Pumps help keep Sydney’s water safe

Sydney Water Analytical Services plays an important role auditing treated and untreated water samples from various locations in Sydney’s water network, and Watson-Marlow pumps have been an integral part of its services for over 10 years.

The Sydney Water Analytics team, working out of the West Ryde facility, process a variety of water samples that come in from the field ranging in 10-100 L volumes. There are five identical filtration skids in the lab to process the samples efficiently. Due to the importance of this data and strict turnaround times, one of the skids is used for extra capacity in busy times and there is a duplicate 6th skid off-site for business continuity if the lab is closed, for example, by natural disaster.

Watson-Marlow 620SN/R pumps have recently been installed on each skid downstream of the flat-bed membrane. The pumps, which typically run around 135 rpm, have a good suction capability and draw fluid from the sample bag through the filtration membrane for any solid material to be filtered and analysed with a microscope for microorganisms. In particular, the microscopic parasties that are looked for are Cryptosporidium and Giardia, which can cause gastrointestinal illness.

“Watson-Marlow pumps have a good track record in this facility,” said Peter Beatson, Senior Analyst at the lab. “The older model 604S/R pumps were installed in this application and had over 10 years of reliable service. When we were going through the approval process for new equipment, that was a major plus when comparing potential suppliers - we knew they would be a good investment.”

The 620SN/R pumps have been set up with Watson-Marlow’s most recommended Marprene peristaltic pump tubing (a thermoplastic elastomer), which has a long running life and is widely compatible with chemicals. With a duty cycle of 2-3 hours a day, the maintenance on the pumps is minimal with a tube change required only every two months. “Changing the tube takes just minutes, it is very simple to replace and get the pump going again.”

Sydney Water’s Analytical Services laboratory has been testing for these organisms since the mid-nineties.

Occurrence of Cryptosporidium and Giardia in untreated water, associated with water-related disease worldwide, can follow large rainfall events and contamination by sewage effluents or animal waste. Waterborne outbreaks have been reported mostly in North America and Europe. 

In 1998 a number of Cryptosporidium were detected in Sydney’s water supply after flooding in the catchment. The public were asked to boil drinking water as a precaution, but no illnesses were recorded.

The laboratory remains ever vigilant, checking on a daily basis for Cryptosporidium and Giardia in the water supplies to ensure that the water is safe for consumers, and using Watson-Marlow pumps in the process to help them do so.