Proposal of a regulatory index of quality of water supply services-RIQS.

Among the challenges faced by regulatory authorities in the water sector, the large number of municipal supply services to be inspected and the cost of on-site inspections are prominent. To overcome these issues, decisions regarding the priority of inspections based on indicators is an alternative. Therefore, this research aims to propose and evaluate the Regulatory Index of Quality of Water Supply Service (RIQS) to triage on-site inspections of water supply systems in cities of the state of Minas Gerais. The study was conducted with information from the Regulatory Agency of Water Supply and Sanitation Services of Minas Gerais (Arsae-MG). The methodology followed seven steps: (i) selection of available indicators; (ii) grouping of indicators according to their typology; (iii) screening of indicators; (iv) establishment of standardized scale; (v) evaluation of the relative importance of typologies and indicators, through the adaptation of the analytic hierarchy process (AHP); (vi) determination of the RIQS; and (vii) analysis of results. As a result, we selected 12 indicators to compose the RIQS, which deal with efficiency, effectiveness, and customer relationship. We noticed that the indicator of water supply service coverage (17.2%) had the highest weight in the calculation of the RIQS, and the index of requests for an inspection of the water connection served on time (2.1%) had the lowest weight. In addition, 95.1% of the 591 municipalities evaluated presented excellent or good performance. Based on these results, we show that the RIQS can be used to identify cities with low performance and prioritize inspections in the most urgent water systems. Furthermore, these outcomes reveal the possibility of extending and adapting the methodology to other regulatory agencies around the world for identifying the priority of inspections in water supply systems at a municipal level.

Assessment of performance indicators for different sizes of water supply systems in Minas Gerais, Brazil.

Indicators are important tools to improve the efficiency of water supply systems. Considering that the performance could vary according to the systems' sizes, this research proposed financial, operational, and water quality indicators for water supply systems of municipalities with different populations in Minas Gerais, Brazil. The organisation and selection of the sample were based on available information in the National Sanitation Data System of 2014. We selected 363 municipalities of Minas Gerais and 56 predictors. Through multiple linear regression (MLR), we found that the commitment of revenues with expenditures and the ratio among revenues and expenses are the most relevant variables to describe the financial performance. Furthermore, water loss per connection and water-billing index were the most important to describe the operational performance. Finally, models related to water quality performance could not be established due to the low value of the coefficient of determination. We observed that supply systems have distinct variables to describe their financial and operational performance, according to their sizes. Small municipalities have a strong relationship with financial performance and expenses. Large counterparts have their performance related to the collection, which can be explained by the economy of scale. Considering the operational performance, we observed that larger municipalities have a strong relationship between their operational performance and water loss. These models are potential tools in the decision-making processes, which can be used to promote improvements in water supply systems.

Preliminary assessment of antimicrobial activity and acute toxicity of norfloxacin chlorination by-product mixture.

Among drugs and personal care products, antibiotics arouse interest since they are widely used in human and veterinary medicine and can lead to the development of bacterial resistance. Usually, sewage treatment does not remove most of these compounds. So, these drugs can reach water treatment plants (WTP), where disinfection with chlorine compounds is common. This work aimed to evaluate the antimicrobial activity and preliminary toxicity of the mix of by-products forming due to the chlorination of norfloxacin. This is a fluoroquinolone antibiotic indicated for the treatment of urinary infection and gonorrhea, with sodium hypochlorite (NaClO). The drug was subjected to chlorination tests, on a bench scale, with several reaction times (from 5 min to 24 h). Analyses of high-resolution mass spectrometry (MS) were performed for the characterization of the by-products. The MS results showed five peaks attributed to the by-products' formation, of which four were identified. The antibiogram results indicated that the solution that contained the mixture of the by-products lost antibacterial activity against the E. coli strain studied. The acute toxicity tests for the Artemia salina microcrustacean showed that the blend of the by-products exhibited higher toxicity than pure norfloxacin.

Water tariff forecasting models applied to municipal and private companies in the south and southeast regions of Brazil.

This paper has as a main goal to evaluate how models of the forecast will work with a group of variables that were selected based only on their correlation with the average tariff variation. Two forecast models are used, the first based on multiple linear regression techniques and the second based on the application of artificial neural networks (perceptron). We intend to use those models to reach the current water tariff based on the historic variation of the charge and the selected variables applied to municipal and private companies that operate water supply and wastewater systems in the South and Southeast regions of Brazil. The subsidiary data for the elaboration of the models were obtained through the National Sanitation Information System (SNIS). The obtained results indicated that the forecasting processes, in both models used, were able to forecast with high accuracy the fees, and guaranteed the maintenance of the surplus for the analyzed systems.