Brunswick Area Sewerage Augmentation Scheme

Upgrade of the Sewerage Treatment System for Mullumbimby and Brunswick Heads

Introduction: Brunswick Area Sewerage Augmentation Scheme

Our community identified in the late 1990’s that the ever increasing demands of tourism and being a popular retirement destination is placing environmental pressures on the Shires waterways threatening the long term sustainability of the Brunswick River Estuary that is vital for our two main economic drivers; tourism and agriculture and critical for our biodiversity.

As such Council established the Brunswick River Wastewater Steering Committee and the Brunswick Estuary Management Committee aiming to engage our passionate and knowledgeable residents in a process to assist Council in developing recommendations for their preferred wastewater management strategy and rehabilitation objectives for the Brunswick River Estuary.

Committee members, Residents and government agencies have worked together with Council for ten years to deliver the Brunswick Area Sewage Augmentation Scheme 7.22 MB (BASAS) a major component of the Brunswick Estuary Management Plan 15.91 MB (BEMP).

Background

Sewage from the towns of Mullumbimby and Brunswick Heads is presently processed by two sewage treatment plants (STPs), one discharging to the Brunswick River at Mullumbimby with the Brunswick Heads STP discharging to Simpson’s Creek. These thirty year old STP’s cannot treat sewage to acceptable modern standards required to protect the water quality and environmental health of the Brunswick River Estuary.

The New Brunswick Valley Sewage Treatment Plant (STP), located on Council owned land at the end of Vallances Road in Mullumbimby, is designed to replace both STP’s with modern technology designed to meet the population growth demands for both townships whilst minimising energy and chemical consumption and providing high quality effluent for reuse in local farms or discharge to the River.

Brunswick Area Sewerage Augmentation Scheme (BASAS) Development Stages

Main Arm Effluent Reuse

Council commissioned the Main Arm effluent reuse scheme in 2003. The scheme diverts dry weather discharges from the existing Mullumbimby Sewage treatment plant towards beneficial reuse on local farms via five kilometres of pipelines. This reduces dependence on other freshwater resources and fertilisers whilst helping protect estuary health. The new STP, including sewage flows from Brunswick heads, is also connected to reuse.

Riparian Rehabilitation Works

The 110ha site of the new STP is part of a regionally important wildlife corridor with 4.5 kilometres of riparian zones (river bank) including 2.5 kilometres of Brunswick river front and two billabongs.

The riparian zone was suffering the adverse impacts of uncontrolled cattle access and vegetation removal leading to severe erosion and severe impacts on saltmarsh and mangrove fishery habitat. The western billabong was deoxygenated and hosted several noxious aquatic weed species.

Unique amongst most developments Council commenced rehabilitation works well before turning the first sod of the BASAS development.

Since 2006 Council has completed the following integrated natural resource management initiatives at and surrounding the site:

• Installed 4.5km of riparian cattle exclusion fencing
• Planted 40,000 trees for erosion protection, habitat enhancement and carbon sequestration.
• Invested more than 1000 hours of bush regeneration activities – removing weed species and recruiting native seedling.
• Removed two barriers to fish passage opening up a further 8ha of potential saltmarsh and mangrove habitat.
• Reintroduced tidal influence to the western billabong for weed management, and habitat enhancement.
• Stabilised more than 300m of slumping riverbank reducing the sediment load on sensitive estuarine environments including seagrass.

Funding has been assisted with grants from the NSW Department of Primary Industry Recreational Fisheries Trust fund, NSW Environmental Trust, NSW DECC Estuary Management Program and the Federal Government’s Community Water Grants.

STP Access Road Construction

Vallances Road Mullumbimby was chosen as the site for the new sewage treatment plant because of its central location between Mullumbimby and Brunswick Heads, whilst being close to existing and potential effluent reuse sites and future connection of Ocean Shores STP to effluent reuse, however to facilitate construction and operation traffic Vallances Road required upgrading with a new 1.3 kilometre extension to the new STP site.

Vallances Road is located within sensitive Koala habitat and wildlife corridors, so measures were implement to mitigate against potential impacts on wildlife and offset any losses of habitat incurred during construction. Consequently a Koala plan of management was developed for the site with Council planting in excess of 1000 koala feed trees and installing thirty nesting boxes to replace the lost or damaged trees and hollows. Trees removed to facilitate construction were reused as part of Council fishery habitat management initiatives at the site.

Pump Station and Pipelines

Two pump stations have been built to pump sewage from Mullumbimby and Brunswick Heads to the new STP via the new pipelines, they utilise current technologies and are located to mimimise noise, odour and visual impacts. The pumps stations include large storages to minimise local overflows in the event of equipment or power failures.

Three pipelines totalling about 3 kilometres have been constructed to connect Brunswick Heads and Mullumbimby with the new STP and the new STP with the Main Arm effluent reuse scheme. The pipelines traversed private, public and Council lands and involved tunnelling under the Pacific Highway and five Brunswick River crossings.

Sewage Treatment Plant

The new STP is a biological nutrient reduction system that uses mainly microbial activity with the addition of some chemicals for pH correction and flocculation treat sewage to a level suitable for rural reuse. This process was chosen for its superior energy and chemical performance.

Treated effluent will be made available for beneficial reuse on local farms thereby limiting discharges to the Brunswick River to periods of extended wet weather.

The STP includes a purpose built biosolids processing section that will improve biosolids management and handling for beneficial reuse on farms as a soil conditioner.

Project benefits

• The two new pump stations are designed to maximise storage (in the event of breakdown or power failures) minimising the incidence of untreated effluent discharges to the Brunswick River.
• Higher quality effluent is being discharged when not being reused.
• Improved protection of public and environmental health
• The new STP and pump stations are designed to cope with projected population growth and tourism.
• Maximise reuse of biosolids and effluent, improving the sustainability of our agricultural industry.
• Improve Brunswick River health helping sustain our tourism and fisheries industries.
• Reduced chemical and energy consumption per litre treated.
• Improved ecological condition in and around the site

The old Mullumbimby and Brunswick Heads STP’s will be closed after the new BVSTP is fully operational. This means no more discharges to the Simpsons creek at Brunswick heads.

Milestones

1998

Brunswick River wastewater and Estuary Management committees appointed.

2000

Vallances Road Land purchased

2003

Mullumbimby STP connected to rural reuse

2005

Council adopts the BASAS EIS

2006

Vallances Road riparian rehabilitation works Commence

2007

Council approves construction of BASAS

2008 October

Vallances Road upgrade commences

2008 December

STP Construction tender awarded

2009 April

Pipeline and Pump station construction commences

2009 March

Vallances Road construction complete

2009 April

Sewage treatment plant Construction commences

2009 December

Pipeline and Pump station construction complete

2010 June

BASAS wins National Local Government Award and United Nations World Environment Day Awards for excellence in Natural Resource Management

2010 October

STP construction completed

2010 November

STP pipeline and pump station commissioning and proving.

2011 February

Scheduled handover to Council

For further information contact Phil Warner, Executive Manager Water and Recycling, 02 6626 7000 or call the HOTLINE 02 6626 7321.