PFAS-focused groundwater sampling

Client Name
TruRoots, LLC and Kirkland & Ellis LLP
Chico, California, USA
  • Environmental management, permitting & compliance


The project site was located in Chico, California, USA, a regional area that was known - based on pre-existing publicly available data - to have PFAS present in the groundwater. The client requested a focused groundwater sampling study to further assess and confirm, to the extent possible, the regional nature of the PFAS present at the site and whether the site itself represented a potential contributor to the known PFAS impacts.


SLR had previously completed an EHS due diligence assessment and a Phase I ESA of Smuckers, on behalf of the client, in support of the client’s proposed acquisition of the company. The findings of both assessments led the client to request SLR conduct a round of focused groundwater sampling at the site.

SLR’s team collected groundwater samples from 17 onsite groundwater monitoring wells. The sampling was performed in accordance with current California and federal PFAS sampling guidelines. The exercise included thorough pre-sampling preparation to ensure that no materials used during the sampling event contained PFAS contaminants. This included staff clothing, sampling materials, food and beverage, pumping equipment and tubing, and more. The sampling exercise also required meticulous attention at each stage to ensure no cross contamination occurred. Sampling was performed using low-flow sampling techniques and all 17 wells were sampled in less than five days.


Several PFAS congeners were identified in the sampled wells, however based on a thorough evaluation of the data, SLR advised the client that the site itself did not appear to represent a source of PFAS to the regional or local groundwater, and that the PFAS in the site groundwater likely originated from offsite sources. This conclusion was based on data indicating that PFAS was present across the site. The highest concentrations were found upgradient of the onsite buildings and were present mainly in the deeper zones of the aquifer and not in the shallower zones, indicating that PFAS was migrating onto the site from an offsite source.

The results of SLR’s focused groundwater sampling efforts led the client to agree to proceed with acquisition of the company.

A member of the SLR team carries out PFAS-focused groundwater sampling onsite.