OSWER/OSRTI 

Washington, DC 20460 

NATIONAL PRIORITIES LIST (NPL) 

***Proposed Site*** September 2011 

COROZALWELL Corozal, Puerto Rico 

 Site Location: 

The Corozal Well site, which consists of a ground water plume with no identified source(s) of contamination, is 

located in Barrio Palos Blancos, Corozal, a rural community in interior north-central Puerto Rico. The site straddles 

the border between the municipalities of Corozal and Naranjito. 

 Site History: 

Ground water contamination in the Comunidad Santana well was discovered in November 2010, when the Puerto Rico 

Aqueduct and Sewer Authority (PRASA) collected samples from non-PRASA system wells on behalf of the Puerto 

Rico Department of Health (PRDOH). Samples collected from the Comunidad Santana well on November 12 and 23, 

2010 indicated the presence of tetrachloroethene (PCE), a solvent used for many industrial purposes, at concentrations 

above EPA’s Safe Drinking Water Act Maximum Contaminant Level (MCL). Due to the confirmed exceedance, 

PRDOH ordered the well to be closed and an alternate water source was provided. Additional samples collected by the 

Puerto Rico Environmental Quality Board (PREQB) and EPA from November 2010 to February 2011 confirm the 

presence of PCE in the well. PREQB surface water sampling also indicates the presence of PCE in the unnamed creek 

adjacent to the well, at concentrations ranging from nine to 23 μg/L. Samples collected by PREQB from the two 

closest known commercial/industrial facilities did not indicate the presence of PCE. 

 Site Contamination/Contaminants: 

PCE is present in ground water and surface water near the Comunidad Santana well. PCE is a solvent used as a 

degreaser and other industrial purposes. The PCE concentrations detected in the Comunidad Santana drinking water 

well exceeded EPA’s Safe Drinking Water Act Maximum Contaminant level prior to the well closure. 

 Potential Impacts on Surrounding Community/Environment: 

The contamination currently affects the Comunidad Santana well (Public Water System ID [PWSID] # PR0724147), 

which is the sole source of drinking water for a rural community of more than 200 people. Other community supply 

wells are located within approximately one mile of the plume. Currently, PCE has not been detected in these wells. 

 Response Activities (to date): 

PRDOH ordered the well to be closed upon discovery of the contamination. The pump was removed from the well to 

avoid usage, while PRASA, the National Guard and EPA provided an alternate water source for the affected residents. 

In February-March 2011, EPA installed a granular-activated-carbon (GAC) treatment system at the site, reinstalled the 

well pump, and began to pump treated well water into the community water supply for distribution. EPA is in the 

process of investigating possible source areas, but the specific source(s) of contamination has not yet been identified. 

 Need for NPL Listing: 

Other federal and state cleanup programs were evaluated, but are not viable at this time. EPA received a letter of 

support for placing this site on the NPL from the Commonwealth of Puerto Rico. 

[The description of the site (release) is based on information available at the time the site was evaluated with the HRS. The description may 

change as additional information is gathered on the sources and extent of contamination.] 

For more information about the hazardous substances identified in this narrative summary, including general information regarding the effects of exposure to 

these substances on human health, please see the Agency for Toxic Substances and Disease Registry (ATSDR) ToxFAQs. ATSDR ToxFAQs can be found on 

the Internet at http://www.atsdr.cdc.gov/toxfaq.html or by telephone at 1-888-42-ATSDR or 1-888-422-8737.