TasWater’s $1 billion investment in sewerage

Before complaining about our rising TasWater bills, it’s worth considering the work that is being done to improve Tasmania’s water quality

TasWater is undertaking a massive program of works, started by its predecessors, to upgrade drinking water and sewerage treatment infrastructure across the state. This promises to have very significant benefits for its customers and the natural environment.

TasWater commenced operation on 1 July 2013 as the statewide provider of water and sewerage services, replacing three regional water and sewerage authorities. It is responsible for collection, storage, reticulation and treatment of sewage and collection, storage, treatment and reticulation and supply of water. This corporation is owned by the local governments of Tasmania. Some operations are regulated by state government and some by the local government itself. The Office of the Economic Regulator reviews TasWater’s overall performance, in particular because it has a complete monopoly on provision of these services.

TasWater provides water services to 201,800 properties and sewerage services to 179,100 properties – including the majority of businessand industry users. Many residences are not serviced by TasWater so acquire their own drinking water and manage their own sewage. As of 2014 TasWater’s total net assets value is in excess of $2 billion. These assets include:

  •  6,380km of water mains
  • 60 drinking water treatment plants or dosing stations
  • 121 water supply dams
  • 716 pump stations
  • 4774km of sewerage mains
  • 31 level 1 sewage treatment plants
  • 79 level 2 sewage treatment plants

Level 2 Waste Water Treatment Plants (WWTPs), or sewage treatment plants, generally have a design capacity of at least 100 kilolitres (1000 litres) of average dry-weather flow per day of sewage or waste water, with level 1 WWTPs being less that 100 kilolitres per day. Level 2 WWTPs are regulated by the EPA and local government is responsible for regulating Level 1.

TasWater will be investing more than $1 billion over the next 10 years in upgrading its infrastructure, most directed into upgrading WWTPs. In the 2014–15 financial year, TasWater’s capital works budget is $110 million, with nearly two-thirds being spent on sewerage infrastructure. This program will have enormous benefits to the natural environment as well as reducing odour problems, but there is no simple statistic to sum up these beneficial outcomes.

Over the past few years TasWater, and the regional authorities before it, focused on upgrading drinking water infrastructure and by next year it will be close to supplying all customers with water that they can drink. WWTPs will increasingly become the focus of TasWater’s infrastructure investment.

While WWTPs appear to be performing adequately against the licensed emission standards, many operate under old licences.

The state government’s economic regulator stated in its most recent review, ‘Tasmanian Water and Sewerage State of the Industry Report 2012–3’, that, while level 2 WWTPs were achieving high levels of compliance, this is because most operate under very old licences; when compared to modern emission standards – as is becoming normal for mainland plants – only seven WWTPs achieved high compliance.

The Economic Regulator concluded that ‘Compliance achieved by Tasmanian water corporations in relation to emission limits specified for Level 2 WWTPs was poor compared to similar sized utilities on the mainland’.

The economic regulator notes that ‘The environmental impact of waste water on the state’s rivers and coastal waters continues to be of concern with effluent containing significant organics loads, elevated nutrients and faecal bacteria concentrations discharged to the environment.’

TasWater ais working with the Environment Protection Authority (EPA) and CSIRO to fine-tune emission standards to ensure that treatment-plant effluent standards are set to a level that is actually safe for the local receiving environment. This is ground breaking not just because many of Tasmania’s WWTPs are old and ineffective but because in the past standards were set for the general type of receiving environment, i.e. river, enclosed wetland river or coastal waters, with little understanding of the differences between sites.

Concerns also relate to complaints about odours emitted from WWTPs and the EPA is developing a framework for ambient monitoring around each treatment plant.

Over time the EPA will also be setting new and higher emission standards. Most of these are linked to infrastructure upgrade, which means they cannot be immediately implemented.

Some WWTPs have been operating well above their volumetric capacity and this is one area where there has been good progress. Outstanding examples include the Queenstown WWTP which operated in 2012–13 at more than 400%of its licensed capacity, Sheffield operated at 244%, Margate at 283% and Burnie/Ridgley at 244%.

Some examples of TasWater projects currently under way give a vivid picture of just how inadequate many WWTPs are and the past failure of local councils to properly plan for these most essential of services.

The Taroona WWTP did not meet modern treatment standards and it was decided that it was preferable to close it rather than fix the problems, and to build a pipeline to take the waste water to Selfs Point at a cost of $5.2 million. Planning is under way to decommission Electrona and Margate WWTPs with the waste being sent to an upgraded Blackmans Bay plant.

Upgrades to Ti-Tree bend WWTP in Launceston, to address odour problems, will cost $1.1 million this year.

Many rural communities are the beneficiary of these investments:

-          $3.8 will be spent in Deloraine to upgrade and improve its WWTPs capacity and performance

-          $7.1 million for a totally new WWTP at Roseberry

-          $2.8 million to upgrade the WWTP at Cradle Valley

-          $5.5 million on a new scheme to reuse effluent from the Bridport WWTP.

Launceston has a sewerage and storm water system designed in the late 19th century which regularly results in sewage spilling into the storm water and vice versa. Planning for a Greater Launceston Sewerage Strategy to reduce impacts on the Tamar Estuary is progressing and the options currently being assessed. They are costed at between $200 and $250 million and may take 10 years to implement. 

Although WWTPs in the Hobart area do not seem to face the same challenges, all those plants that emit into the River Derwent will be assessed together, prior to upgrades to plants.

Peter McGlone