TasWater: applying sustainable solutions

TasWater applied Pentair X-Flow Hollow-fiber Nanofiltration (HFNano) Membrane Elements in a full-scale system.

Entering a bigger pond

Access to clean, safe water is essential for life. However, challenges such as water scarcity, water quality and regulatory pressures are top of mind for many water utilities.

The demand for sustainable solutions have given rise to new and evolving technologies that help enable the reuse of wastewater and potential of surface water as sources to produce drinking water. Of these emerging technologies and approaches, nanofiltration should be one that all water utilities responsible for potable water production start to consider.

Pentair X-Flow HFNano Solution at TasWater

Facing a challenge of water quality and consistency

The Ringarooma river in Australia supplies potable water to the cities of Ringarooma, Winnaleah, Branxholm, Derby and Legerwood. Ringarooma River is usually low in hardness, alkalinity and conductivity with moderately high dissolved organic levels. During storm events, the water experiences high turbidity and bacteriological contamination.

This creates challenges for the water utility, TasWater and its water treatment plant as they received customer reports about water quality issues. Considering the water treatment plant is responsible for providing clean drinking water to the Tasmanian population per the Australian Drinking Water Guidelines, such reports meant a call for action. TasWater needed a sustainable solution.

Regulating water reuse with irrigation

The water treatment plant is co-located with an irrigation scheme. It was determined the conditions of the water and this co-location environment were a fit for applying a nanofiltration solution. TasWater applied Pentair X-Flow Hollow-fiber Nanofiltration (HFNano) Membranes in a full-scale system. The design capacity for the system is 60 m3/hr. From the co-location, there is a shared river water intake and nanofiltration backwash waste is able to be reused as irrigation water, which eliminates the need for wastewater treatment or sewer connection. This helps the utility avoid additional costs in operations and resources.

Pre-and post treatment that support you in the need for high quality drinking water

Complementary to the nanofiltration membrane skids, TasWater leverages pre- and post treatment technologies and approaches to help ensure continuous supply of excellent drinking water. These technologies and approaches are scoped and installed by specialised third-party suppliers and should be considered for a more holistic approach to help achieve sustainable water quality:

Feed strainer to protect the membranes from ingress of harmful matter
Granular Activated Carbon to remove small organics
CO2 dosing and calcite contactors for control of corrosiveness
UV treatment as second microbiological barrier
Chlorine and fluoride dosing for transport safety and dental protection.

“The upgrade will mean that more Tasmanian households will have access to water they can drink straight from the tap.” CEO, Mike Brewster from TasWaster

The giga power of Hollow-fiber Nanofiltration

Like TasWater, many drinking water suppliers are dependent on the surface water of declining quality, often due to increased levels of Natural Organic Matter (NOM). Nanofiltration is used in the production of high-quality drinking water as it rejects trace organic compounds, heavy metals, and viruses at a lower energy demand than reverse osmosis.

Other benefits of industry-leading hollow-fiber nanofiltration membranes such as Pentair X-Flow HFNano Membranes include:

Retaining NOM without coagulation and with minimal hardness retention
High permeate quality 1
A scalable system with low chemicals and power consumption
Minimal brine waste 2
Certified for bacteria and viruses (LOG 4 virus and LOG 6 bacteria removal) 2
Minimal pretreatment required (strainer).

When should you consider Hollow-fiber Nanofiltration?

Some surface water condition indicators that may suggest potential for Hollow-fiber Nanofiltration solutions include:

Feedwater color: up to 100 Hazen units
Feedwater TOC (Total Organic Carbon): up to 50 mg/l
Low salinity, low hardness
Microbiological contamination requiring multiple barriers (e.g. combining NF with UV and chlorine)

Please keep in mind the ideal solution is determined by your site-specific conditions and your water quality. In general, flow demand and the availability of proper sludge discharge facilities drive the choice.

Pentair X-Flow HFNano Solution with Pentair X-Flow HFW1000 Membrane Elements for visitor center

Want to learn more? Meet with Pentair X-Flow Experts at Aquatech

Visit the Pentair X-Flow Booth 243 in Hall 1 to explore the Pentair X-Flow HFNano Solution. Our experts are available to learn more about your challenges and help you determine what type of membrane technology is an ideal fit to address them.