Remedial Investigation: What is the Purpose of Treatability Investigations

Treatability investigation helps identify whether a proposed technology is well-suited to meet remedial goals set out in the Superfund site’s Record of Decision, based on site-specific conditions. Ideally, initial site scoping should indicate whether treatability testing is needed, so that further study becomes part of the remedial investigation and feasibility study (RI/FS) process.

It’s purpose is to streamline the remedial investigation process, but the primary goal is to ensure the final clean-up plan meets SARA standards for maximizing the value of chosen treatment options. Those standards include:

• Reduced uncertainty regarding both cost and performance.
• Consolidating the RI/FS timeframe by determining early on whether treatability study is necessary.

Overall, a treatability testing program will include:

• Creation of work plan (WP), sampling and analysis plan (SAP) and health and safety plan (HSP).
• Gathering any necessary field samples.
• Actual testing.
• Analyzing and interpreting results.
• Documentation of findings in a report.

A literature survey is conducted first, to review existing information about the proposed treatment technology’s applicability, potential efficacy and comparative cost. If enough information is not available, actual testing will need to be performed to evaluate the technology. This can be done concurrent with other remedial investigation field work, to save time.

Which Testing Method to Use?

Bench testing is the most cost-effective way to determine if a particular technology offers suitable chemical parameters. It’s useful in a variety of operating conditions, it’s fast, less expensive and produces low volumes of waste. However, it can be difficult to predict actual performance levels using bench testing. Choosing this method depends on:

• Whether the candidate technology is well-developed.
• The site’s waste composition.
• Data type and “representativeness.”

Pilot testing simulates the physical and chemical parameters of a full-scale treatment process. It’s more time-consuming and costly, but it provides a better estimation of performance. Pilot testing is the best choice when:

• Only limited information is available regarding probable full-scale treatment conditions.
• It’s important to study secondary effects of the treatment process.
• Site waste composition is complex or unique.

Later, during the Remedial Design/Remedial Action (RD/RA) phase, treatability investigation is used to confirm that the chosen technology can accomplish site clean-up as specified, to refine the clean-up plan including outlining operating conditions and to make more accurate cost estimates.