CROMWELL, Conn. (AP) - It took seven hours for firefighters from four departments to knock out a blaze that tore through a sewage treatment plant in Cromwell.

The fire was reported in the incineration wing of the Mattabassett District sewage treatment facility at about 7:30 a.m. Monday. Crews from Cromwell, Middletown, Westfield and Rocky Hill responded.

Executive director Arthur Simonian says staff called in the blaze after noticing that a tank that stores granular carbon was too hot and starting to smoke.

Officials say water treatment is not affected but sludge burning has been temporarily halted.

Simonian says it's too soon to know how much repairs will cost, but they are expected to take between three to five months to complete. The full extent of the damage to the facility is not yet known.