A contaminated water supply was discovered recently during a scheduled sampling event performed by the Puerto Rico Department of Health. Analysis revealed levels of at least one organic solvent in concentrations 4xs that of the MCL for drinking water.. The solvent is "believed" to be Tetrachloroethene, that among its many industrial uses is still used to degrease metal prior to painting or other finishing. The source of the contamination is unknown; however, it was discovered that the supply well casing has been compromised and there is an auto body facility located in close proximity to the site. The water supply system serves approximately 82 residences.
EPA was requested to assist the Commonwealth government via a verbal from the EQB.
A EPA sampling event is being set up to sample the raw well water and the cistern which stores the finished water supply which will confirm the type of contaminates present and at what concentration. Samples will be sent to a CLP laboratory with a 48 hour turn around time. Once the data is reviewed an eligibility determination will be made to assist the government of Puerto Rico by continuing to supply the affected residents with a temporary potable water supply. The PR National Guard is currently being used to transport potable water into the system.
ERT has been requested to assist OSC Rodriguez with determining the sources of contamination and developing options to reestablish a permanent water supply system. Discussions have already started looking at the possibilities of repairing the existing well, installing a new well, installing an air stripper and or carbon filtration system.
The ERRD pre-remedial branch is being engaged to assist in the investigation of the contamination source and will be using the information obtained in the investigation to determine if this site can be listed on the NPL.
