Geotechnical Soil Borings/Soil Core Hole Drilling Considerations:

If hazardous material contamination is suspected, then any required soil core hole drilling for pavement, retaining walls, bridges and other structures can be combined with required environmental sampling and analysis to minimize costs.

Additional provisions or contingency language may be needed in the scope of services or proposals for geotechnical soil boring/soil core hole contracts on a project-specific basis if contaminated soil and/or groundwater might be encountered. For example, special considerations for health and safety monitoring, personal protective equipment, proper handling and disposal of soil cuttings, alternative drilling techniques to prevent migration and plugging may be required for soil core hole drilling.

Right-of-Way Considerations:

Regardless of the potential for encountering contamination during construction, special considerations for hazardous material concerns during the right-of-way negotiation and acquisition process may be necessary. Regulatory agency and property owner coordination may still be required, depending upon the regulatory status of a site. For example, plugging of groundwater monitoring or exploration wells may be required by applicable regulations. Other concerns can include asbestos, underground storage tank removal, permit status notifications, and site closure.

Land use restrictions or post-closure care requirements may be recorded in the deeds of parcels to be acquired. Corrective action cases may need to be re-opened for sites or facilities due to proposed land use changes. The terminology and requirements for corrective action cases differ from those of a risk-based assessment for a facility according to the federal or state regulatory status. For example, requirements for a permitted landfill will differ from those for a petroleum storage tank facility. Additional information on asbestos-containing materials, petroleum storage tanks, leaking petroleum storage tank facilities and other permitted or regulated sites is provided in Chapter 3, “Right of Way.”

Utility or Pipeline Agreement and Adjustment Considerations:

Abandoned utilities or pipe-lines containing crude oil, polychlorinated biphenyls (PCB) or asbestos-containing materials (ACM) may have to be removed during construction. TxDOT utility installation notices, joint use and standard utility agreements typically include general statements about following applicable federal, state, and local regulations. The responsibilities for handling or disposing of hazardous materials must be determined. On a case-by-case basis, specific hazardous material or spill reporting requirements should be considered in the agreements. If unknown or unanticipated contamination is encountered during utility maintenance, adjustments or installation, the utility company should be required by the agreement to notify the district so that possible involvement during any proposed construction can be determined.

The potential for encountering contamination should be addressed early in project development to prevent or minimize delays in completing utility adjustments. Adjustments to utilities or pipelines that involve hazardous materials may impact construction projects. A district may decide that a particular project requires joint bids with the municipalities to handle utility adjustments during construction. Whether the utilities are adjusted prior to or during construction, the extra time needed to arrange for special handling of contamination may delay construction, or impact construction scheduling. For example, installation or adjustment of telephone fiber optic cable within contaminated soil may require special protection, such as trench lining and/or soil disposal.

Hydraulic and Storm Sewer Design Considerations:

If handled improperly, de-watering and storm sewer installation in contaminated soil or groundwater are at the greatest risk of worker exposure and further releases into the environment. If unanticipated contamination is encountered and special provisions or arrangements have not been made, then construction delays and/or contractor disputes or claims are likely. Areas needing significant excavation, trenching, tunneling and/or de-watering typically require more assessment and/or further investigation to determine if contamination will be encountered during construction. If de-watering of contaminated groundwater is necessary, then specialty contractors, engineering controls, monitoring and testing, temporary collection, filtration, approval from regulatory agencies and/or discharge permits may be required.

Design Changes and Re-Evaluations:

The following steps should be performed for design changes and re-evaluations:

Plans, Specifications and Estimates (PS&E) Considerations

: If site remediation cannot meet regulatory closure requirements prior to construction or during the right-of-way acquisition process, then monitoring of remediation systems and their access may need to be integrated into the design of the proposed project. Coordination with regulatory agencies and the property owner/responsible parties may be necessary to ensure that the roadway construction does not adversely affect remediation, site closure and/or post-closure care of the site.

The management and disposal of contaminated soil, groundwater and waste must be conducted in accordance with applicable federal and state requirements and in a manner that will not adversely affect human health and/or the environment. If a hazardous material concern cannot be avoided prior to construction, a preventive action plan, such as a Soil and Groundwater Management Plan, will serve to reduce the impact of contamination encountered during construction. A preventive action plan may include, but is not limited to, the following:

Special specifications, provisions or contingencies can be incorporated into the PS&E to reduce the potential for construction delays, claims, forced accounts, or field change orders. Employed by the local entity, TxDOT or the prime highway contractor, specialty contractors, or subcontractors can be used to implement the preventive action plan during construction. Incorporating special specifications, provisions or considerations into the development of the PS&E is further discussed in Chapter 4, “Design.”

Property Management or Maintenance Considerations:

If a site cannot meet regulatory closure requirements prior to construction or during the right-of-way acquisition process, then closure may need to be obtained after project construction. Additionally, a site may have post-closure requirements for maintaining vegetation, caps or drainage after construction. Any post-closure responsibility must be communicated to the district maintenance staff.