The Environmental Protection Agency (EPA) has published its proposed 2022 National Pollutant Discharge Elimination System (NPDES) Construction General Permit (CGP) for public comment. The CGP authorizes operators to discharge stormwater from construction activities in jurisdictions where the EPA is the NPDES permitting authority. While these changes only apply to areas under EPA jurisdiction, many NPDES-authorized states model their own CGP after the EPA’s. Therefore, many operators in states where the EPA is not the permitting authority can expect to be subject to the changes outlined below. The EPA’s invitation for public comments closed July 12, 2021. The following synopsis summarizes several key changes from the current 2017 CGP.
Summary of Significant Changes
Perimeter control requirements. The proposed 2022 CGP (2022 CGP) clarifies that sediment perimeter controls must be installed upgradient of any natural buffers present.
Final site stabilization photographic documentation. The 2022 CGP requires that photographic evidence of compliance with site stabilization requirements be presented when the operator seeks to terminate coverage (i.e., NOT).
On-site chemical containers. The 2022 CGP requires that all chemicals, regardless of the volume, to be stored in water-tight containers. All containers 55 gallons or less and stored outside must be stored on a spill containment pallet with an available spill kit to respond to leaks/spills. Containers greater than 55 gallons must be stored at least 50 feet away from all waters and drainage systems, and must be provided with cover or secondary containment.
Greater specificity on dewatering controls. The 2022 CGP proposes that all dewatering water must be routed through sediment control(s) designed to prevent a discharge with visible turbidity. Additionally, the discharge may not cause a sheen or hydrocarbon deposit on the bottom or shoreline of a water body. In order to reduce erosion, the 2022 CGP requires that a stable, erosion-resistant surface be used for discharge (e.g., erosion matting, landscape fabric, etc.), that controls not be placed on steep slopes, and that the discharge not cause the re-suspension of sediment in the receiving waters. No dewatering discharges are allowed from contaminated sites (e.g., Superfund, NPL, VRP, etc.).
Inspection protocol modification. The 2022 CGP requires that daily inspections occur when discharging dewatering water. Required inspection documentation includes:
Dewatering discharges to “sensitive waters” turbidity monitoring. The EPA is considering requiring either turbidity benchmark monitoring or turbidity indicator monitoring. Under turbidity benchmark monitoring, a weekly average benchmark turbidity level would be set, and any exceedances would cause applicable corrective action to determine the problem source and to make necessary changes. Turbidity indicator monitoring would require operators to monitor and report turbidity with no required corrective action.
Inspection/Corrective Action Requirements
Inspection requirements during snowfall conditions. The 2022 CGP would require a site inspection within 24 hours of discharge caused by snowmelt associated with 3.25 inches or greater snow accumulation. This level is determined equivalent to a 0.25 inch rain event.
Seasonally dry period inspections for arid and semi-arid areas. The EPA’s 2022 CGP clarifies a seasonally dry period as “a month in which the long-term average total precipitation is less than or equal to 0.5 inches.” During the seasonally dry period, inspection frequency may be reduced to once per month. The EPA’s new climate look-up tool allows individuals to determine if the area they are in is considered an arid or semi-arid climate and, if so, what months out of the year are considered seasonally dry. A link to the look-up tool is provided here: https://www.regulations.gov/document/EPA-HQ-OW-2021-0169-0028
Documenting signs of sedimentation from discharge. The 2022 CGP would require inspection downstream of the point of each discharge in order to check for sedimentation. If sedimentation is found, then the operator must document its presence and assess whether it can be attributed to any discharge(s) from the site.
Construction inspection training requirements. The 2022 CGP proposes that any personnel conducting stormwater inspections on a permitted site must complete the EPA’s construction stormwater inspection course and pass the associated exam or have a valid construction stormwater inspection license or certificate from a third-party program that addresses the same principles as the EPA’s course. Many states have implemented their own training and certification program(s). The EPA online certification program is anticipated to be released in Q3 of 2021.
Clarification between routine maintenance and corrective action. Under the 2022 CGP, routine maintenance is defined as repairs or replacements that can be completed within a 24-hour period. If a routine maintenance activity must be performed 3 or more times, a repair/replacement takes longer than 24-hours to complete, or the subject control was not designed or installed correctly, then the activity becomes classified as a corrective action (CA).
Documents in electronic form. The 2022 CGP clarifies that providing electronic versions of inspection reports and corrective action logs is permitted. Maintaining paper copies is not required; however, the operator must be able to provide ready access to electronic records when requested. The list above is not a comprehensive list of all proposed changes present in the 2022 CGP. The full document can be found at https://www.epa.gov/npdes/proposed-2022-construction-general-permit-cgp-and-related-documents.