An aquatic life/human health hazard assessment is the development and integrated use of information on the aquatic and human toxicology and aqueous environmental chemistry in a tiered decision matrix to evaluate the expected exposure (concentrations of available forms/contaminant availability, and duration of exposure) relative to that which could cause adverse impacts on beneficial uses of the water/sediment. In this case, the assessment involved the determination of the availability of the copper in the sediment to cause toxicity to aquatic life, adverse impacts to terrestrial animals or people who use aquatic organisms for food, or other adverse impacts on recreation and other beneficial uses of the waters of the area. The approach used by the authors in conducting the hazard assessment was to establish a plausible worst-case scenario screening testing/evaluation program to determine if copper in the NCMT-area sediments, independent of source, was likely adverse to the designated beneficial uses of San Diego Bay which had been specified to be industrial service supply, navigation, contact recreation, non-contact recreation, ocean commercial and sport fishing, saline water habitat, preservation of rare and endangered species, marine habitat, fish migration, and shellfish harvesting. In addition to the critical review of the previous NCMT-area studies, and the literature in general as well as pertaining to similar situations at other locations, a series of sediment screening toxicity tests was used to confirm results of the previous NCMT-area studies.

It was found that the copper ore concentrate-contaminated sediments, with whatever other contaminants were also present in them, were not sufficiently toxic/available to adversely affect aquatic life and therefore to adversely affect higher organisms, including man. This finding was based on the aquatic chemistry and toxicology of the copper ore concentrate in the sediment and water, assessments of aquatic life toxicity of the sediments, determinations of bioaccumulation of copper in organism tissue, and the nature and abundance of aquatic life in the area. The key findings included the following.

• Toxicity tests on NCMT-area sediments showed no toxicity to the nine types of sensitive organisms tested, including embryos of Pacific Oyster, reported by the US EPA to be one of the most sensitive organisms/stages to copper in salt water. Not only was the chalcopyrite in the sediment non-toxic, but also none of the other forms of copper or other contaminants in the NCMT-area sediments tested was toxic.
• Mytilus edulis occur naturally in an area of the NCMT in which the sediments contain some of the highest concentrations of copper reported. The US EPA found that embryos of Mytilus edulis are the most acutely sensitive to copper of the marine organisms it evaluated. It was the sensitivity of Mytilus edulis that formed the basis for the US EPA water quality criterion for copper, which in turned served as the basis for the water quality objective (standard) for San Diego Bay waters.
• The bioaccumulation of copper in mussels taken near the NCMT was not different from that in mussels from other areas of the San Diego Bay.
• Based on the expected aqueous environmental chemistry of copper in San Diego Bay water and sediments, the copper ore concentrate in the NCMT area sediments would not be expected to be in toxic/available forms in sufficient amounts to be adverse to aquatic life.

It was concluded that there was no need to remove the copper ore concentrate-contaminated sediment from the NCMT area of San Diego Bay in order to protect the designated beneficial uses of the Bay.

Remediation Objective of 1000 mg/kg
Technical Considerations

"Technical" Basis:

• Equilibrium Partitioning Approach with
• WESTEC Estimates of Interstitial Water Concentration of "Soluble" Copper

Basis Not Technically Valid

• Procedures Used by WESTEC to Separate "Soluble" Copper Component of Interstitial Water Overestimate "Soluble" Fraction
• Filtration Method Can Allow Passage of Appreciable Amounts of Particulate, Non-Toxic Forms of Copper and Inclusion in Measurements of "Soluble" Copper
• Equilibrium Partitioning Approach Not Demonstrated to Be Applicable to Heavy Metals, Such as Copper, in This Type of Sediment
• Based on Chemistry of Copper, Approach Would Not Be Expected to Be Appropriate for Copper in San Diego Bay Sediment
• Water Quality Criterion and Objective Values Not Appropriate for Judging Significance of Interstitial Water Copper
• Sensitivity and Significance of Organisms
• Dissolved Oxygen
• Relationship between Interstitial Water Copper and Sediment Copper Not Highly Significant (best r²=0.35)
• Some Soluble Species of Copper Are Not Available-Toxic

NCMT Pacific Oyster Larvae Toxicity Test Results
Compared with California Water Quality Objective

Dilution Water: <2 µg Cu/L
Station Identification: Transect/Distance from Pierface-Replicate
48-hr Exposure

California Water Quality Objective:
1-hr Average Not to Exceed 2.9 µg Cu/L

California Water Quality Objective
Equivalent to US EPA Water Quality Criterion

US EPA Criterion: Concentration That Would Not Cause Lethality to Embryo of Mussel, Mytilus edulis, Would Not Cause Chronic Toxicity

Mytilus edulis Live Naturally in NCMT Area, and Were Harvested as Part of Study from Area at NCMT Pierface at Which Highest Concentrations of Sediment-Associated Copper in Area Have Been Found

KEY

From WESTEC (1986)

Location of Station Groups
Identified by Dendrogram Analysis

Risk Assessment

Selective, Sequential Testing and Evaluation of

• Aquatic Chemistry (Chemical Nature, Fate and Transport) of Contaminant(s)) of Concern, and
• Their Aquatic Toxicology (Impact) in a
• Tiered Framework of Increasing Sophistication of Specificity

Yield Assessment of

• Adverse Impacts That the Given Situation Has on Designated Beneficial Uses
• Degree of Contaminant Control Needed to Protect Designated Beneficial Uses
• Evaluate Improvement in Water Quality That Could Be Achieved as a Result of Implementing Various Contaminant Control Approaches

Chemical Contaminants Exist in Aquatic Systems in a Variety of Forms, Only Some of Which Are Toxic-Available to Adversely Affect Aquatic Life

Risk Assessment Study
Approach

Synthesis Evaluation of

• Information Generated from Previous Studies, Augmented by

Results of Summer 1991 Investigation

Objectives:

• To Evaluate Whether Attaining the Water Quality Control Board Order no. 85-91 Remediation Objective of 1,000 mg Cu/kg dry wt. Would Be Protective of Beneficial Uses of San Diego Bay
• Examine Existing and New Information for Implications for Impact on Beneficial Uses of San Diego Bay from Higher Remediation Objective

Summary of Results of Lee & Jones
Risk Assessment Study

Findings:

• NCMT-Area Sediments Contain Copper to 50,000 mg Cu/kg dry wt. (at 2-3 ft deep)
• Toxicity Tests with NCMT-Area Sediments Containing 18,000 mg Cu/kg dry wt. Did Not Adversely Affect Sensitive Test Organisms
• Overall, 9 Different Types of Organisms Tested
• Considered 14 Response Parameters
• Shrimp, Flat Fish, Sea Urchin Eggs & Embryos, Clams, Worms, 2 Types of Amphipods, Fish Larvae, Pacific Oyster Embryos/Larvae
• Embryos of Pacific Oyster Reported by US EPA to Be One of the Most Sensitive Organisms/Stages to Copper in Salt Water
• Mytilus edulis (mussel) Occurs Naturally in Area of NCMT in Which Sediments Contain Some of Highest Concentrations of Copper Reported
• US EPA Found That Embryos of Mytilus edulis Were the Most Acutely Sensitive to Copper of the Marine Organisms It Evaluated
• Sensitivity of Mytilus edulis Basis for US EPA Water Quality Criterion for Copper

"Although Quite Limited, the Benthic Community Found near the Paco Terminal Pier Provides Evidence That Some Bivalvia Mollosks (sic - Bivalve Molluscs), Like Clams, Mussels, Have Become Established on Sediment Which Is ... Quite High in Copper Ore." "These Adult and Juvenile Forms of Mussels in an Area Where They Would Have Had a (sic - to) Settle Out of the Water Column. So It Did Provide Information That This Wasn't Severely Toxic. Otherwise These Very Sensitive Stages of These Organisims (sic - Organisms) Wouldn't Have Been Able to Settle Out and Live and Mature into Adult Forms."

Deposition of Greg Peters
July 24, 1991

Summary Testimony of
G. Fred Lee, Ph.D. and R. Anne Jones, Ph.D.
G. Fred Lee & Associates
El Macero, CA

Dr. G. Fred Lee and Dr. R. Anne Jones (Lee and Jones) were contracted by the Port of San Diego through Woodward-Clyde Consultants (WCC) to conduct a water quality risk assessment for the copper ore concentrate present in the sediments near the National City Marine Terminal (NCMT)

The Lee and Jones report of the results of the risk assessment were submitted by WCC to Port and to San Diego Regional Board last August.

Objectives

• Investigate Whether Copper Ore-Contaminated Sediments near NCMT Is Adversely Affecting Beneficial Uses of San Diego Bay
• Evaluate Whether Attaining the Water Quality Control Board Order No. 85-91 Remediation Objective of 1,000 mg Cu/kg dry wt. Would Be Protective of Beneficial Uses of San Diego Bay
• Examine Existing and New Information for Implications for Impact on Beneficial Uses of San Diego Bay from Higher Remediation Objective

Conclusions

Based on the aquatic chemistry and toxicology of copper, the copper in the NCMT-area sediments that was derived from copper core concentrate is expected to have been and now be informs largely unavailable to adversely affect water quality.

Whatever the specific forms of copper, and whatever other chemical contaminants may exist in the NCMT-area sediments, and whatever the forms and concentrations of copper in interstitial water:

• the broad spectrum of toxicity tests conducted showed that the sediments did not adversely affect test organisms;
• mussels known to be highly sensitive to copper exist naturally in the NCMT-area sediments highly contaminated with copper ore concentrate;
• work of WESTEC on the benthic organism community composition, numbers, and diversity in the NCMT area has shown that the differences and similarities between organism assemblages in that area are not related to the amount of copper in the sediments.

No technical justification for the selection of the 1,000 mg Cu/kg dry wt. remediation objective.

No discernible water quality significance of potential spreading of NCMT-area sediment into Bay

The technical information available indicates that a clean-up objective on the order of 15,000 to 20,000 mg Cu/kg dry wt for the NCMT-area sediment could potentially be justified; it is possible that further study could also justify an even higher objective.

DHS has established TTLC of 4,000 mg Cu/kg dry wt. for classification as "hazardous waste."

It is not technically defensible to apply DHS TTLC values to NCMT-area sediment for determination of need for or extent of remediation.

Establishment of an appropriate and acceptable clean-up level above 4,000 mg Cu/kg dry wt. (TTLC value) would likely require additional time in permitting, obtaining variance, and further testing.

Extensive review and testing has led to the conclusion that at present the copper in the NCMT-area sediments in not having an adverse impact on water quality; this would not be expected to change to a situation in which it would become adverse. Therefore, delay of whatever remediation may be decided upon would not be expected to adversely affect water quality.

Water Quality Significance of
Potential Spreading of Copper Ore Concentrate
in San Diego Bay

Evidence does not indicate substantial spreading.

Even if copper ore concentrate-contaminated sediment spreading occurred further into San Diego Bay, there would not likely be adverse impact on water quality

• Concern would be the oxidizing environment
• Oxidizing environment occurred during toxicity testing that showed no toxicity

Bioaccumulation of Copper in
NCMT-Area Organisms

Concern: Accumulation of contaminant in an aquatic organism's flesh to levels that would adversely affect higher trophic-level organisms (primarily man and fish-eating birds) that consume the aquatic organism.

"Excessive" body burden determined by FDA Action Levels

No FDA Action Level, or other accepted, reliable guideline for assessing significance of copper

• Copper not particularly toxic to man
• NAS Food & Nutritional Board review (Ahmed, 1991) did not consider bioaccumulation of copper in seafood to be represent a potentially significant health hazard to humans

Summer 1991 study included analysis of 2 types of existing, naturally occurring mussels:

• Mytilus edulis ("watercolumn mussel") and
• Musculista senhousia ("benthic mussel")

collected from 2 locations:

• near pierface (17,000 mg Cu/kg dry wt.)
• WQCB-SC reference site (150-300 mg Cu/kg dry wt.)

Little difference in body burdens in mussels from contaminated and reference areas.

Impact of Further Delay in Remediation
of NCMT-Area Sediment

Copper in NCMT-Area Sediments from Copper Ore Concentrate Expected to Have Been and Now Be in Forms Largely Unavailable to Affect Water Quality

• Expected Based on Aquatic Chemistry of Copper
• Substantiated through Toxicity Testing and Presence of Copper-Sensitive Mussels at Site

Chemical Processes That Occur in Sediment/Water Environment over Time Would Be Expected to

• Maintain the Copper in Unavailable Forms
• Reduce the Availability of More Available Forms

Therefore, Delay of Whatever Remediation May Be Decided Would Not Be Expected to Adversely Affect Water Quality

Copper Ore Concentrate as
Source of Copper

Copper Exists in a Variety of Chemical Forms, Only Some of Which Are Available-Toxic to Aquatic Life

Copper Introduced into NCMT Area from Transfer of Copper Ore Concentrate:

Finely Divided Ore - Cupric Ferrous Sulfide

One of the Most Stable, Insoluble, and Thus Unavailable Forms of Copper

Availability of Copper Derived from Other Sources May Be Significantly Different from That Derived from Copper Ore Concentrate

Remediation Objective >1,000 mg Cu/kg
Consistent with Objectives of Ocean Plan
and Enclosed Bays and Estuaries Plan

Intent of Ocean Plan Objectives:

"to ensure the reasonable protection of beneficial uses and the prevention of nuisance."

Intent of Enclosed Bays and Estuaries Plan Objectives:

"to ensure the reasonable protection of beneficial uses and the prevention of nuisance."

Aquatic Life Risk Assessment
Copper-Contaminated Sediments near
National City Marine Terminal

Areas of Expertise:

• Aquatic Biology/Toxicology
• Aquatic Chemistry
• Environmental Engineering
• Public Health
• 30/15 yrs. Experience Evaluating the Significance of Chemical Contaminants in Sediments

Tentative Addendum No. 7

Assumes "violation" of numeric water quality objective for copper caused by NCMT-area sediment

Reference as: "Jones-Lee, A., and Lee, G. F., 'Evaluation of the Water Quality Significance of Copper in San Diego Bay Sediments,' Division Environmental Chemistry, American Chemical Society meeting, extended abstract, Washington, DC, pp. 107-108, March (1994)."