Wastewater System - Tavistock
The County maintains a diverse portfolio of assets that are required to provide the community of Tavistock with the safe collection and treatment of wastewater. The Tavistock wastewater sewage lagoon provides wastewater treatment for residential, commercial, and industrial users in the Village of Tavistock.
The wastewater collection network transports residential, commercial, and industrial waste to the lagoon for treatment. The wastewater collection network consists of a mix of gravity mains, low pressure mains and forcemains. Wastewater flows by gravity wherever possible, where changing elevations require the use of sewage pumping stations (SPS). Other specialized structures such as manholes, valve vaults, meter stations, diversion structures and siphons are required to convey wastewater to the lagoon.
Inventory
| Asset Component | Unit | Current Inventory | Replacement Cost |
| Sewage Lagoon System | site | 1 | $20,927,574 |
| Sanitary Pumping Station | bldg | 3 | 3,395,293 |
| Other Facilities | bldg | 2 | 71,158 |
| Equipment | total | N/A | 9,027,188 |
| Sanitary Main (﹥=450mm) | metre | 1,409 | 1,817,622 |
| Sanitary Main (﹤450mm) | metre | 23,838 | 16,434,060 |
| Sanitary Service Connection | each | 1,329 | 6,097,452 |
| Total Replacement Cost | $57,770,347 | ||
The replacement cost valuation for the linear assets in this portfolio are based on current tender prices, where available. The replacement cost valuation for wastewater vertical is based on the latest information available, which includes current replacement costs, insurance valuations, inflation, and valuations from studies / assessments completed in prior years.
Condition
The assessment approach for our wastewater assets utilizes a combination of physical assessments, asset attributes, such as material and sizing, as well as established anticipated useful lives.
The percentage of assets in poor or critical condition has increased from 13% as reported in the 2022 AMP to 19%. The percentage of assets in good or excellent condition has increased from 49% as reported in the 2022 AMP to 53%. As assets continue to age their condition rating will decline until lifecycle strategies are triggered and completed.
Key Performance
| Key Service Attribute | LOS Statement | Performance Measure | 2022 | 2023 | Target |
| Reliability | Providing wastewater services with minimal interruptions | % of properties within the system boundary connected to the municipal wastewater system | 99% | 99% | TBD |
| The number of connection-days per year due to wastewater backups compared to the total number of properties connected to the municipal wastewater system. | 0 connection-days to 1,195 connections | 0 connection-days to 1,240 connections | TBD | ||
| Environmental Stewardship | Providing wastewater services that have minimal impacts on the environment | The number of effluent violations per year due to wastewater discharge compared to the total number of properties connected to the municipal wastewater system. | 0 violations to 1,195 connections | 0 violations to 1,240 connections | 0 |
Funding Gap Analysis
This portfolio is currently funded through an annual contribution to the Wastewater - Norwich reserve, by wastewater rates in Norwich, along with an annual allocation of interest earned.
The graph illustrates the anticipated asset management needs (expenditures) and anticipated funding for the 10-year period of 2024-2033, reflecting an approximate $10.6 million surplus in funding availability over the period.
The 2024 long-term capital budget does not reflect the expansion of the Tavistock wastewater treatment system. While additional sources of funding are anticipated towards this project, a funding obligation on the existing system and reserve will remain. As the reserve balance is drawn down, the timing of the expansion project is anticipated to result in the requirement for additional debenture funding.
Although the current investment exceeds the annual requirement, the long-term debenture obligations will likely result in the current investment to remaining in an overall annual surplus position over the 2024 to 2033 period.