University of Wollongong Thesis Collections

University of Wollongong Thesis Collection

University of Wollongong Year

Trace metal contamination of soils and

sediments in the Port Kembla area, New

South Wales, Australia

Yasaman JafariUniversity of Wollongong

Jafari, Yasaman, Trace metal contamination of soils and sediments in the Port Kem-bla area, New South Wales, Australia, Master of Environmental Science - Research thesis,School of Earth & Environmental Sciences - Faculty of Science, University of Wollongong,2009. http://ro.uow.edu.au/theses/3133

This paper is posted at Research Online.

10

Chapter 2

Literature Review

2.1 Historical Development of Industry in the Illawarra Region:

In order to obtain an outlook on the possible sources of trace metal pollution in the Lake

Illawarra catchment, historical record of industrial activity within a 5-10 km radius from the

lake’s perimeter was garnered from Depers (1992) and Yassini et al. (1992).

Based on Depers (1992) and Yassini et al. (1992), there were five phases of anthropogenic

development from 1817 to 1992 in the area. The first anthropogenic activity occurred

between 1817 and 1896 and produced particulate material emissions (mainly carbonaceous

ash) prior to industrial development. During this period of time wheat farming and two

flour mills were operating in the region, however rusting of machinery changed the farming

practices to dairying. Also clearing and burning of the natural vegetation produced the first

significant particulate emissions in the area. In 1887 the railway line between Wollongong

and Dapto was completed, with trains being fuelled by locally produced coal and coke.

In 1876 the first coke ovens operating at Wollongong Harbour were established and in 1888

the Australian Coke Company established a large coke works at Unanderra, 3.5 km from

the lake. The latter company had 54 beehive structures that produced 300-400 tonnes of

coke per week (Bayley, 1963). Other sources of particulate emissions were the Mount

Pleasant Coke Works and the Wollongong Gas Works, both located in North Wollongong

(Smith, 2001).

Coal mining began within the lake’s catchment area at Mount Kembla in 1883. Other

collieries established in this period were Southern Coal Co. in 1888, South Kembla in 1888

and Tongarra near Macquarie Pass in 1893 The coal most probably was used in small

industries at Albion Park and elsewhere, e.g., the Tongarra creamery and for domestic fuel-

fired stoves and ovens. The burning dumps also created particulate material emissions, with

the by-product being coke. It was, therefore, by accident that the local coal was discovered

11

to produce a strong coke, suitable for industrial use (Depers, 1992; Yassini et al., 1992: 10-

11).

The second phase of industrial development in the area came about between 1896 and

1910. In 1896 the Smelting Company of Australia Ltd established a Pb-Zn-Cu-Ni sulphide

ore smelting plant on the western shore of Lake Illawarra. Sulphide ore from a variety of

mines was used while coal was used on site to fuel the boilers and the small power station

located there. The refining plant was closed in 1906 and moved to Port Kembla, where it

was later used by the Electrolytic Refining and Smelting Company of Australia Ltd. In

1899, the Mount Lyell Coke Works was established at Port Kembla, where coke was

produced and exported to Tasmania (Depers, 1992; Yassini et al., 1992).

The third phase from 1910 to 1954 is considered as a period of rapid industrial expansion in

the Port Kembla area. The base metal (Cu) refining plant was reopened in 1910, metal

Manufactures Ltd. commenced operation in 1918 and Australian Fertilizer Ltd began

producing superphosphate in 1921. Several other major industries were also opened during

this time. Many of the previously built coke works were demolished and a new coke battery

was built in 1910 at North Wollongong. Two steel strip mills were constructed during this

time, the first opening in 1936 at John Lysaghts (Aust.) Ltd and the second at the

Commonwealth Rolling Mills in 1939 (Depers, 1992; Yassini et al., 1992).

A power station was raised at Port Kembla in 1913 and fuelled by local coal supplies.

Wongawilli Coke Works was constructed in 1917 in the west, within the lake’s catchment.

It comprised six ovens initially and was expanded to 120 ovens by 1927 and was the largest

beehive type coke oven battery in NSW at the time. The coke was primarily sent by railway

to Lithgow, but when G and C Hoskins moved their Lithgow plant to Port Kembla in 1927,

the Wongawilli coke works became the main source of coke for the new steelworks

(Depers, 1992; Yassini et al., 1992).

In 1928 Australian Iron and Steel Pty Ltd (AIS) was opened, the no.2 blast furnace was

commissioned in 1938 and the no.3 in 1953. With the very rapid expansion of AIS Pty Ltd,

12

the no.1 power station was commissioned in June 1928. With the closure of the Lithgow

Works during the depression, equipment was transferred to the Port Kembla site (Anon

1969; Depers, 1992; Yassini et al., 1992). The production of pig iron increased gradually

from 130 000 tons in 1929 to 773 000 tons in 1953, the steel ingot production rose from 59

000 tons to 808 000 tons; however there was decreased production during the depression

and World War ІІ (Hughes, 1964; Depers, 1992; Yassini et al., 1992).

The Wongawilli Coke Works was closed in 1954, due to the age of structures and AIS Pty

Ltd installed its first battery of seventy two Wilputte by-product coke ovens in 1938. Forty

eight more ovens were commissioned in 1950 and another 24 ovens were commissioned

three years later (Hughes, 1964; Anon, 1969; Southern, 1978).

The fourth phase of industrial activity within the region occurred from 1954 to 1989 with

the commissioning of the Tallawarra Power Station in late 1954. Coal was initially supplied

from the Tongarra mine till 1955, when coal was sourced from the Huntley Colliery. In

1961 and 1962 two 100 MW generators were commissioned, however, the Tallawarra

Power Station was decommissioned in 1989 (Bayley, 1959; Depers, 1992; Yassini et al.,

1992).

The Port Kembla Power Station was decommissioned in 1963, followed by the closure of

the Federal Coke Works in 1971 and the Mount Pleasant Coke Works in 1978. In 1959 the

Commonwealth Steel Company commenced operations to cater for the demand for

specialized steel. AIS Pty Ltd continued to expand operations by commissioning 96 coke

oven batteries in 1960 and a further 66 ovens in 1966 (Anon, 1969; Depers, 1992; Yassini

et al., 1992).

The fifth phase between 1989 and 2009 includes companies and industries which have

continued operations within the region. These include BHP Billiton-Steel International

Group, Slab and Plate Products Division (formerly AIS Pty Ltd and Commonwealth Steel

Co. Ltd); Incitec Ltd (formerly Australian Fertilizers Ltd.); Port Kembla Copper (formerly

13

Southern Copper ERS Ltd which was decommissioned in August 2003); John Lysaghts

(Aust.) and the Port Kembla Coal Loading Facility.

2.2 Selected studies of trace metal pollution and bioavailability on soils from

Australian and worldwide:

Soil is considered as an important and precious resource which supports and provides the

basis of all human and animal life. It is a very valuable and significant component of the

biosphere, acting as a natural buffer for the transport of chemical substances into the

atmosphere, hydrosphere and biota (Pacheco, 1999). Trace metals as naturally occurring

elements, could be dispersed in the environment by natural processes such as weathering of

the Earth’s surface and volcanic activity (Fernandez et al., 2001). Since the industrial

revolution, the soil environment has been used as a site for trace metal deposition and

accumulation, specifically acting as a chemical sink for toxic and hazardous wastes

(Pacheco, 1999). Some trace elements like Cu, Zn, As, Cd and Pb arise from various

industrial activities and waste products like tailing dams, emissions from metal processing

factories, oil combustion and power stations. Also urban and agricultural pollutants which

result from utilization of leaded petrol, lead based paints and utilization of fertilizers could

add to the metal concentrations in the environment (Pacheco, 1999; Fernandez et al., 2001).

Due to the possible health risks trace elements pose to humans, many communities have

become increasingly concerned by environmental soil pollution in relation to their daily

lives (Tiller, 1992; Fernandez et al., 2001). Government agencies have given more

significant attention to soil, considering its role as a repository of much pollution, as a

transmitter of undesirable materials to the groundwater and as a supplier of contaminants to

crops (Tiller, 1992). In Australia, public attitudes toward environmental issues had changed

slowly relative to North America and Europe, but they have shifted rapidly to higher levels

of concern during recent decades. Pollution rates in Australian cities would be expected to

be at lower levels than in European ones, but the upsurge of environmental pollution since

the industrial revolution has obviously caused significant pollution of major Australian

urban centres (Tiller, 1992).

14

2.2.1 Soil Formation:

Factors controlling the derivation of soils are divided into three components; lithogenic,

pedogenic and anthropogenic (Pacheco, 1999). Lithogenic soils are directly associated with

parent material, inherited from the lithosphere. The pedogenic component of soil includes

the concentration and distribution of materials resulting from natural weathering processes,

lithospheric and anthropogenic sources. Anthropogenic elements in soils are deposited

directly onto the soil as a result of human activities (Pacheco, 1999).

2.2.2 Background Trace Metal Concentrations:

Environmental and health authorities, in defining a yardstick to determine what levels of

soil contamination needs investigation, tend to use ‘normal’ background concentration

which monitors the amount of contamination in everyday life by most of the population.

These ‘normal’ background concentrations have been considered as contaminants scattered

by wind and water transport which are superimposed on the natural geochemical

contribution from rocks and sediments (Tiller, 1992). In previous studies, background

concentrations of some trace metals have been estimated using soil samples from non-

industrial and pristine areas or samples developed directly from parent rocks (Beavington,

1975; Tiller, 1992; Martley et al., 2004; Kachenko and Singh, 2006). Based on these

investigations background amounts of some trace metals in New South Wales are listed in

Table 2.1.

Table 2.1: Background concentrations of trace metals in surface soils from non-industrial sites in New South Wales.

Trace metal Concentration ranges(ppm)

As <0.3-11

Cd <0.05-0.7

Cr 1.3-380

Cu 2.1-72

Pb 2.7-170

Mn 20-3300

Ni <0.05-180

Zn 2.1-450

15

2.2.3 Sources of Urban Soil Contamination:

Urban environments have been influenced by a range of contaminants which pose different

impacts within and between different cities. Trace metals in urban soils have been

considered as useful tracers of environmental pollution (Tiller, 1992; Manta et al., 2002).

The various industries and land uses associated with soil contamination have been

summarized in Table 2.2 (Tiller, 1992).

Table 2.2: Sources of trace metal pollution in soils from (Tiller, 1992).

Acid/alkali plant and formulation Metal treatment

Airports Mining and extractive industries

Asbestos production and disposal Oil production and storage

Chemicals manufacture and formulation Paint formulation and manufacture

Defence works Pesticide manufacture and formulation

Drum re-conditioning works Pharmaceutical manufacture and formulation

Dry cleaning establishments Power stations

Electrical manufacturing Railway yards

Electroplating and heat treatment premises Scrap yards

Engine works Service stations

Explosive industry Tanning and associated trades

Gas works Waste storage and treatment

Iron and steel works Wood preservation

Land fill sites

2.2.4 Trace Metal Concentrations and Sources in Soils of the Port Kembla Area:

Anthropogenic emissions of metals from industrial sources such as smelters are an

international problem, but there is limited published information in Australia.

Beavington (1973) examined contamination of the Illawarra region by investigating Cu, Zn,

Cd and Pb levels in soils using acetic acid and EDTA extractions. The levels of these

metals were estimated at about up to ten times greater than those in rural control areas. A

significant concentration was observed in the Port Kembla area. The contaminants

accumulated in the surface horizons of the soils, indicating an airborne origin.

Using Pb isotopes, Chiaradia et al. (1997) identified historical Pb pollution in the roof dust

and recent lake sediments of the Illawarra region, indicating four major sources of

anthropogenic pollution and one natural source of Pb in the lagoon. The suggested

16

anthropogenic sources were an old disbanded base-metal lead smelter at Kanahooka, the

copper smelter, gasoline-air derived Pb and industries utilizing coal such as a thermal coal-

fired power station, while the natural source consisted of Permian rocks cropping out in the

catchment area (Chiaradia et al., 1997).

The long term environmental effects associated with modern development were assessed by

analysing the amount of Cu, Zn, Ni and Pb of the soil of the environment at and around an

abandoned Pb smelter located at Kanahooka, south of Wollongong (Pacheco et al., 2009, in

prep). Also the relatively wide dispersal of contaminants around the smelter site at

Kanahooka indicated that the main mechanism of trace metal dispersal was atmospheric

transportation and fallout (Pacheco, 1999).

In previous studies in the Illawarra region (Beavington, 1973; Chiaradia et al., 1997;

Chenhall et al., 2001) it was suggested that the Port Kembla copper smelter has been the

major source of metals to the surrounding environment. Therefore, a comprehensive

investigation on the regional metal distribution in soils (0-5 and 5-20 cm) in the vicinity of

the industrial complex in the Port Kembla area was done by Martley et al. (2004). Elevated

levels of Cu and As were mainly observed within 4 km from the industrial complex but

some Cu and As concentrations in the soils were probably related to the composition of the

parent rock. Moreover, there were no obvious differences of metal concentrations at depth

of 0-5 and 5-20 cm, except for Pb and Zn.

Overall, Port Kembla industries comprising the steelworks, closed copper smelter and other

associated industries seem to have contaminated the surrounding soils to a distance of 1-13

km depending on the element, but most likely to < 4 km (Beavington, 1973; Pacheco, 1999;

Martley et al., 2004; Kachenko and Singh, 2006). Also the extent of the pollution depends

on various factors such as the size and duration of the industrial operation, atmospheric

conditions, height of the stack, the amount of metals released to the atmosphere, physical

and chemical properties of the emitted particles and the sensitivity of detection of low metal

contamination which depends on factors like natural heterogeneity of metals in the soil, soil

properties, presence of multiple sources (Pacheco, 1999; Martley et al., 2004). In high

population density regions, the determination of fallout patterns around the smelter areas

may be complicated due to superimposed pollution from other industrial sources, car

exhaust fumes, urbanization and soil disturbance, thus many reports accentuate strong

17

dependence of fallout on distance from the smelter and climatic conditions (Tiller et al.,

1975). Rapid urbanization and agricultural activities could be considered as other lesser

sources of metal pollution in the area (Smith, 2001).

Before 1970s, no severe environmental pollution control measures were enforced in ore

handling or dust/ash distribution, so this resulted in extremely high contamination around

the area (Pacheco, 1999).

2.2.5 World-wide Contamination from Smelting Activities:

Smelting complexes are associated with anthropogenic metal pollution and release large

amounts of trace metals into the surrounding environments. These areas definitely become

vulnerable to the direct contribution of waste through slag, accidental spillage from

transportation, processing and refining in addition to fume, ash and dust released through a

smelter stack. Emissions from a stack could be transported through the atmosphere before

settling as particulate matter, thus affecting both close to and at great distances away form

the point source (Pacheco, 1999).

Due to the potential health risks posed by trace metals to humans, significant concern and

interest has focused on the impact of trace elements associated with smelter activities in

residential and agricultural soils (Fernandez et al., 2001).

Trace metal investigations in soils surrounding the Port Pirie Pb smelter, South Australia,

indicated that widespread dispersal of EDTA-extractable Zn, Cd and Pb in the area with

decline in concentration with increasing distance from the smelter. In close proximity to the

site, the fallout was consistent with surface winds, while major contaminants depend upon

the meteorology and topography of the region. Further, the Pb/Cd and Zn/Cd ratios in soils

decrease with distance from the smelter, indicating that over short distances soil

contamination resulted from the fallout of particulate emissions. Beyond about 15 km trace

metals would probably be dispersed mainly as aerosols. Also it was concluded that soil

leaching was negligible due to the high alkalinity, thus metal availability to plants was

relatively low (Cartwright et al., 1976).

Housedusts and garden soils were taken from an area of 2 km2 covering grounds and

surrounding residential areas near a secondary Pb smelter situated south-west of the Czech

capital, Prague, and analysed for concentrations of Pb, Zn, Cu, Cd, As and Hg (Rieuwerts

18

et al., 1999). Contour maps derived from the grid data suggested notable contamination in

the area with the maximum Pb concentrations of 58500 µg/g, particularly downwind of the

smelter grounds. Also there were no significant correlations between metal levels in garden

soils and housedusts while notable correlations were observed with distance from the

smelter; garden soil metal concentrations against each other; housedust metal

concentrations against each other; and house age against garden soil metal concentrations

(Rieuwerts et al., 1999).

A preliminary survey of metal concentrations was undertaken in the town of Zlatna, in

western Romania which is dominated by a large Cu smelter (Pope et al., 2005). Levels of

the elements Cu, Zn, Cd, As and Pb in soils and vegetables of the area were measured.

Concentrations of trace metals in the soils in Zlatna were significantly high and exceeded a

number of soil guideline values. Also the soils seemed to be phytotoxic, with toxic

elements entering the food chain. Lead and cadmium intake by people from home grown

vegetables and other diet sources may be high and needs further investigation. Trace

element concentrations in the area and in school grounds in particular, could cause a

concern from a children’s health perspective. The metal levels at five sampling sites in the

grounds were unacceptably high, especially when taking into account the amount of time

children spend in the school, the vulnerability of the exposed population, its close

proximity to the smelter and children’s activities in the area like digging around in the dirt

leading to ingestion and skin contact (Pope et al., 2005).

2.2.6 Trace Metal Extractability and Bioavailability in Soils:

Trace metals in soils and sediments may exist in various chemical forms. In unpolluted

soils or sediments trace metals have been found to bind to silicates and primary minerals

forming relatively immobile species, while in polluted areas trace metals are generally

more mobile and bound to other soil or sediment phases(Rauret, 1998). From an

environmental point of view, determination of the different ways of binding provides more

information on trace metal mobility and also bioavailability and toxicity. To do this,

various approaches have been used for soil and sediment analysis, many of them focused

on pollutant desorption from the solid phase; others aimed to detect the pollutant adsorption

from a solution by the solid phase. There are two types of extraction: (single and sequential

19

extraction methods) widely used in soil science. Single extraction procedures usually

dissolve a phase whose elemental content is associated with the availability of the element

to plants. Such extraction methods are well designed for major elements and nutrients as

well as studies of fertility and quality of crops, to predict the uptake of essential elements,

to diagnose deficiency or excess of one element in a soil and studies of the physical-

chemical behaviour of elements in soils (Rauret, 1998). To a lesser extent they are applied

to determine trace and trace metal pollutants. The use of these extraction procedures is

mainly focused on the potential availability and mobility of pollutants for both soil-plant

transfer and metal migration in a soil profile, which are usually connected with

groundwater problems (Rauret, 1998).

The content of mobile trace metals also depends on the nature of the metal ion, the nature

of extractant and the pH (Sabienë et al., 2004). For example, the mobile forms of Cd, Cu

and Pb were investigated by using ammonium nitrate, ammonium acetate (pH 7 and 4.8),

0.1 M HCl and 0.05 M NH4-EDTA (pH 7). The lowest amounts were extracted with

ammonium salt solutions ever through the content of trace metals extracted with

ammonium acetate (pH 4.8) was greater than those extracted with ammonium acetate (pH

7). Even more significant contents of trace metals were extracted with 0.1 M HCl while

0.05 M NH4-EDTA (pH 7) was capable of extracting not only the trace metals participating

in the exchange processes, but also trace metals in carbonates and organic complexes in the

soil. In addition, a comparison of the mobile forms of trace metals extracted from clean and

highly polluted soils has indicated that in the polluted soils a higher portion of trace metals

exists in a mobile form (Sabienë et al., 2004).

In Western Europe, policy makers have shifted their attitudes towards a major integrated

risk-based approach of soil contamination assessment to determine trace metal mobility and

bioavailability by single extraction procedures (Meers et al., 2007). The notion behind this

is the fact that total soil content of metals by itself is not an appropriate measure for

assessing their bioavailability and not a very useful tool to determine potential risks from

soil and sediment contamination.

The levels of Cu, Zn, Pb, Cd, Ni and Fe were investigated in leaf vegetables and their

supporting soil in the vicinity of a copper smelter and steelworks in Wollongong, Australia

by Beavington (1975). Mean levels of Pb, Cd and Ni in lettuce were 23, 4.5 and 2.7 mg/kg,

20

respectively, while extractable levels of metals in the supporting soil were also found to be

high. Notable correlations were found between distance from the Port Kemble copper

smelter stack and the levels of easily-extractable Cu, Zn, Pb and Cd in soils. The low

correlation between Fe and other trace metals in lettuce was related to the basalt-derived

soil or the steelworks as the main sources of Fe in the area. In addition, notable correlations

observed among the levels of most other trace metals in both soil and vegetables indicated

the ‘blanket effect’ of fallout coating both vegetation and soil. Also when compared to the

World Health Organization (1972) recommended maximum Provisional Tolerable Weekly

Intake levels for adults, the levels of Pb, Cd and other trace metals in leaf vegetables

prepared for human consumption, especially lettuce, grown around the smelter are a matter

of concern (Beavington, 1975).

Sources and the extent of trace metal contamination in soil and vegetable samples across

four vegetable growing regions, namely Boolaroo, Port Kembla, Cowra and the Sydney

Basin in New South Wales, were investigated by Kachenko and Singh (2006) since the

dietary exposure to trace metals like Cd, Cu, Zn and Pb has been suggested as a risk to

human health through the consumption of vegetable crops. The amount of metal

contamination in soil samples located in the neighbourhood of smelters like Boolaroo and

Port Kembla was greatest, decreased with depth at these two sites, reflecting contamination

due to anthropogenic activities. Also contamination of vegetables with trace metals was

observed in samples from the residential regions of Boolaroo and Port Kembla with

samples from Port Kembla having the highest mean levels of Cu in all vegetable types. At

Boolaroo, nearly all the vegetable samples exceeded the Australian Food Standard

maximum levels for Cd and Pb whereas all vegetable samples from Cowra, which is a

relatively pristine site, had Cd and Pb levels below these guideline values. Thus, these

findings suggest that the cultivation of leafy vegetables for human consumption near

smelters should be avoided (Kachenko and Singh, 2006).

The relationships between the trace metal concentrations of vegetables, agricultural soil and

airborne particulate matter were investigated in the industrial area of Thessaloniki, northern

Greece (Voutsa et al., 1996). Despite the airborne particulate matter that was significantly

enriched with Zn, Cd, Pb and Mn, trace metal contents of agricultural soils were found to

be relatively low; however, elevated concentrations of these metals were observed in leafy

21

vegetables. Also the main pathway for most trace metals to vegetable roots was from the

soil, while trace elements in vegetable leaves seemed to originate from the atmosphere.

Significant accumulation of Pb was found in lettuce and Cr and Cd are concentrated in the

leafy vegetables generally as a result of atmospheric deposition. In contrast root vegetables

appeared to accumulate soil Cd much more efficiently than other trace metals (Voutsa et

al., 1996).

Generally, the high metal concentrations observed in soil and vegetable samples in the

vicinity of industrial and urbanized activities could cause serious environmental problems

which in turn affect human life (Fernandez et al., 2001; Fytianos et al., 2001; Sponza and

Karaoğlu, 2002; Manta et al., 2002; Krishna and Govil., 2004; Liao et al., 2005).

2.2.7 Soil Quality Guidelines:

Following the recognition of contaminated soils in Europe and the USA in the early 1970s,

guidelines were designed in order to estimate the extent, spread and risk of exposure to

humans, as well as the immediate and surrounding ecosystems. Thus, each set of guidelines

was essentially developed to suit the needs for detecting a specific problem in a particular

region. One of the most widely used guidelines to assess contaminated soils and

groundwater are the Dutch Guidelines (Tiller, 1992; Pacheco, 1999). Other soil guidelines

established by other environmental organizations have comprised and adapted many

aspects of the Dutch values for their own purposes, such as the Australian and New Zealand

Environment and Conservation Council and National Health and Medical Research Council

(ANZECC/NHMRC, 1992).

The Dutch Approach:

In response to the estimated 100 000 contaminated sites which required cleanup, the

Netherlands has carried out much research in order to assess and cleanup the

contaminated soils. Their approach aimed to define three indicative levels, an A-

value (reference value) which defined the upper limit of the natural background

range but was not based on ecotoxicological effects. A second indicative level, B-

value, was the trigger value for further investigation. This investigation would be

applied to the affected site and soil factors to determine bioavailability, transport of

22

pollutants and critical pathways in relation to the desired land use. A third indicative

value, C-value, defined a limit which required cleanup. The Dutch indicative

C-values for cleanup consider human-toxicological arguments but are not based on

any accepted risk assessment methodology. Cleanup provisions should aim to return

the site to the A value which would allow a flexible, unrestricted or multifunctional

use of the land. Overall the Dutch approach has had immense impacts world-wide

(Tiller, 1992). Table 2.3 shows the concentrations pertaining to these three

indicative levels for several trace metals.

A = Reference value (top of background range). B = Indicative value for further

investigations. C = Indicative value for cleaning up.

Table 2.3: Dutch standards for soil contamination assessment (Tiller, 1992). (Total concentrations in soil: mg/kg)

Metal A B C

Cr

Co

Ni

Cu

Zn

As

Mo

Cd

Sn

Ba

Hg

Pb

100

20

50

50

200

20

10

1

20

200

0.5

50

250

50

100

100

500

30

40

5

50

400

2

150

800

300

500

500

3000

50

200

20

300

2000

10

600

ANZECC/NHMRC Guidelines:

In Australia, control and remediation of contaminated sites has been conducted by

different state health and environmental departments and agencies. Some of these

agencies have had interim regulations under State legislations pending the moves

towards national Australian and New Zealand guidelines for contaminated sites

developed under the auspices of the Australia and New Zealand Environment and

23

Conservation Council (ANZECC) and the National Health and Medical Research

Council (NHMRC; Tiller, 1992).

ANZECC/NHMRC provided modified guidelines from research and knowledge

based on international information in order to develop guidelines for investigation

as information become available. Figure 2.1 illustrates the recommended approach

for initial evaluation of potentially contaminated sites (ANZECC/NHMRC, 1992).

Figure 2.1: Recommended approach to the assessment and management of a

potentially contaminated site (ANZECC/NHMRC, 1992).

Initial Evaluation

Site history/ Site description/ Preliminary sampling

Apply Soil Investigation Guidelines

No problem Potential Problem

Second Stage Investigation

Assess nature and extent of problem

Assess potential public occupational health risks (toxicology)

Assess environmental impacts

No problems for agreed land use

No action

Unacceptable impacts detected Determine criteria for site cleanup Determine options for site management Determine cleanup methods

Action

Monitoring

24

2.3 Selected studies of trace metal contamination on sediments from local and world-

wide previous investigations:

The distribution of trace metals in aquatic systems has been widely studied during the last

two decades for reasons of environmental concern. The geochemistry of aquatic

environments like rivers, lagoons, estuaries and creeks is governed by a complex interplay

of hydrodynamic factors, industrial and municipal wastewater discharges and

biogeochemical processes (Smith, 2001). Also several studies in Australia have indicated

instances of noticeable metal pollution of estuarine waters (Eustace, 1974; Furzer, 1975).

Some previous studies chose to investigate metals in sediments instead of water due to

higher concentrations of metals in sediments (within the range of direct determination by

atomic absorption spectroscopy without preconcentration) and also because sediments are

less susceptible to short term variations as a result of lateral mixing, wind direction,

flushing by rainwater, etc. (Ellis and Kanamori, 1977). Also sediments are important

because they are both a source and a sink for contaminants.

“Because the geochemical processes that influence metal accumulation in the environment

are reversible it is important to realize that the environmental sink for today may become

the pollutant source of tomorrow. “ (Clark et al., 1997)

2.3.1 Background Trace Metal Concentrations:

Background concentrations of trace metals in soils from the Port Kembla area have not

previously been reported in the literature. These soils have mainly developed in situ and

would reflect the composition of the parent rocks from which they were derived. Parent

rock compositions have therefore been analysed as part of this study.

Background concentrations of trace metals in Lake Illawarra have been estimated in a

number of previous studies (Ellis & Kanamori, 1977; Payne et al., 1997; Chenhall et al.,

2004). Concentrations of Cu, Zn and Pb exhibit a notably uniform distribution with depth

therefore, providing the basis for determination of background (pre-industrial) values for

these elements. Despite the different methods of sample collection and analysis, the

background concentrations of Cu and Pb have been in reasonable agreement in previous

studies and were estimated at about 33-38 ppm and 15-18 ppm respectively (Ellis and

25

Kanamori, 1977; Payne et al., 1997 and Chenhall et al., 2004). Significant differences

between the Zn background values in these studies could be probably due to different

analytical factors and the unusual grain size normalization applied by Ellis and Kanamori,

(1977) which included a portion of the fine sand sediment fraction. Also a more feasible

explanation is that the deep (10-20 m) sediments investigated by Ellis and Kanamori,

(1977) were in fact part of the geochemically distinct underlying Pleistocene succession.

Sediment grain size factors and different sample preparations have been considered as other

factors for different background values of Zn concentration (Chenhall et al., 2004).

Background concentrations of Zn were estimated at about 44 ppm by Ellis and Kanamori,

(1977) and 84 ppm in a study by Chenhall et al., (2004).

Further, in a later study by Gillis and Birch (2006), background concentrations of Cu, Zn

and Pb have estimated around 19, 87 and 39 ppm, respectively.

2.3.2 Trace Metal Abundant in Lake Illawarra:

To have a better idea about the extent to which contaminant concentrations exceed

background values and also the impact of anthropogenic activities on the catchment,

enrichment factors of some trace metals have been calculated using the expression below

(Payne et al., 1997):

Enrichment Factor: mean concentrations of trace metal in the top 20 cm of sediment background concentration (below 45 cm)

Previous studies indicated that the enrichment of some trace metals like Cu, Zn and Pb in

the upper 50 cm of sediment profiles in Lake Illawarra could be equated with European

(industrial) impact on the lake. The maximum enrichments for Cu, Zn and Pb were

estimated at about 4, 34 and 11 respectively, at Griffins Bay in the north-east corner of the

lake, which is closest to the Port Kembla industrial complex (Roy & Peat, 1974; Ellis &

Kanamori, 1977). Also in studies by Chenhall et al. (1994) and Payne et al. (1997) the

enrichment factors of Cu, Zn and Pb were calculated around 1.8, 5.9 and 3.5 respectively.

Gillis and Birch, (2006) indicated that in Griffins Bay, Cu and Zn were elevated above

background values by more than 3 times while the enrichment factors for Pb and Cd were

just less than 6.

26

Trace metal concentrations in Lake Illawarra are higher than in less polluted or pristine

areas such as Burrill Lake, NSW, or Bells Creek catchment, Queensland, (Jones et al.,

2003; Liaghati et al., 2003) and significantly lower than heavily polluted areas like Port

Pirie, South Australia, Derwent River, Tasmania, Lake Macquarie, NSW; Parramatta River

catchment, NSW, and Deule- canal sediments, France (Cartwright et al., 1976; Batley,

1987; Birch et al., 2000; Jones et al., 2003; Boughriet et al., 2007).

2.3.3 Sediment Chronology:

Increased sediment supply to estuaries can be caused by natural phenomena like flood

cycles, but additional sedimentation can also be the result of anthropogenic activities,

comprising industrial practices, initial deforestation, clearing of the catchment and also

increased rates of erosion and transportation of sediment as a result of urban expansion,

construction of roads and housing developments.

Accelerated sedimentation in shallow coastal lagoons poses significant environmental

impacts like shoaling, degradation of seagrass beds, and increased turbidity with

consequent loss of aesthetic appeal (Chenhall et al., 1995).

Pre-European sedimentation rates in Lake Illawarra were estimated at less than 1 mm/year

by radiocarbon dating methods on shells (Notospisula trigonella) preserved in the

sediments (Chenhall et al., 1995). This method is not without limitations including its

limited applicability to sediments less than 200 years in age and also the potential for

erroneous 14C ages if older carbon, in the form of reworked, redeposited shells is

incorporated in the sediment (Chenhall et al., 1995). Modern (< 200 years) radiocarbon

ages have been estimated from shells at a depth of 1 m around the sandy deltaic margins of

the lagoon, indicating that the rates of sediment accretion since the European settlement

would be >5 mm/year (Chenhall et al., 2001).

The chronology of sediments deposited in the last 120 years can be detected using the

modelling of 210Pb and 137Cs depth-decay curves (Chenhall et al., 2001). However these

techniques are not without their limitations including availability of facilities, costing and

in the southern hemisphere the very small quantity of 137Cs in the samples (Smith, 1982;

Loughran and Campbell, 1983). Furthermore, sediment-age profile constructed using 210Pb

data may not coincide with the profile generated by site-specific markers such as trace

27

metals (Killby and Batley, 1993). 137Cs dating results on Lake Illawarra in 1990 were

somewhat disappointing, mainly due to non-measurable 137Cs activity in some cores,

because of low clay content and very rapid sediment accumulation rates (Chenhall et al.,

2001).

Moreover, using trace metal-depth concentration profiles and anthropogenic markers in

conjunction with the time of industrial development, near surface sedimentation rates

ranged between 3 to 5 mm/year at Griffins Bay to more than 16 mm/year at Macquarie

Rivulet. Sedimentation rates of approximately 10 mm/year seemed to be typical of the

western and southwestern portions of the lagoon (Chenhall et al., 1995; Payne et al., 1997).

Trace-metal concentration-depth and ash concentration-depth profiles indicated the typical

rates of sedimentation of between 3 to 5 mm/year over the last 70-90 years for the northern

and north-central parts of the lagoon (Chenhall et al., 2001). It should be noted that

limitations attached to this method are potential trace metal mobility, and biogenic and

physical distribution of the sediments. Thus, sites far from known point sources could not

be assessed by trace metal profiling mainly due to uncertainties about the dates of

introduction of trace metals into the sediment profiles depending on selection of 1910

(Southern Copper) or 1928 (BHP Steel) as the starting date (Payne et al., 1997).

Based on other estuarine investigations, rates of sediment accretion in Lake Illawarra have

been identified as higher than Burrill Lake, which is about 1.7 mm/year, but lower than

Lake Macquarie, NSW, Australia (Batley, 1987; Jones et al., 2003).

2.3.4 Trace Metal-Sediment Grain Size Relationships:

Fine-grained, clay-rich sediments generally have significant metal retention due to

increased specific surface area and the strong adsorptive properties of clay minerals. Clay

particles, i.e., aluminosilicates, are negatively charged since at the end of silicon-oxygen

chains, oxygen atoms carry an extra electron because they are only bonded to one atom

instead of the usual two, and aluminium atoms are bonded to four oxygens instead of the

usual three (Smith, 2001). Therefore, clays are regarded as anions and metals like Cu, Pb

and Zn are positively charged cations. Because of this affinity, trace metals are

preferentially bonded with fine-grained sediments (clays and silts) and colloidal materials

due to particularly strong cation exchange potential upon clay surfaces (Smith, 2001).

28

Rubidium is also a cation and is geochemically coupled to potassium, a component

associated with illite and smectite clays, therefore, can be used as a proxy indicator for

grain size (Payne et al., 1997). As a result, the Rb distribution in Lake Illawarra sediments

is directly associated with the content of fine silt and clay and can be applied as a useful

measurement of grain size variation in relation to retention of trace elements by silt and

mud particles (Payne et al., 1997).

Also like clays, organic matter shows the ability to bind different metal ions to its surface;

the strength of the bound created between organic matter and metal ions is directly related

to factors such as pH, influx of sediment and redox potential. The organic material forms

metallic complexes readily (Smith, 2001).

As a result of the above, the distribution of Cu, Pb and Zn in the upper 20 cm of sediments

in Lake Illawarra is directly related to the proportion of mud-dominated (> 50 % silt &

clay) sediment while high organic matter content and biogenic processes (bacterially-

mediated sulphate reduction) assist trace metal retention via sulphide formation in the

sediment (Payne et al., 1997). In contrast, sand dominated (> 50 % sand) sites in Lake

Illawarra are characterised by lower concentrations of metals like Cu, Pb and Zn (Payne et

al., 1997).

2.3.5 Sediment Quality:

Lake Illawarra sediments are generally identified by low (< 2.5) enrichment factors for

trace metals like Cu, Pb and Zn with the maximum concentrations of these metals in the

upper 20 cm of sediment profiles. However, a remarkable exception is the sediment from

southern Griffins Bay with enrichment factors of 3 to 6 for these metals (Chenhall et al.,

1994 and 2001; Payne et al., 1997; Gillis and Birch, 2006). Higher enrichment factors of

trace metals in this part of the lake reflect the close proximity of this site to the Port Kembla

industry and its associated surface runoff (Chenhall et al., 2004). Trace metal data for Lake

Illawarra have been assessed against the ANZECC & ARMCANZ (1992 and 2000)

sediment quality guidelines in previous studies (Ellis & Kanamori, 1977; Payne et al.,

1997; Chenhall et al., 2004; Gillis & Birch, 2006) that suggested the sediments in Lake

Illawarra could be generally classified as low risk. However, sediments from Griffins Bay

may exceed the high trigger value (ISQG-high) for Zn and the low trigger value (ISQG-

29

low) for Cu and Pb indicating that sediments from this embayment may be having an

adverse effect on benthic populations (Chenhall et al., 2004; Gillis & Birch, 2006).

2.3.6 Trace Metal Bioavailability and Toxicity:

Contaminated sediments have the potential to release metals into the water column and be a

source of bioavailable contamination to benthic biota and enter the food chain (ANZECC &

ARMCANZ, 2000).

Trace metals in sediments can be divided into three fractions based on geochemical

associations between the metals and constituents in the sediment. Fraction 1: refers to

metals which are exchangeable or loosely adsorbed, bound to carbonate, aluminium, iron

and manganese oxyhydroxides. This is generally referred to as the ‘bioavailable fraction’.

Fraction 2; refers to metals which are bound to organic matter and sulphides. Fraction 3;

refers to the detrital or lithogenic fraction (Smith, 2001).

Using dilute HCl and EDTA indicated that a large amount of Cd, Pb and Zn may be

available to benthic species in Griffins Bay sediments: however, it is believed that

sediments in Griffins Bay and northern Lake Illawarra are unlikely to be toxic to benthic

organisms because the acid-volatile sulphide simultaneously extracted metals (AVS/SEM)

are > 1 (Gillis & Birch, 2006).

2.3.7 Sediment Quality Guidelines:

The Australian Water Quality Guidelines for Fresh and Marine Waters (ANZECC and

ARMCANZ, 2000) established the framework for managing water quality. It was indicated

that total load and fate of contaminants should be considered. Sediments are important

because they are both a source and a sink for contaminants (ANZECC and ARMCANZ

2000). The development of Sediment Quality Guidelines can be used to evaluate the extent

of sediment contamination, or to implement measures designed to limit or prevent

additional contamination (McCauley et al., 2000). The ANZECC and ARMCANZ (2000)

sediment quality guidelines have outlined three categories in which the determination of the

sediment quality is assessed for the aquatic ecosystems. For an aquatic ecosystem to be

considered as: Condition 1: chemicals from human activities should be undetectable, i.e.,

trace metal concentrations should not be elevated above background concentrations;

30

Condition 2: moderately contaminated by anthropogenic activity; and

Condition 3: highly disturbed and contaminated aquatic ecosystems.

The principal philosophies behind the ANZECC and ARMCANZ (2000) sediment quality

guidelines are to recognize contaminated sites which could cause adverse effects to

ecological health, to establish the potential for remobilization of contaminants into the

water column and the aquatic food chain and to indicate areas which have not been affected

by anthropogenic practices (ANZECC and ARMCANZ 2000). The ANZECC and

ARMCANZ (2000) Sediment and Water Quality Guidelines involve a decision tree

approach, where the guidelines should not be used on a pass or fail basis. Therefore, if

trigger values are exceeded, further action as defined by the decision tree should be

undertaken (Figure 2.2; ANZECC & ARMCANZ 2000). The first level screening compares

the total metal contaminant concentration in the sediment to the trigger values set in

ANZECC and ARMCANZ (2000) Sediment Quality Guidelines. If contaminant levels

exceed trigger values, then either management and/or remedial action are triggered or

further investigation is required to consider the fraction of contaminant that is bioavailable

or can be transformed and mobilized into a bioavailable form. The decision making process

is illustrated in Figure 2.2 (ANZECC and ARMCANZ 2000).

2.3.8 Sources of Pollution in Lake Illawarra:

Although trace metals arising from different sources, for instance, Zn from galvanized iron,

Pb from the combustion of petrol-Pb additives and trace metals associated with domestic

discharges, probably contribute to the trace metal loading in Lake Illawarra, a noticeable

correlation between fine fraction sediments, Cu, Pb and Zn indicated that these trace metals

have had a common but not unique source of pollution (Chenhall et al., 2004; Gillis &

Birch, 2006). The Port Kembla industrial complex has been suggested as an important

source of trace metals in the area and concentrations of these elements have been observed

to decrease rapidly with distance from the complex (Roy & Peat, 1975; Ellis & Kanamori,

1977; Chiaradia et al., 1997; Gillis & Birch, 2006).

31

Define primary management aims

Determine appropriate guideline trigger values for selected indicators.

Sediment contaminant characterisation. Measure total then dilute acid-soluble metals, organics

plus TOC, grain size

Test against guideline values. Compare contaminant/stressor concentration with lower and

upper guideline values

Below low value

Low risk No action

Between upper & lower values

Check backgroundconcentrations

Below

Low risk (no action)

Above

Examine factors controlling bioavailability (optional) e.g. AVS: pore water concentrations

sediment speciation organic carbon

Test against guideline value Compare bioavailable concentration with lower guideline value

Above upper value

Low risk (no action)

Acute toxicity testing

Chronic toxicity testing Highly contaminated (Initiate remedial action)

Low risk (no action)

Moderately contaminated (initiate remedial action)

Not toxic Toxic

Toxic Not toxic

Below Above

Figure 2.2: Decision tree for the assessment of contaminated sediments

(ANZECC and ARMCANZ 2000)

32

Potentially, a main contributor to trace metal contamination in the Port Kembla area is

aerosols generated by the Port Kembla industrial complex since1910. Previous studies have

indicated that the greatest concentrations of trace metals like Cu, Pb and Zn occur in both

lagoonal and salt marsh sediments on the south side of Griffins Bay, adjacent to the

complex (Ellis & Kanamori, 1977; Payne et al., 1997; Chenhall et al., 2001, 2004). Also

sediments in creeks discharging into Griffins Bay contain higher trace metal concentrations

than sediments mantling Griffins Bay, indicating that these creeks, which drain sub-

catchments related to urban and industrial areas adjacent to the complex, are a source of

trace metals to the embayment (Gillis & Birch, 2006).

Urban runoff can also be considered as a source of trace metals to these creeks since metals

like Cd, Cu, Pb, and Zn are common constituents of urban stormwater runoff from vehicle

wear and exhaust emissions, corrosion of plumbing, roofs, etc. (Sutherland, 2000). Due to

limited water exchange between Griffins Bay and the main body of the lake, Griffins Bay

acts as a sink for sediment and affiliated trace metals entering the embayment (Gillis &

Birch, 2006). Sediment resuspension in Griffins Bay occurs during strong wind conditions

and northeast winds may result in an exchange of water between Griffins Bay and the main

body of the lake (Yassini & Depers, 1995). Also strong southerly and westerly winds in

summer and winter, respectively, would probably restrict resuspended material within

Griffins Bay due to the orientation of the embayment in the northeast corner of Lake

Illawarra (Gillis & Birch, 2006).

Significantly, near surface sediments in this portion of the lagoon contain abundant

anthropogenic ash uniquely sourced from both the steelworks and the copper smelter

(Payne et al., 1997). Little published analytical data are available for the aerosols generated

either by the smelter or the steelworks.

Historical industrial sources of trace metals existed on the western foreshore of the

catchment including the Smelting Company of Australia Ltd at Kanahooka (1896-1906)

and the Tallawarra Power Station (1954-1989) but these make a negligible metal

contribution to north eastern portion of the lake due to their locations and short periods of

operation (Gillis & Birch, 2006).