As decades of growth increased Mount Pleasant's population more than tenfold, the town greatly expanded its municipal limits, yet many parts of what appear to be Mount Pleasant aren't in the town at all.

Many businesses along U.S. Highway 17, well-known landmarks such as Boone Hall Plantation, and most homes in some historic communities such as Snowden, are encircled by Mount Pleasant but remain part of unincorporated Charleston County.

Lately, the town has been taking a more aggressive approach to annexing some of those "doughnut hole" properties.

"You have people who are using the roads we paid for, enjoying the parks we pay for, and they are freeloading - freeloading," said town Administrator Eric DeMoura.

He said property owners north of Long Point Road would see financial benefits from annexing into Mount Pleasant, while others might not. The town has a calculator on its website, tompsc.com, where people can get estimates.

Some don't have the option of annexation because they are within such a large "doughnut hole" that their property does not touch the town, which is a requirement under state law.

Freddie Jenkins lives in Snowden, an historic black community that sits next to the Longpoint development. He annexed into the town decades ago and is glad he did.

"I looked at several reasons, one of them being that we couldn't vote in the municipal elections," he said. "With all the growth going on, I want to be able to vote on what I want to see in Mount Pleasant.

"We figured out the math, and it was cheaper to be in the town," Jenkins said. "And, when I got into the town my fire protection (insurance) policy dropped tremendously, and I saved money all the way around."

Jenkins, a member of the Snowden Civic Association's board, said some residents of Snowden fear that the community would change if they annexed into the town. Other residents own property that doesn't touch town boundaries, and some live on what's known as heirs' property, where the property ownership is clouded by complex estate issues that would stand in the way of annexing.

"Some of the older generation, they believe someone is going to take their property if they annex into the town, but that's not true," Jenkins said.

Although most of Snowden is outside the town limits, Mount Pleasant police serve the area under contract with Charleston County, rather than the sheriff, and the Mount Pleasant Waterworks helped secure millions of dollars in grants to extend modern sewer service to hundreds of homes there.

"A specified challenge and opportunity is to better integrate traditional African-American communities into the Town of Mount Pleasant," says the town's 2013 Annexation Plan. "Several of these communities have existed for generations in what remained essentially rural areas with few or no services."

Mount Pleasant wants to annex already-developed residential properties, but commercial properties are more valuable tax-wise. To encourage annexation, the town in 2011 decided to charge twice as much for sewer service to properties outside town limits that were already receiving service. For undeveloped property, petitioning to annex is a requirement for getting sewer service.

DeMoura said the higher sewer fees led the Meridian complex on Highway 17 - an apartment complex later converted to condominiums - to join the town.

"There's a stick approach, and there's a carrot approach," he said. "The primary objective is long-term control of these properties and influence by the citizens of our community."

"It really isn't about the money," said DeMoura.

The Sunoco gas station and convenience story on Highway 17 near Interstate 526 annexed into the town last year.

"The town did encourage us to do that, and it has a dual benefit for the town and for us," said Jeff Shields, a spokesman for Sunoco in Philadelphia. "They get the tax revenues from the property, and we get the higher level of service."

Along S.C. Highway 41, the entire Sunchaser subdivision recently asked to join the town.

Homeowners' association President Bill Riley said it took several years to convince all 14 property owners to annex, and now the entire community has petitioned to join, along with some neighboring property owners.

"A lot of folks who live here wanted better fire and rescue services, which Mount Pleasant has," Riley said.

The community also expects to see reduced property insurance bills from being within the town, garbage collection by the town rather than private haulers, and the town will pay the electric bill for the street lights.

"That's the second-biggest ticket on the HOA's budget," Riley said.

For some property owners, however, the hesitation to annex seems obvious. For those south of Long Point Road, Mount Pleasant property taxes would be higher than in unincorporated areas, and some businesses don't have big sewer charges, so lower sewer rates matters little.

"Abide-A-While (Garden Center) is a good example," DeMoura said. "They would pay more if they came into the town."

Efforts to reach an Abide-A-While owner for comment were unsuccessful.

For the owners of large, undeveloped properties, remaining outside the town means having some leverage when it comes to development plans. They would have to annex, or have a petition to annex denied, in order to get sewer service, but faced with the potential of a large development outside the town boundaries, Mount Pleasant has typically compromised in order to have control.

Oyster Point, a nearly 600-home subdivision off Rifle Range Road, is a recent example.

"We didn't have the power to say no," said DeMoura. "They could have developed the property in the county otherwise, with no benefit to the town."

And at the north end of Mount Pleasant - the only direction in which the town can grow - annexation is also seen as a strategic concern about the town's future.

"What about the property on the outskirts of town?" said DeMoura. "Somebody could put in the state's largest shopping mall, and we would get all that traffic."

"We almost have to get as aggressive as the law allows," he said.

Mount Pleasant's town limit now runs north up U.S. Highway 17 nearly to Seewee Road, which is the southern limit of the town of Awendaw. However, in the area north of Wando High School, most of the land on the west side of the highway remains outside Mount Pleasant's boundaries.

DeMoura said these issues could be avoided if South Carolina allowed municipalities to grow, and to annex everything within their outer boundaries, as do other states such as Georgia.

"Instead (South Carolina) allows developers to pit one municipality against another," he said. "We are doing this to protect our citizens, and to defend our borders for the future."

Reach David Slade at 937-5552