"Manageable level" refers to a point or situation that is under control and can be easily handled or dealt with. It suggests that the task or problem is not too difficult or overwhelming, making it possible to handle effectively. Full definition
This damage can be repaired if it is kept at manageable levels. (whfoods.com)
I have it to a much more manageable level now — roughly an extra 10 ounces a day which can still take up freezer space pretty fast. (breastfeedingmamatalk.com)
The government is seeking to reduce the public spending deficit to manageable levels by the end of the parliament. (politics.co.uk)