Common queries are below – for other queries or to arrange a free consultation or please contact us using the above email address.


Where is NX based?

Our headquarters is located in Altrincham, Greater Manchester.​  However, NX deliver work across the UK; including Scotland and Wales.

Can you provide a quote over the phone?

We can provide typical budget costs but prefer not to provide a quote directly over the phone. If you’d like a quote, please send us a red line plan of your site and the proposed development works.

How long does it take to receive a quote?

Providing we receive your site plans via email, we endeavour to provide a quote within 48 to 72hours.

Why do I need a site investigation?

Basically, to reduce the risk of incurring abnormal development costs associated with unforeseen ground conditions and to provide information to your development team and to discharge planning conditions associated with your development.

What is a site investigation?

During a site investigation the engineering properties of soil and rock and groundwater are obtained to establish how they will interact with your proposed development. An assessment of potential contamination risks to humans, groundwater and the wider environment is also made to establish whether any remediation works required prior to and/or during development.

Site investigations are carried out in a phased manner, generally comprising:

Phase 1 — desk study
Phase 2 — intrusive investigation
Phase 3 — remediation strategy
Phase 4 — validation


Phase 1 Desk Study Report  – Guidance set out in UK guidelines CLR111, and the National Planning Policy Framework states that a Preliminary Risk Assessment with a site reconnaissance is required as a minimum to ascertain if there is a potential contamination risk as a result of a proposed development.  In this phase, a conceptual site model (CSM) & preliminary risk assessment (PRA) is created.  A CSM is a written and/or illustrative picture of the development site and the likely processes that control the transport, migration and potential impacts of contamination from soil, air, ground water and surface water to human and/or ecological receptors.

The purpose of the CSM & PRA is to review the site history in order to assess the likely ground conditions and hence the potential for poor ground to be present in relation to foundation engineering, or contaminated ground resulting from former site uses.  A walkover survey allows an inspection of any obviously contaminated areas of the site, a basic geomorphological assessment, and consideration of any constraints that could affect access for investigation plant.


Typically data sources will be reviewed as part of the preliminary risk assessment comprise; Historic Ordnance Survey mapping, environmental database including Environment Agency records (pollution incidents, abstraction licences, discharge consents, landfill register), British Geological Survey records, and records of current and former industrial landuse.


The preliminary risk assessment is used to further refine the Conceptual Model for the site development and to design the scope of the Phase 2 physical investigation works based on potential contaminated areas resulting from former development site uses.


Phase 2 – Intrusive Investigation


If a potential risk be identified, then an intrusive investigation (or phase 2 investigation) will be required to establish the likelihood and extent of the perceived risk. This can use a number of different intrusive methods such as hand excavated sampling, trial pitting, cable tool percussion drilling, window sampling, rotary rock core drilling.  It enables soils, groundwater and rock to be sampled, logged and submitted for analysis. Geotechnical data may also be gathered to obtain enable foundation and infrastructure design. The data gathered will be used to refine the conceptual model and risk assessment to establish whether a risk is present.


Phase 3 — Remediation Strategy


Should a risk be identified, then the next phase will be to carry out remediation. Soils may have become contaminated associated with the site history. Consequently, they may pose a risk to site users and also to the wider environment if they are not dealt with appropriately. These sources are not just restricted to soils in industrial areas. Agricultural land use may have introduced contaminants into soils including old orchards where lead and arsenic were used as a pesticide. There may also be a risk from ground gas arising from landfill sites or filled ground – this may migrate over quite large distances and has been known to cause explosions destroying domestic properties if not dealt with adequately.


We can guide you on this aspect too and find the most cost effective, appropriate way to deal with risks on your site.

Phase 4 — validation


Where developments have land quality planning conditions (Environment Agency, NHBC or Local Authorities) associated with any necessary remediation works, supervision and validation of remediation works are required to provide a  thorough and concise record of the remediation process which has been carried out.  A report or in some instances a certificate is produced which  are generally produced on a plot by plot/block by block basis during the development programme.


We’ll help you to clean up your land, get the results validated and signed off so that you can get on with building.


How long does it take to complete a Desk Study?

After instruction, we can provide a desk study within a week to 2 weeks of completing a site walkover.