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Key departmental publications, e.g. annual reports, budget papers and program guidelines are available in our online archive.

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Everhard Industries: Using Environmental Life Cycle Assessment as a tool to compare similar products made from different materials

Everhard Industries is a leader in the production and service of small systems for water and wastewater treatment. The company viewed Environmental Life Cycle Assessment (LCA) as a tool for generating consistent and useful complimentary environmental product design data, particularly with respect to the production and marketing of its products and expanding its customer base. As a pilot study, Everhard Industries used LCA to understand the environmental attributes of septic tanks made from polypropylene and concrete. LCA data collected and analysed subsequently revealed a clear comparison of environmental performance between the two materials, and also helped the company to plan long-term product design research to manage contentious environmental issues facing the end-of-life disposal of the tanks.

Background

Everhard Industries Pty Ltd is a private family-owned company established in Brisbane in 1926. The company now employs more than 300 people at 10 sites in Queensland, New South Wales and Victoria, with agents in all other states of Australia and New Zealand. Everhard Industries has four manufacturing divisions - Precast Concrete, Steel Grating, Light Plastic and Macro Plastics. The company now makes a diverse range of plastic products - the flagship Glo-Tub laundry units with both metal and plastic cabinets, Nugleam laundry units with stainless bowls, Everdrain U-channel and grate systems, Everglas sullage/effluent drainage trench, and a range of Stormwater Field Gully pits.

Everhard Industries manufactures a wide range of products for the water and wastewater industry. In particular, the company is a market leader in small systems for wastewater treatment and distributes these products throughout Australia. The company also has an active research program to develop new products and improve product design. The company looked to obtain useful information from a comparative LCA on a selected product range to help not just in assessment of manufacture, but also in subsequent promotion of a product based on the environmental profile of its products.

A major product line is the 3000 L tanks used for on-site domestic wastewater treatment, such as septic or aerobic systems. This line includes tanks made in precast concrete (Figure 1) and a similar plastic range made from polypropylene (Figure 2).

3000 L Concrete Tanks

Figure 1: 3000 L Concrete Tanks

Tanks made from these two materials are likely to have very different environmental burden profiles. As the concrete tank weighs around 2500 kg, and the plastic one 115 kg, they clearly also have significantly different transportation and handling characteristics - factors crucial to the (usually remote) market sector that these tanks serve.

Despite the important environmental role that these tanks fulfill while actually in-use, no study had been undertaken to assess the respective environmental impacts of their manufacturing and distribution.

As explained below, the LCA was undertaken to produce different environmental profiles for these two products, and to identify the environmental impacts where one product is superior to the other. Such information could also form the basis of a marketing strategy through promoting certain environmental benefits of one product over another.

Stacked 3000 L Plastic Tanks

Figure 2: Stacked 3000 L Plastic Tanks


Life Cycle Assessment (LCA) - An Eco-Efficiency Tool

LCA is a tool that has been developed to understand the environmental impacts of a product as it moves along the supply chain - i.e. from 'cradle to grave'. The LCA concept is to develop an environmental impact profile for a product (such as a concrete or polypropylene tank) from its production of inputs through to its manufacturing, distribution, use and disposal. An LCA seeks to quantify the inputs such as energy, land, water, chemicals, etc. to the value chain. Input use is then related to the environmental outputs from the chain (e.g. emissions to air, water and land), and an assessment is made of the whole-of-life environmental performance along the value chain to final use phase. More information about life cycle assessment.

Environmental Life Cycle Assessment in Four Steps


Step One: Goal and Scope Definition

This is a planning step, which involves defining and describing the product, process or activity; detailing the aims and context in which the LCA is to be performed; and identifying the life cycle stages, data to be collected and environmental impact categories to be examined as part of the assessment.

Step Two: Life Cycle Inventory Analysis

This involves identifying and quantifying energy, water, materials and land usage, and the environmental releases data (e.g. air emissions, solid waste, wastewater discharge) during each life cycle stage.

Step Three: Life Cycle Impact Assessment

This step estimates likely human and ecological effects of material consumption and environmental releases identified during the inventory analysis.

Step Four: Life Cycle Evaluation

This step interprets the findings of the two preceding steps in line with the first step. It is aimed at identifying the most significant environmental impact category and the life cycle stage. Life Cycle Interpretation can also be expanded to identify and evaluate eco-efficiency opportunities, so that the LCA becomes helpful in achieving improvements in environmental and economic performance of the product life cycle.

It is also worth noting that the structure of an LCA assessment is governed by a series of international standards - AS/NZS ISO14040, 14041, 14042 and 14043. These standards provide a procedure for conducting LCAs. As the scientific understanding of environmental impacts improves, the standards leave significant degrees of freedom for users to customise the details of the LCA methodology to suit the specific value chain characteristics (i.e. steel versus car versus food production).

Cleaner Production Initiative

Everhard Industries undertook a pilot project in the application of LCA for profiling the comparative environmental burdens of 3000 L concrete and plastic tanks

Information was gathered on the manufacturing operations used to produce the concrete and plastic products. Process trees for the life cycle of the tanks were developed as presented in Figures 3 and 4.

The approach then adopted to carry out the LCA study involved the standard steps:

Life Cycle Tree for a Concrete Tank

Figure 3: Life Cycle Tree for a Concrete Tank

Life Cycle Tree for a Plastic (Polypropylene) Tank

Figure 4: Life Cycle Tree for a Plastic (Polypropylene) Tank


For a comparative LCA, it is essential to establish a basis for comparison in which the end-use performance delivered by both products is the same. In this study, it was required that this comparison be made on the basis of the use of the tanks in a wastewater system used to treat the same quantity of water over a fixed number of years.

Since the polypropylene and concrete tanks when used for this purpose have the same expected lifetime (15 years), the choice of a functional unit for this study was simplified by choosing tanks which have the same holding capacity - hence the chosen product unit of study was a 3000 L tank.

For each product, the system boundary was defined to include the production of raw materials in Australia (BHP EMMA LCA database), the delivery of raw materials to the factory, the manufacture of the tanks, and the delivery of the tanks to customers. The environmental impacts resulting from the operational (in-use) stage of the tanks were not included as it was considered reasonable to assume that these would be identical.

Environmental burdens in terms of resource consumption and emissions for the raw materials used in the production processes were directly obtained from production operations along the supply chain and cross-checked with available LCA databases.

The following environmental impact categories were used to compare the tanks:

Transportation stages involve road and sea delivery of raw materials, and road transport of fabricated tanks to customers. The emission factors for use in the transportation models used for this study were derived from the Australian Greenhouse Office (AGO) workbooks for transport and fuel combustion activities. Additional information was obtained from the Queensland Road Transport Department and the Ship Owners Association of Queensland.

With respect to assessing operations within the company premises, because Everhard produces a range of diverse products, difficulties arise in dealing with the allocation of emissions between the various products. That is, unlike a single product company, it is not possible to allocate factory inputs and outputs to each product from knowledge of total factory consumption of energy and raw materials, as well as the subsequent discharges. The manufacturing processes for both the products chosen for the study therefore had to be broken down into individual manufacturing steps. Then, providing information was available on energy and material usage on the selected per unit of product (3000 L tank) basis, it was possible to directly calculate both resource consumption and emissions for each of the two units.

To enable direct comparison of the environmental life cycle impact of the two products, the impact categories previously defined were determined for the following four key life cycle stages:

  1. Raw material production
  2. Raw material transport
  3. Manufacture of tank
  4. Transport of tanks to customer

Advantages

The environmental burdens for the impact categories were calculated and the results for the four key impact categories are summarised in Table 1 (for an example delivery distance of 250 km). In practice, these tanks are delivered Australia-wide, and as mentioned previously, the key transportation issues are the tank weights and ability to stack them.

Table 1: Comparative environmental burdens of a concrete and polypropylene septic tank
 
Environmental Impacts per 1 Septic Tank of 3000 Litres Holding Capacity
Global Warming 1
Atmospheric Acidification 2
Non-methane VOCs 3
Resource Energy Consumption 4
Concrete
Poly-prop
Concrete
Poly-prop
Concrete
Poly-prop
Concrete
Poly-prop
Raw materials
515
219
1.25
0.935
0.026
8.03
3.65
9.20
Transport - inputs
8
3
0.19
0.096
0.063
0.033
0.112
0.045
Production
14
93
0.08
0.52
0.0003
0.002
0.15
1.00
Transport - product (250 km)
50
10
0.53
0.109
0.116
0.024
0.79
0.16
Total
587
325
2.05
1.66
0.205
8.09
4.7
10.4

1 kg of CO2 equivalents;
2 kg of SO2 equivalents;
3 kg; and
4 Giga Joules

It can be seen that the concrete tank has the lower resource energy consumption, which stems mainly from the large difference in favour of concrete at the raw material stage. Resource energy is the basic fossil fuel energy used in each stage of the life cycle of the tanks, and is inclusive of the energy content of all the feedstock materials used. Since polypropylene is derived from fossil fuels while concrete is not, the resource energy consumption of polypropylene production is much higher than that for concrete.

Currently, 100% virgin plastic is used in manufacture due to concerns over longevity in the field - in particular, with respect to exposure to ultra violet (UV). If, however, research could lead to incorporation of recycled material, then significant inroads may be made into reducing this impact. The feedstock energy in polypropylene could be also recovered by incineration of the plastic tank at the end of its useful life, although gains would be partially offset by a further release of greenhouse gases. It is estimated that the thermal disposal of a polypropylene tank (115 kilograms) after its useful life releases approximately 360 kg of CO2 while the CO2 emissions from the end-of-life disposal for concrete tanks (in terms of crushing and subsequent land filling) are unknown.

The plastic tank appears to be more attractive, however, when the key factor of transportation to customer sites is taken into account. To assess this in more detail, a model was devised to analyse the situation and incorporate the crucial impact of the distance the tank is transported. This model was developed on the assumption that within 50 km of the factory, tanks would be delivered by small and medium sized trucks, and for longer hauls, sets of tanks are delivered on 12 m semi-trailers. Unlike the concrete tanks, plastic tanks can be stacked (typically 4, as shown in Figure 2) and they have a much lower mass (115 kg) compared to the concrete tank (2500 kg). As a consequence, a typical long-distance (> 50 km) trailer load will be 24 plastic tanks for use in septic systems or 12 for use in aerated systems (more complex inner-components), as compared to only 6 concrete tanks. As a result, substantial environmental burden savings in terms of overall life cycle emissions per 3000 L tank were identified for those manufactured in polypropylene.

The results of the model are illustrated in Figure 5 for greenhouse gas emissions generated throughout the life of each 3000 L tank. This environmental burden issue is clearly very much at the forefront of government and public attention, and hence one by which a valid and meaningful comparison can be made. There are also further benefits to be gained at the installation site from the unloading and handling of plastic tanks as compared to concrete tanks. Whilst these benefits were not quantified in Figure 5, for remote and/or offshore regions they are significant (e.g. two operators could handle a plastic tank, whereas a crane is needed for the concrete version).

In addition to significantly better transportation and handling characteristics, the results of the study clearly demonstrated that polypropylene tanks, throughout their lifetime, impose a much lower environmental burden with respect to greenhouse gas emissions - a key high-profile issue for the government and public. The significantly lower impact of polypropylene tanks in this regard arises from two sources: the high emissions of carbon dioxide associated with the manufacture of clinker for concrete, and the higher quantities of fuel on a per unit tank basis used to deliver the end-product to the company's customers.

Impact of Delivery Distance and Tanks per Trailer Load on Greenhouse Gas Emission per Delivered Tank

Figure 5: Impact of Delivery Distance and Tanks per Trailer Load on Greenhouse Gas Emission per Delivered Tank


Benefits

The results from the LCA study helped Everhard Industries to identify the life cycle stages in the supply chain of the tanks and the most significant environmental impacts along the chain. It also highlighted the potential environmental risk issues associated with the end-of-life disposal of tanks and how to manage them by proactive design and delivery in light of anticipated future legislations such as Extended Producer Responsibility (EPR).

As a consequence, the study has highlighted potential promotional opportunities for the polypropylene tanks over the concrete tanks, due to their smaller environmental loads with respect to greenhouse gas emissions generated from transportation and on-site installation.

Barriers

Mostly all the barriers to achieving improvements in environmental performance are institutional by nature. Companies like Everhard Industries are hard pressed to allocate the necessary time, capital, and personnel to undertake environmental research initiatives in the areas of recyclable non-halogenated plastics (e.g. biopolymers) and their applications in the construction industry. The company needs strong environmental R&D support to make real cutting-edge cleaner production gains in areas such as biopolymers and their potential use in construction industry.

Contacts

LCA Project Leader

Dr Jim Ness
Research Fellow
School of Environmental Engineering
Griffith University, Nathan Campus
QLD 4111
Tel: 07-3875 5507
Fax: 07-3875 5288
Email: J.Ness@mailbox.gu.edu.au

Company Contact

Lou Florakx
Chief Executive Officer
Everhard Industries Pty Ltd
405 Newman Road, Geebung QLD 4034
Tel: 07-3637 6444
Fax: 07-3265 2111
Email: lou_florakx@everhard.com.au

Disclaimer

The LCA approach used in this case study is not a comparative assertion LCA performed to establish the environmental superiority of one tank type over the other. The study does not claim to follow the standards and principles set out in the clause 7 of AS/NZS ISO 14040:1997 and AS/NZS ISO 14041:1998 and clause 9 of AS/NZS ISO 14042:1999.