Article Courtesy of The Tampa Bay Times

By Susan Taylor Martin

Published August 18, 2016

ST. PETERSBURG — With its charming old houses and pastoral setting, St. Petersburg's Crescent Lake area has long been one of Tampa Bay's most desirable neighborhoods. Now it's the latest flashpoint in the strife between existing homeowners and new-home builders.

At issue this time is hydraulic pile driving, and whether the steady bang, bang, bang of pilings being pounded into place for a big new house will damage nearby homes and aggravate a known sinkhole problem.
  

Neighbors are angry at the city for giving Richard McGinniss a pile-driving permit despite what they say were code violations and damages caused in his company's construction of another home on scenic Crescent Lake Drive. "The issue is with the city because they issued a permit for pile driving despite the fact he's committed multiple (code-related) atrocities,'' said Peter Betzer, president of the St. Petersburg Downtown Partnership. "We're really worried because when Mr. McGinniss did his (previous) pile driving he did some damage to adjacent houses.'' A report by a professional engineer documented a large historic sinkhole in the Crescent Lake area that, Betzer says, "puts all of our homes in an especially precarious position.'' He and others fear that more pile driving could fracture the fragile subsurface limestone and increase sinkhole activity.

   
McGinniss, owner of Modern Tampa Bay Homes, counters that his own engineering studies show no risk to adjacent structures from pile driving. In addition, he says, the company is taking extra steps to monitor vibrations and evaluate conditions pre- and post-construction.

"We have all of the factual information that you could possibly garner in a situation like this . . . while what they have is a vague idea that somehow this is going to impact them,'' McGinniss said of his critics. "It's more of a psychological response than a rational response.''

Just five minutes from bustling downtown St. Petersburg, Crescent Lake is among those attractive bay area neighborhoods that have drawn interest from builders eager to satisfy the demand for new homes in urban areas where developable lots are in short supply.

On Tampa's Davis Islands and in St. Petersburg's Snell Isle, homeowners have complained loudly — though to little avail — as huge new homes dwarf more modest dwellings or are jammed two abreast on lots where a single home once stood.

While those neighborhoods are flood prone, forcing new homes to be elevated, the inland Crescent Lake area poses its own construction challenges.

Crescent Lake, like much of the Tampa Bay region, lies in a "sinkhole alley'' with underground limestone caverns full of voids that can collapse due to fluctuating water levels. As water receded from the lake itself, it left behind organic-rich sediments — tree limbs, leaves, etc. — on which houses were built.

Over the years, the organic material decomposed and the surface of the land subsided. Soil subsidence and sink hole-like activity have caused such serious cracking that some Crescent Lake homes have collapsed and others — including Betzer's — have needed tens of thousands of dollars in structural repairs.

Two years ago, McGinniss' company began building two strikingly modern houses on Crescent Lake Drive. Patty McConnell, who lives across the alley, said the vibrations from the pile driving damaged her 1930s-era home.

"We had the whole inside replastered and all the cracks came back because of all the pounding and vibration going on,'' she said. "It's not hairline cracks, these are pretty extensive cracks in almost every room.''

Betzer, former dean of the University of South Florida College of Marine Sciences, said the vibrations damaged a "very nice piece'' of granite in one of his bedrooms and caused extensive cracking at another neighbor's house.

In seeking to block pile driving at the new site, Betzer sent the city a report by geotechnical engineer George Sinn. Noting that the Crescent Lake neighborhood is located over a "very large relic sinkhole,'' it said that other engineering firms as well as rulings in sinkhole-related lawsuits determined that:

"Numerous homes constructed along the western side of the lake have in recent years (2005 to 2010) had unusual and/or recurring damage that was found to be the result of both organic laden soils and sinkhole activity.''

However, city building official Rick Dunn said he is convinced that pile driving "didn't have anything'' to do with any damage to Betzer's home or others.

"It was the subsidence of the soil — the upper soils had an excessive amount of organic material so that's what caused the damage,'' Dunn said.

Pile driving — in which a heavy weight is lifted and dropped onto a piling, pushing it farther into the ground — is used in both residential and commercial construction in many parts of the Tampa Bay area, including the beaches. It is less expensive than some other methods of foundation construction and can by annoying to those nearby — residents in one downtown St. Petersburg area say they were nearly driven crazy by months of relentless pounding at the site of a new 19-story apartment building.

To reduce the amount of pile driving needed at the Crescent Lake house, the eight -inch wooden piles will be sunk into pre-bored holes about 10 feet deep, said Jeanne Berg, a geotechnical engineer hired by McGinniss, The hydraulic pressure that will push them 15 or 20 feet farther into the ground will be monitored at the start and "tweaked'' if needed to keep vibrations to a minimum.

The work shouldn't last more than a few days and the piles will not go into "the deeper limestone area,'' she said.

That does not totally mollify Betzer and other neighbors. They are also irritated at McGinniss' company for cutting down a live oak without a permit (he was fined $500). One neighbor even decided to move after cataloging numerous aspects of one of the Modern Tampa Bay Homes that he claimed violated city codes and hurt the character of the Crescent Lake area.

McGinniss, who has built numerous houses on Florida's gulf coast, said he remedied any actual violations. He thinks the real issue, though, is the style of modern homes with their geometric angles and plain exteriors.

"Some people love our homes and some don't,'' he said. "We feel like we're adding some cool architecture to a community and not everybody looks at it that way."

McGinniss' Modern Tampa Bay Homes are not the only new ones around Crescent Lake. About a year before he started his projects, another company had to use a more expensive method of foundation construction for a house it was building after the city nixed plans for pile driving.

"The city said we could not do that — they said they were afraid we'd cause too much vibration and maybe harm some of the surroundings,'' recalls Rich Agan, a partner in Howell Construction. "I was kind of surprised (by McGinniss' permits) because I just presumed that was a standard thing the city had instituted around the Crescent Lake area."