Shell Todd's consent application - Climate Justice Taranaki

URS New Zealand Limited City Chambers, 142 Featherston Street PO Box 3367, Wellington 6140 New Zealand T:64 4 496 3750 F:64 4 496 3755

J:\Jobs\42780930\5 Works\NES Consenting\KA2\Blowdown Pit at Kapuni Wellsite KA2 for Shell Todd Oil Services Ltd (Letter).docx

27 March 2012 Project No. 42780930

South Taranaki District Council Private Bag 902 Hawera, 4640 Attention: Blair Sutherland

Planning Team Leader Dear Blair Subject: Resource Consent Application - Removal/Remediation of Flare/Blowdown Pit

at Kapuni Well site KA2 for Shell Todd Oil Services Ltd

1 Introduction

This letter has been prepared by URS New Zealand Limited (URS) on behalf of Shell Todd Oil

Services Ltd (STOS) in support of a resource consent application for the removal of the

flare/blowdown pit and potential removal of associated contaminated soil at Kapuni Well site KA2

pursuant to Regulation 11 of the Resource Management (National Environmental Standard for

Assessing and Managing Contaminants in Soil to Protect Human Health) Regulations 2011.

The works will include the removal of the flare/blowdown pit earthen bunds and potential removal of

contaminated soil from beneath and adjacent to the bunds for investigation and/or remediation

purposes.

This letter describes the activities that will be undertaken, the potential environmental effects

associated with the activities and the measures proposed to mitigate these effects.

Site: Kapuni Well Site KA2, Rapid # 140, off Palmer Road, Kapuni

Legal Description: Lot 1 DP 10168 TNF2/103 (Certificate of Title Attached)

Applicant: Shell Todd Oil Services Ltd (STOS), Private Bag 2035, New Plymouth

Address for Service: URS New Zealand Limited, City Chambers, 142 Featherston Street, P.O.

Box 3367, Wellington, 6140

Attention: Suzanne Lowe, Ph: 04 496 3766, Email: [email protected]

2 Site Description

The site is an operating production well site (gas) and is owned and operated by STOS. A site

layout plan is attached.

A flare/blowdown pit is located on the central northern boundary of the well site and is estimated to

extend approximately 1.5 to 2.5 m below surrounding grade and has not been used since

approximately 2006.

mailto:[email protected]

Blair Sutherland Planning Team Leader 27 March 2012 Page 2

J:\Jobs\42780930\5 Works\NES Consenting\KA2\Blowdown Pit at Kapuni Wellsite KA2 for Shell Todd Oil Services Ltd

(Letter).docx

3 Description of the Proposed Activity

3.1 General

Flare/blowdown pits were historically used to contain potentially contaminated vapour, water and

condensate associated with gas well development, maintenance and operation. Standing water

arising from these activities was generally removed for off-site disposal.

STOS has undertaken to decommission the flare/blowdown pit and the associated containment

bunds at this site. During decommissioning work STOS also intends to remove soil from the

flare/blowdown pit area that is assessed as not suitable for remaining on site. Such soil would be

transported to an off-site facility licensed to accept such waste.

The sketch below shows a schematic section of the bunds, the flare/blowdown pits, and extent of

excavation beneath the pit required to remove soil not suitable for remaining on site.

Sketch: Schematic Section of Flare/Blowdown Pit – extent of contamination is unknown

The extent of excavation will be determined on site based on observation of the condition of the soil

(discolouration, odour, free-phase product, etc) and confirmed later through laboratory analyses of

soil samples. As a result the actual earthwork quantities are not known. However, the estimated

earthworks quantities are on the order of 100 to 500 cubic metres of soil disturbance over an

approximate area of 60 to 100 square metres.

Works will be undertaken and supervised by qualified personnel in accordance with STOS’

comprehensive health and safety requirements. A site-specific health and safety plan will be

developed and implemented for the works. All works will be conducted in accordance with

applicable Department of Labour/Occupational Health and Safety rules.

The works are likely to take two to six weeks to complete and would commence following granting

of the consent.



(Letter).docx

The proposed works are not significantly different to the majority of maintenance works completed

by STOS at the Kapuni well sites.

A description of the proposed flare/blowdown pit decommissioning and contaminated soil removal

methodology is provided below.

3.2 Stockpile Areas

Temporary stockpile areas will be established on site to allow for characterisation of soil to

determine whether it is suitable to remain on site or will be removed to an off-site facility consented

to accept waste soil. Soil assessment criteria are described in Section 3.4.

Stockpile areas will be established at locations not subject to stormwater run-on and remote from

drains, soakage areas, etc.

If stockpiled soils are inferred to be contaminated the stockpile area would be established/managed

as follows:

Construction of an earthen (300mm) or staked hay bale bund at the periphery of the stockpile

Lining of the bund with PVC, HDPE or EPDM liner with a minimum 300 mm overlap at for each

liner sheet (not welded or glued)

Stockpiles to be less than 4 m in height and with a stable slope

Covering or wetting of stockpiles to minimise odour and dust effects.

Stockpiled soils inferred to be not contaminated will be managed similarly but would not be

provided with a liner.

3.3 Earthworks

Proposed earthworks include decommissioning of the existing flare/blowdown pit bunds and

removal of soil assessed to be not suitable to remain on site. It is anticipated that the majority of

soils will be suitable for reinstatement on site. Soil assessment criteria are described in

Section 3.4.

The sequence of earthworks will be as follows:

Isolation/protection of stormwater drains in the immediate vicinity of the works.

Standing water present in the flare/blowdown pits will be pumped from the pit and transported

off site for disposal/treatment at a facility licensed to accept such waste.

Excavation of existing flare/blowdown pit bunds to stockpile, segregation of soil visually

assessed as contaminated to separate stockpile.

Test pitting of soils adjacent to the flare/blowdown pit to determine the extent of potentially

contaminated soil.

Excavation of overburden soil to stockpile, segregation of soil visually assessed as

contaminated to separate stockpile.

Excavation of contaminated soil to stockpile. The maximum anticipated depth of excavation is

1 m below the groundwater table. Wet soil would be allowed to drain back to the excavation

from the excavator bucket prior to placement in stockpile.



(Letter).docx

Collection of soil samples from stockpiles, excavations and testpits to characterise the extent, if

any, of contaminated soil.

Observation of water within the excavation (if any) to determine the presence of sheen or other

indication of free-phase hydrocarbons. Removal of free-phase hydrocarbons to an off-site

facility licensed to accept/ treat such waste.

Backfill of the excavation below the water table with imported clean rock and/or gravel material

or suitable stockpiled soil.

Backfill and compaction of excavation with stockpiled soils assessed to be suitable or with

imported hardfill.

When suitable excess soil from excavations is available the remaining soil would be filled and

blended on site to match surrounding grades.

The area surrounding excavations will be graded to direct ground surface stormwater away from

the excavations. Dust and odours will be controlled by limiting works during high winds and/or

wetting soils as required to minimise off-site effects.

3.4 Contaminated Soil Characterisation

Soils will be characterised for off-site disposal or on-site filling based on the following criteria:

Ministry for the Environment “Guidelines for Assessing and Managing Petroleum Hydrocarbon

Contaminated Sites in New Zealand”, Revised 2011 (hereafter referred to as the Oil Industry

Guidelines)

The hierarchy set out in the Ministry for the Environment “Contaminated Land Management

Guidelines No. 2”, 2011

Resource Management (National Environmental Standard for Assessing and Managing

Contaminants in Soil to Protect Human Health) Regulations 2011

Excavated soils not meeting the above criteria will be disposed of off-site at a facility licensed to

receive such waste. Soils identified for off-site disposal will be characterised as required by the

receiving facility.

Soil samples in support of soil characterisation will be collected and analysed in accordance with

Contaminated Land Management Guidelines No.5: Site Investigation and Analysis of Soils (2011).

3.5 Off-site Disposal of Contaminated Soil

3.5.1 Disposal Locations

Soil not suitable for remaining on site will be disposed of at an off-site facility consented to receive

such waste soil. Preliminary off-site soil disposal locations include the following:

Colson Road Landfill, New Plymouth

Bonny Glen Landfill, Marton

Remediation New Zealand, Mokau Rd, Uruti

BTW Oeo Facility, Pihama

BTW Brown Road Facility, Waitara



(Letter).docx

The actual off-site disposal location will be determined based on the soil characterisation described

in Section 3.4 and the requirements of the receiving facility.

3.5.2 Transportation

Off-site transport of waste soil and waste liquids will be in accordance with the Land Transport

Rule: Dangerous Goods 2005. All off-site loads shall be covered and free liquids shall be removed

from waste soil loads for separate off-site disposal prior to transportation. Wheels will be inspected

prior to leaving the site and cleaned if required to minimise off-site tracking of soil.

The contractor will implement appropriate traffic management during the works, in accordance with

industry practice.

4 Requirement for Consent under the National Environmental Standards

The Resource Management (National Environmental Standard for Assessing and Managing

Contaminants in Soil to Protect Human Health) Regulations 2011 came into effect on 1 January

2012. Regulation 8(3) sets out the requirements for disturbing soil on potentially contaminated

sites (those sites listed as being on the hazardous activities industries list) that must be met in

order for the activity to be a permitted activity.

It is considered that the soil disturbance and soil removal required for the works described above

will exceed the permitted activity threshold of 25 m3 (disturbance) and 5m

3 (removal) per 500 m

2 of

land per year, respectively. Therefore, resource consent will be required.

In order to be considered as a controlled or a restricted discretionary activity under the NES, a

detailed site investigation of the piece of land must exist. In this case, a detailed site investigation

for the flare/blowdown pit area has not been undertaken. Therefore, consent is required as a

discretionary activity pursuant to Regulation 11.

5 Assessment of Environmental Effects

This section describes the potential environmental effects of the activity and the mitigation

proposed.

Overall the proposed works are likely to have a positive effect on the local environment through

decommissioning the flare/blowdown pits and through removal of soil, not suitable to remain on-

site, to an appropriate off-site disposal facility.

Risk to Human Health

Historic discharges to the flare/blowdown pit may have contaminated adjacent soils. During the

proposed activities site workers may be exposed to contaminated soils, which may present a

human health risk. The proposal includes development and implementation of a site-specific



(Letter).docx

health and safety plan in accordance with applicable rules to manage these (and other) risks. In

addition, STOS’ comprehensive health and safety requirements will be implemented during these

works.

The proposal may also involve off-site disposal of contaminated soil; thereby, reducing the overall

risk profile of the site in terms of soil contamination.

Based on the above it is considered that risks to human health associated with the proposed works

will be temporary and less than minor.

Transportation, disposal and tracking of soil and other materials

It is anticipated that the incremental effect of proposed works on traffic in the area of the site will be

less than minor. If required, traffic management will be in accordance with industry practice.

Contaminated soils and liquids will be removed for off-site disposal. Therefore, there is the

potential for releases/exposure during transportation and disposal.

In summary, the proposed controls include the following:

Transportation of waste soils and liquids off site in accordance with applicable rules

Covering waste soil loads during transportation and utilising water-tight truck beds as required

Checking and cleaning wheels, as required, to minimise off-site tracking of soil and debris

Disposal of soils and/or liquid wastes at facilities licensed/consented to receive such wastes

Based on the implementation of the above controls, the effects from transportation, disposal and

tracking of soil and other materials to the environment are considered to be less than minor.

Surface Water Quality

During the works there is potential that stormwater may come in contact with contaminated soil

and/or liquids. The proposed controls include the following:

Directing stormwater away from stockpiles, excavations and disturbed soil.

Isolation of stormwater drains and other features that may be impacted by the works.

Stockpile management controls, including lining, covering and height limitations. Covering

waste soil loads during transportation.

Based on these mitigation measures it is considered that the effects of proposed works on surface

water quality will be temporary and less than minor.

Air quality management – odour and dust

During the works odour and dust may be generated. The proposed controls include limiting works

during strong winds, appropriate stockpile management procedures, and, if required, wetting or

covering exposed soils. The site is located in a rural area away from any nearby residential

dwellings.

Based on these mitigation measures it is considered that the off-site effects of odour and dust will

be temporary and less than minor.



(Letter).docx

Noise

Noise will be generated by mechanical plant used on site for excavation, backfilling, stockpiling and

off-site transport. Although the duration of the works is anticipated to be four to six weeks, physical

works will likely only occur during the first and last week of that period (with the interim period used

to conduct soil quality laboratory analyses). The site is located in a rural area away from any

nearby residential dwellings.

Based on this it is considered that the off-site effects of noise will be temporary and less than

minor.

6 Consultation with Potentially Affected Parties

The site is owned and operated by STOS. No other parties are considered to be affected or

potentially affected by the proposed works due to the way the works are planned to be undertaken

and given the mitigation measures that will be implemented to control the works.

7 Suggested Draft Conditions for Consent

The following are suggested draft conditions for consent:

The works shall be undertaken in general accordance with this resource consent application.

Applicant to notify STDC of the intended start date, no less than one week prior to works

commencing.

Applicant to dispose of contaminated natural soil to a facility authorised to receive the soil, and

must notify STDC of the soil disposal facility to be used.

Applicant to submit a report to STDC following completion of the works, documenting the

decommissioning of the flare/blowdown pit.

8 Conclusion

Overall the proposed works are likely to have a positive effect on the local environment through

decommissioning the flare/blowdown pits and by implementing mitigation measures during the

works in accordance with current best practice.

The potential effects on the environment from the proposed are considered to be less than minor

and appropriate mitigation measures will be implemented as outlined above. STOS owns and

operates the site. No other parties are considered to be affected or potentially affected by the

proposal.

Therefore, it is requested that this consent is processed as a non-notified application in accordance

with Section 95(2)(A) of the Resource Management Act because the adverse effects of the activity

on the environment will be less than minor.

As such, it is considered that consent should be granted. Prior to the approval of the consent it is

requested that a copy of the draft conditions be provided for our review.

Please contact the undersigned if you have any questions.

Final

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File: Drawn: SS Approved: SL

Figure:

A4

1

STOS KAPUNI FLARE/BLOWDOWNPIT INVESTIGATION

SHELL TODD OILSERVICESLIMITED(STOS)

SITE LOCATION PLAN

Whilst every care is taken by URS to ensure the accuracy of the digital data, URS makes no representation or warranties about its accuracy, reliability, completeness, suitability for any particular purpose and disclaims all responsibility and liability (including without limitation, liability in negligence) for any expenses,

losses, damages (including indirect or consequential damage) and costs which may be incurred as a result of data being inaccurate in any way for any reason. Electronic files are provided for information only. The data in these files is not controlled or subject to automatic updates for users outside of URS.This drawing is subject to COPYRIGHT.

Rev.ADate: 19/03/201242780930\Site_Locations.mxd

0 1 2 3 40.5km

1:50,000Scale

ProprietorsShell Todd Oil Services Limited

Estate Fee SimpleArea 1.3673 hectares more or lessLegal Description Lot 1 Deposited Plan 10168

InterestsAppurtenant hereto is a right to take, convey and lead water and other rights created by Transfer 274929.5 -17.2.1981 at 12.10 pm

Identifier

Search Copy

Land Registration DistrictDate Issued 17 February 1981

Taranaki

COMPUTER FREEHOLD REGISTERUNDER LAND TRANSFER ACT 1952

TNF2/103

Prior ReferencesTN266/29 TNC1/857

Transaction IdClient Reference 42780930.00500

Search Copy Dated 19/03/12 11:51 am, Page 1 of 2Register Only

Identifier TNF2/103

Transaction IdClient Reference 42780930.00500

Search Copy Dated 19/03/12 11:51 am, Page 2 of 2Register Only

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Shell Todd's consent application - Climate Justice Taranaki