DRIVER-WATER-WELL-TREATMENT-CHEMISTRY The main purpose of water well rehabilitation is to restore lost water volume and/or quality. Rehabilitation methods fall into two main categories: chemical or mechanical. Chemical rehabilitation involves discovering the cause(s) of well plugging and adding a chemical solution designed to dissolve the plugging material. Although various chemical formulas are offered by different companies, the basic approach is the same: a successful chemical reaction in the well.

"The present study found that approximately 63% of the hotels which were inspected following a Legionnaires' disease case notification were found to be colonized with Legionella spp. The study also evaluated the significant factors that contribute to the maintenance, management and disinfection of water distribution systems, including the successful implementation of WSPs to improve hotel water supply and sanitation systems. Chemical treatment and the monitoring of drinking water quality, including chlorine disinfection, pH adjustment, and water temperature control of hot water systems are recommended as control measures in water safety plans, in conjunction with other procedures. It has also been found that antiquated hotel buildings are at increased risk in terms of the safety and quality of the water in their distribution systems. To conclude, risk assessment, environmental monitoring and disinfection of water systems, as well as the implementation of preventive control measures (WSPs) are the key elements for preventing contamination by pathogenic microorganisms in large public and private water distribution systems."

"Installing chlorine booster stations at strategic network locations or increasing the outlet disinfectant dose directly at the sources are among commonly used measures to increase disinfectant residuals throughout the network [29]. To test the network robustness to lower demand, the chlorine concentrations at the outlet of each of the three WTPs were increased to 2 mg/L. This allowed for investigating the potential of increasing chlorine dosage at the WTPs to compensate for the performance degradation under water conservation scenarios. "

"However, in this configuration, the alluvial aquifers are also highly vulnerable to pollution. To address the issue of pollutant transfer, it is common to use natural or artificial tracing methods. In particular, the stable isotopes of the water molecule (2H, 18O) have many applications, allowing a better understanding of hydrosystems. They are used to estimate the recharge, to know the origin of water, the mixing processes and the transit times [2,3,4,5,6,7,8,9,10,11]. The use of this tracer is particularly relevant in the context of short transit times within the aquifer, as is the case for exchanges between alluvial aquifers and rivers. However, it is necessary to have a marked isotopic signature for the input signal to the system and a different signature between the input and output signal [11]."

"The directive sets essential quality standards at the EU level. One requirement of the directive is that a total of 48 microbiological, chemical and indicator parameters must be regularly monitored and tested. When transposing the Drinking Water Directive into national law, EU member states can set higher but not lower standards. The limits of the microbiological, chemical and indicator parameters are specified in the annexes to the Drinking Water Directive. For water meters, this means that the measurement accuracy must be maintained for all types of water that comply with the parameter limits specified in this document. This can pose a real challenge in terms of the measurement accuracy and particularly the measurement stability of water meters for some of the parameters"

"Improving the microbial quality of agricultural water through filtration can benefit small farms globally. The incorporation of zero-valent iron (ZVI) into sand filters (ZVI-sand) has been effective in reducing E. coli, Listeria spp., and viruses from agricultural water. This study evaluated ZVI-sand filtration in reducing E. coli levels based on influent water type and the percentage of ZVI in sand filters"

"Excess release of phosphorus is the main culprit for the eutrophication of freshwater and marine ecosystems [1]. Phosphorus is a nonrenewable and irreplaceable element for plant growth, and its role is crucial in agricultural production [2]. The accelerated growth in food demand has also increased the demand for phosphate fertilizers, which has placed stress on phosphate rock sources and is exhausting existing deposits [3]. The phosphate mining industry is also facing serious challenges regarding water availability for the mining process and a decrease in the quality of phosphate rocks"