Vieques Island/Atlantic Fleet Weapons Training Area
The next Restoration Advisory Board (RAB) meeting is tentatively scheduled for Tuesday, November 17, 2015, 6:00 PM, at the Punta Mulas Lighthouse.
Sampling in the Laguna Anones Area | Español
As part of the ongoing work at the Atlantic Fleet Weapons Training Area - Vieques Superfund site, the Navy is investigating contamination in the Laguna Anones area, which is part of a larger area that is being investigated. Under EPA and Puerto Rico Environmental Quality Board oversight, the Navy has been evaluating this area for several years to determine if chemical contamination or munitions are present. As part of this work, soil in areas immediately surrounding the lagoon (see Map [PDF 877 KB, 1 pp]) was sampled in March 2013.
Due to dry weather conditions and low water levels, it was not possible to take surface water samples in March. Soil surrounding Laguna Anones was sampled and the EPA has received the first validated data from ten samples collected by the Navy (see Sampling Results [PDF 25 KB, 2 pp]). The sampling is ongoing and the Navy will take over 200 samples from the area over the next several months, including 15 sediment samples and 6 surface water samples from Laguna Anones.
Five “multi-increment” soil samples were taken in the top 2.5 inches of soil. Multi- increment sampling is a technique that is used to get representative samples in surface soil. In addition, five deeper surface soil samples were taken from a depth of 2.5 inches to 24 inches.
The samples were analyzed for explosives and a variety of metals. The results were compared to screening levels, including human health, ecological health and migration to ground water levels, which are levels at which a contaminant might be expected to penetrate soil and get into ground water. These screening levels are used to help identify areas, contaminants and conditions that require further evaluation. Concentrations below these levels generally do not require additional assessment.
Explosives were not detected in seven of the ten samples and none of the ten samples had levels of explosives that exceed human health screening levels. Four explosives, HMX, nitroglycerin, RDX and perchlorate, were detected in three multi-increment samples of surface soil. In one case, RDX exceeded the ecological screening value. HMX, nitroglycerin and RDX in two of the multi-incrementsamples were detected at levels that exceed migration to ground water soil screening levels. No explosives were detected in the deeper soil samples.
In one multi-increment and two deeper surface samples arsenic was detected above the human health screening level. Cobalt, manganese and vanadium exceeded ecological screening values in several samples. A number of metals including arsenic, antimony and manganese were found at concentrations that exceeded levels that could migrate into ground water in samples taken from both the immediate surface and from between 2.5 and 24 inches deep. Arsenic, as well as some other metals, occur naturally in the soil. The Navy, with EPA and PREQB oversight, will evaluate if these metals could be attributed to “background” concentrations, levels expected to be found in an area under normal conditions.
The initial round of ten samples does not provide enough information on which to draw any conclusions. Additional data from ongoing Navy sampling will be used to more fully characterize environmental conditions in the area.
Samples of ground water have also been taken to determine if the ground water has become contaminated and what contaminants may be present. The results of the ground water sampling are not yet available but they will be shared with the public, as well as the results of samples taken by the Navy in the area over the next few months. The EPA is committed to sharing information with the Vieques community as soon as it becomes available.