text: The chemistry component incorporates both bioavailability and potential effects on benthic community. The potential of sediment toxicity for a given site is based on a linear regression model (LRM).  A chemical score index (CSI) of the contaminant describes the magnitude of exposure relative to benthic community disturbance. An optimal set of index-specific thresholds are selected for the chemistry component by statistically comparing several candidates to evaluate which set exhibited greatest overall agreement (Bay and Weisberg, 2012). The magnitude of sediment toxicity is determined by multiple toxicity tests conducted in the lab to complement chemistry component. Toxicity LOE are determined by the mean of toxicity category score from all relevant tests. Development of LOE for benthic component is based on community metrics and abundance. Several indices such as benthic response index (BRI), benthic biotic integrity (IBI), and relative biotic index (RBI) are utilized to assess biological response of the benthic community. The median score of all individual indices will establish benthic LOE.
  Each component of the triad is assigned a response category: minimal, low, moderate, or high disturbance relative to background conditions. Individual LOEs are ranked into categories by comparing test results of each component to established thresholds (Bay and Weisberg, 2012). Integration of benthos and toxicity LOE classify the severity and effects of contamination. LOE of chemistry and toxicity are combined to assign the potential of chemically-mediated effects. 
  A site is assigned an impact category by integrating the severity of effect and the potential of chemically mediated effects. The conditions of individual sites of concern are assigned an impact category between 1 and 5 (with 1 being unimpacted and 5 being clearly impacted by contamination). The SQT triad can also classify impact as inconclusive in cases when LOE between components are in disagreement or additional information is required (Bay and Weisberg, 2012).