Romsey water quality report
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This report gives you information and updates about water quality sampling and testing at Romsey Recycled Water Plant and nearby waterways.
Update - July 2026
On 20 July 2026, Greater Western Water (GWW) began a controlled emergency release of Class B recycled water into Deep Creek from the Romsey Recycled Water Plant.
This carefully managed, last-resort measure is necessary to maintain safe storage levels at the plant and ensure the continued delivery of essential wastewater services to the community.
Read our full statement at Controlled release of recycled water from Romsey plant.
What we test for
We test four main water quality parameters that are established indicators for protecting the environment and human health:
- pH – This is a scale of acidity from 0 to 14. It tells us how acidic or alkaline the water is. More acidic water will have lower pH, while more alkaline solutions have higher pH. Neutral solutions (that aren't acidic or alkaline) usually have a pH of 7.
- Suspended solids - Small solid particles that remain in suspension in water. This is an indicator of water quality. The more solids in the water, the less clear the water will be.
- E. coli - E. coli are common bacteria, normally found in the gut of warm-blooded animals. There are many types of E. coli bacteria, most of which are harmless. However, some types of E. coli produce toxins (poisons) that can cause gastroenteritis (gastro). Read more at betterhealth.vic.gov.au.
- Biological oxygen demand (BOD) - BOD measures the amount of dissolved oxygen used by aerobic microorganisms to break down organic material present in water. It directly affects the amount of dissolved oxygen in rivers and streams. The higher the BOD, the more rapidly oxygen is depleted in the stream, which means there is less oxygen available to aquatic life.
How to read our water quality testing report
The table below shows the quality of recycled water released from Romsey Recycled Water Plant (sampling point 4 on the map below), as assessed by the independent laboratory. We will publish the results as they become available.
2026 testing results
| Date of release | 16-21 July | 24 July |
|---|---|---|
| Test | Results | Results |
| pH Levels are between 6 - 9 |
Pass (Class B) | Pass (Class B) |
| Suspended solids Levels are under 30 mg/L |
Pass (Class B) | Pass (Class B) |
| E. coli Levels are under 100 org per 100ml |
Pass (Class B) | Pass (Class B) |
| Biological Oxygen Demand Levels are under 20 mg/L |
Pass (Class B) | Result pending |
Green = Pass Class B
Results meet or exceed EPA guidelines for Class B recycled water.
Orange = does not meet Class B (E. coli) guidelines
Results do not meet Class B guidelines for E. coli. If E. coli results exceed 100 org/100ml on two consecutive occasions, we will stop releasing the water and take additional measures to improve water quality. This is a higher standard than previously required by the EPA and demonstrates our commitment to protecting Deep Creek and the community.
Red = Fail Class B
Results do not meet Class B guidelines. GWW will pause the release and take additional measures to improve water quality.
Sometimes sampling point results may be impacted by other water or substances entering Deep Creek outside GWW’s control. For example, during heavy rainfall, stormwater from the stormwater drain upstream of the Romsey release point (sampling point 4) may enter the waterway.
Water quality test results
Recycled water release volumes
The Romsey Deep Creek sampling locations
Previous testing results
Expand all
Update - 27 October 2023
The release of recycled water from the Romsey Recycled Water Plant (RWP) into Deep Creek has ended.
This controlled release was a last resort decision which has allowed us to maintain a safe storage level at the plant during the wetter months, and ensured that the risk of harm to human health and the environment were minimised as far as reasonably practicable. With warmer days forecast and the farmland surrounding the RWP now starting to dry out, we expect to commence local irrigation in the coming weeks.
We know maintaining the health of Deep Creek is important to the community and we share those values. The release has been conducted in a highly controlled manner to safeguard the health of the environment and community.
Read our full statement Emergency controlled release from Romsey Recycled Water Plant.
Water quality results
The table below shows the quality of recycled water released from Romsey Recycled Water Plant (sampling point 3).
How to read our sampling and testing report
We use a risk-based approach to track the performance of the Romsey Recycled Water Plant. This determines how often we sample and test the water quality.
Green = Pass Class B
Results meet the EPA guidelines for Class B recycled water.
Orange = does not meet Class B (E. coli) guidelines
Results do not meet Class B guidelines for E. coli. If E. coli results exceed 400 org/100ml on two consecutive occasions, we are required to stop releasing the water and take additional measures to improve water quality.
Red = Fail Class B
Results do not meet Class B guidelines. GWW will pause the release and take additional measures to improve water quality.
| Date of release | 4-8 October | 9-15 October | 16-23 October | 23-30 October |
| Test | Results | Results | Results | Results |
| pH | Pass (Class B) - Levels are between 6 - 9 |
Pass (Class B) - Levels are between 6 - 9 |
Pass (Class B) - Levels are between 6 - 9 |
Pass (Class B) - Levels are between 6 - 9 |
| Suspended solids | Pass (Class B) - Levels are under 30 mg/L | Pass (Class B) - Levels are under 30 mg/L | Pass (Class B) - Levels are under 30 mg/L | Pass (Class B) - Levels are under 30 mg/L |
| E. coli | Pass (Class B) - Levels are under 100 org per 100ml | Pass (Class B) - Levels are under 100 org per 100ml | Pass (Class B) - Levels are under 100 org per 100ml | Pass (Class B) - Levels are under 100 org per 100ml |
| Biological Oxygen Demand | Pass (Class B) – Levels are under 20 mg/L | Pass (Class B) – Levels are under 20 mg/L | Pass (Class B) – Levels are under 20 mg/L | Pass (Class B) – Levels are under 20 mg/L |
The release of recycled water into Deep Creek was completed on 24 October 2023.
Data from all sampling points and information about how much recycled water was released: