Bill capping house-rattling blast mining levels gets a workshop, but no committee hearing

Tom Fabricio FLorida House
It's a rocky issue about which Miami-Dade residents have complained for years.

Rep. Tom Fabricio has been trying for years to get limestone mining companies in northwest Miami-Dade County to reduce the power of their explosions, which residents complain damage their homes.

He’s filed legislation every year since 2021 to mandate lower blast levels in and around residential areas. It was a top campaign priority when he ran for office in 2020. And accordingly, it’s been the focus of the first bill the Miami Lakes Republican files every year before Session.

So far — and likely again this year, as the House ends most subcommittee meetings — lawmakers have ignored his proposal. But some heard testimony last week from exhausted residents and experts on the issue at a House panel discussion Fabricio organized to help educate his peers and give his cause traction.

The panel discussion, which Fabricio said was “four years in the making,” was not about the bill itself but on the impact blast mining has on nearby structures and residential areas — a designation made clear by Merritt Island Republican Rep. Tyler Sirois, who chaired the committee that hosted the talk.

Industry professionals maintained that while quarry explosions may cause cosmetic damage to buildings close to dig sites, including small cracks in drywall and other comparatively weak materials, they’re not strong enough to cause structural damage at the currently allowed level.

Residents and members of a Miami-Dade advisory board tasked with analyzing the problem disputed that assertion and argued any damage — including photographed cracks in the concrete, floors and roofs of their homes — is unacceptable.

Fabricio said his goal is to strike a compromise enabling mining companies to continue excavation of vital construction and road materials while also delivering a peaceful, fair arrangement to his constituents.

“Our view is pretty simple. We believe that the limestone quarry blasting limits in the state are generally fine,” he said. “However, in situations where we are about 1,000 yards from a residential community, where the homes are shaking every day and causing damage to the homes, it’s a problem.”

A map of limestone quarries near residential areas in northwest Miami-Dade County. Image via the Miami-Dade Limestone Products Association.

Like their past iterations, Fabricio’s bill (HB 245) and an identical companion measure (SB 198) by Miami Springs Republican Sen. Bryan Ávila would cap the force of blast mining at quarries within a mile of residentially zoned areas to 0.15 inches per second, a measure of particle velocity based on the force of an explosion.

That level, he said, is proven to still be effective for mining while also being low enough to eliminate most inadvertent structural harm. The current level is 0.5 inches per second, which the Division of State Fire Marshal set in accordance with a 2018 study by South Dakota-based engineering and mining firm RESPEC.

One major flaw in that study, Fabricio said, is that RESPEC conducted the study in Pennsylvania, where the bedrock is composed mostly of sandstone, siltstone and shale rather than the porous limestone atop which the Florida Peninsula sits.

“There are reverberations, vibrations that occur at much different vibrational waves here in Florida than in Pennsylvania,” he said.

According to Fabricio’s office, six mining companies operating at eight quarries in northwest Miami-Dade detonate tons of explosive materials every week to dislodge rocks referred to as “aggregate” from underground.

A brief history of recent blast mining legislation

County residents and their neighbors in southwest Broward have complained for years about the blasting. And lawmakers from South Florida have taken some steps to address the issue.

In 2019, Republican Education Commissioner Manny Díaz Jr. and Doral Republican Sen. Ana Maria Rodriguez, then a Senator and Representative, respectively, passed legislation requiring the State Fire Marshal to set ground vibration limits and mandate that mines use seismographs to monitor each explosion to ensure compliance.

The following year, Ávila, Díaz and Miami Gardens Democratic Sen. Shevrin Jones successfully sponsored another measure giving the Fire Marshal exclusive authority to regulate and adopt construction mining standards. It also established the Miami-Dade Construction Mining Pilot Program to monitor and report each blast and required the Division of State Fire Marshal to hire a seismologist to oversee the program.

Today, a roughly one-page section of Florida Statutes covers the governing laws for blast mining statewide.

JoAnne Rice, Director of the Division of State Fire Marshal, told lawmakers during the Feb. 6 panel discussion that her agency launched the pilot program in 2021. It also developed “blasting activity reports” each licensed mine must provide to the state and launched an online Mine Activity Clearinghouse to collect blasting data and receive complaints.

Since 1996, White Rock Quarries, the largest mining company operating in the county near I-75 and the Turnpike, has made $422,000 worth of in-state donations to Florida lawmakers. Ávila is among its biggest beneficiaries, having received $32,500 from the company between 2014 and 2023.

In total, nearly half of Florida’s 40 sitting Senators and a fifth of its Representatives have accepted contributions from the company, which was one of several industry members to lobby on HB 235 this year.

Cracks in the floors and walls at Spanish Lakes Elementary in Hialeah. Image via the Miami Lakes Blasting Advisory Board.

A rocky issue

Limestone from rock quarries is used in virtually every construction project in Florida, which consumes more than 130 million tons of the material yearly, according to Ananth Prasad, President of the Florida — Builders Association.

More than a third of that supply comes from Miami-Dade, some of whose county and city governments have formed advisory committees to examine and make recommendations on how to improve matters.

Two members of Miami Gardens’ Blasting Advisory Board spoke as panel members last week.

Miguel Martinez, the board’s Chair, noted that a study the city conducted of White Rock Quarries’ blasting activity found hundreds of thousands of homes and commercial properties experience ground vibrations and air pressure changes that briefly but repeatedly “inflate” buildings by as much as half a centimeter.

“This is what’s causing the damage to our drywall,” he said, adding that the ground vibrations are what cause concrete “debonding” and cracks throughout homes.

David Teasdale, a Senior Vice President at Haag Engineering, said all buildings get cracks, and it’s predictable they’ll happen at known stress points throughout a structure. Florida’s regulation of blast mining is already “very stringent,” he said, and “protects structures of all types, and blasting is not the cause of damage to homes around mines.”

“The Florida standard is the industry standard,” he said. “It’s field tested, and it’s reliable.”

Jeffrey Straw, Vice President and area manager for Davie-based vibration consulting firm GeoSonics, cited multiple studies between 1995 and 2018 by the U.S. Bureau of Mines, Miami-Dade and RESPEC that he said show “no scientific basis” for “any reduction” in blast intensity.

“There’s not another means to be able to break the rock in the volume that’s produced and necessary,” he said. “There’s a potential to lose jobs with this, and certainly there are standards that would work within the state.”

Rock ingredients for state and local transportation construction projects overwhelmingly come from Miami-Dade County. Image via the Florida Transportation Builders Association.

Miami Lakes Blasting Advisory Board Secretary Steve Herzberg acknowledged Straw’s concern about industry impacts, but pointed out that Fabricio’s proposal would only lower the blasting limit near residential areas.

Herzberg said his board has asked for years to meet with the mining companies to no avail. Instead, he said, the companies and trade advocacy groups like the Miami-Dade Limestone Production Association — one of the lobbyists on HB 245 — have spread “disinformation,” including claims that slamming doors and kids jumping on beds does more damage to a house than subterranean detonation.

And the proposed change wouldn’t be that seismic, he continued, citing information from CFO and Fire Marshal Jimmy Patronis’ office showing that close to 60% of the 764 reported mining blasts in Florida between Nov. 2021 and March 2023 were at or below 0.15 inches per second. The average blast, he said, was 0.158 inches per second.

Some companies are more considerate actors than others. Of the 305 mining detonations White Rock Quarries conducted over that period, 45% exceeded the proposed 0.15 inches per second limit.

Cemex, a Mexico-headquartered building materials company operating in Miami-Dade that has made $347,000 worth of in-state political donations since 2001, exceeded 0.15 inches per second in 51% of its blasts.

“To be clear, nobody is asking these mines to stop blasting. That is not what House Bill 245 does. It only asks them to be good neighbors and lower that intensity,” he said. “This is not something that’s going to affect a statewide industry. This is something that’s going to affect specific mines that are close to our homes, close to our schools, close to our businesses.”

Even if the measure hampers current mining practices to the degree that it affects companies’ bottom lines and construction material costs, it shouldn’t stop lawmakers from passing it, according to Miami Lakes Council member Marilyn Ruano.

Ruano said she’s visited hundreds of homes in her town and surveyed “significant property damage” that residents have to “continually repair their homes.”

“I understand that the industry is very important to the state; however, there is no other industry that is allowed to damage their neighbors’ properties and have there be no consequences. The industry that is mining for the aggregate to build our homes is subsequently destroying our homes,” she said. Having a daily earthquake and watching your property crumble before your eyes is very difficult, and as local elected officials, this is out of our hands. There is nothing we can do. It is in your hands … to try to bring us some relief.”

Jesse Scheckner

Jesse Scheckner has covered South Florida with a focus on Miami-Dade County since 2012. His work has been recognized by the Hearst Foundation, Society of Professional Journalists, Florida Society of News Editors, Florida MMA Awards and Miami New Times. Email him at [email protected] and follow him on Twitter @JesseScheckner.


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