C.1.1 Background and Previous Investigations

This case study summarizes the investigation of a former landfill site on Kure atoll, a remote island in the central Pacific Ocean. A detailed discussion of the investigation is presented in the report Evaluation of Green Island Landfill and Reburial Pit, Former U.S. Coast Guard LORAN Station Kure (USCG 2009). A copy of the report is available from the HDOH Hazard Evaluation and Emergency Response Office.

Kure atoll is the northernmost island in the Hawaiian island chain, located approximately 1400 miles northwest of the island of Oahu and 56 miles northwest of Midway atoll (see Figure C.1-1). The atoll consists of a lagoon encircled by a reef and a single, vegetated island (Green Island, Figure C.1-2). Green Island is just under 1.5 miles long and about 0.35 miles wide and has a maximum elevation of around 15 feet. The island is not inhabited on a permanent basis although it is visited periodically by marine research groups.

A USCG station was located on the atoll from the 1960s through the 1990s. When the station was operating, a small, approximately ½-half acre area on the southwest corner of the island was used to dispose of old electrical components and scrap metal (e.g., capacitors, batteries, and transformers, see Figure C.1-2). Debris and approximately 700 yd3 of PCB-contaminated soil were removed from the site in 1993. Discrete, confirmation soil samples identified concentrations of PCBs as high as 170 mg/kg within the former landfill footprint (see Figure C.1-3). Soil, sediment, and biota samples collected in the surrounding area indicated that PCB contamination was primarily restricted to the landfill site.

Kure Atoll location map.

Figure C.1-1. Kure Atoll location map.
Source: USCG 2009, Figure 2-1.

 

Green Island map showing location of former landfill area.

Figure C.1-2. Green Island map showing location of former landfill area.
Source: USCG 2009, Figure 2-2.

 

Summary of 1992 and 1993 soil sample PCB data.

Figure C.1-3. Summary of 1992 and 1993 soil sample PCB data.
Source
: USCG 2009, Figure 2-3.