Navigating the New Waters: EPA Construction General Permit Updates Drive Demand for Dewatering Solutions
As construction sites expand and regulations tighten, staying compliant with the Environmental Protection Agency’s Construction General Permit (CGP) is more complex—and more critical—than ever. The 2024 updates to the CGP have introduced significant changes aimed at improving water quality and reducing sediment runoff. Among the most impactful shifts? A renewed emphasis on effective dewatering practices, making tools like dewatering bags and flocculants essential components of stormwater pollution prevention plans (SWPPPs).
A New Era in Compliance
The EPA’s Construction General Permit governs how developers and contractors manage stormwater discharges from construction activities that disturb one acre or more. While previous permits focused on silt fences, sediment basins, and stabilized entrances, the 2024 CGP now places greater scrutiny on dewatering activities—particularly when groundwater or stormwater is pumped off-site.
The updated permit includes:
Stricter turbidity and Total Suspended Solids (TSS) limits for water discharged from dewatering operations
Mandatory treatment requirements before discharging water to surface bodies
Expanded inspection and monitoring protocols for dewatering practices
Site-specific documentation of BMPs, including justification for selected treatment methods
These changes aim to close the gap between dewatering discharges and water quality goals outlined in the Clean Water Act. But with tighter restrictions comes a growing demand for practical solutions that meet both environmental standards and operational needs.
The Rise of Dewatering Bags
Dewatering bags, also known as sediment filter bags or silt bags, have emerged as a go-to solution for managing sediment-laden water. Placed at the discharge point, these geotextile bags filter out sediment while allowing water to percolate through. Their portability, affordability, and ease of use make them an attractive choice for sites that need quick, scalable compliance tools.
Contractors are increasingly turning to dewatering bags for:
Pumped water from excavations
Stormwater pond drawdowns
Emergency flood response efforts
Stream bypass or diversion operations
Not only do they help meet the CGP's discharge requirements, but they also reduce the need for more costly and permanent infrastructure.
Flocculants: The Chemical Edge
However, for high-clay soils, fine particulates, or heavily disturbed sites, filtration alone isn’t enough. That’s where flocculants come in. These chemical agents cause suspended solids to clump together, making them easier to remove through filtration or sedimentation.
The 2024 CGP now encourages—or in some cases, mandates—the use of treatment additives like flocculants for sites discharging to sensitive waters, such as those with Total Maximum Daily Load (TMDL) impairments or downstream wetlands.
Popular forms include:
Polyacrylamide (PAM) – Effective in a wide range of soil types
Gel blocks and dosing systems – For passive or in-line dosing during pumping operations
Jute & Coir Netting: many flocculants are used in conjunction with jute netting or COIR blankets and wattles to create a “treatment train” as water leaves an outfall or before going into a sediment basin.
Still, with their use comes responsibility. The new permit outlines strict usage, handling, and monitoring protocols, requiring contractors to document dosing methods and conduct field verification of effectiveness.
Best Practices and Future Outlook
As contractors adapt to the revised CGP, stormwater professionals emphasize an integrated approach:
Conduct detailed site assessments before choosing treatment methods.
Combine physical filtration (like dewatering bags) with chemical treatment (like flocculants) where necessary.
Document all decisions in the SWPPP, including justification for BMPs and emergency procedures.
Train crews on product use, maintenance, and permit compliance.
Industry experts expect state-level permits to follow suit, with many Departments of Environmental Quality (DEQs) incorporating similar language into their own regulations.
Take Action!
The new CGP reflects a larger trend: the EPA is placing greater responsibility on construction professionals to be stewards of water quality. While this means more upfront planning and investment, it also opens the door for smarter, cleaner, and more resilient construction practices.
Dewatering bags and flocculants, once optional tools, are now part of the modern contractor’s essential toolkit. For those willing to adapt, they’re not just a path to compliance—they’re a key to environmental leadership in an industry under pressure to do better.
Sidebar: Quick Tips for Compliant Dewatering
✅ Always discharge through a stabilized outlet
✅ Use dewatering bags with appropriate flow ratings
✅ Pre-treat water with flocculants for high-turbidity discharges
✅ Perform daily inspections of equipment and discharges
✅ Document everything—what’s not recorded, doesn’t count
