7.11 Environmental Design
7.11.1 Miscellaneous Permits
Numerous state and federal agencies and others regulate the impact of construction activities on their operations or environmental features. These entities have permitting requirements for this purpose (see
). See
for more information on the environmental process during project development.
Since approvals of impacts often require substantial completion of detailed plans, it is important to coordinate early with these entities. Some environmental permits may have been identified during preliminary engineering as part of the environmental work on the project. These permits may not be received until environmental clearance is obtained, but coordination must be well underway by this point in the project development process.
Considerations concerning environmental permits include:
- Communicate all assumptions and decisions made during preliminary engineering phase with District environmental staff;
- Coordinate with designers to evaluate impacts to resources and entities early and often;
- Investigate possible design modifications to reduce or eliminate impacts;
- Alert District environmental staff as soon as possible to any design modifications that may impact the environmental document; and
- Resource agencies consider impact minimization or avoidance of utmost importance. Conduct a thorough analysis of preliminary engineering assumptions and conclusions regarding impacts if not previously performed;
Obtaining permits can be a lengthy process and is often critical in the project development schedule. Coordination must begin as soon as the need is identified and must be followed throughout project development.
7.11.2 Environmental Permits, Issues and Commitments (EPIC) Sheet
The Environmental Permits, Issues and Commitments (EPIC) sheet is used to summarize the special requirements and restrictions related to the construction activity that has been permitted and the conditions of any permits. The EPIC sheet provides to the contractor a single point environmental guidance document. For example, it may depict areas to be avoided during construction due to the presence of endangered species, wetlands, etc. The EPIC sheet is not an engineering document and shall not be signed and sealed.
Consult Environmental district staff for assistance or to draft EPIC information to be put on the EPIC sheets.
Considerations concerning the EPIC sheet include:
- Review the environmental document and all permits and clearances to determine what requirements or restrictions apply to the project;
- Review Form 2443 – PSE Stage Gate Checklist to ensure incorporation of all requirements in the plans;
- Ensure that areas to be avoided during construction due to endangered species, wetlands, or for other reasons are clearly identified on the EPIC sheet and other environmental plans;
- Coordinate with the District environmental coordinator to review the draft EPIC sheet for compliance with the environmental document;
- Violating the condition of any permit may result in costs and delays to the project. Be sure that all conditions are clearly outlined on the EPIC sheet;
- Field conditions may change, and this can warrant additional data collection, especially in urban areas; and
- Other issues, such as environmental mitigation, roadway access, and retaining and noise wall locations, are often determined after performing initial field surveys.
7.11.3 Stormwater Pollution Prevention Plan (SWP3) Summary Sheet and Environmental Layouts
Designing erosion and sediment control devices includes determining the type and size of facilities for minimizing erosion and siltation during and after project construction. SWP3 Summary Sheet and environmental layouts are prepared to show the construction of devices that minimize erosion and siltation during construction. Various grasses, and other typically proprietary devices, are used to control long-term erosion.
For projects that do not disturb soil (traffic signals, overlays, seal coats, etc.) a standardized General Note and inclusion of Item 504 will serve as the project SWP3. Refer to TxDOT’s
PS&E Preparation Manual
for more details on developing these sheets.Considerations in preparing the SWP3 Summary Sheet and environmental layouts include:
- Prepare environmental layouts to indicate erosion control by construction stage if possible; and
- Consider roadside safety in selecting the type of devices to include.
7.11.4 Environmental Mitigation Plans
Mitigation for impacts due to highway improvements must be defined in project environmental documents, permit conditions, or agreements with regulatory or resource agencies. Mitigation measures are typically defined, without much detail, during preliminary engineering. Mitigation details to be implemented during construction must be delineated in plans and specifications.
Mitigation of environmental impacts due to the presence of hazardous materials may also be necessary. Mitigation measures typically include soil liners to contain hazardous materials, groundwater removal and treatment, and soil removal and disposal. Often, design modifications can be made to eliminate migration of underground contaminants and thereby eliminate the need for mitigation.
Mitigation details may include design drawing details showing special features such as protection of historic properties or mitigation of environmental concerns. Obtain design input from a landscape architect and biologist with knowledge of biologic processes and skills to meet the mitigation commitment.
Offsite mitigation may justify separate construction contracts and schedules for this work. Developing regional mitigation alternatives may be desirable for TxDOT and regulatory agencies. The TxDOT PM should consult with the Director of Transportation Planning and Development and ENV at the start of detailed design.
Considerations concerning mitigation plans include:
- Coordinate with District environmental staff, landscape architect and drainage design staff to determine the most cost-effective, sustainable solution to meet the environmental commitment;
- Mitigation may need to be completed before construction, and if mitigation requires the acquisition of property, acquisition of these parcels must be prioritized;
- For mitigation requiring post-construction monitoring, have the technical expert develop a reporting process for monitoring. Monitoring may likely be long term, and a defined reporting process will ensure uniformity during this time; and
- Timing of the completion of mitigation plans is project-specific and must be driven by the terms of agreement and permit requirements with resource agencies.
7.11.5 Hazardous Material Remediation Plan
Department personnel or environmental consultants under contract with the department will conduct an initial site assessment (ISA) and/or Phase I Environmental Assessment (ESA) of the project area to determine the likelihood that hazardous substances or petroleum contamination exist on the property and the extent to which further investigation and/or remediation may be necessary. On transportation projects, hazardous materials may vary from lead paint on bridges to asbestos in structures, or soil contaminated with gasoline from underground storage tanks.
The plans will provide a layout of anticipated areas of contamination within the project limits; the plan sheet(s) will have a list of contractor information notes to be followed while working in the layout area. An onsite qualified inspector will be required to monitor and supervise construction activities in the contaminated area.
Unanticipated hazardous materials encountered during construction must be properly handled and disposed of. Contact the District environmental project manager for procedures to follow.
Cleanup of contaminated materials will be done by properly trained and equipped personnel under a contract work authorization.
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