You can modify the threshold and critical limit for the sites hosted on your server. These limits are common to all the sites hosted on the server.
To set the threshold:
eplconf set quota_threshold=<value>
where <value> is the new threshold value
service epld restart
To set the critical limit:
eplconf set quota_critical_limit=<value>
where <value> is the new value for the critical limit
service epld restart