A day in the life of Terry Coates

Terry Coates, Water Operator

Cradle Valley sewage treatment plant.

Cradle Valley sewage treatment plant at the edge of a national park is one of 112 TasWater plants around the state. TasWater deal with 137 million litres of sewage a day and approximately 250,000 litres of this passes through Cradle Valley sewage treatment plant. 

The plant receives sewage from the national park and a few surrounding private properties.


Treatment is carried out via a membrane bioreactor process, which results in high-quality effluent. This enables TasWater to ensure the surrounding environment remains pristine. Membranes were recently replaced to manage existing demand along with four new units to cope with the increased flows during periods of wet weather, while accounting for future growth in development and tourism at Cradle Mountain.   TasWater spends around $675 per-household, per-year on infrastructure to ensure Tasmania can meet its demands now and in the coming decades. 

The Cradle Valley plant is operated by Terry Coates. For the past eight years, Terry has been travelling the one hour journey from his home near Devonport to the Cradle Valley plant.


Terry has routine duties that he must carry out every day. Upon arrival at 7 am, Terry will check all the pumps and alarms followed by a walk around for a visual check. Checks are then carried out on flow meter readings and mixed liquor suspended solid readings (concentration of suspended solids, in an aeration tank during the activated sludge process, which occurs during the treatment of waste water).

Terry will then take daily recordings of temperatures, inlet, flow, ultra violet, chemicals, gas, rain, PH and lagoons levels. Effluent samples are collected, with data recorded on the bottles.

In addition to this, Terry is also responsible for making sure lab instruments are calibrated and the plant site remains safe.

''We have a closed treatment system, so everything happens inside big tanks,” Terry said. “It gets cold up here so this set-up means we can heat the waste to make sure it’s the optimal temperature for the microbes to do their job." While heat is critical for the plant to function properly the temperature can also have an impact on Terry, there has been several occasions where Terry has not been able to drive to the plant due to snow.

Terry ends his day by dropping samples at the Sheffield sewage treatment plant by 3 pm, so couriers can take samples to Selfs Point, in Hobart, for testing.

Although Terry works as a unaccompanied, he does get an occasional visit from the local friendly Wombat.