Site Name: COMMENCEMENT BAY, NEAR SHORE/TIDE FLATS

EPA ID: WAD980726368 EPA Region: 10 Metro Statistical Area: 8200

ADJ TO RUSTON WAY & TIDEFLATS IND AREA, TACOMA, WA 98402

Operable Unit:

ROD ID: EPA/ROD/R10-89/020 ROD Date: 09/30/89

Contaminant: ORGANICS; PCBS; PAHS; METALS; ARSENIC; LEAD

Keys: ARSENIC; CAPPING; CARCINOGENIC COMPOUNDS; CLEAN WATER ACT; DIRECT CONTACT; DREDGING; EXCAVATION; FLOODPLAIN; INSTITUTIONAL CONTROLS; LEAD; METALS; OFFSITE DISPOSAL; ONSITE CONTAINMENT; ONSITE DISPOSAL; O&M; PAHS; PCBS; RCRA; SAFE DRINKING WATER ACT; SEDIMENT; STATE PERMIT; STATE STANDARDS/REGULATIONS; WATER QUALITY CRITERIA; WETLANDS

Abstract:

THE COMMENCEMENT BAY NEARSHORE/TIDEFLATS SITE IS IN TACOMA, PIERCE COUNTY, WASHINGTON AT THE SOUTHERN END OF THE MAIN BASIN OF PUGET SOUND. THE SITE ENCOMPASSES AN ACTIVE COMMERCIAL SEAPORT AND INCLUDES 10-12 SQUARE MILES OF SHALLOW WATER, SHORELINE, WATERWAYS AND ADJACENT LAND. SITE CONTAMINATION IS THE RESULT OF A LONG HISTORY OF INDUSTRIAL ACTIVITY IN THE AREA. MORE THAN 281 ACTIVE INDUSTRIAL FACILITIES ARE IN THE AREA AND APPROXIMATELY 34 OF THOSE ARE NPDES PERMITTED DISCHARGERS. RELEASES OF HAZARDOUS SUBSTANCES TO THE MARINE ENVIRONMENT HAVE RESULTED IN CONTAMINATION OF BOTTOM SEDIMENT IN THE WATERWAYS OF THE TIDEFLATS INDUSTRIAL AREA, AND ALONG THE SHORELINE IN THE NEARSHORE AREA. THIS RECORD OF DECISION REPRESENTS TWO OF SIX OPERABLE UNITS FOR THE SITE AND WILL ADDRESS SOURCE CONTROL AND MARINE SEDIMENT CONTAMINATION IN THE NEARSHORE/TIDEFLATS ENVIRONMENT. EIGHT PROBLEM AREAS ARE BEING ADDRESSED INDEPENDENTLY BY THIS REMEDY. THE REMAINING OPERABLE UNITS WILL ADDRESS REMEDIAL RESPONSE TO RELEASES OF HAZARDOUS SUBSTANCES ASSOCIATED WITH THE TACOMA TAR PITS AND THE ASARCO TACOMA SMELTER. THE PRIMARY CONTAMINANTS OF CONCERN AFFECTING THE SEDIMENT ARE ORGANICS INCLUDING PCBS AND PAHS; AND METALS INCLUDING ARSENIC, MERCURY, LEAD, AND ZINC.

THE SELECTED REMEDIAL ACTION FOR THIS SITE INCLUDES AN 8-YEAR ACTIVE CLEANUP PHASE FOR SOURCE CONTROL AND SEDIMENT REMEDIATION, AND A 10-YEAR NATURAL RECOVERY PHASE. SOURCE CONTROL REMEDIATION INCLUDES THE IDENTIFICATION AND CONTROL OF SOURCES OF CONTAMINATION INTO THE MARINE ENVIRONMENT AT THE SITE. SEDIMENT REMEDIATION INCLUDES A COMBINATION OF NATURAL RECOVERY FOR AREAS EXPECTED TO RECOVER NATURALLY WITHIN A 10-YEAR PERIOD AFTER SOURCE CONTROL MEASURES ARE IMPLEMENTED, AND THE UTILIZATION, AS APPROPRIATE, OF FOUR ACTIVE SEDIMENT CONTROL ALTERNATIVES TO REMEDIATE APPROXIMATELY 1,181,000 CUBIC YARDS OF CONTAMINATED SEDIMENT. THE FOUR SEDIMENT CONFINEMENT OPTIONS INCLUDE IN SITU CAPPING, (PLACEMENT OF CLEAN MATERIAL ON TOP OF EXISTING SUBSTRATE), CONFINED AQUATIC DISPOSAL (REMOVAL OF CONTAMINATED SEDIMENTS WITH CONFINED DISPOSAL IN SHALLOW OR OPEN-WATER AQUATIC ENVIRONMENTS USING CAPPING WITH CLEAN DREDGED MATERIAL), CONFINED NEARSHORE DISPOSAL (REMOVAL AND CONFINED DISPOSAL IN THE NEARSHORE ENVIRONMENT WITH CAPPING AND DIKING), AND REMOVAL AND UPLAND DISPOSAL (TRANSFERRING DREDGED MATERIAL TO A LAND-BASED CONFINEMENT FACILITY. IN ADDITION, THE REMEDY WILL IMPLEMENT SITE USE RESTRICTIONS, AND SOURCE AND SEDIMENT MONITORING. THE ESTIMATED TOTAL COST FOR SEDIMENT REMEDIATION AT THE SITE IS $32,300,000, WHICH INCLUDES O&M COSTS FOR 10 YEARS. COSTS ASSOCIATED WITH SOURCE CONTROL ACTIVITIES ARE NOT INCLUDED IN THIS ROD BECAUSE OF THE DIFFICULTY IN DETERMINING WHAT PROPORTION OF TOTAL SOURCE-RELATED COST CAN BE ATTRIBUTED DIRECTLY TO ACHIEVING REMEDIAL OBJECTIVES.

Remedy:

THE REMEDY SELECTED IN THIS RECORD OF DECISION COVERS TWO CB/NT OPERABLE UNITS, SOURCE CONTROL (OPERABLE UNIT 05) AND SEDIMENT REMEDIATION (OPERABLE UNIT 01), WHICH WERE FORMERLY REFERRED TO AS A COMBINED OPERABLE UNIT, AREAWIDE. THE FUNCTION OF THE COMPREHENSIVE REMEDY FOR THESE TWO OPERABLE UNITS IS TO PROTECT THE MARINE ENVIRONMENT AND THEREBY REDUCE ASSOCIATED PUBLIC HEALTH CONCERNS.

IN THE COMMENCEMENT BAY NEARSHORE/TIDEFLATS FEASIBILITY STUDY (TETRA TECH 1988A), WHICH COVERED THE FORMER OPERABLE UNIT AREAWIDE, NINE PROBLEM AREAS WERE IDENTIFIED THAT WARRANTED SOURCE CONTROL AND SEDIMENT REMEDIATION:

* HEAD OF HYLEBOS WATERWAY * MOUTH OF HYLEBOS WATERWAY

* SITCUM WATERWAY * ST. PAUL WATERWAY

* MIDDLE WATERWAY * HEAD OF CITY WATERWAY

* WHEELER-OSGOOD WATERWAY * MOUTH OF CITY WATERWAY

* RUSTON-PT. DEFIANCE SHORELINE.

RESPONSE ACTIONS GOVERNED BY THIS RECORD OF DECISION ARE LIMITED TO EIGHT OF THE NINE CB/NT PROBLEM AREAS LISTED ABOVE. AS A RESULT OF NEW INFORMATION RECEIVED DURING PUBLIC COMMENT ON THE CB/NT FEASIBILITY STUDY, THE US ENVIRONMENTAL PROTECTION AGENCY (EPA) HAS DECIDED TO RECONSIDER THE PROPOSED PLAN FOR THE RUSTON-PT. DEFIANCE SHORELINE PROBLEM AREA. A REVISED FEASIBILITY STUDY FOR THAT PROBLEM AREA, NOW ESTABLISHED AS OPERABLE UNIT 06 (ASARCO SEDIMENTS) IS CURRENTLY BEING PREPARED BY EPA FOR FURTHER PUBLIC COMMENT.

THE SELECTED REMEDY FOR THE EIGHT REMAINING CB/NT PROBLEM AREAS IS DEFINED ACCORDING TO CLEANUP OBJECTIVES FOR BOTH SOURCE CONTROL AND SEDIMENT REMEDIATION. THE REMEDY ESTABLISHES A CLEANUP OBJECTIVE AND A MULTI-ELEMENT REMEDIAL STRATEGY DESIGNED TO ACHIEVE THE OBJECTIVE. IN GENERAL, THE SELECTED REMEDY WILL BE IMPLEMENTED IN EACH OF THE DIFFERENT PROBLEM AREAS INDEPENDENTLY OF ONE ANOTHER. THE OVERALL REMEDY INCLUDES AN 8-YEAR ACTIVE CLEANUP PHASE FOR SOURCE CONTROL AND SEDIMENT REMEDIATION, AND A 10-YEAR NATURAL RECOVERY PHASE.

REMEDIAL TECHNOLOGIES FOR SOURCE CONTROL, THE FIRST STEP IN THE SELECTED REMEDY, INCLUDE A FULL RANGE OF ALL KNOWN AVAILABLE AND REASONABLE METHODS OF TREATMENT (AKARTS). THE SCHEDULE FOR SOURCE CONTROL VARIES AMONG PROBLEM AREAS BUT IS EXPECTED TO BE LARGELY ACCOMPLISHED DURING THE NEXT 8 YEARS. THE WASHINGTON DEPARTMENT OF ECOLOGY (ECOLOGY) IS THE LEAD MANAGEMENT AGENCY FOR SOURCE CONTROL UNDER A COOPERATIVE AGREEMENT WITH EPA.

THE SECOND STEP IN THE SELECTED REMEDY, CORRECTION OF SEDIMENT PROBLEMS, WILL BE ACCOMPLISHED THROUGH A COMBINATION OF NATURAL RECOVERY AND ACTIVE SEDIMENT REMEDIATION. AREAS EXPECTED TO RECOVER NATURALLY WITHIN A 10-YEAR PERIOD AFTER SOURCE CONTROL MEASURES ARE IMPLEMENTED WILL BE MONITORED ANNUALLY TO CONFIRM THAT PREDICTION. SITE USE RESTRICTIONS, SUCH AS ADVISORIES AGAINST SEAFOOD CONSUMPTION, WILL BE IMPLEMENTED TO PROTECT HUMAN HEALTH UNTIL RECOVERY IS COMPLETE.

AREAS NOT EXPECTED TO RECOVER NATURALLY IN A TIMELY MANNER WILL BE ACTIVELY REMEDIATED WHEN SOURCE CONTROL MEASURES ARE DESIGNATED ACCEPTABLE BY ECOLOGY AND EPA.

ACTIVE REMEDIATION OF PROBLEM SEDIMENTS WILL BE ACCOMPLISHED BY UTILIZING A LIMITED RANGE OF FOUR CONFINEMENT TECHNOLOGIES, EACH OF WHICH CAN PROVIDE A FEASIBLE AND COST-EFFECTIVE MEANS OF ACHIEVING THE CLEANUP OBJECTIVE FOR THE SITE. THESE TECHNOLOGIES ARE IN-PLACE CAPPING, CONFINED AQUATIC DISPOSAL, NEARSHORE DISPOSAL, AND UPLAND DISPOSAL. THE SELECTED REMEDY PROVIDES PERFORMANCE OBJECTIVES FOR EACH OF THESE CONFINEMENT TECHNOLOGIES AND ALLOWS THE FLEXIBILITY TO IMPLEMENT ANY OR ALL OF THEM DURING THE ACTIVE CLEANUP PHASE OF THE PROJECT. EPA WILL BE THE LEAD AGENCY FOR IMPLEMENTING SEDIMENT REMEDIATION. THE PUYALLUP TRIBE OF INDIANS HAS BEEN ESTABLISHED AS A SUPPORTING AGENCY FOR THE PROJECT THROUGH A COOPERATIVE AGREEMENT WITH EPA.