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EPA Approves Puerto Rico’s List of Impaired Waters: New Pollutants Included for Waters of San Juan Bay Estuary, Rio Bayamon, Rio Grande de Arecibo

Release Date: 09/29/2010
Contact Information: Sophia Kelley (212) 637-3670, or Brenda Reyes (787) 977-5869,

(San Juan, P.R.) U.S. Environmental Protection Agency (EPA) has just approved the 2010 proposed list of waters in Puerto Rico considered either impaired or threatened by pollution, clearing the way for the Commonwealth to move forward to prioritize and address current water pollution threats. An impaired water body is one that does not meet water quality standards even after pollution controls have been put in place. A threatened water body is one that is expected to be impaired within two years. The Clean Water Act requires states to assess the quality of their waters and to report their findings every two years to EPA. In Puerto Rico, the list is created by the Puerto Rico Environmental Quality Board (PREQB) and is a valuable tool for reaching the goal of “fishable and swimmable” waters for the entire Commonwealth.

“Identifying and prioritizing Puerto Rico’s impaired waters is an important step in the fight against water pollution,” said Judith Enck, EPA Regional Administrator. “In the almost 40 years since the Clean Water Act was passed, we have made progress, but we still have a long way to go. The list of impaired waters helps local governments, businesses and concerned citizens create the best plans for addressing troubled bodies of water.”

Puerto Rico’s 2010 list identifies 593 instances in which a pollutant is causing an impairment of a water body that keeps it from supporting its designated use for drinking water, swimming and recreation, fishing or other activities specified by the Commonwealth. The most common pollutants causing impairment include pathogens, arsenic and dissolved oxygen.

The list also notes the sources of water pollutants. The most common sources include onsite wastewater systems, urban and stormwater runoff, and confined animal feeding operations. A pollutant may come from more than one source.

The list specifically includes impaired waters for which the development of a total maximum daily load (TMDL), a budget for water pollution, is necessary. TMDLs define the maximum amount of a pollutant that a water body can receive and still meet water quality standards. They are developed by states and approved by EPA once the Agency determines that the TMDL will allow the water body to achieve water quality standards.

In Puerto Rico, water bodies are assessed every two years for the presence of new pollutants. In 2010, new pollutants were included for waters in the basins of the San Juan Bay Estuary, Rio Bayamon, Rio Grande de Arecibo, and others. EPA will continue to build partnerships throughout the Commonwealth to ensure that impaired waters receive proper attention. Removal of a water body from the list may indicate that the water is restored or that it is receiving management attention that is expected to result in the attainment of water quality standards. Sixty-six waters were taken off Puerto Rico’s 2010 impaired waters list.

The complete list of impaired waters is available at:

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