7 February 2020
Memorandum
To:
Devonport-Takapuna, Hibiscus and Bays, Kaipātiki and Upper
Harbour Local Boards
Subject:
Trial of Foamstream for the management of weeds in the road
corridor.
From:
Jenny Gargiulo
Principal Environmental Specialist, Community Facilities
Purpose
1.
To inform elected members about an upcoming trial of a weed management product called
Foamstream within the road corridor across the Tahi region.
Summary
• In April 2019 Community Facilities took over the responsibility for weed management in the
road corridor. Auckland Transport previously held the weed management contract.
Community Facilities has continued to use the same treatment methodology employed by
Auckland Transport in the Tahi region. A mix of hot water and mechanical removal with
some spot spraying for the treatment of specific weeds.
• Hot water treatment is not an effective way of killing the entire plant including the root
system. Hotwater treats the foliage and can prevent/reduce seed production and restrict
growth. Hot water does not destroy the foliage of some types of weeds (nutgrass and
kikuyu for example)
• Ventia, the Full Facilities supplier for the Tahi local boards, is investigating the use of a
product called Foamstream for use within the road corridor in the areas where hotwater is
currently being used.
• Foamstream is a product used to manage weeds. When added to hot water it creates a
thermal layer that has been found to make it more effective in killing weeds than hot water
alone. It is non-toxic and approved for use by the Environmental Protection Agency.
• The Auckland Council Weed Management Policy encourages the investigation into
alternative methods of weed management.
• For any weed management product to be considered for use on public land it must comply
with all Auckland Unitary Plan rules, have approval from the Environmental Protection
Agency and consider organisational targets for environmental improvement. This would
include any impact of the foam on the waterways.
• In February 2020, a three-month trial of Foamstream will commence in the Tahi full
facilities contract region to evaluate the product for use to manage weeds in Auckland.
Context/Background
2. Due to Auckland’s temperate climate the region is particularly vulnerable to weeds and introduced
pest plants which can spread if unchecked, displacing native plants and threatening biodiversity.
3. Council uses different weed control methods depending on the species, site characteristics,
infestation level, wider landscape characteristics and other factors such as legislative
requirements. Our weed control methodologies include manual control, mechanical control,
biological control, hot water and herbicide.
4. Options for weed management completed by the council must take into consideration the eight
objectives of the Weed Management Policy 2013 and all the Auckland Unitary Plan rules. For the
use of herbicide, the council follows the guidance of the Environmental Protection Agency which
grants approvals and conditions for weed control products
Weed Management in the Road Corridor
5. Since April 2019 vegetation in the road corridor has been managed by Community Facilities
through the full facilities contracts. For the first year of the contract Community Facilities has
continued with the legacy methodologies from Auckland Transport (Attachment A).
6. This continuation of legacy arrangements means that there are differences between local board
areas in the methods used to meet weed management outcomes. In Devonport-Takapuna,
Kaipātiki and part of Upper Harbour and Hibiscus and Bays local boards the methodology used to
control weeds in the road corridor is predominately hot water and mechanical, with some spot
spraying of glyphosate for specific weeds e.g. nutgrass.
7. Hot water treatment is not an effective way of killing the entire plant including the root system.
Hotwater treats the foliage and can prevent/reduce seed production and restrict growth. Hot
water does not destroy the foliage of some types of weeds (nutgrass and kikuyu for example).
Additionally, this methodology uses 5000L to 6000L of water per day of deployment.
8. Venita, the full facilities contractor in the northern region has asked to use the Weedingtech
product Foamstream for managing weeds across the Devonport-Takapuna, Hibiscus and Bays,
Kaipātiki and Upper Harbour Local Board areas. They will be trailing Foamstream in place of
hotwater to evaluate if it is more effective at managing weeds. This would mean less visits and
reduced cost and water usage.
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ce https://www.weedingtech.com/nz/
9. Community Facilities is supportive of the trial as it complies with the Auckland Council Weed
Management Policy, which states that council should “together with our CCOs, trial alternative
methods of weed management and, where successful, promote them internal y and external y.”
10. Foamstream is a soluble concentrate which is added to hot water to create a foam that is applied
to unwanted vegetation. It contains sugars as the foaming agent, plus other components
(coconut, palm kernel and rapeseed oils, glucose from potato, maize and wheat, and
polysaccharides). Foamstream has herbicidal properties through a non-toxic mode of action; the
herbicidal effect comes from the prolonged heat of the foam. The foam acts to keep the
formulation on the plants longer, as well as being an insulator to keep the heat higher for longer.
Foamstream trial
11. Foamstream will be used for the weed management in kerb and channel and berms in the road
corridor across the northern region from February to May 2020.
12. The Healthy Waters Lifecycle Teams will be monitoring the stormwater to ensure there is no foam
discharges on the network or mobilization of pollutants. Community Facilities will liaise with
Healthy Waters and Auckland Transport to ensure there is no impact to the stormwater or
infrastructure.
Application and appearance and of the foam
13. Foamstream is applied by trained staff through a hose and lance at a rate of 12L/minute. The low
pressure makes it very safe. After application the non-toxic foam will be present for 15 to 20
minutes. Signage on the machinery and onsite will include information on the non-toxic foam.
14. Any further questions from the public on the foam and its use can be directed to the weed
management team in Community Facilities at
[email address].
During application
20 mins after application
Next steps
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15. From February 2020 Ventia will be using Foamstream across the Tahi region. There will be
regularly reporting to council on the locations where the product is been used which can be made
available to local boards if required.
16. The intent of the trial is to see if including a foam with the hotwater will make for more effective
weed control, resulting in less cost and water usage to meet the weed management service
levels.
17. At the end of the trial a memo will be provided to elected members with information on the results
and any plans for its inclusion into the integrated weed management approach by Auckland
Council.
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