It's Time for Major review North Head Sewage Plant

North Head Sewage Plant

Raw sewage was released over cliffs during power failure.

The environment license for North Head Sewage Treatment Plant is up for review, with public submissions a part of the review process. 

The Plant serves nearly one million customers from Blacktown, along the suburbs north of the Parramatta River to the Northern Beaches.  It treats on average 345,000 tonnes of wastewater every day.

Since the sewage plant began operations in 1986, the Manly community has criticised its failure to treat sewerage adequately before discharging it into the ocean. As well, offensive odours have been an ongoing problem and recently plant operator Sydney Water was named as the nation's biggest dumper of mercury - a heavy metal toxic to the marine environment. 

While major sewage treatment plants in every other capital city in Australia perform a two or three stage treatment process, the North Head Plant carries out one stage only before releasing sewage into the ocean.  And even this one stage - screening - is not a full treatment.

The screening process at North Head, which is meant to filter grease and solid material from sewage, only removes 30 % of this material, meaning that 70 % of sewage solids go straight into the ocean. And materials which are dissolved or suspended in the wastewater, nutrients such as phosphates and nitrates, and bacteria, viruses and parasites are not removed at all. This minimally-treated sewage is then pumped into the ocean 3km off-shore.  In the USA and throughout the European Union this sort of pollution has been illegal for years.  The bio-solids are trucked out of the area,  twice a day, leaving a pong everywhere they travel.

But sometimes the sewage is not even pumped out to sea.  Recently a severe storm coincided with a power outage. North Head plant has no back-up power generator, so it could not pump sewage off shore. Due to the storm, there was a big inflow of storm water which exceeded the capacity of its tanks. So the plant discharged minimally-treated sewage right at the North Head cliff face. 

This is incredibly inappropriate anywhere, but it's outrageous at Manly which, along with the rest of the Northern Beaches area, is a major tourist attraction and one of Australia's most popular areas for swimming and surfing. 

The State Government has made many promises to improve the quality of effluent discharged by the North Head Plant, including a promise twenty five years ago for full three-stage (tertiary) treatment of sewage at the plant.  None of these promises have been honoured. 

In a written submission Good For Manly has called on the licensing authority - the Environment Protection Authority - to address these problems in its assessment of the North Head Sewage Treatment Plant. Specifically, Sydney Water's license to run the plant should only be renewed if it commits to upgrading to full primary and secondary sewage treatment and to providing back-up power in the event of a power outage. As well Sydney Water must eliminate North Head's offensive odours and slash the amount of mercury discharged into our marine environment. 

Good For Manly Cr Candy Bingham has  asked Manly Council to formally write to local MP and State Premier Mike Baird asking, as a matter of urgency, for funds for a back-up power generator for the North Head Treatment Plant. 


Update - Sydney Water Responded to our blog with the following comments:
Mercury dumping

·         Sydney Water is the largest water utility in Australia servicing around 4.6 million customers across our area of operation. Our plants at North Head and Malabar are the largest in Australia, treating and safely discharging the waste of more than two million people every day, helping to protect the community and environment.

·          In the 2013/14 financial year Sydney Water discharged a total of 30kg of mercury from North Head and 9.2kg from Malabar. This was reported in the latest data from the National Pollutant Inventory (NPI), which details omissions from over 4,300 industry facilities.

·          The level of mercury discharged from North Head and Malabar in 2013/14 falls well within the licence limits of 60kg/yr at North Head and 103kg/yr at Malabar, which are set by the EPA and are implemented through the Environment Protection Licence for each plant.

·          In fact, the concentration of mercury discharged is at least 10 times less what is considered safe to appear in drinking water and at no stage has Sydney Water breached its Environment Protection Licence. All of our plants adhere to strict environmental requirements set by the EPA, which are monitored and reported regularly.

·          Sydney Water does not produce mercury however it is our responsibility to treat wastewater and trade wastewater that can include traces of mercury and other metals.

·          This is a responsibility we take seriously, which is why we monitor our wastewater discharges for mercury and toxicity across our area of operation.

·          We also undertake Ocean Sediment Monitoring to see if there is any impact on marine ecosystem health at our deep ocean outfalls.

·          The program has been in place for over ten years with data showing no measurable impact on marine ecosystems. More information is available about this if interested.

Treatment process

North Head WWTP has a three step process: screening, grit removal and sludge removal.
 
Upgrading North head WWTP to a secondary or tertiary treatment is costly and would mean North Head WWTP has a far greater footprint (which would reduce the amount of National Park and possibly encroach on the North Head Sanctuary), uses significantly more energy and would have greater number of truck movements through Manly.

Additionally, ongoing monitoring  of the ocean has failed to identify significant environmental differences between locations close to and remote from the deepwater ocean outfalls, which would indicate that the end product is not impacting on the local marine environment.

The screens at North Head remove upwards to 100% of material greater than 5mm in size and the primary sedimentation system removes around 30% of the organic solids from the process.

James Feary
Plant Manager WWTP, 
Sydney Water.  20/5/15
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