Next Article in Journal
Experimenting with Coupled Hydro-Ecological Models to Explore Measure Plans and Water Quality Goals in a Semi-Enclosed Swedish Bay
Previous Article in Journal
Comparative Analysis of Water Quality between the Runoff Entrance and Middle of Recycling Irrigation Reservoirs
Article Menu

Export Article

Open AccessArticle
Water 2015, 7(7), 3878-3905; doi:10.3390/w7073878

Review of Risk Status of Groundwater Supply Wells by Tracing the Source of Coliform Contamination

South Australian Water Corporation, 250 Victoria Square, Adelaide, SA 5000, Australia
*
Author to whom correspondence should be addressed.
Academic Editor: David Polya
Received: 22 December 2014 / Revised: 3 July 2015 / Accepted: 3 July 2015 / Published: 14 July 2015
View Full-Text   |   Download PDF [2261 KB, uploaded 14 July 2015]   |  

Abstract

Coliform source tracking was undertaken on 48 water sources of which 42 are potable in 26 water supply systems spread across South Australia. The water sources in the study vary from unprotected springs in creek beds to deep confined aquifers. The frequency analysis of historical coliform detections indicate that aquifer types, depth to water and casing depth are important considerations; whilst maintaining well integrity and the presence of low permeable clay layers above the production zone are the dominant parameters for minimizing coliform contamination of water supply wells. However, in karst and fractured rock aquifers, pathways for coliform transport exist, as evidenced in the >200 MPN/100 mL level of coliform detection. Data indicate that there is no compelling evidence to support the contention that the wells identified as low risk are contaminated through geological strata and clay barriers. However, data strongly supports the suggestion that coliform detection from sample taps and wellheads stem from the surrounding groundwater and soil-plant sources as a result of failed well integrity, or potentially from coliform bacteria that can persist within biofilms formed on well casings, screens, pump columns and pumps. Coliform sub-typing results show that most coliform bacteria detected in town water supply wells are associated with the soil-water-plant system and are ubiquitous in the environment: Citrobacter spp. (65%), Enterobacter spp. (63%), Pantoea spp. (17%), Serratia spp. (19%), Klebsiella spp. (34%), and Pseudomonas spp. (10%). Overall, 70% of wells harbor detectable thermotolerant coliforms (TTC) with potentially 36% of species of animal origin, including Escherichia coli species found in 12% of wells. View Full-Text
Keywords: risk assessment; groundwater risk assessment model (GRAM); coliforms; risk management; town water supply; coliform source tracking risk assessment; groundwater risk assessment model (GRAM); coliforms; risk management; town water supply; coliform source tracking
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).

Scifeed alert for new publications

Never miss any articles matching your research from any publisher
  • Get alerts for new papers matching your research
  • Find out the new papers from selected authors
  • Updated daily for 49'000+ journals and 6000+ publishers
  • Define your Scifeed now

SciFeed Share & Cite This Article

MDPI and ACS Style

Somaratne, N.; Hallas, G. Review of Risk Status of Groundwater Supply Wells by Tracing the Source of Coliform Contamination. Water 2015, 7, 3878-3905.

Show more citation formats Show less citations formats

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Water EISSN 2073-4441 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top