MERCER COUNTY AREA — County officials are looking ahead to possible long-term power outages as Hurricane Sandy whips through the area and are prepared to open a shelter if necessary, said Frank A. Jannetti Jr., director of the county’s Department of Public Safety.

Officials are expecting downed power lines not only from the winds but from toppled trees. As of Monday afternoon, National Weather Service forecasters were expecting about 3 inches of rain. That’s not enough, Jannetti said, to cause widespread flooding locally.

“However, certain roadways can flood, and the saturated ground could make trees and root systems become compromised,” he said.

The 911 center will have extra personnel on duty during the storm, and Jannetti said emergency response personnel should prepare for power outages, minor flooding and trees down. He encouraged first responders to check equipment and tools that are needed for a storm response.

A shelter will be opened if necessary, Jannetti said, but its location will be determined by the need. “Obviously if power is out in Greenville, we’ll open one in Greenville. If it’s out in Hermitage, we’ll open in Hermitage. If it’s widespread we’ll try to open it in a central location.”

Residents should always have an emergency kit ready, not just in cases where a storm is expected. “A power outage could happen at any time, and we always encourage people to be ready. People should get together whatever they need to sustain themselves for a few days,” he said.

The American Red Cross recommends people have a three-day supply of water for each person in the house, nonperishable food, flashlights, a battery-operated radio and a first aid kit.

Families should also put into place an emergency plan if they have to leave home, according to a news release issued by the American Red Cross.

For those who may be without power for several days, Brookfield Fire Chief Keith Barrett encouraged people to be careful when using generators, stoves, candles and kerosene heaters.

“All generators must always be outside. Never, ever bring it indoors,” he said. “Carbon monoxide fumes have killed people who put the generator in the basement or in an attached garage.”

“Be careful with candles. Don’t go out and leave them burning. Be extremely careful with using your stove for heat. And never, ever use gasoline in the house. Ever.” he said.

He also encouraged everyone to stay indoors. “Just stay in. And stay away from any downed lines. Assume it’s live. Don’t go near it,” he said.

National Fuel Gas Corp. advises those whose basements flood:

• Do not attempt to relight pilot lights on natural gas appliances such as a furnace or hot water tank. If the appliance’s controls are submerged, the floodwater may have caused damage that could affect the safe operation of the equipment.

• Do not attempt to adjust any gas equipment or gas meter while the basement is flooded.

• Do not turn on any gas valve that has been turned off by NFG or emergency personnel. Once the water recedes, contact NFG at: 800-444-3130 and the company will test and restore the service at no charge.

• Open a window for ventilation if a gas odor is present, leave the premises and call NFG.

Verizon said it is prepared to repair damaged service but customers may have to wait for approval from the local power company and emergency responsders.

The main contact number for Verizon is: 800-837-4966.

Verizon also has a “Hurricane Sandy’’ webpage at: www22.verizon.com/about/community/sandy2012.htm

The page will serve as a main source for storm coverage and provides links to resources for reporting service issues.

Also, www.verizon.com/outage is online and will provide information on service tips, resources and updates.

Along with all the people in the projected path of the storm, hundreds of pets also are at risk, according to a release from the American Humane Association. They offered these tips to keep pets safe during and after the storm:

• Bring pets inside, including animals that normally stay outdoors. Use a crate large enough for them to turn around in.

• Double-check emergency supplies of pet food, bowls and water.

• Have a carrier ready.

• If your family will be leaving home, take the pets with you.

• Know a pet’s hiding places. They may run if frightened.

• Secure exits and doors so pets can’t escape into the storm.

• Do not tranquilize pets. They may need their survival instincts if conditions deteriorate.

• Give pets time to become reoriented after the storm. Familiar scents and landmarks may change and cause a pet to become aggressive or self-protective.

Pennsylvania’s Agriculture Secretary George Greig reminded residents to take food-safety precautions in the coming days.

“During and after a power outage or flood, simple steps like monitoring the temperature and condition of food can make the difference between safe food and dangerous food,” he said.

“Remember: When in doubt, throw it out,” he added.

During an outage, keep refrigerator and freezer doors closed as much as possible to maintain cold temperatures. Refrigerators will keep food safely cold for about four hours if unopened. A full freezer will hold its temperature for about 48 hours if not opened.

Other safety tips:

• Never taste food to determine its safety.

• Use dry or block ice to keep refrigerators and freezers as cold as possible during prolonged outages.

• If the food still contains ice crystals, it is still safe.

• Discard perishable food such as meat, poultry, fish, soft cheeses, milk, eggs, leftovers and deli items after four hours without power.

• Throw away any food that has been submerged in flood water.