Miami-Dade rock miners continue to blast away with help from Legislature

rock blasting
rock blasting
Homes in southwest Broward County near a limestone quarry

By Ann Henson Feltgen,

Miramar Mayor Wayne Messam has lambasted as virtually worthless a new state program to monitor rock blasting in northwestern Miami-Dade in response to residents’ complaints that it reverberates powerfully through nearby homes.

“The legislation that passed falls short of what I think, and our neighbors think, would resolve the issue,” Messam told Florida Bulldog. “It creates a monitor for Miami-Dade County for mining, but it doesn’t provide any new limits on blasting.”

For years, residents have complained about explosions they say leave cracks in walls, floors, patios and pools – while fraying nerves, scaring their children and waking up sleeping babies. Complaints became an outcry this spring when residents were quarantined in their homes due to the COVID-19 pandemic.

The blasting is used to excavate limestone underneath the South Florida crust. The industry contends it sends out “good vibrations” that are “little more than an annoyance as opposed to a cause of actual damage. These vibrations are less impactful than those caused by everyday activities, such as slamming a door,” the Miami-Dade Limestone Products Association states on its website.

A limestone mine. Photo: Miami-Dade Limestone Products Association

Gov. Ron DeSantis made blasting more frequent when he fast-tracked road construction projects during the COVID-19 pandemic.

The legislation flew through the Legislature without opposition, and DeSantis signed it into law last Friday, Sept. 19. It takes effect Oct 1.

New rock blasting scrutiny?

Supporters say it will bring new scrutiny to Miami-Dade’s rock mining industry that produces a third of the aggregate produced in Florida – 60 million tons of rock annually – that’s used to build roads and bridges and other construction projects.

Some 6,600 residents from Miramar, Pembroke Pines, Doral and other nearby communities in Miami-Dade and Broward counties signed a petition that sought to temporarily stop the blasting.

Miramar Mayor Wayne Messam

Likewise, the Miramar City Commission passed a resolution in April asking the governor to halt the blasting until the COVID-19 pandemic subsided. Miramar is just north of one of the White Rock Quarries that has operated since the 1980s, before the area’s housing boom.

But what Florida’s Republican-controlled Legislature produced is “woefully shortsighted,” providing no relief for area property owners whose homes have been damaged by years of blasting, Messam said.

The new law “will not be the fix local city leaders and homeowners say they need, namely a method for homeowners to seek compensation for property damage due to the blasting,” the mayor stated. “Nor does the legislation allow for any changes in the rate or power of the explosions that produce the aggregate.”

Instead, the law requires the state fire marshal, whose office oversees the rock blasting companies, to hire or contract with seismologists to monitor and report each blast. A legislative summary says the report would contain a summary of each blast, including its date and time and ground vibration, intensity and air blast. The reports would be sent to the state fire marshal and be made available to the public on the Department of Financial Services website. Financial Services oversees the fire marshal’s office.

The cost for the legislation’s pilot project includes a $600,000 recurring sum plus two onetime sums of $440,000 and $1 million to implement the pilot project. The $440,000 would come from the general revenue fund and the $1 million from the Insurance Regulatory Trust Fund. The summary does not state how the recurring $600,000 would be funded.

Study after study

Two years ago, a study ordered by the Legislature concluded that the operating mines were compliant with both federal and state blasting vibration limits.

Following that study, the Legislature attempted to create a law to remedy property owners who experienced damage from the constant blasting. However, then-Gov. Rick Scott killed the bill because a line item called for assessing a sales tax on aggregate. The tax would have been used to pay claims for damage caused by the blasting.

Quarries are permitted to blast Monday through Friday from 8 a.m. to 5 p.m.

“Each blast may be up to 0.5 PPV, peak particle velocity,” said Ruben Cantillo, the fire protection specialist for Florida’s southeast region, in mid-April. “Every single blast from the closest quarry during March 2020 has been accounted for and determined to be within normal allowable limits.”

In Florida, the fire marshal has the exclusive authority to decide on standards, limits and regulations on the use of explosives involved with rock blasting. Each state has its own set of standards, limits and regulations depending on the type of mining, area population and other factors.

In Florida “this authority includes the operation, handling, licensure and permitting of explosives. The Department of Financial Services rules establish limitations for ground vibration, frequency, intensity, blast pattern and air blast as well as restrictions on when explosives may be used. It also requires mining companies to provide notice to local governments in which the entity will conduct mining activities,” the legislative report accompanying the new law stated.

The federal government’s various implementing regulations establish the basic safety, health, certification, reporting and environmental requires for the use of explosives in mining operations.

Print Friendly, PDF & Email

Latest comment

  • If they blast on a clear sky day it is a nonissue. But if they plant when it is partly cloudy, or a complete total overcast day then blast physics come into play. In a nutshell the concussion waves bounce off of the cloud cover and travel great distances. It’s all about science.

leave a comment