Progress Report

Status update #7 - 18 September 2020

After several weeks of sludge removal works, 1,200 dry tonne of sludge has now been moved from the lagoon and into the custom built sludge drying pan next to the facility. This completes the sludge removal stage of the project and the focus will now shift onto the remaining repair works on the HRAL.

Replacement of the 1000m long concrete edge beam has also been completed, with works to construct an outlet weir to begin soon, which will take 3-4 weeks. The water level is currently being lowered to allow these works to take place. Initially this stage was intended to be done by bypassing the lagoon using existing pipes, however given some recent odour impacts we have now altered the plan in an attempt to reduce odour from the site. 

The new cover materials have arrived on site and the works barge to enable installation of the cover was assembled on the lagoon last week. Installation over the reaction zone is due to begin in the week of 28th September - this stage of the works should be completed in November, and at that point the installation of the remaining cover sections will begin.

Regarding odour, the misting sprays continue to operate but as we have seen the misting has not addressed this issue effectively in all cases. An odour consultant has visited the site and we are awaiting further advice on what further actions may be available to mitigate odour.

Thanks again to customers and residents for their patience as these works continue, we do appreciate your understanding while we undertake these critical works.

 

Status update #6 - 4 September 2020

Continuing works while the cover is removed (see update below) and weather conditions means odour is continuing to persist and has lingered in some areas of northern Shepparton overnight. We're really sorry for the impact. This odour should dissipate as the temperature rises.

Northerly winds are predicted over coming days, which means odour may be intermittently experienced again. Generally, odour will dissipate in the mornings as the temperature rises or with a wind change away from the north. Odour minimising systems are in place to help throughout the project - we appreciate your patience while we carry out these critical works.

Status update #5 - 3 September 2020

Works to desludge the High Rate Anaerobic Lagoon (HRAL) are continuing, and odour has become more evident again today for residents in some parts of North Shepparton.

The project to replace the cover is several months in, and will continue until March 2021. The cover was removed at the end of July and GVW is taking the opportunity to remove 1000 tonnes of sludge and scum out of the lagoon before installing the replacement.

The scum and sludge from the base of the lagoon is mixed using an excavator and is then pumped to a sludge drying pan using a large pump, which is expected to take around four weeks to complete.

Once the scum and sludge is removed a works platform will be assembled on the lagoon to allow the new cover installation to commence, which should begin by the end of October.

GVW will continue to investigate the source of any feedback to our call centre on odour so please feel free to provide accurate, factual information to GVW's service desk that may alert staff to an issue. 

Again we apologise if these works are having an impact on the community, progress to replace the HRAL cover is on schedule and so it is hoped that as the project nears completion the impacts will be minimised. Thank you to our customers and residents in the impact zone of the project for their patience and understanding.

 

Status update #4 - 19 August 2020

We are now eight weeks into our significant Wastewater Management Facility upgrade project, to replace the cover of the High Rate Anaerobic Lagoon (HRAL).

Some residents in north Shepparton have fed back to GVW that they are experiencing intermittent odour in their residential area.  

We value the feedback on this, odour complaints from the public are an essential part of GVW's maintenance program. As we are unable to have staff at all sites at all times, we do rely on accurate and timely complaints. These are then further investigated by trained staff, to assist us in managing our extensive sewerage network and associated infrastructure, including wastewater management facilities, and to assist us to understand the source.

There are a number of facilities in the area that at times are the source of a range of odour issues.

It is most likely that any odour impacts are increased by the weather conditions and we continue to log feedback received on this. In most cases we expect the impacts to come and go, they tend to come in bursts due to the way we expect odour to behave in various weather conditions.

We are sorry for any impacts of GVW's works on the community, we are working to complete these works as quickly as possible but we are only part way through and there is still some time before the cover will be back on the HRAL. We again thank customers and residents for their patience regarding this project.

 

Status update #3 - 07 August 2020

The HRAL cover has now been off for two weeks, and the surface of the lagoon has been entirely exposed during this time.

Our customers and the local residents have been very patient, we thank them for their understanding regarding the odour impacts and the construction work at the site. These impacts are lower than we had anticipated so far, likely due to the very cold conditions, so for now we are pleased that the impact of odour on surrounding areas has been minimal. This may continue, or could change as the weather warms up, and if so we will respond to customer queries on this accordingly.

Since the last update, investigations on the sludge have shown that over 1000 tonnes of sludge is lining the lagoon and requires removal. Works have commenced to prepare an area for sludge drying in a GVW paddock adjacent to the lagoon. Removal of this sludge and scum from the lagoon to enable the construction of the new cover will commence within the next two weeks, and the removal is expected to take at least five weeks.

It is not expected that construction timelines will be impacted by any restrictions but if this changes we will advise.

 

Status update #2 - 24 July 2020

We are almost four weeks into the HRAL cover removal project. The entire cover has been removed from the HRAL lagoon, and desludging of the lagoon will now be required before work can begin on the structure itself.

The picture below shows the lagoon and the amount of thick sludge that was beneath the cover. Sludge, or biosolids, is the accumulation of solid waste that bacteria produce when they break down wastewater. These solids settle to the bottom of the lagoons and form a sludge deposit, and it slowly builds up over time.

A sample of this is being laboratory tested and results will determine next steps. There is more than expected there and this may impact timelines down the track - at this stage we are working to schedule but due to the volumes of sludge there may be more work required here than first planned.

In the meantime scope of works are being finalised for repairing the 150m long edge beam of the lagoon.

The sludge build up is significant and next steps are being considered

 

Status update #1 - 10 July 2020

Two weeks into the HRAL cover removal project, works are progressing at the expected rate.

Half the cover over the settling section of the lagoon has now been removed, which equates to around a quarter of the entire cover. It is a slow process as the cover material is very weak, as can be seen in the video footage further below.

The cover is cut into strips by two people out on the water in an inflatable boat, and the strips are then removed using a small excavator.

As the strips are removed the material is washed with a high pressure hose to remove the muck including sewage, sludge and scum. The material is then loaded into a skip bin using the excavator.

Some sections of the cover are now submerged. These sections have to have the water pumped off before the cover can be removed, as being submerged tends to make these sections messier and require more cleaning. Whilst we apologise to our customers for any odours spare a thought for these people! They are expert at what they do but the work would seem a little 'on the nose' to most.

The cover is cut into strips which are removed using a small excavator

 

About 25% of the cover has been removed so far

 

Facility overview and project summary

Wastewater management in Shepparton

Goulburn Valley Water (GVW) is a regional urban water corporation and provides urban water and wastewater services to residences and businesses in over 50 towns in the northern Victorian area. The largest of these serviced towns is Shepparton, with others including Seymour, Kilmore, Mansfield and Cobram, and their surrounding regions.

Wastewater (from household drains, showers and toilets etc, or industrial customers) from Shepparton is then sent to the Wastewater Management Facility (WMF) situated 8.5km north from the city centre, off Barmah-Shepparton Rd. The wastewater received by the plant is a combination of both domestic and industrial output, with over 80% of the average daily inflow produced by food processing centres such as SPC Ardmona and Campbell’s Soup.

The Shepparton Wastewater Management Facility is located 8.5km north of the city centre - photo dated 2011

Wastewater treatment processes used
This unique make up of high industrial contribution results in an inflow equivalent to that of a population of 1.1 million, and to cater for this the Shepparton WMF is home to a particular style of wastewater treatment basin known as a High Rate Anaerobic Lagoon (HRAL). Shepparton’s HRAL - the first of 17 lagoons in the  wastewater treatment process - is nearly 50,000m2 in size and is covered by a large 1.14mm thick flexible geosynthetic cover, which is in place to promote ideal anaerobic conditions.

The cover also allows GVW to control odour, and enable the collection and storage of methane gas, which is either burnt off or sold to a third party and used to generate electricity. To put this in perspective, the Western Treatment Plant in Werribee also uses a covered anaerobic lagoon process to cater for the large inflow received from over 1.6 million residential and business customers in Melbourne’s central, northern and western suburbs.

HRAL cover damage
The cover has to contend with repeated pressurisation/depressurisation, UV radiation, high temperatures, contact with byproducts of the treated waste and attack from wildlife such as corellas. A severe wind storm in 2015 also contributed to the development of a large, 200m tear in the cover, which is visible from Google Earth. These issues have contributed to the steady decline of the cover over recent years and it is now at the end of its service life.

Planned works
GVW has been planning a necessary upgrade to the cover on the Shepparton HRAL. Many stopgap repairs have taken place over recent years but GVW has now scheduled a $10.4m project to fully replace the cover to take place during 2020/21. Replacement of the cover will occur over a nine-month period, with the first stage being to remove the old cover which is attached to a concrete edge beam. The new cover will be 2mm-thick High Density Polyethylene (HDPE), which is regarded as one of the most robust materials in the industry for this particular use. GVW has engaged a specialist contractor experienced in the design and construction of lagoon covers.

Customer impacts - short vs. long term
Over the duration of the works there is expected to be an increase in odour in the area, which will vary in its degree and frequency and will be difficult to predict. These impacts will depend on weather conditions, wind strength/direction, inflow concentration due to industry processing schedules, and distance from the site, among other factors. The works may also impact customers and visitors to parts of Shepparton over this time, and result in a small increase in work traffic on Barmah-Shepparton Rd.

The new cover has been designed to accommodate fluctuations in pressure and ensure optimal anaerobic conditions for an expected life span of 20 years.

Mitigation efforts
We will do everything we can to minimise any impacts on residents and businesses in surrounding areas:
• cover removal timing to coincide with cooler weather and lower industrial flows
• odour modelling to predict the extent and magnitude of the odours
• ongoing odour monitoring during the works to assess what is actually happening
• an odour misting system will be employed onsite and used as required to reduce the extent and magnitude of the odours
• ongoing communications with residents and businesses to address concerns or issues

Other maintenance
While the cover is removed, further maintenance works will take place. Desludging is a common sewerage maintenance process that takes place approximately every 25 years, and involves removal of solids and debris from the bottom of the lagoon.

These biosolids are then stockpiled and left to dry out for 6-12 months, and then used onsite as soil conditioner. Installation of extended biogas collection pipework will also take place. These works, among
other maintenance jobs, will be undertaken during this time.

Project time frames
Works will begin in June, 2020 and could take up to nine months. Following early site preparation works in June, the entire cover will be removed and then the new cover over the high activity reaction zone area of the HRAL will be installed. This is expected to be completed in November 2020, and then the new cover will be installed over the settling zone section.

The entire project is expected to be complete in March 2021, but timeframes may change as a result of any weather impacts on the schedule.

There are no health risks associated with any noticeable increase in odour, and GVW is working with the Environment Protection Authority to ensure appropriate protections are in place.

GVW thanks residents, businesses and visitors to the impacted vicinity in advance for their patience and cooperation. Efforts will be made to complete the works as quickly as possible to ensure the odour effects will not persist for any longer than necessary while these critical repairs are carried out.

Want to stay in the loop on this project?
If you would like updates on this project, please let us know your email address and mobile phone number by emailing communications@gvwater.vic.gov.au with ‘HRAL project’ in the subject line.
 

The tear in the cover is significant, measuring over 200m in length - photo dated 2020

 

​The works to replace the damaged cover will soon be underway - photo dated 2020

 

Culturally and Linguistically Diverse (CALD) resource available

It is estimated that over 15% of GVW’s customers living in the vicinity of this project speak a language at home other than English – Shepparton has a highly culturally diverse population . If someone you know needs help to understand the purpose and the impacts of this work then please share this video with them.

Summary of HRAL Cover Removal resources available for download

  • The fact sheet is available as a PDF here (804kb).
  • The video showing the Shepparton WMF including cover damage is available here.
  • The CALD video resource explaining the project is available here.