Management of the Occoquan River basin: a 20-year case history

1995 ◽  
Vol 32 (5-6) ◽  
pp. 235-243 ◽  
Author(s):  
C. W. Randall ◽  
T. J. Grizzard
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Drinking Water ◽  
Wastewater Treatment ◽  
Water Supply ◽  
Land Use Changes ◽  
Treatment Plant ◽  
Water Reservoir ◽  
Land Use Management ◽  
Early Results

The high dam on the Occoquan River of Northern Virginia, United States of America, was constructed in 1957, forming a drinking water reservoir with a capacity of 37.1 × 106m3 formed by drainage from a 1 460 km2 watershed, and providing a safe yield of 189 251 m3 per day. Deteriorating water quality in the late 1960s led to a special “policy” for the watershed, designed to preserve the reservoir as a drinking water supply. Key provisions of the policy mandated replacement of the watershed's 11 publicly owned wastewater treatment works with a single advanced wastewater treatment plant (AWT), and establishment of the Occoquan Watershed Monitoring Programme. Early results from the programme established non-point nutrient pollution as a major cause of water quality deterioration and resulted in the implementation of non-point pollution controls throughout the watershed during the late 1970s. The AWT plant went on-line in July 1978. Continuous monitoring since 1973 has demonstrated both the necessity and the effectiveness of point and non-point nutrient controls for the preservation of the reservoir's water quality. The AWT plant provides excellent removal of organics and phosphorus, plus complete nitrification. The nitrates are discharged to the receiving stream to enhance conditions in the reservoir. Control policies include land-use management for the preservation of this essential water supply for 750 000 people in the Washington, D.C. suburbs. Land-use management decisions are based on the results obtained with a watershed-reservoir linked computer model which predicts water quality changes resulting from land-use changes.

A national approach to risk assessment for drinking water catchments in Australia

2005 ◽  
Vol 5 (2) ◽  
pp. 123-134 ◽  
Author(s):  
R. Miller ◽  
B. Whitehill ◽  
D. Deere
Keyword(s):  
Water Quality ◽  
Risk Assessment ◽  
Land Use ◽  
Drinking Water ◽  
Water Supply ◽  
Supply System ◽  
Drinking Water Quality ◽  
Water Utilities ◽  
Quality Data ◽  
Water Quality Data

This paper comments on the strengths and weaknesses of different methodologies for risk assessment, appropriate for utilisation by Australian Water Utilities in risk assessment for drinking water source protection areas. It is intended that a suggested methodology be recommended as a national approach to catchment risk assessment. Catchment risk management is a process for setting priorities for protecting drinking water quality in source water areas. It is structured through a series of steps for identifying water quality hazards, assessing the threat posed, and prioritizing actions to address the threat. Water management organisations around Australia are at various stages of developing programs for catchment risk management. While much conceptual work has been done on the individual components of catchment risk management, work on these components has not previously been combined to form a management tool for source water protection. A key driver for this project has been the requirements of the National Health and Medical Research Council Framework for the Management of Drinking Water Quality (DWQMF) included in the draft 2002 Australian Drinking Water Guidelines (ADWG). The Framework outlines a quality management system of steps for the Australian water industry to follow with checks and balances to ensure water quality is protected from catchment to tap. Key steps in the Framework that relate to this project are as follows: Element 2 Assessment of the Drinking Water Supply System• Water Supply System analysis• Review of Water Quality Data• Hazard Identification and Risk Assessment Element 3 Preventive Measures for Drinking Water Quality Management• Preventive Measures and Multiple Barriers• Critical Control Points This paper provides an evaluation of the following risk assessment techniques: Hazard Analysis and Critical Control Points (HACCP); World Health Organisation Water Safety Plans; Australian Standard AS 4360; and The Australian Drinking Water Guidelines – Drinking Water Quality Management Framework. These methods were selected for assessment in this report as they provided coverage of the different approaches being used across Australia by water utilities of varying: scale of water management organisation; types of water supply system management; and land use and activity-based risks in the catchment area of the source. Initially, different risk assessment methodologies were identified and reviewed. Then examples of applications of those methods were assessed, based on several key water utilities across Australia and overseas. Strengths and weaknesses of each approach were identified. In general there seems some general grouping of types of approaches into those that: cover the full catchment-to-tap drinking water system; cover just the catchment area of the source and do not recognise downstream barriers or processes; use water quality data or land use risks as a key driving component; and are based primarily on the hazard whilst others are based on a hazardous event. It is considered that an initial process of screening water quality data is very valuable in determining key water quality issues and guiding the risk assessment, and to the overall understanding of the catchment and water source area, allowing consistency with the intentions behind the ADWG DWQM Framework. As such, it is suggested that the recommended national risk assessment approach has two key introductory steps: initial screening of key issues via water quality data, and land use or activity scenario and event-based HACCP-style risk assessment. In addition, the importance of recognising the roles that uncertainty and bias plays in risk assessments was highlighted. As such it was deemed necessary to develop and integrate uncertainty guidelines for information used in the risk assessment process. A hybrid risk assessment methodology was developed, based on the HACCP approach, but with some key additions and modifications to make it applicable to varying catchment risks, water supply operation needs and environmental management processes.

Исследование влияния изменения ионного состава воды на дзета-потенциал и окислительно-восстановительный потенциал

2020 ◽  
Author(s):  
V. Kichigin ◽  
I. Egorova ◽  
N. Atanov
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Supply ◽  
Redox Potential ◽  
Water Reservoir ◽  
Distribution Networks ◽  
Water Supply Systems ◽  
Ion Composition ◽  
High Concentration ◽  
The City

Приведены результаты исследований питьевой воды системы централизованного водоснабжения г. Самары. При определении органолептических показателей качества воды было выявлено увеличение цветности исходных проб на 13 град в пределах погрешности метода измерения. Это может быть связано с высоким содержанием железа и его соединений или гуминовых веществ в пробах в дни проведения эксперимента, а также с высоким физическим износом водопроводных сетей (как уличных, так и внутри здания) и общим ростом цветности воды в Саратовском водохранилище в районе г. Самары за последние годы. Установлена зависимость -потенциала от величины окислительно-восстановительного потенциала и ионного состава воды. Определен физико-химический состав изучаемой воды, сделан анализ полученных результатов. В ходе исследований дополнительно определялись такие показатели, как pH, температура, мутность и щелочность для получения полной картины качества воды. Установлено соответствие всех изучаемых показателей воды нормам СанПиН 2.1.4.1074-01 Питьевая вода. Гигиенические требования к качеству воды централизованных систем питьевого водоснабжения. Контроль качества . Приведены математические зависимости между -потенциалом, жесткостью, содержанием анионов и катионов в исследуемой воде с достоверностью аппроксимации R2 не ниже 0,83. Это позволяет рассчитать ионный состав и мутность питьевой воды г. Самары только по величине -потенциала или окислительно-восстановительного потенциала без проведения дорогостоящих трудоемких химических анализов. Предлагаемый метод рекомендуется использовать в качестве экспресс-анализа питьевой воды.The results of studies of drinking water in the public water supply system of the city of Samara are presented. While determining the organoleptic indicators of the water quality, an increase in color of the initial samples by 13 degrees within the procedural error was revealed. This may be due to the high concentration of iron and its compounds or humic substances in the samples on the days of the experiment, as well as to the high physical deterioration of the water distribution networks (both street networks and plumbing in the buildings), and the general increase in water color in the Saratov water reservoir in the city of Samara in recent years. The dependence of the -potential on the redox potential value and ion composition of water is established. The physicochemical composition of the studied water is determined, an analysis of the results is carried out. In the course of the research, such indicators as pH, temperature, turbidity and alkalinity were additionally determined to obtain an aggregate picture of the water quality. The compliance of all studied water indicators with the requirements of SanPiN 2.1.4.1074-01 Drinking water. Hygienic requirements for water quality of centralized drinking water supply systems. Quality control was confirmed. Mathematical dependences between the -potential, hardness, and the concentration of anions and cations in the water under study are given with an approximation authenticity R2 higher than 0.83. This allows calculating the ion composition and turbidity of drinking water in Samara only by the value of the -potential or redox potential without expensive labor-intensive chemical analyzes. The proposed method is recommended to be used as an express analysis of drinking water.

The effect of catchment afforestation on public water supplies in Strathclyde Region, Scotland

1987 ◽  
Vol 78 (4) ◽  
pp. 335-340 ◽  
Author(s):  
L. A. Greene
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Water Supply ◽  
Capital Expenditure ◽  
Land Use Changes ◽  
Water Quality Monitoring ◽  
Water Supplies ◽  
Quality Of Water ◽  
Run Off ◽  
The Impact

ABSTRACTIntensive coniferous afforestation of many water supply catchments is taking place in Strathclyde Region. The current concern over the impact of this significant change in land use on the quantity and quality of water supplies is discussed. Some effects, such as high sediment run-off associated with ploughing and road development, may be of dramatic short-term effect, while others, such as reduction in quantitative yield, the development of eutrophication or acidification with aluminium leaching from soils, may take longer to materialise. Selective routine water quality monitoring work commenced in 1984 in a number of water supply catchments aimed at identifying forestry-related water quality trends. The initial results of this work are presented. Against the background of catchment land use changes, new European Community water supply standards were imposed in 1985 committing the Region to a substantial capital expenditure programme over a ten-year period in order to upgrade water treatment works. Any significant long-term changes in water quality associated with forestry activity will make this programme more costly to achieve. It is considered that the water supplies most susceptible to forestry related quantity or quality problems are the small supplies in areas of Argyll, Ayrshire and the Islands. It is suggested that the way forward is for improved advance consultation and planning on a site specific basis to protect public water supply interests.

scholarly journals Re-examination of hydrochemistry and groundwater potentials of Cross River and Imo-Kwa-Ibo intersecting Tropical Basins of South-South Nigeria

2020 ◽  
Vol 2 (3) ◽  
Author(s):  
Saadu Umar Wali ◽  
Ibrahim Mustapha Dankani ◽  
Sheikh Danjuma Abubakar ◽  
Murtala Abubakar Gada ◽  
Kabiru Jega Umar ◽  
...  
Keyword(s):  
Water Quality ◽  
Electrical Conductivity ◽  
Land Use ◽  
Drinking Water ◽  
Groundwater Quality ◽  
Land Use Changes ◽  
Quality Indices ◽  
Cross River ◽  
Groundwater Aquifers ◽  
The Impact

This review attempted a detailed description of geological and hydrogeological configurations of Cross River and Imo-Akwa Ibo basins. It presented a synthesis of hydrochemistry and a description of the hydrogeological configurations of the two basins. Hydrogeologically, most areas under Cross River and  Imo-Kwa-Ibo are poor in terms of groundwater potentials. Based on the hydrochemistry, the basins hold water of excellent quality.  Groundwater sources fall in soft to moderately hard classes. The entire sources groundwater has a TDS concentration of less than 500 mg/l. Groundwater classification based on electrical conductivity (EC) showed EC levels were less than 500  µS/cm. Most of the examined cations and anions are within WHO reference guidelines for drinking water quality. However, no broad analysis of water quality based on water quality indices. Also, studies modeling pollution or the impact of land use changes on groundwater quality are wanting. Thus, further analysis of the hydrochemistry of groundwater aquifers is recommended.

Pollution by phosphorus and nitrogen in water streams feeding the Zelivka drinking water reservoir

1999 ◽  
Vol 39 (12) ◽  
pp. 207-214 ◽  
Author(s):  
Jiri Holas ◽  
Marketa Holas ◽  
Vladimir Chour
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Bottom Sediments ◽  
Arable Land ◽  
Treatment Plant ◽  
Water Reservoir ◽  
Phosphorus Release ◽  
Phosphorus Compounds ◽  
Reservoir Water ◽  
Drinking Water Reservoir

This case study refers to long term monitoring of Martinicky and Sedlický Brooks, which represent general water-quality characteristics well related to the watershed of the whole Zelivka drinking water reservoir. For a period of more than ten years water-quality indices were systematically monitored at each profile together with actual discharges recorded at selected profiles. It is seen that the only critical pollutants are nutrients, namely nitrate nitrogen and total phosphorus, originating from both urban and agricultural sources, while industrial pollution is relatively marginal in the watershed. Phosphorus concentrations do not display any simple time regularity. Persistent all-year background phosphorus load gives evidence of the urban origin of pollution. Total input of phosphorus into the reservoir came mainly from surface inflows, out of rainfall and out of bottom sediments. Phosphorus was found to be the limiting nutrient for phytoplankton growth and was therefore recognised as the principal element responsible for reservoir eutrophication rates, which could probably be effectively controlled by concerted abatement actions. Most of the watershed born nitrogen pollution has a distinctly non-point (diffuse) character. Typical yearly pattern of nitrate concentrations means distinct and regular increase during end-of-winter and spring period due to processes of mineralization, typical for productive arable land on soils with good drainage properties. The process of state economy transition, which was initiated in 1989, has led to dramatic decrease of fertiliser inputs per hectare of land. Reduced fertilisation of arable land has not yet been reflected in improved quality of surface waters. The proposed strategy for prevention and abatement in the Zelivka reservoir eutrophication should be based on win-win principles applied throughout the entire watershed and, at present, preferentially focused on:phosphorus cycle control and improvement within both the watershed and reservoir water (diminished use of chemicals producing reactive phosphorus compounds, improved phosphorus removal from urban waste water, to prevent phosphorus release from bottom sediments)general soil erosion control and prevention - grassland cultivation on vulnerable areas and buffer zones and subsidy for cultivating plants on arable land even between growing periodsproper maintenance and improvement of treatment plant technology to maintain actual standards of produced drinking water.

Analysis on the Temporal and Spatial Pattern of Ecosystem Services Based on Land-Use Changes: A Case Study of Guanting Reservoir Watershed in China

2013 ◽  
Vol 807-809 ◽  
pp. 1743-1757
Author(s):  
Yi Hui Wen ◽  
Gui Huan Liu ◽  
Hai Guang Hao ◽  
Shu Fang Liu
Keyword(s):  
Land Use ◽  
Drinking Water ◽  
Ecosystem Services ◽  
Water Supply ◽  
Land Use Changes ◽  
Compensation Mechanism ◽  
Ecosystem Service Value ◽  
Service Value ◽  
Guanting Reservoir ◽  
Reservoir Basin

Being located in the northwest of Beijing, Guanting Reservoir has been an important source to supply water for life, production and landscape; however, with the increasing urbanization and population agglomeration in the upstream since 1980s, the resource and environment of Guanting Reservoir Basin was also undertaken an increasingly pressure accordingly with water quantity dropped and quality deteriorated, so Guanting Reservoir was ruled out of the drinking water supply system of Beijing since 1997. As a series of ecological protection and management project have been implemented with the 21st century coming, Guanting Reservoir restored its water-supply function for agriculture, ecology and industry in 2003, and restored its function as drinking water source in 2007, so it became an emergency water-supply source of Beijing again. The environmental protection status and economic development model of Guanting Reservoir Basin plays an essential role for water security of Beijing. In this paper, taken Guanting Reservoir Basin as the study case, the land use data of different periods since 1980s have been extracted from remote sensing images of the study area to analyze the land use changes. Based on the land use data, Costanza ecosystem service value formula and correction parameter suitable for China situations, the basin ecosystem service value is calculated to analyze the changes in leading ecosystem function of Guanting Reservoir Basin in different periods. In combination with the social and economic statistical data, the driving factors are discussed for changes in the leading function, and the approaches are put forward to enhance the upstream ecosystem function, so as to guarantee the sustainable economic and social development in the Basin. It is indicated from the research results that: (1) the driving forces for the changes in dominate ecosystem functions of Guanting Reservoir Basin mainly result from policy factor, population factor and economic factor; (2) the ecosystem services of Guanting Reservoir Basin are presented as asymmetric spatial characteristic; and (3) the eco-compensation mechanism is an important means to balance the asymmetry of ecosystem services between the upstream and downstream of Guanting Reservoir Basin and enhance the upstream capacity for provision of ecosystem services. The quantitative eco-compensation mechanism is the key point of follow-up research to enhance ecosystem services; the scenario analysis will have a prospective potential to propose some policy suggestions with more operability.

scholarly journals Quantifying the impact of runoff events on microbiological contaminant concentrations entering surface drinking source waters

2005 ◽  
Vol 3 (4) ◽  
pp. 453-468 ◽  
Author(s):  
R. S. Signor ◽  
D. J. Roser ◽  
N. J. Ashbolt ◽  
J. E. Ball
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Treatment Plant ◽  
Water Reservoir ◽  
Weighted Average ◽  
Health Concern ◽  
Quality Data ◽  
Parameter Estimates ◽  
The Impact ◽  
Runoff Events

Concentrations of microbiological contaminants in streams increase during rainfall-induced higher flow ‘event’ periods as compared to ‘baseflow’ conditions. If the stream feeds a drinking water reservoir, such periods of heightened pathogen loads may pose a challenge to the water treatment plant and subsequently a health concern to water consumers downstream. In order to manage this risk, it is desirable to first quantify the differences in surface water quality between baseflow and event conditions. The Event Mean Concentration (EMC) is a flow-weighted average concentration of a contaminant over the duration of a single event, proposed here as a standard parameter for quantifying the net effect of events on microbial water quality. Application of the EMC concept was assessed using flow and quality data for several events from an urbanised catchment. Expected mean EMCs were significantly larger than expected mean baseflow concentrations (p-value≤0.012) for three microbial agents - Escherichia coli (13,000 [n = 7] v. 610 [n = 16] mpn/100 ml), Cryptosporidium (234 [n = 6] v. 51 [n = 16] oocysts/10 litres) and Campylobacter (48 [n = 5] v. 2.1 [n = 16] mpn/100 ml). These parameter estimates were complemented by estimating data variability and uncertainty in the form of second-order random variables. As such the results are in a format appropriate for potential use as components in probabilistic risk assessments evaluating the effect runoff events have on drinking water quality.

Methodological Approaches to Organization of Drinking Water Quality Monitoring Programs

2020 ◽  
pp. 4-8
Author(s):  
Yu.A. Novikova ◽  
I.O. Myasnikov ◽  
A.A. Kovshov ◽  
N.A. Tikhonova ◽  
N.S. Bashketova
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Supply ◽  
Cold Water ◽  
Water Quality Monitoring ◽  
Drinking Water Quality ◽  
Quality Monitoring ◽  
Water Supply Systems ◽  
Monitoring Programs ◽  
Supply Systems

Summary. Introduction: Drinking water is one of the most important environmental factors sustaining life and determining human health. The goal of the Russian Federal Clean Water Project is to improve drinking water quality through upgrading of water treatment and supply systems using advanced technologies, including those developed by the military-industrial complex. The most informative and reliable sources of information for assessing drinking water quality are the results of systematic laboratory testing obtained within the framework of socio-hygienic monitoring (SGM) and production control carried out by water supply organizations. The objective of our study was to formulate approaches to organizing quality monitoring programs for centralized cold water supply systems. Materials and methods: We reviewed programs and results of drinking water quality laboratory tests performed by Rospotrebnadzor bodies and institutions within the framework of SGM in 2017–2018. Results: We established that drinking water quality monitoring in the constituent entities of the Russian Federation differs significantly in the number of monitoring points (566 in the Krasnoyarsk Krai vs 10 in Sevastopol) and measured indicators, especially sanitary and chemical ones (53 inorganic and organic substances in the Kemerovo Region vs one indicator in the Amur Region). Discussion: For a more complete and objective assessment of drinking water quality in centralized cold water supply systems, monitoring points should be organized at all stages of water supply with account for the coverage of the maximum number of people supplied with water from a particular network. Thus, the number of points in the distribution network should depend, inter alia, on the size of population served. In urban settlements with up to 10,000 inhabitants, for example, at least 4 points should be organized while in the cities with more than 3,000,000 inhabitants at least 80 points are necessary. We developed minimum mandatory lists of indicators and approaches to selecting priority indices to be monitored at all stages of drinking water supply.

Leading the City of Baltimore into the 21st Century: Flexible Treatment Solutions and Integrated Raw Water Management

2010 ◽  
Vol 5 (4) ◽  
Author(s):  
J. L. Manuszak ◽  
M. MacPhee ◽  
S. Liskovich ◽  
L. Feldsher
Keyword(s):  
Water Management ◽  
Water Quality ◽  
Water Supply ◽  
Conceptual Design ◽  
Membrane Filtration ◽  
Treatment Plant ◽  
Low Pressure ◽  
Management Tool ◽  
Raw Water ◽  
The City

The City of Baltimore, Maryland is one of many US cities faced with challenges related to increasing potable water demands, diminishing fresh water supplies, and aging infrastructure. To address these challenges, the City recently undertook a $7M study to evaluate water supply and treatment alternatives and develop the conceptual design for a new 120 million gallon per day (MGD) water treatment plant. As part of this study, an innovative raw water management tool was constructed to help model source water availability and predicted water quality based on integration of a new and more challenging surface water supply. A rigorous decision-making approach was then used to screen and select appropriate treatment processes. Short-listed treatment strategies were demonstrated through a year-long pilot study, and process design criteria were collected in order to assess capital and operational costs for the full-scale plant. Ultimately the City chose a treatment scheme that includes low-pressure membrane filtration and post-filter GAC adsorption, allowing for consistent finished water quality irrespective of which raw water supply is being used. The conceptual design includes several progressive concepts, which will: 1) alleviate treatment limitations at the City's existing plants by providing additional pre-clarification facilities at the new plant; and 2) take advantage of site conditions to design and operate the submerged membrane system by gravity-induced siphon, saving the City significant capital and operations and maintenance (O&M) costs. Once completed, the new Fullerton Water Filtration Plant (WFP) will be the largest low-pressure membrane plant in North America, and the largest gravity-siphon design in the world.

Sign in / Sign up

Export Citation Format

Share Document