Department of Health Seal

TGM for the Implementation of the Hawai'i State Contingency Plan
Section 21.5

21.5 Summary of Decision Logic for ERAs

The HEER Office applies the decision logic indicated in Tables 21-10 and 21-11, and Figure 21-8 for sediment investigations (see below). It is important to note that the linear flow of the decision tree shown in Figure 21-8 should just be used as a starting point as it is not the only way to approach an ERA. The specific approach should be based on the process outlined in the DQOs and an iterative assessment of meaningful effects, dependent on the particular chemicals and receptors of concern at a site. Many of the items in Table 21-10 and Figure 21-8 are conducted as part of the BERA, such as toxicity testing and tissue sampling. Required, preferred, and optional data for sediment ERAs are summarized in Table 21-11.

Table 21-10. Questions Guiding Decision Logic for Contaminated Sediment Investigation
Question Method Step
Do any chemicals in sediment in the DU exceed HDOH interim No Effect SQGs? Compare with HEER Interim No Effect SQGs SLERA Step 2
Could chemicals in prey organisms at the site adversely affect other organisms that consume them? Evaluate using food chain modeling SLERA Step 2
Are the chemicals present at concentrations greater than what occur naturally in these sediments or typically in the local environment? Compare with background/ambient/reference locations SLERA Step 3A
Are the chemicals in a bioavailable form representing exposure to organisms? Evaluate factors affecting bioavailability SLERA Step 3A
Are organisms at the site directly affected by exposure to chemicals in sediment? Conduct direct toxicity test or model using representative data BERA
Are organisms at the site bioaccumulating chemicals from the sediment? Measure field collected organisms or model bioaccumulation using representative data BERA
If yes, could organisms at the site be adversely affected by the chemicals in their tissues? Evaluate using appropriate tissue effect levels BERA

Figure 21-8. Interim Decision Logic for Sediment Investigations in Hawaiʻi

Figure 21-8 (continued). Interim Decision Logic for Sediment Investigations in Hawaiʻi

Table 21-11. Required, Preferred, and Optional Data for Sediment ERAs  
Data Type Required Preferred Optional
Sediment (for SLERA or BERA)
Multi Increment Sediment (MIS) Samples in appropriate decision units (DU)    
Pre-approved Reference Location – all sample types    
Background metals analysis (literature)    
Total 0rganic carbon    
Grain size distribution    
Acid-volatile sulfide and simultaneously extracted metals (AVS/SEM)    
Pore water    
Surface water    
Site-specific tissue (for bioaccumulating chemicals)    
Laboratory Tests (typically just for the BERA)
Bioaccumulation Test (using native Hawaiian species1) (if known bioaccumulator is present or suspected)    
Lethal and sublethal toxicity tests using native Hawaiian species (if one or more chemicals is greater than the Probable Effect SQG) (if one or more chemicals is between the No Effect SQG and the Probable Effect SQG)  
Field-Collected Tissue (typically just for the BERA)
Field-Collected Tissue (Benthic/epibenthic invertebrate such as crab or octopus; fish species with direct or indirect exposure to sediment) (if known bioaccumulator is present or suspected) (in general)  
Passive sampling device (for PCBs)     if PCBs exceed No Effect SQG
1 If no standard test using a native species is available, provide rationale for a carefully-selected surrogate species