upland plant and animal bioaccumulation and toxicity ......mar 06, 2019 · bioaccumulation in...

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Upland plant and animal bioaccumulation and toxicity evaluationsGui Lotufo

SUSTAINABLE SEDIMENT MANAGEMENT AND DREDGING SEMINAR6-8 MARCH 2019 SAUSALITO, CA

128-30 Nov 2018 Galveston, TX

UNCLASSIFIED

UNCLASSIFIED

Distribution C: Distribution authorized to U.S. Government Agencies and their contractors; Vulnerability Information; January 2015. Other requests for this document shall be referred to US Army ERDC, ATTN: CEERD-GSV, 3909 Halls Ferry Rd., Vicksburg, MS 39180-6199.

US Army Corps of Engineers • Engineer Research and Development Center

Sustainable Sediment Management and Dredging Seminar

6-8 March 2019 Sausalito, CAUNCLASSIFIED // FOR OFFICIAL USE ONLY

Upland placement• Regulatory overview

• CWA (effluent and surface runoff) and NEPA provide strong mandates for placement in CDFs and nearshore beneficial use

• When dredged sediment will be placed in an upland setting outside of the authority of the CWA, state authority is the sole authority for permitting upland beneficial use not regulated under CWA

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Terrestrial and wetland food webs

• Potential for contaminants of concern from dredging material to bioaccumulate in tissues of plants and soil invertebrates, with further dietary transfer to herbivores and predators

• COCs can be passed up the food chain within and outside placement sites as wildlife migrate in and out of area

• Humans and threatened and endangered species may be receptors of concern (ROC)

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Beneficial use and confined disposal evaluations

• For confined disposal, consider only potential for bioaccumulation in offsite receptors that may forage at the CDF

• Do not evaluate direct toxicity as unsuccessful colonization generally means lower bioaccumulation in offsite receptors

• Bioaccumulation is evaluated in regard to toxic effects to wildlife and humans, if applicable.

• For beneficial use, consider receptors inhabiting the placement site

• Evaluate bioaccumulation • Evaluate toxicity, as successful colonization and

establishment of key species is desired

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Evaluation overview

• Determine the need for contaminant evaluation (applicable exclusionary criteria)

• Define complete routes of exposure and receptors of concern• Select upland disposal COCs

• For plants, metals are more relevant• For soil invertebrates, organic chemicals are more relevant

• If warranted, conduct pre-screening procedures• If warranted, conduct upland plant and soil invertebrate evaluation

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Initial Evaluation (Tier I)

• Beneficial use• Develop a conceptual site model (define complete exposure routes)• Comparison to background: If the dredged material does not contain

statistically significant higher concentrations of a constituent than what already would be expected at the placement site (or refence site outside area of contamination), that constituent generally does not need further evaluation

• Confined disposal facility• Evaluate existing information• Develop a conceptual site model

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Screening Evaluations (Tier II)• Comparison with ecological soil screening levels (Eco-SSLs)

• Eco-SSLs are screening values protective of ecological receptors (e.g., birds and mammals that consume plants and soil invertebrates).

• Should be used to identify the COPCs that require further evaluation.• Should be used with caution as they were not developed using dredged materials

(i.e., sediments)

• Soil invertebrate bioaccumulation evaluation• Predict nonpolar organic COC bioaccumlation using TBP

• Plant bioaccumulation evaluation• Predict metal bioaccumulation for freshwater placement using the

diethylenetriaminepentaacetic acid (DTPA) extraction procedure and the Plant Uptake Program (PUP), a computerized program

• Compare the DM and reference sediment (or soil) results

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Plant bioassay (Tier III)• Cyperus: saltwater terrestrial, freshwaterwetland, and freshwater terrestrial habitat; 45-day exposure

• Spartina: saltwater wetland habitat; 90-dayexposure

• Or other species relevant to placement site habitats or intended use (e.g., grass for use in a soccer field) using stakeholder input

Results & Data Interpretation• Assess survival and growth endpoints for

determination of toxicity• Determine COC bioaccumulation• Compare results between dredging material

and reference• Evaluate potential impacts to ROC

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Cyperus esculentus (yellow Nutsedge)

Spartina alterniflora(smooth cordgrass)




Soil invertebrate bioassay (Tier III)• Earthworm Eisenia fetida 28-day exposure • Aquatic infaunal invertebrate if aquatic (e.g,

submerged wetland habitats)

Results & Data Interpretation• Assess survival endpoint for determination of

toxicity • Determine COC bioaccumulation• Compare results between dredging material and

reference • Evaluate potential impacts to ROC

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Eisenia fetida




Summary• Evaluation different for CDF disposal and beneficial use

• Toxicity is relevant for most beneficial use options• Assess applicable exclusionary criteria• Develop conceptual model• Evaluate potential impacts to plants and soil invertebrates

(beneficial use only) and to wildlife • Assess the need for management and controls

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Factors to consider• Testing should rarely be necessary if regional EcoSSLs are established

and used when COCs exceed reference cocentrations

• Mercury not expected to pose a problem in an upland settings

• Dredged material can be safely used for wetland restoration so as not to cause increased food web uptake

• Regional upland/wetland reference sites should be established

• Comparisons should be made using neighboring areas

• Include spatial considerations (size matters)




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upland plant and animal bioaccumulation and toxicity ......mar 06, 2019 · bioaccumulation in...

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