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

Much of the material listed on these archived web pages has been superseded, or served a particular purpose at a particular time. It may contain references to activities or policies that have no current application. Many archived documents may link to web pages that have moved or no longer exist, or may refer to other documents that are no longer available.

Hobart City Council: Taking a holistic approach towards decreasing greenhouse emissions and recycling waste

Utilising Cleaner Production tools has helped the Hobart City Council (HCC) meet many of its Greenhouse Gas Emission reduction targets and address the overall environmental performance of its operations. The 2001 - 2002 Taste of Tasmania saw nearly eighty percent of all waste generated from the event recovered for recycling or composting through good housekeeping, reuse and recycling techniques. The reduction in environmental impact and the bottom line benefit was clearly demonstrated from reducing waste disposal costs through less waste going to landfill burial. By recently completing milestone 4 of their Cities for Climate ProtectionTM program, the Council has also started to implement its Local Action Plan with outstanding results. New strategies have included the capture of methane gas in local wastewater treatment plants (which is reducing energy intensity), using resources more efficiently, and decreasing greenhouse emissions that contributed significantly to odour problems in the vicinity of the plants. These programs are part of a holistic strategy undertaken by the HCC to address the environmental impact of many of its operations.

Background

The HCC is the local government authority for the City of Hobart, which is the capital city of Tasmania located on the Derwent River estuary in the south of the island.

The greater Hobart area, which includes four other local government areas, is the 10th largest urban centre in Australia and has approximately 1.1% of the Australian population. The population of the greater Hobart area is 189,944 representing 41% of the state's population. The HCC has a municipality of approximately 47,600 people, with a growth rate of around 0.04% per annum.

The HCC employs around 650 personnel within seven divisions with a total annual budget of approximately $70M.

HCC strategic directives for 2001 - 2005 include the creation of a liveable city, the management of the environment, the protection of its heritage, growth of the economy, providing a gateway to Tasmania, and the sustainable management of its resources.

The Eco-efficiency and Cleaner Production initiatives follow on from a number of programs developed by HCC over the past few years. As with other local councils, various international treaties and local government activism have encouraged the formulation of national policies and new legislation.

The HCC joined the Cities for Climate ProtectionTM (CCPTM ) program in 1999. Being a signatory to the CCPTM has served as a catalyst to develop clearer objectives and goals, which are carried out with well-defined milestones. Eco-efficiency and Cleaner Production concepts have assisted in the implementation of programs to meet set objectives.

The HCC undertook an inventory of its corporate emissions as part of the Milestone One requirement of the CCPTM program. The base year of 1996 was used as the benchmark against which the Council would reduce its greenhouse emissions by 2010. Emissions in the 1996 financial year were calculated at 12,815 tonnes of CO2 equivalent and are expected to increase by approximately 5% in the forecast year 2010/11. The emissions inventory was undertaken according to the requirements of the CCPTM software. The software divides corporate emissions into six categories:

  1. Council Buildings
  2. Council Vehicle and Fleet
  3. Street Lighting - Emissions from this sector account for emissions resulting from the energy use of street lighting, including Aurora street lighting and Council decorative lighting *
  4. Water Used on Council Owned Property
  5. Waste (Organic Waste Breakdown)
  6. Other - Emissions (Sewage Treatment)

Corporate greenhouse emissions for the Hobart City Council relating to Vehicle, Waste and Other (Sewage Treatment Plants) (see Graph 1) are the only sectors recording greenhouse gas emissions against them due to the exclusive use of greenhouse neutral hydro-electricity in the other sectors. The graph below is based on the CCPTM software package and is specific to Tasmania.

Corporate Greenhouse Gas Emissions eCO2 tonnes and Energy (GJ)

Graph 1: Corporate Greenhouse Gas Emissions eCO2 tonnes & Energy (GJ)

"Other Emissions: Sewage Treatment Plant" accounts for nearly three-quarters (72.9%) of the total emissions from the corporate sector. The waste and vehicle sectors respectively account for the balance of emissions.

The City of Hobart has recently completed Milestone 4 (M4) of the CCPTM program, which is the implementation of the Local Action Plan.

To achieve M4, it is necessary for a participating Council to demonstrate:

The Council has previously achieved the first three program milestones. Most notably the Council set the highest Corporate Emission Reduction Goal (70% corporate reduction goal) for Milestone 3 of any participating Australian Council.

After completion of M4 the Council will then be required to monitor and report on its achievements.

It is within this context that the Eco-efficiency and Cleaner Production initiatives arose, resulting in the development of the reuse and recycling strategies adopted and implemented at the HCC Taste of Tasmania event, and the methane gas emission reduction programs at the Council' wastewater treatment plants.

The Process


The Taste of Tasmania

The Taste of Tasmania evolved out of a desire to hold a festival incorporating fine food and wine that coincided with the New Year period and the conclusion of the Sydney to Hobart Yacht Race. The event is housed in a portside warehouse, known as the Princess Number 1 Wharf, that is converted each year to cater for over fifty stalls offering a wide range of cuisine and wines specialising in Tasmanian products and produce.

In the initial Tastes, all material cleared from tables including disposable cutlery and crockery was treated as refuse, placed in bins, emptied into trucks and taken to the landfill to be buried. Subsequent events became a little more sophisticated with recycling bins introduced for beverage containers; however, levels of contamination remained high with quantities to landfill not being reduced.

The event runs for a little over a week, usually receives around 200,000 visitors, and generates large quantities of liquid and solid wastes. The management of liquid waste has been improved with the installation of a number of portable grease arrestor units in the "temporary" plumbing system set up for kitchen and food preparation cleaning and washing.

The continuous clearing of tables and disposal of the waste material in the bins provided is normally undertaken by "Clean Teams" made up of non-profit organisations that utilise volunteer members to undertake the work for an established fee. Occupational health and safety of the volunteers associated with the Clean Teams undertaking the waste collection activity was considered paramount.

The challenge was to develop a system/process that would overcome these issues and produce an event where waste management was consistent with the clean, green image of Tasmania.

Wastewater Treatment Plants

The HCC operates two wastewater treatment plants at Selfs Point at the northern boundary of the city and at Macquarie Point, which lays within the port area and in close proximity to a number of commercial transport related operations. Sewage generated from Hobart's municipal area is treated to secondary level at the Macquarie Point Wastewater Treatment Plant and to nutrient removal standard at the Selfs Point plant.

The Macquarie Point plant was upgraded to secondary treatment standard in the late 1980s, whereas the Self Point plant was recently upgraded to nutrient removal standard in the late 1990s. The management of methane gas generation within the anaerobic digestion activities has been an ongoing issue at both plants. The process of anaerobic digestion of the solids taken from the sewerage stream generates a gas mixture with high levels of methane (up to 80%). The gas mixtures are odorous and their escape into the atmosphere in large quantities can create serious odour nuisances adjacent to the plants.

All digestion processes involve keeping the sludges warm at a temperature of around 35-38 degrees Centigrade. The sludges are heated and maintained at this temperature through a system of heat exchangers and boilers that normally involve burning the methane generated within the digestion process.

The quantities of methane generated invariably are significantly greater than the demand for boiler fuel for the heating of the digester sludges. The problem of surplus methane production and odour nuisance complaints was particularly acute at the Macquarie Point plant due to its close proximity to the port.

In addition, the issue of greenhouse gases and the environmental consequence of uncontrolled releases of these gases had become a political and an environmental concern to the community and the Council.

To assist in dealing with these issues the HCC has conducted an ongoing campaign to address Greenhouse Gas emissions and undertaken a number of programs, including targeting energy efficiency, changing to cleaner fuels for energy usage, undertaking waste minimisation strategies to decrease waste to landfill, reusing methane from landfill and addressing transportation. These and other strategies have provided cost effective and positive actions that have reduced energy use intensity and greenhouse gas emissions.

Cleaner Production Initiative


Taste of Tasmania

As part of a HCC directive to have a positive effect on the health and wellbeing of the communities it represents, the 2001 - 2002 Taste of Tasmania saw nearly eighty percent of all waste generated from the event recovered for recycling or composting.

Environmental initiatives unique to the Taste of Tasmania have been the installation of three 1000 litre grease traps to treat the greasy waste generated from cooking at the event, thereby preventing sewer blockages and litter entering the Derwent River. Daily stormwater pit pump outs of all the pits in the proximity of the Taste of Tasmania prevented spills. A used cooking oil drop-off and collection service at the event for stallholders was also provided. The used cooking oil will be used for a variety of alternative uses, including cosmetics, livestock food pellets and now biodiesel; an alternative and environmentally friendly fuel source for vehicles.

In terms of the management of solid waste at the Taste of Tasmania, environmental initiatives introduced include:

The improved recovery results were attributable to a number of factors, including the introduction of cardboard recycling for stallholder packaging, Waste Smart Training Sessions for stallholders to reduce waste and pollution at the event, contributions from the volunteer Clean Team in sorting and separating appropriate waste/recyclables and compostables, as well as patrons at the event using the recycling and compostable disposal facilities provided.

The table below provides a breakdown of waste recovery, recycling and composting for the 2001 - 2002 Taste of Tasmania. Figures are compared with last year's event.

Waste Category
2001-2002 Taste
2000 - 2001 Taste
Increase/decrease
Refuse (Non-recoverable)
17.92 tonnes
19.88 tonnes
-1.96 tonnes
Glass
44.88 tonnes
36.75 tonnes
+8.13 tonnes
Compostables
8.7 tonnes
7.56 tonnes
+1.14 tonnes
Cardboard
6 tonnes
0 tonnes
+6 tonnes
Used Cooking Oil
1.18 tonnes
1.1 tonnes
+0.08 tonnes
Total Waste
78.68 tonnes
65.29 tonnes
+13.39 tonnes
Total Amount Recovered
60.76 tonnes
45.41 tonnes
+15.35 tonnes

Approximately 79 tonnes of waste had been collected during the eight days that the 2001 - 2002 Taste of Tasmania were held (17 percent increase in waste generation rates, compared with last years event total of 65.29 tonnes). Of this amount 60.76 tonnes (77%) of waste was recovered for recycling/composting. For 2000-2001 Taste of Tasmania only 45.41 tonnes (69%) of waste was recovered.

Wastewater Treatment Plants

HCC has used Cleaner Production and Eco-Efficiency tools to enhance materials recycling and reduce the energy intensity of wastewater treatment plant operations. This has taken place through a plant upgrade and the installation of the Cogeneration Units.

After some earlier trials using a number of small second hand cogeneration units at the Macquarie Point plant, the decision was taken to install one larger unit that was capable of using up all the available methane fuel.

A single 140 kW unit is to be installed at an estimated total cost of $270,000. Net operational savings of approximately $75,000 are anticipated - made up from reduced power consumption ($50,000) and sale of Renewable Energy Certificates ($25,000). Thus a four to five year payback on investment is expected.

As part of its CCPTM Local Action Plan, HCC resolved to curb the significant emissions arising from sewage treatment plants by:

Advantages


Taste of Tasmania

The net effect of all the environmental initiatives at the Taste of Tasmania include reduced volumes of waste going to McRobies Gully Landfill (helping to extend the life of the site), waste material being reused or recycled on a large scale, saving resources and the use of virgin product, preventing blockages and improving performance of the sewer system, and reducing discharges to the Derwent River.

Wastewater Treatment Plants

During various works to upgrade the sewage treatment plants, in the period 1996 to 2000, Council installed cogeneration units at both the treatment plants. The cogeneration units enable an increase in the combustion capacity of methane produced by the digesters. Further, the heat removal system of boilers and heat exchanges combusts the balance of methane, not utilised through cogeneration or required to heat sludge, with the heat wasted to atmosphere rather than uncombusted methane.

Graph 4 indicates the amount of methane captured following the installation of cogeneration infrastructure. Council achieved cost savings of around $20,000 per annum at Self Point and $40,000 per annum at Macquarie Point following the installation of cogeneration.

STP Methane Capture

Graph 4: STP Methane Capture

The installation of the cogeneration resulted in major savings in Council's overall corporate greenhouse gas emissions and achieved significant financial benefits.

Incentives


Taste of Tasmania

As one of the premier food and wine festival events in Tasmania, the Taste of Tasmania presented an opportunity to display best practice environmental management in dealing with liquid and solid wastes generated at the event.

The challenge was to minimise the amount of solid waste going to landfill and increase the level of recycling and value adding through composting of the organic material including compostable cutlery and crockery.

It needs to be appreciated that the Taste of Tasmania has developed over a number of years with improvements, changes and a heightened profile occurring with each new event.

Wastewater Treatment Plants

The key drivers for the change to more environmentally efficient performance can be summarised as follows:

Economic - the deregulation of the electricity industry has allowed the flexibility for cogeneration to be utilised to reduce power usage. The power costs saved through cogeneration can provide a pay back of the investment in around five to seven years.

Regulatory - the release of methane and associated digester gases to the atmosphere created nuisance odour problems for occupiers of premises in the vicinity of the plants, particularly the Macquarie Point plant. The measures implemented to resolve the odour issues were undertaken in cooperation with the Regulator.

Environmental - the uncontrolled release of greenhouse gases into the atmosphere was unsustainable, and joining the CCPTM presented a further incentive to participate in a greenhouse reduction program.

Barriers

The significant barriers generally related to budgeting and provision of the necessary finance in an environment of competing interests for limited funding.

As far as the cogeneration project was concerned, the technology was known, available and accepted by plant operators.

Again with the Taste of Tasmania, the main hurdle was including the new innovations within the context of a limited budget. Associated with this was a level of reluctance on the part of some officers involved with the development of the event. However, these concerns were ameliorated through the benefits and improved environmental outcomes the initiatives produced.

Further Developments


Taste of Tasmania

The HCC have been pleased with the 80% waste recovery results, which are inline with the goal of 100% future recovery of all food and beverage packaging generated from the event. These results have enable the HCC to promote the Taste of Tasmania as both the State's premier Food and Wine Festival and the most environmentally friendly.

Future Taste of Tasmania initiatives include a waste packaging covenant (to help reduce the amount of packaging at the event), trialling different stormwater litter traps near the Prince Wharf Shed, and a litter education campaign at the event targeting problem litter items such as cigarette butts.

Wastewater Treatment Plants

HCC has reduced its greenhouse gas emissions from sewage treatment plants through the installation of cogeneration units. Whilst this has resulted in a significant reduction in Council's corporate greenhouse gas emissions, further reductions are possible through the pursuit of the following opportunities:

Contacts

Mr. Mike Street
Group Manager Hydraulics and Waste Engineering
Hobart City Council
GPO Box 503 Hobart 7001
Telephone: 03 6238 2829
Fax: 03 6234 9757
Email: streetm@mailnet.hcc.tas.gov.au
Website: http://www.hcc.tas.gov.au

Implementation Date: 2001 to 2003
Case developed by the Centre of Excellence in Cleaner Production (Curtin University of Technology)
Last modified: March 2003