A pipeline connection technique more appropriate to the 19th century than the 21st has left a contamination legacy which could mean serious remedial expenditures by several state governments.
The problem is lead used to solder joints in water supply pipelines, ranging from domestic and suburban reticulation through the major, long-distance pipelines such as the Kalgoorlie Golden Pipeline in Western Australia.
The issue has been highlighted by an environmental research study conducted by academics at Sydney's Macquarie University. The study was led by Paul Harvey and Mark Taylor.
An assessment of long-established pipelines, built in Australia and overseas with lead-jointing and lead-painting, indicated there were a number of contamination problems which would be costly and difficult to deal with. The study was backed up with a detailed examination of the Chichester Trunk Gravity Main corridor at Woodberry in the Hunter Valley of NSW.
The study found agricultural soils to have been heavily contaminated with lead as a direct result of the use and maintenance of lead in the collars of pipe joints.
The soils contamination was linked to toxicity and mortality in several a farm animals and to elevated contamination of grass fodder (up to 50 mg/kg of lead) close to the pipeline.
"Soil lead contamination along the CTGM is extreme with concentrations reaching 20,600 mg/kg at the pipeline," said Mr Harvey, the lead author. "Cattle formerly permitted to graze along the CTGM corridor have displayed signs of lead poisoning leading to death in some cases. While fencing along the pipeline corridor will prevent access, it does not combat the legacy problem of the contaminated land.
"Other similar large-scale above ground reticulation systems in the Sydney metropolitan region and adjacent to the 560-km long Kalgoorlie Golden Pipeline in WA are shown to have resulted in similar environmental hazards."
Studies of inner city suburbs initially fitted with actual lead pipes, as distinct from just soldered at the joints, have demonstrated serious reductions in assessed IQ.
Use of lead piping has been forbidden for decades, and the general issue of contamination through lead-based paints has also been dealt with.
But the Macquarie academics believe they have spotlighted a new variant on the recurring theme of heritage environmental residues from the past. "Our study of the Hunter Valley CTGM pipeline and our assessment of other pipelines in Australia and overseas indicate that soil lead contamination is a potentially significant environmental contamination issue that has gone largely unnoticed until now," Professor Taylor said.
"Many long-distance pipelines built around the 1900s to service water scarce townships were constructed using lead-welded joints.
"Lead-jointed and lead-painted pipelines pose a potentially significant contamination risk to the adjacent environment, particularly during repair and maintenance phases.
"It is clear that better promulgation of this issue is needed to ensure livestock are protected and landowners and the wider community are aware of the risks."
The detailed research article points out that lead is a potent neurotoxin that causes neurocognitive damage when accumulated in the blood, including intelligence falls, behavioural problems and, at high levels, death.
It cited earlier research by Canfield et al (2003) and Lanphear et al (2005) which showed there was no minimum threshold for lead exposure effects.
Moreover, the biggest relative damage occurred at low levels of exposure, making lead a particularly troublesome environmental contaminant. Livestock, like humans, are susceptible to lead, with cattle particularly sensitive.
One study in the US found that dairy cattle in Minnesota affected by depositions from a lead smelter many kilometres way suffered loss of motor control and ultimately death. Given that Australia, as a dry country, has a considerable number of water pipelines running inland from coastal water supplies, the problems of lead contamination from an earlier period is something state administrations could well do without.