Construction Stormwater Program Management, Tracking, Reporting, and Compliance (2025)
Chapter: 5 Summary of Findings
CHAPTER 5
Summary of Findings
By the late 1960s, industrial discharges, deficiencies in sewage treatment, and agricultural runoff had mounted a growing cause for concern about water quality. This situation and events such as the Cuyahoga River Fire led to a call for action; consequently, the Clean Water Act (CWA) of 1972 was passed into law. The National Pollutant Discharge Elimination System (NPDES) permitting program’s construction general permit (CGP) is a critical component of the CWA and is administered by the EPA. It regulates the discharge of pollutants from construction activities to protect water quality. The CGP covers stormwater discharges from construction activities that disturb 1 or more acres of land. It requires construction site operators or owners, including state departments of transportation (DOTs), to implement measures to control sediment and pollutants in stormwater runoff. As part of this process, state DOTs must navigate a multi-stage permit and implement elements such as a stormwater pollution prevention plan (SWPPP) detailing how erosion and sediment discharges are controlled during construction.
This synthesis summarizes an investigation of state DOTs’ approaches to implementing and maintaining compliance with the CWA, NPDES program, and federal and state stormwater permits (e.g., the CGP). This synthesis documents state DOT practices, tools, and approaches for managing compliance with state and federal construction stormwater permit requirements. The synthesis was completed through a literature review, a survey of state DOTs, and interviews with select state DOTs.
Literature Review
The synthesis reviews academic and research literature, FHWA and AASHTO documents, reports, websites, and relevant legislation and policy. The literature review demonstrates that most states have regulatory agencies authorized to implement the NPDES programs on behalf of the EPA and that the state NPDES must be at least as stringent as the federal requirements. In these cases, state DOTs must comply with federal and state-specific requirements. For compliance with state-authorized NPDES permitting programs and the associated CGP for construction, DOTs typically work closely and in coordination with state environmental and regulatory agencies.
The literature review also includes information about best management practices (BMPs) and associated erosion and sediment control (E&SC) measures. These devices or treatments may be temporary or permanent during active construction; that is, they remain in place after project completion and continue to treat runoff and discharge from the project. The literature review notes differences in the terminology used to describe construction BMPs across state DOTs. Based on a review of specifications and manuals, BMPs may be referred to by different names. The review of specifications also indicated that payment terms and responsibilities (between
state DOTs and contractors) vary. These differences in payment terms and responsibilities were further discussed in the feedback from the state DOT survey.
Survey Questionnaire
The objective of the survey questionnaire is to identify current practices in use by state DOTs to address, track, monitor, and manage construction stormwater compliance requirements. The survey collected 42 DOT responses from its distribution to 50 state DOTs, the District of Columbia, and Puerto Rico DOTs (81% response rate). The survey was distributed to the voting members of the AASHTO Committee on Construction. The following summarizes the survey findings.
In relation to how programs are managed for construction stormwater, 33 of 42 responding state DOTs (79%) noted having a statewide program; 27 of 42 DOTs (64%) have a project-by-project approach; and 14 of 42 DOTs (33%) have a program based on types of projects. In relation to SWPPPs, the survey responses indicate that most SWPPPs (25 of 42 DOTs, 60%) are prepared during the design and engineering phase of the project, with 15 of 42 DOTs (36%) noting that they are prepared during the pre-construction phase. While the results indicate shared responsibilities between design engineers (26 of 42 DOTs, 62%), contractors (24 of 42 DOTs, 57%), and consultants (21 of 42 DOTs, 50%) in preparing the project site-specific SWPPP, most DOTs indicated that managing SWPPPs is the responsibility of the contractors (33 of 42 DOTs, 79%) or construction project managers (26 of 42 DOTs, 62%).
Similarly, the results indicate that the state DOTs are responsible for design guidelines development (36 of 41 DOTs, 88%), monitoring and tracking control measures (36 of 41 DOTs, 88%), inspections (35 of 41 DOTs, 85%), training project personnel (34 of 41 DOTs, 83%), and reporting (33 of 41 DOTs, 80%). Contractors are responsible for the installation of BMPs (41 of 41 DOTs, 100%), violation remediation (40 of 41 DOTs, 98%), BMP maintenance (39 of 41 DOTs, 95%), inspection deficiency remediation (36 of 41 DOTs, 88%), and monitoring and tracking control measures (33 of 41 DOTs, 80%).
In relation to inspection of control measures, most state DOTs (35 of 42 responses, 83%) have an inspection process in place. These approaches include regular site investigations (33 of 42 DOTs, 79%); 20 of 42 DOTs (48%) constantly review control measures; and 16 of 42 DOTs (38%) have used their internal audits to monitor the performance of construction stormwater management requirements. Alternatively, 4 of 42 DOTs (10%) noted using performance-based metrics to monitor their construction stormwater management requirements.
The survey indicated the differences among state DOTs in recording, reporting, maintenance, inspection program responsibilities, training, qualifications, and certification requirements. Similarities were also found between responding state DOTs related to the common BMPs used for construction stormwater management, such as erosion control logs, check dams, stabilized construction entrances and exits, silt fences and barriers, sediment basins, temporary or permanent hydromulching/seeding, and many more. However, as mentioned earlier, these BMPs may not be referred to with the same name from state to state.
Case Examples
The case examples were conducted to provide details about the survey findings related to state DOT practices, tools, and approaches for managing compliance with state and federal construction stormwater permit requirements. Colorado, Florida, Iowa, New York, Pennsylvania, and Texas were selected for case example interviews.
The case example interviews describe the differences and successes among construction stormwater management programs from state to state. For example, Colorado and Texas DOTs operate under the general statewide CGP and municipal separate storm sewer system (MS4) permits and associated requirements, whereas Iowa DOT does not have a state-level MS4 permit. Additionally, New York State DOT has a State Pollutant Discharge Elimination System for administering the NPDES CGP; recently, the DOT has started to map out and track the locations of temporary and permanent BMPs. Florida DOT is moving toward performance-based specifications for construction stormwater management and placing the responsibility on the contractor for filing for the CGP and its compliance. The contractor is also involved in developing the project site-specific SWPPP at Florida DOT. Colorado DOT follows a practice-based approach, encouraging contractors to proactively manage construction stormwater.
The case examples noted the importance of being proactive and consistent in construction stormwater management. They also noted that consistency can be improved through inspection programs built specifically for state DOTs. Implementing uniform guidelines, forms, and templates, as mentioned by the Iowa, Pennsylvania, and Texas DOTs, can be another approach to building consistency within construction stormwater management programs (SWMPs). DOTs also mentioned that recently implemented changes to their construction SWMPs allow them to hold the contractor more accountable in their actions related to construction stormwater management. This situation is indicated by the liquidated damages mechanism in place at Colorado DOT, the requirement to photograph corrective actions by New York State DOT, and DOT and contractor co-permittees, as mentioned by Florida and Texas DOTs. In each case example, interviewees noted that resource constraints limit the time available for the DOT to inspect construction sites for stormwater management. The responsibility must be shared with the contractor through well-developed specifications and permit requirements.
Knowledge Gaps and Suggested Future Research
The gaps in knowledge and practice identified in this synthesis may serve as potential future research topics. Each of these gaps will require greater insight and development before performing the research. Therefore, to improve and enhance state DOT practices, tools, and approaches for managing compliance with state and federal construction stormwater permit requirements, future research is suggested in the following areas:
- Develop guidelines for construction SWMPs, including alternative contracting methods (e.g., design-build, construction manager/general contractor), uniformity in training and certifications, phasing approaches to minimize ground disturbances during construction, monitoring discharges during construction, and technologies, programs, and applications used for construction stormwater management.
- Develop consistency in BMP and construction stormwater management terminology and applications by creating guidelines for stormwater management and BMP programs during and after construction.
- Conduct a synthesis on MS4 programs and DOT compliance with permit requirements for construction, operations, and maintenance.
- Conduct a synthesis on state DOT implementation, maintenance, and inspection of post-construction BMPs for stormwater management after a project is complete and in operation.
These areas are interconnected for standardization across programs; thus, they would build consistency into BMP terminology and applications. Consistency would create efficiencies among states in areas such as approved products (i.e., states could use the approved products list of other states if they share similar requirements and standards). Greater consistency may-
also enable more uniform construction stormwater management training programs. If training programs were similar, certification could be transferable from state to state, making work across state lines more efficient for contractors and consultants. Additionally, stormwater management tends to be handled differently for design-build and construction manager/general contractor delivery methods. Investigating different approaches would help DOTs improve stormwater management for innovative contracting projects. Finally, investigating the current state of the practice in compliance with MS4 programs and implementing post-construction BMPs would benefit state DOTs and their associated contractors and consultants.
