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Waitākere
Ranges Local Board
09 June 2016
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7
December 2015
Letitia McColl
Property review team
Panuku Development
Auckland
Review
of land for disposal in Glen Eden – Feedback from Waitakere Ranges Local Board
Panuku
Development Auckland has asked the local board for comment on two council owned
properties in Glen Eden which are being considered for sale.
Glen
Eden is zoned for growth and is currently regarded as under supplied with open
space. A study of the future open space needs of Glen Eden should be undertaken
to inform decisions around property disposals.
The
local board went on a site visit to the two sites in question and we provide
the following feedback:
315a
Glengarry Road, Glen Eden – support retaining for park use
The
Glengarry Road property should be retained by council for use as a local park.
It has great amenity value and is ready for use as a pleasant park in its
current state.
The
land has a significant street frontage and considerable flat land which could
in the future lend itself to a range of recreational and community uses.
The
local board asks that the property be transferred to local parks. A modest
investment may be looked at in future to enhance the park with signage and
furniture and activation.
Glen
Eden overall is undersupplied with open space.
The
local board is currently looking at how to improve the local park network in
and around Glen Eden. We need to make better use of our existing parks, and to
look for the opportunity to expand the open space network and improve walking
and cycling connections.
The
land has value as a greenways connection to the nearby Nicholas Reserve, which
provides access through to West Coast Road. The local board is working with
Auckland Transport to create a shared walking and cycling path along West Coast
Road, and this provides a further link. In future we would look for the
opportunity to connect 315a Glengarry Road, though to the reserve on Milan
Drive.
1/16
Sarona Avenue, Glen Eden
In
the proposed Auckland Unitary Plan, this part of Glen Eden is zoned for
intensification. The Sarona Avenue property is a ten minute walk from Glen Eden
train station and town centre, and is located on the edge of the Terrace
Housing/Apartment Zone where it transitions to a mixed housing urban zone. See
attached map.
The
area is undersupplied with open space, which will become more of an issue as
housing density and population increases.
Glucina
Reserve is connected to 1/16 Sarona Avenue by a stream, though the Sarona Ave
property is otherwise inaccessible from the park and looks to be neglected. As
a first step we would like to see the property and the area around it cleaned
up. Rubbish and debris has been dumped into the stream and one side is very
overgrown with weeds.
The
piece of land in question has some challenges as a park though, given the
zoning of the surrounding area, we think it could be retained and planted up as
a streamside bush reserve to provide some green space and a wildlife link.
There
is a 26 unit Housing New Zealand property at 4100 Great North Road which is
connected to Glucina Reserve by a streamside walkway. This is on the opposite
side of the stream from 1/16 Sarona Ave. Some consideration should be given as
to whether 1/16 Sarona Ave can be made accessible from this walkway to provide
a communal space for surrounding residents, including the HNZ tenants. Could it
be a community garden for instance?
The
property has no street frontage and is on a flood prone area alongside a
stream. On the face of it, the land would have limited market value should
council to decide to dispose of it which may beg the question of whether it is
worth selling. The local board would like to know the estimated sale value of
the property.
Glen
Eden zoning in proposed Unitary Plan
Purpose
1. To seek
landowner approval from the Waitākere Ranges Local Board to replace the
leaking underground leachate storage tank system at the closed landfill at Waitākere
War Memorial Park with an above ground storage tank system.
Executive summary
2. Auckland
Council (Council) is the owner and operator of the Waitākere War Memorial
Park closed landfill which has a leachate system located at 13 Bethells Road,
Waitakere, legally described as Pt Allot 27 Psh of Waipareira SO 36531
(2.0133HA).
3. This leachate
system is part of the closed landfill which sits underneath the Waitakere War
Memorial Park. Leachate is the name given to rainwater and groundwater which
flows through the rubbish within a closed landfill. It picks up contamination
along the way and in this instance drains into an underground storage tank
located at the eastern end of the site. This tank is regularly emptied by a mobile
tanker, transported to the waste transfer station in Henderson and discharged
to the wastewater network.
4. The leachate
collection tank at the Waitākere War Memorial Park is a below ground
structure. It has failed and urgently needs to be replaced to prevent leachate
entering the adjacent stream.
5. To
temporarily manage this risk a bypass arrangement has been installed. This has
only been partially successful and with increased rainfall through the winter
months council urgently needs to get a permanent solution in place to prevent
direct discharge of leachate to the stream.
6. Staff have
assessed three options for replacement of this tank. Two material options
comprising an above ground tank and a below ground tank have been analysed and
assessed. A do nothing approach is not acceptable. A detailed multi-criteria
analysis was completed and is attached to this report as attachment A. The key
criteria considered are:
· Health and safety for council staff and
contractors and park users,
· Environmental performance of the
installation options
· Flexibility and or future proofing of the
installation options
· Impact on stakeholders, and
· Cost
7. Particular
focus has been paid to safety in design when considering the options. The
Health and Safety at Work Act 2015 requires council to assess the design
aspects of its facilities with regard to safety. Under this new legislation
council is required to eliminate or mitigate health and safety risks throughout
the lifetime of the asset. A significant risk to be mitigated is the
contractor’s exposure to methane in an enclosed space. Placing the tank above
ground eliminates this risk. This risk cannot be eliminated from the below
ground option.
8. Each of the
above criteria were weighted with health and safety being given the highest
weighting and cost the lowest.
9. Overall the
above ground option can achieve a better level of environmental performance,
eliminates a significant risk, allows for more flexibility for future leachate
management and finally is significantly more cost effective.
10. On the basis
of this analysis, it is recommended that the above ground option be progressed.
11. Concerns about
the loss of visual amenity value and the potential impact of the above ground
tanks on the park have been raised. To address these concerns it is proposed
that a landscape architect be engaged to provide options for mitigating this
impact. These options may include landscape appropriate tank colouring and
native screen planting. Any existing parks management plans and local board
preferences would be part of the consideration for this mitigation. Other
suggestions from the board to mitigate this impact, including the footprint and
height of the existing security fence, landfill cap improvements to support the
community aspiration for footpath and community input to the mitigation, will
be incorporated in the project.
Comments
Problem Definition
and Proposal
12. The leachate
system, which is part of the closed landfill at the Waitākere War Memorial
Park 13 Bethells Road, Waitakere, legally described as Pt Allot 27 Psh of
Waipareira SO 36531 (2.0133HA), has failed. Council needs to urgently replace
this leachate system to remove the risk of leachate discharging directly to the
adjoining stream and the ground around the tank becoming undermined.
13. Staff have
assessed options for replacing this system and recommend the installation of a
two tank above ground system for the storage of leachate at Waitākere War
Memorial Park. This report seeks landowner approval from the board for this
system.
Options
14. Two options of
an above ground and a below ground tank have been assessed. A detailed
multi-criteria analysis is attached to this report as attachment A. The key
criteria considered are:
· Health and safety for council staff,
contractors and park users,
· Environmental performance of each option
· Flexibility and or future proofing of the
installation options
· Impact on stakeholders, and
· Cost
15. These criteria
have been weighted as follows:
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Attribute
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Weight
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Safety
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4
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Environment
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3
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Stakeholder disruption / added
value
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2
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Cost
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1
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Table One: Criteria Weightings for
Waitakere Leachate Tank Options
16. Each of the
above criteria were weighted with health and safety being given the highest
weighting and cost the lowest. The above ground option scored highest overall.
It is recommended that the above ground option be progressed.
17. A number of
scenarios were considered under each option and the impact of these were scored
out of 10. With one being the less effective and ten being the most effective.
This scoring is described in detailed in attachment A. A summary of the scoring
is:
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Considerations
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Option
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Safety
Implications for contractors and park
users
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Environment
Potential
impacts on surface water, groundwater and soil quality
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Stakeholders
Landfill managers, park managers and users, neighbours
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Value
Capital and operational expenditure
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Combined score
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Above ground tank Option
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57.3
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43.5
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31.3
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13
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145.1
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Underground tank option
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45.3
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39
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30
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12
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126.3
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Table Two: Evaluation of Options for
Waitakere Leachate Tank Options
18. Overall the
above ground tank option is recommended because it can achieve a better level
of environmental performance, it will allow staff to have immediate visual
indicators in the event that the tank or the piped connections leak, and it
will offer more flexibility in the future should the need to change the way
that leachate is managed or the need to replace the tanks arises.
19. A significant
consideration in analysing these options was health and safety. Due to the
nature of the landfill environment the risks associated with the installation
and operation of subsurface structures, in particular the presence of landfill
gas, are significant. The above ground tank installation is recommended
selected as it removes the need for works in a below ground pit as part of the
installation and ongoing maintenance of the tank.
20. Also the above
ground design is significantly cheaper than an underground option with initial
quotes suggesting that it is around $150,000 cheaper.
21. In making this
recommendation particular focus has been paid to safety in design. The Health
and Safety at Work Act 2015 requires council to assess the design aspects of
our facilities with regard to safety. Under this new legislation council is
required to eliminate or mitigate health and safety risks throughout the
lifetime of the asset. One of the large risks to contractor safety is exposure
to methane in an enclosed space. Placing the tank above ground eliminates this
risk. This risk cannot be eliminated from the below ground option.
22. It is
understood that under the new health and safety legislation there are
overlapping Persons in Control of Business or Undertaking (PCBU)
responsibilities with respect to this installation. Board members and council
officers would be considered to be the PCBU in this instance and therefore have
a primary duty to provide a safe working environment, safe plant, safe systems
of work as well as other duties around provision of information training,
supervision, facilities and monitoring or health and conditions of work
23. The below
ground option does not eliminate the risk associated with working in an
enclosed space with a hazardous atmosphere. The intent of the legislation is
that where overlapping PCBU responsibilities exist, the parties work together
to identify the best way to eliminate these risks. If elimination of risks is
not possible then controls should be put in place to minimise them. The above
ground option eliminates these risks.
Potential
Effects and Mitigation
24. Concerns about
a reduction in visual amenity at the site from the preferred option have been
raised. It is recognised that there will be some minor visual impact as a
result of locating the tanks above ground. However, it is considered that this
is minor and not out of context with the setting, where there are existing
leachate maintenance structures such as raised manholes. Furthermore, water
tanks, which look very similar in shape and size to the leachate tanks
proposed, are a common feature in a rural settlement such as Waitākere,
where residents harvest rainwater from their roofs.
25. A photo
montage of what the above ground dual system
installation would like without any mitigation is provided in attachment B.
26. It is proposed
that we seek advice from a landscape architect on how to mitigate the minor
visual impact of these tanks for example by painting them a colour which blends
with the local landscape and by incorporating some screen planting in
consultation with the local community. A meeting to discuss this was held with
community members on 8 June 2016.
27. The community
were satisfied with the above ground tank option but would like to see some
screening of the facility to minimise the loss of visual amenity. They asked
for the tank to be painted a colour that would assist with blending into the
background such as green or brown.
28. In addition to
the visual impact there are a number of beneficial effects associated with the
tank replacement, namely that the replacement tank system is expected to
improve the performance of the site by minimising losses to leachate to the
adjacent stream. In addition the dual tank system will allow us to complete
maintenance of tanks without taking the system offline.
29. Unlike with an
underground tank, the above ground system will enable maintenance contractors
to immediately see if there are any leaks from the tank connections rather than
these being hidden underground as at present. Maintenance of the tank
installation will not require ground breaking works or the need for enclosed
space entries.
30. Following a
workshop with the local board some areas for consideration were raised around
the preferred option and associated works with the landfill. Staff can
incorporate the following into the project:
· Ensuring the above ground storage does
not increase the existing security fence compound footprint.
· Ensuring the above ground storage does
not exceed the height of the existing security fence compound.
· Supporting the community proposed and
funded park footpath by completing cap improvements beneath the footpath out of
regional landfill maintenance budgets.
· Work with the community to identify an
appropriate level of screening around the existing security fence compound. A
community meeting was held on 8 June 2016 to agree on the value adding features
they would like to see.
Consideration
Local board views and implications
31. The options
and recommendation were discussed with the local board at a workshop on 2 June
2016. Staff understand that the board’s key concern is around the loss of
visual amenity value at the park. As described above staff have taken this
feedback on board and will address this concern by painting the tank a colour
that will blend with the surrounding landscape and with appropriate screen
planting following community engagement. In addition staff note the factors
around the footprint of the existing site and will ensure these aspects are
covered off as described above.
32. At this same
workshop with the local board on 2 June 2016, staff discussed the possibility
of reviewing the current performance of the landfill cap on the site with a
view to undertaking further improvements to the park surface to offset the loss
of amenity value. Improvements to the performance of the cap would be expected
to reduce the volume of leachate generated by this site. Improvements to the
cap would also improve the usability of the park which we consider would be a
positive benefit to the community and may off- set concerns around the minor
visual impact. Staff will work with the community to look at options for
remediating this in time for the proposed footpath works and most likely in the
earthworks season.
Māori impact statement
33. Due to
emergency nature of this work, consultation with Mana Whenua has not been
undertaken to date.
34. As the site is
a closed landfill and there is an existing underground tank in the location of
the proposed works it is considered unlikely that there are known sites of
significance to Mana Whenua located within the vicinity of the works area.
Implementation
35. Landfill
control infrastructure is not formalised through a designation at this site and
will be subject to the standard provisions of the Proposed Unitary Plan, the
Auckland Regional Plan: Air Land and Water and the Rodney District Plan. Due
to the urgent nature of these works they would be completed under the Emergency
Provisions (Sec. 330) of the Resource Management Act and consent applied for
retrospectively.
36. The granting
of land owner approval for the proposed works is undertaken as part of the
local board’s role and landowner of local parks. This approval does not bind
council in its capacity as a regulatory authority in any way, and any consent
given under this agreement is not an approval or consent in its regulatory
capacity, and vice versa. Council will not be liable to any other party if, in
its regulatory capacity, council declines or imposes conditions on any consent
any party seeks for any purpose associated with this approval.
