Water Quality Improvement Programs Research Articles

Uncertainty and Sensitivity Analysis of the Effective Implementation of Water Quality Improvement Programs for Citarum River, West Java, Indonesia

Pollution of rivers is a challenge for many countries. In the Citarum watershed, Indonesia, where pollution has been an emerging issue nationwide, many programs and policies have been set up. However, implementation of all the planned programs and the significance of their contributions toward water quality improvement of the Citarum River have not been analyzed. In this paper, we present original research on evaluating water quality programs planned to achieve outputs by using uncertainty and sensitivity analysis for a river. The essential inputs included: (1) key parameters, (2) priority planned programs, and (3) interrelationships between programs, parameters, and the level of successfulness of water quality control programs. The first and second inputs were prepared simultaneously using Principal Component Analysis (PCA) and Analytical Hierarchy Process (AHP). The latter was obtained using the Delphi method to obtain the related stakeholders’ opinions. Finally, we explore Monte Carlo simulation to analyze parameter uncertainty and sensitivity contributing to the program’s effectiveness. By implementing all the water quality control programs, the results showed that cadmium, BOD, and fecal coliform were the most affected parameters. In addition, the most effective programs to improve the pollution index were domestic waste, farming, solid waste, and water resource programs. If those programs were implemented collectively, the probability of reducing the pollution index was within a range 2.01–36.22% from the base case.

Performance of deep learning in mapping water quality of Lake Simcoe with long-term Landsat archive

Remote sensing provides full-coverage and dynamic water quality monitoring with high efficiency and low consumption. Deep learning (DL) has been progressively used in water quality retrieval because it efficiently captures the potential relationship between target variables and imagery. In this study, the multimodal deep learning (MDL) models were developed and rigorously validated using atmospherically corrected Landsat remote sensing reflectance data and synchronous water quality measurements for estimating long-term Chlorophyll-a (Chl-a), total phosphorus (TP), and total nitrogen (TN) in Lake Simcoe, Canada. Since TP and TN are non-optically active, their retrievals were based on the fact that they are closely related to the optically active constituents (OACs) such as Chl-a. We trained the MDL models with one in-situ measured data set (for Chl-a, N = 315, for TP and TN, N = 303), validated the models with two independent data sets (N = 147), and compared the model performances with several DL, machine learning, and empirical algorithms. The results indicated that the MDL models adequately estimated Chl-a (mean absolute error (MAE) = 32.57%, Bias = 10.61%), TP (MAE = 42.58%, Bias = −2.82%), and TN (MAE = 35.05%, Bias = 13.66%), and outperformed several other candidate algorithms, namely the progressively decreasing deep neural network (DNN), a DNN with trainable parameters similar to MDL but without splitting input features, the eXtreme Gradient Boosting, the support vector regression, the NASA Ocean Color two-band and three-band ratio algorithms, and another empirical algorithm of Landsat data in clear lakes. Using the MDL models, we reconstructed the historical spatiotemporal patterns of Chl-a, TP, and TN in Lake Simcoe since 1984, and investigated the effects of two water quality improvement programs. In addition, the physical mechanism and interpretability of the MDL models were explored by quantifying the contribution of each feature to the model outputs. The framework proposed in this study provides a practical method for long-term Chl-a, TP, and TN estimation at the regional scale.

Relative efficacy of three approaches to mitigate Crown-of-Thorns Starfish outbreaks on Australia’s Great Barrier Reef

Population outbreaks of Crown-of-Thorns Starfish (COTS; Acanthaster spp.) are a major contributor to loss of hard coral throughout the Indo-Pacific. On Australia’s Great Barrier Reef (GBR), management interventions have evolved over four COTS outbreaks to include: (1) manual COTS control, (2) Marine Protected Area (MPA) zoning, and, (3) water quality improvement. Here we evaluate the contribution of these three approaches to managing population outbreaks of COTS to minimize coral loss. Strategic manual control at sites reduced COTS numbers, including larger, more fecund and damaging individuals. Sustained reduction in COTS densities and improvements in hard coral cover at a site were achieved through repeated control visits. MPAs influenced initial COTS densities but only marginally influenced final hard coral cover following COTS control. Water quality improvement programs have achieved only marginal reductions in river nutrient loads delivered to the GBR and the study region. This, a subsequent COTS outbreak, and declining coral cover across the region suggest their contributions are negligible. These findings support manual control as the most direct, and only effective, means of reducing COTS densities and improving hard coral cover currently available at a site. We provide recommendations for improving control program effectiveness with application to supporting reef resilience across the Indo-Pacific.

Study on Technical Schemes for Major Pollutants Emission Reduction in Beijing North Canal River Basin Based on Watershed Water Quality Target Management

Water quality target management in watershed is the fundamental choice of city rivers suffering both serious pollution and severe water shortage. In this study, we performed a case study regarding river pollution control plan based on water quality target management in the North Canal River catchment of Beijing section, in order to obtain effective water quality improvement programs. The ammonia nitrogen (NH3-N) and chemical oxygen demand (COD) were taken as the main controlling pollutants. Water quality targets and basic water quality improvement scenarios were set up considering different intensities of population regulation scenarios and gradually strengthening emission control measures. The MIKE11 model was adopted to simulate the effects of a range of water quality improvement scenarios. Results indicated that the basic scenarios could dramatically improve the surface water environment. However, additional intensive and combined measure programs should be implemented to ensure that the water quality would basically meet the targets of corresponding water function zones. The results highlight the need to implement water conservation in water shortage urban river basin and show the importance of enhancing drainage communication and conducting ecological water replenishment in such kind basins. It is expected to provide a reference for the water environment management practice of other metropolis in the world facing both crisis of water resource shortage and water environment pollution.

Study on Technical Schemes for Major Pollutants Emission Reduction in Beijing North Canal River Basin Based on Watershed Water Quality Target Management

Water quality target management in watershed is the fundamental choice of city rivers suffering both serious pollution and severe water shortage. In this study, we performed a case study regarding river pollution control plan based on water quality target management in the North Canal River catchment of Beijing section, in order to obtain effective water quality improvement programs. The ammonia nitrogen (NH3-N) and chemical oxygen demand (COD) were taken as the main controlling pollutants. Water quality targets and basic water quality improvement scenarios were set up considering different intensities of population regulation scenarios and gradually strengthening emission control measures. The MIKE11 model was adopted to simulate the effects of a range of water quality improvement scenarios. Results indicated that the basic scenarios could dramatically improve the surface water environment. However, additional intensive and combined measure programs should be implemented to ensure that the water quality would basically meet the targets of corresponding water function zones. The results highlight the need to implement water conservation in water shortage urban river basin and show the importance of enhancing drainage communication and conducting ecological water replenishment in such kind basins. It is expected to provide a reference for the water environment management practice of other metropolis in the world facing both crisis of water resource shortage and water environment pollution.

Groundwater quality assessment for domestic and agricultural purposes in Yan’an City, northwest China: implications to sustainable groundwater quality management on the Loess Plateau

Groundwater is critical for the sustainable development of the Loess Plateau, while groundwater quality is generally poor in this area due to natural factors and anthropogenic pollution. This study was carried out to investigate the suitability of groundwater for domestic and agricultural purposes in Yan’an City on the Chinese Loess Plateau and to assess its implications to sustainable groundwater management on the plateau. The index levels were compared with the threshold values established by the national and the WHO drinking water guidelines, and the suitability of groundwater for irrigation purposes was assessed using multiple agricultural water quality indicators. An entropy-weighted Technique for Order Preference by Similarity to an Ideal Solution (entropy-weighted TOPSIS) was adopted for overall groundwater quality assessment. The results indicate that the study area is characterized by saline, hard, and slightly alkaline groundwater, mainly of the HCO3–Ca·Mg type, accompanied by some minor SO4·Cl–Ca·Mg type. The dissolution of carbonates and gypsum and the leaching of soluble salts are important natural processes influencing the groundwater ion chemistry. The parameters TH, TDS, and SO42− are major indices, while Fe, Mn, F−, and NH4+ are minor contaminants affecting groundwater quality. The overall groundwater quality is generally acceptable for irrigation, and most of the water is suitable for drinking. Rainwater harvesting, water quality improvement programs, regular water quality monitoring, and multidisciplinary water research programs are suggested as measures for sustainable groundwater management on the Loess Plateau.

Distributional Weights in Environmental Valuation and Cost-benefit Analysis: Theory and Practice

Cost-benefit analysis (CBA) is built on the Kaldor-Hicks efficiency criterion whereby projects that have aggregate positive net benefits are recommended even if those who lose are not compensated for their losses. Two kinds of problems can be identified with the use of the criterion. First, as income tends to affect monetary welfare changes positively, the preferences of those with higher wealth have a larger weight in societal decision-making. Second, monetary welfare changes can be thought of as changes in real income, which matter more for those with a lower initial wealth level. Both problems can be mitigated with distributional weighting. Despite their strong theoretical pedigree, distributional weights have been largely neglected in practical CBAs, one exception being analyses in climate change economics. We present the theory of distributional weighting and illustrate how weights can be applied empirically in an international environmental CBA that deals with marine water quality improvements. We show that different weighting schemes can result in different policy recommendations. We also show that taking the income distribution within countries into account can change a country's willingness to participate in the water quality improvement program and that the income elasticity of willingness to pay (WTP) is an important indication of the direction of change.

Working With an Aboriginal Community to Understand Drinking Water Perceptions and Acceptance in Rural New South Wales

This study explored the Walhallow Aboriginal community’s experiences with drinking water to gain a shared understanding about community concerns and to develop ways to address these concerns together. There is a strong connection between people and water, as well as a need to appreciate the social factors associated with the unique cultural and socioeconomic factors that the provision of drinking water has for Aboriginal communities. We used a mixed method design within a community-based participatory action Research (PAR) framework. Water hardness and parental influence were the key factors associated with participants’ decisions to drink rainwater. This study provides important insights for water supply authorities when assessing health risks and when choosing appropriate mitigation measures for water quality improvement programs in Aboriginal communities.

Costs of Water Quality Goals under Climate Change in Urbanizing Watersheds: Difficult Run, Virginia

Reducing nutrient loadings in urban areas is important for water quality improvement programs in many watersheds. Urban nutrient loadings are expected to increase and become more variable under climate change (CC). In this study, a water quality simulation model (SWMM), land cover data layers, and mathematical programming models were used to compare costs of abating nutrient loads under CC in the Difficult Run Watershed located in Fairfax County, Virginia. Predicted costs of abating mean total nitrogen (TN), total phosphorus (TP), and total suspended sediment (TSS) loadings under current climate conditions were compared with those for CC under certainty with a Cost Minimization Model and under uncertainty with a Safety First Model. Total nitrogen loadings abatement had the highest cost followed by TP and TSS abatement in that order. Costs of controlling TP and TSS increased with CC, whereas there was little change in TN control costs. Introducing uncertainty of loadings caused control costs to increase substantially for all three pollutants. The preferred pollutant control strategy was urban stream restoration. Policy makers seeking to meet water quality goals over a multiyear horizon should consider front-loading supplemental best management practices (BMPs) to offset the changes in nutrient loadings predicted for CC.

Measuring the willingness to pay for drinking water quality improvements: results of a contingent valuation survey in Songzi, China.

The aim of this study is to elicit local residents' willingness to pay (WTP), by applying the contingent valuation method as a surcharge on their water bill, for a given improvement in the drinking water quality and the supply reliability. The mean WTP for the drinking water quality improvement program was estimated to be 16.71 yuan (0.3% of total household income). The results note that more educated respondents and households with higher income and with fewer household members are, on average, willing to pay more. This study also demonstrates that respondents' concerns regarding drinking water quality and perceptions of the health risk of drinking water quality can have significant positive impacts on people's WTP. The research results can help decision-makers understand the local population's demand for improved drinking water quality and undertake an environmental cost-benefit analysis.

Application of QUAL2K model to assess ecological purification technology for a polluted river.

Industrialization and urbanization have caused water pollution and ecosystem degradation, especially in urban canals and rivers in China; accordingly, effective water quality improvement programs are needed. In this study, the Tianlai River in Jiangsu, China was taken as a research site, and a combination of ecological purification technologies consisting of biological rope, phytoremediation, and activated carbon were applied in a laboratory-scale study to examine degradation coefficients under dynamic water conditions. Coefficients were then input into the QUAL2K model to simulate various hypothetical scenarios and determine the minimum density of ecological purification combination and hydraulic retention time (HRT) to meet Grade V or IV of the China standard for surface water. The minimum densities for Grade V and IV were 1.6 times and 2 times the experimental density, while the minimum HRTs for Grade V and IV were 2.4 day and 3 day. The results of this study should provide a practical and efficient design method for ecological purification programs.

Private transaction costs of participation in water quality improvement programs for Australia's Great Barrier Reef: Extent, causes and policy implications

The direct private cost to landholders of participating in programs that result in improved farming activities (IFAs) is generally well understood. However, the private indirect or transaction costs, such as the cost of a landholder's time and the expense to learn about IFAs and apply for assistance to implement these changes on‐farm, are not so well understood. Where these have been studied, they have been shown to be extensive. We assess the extent and causes of private transaction costs incurred by sugarcane growers participating in the Australian Government's Reef Rescue scheme which pays farmers to adopt environmentally beneficial farm management practices. Utilising a mail‐out‐mail‐back survey of 110 growers, we found that the average total transaction cost per farm of participating in the program was AU$8389. The average total transaction costs per farm as a percentage of the average funding provided was 38 per cent. We also assessed which type of improved farming activity (soil, nutrient, pest or water management) generated the greatest transaction costs and how landholder characteristics such as bounded rationality, opportunism and social connection impacted on the extent of transaction costs.

Simulating Agricultural Drainage Water Reuse Using QUAL2K Model: Case Study of the Ismailia Canal Catchment Area, Egypt

AbstractThis paper proposes and evaluates a number of drainage water mixing projects in canals applying QUAL2K, which is a river and stream water quality model recommended by the United States Environmental Protection Agency (U.S. EPA). Mitigation measures and precautions were suggested fur use as guidelines for environmentally safe application. The results showed that QUAL2K proved to be an effective tool in the comparative evaluation of potential water quality improvement programs, particularly on the salinity and water quality parameters that address agriculture practices. Simulation results showed that most selected water quality parameters for most of the considered projects complied with the standards of Egyptian law. Moreover, electrical conductivity (EC) predictions were found within the permissible limit with the recommended fit crops. The reduction in drain discharge reduces pollutant loads entering Temsah Lake and might help save the flora and fauna to support recreation activities.

Selection of optimal river water quality improvement programs using QUAL2K: A case study of Taihu Lake Basin, China

In recent years, water quality degradation associated with rapid socio-economic development in the Taihu Lake Basin, China, has attracted increasing attention from both the public and the Chinese government. The primary sources of pollution in Taihu Lake are its inflow rivers and their tributaries. Effective water quality improvement programs need to be implemented in these rivers to improve the water quality of Taihu Lake, and to ensure sustainable development in the region. To ensure effectiveness and efficiency, it is important that the optimal water quality improvement program for a specific situation be selected. The aim of this study was to facilitate the selection of this optimal program. The QUAL2K model for river and stream water quality was used to simulate the effects of a range of water quality improvement scenarios in the Hongqi River, which is a polluted tributary in the Taihu Lake Basin. These scenarios consisted of a series of three water treatment technologies in different configurations, from upstream to downstream. The results showed that the optimal scenario comprised a bio-contact oxidation system upstream, followed by an ecological floating bed, and a vertical moveable eco-bed downstream. The reduction rates achieved by this scenario for biochemical oxygen demand (BOD), ammonia nitrogen (NH3–N), total nitrogen (TN), and total phosphorus (TP) were 49.50%, 32.81%, 35.94%, and 45.27%, respectively. The QUAL2K model proved to be an effective tool in the comparative evaluation of potential water quality improvement programs. The method applied in this study can prevent the implementation of water quality improvement programs that would not achieve the desired goals.

Evaluation of spatial variability on hydrology and nutrient source loads at watershed scale using a modeling approach

Understanding the effects of spatial variability on hydrologic parameters and nutrient source load distribution is essential to develop water quality improvement programs. The objective of this research was to evaluate spatially distributed hydrologic variability, nutrient sources, and their loadings at the watershed scale using a modeling approach. The Soil and Water Assessment Tool (SWAT) was applied to assess spatial variability of annual average water, sediment, total phosphorus (TP), and total nitrogen (TN) yields from the Upper Pearl River Watershed (UPRW) in Mississippi, USA. The SWAT model was successfully calibrated, validated, and verified with good model efficiency (R2 = 0.70 and E = 0.59) using monthly measured stream flow, daily observed flow, sediment, TP, and TN yields. The SWAT model results determined that spatial variability of annual average pollutant loads of water yield ranged from 877 to 206 mm, sediment yield ranged from 1.71 to 0.17 t ha−1, TP ranged from 1.39 to 0.02 kg ha−1, and TN ranged from 10.22 to 0.69 kg ha−1 in the watershed sub-basins. Understanding of the spatial variability of hydrologic and nutrient source loads distribution helps watershed managers focus their management efforts to the most needy watershed sub-basins.

The impact of water quality on health: Evidence from the drinking water infrastructure program in rural China

This paper investigates the effect of a major water quality improvement program in rural China on the health of adults and children. Using panel data covering about 4500 households from 1989 to 2006, I estimate the impact of introducing village-level access to water from water plants on various measures of health. The regression results imply that the illness incidence of adults decreased by 11 percent and their weight-for-height increased by 0.835kg/m, and that children's weight-for-height and height itself both rose by 0.446kg/m and 0.962cm respectively, as a result of the program. And these estimates are quite stable across different robustness checks.

Water quality management of aquifer recharge using advanced tools

Managed aquifer recharge (MAR) with recycled water or other alternative resources is one of the most rapidly growing techniques that is viewed as a necessity in water-short areas. In order to better control health and environmental effects of MAR, this paper presents two case studies demonstrating how to improve water quality, enable reliable tracing of injected water and better control and manage MAR operation in the case of indirect and direct aquifer recharge. Two water quality management strategies are illustrated on two full-scale case studies, including the results of the combination of non conventional and advanced technologies for water quality improvement, comprehensive sampling and monitoring programs including emerging pollutants, tracer studies using boron isotopes and integrative aquifer 3D GIS hydraulic and hydrodispersive modelling.

Assessing sensitivity of hydrologic responses to climate change from forested watershed in Mississippi

AbstractThe climatic processes such as changes in precipitation, temperature and atmospheric CO2 concentration can intensify the effects on water resources. An assessment of the effects of long‐term climate change on water resources is essential to the development of water quality improvement programs. This study was conducted in the Upper Pearl River Watershed (UPRW) in east‐central Mississippi to assess the effects of long‐term potential future climate change on average mean monthly stream flow from the five spatially distributed U. S. Geological Survey (USGS) gage stations in the UPRW using the Soil and Water Assessment Tool. The model was calibrated (January 1981 to December 1994) and validated (January 1995 to September 2008) using monthly measured stream flow data. The calibrated and validated model determined good to very good performance for stream flow prediction (R2 and E from 0·60 to 0·86) between measured and predicted stream flow values. The root mean square error values (from 14 to 37 m3 s−1) were estimated at similar levels of errors during model calibration and validation. The results showed that long‐term (50 years) average monthly stream flow sensitivity due to climate change effects was found the greatest as a result of percentage change in the precipitation followed by carbon dioxide (CO2) concentration and temperature. The long‐term model simulation scenarios as compared with the base scenario for all five spatially distributed USGS gage stations in the UPRW estimated an average monthly stream flow decrease (from 54 to 67%) and average monthly stream flow increase (from 67 to 79%) depending on the spatial characteristics of the USGS gage stations. Overall, the results indicate that the UPRW hydrology is very sensitive to potential future climate changes and that these changes could stimulate increased streamflow generation from the watershed. Copyright © 2010 John Wiley & Sons, Ltd.

Achieving sustainable recycled water initiatives through public participation

Sustainability or “Development that meets the needs of the present without compromising the ability of future generations to meet their own needs” [1] remains a relatively new concept for the water industry. The challenge is to develop sustainable recycled water projects that meet the needs of a water business as the responsible service authority, while at the same time meeting the individual needs of a particular community. The community consultation model that has been adopted by Grampians Wimmera Mallee Water to assist in the implementation of our urban Water Quality Improvement Program is widely considered to be a water industry benchmark. The integration of this tried and tested consultation model with our recently adopted Recycled Water Strategy is now providing us with a framework for informing and educating local communities and other key stakeholders about recycled water. The model also encourages local stakeholders to play a major role in identifying and evaluating opportunities for potential sustainable recycled water projects to meet the needs of their particular community. The successful elements of the model that have been further developed include community newsletters, information packages and public workshops. Initial newsletters and an information workshop seek local community input into identifying potential projects. Subsequent information packages and workshop(s) provide further information for interested individuals and/or organisations in the development of project proposals. Local community input into prioritising the criteria used to assess project proposals are also sought, usually through these workshop(s). Grampians Wimmera Mallee Water has challenged the perceived ‘we know what's best for you’ culture by providing key stakeholders with the opportunity to have informed input during the decision making process. This is allowing us to develop sustainable recycled water projects that take into consideration the needs of individual communities and key stakeholders. It is also assisting us to build strong relationships with our customers through educated and informed communities.

WATER QUALITY IMPROVEMENT PROGRAM EFFECTIVENESS FOR CARBONATE AQUIFERS IN GRAZED LAND WATERSHEDS

Water quality indicators of two agriculturally impacted karst areas in southeastern West Virginia were studied to determine the water quality effects of grazing agriculture and water quality trends following initiation of water quality improvement programs. Both areas are tributaries of the Greenbrier River and received funding for best management practices under the President's Initiative for Water Quality and then under the Environmental Quality Incentives Program (EQIP). After 11 years of study there was little evidence to suggest that water quality improved in one area. Three and a half years of study in the other area showed little evidence of consistent water quality improvement under EQIP. Lack of consistent water quality improvement at the catchment scale does not imply that the voluntary programs were failures. Increased livestock numbers as a result of successful changes in forage management practices may have overridden water quality improvements achieved through best management practices. Practices that target well defined contributing areas significantly impacting aquifer water quality might be one way to improve water quality at catchment scales in karst basins. For example, a significant decrease in fecal coliform concentrations was observed in subterranean drainage from one targeted sinkhole after dairy cattle were permanently excluded from the sinkhole.