COMANCO’s Approach to Managing Stormwater Risk in Phosphate Gypstack Closures
Why Lined Ditches Matter
Closing a phosphate gypstack is not just about placing a final cover and walking away. Managing stormwater across the site is one of the most critical and often overlooked components. Improper stormwater control allows water to contact gypsum, creating long-term environmental risks. This is especially important on active closure projects where multiple contractors and phases overlap.
On a recent phosphate facility closure project in Central Florida, COMANCO’s Phase II work showcased the importance of lined stormwater ditches in safeguarding system integrity and minimizing contamination risks.
The Risk of Uncontrolled Stormwater
Phosphate facilities require strict control of water movement. When stormwater interacts with gypsum, it can mobilize contaminants and create compliance challenges. This risk increases during closure as crews finalize slopes, stage materials, and transition areas from active work zones to completed systems.
Stormwater ditches may seem like a secondary feature, but they serve as the first line of defense. Without proper lining, infiltration and erosion can compromise both environmental protection and long-term performance.
In projects like this, sequencing constraints compound the challenge. Subgrade is not always available in a linear fashion, and crews must adapt to changing conditions while maintaining system continuity.
Real-World Challenges in the Field
This phase of the project involves installing multiple geosynthetic materials, including 40 mil and 60 mil HDPE geomembranes and a 10 oz geocomposite. Each material serves a specific purpose, and transitions between them require careful planning and execution.
One of the primary challenges is the amount of tie-in welding required. Every seam must connect properly across different materials and elevations to ensure a continuous barrier. These critical transitions demand consistent quality control.
Another challenge is coordination. Multiple contractors are working in the same area, and progress depends on the availability of subgrade. Crews cannot simply move in a straight line. Instead, they must shift between areas as they become ready, which requires constant communication and flexibility.
This type of environment introduces risk. Without clear coordination, delays and rework can occur. More importantly, safety risks increase when multiple teams are operating in close proximity.
Practical Solutions for Complex Site Conditions
Successful execution in these conditions comes down to three key factors: planning, communication, and quality control.
Effective planning requires teams to understand how they will install each material and complete each transition. Sequencing must account for subgrade readiness and access constraints.
Crews rely on clear communication when multiple contractors are working in the same area. Daily coordination enables teams to clearly define work areas and keep crews working efficiently without interfering with one another.
Quality control is the final layer of protection. Quality control teams inspect and test tie-in welds, seams, and material interfaces to ensure performance. Small issues at this stage can lead to significant problems later if left unaddressed.
Project teams incorporate safety into every step of the work. Crews must remain aware of changing site conditions and maintain clear communication to avoid conflicts and hazards.
COMANCO’s Approach in the Field
On this project, COMANCO is installing over 2.1 million SF of 40 mil HDPE, with more than 1.5 million SF completed to date. The team has installed 636,224 SF of 60 mil HDPE, with approximately 8,000 SF remaining. In addition, 77,485 SF of geocomposite has been installed.
The current focus includes lining stormwater ditches with 40 mil HDPE and completing the final 60 mil geomembrane ramp on the southwest corner of the gypstack.
Foreman Ubaldo Mancilla, Leadman Abnel Lopez, and Master Seamer Carlos Grenados Cruz lead the execution. Their coordination with other contractors has been a key factor in maintaining steady progress.
Because subgrade is released in phases, crews are moving between work areas to stay productive while maintaining installation quality. This requires constant communication and a clear understanding of priorities across the site.
Tie-in welding is performed with close attention to detail to ensure all materials function as a single system. Each seam is treated as a critical component of the overall containment strategy.
Safety performance on this project has been strong. The leadership team emphasizes communication and situational awareness, which helps crews operate safely in a complex, multi-contractor environment.
Long-Term Impact of Proper Stormwater Management
The primary outcome of this work is straightforward but critical. Properly lined stormwater ditches prevent water from contacting gypsum. This reduces the risk of contamination and supports long-term compliance with environmental regulations.
Beyond compliance, it also protects the investment in the closure system. When stormwater is effectively managed, erosion is minimized, and the integrity of the final cover system is preserved.
Projects like this demonstrate that stormwater control is not a secondary detail. It is a core component of successful closure work. Getting it right the first time ensures the system performs as intended for years to come.
The Value of Proper Execution
Stormwater management in gypstack closures requires more than basic drainage design. It demands careful sequencing, precise installation, and strong coordination across multiple teams.
Lined ditches play a critical role in keeping clean water separate from impacted materials. When installed correctly, they protect both the environment and the site’s long-term performance.
COMANCO approaches this work with a focus on safety, quality, and practical execution in the field. By addressing challenges as they arise and maintaining strict quality standards, the team delivers systems that are built to perform.
SAFETY ★ QUALITY ★ SERVICE
COMANCO is an environmental, commercial, and civil construction company specializing in constructing containment facilities.
Closure projects demand practical solutions that perform under real-world conditions. Lined stormwater ditches help manage water flow while protecting critical containment systems. Consistent communication and quality execution ensure long-term reliability.
Contact COMANCO to learn more about our field-proven approach.
📍 4301 Sterling Commerce Dr, Plant City, FL 33566
📞 (813) 988-8829
🌐 www.comanco.com