Progress engineered. Problems solved.
contaminated land remediation
Contaminated sites pose risk to human health, environment and development value. At GWE, we deliver full-spectrum environmental engineering services from site investigations and risk assessment through remediation, validation, compliance and expert evidence. We help clients transform risk into opportunity, with technical solutions that stand up to regulators and communities alike.
Why GWE for Contaminated Land Remediation
Risk-based clarity
we assess and prioritise contamination sources, focusing efforts where it matters.
Defensible delivery
our remedial plans, validation and reporting align with regulation and scrutiny.
Regeneration focus
we don’t just clean up; we support safe redevelopment of brownfields.
Multi‑Contaminant Remediation Expertise
What we do
GWE assists owners of contaminated sites to meet the requirements of the National Environmental Standard for Assessing and Managing Contaminants in Soil to Protect Human Health (the NES). GWE reports are certified by in-house Suitably Qualified and Experienced Practitioners (SQEPs), as required by NES. We can provide our clients with the following services:
Resource consent application and guidance
We prepare clear, evidence-based resource consent applications and provide practical guidance to navigate regulatory requirements, ensuring faster approvals and reduced compliance risk.
Preliminary Site Investigations
Our contaminated land specialists routinely carry out Preliminary Site Investigations. A Preliminary Site Investigation (PSI) is often referred to as a desktop study because it doesn’t usually involve sampling and analysis of the soil. The main objective of a PSI is to gather information about a piece of land to determine whether it may potentially be contaminated, to assess the suitability of the land for its current or intended land use and to design a detailed site investigation (if required).
Due diligence, pre-purchase investigations
Existing residential, commercial, industrial and rural sites
Proposed subdivisions and changes in land use and soil disturbance
Detailed Site Investigations
Our contaminated land specialists routinely carry Detailed Site Investigations. A Detailed Site Investigation (DSI) involves the collection of field data and samples using intrusive (and possibly non-intrusive) techniques to identify, in a statistically robust manner, the nature of the contamination present on a site and delineate its extent.
Heavy metals eg; arsenic, cadmium, copper, chromium, nickel, lead, zinc and mercury
Pesticide residues eg; organochlorine pesticides such as DDT and Dieldrin
Asbestos eg; asbestos containing material (ACM) or asbestos fibres
Hydrocarbons eg; TPH, PAH and BTEX
Remediation Action Plans
We work closely with our clients to prepare cost-effective Remediation Action Plans (RAP) to mitigate the risk posed by contaminants. Before developing a RAP, an analysis of remedial methods may be prepared to determine the most appropriate methodology (or methodologies) for the site. This analysis may form part of the RAP or may also be prepared as a separate remedial options report.
Horticultural use (market gardens, glass houses, spray sheds, orchards, vineyards)
Asbestos in poor condition or in soil following building demolition
Livestock dip and spray races
Mechanics or wrecker’s yard
Uncontrolled or non-engineered fill
Septic tank or on-site wastewater system
Gas stations
Site Management Plans
The key purpose of a Site Management Plan (SMP) is to ensure that when undertaking works on contaminated sites the potential risks to the health of workers, the on-site environment and the off-site environment are adequately managed. In less complex cases all the requirements of an SMP could be included in a remediation action plan (RAP). An SMP will cover aspects such as:
Site management, roles and responsibilities
Preliminary works
Waste soil classification
Contamination protection measures
Potential presence of asbestos
Air monitoring, dust and odour control
Unexpected contamination discovery
Site Validation & Certification
Effective remedial design should be closely monitored and certified by a qualified professional. GWE is regularly involved with contaminated land and groundwater remediation projects with strict clean up goals and achieving validation. We summarise our findings in a validation certifying report which is required by council to satisfy consent conditions. An SV&C Report will cover aspects such as:
Rationale and justification for the validation strategy
Verification of compliance
Conclusions and recommendations
Analysis of the validation results
Documentation and chain of custody records
Expert Support & Consent Assistance
We provide expert evidence, regulatory liaison, consenting support and professional guidance through environmental approvals and audits.
Why choose GWE
Early intelligence
PSI/DSI focus effort where it matters, saving time and cost.
SQEP‑certified compliance
NES‑aligned, consent‑ready reporting and expert evidence that withstand scrutiny.
End‑to‑end delivery
due diligence, PSI/DSI, RAP & SMP, remediation, validation and certification.
Proven across contaminants
heavy metals, hydrocarbons, solvents, pesticides and asbestos; enabling safe redevelopment.
How we work (LIFT)
L
Listen
we begin by understanding contaminant sources, site use and stakeholder risk tolerance.
I
Innovate
we apply tailored remediation technologies that balance cost, effectiveness and environmental impact.
F
Follow Through
we don’t stop at the plan; we manage remediation, validate results, certify outcomes and monitor long-term performance.
T
Team Up
we coordinate with clients, regulators, engineers and specialists to achieve safe, sustainable outcomes.
Frequently Asked Questions.
What is a Remediation Action Plan (RAP)?
A RAP is a site-specific strategy that outlines how contamination will be managed, defining remedial objectives, methods, timeframes and validation.
Do all contaminated sites need remediation?
Not necessarily, often risk assessments guide whether intervention is needed or if monitoring controls suffice.
How long does remediation take?
Timing depends on site size, contaminant type and strategy, and can be anywhere from weeks to months or longer for more complex sites.
Can you redevelop land after remediation?
Yes, we validate sites to meet regulatory closure, then hand-over cleaned sites that are safe for redevelopment.