...

- Convert this annual mass (kg) to a volume (m
^{3}) using the following density for wet (drained) gross pollutants: 260 kg/m^{3}(Alison Allison et al., 1998).

- Scale up the volume of trapped gross pollutants per annum to an estimated volume of trapped gross pollutants and coarse sediment per annum using the following relationship:
**Total volume of trapped gross pollutants and coarse sediment (m**^{3}/year) = volume of trapped gross pollutants (m^{3}**/year)•1.4**. This allows for the volume typically occupied by trapped coarse sediment (i.e. typically ~29% by volume) and was derived from a NSW data set involving 12 different sites, each hosting the same brand of proprietary in-ground GPT.

...

###### Table 1. Summary of cost-related relationships for ‘generic’ GPTs.

Element of Life Cycle Costing Model | Default Option for Estimation in music | Alternative(s) | Notes | ||
---|---|---|---|---|---|

Life cycle | 63 years. n = 2 | No alternative in music. | Upper and lower estimates derived using a 84th and 16th percentile, respectively. | ||

Total acquisition cost (TAC) | TAC ($2004) = 22460 x (VU)0.4702
Where: VU = total volume of all stormwater and trapped pollutants in the unit when it is operating at its peak design flow (m3). | TAC ($2004) = 31430 x (
Where: For literature values, see Taylor (2005b) - Included in Appendix H: Costing information.* |
The alternative algorithm has been derived from a combined data set involving in-ground proprietary GPTs and open GPTs with no unusual cost elements. Upper and lower estimates derived using a 68% (or 1 standard deviation) prediction interval for the regression. If users want to manually enter their own TAC value in music but only have a total construction cost estimate, they can use the following approximate relationships that have been derived from the CRCCH’s data set for all types of GPTs: Total construction cost ≈ 94% of TAC. | ||

Typical annual maintenance (TAM) cost | TAM ($2004) = 698.3 x (V)0.7766
Where: | See Table 1 for alternatives. For literature values, see Taylor (2005b).* | Upper and lower estimates derived using a 68% (or 1 standard deviation) prediction interval for the regression. Currently music estimates | ||

Annualised renewal / adaptation cost (RC) | RC ($2004) = 0.70% of TAC p.a.
| No alternative size / cost relationships in music. For literature values, see Taylor (2005b). |
Upper and lower estimates derived using a 68% confidence interval around the mean. | ||

Renewal period | 1 year | No alternative in music. | Default position due to lack of high quality data supporting an alternative period. | ||

Decommissioning cost (DC) | DC ($2004) = 23% of TAC
| No alternative size / cost relationships in music. |
| ||

General caveats / notes for this type of device | * There are several estimates of capital and maintenance costs reported in the literature for open GPTs (see Taylor, 2005b or Appendix H: Costing information for a summary). |

###### Table 2. Summary of cost-relationed relationships for open GPTs (ie. sediment basins with trash racks)

Element of Life Cycle Costing Model | Default Option for estimation in MUSIC | Alternative(s) | Notes | ||
---|---|---|---|---|---|

Life cycle | 63 years.
| No alternative in MUSIC | Upper and lower estimates derived using a 84th and 16th percentile, respectively. | ||

Total acquisition cost (TAC) | TAC ($2004) = 22460•(VU)
p < 0.01; n = 72.Where: VU = total volume of all stormwater and trapped pollutants in the unit when it is operating at its peak design flow (m | TAC ($2004) = 22460•(VU)
p < 0.01; n = 121.Where: C = area of the GPT’s catchment in ha. For literature values, see Taylor (2005b) – Included in Appendix H: Costing information |
The alternative algorithm has been derived from a combined data set involving in-ground proprietary GPTs and open GPTs with no unusual cost elements. Upper and lower estimates derived using a 68% (or 1 standard deviation) prediction interval for the regression. If users want to manually enter their own TAC value in music but only have a total construction cost estimate, they can use the following approximate relationships that have been derived from the CRCCH’s data set for all types of GPTs: Total construction cost ≈ 94% of TAC. | ||

Typical annual maintenance (TAM) cost | TAM ($2004) = 698.3•(VU)
p < 0.01; n = 57.Where: V = average annual volume of removed trapped material (i.e. gross pollutants, coarse sediment and TSS) in m | See Table 1 for alternatives. For literature values, see Taylor (2005b).* |

Annualised renewal / adaptation cost (RC) | RC ($2004) = 0.70% of TAC p.a.
| No alternative size / cost relationships in MUSIC. For literature values, see Taylor (2005b). |
Upper and lower estimates derived using a 68% confidence interval around the mean. | ||

Renewal period | 1 year | No alternative in MUSIC | Default position due to lack of high quality data supporting an alternative period. | ||

Decommissioning cost (DC) | DC ($2004) = 23% of TAC
| No alternative size / cost relationships in MUSIC. |
| ||

General caveats / notes for this type of device | *There are several estimates of capital and maintenance costs reported in the literature for open GPTs (see Taylor, 2005b or Appendix H: Costing information for a summary). |

###### Table 3. Summary of cost-related relationships for in-ground GPTs.

Element of Life Cycle Costing Model | Default Option for Estimation in music | Alternative(s) | Notes |
---|---|---|---|

Life cycle | 50 years.
| No alternative in music. | Upper and lower estimates derived using a 84th and 16th percentile, respectively. |

Total acquisition cost (TAC) | TAC ($2004) = 22460 x (VU)0.4702
Where: VU = total volume of all stormwater and trapped pollutants in the unit when it is operating at its peak design flow (m3). | TAC ($2004) = 31430 x (C)0.3971
Where: For literature values, see Taylor (2005b) - Included in Appendix H: Costing information.* | The default algorithm has been derived from data involving in-ground, proprietary GPTs with no unusual cost elements. The alternative algorithm has been derived from a combined data set involving in-ground proprietary GPTs and open GPTs with no unusual cost elements. If users want to manually enter their own TAC value but only have a total construction cost estimate, they can use the following approximate relationships that have been derived from the CRCCH’s data set for all types of GPTs: Total construction cost ≈ 94% of TAC. |

Typical annual maintenance (TAM) cost | TAM ($2004) = 1202 x (C)0.3130
Where: | See Table 1 for alternatives. For literature values, see Taylor (2005b).* | |

Annualised renewal / adaptation cost (RC) | RC ($2004) = 0.54% of TAC p.a.
| No alternative size / cost relationships in music. For literature values, see Taylor (2005b).* | Upper and lower estimates derived using a 68% confidence interval around the mean. |

Renewal period | 1 year | No alternative in music. | Default position due to lack of high quality data supporting an alternative period. |

Decommissioning cost (DC) | DC ($2004) = 20% of TAC
| No alternative size / cost relationships in music. | Upper and lower estimates derived using a 68% confidence interval around the mean. |

General caveats / notes for this type of device | * There are several estimates of capital and maintenance costs reported in the literature for in-ground GPTs (see Taylor, 2005b or Appendix H: Costing information for a summary). Quotes on ‘supply and install costs’ (the main component of total acquisition costs) can also be readily obtained from suppliers of GPTs with propriety designs. |

###### Table 4. Summary of cost-related relationship for trash racks and litter baskets.

Element of Life Cycle Costing Model | Default Option for Estimation in music | Alternative(s) | Notes |
---|---|---|---|

Life cycle | 25 years.
| No alternative in music. | Upper and lower estimates derived using a 68% confidence interval around the mean. |

Total acquisition cost (TAC) | TAC ($2004) = 22460 x (VU)0.4702
Where: VU = total volume of all stormwater and trapped pollutants in the unit when it is operating at its peak design flow (m3). | TAC ($2004) = 31430 x (C)0.3971
Where: For literature values, see Taylor (2005b) - Included in Appendix H.* | Warning: The default algorithm has been derived from data involving in-ground, proprietary GPTs with no unusual cost elements. If users want to manually enter their own TAC values but only have a total construction cost estimate, they can use the following approximate relationships that have been derived from the CRCCH’s data set for all types of GPTs: Total construction cost ≈ 94% of TAC. |

Typical annual maintenance (TAM) cost | TAM ($2004) = 421.7 x (V)0.6890
Where: V = average annual volume of removed trapped material (i.e. gross pollutants, coarse sediment and TSS) in m3. | See Table 1 for alternatives. For literature values, see Taylor (2005b).* | Currently music estimates V using the combined estimated volume of gross pollutants, coarse sediment and TSS that are trapped in the GPT per year. To adjust this manually (i.e. to include only one or two of these three elements), use the procedure provided in the tip box within Life-Cycle Costing - Ponds and Sedimentation Basins. |

Annualised renewal / adaptation cost (RC) | RC ($2004) = 0.85% of TAC p.a.
| No alternative size / cost relationships in music. For literature values, see Taylor (2005b). | Upper and lower estimates derived using a 68% confidence interval around the mean. |

Renewal period | 1 year | No alternative in music. | Default position due to lack of high quality data supporting an alternative period. |

Decommissioning cost (DC) | DC ($2004) = 7.3% of TAC
| No alternative size / cost relationships in music. | Upper and lower estimates derived using a 68% confidence interval around the mean. |

General caveats / notes for this type of device | * There are some estimates of capital and maintenance costs reported in the literature for trash racks and litter baskets (see Taylor, 2005b or Appendix H: Costing information for a summary). |

###### Table 5. Summary of cost-related relationships for release of net GPTs.

Element of Life Cycle Costing Model | Default Option for Estimation in music | Alternative(s) | Notes | ||
---|---|---|---|---|---|

Life cycle | 10 years.
| No alternative in music. | Upper and lower estimates derived using a 68% confidence interval around the mean. | ||

Total acquisition cost (TAC) | TAC ($2004) = 22460 x (VU)0.4702
| TAC ($2004) = 31430 x (C)0.3971
Where: | Warning: The default algorithm has been derived from data involving in-ground, proprietary GPTs with no unusual cost elements. | ||

Typical annual maintenance (TAM) cost | TAM ($2004) = 652.6 x (V)0.4920
Where: V = average annual volume of removed trapped material (i.e. gross pollutants, coarse sediment and TSS) in m3. | See Table 1 for alternatives. | Currently music estimates V using the combined estimated volume of gross pollutants, coarse sediment and TSS that are trapped in the GPT per year. To adjust this manually (i.e. to include only one or two of these three elements), use the procedure provided in the tip box within Ponds and Sedimentation Basins (Costing). | ||

Annualised renewal / adaptation cost (RC) | RC ($2004) = 31% of TAC p.a.
| No alternative size / cost relationships in music. | Upper and lower estimates derived using an 84th and 16th percentile, respectively. | ||

Renewal period | 1 year | No alternative in music. | Default position due to lack of high quality data supporting an alternative period. | ||

Decommissioning cost (DC) | DC ($2004) = 4.3% of TAC
| No alternative size / cost relationships in music. |
| ||

General caveats / notes for this type of device | Quotes on ‘supply and install costs’ (the main component of total acquisition costs) can also be readily obtained from suppliers of GPTs with propriety designs. |

###### Table 6. Summary of cost-related relationships for side entry pit trap GPTs.

Element of Life Cycle Costing Model | Default Option for Estimation in music | Alternative(s) | Notes | ||

Life cycle | 5 years.
| No alternative in music. | Upper and lower estimates derived using a 84th and 16th percentile, respectively. | ||

Total acquisition cost (TAC) | TAC ($2004) = 22460 x (VU)0.4702
| TAC ($2004) = 31430 x (C)0.3971
Where: C = area of the GPT’s catchment in ha. For literature values, see Taylor (2005b) - Included in Appendix H: Costing information.* |
| ||

Typical annual maintenance (TAM) cost | TAM ($2004) = 292.2 x (V)0.7353
| See Table 1 for alternatives. For literature values, see Taylor (2005b).* | Currently music estimates V using the combined estimated volume of gross pollutants, coarse sediment and TSS that are trapped in the GPT per year. To adjust this manually (i.e. to include only one or two of these three elements), use the procedure provided in the tip box within Ponds and Sedimentation Basins (Costing). | ||

Annualised renewal / adaptation cost (RC) | RC ($2004) = 0.70% of TAC p.a.
| No alternative size / cost relationships in music. For literature values, see Taylor (2005b). |
Upper and lower estimates derived using a 68% confidence interval around the mean. | ||

Renewal period | 1 year | No alternative in music. | Default position due to lack of high quality data supporting an alternative. | ||

Decommissioning cost (DC) | DC ($2004) = 16% of TAC
| No alternative size / cost relationships in music. |
Upper and lower estimates derived using a 68% confidence interval around the mean. | ||

General caveats / notes for this type of device | * There are some estimates of capital and maintenance costs reported in the literature for side entry pit traps (see Taylor, 2005b or Appendix H: Costing information for a summary). Quotes on ‘supply and install costs’ (the main component of total acquisition costs) can also be readily obtained from suppliers of GPTs with propriety designs. |