Velz, Clarence J. <br/><br/>
Applied stream sanitation 
Clarence J. Velz. 
 - New York  Wiley-Interscience  c1970 
 - ix, 619 p.  illus., maps.  23 cm. 
<br/><br/>Includes bibliographical references and index. 
<br/><br/><label>ISBN: </label>0471905259 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Stream self-purification.