The owners of a South San Francisco salami plant will pay nearly $700,000 and overhaul its refrigeration system as part of a federal judgment stemming from an ammonia leak that sickened almost four dozen people.

The U.S. Environmental Protection Agency and Department of Justice say Columbus Foods will pay the penalty for the August 2009 gas release without acknowledging wrongdoing. The sausage maker also agreed to spend $6 million upgrading its refrigeration system and improving emergency notification procedures.

Seventeen people were hospitalized and 30 others sought medical attention after built-up pressure caused a pipe to burst and sent 200 pounds of anhydrous ammonia into the air.

Employees of the biotechnology firm Genentech were among those sickened, and the company reached a confidential settlement with Columbus Foods last year.