EMB ERJ 170/175 ER/LR
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Less Severe
Air Traffic Control Issued New Clearance; Flight Crew Overcame Equipment Problem; Flight Crew Took Evasive Action
Aircraft
Approximately 10-15 minutes after leveling off at FL300; I noticed the cabin altitude was at 8;700 ft and slowly climbing; 100 ft every 5-10 seconds.  We accomplished the cabin altitude hi checklist; [advised] ATC; and descended to 10;000 ft. At 10;000; the pressurization seemed to work fine. We never lost pressurization and the highest the cabin altitude got to was 10;100. After contacting dispatch; we decided to continue to [destination] at 10;000 ft. We told ATC we had the problem under control and that we would like to continue. We had no further problems. Pack 1 had been just deferred prior to this flight.
[Report narrative contained no additional information.]
ERJ-170 flight crew reported descending to an appropriate altitude when their pressurization system malfunctioned.