We recently published an article in STEP Matters about the sorry tale of construction of the new synthetic playing field at Norman Griffiths Oval in West Pymble. Four months later and nearly a year after the oval was due to be completed by November 2023, the work on the stormwater detention system is still continuing. According to council’s website the completion date is now due to be November 2024.

The original cost estimate was $3.3 million. It is now $5.5 million.

Initial pollution incidents

In April 2024 there was a disruption to the works after heavy rain caused a lake to develop on the site. Bushcarers who have been working along Quarry Creek that leads from the field discovered large quantities of sediment-laden water going down the creek. This has happened numerous times. The process of draining the lake must not impact this creek that leads to Lane Cove National Park.

After this flooding was reported to the Environment Protection Authority (EPA) the EPA made several inspections. They noted three pollution incidents:

• 6 to 8 April – the north-east wall of the sediment basin had collapsed and damaged a pipe which resulted in an uncontrolled discharge of sediment laden water into Quarry Creek
• 13 to 15 April – discharge of sediment-laden water from a stormwater outlet on the oval site into Quarry Creek
• around 19 April – as a result of sediment-laden water being leaked, spilled, otherwise escaped or deposited from the oval into water of Quarry Creek, signs of impact were observed in waters of Quarry Creek including the presence of algae and suspended solids for over 200 metres

Council subsequently advised the EPA that the damaged pipe was plugged and a faulty joint in a stormwater pipe had been identified and repaired where sediment laden water had been seeping into Quarry Creek.

Nevertheless, the evidence of pollution led the EPA to issue a clean-up notice on 26 April to repair pollution as defined under the Protection of the Environment Operations Act 1997.

The clean-up notice required council:

• to repair the collapsed sediment dam wall, repair the damaged section of pipe leading from the dam to the stormwater system and reinstate the holding capacity of the sediment dam;
• to assess the condition and operational status of all stormwater pipes running underneath or above at the premises to prevent any further sediment-laden water from entering the stormwater system from the premises;
• to arrange for the sediment-laden water at the premises to be lawfully disposed of and/or discharged in an appropriate fashion that does not result in further environmental harm;
• to remove the build-up of any sediment originating from the premises in Quarry Creek as well as algae and suspended solids in waters of Quarry Creek for at least but not limited to 200 m from the stormwater outlet.

Council was also required to engage an independent and suitably qualified person to review all sediment and erosion controls and identify any existing controls which are in a poor condition or ineffective. This entailed a detailed ‘Sediment and Erosion Control Plan’ for the site. Also, Council was required to engage a consultant to conduct a comprehensive inspection and assessment of the drainage systems beneath the Oval.

The project has been delayed because of the need to construct an extra retaining wall at the north-eastern corner, pump out the accumulated muddy water into trucks and repair the damaged pipes.

But the pollution has continued

Despite all these actions, in June and August there have been more incidents of sediment flowing down Quarry Creek. Some of these incidents have coincided with a rainfall event, but not all.

There is still a significant build-up of sediment along the creek even as far as Lane Cove National Park below Yanko Road. A relatively clean creek with clear water flowing over bedrock now has many pockets of sand and gravel sediment. The clean-up action has not been completed.

Council has acknowledged that the overflows at Norman Griffiths have been ongoing, and it has been working closely with contractors to address them. They advised that a significant issue, which was not immediately apparent, involved turbid water releases linked to the underground infrastructure. Action has now been taken to make the site more resilient, and the contractors are fully aware of their water management responsibilities. Council staff have said they will continue to monitor the creek, and operations staff will maintain the temporary sediment control measures until the oval works are complete.

The EPA is still considering all these incidents and may take further action.

Insights from the court case

In Issue 222 of STEP Matters we describe the case taken to the Land and Environment Court by NGANG (Natural Grass at Norman Griffiths, a group of local residents) for a judicial review of the decision to proceed with the project. The evidence presented during the case revealed shortcomings in the review of environmental factors (REF); that is the report that details the project and explains how the risks during construction and operation of the field will be managed. In this case the REF used assessments undertaken by council and the contractor.

The contractor chose to embark upon construction relying on two REF appendices that were for the installation of ‘a synthetic surface’. They were in no way based on the final design of the field as they were completed almost a decade ago – a geotechnical report (Appendix 6) and supplementary contamination investigation report (Appendix 5). Both reports highlighted the need for further investigation of the unconsolidated fill and asbestos risk. In fact, asbestos has been found during construction and buried onsite so that additional costs have been incurred.

The on-site water detention system is a major part of the project. The previous field area has acted as a stormwater detention system and there were pipes under the field taking water from the upper part of Quarry Creek across to the outlet near the swimming pool. The synthetic turf is not absorbent so the surface rainwater and water running onto the field from the surrounding slopes has to be controlled as well as Quarry Creek water from across Lofberg Road. A new system has had to be designed to allow the water to flow slowly through detention tanks and gravel beds under the surface. The large cost of this system was the reason the original plan to put synthetic turf on the oval was rejected back in 2017.

Given the shortcomings of the REF, the issues with the project were foreseeable and should have been carefully investigated before construction began. Further, the REF’s so-called ‘construction environmental management plan’ that is meant to protect the environment from harm, has already failed on more than one occasion and led to impacts on Quarry Creek, an EPA notice, and further delays.

Following the case, council has had to redesign the field and put in further mitigation measures against microplastic movement.

A clearly inadequate REF has already had major implications for ratepayers - not just adding approximately $1 million to the project that ratepayers have borne - but directly causing substantial delays to the project.

The contract stipulates an ‘external, independent review of the proposed design’ should be undertaken. Has this occurred?

Updated flood study still required

The community’s concern is that ratepayers will continue to pay the price for the REF’s inadequacies. This includes serious issues, some of which were highlighted during the court case:

• a lack of flood study modelled on the current design;
• the lack of examination of the impacts of a probable maximum flood as a result of this development as required under 171A of the Planning Act and its possible catastrophic environmental consequences.

There is also an unacceptable fire report which claims synthetic (plastic) fields are flame resistant.

A flood study on the current design is important for two reasons.

• Firstly, because previous comprehensive flood studies of a proposed synthetic field showed damage to Quarry Creek and led to the project being initially rejected in 2017.
• Secondly, control measures are in place for expected rain events, but uncontrolled flooding could lead to tonnes of plastic blades fragments and cork sludge escaping from the field and polluting Quarry Creek. The synthetic turf has plastic blades that are highly buoyant and can break off as the field is played on. Cork will be used as infill to hold up the plastic grass blades to simulate natural grass. While cork is preferable to rubber tyre crumb infill (which is now banned in many countries because of toxic chemical runoff) the stability of cork infill is not proven in heavy rainfall events as has been demonstrated by the cork sludge runoff from ELS Hall field in North Ryde.

It could be that the area is never under threat from a bushfire or fire on the field, but the REF’s bushfire report is not only factually inaccurate but also completely at odds with the Chief Scientist who recommended these fields should not be placed in fire prone (or flood prone) areas. This recommendation occurred before council's decision to go ahead was made.

Questions and actions for the new council

As noted above, we would like the new council to ask questions about why ratepayers are paying for variations for the contractor hitting unconsolidated fill and asbestos given the contractor chose to rely on these completely inadequate studies to tender for the project.

We would like the new council to follow up on ecologist Roger Lembit's report that noted threats to the Sydney Turpentine Ironbark Forest and the orchids (some classified as endangered) around the oval due to changes to hydrology caused by the construction.

Also unknown is the whereabouts of the vulnerable microbats which were mapped at the oval, as well as the Powerful Owl which roosted in the forest above it. There was also no examination on the impact of the multiple high fences around the field given the area is a wildlife corridor.

We remain unconvinced that plastic blades and cork infill will be kept out of Quarry Creek in extreme rainfall conditions, and we will be watching this very closely. The Chief Scientist recommended that pollutant testing be carried out near synthetic fields. Council has now set up a microplastic monitoring process after intensive lobbying from the bushcare group.

The clean-up of the sediment build up needs to be completed. Council also needs to undertake the flood study of Quarry Creek to ensure is not further damaged by erosion and scouring from excess water coming off the synthetic field. Previous council flood studies clearly highlighted the risk of damage to Quarry Creek, where there is a beautifully regenerated bushcare site. We will be asking council to make any flood studies public and outline how Quarry Creek will be monitored and protected. It is not clear whether the Lane Cove Northern catchments flood study that commenced in 2022 has been completed.

It is a great shame that the local community had to raise money to get the council to assess the field adequately – it is the local community that have somewhat abated a complete flood/pollution disaster at that field. Expert witness reports by Dr Daniel Martens (flood expert) and Roger Lembit (ecologist) warning of issues were sent to council staff and councillors and the court case was only initiated when they were completely ignored. Even after the NPWS called for more time to further assess the REF, the majority of councillors rejected a motion by Councillor Kay that a consultation on the REF should be examined further. Some councillors even tried to pass a motion that NGANG should be made to pay council’s costs for the case. Sadly the experts’ concerns have proven to be justified.

Proper consultation is essential for these expensive projects

This project is a prime example of the need for councillors to take notice of expert advice and carry out transparent consultation. This can provide great insights into the impacts, good and bad of a project.

Currently the legislation does not require a council to carry out detailed consultation or an environmental impact assessment (more rigorous than a REF) on a project like Norman Griffiths Oval as it is deemed to be general maintenance. There were numerous submissions to the draft Guidelines on the Use of Synthetic Turf calling for this to be remedied.

Image: Muddy water in Quarry Creek near Yanko Road (30 June 2024)