PFAS in boreholes in the La Pulente area

WQ.84/2026

WRITTEN QUESTION TO THE MINISTER FOR THE ENVIRONMENT

BY DEPUTY J. RENOUF OF ST. BRELADE

QUESTION SUBMITTED ON MONDAY 16th 2026

ANSWER TO BE TABLED ON MONDAY 23rd 2026

Question

"Further to Oral Question 34/2026, regarding PFAS levels in private boreholes in proximity of the airport plume area', will the Minister advise –

1. whether Jersey Water or any other body has tested boreholes in the La Pulente area to determine whether the PFAS signature' of airport firefighting foam, specifically Aqueous Film Forming Foam (AFFF), has been detected in the water, thereby ground truthing' the Arcadis model of the plume distribution;
2. whether any such testing indicates that the plume signature' may be present in the La Pulente area, either at 100ng/l or through the detection of any of the four main PFAS chemicals;
3. the cost per test to establish the level of the four PFAS chemicals related to the firefighting foam plume in borehole water; and
4. the rationale for the Environment Department not testing the La Pulente boreholes to establish whether the PFAS plume has extended to La Pulente?"

Answer

1. I can advise that neither the Natural Environment Team within Infrastructure and Environment Department, nor Jersey Water or Arcadis (to my knowledge) have tested boreholes in the La Pulente area in the past 3 years to determine whether the PFAS signature' of airport firefighting foam is present, specifically Aqueous Film Forming Foam (AFFF). Jersey Water have undertaken tap tests last year as part of the requests from Water Quality and Safety Programme in 2025 to determine the levels of PFAS in drinking water within the home.

Broader groundwater monitoring took place during 2023-2024 to inform the hydrogeological model (PFAS distribution in a plume area defined by PFAS levels detected). This was reported in the  PFAS  Hydrogeological  Study,  Phase  2  Report  Hydrogeological  Risk  Assessment  and Remediation Optioneering Ref: Prepared By: Arcadis Consulting (UK) Ltd (available via this link Microsoft Word - 10050570-ARC-XX-XX-RP-ZZ-0005-P3-Hydrogeological Risk Assessment & Remediation Optioneering P3 ISSUE

2. Tap testing at La Pulente properties was carried out in 2025 to determine the quality of drinking water. One of the tap tests carried out in August 2025 was sent to Arcadis for a preliminary assessment of the PFAS AFF signature. Their response (sent to the residents on 11 December 2025) confirms that the La Pulente area is outside of the conceptual plume area defined by the Arcadis Hydrogeological Survey 2025. The assessment from Arcadis states that "while the catchment is complex and some connection to the plume area cannot be ruled out, the PFAS signature within the [La Pulente] borehole water is not clearly similar to the PFAS signature as observed within the plume area".  

However Arcadis qualify their assessment, which was based on a single tap test from a third party and therefore their comments are a high-level review of a single data point, and no reliance can be given to the commentary. This is reasonable given that a full investigation into the multiple sources of PFAS is a complex and time-consuming process and not one that can be conclusively delivered by a single data point. This was also confirmed by the PFAS Scientific Advisory Panel in their public online meeting on 12 March 2025 when they directly addressed this point and confirmed that in private meetings with residents, they are careful not to draw conclusions regarding the plume boundary, and in particular that scientific conclusions should not be drawn from single data sets. These meetings are recorded and available to view by emailing [email protected]

3. I am advised that water tests cost:

Broad suite in waters - £272.02 per sample

TOP Assay in waters - £425.72 per sample

Price s for these will increase in April 2026. Fingerprinting analysis would require both tests in combination,  and a broad suite  would cover the "four  chemicals", over  multiple  sampling occasions  over  through  a  year  to  include  seasonal  effects.  In  addition,  an  assessment  by hydrogeological / PFAS consultancy with expertise in PFAS type signatures would also be needed, for which I do not have accurate costing as they are subject specific.

4. The Natural Environment Team within Infrastructure and Environment Department, and Arcadis undertook sampling in 2023-2024 at multiple points around the airport to establish the conceptual plume'. They continue to monitor borehole A3 which is in the wellfield and is the closest to the La Pulente properties. Given the level of trace detections on this borehole, this continues to delineate the edge of the plume. Plumes are more concentrated by the source and will only increase again further away with additional inputs (sources). As a result, it was deemed unnecessary to test further away from the source and into La Pulente. The same rationale was used in deciding the northern edge of the plume.