2 ) catchment with a series of spring sources in the Oolitic Limestone in Oxfordshire, whilst the Pollington NSA is the much larger (358 km 2 ) catchment of three large public water supply sources (PWS) in the Sherwood Sandstone of North Yorkshire. Soil leaching model results suggest that the Scheme reduced root zone nitrate concentrations from 98 mg/l in 1994 to 69 mg/l in 1998 at Pollington NSA, and from 43 mg/l in 1990 to 37 mg/l in 1998 at Old Chalford NSA. These data served as inputs into flow modelling to quantify the effect of changes in the soil zone on groundwater concentration. At Old Chalford changes in the soil zone had a measurable effect at abstraction points after only two years, whereas Pollington NSA has shown little effect of the Scheme on abstracted groundwater concentration to date as the geology and geometry of the source catchment zones are expected to lead to a noticeable impact only after 30 years. Although results demonstrate the effectiveness of the Scheme in reducing root zone nitrate leaching, the timescales involved in groundwater responses mean that, in many areas, the impact of such pollution control measures will not be realized for several decades.

Identification of degradation characteristics – exemplified by Gd–DTPA in a large experimental column

Surface water from rivers or lakes, infiltrating through porous media, is increasingly used as a source of public water supply. During bank filtration the water chemistry is substantially changed by various processes such as biodegradation, sorption and mixing with ambient groundwater, but the details of this natural attenuation are not yet entirely understood. In order to gain a better understanding, the degradation of an organic substance (DTPA) is examined here using various model approaches for steady state conditions. Models are fitted on data from an experimental study under near-field conditions. The results show advantages and disadvantages of the different model approaches and provide a guideline for the modelling of other organic substances under different but similar conditions.

Failure of an industrial wastewater lagoon in a karst terrain and remedial action

Failure of a wastewater lagoon, caused by development of a sinkhole underneath the lagoon at a site in the Lehigh River Valley near Allentown, Pennsylvania, allowed waste water to enter into the underlying karstified carbonate aquifer, a source of public water supply in the area. Identification of the contamination and development of an appropriate site-specific remediation plan required understanding of site geology, stratigraphy, hydrogeologic setting and aquifer characteristics. Information on site geology and hydrogeology, including aquifer geometry and matrix, occurrence and flow of groundwater were collected and evaluated. Core holes were drilled, geophysically logged, and correlated to define stratigraphy and structural controls to the movement of groundwater and pollutants. Monitoring wells were installed. Water level data collected on a continuous basis were used to determine the direction and gradient and also correlated with climatic changes to define amplitude of fluctuations of groundwater. Correlation of lithologic logs and interpretation of geophysical logs identified five water-producing zones separated by semi-confined layers within the carbonate aquifer. Water samples were collected from different water producing zones and analyzed to delineate vertical and horizontal extent of contamination. Pentaerythritol (PE), which was directly linked with the failure of lagoon, was identified as a pollutant in groundwater. PE was found to be present in the lower water-producing zones. Based on a geologic and hydrogeologic model of the site and understanding of flow regime and presence of PE in the lower water producing zones, a remedial plan (a pump-and-treat system) was developed and implemented to remediate the aquifer. This remedial action has reduced the PE level in groundwater and also created a pressure trough as a barrier to off-site migration.

A tracer study of the danger posed to a chalk aquifer by contaminated highway run-off

Multiple tracer tests have been undertaken in the Chalk aquifer of Hertfordshire over distances in excess of 3 km. Both fluorescent and bacteriophage tracers were used. Unlike most previous tests, which have involved introducing tracer into features such as swallow holes and observing its discharge at springs, the present study involved inserting tracers at an arbitrary point in the aquifer and detecting them at wells (both pumped and static). Flow speeds of about 2 km/day were indicated, but recoveries were very low, suggesting highly dispersive flow within fissures but with much of the tracer either being adsorbed or travelling too slowly through the aquifer to be detected within the two-month period of each experiment. The field results were interpreted on the basis of a Monte Carlo simulation model of flow and dispersion in fissures, based on classical well hydraulics and both Fickian and non-Fickian dispersion. Travel times and dilution factors showed general agreement with the fissure-flow and matrix-diffusion aspects of the model, but field tracer recoveries were too low for detailed comparison. The tests were undertaken as part of a study to determine whether or not, and, if so, in what time, a substance accidentally entering soakaway drains at the M25/M1 interchange would reach any source of public water supply.

Management and protection of quality of groundwater resources in the english midlands

The aquifers of the Severn-Trent region of the U.K. are important sources of public water supply. They are threatened by a variety of local and diffuse quality problems and significant contamination of these aquifers has occurred in some locations. This paper outlines some of these problems and describes the groundwater quality management and resource protection strategy adopted for the Severn-Trent area.

Protection of groundwater in relation to waste disposal in Wessex water authority

Wessex Water Authority, as one of the 10 water authorities of England and Wales, has the responsibility of liaising with Waste Disposal Authorities, that is the County Councils, to ensure that the water resources both groundwater and surface water are not polluted by waste disposal activities. The general policy adopted by Wessex in waste disposal liaison is to discourage waste disposal sites on aquifers. However, taking a realistic view on the subject and bearing in mind that a very large proportion of Wessex area is aquifer outcrop and the need to balance all interests, sites on aquifers are not ruled out automatically. All sites are looked at individually with all advantages and disadvantages being considered and if adequate reliable evidence can be provided to show that a site will not have a detrimental effect on a particular aquifer then the site would be accepted if the need was sufficiently great. This practical approach has been generally well accepted by all parties involved in Wessex and it has resulted in a wide variety of types of site and mechanisms employed to protect both surface water and groundwater. Three sites are described which represent very different circumstances. One is a large site in an isolated area of Carboniferous Limestone for which the proposed technique is to control groundwater levels around the site to ensure inflow to the top rather than outflow. The collected groundwater and leachate is then discharged to a sewer for treatment. A different approach used at a site on Forest Marble which is a fairly clayey material, which although used for small private supplies is not used for major public water supply sources to any significant degree, has been to line the site with a butyl rubber lining in order to contain the leachate and then dispose for treatment. The next approach considered is the acceptance of the dilute and disperse approach at an existing site on chalk; a limestone aquifer which is extremely permeable due to a profusion on inter connected fissures. Finally a proposed site at a non-aquifer site is described which avoids many of the problems encountered at sites situated on aquifers where groundwater has to be protected. The general conclusion reached is that waste disposal requires a flexible approach which results in a wide range of types of site. Such an approach can prevent many problems that can be caused by too rigid an approach.

Determination of residual chlorine in water with computer automation and residual-chlorine electrode

A method of determining active chlorine in water in the concentration range 3 to 100 ppB with an accuracy of 2 ppB has been developed. The method uses the Orion model 97-70 residual-chlorine electrode and the known standard-addition potentiometric technique to measure the potential difference between iodide and iodine that is generated by active chlorine. The assay is computer-automated to carry out the multiple addition of a standard; measure the potentials; plot the potentiometric curve, its Gran version, and an error function; and calculate the concentration of active chlorine in the assay solution. The electrode, the chemical reactions that occur during the assay, the preparation and storage of standards, and the procedure are discussed. Data obtained from the assay of standards prepared from deionized water, two sources of public water supply, and one swimming pool are presented. 1 table, 8 figures.

Oil Pollution of Water Supplies: Task Group Report

This report discusses the frequency and severity of accidental oil spills that pollute public water supplies, their impact on the water supply industry, and preventative and emergency measures to deal with them. AWWA Task Group 2500R was established in the fall of 1964 in response to the growing magnitude of the problem. It has focused on the protection of water sources from oil spills through best use of such water utility management tools as planning, communication, and interindustry relations. Several examples of spills are reported in detail that polluted or threatened to pollute sources of public water supply. They cover a variety of situations and help give perspective on the nature of the problem.

Selected Data on Public Supplies of the 100 Largest Cities in the United States, 1962

The U.S. Geological Survey (USGS) has been recording the changes that have occurred in municipal water utility practices for the last four decades. The scope of the latest study was limited to the 100 largest cities in the United States, as determined by the 1960 census, in order that comprehensive spectrographic and radiochemical analyses could be included. This article presents a summary of the study, including the following information for each of the 100 cities: suburban towns supplied by the city system; population of the city; total population served; sources of supply; auxiliary and emergency sources of supply; if available, the lowest 30‐day mean discharge of streams used for public water supply; treatment; rated capacity of each treatment plant; and, raw‐water and finished water storage capacity. Diagrams have been prepared for 58 cities showing the sources, treatment plants, and areas served by the municipal system. This article provides a list of the 100 largest cities in the U.S., according to the 1960 census, showing population served, sources of public water supply, treatment, and type of raw‐ and treated‐water analyses reported.