In early 2024, Wiser Environment was appointed by Element Materials Technology to carry out groundwater monitoring for a large coastal industrial site in Southern England.
The monitoring formed part of the site’s Site Protection and Monitoring Programme, a requirement under its IPPC permit linked to the operation of its boiler system for heating and hot water. Our role was to deliver a clear, compliant, and reliable snapshot of groundwater conditions across key areas of the site, helping to support both regulatory obligations and long-term environmental management.
Our Approach
Our work began with two main focus areas: the Central Boiler House and the Former East Boiler House. These locations were selected based on their proximity to known historical activities and potential contamination risks.
From there, we set out to collect groundwater samples from eight boreholes across the site, strategically positioned to give a comprehensive picture of current conditions.
Before sampling, we measured groundwater levels and borehole depths using an electronic dip meter, then purged each location of standing water using a high-density polyethylene (HDPE) bailer, which helps ensure samples reflected current groundwater conditions and not stagnant water.
Once collected, samples were packaged and securely transported under strict chain-ofcustody protocols to the Deeside laboratory, where Element carried out detailed chemical analysis. The testing looked for a wide range of potential contaminants, such as hydrocarbons, metals, inorganics, and general water quality indicators like total organic carbon and suspended solids.
Access was also a consideration. One borehole was temporarily blocked by site infrastructure, and another could not be located, likely due to earlier groundworks.
During fieldwork, we observed strong visual and olfactory signs of hydrocarbon contamination in one northern borehole not previously investigated in 2019. Lab results later confirmed the presence of diesel-related compounds, aligning with these initial observations.
In contrast, other sampling points showed stability, with no detectable levels of petroleum hydrocarbons and consistent with findings from previous monitoring. One borehole, however, returned a noticeably higher reading, prompting further review. As this location wasn’t included in earlier datasets, a direct comparison wasn’t possible — but the result highlighted an area worth ongoing attention.
Outcomes
The monitoring confirmed stable groundwater quality across much of the site. However, hydrocarbon impacts remain in some locations, particularly in the northern area. This aligns with the site’s known history, including a diesel release near the Central Boiler House in 2011–2012.
Since then, remedial efforts have targeted the removal of floating contaminants, but our recent observations suggest some residual presence may persist beyond the originally affected area. While we haven’t confirmed the direction of groundwater flow, the location of these findings may indicate the value of further monitoring in the northern area.
Our work at HMNB Portsmouth has delivered clear, actionable insights to support compliance and guide future site management. By combining field expertise with careful reporting, we’re helping ensure long-term environmental protection and informed stewardship of this historically significant location.