Journal of Environmental Protection, 2009, 1, 31-39
Published Online November 2009 (http://www.SciRP.org/journal/jep/).
Environmental Lead and Nickel Contamination of Tank
Rainwater in Esperance, Western Australia:
An Evaluation of the Cleaning Program
Jane S HEYWORTH1, Narelle MULLAN2
1School of Population Health, The University of Western Australia, Western Australia
2Environmental Health Directorate, Department of Health, Western Australia
Abstract
A significant number of birds in the port town of Esperance, Western Australia died in the summer of
2006/2007 and elevated lead levels were found in the kidneys, livers and brains of autopsied birds. These
elevated lead levels alerted Government authorities to investigate the public health impacts of potential lead
contamination in the community resulting from transport of lead carbonate from the Esperance Port. Water
samples from domestic rainwater collection systems were collected to determine the extent of heavy metal
contamination; 19% and 24% of tanks had lead and nickel levels above the Australian Drinking Water
Guidelines. The aim of this study was to evaluate whether cleaning of rainwater tanks had reduced exposure
to lead and nickel contamination in the community. Follow-up sampling of 176 tanks across Esperance indi-
cated that that there had been reductions in both lead and nickel concentrations, but that the reduction has
been greater for nickel concentrations. The reduction in nickel concentration was significantly associated
with cleaning status, whereas this was not the case for lead. Proximity to the Esperance Port was an impor-
tant determinant of lead concentration. Tank and roof characteristics did not significantly influence the fol-
low-up lead concentrations. The results suggested that there was ongoing contamination of rainwater tanks
from the environment.
Keywords: Lead Carbonate, Lead, Nickel, Rainwater Tanks, Environmental Exposure, Australia, Shipping Port
1. Introduction
In early 2007 residents and health authorities in Western
Australian became concerned about the potential health
impact of environmental lead exposure in the port town
of Esperance, located on the Southeast coastline of
Western Australia (WA). The population of the Shire of
Esperance is approximately 13,000 and while the Shire
covers an area of 42,450 square kms [1], the majority of
the population lives in the Esperance town site. In April
2005 the Esperance Port Authority (EspPA) began ship-
ping lead carbonate through the Esperance Port [2]. The
lead was transported via rail from a mine site near
Wiluna almost 900kms to the north. In December 2006 a
significant number of bird deaths was reported and by
the end of January 2007 up to 4000 birds were estimated
to have had died [3]. High levels of lead were found in
the livers, kidney and bones of dead birds. While lead
was later determined unlikely to be the cause of the bird
deaths, the elevated lead levels in these birds alerted
Government authorities to investigate the potential pub-
lic health impacts of lead contamination in the commu-
nity. The EspPA put an immediate stop to any further
shipments of lead carbonate from the Port [2].
The health effects of environmental lead exposure are
well recognised with more recently attention focussed
upon the health effects of lead exposure of 10µg/dL or
less in blood [4]. In 2005, the United States Centers of
Disease Control and Prevention concluded that the
weight of evidence supports an inverse association be-
tween blood lead levels of less than 10µg/dL and cogni-
tive function in children, but that it is as yet unclear re-

32 J. S. HEYWORTH ET AL.
garding the size of effect [5]. Currently the Australian
standards for blood lead are under review, but the inter-
vention level for community-wide prevention strategies
set by both the World Health Organisation and the
United States Centre of Disease Control and Prevention
is 10µg/dL. The Western Australian Department of
Health established a precautionary intervention level of
5µg/dL, in acknowledgment of the community concerns
about chronic exposure to lower lead levels, particularly
among children [2].
Between March and August 2007 blood testing was
offered to all residents and 2,219 blood samples were
taken. Thirty-three samples had lead levels of 10µg/dL
or more. Seven of the 404 children aged less than five
years had blood lead levels of 10µg/dL or more [6].
While lead exposure through air and dust were con-
sidered important exposure pathways, there was just
one air monitoring station in Esperance. Hence it was
not possible to characterise the extent and distribution
of lead contamination across the town site using these
data. Tank rainwater provided an alternative sampling
framework for this purpose. A large proportion of
households across the Esperance township collect
rainwater from domestic roof catchments to supplement
their mains water supply. The domestic roofs served as
a catchment for airborne and dust-borne lead contami-
nation that was the washed into the tanks. Thus water
from rainwater tanks was potentially an important
source of lead exposure.
As part of the investigation into the extent of lead con-
tamination, the Department of Health, in conjunction
with the Shire of Esperance, tested 1,539 rainwater tanks
for heavy metals (Figure 1). The results of this tank
rainwater testing showed that lead levels in rainwater
exceeded the Australian Drinking Water Guidelines
(ADWG) for lead (0.01mg/L) in 285 (19%) of tanks.
Nickel levels in 369 (24%) of rainwater tanks also ex-
ceeded the ADWG (0.02mg/L) [7,8].
Subsequently, the EspPA coordinated the cleaning of
rainwater tanks and gutter systems for 1) residences
identified with high lead levels in their tank rainwater
sample and 2) tanks in the area identified by the Depart-
ment of Health as more likely to have been impacted by
lead pollution. The cleaning process involved: draining
water from the tanks and pressure cleaning of the internal
sides and bottom of the tank; vacuuming sludge residues
Figure 1. Location of rainwater tanks that were eligible for re-sampling, Esperance, October 2007.

J. S. HEYWORTH ET AL. 33
out of the tank; and pressure cleaning gutters and the
bottom part of roof area.
A total 423 tanks were cleaned as a part of this follow
up program.
This paper reports on the follow up sampling under-
taken to evaluate the rainwater tank cleaning program.
The aims were to determine whether cleaning of rain-
water tanks had been successful in reducing the lead and
nickel levels to below the ADWG for lead (0.01mg/L)
and nickel (0.02mg/L) and, if the levels remained high,
what factors contributed to those elevated levels.
2. Methods
2.1. Study Population
A subset of rainwater tanks in Esperance were selected
from initial population of rainwater tanks that weretested
as part of the ongoing investigation of lead contamina-
tion in Esperance (Figure 1). Tanks in the suburb of Cas-
tletown (outside the grid area of Figure 1) were excluded
in this follow-up investigation because this area was at
low risk of lead contamination. The final study area
contained 806 rainwater tanks that were eligible for re-
testing.
The study area was stratified by a 1 km square grid,
resulting in 25 cells (Figure 1). A random sample of 236
tanks was selected from across the grids, proportional to
the number of rainwater tanks initially tested in each grid.
Consent to sample tanks as well as access to the property
was gained for 179 tanks out of the 236 tanks.
2.2. Water Sampling and Analysis
Baseline water samples were collected by the Depart-
ment of Health and the Shire of Esperance between April
and June 2007. Follow-up samples were collected after
the period during which rainwater tanks had been
cleaned. The follow-up samples were collected by the
Department of Health and the Shire of Esperance from
15 to 29 October 2007 and taken from tanks that were
cleaned and those that were not.
All samples were analysed for lead and nickel concen-
trations by the NATA accredited Chemistry Centre
(Western Australia) using the method, 3120B Inductively
Coupled Plasma Method from the Standard Method for
the Examination of Water and Wastewater [9].
2.3. Rainwater Tank Data
When the baseline samples were collected, data regard-
ing the tank and catchment characteristics were obtained
by the officer taking the sample. For 143 households, the
resident was also surveyed to obtain additional informa-
tion on: location; roof catchment material-tile, asbestos
cement, Colourbond, zincalume; condition of roof
catchment; gutters material, tank material-zincalume,
galvanised iron, plastic, concrete, other; condition of the
rainwater tank; presence of first flush diverter; opening
on tank roof; other possible sources of lead including
lead flashing, gutter type, etc.; date on which the tank
was last cleaned, if not cleaned by EspPA.
Ninety-seven tanks were cleaned by EspPA between
May and August, 2007. In the survey of residents (n=
143), an additional 29 tanks were reported to have been
cleaned privately between March and September of 2007.
The time between cleaning and the second sample
ranged from 6 to 33 weeks, with a mean of 19 weeks.
2.4. Statistical Analysis
Descriptive statistics for lead and nickel concentrations
and changes over time were determined. Medians are
presented because the lead and nickel concentrations
were skewed towards zero. These results were compared
with the ADWG, that is 0.01mg/L for lead and 0.02mg/L
for nickel.
Results were mapped using the ESRI ArcMap soft-
ware. Smooth grids of the testing results were achieved
with ESRI Spatial Analyst, using the kernel density tool
that transforms point data into a smoothed grid via a
moving window technique [10].
Tank and roof characteristics, cleaning status and dis-
tance from the Port were compared across lead and
nickel samples above and below the ADWG. The rela-
tionships between the lead and/or nickel concentrations
at follow-up and cleaning status, distance from the Port,
rainwater tank and roof catchment characteristics and
adjusting for baseline lead or nickel concentration, were
modelled using linear regression. The natural logarithms
of the lead and nickel levels were used in all models be-
cause these data were skewed to the left. The dependent
variable was the follow-up lead reading, with the first
metal reading included in the model. Distance was
measured in kilometres and as a continuous variable.
Cleaning was modelled as a dichotomous variable.
The statistical analysis was conducted using STATA 9
exas) statistical packages [11]. (T
3. Results
3.1. Descriptive Analysis of Lead and Nickel
Concentrations
Among the 236 tanks randomly selected for re-sampling,
176 households agreed to have their rainwater tanks
re-sampled. The median concentrations of both lead and
nickel decreased between baseline and follow-up sam-
ples (Table 1). At baseline the median concentrations for

34 J. S. HEYWORTH ET AL.
lead was at the ADWG and for nickel it was above the
ADWG. At follow up, the median level had reduced by
55% for lead and 85% for nickel.
Figures 2(a) and (b) present smoothed maps of lead
concentrations in the study area at baseline and follow-up.
Figures 3(a) and b are smoothed maps of nickel concentra-
tions in the study area as at baseline and follow-up.
3.2. Comparisons by Cleaning Status
Data on whether the rainwater tank had been cleaned
were available for 161 tanks. There were reductions in
median lead and nickel concentrations in both tanks
that were cleaned and those not cleaned (Table 1). The
reduction was greatest for nickel in cleaned tanks. The
percentage reduction in median nickel concentrations
was 88%, whereas for those tanks not cleaned the re-
duction in nickel concentration was 63%. For lead
there was little difference in the reduction between the
cleaned tanks and not cleaned tanks; the reductions in
the median concentrations were 58% and 60% respec-
tively. An analysis of variance indicated that the dif-
ference in the median concentration between follow-up
Figure 2(a). Spatial distribution of lead levels in rainwater tanks at baseline, esperance March-June 2007.
Table 1. Lead and Nickel concentrations (mg/L) in tank rainwater at baseline and follow-up for all tanks (n=176) and by
cleaning status, Esperance 2007 (n=161)1.
All Tanks (n=176) Tanks cleaned by EspPA2 or privately (n=125) Tanks not cleaned (n=36)
Lead Median Range Median Range Median Range
Baseline 0.010 0.001-0.160 0.012 0.001-0.160 0.005 0.001-0.100
Follow up 0.004 0.0004-0.100 0.005 0.001-0.110 0.002 0.000-0.038
Nickel
Baseline 0.027 0.001-0.700 0.032 0.001-0.680 0.008 0.002-0.110
Follow up 0.003 0.000-0.110 0.004 0.002-0.700 0.003 0.001-0.110
1. cleaning status not known for 15 tanks; 2. EspPA- Esperance Port Authority.

J. S. HEYWORTH ET AL. 35
Figure 2(b). Spatial distribution of lead levels in rainwater tanks at follow-up, Esperance, October 2007.
Figure 3(a). Spatial distribution of nickel levels in rainwater tanks at baseline, Esperance, March-June, 2007.

36 J. S. HEYWORTH ET AL.
Figure 3(b). Spatial distribution of nickel levels in rainwater tanks at follow-up, Esperance, October 2007.
gutters, 44% of households cleaned their gutters at least
annually, whereas 56% never or irregularly cleaned gutters.
and baseline was not significantly associated with
cleaning status for lead (p=0.228) but was for nickel
(p<0.001). Comparisons were made of lead and nickel concentra-
tions at follow-up sampling by tank or roof catchment
characteristics (Table 2). Opening in the tank roof was
statistically significantly associated with higher nickel
concentrations. While there were no significant differ-
ences in the distribution of metal concentration by tank
and catchment characteristics, there was a tendency for
higher lead levels to be associated with plastic tanks, tile
or asbestos roofs and an opening in the tank roof. For
nickel, there was a tendency for higher concentrations for
colourbond roofs and gutters.
For lead, the proportion above the ADWG reduced by
61% in the cleaned group compared with 33% in the not
cleaned group. For nickel, the proportion above the
ADWG reduced by 92% compared with 50% in the not
cleaned group.
When the cleaned tanks were stratified by date of
cleaning, that is the period, March to June, compared
with July onwards, the follow up medians were the same.
3.3. Characteristics of Tanks Sampled
3.4. Lead and Nickel Concentrations at Follow
up by Distance from the Port
The characteristics of the tanks and their roof and gutter
catchment areas were available for maximum of 143
tanks. Tanks were predominantly made of zincalume
(38%) and plastic (32%) with some colourbond (21%)
and fibreglass tanks (8%). There were no concrete tanks.
Nearly all tanks (96%) were reported to be in good con-
dition. Five per cent of tanks had a first flush diverter,
and most did not have an opening on the tank roof. Over
half the tanks (55%) had a screened inlet.
The distributions of lead concentrations for all 176 sam-
ples at follow up by distance from the Esperance Port are
shown in Table 3. Water samples that were above the
lead ADWG tended to be from tanks closer to the Port;
69.5% of samples were within 1.5 kms of the Port com-
pared with 54% of samples below the ADWG for lead
(p=0.025).
The most common roof material was Colourbond, fol-
lowed by tile. For gutters Colourbond was the most
common material. Of the 132 tanks for which the roof
condition was noted, 86% were in a good condition. For
Just 13 samples were at or above the ADWG for
nickel at follow-up; six of these were located within 1
km of the Port, five between 1.01 km and 1.5 km, and
wo were more than 2 km from the Port. t

J. S. HEYWORTH ET AL. 37
Table 2. Cross-tabulation of tank and catchment characteristics by proportion of samples above and below 0.01mg/L lead
and above and below 0.02mg/L nickel at follow up sampling (n=143).
Lead concentration Nickel concentration
Tank and roof characteristics1 <0.01mg/L <0.01mg/L <0.02mg/L ≥0.02mg/L
n % n % n % n %
Zincalume 43 39.1 10 33.3 48 37.8 5 38.5
Colourbond 23 20.9 7 23.3 27 21.2 3 23.1
Plastic 34 30.9 11 36.7 41 32.3 4 30.8
Tank material
Fibreglass 10 9.1 2 6.7 11 8.7 1 7.7
Zincalume 19 17.3 6 20.0 23 18.1 2 15.4
Colourbond 51 46.4 10 33.3 53 41.7 8 61.5 Roof material
Asbestos cement 6 5.4 3 10.0 7 5.5 2 15.4
Tile 34 30.9 11 36.7 44 34.7 1 7.7
Zincalume 32 28.3 9 30.0 39 30.0 2 15.4
Colourbond 54 47.4 16 53.3 62 47.7 8 61.5
Plastic 5 4.4 1 3.3 6 4.6 0 0.0
Gutter material
Other 22 19.5 4 13.3 23 17.7 3 23.1
No 94 83.2 24 80.0 110 84.6 8 61.5
Opening in tank
roof 2 Yes 19 16.8 6 20.0 50 15.4 5 38.5
Roof condition Poor/average 17 16.3 1 3.6 15 12.5 3 25.0
Good 87 83.7 27 96.4 105 87.5 9 75.0
1. Total may not add to 143 due to missing data; 2. Significant difference for nickel p=0.037.
Table 3. Lead concentrations by distance from the Esperance port (n=176).
Distance from port Lead concentration at follow-up
<0.01mg/L ≥0.01mg/L
Total n % n %
0-1.00 km 26 15 10.7 11 30.6
1.01- 1.50 km 75 61 43.6 14 38.9
1.51- 2.00km 44 38 27.1 6 16.7
More than 2.00 km 31 26 18.6 5 13.9
Table 4. Linear Regression Models: Effect of cleaning, distance from Port and baseline concentration on follow up concentra-
tion of (1) lead and (2) nickel, (n=161).
Coefficient t-statistic 95% Confidence Interval P-value
Model for Lead
Constant -2.825 -7.35
LnPb-Baseline 0.437 7.39 0.320 0.554 <0.001
Cleaned versus not cleaned 0.106 0.62 -0.232 0.444 0.537
Distance in kilometres -0.416 -3.45 -0.654 -0.177 0.001
Model for nickel
Constant -3.049 -9.16
LnNi-Baseline 0.288 4.30 0.156 0.421 <0.001
Cleaned versus not cleaned -0.666 -3.72 -1.020 -0.312 <0.001
Distance in kilometres -0.569 -4.09 -0.844 -0.294 <0.001

38 J. S. HEYWORTH ET AL.
3.5. Linear Regression Models
Distance from the Port was significantly related to the
second lead reading. As distance from the Port increases
the lead concentration decreases. Cleaning status had no
significant influence on the second lead reading. For nickel,
both cleaning status and distance from the Port led to a
significant reduction in the second nickel concentration.
None of the tank and catchment characteristics were
associated with lead or nickel concentrations when in-
cluded in the model (data not presented).
4. Discussion
These data indicate that that there have been reductions in
both lead and nickel concentrations, but that the reduction
has been greater for nickel concentrations. The reduction
in nickel concentration was significantly associated with
cleaning status, whereas this was not the case for lead.
While the lead levels in rainwater tanks have reduced, the
reduction is less with increasing proximity to the Port.
Tank and roof characteristics did not significantly influ-
ence the follow-up lead concentrations.
The effect of distance from the Port on follow-up lead
levels may have reflected one of four possibilities. First,
the Port may have been a source of ongoing lead con-
tamination. While lead carbonate was no longer handled at
the Esperance Port, the buildings, railway lines and
grounds within the Port that surrounded areas where the
lead carbonate was unloaded from kibbles and loaded onto
ships, may have been still contaminated with lead. This
lead could then have been re-entrained into the air and
contaminated rainwater tanks closer to the Port. Second,
trees and shrubs and soil in the local environment may still
have been contaminated with lead and this lead could have
been re-entrained by wind into the air and deposited on
roof catchments. Investigations in Port Pirie, where a large
lead-zinc smelter exists, have illustrated the persistence of
higher levels of contamination nearest the smelter. May-
nard el al. (2003) in a review of the Lead Decontamination
Program, concluded that re-entrainment from the smelter
and environs was a more important contributor to air
borne lead levels than re- entrainment from contaminated
areas in the city.
The winds most likely to pick up contamination from
the Port and the surrounding areas and then transport this
across the town site were from the North through to the
South-East. During the months between the baseline and
follow up samples, winds followed either an autumn or
winter pattern. During autumn the prevailing winds in
the morning are from the North/ North-West and North-
East, and in the afternoon they are from the South-East
and South. In winter period the prevailing winds were
from the North-West/ North and West for both morning
and afternoon (http://www.bom.gov.au/climate/averages
/wind/selection_map.shtml). Hence it is possible that
rainwater tanks have been re-contaminated by lead in the
environment.
Third, the cleaning protocol for rainwater required
only that the bottom part of the roof (one metre) be
cleaned. Cleaning of the roof catchment may not have
adequately removed lead from this environment, with
those closest to the Port having the higher levels of lead
deposition in the past. With time this contamination
would have been washed into the rainwater tanks.
Last, it may have been a combination of these and as
a result a range of responses may be required. While
children living closest to or downwind of the Port Pirie
smelter have continued to have the highest blood lead
levels, there is evidence that some interventions have
been successful reducing blood lead levels in Port Pirie
children [12]. These have included avoidance of tank
rainwater, reduction of airborne smelter emissions,
relocation of children to lower exposure suburbs,
worker hygiene improvements, community education
and house decontamination. While not all are relevant
to Esperance, where the exposure is has a short history,
is lower and no longer ongoing, a broader based inter-
vention is required.
There are a number of reasons as to why nickel may
not have re-contaminated tanks and for levels to have
reduced to a greater extent than lead. Nickel has been
handled at the Port for about 30 years and any cleaning
of the Port environment would have removed deposits
that have built up over a long period of time. The con-
centrate is between 8%-15% nickel, whereas for lead, the
concentrate is in the order of 65% lead. There has been a
number of engineering upgrades at the Port to reduce the
potential for nickel dust. The EspPA has specified the
minimum moisture content and pH of nickel arriving at
the Port and maintained the moisture content during
storage in sheds at the wharf. There has been a presence
of Department of Environment and Conservation officers
monitoring nickel concentrate loaded onto ships.
The extensive use of domestic rainwater collection
systems across Esperance allowed us to obtain a com-
prehensive picture of the extent and distribution of lead
and nickel contamination across the town. This would
not otherwise have been obtainable in a small commu-
nity such as Esperance. However, an important limitation
of this study was the extent of missing data. Data were
collected as part of an ongoing investigation, rather than
for research purposes. While some residents had given
their consent for sample collection, they were not able to
be present at the time of sampling. Hence there are
missing data on tank and roof characteristics as well as
tank cleaning status. In other cases where surveys were
administered, it was sometimes difficult for the resident,
who may have been a tenant, to know or recall informa-
tion on tank and roof characteristics.

J. S. HEYWORTH ET AL. 39
In conclusion, the most important factor influencing
the follow-up lead readings was the distance from the
Port. As the distance from the Port increased, the fol-
low-up lead concentration decreased. On the other hand,
whether a tank was cleaned had no apparent effect on the
follow-up lead concentration. These findings suggest that
there may be ongoing contamination of rainwater tanks
from the environment. The pattern of continuing high
lead levels may be a result of ongoing contamination
arising from the Port environment, the re-mobilisation of
existing lead contamination of the environment, the dif-
ficulties in removing residual lead from the roof catch-
ment areas or a combination of these. Nickel levels have
been reduced substantially as a result of the rainwater
tank cleaning program.
As a result of these findings it was recommended that
people in Esperance continue to be advised not to drink
rainwater. In addition, it was recommended that there be
further investigation of lead levels in the Port environs,
the surrounding residential areas and roofs to identify
and address any environmental sources of lead.
5. References
[1] Shire of Esperance, cited September 4, 2008,
http://www.esperance.wa.gov.au/.
[2] Education and Health Standing Committee, Legislative
Assembly, “Response of the Western Australian Gov-
ernment to the Western Australian in relation to the cause
and extent of lead pollution in the Esperance Area,” Perth:
Government of Western Australia, 2007.
[3] Department of Environment and Conservation, “Update
#2: Esperance bird deaths. 2007,” [cited 4 September
2008]; 13 March 2007: [Available from: http://portal. en-
vironment.wa.gov.au/pls/portal/docs/PAGE/DOE_
ADMIN/MEDIA_REPOSITORY/TAB108326/
TAB6428377/BIRD_UPDATE23032007.PDF.
[4] T. A. Jusko, C. R. Henderson, B. P. Lanphear, et al.,
“Blood lead concentrations < 10 microg/dL and child in-
telligence at 6 years of age,” Environmental Health Per-
spectives, Vol. 116, pp. 243-248, February 2008.
[5] Centers for Disease Control and Prevention, “Preventing
lead poisoning in young children,” Atlanta: CDC, 2005.
[6] Education and Health Standing Committee Legislative
Assembly, “Inquiry into the cause and extent of lead pol-
lution in the Esperance Area,” in: Printer G, editor: State
Law Publisher, Western Australia, 2007.
[7] Environmental Health Directorate, DoH, Western Austra-
lia, “Rainwater tank sample results. 2007,” cited Septem-
ber 4, 2008, http://www.health.wa.gov.au/envirohealth/
home/docs/RWT_Summary_Stats.pdf.
[8] NHMRC, NRMMC, “Australian drinking water guide-
lines 6,” Canberra: National Health and Medical Re-
search Council and Natural Resource Managment Minis-
terial Council, 2004.
[9] American Public Health Association, “Standard method for
the examination of water and wastewater, 20th Edition,
Method 3120B inductively coupled plasma method,” 1998.
[10] ESRI, “Using ArcGIS spatial analyst: ArcGIS9,” Red-
lands: ESRI Press, 2004.
[11] StataCorp, “Stata statistical software: Release 9,” College
Station, TX: StataCorp LP, 2005.
[12] E. Maynard, R. Thomas, D. Simon, et al. “An evaluation
of recent blood lead levels in Port Pirie, South Australia,”
Science of The Total Environment, Vol. 15, No. 303, pp.
25-33, February 2003.