Approaches for Determining and Complying with TMDL Requirements Related to Roadway Stormwater Runoff (2019)

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7 This chapter shows the state DOT how to negotiate TMDLs and engage in TMDL–WLA development with the regulator. It identifies the various strategies state DOTs can use, illustrated in several flow charts that depict the step-by-step phases of TMDL predevelopment, develop- ment and approval, and implementation. State DOT Involvement in the TMDL Process Tracking of 303(d)-listed impaired waters that are not meeting water quality standards prior to TMDL development can be a key component for a state DOT to know if a waterway may get listed as a contributor of pollutant loads into the receiving water body. It is beneficial for a state DOT to be involved throughout the listing process of an impaired water body and the develop- ment of a TMDL in any watershed that may have a significant highway footprint within it. Pro- actively coordinating with regulatory agencies developing TMDLs to provide monitored data (e.g., characterization of POCs within highways) can also be beneficial. As part of the state DOT involvement process within a TMDL development, the department should determine its contri- bution within the watershed and analyze it with its highway characterization (or concentration) to distinguish its impacts for the impaired water body. State DOTs may also use existing highway runoff characterization data to assess their anticipated contributions to the receiving water body identified by the regulating agency to determine the accuracy of the WLAs assigned to them. Figure 2 provides the methodology to assess a TMDL from a state DOT’s perspective. The process starts with the department verifying whether any of its highways or facilities are within the watershed of concern and listed as a potential source or discharger within the TMDL. If the state DOT is not named and its facilities are not located within the watershed, then the depart- ment should track the progress of TMDL development to avoid being named as a contributor in TMDL reports. If a state DOT is named in a TMDL, then the department can assess the pol- lutant and analyze its load contribution within the watershed based on the drainage areas. These estimates should be compared with the state DOT’s WLAs in the TMDL to determine whether the estimate is reasonable. Furthermore, a state DOT should determine whether the impaired constituent is a typical state DOT pollutant to decipher the appropriate watershed-based com- pliance strategy. Alternatively, if the pollutant is not a POC for a state DOT, the department should provide scientific data (to the regulating agency during the TMDL adoption or re-opener process) that support its claim of being excluded from the list of stakeholders. If the TMDL report does not identify the state DOT as a primary source contributor of the impaired constitu- ent in the watershed, then the department may participate on an appropriate level of cooperative implementation opportunity with other watershed dischargers to achieve TMDL compliance. If a collaborative or watershed approach strategy is not available for a specific TMDL, then on-site pollutant-based compliance strategies may be implemented. Pollutant-based compliance C H A P T E R 2 State DOT TMDL Negotiation and Engagement

8 Approaches for Determining and Complying with TMDL Requirements Related to Roadway Stormwater Runoff strategies for state DOT POCs (i.e., sediment, metals, nutrients, bacteria, and others) are dis- cussed further in Chapter 4. Figure 3 describes the process a regulator goes through to develop a TMDL, from the begin- ning to its final approval and adoption by EPA. Prior to the development and implementation of a TMDL, a water body is listed as impaired and not meeting its beneficial uses in Section 303(d) of the Clean Water Act. The listed water body is then prioritized by the delegated state regu- lator or EPA (in Idaho, Massachusetts, New Hampshire, New Mexico, Washington, D.C., and on federal and tribal lands) for TMDL development based on the level of impairment. Once the water body is placed on a TMDL development list, the delegated state agency can prioritize the impaired water bodies for TMDL development. Then a TMDL is developed by either the delegated state agency or EPA. Throughout the TMDL development process, numeric targets, loading capacity, WLAs, implementation plans, and monitoring programs are identified for the impaired water body based on assessed data for the water body and other studies conducted by the regulatory agencies. A state DOT should participate in stakeholder Is state DOT in TMDL watershed? Watershed Management (Off-site compliance) Funding Program (Payment for load exceedances) Source Control (Erosion control/ slope stabilizaƒon) Sediment Source Control (Erosion control/ slope stabilizaƒon) Source Control (Landscape pracƒces) Pathogens Pollutant-Based Compliance Strategies Source Control (Erosion control/ galvanized structures) Nonstructural (Public educaƒon/ inspecƒons) Alternaƒve Deicer Methodology (Limited usage) Alternaƒve Paving Materials (Roadway heaƒng) Infiltraƒon/ Filtraƒon/Detenƒon Infiltraƒon/Filtraƒon/ Sedimentaƒon Street Sweeping/ Catch Basin Cleaning Street Sweeping/ Catch Basin Cleaning Infiltraƒon/Filtraƒon/ Detenƒon Infiltraƒon/Filtraƒon/ Retenƒon Evaporaƒon/ Detenƒon Ponds Salinity/ Total Dissolved Solids/ Chlorides/Sulfates Pervious Fricƒon Course/Vegetated Conveyances Pervious Fricƒon Course/Vegetated Conveyances Stream Restoraƒon– Preservaƒon Pollutant Equivalency (Crediƒng/Banking) Comply with permit. Comment during TMDL development to remove state DOT from WLAs/TMDL. Is state DOT assigned a waste load allocaƒon (WLA) or incorporated in an MS4 permit? Is pollutant of concern a primary pollutant of state DOT? Treatment Opƒons (Off site or On site) Nutrients Toxics/Metals Sediment/Turbidity State DOT is not required to comply with TMDL. NO YES YES YES Off-Site Planning Track On-Site Planning Track NO NO Figure 2. TMDL review and potential implementation process.

State DOT TMDL Negotiation and Engagement 9 meetings during the TMDL development process and show its involvement from the initial stages of 303(d) list identification wherever practical. It should also provide monitored data to the state regulators developing the TMDL to further validate the known issues with the water body in consideration. Upon completion of the TMDL development by the regulating agen- cies, the reports go through a public approval process. In this phase of TMDL development, a state DOT can assess any loads assigned to highway runoff and validate their accuracy and equity. Otherwise, a state DOT should respond at the public approval stage—either through the federal or state TMDL approval process—to negotiate removal of their WLAs if they are not a source or have a negligible impact. After approval of the TMDL by the appropriate agencies, including EPA, the stakeholders may collaborate to implement appropriate mea- sures for addressing the TMDL requirements and improving water quality within the water body. Compliance strategies and alternatives for state DOTs with regard to various POCs are summarized in Chapter 4. Figure 4 is developed to help state DOT practitioners assess whether they should partici- pate as a stakeholder in the predevelopment stage of a TMDL. Factors that the department Is receiving water listed on 303(d) list? TMDL development not applicable STATE DOT INVOLVEMENT: Provide useful data and idenfy any known water body concern. Priorize lisng for development of TMDL EPA or delegated state agency to develop TMDL Problem Idenficaon, Pollutant of Concern, Pollutant Sources Determine applicable water quality standards/targets Establish load allocaons/ waste load allocaons OPTIONAL: Develop implementaon plan Public Review/ Comments TMDL Approval (EPA) Implement TMDL Monitoring Program/ Technical Studies NO YES Figure 3. TMDL development and approval process.

10 Approaches for Determining and Complying with TMDL Requirements Related to Roadway Stormwater Runoff should consider when participating in the predevelopment stages of a TMDL include the following questions: • Are there are any state DOT facilities within the TMDL watershed? • Is the water body’s POC one of the primary highway runoff pollutants? As shown in Figure 4, the state DOT should assess its impacts within each receiving water body and the watershed through highway facilities (including but not limited to roads and properties, such as park and rides, rest areas, and maintenance yards), POCs, and runoff concentrations. In instances where a state DOT is in the watershed going through a TMDL development, the department can provide valuable input to the regulating agency based on available stormwater runoff characterization studies or technical studies conducted within the watershed for the receiving water body. Furthermore, the state DOT’s collaboration with the regulator throughout the TMDL development process may provide validation to the impairment of the receiving water body. State DOT input into the TMDL development stages may be beneficial when the WLAs or load contributions for stakeholders are estimated. Therefore, it is beneficial for a state DOT to participate throughout the 303(d) listing and development phase of a TMDL to identify the department’s baseline prior to the adoption or approval of a TMDL. TMDLs may include a schedule for compliance (i.e., a schedule for compliance or a schedule for milestone compliance for achieving the waste load reduction). A state DOT can request a specific TMDL compliance schedule separate from a schedule provided to other traditional MS4 urban dischargers. One justification for a state DOT–specific schedule is the uniqueness of department project delivery and funding processes. Negotiating a feasible compliance schedule can be part of the state DOT negotiation through the National Pollutant Discharge Elimination System (NPDES) permit renewal process. In addition, extended timelines for implementation of projects and associated BMPs can also reduce the level of improvement in the early years of an agreement. For state DOTs that must comply with multiple TMDLs for multiple pollutants, it NO NO NO NO YES YES YES YES Enhanced Compliance Measures (Watershed credits) Watershed Management (Monitoring/Special Study/Outreach) Site-Specific Objecves Is state DOT in impaired water body watershed? Is pollutant of concern a primary pollutant of state DOT? Evaluate highway runoff concentraons. Are there high state DOT loads? Is there an alternave methodology for waterbody compliance? Comply with applicable laws and regulaons. Track status of water body/TMDL. Comply with applicable laws and regulaons. Track status of water body/TMDL. Provide monitoring results. Parcipate in TMDL development. Pollutant-Based Compliance Strategies Water Effects Rao Parcipate in TMDL development Figure 4. TMDL predevelopment assessment process.

State DOT TMDL Negotiation and Engagement 11 may be possible to negotiate a schedule to streamline compliance with reasonable milestones— for example, 5 years, 10 years, 20 years, or 30-plus years—and align with the department’s capital improvements project delivery schedules. Alternatives for TMDLs with Challenging Compliance Requirements Several state DOTs are faced with WLA goals that are, at times, not attainable because of technical infeasibility, inappropriate TMDL allocation, and site constraints. TMDLs primar- ily require their watershed entities or stakeholders to improve water quality to the point that the water body is restored to its natural condition. There are several ways that state DOTs can approach a TMDL with a goal that is not achievable or that seems endless. Prior to final TMDL implementation, it is in the state DOT’s interest to participate in the TMDL development pro- cess to identify the accuracy of assigned WLAs. There can be instances when a state DOT is assigned an allocation for more than the load that is being discharged from its right-of-way. In such situations, participation in the TMDL development process can help a state DOT to adjust its assigned loads prior to final adoption to prevent consequences caused by failure to achieve the targets. Once a TMDL is developed with unachievable targets for a state DOT, it becomes challenging to modify the TMDL. However, there are viable alternatives, including working diligently with the state regulators and emphasizing the state DOT’s capability to achieve compliance with the TMDL. If it is known that a TMDL has assigned an allocation that is unachievable, then the state DOT should look to evaluate the allocations through a feasibility study and identify the appro- priate targets for its right-of-way. Appropriate data analysis of the TMDL targets and assigned allocations to the state regulators can lead to TMDL renegotiation. It is critical for the state DOT to present the most appropriate known factors for the TMDL watershed and to provide reasonable support as to why it is unable to achieve compliance. State DOTs should also indicate to the regulators that they plan to implement compliance measures and reduce loads from the downstream receiving waters to the maximum extent practical. In addition, state DOTs can indicate the challenges with achieving compliance due to the aggressive schedule, funding limitations, or technical infeasibility. Several TMDLs may be within heavily urbanized areas; therefore, a state DOT may find it challenging to implement BMPs within its right-of-way. There are several alternatives for a department to consider when TMDL targets seem challenging to attain. A state DOT can negotiate the removal of a pollutant or category—such as bacteria because of its negligible and uncontrollable impacts within the department’s right-of-way—from sources such as wildlife and unauthorized encampments. However, if the regulator is open to removing from basin plans or from TMDL reports those pollutants that have negligible impacts on the state DOT’s discharge, then such action can ensure that the state DOT constituents with a higher potential to adversely affect the water quality of a water body are given priority through available resources. Additionally, the state DOT can ensure the identification of appropriate source control strategy—such as removal of unauthorized encampments from its right-of-way to address bacteria issues—within its stormwater management program to assure the regulator that the department is implement- ing measures to address the negative impacts of their discharge on water quality. State DOTs should note that negotiating a TMDL—even after development—is possible with appropriate preparation of supporting data analysis that indicates why it is unachievable and that identi- fies the primary source, appropriate control measures, and level of compliance necessary and attainable to meet TMDL requirements. State DOT resources, therefore, can be reallocated from small benefit targets to primary target constituents.