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Delta Electricity operates four power station sites in NSW: Mt Piper and Wallerawang located west of Sydney near Lithgow, and Vales Point and Munmorah located north of Sydney on the Central Coast. Whilst the operating principles and processes involved in the production of electricity are similar for these power station sites their geographic locations are different and the influence on the surrounding environment may differ.
Delta Electricity’s management structure and systems have been developed to manage these site specific or regional environmental issues in relation to emissions to air, land and water, resource utilisation, social and economic environment, and community expectations. Scientific investigations and measures to understand or mitigate impacts on the environment are mainly the responsibility of the Western and Central Coast business units. However, environmental issues concerning the whole of Delta’s operations including inter regional air pollutant transportation is the responsibility of the Corporate Strategy group.
The following sections relating to water, air and land have been structured to provide information on a regional basis. For more information about Delta’s environmental performance in regard to air, land and water refer to the Environmental Reports section of this site.
Water
Fresh water is an essential resource for the generation of electricity. It is used for the production of high purity steam, condensate cooling, supply of domestic water and miscellaneous operations including dust suppression.
Delta’s management of fresh water supplies is unique for each power station site with the usage depending upon the power stations locality and it’s operational requirements. Fresh water usage requirements of coastal power stations are much less than for inland power stations.
Located on the NSW Central Coast, Munmorah and Vales Point Power Stations, draw water for condensate cooling from estuarine lakes. Munmorah Power Station draws saline cooling water from Lake Munmorah, whilst Vales Point Power Station draws its saline cooling water from Chain Valley Bay on Lake Macquarie. Both Central Coast power stations utilise less than 1,000 million litres of fresh water per annum for their operations.
Wallerawang and Mt Piper Power Stations are located inland approximately 170 kilometres west of Sydney. Water is extracted for condensate cooling from fresh water sources including the Coxs River and Fish River. The annual usage of fresh water for both Wallerawang and Mt Piper Power Stations is in the order of 22,000 million litres.
To ensure the continuity of this water supply for the Western power stations a number of fresh water reservoirs have been constructed including Lake Wallace, Lake Lyell and Thompsons Creek Dam.
Delta Electricity extracts water from Coxs River at Lake Lyell under conditions outlined in a Water Licence, which establishes the conditions for water releases from Lake Lyell which ensure the on-going environmental health of Coxs River.
Water Discharges
The management of process water discharges from Delta Electricity’s four power station sites varies depending on the original plant design and installation of containment systems.
Operating licence conditions specified by the NSW Environment Protection Authority for each site reflects these differences.
Mt Piper Power Station built in the early 1990s was designed to achieve zero discharge of process water. All process waters from this site including cooling tower blowdown, plant wash down, water treatment plant effluent and sewage are recycled and reused by the power station.
Wallerawang Power Station built between 1974 and 1981 was not designed as a zero discharge site, but since its construction it has undergone a number of modifications to process water containment systems. These include a redirection of station drains, installation of new oil and grit trap facility and settling ponds. At present Wallerawang Power Station has five licence discharge points for cooling tower blowdown, oil and grit facility overflow and ash dam discharges to the Coxs River.
Vales Point Power Station built in the late 1970s was not designed as a zero discharge site, but has during its years of operation undergone a number of modifications to process water containment systems. These modifications include stormwater diversion from the coal stockpile and ash dam, redirection of station drains, installation of settling ponds and upgrades to oil and grit trap facility. At present Vales Point Power Station has two licence discharge points for ash water discharges to Lake Macquarie.
Munmorah Power Station built in 1967 was not designed as a zero discharge site. It too has, since its construction, had a number of alterations to its process water drainage and containment systems. These alterations include the separation of station and stormwater drains, installation of oil and grit facilities and settling ponds, and diversion of stormwater from the coal stockpile. At present Munmorah Power Station has one licence discharge point to Lake Budgewoi.
Air
As part of the operating licence conditions both Source Monitoring and Community Air Monitoring are required at each of Delta’s four power stations. The difference between these two licence requirements is that Source Monitoring is a measure of power station stack gas emissions at the point of discharge and includes measurement of the following pollutants:
- Oxides of Nitrogen (NOx)
- Sulfur Dioxide (SO2)
- Particulate Emissions
- Total Fluoride
Community Air Monitoring is a measure of the air quality at a determined distance away from the power stations and includes the following:
- Oxides of Nitrogen (NOx)
- Sulfur Dioxide (SO2)
- Dust Deposition
- Total Fluoride
Delta Electricity operates four ambient air monitoring stations in NSW: two on the Central Coast at Wyee and Munmorah and two in the Western region at Blackmans Flat and Wallerawang. These monitoring stations continuously monitor the ambient air quality of both regions providing data to compare against appropriate National and State health standards. Results for oxides of nitrogen and sulfur dioxide as measured at our ambient monitoring stations against the National Environment Protection Council standards are shown in the following graphs.
For more information about Delta’s environmental performance in regard to atmospheric emissions refer to the Environmental Reports section of this site.
Land
Delta Electricity owns approximately 6,000 hectares of land for power generation activities. Delta Production Central Coast manages approximately 2,500 hectares of land located within the Lake Macquarie and Wyong local government areas. Delta Production Western manages approximately 3,500 hectares of land located within the City of Greater Lithgow local government area. Whilst a third of this land is utilised for Delta’s power station activities the remaining land either forms a buffer zone around each site to minimise impacts to surrounding landowners or is land surrounding fresh water reservoirs.
The management of landholdings for both the Central Coast and Western regions is unique owing to their geographic locations. On the Central Coast the bulk of land surrounding Munmorah and Vales Point Power Stations comprise of native plant species including flora listed under the Threatened Species Conservation Act 1995.
Land surrounding Mt Piper and Wallerawang Power Station, Thompsons Creek Dam and Lyell Dam comprises both native plant species and areas of radiata pine. Management of these land holdings and the development of strategies to maintain or improve their integrity are the responsibility of the regions. Strategies developed at both regions to address land management issues include:
- Erosion and sediment control
- Noxious plant and animal control
- Bushfire planning
- Habitat restoration
- Revegetation programs
- Protection and enhancement of biodiversity
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