Bathing Waters

Verification of Bacteroidetes Microbial Source Tracking with Emperical Ground Truth Data

Reference: 08/WW/11/12
ISBN: 1 84057 527 1
Published Date: 04/03/2009

This study reports a 'field-scale' test of the emerging technique of microbial source tracking (MST). The project acquired 'ground-truth' data to test the operational utility of Bacteroidetes MST data. The work has resulted in a very significant data set which is believed to be the largest collected to-date world-wide. This allows a comparison of Bacteroidetes MST data with standard faecal indicator organism (FIO) concentrations in streams, effluents and bathing waters.
The study illustrated the need for any sampling programme to be designed to measure and characterise extreme temporal and spatial variability. Furthermore, it is imperative that the Bacteroidetes MST signal of any industrial discharge is fully understood prior to the interpretation of results from bathing beaches.
At this stage in the development of this tool, it would be imprudent to use the percentage human and/or ruminant contributions, as indicated by MST data acquired for a bathing water, as the sole or principal element in the evidence-base used to guide major expenditure decisions and/or regulatory action.

Price: £19  

Evaluation of T90 Decay Rates for a Range of Micro-organisms Indicative of Sewage Contamination: Phase 2 - Building and Validation of Predictive Models

Reference: 07/WW/11/11
ISBN: 1 84057 440 2
Published Date: 28/06/2007

The sunlight-induced inactivation of bacterial indicator organisms, F-specific bacteriophage and poliovirus 2 was investigated in a series of experiments.
An artificial light source was used to irradiate a range of sewage-spiked waters formulated to provide a pertinent range of temperature, turbidity and salinity combinations.  Inactivation curves were generated for each of the microorganisms (primary linear model).  Enterococci were the most resistant.
Although all primary model fits were excellent, secondary models (predictive equations) were fitted with varying degrees of success.  The faecal coliform data produced the best fit, but enterococci inactivation rates could not be modelled.  The heterogeneity of the enterococci group, their cell physiology and their propensity to occur in chains were identified as potential sources of variability in their response to light-mediated inactivation.
The validity of the predictive equations was assessed by producing inactivation data using natural waters and light and comparing them with predictions from the models.  For faecal coliforms, there was a consistent correlation between observed and predicted values.  No equivalent correlation was observed for the other microorganisms.  When the artificial light was replaced with natural sunlight, the fit was poor for all the microorganisms.

Price: £25  

Preparation for a New Bathing Water Directive: Costing the Second Reading Amendments of the Proposed Revisions to the Bathing Water Directive

Reference: 06/WW/11/10
ISBN: 1 84057 398 8
Published Date: 28/03/2006

A study into the potential costs of the new Bathing Waters Directive was undertaken in 2003. Following progress with the new Directive, standards have been clarified, and as such a further study was required to understand the cost implications of the final version of the Directive. 
The 2003 methdology was used, employing the Integrated Cost Estimate (ICE) costing model to predict potential costs associated with managing intermittent (wet weather) discharges.  Assumptions were made regarding continuous discharges, telemetry requirements and operational expenditure. 
Additional Bathing Water sampling data was integated into the study. 
The study delivered a range of potential costs, dependent on the standard to be achieved (Excellent, Good or Sufficient) and the delivery strategy (Spill Frequency or Risk Based Environmental Quality approach). 
This report discusses the approach, methdology and results, and presents conclusions and recommendations based on the findings.

Price: £14