Determining Recovery Potential of Dredged Material for Beneficial Use Site Characterization: Statistical Approach

ERDC TN-DOER-C15

July 2000

Determining Recovery Potential

of Dredged Material for Beneficial Use

Site Characterization: Statistical Approach

PURPOSE: This technical note is the third in a series of three technical notes providing guidance

on evaluating the potential for recovery of dredged material for beneficial use (BU), either as is or

using physical separation (soil washing) to meet BU specifications. This technical note introduces

statistical methods for developing a sampling plan and interpreting and extrapolating the resulting

data. The first technical note (Olin-Estes and Palermo 2000b) introduces physical separation

concepts and presents mathematical relationships for estimating material recovery potential (MRP).

A prescriptive approach to estimating volumes meeting BU requirements based on available

information, or information obtained from limited sampling, is outlined in the second technical note

(Olin-Estes and Palermo 2000a).

BACKGROUND: The principal motivation for BU recovery of dredged material is the growing

shortage of storage capacity in confined disposal facilities (CDFs). The fundamental purpose of

these technical notes is to assist in determining when material recovery is technically and economi-

cally feasible, and provide a strategy for obtaining and using physical and chemical information

necessary for this evaluation at the least possible cost. The fundamental approach is to begin with

available information and progress to targeted sampling and analysis as needed.

Olin-Estes and Palermo (2000a, 2000b) introduce prescriptive (limited sampling) site charac-

terization methods, and physical separation concepts and methods for estimating MRP, respectively.

The feasibility of separation as a management approach is dependent on several factors, including

ability to identify distinct fractions within the material meeting BU criteria, ability to separate

suitable fractions, and MRP as determined by available volumes of suitable material. This technical

note introduces statistical sampling and data estimation methods for extensive site characterization.

INTRODUCTION: When separation appears to be necessary to meet material specifications for

identified BUs, more detailed sediment/site characterization and evaluation are needed to estimate

MRP. Extensive site sampling and data interpretation are addressed in the following sections.

Figure 1 illustrates the position of extensive site sampling and characterization in evaluating

feasibility of BU recovery. Olin-Estes and Palermo (2000b) describes the overall evaluation

approach more extensively.

DATA REQUIREMENTS: The objective of extensive site characterization is to address the same

data requirements as described in the two previous technical notes. These requirements are repeated

here for clarity and ease of reference.

There are essentially two levels of MRP estimates: screening level, based on existing information,

and definitive, based on more extensive site sampling. Several types of data are required to estimate

MRP: