Equipment Acquisition

Representativeness and comparability are qualitative criteria, and completeness is

a quantitative criterion. Representativeness is a key concern during field

sampling activities, and expresses the degree to which sample data accurately

represent the site, specific matrices, and parameter variations at a sampling point.

Representativeness is dependent on the proper design of the sampling program,

proper selection of laboratory methods for the matrix under scrutiny, and stability

of the laboratory methods. The representativeness criterion is best satisfied by

making certain that the sampling locations, procedures, and quantities are

selected based on the project objectives, and that suitable analytical procedures

are utilized, preservation requirements are met, and holding times are not

exceeded in the laboratory.

Comparability expresses the confidence with which one data set can be

compared with another. The analysis of certified reference materials is used to

provide data on comparability. The data obtained within this project will be

comparable because all the standard operating procedures used in the

determinations are based on methods with proven protocols and proven internal

and external audit compliance relative to performance testing on certified

reference material soils. All analyses of a single type will be conducted at the

same laboratory. Completeness of the deliverable is measured for each set of

data received by dividing the number of valid (passing quality assurance/quality

control (QA/QC) requirements) measurements actually obtained by the number

of measurements made. Each of the analytical parameters is evaluated separately

in terms of precision, accuracy, and data acceptability. Precision pertains to the

repeatability of the test, and is determined using a relative percent difference for

duplicate samples and, for three or more replicate analysis, as a relative standard

deviation or coefficient of variation. Most literature suggests that the goal for

precision among field duplicates should be within 30 percent expressed as a

relative percentage difference. Accuracy pertains to the closeness to the true

value, and is evaluated using matrix spike recoveries expressed as a percent

recovery. Completeness is then calculated on the basis of the number of samples

meeting the established QA/QC requirements, as previously described.

Acceptable completeness for a data set has been set at 90 percent meeting

QA/QC requirements.

Completeness of the data was above 90 percent for all three data sets (Cells 4

and 5 characterization and field demonstration data). Some data were qualified

due to minor problems. Corrective actions and data qualifications are detailed in

the individual data validation sheets attached in Appendix C.

Equipment Acquisition

On the basis of the performance of the 0.6-m (24-in.) MDS, a 0.3-m (12-in.)

MDS was purchased for laboratory and field-scale feasibility testing. The

capacity of the 0.3-m (12-in.) MDS is not sufficient for large-scale processing,

but is better suited for feasibility testing because the volumes of process water

required are more manageable, and the supporting equipment is correspondingly

smaller and more widely available. A vibrating wet screen was also purchased

for screening out oversize prior to the sump of the hydrocyclone, and fitted with

13-mm (1/2-in.) and 6-mm (1/4-in.) screens. Either dry or slurried material can

Chapter 2 Project Description