North Head odours Addressed but concerns remain

While the admission by Sydney Water that odours at North Head are of such significance that it has allocated $4 million over 4 years to solve the problem (Sun-Herald 10/5/15) is welcomed, ongoing community concerns about actual  the treatment process continue.

Sydney Water currently releases 70% of solids into the ocean (3kms out to sea). Is this acceptable? Not according to international leaders

Toxic Mercury Pollution
Sydney Water has correctly pointed out that the level of Mercury falls within the limits set by the EPA 
but what is not stated is that the EPA has not reduced the North Head Sewage Treatment 
Plant licence for Mercury discharged to coastal waters since it was established in 1992. This 
is a matter of great concern to the Manly community.  

Treatment Process
In relation to upgrading North Head Sewage Treatment Plant, Project North Head Upgrade 2003 documents costed all items and it is acknowledged that major funding was needed.

However the community is concerned that:

1.    The 1991 planned upgrade to the ocean outfall plants did not proceed.

2. The 2002 consultation process with the Manly community undertaken by Sydney 
Water identified Preferred Option upgrade to full primary with 65% solids capture 
and secondary treatment – all within plant boundaries. However, EPA said 
upgrading of ocean outfall plants was not a priority and the Independent Pricing and 
Regulatory Tribunal believed ‘that Sydney Water has not provided sufficient 
justification’ for the $6M they requested. Preferred Option did no proceed.  

3. As Sydney Water fails to see or acknowledge that any improvement in the treatment 
process is necessary that this current licence review will not lead to any improvements as well.

4. The suggestion that upgrading the North Head WWTP to secondary and tertiary treatment 
would necessarily result in a footprint which would reduce the size of the National Park land 
is unacceptable – put the plant underground, decentralise/interception with treatment along 
the Northern Suburbs Ocean Outfall System that flows to North Head Sewage Treatment 
Plant. 

5. Regarding biosolids truck numbers Sydney Water has repeatedly told the Manly community the 
treatment at the plant dictates the number of biosolids trucks and to minimise truck 
movements the treatment option would be anaerobic digestion followed by heat drying. 

Sydney Water states that 30% of solids are removed from the influent – that means 70% of solids 
are discharged to the ocean which is  not acceptable. This is simply  not appropriate to Sydney’s image 
as a clean city in the 21 century that we continue to dump our sewage in the ocean. 

It is worth noting that in a print article about the North Head Sewage Treatment Plant 
Mercury pollution, the Associate Professor at the School of Civil and Environmental 
Engineering UNSW, Stuart Khan was quoted as saying “the real solution though would 
be to apply more advanced treatment processes, which are commonly employed at 
sewage treatment plants around the world. In the US, the EPA has banned the 
discharge of primary Sewage to the ocean”.

It is time to start planning to implement the ‘ultimate aim’ of Section 27(1) of the Sydney 
Water Act 1994, which states, inter alia :

‘the corporation is to adopt as an ultimate aim the prevention of all dry weather discharges of sewage to waters, including from ocean outfalls, except to the extent that this is necessary to safeguard public health or prevent environmental degradation, or both.’

(Our thanks to Beverley Trevenen who assisted providing the facts for this article)