The ins and outs of efficient soil transfer

Developers in California are well aware of the high cost of moving large quantities of soil in development and demolition projects.

Those costs only increase when some or all of that soil contains regulated contaminants, such as petroleum hydrocarbons or metal concentrations. These contaminants are above safe background levels because of past activities on properties.

Assessing and managing regulated waste soil and “clean” or inert soil is an important element in construction and demolition (C&D). To succeed, it’s necessary to understand the regulatory and legal framework regarding proper soil transport and disposal in a development setting and to develop best practices to avoid the risk and liability of shipping contaminated soil to unauthorized destinations.

Proper planning

The California Water Code and Titles 23 and 27 of the California Code of Regulations often are interpreted to mean that any soil with detectable concentrations of hazardous substances or metals above background levels is “waste” upon excavation and must be exported from a job site. If exported soil is characterized as waste, developers must discharge it to a licensed and permitted waste management unit for treatment or to a disposal facility. These facilities treat, store, dispose of or reuse soils under appropriate local, state and federal regulations.

By proactively complying with regulations and completing a progressive assessment process, remediation contractors can avoid project delays and minimize the risks of improper disposal. The assessment starts with completing a Phase I Environmental Site Assessment (ESA) report to identify the recognized environmental concerns (RECs) that may exist at a site. If a Phase I ESA report indicates that RECs or environmental concerns exist, contractors must move to a second step. Phase II could indicate the presence of soil impacts from chemical constituents, such as petroleum hydrocarbons, solvents and pesticides.

Naturally occurring metals such as arsenic can be elevated because of regional geologic sources that exceed regulatory screening levels and disposal standards. Are these hazardous wastes? That depends on the concentrations of the chemical constituents or metals in the soil. Properties with previous land use often show concentrations of these constituents in soil below hazardous waste levels but high enough to designate certain soils as regulated nonhazardous waste. Contractors must dispose of or recycle this soil at a properly licensed facility.

Whether you’re profiling waste soil for off-site disposal at a licensed receiving facility or characterizing the extent and composition of inert soil for transportation to another nearby construction site that needs fill soil, the process will be guided by soil sample collection and analyses of various substances identified in the Phase I ESA report. Information gleaned during that analysis will help facilitate the approval of various soil waste types at the appropriate disposal facilities.

Although justifications can be made for using older data if it can be demonstrated that the soil samples are still representative of current site conditions, most landfill and treatment facility operators will want waste profiling completed with data no more than one year old.

Proper design and completion of soil sampling plans by qualified professionals should provide sufficient data to answer two important questions: “How much waste soil do we have?” and “What disposal facilities can we send it to?” If a contractor also needs to move clean soil, the firm must determine whether the clean soil proposed for export meets local criteria for clean fill.

Early characterization of contaminated and inert soil provides a higher degree of confidence in disposal cost ranges used to plan projects and enables contractors to develop different disposal or recycling strategies to limit the quantity of impacted soil that is exported. It also helps minimize potential future litigation associated with toxic tort and improper waste disposal practices.

While some contaminants might not be present in concentrations below certain screening levels, soil with detectable chemical constituents or metals above background concentrations is considered a regulated waste, which costs more to export. Enabling clear communication between the grading contractor and an environmental consulting company can help characterize soil earlier and minimize cost overruns or delays. Alternatively, waiting until grading starts to test soil could delay the project and increase the cost of rushed laboratory analyses, creating unexpected additional disposal costs to meet construction schedule needs.

Developing value-added strategies with the help of an environmental consultant and various members of the project’s design and construction teams can reduce soil disposal costs, as well.

When exporting soil is required, material with contaminant levels that are below human health risk screening criteria but that still are a regulated waste requires the preferential reuse or burial of that soil on-site, which can result in significant savings because it allows the preferential disposal of inert soil as opposed to the costlier disposal of impacted soil. This can be completed if the limits of the impacted soil versus inert soil are delineated through prior soil sampling and analysis, which provides the confidence of knowing which soils are inert and which soils are contaminated when it comes time to grade and export them.

Any qualified environmental professional with a proven background servicing the construction sector can guide a contractor through the nuances of applying the appropriate regulatory guidance, as well as coming up with various strategies to minimize soil disposal costs.

Environmental consultants can help prepare a commonly used document called a soil management plan to examine all aspects of proper handling and management of waste soil during development. A trusted consultant also can work with a design or construction team to develop soil management strategies to reduce disposal costs.

During the grading process, an environmental professional should oversee execution of the soil management plan during the movement of impacted soil to minimize environmental risks from improper disposal during grading, which could result in fines or the need to remove impacted soil from an import site.

An environmental professional also can minimize delays resulting from the discovery of previously unknown soil impacts potentially uncovered during grading from old, forgotten underground fuel tanks or previous dumping areas. Environmental oversight during grading and having a soil management plan often are required when regulatory oversight is being provided, whether through voluntary oversight programs or when regulatory oversight is a condition of obtaining a grading permit from a municipality.

Clean soil export considerations

In California, exporting fill material from a previously listed contaminated site could need the approval of the local regional water quality control board.

Failure to properly assess whether a particular site is governed by these requirements could lead to costly state fines. Not only could the site require approval to export the soil, but the receiving facility also could need regional board approval. In our experience, the landowner and contractor could face liability in both these scenarios.

Clean soil import considerations

Long Beach, California-based SCS Engineers is assisting on a large infill development requiring more than 1 million cubic yards of clean fill to achieve the final grade. Potential sources are identified from other C&D projects and supply facilities to meet the project’s import requirement. Project-specific environmental and geotechnical import specifications were developed detailing the number of soil samples and laboratory analyses based on design and regulatory standards. Whether analytical data are provided by the export site or the cost of soil sampling at an export site is taken on by the soil importer, an environmental professional should be employed to review the soil’s analytical data prior to import for adherence to the project’s import specifications.

This vetting process for imported soil quality often is documented in what is commonly referred to as a “clean” or inert soil letter.

Depending on the availability of adequate clean soil sources in the market, a developer or contractor could face project delays and increased costs associated with importing soil if finding an acceptable clean fill source proves difficult.

Additional fees could apply

Any generator site in California that disposes of 5 or more tons of hazardous waste soil within a calendar year is assessed a hazardous waste generation and handling fee of $49.25 per ton.

Generators also must maintain waste manifests for each truckload of exported soil and weight tickets associated with hazardous waste disposal so they can register and report hazardous waste disposal quantities to the California Department of Tax and Fee Administration.

Failure to register and pay these state fees results in auditing and significant fines. Generators often also are required to obtain an Environmental Protection Agency identification number.

The author is a project manager at Long Beach, California-based SCS Engineers. Email him at ketchells@scsengineers.com.