Phase One Environmental Surveys: Managing the Environmental Risk with a Desk Top Study

Various activities undertaken at industrial sites can pose a potential environmental risk to that site or the surrounding environment. Commonly, previous occupants of a site or neighbouring premises can significantly impact on the contamination levels present in the land.  

Through their site operations, processes and material management, land can become contaminated with a variety of pollutants including hydrocarbons, heavy metals, process chemicals and asbestos containing materials. Careful environmental management and monitoring is fundamental to ensure the site is of a satisfactory state with regard to minimising any impact on human health or the wider environment.

Within the rail industry, previous and current activities carried out at railway engineering works, maintenance depots, stabling sidings and marshaling/goods yards can all impact the actual site and the surrounding environment.  

What is the aim of a Phase One Survey?

The principal aim of a Phase One Environmental Survey is to determine whether there is a potential for contamination to be present which could impact on current or future uses of a site and potentially pose a risk to occupiers, neighbours or the wider environment. 

Additionally with regard to site development the potential for contamination may significantly constrain the proposed future use of a site or affect the development process.  For any proposed development or land restoration projects, establishing environmental or contamination risks on the site will usually be a requirement of your local planning authority.

What is the scope of a Phase One survey ?

The scope of the Phase One Environmental Assessment includes the following: 

  • examination of historic, recent and current Ordnance Survey plans to identify past and present activities which might have led to contamination of soil or groundwater both on the subject site and on adjacent sites (for example, from manufacturing processes, storage activities or waste disposal practices);

  • examination of published records and plans of the shallow and deep geology and hydrogeology of the site which allows for assessment of groundwater and surface water vulnerability to potential contamination, if present, and the possible direction of movement off site, if mobile; 

  • search of proprietary databases for environmental permits, consents to discharge, records of previous environmental incidents at the site and within the surrounding area as well as the location of above ground or below ground licensed fuel storage facilities; 

  • enquiries of the Local Authority Environmental Health Department to obtain information on environmental conditions, incidents and known contamination risks and on the Local Authority’s Contaminated Land Strategy; 

  • enquiries of the Environment Agency to determine if there are any records of known contamination issues or complaints, enforcements, prosecutions or other regulatory involvement affecting the site or surrounding area 

  • a site walkover survey to establish land uses and activities carried out on site which could pose an environmental risk. This includes storage and use of oils, fuels and other chemicals, locations of surface water/trade effluent drainage systems and the location of nearby water courses such as streams and brooks.

Sampling and analysis of soils, waters or other materials is not normally undertaken at the Phase One Stage.

What does a Phase One Environmental Survey report consist of?

A Phase One Survey report typically consists of: 

  • the historical environmental review including OS mapping
  • the findings of the various database searches
  • full details of the site walkover survey
  • a preliminary risk assessment
  • a conceptual model of site contamination

If significant risks are identified then further assessment is undertaken to evaluate pollutant linkages, set out criteria for evaluating the risk and outline appropriate actions to be taken.
In order to assess the risks associated with the presence of ground contamination, the linkages (or pathways) between the sources and potential receptors need to be established and evaluated.  This is in accordance with Part 2A of the Environmental Protection Act (EPA) 1990, which provides a statutory definition of Contaminated Land.

To fall within this definition it is necessary that, as a result of the land condition, contamination/pollution may be present on or under the land such that: 

  • Significant environmental harm is being caused or there is a significant possibility of such harm being caused; or 
  • Significant pollution of land and/or controlled waters is being, or is likely to be caused. 

The risk posed by contamination is assessed by considering the possible linkages and potential pathways between contaminant sources and potential receptors which could be harmed or polluted. 

Not only does a Phase One survey ensure the safe risk management for the well being of human health and the environment, it also outlines an action plan for a Phase Two Site investigation, if required. This tiered approach to environmental risk management means that if the Phase One report highlights any contamination or issues which would determine the site unsuitable for its proposed use then a Phase Two site investigation can be undertaken to determine the extent of the contamination, and to propose actions to remediate or rectify the problem.

For more information on our environmental monitoring services, please get in touch

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