Drupal places a  after text automatically?
I didn't see this problem before but maybe try to rewrite code above as follows:

&lt;?php 
//Drop Down Select
$sql = "SELECT user_id, concat (user_firstname,' ', user_surname) as username                       FROM   user_tbl WHERE coordinator='True'";
    $result = pg_query($sql);
         echo "Coordinator:&lt;select name='user_id'&gt;";
       while ($row = pg_fetch_array($result)) {
          echo  "&lt;option value='" . $row['user_id'] . " '&gt;" . $row['username']     ."&lt;/option&gt;";
 }
         echo "&lt;/select&gt;";
?&gt;