SWMU 05 - IRFNA/MAF-4 Disposal Site

 

SMWU 5 is a site where, in 1975, approximately 7,000 pounds of fuel was emptied from leaking drones into a low spot in a road near Building 422. The Quebrada where the disposal took place is in the probable surface recharge area for one of the few naturally occurring springs on the island that flows year-round. The site is less than 2 miles from Cattle Cooperative Well 3PW01 and a spring, both of which were used by the local cattle cooperative until 1992.

The fuel contained 5,275 pounds of inhibited red fuming nitric acid (IRFNA) and 1,775 pounds of mixed amine fuels (MAF-4) which were emptied into the Quebrada. Although much of the material has likely evaporated or decomposed naturally since 1975, site investigations were conducted during the PA/SI to evaluate the potential presence of nitrogen-containing chemicals in the soil.

Surface and subsurface soil samples were collected from the entire length of the ditch that was reported to have received the IRFNA/MAF-4 fuel spill runoff in 1975. Soil was monitored at several depth intervals up to the underlying granite rock. The only chemical of potential concern identified for SWMU 5 was benzo[a]pyrene in surface soil. This chemical is probably not related to the IRFNA/MAF-4 spill and may be associated with migration of polycyclic aromatic hydrocarbons (PAHs) from the asphalt road or vehicle emissions to the adjacent ditch.

The risks at SWMU 5 are within acceptable human health limits for maintenance workers, industrial workers, recreational visitors, and or residents (if the site were to be developed for housing in the future). SWMU 5 does not present a health risk concern to current or future users of this site and was therefore recommended for No Further Action.