Fact Sheet

EPA Sequential Sampling Study in St. Croix, U.S. Virgin Islands

November 2023

The U. S. Virgin Islands (USVI) has been investigating the cause of "red" drinking water on the islands of
St. Croix, St. John, and St. Thomas, USVI. The main cause is likely to be aging infrastructure, which is
predominantly comprised of ductile iron that is rusting. The USVI government and EPA conducted
sampling in St. Croix on September 28 and 29, 2023. A total of 108 samples were collected at 66
sampling locations. Of the 108 samples taken from 66 sampling locations, 38 samples taken from 36
locations exceeded EPA's Lead Action Level. VIWAPA conducted follow-up sampling of the 36 locations
in mid-October and confirmed the results of the first study. EPA is providing technical support to the
USVI government as it works to address these lead levels.

EPA's highest priority is protecting people from exposure to lead in drinking water. A key step to
learning more about St. Croix's drinking water is to conduct sequential sampling to determine if lead is
present in homes and if it is coming from the home's plumbing or water service line.

In response to the samples containing high levels of lead and copper, EPA is conducting a study, called a
Sequential Sampling Study, of 11 homes in St. Croix the week of November 6, 2023. The homes were
selected based on the results of the September and October water meter sampling events, which
identified homes with elevated lead that are regularly using WAPA water. The University of the Virgin
Islands partnered with EPA to schedule the sampling with homeowners and provide a fact sheet to help
communicate the sampling procedure. The USVI government helped EPA collect the samples.

The EPA's Sequential Sampling Study is designed to help determine the extent and location of lead and
copper contamination within the service lines to each of the homes. It will profile the plumbing line from
the faucet tap back to the main distribution line. This study will help EPA and USVI partners determine
potential sources of the lead to better understand the problem so it can be addressed.

The sampling consisted of taking multiple unfiltered water samples from the customer's tap, one after
another, to determine the sources of lead in the home. This could include plumbing products containing
lead. Examples of such products include brass fixtures, solder, galvanized water lines and lead service
lines.

The samples that EPA collected the week of November 6 have been sent for analysis to the EPA Region 2
Laboratory in Edison, NJ. Upon completion of sample analysis, EPA experts will develop a final report
that will be shared with the USVI government and federal partners, as well as posted to EPA's web page.
This final report is expected to be complete by mid-December 2023.

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