The EPA has undertaken its review of Snowy Hydro Limited’s Annual Compliance Report (the report), in accordance with the Act and the approved Environmental Management Plan. In carrying out its review of the report, the EPA consulted with the Department of Climate Change, Energy, the Environment and Water (DCCEEW). The EPA also consulted with the National Parks and Wildlife Service (NPWS) in respect to cloud seeding operations that took place within Kosciuszko National Park.
Findings
The review of the 2023 Annual Compliance report found that:
- Snowy Hydro Limited has complied with all of its obligations as outlined in the Act. Snowy Hydro Limited complied with all its obligations within the Environmental Management Plan.
- There were no accidents or breakdowns to report that resulted in spillage of cloud seeding agents or fuel, or failure of controls specified in the Environmental Management Plan.
- Monitoring was carried out in accordance with the Environmental Management Plan.
- Analysis of the monitoring data did not detect any evidence of significant adverse environmental impacts associated with cloud seeding activities.
- Cloud seeding is not having a measurable effect on the concentrations of silver in various parts of the environment.
- There were no new operations involving land-based methods of discharge of seeding or tracing agent within any area of land managed under the National Parks and Wildlife Act 1974.
- Minor modifications were made to equipment at three existing cloud seeding weather station sites to install new meteorological instrumentation following the 5-yearly review of the EMP.
Discussion
During 2023 cloud seeding operations, Snowy Hydro Limited dispersed approximately 13.8 kilograms of the approved seeding agent, silver iodide, into suitable storm systems. Weather conditions suitable for seeding in the Snowy Mountains during the 2023 period resulted in 36 hours and 16 minutes of cloud seeding events, and a decrease of 20 hours and 44 minutes on the previous year. Consequently, this resulted in a decrease of silver iodine being used, with 5.3 kilograms less than in the previous year.
During the 2023 cloud seeding season, there were no new operations involving land-based methods of discharge of seeding or tracing agent within any area of land. SHL advised that with the exception of a fuel leak, no accidents or breakdowns resulting in spillage of cloud seeding agents occurred.
The Environmental Management Plan includes an adaptive environmental monitoring program where the future program is informed by the results of the previous environmental monitoring. Based on the analysis of samples collected from 2004 to 2019, the Environmental Management Plan’s prescribed five-year interval between environmental monitoring programs was found to be appropriate.
Given this, during the 2023 season, all matrices were sampled as required by the Environmental Management Plan. The Annual Compliance Report indicated that most 2023 samples were similar to those from previous years.
Four of the samples taken as part of the 2023 sampling program exceeded the GTV of 1 mg/kg. Snowy Hydro have committed to resampling these locations as part of the 2024 cloud seeding season to determine the potential cause of higher silver concentrations as these sites. It is suspected that the cause of these exceedances is in response to the 2019/2020 bushfires as these samples were taken in fire affected locations.
However, silver concentrations have increased from previous years but remain several orders of magnitude below relevant guideline values. Analysis of silver concentrations from samples collected through the environmental monitoring program prior to the commencement of cloud seeding in 2004 through to 2023 showed no evidence that cloud seeding has contributed to increased levels of silver in any area or in any environmental matrix monitored.
Macroinvertebrate sampling took place during the 2023 cloud seeding season in accordance with the EMP. Analyses of data collected following the 2018 and 2023 season has shown no evidence of any difference over time in the impairment of the macroinvertebrate assemblages.
Internal audits of cloud seeding sites were undertaken by Snowy Hydro personnel with NPWS, although no site visits were undertaken by NPWS in the 2023 reporting period. NPWS requested that SHL continue its site inspection and auditing process and requested reports of any significant issues or change
Snowy Hydro Limited reported that there was no new infrastructure established or decommissioned during the reporting period, however minor modifications were made to existing infrastructure to install new meteorological instrumentation. No accidents or breakdowns were reported that resulted in spillage of cloud seeding agents or fuel, or failure of any of the controls specified in the Environmental Management Plan.
No current or emerging issues were formally raised by stakeholders for the 2023 cloud seeding season, mechanisms within the Environmental Management Plan allow relevant agencies of the Minister for the Environment to request consideration by Snowy Hydro Limited of emerging environmental issues between each five-yearly review.
Conclusions and recommendations
After reviewing the Snowy Hydro Limited 2023 Annual Compliance Report and Snowy Hydro Limited on-ground operations, the EPA concludes that:
- Snowy Hydro Limited has complied with all obligations as detailed in the Act.
- Snowy Hydro Limited has complied with all obligations as detailed in the Environmental Management Plan for cloud seeding operations approved by the relevant Ministers in July 2023.
- Snowy Hydro Limited has complied with all obligations as detailed in the Protection of the Environment Operations Act 1997.
- Analysis of sampling across all matrices carried out during the 2023 cloud seeding season showed silver concentrations remain several orders of magnitude below relevant guideline values.
It is recommended that:
- Monitoring should be continued as per the schedule of the EMP, and data compared over time to identify trends.
- Future reviews are also undertaken in consultation with input from partner agencies of the NPWS and DCCEEW.
- Snowy Hydro Limited continues to pursue research opportunities on the cloud seeding operations in the Snowy Mountains.
- The outcomes of this review are communicated to the relevant Ministers.