Statistical Procedures, Assumptions and Analysis (Cont.)

only comparisons with a power greater than 0.75. From the overflow and

silt/clay data one would conclude that the zinc, oil and grease, and TRPH

overflow mean concentrations are equal to the silt/clay mean concentrations and

the arsenic, cadmium, chromium, copper, lead, mercury, nickel, selenium, silver,

barium, TOC, PCB 1242, and PCB 1260 overflow mean concentrations are not

equal to the silt/clay mean concentrations (Table B5). For the current

experimental design, the power of the comparison for arsenic, cadmium,

chromium, copper, lead, mercury, nickel, selenium, silver, barium, PCB 1242,

PCB 1260, and TOC was greater than 0.75. From the feed and bulk data one

would conclude that the arsenic, cadmium, chromium, copper, lead, mercury,

nickel, selenium, silver, zinc, barium, TOC, oil and grease, and TRPH feed mean

concentrations are equal to the bulk mean concentrations and the PCB 1242 and

PCB 1260 feed mean concentrations are not equal to the bulk mean concentra-

tions (Table B8). For the current experimental design, the power of the

comparison for arsenic, chromium, nickel, barium, PCB 1242, PCB 1260, oil and

grease, and TRPH was greater than 0.75.

Appendix B Statistical Analysis of Results