Army Corps of Engineers

Numerical sediment quality guidelines (SQGs) for freshwater ecosystems have previously been developed using a variety of approaches. Each approach has certain advantages and limitations which influence their application in the sediment quality assessment process. In an effort to focus on the agreement among these various published SQGs, consensus-based SQGs were developed for 28 chemicals of concern in freshwater sediments (i.e., metals, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and pesticides). For each contaminant of concern, two SQGs were developed from the published SQGs, including a threshold effect concentration (TEC) and a probable effect concentration (PEC). The resultant SQGs for each chemical were evaluated for reliability using matching sediment chemistry and toxicity data from field studies conducted throughout the United States. The results of this evaluation indicated that most of the TECs (i.e., 21 of 28) provide an accurate basis for predicting the absence of sediment toxicity. Similarly, most of the PECs (i.e., 16 of 28) provide an accurate basis for predicting sediment toxicity. Mean PEC quotients were calculated to evaluate the combined effects of multiple contaminants in sediment. Results of the evaluation indicate that the incidence of toxicity is highly correlated to the mean PEC quotient (R(2) = 0.98 for 347 samples). It was concluded that the consensus-based SQGs provide a reliable basis for assessing sediment quality conditions in freshwater ecosystems.

https://www.waterboards.ca.gov/water_issues/programs/peer_review/docs/dfg_suction_dredging/03_Ch4_2WQTOX_references_Feb2011/661_MacDonald_2000.pdf

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems.

http://michele.scardi.name/corsi/ambi.pdf

A Marine Biotic Index to Establish the Ecological Quality of Soft-Bottom Benthos Within European Estuarine and Coastal Environments

The weight-of-evidence approach to the development of sediment quality guidelines (SQGs) was modified to support the derivation of biological effects-based SQGs for Florida coastal waters. Numerical SQGs were derived for 34 substances, including nine trace metals, 13 individual polycyclic aromatic hydrocarbons (PAHs), three groups of PAHs, total polychlorinated biphenyls (PCBs), seven pesticides and one phthalate ester. For each substance, a threshold effects level (TEL) and a probable effects level (PEL) was calculated. These two values defined three ranges of chemical concentrations, including those that were (1) rarely, (2) occasionally or (3) frequently associated with adverse effects. The SQGs were then evaluated to determine their degree of agreement with other guidelines (an indicator of comparability) and the percent incidence of adverse effects within each concentration range (an indicator of reliability). The guidelines also were used to classify (using a dichotomous system: toxic, with one or more exceedances of the PELs or non-toxic, with no exceedances of the TELs) sediment samples collected from various locations in Florida and the Gulf of Mexico. The accuracy of these predictions was then evaluated using the results of the biological tests that were performed on the same sediment samples. The resultant SQGs were demonstrated to provide practical, reliable and predictive tools for assessing sediment quality in Florida and elsewhere in the southeastern portion of the United States.

/pdf/development-and-evaluation-of-sediment-quality-guidelines-4noqg83836.pdf

Development and evaluation of sediment quality guidelines for Florida coastal waters.

Indirect effects of contaminants in aquatic ecosystems.

Matching biological and chemical data were compiled from numerous modeling, laboratory, and field studies performed in marine and estuarine sediments. Using these data, two guideline values (an effects range-low and an effects range-median) were determined for nine trace metals, total PCBs, two pesticides, 13 polynuclear aromatic hydrocarbons (PAHs), and three classes of PAHs. The two values defined concentration ranges that were: (1) rarely, (2) occasionally, or (3) frequently associated with adverse effects. The values generally agreed within a factor of 3 or less with those developed with the same methods applied to other data and to those developed with other effects-based methods. The incidence of adverse effects was quantified within each of the three concentration ranges as the number of cases in which effects were observed divided by the total number of observations. The incidence of effects increased markedly with increasing concentrations of all of the individual PAHs, the three classes of PAHs, and most of the trace metals. Relatively poor relationships were observed between the incidence of effects and the concentrations of mercury, nickel, total PCB, total DDT and p,p′-DDE. Based upon this evaluation, the approach provided reliable guidelines for use in sediment quality assessments. This method is being used as a basis for developing National sediment quality guidelines for Canada and informal, sediment quality guidelines for Florida.

Incidence of adverse biological effects within ranges of chemical concentrations in marine and estuarine sediments

A Preliminary Evaluation of Sediment Quality Assessment Values for Freshwater Ecosystems

CCME Canadian Environmental Quality Guidelines for mercury have been recommended or are under development for soil, water and sediments. These guidelines provide nationally consistent benchmarks for environmental quality across Canada and are intended as decision support tools in protecting and sustaining aquatic and terrestrial ecosystems in Canada and the beneficial uses they support. A Canadian water quality guideline for protection of aquatic life was recommended in 1987 as 0.1µ L−1 Currently, mercury guidelines for soils and sediments are under development. Preliminary calculations indicate that interim marine and freshwater sediment guidelines for the protection of aquatic life will both be 0.14 rng kg−1 and that soil quality guidelines will be 2.0 mg kg−1 (agricultural and residential land uses), and 30.0 mg kg−1 (commercial and industrial land uses). Final recommended values are subject to change pending final approval by the Canadian Council of Ministers of the Environment.

Sherri L. Smith

Papers

Incidence of adverse biological effects within ranges of chemical concentrations in marine and estuarine sediments

A Preliminary Evaluation of Sediment Quality Assessment Values for Freshwater Ecosystems

Canadian Environmental Quality Guidelines for mercury

How should numerical criteria be used? The Canadian approach

Development of proposed Canadian Environmental Quality Guidelines for cadmium