4C) Improved environmental and community recreation outcomes in riparian zones - through environmental offsets projects

About this project

In response to wastewater treatment capacity constraints, we have developed an Environmental Offsets Project that involves low energy treatment upgrades and in-stream catchment and riparian improvements, rather than relying upon traditional engineering responses.
This involves upgrading an existing lagoon-based treatment system with low energy treatment technologies – such as efficient aeration, rock filters, treatment wetlands, nutrient removal and disinfection – to improve the final water quality prior to discharging it to a creek, and then implementing offsets within the catchment, such as fencing of stock from waterways, riparian zone improvement or erosion rehabilitation, to improve stream health.

Actions to date

Construction upgrades at the Kilmore Wastewater Management Facility (WMF) to improve final water quality are now complete and signed off by the EPA, including upgraded aeration, nutrient removal processes, polishing wetlands and disinfection systems. We received an amended EPA licence in June 2020 for discharges and completed the first, small discharge in August. As flows at the WMF increase, we’ve continued licence compliant discharges to the waterway via the treatment wetland.
Based on catchment modelling, we set a target to remove 945kg of phosphorus from Kilmore and Kurkurac creeks catchments by 2025 via environmental catchment offsets. We have nine landowner agreements in place that are modelled to remove 1026kg of phosphorus - more than our target.
On-ground works (such as re-vegetation, creek fencing, weed management and gully erosion works) are complete. Annual inspections for all landholders continue, with all meeting their agreement expectations; while supplementary planting and weed management continues as needed or based on inspections. Participating landholders are passionate about the project, and many have asked if they can help by carrying out some of the maintenance work themselves at no cost to GVW - like weed management labour, brushcutting, revegetation labour and provision of some materials.

What's next?

The project has transitioned into a business-as-usual phase, where we complete ongoing annual landholder inspections and carry out weed management and supplementary planting as needed. We’ll continue to discharge to the waterway under our licence agreement, with discharges expected to become more frequent/increasing in volume based on increasing inflows to the WMF. We’ll continue frequent water quality monitoring as part of assessment on waterway impacts and licence compliance.
After an extensive investigation process for environmental offsets at Mansfield, we found a similar implementation would not be feasible due to site constraints. We’re currently developing plans for new winter storage lagoons, which will create the best outcomes for community, environment and our customers to meet the growing needs of the Mansfield region.

Our accountability for this project

If GVW is not successful in implementing EOPs we will face possible sanctions from the EPA, and will then have to make compensating expenditures (possibly by traditional means) to rectify the situation. This provides incentive for us to deliver these projects and outcomes.

For this information in PDF form, click here to download the factsheet (PDF: 151KB)