The Blades Groundwater site sits in Blades, Sussex County, Delaware, near Morgan Branch and the Nanticoke River. EPA added it to the National Priorities List in September 2020. Contamination is found in groundwater and in residential and public water supply wells drawing from the Nanticoke and Columbia Aquifers. The site is divided into two operable units. Operable Unit 02 (OU 02) covers an interim remedy and is further along in the process. Operable Unit 01 (OU 01) will address the full sitewide cleanup.
Five contaminants of concern have been identified: chromium(VI), cobalt, lead, perfluorooctane sulfonic acid (PFOS), and perfluorooctanoic acid (PFOA). PFOS and PFOA are per- and polyfluoroalkyl substances, often called PFAS. The metals are linked to electroplating compounds. Both PFAS and the metals can cause adverse human health effects. The City of Blades' public drinking water is treated to remove PFOA and PFOS and meets federal and state standards. The Delaware Department of Natural Resources and Environmental Control (DNREC) has supplied filtration systems to residents whose water meets the state action level for PFAS but not the EPA action level.
In summer 2022, EPA completed a Time-Critical Removal Action, installing water filtration systems at homes where sampling showed contaminant levels above EPA's action levels. A removal action for OU 02 ran from March 2022 through December 2024. In February 2024, EPA issued a Record of Decision selecting an interim remedy for OU 02. That remedy includes point-of-use and point-of-entry water treatment systems, connection to a municipal water supply, and local ordinances to prevent new well installations. Remedial design for OU 02 is estimated to finish between February and April 2027. For OU 01, the remedial investigation and feasibility study began in December 2020 and is estimated to finish between October and December 2027, with a Record of Decision expected around the same time.
EPA is still investigating the source of contamination. Human exposure and groundwater migration status both have insufficient data to draw firm conclusions. Physical construction of the cleanup is not yet complete across the entire site. One business currently operates at the site, employing 10 people and generating about $1.9 million in annual sales revenue.
Community members can review site records at the Seaford District Library at 600 N. Market Street Extended in Seaford, Delaware, or at the U.S. EPA Region 3 office in Philadelphia. EPA held a public meeting on July 20, 2023 at the Blades Fire Company and accepted public comments from June 29 through July 28, 2023. Responses to public comments are included in the 2024 Record of Decision. Residents with questions can also contact the EPA staff assigned to the site.
