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Florida’s stormwater regulations have undergone significant changes, impacting how we assess water quality and manage stormwater systems. It began with Senate Bill 7040, known as the Statewide Stormwater Rule Ratification Bill, which was signed into law on June 28, 2024.
The legislation establishes minimum stormwater treatment performance standards, requiring new development, including redevelopment over one acre, to reduce total phosphorus by 80% and total nitrogen by 55% to improve water quality. For project design, it mandates cost estimates for the annual operation and maintenance of stormwater management systems and establishes criteria for qualified stormwater inspectors.
The central component of the updated regulations is the concept of net improvement. According to Florida Administrative Code R. 62-330.301(2), net improvement refers to the enhancement of water quality through the implementation of onsite mitigation measures. These measures can include changes in land use or the implementation of stormwater Best Management Practices (BMPs). The goal is to demonstrate that the proposed activity will result in a net improvement of the nutrient parameters regulated by the state, specifically Total Nitrogen (TN), Total Phosphorus (TP), and Total Suspended Solids (TSS).
In practice, net improvement can be achieved through enhanced BMPs such as increased retention volume, nutrient-reducing media, biofiltration systems, or other onsite measures that provide additional pollutant removal capacity. Tools such as BMPTrains, or equivalent modeling or manual calculations, may be used to support net improvement evaluations.
Before the 2024 rule change, only projects discharging directly or indirectly to impaired water bodies were required to demonstrate net improvement for TN and TP. Following the ratification of Senate Bill 7040, this requirement now applies to all sites, regardless of the impairment status of the receiving water body, and includes TSS as an additional parameter. Net improvement must be demonstrated using the more protective of the two approaches: a pre- versus post-development runoff analysis for TN, TP, and TSS, or a nutrient reduction efficiency method that specifies required reduction percentages for each parameter.
The Statewide Stormwater Rule also introduced more rigorous operation and maintenance requirements for stormwater management systems. Entities responsible for these systems must now submit a cost estimate for perpetual operation and maintenance, along with a financial capability certification, as part of the Environmental Resource Permit (ERP) application package. In addition, the updated rule mandates the development of a comprehensive operations and maintenance plan that outlines procedures to ensure long-term system functionality and continued compliance with water quality standards. These requirements ensure that stormwater systems remain functional throughout their lifespans, rather than meeting performance targets only at construction.
The new rule also requires that stormwater management system inspections be conducted, certified, and submitted by a qualified inspector. To meet this requirement, the inspector must either be a registered professional, work under the supervision of one with proper documentation, or have completed training within the past five years that covered key topics such as reading construction plans, understanding traditional and non-traditional BMPs, identifying system failures, and performing inspections in compliance with applicable regulatory standards. As part of the certification process, the qualified inspector must also submit a Stormwater Facility Inspection Checklist.
The stormwater rules do not apply retroactively to existing site developments with valid, unexpired conceptual, general, or Individual ERPs issued before the effective date of June 28, 2024. Existing developments are not required to retrofit their stormwater management systems unless a major modification is proposed. Minor modifications remain subject to the original permitting rules, provided they do not result in significant impacts on water resources. To qualify for this grandfathering provision, applicants must demonstrate that the proposed changes will not affect treatment, attenuation, or discharge functions; increase off-site discharge or environmental impacts; or reduce retention/detention capacity, flood-control elevations, or pollution-removal efficiency. Additional grandfathering provisions for public transportation projects, projects submitted to local government agencies, projects involving ecosystem management agreements, and Developments of Regional Impact, defined as developments that substantially affect the health, safety, or welfare of citizens in multiple counties, are outlined in Section 3.1.2 of the ERP Applicant’s Handbook, Volume I, effective June 28, 2024.
The new net improvement requirements established by the Statewide Stormwater Rule took effect on June 28, 2024, making the implementation date December 28, 2025. ERP applications that are deemed complete before this deadline are exempt from these updated standards. In contrast, other components of the rule took effect immediately on June 28, 2024, including the requirements for operation and maintenance plans, long-term cost estimates, and system inspections. The qualified inspector provisions, which outline specific credentials and training standards for inspectors, became effective one year later, on June 28, 2025.
Understanding these requirements early in project planning is critical, as incorporating net improvement strategies and O&M obligations upfront can prevent costly redesigns later in the permitting process. By staying informed and adapting to the new regulations, we can ensure that our projects do not adversely impact Florida’s water quality or environmental health.
About the Authors:
Mike Radford, P.E., is a licensed Professional Engineer with nearly two decades of experience specializing in landfill and solid waste design, stormwater management, and construction oversight. He has served as Project Manager and Engineer of Record for numerous landfill projects, including cell design, expansions, closures, and methane gas management systems.
Sara Perez Lopez, Staff Professional, provides engineering support for landfill design, permitting, and reporting in the southeastern U.S. Sara’s experience includes preparing Environmental Resource Permit applications for landfill expansions and renewable natural gas facilities, conducting NPDES inspections, and performing Title V visible emissions testing for landfill gas flares. Her experience includes working with the Florida Department of Environmental Protection and the Southwest Florida Water Management District, regulating wetland dredging, filling, and stormwater runoff activities.
Additional Stormwater Resources:
As large tracts of geographically desirable vacant land become scarcer, residential and commercial property developers are increasingly turning to old landfills or former dumps. However, such redevelopment is complex and rife with uncertainties. When compared to greenfield development, the land acquisition costs are lower. Still, any savings are typically offset by greater environmental and infrastructure costs associated with the foundation, landfill gas management, stormwater management, groundwater impacts, meeting closure requirements, and multiple regulatory agency coordination. Therefore, it is important to maximize the developable area while providing engineering solutions to make the project economically feasible. In this blog, we identify some options to reuse challenging sites and lessons learned to contribute to successful redevelopment projects.
Deep Dynamic Compaction
Old landfills or dumps present some unique soil stability challenges. Deep dynamic compaction (DDC) is a ground stabilization technique that has gained popularity in recent years to improve subsurface soil conditions. DDC involves dropping 6 to 30-ton weights from a height between 30 and 75 feet to achieve the desired soil compaction. DDC can effectively apply to a range of subsurface materials, including former C&D debris or municipal solid waste dumps.
DDC provides a stable foundation for future development, minimizes differential settlement while leaving the landfill waste in place, and eliminates the costs associated with removing, transporting, and disposing of buried waste, costing millions of dollars. For simplicity’s sake, let’s consider a 1-acre old landfill or a dumpsite with an average of 15 feet of waste. If excavating the waste and replacing it with clean fill, the disposal fee costs for the excavated waste alone could exceed $400,000. Alternatively, DDC costs range from $1.50 to $2.00 per square foot or $65,000 to $87,120 per acre, excluding mobilization, which costs around $30,000.
Gas Mitigation Systems
Constructing buildings on top of dynamically compacted areas generally requires a combustible gas barrier layer below the building foundation to manage subsurface combustible gases (typically methane). The barrier is required because the waste remains in place. In its simplified form, gas mitigation systems include:
These gas mitigation systems can be either a passive or an active system with a blower. The cost of such systems varies depending on the size of the building, location, and type of liner system used. Typical capital costs for passive systems are in the range of $7 to $9 per square foot for the spray-applied liner and $3 to $4 per square foot for the HDPE liner. For an active system using blowers, add $3 to $4 per square foot. The designer configures a system from these options to address the client’s risk preference and considering future tenant preferences.
Using innovative approaches, impaired lands are increasingly attractive to developers. Beyond the cost-saving benefits to developers realized through DDC and an appropriate gas mitigation system, such projects also create local jobs, increase the tax base, and protect public health and the environment.
About the Authors:
Somshekhar Kundral – Mr. Kundralis, PE, is a Senior Project Manager with over 12 years of broad and diverse environmental engineering experience that includes projects in landfill redevelopment, landfill gas management system design, site assessment, groundwater remediation system design, stormwater management, and injection well system construction. Som is experienced with site permitting, compliance reporting and construction administration services, and remediation systems’ operation and management.
Stormwater management at landfills is changing as owners/operators are adapting their operating plans and designs to minimize the risks that come with heavier rainfall, and severe storm conditions. Landfill engineers are “overdesigning,” in regions hard hit in recent years by severe weather, and not designing for what is labeled as a statistically probable 25-year-storm.
Operations and maintenance are also preparing for changing conditions. William Mojica, Republic Services Director of Environmental Compliance is quoted in this article saying “It’s understanding the facility’s lifecycle, what best management practices (BMPs) are required and anticipating what may come.”
Jonathan Meronek, of SCS Engineers, notes similar strategies are being explored or employed along the U.S. coastlines including designing retention facilities to handle much larger storms.
By October 17, 2016, coal combustion residual (CCR) landfills subject to the Environmental Protection Agency’s (EPA) CCR regulations published at 40 CFR 257, Subpart D, also known as the Federal CCR Rule, were required to prepare a Run-on and Run-off Control System Plan. Your plan documents how you have designed and constructed your landfill to prevent storm water from running onto or off the active landfill. But, what’s next?
Have you addressed run-on and run-off control system operation and maintenance?
Spring is a great time to review your storm water control plans and, more importantly, your storm water controls. The snow is gone now and spring rains are on their way, so knowing that your storm water controls are working and water is going where you intend it to go should be part of your spring inspection routine. Don’t want to waste money managing clean storm water with your leachate management system, or put your facility at risk by allowing unintended runoff from the landfill. A few basic inspection tasks will help ensure you don’t.
A spring run-on and run-off control system inspection should include the following:
Don’t let spring rains catch you off guard. SCS Engineers can help you assess the effectiveness of your run-on and run-off control systems. For help conducting storm water inspections as well as studies to review leachate, contact water, and storm water minimization and reuse opportunities, or for questions about run-on and run-off control system inspections or more information about minimization and reuse studies, please contact:
Mike McLaughlin, PE, Senior Vice President
Eric Nelson, PE, Vice President
Steve Lamb, PE, Vice President
Kevin Yard, PE, Vice President
Or, contact your local SCS Engineers office.
Learn more about the author Eric Nelson:
Eric J. Nelson, PE, is a Vice President of SCS Engineers and our National Expert for Coal Combustion Residuals (CCR). He is an experienced engineer and hydrogeologist. His diverse experience includes solid waste landfill development, soil and groundwater remediation, and brownfield redevelopment.
Mr. Nelson has worked with utility clients to complete numerous projects for dry CCR landfills, CCR ponds, and general environmental monitoring and compliance. He has been involved with CCR landfill projects that include feasibility analyses and permitting of landfill expansions; hydrogeologic and geotechnical site investigations; site design and operating plans; soil borrow source identification and permitting; liner and final cover construction liner, cover, and storm water management repairs. He has worked with utility clients to evaluate, plan, permit and complete CCR pond repairs and closures.
Mr. Nelsons environmental monitoring and compliance experience includes groundwater monitoring; oil containment design and construction; and Spill Prevention, Control, and Countermeasure (SPCC) planning. This diverse project experience has provided him the opportunity to work on challenging and innovative projects that have included design and permitting for wetland and stream mitigation, identifying and avoiding former underground mines during site design, and assessing the feasibility of installing a solar photovoltaic system on a closed CCR landfill.
Mr. Nelsons additional areas of expertise include remedial action planning, cost estimating, bidding and construction documents, and construction quality assurance. He has worked with electric utilities, solid waste facility owners/operators, and private property owners and developers.
Jim Bowlby of SCS-Denver was just selected by a committee of his peers to be the featured member on the HBA’s website. Each week the HBA puts a “Spotlight On” an individual to introduce and acknowledge their accomplishments and contributions in support of home building within the industry.
What accomplishment or contribution to the Home Building industry are you most proud? “My active participation in the Stormwater Committee for the past 12-13 years, now as chair for the last three years,” replied Jim. “We’ve disseminated information, commented on pending regulations, met with most of the Denver Metro Front Range Municipal stormwater managers and the State Health Department, and provided an avenue for exchanging information and ideas.”
To learn more about Stormwater Management click here.
For the full article go to the HBA website or click here.
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