Quality Assurance Project Plan Including Sampling And Analysis Plan (Page 59 of 67) in pdf

Hunters Point Shipyard Parcel F ESTCP Demonstration Plan

Appendix A: Quality Assurance Project Plan

Table A-3. Data Quality Objectives for Secondary Quant. Performance Criteria of ESTCP DP

(continued)

STEP 6: Evaluate Decision Errors

Just the mixing of sediments in Plots C, D, F, and G will have a large impact on the community structure.

Quadrats to assess community structure will be taken six and eighteen months after the treatments occur to give

the benthic community time to reestablish itself. If this time period is insufficient, then it will be difficult to

decide if it was the mixing or actual AC that affected the community structures.

STEP 7: Optimize the Design for Obtaining Data

Sediment PCB and Aqueous Equilibrium PCB Concentrations

Subsamples from the total of 75 cores will be analyzed for total PCB sediment concentrations and aqueous

equilibrium concentration of PCBs.

Sediment PCBs Desorption Characteristics

Subsamples from two sediment cores per plot (taken once before and twice after treatments) will be analyzed to

evaluate PCB desorption characteristics. The desorption tests on the sediment core subsamples will follow

previously published methods (Ghosh et al., 2000) These analyses will allow us to assess the change in PCB

availability for desorption to the aqueous phase after treatment.

Benthic Community Structure Analyses

Surface sediment (0-10 cm) will collected from five randomly selected 0.25-m quadrats per plot once before and

twice after plot treatments. The benthic organisms existing in these quadrat sediment samples will be sieved using

a 500µm sieve, preserved in 10% formaldehyde solution in the field, and transferred to the laboratory in 500mL

polyethylene jars. A total of 75 quadrats will be sieved during the entire study producing 75 benthic community

samples. By comparing the macrofaunal composition that exists in the benthic community samples collected

before and after treatments, the AC treatment effects upon benthic recolonization, community structure and

organism growth can be determined.

PCB Uptake into SPMDs

Five semi-permeable membrane devices (SPMDs) will be deployed inside of the clam tubes in each plot once

before and twice after plot treatments. A total of 75 SPMDs will be deployed during the entire project.

Measurement of PCB uptake into these devices will simulate the in situ bioavailability of PCBs to biota. The

SPMDs will be vertically oriented 3 cm below the sediment surface inside each clam tube. The SPMDs will be

contacted with sediment for one month before removal, processing, and analysis.

Depth and Homogeneity of the Mixed AC

In each plot, 2.0-inch-diameter sediment core samples will be collected at five randomly distributed sampling

locations once before and twice after plot treatments. Each of the core samples collected will be one foot in length

(minimum) and divided into 2-inch-long core cross sections. A direct correlation exists between measured TOC

and the amount of AC added in sediment, so TOC analysis will be performed on a subsample of each core section

to evaluate the degree of AC mixing into sediment.

Stability of AC/Sediment Mix

Total Organic Carbon (TOC) values measured for sediment cores from Plots D and F taken after six and eighteen

months will compared to evaluate if there are any significant differences in the amount of AC in these plots

between the two sampling time points.

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Quality Assurance Project Plan Including Sampling And Analysis Plan Page 59