Perry Lakes Business Plan.pdf
Perry Lakes Aquifer Replenishment Project
Council decided not to progress to the construction phase of the Perry Lakes Aquifer Replenishment Project and will return the unused portion of Federal Government grant funding.
Groundwater levels have gradually decreased as a result of drier winters and groundwater extraction used for irrigation. As the water table has decreased, Perry Lakes dried and the availability of water for irrigation greatly reduced.
Cambridge previously considered a CSIRO developed proposal to raise water levels by injecting treated wastewater into the aquifer. With 22 billion litres of treated wastewater discharged from the Subiaco Wastewater Treatment Plant each year into the ocean, approximately 1.8 billion litres could be diverted to the Perry Lakes' aquifer; this could have replenished the water table thereby restoring lake water levels.
The Town was successful in seeking a Federal Government grant of $2.6 million to undertake construction. Since 2010, specialist consultants have engaged in:
- refining concept designs and reviewing similar projects;
- settling on detailed designs for the project;
- addressing issues regarding treatment and impacts of treated waste water; and
- undertaking risk assessments to meet regulatory requirements.
Letters of support from the Water Corporation and Department of Water were received and all parties were comfortable in proceeding to detailed investigation and design phase.
It became apparent to Council in mid 2011 a significantly higher ongoing cost was required to operate the system along with the possibility of further unforseen risks.
Council determined in August 2011 that it wouldn't take on the ongoing long-term operational and risk impacts and would cancel the project.
The following key matters influenced Council's decision.
The preferred design was assessed against the risk frameworks set out by regulatory agencies. It was determined by groundwater modelling that there was a likelihood of treated waste water mixing with groundwater. Over time a small proportion of this treated waste water would permeate into the lakes' water.
Technical advisors proposed cost effective solutions to mitigate risks; however the regulators were in favour of a more expensive alternative to further filter and treat the water. This had significant capital and operating cost implications beyond the project's funding.
The state regulators gave conditional approval to proceed to the construction phase but were quite clear Cambridge would take on all risks. Council generally felt this left them largely exposed.
This project was promoted as a partnership between Cambridge, the Water Corporation and the Department of Water using the CSIRO's expertise. It was anticipated once funding was cleared, State Government departments would enter into cost negotiations. The benefits of the project extend beyond Cambridge and provide a benchmark that other projects in WA could follow.
Partnership funding would see financial support for two to three years to partially cover operating costs. From there, Cambridge was faced with at least $250,000 every year in ongoing expenses to maintain water in the Lakes - an impost Council couldn't accept. The Town would also be faced with potential costs for any corrective actions required by Regulators without consideration of the impacts of these decisions.
The Water Corporation is the lead agency in WA responsible for provision and disposal of water. Their corporate goal is the environmentally-conscious disposal of waste water with an objective to reuse it in the short-term. This project was seen as one way in which the Water Corporation would achieve its own objectives - however there was no ongoing commitment provided.
Council has decided to not proceed with the project for the following reasons:
the Town wasn't able to establish a reasonable partnership arrangement with Water Corporation and the State Government where risks were shared;
the cost sharing arrangement for the life of the project wasn't equitable;
The health and environmental risks have unquantifiable potential costs holding Cambridge responsible for any corrective action;
It isn't local government's role to take the lead in innovative water research projects that have broader benefits and expose the Town's ratepayers to unquantifiable costs; and
The State Government and Water Corporation have a responsibility to dispose of wastewater in a more environmentally sensitive manner rather than discharging it into the ocean.
Last Updated: 15/03/2013