Source tracking of leaky sewers: a novel approach combining fecal indicators in water and sediments.

In highly urbanized areas, surface water and groundwater are particularly vulnerable to sewer exfiltration. In this study, as an alternative to Microbial Source Tracking (MST) methods, we propose a new method combining microbial and chemical fecal indicators (Escherichia coli (E. coli)) and wastewater micropollutants (WWMPs) analysis both in water and sediment samples and under different meteorological conditions.

Spatial and temporal variations of manganese concentrations in drinking water.

The objective of this study was to assess the variability of manganese concentrations in drinking water (daily, seasonal, spatial) for eight communities who participated in an epidemiological study on neurotoxic effects associated with exposure to manganese in drinking water. We also assessed the performance of residential point-of-use and point-of-entry devices (POE) for reducing manganese concentrations in water. While the total Mn concentrations measured during this study were highly variable depending on the location (< 1-2,700 μg/L), daily or seasonal variations were minimal.

Performance of point-of-use devices to remove manganese from drinking water.

A recent epidemiological study reported significant cognitive deficits among children in relation with consumption of water with manganese concentrations in the order of 50-100 ug/L. Concerns for neurotoxic effects of manganese raises the need for evaluating the efficiency of domestic water treatment systems for removal of this metal. The objective of the present study was to determine whether POU devices are efficient at reducing dissolved manganese concentration in drinking water.

A simulation model of waterborne gastro-intestinal disease outbreaks: description and initial evaluation.

We present an agent-based simulation model for generating realistic multivariable outbreak signals. The model defines a synthetic population and simulates the dissemination of pathogenic organisms through a municipal water distribution system, the mobility of individuals between geographic locations, their exposure to pathogens through water consumption, and disease progression in infected individuals. We present the results of an initial evaluation of the model - a simulation study replicating the historical outbreak of cryptosporidiosis in Milwaukee in 1993.

Vulnerability of Quebec drinking-water treatment plants to cyanotoxins in a climate change context.

Cyanobacteria are a growing concern in the province of Quebec due to recent highly publicised bloom episodes. The health risk associated with the consumption of drinking water coming from contaminated sources was unknown. A study was undertaken to evaluate treatment plants' capacity to treat cyanotoxins below the maximum recommended concentrations of 1.

Including operational data in QMRA model: development and impact of model inputs.

A Monte Carlo model, based on the Quantitative Microbial Risk Analysis approach (QMRA), has been developed to assess the relative risks of infection associated with the presence of Cryptosporidium and Giardia in drinking water. The impact of various approaches for modelling the initial parameters of the model on the final risk assessments is evaluated. The Monte Carlo simulations that we performed showed that the occurrence of parasites in raw water was best described by a mixed distribution: log-Normal for concentrations > detection limit (DL), and a uniform distribution for concentrations < DL.

Virus occurrence in municipal groundwater sources in Quebec, Canada.

A 1 year study was undertaken on groundwater that was a source of drinking water in the province of Quebec, Canada. Twelve municipal wells (raw water) were sampled monthly during a 1 year period, for a total of 160 samples. Using historic data, the 12 sites were categorized into 3 groups: group A (no known contamination), group B (sporadically contaminated by total coliforms), and group C (historic and continuous contamination by total coliforms and (or) fecal coliforms).