HAMPDEN – The number of people calling Pine Tree Landfill’s odor complaint hot line in recent months is on the rise, a spike that one landfill official attributes to hot, humid weather and the company’s recently filed application to boost capacity.

The landfill received 15 odor complaints through the hot line in July and 12 complaints in June, up from zero complaints in all of the previous months of 2005, Donald Meagher, manager of planning and development for Casella Waste Systems Inc., which owns Pine Tree Landfill, said Friday.

Besides the weather, other contributors to the odor are deliveries of wastewater sludge and municipal solid waste, as well as construction of the last phase of landfill capacity that was approved in 1998, Meagher said.

“When we’re doing construction there is some scraping off of cover that needs to be done,” which exposes waste underneath, he said.

Besides the heat, however, landfill activity over the past couple of months hasn’t been anything out of the ordinary, Meagher said. What is new is Casella’s recently filed application to boost capacity at Pine Tree by nearly 50 percent, which has drawn greater public attention to the landfill, he said.

“We have much more visibility in people’s minds,” Meagher said. “Odor is always something that comes to the top of the list when we have a new project.”

Of the 15 odor complaints received in July, nine were deemed “legitimate,” meaning the caller was at a fixed location, called soon after detecting the odor, and the smell did not originate from another source.

It’s difficult to pinpoint the cause of the smell if the caller catches a whiff of it as they drive by the landfill or call hours after noticing it, Meagher said.

“How do we verify that?” he said.

Residents at a meeting earlier this week of the Hampden Citizens Coalition, a group opposed to the landfill expansion, said calling to complain about the odor as it’s detected often is impractical, and won’t lead to any improvements anyway.

During an informal poll at the meeting, many people raised their hands to indicate they think odor is problem at the landfill.

Overall, the number of complaints received through the hot line has decreased since 2001, the first full year the hot line was in use, Meagher said.

In 2004, 19 complaints were received, compared to 34 in 2003 and 36 in 2002, Meagher said.

The number of complaints tends to rise during the warmer months, with the bulk of the calls coming in between July and September, he said.

The odor complaint hot line is staffed 24 hours a day, seven days a week. The caller’s name, address, phone number and complaint are recorded and forwarded to landfill officials.

If the call is received during the day, town officials also are notified, Meagher said.

Landfill officials then review recent deliveries and check the wind direction at the time of the complaint, and sometimes schedule a visit to the site of the reported smell.

The telephone number for Pine Tree Landfill’s odor complaint hot line is 862-5427.