Landfills

From mid-2021, there’s been a distinct increase in the number of odour notifications for the Spicer Landfill. Run by Porirua City Council, the landfill is located at the end of Broken Hill Road next to Tawa and Kenepuru.

Unpleasant odour can have a real impact on the surrounding communities. We’re working together with Porirua City Council, Envirowaste, odour experts and residents of the area to better understand and resolve this problem.

Te Whatu Ora (Health New Zealand) have provided public health advice to residents living near Spicer Landfill:

Advice for Residents Living Near Spicer Landfill

From Te Whatu Ora - Health New Zealand Read more here

date_range Published 07 Oct 2022

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What makes an odour 'offensive or objectionable'? 

The term ‘objectionable’ is used in consent conditions; it is a subjective term and is open to interpretation. There is guidance from case law (Donnely v Gisborne District Council) in which the normal meaning was applied: that is the odour is considered undesirable, displeasing, annoying or open to objection.

GW has developed a standard practice and procedure to assess odour to limit the subjectivity of our odour assessments. We record the frequency, intensity and duration of the odour, as well as the level of offensiveness and the location in which the odour is detected. For example, an industrial area or a rural environment might have a higher tolerance for certain odours than a residential area. This procedure ensures that our odour assessment can stand up to challenge. You can see an example of our  odour assessment sheets here (XLS 253 KB) .

If you smell an offensive or objectionable odour from Spicer landfill:

• Please call Porirua City Council on 0800 237 1500. This is a 24/7 number, and they will notify us.
• Provide details of the odour, such as how intense it is and where you think it might be coming from.
• You’ll also need to provide your name, address, and phone number. These will be confidential and will not be released to other parties.

Anyone in the community can report an odour issue. Please notify us when the odour is occurring so that an officer can assess it.

All calls will be recorded and triaged as appropriate.

What resource consents do PCC hold to operate the landfill?

PCC holds a suite of discharge consents issued by GW under the Resource Management Act 1991. These include consents to discharge refuse to land, and odour to air. These resource consents were issued in 1996 via a full public process, which was open to submissions, and expire in 2030.

PCC and GW are in the process of reviewing the consent conditions to modernize them so that they align with best practice. PCC are managing this process and will be seeking input from the community in the near future. For further information on the change of conditions, please contact PCC. 

Why are they allowed to discharge odour?

The consents only allow odour discharges to a certain threshold – much like noise is allowed to a certain decibel limit. This threshold is known as ‘offensive and objectionable’.

There is guidance from case law (Donnely v Gisborne District Council) in which the normal meaning was applied: undesirable, displeasing, annoying or open to objection.

A test will be applied by the court that the term objectionable will be as it applies to "the minds of a significant cross section of reasonable people in the community". 

How do you measure odour? 

Odour can only be measured by the human nose currently.

The duty officers who respond to odour complaints have all been trained on how to assess odour, and we have a  standardised system to record the odour monitoring undertaken. (XLS 253 KB)  

What makes the odours? 

As with your household rubbish, refuse disposed at the landfill breaks down releasing gases – some of which are odorous. Different areas of the landfill release different odour depending on the type and age of the underlying refuse.

Why doesn't PCC stop these odours?

PCC owns the solution to these odour issues – the key is that PCC needs to manage the site to prevent offensive and objectionable odours being experienced in the community.

Why do the odours only occur sometimes?

The weather, wind and on site practices all play a part in whether an odour is experienced in the community. The site management needs to take account of all these factors to prevent offensive or objectionable odours in the community. There is still work PCC needs to do to get it right.

So what does the resource consent exactly say regarding odour?

The resource consent conditions for odour states that:

“The consent holder shall take all practicable steps to prevent offensive or objectionable odours being detected at or beyond the boundary of the site as defined by the District Plans. Offensive odour shall be determined by an enforcement officer of the Wellington Regional Council.”

This means PCC needs to do everything within their means to prevent offensive or objectionable odours beyond the landfill boundary – by putting measures in place to reduce or mitigate odours and operating within ‘best practice’ landfill management practices at all times.

As mentioned above, PCC is working towards changing these conditions. 

Who determines offensive odours?

The public and residents who live round the landfill advise GW of offensive or objectionable odours, and GW officers assess if it is offensive or objectionable. The resource consent conditions state this.

What is an abatement notice?

An abatement notice is an enforcement tool which regulators of the Resource Management Act 1991 use to set a specific timeframe by which the individual or company (those on whom the abatement is served) shall either do a certain thing or shall cease a certain activity. 

In the case of an activity where there is a consent, an abatement notice is a powerful tool in order to help bring a consent holder into compliance with their consent, within a set time period. 

What makes an odour 'offensive and objectionable'?

The term ‘objectionable’ is used in consent conditions; it is a subjective term and is open to interpretation. There is guidance from case law (Donnely v Gisborne District Council) in which the normal meaning was applied: that is the odour is considered undesirable, displeasing, annoying or open to objection. GW has developed a standard practice and procedure to assess odour to limit the subjectivity of our odour assessments. We record the frequency, intensity and duration of the odour, as well as the level of offensiveness and the location in which the odour is detected. For example, an industrial area or a rural environment might have a higher tolerance for certain odours than a residential area. This procedure ensures that our odour assessment can stand up to challenge. You can see an example of our  odour assessment sheets here (XLS 253 KB) . Our odour assessment procedures are in accordance with national best practice and the Ministry for the Environment Good Practice Guide (which is currently being updated).

What about impacts on my health? 

Te Whatu Ora - Health New Zealand  is aware that residents living near Spicer Landfill are expressing their concerns about the health effects in relation to the odour issues from the landfill.

Te Whatu Ora - Health New Zealand have provided some guidance in relation to health concerns raised. You can read this guidance here:

Advice for Residents Living Near Spicer Landfill

From Te Whatu Ora - Health New Zealand Read more here

date_range Published 07 Oct 2022

Download now (PDF 219 KB) get_app

T and T Landfills Limited operate a construction and demolition landfill in the Owhiro Stream catchment. The site holds a suite of resource consents to operate from Wellington Regional Council and Wellington City Council. The site is located at 289 Happy Valley Road.

In addition to T and T, two other landfills operate in the catchment, the Wellington City Council Municipal 'Southern Landfill' and another construction and demolition landfill known as C and D Landfill.

This page aims to provide easily accessible information to the public and community affected by these water quality issues; and to assist in understanding the process for reporting environmental incidents to GWRC. 

If you have a question, or would like to find out more, please contact our Environmental Help Desk at 04 830 4255 or email us at notifications@gw.govt.nz

To log an incident regarding the T and T Landfill site, or water quality in the Ōwhiro Stream, please follow this process: 

• Call the GWRC Environmental Hotline on 0800 496 734; and
• Provide details of the incident and your contact details such as your name, address and phone number (these will be confidential and will not be released to other parties unless we have your permission to do so). 

A duty officer will determine if a site investigation is warranted to collect information, and if so, will head out to the area. They may call you to seek additional information or clarification about the issue.  

If we find the site is not complying, we will take follow up action. 

Are T and T landfills allowed to discharge to the Ōwhiro Stream?

Yes, but only if they meet their consent conditions. The consent sets limits on contaminants to ensure the stream environment impact is minimised to an acceptable level.

What is the adaptive management framework under T&T Landfill Limited discharge consent?

T&T Landfill Limited have a suite of resource consents for the operation of the landfill. One of these consents is a discharge permit which allows T&T Landfill Limited to discharge contaminants including sediment-laden stormwater, leachate from the site to tributaries of the Ōwhiro Stream. The discharge is subject to a number of resource consent conditions which T&T Landfill Limited needs to comply with to manage the effects of the discharge on Ōwhiro Stream and its tributaries. In particular, the resource consent sets out discharge quality limits and an adaptive management framework. Under their consent conditions T&T Landfill Limited is required to:

• Undertake quarterly groundwater and surface water quality monitoring and get these samples analysed for a range of parameters;
• Do a comparison of the quarterly water quality sample results with the limits set out in the consent conditions and with Australia and New Zealand Guidelines for Fresh and Marine Water Quality Guidelines (ANZECC Guidelines);
• If the consent limit for any parameter is exceeded, and where that parameter also exceeds the latest ANZECC Guideline, a further round of sampling must be undertaken within 1 month of the exceedance being detected.
• If the results of the second round of sampling show an increase in the level of any one contaminant, T&T Landfill Limited must engage an independent ecologist to provide an assessment of the ecological effects of the discharges from the site. The assessment must include (amongst other things) an assessment of whether the treatment methodology for the discharge is the best practicable option and recommendations on methods that could be used to further treat the discharge.
• The recommendations from the ecological assessment which are approved by GWRC must then be implemented by T&T Landfills within the timeframe specified by GWRC.

Have T and T Landfills met all their consent requirements?

No, T and T are currently not complying with their consent, and GWRC already has taken enforcement action in the form of an Abatement Notice.

What requirements of the consent have T and T Landfills not met?

There are two interlinked matters that T and T have not met for the consents they hold for the site:

1. A wetland to capture and treat leachate in place of the current stilling basin has not been constructed (due to the need to divert clean stormwater around the site and out of the wetland area)
2. A clean stormwater diversion system has not been constructed yet

T and T landfill currently have a resource consent application with GWRC awaiting approval for the stormwater diversion system. T and T have been working with WCC property team who own the lower part of the site to resolve issues relating to the design of the system.

Why don't you close them down until they comply?

GWRC does not have the power to close sites under the Resource Management Act. Our first response to incidents such as this is always to work with the consent holder to address and reduce the environmental effects. Secondly we investigate to determine the seriousness of any non-compliance and whether enforcement action is required. 

What sort of landfill is T and T?

T and T is a construction and demolition waste landfill, and cannot accept any hazardous or household waste for disposal. However, the site has operated for a number of years (since the 1960's) and the nature of the waste in the first stages of the landfill is known to contain material that would not be allowed today.

Has there always been a landfill there? 

Here is a brief history of landfilling at the site (source 2006 GWRC report to Hearing Committee):

“While historical information for the area is scarce, it is believed that the large gully that is subject to the filling activity has had some form of landfill or dumping since the 1960’s. Some form of informal agreement between WCC and the operators at the time is believed to have existed to allow the site to run as a landfill with minimal waste acceptance protocols in place. Between 1991 and 1995, a company known as Ace Demolition Limited, took over the site, operating it as a construction and demolition landfill – permitting concrete, reinforced steel and the like to be placed within the landfill. The applicant (T and T Landfills) took over the site in 1995 and has operated the site as a construction and demolition landfill until the present date.”

Is it safe to use the water from the stream to water plants?

The results of testing the stream for iron, manganese and zinc have shown that the levels of these do not pose a health risk when used for watering plants.  However, we are waiting on the results of further testing of Ōwhiro Stream to make sure there are no other contaminants of concern. As a precautionary approach we recommend using an alternative water source until these results are back, for example, rain water or tap water.

In general, stream water would not be recommended for watering vegetables during and for 48 hours following heavy rain, as urban streams can be contaminated by run-off from surrounding land.

What did the soil testing find?

Testing of the community garden soil was done on 8^th December 2016 and involved mixing samples from 4 different sites in the garden. The soil was tested for arsenic, chromium, copper, iron, lead, manganese, zinc and pH.  All of the levels, except for arsenic, were below concentrations with a potential risk to human health. The levels of arsenic were slightly elevated above the guidelines recommended for soil used for home grown vegetables and fruits (22mg/kg versus the recommended <17mg/kg).

What are T and T doing to stop this discharge?

 On 7^th December 2016, GWRC met with the landfill operator, their planning consultant and engineer to discuss any immediate actions that can be taken onsite to avoid, remedy or mitigate the effects of this discharge. T and T advised they will:

• Enlarge the wetland/ stilling basin onsite to increase its volume and therefore detention time. This wetland/ stilling basin receives all water that flows through the site and the engineer was confident that this would increase treatment.
• Begin works to divert clean water in the gully systems upstream of the landfill around the active landfill area before it enters the stream. This will reduce the amount of water leaching through the landfill.
• Remove dead vegetation from a gully which may be decaying and causing deoxygenation which could result in higher contaminant concentrations. 

What has been the impact on stream and fish life?

It’s clear from our inspections of the stream that there is a visible ‘iron/manganese flocculant’ in the bed of the stream, and this is still clear on the Ōwhiro Bay beach. While this is ‘visually’ concerning, we are seeking advice from our GWRC Science Team as to what ecological assessment of the stream life needs to be done.  We will also seek their view on the causes of the ‘foam’ which was present in the stream during rain.

What impacts did the discharge likely cause? 

GWRC Environmental Science advised that the discharge from the landfill may have had the following impacts on stream ecology - however, what is to early to say at this stage is the severity of these impacts (more on this below):

• Physical disturbance due to smothering from high suspended sediments and iron/manganese flocculant
• Toxicity associated with high metal loads both in dissolved and total phase
• Reduced light penetration thus impacting on aquatic plant life
• Potential reduction in oxygen availability in the stream
• Clogging of gills of resident aquatic biota (invertebrates/crustaceans as well as fish),
• Probable toxicity from ammoniacal-N and reduced dissolved oxygen availability
• Ongoing aesthetic impacts of deposited orange precipitate

We appreciated that these effects do raise concern, and that is why this initial 'screening' of the water quality samples have highlighted the need for a more intensive ecological assessment of the stream environment, to understand the degree of any impact from this discharge event in late November.

What is the source of the foam?

Foam forms when the water contains higher concentrations of dissolved organic matter (DOM) – such as from decaying matter washing downstream as well as that potentially mixed from the landfill.  It can be naturally occurring.  In this case, it is probably a combination of both naturally occurring DOM washing rapidly downstream from the surrounding catchment, mixed in with an unknown concentration of organic based chemical leachate from the landfill that has been flushed out of this system.  It is unlikely that the foam is purely landfill based contaminant leachate, and will contain a high amount of DOM washed down from the catchment.

What is the source of the red deposits on the stream bed?

This is largely due to deposited iron/manganese flocculant, sourced from the landfill leachate. This type of orange coloured precipitate occurs when reduced groundwater (i.e. low oxygen, but containing elevated concentrations of dissolved iron & manganese) then enters surface water and comes into contact with oxygen.  The iron & manganese then become oxidised in the surface water which forms the orange/rust coloured precipitate/floc that is then deposited as a fine layer in the stream bed.  

What are the Guideline levels for arsenic in soil?

The level of arsenic in soil is slightly higher than recommended for growing home produce. In New Zealand the primary source of information on soil contaminants is the National Environmental Standard for Assessing and Managing Contaminants in Soil to Protect Human Health. These National Environmental Standards (NES) include an indication of the maximum concentration of substances in soil to protect human health. The recommended maximum concentration varies depending on what the land is used for – for example, lower levels are recommended for a lifestyle block (where it’s assumed 25% of produce will be consumed from the land) and much higher for commercial or industrial land or sports fields. The guidelines recommend arsenic levels of 17 and 20mg/kg when 25% and 10% of produce is consumed from home gardens, respectively.  This level is considered to be conservative with a high safety factor to protect against potential health effects.

What should I do to minimise my exposure to arsenic in soil? 

We are all exposed to a background level of arsenic from the environment (via food, water, soil and dust) and swallowing small amounts of arsenic every day for a long time does not lead to obvious health effects. The main way that we are exposed to arsenic from a garden is via swallowing small amounts of soil contaminated with arsenic.  We should aim to lower the amount of arsenic we are exposed to from the soil by following these simple steps:

• Washing all produce thoroughly before consuming. We also recommend peeling root vegetables before consuming.
• Using gloves when gardening and washing hands carefully when finished
• Removing shoes that have been used in the soil before entering the house

The Ministry of Health have a booklet ‘Arsenic and Health’, which is a great source of additional information and advice and can be accessed online:

Arsenic and Health

This booklet contains information for people who live in areas contaminated with arsenic. It gives information on what you need to know and actions you can take to protect your… Read more here

date_range Published 01 Oct 2015

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The information in this pamphlet also covers situations where the level of arsenic is much higher than the level found from the soil sampling in Ōwhiro Community Garden.

Is it safe to eat vegetables in soil with slightly elevated arsenic levels?

The main way that arsenic enters the body from home gardens is via swallowing contaminated soil. The guideline level assumes that 100% of the arsenic in the soil we swallow will be absorbed by the body.  We know that the actual amount the body can absorb is a lot lower (around 70%) and so the level is set with a high safety factor. People can swallow small amounts of arsenic every day for a long time without any obvious health effects.

Although plants can absorb arsenic from soil, the levels absorbed will be much lower than what is found in the soil.  It is more important to remove soil and dust from the surfaces of vegetables and fruits.

We do not believe that the current level of arsenic is high enough to stop using the garden. However, it is important to take steps to reduce the amount of soil that might be swallowed, for example, dirt on unwashed vegetables or transferred from hands to mouth, while in the garden.  This includes ensuring vegetables are washed to remove any dirt from the roots and surfaces.  We also recommend that root vegetables are peeled before eating.

Eating fresh fruit and vegetables is important for good health, as is participating in the community garden.  The benefits of these activities for improving health are greater than any potential risk from arsenic in the soil. 

Is it safe to garden at the site?

We are exposed to small amounts of arsenic from the environment over our lifetime and when we are aware of a potential source, the aim is to reduce the amount of exposure.  Some simple steps can be taken to reduce the amount of arsenic exposure from gardening by limiting the amount of soil that could be swallowed.  This includes using gloves for gardening, washing hands after gardening and before eating, removing shoes used in the garden before entering the house.  The good thing about following this advice is it also helps protect against other illnesses that can be associated with gardening, for example, legionella and other bacteria.  Wearing a mask while gardening is also recommended to prevent breathing in legionella bacteria from soil and compost.

Is it safe for children to play in the garden? 

Young children tend to have more exposure to soil due to their higher level of hand to mouth activity.  It will be important to, as much as practicable, minimise the amount of soil swallowed by children by discouraging children from putting soil in their mouths, washing children’s hands frequently and washing children’s outdoor toys frequently to remove soil and dust.

The arsenic level detected in the garden is acceptable for soil used in parks and recreational areas, but above the guideline recommended for eating home grown produce. It will be important to limit as much as practicable the amount of soil swallowed by children while taking part in gardening activities.

Is it safe to swim in Ōwhiro Bay? 

The levels of contaminants sampled from Ōwhiro Stream are not of concern for swimming in Ōwhiro Bay.  However, at times the water in Ōwhiro Bay is not suitable for swimming, usually during and within 48 hours after heavy rainfall.  The water quality of Owhiro Bay is monitored weekly during the summer season. See here for information about the water quality at this site and any warnings that are in place. 

In general, urban streams are not recommended for recreational use such as swimming or paddling as the water quality can be unsuitable at times.  If there is contact with the stream water we recommend that people follow good washing hands practice after activity in or with the stream.