Agenda of Water, Waste and Sewer Advisory Committee Meeting

CONFLICT OF INTERESTS

What is a “Conflict of Interests” - A conflict of interests can be of two types:

Pecuniary - an interest that a person has in a matter because of a reasonable likelihood or expectation of appreciable financial gain or loss to the person or another person with whom the person is associated.

Non-pecuniary – a private or personal interest that a Council official has that does not amount to a pecuniary interest as defined in the Local Government Act (eg. A friendship, membership of an association, society or trade union or involvement or interest in an activity and may include an interest of a financial nature).

Remoteness – a person does not have a pecuniary interest in a matter if the interest is so remote or insignificant that it could not reasonably be regarded as likely to influence any decision the person might make in relation to a matter or if the interest is of a kind specified in Section 448 of the Local Government Act.

Who has a Pecuniary Interest? - a person has a pecuniary interest in a matter if the pecuniary interest is the interest of the person, or another person with whom the person is associated (see below).

Relatives, Partners - a person is taken to have a pecuniary interest in a matter if:

§ The person’s spouse or de facto partner or a relative of the person has a pecuniary interest in the matter, or

§ The person, or a nominee, partners or employer of the person, is a member of a company or other body that has a pecuniary interest in the matter.

N.B. “Relative”, in relation to a person means any of the following:

(a) the parent, grandparent, brother, sister, uncle, aunt, nephew, niece, lineal descends or adopted child of the person or of the person’s spouse;

(b) the spouse or de facto partners of the person or of a person referred to in paragraph (a)

No Interest in the Matter - however, a person is not taken to have a pecuniary interest in a matter:

§ If the person is unaware of the relevant pecuniary interest of the spouse, de facto partner, relative or company or other body, or

§ Just because the person is a member of, or is employed by, the Council.

§ Just because the person is a member of, or a delegate of the Council to, a company or other body that has a pecuniary interest in the matter provided that the person has no beneficial interest in any shares of the company or body.

Disclosure and participation in meetings

§ A Councillor or a member of a Council Committee who has a pecuniary interest in any matter with which the Council is concerned and who is present at a meeting of the Council or Committee at which the matter is being considered must disclose the nature of the interest to the meeting as soon as practicable.

§ The Councillor or member must not be present at, or in sight of, the meeting of the Council or Committee:

(a) at any time during which the matter is being considered or discussed by the Council or Committee, or

(b) at any time during which the Council or Committee is voting on any question in relation to the matter.

No Knowledge - a person does not breach this Clause if the person did not know and could not reasonably be expected to have known that the matter under consideration at the meeting was a matter in which he or she had a pecuniary interest.

Participation in Meetings Despite Pecuniary Interest (S 452 Act)

A Councillor is not prevented from taking part in the consideration or discussion of, or from voting on, any of the matters/questions detailed in Section 452 of the Local Government Act.

Non-pecuniary Interests - Must be disclosed in meetings.

There are a broad range of options available for managing conflicts & the option chosen will depend on an assessment of the circumstances of the matter, the nature of the interest and the significance of the issue being dealt with. Non-pecuniary conflicts of interests must be dealt with in at least one of the following ways:

§ It may be appropriate that no action be taken where the potential for conflict is minimal. However, Councillors should consider providing an explanation of why they consider a conflict does not exist.

§ Limit involvement if practical (eg. Participate in discussion but not in decision making or vice-versa). Care needs to be taken when exercising this option.

§ Remove the source of the conflict (eg. Relinquishing or divesting the personal interest that creates the conflict)

§ Have no involvement by absenting yourself from and not taking part in any debate or voting on the issue as if the provisions in S451 of the Local Government Act apply (particularly if you have a significant non-pecuniary interest)

RECORDING OF VOTING ON PLANNING MATTERS

Clause 375A of the Local Government Act 1993 – Recording of voting on planning matters

(1) In this section, planning decision means a decision made in the exercise of a function of a council under the Environmental Planning and Assessment Act 1979:

(a) including a decision relating to a development application, an environmental planning instrument, a development control plan or a development contribution plan under that Act, but

(b) not including the making of an order under Division 2A of Part 6 of that Act.

(2) The general manager is required to keep a register containing, for each planning decision made at a meeting of the council or a council committee, the names of the councillors who supported the decision and the names of any councillors who opposed (or are taken to have opposed) the decision.

(3) For the purpose of maintaining the register, a division is required to be called whenever a motion for a planning decision is put at a meeting of the council or a council committee.

(4) Each decision recorded in the register is to be described in the register or identified in a manner that enables the description to be obtained from another publicly available document, and is to include the information required by the regulations.

(5) This section extends to a meeting that is closed to the public.

BYRON SHIRE COUNCIL

Staff Reports - Infrastructure Services 4.1

Staff Reports - Infrastructure Services

Report No. 4.1 Water Sensitive Urban Design Strategy

Directorate: Infrastructure Services

Report Author: James Flockton, Drain and Flood Engineer

File No: I2018/956

Theme: Community Infrastructure

Local Roads and Drainage

Summary:

At Council’s meeting of 22 March 2018, Council resolved to develop a financially sustainable strategy to embed and mainstream Water Sensitive Urban Design (WSUD) into Council's planning instruments and policies.

This report provides an update on this project.

RECOMMENDATION:

That the committee note the report.

Attachments:

1 PDF of E2018/56771 Water Sensitive Urban Design WSUD Policy and Strategy Request for Quotation, E2018/74360 , page 7⇩

Report

At Council’s meeting of 22 March 2018, Council resolved Res 18-178:-

1. That Council develop a financially sustainable strategy to embed and mainstream Water Sensitive Urban Design (WSUD) into Council's planning instruments and policies.

2. That formulation of the Strategy consider fundamental changes in various development area ratios to retain pervious areas instead of increasing catchment runoff.

3. That the changes made under this strategy on WSUD aim to:

• reduce flood risk in urban areas

• improve water quality in streams, waterbodies and groundwater

• consume less of our water resources

• reduce the cost of providing and maintaining water and sewer infrastructure

• protect and restore aquatic and riparian ecosystems and habitats; and

• protect the scenic, landscape and recreational values of streams and other waterbodies.

4. That the WSUD Strategy generates changes that:

• promote and encourage WSUD in urban areas

• provide guidance and support for businesses and residents to implement WSUD

• give incentives for the implementation of WSUD in new and existing development

5. That progress on the WSUD Strategy be reported to each Water, Waste and Sewerage Advisory Committee and the Coastal Estuary Catchment Panel quarterly meeting, starting with their next meetings in June 2018.

6. That Council allocate $25,000 in its 2018-19 budget for the development of a strategy.

Councils adopted budget for financial year 2018/19 includes the above budget.

Staff have prepared a scope of works for this task which was sent out to five local consultants to price. The scope of works can be found at attachment 1.

Consultant BMT WBM have now been engaged to prepare a WSUD policy and strategy for Byron Shire. BMT WBM were engaged on the 30 August 2018, therefore, timelines were not available to provide a detailed report to the committee prior to Septembers meeting, however, BMT WBM will present to this meeting.

The purpose of this meeting is to introduce the committee to WSUD, discuss typical strategies used by other Council’s, discuss a draft Policy Statement and enter into a group discussion that seeks to understand the committees desires and preferences for the draft strategy.

A draft strategy will follow at the next committee meeting for further discussion and fine tuning.

Due to the above short timelines it recommended that the committee make use of some online resources. An excellent resource for the committee to use prior to the meeting is http://hlw.org.au/initiatives/waterbydesign and in particular http://hlw.org.au/initiatives/waterbydesign/water-sensitive-urban-design-wsud whilst this information covers the South East Queensland area rather than Northern NSW, it is an excellent resource that is relevant to our climate when compared to information more suited to Sydney and the climate of the majority of NSW.

Financial Implications

There are no financial implications at this stage. The contract cost is below the allocated budget.

Statutory and Policy Compliance Implications

There are no Statutory and Policy Compliance Implications at this time.

BYRON SHIRE COUNCIL

Staff Reports - Infrastructure Services 4.2

Report No. 4.2 Telecommunications Installations on Reservoirs

Directorate: Infrastructure Services

Report Author: Peter Rees, Manager Utilities

File No: I2018/1159

Theme: Infrastructure Services

Water Supplies

Summary:

Following an annual review of Council’s Drinking Water Management Plan with NSW Health, it was agreed NSW Health would fund a consultant to assist Council to develop project plans and negotiate with the Telecommunications companies to allow sufficient access to the water reservoirs to permit replacement of the roofs.

The colocation of telecommunication equipment on reservoirs is presenting problems for local Utilities across Australia to properly operate and maintain critical infrastructure associated with the supply of drinking water.

NSW Health has identified Byron Shire as a potential case study to develop solutions to this widespread issue.

RECOMMENDATION:

That the Committee note the report.

Report

NSW Health has identified Byron Shire as a potential case study to develop solutions to this widespread issue.

Accordingly, Aqualift Project Delivery Pty Ltd (Aqualift) has been engaged by NSW Health to assist Byron Shire Council to facilitate and advance the project for the temporary removal; power down or permanent relocation of telecommunications equipment from the Paterson and Wategos Water Supply Reservoirs in Byron Bay to enable the replacement of the existing roof structures.

The structural integrity of the supporting roof frames and roof drainage systems have become compromised partially due to the presence of a large amount of ancillary telecommunications equipment which has been installed at both reservoir sites including walkways, cable trays, coaxial cables, etc.

The current situation is making it extremely difficult for Council to adequately undertake normal operational and maintenance activities at these water supply reservoir sites including roof

inspections required to monitor and verify the integrity of the roof to prevent any contamination of the water supply and to also undertake repairs to the roof drainage systems to prevent contaminated water ingress to the reservoirs.

Following discussions with reservoir roof contractors, the only practical way to replace the current roofing structures and drainage systems will require all the existing telecommunications equipment to be either relocated or powered down while the existing roofs are removed and the new roofs together with supporting frames are installed. This is due to both physical constraints imposed by the location of the existing equipment and danger of radiation exposure to workers while undertaking these roofing works.

It is necessary to negotiate with the various telecommunication service providers as a group to allow them to undertake concurrent work to their existing installations at each reservoir site to allow this critical project to proceed.

Before commencing negotiations with the telcos, Council needs to have a preferred option for the existing structures. These are:

Option 1

Construction of a permanent tower separate to the reservoirs to which the existing equipment could be relocated. This is the preferred option of NSW Health and the Water Directorate and is certainly Council’s preferred option for all new reservoirs without existing installations. The Paterson Street and Wategos reservoir sites are very constrained and previous discussions with a telco indicated they would require a tower approximately 6 metres higher than the existing reservoir heights.

Option 2

Construction of an ancillary self supporting structure/walkway located around the outside of the roof top perimeter of the existing reservoirs to accommodate the relocation of the existing telecommunications equipment and with no telecommunications equipment then being permitted to be installed upon the existing reservoir walls and/or roofs.

Option 3

Leave the telecommunication equipment located on the reservoir walls but relocate all cable trays and existing telco equipment off the roof. This would require telco agreement to power down their facilities concurrently to allow the roof replacement work to proceed. It is most likely the quickest option to implement both from a telecommunications and planning perspective.

Option 4

Construction of a temporary tower separate to the reservoirs to which the existing equipment could be relocated. This option has similar issues to Option 1.

For all options, to facilitate the project a suitably qualified consultant will need to be engaged to undertake and complete all activities related to the replacement of the existing roofs and drainage systems at these reservoir sites.

This consultancy engagement would include negotiations with the various telecommunication service providers to facilitate the design and replacement of the roofs and drainage systems; design of replacement roof structures incorporating alternative arrangements for all telecommunications equipment as required; contract documentation for roof replacement works, contract management of these works and re-negotiation of lease agreements with the telecommunication service providers.

At a meeting between NSW Health and Council’s Executive Team a plan was developed where NSW Health and Council would jointly work on the project.

Financial Implications

Project budgets for the roof replacement of both the Wategos and Paterson St reservoirs have been included in the 2018-19 water capital programme.

Statutory and Policy Compliance Implications

Provision of safe drinking water for the public.

BYRON SHIRE COUNCIL

Staff Reports - Infrastructure Services 4.3

Report No. 4.3 Rous Regional Water Supply Agreement Liaison Committee Meeting 28 August 2018 Agenda and Business papers

Directorate: Infrastructure Services

Report Author: Peter Rees, Manager Utilities

File No: I2018/1298

Theme: Infrastructure Services

Water Supplies

Summary:

Rous County Council holds quarterly Water Supply Agreement Liaison Committee meetings at which technical representatives from each constituent Council attend to discuss various water issues. The business papers are presented to the WWSAC for information and to inform them of various critical issues being assessed by Rous and the constituent Councils.

In particular at this meeting, the status of the future water strategy groundwater investigations was presented by Rous.

It is intended the business papers for these meetings will be presented to the WWSAC for information each quarter.

RECOMMENDATION:

That Council note the report.

Attachments:

1 RRWSALC 28.08.2018 - Agenda and Business Papers, E2018/72813 , page 37 ⇩

2 RWSALC Mtg 28 August 2018 - Groundwater PPP.pdf, E2018/72812 , page 99⇩

Report

Rous Water and its Constituent Councils hold quarterly meetings where various issues are presented as business papers for discussion. The following papers were on the agenda last week with comments from Council staff.

Groundwater Investigation – refer attached powerpoint presentation E2018/72812. This has been provided for information only. The proving of bore water suitability is currently behind schedule and over budget. Current prices for drilling are inflated most likely due to the drought.

To date there have been some promising results particularly at Woodburn. Curren programme is that if bores feasibility proves to be unacceptable for the long term water strategy, then in 2022 indirect potable reuse will be investigated. The Dunoon Dam option has not yet been closed off.

Water Loss Summary – Rous Water will partner each constituent Council (50/50) to prepare a Water Loss Management Plan (except Lismore who already has a WLMP in place).

Drinking Water Stations – Rous Water have identified portable drinking water stations as part of a demand management / plastic reduction education programme. Choose Tap is a broad, community-based initiative promoting tap water as the best hydration choice for the environment, people’s health and their pocket.

The hydration stations and portable refill stations provide free drinking water to local community festivals, concerts and sporting events. They are provided free of charge and keep attendees healthy and hydrated. Refer link below for more information.

https://www.yvw.com.au/help-advice/community-programs/sponsorships-and-partnerships/book-

hydration-station

Choose Tap Portable Hydration Station

They can ideally be used at festivals and events around the Shire. The cost is approximately $3,500 each. It would be staff’s recommendation that Council purchase 6 units.

Review of Developer Servicing Charges for Secondary Dwellings – No decision by RCC has been made. It will report to its Council the impact of this waiver policy.

Essentially the impacts are increased water demand on the system and a loss of revenue for development of future infrastructure.

It is noted Byron Shire Council has already considered this issue and resolved to:-

“notify the public and seek submissions on the proposal to terminate the waiver of section 94 and section 64 contributions for secondary dwellings”.

Review of Possible Transfer of Rous County Council Water Assets and Retail Customers to the Constituent Council – this was a project initiated by Byron Shire Council. There are significant areas in Byron Shire (Ewingsdale, Skinners Shoot and Bangalow in particular) where Rous Water supplies water to retail customers in competition with Byron Shire. It can be argued this is contrary to the original proclamation forming Rous as a bulk water supplier only.

Rous has indicated this is not a priority for their organisation or other constituent councils other that Byron Shire. Byron Shire Council staff considers the project should be progressed in a considered manner at least for Rous Water retail customers in Byron Shire.

Financial Implications

Nil

Statutory and Policy Compliance Implications

Provision of safe drinking water for the community.

BYRON SHIRE COUNCIL

Staff Reports - Infrastructure Services 4.3 - Attachment 1

PDF Creator

BYRON SHIRE COUNCIL

Staff Reports - Infrastructure Services 4.4

Report No. 4.4 Mullumbimby Inflow and Infiltration update

Directorate: Infrastructure Services

Report Author: Jason Stanley, Systems Planning Officer

File No: I2018/1660

Theme: Infrastructure Services

Sewerage Services

Summary:

Mr Jason Stanley has recently been appointed as Project Manager for the Mullumbimby Inflow and Infiltration project.

The initial stage of the project has focussed on improvement of data acquisition and review of benefits of Water Sensitive Urban Design if fitted throughout Mullumbimby.

A more detailed project scope will be developed during the next 3 months.

RECOMMENDATION:

That the Committee note the report.

Attachments:

1 Mullumbimby sewer catchments, E2018/72975 , page 125 ⇩

2 Mullumbimby Preliminary Photomontages 03.09.18, E2018/73200 , page 126 ⇩

Report

The Mullumbimby Inflow and Infiltration project is in early stages of implementation. The focus of work to date has been towards the improvement of data acquisition prior to anticipated rainfall events and identification of areas where Water Sensitive Urban Design (WSUD) can be effectively implemented to allow for stormwater management.

Improvement of Mullumbimby flow data acquisition

SCADA coding for all sewage pump stations within Mullumbimby has been upgraded to allow for increased flow data acquisition. Derived inflows and outflows from each site have been established with the recent dry weather providing a good opportunity to analyse dry weather flow diurnal flow patterns and baseline groundwater infiltration.

Mullumbimby experienced a rainfall event between 24-27^th August which is currently being assessed to accurately characterise the performance of the sewerage network and identify areas with relatively higher amounts of inflow and infiltration.

Capturing flow data from SPS sites will be an ongoing process for all future dry weather and rainfall events. Regularly reviewing of this data will be performed in order to promptly identify issues. Once a high level of confidence is achieved with flow data integrity, it is anticipated that this SCADA coding will be rolled out to all SPS sites within the Byron Shire.

Water Sensitive Urban Design

The underlying assumption of the WSUD investigation is that a slowing of stormwater runoff to prevent it reaching sewer lines at key locations will reduce the total volume of stormwater being pumped to the Brunswick Valley STP (BVSTP) while also leveraging improved stormwater quality, reduced localised flooding and improved amenity outcomes within the town.

The key steps in the investigation include:-

· Assess existing stormwater infrastructure with regards to function and capacity.

· Identify those locations where stormwater infrastructure and sewer lines are in close proximity.

· Identify those sub-catchments contributing to pump stations with the highest pumping mains following and during rain.

· Compare the relationship between sewer pump rates and rainfall to determine the volume of stormwater that would ideally be intercepted.

· Identify potentially suitable locations where retrofitting of the stormwater infrastructure can be achieved.

· Develop preliminary concepts for discussion.

WSUD as a practice adopts the following principles:-

· Recognition of the value and importance of water in the urban environment through thoughtful landscape and building design.

· Reconnecting communities with the management of their own water supplies through the use of rainwater tanks and greywater recycling.

· Adoption of water management principles that reflect natural hydrological cycles.

· Promotion of evapotranspiration, infiltration and conveyance of stormwater within surface systems that use native vegetation for filtration.

· Reduction of reliance on imported water.

Stormwater Management within Mullumbimby

The adoption of WSUD within Mullumbimby will enhance the local urban environment through installation of green infrastructure while taking pressure off the town’s sewerage network. Presently little to no management of stormwater in what would be considered a water sensitive approach occurs in Mullumbimby. This means that actions to include WSUD are likely to have significant benefit to both the local community and the environment.

A number of issues and opportunities in the development of a water sensitive approach in Mullumbimby have been identified and include:

· Existing stormwater infrastructure is old and often undersized (Ardill Payne, 2018).

· Aging undersized infrastructure with low grade results in poor conveyance and localized flooding.

· Localized flooding leads to sewer infiltration particularly in low lying areas.

· It is likely that there a large number of illegal connections of stormwater to sewer, particularly in older parts of town (possibly 20 – 50% of properties).

· Inspection pits located adjacent to swales represent likely access points for direct inflow to sewer.

· Roof water drains directly to swales and roadways and could be intercepted.

· There are numerous locations where stormwater within laneways cannot physically reach the stormwater network, meaning flooding occurs in even small rainfall events.

Opportunities:

· Large network of swales that are suitable for improvement.

· Large roofs drain into swales and roadways and could be intercepted.

· Increase harvesting of stormwater (e.g. rainwater tanks).

· Increase the use of water sensitive design features to capture and treat stormwater (e.g. raingardens, tanks, biofiltration).

How much water can be captured

It has been demonstrated that installation of WSUD devices can have a significant impact on peak storm flows. Numerous case studies exist where devices such as raingardens have been installed to reduce stormwater discharges from urban environments. Tanks can also be effective for capturing roof run off if they are with connected to a frequent use or provide delayed discharge to a drain.

Potential volumes which can be intercepted have been calculated using the 3-month ARI for Mullumbimby. This corresponds to approximately a 40mm rainfall event. It should be recognised that storage and detention can be increased or reduced depending on available space and priority sub catchments where pressure on the sewer system is greatest.

Table one details storm volumes for sub-catchments around Burringbar Street for the 3-month storm. Also shown are the areas required to detain the design volume in a 300mm deep self-watering garden bed.

Table 1 Sub-catchment areas, flows and volumes for detention in design 3 month event

*Sub-catchment*	*Area m²*	*Q3 month m³/s*	*Volume m³*	*Area required at 300mm deep (m²)*
1/A	3670	0.04	24	80
2/A	3445	0.04	22	75
3/A	1780	0.02	12	39
4/A	2433	0.03	16	53
6/A	4526	0.05	30	98
5/A	767	0.01	5	17
5/B	4927	0.05	32	107
7/A	5353	0.06	35	116
8/A	3606	0.03	16	53
8/B	3555	0.04	23	77
9/A	2425	0.03	16	53
8/C	3009	0.03	20	65
10/A	9335	0.07	43	142
16/A	5757	0.04	23	76
16/B	3412	0.02	12	38

Options for WSUD in Mullumbimby

The following information is intended to be brief and does not cover all potential WSUD opportunities but is considered a reasonable approach following preliminary investigations.

Rainwater tanks

A limited number of properties have rainwater tanks. Rainwater tanks are a simple, cost effective device that can be retrofitted to prevent roof water draining to the street or stormwater network. Rainwater tanks can be used to supply toilet flushing or irrigation of landscaping. Tanks can also be implemented to function in providing detention to reduce the impact of peak flows during rainfall events. Rainwater tank rebates are offered through Rous water to all Byron Shire properties further reducing costs.

Benefits: reduce direct connection with stormwater, reduce peak flows, reduce need for potable water, provision of detention during events

Biofiltration swales

A large network of existing swales is present in Mullumbimby. Some swales are old and do not function as intended. Well maintained swales can be planted or grassed and can be retrofitted to either better convey flows or reduce peak flows during events. Reconfiguration of the existing swale network in key locations is likely to enhance the urban landscape, reduce localized flooding and stormwater infiltration. Inspection pits are frequently located adjacent to swales. If stormwater surcharges swales or inspections pits are damaged, then stormwater enters the sewer network. Improvement to swales can be undertaken in laneways in conjunction with raising of inspection points to reduce the likelihood of inflow.

Benefits: urban landscaping, enhanced conveyance, stormwater detention

Self-watering garden beds and bio-pods

Installation of self-watering garden beds within the streetscape will provide storm detention during a rainfall and take pressure of the sewer pump stations. A number of locations have been identified that are suitable for installation of garden beds that capture run off. These garden beds would include native plants and trees and would reduce peak discharges during rainfall. Self-watering gardens can be located at street corners in the space where cars cannot park, improving pedestrian safety and urban amenity. Bio-pods are small stormwater detention and treatment devices that can be retrofitted into streets to reduce discharge and provide shade reducing summer temperatures

Benefits: urban landscaping, stormwater detention and treatment

Raingardens

Where rainwater tanks are not suitable small raingardens could be installed under down pipes. These would allow for capture, treatment and reuse of rainwater and prevent discharge to the street and stormwater network.

Benefits: urban landscaping, stormwater detention and treatment.

Kerb treatments

Street kerbs can be retrofitted to include plants and provide detention during an event.

Conclusion and next steps

Investigations completed to date confirm that there is a strong and rapid relationship between sewer pumping rates, rainfall and stormwater. Strategies which intercept stormwater in up the 3-month storm event will significantly reduce pressure on the sewage network while leveraging environmental and amenity benefits for Mullumbimby.

Next steps are to:

· further develop stormwater management options,

· seek feedback from Council and other stakeholders,

· develop appropriate designs for priority locations/demonstration sites to enable monitoring and proof of concept.

Community Consultation

A community engagement and education plan will be prepared for the next WWSAC meeting. Advice has been provided that due to the technical aspects of the project, community information forums should be held with the broader community. Given, however, the importance of bringing the community along with the project, a Project Reference Group may be the better option with possibly a combination of both. For discussion at the meeting.

Financial Implications

The direct connectivity between stormwater and the sewer system will allow for funding of this work from the sewer fund. Initially this will be from the currently allocated budget.

Statutory and Policy Compliance Implications

Compliance with EPA licence 13266.

BYRON SHIRE COUNCIL

Staff Reports - Infrastructure Services 4.5

Report No. 4.5 Nutrient Loading in the Belongil

Directorate: Infrastructure Services

Report Author: Peter Rees, Manager Utilities

File No: I2018/1704

Theme: Infrastructure Services

Sewerage Services

Summary:

Council resolution 02-1329 approved the Byron Bay Sewage Treatment plant pursuant to Part 5, Section 112 of the Environmental Planning and Assessment Act 1979. Clause 11 of these consent conditions imposed limits on the total amount of Nitrogen and Phosphorus that could be discharged into the Belongil. These limits were capped at the year 2000 levels from the old treatment plant.

Currently the yearly average is 79% of these limits. In accordance with the resolution we are required to investigate feasible management strategies to reduce the loads below 80%.

The recently adopted Recycled Water management Strategy 2017-27 is a strategy that should reduce the loads as required. The calculation methodology however will need to be reviewed to determine an accurate assessment of the level of nutrients discharged given the configuration of the future recycled water projects.

RECOMMENDATION:

That Council approve a study to determine a new methodology to calculate nutrient discharge into the Belongil to satisfy both Council Resolution 02-1329 and the Recycled Water Management Strategy 2017-27.

Report

Nutrient Load Limit for West Byron STP

Nutrient loads discharged to Belongil Creek, as measured at the outlet of the constructed wetland, shall not exceed 1,502 kg per year for Total Nitrogen and 300 kg per year for Total Phosphorus.

Council shall continuously monitor nutrient loads discharged to the Belongil Creek. Determination of nutrient loads shall be based on a minimum of weekly sampling continuously averaged over a two month period, converted to an equivalent annual load.

In the event that the equivalent annual nutrient load for either Total Nitrogen or Total Phosphorus exceeds 80% of the applicable limits specified in this Approval Condition, Council shall investigate feasible management strategies to reduce loads below 80%.

In the event that the equivalent annual nutrient load for either Total Nitrogen or Total Phosphorus exceeds 100% of the applicable limits specified in this Approval Condition, Council shall meet to discuss appropriate courses of action to prevent further exceedances.

Calculations undertaken recently indicate this consent condition has been exceeded for short periods during the past 15 months. Please note, this consent condition has a much tighter threshold than Council’s EPA licence for the site. There have been no breaches of Council annual total load limits for Total Nitrogen which is 17,456 kilograms. The calculation methods are different for each limit and direct comparisons should not be made except that the consent condition threshold is much tighter than the EPA licence limit.

The graph showing this data is shown below in Graph 1. The exceedences are for total nitrogen only and occur in the peak period of summer – sometimes exacerbated by heavy rainfall such as ex tropical cyclone Debbie last year. It should also be noted the figures in the graph are annual projections based on total nitrogen concentrations averaged on a rolling 2 month basis. If the 12 month average is taken, the total calculated total nitrogen load is 1,191 kilograms or 79% of the Consent Condition limit.

Graph 1 Nutrient Loading Calculated in accordance with Clause 11 of Council Consent Conditions for the Byron May STP

Generally speaking the performance of the system has been above expectations however, the limited recycled water schemes commissioned to date has caused this situation. The new draft Recycled Water Management Strategy should mitigate this situation in the longer term.

To put the situation in context, the graphs below show the actual performance of the treatment plant with nutrient reduction.

From these graphs it can be seen we are well within the EPA licence limits.

Courses of Action to Prevent Further Exceedences of 02-1329

The recently adopted Recycled Water Management Strategy 2017-27 will have a significant impact on the management of nutrients and hydrology in the Belongil. This strategy will see

· Expansion of Wetlands throughout the catchment

· Use of recycled water to rehabilitate degraded water ways

· Expansion of the western corridor

By 2027 it is expected recycled water schemes will equate to 76% of the total STP inflow. The only issue with this is with wetlands outside of EPA Point 4 will not be accounted for in Resolution 02-1329 methodology. This will need to be considered.

Financial Implications

The recently adopted Recycled Water Strategy 2017-27 is to be factored into the Water and Sewer Strategic Business Plan.

Statutory and Policy Compliance Implications

Council resolution 02-1329.

Venue	Conference Room, Station Street, Mullumbimby
Date	Thursday, 13 September 2018
Time	11.30am