Evaluation and Quantification of Anionic Surfactant in the Gomti River at Lucknow City, India

In this paper, an attempt has been made to check the level of surfactants particularly in drinking water, which can lead to toxicity in human body system. In this study, a total of 10 locations were selected to enumerate the concentration of surfactants and other physicochemical parameters with metals in the flowing water of river during pre-monsoon 2019. Analyzed result showed that the concentration of surfactants was significantly high and other parameters were also high. It was also found that river at the vicinity of town areas or midstream in the Lucknow city contained high amount of an anionic surfactants due to the nonpoint sources generated by human activities, low concentration was found in upstream, and average concentration was found in downstream, showing natural degradation of surfactants. The values of other parameters were higher than the prescribed limit, which is the serious problem for human being.

Development of a Cyberinfrastructure for Assessment of the Lower Rio Grande Valley North and Central Watersheds Characteristics

Lower Laguna Madre (LLM) is designated as an impaired waterway for high concentrations of bacteria and low dissolved oxygen. The main freshwater sources to the LLM flow from the North and Central waterways which are composed of three main waterways: Hidalgo/Willacy Main Drain (HWMD), Raymondville Drain (RVD), and International Boundary & Water Commission North Floodway (IBWCNF) that are not fully characterized. The objective of this study is to perform a watershed characterization to determine the potential pollution sources of each watershed. The watershed characterization was achieved by developing a cyberinfrastructure, and it collects a wide inventory of data to identify which one of the three waterways has a major contribution to the LLM. Cyberinfrastructure development using the Geographic Information System (GIS) database helped to comprehend the major characteristics of each area contributing to the watershed supported by the analysis of the data collected. The watershed characterization process started with delineating the boundaries of each watershed. Then, geospatial and non-geospatial data were added to the cyberinfrastructure from numerous sources including point and nonpoint sources of pollution. Results showed that HWMD and IBWCNF watersheds were found to have a higher contribution to the water impairments to the LLM. HWMD and IBWCNF comprise the potential major sources of water quality impairments such as cultivated crops, urbanized areas, on-site sewage facilities, colonias, and wastewater effluents.

Antibiotic Resistance in Recreational Waters: State of the Science

Ambient recreational waters can act as both recipients and natural reservoirs for antimicrobial resistant (AMR) bacteria and antimicrobial resistant genes (ARGs), where they may persist and replicate. Contact with AMR bacteria and ARGs potentially puts recreators at risk, which can thus decrease their ability to fight infections. A variety of point and nonpoint sources, including contaminated wastewater effluents, runoff from animal feeding operations, and sewer overflow events, can contribute to environmental loading of AMR bacteria and ARGs. The overall goal of this article is to provide the state of the science related to recreational exposure and AMR, which has been an area of increasing interest. Specific objectives of the review include (1) a description of potential sources of antibiotics, AMR bacteria, and ARGs in recreational waters, as documented in the available literature; (2) a discussion of what is known about human recreational exposures to AMR bacteria and ARGs, using findings from health studies and exposure assessments; and (3) identification of knowledge gaps and future research needs. To better understand the dynamics related to AMR and associated recreational water risks, future research should focus on source contribution, fate and transport—across treatment and in the environment; human health risk assessment; and standardized methods.

Modeling the Effects of Future Hydroclimatic Conditions on Microbial Water Quality and Management Practices in Two Agricultural Watersheds

Highlights Increased fecal coliform (FC) loading from nonpoint sources is associated with wetter-warmer futures. Drier-warmer futures reduced FC loads but caused more recreational water quality criteria exceedances. More extensive BMP implementation may be needed to meet water quality goals. Abstract. Anticipated future hydroclimatic changes are expected to alter the transport and survival of fecally sourced waterborne pathogens, presenting an increased risk of recreational water quality impairments. Managing future risk requires an understanding of the interactions between fecal sources, hydroclimatic conditions, and best management practices (BMPs) at spatial scales relevant to decision makers. In this study, we used the Hydrologic Simulation Program FORTRAN (HSPF) to quantify potential fecal coliform (FC, an indicator of the potential presence of pathogens) responses to a range of mid-century climate scenarios and assess different BMP scenarios (based on reduction factors) for reducing the risk of water quality impairment in two small agricultural watersheds: the Chippewa watershed in Minnesota, and the Tye watershed in Virginia. In each watershed, simulations show a wide range of FC responses, driven largely by variability in projected future precipitation. Wetter future conditions, which drive more transport from nonpoint sources (e.g., manure application, livestock grazing), show increases in FC loads. Loads typically decrease in drier futures; however, higher mean FC concentrations and more recreational water quality criteria exceedances occur, likely caused by reduced flow during low-flow periods. Median changes across the ensemble generally show increases in FC load. BMPs that focus on key fecal sources (e.g., runoff from pasture, livestock defecation in streams) within a watershed can mitigate the effects of hydroclimatic change on FC loads. However, more extensive BMP implementation or improved BMP efficiency (i.e., higher FC reductions) may be needed to fully offset increases in FC load and meet water quality goals, such as total maximum daily loads and recreational water quality standards. Strategies for managing climate risk should be flexible and to the extent possible include resilient BMPs that function as designed under a range of future conditions. Keywords: Climate, HSPF, Management responses, Microbial water quality, Modeling, Watersheds.

Applying a Watershed and Reservoir Model in an Off-Site Reservoir to Establish an Effective Watershed Management Plan

Off-site reservoirs use water from other watersheds to supplement their water quantity. Water quality is usually better in off-site reservoirs than in onsite reservoirs, because in comparison to onsite reservoirs, watershed areas are smaller and fewer pollutants are collected; moreover, cleaner water is introduced. However, in Taiwan, the water quality of some off-site reservoirs can gradually worsen, and this factor needs to be addressed. In this study, the Liyutan reservoir in central Taiwan was used as an example to demonstrate the process of evaluating pollution in an off-site reservoir. Pollution loads from point sources (PSs) and nonpoint sources (NPSs) were carefully estimated. Domestic sewage and tourist wastewater were considered the major PS loads in this study. The NPS load evaluation was dependent on the results of a verified watershed model, the stormwater management model (SWMM). The observed data in 2015 and 2016 and supplementary total phosphorous (TP) samplings in upstream rivers in 2018 were used to validate the model results. Model calibration and verification were implemented during dry weather and wet weather to ensure the accuracy of the PS and NPS simulations. The results of this study showed that the average total phosphorous (TP) load generated from within the watershed was 9013 kg/y, and that the TP load from outside the watershed was 4545 kg/y. The percentages of TP loads from NPSs and PSs in the watershed were 83% and 17%, respectively. Finally, we used a verified Vollenweider model to convert the TP loads to the TP concentration in the reservoir. The pollution reduction measures and the associated predicted water quality values were assessed using the verified models.

Sources of Groundwater Pollution

In many regions in the world, groundwater represents an important source of fresh water. It is now established that several contaminants enter groundwater from a number of sources and pathways. These sources are both natural and anthropogenic. Contamination of groundwater resources by a variety of anthropogenic pollutants from both point and nonpoint sources represents a key global environmental problem. The most frequently identified contaminant sources are industrial manufacturing, agricultural activities, municipal landfills, and wastes. Frequently detected contaminants included nitrates, volatile organic compounds, arsenic, and fluorides. Other contaminant species include solvents, fuel hydrocarbons, heavy metals, pesticides, disinfectants, detergents, and radionuclides. In this chapter, the main sources and pathways for contaminants in groundwater are reviewed. It identifies challenges that need to be met to minimize risk to drinking water and ecosystems. Particular attention is paid to the occurrence of known and potential endocrine disrupting substances in groundwater.