Appeal from an order of the Supreme Court (Keegan, J.), entered June 11, 1996 in Albany County, which denied a motion by defendant Utica Mutual Insurance Company for summary judgment dismissing the complaint against it.
Plaintiff commenced this action pursuant to Navigation Law article 12 to recover costs it incurred in association with the cleanup of a petroleum product discharge discovered in 1986 at a gas station owned by defendant Ladd’s Gas Station, Inc. Defendant Utica Mutual Insurance Company provided insurance coverage to Ladd’s under several different policies during 1986 and prior thereto. While there was no coverage for property damage resulting from the discharge of pollutants or contaminants affecting the soil and groundwater, an exception to this exclusion existed if said discharge was “sudden and accidental”.
After having successfully moved to amend its answer to assert an affirmative defense based on the policy exclusion (198 AD2d 654) and after joinder of issue, Utica Mutual moved for summary judgment on the ground that the source of the contamination could not have been a sudden and accidental discharge so as to trigger coverage. Supreme Court denied the motion, finding that a question of fact existed as to whether *618the contamination of the property resulted from a sudden and accidental discharge during the policy period.
The evidence presented on both sides of the disputed issue pose material issues of fact. This being so, summary judgment relief is inappropriate and the order of Supreme Court should, therefore, be affirmed (see, Meseck v General Elec. Co., 195 AD2d 798, 799).
Cardona, P. J., Mikoll, Mercure and Yesawich Jr., JJ., concur. Ordered that the order is affirmed, with costs.