Water quality standards regulations 
Puerto Rico. Environmental Quality Board. 
 - [San Juan, P.R.]  The Board  1976. 
<br/><br/> Includes amendments to certain sections.  "The original water quality standards regulation was filed in the Department of State on January 4, 1974, and was later amended on May, 1974.". 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Water quality--Standards--Puerto Rico.<br/>Agua--Contaminación--Derecho y legislación--Puerto Rico.<br/>Calidad de agua--Patrones--Puerto Rico.<br/>Water--Pollution--Law and legislation--Puerto Rico.