Changes in abundance of heterotrophic and coliform bacteria resident in stored water bodies in relation to incoming bacterial loads following rain events.

Microbial properties of harvested rainwater were assessed at two study sites at Newcastle on the east coast of Australia. The investigation monitored daily counts of heterotrophic bacteria (HPC), total coliforms and E. coli during a mid-winter month (July).

Extensive bacterial diversity indicates the potential operation of a dynamic micro-ecology within domestic rainwater storage systems.

The concept that domestic rainwater storage tanks may host sustainable microbial ecosystems has not previously been addressed. The bacterial diversity, cultivated from more than 80 samples from 22 tanks at various locations across eastern Australia, is presented here as prima facie evidence for the potential operation of a functional micro-ecology within rainwater storage systems. Cultivated isolates were found to comprise members of four major bacterial divisions; Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes, including more than 200 species from 80 different genera.

Evaluating potential applications of faecal sterols in distinguishing sources of faecal contamination from mixed faecal samples.

Faecal samples from humans, herbivores, carnivores and birds as well as samples from septic tanks and effluents from a sewage treatment plant (STP) were extracted and analyzed by gas chromatography-mass spectrometry for faecal sterols including coprostanol, epicoprostanol, cholestanol, cholesterol, stigmasterol, campesterol, 24-ethylcoprostanol and beta-sitosterol. Coprostanol was observed in the highest concentrations from the human derived samples, but it was also present in substantial quantities in a range of herbivores. There was no unique marker of human faecal contamination.

Bacterial source tracking from diverse land use catchments by sterol ratios.

Water samples from sites potentially impacted by septic tanks, cattle, sewage treatment plant (STP) and natural forests were collected at regular monthly intervals and within 48 h of rainfall events between October 2004 and June 2006. All samples (n=296) were analysed for faecal coliforms and faecal sterols including coprostanol, epicoprostanol, cholestanol, cholesterol and 24-ethylcoprostanol. Faecal sterol ratios were used to assign human and/or herbivore contamination sources and to estimate their percentage relative contributions in water samples.

Comparisons of water quality parameters from diverse catchments during dry periods and following rain events.

In this study, 12 catchments sites located along the north coast of New South Wales in Australia were grouped into the four categories of septic, cattle, sewage treatment plant (STP) and forested sites via cluster analysis based on their land use patterns. Water samples from all these sites were collected between October 2004 and June 2006 at a regular monthly interval and within 48 h of rain events. The samples were analyzed for bacterial counts including faecal coliform and total coliform; faecal sterols including coprostanol, epicoprostanol, cholesterol, cholestanol, 24-ethylcoprostanol, campesterol, stigmasterol and beta-sitosterol; and the elements including Na, Rb, Sr, Ag, Cd, Sn, Cs, Ba, Hg, Tl, Pb, Bi, U, Mg, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, K, As, Se, P and Mo.