Abstract

After an environmental practitioner devises a sediment collection plan, determines the sediment collection location, collects sediments, properly packages the collected samples, and labels the sample package contents, the samples are carefully transported to an examination and testing laboratory. Such a laboratory is typically tasked with determining certain physicochemical characteristics of the sediments, in conjunction with toxicity testing or chemical analysis or inorganic or organic contaminants. This characterization should include measurement of certain parameters known to mediate the availability of contaminants in sediment (ASTM, 2000f). Bulk chemical concentrations alone should not be used to evaluate bioavailability (USEPA, 1998). The following parameters are generally measured:

pH (porewater)

Ammonia (porewater)

Total organic carbon

Particle size distribution (e.g., percent sand, silt, and clay)

Percent water content

Salinity and hardness of porewater

Conductivity of porewater