Abstract

The remediation of naturally occurring radioactive material (NORM) contaminated sites in wetland, marsh or underwater environments present unique regulatory and engineering problems different from typical land remediations. This paper discusses various issues that must be addressed in the assessment and remediation of these sites as well as some of the techniques, procedures and equipment that have been utilized in addressing these issues. Three case studies of actual remediations in these environments are discussed.

Introduction

The remediation of naturally occurring radioactive material (NORM) contaminated sites in wetland, marsh or underwater environments present unique regulatory and engineering problems different from typical land remediations. Some of these problems include the potential negative environmental impact to the surrounding areas due to the remediation activities. Additional difficulties include specialized equipment and engineering controls that may be required as well as personnel and equipment logistics. Remediation efforts must be coordinated with numerous State and Federal agencies, such as the Environmental Protection Agency (EPA), Coast Guard, Coastal Zone Management, Department of Natural Resources (DNR), and the Department of Environmental Quality (DEQ). Control, discharge and/or disposal of waste waters generated during remediation can present both engineering and economic problems in addition to the solid wastes generated. Management of other materials including oil and grease adds additional complications to the remediation.

A comprehensive pre-remediation site assessment and remediation plan are critical prior to initiation of remediation at a NORM impacted site. An effective assessment is necessary to;

  1. determine the location, aerial extent, depth, volume and radiological activity of the NORM contamination,

  2. design an economical remediation work plan, and

  3. estimate costs or evaluate bids for the site remediation.

Additionally, there are instances where a comprehensive pre-remedial assessment can also be used to obtain regulatory agency variances or approvals for release which can significantly reduce remediation costs. A poor site assessment can lead to excessive cost overruns, missed contamination, an inadequate work plan, and problems with regulatory agencies. Vice-versa, there is a level at which an overly detailed assessment reaches a point of diminishing returns, exceeding the useful benefit of the additional data collected.

This paper discusses;

  1. how to conduct a site assessment,

  2. issues that should be considered when preparing a remediation work plan, and

  3. techniques and methods used in the effective and economical assessment and remediation of NORM contaminated sites in wetland, marsh or underwater environments.

Actual case studies will be used to demonstrate assessment methods, remediation procedures, equipment and engineering controls used to overcome various problems encountered in the remediation of such sites. Case studies that are discussed include,

  1. remediation of NORM contaminated production facilities in a wetland environment,

  2. in-situ remediation of a pit containing NORM in a marsh environment, and

  3. remediation of NORM contamination on a lake bottom under 3 meters of water.

NORM Site Assessments

The first step to remediating any site is a thorough assessment of the type, amount and extent of the contamination. Typically the presence of NORM contamination at levels requiring remedial action is first detected from a confirmatory survey. Most confirmatory surveys are conducted using a hand-held survey meter and probe (microR Meter) capable of reading in a range from 1 to 2,500 microRoentgen per hour (R/hr). P. 121^

This content is only available via PDF.
You can access this article if you purchase or spend a download.