Shoring Up Sediments



ASTM standards will help with assessment and cleanup of sediments.

When you’re walking on the beach, canoeing on a river, or fishing in a nearby pond, you’re enjoying the moment (hopefully, anyway) and the surroundings. You may be talking with someone or thinking about the fish you might catch. But what you’re probably not thinking about is the sediment lying beneath the surface of the water.

Sediment is the stuff that looks like soil but isn’t; it sits at the bottom and sides of a lake, river, stream, or tidal flat. Sediments constantly change: They move with tides and floods, weather and dredging.

Luckily for the rest of us, one ASTM International subcommittee is thinking a lot about sediments.

That’s because spills and urban runoff — metals, polychlorinated biphenyls, oil and gas, and agricultural runoff from pesticides and other chemicals — can make a stew of sediments.

And, “sediments by their very nature are very difficult to assess, to measure, and to clean up,” says Tripp Fischer, PG, vice president and principal hydrogeologist at BSTI, Cochranville, Pennsylvania. He is also chair of the subcommittee on corrective action (E50.04), part of the ASTM International committee on environmental assessment, risk management, and corrective action (E50).

Fischer explains that the situation for sediment corrective action is challenging. Regulatory policies vary. The environments and the water bodies vary. Sources prove hard to pinpoint. And cleanup and monitoring approaches differ.

But with one standard completed, and more underway, the E50.04 group aims to support professionals who address contaminated sediments.

E50.04 members began their work by conducting a survey. Almost 100 sediment remediation and assessment experts were asked what they felt was needed in standards for corrective action.

The common threads from the responses became the basis for the draft standards: how do you determine risk, set the cleanup objectives to address the risk, collect and analyze samples, and monitor the site after remediation?

The completed standard (soon to be published as E3164) from the group is a guide to monitoring strategies for sediment corrective action sites following remedial selection, which describes a decision making framework to accommodate the needs of specific projects.

The draft standards are guides for:

 

  • Sediment corrective action, how to investigate, evaluate risk, and develop remediation metrics (WK51760);
  • Selection and application of analytical procedures used during sediment corrective action, with a toolbox of methods along with their applicability and pros and cons of their use (WK54455); and
  • Non-aqueous phase liquids mobility in sediments, with procedures for assessment; sample collection, handling, and transport; lab testing; and data analysis and reporting (WK62303).

 

Additional needs have come to light as the sediment corrective action group has worked together over the last two years. The NAPL standard started in that way.

Today’s 115-member team weighing in on the standards includes government representatives, environmental consultants, academia, manufacturers, and scientists.

The group envisions that the standards will provide the needed common framework for addressing contaminated sediments. “The framework should put all these perspectives into one aligned plan that will satisfy everyone,” Fischer says.

 

 

 

Issue Month: 
May/June
Issue Year: 
2018
Industry Sectors: 
Construction
Environment