Fourth Five-year Review Report for Bunker Hill Superfund Site Shoshone and Kootenai Counties Idaho

FOURTH FIVE-YEAR REVIEW REPORT FOR BUNKER HILL SUPERFUND SITE SHOSHONE AND KOOTENAI COUNTIES, IDAHO £ z VPR0^0

-------

-------
Contents

Acronyms and Abbreviations	ix

Executive Summary	ES-1

Introduction	ES-1

Site Description	ES-1

Brief Site History	ES-1

Review of Selected Remedies	ES-3

Operable Unit 1	ES-4

Operable Unit 2	ES-5

Operable Unit 3	ES-6

Next Five-Year Review	ES-8

Five-Year Review Summary Form	ES-11

1	Introduction	1-1

1.1	Five-Year Review Process Overview	1-2

1.2	Community	1-2

1.3	Relevant Guidance and Decision Documents	1-3

1.3.1	Guidance and Decision Documents	1-3

1.3.2	Obtaining Decision Documents and Final Five-Year Review

Report	1-3

2	Site Background	2-1

2.1	Site Location, Description, and Characteristics	2-1

2.1.1	Operable Unit 1	2-1

2.1.2	Operable Unit 2	2-3

2.1.3	Operable Unit 3	2-3

2.2	Site History	2-3

2.2.1	Operable Unit 1 History	2-6

2.2.2	Operable Unit 2 History	2-7

2.2.3	Operable Unit 3 History	2-7

2.3	Source and Nature of Contamination	2-7

2.3.1	Source of Contamination	2-7

2.3.2	Nature and Extent of Contamination	2-7

2.4	Applicable or Relevant and Appropriate Requirements	2-12

2.4.1	Operable Unit 1	2-13

2.4.2	Operable Unit 2	2-13

2.4.3	Operable Unit 3	2-13

2.5	Basin Environmental Monitoring Plan	2-14

2.5.1	Surface Water —Operable Unit 3	2-14

2.5.2	Surface Water —Operable Unit 2	2-18

2.5.3	Sediment	2-23

2.5.4	Groundwater	2-26

2.5.5	Biological Resources	2-29

iii

-------
CONTENTS

2.5.6 Summary of BEMP Issues, Recommendations, and Follow-Up

Actions	2-36

3	Review of Selected Remedies for Operable Unit 1	3-1

3.1	Overview of Selected Remedy	3-1

3.2	Review of Operable Unit Remedial Actions	3-2

3.2.1	Residential and Community Areas	3-5

3.2.2	Box Repository	3-32

3.3	Technical Assessment for Operable Unit 1	3-39

3.3.1	Is the Remedy Functioning as Intended by the Decision
Documents?	3-39

3.3.2	Are the Exposure Assumptions, Toxicity Data, Cleanup
Levels, and Remedial Action Objectives Used at the Time of
Remedy Selection Still Valid?	3-41

3.3.3	Has any Other Information Come to Light that Could Call into
Question the Protectiveness of the Remedy?	3-43

3.4	Summary of Operable Unit 1 Issues, Recommendations, and Follow-Up
Actions	3-43

3.5	Performance Evaluation of the Operable Unit 1 Remedy	3-46

4	Review of Selected Remedies for Operable Unit 2	4-1

4.1	Overview of Selected Remedies	4-1

4.2	Review of Operable Unit Remedial Actions	4-2

4.2.1	Hillsides	4-2

4.2.2	Gulches	4-6

4.2.3	Smelterville Flats	4-13

4.2.4	Central Impoundment Area	4-15

4.2.5	Bunker Creek	4-17

4.2.6	Industrial Complex	4-20

4.2.7	Mine Operations and Boulevard Areas	4-24

4.2.8	Milo Gulch	4-25

4.2.9	Central Treatment Plant	4-28

4.2.10	Union Pacific Railroad Right-of-Way Remedial Action in the

Box	4-34

4.2.11	Page Pond Area	4-36

4.2.12	A-4 Gypsum Pond Closure	4-38

4.2.13	Institutional Controls Program	4-41

4.3	Technical Assessment for OU 2	4-44

4.3.1	Is the Remedy Functioning as Intended by the Decision
Documents?	4-44

4.3.2	Are the Exposure Assumptions, Toxicity Data, Cleanup
Levels, and Remedial Action Objectives Used at the Time of
Remedy Selection Still Valid?	4-47

4.3.3	Has any Other Information Come to Light that Could Call into
Question the Protectiveness of the Remedy?	4-48

4.4	Summary of OU 2 Issues, Recommendations, and Follow-Up Actions	4-48

4.5	Performance Evaluation	4-49

5	Review of Selected Remedies for Operable Unit 3	5-1

-------
CONTENTS

5.1	Overview of Selected Remedies	5-1

5.1.1	Upper and Lower Basins	5-7

5.1.2	Spokane River	5-10

5.2	Review of Operable Unit 3 Remedial Actions	5-10

5.2.1	Residential and Community Areas	5-10

5.2.2	Mine and Mill Sites	5-59

5.2.3	Washington Recreation Areas along the Spokane River	5-76

5.2.4	Lower Coeur d'Alene River Basin Recreation Sites (including
Black Rock, Thompson, Anderson, Rose Lake, Medimont, and
Rainy Hill)	5-79

5.2.5	Trail of the Coeur d'Alenes Removal Action	5-84

5.2.6	Repositories	5-86

5.2.7	Clean Waterfowl Habitat (Agriculture-to-Wetland Conversion
Project)	5-92

5.3	Technical Assessment for OU 3	5-94

5.3.1	Is the Remedy Functioning as Intended by the Decision
Documents?	5-94

5.3.2	Are the Exposure Assumptions, Toxicity Data, Cleanup
Levels, and RAOs Used at the Time of Remedy Selection Still
Valid?	5-99

5.3.3	Has Any Other Information Come to Light that could call into
question the Protectiveness of the Remedy?	5-99

5.4	Summary of OU 3 Issues, Recommendations, and Follow-Up Actions	5-100

5.5	Performance Evaluation of the OU 3 Remedy	5-103

6	Statement of Protectiveness	6-1

6.1	Operable Unit 1	6-1

6.2	Operable Unit 2	6-1

6.3	Operable Unit 3	6-2

7	Next Five-Year Review	7-1

8	References	8-1

Appendix

A Coeur d'Alene Lake Management Plan

V

-------
CONTENTS

Figures

2-1	Location Map: Bunker Hill Mining and Metallurgical Complex Superfund Site	2-2

2-2	AWQC Ratios for OU 3 Surface Water Monitoring Locations	2-15

3-1	Communities in OU 1	3-3

3-2	Blood Lead Levels for OU 1 Children by City and Year, 1988-2013	3-18

3-3	Box Remedy Protection Project Areas	3-21

3-4	Page Ponds Repository and Vicinity	3-33

4-1	OU 2 Remedial Action Areas	4-3

5-1	Site Map - Upper Basin	5-3

5-2	Site Map - Lower Basin	5-5

5-3	Summary of Remediation in OU 3 by Property Proportions and Geographic

Area, through 2014	5-14

5-4	OU 3 Area-Weighted Geometric Mean Lead Concentration by Geographic

Area and Year	5-17

5-5	Mean Vacuum Lead Concentrations by Year and Area for OU 3,1996-2013	5-23

5-6	Mean Dust Mat Lead Concentrations by Year and Area for OU 3,1996-2013	5-24

5-7	Percentage of OU 3 Vacuum Samples > 1,000 mg/kg Lead, 1996-2013	5-30

5-8	Percentage of OU 3 Mat Samples > 1,000 mg/kg Lead, 1996-2013	5-31

5-9	Mean Dust Loading Rates by Year and Area for OU 3,1996-2013	5-32

5-10	Mean Lead Loading Rates by Year and Area for OU 3,1996-2013	5-35

5-11	OU 3 Geometric Mean Blood Lead Levels by Geographic Area, 1996-2014	5-47

5-12	OU 3 Geometric Mean Blood Lead Levels by Age, 1996-2014	5-48

5-13	OU 3 Remedy Protection Project Areas	5-51

5-14	Wallace Yard Including Hercules Mill site and Spur Lines	5-63

5-15	Ninemile Creek Watershed Mine and Mill Sites	5-69

Tables

2-1	Statistical Summary for Selected Constituents in Water Samples Collected from

15 OU2 Surface Water Stations, 2009-13	2-19

2-2	Summary of Groundwater Statistical Results	2-27

3-1	Summary of ICP Samples Collected in the Box, 2010-2014	3-8

3-2	Dust Summary Statistics by Community for OU 1, 2013	3-11

3-3	Number of Drinking Water Wells Closed in OU 1	3-14

3-4	Summary of Blood Lead Levels for OU 1 Children, 2010-2014	3-16

3-5	OU 1 Children with Elevated Blood Lead Levels	3-17

3-6	Number of ICP Permits Issued in OU 1, 2010-2014	3-26

3-7	OU 1 and OU 2 ICP Waste Disposal Volumes	3-27

3-8	OU 1 and OU 2 ICP Clean Material Volumes	3-28

3-9	Estimated Waste Volumes Placed at Page Repository 2010-2014	3-36

3-10	OU 1 Summary of Issues and Recommendations	3-44

3-11	OU 1 Action Items that Do Not Affect Remedy Protectiveness	3-45

4-1	Number of ICP Permits Issued in OU 2, 2010-2014	4-41

4-2	OU 2 Action Items that Do Not Affect Remedy Protectiveness	4-49

5-1	Summary of OU 3 Property Remediation	5-11

5-2	OU 3 Properties by Remedial Action Category, through 2014	5-12

vi

-------
CONTENTS

5-3 Summary of Gravel Roads Sampled and Remediated in the Basin,

through 2014	5-16

5-4 ICP Samples Collected in OU 3, 2010-2014	5-19

5-5 Vacuum Dust Summary Statistics by Year and Area for OU 3, 2010-2014	5-25

5-6 Dust Mat Summary Statistics by Year and Area for OU 3, 2010-2013	5-28

5-7 Dust and Lead Loading Summary Statistics by Year and Area for OU 3,

2010-2013	5-33

5-8 OU 3 Dust RAO Summary, Probabilities to Exceed Lead Health Risk Criteria

using Recent House Dust and Soil Data	5-37

5-9 Estimated Number of Residences with Drinking Water MCL Exceedances in

the Upper Basin and Lower Basin	5-39

5-10 Summary of Blood Lead Levels for Children Participating in the LHIP by

Geographic Area in OU 3, 2010-2014	5-41

5-11 Summary of OU 3 Participation Rates in the LHIP, 2010-2014	5-44

5-12 Number of ICP Permits Issued in OU 3, 2010-2014	5-54

5-13 OU 3 ICP Waste Disposal Volumes	5-55

5-14 OU 3 ICP Clean Material Volumes	5-56

5-15 Summary of Actions Completed Since the Last Five-Year Review at Identified

Recreational Sites, 2010-2014	5-80

5-16 OU 3 Summary of Issues and Recommendations	5-101

5-17 OU 3 Action Items that Do Not Affect Remedy Protectiveness	5-102

VII

-------

-------
Acronyms and Abbreviations

AMD
ARAR
ASARCO
AWQC

BAL

Basin

BCR

BCRA

BEIPC

BEMP

bgs

BLM

BMI

BMP

BNSF

BPRP

Bunker Hill Box (the Box)

Bunker Hill Superfund Site
BURP

CaCC>3
CCP
CDC
CERCLA

CERCLIS

CFP
CFR
cfs

CHDPE

CIA

COC

Coeur d'Alene
CTP

acid mine drainage

applicable or relevant and appropriate requirement
American Smelting and Refining Company, LLC
ambient water quality criteria

Borrow Area Landfill
Coeur d'Alene River Basin
Big Creek Repository
Big Creek Repository Annex

Coeur d'Alene Basin Environmental Improvement Project
Commission

Basin Environmental Monitoring Plan

below ground surface

U.S. Bureau of Land Management

benthic macroinvertebrate

best management practice

Burlington Northern Santa Fe

Basin Property Remediation Program

A 21-square mile area surrounding the historic smelter area

that includes the cities of Kellogg, Wardner, Smelterville, and

Pinehurst, Idaho

Bunker Hill Mining and Metallurgical Complex Superfund
Facility

Beneficial Use Reconnaissance Program

calcium carbonate

Comprehensive Cleanup Plan

Centers for Disease Control and Prevention

Comprehensive Environmental Response, Compensation, and

Liability Act

Comprehensive Environmental Response, Compensation, and
Liability Information System

Community Fill Policy

Code of Federal Regulations

cubic feet per second

corrugated high-density polyethylene

Central Impoundment Area

chemical of concern

The drainage area of the Coeur d'Alene River in northern
Idaho and River Basin northeastern Washington
Central Treatment Plant

IX

-------
ACRONYMS AND ABBREVIATIONS

CUA	common use area

CW A	Clean W ater Act

cy	cubic yard

DDR	Design Definition Report

Ecology	Washington State Department of Ecology

ECSM	Enhanced Conceptual Site Model

EFNM	East Fork Ninemile

EMFR	East Mission Flats Repository

EMP	Environmental Monitoring Program

ESD	Explanation of Significant Difference

FFS	Focused Feasibility Study

FS	Feasibility Study

GIS	geographic information system

GWCS	groundwater collection system

H:V	horizontal to vertical

HDS	high-density sludge

HEPA	high-efficiency particulate air filter

HHRA	Human Health Risk Assessment

HHRE	Human Health Remedial Evaluation

HUC	Hydrological Unit Code

1-90	Interstate 90

IC	institutional control

ICA	Interagency Cooperative Agreement

ICP	Institutional Controls Program

IDAPA	Idaho Administrative Procedures Act

IDEQ	Idaho Department of Environmental Quality

IDFG	Idaho Department of Fish and Game

IDHW	Idaho Department of Health and Welfare

IDL	Idaho Department of Lands

IDPR	Idaho Department of Parks and Recreation

IDWR	Idaho Department of Water Resources

IEUBK	Integrated Exposure Uptake Biokinetic

IPS	interim performance standard

IVBA	in vitro lead bioavailability

JEG	Jacobs Engineering Group

LBCR	Lower Burke Canyon Repository

LDS	low-density sludge

X

-------
ACRONYMS AND ABBREVIATIONS

LHIP
LMP

Lower Basin
LUR

Lead Health Intervention Program
Lake Management Plan

The area of the Coeur d'Alene River Basin in OU 3 west of
Cataldo to the mouth of Coeur d'Alene Lake. Includes the
lower Coeur d'Alene River and associated lateral lakes.
Limited Use Repository

(ig/dL

M&/L

M&R

MAPS

MCL

MCLG

MFA

MFG

mg/kg

mg/L

MOA

microgram per deciliter
microgram per liter
maintenance and repair

Monitoring Avian Productivity and Survivorship

maximum contaminant level

maximum contaminant level goal

Maul Foster & Alongi, Inc.

McCulley, Frick, and Gilman

milligram per kilogram

milligram per liter

Mine Operations Area

NA

NCP

NFCDR

North Wind Construction

North Wind

NPDES

NPL

not applicable

National Oil and Hazardous Substances Contingency Plan
North Fork of the Coeur d'Alene River
North Wind Construction Services, LLC
North Wind, Inc.

National Pollutant Discharge Elimination System
National Priority List (list of Superfund sites)

O&M

ODBO

OU1

OU 2

OU 3

OU

operation and maintenance
Operations/Design/Build/Operate

Operable Unit 1, the populated areas within the Bunker Hill
Box

Operable Unit 2, the non-populated areas within the Bunker
Hill Box

Operable Unit 3, the mining-contaminated areas in the
broader Coeur d'Alene River Basin outside of OU 1 and OU 2,
from approximately Mullan, Idaho, west to Coeur d'Alene
Lake and depositional areas of the Spokane River in Idaho and
Washington State. For study purposes, OU 3 was divided into
four areas: the Upper Basin (areas east of Cataldo, Idaho,
outside the Box), the Lower Basin (west of Cataldo to the
mouth of Coeur d'Alene Lake), Coeur d'Alene Lake, and
depositional areas of the Spokane River.

Operable Unit (used to define specific cleanup areas of
Superfund sites)

PCS
PHD

petroleum-contaminated soil
Panhandle Health District

XI

-------
ACRONYMS AND ABBREVIATIONS

PPWTP

Page Pond Wastewater Treatment Plant

PRP

Potentially Responsible Party

PS

performance standard

PTM

Principal Threat Material

RAMP

Remedial Action Management Plan

RAO

remedial action objective

RD

remedial design

RDR

remedial design report

RfD

reference dose

RI

Remedial Investigation

RI/FS

Remedial Investigation/Feasibility Study

ROD

Record of Decision

ROW

right-of-way

RSA

reasonable segregable area

SACA

Support Agency Cooperative Agreement

SCA

Smelter Closure Area

SDR

Schematic Design Report

SDWA

Safe Drinking Water Act

SFCDR

South Fork of the Coeur d'Alene River

Site

Bunker Hill Mining and Metallurgical Complex Superfund



Facility

SMC

Stauffer Management Company

SSC

State Superfund Contract

STI

Star Tailings Impoundment

Superfund

A common name for USEPA's CERCLA program

sy

square yard

TBC	to be considered

TerraGraphics	TerraGraphics Environmental Engineering

ton/yr	ton per year

TSS	total suspended solids

UMG	Upstream Mining Group

Upper Basin	The area of the Coeur d'Alene River Basin in OU 3 east of

Cataldo, Idaho, and outside the Bunker Hill Box. Includes the
South Fork of the Coeur d'Alene River and its tributaries
outside of the Box.

UPRR

Union Pacific Railroad

USACE

U.S. Army Corps of Engineers

USBM

U.S. Bureau of Mines

USEPA

U.S. Environmental Protection Agency

USFS

U.S. Forest Service

USFWS

U.S. Fish and Wildlife Service

XII

-------
ACRONYMS AND ABBREVIATIONS

USGS	U.S. Geological Survey

WCA	Waste Consolidation Area

WENI	West End Natural Infiltration

WY	water year

XIII

-------

-------
Executive Summary

Introduction

The U.S. Environmental Protection Agency (USEPA) Region 10 has completed its fourth
site-wide review of the Bunker Hill Mining and Metallurgical Complex Superfund Site (the
"Bunker Hill Superfund Site" or "Site") located within northern Idaho, sections of the Coeur
d'Alene Reservation, and northeastern Washington.

The Comprehensive Environmental Response, Compensation and Liability Act (CERCLA)
Section 121(c) requires USEPA to perform a review of remedial actions that result in hazardous
substances, pollutants, or contaminants remaining at the Site at least every 5 years. The purpose
of the review is to determine whether the remedial actions are, or will be upon completion,
protective of human health and the environment. Projects implemented with Clean Water Act
(CWA) or other authorities are outside the scope of this review.

This Five-Year Review Report documents the methods, findings, and conclusions based on
issues identified during the review and presents recommendations to address them. The text
and summary tables in this Executive Summary provide an overview of this Five-Year Review
Report.

Site Description

The Bunker Hill Superfund Site (the Site) was listed on the National Priorities List (NPL) in
1983. This NPL Site has been assigned Comprehensive Environmental Response,

Compensation, and Liability Act Information System (CERCLIS) identification number
IDD048340921. The Site includes mining-contaminated areas in the Coeur d'Alene River
corridor, adjacent floodplains, downstream water bodies, tributaries, and fill areas, as well as
the 21-square-mile Bunker Hill "Box" (referred to as the Box) located in the area surrounding
the historic smelting operations. USEPA has the following designated three operable units
(OUs) for the Site:

• The populated areas of the Bunker Hill Box (OU 1);

• The non-populated areas of the Box (OU 2); and

• Mining-related contamination in the broader Coeur d'Alene Basin (the "Basin" or OU 3).

Brief Site History

The Bunker Hill Superfund Site is within one of the largest historical mining districts in the
world. Commercial mining for lead, zinc, silver, and other metals began in the Silver Valley in
1883. Heavy metals contamination in soil, sediment, surface water, and groundwater from over
100 years of commercial mining, milling, smelting, and associated modes of transportation has
affected both human health and environmental resources in many areas throughout the Site.

ES-1

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

The principal sources of metals contamination were tailings generated from the milling of ore
discharged to the South Fork Coeur d'Alene River (SFCDR) and its tributaries or confined in
large waste piles onsite, waste rock, and air emissions from smelter operations. Tailings were
frequently used as fill for residential and commercial construction projects. Spillage from
railroad operations also contributed to contamination across the Site.

Tailings were also transported downstream, particularly during high-flow events, and
deposited as lenses of tailings or as tailings/sediment mixtures in the bed, banks, floodplains,
and lateral lakes of the Coeur d'Alene River Basin and in Coeur d'Alene Lake. Some fine-
grained material washed through the lake, which was deposited as sediment within the
Spokane River flood channel. The estimated total mass and extent of impacted materials
(primarily sediments) exceeds 100 million tons dispersed over thousands of acres (USEPA,
2001c). Over time, groundwater also became contaminated with metals.

Air emissions occurred from ore processing facilities in Kellogg and Smelterville. Although both
the Lead Smelter and Zinc Plant had recycling processes designed to minimize airborne
particulates, significant metals deposition still occurred together with deposition of sulfur
dioxide emissions. In September 1973, a fire destroyed the baghouse and the primary emissions
control for the Lead Smelter. The smelter continued production unabated and the emitted up to
160 tons per month of particulate emissions containing 50 to 70 percent lead compared to 10 to
20 tons per month prior to the fire (TerraGraphics, 1990). These emissions affected areas near
the Smelter and Zinc Plant, poisoned local residents, and greatly contributed to the denuding of
surrounding hillsides. Smelter operations ceased in 1981, but limited mining and milling
operations continued onsite from 1988 to 1991, and small-scale mining operations continue
today.

After site listing on the NPL in 1983, USEPA published the first Site Record of Decision (ROD)
in August 1991 providing the Selected Remedy for OU 1 residential soils (USEPA, 1991). The
second ROD for the Site was published by USEPA in September 1992 addressing contamination
in the non-populated OU 2, as well those aspects of OU 1 that were not addressed in the 1991
OU 1 ROD (USEPA, 1992). Since publication of the 1992 OU 2 ROD, a number of remedy
changes and clarifications have been documented in two OU 2 ROD Amendments (USEPA,
1996a, 2001b) and two Explanations of Significant Differences (ESDs; USEPA, 1996b, 1998a).

USEPA issued an interim ROD for OU 3 in 2002 (USEPA, 2002a) to clean up mining
contamination consisting of an interim ecological remedy and a complete human health remedy
in the communities and residential areas where actions were selected, including identified
recreational areas.

In 2008, USEPA began a Focused Feasibility Study (FFS) to support additional remedy changes
in the existing RODs for all three OUs (USEPA, 2010b). The FFS was completed in 2010 (2010
FFS). The focus of the 2010 Draft Final FFS was to identify additional remedial actions to protect
the human health remedy throughout the Site and reduce metals contamination in surface
water and groundwater in the Upper Basin portion of the Site, including the Bunker Hill Box.

The Upper Basin Proposed Plan (USEPA, 2010a) was published in summer 2010. After an
extended public comment period in 2010, the Preferred Alternative identified in the Proposed
Plan was revised. The revisions were documented in the final FFS Report, which was completed
in late summer 2012 (the 2012 FFS; USEPA, 2012b). The 2012 Final FFS presents and evaluates

ES-2

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

alternatives for cleanup of the Upper Basin portion of the Site. Responses to all comments
received during the extended public comment period were summarized in the Responsiveness
Summary and published as part of the 2012 Upper Basin ROD Amendment (USEPA, 2012a).

The Selected Remedy in the 2012 Upper Basin ROD Amendment is an interim remedy. A final
remedy will be selected in the future as additional knowledge is gained about conditions at
specific locations within the Upper Basin and the effectiveness of remedial actions. The Selected
Remedy for the Upper Basin builds upon the remedies identified in the previous RODs for
OUs 1, 2, and 3 and incorporates additional information obtained since the ROD for OU 3 was
issued in 2002.

In December 2009, as part of the American Smelting and Refining Company, LLC (ASARCO)
bankruptcy settlement, funding was secured for Superfund response actions at the Site.
However, due to a prior settlement with ASARCO for response actions in the Bunker Hill Box,
most of the settlement monies, about $486 million, can only be used to perform USEPA-selected
cleanup actions in mining-contaminated areas of OU 3, outside the Bunker Hill Box (OUs 1 and
2). These funds were placed in a trust, and a trustee was appointed to manage and invest the
funds. The current balance of funds in the Trust is approximately $530 million. From the
bankruptcy settlement, USEPA was reimbursed $8 million for human health protection actions
that the agency had completed in the Bunker Hill Box from 2002 to 2005. The $8 million is
available for additional cleanup work in the Box.

In June 2011, a settlement of $263.4 million plus interest was reached between Hecla Mining
Company and the USEPA, the Coeur d'Alene Tribe, and the State of Idaho that resolved legal
claims stemming from releases of wastes from Hecla's mining operations. Hecla settlement
funds include funds for remediation and restoration of natural resources in the Coeur d'Alene
Basin and can be spent anywhere within the Bunker Hill Superfund Site. Of the $263.4 million,
approximately $180 million will fund response actions throughout the Site, $17 million was
provided to the State of Idaho to fund the Institutional Controls Program (ICP) and the ICP soil
repository (Page Repository) into perpetuity within OU 1, and $65.85 million was provided to
the federal, Tribal, and state Natural Resource Trustees for use in restoration activities in
coordination with cleanup actions.

Review of Selected Remedies

As stated above, this five-year review evaluates the protectiveness of the Selected Remedies that
have been or will be implemented at the Site. This 2015 Site-wide Five-Year Review Report
documents the results of the review, identifies issues found during the review, and presents
recommendations to address them. USEPA will track the identified issues and
recommendations to ensure that follow-up actions are completed.

The remainder of this section summarizes Site activities and remedial actions completed in the
last five years by OU and identifies the issues and recommendations identified during this
review.

ES-3

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Operable Unit 1
Introduction

Operable Unit 1 is located within the 21-square-mile area surrounding the former smelter
complex commonly referred to as the Bunker Hill Box. The Box is located in a steep mountain
valley in Shoshone County, Idaho, east of the city of Coeur d'Alene. Interstate 90 (1-90) bisects
the Box and parallels the SFCDR.

OU 1 is often referred to as the populated areas of the Bunker Hill Box and is home to more
than 7,000 people in the cities of Kellogg, Wardner, Smelterville, and Pinehurst, as well as the
unincorporated communities of Page, Ross Ranch, Elizabeth Park, and Montgomery Gulch.
Cleanup activities began first in OU 1 because this was the area of greatest concern for human
health exposure from smelter emissions, fugitive dust, and mine waste.

OU 1 ROD Issuance

The OU 1 Selected Remedy and remedial action objectives (RAOs) are described in the 1991
OU 1 ROD (USEPA, 1991), the 1992 OU 2 ROD (USEPA, 1992), and the 2012 Upper Basin ROD
Amendment (USEPA, 2012a). The primary goal of the OU 1 Selected Remedy is to reduce
children's intake of lead from soil and dust sources to meet the following RAOs:

•	Less than 5 percent of children with blood lead levels of 10 micrograms per deciliter
(|a,g/ dL) or greater; and

•	Less than 1 percent of children with blood lead levels of 15 jug/ dL or greater.

The 2012 Upper Basin ROD Amendment Selected Remedy supplements the existing Selected
Remedy for OU 1 by including localized drainage improvement actions that will protect those
portions of the existing remedy that are in areas at risk from localized tributary flooding and
heavy precipitation.

Major Components of the Selected Remedy

To achieve RAO, the cleanup strategy includes the following:

•	Implementing a lead health intervention program for local families

•	Remediating all residential yards, commercial properties, and rights-of-way (ROWs) that
have soil lead concentrations greater than 1,000 milligrams per kilogram (mg/kg)

•	Achieving a geometric mean yard soil lead concentration of less than 350 mg/kg for each
residential community in OU 1

•	Controlling fugitive dust and stabilizing and capping contaminated soils throughout the
Bunker Hill Box (OU 1/OU 2)

•	Achieving a geometric mean of interior house dust lead levels of 500 mg/kg or less for each
community, with no individual house dust level exceeding 1,000 mg/kg (1992 OU 2 ROD)

•	Establishing an ICP to maintain protective barriers over time, and to ensure that future land
use and development is compatible with the OU 1 Selected Remedy

ES-4

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

•	For all homes with house dust lead concentrations equal to or exceeding 1,000 mg/kg,
implementing a one-time cleaning of residential interiors after completion of remedial
actions that address fugitive dust. If subsequent interior house dust sampling indicates that
house dust lead concentrations exceed a site-wide average of 500 mg/kg, the need for
additional cleaning will be evaluated

•	Implementing specific remedy protection actions, such as culvert replacements, channel
improvements, small diversion structures, and asphalt ditches, identified in Pinehurst,
Smelterville, Kellogg, and Wardner

•	Identifying generalized remedy protection actions that are expected to be needed in Upper
Basin side gulches

Operable Unit 2
Introduction

OU 2 consists of areas in the Bunker Hill Box that were non-populated, nonresidential areas at
the time of the 1992 OU 2 ROD. OU 2 areas include the former industrial complex and Mine
Operations Area (MOA) in Kellogg, Smelterville Flats (the floodplain of the SFCDR in the
western half of OU 2), hillsides, various creeks and gulches, the Central Impoundment Area
(CIA), and the Bunker Hill Mine and associated acid mine drainage (AMD). The SFCDR within
OU 2 and the non-populated areas of the Pine Creek drainage area are both addressed as part of
OU 3.

OU 2 ROD Issuance

A ROD for OU 2 was published by USEPA in 1992 (USEPA, 1992). Since then, three OU 2 ROD
Amendments (USEPA, 1996a, 2001b, and 2012a) and two ESDs (USEPA, 1996b and 1998a) have
been published. These ROD Amendments and ESDs changed the remedy in various ways.

Major Components of the Selected Remedy

The 1992 OU 2 ROD set forth priority cleanup actions to protect human health and the
environment. Cleanup actions included a series of source removals, surface capping,
reconstruction of surface water creeks, demolition of abandoned milling and processing
facilities, engineered closures for waste consolidated onsite, revegetation efforts, and treatment
of contaminated water collected from various site sources.

Phase I of remedy implementation includes extensive source removal and stabilization efforts,
all demolition activities, all community development initiatives, development and initiation of
an ICP, future land use development support, and public health response actions. Also included
in Phase I are additional investigations to provide the necessary information to resolve long-
term water quality issues, including technology assessments and pilot studies, evaluation of the
success of source control efforts, development of Site-specific water quality and effluent-
limiting performance standards, and development of a defined O&M plan and implementation
schedule. Interim control and treatment of contaminated water and AMD is also included in
Phase I of remedy implementation. Phase I remediation began in 1995, and source control and
removal activities are nearly complete.

ES-5

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

The 2012 Upper Basin ROD Amendment supplements the existing Selected Remedy for OU 2
by including localized drainage improvement actions that will protect those portions of the
existing remedy that are in areas of risk from localized tributary flooding and heavy
precipitation. The Selected Remedy defines Phase II cleanup actions to address ongoing water
quality issues in OU 2. These actions include managing the contaminated discharge from the
Reed and Russell Adits, reducing the flow of contaminated groundwater to the SFCDR, and
collecting and treating contaminated groundwater.

The following are the major components of the Selected Remedy within the Bunker Hill Box
(OU 1 and OU 2) identified in the 2012 ROD Amendment:

•	Actions to reduce the flow of contaminated groundwater entering the SFCDR and
Government Creek

•	Conveyance of effluent from the CTP in Kellogg (i.e., clean, treated water) directly to the
SFCDR in a pipeline to prevent recontamination through contact with contaminated
subsurface Box soil

•	Groundwater collection and treatment and water management actions to reduce the flow of
contaminated discharges near the Reed and Russell Adits

•	CTP expansion and upgrade to treat collected water from OU 2, consistently achieve
discharge requirements, allow for operation in high-density sludge mode, and reduce the
volume of waste sludge generated

•	Continued implementation of the ICP to protect human health

Operable Unit 3
Introduction

OU 3 consists of the mining-contaminated areas in the Coeur d'Alene Basin outside of OU 1 and
OU 2, primarily the following:

•	The floodplain and river corridor of the Coeur d'Alene River (including Coeur d'Alene
Lake) and the Spokane River; and

•	Those areas where mine wastes have come to be located because of their use for road
building or for fill and construction of residential or commercial properties.

Spillage from railroad operations also contributed to contamination across the Basin. OU 3
contaminants are primarily metals, and the metals of principal concern are lead and arsenic for
protection of human health, and lead, cadmium, and zinc for protection of ecological receptors.

OU 3 ROD Issuance

On September 12, 2002, USEPA issued an interim ROD to address mining contamination in the
broader Coeur d'Alene Basin (OU 3) (USEPA, 2002a).

ES-6

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

The 2002 OU 3 ROD includes the following:

•	The full remedy needed to protect human health in the community and residential areas,
including identified recreational areas of the Upper Basin and Lower Basin, as well as
Washington recreational areas along the Spokane River upstream from Upriver Dam.

•	An interim remedy of prioritized actions for protection of the environment that focus on
improving water quality, minimizing downstream migration of metal contaminants, and
improving conditions for fish and wildlife populations.

In 2012, USEPA issued the Upper Basin ROD Amendment to include the eastern portion of OU
3. The Upper Basin Selected Remedy supplements the existing Selected Human Health Remedy
for OU 3 by including actions that will protect the existing remedy. Relatively few elements of
the existing Selected (interim) Ecological Remedy for OU 3 have been implemented. The 2012
Upper Basin Selected Remedy replaces the Upper Basin portion of the interim ecological actions
selected in the 2002 ROD for OU 3 (USEPA, 2002a).

Major Components of the Interim Selected Remedy

For protection of human health in the community and residential areas of the Upper Basin and
Lower Basin, the major remedial components include the following:

•	Providing lead health information and intervention programs for residential and
recreational users

•	Partially excavating and replacing residential soils with lead concentrations above

1,000 mg/kg and/ or arsenic concentrations above 100 mg/kg, implementing a barrier such
as a vegetative barrier to control or limit migration of soils with lead concentrations between
700 and 1,000 mg/kg, and using a combination of removals, barriers, and access restrictions
for street ROWs, commercial properties, and recreational areas

•	Providing alternative drinking water sources for residences using contaminated private
drinking water sources

•	Evaluating lead in house dust, after residential soil remediation is completed, to determine
if interior cleaning is needed

•	Establishing an ICP to maintain protective barriers over time and guide land use and future
development

For environmental protection in the Upper and Lower Basins, three environmental priorities
were identified in the 2002 OU 3 ROD:

•	Dissolved metals in surface water (particularly zinc and cadmium) have harmful effects on
fish and other aquatic life.

•	Lead in soil and sediment is present in the beds, banks, and floodplains of the river system
and has harmful effects on waterfowl and other wildlife.

•	Particulate lead in surface water is transported downstream and is a continuing source of
contamination for the Coeur d'Alene River, Coeur d'Alene Lake, and the Spokane River.
Lead transported in particulate form in the river has affected recreational areas in the Lower

ES-7

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Basin and the Spokane River, resulting in posted health advisory signs at beaches and
swimming areas. During flood events, lead transported by the river also affects the wetlands
and floodplains.

The Selected Remedy for the Washington recreational areas along the Spokane River identified
in the 2002 OU 3 ROD is a combination of access controls, capping, and removals of metals-
contaminated soil and sediment. The remedy includes water quality monitoring, aquatic life
monitoring, remedial performance monitoring of sediments, and contingencies for additional or
follow-up cleanups for the recreational areas.

As stated above, the 2012 Upper Basin ROD Amendment interim Selected Remedy replaces the
Upper Basin portion of the Selected Remedy identified in the 2002 ROD for OU 3. The following
are the major components of the Selected Remedy in the Upper Basin outside the Box (in the
eastern portion of OU 3):

•	Extensive excavation and consolidation of waste rock, tailings, and floodplain sediments

•	Capping, regrading, and revegetation of tailings and waste rock areas

•	Collection and treatment of contaminated adit discharges, seeps, and groundwater

•	Stream and riparian stabilization actions in watersheds where sediment removal actions are
implemented

•	Additional CTP expansions and upgrades to treat collected water from OU 3, consistently
achieve discharge requirements, allow for operation in high-density sludge mode, and
reduce the volume of waste sludge generated

•	Continued ICP implementation to protect human health

•	Specific remedy protection actions, such as culvert replacements, channel improvements,
small diversion structures, and asphalt ditches, identified in Osburn, Silverton, Wallace, and
Mullan.

•	Identification of generalized remedy protection actions that are expected to be needed in
Upper Basin side gulches

EPA did not select a remedy for Coeur d'Alene Lake in the 2002 OU 3 ROD. USEPA deferred
remedy selection in the Lake pending successful implementation of the Lake Management Plan
by the State of Idaho, the Coeur d'Alene Tribe, and federal and local governments using
separate regulatory authorities. The Coeur d'Alene LMP was finalized in March 2009 and is
currently being implemented.

Next Five-Year Review

CERCLA Section 121(c) requires USEPA to perform a review of remedial actions that result in
hazardous substances, pollutants, or contaminants remaining at the Bunker Hill Superfund Site
at least every 5 years. The purpose of the review is to determine whether the remedial actions
are protective of human health and the environment. The trigger date for completion of these
reviews is 5 years after initiation of the first remedial action at the Site. The first remedial action
at the Site started in 1995. Because onsite containment of hazardous substances is part of the

ES-8

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Site's Selected Remedy, the first Five-Year Review was completed on September 27, 2000. The
second Five-Year Review was completed on October 24, 2005. The third Five-Year Review was
completed on November 18, 2010.

The next review (the fifth Five-Year Review) of the Bunker Hill Superfund Site will be
conducted within 5 years of the completion date of this fourth Five-Year Review Report. The
fifth Five-Year Review Report will cover all remedial work, monitoring, operation, and
maintenance activities conducted at the Site. In addition, as stated in the 2002 OU 3 ROD,
USEPA will continue to evaluate Coeur d'Alene Lake conditions in the next and future Five-
Year Reviews.

ES-9

-------

-------
Five-Year Review Summary Form

Five-Year Review Summary Form

SITE IDENTIFICATION

Site Name: Bunker Hill Mining and Metallurgical Complex

EPA ID: IDD048340921

Region: 10

State: ID and

WA

City/County: Shoshone, Kootenai, Benewah
Counties in Idaho, and Spokane County in
Washington

NPL Status: Final

Multiple OUs?

Yes

Has the site achieved construction completion?

No

Lead agency: EPA

If "Other Federal Agency" was selected above, enter Agency name:

Author name (Federal or State Project Manager): Bill Adams, Bunker Hill Team Lead

Author affiliation: USEPA Region 10

Review period: May 1, 2010- December 31, 2014

Date of site inspection: Various dates for individual remedial actions, from May 2010
through May 2015.

Type of review: Statutory

Review number: 4

Triggering action date: Previous Five-Year Review signed November 18, 2010
Due date (five years after triggering action date): November 18, 2015

ES-11

-------
Five-Year Review Summary Form (Continued)

Issues/Recommendations

OU(s) without Issues/Recommendations Identified in the Five-Year Review: OU 2
Issues/recommendations identified forOU 1 and OU 3.

OU(s): OU 1

Issue Category: House Dust



Issue: Results of two pilot studies indicate that house dust lead
concentrations return to pre-cleaning levels within one year of cleaning,
regardless of the cleaning method. Recent data confirm that house dust
lead concentrations have achieved the community mean of 500 mg/kg and
the number of homes exceeding 1,000 mg/kg lead in house dust is
declining.



Recommendation: Evaluate the need for implementation of the interior
cleaning component of the remedy based in part on information on
alternative dust lead sources. Determine additional data and monitoring
needs to support one-time cleaning evaluation.

Affect Current
Protectiveness

Affect Future
Protectiveness

Implementing
Party

Oversight
Party

Milestone Date

No

Yes

IDEQ, USEPA

IDEQ, USEPA

December 31,
2017

OU(s): OU 1

Issue Category: Drinking Water

Issue: Owners of 13 wells that exceeded federal drinking water standards
refused closure. At the time of refusal, all wells were dedicated to non-
potable uses.

Recommendation: Review current use of the 13 wells whose owners
refused closure to identify those being used for potable purposes, if any.

Affect Current
Protectiveness

Affect Future
Protectiveness

Implementing
Party

Oversight
Party

Milestone Date

No

Yes

IDEQ, USEPA

IDEQ, USEPA

December 31,
2016

ES-12

-------
Five-Year Review Summary Form (Continued)

OU(s): OU 3

Issue Category: LHIP

Issue: House dust monitoring currently only occurs every other year
while remediation is ongoing. Therefore, other strategies are needed to
help identify at-risk children annually.

Recommendation: Consider additional alternative approaches to the
2002 OU 3 ROD'S dust intervention protocol to identify at-risk children.

Affect Current
Protectiveness

Affect Future
Protectiveness

Implementing
Party

Oversight
Party

Milestone
Date

Yes

IDEQ, PHD,
USEPA

IDEQ, USEPA

March 2016

OU(s): OU 3

Issue Category: Basin Recreation Sites

Issue: There are numerous contaminated sites used for recreation
throughout the Basin that span the spectrum from informally used to fairly
highly developed. These sites don't fit into established cleanup programs
such as the BPRP. Many have recontamination potential from recurring
flood deposition.

Recommendation: Identify and evaluate Basin recreational sites for
possible exposure reduction or educational outreach measures. Identify
and evaluate cost effective exposure reduction and educational outreach
measures (where appropriate) geared towards various types of recreational
sites.

Affect Current
Protectiveness

Affect Future
Protectiveness

Implementing
Party

Oversight
Party

Milestone Date

Yes

IDEQ, PHD,
USEPA

IDEQ, USEPA

March 2019

Sitewide Protectiveness Statements for all OUs

Protectiveness Determination: Addendum Due Date:

Will be protective Not applicable

Protectiveness Statements:

OU1

The remedy at OU 1 is expected to be protective of human health and the environment upon
completion. In the interim, where remedial activities have been completed to date, they have
adequately addressed all exposure pathways that could result in unacceptable risks in these
areas.

ES-13

-------
Five-Year Review Summary Form (Continued)

Sitewide Protectiveness Statements for all OUs

essential to the long-term performance of the installed human health barriers. House dust lead
levels have declined to below the 500 mg/kg site-wide average RAO. However, further
evaluation is necessary to inform ongoing implementation of the interior cleaning remedy.

Private groundwater wells used for drinking were closed during the years that yard soil
remedial actions were ongoing. Owners of 13 wells that exceeded federal drinking water
standards refused closure. None of these 13 wells was used for drinking water purposes at
the time; however, the current potable or nonpotable status of 13 wells whose owners refused
closure is currently unknown.

OU2

The remedy at OU 2 is expected to be protective of human health and the environment upon
completion. In the interim, where remedial activities have been completed to date, they have
adequately addressed all exposure pathways that could result in unacceptable risks in these
areas.

Implementation of Phase I of remedy as selected in the 1992 ROD, ROD Amendments (1996,
2001, and 2012), and ESDs (1996 and 1998) includes extensive source removal and
stabilization efforts, demolition activities, development and implementation of the ICP, land
use development support, and public health response actions. Phase I includes monitoring
and evaluation of the success of source control efforts. Interim control and treatment of
contaminated water and AMD were also included in Phase I of remedy implementation.

Phase I remedies have removed and consolidated over 2.8 million cy of contaminated waste
onsite in engineered closure areas (the Smelter and CIA closures; see Section 4, Table 4-1).
The use of geomembrane cover systems on these closure areas effectively removes these
contaminated wastes from direct contact by humans and biological receptors. Consolidating
these wastes in engineered closures also substantially reduces the exposure pathway to the
surface water and groundwater environment in comparison to pre-remediation Site conditions.

Over 800 acres of property within OU 2 have been capped to eliminate direct contact with
residual contamination that remains in place within some areas of OU 2. In addition, the
revegetation work conducted as part of the Phase I remedial actions has substantially
controlled erosion and has significantly improved the visual aesthetics of OU 2. The success
of the Phase I revegetation efforts is providing improved habitat for wildlife that was largely
absent for decades in many areas of the hillsides and Smelterville Flats.

All of these efforts have reduced or eliminated the potential for humans to have direct contact
with soil/source contaminants, have reduced opportunities for transport of contaminants by
surface water and air, and are expected to provide surface and groundwater quality
improvements over time throughout the Site. Responsibility for O&M of OU 2 Phase I remedial
actions has been transferred to the State of Idaho upon completion of the remedies.

OU3

ES-14

-------
Five-Year Review Summary Form (Continued)

Sitewide Protectiveness Statements for all OUs

Although the Implementation Plan focuses on cleanup actions selected in the ROD
Amendment, it also identifies additional actions identified in other decision documents and
additional studies that EPA plans to conduct at the site, including the Lower Basin. EPA
continues to pursue data collection efforts in the Lower Basin to support the evaluation of
remedial alternatives for subsequent decision documents.

The Selected Remedy is designed to provide significant improvements to soil, sediments,
surface water, and groundwater, and to greatly reduce the risks posed to human health and
the environment within the Upper and Lower Basin. It is also expected to reduce the
movement of contaminated sediments downstream in the Lower Basin.

Although the remedial action in Basin residential and community areas has not been fully
implemented, environmental data indicate that the remedy is, in general, functioning as
intended by the 2002 OU 3 ROD. As property remediation progresses, soil and house dust
lead concentrations are declining, lead intake rates have been substantially reduced, and
blood lead levels have declined to levels that meet the RAOs. The low level of participation in
the annual Basin blood lead monitoring program remains a concern because it limits the
identification of children who might benefit from intervention.

In addition to cleanup work in the residential and community areas of OU 3, remedial work has
also been completed at a number of mine and mill sites in the Upper Basin as well as at
recreational sites along the Coeur d'Alene and Spokane rivers. In addition to consolidating
mine waste to reduce contaminant loading to surface water and groundwater, the remedial
actions at the mine and mill sites have included barriers or deterrents to all-terrain vehicle and
motorcycle use, which have reduced exposures and are functioning as designed.

Remedial work at the recreational sites along the Coeur d'Alene River have largely involved
grading and capping contaminated materials, installation of site access controls, and
stabilization of adjacent eroded riverbank. Remedial actions at the Spokane River sites have
involved a combination of removing contaminated materials, capping, and installing deterrents
to recreational users. The remedies constructed at recreational sites along both the Coeur
d'Alene and Spokane Rivers are, in general, functioning as designed. A number of additional
privately owned recreational sites and informal, undeveloped sites have been identified that
may present a heavy metal exposure risk to recreationalists.

Three repositories have been designed, constructed, and operated pursuant to the 2002 OU 3
ROD to safely contain waste material and prevent the release of contaminants to surface
water, groundwater, or air in concentrations that would exceed state and/or federal standards.
Based on monitoring results in the last 5 years, the operation of these repositories has
prevented the release of contaminants to surface water, groundwater, or air in concentrations
that would exceed state and/or federal standards.

In addition to the three repositories, the EFNM WCA, which is located in the upper reach of
the EFNM Creek Watershed, was constructed approximately 250 feet above EFNM Creek
outside of the alluvial valley and in an area that is relatively isolated from groundwater. The
WCA was completed in 2014 and began receiving waste from the Interstate Callahan Rock
Dump. It is expected to be operational for approximately 10 years and expanded to
accommodate all the waste from cleanup in EFNM.

USEPA, working with the USFWS and Ducks Unlimited, completed a cleanup and pilot study
project establishing nearly 400 acres of clean feeding habitat for migratory and resident

ES-15

-------
Five-Year Review Summary Form (Continued)

Sitewide Protectiveness Statements for all OUs

swans, ducks, and other wetland bird species in the Lower Basin. The agriculture to wetland
conversion project has demonstrated high water fowl usage on the East Field and an
increasing activity in the West Field as a result of restoration activities conducted by the
Natural Resource Trustees.

The 2002 OU 3 ROD did not identify any remedial actions for Coeur d'Alene Lake, where
large quantities of contaminated mining wastes have been deposited in lakebed sediments.
The ROD indicated that a management plan for the lake would be developed by the State of
Idaho and the Coeur d'Alene Tribe, with input from local, other state, and federal agencies to
focus on controlling riverine inputs of metals and nutrients that continue to contribute to
contamination of the Lake and Spokane River. An important milestone was achieved in March
2009 when the State of Idaho and the Coeur d'Alene Tribe completed a significant revision to
the Lake Management Plan (LMP; IDEQ and Coeur d'Alene Tribe, 2009). Implementation of
initial LMP actions has begun and lake monitoring efforts are underway.

ES-16

-------
1 Introduction

The U.S. Environmental Protection Agency (USEPA) Region 10 has completed its fourth Site-
wide review of the Bunker Hill Mining and Metallurgical Complex Superfund Facility (the
"Bunker Hill Superfund Site" or "Site") located within northern Idaho, sections of the Coeur
d'Alene Reservation, and northeastern Washington. The Comprehensive Environmental
Response, Compensation, and Liability Act (CERCLA) Section 121(c) requires USEPA to review
remedial actions that result in hazardous substances, pollutants, or contaminants remaining at
the Site at least every 5 years. The purpose of a Five-Year Review is to evaluate the
implementation and performance of a remedy to determine whether the remedy is and/ or will
continue to protect human health and the environment. Projects implemented with Clean Water
Act (CWA) or other authorities are outside the scope of this review.

USEPA has prepared this Five-Year Review Report pursuant to CERCLA Section 121 and the
National Oil and Hazardous Substances Contingency Plan (NCP). CERCLA Section 121 states:

If the President selects a remedial action that results in any hazardous substances,
pollutants, or contaminants remaining at the site, the President shall review such
remedial actions no less often than each five years after the initiation of such remedial
action to assure that human health and the environment are being protected by the
remedial action being implemented. In addition, if upon such review it is the judgment
of the President that action is appropriate at such site in accordance with section [104] or
[106], the President shall take or require such action. The President shall report the
Congress a list of facilities for which such review is required, the results of all such
reviews, and any actions taken as a result of such reviews.

USEPA interpreted this requirement further in the NCP (40 Code of Federal Regulations [CFR]
Section 300.430(f)(4)(ii)), which states:

If a remedial action is selected that results in hazardous substances, pollutants, or
contaminants remaining at the site above levels that allow for unlimited use and
unrestricted exposure, the lead agency shall review such action no less often than every
five years after the initiation of the selected remedial action.

Because some of the remedies selected at the Bunker Hill Superfund Site resulted in hazardous
substances remaining onsite above levels that allow for unlimited use and unrestricted
exposure, Five-Year Reviews of the Site must be completed to meet the above statutory
requirements.

This Five-Year Review Report documents the methods, findings, and conclusions of the fourth
(2015) Site-wide review of the Bunker Hill Superfund Site remedies and identifies issues found
during the review and recommendations to address them. The text and Five-Year Review
Summary Form in the Executive Summary provide an overview of the entire Five-Year Review
Report. This section provides an overview of the Five-Year Review process and the relevant
guidance and decision documents that were used in preparing this report.

1-1

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

The remainder of the report is organized as follows:

•	Section 2: Site Background and Site-wide Considerations

•	Section 3: Review of Selected Remedies for Operable Unit 1

•	Section 4: Review of Selected Remedies for Operable Unit 2

•	Section 5: Review of Selected Remedies for Operable Unit 3

•	Section 6: Statement of Protectiveness

•	Section 7: Next Five-Year Review

•	Section 8: References

•	Appendix A: Coeur d'Alene Lake Management Plan

1.1	Five-Year Review Process Overview

This 2015 Five-Year Review was conducted by the USEPA Region 10 Bunker Hill/Coeur
d'Alene team and their contractor, CH2M HILL; the Idaho Department of Environmental
Quality (IDEQ) and their contractor, TerraGraphics; and the Coeur d'Alene Work Trust and
their contractor, Maul Foster Alongi. Sections of this report were contributed by the Panhandle
Health District (PHD), Coeur d'Alene Tribe, U.S. Fish and Wildlife Service (USFWS), U.S.
Geological Survey (USGS), and U.S. Bureau of Land Management (BLM). The review was
conducted and the report prepared in accordance with USEPA Comprehensive Five-Year Review
Guidance (USEPA Guidance; USEPA, 2001a) and Site-specific conditions at the Bunker Hill
Superfund Site.

1.2	Community

During the Five-Year Review process, USEPA provided an opportunity for community
members and other interested parties to offer their input. In November 2014, USEPA initially
notified the public that we were performing a site-wide Five-Year Review, and invited people to
share information and ideas about the site that might assist with the review. USEPA notified the
public using local newspaper advertisements, the USEPA Region 10 website1, and the Coeur
d'Alene Basin Facebook page2. Additionally, USEPA sent direct notice by email to over
3,000 addresses. USEPA presented information on the review to a number of organizations,
including the Coeur d'Alene Basin Environmental Improvement Project Commission (BEIPC),
BEIPC's Technical Leadership Group, and BEIPC's Citizens Coordinating Council.

Under USEPA's Five-Year Review Guidance, a public review of the draft report is not required.
USEPA requested public input on any issues that should be included in the 2015 Five-Year
Review. We did not receive input.

1	The USEPA Region 10 Website: http://go. usa.gov/39vTA

2	The Coeur d'Alene Basin Facebook page: www.facebook.com/cdabasin

1-2

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

1.3 Relevant Guidance and Decision Documents

1.3.1 Guidance and Decision Documents

USEPA Guidance (USEPA, 2001a) was used to prepare this Five-Year Review Report. The key
USEPA decision documents relevant to the Site's Selected Remedies include the three Site
Records of Decision (RODs) and the remedy change documents that were prepared as remedy
has been implemented. Under CERCLA, as amended, remedy changes are required to be
formally documented either in an amendment to the ROD or in an Explanation of Significant
Difference (ESD). USEPA decision documents that define the selected remedies for the Site are
as follows:

• Record of Decision, Bunker Hill Mining and Metallurgical Complex, Residential Soils (OU 1),
Shoshone County, Idaho, August 1991 (USEPA, 1991).

• Record of Decision, Bunker Hill Mining and Metallurgical Complex, Non-Populated Areas,
Shoshone County, Idaho, September 1992. This document selected remedial actions for OU 2
(USEPA, 1992).

• Amendment to the Record of Decision for the Bunker Hill Mining and Metallurgical Complex (Non-
Populated Areas) Superfund Site, September 3,1996. This OU 2 document updates the remedy
for Principal Threat Materials (PTMs) from stabilization to containment to promote remedy
cost-effectiveness (USEPA, 1996a).

• Explanation of Significant Differences for Revised Remedial Actions at the Bunker Hill Superfund
Site, Shoshone County, Idaho. There were two separate ESD documents, published in January
1996 and April 1998, which recorded the revisions to 19 separate remedial actions in OU 2.
The revisions were implemented to ensure that the overall OU 2 remedy maximizes the
benefit to the environment, is cost-effective, and responds to community concerns while
maintaining or increasing the level of human health and environmental protection (USEPA,
1996b and 1998a).

• Record of Decision Amendment: Bunker Hill Mining and Metallurgical Complex Acid Mine
Drainage, Smelterville, Idaho, December 2001 (USEPA, 2001b). This document selected
remedial actions for OU 2.

• Record of Decision, Bunker Hill Mining and Metallurgical Complex, Operable Unit 3 (Coeur
d'Alene Basin), Shoshone County, Idaho, September 2002 (USEPA, 2002a).

• Interim Record of Decision Amendment, Upper Basin of the Coeur d'Alene River, Bunker Hill
Mining and Metallurgical Complex Superfund Site, August 2012 (USEPA, 2012a). This
document selected remedial actions for OU 1, OU 2, and OU 3.

1.3.2 Obtaining Decision Documents and Final Five-Year Review Report

The remedy decision documents listed in Section 1.3.1 and this final version of the 2015 Five-
Year Review Report can be obtained via the following:

• Visiting the USEPA Region 10 website3 for an electronic version of this final report

• Calling USEPA at 1-800-424-4372, extension 8561

^ http://vosemite.epa.aov/r10/cleanup.nsf/bh/five+vear+reviews

1-3

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

• Visiting one of the Site's seven information

USEPA Seattle Office
Superfund Records Center
1200 Sixth Avenue
Seattle, WA 98101
206-553-4494 or 800-424-4372

Kellogg Public Library
16 West Market Avenue
Kellogg, ID 83827
208-786-7231

St. Maries Library
822 W. College Avenue
St. Maries, Idaho 83861
208-245-3732

Coeur d'Alene Field Office, USEPA
1910 Northwest Boulevard, Suite 208
Coeur d'Alene, ID 83814
208-664-4588

Wallace Public Library
415 River Street
Wallace, ID 83873
208-752-4571

Molstead Library (North Idaho College)
Library

1000 Garden Avenue
Coeur d'Alene, ID 83814
208-769-3355

Spokane Public Library

906 West Main Avenue

Spokane, WA 99201-0976

509-444-5336 (reference desk; ask for Dana

Dalrymple)

1-4

-------
2 Site Background

This section provides background information on the Bunker Hill Superfund Site, organized in
the following subsections:

• 2.1, Site Location, Description, and Characteristics

• 2.2, Site History

• 2.3, Source and Nature of Contamination

• 2.4, Applicable or Relevant and Appropriate Requirements (ARARs)

• 2.5, Basin Environmental Monitoring Plan (BEMP)

2.1 Site Location, Description, and Characteristics

The Bunker Hill Superfund Site was listed on the National Priorities List (NPL) in 1983. This
NPL Site has been assigned Comprehensive Environmental Response, Compensation, and
Liability Information System (CERCLIS) identification number IDD048340921. The Site includes
mining-contaminated areas in the Coeur d'Alene River corridor, adjacent floodplains,
downstream water bodies, tributaries, and fill areas, as well as the 21-square-mile Bunker Hill
"Box" located in the area surrounding the historic smelting operations.

The USEPA has designated three OUs for the Site:

• The populated areas of the Bunker Hill Box (OU 1)

• The nonpopulated areas of the Box (OU 2)

• Mining-related contamination in the broader Coeur d'Alene Basin (the "Basin" or OU 3)

Figure 2-1 is a location map of the Bunker Hill Superfund Site. Detailed descriptions of the
physical and cultural settings of the Site can be found in the Site RODs (USEPA, 1991,1992, and
2002a). The general characteristics of each OU are summarized in the following subsections.

2.1.1 Operable Unit 1

OU 1 is located within the 21-square-mile area surrounding the former smelter complex,
commonly referred to as the Bunker Hill Box. The Box is located in a steep mountain valley in
Shoshone County, Idaho, east of the city of Coeur d'Alene. Interstate 90 (1-90) bisects the Box
and parallels the South Fork of the Coeur d'Alene River (SFCDR).

OU 1 is often referred to as the populated areas of the Bunker Hill Box, and is home to more
than 7,000 people in the Cities of Kellogg, Wardner, Smelterville, and Pinehurst, as well as the
unincorporated communities of Page, Ross Ranch, Elizabeth Park, and Montgomery Gulch. The
populated areas include residential and commercial properties, street rights-of-way (ROWs),
and public use areas. Most of the residential neighborhoods and the former smelter complex are
located on the valley floor, side gulches, or adjacent hillside areas. Cleanup activities first began
in OU 1, because this area was of the greatest concern for human health exposure from mine
waste. Current land use in OU 1 is primarily residential and commercial properties. Future land
use is expected to be similar to the current land use.

2-1

-------
Stevens County

Pend Oreille
County

Bonner County

Spokane
Indian
Reservation

Kootenai County

POST
FALLS

Upper Basin,
Coeur d'Alene River,
North Fork

SPOKANE

DiSHMAN OPPORTUNITY

Coeuf
d'Aleoe



/ -Upper Basin,
Coeur d'Alene River,
South Forkx

Spokane County

Lower Basin,
Coeur d'Alene River

Shoshone County

Benewah County

Coeur d'Alene

Indian
Reservation

Whitman County

Colville
Indian
Reservation

Lake

Pend

eng OreiHe Rivg

ID

Oreille

Sanders
County

Lincoln County

Base Map Data: NHDPIus (Hydrography, 2005)
ESRI (Roads, Jurisdictional Boundaries, 2006).

City

The Bunker Hill Box:

Operable Units 1 (Populated
Areas) and 2 (Non-Populated Areas)

Coeur d'Alene River
~ Subbasin Boundary

Tribal Land

Notes:

1.	The geographic extent of the Bunker Hill Mining
and Metallurgical Complex Superfund Site is defined
by Operable Units 1, 2, and 3.

2.	OU3 consists of mining-contaminated areas in the
Coeur d'Alene River Corridor outside of OU1 and OU2,
primarily adjacent floodplains, downstream water
bodies, tributaries) including Coeur d'Alene Lake and
the Spokane River), and fill areas.

0 3.75 7.5

15 Miles

\\CASTAIC\PROJ\EPA\CDABASI N 3S2081\(

Figure 2-1

Location Map: Bunker Hill Mining
and Metallurgical Complex
Superfund Site

2015 Five-Year Review
BUNKER HILL SUPERFUND SITE

	c/EPA

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

2.1.2 Operable Unit 2

OU 2 includes areas of the Bunker Hill Box that were nonpopulated and nonresidential at the
time the 1992 ROD was completed. These areas include the former industrial complex and Mine
Operations Area (MOA) in Kellogg, Smelterville Flats (the floodplain of the SFCDR in the
western half of OU 2), hillsides, various creeks and gulches, the Central Impoundment Area
(CIA), and the Bunker Hill Mine and associated acid mine drainage (AMD). The SFCDR within
OU 2 and the nonpopulated areas of the Pine Creek drainage are both addressed as part of
OU 3.

Current land uses in OU 2 have changed over time and now include open space, recreational,
residential (single and multi-family), and commercial uses. Future land uses may include light
industrial.

2.1.3 Operable Unit 3

OU 3 consists of the mining-contaminated areas in the Coeur d'Alene Basin outside of OU 1 and
OU 2, primarily the floodplain and river corridor of the Coeur d'Alene River (including Coeur
d'Alene Lake) and the Spokane River, as well as areas where mine wastes have come to be
located as a result of their use for road building or for fill and construction of residential or
commercial properties. Spillage from railroad operations also contributed to contamination
across the Basin.

Current land uses in OU 3 are a mix of residential, commercial, agricultural, and open space.
Future land use is expected to be similar to the current land use.

2.2 Site History

More detailed information through 2010 for this section is in the third Five-Year Review1
(USEPA, 2010c). The Bunker Hill Superfund Site is within one of the largest historical mining
districts in the world. Commercial mining for lead, zinc, silver, and other metals began in the
Silver Valley in 1883. Heavy metals contamination in soil, sediment, surface water, and
groundwater from over 100 years of commercial mining, milling, smelting, and associated
modes of transportation has impacted both human health and environmental resources in many
areas throughout the Site. Smelter operations ceased in 1981, but limited mining and milling
operations continued onsite from 1988 to 1991, and several mining operations continue today.

After listing on the NPL in 1983, USEPA published the first Site ROD in August 1991, providing
the selected remedy for OU 1 residential soils (USEPA, 1991). The second Site ROD was
published by USEPA in September 1992, addressing contamination in the nonpopulated OU 2,
as well those aspects of OU 1 that were not addressed in the 1991 OU 1 ROD (USEPA, 1992). A
number of remedy changes and clarifications have been documented in several OU 2 ROD
amendments and two ESDs. USEPA issued an interim OU 3 ROD to clean up mining
contamination in 2002 (USEPA, 2002a). USEPA issued an interim ROD Amendment for the
Upper Basin including portions of OU 1, OU 2, and the eastern portion of OU 3 (USEPA, 2012).

1 The third Five-Year review is available online at: http://ao.usa.aov/39vTA.

2-3

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Since the last Five-Year Review, the Upper Basin Proposed Plan (USEPA, 2010a) and Draft Final
FFS Report (USEPA, 2010b) were published. After an extended public comment period in 2010,
the Preferred Alternative identified in the Proposed Plan was revised. The revisions were
documented in the Final FFS Report, which was completed in late summer 2012 (the 2012 FFS;
USEPA, 2012b). The 2012 Final FFS presents and evaluates alternatives for cleanup of the Upper
Basin portion of the Site. Responses to all comments received during the extended public
comment period were summarized in the Responsiveness Summary and published as part of
the 2012 Upper Basin ROD Amendment (USEPA, 2012a).

The Upper Basin is mostly located in Shoshone County, Idaho, and contains OUs 1 and 2 (the
Bunker Hill Box) and the eastern portion of OU 3. The Selected Remedy in the 2012 Upper Basin
ROD Amendment is an interim remedy. A final remedy will be selected in the future as
additional knowledge is gained about conditions at specific locations within the Upper Basin
and the effectiveness of remedial actions. The Selected Remedy for the Upper Basin builds upon
the remedies identified in the previous RODs for OUs 1, 2, and 3 and incorporates additional
information obtained since the ROD for OU 3 was issued in 2002. The Selected Remedy is
designed to provide significant improvements to soil, sediments, surface water, and
groundwater and to greatly reduce the risks posed to human health and the environment
within the Upper Basin. Although the Lower Basin is not included in the Selected Remedy for
the Upper Basin, actions in the Upper Basin are expected to improve water quality and reduce
the movement of contaminated sediments downstream in the Lower Basin.

A diverse group of governments, Tribes, and agencies, including the State of Idaho, the Coeur
d'Alene Tribe, the Spokane Tribe, the State of Washington, and federal Natural Resource
Trustees, gave support for the 2012 Upper Basin ROD Amendment.

The technical scope of the Upper Basin Selected Remedy addresses contaminant sources (such
as mine tailings, waste rock, adit drainage, and contaminated floodplain sediments), surface
water quality in the SFCDR and its tributaries, and existing human health remedies that are
potentially vulnerable to erosion and recontamination from stormwater runoff, tributary
flooding, and high-precipitation events in the Upper Basin. Major components of the remedial
actions within the Bunker Hill Box (OU 1 and OU 2) and OU 3 are presented in Sections 3, 4,
and 5, respectively.

The significant differences for each OU between the existing selected remedies and the Upper
Basin Selected Remedy are as follows:

•	OU 1 — The existing Selected Remedy for OU 1 (USEPA, 1991), which focused on protecting
human health, was certified complete in 2008. The Upper Basin Selected Remedy
supplements the existing Selected Remedy for OU 1 by including localized drainage
improvement actions that will protect those portions of the existing remedy that are in areas
at risk from localized tributary flooding and heavy precipitation.

•	OU 2—The existing Selected Remedy for OU 2 (USEPA, 1992) identified OU 2 Phase I
source control actions that have largely been completed. Implementation of the portions of
the existing Selected Remedy for OU 2 focusing on protecting human health is also largely
complete. The Upper Basin Selected Remedy supplements the existing Selected Remedy for
OU 2 by including localized drainage improvement actions that will protect those portions
of the existing remedy that are in areas of risk from localized tributary flooding and heavy

2-4

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

precipitation. The Upper Basin Selected Remedy defines Phase II cleanup actions originally
identified in the 2002 ROD to address ongoing water quality issues in OU 2. These actions
include managing the contaminated discharge from the Reed and Russell Adits, reducing
the flow of contaminated groundwater to the SFCDR, and collecting and treating
contaminated groundwater.

•	OU 3—Implementation of the existing Selected Human Health Remedy for OU 3 is ongoing
and will be completed in accordance with previous decision documents. The 2012 Upper
Basin Selected Remedy supplements the 2002 Selected Human Health Remedy for OU 3 by
including actions that will protect the existing remedy. Relatively few elements of the
existing Selected (interim) Ecological Remedy for OU 3 have been implemented. The Upper
Basin Selected Remedy replaces the Upper Basin portion of the interim ecological actions
selected in the ROD for OU 3 (USEPA, 2002a).

The Selected (interim) Remedy will take significant steps towards achieving the remedial action

objectives (RAOs) for the Upper Basin. The Upper Basin Selected Remedy RAOs for human

health include the following:

•	Soil, sediments, and source materials — Reduce human exposure to soil, sediments, and
source materials, including residential yard soil, that have concentrations of chemicals of
concern (COCs) greater than selected risk-based levels for soil.

•	Surface water— Restore surface water designated as beneficial use for drinking water to
meet drinking water and water quality standards; prevent ingestion of surface water used
as drinking water and containing COCs exceeding drinking water standards and associated
risk-based levels for drinking water; and prevent discharge of seeps, springs, and leachate
that would cause surface water to exceed drinking water and water quality standards.

•	Aquatic food Sources — Prevent human exposure to unacceptable levels of COCs via
ingestion of aquatic food sources (e.g., fish and water potatoes).

The Upper Basin Selected Remedy RAOs for ecological receptors include the following:

•	Ecosystem physical structure and function—Reduce COCs in soil, sediments, and surface
water to support a functional ecosystem for aquatic and terrestrial plant and animal
populations (including, but not limited to, waterfowl, riparian songbirds, and other species
protected under the Endangered Species Act, the Fish and Wildlife Conservation Act, and
the Migratory Bird Treaty Act) in the Upper Basin.

•	Soil, sediments, and source materials — Reduce risks from COCs in soil, sediments, and
source materials to acceptable exposure levels that protect ecological receptors and reduce
transport and deposition into surface water and groundwater of COCs from soil, sediments,
and source materials at concentrations above levels that protect ecological receptors.

•	Surface water— Reduce risks from COCs in surface water in the Upper Basin to acceptable
exposure levels that protect ecological receptors.

•	Mine water, including adits, seeps, springs, and leachate — Reduce discharge to surface
water of mine water, including adits, seeps, springs and leachate, containing COCs at
concentrations that cause surface water to exceed levels that protect ecological receptors.

2-5

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

• Groundwater: Reduce discharge to surface water of groundwater containing COCs at
concentrations that cause surface water to exceed levels that protect ecological receptors.

Following are some of the subtle differences between the RAOs developed for the Selected
Remedy for the Upper Basin and the RAOs identified in the RODs for OUs 1, 2, and 3 and the
ROD Amendments for OU 2:

• Site-specific ambient water quality criteria (AWQC) — Updated AWQC cleanup levels
resulted from Site-specific research in the SFCDR conducted by the State of Idaho after the
ROD for OU 3 was issued in 2002. This led to substantially higher AWQC for the SFCDR
than are applied elsewhere in Idaho for lead and zinc. For each of these metals, AWQC are
calculated as a function of hardness. The equations used to calculate the State of Idaho
AWQC and the SFCDR-specific AWQC are different: the SFCDR-specific AWQC equation
yields higher values for a given hardness.

• Lead cleanup level for songbirds —A lead cleanup level that specifically protects songbirds
was not included in the 2002 ROD for OU 3 due to lack of Site-specific data. Since that time,
additional data have been collected to support identifying a Site-specific lead cleanup level
for songbirds of 530 milligrams per kilograms (mg/kg) in soil and sediments in the Upper
Basin.

An adaptive management process and implementation approach will be used to implement the
Selected Remedy. Through the adaptive management process, the remedial actions will be
adjusted as needed to maintain efficient progress towards meeting RAOs.

In December 2009, as part of the American Smelting and Refining Company, LLC (ASARCO)
bankruptcy settlement, funding was secured for Superfund response actions at the Site.
However, due to a prior settlement with ASARCO for response actions in the Bunker Hill Box,
most of the settlement monies, about $486 million, can only be used to perform USEPA-selected
cleanup actions in mining-contaminated areas of OU 3, outside the Bunker Hill Box (OUs 1
and 2). These funds were placed in a trust, and a trustee was appointed to manage and invest
the funds. The balance of funds in the Trust as of September 2015 is approximately $490 million.
From the bankruptcy settlement, USEPA was reimbursed $8 million for human health
protection actions that the agency had completed in the Bunker Hill Box from 2002 to 2005. The
$8 million is available for additional cleanup work in the Box.

2.2.1 Operable Unit 1 History

Information for this section is in the third Five-Year Review (USEPA, 2010c).

2-6

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

2.2.2	Operable Unit 2 History

Information for this section is in the third Five-Year Review (USEPA, 2010c).

2.2.3	Operable Unit 3 History

Information for this section is in the third Five-Year Review (USEPA, 2010c).

2.3 Source and Nature of Contamination

2.3.1	Source of Contamination

Metals related to mining, milling, and smelting activities are present throughout the Site in soil,
sediment, surface water, and groundwater. The most significant contaminants are antimony,
arsenic, cadmium, copper, lead, mercury, and zinc. The principal sources of metal
contamination were tailings generated from the milling of ore and discharged to the SFCDR
and its tributaries or confined in large waste piles onsite, waste rock, and air emissions from
OU 2 smelter operations. Spillage from railroads and other modes of transportation also
contributed to contamination across the Site.

Tailings were also transported downstream, particularly during high-flow events, and
deposited as lenses of tailings or as tailings/sediment mixtures in the bed, banks, floodplains,
and lateral lakes of the Coeur d'Alene River Basin and in Coeur d'Alene Lake. Some fine-
grained material washed through the lake and was deposited as sediment within the Spokane
River flood channel. The estimated total mass and extent of impacted materials (primarily
sediments) exceeds 100 million tons dispersed over thousands of acres (USEPA, 2001d).

Section 2.3.2 describes the nature and extent of contamination in the three OUs. For additional
quantitative data on levels of contamination found during the remedial investigations, see the
applicable OU RODs and previous Five-Year Review Reports.

2.3.2	Nature and Extent of Contamination
2.3.2.1 Contamination Affecting Primarily Human Health

Following are the primary media of concern for human health in all three OUs:

•	Contaminated soil where it occurs in residential yards, ROWs, commercial and
undeveloped properties, and common areas, and airborne dust generated at these locations

•	Contaminated house dust, originating primarily from contaminated soil (the OU 3 ROD also
identified interior house paint as a potential source of lead)

•	Drinking water from local wells or surface water

•	Contaminated floodplain soil, sediments, and vegetation

2-7

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

People can be exposed to COCs by ingesting soil, breathing dust, drinking water, and eating
contaminated fish or homegrown vegetables. The COCs for protecting human health are as
follows:

• Lead and arsenic in soil and sediment

• Lead in house dust

• Arsenic, lead, and cadmium in drinking water from unregulated sources

Although fish and vegetables were not screened for COCs, indicator metals were selected for
these based on toxicity and presence in the basin. The selected indicator metals for fish
consumption were cadmium, lead, and mercury, and for vegetable consumption were arsenic,
cadmium, and lead.

2.3.2.2 Contamination Affecting Primarily Ecological Receptors

Contaminated media that potentially affect ecological receptors are surface water, soil, and
sediment. In addition, groundwater is important as a pathway for migration of metals to surface
water. The ecological COCs for ecological protection are as follows:

• Cadmium, copper, lead, and zinc in surface water

• Arsenic, cadmium, copper, lead, and zinc in soil

• Arsenic, cadmium, copper, lead, mercury, silver, and zinc in sediment

Cadmium, lead, and zinc are pervasive in all environmental media and generally present higher
risks to ecological receptors than arsenic, copper, mercury, and silver.

2.3.2.3 Contamination in Specific Areas of the Site

The following subsections describe the nature and extent of contamination for both human
health and ecological receptors for specific areas of the Site.

The Box (Operable Units 1 and 2)

The main source of contamination in the Box includes jig tailings, flotation tailings, inflow of
contaminants from upstream sources, air emissions from ore processing facilities, particulate
dispersion from ore stockpiles, and residuals from the industrial complex. Spillage from
railroads and other modes of transportation also contributed to contamination across the Site.
Additional sources included gypsum generated from phosphoric acid production and zinc
fuming, and AMD emanating from the Bunker Hill Mine.

Jig and flotation tailings were generated as waste products during concentration of mined ores.
Jig tailings were generated by earlier mine concentrating techniques and were typically
dumped on the valley floor. During flood events, these tailings were transported by the SFCDR,
mixed with alluvium, and deposited on the flood plain. Over time, the valley floor throughout
and downstream of OU 2 became mantled with a mixture of jig tailings, flotation tailings, and
alluvium as floods occurred and as the SFCDR naturally meandered across the valley floor.

Flotation tailings, which were generated by an improvement to ore concentration methods that
came into predominant use in 1930, were typically discharged to the CIA and Page Pond
tailings impoundments. The flotation tailings were identified during the RI/FS as an important
source of airborne contamination, as well as a source of contamination to groundwater and
surface water.

2-8

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Air emissions occurred from ore processing facilities. Although both the lead smelter and Zinc
Plant in Kellogg had recycling processes designed to minimize airborne particulates, significant
metals deposition still occurred together with deposition of sulfur dioxide emissions. In the
1960s, lead emissions from the two lead smelter stacks averaged from 10 to 15 tons per month.
After a September 1973 fire in the baghouse of the main stack, particulate emissions containing
50 to 70 percent lead increased to about 25 tons to over 140 tons per month (USEPA, 1986).
Emissions affected areas near the smelter and zinc plant as well as the surrounding hillsides.

Materials and residues from the smelter complex included ores, concentrates, sinter and calcine,
copper dross flue dust, lead residues, slag, gypsum, and other materials and wastes. These
materials were stored, transported, and occasionally spilled in various areas around the Box.
Gypsum was generated during production of phosphoric acid, and slag was produced by
fuming processes aimed at converting zinc sulfide to zinc oxide. For the most part, these
materials were either concentrated in ponds or deposited in the CIA. AMD from the Bunker Hill
Mine was impounded at the CIA without treatment until 1974, after which the CTP was
constructed and became operational. From 1974 until 1996, AMD continued to be pumped to an
unlined holding pond on top of the CIA prior to treatment.

Upper Coeur d'Alene Basin outside the Box (Operable Unit 3)

The Upper Basin encompasses the steep mountain canyons of the SFCDR and its tributaries.
OU 3 encompasses those Upper Basin areas outside of the Box.

The Upper Coeur d'Alene Basin contains many primary sources for mining-related hazardous
substances (metals), including mine workings, waste rock and other mining waste, mine
tailings, concentrates and other process wastes, artificial fill (tailings and waste rock in roads,
railroads, and building foundations), and other locations. Based on mapping conducted by the
BLM (BLM, 1999), approximately 2,850 acres of land have been disturbed by mining-related
activities or deposition of mining-related wastes in the Upper Basin (not including areas within
OU 1 and OU 2). Approximately 295 acres of disturbed area were identified by the BLM as
riparian. Approximately 1,200 acres of other impacted floodplain areas were identified by the
BLM. As a consequence of the historical mining operations, heavy metals contamination is
present in soils, sediment, surface water, and groundwater.

As discussed more fully in the OU 3 RI, the Upper Basin is a primary source of dissolved metals
in the river system (USEPA, 2001d). Impacted sediments and associated groundwater in the
valley fill aquifers of the Upper Basin are the largest sources of dissolved metals loading in the
river and streams. An estimated 71 percent of the load is derived from impacted sediments and
associated groundwater. Surface water and groundwater percolates through the tailings-
impacted sediments and dissolves metals. The water discharges into the streams and rivers,
carrying the dissolved metal load with it. Metal loading is enhanced by the relatively large
degree of surface water/groundwater interaction that occurs in some parts of the Upper Basin.
In areas where the valley floor widens, streams lose water to the valley fill aquifer. In areas
where the valley floor constricts, groundwater discharges back into the streams, carrying
additional metals load.

An estimated 7 million cubic yards (cy) of tailings-impacted sediments are present in the Upper
Basin, including an estimated 3 million cy of sediments that potentially cannot be accessed for
excavation because they are beneath the 1-90 embankment, other roads, or residential or
commercial structures. In addition to the estimated 7 million cy of sediments, analysis of deeper

2-9

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

sediment samples indicates metals concentrations generally exceed background concentrations
to depths of 10 to 30 feet. These deeper sediments are potentially an important secondary source
of metals. Relatively little of the dissolved metals in the river system comes from discrete
sources. Discrete sources include National Pollutant Discharge Elimination System (NPDES)-
permitted discharges and unpermitted discrete discharges (adit and seep discharges). The
estimated loads from the discrete discharges account for only about 8 percent of the estimated
dissolved zinc load in the SFCDR at Pinehurst located at the western end of OU 2.

Lower Coeur d'Alene Basin (Operable Unit 3)

The Lower Basin extends along the 37 mile length of the mainstem Coeur d'Alene River,
including the lateral lakes (or "chain lakes") area, and extensive surrounding floodplain
wetlands. Flows in the river range from a few hundred cubic feet per second (cfs) in fall to flood
stage flows of approximately 20,000 cfs and greater. Water surface elevations in the Lower Basin
are often influenced by the level of Coeur d'Alene Lake. Backwater from the lake, during both
summer months and during periodic flooding in winter and spring, extends nearly 30 miles up
the river to the river grade break near Cataldo.

Large portions of the mine tailings released in the Upper Basin, into the South Fork and its
tributaries, were transported to and deposited within the river channel and floodplains in the
Lower Basin, especially during flood events. Erosion and resuspension of contaminated
sediment from the river bed is the major current source of mobile metals, approximately
80 percent of the lead load at Harrison is mobilized from the river bed. Inflow from the Upper
Basin and erosion of contaminated sediment deposits in river banks contribute relatively small
portions of the total lead load at Harrison (about 10 percent each) (CH2M HILL, 2014b).
Investigations conducted in the since 2008 have allowed USEPA to improve on previous
estimates of the amount of contaminated sediment in the river bed, and are generally
constrained to a range between about 6 and 11 million cy (CH2M HILL, 2014c). Surface
concentrations of lead in the river bed average between about 1,500 and 3,000 mg/kg, while
underlying layers contain concentrations more typically three to five times higher but have been
measured as high as 70,000 mg/kg (CH2M HILL, 2014b). The depth of contaminated sediment
is variable, ranging from zero (where native river bed is exposed) to more than 15 feet
(CH2M HILL, 2014b). The average concentration of lead in over 2,000 nonrandom sediment
samples within the floodplain collected in the Lower Basin is 3,100 mg/kg (USEPA, 2001d).

The Lower Basin is currently net erosional for both sediment and lead - that is, more sediment
and lead leave the basin than enter it. On average, over the past 25 years, approximately two
times as much sediment and seven times as much lead has discharged from the Coeur d'Alene
River at its mouth (near Harrison) than entered it (at Cataldo); the Lower Basin has averaged
about 34.2 metric tons per year of lead inflow, with approximately 250 metric tons per year of
outflow.

Lower Basin wetlands and lateral lake sediments are significant points of exposure of waterfowl
and other animals to contaminated sediment. An estimated 18,300 acres, or 95 percent, of
floodplain surficial sediments contain more than 530 mg/kg of lead (the lowest observed
adverse effects level for waterfowl), and 80 percent of floodplain sediments contain more than
1,800 mg/kg of lead (the mortality threshold concentration for waterfowl) (USEPA, 2001d).

Detailed discussion and information pertaining to the nature and extent of contamination and
fate and transport of contaminants in the Lower Basin is documented in the Enhanced

2-10

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Conceptual Site Model (CH2M HILL, 2010). As discussed in Section 2.5.1, surface water quality
at 18 streamflow-gaging and water-quality sampling sites in the Coeur d'Alene and Spokane
River Basins are monitored and evaluated by the USGS.

Coeur d'Alene Lake (Operable Unit 3)

Coeur d'Alene Lake is a natural lake, but Post Falls Dam controls its elevation. Coeur d'Alene
Lake encompasses 49.8 square miles at its normal full-pool elevation (2,128 feet above mean sea
level), with a maximum water depth of 209 feet. The 2,128-foot above elevation is the level
defined by Avista's Federal Energy Regulatory Commission license as the maximum permitted
lake level. The lake has a drainage area of 3,741 square miles. Its principal tributaries are the
St. Joe and Coeur d'Alene Rivers. The discharge from the lake forms the Spokane River.

The beaches and wading areas adjacent to Coeur d'Alene Lake were sampled in 1998, and
concentrations of metals did not exceed risk-based levels for recreation (USEPA, 2002a). The
only exceptions are Harrison Beach, which was remediated as part of the UPRR ROW removal
action, and Blackwell Island near the mouth of the Spokane River which only exceeded
background values for arsenic. No mining contamination has been found in the residential and
commercial areas in the cities of Coeur d'Alene, Post Falls, or Harrison.

According to the OU 3 ROD (USEPA, 2002a), the water in Coeur d'Alene Lake meets the safe
drinking water standards for metals, except when discharge from the Coeur d'Alene River is
high (e.g., during high spring runoff or during flood events), which causes short-term lead
concentrations that exceed the drinking water standard. The water in the lake exceeds the water
quality standards for protection of aquatic life for cadmium and zinc and intermittently for lead.

The 2001 Human Health Risk Assessment for the Coeur d'Alene Basin indicated that more
information was needed about fish in Lake Coeur d'Alene (TerraGraphics, 2001); the Coeur
d'Alene Tribe and a collaborative interagency team agreed. As a result, these groups
cooperatively conducted a study to determine the contaminant levels in fish from Lake Coeur
d'Alene. The Agency for Toxic Substances and Disease Registry (ATSDR) and the Idaho
Department of Health and Welfare, Idaho Division of Health (IDOH) were asked to review the
data from this study (USEPA, 2002b) and evaluate the potential health risks for tribal and
recreational fishers that may result from consumption of three fish species found in Lake Coeur
d'Alene.2

Based upon this evaluation, Idaho and the Coeur d'Alene Tribe jointly issued a fish
consumption advisory in June 2003. The advisory was issued because study results detected
lead, mercury, and arsenic at levels that may affect some people's health if they eat more fish
than recommended. The advisory also noted that by following the consumption limits in the
advisory, the public can continue to enjoy the health benefits from a diet that includes fish
caught from Coeur d'Alene Lake. The advisory is posted at boat launches and other locations
on Coeur d'Alene Lake. Information about the specifics of the fish advisory is available on the
IDHW web page3.

A large volume of metals-impacted sediment has been deposited in Coeur d'Alene Lake. There
are an estimated 44 to 50 million cy of contaminated sediments at the bottom of the lake
(USEPA, 2001d). Surface water and suspended sediment sampling indicate that trace metals

2 This study can be accessed at http://www.atsdr.cdc.aov/HAC/pha/pha.asp?docid=1045&pq=1#purp

3 The IDHW web page: http://healthandwelfare.idaho.gov

2-11

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

continue to be delivered to the lake. Studies by the USGS suggest that, under current lake
conditions, there is some movement of the metals from the sediment into the water column;
however, concurrent releases of dissolved iron facilitate formation of iron-metal complexes in
the lake's lower water column. The rate of release of metals in the sediments into the water
column could increase if nutrient enrichment causes decreases in near-bottom dissolved-oxygen
and pH as a consequence of enhanced biological activity. The lake's geochemical and biological
responses to future remediation activities will be influenced by reductions in zinc's suppressive
effects on biological productivity. Concomitant reductions in nutrient inputs, particularly
phosphorus, may be needed to counteract reductions in zinc concentrations. Limnological data
collection and modeling are underway to provide lake managers with knowledge of the
interaction of metal contamination and nutrient enrichment in the lake.

Spokane River (Operable Unit 3)

The Spokane River flows from Coeur d'Alene Lake and is dammed at six locations above its
terminus at Lake Roosevelt. The riverbed primarily consists of coarse gravel and cobbles, and
the floodplain and riparian areas are relatively narrow. Metals contamination is present in
depositional areas within the river's floodway and behind the Upriver Dam.

The beaches and wading areas adjacent to the Idaho portion of the Spokane River were sampled
in 1998 and were found to be safe for human health (i.e., concentrations of metals did not
exceed risk-based levels for recreation). Sediment depositional areas in the state of Washington
portion of the Spokane River were sampled in 1998,1999, 2000, and 2004. Several depositional
areas were found to contain lead at concentrations exceeding the risk-based levels. The water in
the Spokane River meets the safe drinking water standards for metals.

In the Spokane River sediment samples, 82 percent of the samples contained lead above the
upper background concentration. The average concentration of lead was 400 mg/kg in
265 sediment samples collected in the Spokane River floodway between Coeur d'Alene Lake
and Long Lake. The sediment lead cleanup level for the Washington recreational areas along
the Spokane River is 700 mg/kg for recreational use (USEPA, 2002a). The sediment arsenic
cleanup level as selected by USEPA is 20 mg/kg for recreational use.

Because there are relatively few depositional areas along the Spokane River, the volume of
contaminated sediments is small compared with the Upper and Lower Basins. An estimated
volume of 260,000 cy of contaminated sediments are present upstream from Upriver Dam.

Additional contaminated sediments are present downstream from Upriver Dam but have not
been quantified. Surface water in the Spokane River has been affected by metals including
particulate lead transported into the Spokane River, particularly during winter storm events
and spring runoff.

2.4 Applicable or Relevant and Appropriate Requirements

This section provides a review of the ARARs and presents the revised and new standards that
have been evaluated since the last Five-Year Review.

2-12

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

2.4.1 Operable Unit 1

ARARs and to be considered (TBC) items from the 1991 OU 1 and the 1992 OU 2 RODs were
reviewed as part of the 2000, 2005, and 2010 Five-Year Reviews. The 2000 Five-Year Review
(USEPA, 2000a) identified changes or newly promulgated standards related to air and blood
lead level goals. However, the modifications were found not to affect the protectiveness of the
remedy selected in the 1991 and 1992 RODs. Since that time, promulgated standards affecting
the protectiveness of the OU 1 human health remedy have remained unchanged.

2.4.2 Operable Unit 2

The remedies selected in RODs, ROD Amendments, and ESDs are intended to protect human
health and the environment and to comply with federal and state standards that are ARARs.

As part of the 2000, 2005, and 2010 Five-Year Reviews, the ARARs and TBC guidance identified
in the 1992 OU 2 ROD were reviewed, and any new or revised standards were identified and
summarized within those OU 2 Five-Year Review Reports. Based upon these reviews, USEPA
determined that the 1992 ARARs and TBCs still protected the remedies for OU 2 (USEPA,
2000b, 2005, 2010c).

With this 2015 Five-Year Review, the 1992 OU 2 ROD ARARs and TBCs were again reviewed,
as well as those in the 2001 OU 2 ROD Amendment and the 2012 Upper Basin ROD
Amendment. Standards were not revised or promulgated since the last Five-Year Review. As
with the earlier reviews, USEPA has determined that the OU 2 ARARs and TBCs are still
protective.

2.4.3 Operable Unit 3

The federal, state, and Tribal requirements that are applicable or relevant and appropriate to the
scope of the remedial action selected in the 2002 OU 3 ROD are included in Section 13.2
(Compliance with Applicable or Relevant and Appropriate Requirements) of the 2002 OU 3 ROD.
The ARARs, guidance, and other documents TBC were reviewed.

Additionally, USEPA reviewed the federal, state, and Tribal requirements that are applicable or
relevant and appropriate to the scope of the remedial action selected in the 2012 Upper Basin
ROD Amendment. These requirements are included in Section 13.2 (Compliance with Applicable
or Relevant and Appropriate Requirements) of the 2012 Upper Basin ROD Amendment, which
describes the federal and state ARARs and other available information that does not constitute
an ARAR (e.g., advisories, criteria, guidance, and TBC criteria that are useful in selecting,
designing, and implementing the remedy). Tables 13-1 through 13-3 in the 2012 Upper Basin
ROD Amendment present the ARARs and TBCs for the Upper Basin OU 3 Selected Remedy
along with summaries of each ARAR and an evaluation of how the ARAR applies to the
Selected Remedy.

A lead cleanup level that specifically protects riparian songbirds was not included in the 2002
OU 3 ROD due to lack of Site-specific data. Since that time, a riparian songbird study was
conducted by the USFWS (Hansen, 2007), and a Focused Ecological Risk Assessment was
prepared (CH2M HILL, 2006). Given the absence of promulgated criteria for metals in soil and
sediments, and using the results from these studies with other relevant information, USEPA has
made a risk-management-based determination to use a Site-specific protective value of
530 mg/kg for lead in soil and sediments, to protect riparian songbirds in the Coeur d'Alene

2-13

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Basin (see Attachment 4-1 in the 2012 FFS for details). This has resulted in an RAO and site-
specific ecological risk lead cleanup level in the 2012 ROD Amendment of 530 mg/kg.

Standards were not revised or promulgated since the last Five-Year Review. As The ARARs
identified in the 2002 OU 3 ROD and subsequent changes identified in the Five-Year Review
Report (USEPA, 2010c), and the ARARs identified in the 2012 Upper Basin ROD Amendment
continue to be protective.

2.5 Basin Environmental Monitoring Plan

In March 2004, USEPA released the Basin Environmental Monitoring Plan (BEMP), which
implements the environmental monitoring program established as part of the ecological
component of the OU 3 Selected Remedy. The BEMP established a monitoring plan for surface
water, suspended and depositional sediment, and biological resources. Refer to the BEMP for
further information on development, goals, and objectives (USEPA, 2004).

In 2006, the Environmental Monitoring Program (EMP) was developed to guide the collection,
analysis, and interpretation of water quality and biological resources data to assess the
effectiveness of the Phase I remedy for OU 2 based on the goals and objectives identified in the
1992 ROD (USEPA, 1992), ROD Amendments (USEPA, 1996a and 2001b), and explanations of
significant differences (ESDs) (USEPA, 1996b and 1998a). The EMP established a monitoring
plan for surface water, groundwater, suspended and depositional sediment, and biological
resources. Refer to the EMP for further information on development, goals, and objectives
(USEPA, 2006).

At the time of this Five-Year Review, USEPA is working to update and consolidate the BEMP
and EMP to create one consolidated environmental monitoring program for OU 2 and OU 3 of
the Bunker Hill Superfund Site.

2.5.1 Surface Water—Operable Unit 3
2.5.1.1 Monitoring Activities

The USGS has been collecting surface water data as part of the BEMP since 2004. In 2014, USGS
published Sources, Transport, and Trends for Selected Trace Metals and Nutrients in the Coeur d'Alene
and Spokane River Basins, Northern Idaho, 1990-2013 (Clark and Mebane, 2014). This report
contains an evaluation of the status and trends in surface water for the Five-Year Review.
Information from the report is summarized as follows.

Data collected at 18 streamflow-gaging and water-quality sampling sites in the Coeur d'Alene
and Spokane River Basins of northern Idaho (excluding Lake Coeur d'Alene) were used to
estimate mean streamflow-weighted concentrations and annual loads of total and dissolved
cadmium, lead, and zinc, and total phosphorus and nitrogen for water years (WYs) 2009-13.
Chronic AWQC and AWQC ratios also were calculated to evaluate Idaho aquatic life criteria for
chronic exposure to cadmium and zinc in streams. AWQC ratios for cadmium and zinc for WYs
2009-2013 are presented in Figure 2-2. At four sites with a longer period of record (Enaville,
Pinehurst, Harrison, and Postfalls), a Seasonal Kendall trend test was used to assess historical
trends in the concentrations of total cadmium, lead, and zinc, and chronic AWQC ratios for
cadmium and zinc during WYs 1990-2013 and to understand the variability with time.

2-14

-------
<
<> ^ ^ <$ <$?
& / # <$>

rs/././/////

V///A////

/ <*f c# a
$? ^

<$s
<£•

vo>~ <^ <^ ^
^ ,<^ ,<^

^ 45?

<>
>£

£r

«£ c<^' J?~ >"

^ # # 0- ^

#//

<^>

rX> &
-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

2.5.1.2 Key Findings

The results indicate that, during WYs 2009-13, cadmium and zinc entering Coeur d'Alene Lake
and transported downstream in the Spokane River were derived primarily from mining-
affected tributaries to the SFCDR and from groundwater discharge to the SFCDR near the CIA.
Cadmium and zinc were transported in streams predominantly in the dissolved phase (less
than 0.45 micrometer), and at most sites, concentrations were inversely correlated with
streamflow and varied widely over the range of streamflows sampled. In contrast to cadmium
and zinc, lead was transported in streams primarily in the particulate form, and total lead
concentrations were positively correlated with streamflow. Transport of lead occurred primarily
during high streamflow when lead-rich sediments stored in stream channels and the flood plain
of the Coeur d'Alene River are eroded, transported, and redistributed downstream. Control of
the transport of contaminated sediment as well as dissolved metals in surface water through the
Coeur d'Alene and Spokane River Basins is a key factor for ensuring the long-term effectiveness
of remedial activities in the SFCDR and Coeur d'Alene River.

Trace metal concentrations increased by 2 to 4 orders of magnitude along the SFCDR from near
Mullan (upstream from historic mining) downstream to near Pinehurst. Mean streamflow-
weighted concentrations of total cadmium, lead, and zinc in the SFCDR near Pinehurst for WYs
2009-13 were 3.71, 61.4, and 514 micrograms per liter (|ig/L), respectively. Major tributary
sources of trace metals to the SFCDR are Canyon Creek and Ninemile Creek. Combined, these
two tributaries contributed estimated mean loads of about 0.575 tons per year (ton/ yr) of total
cadmium, 5.29 ton/yr of total lead, and 90.9 ton/yr of total zinc to the SFCDR during WYs
2009-13. Bunker Creek, Government Gulch, and groundwater discharge near the CIA between
Kellogg and Smelterville were other major sources of cadmium and zinc to the SFCDR,
contributing an estimated 1.39 and 143 ton/yr, respectively, during WYs 2009-13.

Although concentrations of cadmium, lead, and zinc in streams throughout the Coeur d'Alene
and Spokane River Basins have shown significant decreases since the early 1990s in response to
remedial activities, the rate of decrease has slowed since 2003, especially downstream of the
CIA. Additionally, significant decreases in dissolved cadmium and zinc concentrations in the
lower SFCDR and Coeur d'Alene River would require reducing the load of these trace metals
being discharged to the SFCDR from groundwater near the CIA. The loading estimates from
this study provide a valuable baseline for evaluating the efficacy of future remedial activities
designed to reduce cadmium and zinc loading from groundwater to discrete reaches of the
SFCDR. These loading estimates also provide a baseline for evaluating the efficacy of current
and future remedial activities in the Canyon and Ninemile Creek tributaries to the SFCDR.

A large part of the trace-metal load entering Coeur d'Alene Lake from the Coeur d'Alene and
St. Joe Rivers is retained in the lake, most likely in sediments on the lake bottom. On an annual
mean basis, Coeur d'Alene Lake received nearly 1,100 tons of cadmium, lead, and zinc
combined, about 99 percent of which was delivered from the Coeur d'Alene River. Of the total
trace-metal load entering the lake, about one-third, or about 370 ton/yr, were transported from
the lake and into the Spokane River. The mean streamflow-weighted concentrations of total
cadmium, lead, and zinc in the Spokane River near Post Falls (site 18) were 0.231, 2.91, and
48.9 (ig/L, respectively, substantially smaller than the concentrations entering the lake from the
Coeur d'Alene River. About 1.48 tons of total cadmium, 18 tons of total lead, and 350 tons of
total zinc exited Coeur d'Alene Lake and entered the Spokane River annually during
WYs 2009-13.

2-16

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

2.5.1.3 Progress toward Remedial Action Objectives

Because they account for toxicity effects on aquatic organisms, AWQC ratios are important
benchmarks for establishing the effectiveness of remedial activities in the Coeur d'Alene and
Spokane River Basins. Although long-term monitoring sites in the sampling network have
shown great improvement in the chronic AWQC for cadmium and zinc since the early 1990s,
the chronic AWQC was achieved only at sites on the North Fork of the Coeur d'Alene River
(NFCDR) at Enaville, the SFCDR near Mullan, and the St. Joe River near St. Maries. Chronic
AWQC ratios at both sites on the Spokane River generally were close to achieving benchmark
values. Sites the farthest from achieving the chronic AWQC criteria were located on Canyon
Creek, the East Fork of Ninemile Creek, and Ninemile Creek. The downstream site on the East
Fork of Ninemile Creek had mean streamflow-weighted AWQC ratios for cadmium and zinc of
64 and 51, respectively, more than twice the ratio of any other site in the sampling network.

Trend results indicate that remedial efforts in the SFCDR valley and its tributaries since the
early 1990s have been successful in reducing concentrations of trace metals in the SFCDR, Coeur
d'Alene River, and Spokane River. By significantly reducing sources of dissolved metals to the
SFCDR river system, this will effectively reduce surface water concentrations in the lateral lakes
due to the hydraulic connectivity between these systems. Statistically significant downward
trends were noted during WYs 1990-2013 for all constituents evaluated in the SFCDR at
Elizabeth Park and the SFCDR near Pinehurst, in the Coeur d'Alene River near Harrison, and
for total lead and total zinc in the Spokane River near Post Falls. During WYs 2003-13, the
SFCDR at Elizabeth Park continued to indicate significant downward trends in total cadmium
and zinc concentrations and their AWQC ratios. Of the other three long-term sites, only the
Spokane River near Post Falls showed significant trends during WYs 2003-13: a downward
trend in total zinc concentration and an upward trend in the chronic AWQC ratio for dissolved
cadmium. Further significant reductions in cadmium and zinc concentrations in the Spokane
and Coeur d'Alene River Basins likely would necessitate reducing loads entering the SFCDR
from cadmium- and zinc-enriched groundwater near the CIA.

Load models developed in this study are a valuable tool for estimating streamflow-weighted
concentrations and loads of trace metals and nutrients in the Coeur d'Alene and Spokane River
Basins. As additional data are collected, they can be integrated into the existing models to
improve the understanding of how trace metals and nutrients are transported and deposited
throughout the basins. Future data-collection activities should continue to target the
hydrograph to incorporate data from a variety of streamflow conditions necessary for model
development. Additionally, continued sampling at sites such as the SFCDR near Elizabeth Park,
the SFCDR near Pinehurst, the Coeur d'Alene River near Harrison, and the Spokane River near
Post Falls would provide data for evaluating trends and assessing the efficacy of remediation
activities designed to reduce trace-metal loading to streams in the Coeur d'Alene and Spokane
River Basins.

2.5.1.4 Program Updates

In 2014, changes were made to the surface water monitoring program (USEPA 2015a). This
includes the addition of a surface water sampling location at Rose Lake. Surface water will be a
key indicator of both short and long-term remedy effectiveness for current and future remedial
actions including work in East Fork Ninemile (EFNM) Creek and the CIA GWCS. USEPA is
preparing remedial action effectiveness plans for EFNM Creek and the GWCS. The plans will

2-17

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

identify monitoring objectives for estimating dissolved metal loads to EFNM Creek and the
SFCDR, respectively, determining remedy performance and effectiveness, and evaluating long-
term response to the remedial actions.

At this time, USEPA is not proposing any additional changes to surface water sampling
(location and frequency). USEPA will continue to work with USGS to determine the most
representative locations for remedy short- and long-term effectiveness monitoring, define the
surface water baseline dataset, and refine both remedy effectiveness and long-term monitoring
objectives. In future publications, USEPA will be reporting progress achieved toward both acute
and chronic metals AWQC.

2.5.2 Surface Water—Operable Unit 2

2.5.2.1 Monitoring Activities

Surface water quality monitoring activities within OU 2 apply to the tributaries of the SFCDR
within the Box. The SFCDR as it passes through the Box is included in OU 3 and is discussed
above. Until recently, OU 2 monitoring goals have focused on evaluating the tributaries with
respect to compliance with AWQC, potential impacts to SFCDR from these tributaries, and
evaluating the cumulative effect of Phase I remedial actions. A statistical summary of
monitoring results for cadmium, lead and zinc collected from selected tributaries during the
five-year period (2009 to 2013) is presented in Table 2-1.

2.5.2.2 Key Findings

During the period from 2009 to 2013, median dissolved cadmium and zinc concentrations
continue to exceed the AWQC at all monitoring stations, with the exception of Grouse and Pine
Creeks where zinc concentrations fall below the AWQC. Mean streamflow-weighted
concentrations and load estimates require streamflow information that is not collected at these
stations. However, Table 2-1 indicates that the largest source of cadmium and zinc to the
SFCDR in the reach between Kellogg and Smelterville is represented by the seeps north of the
CIA (BH-CS-0001). These seeps most likely reflect groundwater concentrations at the interface
with the SFCDR. Of the remaining stations, Milo Creek, Bunker Creek, and Government Gulch
contribute the most cadmium and zinc. Milo Creek is the largest source of lead. A Mann-
Kendall trend test was performed on all stations with at least 15 data points between 2002 and
2014. All stations show a significant decreasing trend for cadmium, lead, and zinc with the
notable exception that the seeps north of the CIA show an increasing trend for cadmium.

2.5.2.3 Progress Toward Remedial Action Objectives

Decreasing concentration trends at most OU 2 monitoring stations indicate that progress is
being made toward RAOs. Increased concentrations at the seeps north of the CIA will be
addressed by the groundwater collection and treatment system scheduled for construction in
2016.

2-18

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TABLE 2-1

Statistical Summary for Selected Constituents in Water Samples Collected from 15 OU2 Surface Water Stations, 2009-13
2015 Five-Year Review, Bunker Hill Superfund Site

OU2 Station Name

OU2 Station
Number

Statistic

Dissolved
Cadmium (ug/L)

Total
Cadmium
(ug/L)

Dissolved Lead
(ug/L)

Total Lead
(ug/L)

Dissolved Zinc
(ug/L)

Total Zinc
(ug/L)

AWQC*
0.62 (ug/L)

AWQC*
14.7 (ug/L)

AWQC*
123 (ug/L)

Milo Creek Outfall at
SFCDR at Kellogg, ID

BH-MC-0002

Number

Minimum

1.0

160

Maximum

9.7

9.9

150

270

3,600

3,500

Median

2.4

110

630

190

Bunker Hill Mine Yard
Seep East Pipe at
Kellogg, ID

BH-MY-0001

Number

Minimum

1.0

1.1

1.9

5.1

140

150

Maximum

4.3

4.2

730

720

Median

2.1

2.2

3.8

340

Portal Gulch Drainage
West Pipe at Kellogg,
ID

BH-PG-0001

Number

Minimum

1.9

2.0

9.8

7.1

140

Maximum

3,900

3,500

Median

2.6

2.7

180

190

Railroad Gulch above
McKinley Avenue at
Kellogg, ID

BH-RR-0001

Number

Minimum

1.0

5.1

560

580

Maximum

5.2

800

870

Median

1.2

760

780

2-19

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TABLE 2-1

Statistical Summary for Selected Constituents in Water Samples Collected from 15 OU2 Surface Water Stations, 2009-13
2015 Five-Year Review, Bunker Hill Superfund Site

OU2 Station Name

OU2 Station
Number

Statistic

Dissolved
Cadmium (ug/L)

Total
Cadmium
(ug/L)

Dissolved Lead
(ug/L)

Total Lead
(ug/L)

Dissolved Zinc
(ug/L)

Total Zinc
(ug/L)

AWQC*
0.62 (ug/L)

AWQC*
14.7 (ug/L)

AWQC*
123 (ug/L)

Deadwood Gulch
Creek at Kellogg, ID

BH-DW-0001

Number

Minimum

1.1

1.3

1.5

1.7

180

Maximum

2.9

390

400

Median

1.7

1.8

3.4

8.6

270

Magnet Gulch Creek
at Tailings Pond at
Kellogg, ID

BH-MG-0001

Number

Minimum

0.61

0.81

720

710

Maximum

4.4

1,900

Median

1.4

2.1

1,400

1,500

Bunker Creek at
Mouth of Culvert at
Kellogg, ID

BH-BC-0001

Number

Minimum

8.6

9.0

0.20

0.69

600

Maximum

4.4

6.6

2,400

Median

1.0

2.2

1,300

Seeps North of
Deadwood Gulch
Tailings at Kellogg, ID

BH-CS-0001
and 0002

Number

Minimum

0.23

0.27

11,000

9,800

Maximum

230

250

1.0

5.9

25,000

27,000

Median

130

160

1.0

17,000

2-20

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TABLE 2-1

Statistical Summary for Selected Constituents in Water Samples Collected from 15 OU2 Surface Water Stations, 2009-13
2015 Five-Year Review, Bunker Hill Superfund Site

OU2 Station Name

OU2 Station
Number

Statistic

Dissolved
Cadmium (ng/L)

Total
Cadmium
(ng/L)

Dissolved Lead
(ng/L)

Total Lead
(ng/L)

Dissolved Zinc
(ng/L)

Total Zinc
(ng/L)

AWQC*
0.62 (ng/L)

AWQC*
14.7 (ng/L)

AWQC*
123 (ng/L)

Government Gulch
Creek below Plant
near Smelterville, ID

BH-GG-0008

Number

Minimum

9.9

1.3

2.7

450

470

Maximum

6.0

3,000

2,600

Median

2.7

5.8

1,700

1,800

Government Gulch
Creek at SFCDR, ID

BH-GG-0004

Number

Minimum

1.4

2.5

490

520

Maximum

7.8

3,300

2,900

Median

2.3

5.1

1,700

1,600

Government Gulch
Creek near Mouth at
Smelterville, ID

BH-GG-0001

Number

Minimum

0.50

1.3

490

550

Maximum

6.6

2,000

2,300

Median

1,300

1,400

Grouse Creek at
Smelterville, ID

BH-GC-0001

Number

Minimum

0.21

0.32

0.07

4.4

Maximum

0.50

0.53

5.0

5.8

Median

0.36

0.42

2.5

5.1

2-21

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TABLE 2-1

Statistical Summary for Selected Constituents in Water Samples Collected from 15 OU2 Surface Water Stations, 2009-13
2015 Five-Year Review, Bunker Hill Superfund Site

OU2 Station Name

OU2 Station
Number

Statistic

Dissolved
Cadmium (ng/L)

Total
Cadmium
(M9/L)

Dissolved Lead
(Mg/L)

Total Lead
(ng/L)

Dissolved Zinc
(Mg/L)

Total Zinc
(Mg/L)

AWQC*
0.62 (ng/L)

AWQC*
14.7 (Mg/L)

AWQC*
123 (ng/L)

Humboldt Creek
above Lagoon near
Smelterville, ID

BH-HC-0001

Number

Minimum

2.4

1.0

0.52

1.8

570

580

Maximum

4.5

4.3

4.1

100

1,000

1,100

Median

3.0

3.2

2.4

710

750

West Page Swamp
Outfall at Pinehurst,
ID

BH-WP-0001

Number

Minimum

0.12

0.45

2.4

9.0

220

280

Maximum

1.0

1.4

8.1

700

770

Median

1.0

3.9

570

660

Pine Creek at SFCDR
near Pinehurst, ID

BH-PC-0001

Number

Minimum

0.09

0.17

0.46

Maximum

1.0

6.1

130

160

Median

1.0

* SFCDR-specific chronic AWQC, as specified in ADAPA 58.01.02.284, which is a function of hardness and calculated at a hardness of 50 mg/L as calcium
carbonate (CaCC>3).

2-22

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

2.5.2.4 Program Updates

As part of the BEMP optimization, each OU 2 surface water station was evaluated. Starting in
2015, monitoring has been discontinued pending further data analysis at those Phase I remedy
locations where the data indicate decreasing or no trend over time. The program was also
streamlined to discontinue monitoring if a station was redundant with other monitoring
programs (i.e., Page Repository and A-4 Gypsum Pond) or if there was insufficient flow during
the base flow sampling event. Monitoring two times per year was retained at the north CIA
seeps and at three stations (Milo Creek Outfall, Bunker Creek near the mouth, and Government
Gulch near the mouth). These stations measure the more significant contributions of metals to
the SFCDR and some will monitor Phase II remedy effectiveness of the groundwater collection
and treatment system. The frequency and location of OU 2 surface water sampling will be
adaptively managed throughout implementation of the Phase II remedy.

2.5.3 Sediment
2.5.3.1 Monitoring Activities

Focused sediment sampling under the BEMP began in 2008 for filling data gaps in the Lower
Basin Enhanced Conceptual Site Model (ECSM). The ECSM provided the data needed for
developing hydraulic and sediment transport models. Sampling has included high-volume
suspended sediment sampling to allow measurement of particle size distribution and metals
content by size fraction at 12 locations in the Upper and Lower Basins (including key
tributaries). Sampling has also included collection of depositional sediment for similar data at
22 locations, including 16 locations within or near the river channel, and 6 locations in wetlands
or lateral lakes.

It should be noted that the surface water sampling described in Section 2.5.1 included collection
and analysis of suspended sediment, providing data on suspended sediment concentration and
the concentration of metals in the sediment. The sampling and data described in this section
also include suspended sediment concentration and bulk metals data from the high-volume
sampling, and data from both BEMP efforts (water quality and sediment) are combined and
used as an expanded dataset to support modeling efforts and the Lower Basin ECSM. However,
for consistency and comparability, the findings summarized here specifically address data
related to the high-volume suspended sampling.

Annual summary reports of the BEMP sediment data have been prepared for WYs 2011, 2012,
2013, and 2014; each is titled Water Year 201X BEMP Sediment Sampling Data Summary. These
reports contain data summaries from each water year as well as cumulative data for some
parameters (primarily lead concentrations). A more detailed summary of the sediment data
obtained during this period is presented in, Five-Year Data Summary, BEMP Sediment Monitoring
Program, Water Years 2010-2014 (CH2M HILL, 2015).

Suspended Sediment

High-volume suspended sediment samples were collected at seven locations in the Upper
Basin, including five locations on the SFCDR (Shoshone Park, Wallace, Elizabeth Park,
Smelterville, and Pinehurst), and the mouths of Canyon and Ninemile Creeks. Samples were
also collected at four locations in the Lower Basin, including the mouth of the Latour Creek, and
three locations on the Coeur d'Alene River (Cataldo, Rose Lake, and Harrison), as well as the
mouth of the NFCDR at Enaville. Samples were collected as close to peak flood flow conditions

2-23

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

as possible, targeting large (bank full or greater) winter floods and spring runoff. Sampling was
targeted to occur within 2 days, with more upstream sites generally conducted on the first day
to account for the delay of peak flow conditions in the Lower Basin.

Samples were filtered in the laboratory to obtain suspended sediment concentration, and sieved
to separate sediment into size classifications to obtain data on mass and metals by size class.
Metals analyses included arsenic, cadmium, copper, lead, mercury, silver, and zinc. Data were
reported for three size classes (bulk, fine sand, and silt/clay), with an additional size class break
between fine sand and very fine sand added for WY 2014. Data on river flow and current
velocity were obtained from USGS gages or, if none were present, velocity meters.

Data are used to assess temporal and spatial patterns of suspended sediment concentration and
metals, including metals by particle size class. Data are also used to calculate the amount of lead
and other metals being transported (known as flux, load, or discharge) and to assess data
variability as a function of flood magnitude (flow rate), as well as flood type. Winter floods,
flowing into relatively empty lakes, tend to have steeper gradient and higher velocities than
longer-lasting spring floods, during which lake levels are typically higher.

Depositional Sediment

Depositional samples were collected at 22 locations, with 5 sites in the Upper Basin and 17 in
the Lower Basin. Most samples were collected at locations in or near the channel banks, where
stakes were used to measure depths of deposition (or erosion), allowing collection of material
that had been deposited within that water year. All sampling locations in the Upper Basin, and
11 in the Lower Basin, were sampled in this manner. Samples were also collected at six off-
channel areas from horizontal "tiles" on which sediment was deposited during overbank
flooding.

All depositional samples were analyzed for particle grain size distribution, and metals (arsenic,
cadmium, copper, lead, mercury, silver, and zinc) in each size class (bulk, fine sand, and
silt/clay). An additional size class break between fine sand and very fine sand was added in
analyses for WY 2014.

2.5.3.2 Key Findings
Suspended Sediment

Samples collected at Harrison, where the Coeur d'Alene River discharges to Coeur d'Alene
Lake, showed the highest average suspended sediment concentration, lead concentrations (in
the mainstem) and lead flux (all by significant margins). These parameters generally increased
in the downstream direction below the confluence of the SFCDR and the NFCDR. Conditions at
Cataldo reflect the dilution of sediment from the SFCDR (averaging 2,225 mg/kg lead at
Pinehurst), with lower concentrations from the NFCDR (averaging 214 mg/kg at Enaville),
though flood flows in the NFCDR averaging 4 to 5 times those of the SFCDR. Lead
concentrations at Cataldo averaged 1,045 mg/kg, and increase downstream as more
contaminated sediment is re-suspended from historical deposits in the riverbed (and to a lesser
degree, river banks). As a result, the mean concentration of lead at Harrison (3,649 mg/kg) is
significantly higher than the mean concentration at Cataldo. The finer fractions of sediment
have higher concentrations of lead than bulk mixtures, with the fine-to-very-fine sand fraction
showing the highest concentrations at Cataldo and Rose Lake, and the silt/ clay fraction
showing the highest concentrations at Harrison. The proportion of suspended sediment load

2-24

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

represented by each size class is highly variable as a function of the variability of the flowrate
and flow gradient.

Lead flux (also known as load or discharge) is the product of lead concentration, suspended
sediment concentration, and flow, and provides an indication of the amount of lead being
transported at a given location. This parameter is important because while high concentrations
of lead or suspended sediment concentration in tributaries may be significant at specific
locations, the higher river flow rates below the confluence are able to convey much larger
masses of lead through and out of the Lower Basin. The highest average single-day flux during
the reporting period was 35.5 tons/day at Harrison, compared with 3.25 tons/day at Cataldo,
and 2.16 tons/ day at Pinehurst.

A number of factors contribute to data variability in suspended sediment data, including the
range of peak river flows, the location of sampling, the timing of sampling relative to peak flow,
the gradient of the river (influenced by levels of the receiving water in Coeur d'Alene Lake),
and inherent variability associated with sampling methods. Peak flows at Cataldo, for flood
events sampled during water years 2011-2014, ranged from 12,800 to 33,000 cfs (1- to 6-year
recurrence intervals, respectively). The correlation of suspended sediment concentration to flow
was highest at Cataldo (R2 = 0.85, where the riverbed includes armoring gravels and cobbles)
and lowest at Harrison (R2 = 0.0.54, in a sand bed section with variable flow gradients). No
temporal trend was apparent during the reporting period, as the number and range of other
variables affecting the dataset is large.

Depositional Sediment

Concentrations of lead in near-channel depositional samples generally follow a similar pattern
to that observed with suspended sediment. However, although concentrations in suspended
sediment generally increase in the downstream direction, lead concentrations in the
depositional dataset decrease at Harrison rather than increase as they do with the suspended
dataset. Average concentrations of lead in bulk depositional samples were 2,164 mg/kg near
the Cataldo dredge site, increased to about 4,000 mg/kg near Dudley, but dropped to
2,399 mg/kg near Harrison. The ecological risk cleanup level for lead in soil and sediments is
530 mg/kg. The decrease in lead in the bulk samples between Dudley and Harrison reflects a
higher proportion of sands (with lower concentrations of lead than the fine fraction) than
samples further upstream. The silt/clay fraction of depositional samples at Harrison ranged
between 4 and 17 percent of the sample mass, with lead concentrations averaging about
6,300 mg/kg, compared with 2,399 mg/kg for bulk samples; therefore, changes in particle size
distribution of deposited material (controlled by flow rates and flood type) can significantly
affect the bulk lead concentrations. Lead concentrations in depositional sediment at Harrison is
generally less variable than in suspended sediment from the same location, with depositional
sediment ranging between 2,030 and 3,650 mg/kg lead, compared with a range of 1,550 to
4,900 mg/kg for suspended sediment samples. The difference is assumed to reflect the higher
proportion of fines comprising the suspended load, relative to coarser material deposited
within the channel banks. The higher sand content deposited at Harrison may reflect the steeper
flow gradients at the mouth of the river, though the reason for this pattern is not yet known.

Concentrations of lead in off-channel areas, measured on tiles, ranged between 1,664 mg/kg at
Strobl Marsh to 4,614 mg/kg at Anderson Lake. Most of the sample material from off-channel
samples consists of silt and clay size fractions. The variability of conditions at these sampling

2-25

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

locations makes comparison among them difficult. A sediment transport model is being
developed to assist in evaluating sediment deposition patterns in the floodplain.

The thickness of deposited sediment was measured at sampling sites. While the primary
purpose of these measurements was to ensure that samples were collected from depth intervals
reflecting sediment from that water year, they also provide indications of relative rates of
deposition and erosion. The Harrison station had the highest rates of both deposition
(30 centimeters) and erosion (-13.2 centimeters), significantly higher than the range of all other
near-channel sites (18 to -10 centimeters). As noted previously, this may reflect higher current
velocities near Harrison during certain flood conditions. The deposition rates on tiles averaged
about 5 millimeters, ranging from 1 to 16.6 millimeters.

2.5.3.3 Progress toward Remedial Action Objectives

The number of variables affecting measurement of suspended and depositional sediment data,
as noted above, make identifying and evaluating trends in sediment transport and metals
concentrations difficult. Given the current understanding of the conceptual site model,
approximately 80 percent of the lead loading in the Lower Basin originates from erosion of
sediment from the riverbed; only 11 percent is attributed to inflow from the SFCDR. Remedial
actions in the Lower Basin riverbed are likely necessary before significant and measureable
reductions in lead concentrations and loading are observed in monitoring data.

2.5.3.4 Program Updates

Revisions were made to the BEMP sediment sampling program during the reporting period to
improve the resolution of data and the efficiency of the data collection program, as the need for
focused sediment sampling to address data gaps in the ECSM has decreased. Starting WY 2015,
high volume sediment sampling has been reduced to hydrograph events with flows exceeding
25,000 cfs at Cataldo. The USGS water quality monitoring program will continue to include
suspended sediment concentration and bulk metals sampling and will have an additional water
quality station at Rose Lake. Currently, USEPA is working to define the sediment baseline
dataset and monitoring objectives, and update data quality objectives.

2.5.4 Groundwater

The 1992 OU 2 ROD requires water quality monitoring to evaluate compliance with
groundwater ARARs (maximum contaminant levels [MCLs]) as well as potential impacts to
SFCDR water quality and to evaluate the performance of remedial actions. Since 2004, IDEQ has
administered groundwater monitoring in accordance with the OU 2 EMP. In 2014, optimization
of the groundwater monitoring program began in an effort to integrate groundwater
monitoring into the BEMP.

2.5.4.1 Monitoring Activities

The groundwater monitoring network stretches from the eastern OU 2 boundary, near
Elizabeth Park, to the western boundary near Pinehurst Narrows. Monitoring events take place
during the spring and fall of each year to collect data during high and low flow conditions.
During the spring of 2010 to 2014, samples were collected from 74 sites, which include a
combination of wells and piezometers. During the fall of 2010 to 2013, samples were collected
from 88 sites. Optimization efforts during the summer of 2014 reduced the fall 2014 sampling

2-26

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

event to 71 sites. During all events, field parameters were collected and samples underwent
laboratory analysis for a number of dissolved metals at all sites and total phosphorus at select
sites.

2.5.4.2 Key Findings

The OU 2 groundwater network is subdivided into decision units based on transects and areas
of past remedial actions. To assess groundwater conditions, statistical analysis was performed
for 61 sites using groundwater data for dissolved cadmium and zinc collected between October
2002 and October 2014. Results are summarized in the Operable Unit 2 Groundwater Annual Data
Summary Report for Calendar Year 2014 (IDEQ, 2015). This timeframe represents the post-Phase I
remedial action implementation period. For 36 of these 61 sites, previous statistical analysis of
OU 2 groundwater data was completed for October 2002 to October 2009, as summarized in
Statistical Analysis of Groundwater Monitoring Data for Operable Unit 2 (CH2M HILL, 2012a). The
purpose of this analysis is to establish baseline information for the optimization efforts and
continue to maintain long-term groundwater quality information.

Analyses included trends over time, median MCL ratios (to compare the median concentration
to the contaminant MCL), and interpretation of a current condition for each site based on the
trend and ratio. Current conditions include the following: Not Improving (no statistically
significant trend and ratio is greater than 1), Improving (decreasing trend and ratio is greater
than 1), Caution (increasing trend and any ratio), and Stable (no statistically significant trend or
decreasing trend and ratio less than or equal to 1). For sites with not improving or caution
conditions, the short-term goal is transition to an improving condition (a decreasing trend). The
target end goal for all sites is an improving or stable condition. The following discussion
describes the results across OU 2; however, this interpretation is limited based on the location
and number of sites included in this analysis.

2.5.4.3 Progress toward Remedial Action Objectives

Groundwater statistical results are summarized in Table 2-2. For comparison purposes, this
table only shows percentages using the 36 sites analyzed during both periods (2002 to 2009 and
2002 to 2014). Overall, 27 of the sites showed no change in trend between the two periods. The
percentage of sites showing improving conditions increased because trends in five sites for
cadmium and three sites for zinc changed from no statistically significant trend to a decreasing
trend. Decreasing or increasing trends are only included for sites with statistically significant
trends. The percentage of caution sites increased because three sites for both cadmium and zinc
changed from no trend to an increasing trend. Conditions across all of OU 2 are described as
follows.

TABLE 2-2

Summary of Groundwater Statistical Results
2015 Five-Year Review, Bunker Hill Superfund Site

Current Condition

Not Improving

Improving

Caution

Stable

Cadmium

2002-2009

25%

28%

14%

33%

2002-2014

14%

36%

22%

28%

Zinc

2002-2009

36%

19%

36%

2002-2014

31%

22%

14%

33%

2-27

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

For both periods, current conditions for both cadmium and zinc are stable in the one site
analyzed upgradient of OU 2 (Transect 1). This site represents background conditions for
groundwater flow entering OU 2. Within the easternmost portion of OU 2, a single unconfined
aquifer is present. Transition to an upper and lower aquifer occurs to the west and upgradient
of the CIA (upgradient of Transect 2). The upper, unconfined aquifer is associated with the
mainstem SFCDR valley and defined by the presence of the underlying fine-grained confining
unit. The lower, confined aquifer is associated with the mainstem SFCDR valley and defined by
the presence of the overlying confining unit.

Most of the sites included in this analysis (39 of 61 sites) are located near the CIA (Transect 2
to 3), downgradient of the CIA (Transect 3 to 5), near the Smelter Closure Area (SCA), and near
Transect 4. The highest median contaminant ratios compared to the MCL for cadmium in all of
OU 2 are located within this area, including peak ratios of 99.8 between Transects 2 to 3, 85.2
between Transects 3 to 5,192.0 for the SCA, 60.6 near Transect 4, and 896.0 in the upper part of
Government Creek. Zinc within this area also had the highest ratios for OU 2, including peak
ratios of 4.9 between Transects 2 to 3, 5.3 between Transects 3 to 5,1.7 for the SCA, 3.7 near
Transect 4 and 16.7 in the upper part of Government Creek. Over the last five years, most sites
have shown no change in condition or have changed to improving. Exceptions include a change
to caution for cadmium at three sites and zinc at two sites. In addition, one site changed to
stable for zinc. Construction and operation of the GWCS will target improving groundwater
conditions near and downgradient of the CIA. As for the vicinity of Transect 4, remedial actions
for Government Creek were previously determined to be of lower priority because actions in
this area would provide significantly less reduction in dissolved metals loading to surface water
when compared to remedial efforts in other areas of OU 2 and OU 3 (USEPA, 2013).

Throughout OU 2, several upland tributary groundwater systems, located in the gulches and
hillsides of the SFCDR valley floor, discharge directly to the single unconfined aquifer or upper
aquifer. Conditions associated with two tributaries to Bunker Creek, located south of the CIA,
show improving conditions for cadmium (Deadwood and Magnet Gulch), stable conditions for
zinc (Deadwood Gulch), and not improving conditions for zinc (Magnet Gulch) from 2002 to
2014; however, interpretation of these conditions are limited by only one site analyzed within
each of these gulches. Over the last 5 years, cadmium changed from not improving to
improving at the one site in Deadwood Gulch. No comparisons were made for Magnet Gulch.

From Smelterville Flats to downgradient of the Page Repository (Transect 5 to 6), upper aquifer
conditions were analyzed in seven sites from 2002 to 2014. Conditions for cadmium are not
improving in three sites, improving in three sites, and stable in one site with ratios ranging from
0.6 to 16.2. Conditions for zinc are not improving in two sites, improving in one site, and stable
in four sites with ratios ranging from 0.04 to 1.8. Over the last five years, cadmium changed
from improving to not improving at one site and zinc changed from improving to stable at one
site.

Confluence with the Pine Creek groundwater system is present in the westernmost section of
OU 2. Conditions above the confluence (Transect 6) are monitored in one upper and one lower
aquifer site. From 2002 to 2014, conditions are stable in both sites for cadmium and in the lower
site for zinc (ratios ranging from 0.1 to 0.5); while improving for zinc in the upper site (a ratio
of 1.1). Over the last five years, zinc at this upper site changed from not improving to
improving.

2-28

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Below the confluence, which represents groundwater flow exiting the OU 2 boundary
(Transect 7), conditions are monitored at two upper and two lower aquifer sites. From 2002 to
2014, conditions are stable in three sites for cadmium (one upper and two lower) and two sites
for zinc (one upper and one lower), with ratios ranging from 0.002 to 0.2. One upper site below
the confluence is improving for cadmium (a ratio of 1.1); while one upper and one lower site are
caution for zinc (ratios of 0.007). Over the last 5 years, one site changed from not improving to
improving for cadmium and one site changed from stable to caution for zinc.

2.5.4.4 Program Updates

As part of ongoing optimization efforts in 2014, USEPA reduced groundwater monitoring
frequencies to 27 sites during spring events, 59 sites during fall events, and 12 additional sites
on a 5-year basis during the fall event. In addition, the analyte list was reduced to include only
the contaminants identified in the 2012 ROD Amendment at all sites and total phosphorus at
select sites. Mercury will be analyzed on a 5-year timeframe. Presently, an OU 2 groundwater
quality assurance project plan is being prepared to integrate the optimized groundwater
monitoring program into the BEMP. USEPA is also preparing a GWCS remedial action
effectiveness plan, which will identify monitoring objectives for estimating dissolved metal
loads to the SFCDR, determining remedy performance and effectiveness, and evaluating long-
term response to the collection system operations. The GWCS remedial action effectiveness plan
will include a statistical analysis of data collected to date to establish baseline groundwater
concentrations. For sites where the baseline is established, monitoring will be discontinued until
after construction of the GWCS remedy. Post construction monitoring frequencies will be
determined based on the need for measuring remedial effectiveness and long-term monitoring
objectives.

2.5.5 Biological Resources
2.5.5.1 Monitoring Activities

Biological monitoring is being conducted by USFWS. USFWS monitored the following during
this Five-Year Review period:

• Lacustrine/Palustrine Habitat

- 2010-2014: Waterfowl- Population/ Swan Mortality

- 2013: Fish Exposure Bullhead- Liver Tissue Metals

- 2013: Waterfowl- Blood Lead

• Riparian Habitat

- 2010-2014: Songbirds

- 2011: Songbirds- Blood Lead

- Long-term and Pre-Remedial monitoring

• Upland Habitat

- 2014: Small Mammals

2-29

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

2.5.5.2 Key Findings

Lacustrine/Palustrine Habitat
Waterfowl Surveys/Tundra swan mortality

Annual spring waterfowl surveys from 2010 to 2014 increased the understanding of how
natural weather variability and associated hydrology affects waterfowl wetland use in the
Basin.

Water levels throughout the Basin are important for waterfowl feeding and determine food
accessibility during spring migration. During spring flooding events, waterfowl feeding habitat
becomes inundated with water, limiting access to food sources. During these times, waterfowl
are attracted to areas within the Basin where food is accessible and available. Understanding
when and where waterfowl feed throughout the Basin is important for developing strategies for
reducing waterfowl lead exposure and mortality during migration. High-waterfowl-use
wetlands continue to include lead-contaminated Canyon Marsh, Cave Lake, Lane Marsh, and
Harrison Slough; however, feeding areas shift within and among these wetlands depending on
water levels and subsequent accessibility of preferred food types. Understanding the annual
fluctuations among and within high-use feeding areas enables the USEPA and partners to
develop strategies to assist with the overall goal of providing clean feeding waterfowl habitat
and reducing exposure to lead.

Spring flood conditions in 2014 provided a clear example of how the Basin hydrology affects
wetland use for feeding waterfowl. The agriculture-to-wetland conversion project easement has
supported some of the highest overall waterfowl use and diversity from 2008-2013, although,
swan use was limited until 2014 (see section 5.2.7). In 2014, early spring flooding coincided with
an atypical shift in swan use from flooded Lane Marsh to clean feeding habitat provided at the
Agriculture-to-Wetland Conversion Project (Schlepp remedial action pilot project). Control of
water levels on the easement allow for creation of optimum feeding conditions in clean habitat.
Results from weekly 2014 waterfowl surveys not only documented water level management
and swan attraction techniques, but also captured how flooding is a useful strategy to deter
waterfowl use of contaminated wetlands. Annual waterfowl surveys allow USEPA to monitor
behavior and document shifts in use of specific wetlands and wetlands Basin-wide during
spring migration.

Waterfowl exposure and mortality will continue as long as there is continued exposure to lead-
contaminated sediment moving through the Basin and until sufficient clean feeding habitat is
provided. Additional clean habitat providing ample preferred food types for waterfowl is
essential to reducing lead exposure and mortality. Annual swan mortalities typically increase
when high-water transport of contaminated sediments onto the floodplain is followed by high
numbers of swans feeding in the Basin for an extended period. In further support of this trend,
only one dead swan was observed in 2014 when relatively fewer swans stopped to feed in the
Basin for only a few days. Feeding occurred in clean habitat provided by the Schlepp Project,
reducing lead exposure and mortality before continuing migration north.

Annual waterfowl surveys continue to provide information on the relationship between water
levels and preferred food sources for waterfowl throughout the Basin. Understanding the
annual and seasonal fluctuation of waterfowl use within the Basin, and within wetlands, is
imperative to successfully providing clean feeding habitat and reducing exposure. Additional
strategies under development using waterfowl survey data will inform the formation of

2-30

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

waterfowl attraction techniques (e.g., planting preferred food types) and areas where additional
clean feeding habitat can be established through remediation/restoration,
remediation/enhancement, or enhancement.

Fish Exposure

Biological resource monitoring within lacustrine and palustrine habitats in the Lower Basin has
not included monitoring fish exposure to contaminated sediments. This lack of information on
fish exposure was identified as a data gap for the BEMP and brown bullhead were sampled in
2013 by the USFWS to address this concern. Brown bullhead liver metals concentrations were
elevated throughout much of the study area indicating they are sensitive bioindicators of
widespread metals contamination within lacustrine and palustrine habitats. Bullhead liver lead
concentrations generally followed sediment lead concentration gradients, with the highest lead
concentrations found in livers from fish in the most contaminated lakes and wetlands (USFWS,
2015 in progress). Concentrations of arsenic, cadmium, and zinc co-varied with lead
concentrations. Strong correlations were evident for cadmium, but sediment concentrations for
these metals were lacking for a more complete analysis. The USFWS did not evaluate the
contribution of metals (arsenic, cadmium, lead, and zinc) from water and dietary pathways as
part of this study. It is unknown how much these pathways contributed to bioavailable metals
concentrations reported within bullhead liver tissues. However, bullhead liver metals
concentrations do reflect the integrated pathway exposure of bullhead to bioavailable metals
within lake and wetland habitats. Therefore, bullhead liver metals concentrations may be used
to determine if remedial actions are reducing bioavailable metals exposure to aquatic receptors.

Part of the selected remedy for OU 3 focuses on cleaning up sediments in the portions of the
lateral lakes where the water depth is 6 feet or less. These water depths represent the high-use
feeding areas for brown bullhead and other aquatic dependent species and, consequently, the
areas of greatest exposure. The brown bullhead has been identified by the USFWS as the best
aquatic indicator species for the ecological health of the lakes. Another interval of sampling is
recommended to augment this dataset, which will provide more certainty in evaluating future
reductions in metals exposure to aquatic receptors because of Basin-wide remedial activities.

Waterfowl Blood Lead

Blood lead concentrations in Basin waterfowl show continued exposure at concentrations that
may result in injury, including mortality, but datasets are limited in size and geographic scope.
Over the past two decades, blood lead concentrations have not declined within wetlands such
as Thompson Marsh where long-term datasets exist. However, comparable long-term datasets
are limited to Thompson Marsh, Campbell Marsh, and Schlepp's East Field. Based on these
data, waterfowl blood lead concentrations continue to exceed toxicity thresholds, resulting in
injury to migratory waterfowl at un-remediated sites. However, mean waterfowl blood lead
concentrations have decreased by 30 percent within the remediated Schlepp's East Field and
long-term data continue to demonstrate the efficacy of this pilot project in terms of reducing
lead exposure in waterfowl by providing clean feeding habitat within the Lower Basin.

Riparian Habitat

2010-2014 Songbird Surveys- Monitoring Avian Productivity and Survivorship

The 2010-2014 Monitoring Avian Productivity and Survivorship (MAPS) study was developed
to compare songbird use, productivity, and survivorship between Smelterville Flats in OU 2
and an uncontaminated reference site along NFCDR. This study was established to determine if
songbird lead exposure manifests into discernible population-level effects and to evaluate the

2-31

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

protectiveness of the selected remedy in OU 2. Adverse health effects are suspected to occur in
ground-feeding songbirds (e.g., song sparrows) on Smelterville Flats, as soil lead concentrations
remain above the cleanup level of 530 mg/kg level protective of ground-feeding species. A
variety of songbirds breeds in the post-remedial habitat at Smelterville Flats. However, yearly
songbird return rates, as well as song sparrow abundances, were lower at Smelterville Flats
than those observed at the reference site (USFWS, 2015 in progress), suggesting decreased rates
of survival and recruitment at Smelterville Flats. However, songbird return rates were relatively
low at both sites, and even under favorable conditions, only 30 percent of birds can be expected
to return and be recaptured using the MAPS protocol (Nur et al., 1999). Because estimates of
year-to-year survival are based on relatively few mark-recaptures and affected by many other
factors, the MAPS protocol does not appear to be the most efficient method of evaluating
songbird lead exposure and protectiveness of selected remedies under the BEMP.

2011: Songbirds- Blood Lead

Results of the 2011 blood collection demonstrated that representative songbirds using
contaminated riparian habitats in the Basin continue to be exposed to and accumulate lead at
concentrations above toxicological thresholds (USFWS, 2014). Songbird blood lead
concentrations in birds from the reference sites (North Fork and Little North Fork of the Coeur
d'Alene River) were low with mean lead concentrations at background levels. Of the three
songbird species targeted for blood collection (American robin, song sparrow, and Swainson's
thrush), the American robin sample size was too small for comparison and Swainson's thrush
had the lowest blood lead levels (background levels) across all sites, consistent with results
obtained by Hansen (2007). Song sparrows collected from Springston showed 20 percent of the
birds had blood lead levels in the sub-clinical range, as categorized by Fransen and Pain (2011).
Forty percent of Osburn song sparrows showed sub-clinical blood lead levels, 40 percent
clinical levels, and 20 percent severe clinical levels (USFWS, 2014). The three American Robins
sampled from Osburn had blood lead concentrations in the clinical toxicity category. Mean
blood lead concentrations of all songbirds were highest at Osburn, 3.3 mg/kg. Mean soil lead
concentrations at contaminated sites ranged from 339 to 1,260 mg/kg with the highest mean
concentrations at Osburn. Considerable variability in soil lead concentrations were observed
among net locations, particularly at Osburn, as shown by high standard deviations associated
with the means. Concentrations of songbird blood lead and corresponding soil lead
concentrations from net locations at contaminated sites were not significantly correlated (P =
0.44) (USFWS, 2014).

Based on the results of the 2011 blood collection and those by Hansen (2007), Swainson's thrush
may not be a suitable bioindicator for evaluating riparian exposure to metals of concern. This is
due primarily to feeding behavior at greater heights than American robin and song sparrow,
gleaning insects from foliage, capturing insects from the air, and foraging on berries (Mack and
Young, 2000; Hansen, 2007). As remedial actions are implemented and other factors such as
natural attenuation and habitat changes occur, songbird exposure to lead should be reduced.

Habitat Assessment

In 2014, the riparian vegetation monitoring study was incorporated into the aquatic habitat
assessment designed to include additional habitat measurements enhancing stream habitat
characterization. Riparian vegetation data was collected at locations where riverine habitat
assessments were conducted. Riparian habitat assessment included horizontal pattern, vertical

2-32

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

structure, and vegetation types within 30 meters of the water's edge. The assessment defined
habitat conditions known to effect quality of water and aquatic resources.

Previously, in 2006, the USFWS monitored riparian vegetation at four locations (Ninemile
Creek, Pine Creek, South Fork (Osburn), and Lower Basin [Springston]) to provide baseline
information that could be used to evaluate progress towards meeting ecological benchmarks of
the Selected Remedy. At that time, a larger-scale vegetation monitoring effort (e.g., using
geographic information system [GIS]) was identified to more effectively assess the long-term
status and trends of Basin-wide riparian health as it pertains to metals contamination. This
approach would require substantive effort, and is not as practical as monitoring floodplain soil
to evaluate reduced metals toxicity in riparian habitats. Therefore, in 2014, the decision was
made to conduct only riparian vegetation monitoring at aquatic habitat assessment locations
aiding in the evaluation of a more comprehensive riverine habitat assessment to determine its
capability of supporting a functional ecosystem.

Long-Term Monitoring

Aquatic habitat data at long-term monitoring locations were collected in 2013. In addition to the
SFCDR and tributary locations sampled in 2005 and 2006 a reference location was added on the
Little NFCDR. In 2013, the aquatic habitat assessment included riparian vegetation data
collection to enhance the evaluation of physical condition measures. Fish, benthic
macroinvertebrate (BMI), and periphyton diversity and abundance surveys were conducted.
BMI and periphyton samples were taxonomically sorted, identified, and metrics were
calculated. Fish and BMI samples were collected for tissue concentrations of lead, arsenic,
cadmium, and zinc. Aquatic habitat and indicator species data were collected in 2013 to meet
IDEQ's Beneficial Use Reconnaissance Program (BURP) requirements (IDEQ, 2012a). All
applicable data were entered into IDEQ's BURP database. The data are available for inclusion in
the statewide water quality program. Long-term aquatic data collection is considered early pre-
remedial data; it establishes baseline ecological conditions prior to future remedial actions in the
Basin.

Remedial Effectiveness Monitoring

Pre-remedial ecological resource monitoring was conducted during 2012 to 2014 in East Fork
Ninemile and Canyon Creeks. Monitoring locations are downstream of the primary loading
sources. Riverine habitat and aquatic resource data was collected at locations upstream of
identified clean-up sites to act as reference conditions for monitoring locations below areas
targeted for remediation. Post-remedial monitoring will evaluate ecological changes in
downstream monitoring locations of remedial activities as they compare to the reference
location.

Aquatic habitat assessment included riparian vegetation data collection to measure the physical
condition of designated reaches prior to remedial activities. Fish, BMI, and periphyton diversity
and abundance surveys were conducted to establish pre-remedial aquatic resource conditions.
Fish and BMI samples were collected and analyzed by USEPA's Manchester Environmental
Laboratory for tissue concentrations of lead, arsenic, cadmium, and zinc. As with long-term
monitoring, aquatic habitat and indicator species data were collected to meet IDEQ's BURP
requirements (IDEQ, 2012a). All applicable data were entered into IDEQ's BURP database. The
data are available for inclusion in the statewide water quality program.

2-33

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Habitat and indicator species pre-remedial data for East Fork Ninemile and Canyon Creeks
show decreasing ecological conditions at downstream locations as additional elevated
concentrations of metals enter the systems. East Fork Ninemile Creek habitat conditions are
good to fair at all monitoring locations. A total of 152 fish were sampled from the two upper
most (Reach 4 [reference site], Reach 3 [below IC Rock Dumps]) monitoring locations in 2012
and 2013, no fish were present within the two lower monitoring locations (Reach 2 [below
Success], Reach 1 [Ninemile Creek]). Two species of salmonids were identified consisting of
135 westslope cutthroat (88 percent), 17 brook trout (12 percent), and one unidentified
salmonid. Sculpin were not present within East Fork Ninemile Creek. Of the three reaches in
EFNM sampled for BMI tissue metals analysis, samples from Reach 2 contain the highest
concentrations of lead and zinc.

Habitat conditions are good in the uppermost reach of Canyon Creek, while three lower sample
reaches have poor habitat conditions. Of the 548 salmonids sampled in Canyon Creek during
2013 and 2014, no fish were captured in the lowest reach and 97 percent of the salmonids
sampled were from Reaches 4 (reference site) and 3 (below Burke). All 320 sculpin species
captured were in Reach 4. Only one brook trout was caught in Canyon Creek. BMI diversity
and abundance data shows Reach 3 and 4 in better overall condition than the lower two
reaches. The 2013 metals tissue data shows the highest concentrations of zinc and lead in BMI
collected from Reach 2 (below Gem).

Upland/Terrestrial Habitat
Small Mammals

USFWS analyzed livers of deer mice, shrews, and voles from upland and riparian areas within
Smelterville Flats to determine tissue concentrations of arsenic, cadmium, lead, and zinc. Mean
liver metals concentrations were higher in shrew species than in deer mice or voles, reflecting
their different life history and foraging strategies. Compared to 2001 and 2008 USFWS data,
preliminary results show decreased mean arsenic and lead concentrations, similar mean zinc
concentrations, and increased mean cadmium concentrations. Concentrations of cadmium and
lead in small mammals inhabiting Smelterville Flats remain above levels previously shown to
be associated with adverse effects in small mammals.

2.5.5.3 Progress toward Remedial Action Objectives
Smelterville Flats

As part of long-term and remedial effectiveness biological monitoring, habitat-specific indicator
monitoring was conducted in the palustrine, riparian and upland habitats on remediated
portions of Smelterville Flats. Elevated concentrations of metals in avian and fish tissue and
soil/ sediment are indicators of exposure to metals in the environment. Blood lead
concentrations in waterfowl using wetland habitat is an indicator of waterfowl lead exposure
through sediment and is used to compare the success of remedial activities conducted at
Smelterville Flats with exposure at remediated and unremediated areas within OU 3
(Thompson Marsh, Campbell Marsh, and Schlepp Agriculture to Wetland Conversion Project).
Soil and sediment clean-up goals for Smelterville Flats were set at 3,000 mg/kg for lead prior to
the establishment of a cleanup standard of 530 mg/kg lead in sediments as protective of avian
species. Remediation at sites such as Smelterville Flats improves riparian and wetland habitat,
yet waterfowl could continue to be exposed to lead levels above established cleanup standards.
Post-remedial biological monitoring is a valuable tool for assessing clean-up success and
recovery of ecological s.

2-34

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

2.5.5.4 Program Updates
Fish Exposure

Based on the data collected as part of the BEMP monitoring effort, the USFWS (Service)
recommends continued monitoring of brown bullhead liver metals concentrations within
lacustrine and palustrine habitats.

Monitoring Avian Productivity and Survivorship

The Service recommends discontinuing Monitoring Avian Productivity (MAPS) as part of
songbird monitoring under the BEMP. However, because remediation/ restoration is not
permitted for "take" under the Migratory Bird Treaty Act, cleanup needs to support the health,
survival, and reproduction of individual migratory birds. A more cost-effective approach for
evaluating clean-up protectiveness is to continue monitoring lead levels in songbird blood and
the associated riparian soils, and begin monitoring songbird diversity and abundance using
simple point counts before and after floodplain remediation.

Songbird Blood

Because established toxicity thresholds exist for lead in migratory bird blood, the USFWS
recommends eliminating the North Fork and Little North Fork reference sites. Additionally,
because future remedial actions are not likely to occur within Pine Creek, it is also
recommended to eliminate these sites (Pine Creek/Highland Creek, Lower Pine Creek) for
future sampling.

Small Mammals

Without any additional remedial activities conducted at Smelterville Flats, two small mammal
tissue lead concentration datasets are sufficient to understand small mammal exposure through
soil. Additional data may be collected after future significant remedial actions influencing lead
in floodplain soils are implemented.

Periphyton

Periphyton can be a useful monitoring tool for riverine systems by contributing an additional
sensitive trophic level, but obtaining reliable data is problematic and challenging. Accurate and
meaningful assessments of peri phytic resources require, at minimum, intensive and robust
sampling efforts, development of region- or site-specific metrics, and costly specimen
identification using contracted specialists. Fish and BMI diversity and abundance data will
provide sufficient information to evaluate the effectiveness of remedial actions and the long-
term status of aquatic resources throughout the Basin. These considerations, in addition to high
costs, high seasonal variability, and the potential for confounding or uninformative data, lead
the USEPA to recommend that periphyton monitoring be discontinued.

Currently, USEPA is working with USFWS to define the biological resources baseline dataset
and monitoring objectives, and update data quality objectives.

2-35

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

2.5.6 Summary of BEMP Issues, Recommendations, and Follow-Up Actions

The 2010 Five-Year Review included the following recommendations.

• Recommendation: Continue to implement the BEMP (an ongoing 2005 Five-Year Review
rec ommendation).

Discussion: The BEMP provided monitoring data to evaluate the ecological remedy Bunker
Hill Superfund Site cleanup and as such, these activities will continue as appropriate as an
integral part of the various remedies. USEPA is currently evaluating BEMP data and will be
updating the BEMP data quality objectives and monitoring parameters and frequency to
more effectively implement to program. This recommendation is complete.

• Recommendation: Continue implementation of remedial action effectiveness monitoring at
recreational areas and include remedial effectiveness monitoring in the designs and
implementation plans for ecological-related remedial actions (an ongoing 2005 Five-Year
Review recommendation).

Discussion: USEPA is working to incorporate remedial action effectiveness monitoring
plans in remedial action designs, including in the Interstate Callahan and GWCS remedial
actions. USEPA is also developing a template for remedial action effectiveness monitoring
that can be used for future remedial actions. This recommendation is complete.

2-36

-------
3 Review of Selected Remedies for
Operable Unit 1

This section documents the studies and remedial actions completed in OU 1. The information in
this section is organized as follows:

• 3.1 Overview of the Selected Remedy

• 3.2 Review of Operable Unit Remedial Actions

• 3.3 Technical Assessment

• 3.4 Issues and Recommendations

• 3.5 Performance Evaluation of the OU 1 Remedy

A review of actions taken since the last Five-Year-Re view and progress on Issues and
Recommendations is included in the review of each remedial action in Section 3.2 as
appropriate. A protectiveness statement for OU 1 is provided in Section 6 of this report.

Figure 3-1 is a map of the communities in OU 1.

3.1 Overview of Selected Remedy

The OU 1 Selected Remedy and RAOs are described in the 1991 OU 1 ROD (USEPA, 1991) and
the 1992 OU 2 ROD (USEPA, 1992). The primary goal of the OU 1 Selected Remedy is to reduce
children's exposure to and intake of lead from soil and dust sources to meet the following
RAOs:

• Less than 5 percent of children with blood lead levels of 10 micrograms per deciliter
(|a,g/ dL) or greater; and,

• Less than 1 percent of children exceeding a blood lead level of 15 jug/ dL.

The long-term strategy to achieve the blood lead goals is to remediate surface soils through
removal and replacement with clean soil or other barriers, manage those barriers into
perpetuity, and stabilize other contaminated areas throughout the Site to effect reductions in
house dust lead levels. The 1991 OU 1 ROD and previous investigations identified house dust
as the primary source of lead intake and subsequent absorption among young children in OU 1
(PHD, 1986). This pattern has been widely observed and supported by many subsequent
studies. One of the primary sources of house dust is soil around homes and throughout
community areas. (Lanphear and Roghmann, 1997; Succop et al., 1998; Manton et al., 2000;
Lanphear et al., 2002; Lanphear et al., 2003; Laidlaw et al. 2005, von Lindern et al., 2003a, von
Lindern et al., 2003b, Zahran et al., 2013a, Zahran et al., 2013b).

To achieve the RAOs, the cleanup strategy includes the following:

• Implementing a Lead Health Intervention Program (LHIP) for local families;

• Remediating all residential yards, commercial properties, and ROWs that have soil lead
concentrations greater than 1,000 mg/kg;

3-1

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

• Achieving a geometric mean yard soil lead concentration of less than 350 mg/kg for each
residential community in OU 1;

• Controlling fugitive dust and stabilizing and capping contaminated soils throughout the
Box;

• Achieving a geometric mean of interior house dust lead levels for each community of
500 mg/kg or less, with no individual house dust level exceeding 1,000 mg/kg; and,

• Establishing an ICP to maintain protective barriers over time and to ensure that future land
use and development is compatible with the OU 1 Selected Remedy.

A more detailed overview of the OU 1 selected remedies can be found in the third Five-Year
Review Report (USEPA, 2010c)1.

The Interim ROD Amendment (USEPA, 2012b) identified remedy protection actions to protect
existing human health remedies against stormwater runoff, tributary flooding, and heavy rain.
The remedy protection actions are a modification to the OU 1 Selected Remedy (USEPA, 1991).
Additional details on specific remedy protection projects are summarized in Appendix G
(Human Health Remedy Protection) of the FFS Report (USEPA, 2012b). Stormwater drainage
and localized flooding pose risks to the permanence of the existing human health remedies. In
particular, risks to the barriers are associated with three discrete threats:

• Water containing contaminated sediment flooding remediated or "clean" areas;

• Stormwater causing scouring (erosion) of barriers; and

• Contaminated sediment being mobilized and carried into the communities by runoff and
deposition.

Such risks are associated with failures of existing local drainage systems and flooding in areas
with no existing water management systems. Major components of the remedy protection
actions include the following:

• Culvert replacements, drainage ditches, channel improvements, diversion structures, bypass
systems, and subsurface road drainage systems identified in the eight primary Upper Basin
communities (Pinehurst, Smelterville, Kellogg, Wardner, Osburn, Silverton, Wallace, and
Mullan)

• Identification of generalized actions expected to be needed in Upper Basin side gulches.

3.2 Review of Operable Unit Remedial Actions

This section describes the progress to date in implementing the Selected Remedy and achieving
the RAOs in OU 1. This information is presented in the following subsections: 3.2.1, Residential
and Community Areas, and 3.2.2 Box Repository.

^ The third Five-Year Review Report is available online at http://ao.usa.aov/39vTA.

3-2

-------
The Bunker Hill Box

Italian
Gulch

Jackass
Creek

dy\|ene R,Ver

Kingston

Smelterville

Pinehurst

Montgomery
Gulch

Kellogg

Ross Ranch

Magnet
ljulch

Humboldt
v Gulch

Wardner

Elizabeth Park

Grouse
Creek

Pine
Creek

Little
Pine
Creek

Base Map Data
NHDPIus (Hydrography, 2005)
ESRI (Roads, Jurisdictional Boundaries, 2006)
NAIP (Aerial Imagery, 2009).

Deadwood
Gulch

Interstate 90

Government
Gulch

Streams and Tributaries

South Fork Coeuf d'Alene River

Milo
Creek

Limits

Box Boundary

" OU1 is defined by a map appended to the 1994 CD
and is not depicted on this map. OU2 comprises all
other areas within the Box.

0 0.225 0.45

1 I I I I L.

0.9 Miles
J I I

Figure 3-1

Map of Box Boundary and OU1 Communities

2015 Five Year Review

BUNKER HILL SUPERFUND SITE

Path:

&EPA

-------
-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

3.2.1 Residential and Community Areas

3.2.1.1 Human Health Barriers
Background and Description

The long-term strategy to achieve the OU 1 blood lead RAOs was to protect residents from
exposure to lead and other metals in soil and dust by removing and replacing contaminated
surface soils and wastes and establishing barriers in residential yards, commercial properties,
and ROWs that contain contamination above levels determined to be protective. Implementing
remedial activities began in 1989 with the objective of achieving a geometric mean yard soil lead
concentration of less than 350 mg/kg for each residential community in OU 1.

Detailed discussions of the historical context of the remedy, including the soil lead
concentration data, are provided in the 2010 Five-Year Review (USEPA, 2010c). Remediation of
Box residential yards, commercial properties, and ROWs was largely complete by 2007, and
certified complete by USEPA in 2008 (USEPA, 2008a). As part of the 2008 certification, the
Potentially Responsible Parties (PRPs) provided a cash-out payment for the remaining
properties whose owners had refused soil remediation. The payment is held in trust overseen
by the State of Idaho for remediation of these properties if current or future owners agree to
cleanup. At the time of the 2010 Five-Year Review, the 350 mg/kg soil RAO had been achieved
in all communities.

The Paved Roads program began in 2013 to assist local communities to maintain paved roads
that serve as protective barriers to underlying contaminants. The objective is to help maintain
the long-term effectiveness of barriers installed in ROWs and to repair damage done to roads
during the implementation of the soil remedy in OU 1. The program provides monetary
assistance to local roadway jurisdictions with proposed road improvement projects covered by
the approved roads strategy (IDEQ, 2012b). The local jurisdictions are responsible for project
planning, design, construction, documentation, and long-term maintenance of the completed
work.

Operations and Maintenance and Actions since the Last Five-Year Review
Residential Soil and Gravel

Four residential refusals were remediated since the last Five-Year Review (one in each year
from 2010 through 2013). As of the end of 2014, with the exception of 14 properties that continue
to refuse remediation, all remaining properties within OU 1 have been completed. These
properties that continue to refuse remediation are located throughout the Box: six properties in
Pinehurst, three in Kellogg, two each in Wardner and Elizabeth Park, and one in Page. The last
Five-Year Review included the following recommendations. Discussions and any actions taken
since 2010 follow each recommendation.

• Recommendation: Develop an approach (or program) that defines how barrier integrity for
all remediated properties would be maintained and monitored over time.

Discussion: The main purpose of the ICP is to have an approach or program to monitor and
maintain barriers into perpetuity. USEPA has no reason to believe the ICP has not been
effective in achieving this goal. However, a widespread evaluation of the status of property
barriers has not been completed since the PRP certification of remedial activities.

3-5

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

This activity will not be retained in the table of issues and recommendations because it does
not directly affect protectiveness. It will instead be included in the table of planned action
items. This recommendation is repeated in OU 3.

• Recommendation: Conduct ROW sampling and analysis to determine whether lead
concentrations have remained stable (an ongoing 2005 Five-Year Review recommendation).

Discussion: The potential for ROW recontamination is increased by: vehicular traffic, road
or shoulder grading, general tracking of materials from unremediated areas, and mixing of
underlying soils during excavations. ROW monitoring from 1998 to 2008 indicated
occurrences of lead levels in excess of 1,000 mg/kg, although geometric mean ROW results
were generally less than 350 mg/kg (USEPA, 2010c). No additional ROW monitoring was
conducted for this Five-Year Review. The Paved Roads program has addressed some of
these recontaminated ROWs. The question of monitoring remediated ROWs will be
addressed along with other human health barriers in the previous action item. This
recommendation is complete.

• Recommendation: Evaluate unaddressed hillside sloughing areas adjacent to residential
yards and determine whether control measures are needed (an ongoing 2005 Five-Year
Review recommendation).

Discussion: O&M inspections of the hillsides continued during the last five years and are
summarized in Section 4.2.1. No activities associated with hillsides adjacent to residences
occurred in the last five years because the hillsides were considered stable. However, in
August 2011, a fire on the hillsides around Kellogg and Wardner burned more than 17 acres
and compromised the vegetation controlling erosion (PHD, 2011a). In November 2013,
representatives from USEPA, PHD, Idaho Department of Lands (IDL), and IDEQ met to
discuss hillside erosion and control in the event of a disaster or clear cutting. The group
concluded that PHD will continue to monitor hillsides, and IDL will ensure best forest
management practices are followed. Currently, the ICP is the "control measure'" to manage
the several hundred acres of developable hillside areas that exceed the soil removal action
level. Appropriate information must continue to be made available to interested developers
to ensure adequate understanding of ICP permitting and barrier installation requirements.
This recommendation is complete.

Paved Roads

Paved roads provide barriers to underlying contamination and are therefore a component of the
human health barriers cleanup. The Paved Roads program was established in response to the
communities' recognition that damage to roads in community areas had occurred over a
number of years from cleanup activities, and the 2010 Five-Year Review recommendation to
develop an approach for addressing roads as long-term barriers in collaboration with state,
county, and local entities.

Approximately 14 miles of Box roads underlain by contaminated soils were rebuilt, patched, or
chip sealed in 2013 and 2014. While implementation of this program is expected to address a
significant number of paved roadways, it is not intended to address all problems with all of the
paved roads in the Box.

3-6

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Remedy Status

The soil remedy is largely complete: all properties in OU 1 have been remediated, with the
exception of 14 properties that refused remediation. These 14 properties can be remediated in
the future through use of funds provided by Upstream Mining Group (UMG) held in trust by
the State. New property development and future modifications to existing properties are
required to establish barriers following the ICP guidance.

The community mean soil target of 350 mg/kg lead was achieved in all communities as of 2008
(USEPA, 2010c). PHD continues to manage soils through the ICP according to the Rules of the
Panhandle Health District 1 (IDAPA 41.01.01) to reduce lead levels in community soils and to
maintain the community mean target goal. The ICP is monitoring and permitting projects
throughout the Box (discussed in Section 3.2.1.6), and directs disturbed soils with lead
concentrations greater than 350 mg/kg to one of the designated repositories or to be placed
under a cap. Clean soil criteria for backfill material cannot be greater than 100 mg/kg lead.
Consequently, soil lead concentrations in community areas as of this Five-Year Review are
assumed to be similar to the community soil means presented in the 2010 Five-Year Review
(USEPA, 2010c), which were below 350 mg/kg.

Substantial subsurface and some surface contamination remains in the Box and poses a risk of
recontamination. Catastrophic events pose potential challenges with maintaining a protective
barrier. Hillsides (most of which are well vegetated) and unremediated mine dumps pose
additional risk of exposure and soil recontamination. Since the last Five-Year Review, two
programs have been implemented to ensure contaminated materials >1,000 mg/kg remain
under a barrier: remedy protection projects and the human health barriers paved roads
program. The 2012 ROD Amendment selected remedy protection projects intended to enhance
the protection of human health remedies vulnerable to erosion, and recontamination from
stormwater drainage and localized flooding, as discussed in Section 3.2.1.5.

Opportunistic soil and sediment sampling conducted as part of the ICP provides additional
data to evaluate continued remedy performance. Results from three samples collected in 2011
from a pile of material generated during road sweeping stored at the State of Idaho's
Department of Transportation site along the Interstate 90 (1-90) corridor were less than
350 mg/kg (Table 3-1). Snow pile debris samples collected in Kellogg in 2011, 2012, and 2014
had lead concentration averages of about 1,000 mg/kg. The snow pile storage areas should
drain so excess sediment can be collected and disposed annually after the snow has melted.
Regrinds and "other non-surface soil" samples collected since 2010 for ICP monitoring and
permitting purposes show lead levels up to approximately 45,000 mg/kg, reinforcing the
necessity for an ICP to protect public health by managing the human health barriers to
contaminants left in place. One sample collected in 2014 indicated recontamination of a Kellogg
ROW due to stormwater runoff from the Bunker Hill Mine. IDEQ subsequently cleaned a
drainage ditch that directs stormwater from the Bunker Hill Mine Area to a storm drain off
Mine Road (also see Section 3.2.1.6).

3-7

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TABLE 3-1

Summary of ICP Samples Collected in the Box, 2010-2014
2015 Five-Year Review, Bunker Hill Superfund Site

Type

Year

Number of
Samples

Minimum Lead
Concentration
(mg/kg)

Maximum Lead
Concentration
(mg/kg)

Average Lead
Concentration
(mg/kg)

Standard
Deviation

Percentage
of Samples >
350 mg/kg
Lead

Snow Pile

2010

2011

383

2,637

958

948

100%

2012

555

2,130

1,161

731

100%

2013

551

100%

2014

645

2,650

1,367

1,114

100%

City

Sweepings

2010

2011

149

204

168

2012

2013

2014

Reg rinds3

2010

887

8,532

100%

2011

10.8

638

21%

2012

2013

2014

Other Soils3

2010

45,305

49%

2011

12.3

2,518

42%

2012

15.1

2,860

50%

2013

4.21

3,680

32%

2014

676

8,040

100%

Note:

a These samples were collected during ICP inspections of permitted projects, projects undertaken by the utilities or
government, or to monitor erosion and/or tracking. Soils that tested greater than 100 mg/kg lead were directed to the
repositories or capped under barriers. For this reason, averages and standard deviations were not calculated.

Maintenance of the community mean soil target of 350 mg/kg lead cannot be directly measured
without a representative large-scale soil sampling program to monitor barrier integrity and
potential recontamination. Rather, house dust and blood lead monitoring data (see
Sections 3.2.1.2 and 3.2.1.4, respectively), achievement of the blood lead RAOs (Section 3.2.1.4),
and continued ICP performance (Section 3.2.1.6) indicate success of the Selected Human Health
Remedy in OU 1.

3.2.1.2 House Dust
Background and Description

Previous investigations identified house dust as the primary source of lead intake and
subsequent absorption among young children in OU 1 (Yankel et al., 1977; TerraGraphics
Environmental Engineering [TerraGraphics], 1990; PHD, 1986; von Lindern et al., 2003a and
2003b). The cleanup strategy outlined in USEPA remedy decision documents includes the
objective of achieving a geometric mean lead level of 500 mg/kg or less for interior house dust
in each community. One part of the Selected Remedy is a one-time interior cleaning for any

3-8

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

home with house dust concentrations at or above 1,000 mg/kg, but this component has not
been implemented to date. USEPA, IDEQ, and PHD decided not to clean home interiors until
exterior contamination sources were controlled. The rationale for waiting until completion of
soil remediation was based on an initial 1990 pilot cleaning study in which some homes in the
Box received interior cleaning, yet within one year, lead concentrations in the home had
returned to pre-cleaning levels (CH2M HILL, 1991).

In 2000, USEPA and IDEQ conducted a follow-up interior cleaning pilot project in Smelterville
to determine whether reduced house dust lead levels would be better sustained following
completion of yard soil remediation in that community. Yard remediation in Smelterville was
complete by 1997. The second study confirmed conclusions of the initial study: sustained
reductions in lead dust concentrations would require frequent and repeated interior cleanings
following comprehensive commercial cleaning protocols and carpet replacement; without these
significant and long-term efforts, dust lead levels would return to pre-cleaning levels within
months to a year (TerraGraphics, 2002).

Completion of yard and community remediation controls a significant source of lead in house
dust. However, the Selected Remedy does not address other anthropogenic house dust lead
sources, such as residents' hobbies, habits, and activities, as well as dust generated from lead-
based paint. Based on these factors, a one-time cleaning is not likely to achieve the house dust
objectives.

IDEQ and PHD sampled house dust from vacuum bags and dust mats annually from 1988
through 2005, and periodically thereafter in 2008 and 2013 to evaluate lead concentrations
within homes and to assess progress towards meeting the community geometric mean dust
lead concentration target of 500 mg/kg. Detailed discussions of the historical context of the
remedy, sampling methods, and the house dust lead concentration data are provided in the
2010 Five-Year Reviews (USEPA, 2010c). Data collected during the past five years are discussed
below.

The success of the remedy depends on achieving target lead dust concentrations, and
maintaining house dust lead levels at or below post-remedial soil levels. The risk management
strategies expected to achieve and maintain the community house dust target include remedial
actions to address community soils (Section 3.2.1.1) and fugitive dusts (Section 4.2), and the ICP
high-efficiency particulate air filter (HEPA) vacuum loan program and ICP regulation of
exterior soils and interior renovation projects (Section 3.2.1.5).

Operations and Maintenance and Actions since the Last Five-Year Review

The 2010 Five-Year Review (USEPA, 2010c) presented the following recommendations
regarding the house dust remedy:

• Recommendation: Evaluate the need for implementation of the interior cleaning component
of the remedy based in part on information on alternative dust lead sources. Determine
additional data and monitoring needs to support one-time cleaning evaluation.

Discussion: Based on the collective discussion below, this activity will be retained in the
table of issues and recommendations because it directly affects protectiveness.

• Recommendation: Determine whether additional work is needed to identify alternative
lead sources, such as lead-based point, that may be contributing to house dust lead levels.

3-9

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Discussion: Based on the collective discussion below, this recommendation will be rolled
into the above recommendation and not retained in the table of issues and
recommendations separately.

• Recommendation: Evaluate need for implementation of the interior cleaning component of
the remedy. Continue monitoring house dust concentrations annually as soil remediation is
completed (an ongoing 2005 Five-Year Review recommendation).

Discussion: Based on the collective discussion below, this activity will be rolled into the
above recommendation and not retained in the table of issues and recommendations
separately.

Collective Discussion: To begin addressing these three recommendations, vacuum and dust
mat samples were collected from 270 homes in 2013. The sample data were assessed relative to
a) past data and trends, b) the risk assessment completed for OU 1, and c) risk management
strategies incorporated as part of the Selected Remedy (TerraGraphics, 2015a).

Potential sources and cofactors influencing house dust lead levels were evaluated using
questionnaire data. Several analyses identified factors that appear to be associated with a higher
likelihood of elevated dust lead levels (greater than or equal to 1,000 mg/kg; TerraGraphics,
2015a). The condition of exterior paint, the age of the house, remodeling activities, and the
presence of interior lead-based paint were observed as possible reasons for elevated dust lead
concentrations. However, these same co-factors were also common responses among homes
with lead levels less than 1,000 mg/kg, and alone do not indicate that a home will have elevated
dust lead concentrations. Exploratory statistical analysis identified potential risk co-factors such
as, the total number of people living in the home, total number of recreational activities in
which any members of the household partake, interior paint condition, forced air heating or
cooling, whether the home was built prior to 1960, and whether the ground immediately
surrounding the residence had been flooded. The conclusions from these analyses were that few
variables appear to be risk co-factors at this time, and questionnaire responses alone cannot
identify a home with elevated dust lead concentrations in the Box.

Remedy Status

Dust Lead Concentrations and Dust and Lead Loading Rates

Mean house dust lead concentrations decreased as exterior soil remediation progressed. As of
2002, all communities had geometric mean house dust levels below 500 mg/kg lead (USEPA,
2005), the established community-mean performance standard for house dust. Since the 2010
Five-Year Review, the one year of house dust lead monitoring indicates minimal change.
Community geometric mean lead concentrations in 2013 continue to remain well below
500 mg/kg, ranging from 160 mg/kg to 288 mg/kg for vacuum samples, and from 151 mg/kg
to 322 mg/kg for dust mat samples (Table 3-2). The remedy has reduced dust lead levels to
geometric mean concentrations that are near post-remedial soil community average lead levels
(i.e., <350 mg/kg). Mean house dust levels in the Box are also near or within three times
background levels previously observed from similarly aged housing and socio-economically
situated communities in northern Idaho outside the mining district. Geometric mean
background vacuum sample lead levels were 120 mg/kg in 1999 and 129 mg/kg in 2004, and
dust mat lead levels were 95 mg/kg in 1999 and 79 mg/kg in 2004 (Spalinger et al., 2000). The
2013 Box dust mat sampling results continue to indicate that remaining external sources of lead
in the Silver Valley are likely causing mat lead levels to exceed background levels.

3-10

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TABLE 3-2

Dust Summary Statistics by Community for OU 1, 2013
2015 Five-Year Review, Bunker Hill Superfund Site

Sample
Type

City

Number of
Samples

Sample Concentrations
> 1,000 mg/kg Lead

Lead Concentration Range
(mg/kg)

Mean House Dust Lead Concentration (mg/kg)

Arithmetic
Mean

Arithmetic
Standard
Deviation

Geometric
Mean

Geometric

Standard

Deviation

Number

Percent

Minimum

Maximum

Vacuum

Kellogg

102

1,520

369

257

288

2.20

Page

718

238

208

160

2.98

Pinehurst

2,200

319

421

195

2.61

Smelterville

859

243

146

202

1.96

Wardner

112

454

268

109

248

1.56

Box Total

224

2,200

323

297

235

2.32

Dust
Mat

Kellogg

105

91,200a

1,375

8,928

322

2.90

Page

665

321

229

245

2.30

Pinehurst

9,600

369

1,143

151

3.00

Smelterville

1,060

276

204

209

2.20

Wardner

605

285

173

231

2.10

Box Total

241

91,200

784

5,934

231

2.90

Note: Corresponding vacuum result was less than 1,000 mg/kg.

3-11

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Statistical evaluation of paired vacuum and mat dust data from 2008 and 2013 indicates that
site-wide lead concentrations do not differ significantly between the two sampling
methodologies (TerraCraphics, 2015a). The fact that both methods produce similar results
suggests that exterior soils and interior dusts in the Box are in equilibrium.

In general, geometric mean Box dust loading rates have remained similar over time, but the
amount of lead tracked into homes has decreased because of reduced exterior lead
concentrations in remediated soils. By 2002, geometric mean lead loading rates were at an all-
time low for the larger communities, near 0.1 milligrams per square meter per day
(TerraGraphics, 2015a). Since then, geometric mean lead loading rates have remained similar.
For information that is more detailed about the 2013 house dust sampling results, see OU 1 2013
House Dust and Blood Lead Data Evaluation and Risk Management Evaluation (TerraGraphics,
2015a).

One-time Interior Cleaning Remedy

The Second and Third Five-Year Reviews recommended evaluating the one-time cleaning
component of the Selected Remedy because some individual homes continue to demonstrate
lead concentrations above 1,000 mg/kg. In 2013,17 homes, or 6 percent of sampled OU 1
homes, had vacuum bag and/or dust mat lead concentrations >1,000 mg/kg (TerraGraphics,
2015a). Extrapolating to the entire estimated housing population of OU 1, this equates to an
estimated 175 homes in the Box that may have elevated house dust lead concentrations, even
after yard soil remediation has been completed (TerraGraphics, 2015a).

Review of house dust data indicates that measured house dust lead levels for an individual
home can vary from year to year and may differ depending on sampling methodology. Houses
with high concentrations in one year may show lower levels in following years, even without
intervention. Few homes consistently show elevated lead levels over time (through 2013,
21 homes were identified based on multiple samples collected six or more years after the
associated yard was remediated). Observed fluctuations in individual house dust lead
concentrations suggest that residents' hobbies and activities may affect dust lead levels
(TerraGraphics, 2005, 2008a, and 2015a).

IDEQ and USEPA have not yet implemented the interior cleaning component of the OU 1
Selected Remedy. The interior cleaning pilot studies conducted in 1990 and 2000 (CH2M HILL,
1991; TerraGraphics, 2002) suggest that one-time residential interior cleaning is not likely a
sustainable remedy. In some cases, the elevated lead levels may be attributed to other sources of
contamination, including the following:

• Soil and sediment from the hillsides, Coeur d'Alene River Basin, and Upper Basin mine and
mill sites where many residents recreate;

• Erosion from hillsides surrounding OU 1, especially those that abut residential properties;

• Occupational sources;

• Lead-based paint;

• Interior legacy reservoirs such as attics, basements, and crawl spaces; and/ or

• Personal activities, occupations, or hobbies.

3-12

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

The Selected Remedy does not address those anthropogenic lead sources that cannot be
controlled by CERCLA cleanup activities, and no systematic effort has been made to reduce
lead paint exposure in the Box. The cost-effectiveness and efficacy of a one-time interior
cleaning of homes with dust lead concentrations >1,000 mg/kg versus other methods of
reducing a typical child's risk of elevated blood lead levels in such homes has yet to be resolved,
and additional work to determine a risk management strategy for these homes is ongoing
(TerraGraphics, 2015a).

3.2.1.3 Drinking Water
Background and Description

Part of the Selected Human Health Remedy for OU 1 properties was to close domestic drinking
water wells that exceeded the federal drinking water standards for total arsenic, cadmium, lead,
or zinc, and attach the affected residences to a municipal water system (USEPA, 1992; USEPA
and Idaho Department of Health and Welfare [IDHW], 1994). The PRPs, collectively referred to
as the UMG, entered into a CD with USEPA and IDHW in 1994 to complete remediation in
OU 1, including domestic water well closures (USEPA and IDHW, 1994).

Remedial action certification reports developed as part of USEPA certification process include
the domestic well test results and whether a well was closed or left operational (MFG, 1997 and
1999; UMG, 1998; LFR, 2008a, 2008b, 2008c, 2008d, and 2008e). Table 3-3 summarizes the status
of drinking water well closures in the reasonable segregable areas (RSAs). Owners of 13 wells
that exceeded federal drinking water standards refused closure. None of these 13 wells was
used for drinking water purposes at the time.

The Idaho Department of Water Resources (IDWR) continues to designate the upper and lower
zones of the main valley groundwater system within OU 1 and OU 2 as an "area of drilling
concern" to protect public health and prevent increased aquifer contamination.

Operations and Maintenance and Actions since the Last Five-Year Review

None.

Remedy Status

The metals concentrations and potable or nonpotable status of the 13 wells whose owners
refused closure are currently unknown, although at the time of refusal these wells were not
used for drinking water. The area of drilling concern, as designated by IDWR, continues to
protect residents from developing new private drinking water wells in the main valley aquifer.

3-13

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TABLE 3-3

Number of Drinking Water Wells Closed in OU 1
2015 Five-Year Review, Bunker Hill Superfund Site

RSA

Closed,
Destroyed, No
Longer Exists, Not
Found, or
Inaccessible

Did Not
Require
Testing or
Closure

Refused
Closure

Comments

Smelterville

One well was determined to be out of the
influence from the main valley aquifer and
therefore closure or hook-up following refusal
was not necessary

Kellogg
North of 1-90

Kellogg
South of 1-90

Pinehurst

None of the wells sampled in the Pinehurst RSA
exceeded primary or secondary drinking water
standards for metals and the RSA wells were
not collectively classified as requiring closure

Wardner

Page

With one exception, sampled wells in Humboldt
Gulch were not considered affected by the Page
Mine or waste rock dump and so wells in this
RSA were not collectively classified as requiring
closure

Elizabeth
Park /

Montgomery
Gulch / Ross
Ranch

Total

NA = not applicable

3.2.1.4 Lead Health Intervention Program
Background and Description

Since 1985, the LHIP, administered by PHD as a public health service, has served to minimize
lead exposure through non-engineering means. The LHIP, as selected by the 1991 OU 1 ROD,
offers activities designed to intervene in lead absorption pathways through biological
monitoring, follow-up, parental awareness, counseling, and education. The basic elements of
the LHIP effort are as follows:

• Biological (annual fixed-site child blood lead testing) and dust lead monitoring

• Follow-up for children with elevated blood lead levels

• Education and awareness for parents and children

• Vacuum loan program for cleaning residences

A detailed discussion of these elements and the historical context of the LHIP, including blood
lead data and educational and awareness programs, can be found in the 2010 Five-Year Review
as well as the Overview of the Silver Valley Lead Health Intervention Program (USEPA, 2010c; PHD,
1999).

3-14

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

The Human Health Remedial Evaluation (HHRE) provides a thorough discussion of blood lead
levels from 1988 through 2002 (TerraCraphics, 2004). The blood lead monitoring data from 2003
through 2013 are evaluated in the Bunker Hill Mining and Metallurgical Complex Superfund Site
OU 1 House Dust Remedy and Risk Management Evaluation (TerraGraphics, 2015a).

Operations and Maintenance and Actions since the Last Five-Year Review

Since the 2010 Five-Year review, the LHIP continued to offer the same services previously
described in detail (USEPA, 2010c). From 2010 through 2012, the same services were offered.
These were a fixed-site blood lead screening offered annually at no cost to and with no financial
incentive for Box residents. Participation was low, with a total of 36 children participating over
the three years (less than 20 children each year, Table 3-4). In 2013, PHD, IDEQ, and USEPA
reinstated the door-to-door survey and incentive program for one year to increase participation
and to help inform the regulatory agencies about the status of current exposures; 11 years after
observed blood lead levels had dropped below the RAOs (USEPA, 2005) and five years after
residential areas were certified complete (USEPA, 2008a).

The 2013 LHIP door-to-door survey identified an estimated total of 502 children residing in the
Box based on consenting participants and information from neighbors or Site observations to
determine if children lived at homes where no contact was made. The estimate is within
10 percent of the estimated number of children between 6 months and 9 years (555) based on
school enrollment data. A total of 276 children, or 50 percent of the estimated eligible
population based on school enrollment data, provided blood lead samples in 2013. This
participation rate is similar to those from 1990 through 1998, which averaged 50 percent or more
(TerraGraphics, 2004). In 2014, only four children participated in the fixed-site blood lead
screening.

Beginning in 2012, the Centers for Disease Control and Prevention (CDC) recommended
eliminating use of the term "blood lead level of concern" because evidence suggests that
negative effects appear to be present at any blood lead level, and they urged primary
prevention of lead exposure (CDC, 2012). The CDC recommends the use of a reference value
(currently 5 pg/dL) to identify children with elevated blood lead levels. In 2013,10 of the
children tested (4 percent) had blood lead levels greater than or equal to 5 pg/dL, compared to
40 children (11 percent) in 2002 (Table 3-5).

In response to the CDC recommendations, PHD began offering follow-up services in 2012 to the
parents of all children exhibiting a blood lead level of 5 pg/ dL or greater (as opposed to
10 pg/dL, which had been previously used). Since the last Five-Year Review and for the years
of 2010 through 2012 and 2014, one family was offered and accepted follow-up services (in
2010). Nine families were offered follow-up services in 2013, and two families (with a total of
three children) accepted. In general, PHD determined that exposures were likely occurring from
recreation activities in unremediated areas of the Coeur d'Alene Basin.

3-15

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TABLE 3-4

Summary of Blood Lead Levels for OU 1 Children, 2010-2014
2015 Five-Year Review, Bunker Hill Superfund Site

Blood Lead Level Range
(pg/dL)

Blood Lead Level (|jg/dL)

Children with
Blood Lead
Levels >15 |jg/dL

Children with
Blood Lead Levels
>10 |jg/dL

Year

City

Number of
Observations

Minimum

Maximum

Arithmetic
Mean

Arithmetic
Standard
Deviation

Geometric
Mean

Geometric

Standard

Deviation

Number

Percent

Number

Percent

2010

Site-wide

1.6

3.5

2.2

3.0

1.7

2011

Site-wide

1.4

5.0

2.3

1.3

2.0

1.6

2012

Site-wide

1.6

4.1

2.6

0.84

2.4

1.4

Kellogg

147

1.0

2.6

2.1

2.3

1.6

Page

1.4

4.4

2.6

1.1

2.4

1.6

2013

Pinehurst
Smelterville

68
45

1.4
1.4

6
6

2.1
2.3

1.0
1.0

1.9
2.1

1.5
1.5

0
0

0%
0%

0
0

0%
0%

Wardner

1.4

4.6

2.5

1.1

2.3

1.5

Site-wide

276

1.0

2.4

1.7

2.2

1.6

2014

Site-wide

2.0

2.7

0.9

2.6

1.4

3-16

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TABLE 3-5

OU 1 Children with Elevated Blood Lead Levels
2015 Five-Year Review, Bunker Hill Superfund Site

Number >

% > 5

Number >

Year

City

Number

5 |jg/dL

|jg/dL

10 |jg/dL

15 |jg/dL

Kellogg

195

11%

Page

25%

Pinehurst

115

2002

Smelterville

13%

Wardner

Site-Wide

368

11%

Kellogg

147

Page

Pinehurst

2013

Smelterville

Wardner

Site-Wide

276

The vacuum loan program continues to be a valuable part of the LHIP. From 2010 through 2014,
there was an annual average of 127 vacuum checkouts for Box and Basin homes (there is no
breakdown of activity by OU). An average of 105 people checked out the vacuums annually
from an average of 103 addresses, indicating this resource is still being used by the community.

PHD's LHIP staff works in cooperation with IDEQ to provide outreach and education to raise
awareness about the human health risks associated with lead exposure and recreating in the
Coeur d'Alene River Basin. The goal is to inform residents and recreational users of exposure
routes and protective measures that can be taken. Since 2010, this goal has been accomplished
using various media types, including the following:

• Twelve human health signs posted at public recreation access sites;

• Brochures and posters;

• Audio public service announcements run throughout the summer during the peak of
outdoor recreation;

• Children's activity books disseminated to more than 600 children in kindergarten through
third grade; and

• Presentations to community groups and school-aged students.

• Classes for students in kindergarten through third grade were conducted at seven schools
each year from 2010 through 2012 and at eight schools each year in 2013 and 2014.

3-17

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Remedy Status

Blood lead sampling provides useful information to target families and children in need of
intervention and to evaluate the performance of the human health Selected Remedy. Few
families took advantage of the annual fixed-site screenings from 2003 through 2012, with only
130 children tested in those 10 years. Five of those children had blood lead levels exceeding
10 pg/ciL, and none exceeded 15 pg/dL (TerraCraphics, 2015a).

In 2013 when an estimated 50 percent of children in the Box were tested, two children
(1 percent) had blood lead levels >10 pg/dL, and one child had a blood lead level >15 pg/dL
(Table 3-5). The 2013 arithmetic mean blood lead levels ranged from 2.1 pg/dL in Pinehurst to
2.6 pg/dL in Page and Kellogg and either continued to decline or remained similar to 2002
levels (Figure 3-2).

The LHIP continues to provide voluntary blood lead screening services, environmental health
follow-up for children with blood lead levels >5 jag/ dL, and education and awareness
programs. Blood lead monitoring participation rates in the Box appear to be highly dependent
on monetary incentives. Consequently, blood lead results from the low number of participants
in 2010-2012 and 2014 do not represent the childhood population and limit the identification of
children who require intervention.

Education and outreach continues to occur at the schools, and PHD's personnel have noted that
children recall and reiterate what was taught from the previous year. The vacuum loan program
continues to be used by local residents.

FIGURE 3-2

Blood Lead Levels for OU 1 Children by City and Year, 1988-2013

2015 Five-Year Review, Bunker Hill Superfund Site

| « KELLOGG ¦ PAGE * PTNEHURST • SMELTERVILLE :¦ WARDNER |

Note: Data from 2003 through 2012 are not displayed because there were few participants.

3-18

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

USEPA recommends the use of its Integrated Exposure Uptake Biokinetic (IEUBK) Model, not
actual blood lead levels, to evaluate lead health risk using environmental exposure data and to
develop consequent cleanup criteria. The model is used to predict the risk of elevated blood
lead levels in children under the age of seven. IEUBK Model analysis was conducted in 2014 to
predict childhood residential lead health risk and assess if the most recent environmental
exposures achieve the RAOs. The success of the risk management strategy was contingent upon
post-remedial dust lead levels, in combination with soils, drinking water, and air, that predict
blood lead levels below the RAOs.

The 2014 modeling used observed house dust lead concentrations from vacuum samples
collected in the most recent year (either 2013 or 2008), in combination with current community
geometric mean and yard soil lead concentrations (assuming a concentration of 100 mg/kg lead
for soil at remediated properties). The IEUBK modeling results indicate that all Box
communities achieve both community blood lead RAOs (i.e., <5 percent of children with blood
lead levels >10 pg/ dL, and <1 percent with blood lead levels >15 pg/ dL).

3.2.1.5 Remedy Protection
Background and Description

The Interim ROD Amendment (USEPA, 2012b) selected remedy protection actions to protect
existing human health remedies against stormwater runoff, tributary flooding, and heavy rain.
The remedy protection actions are a modification to the OU 1 Selected Remedy (USEPA, 1991).
Additional details on specific remedy protection projects are summarized in Appendix G
(Human Health Remedy Protection) of the FFS Report (USEPA, 2012b).

Stormwater drainage and localized flooding pose risks to the permanence of the existing human
health remedies. In particular, risks to the barriers are associated with two discrete threats:

• Water containing contaminated sediment flooding remediated or "clean" areas

• Stormwater causing scouring (erosion) of barriers

Such risks are associated with failures of existing local drainage systems and flooding in areas
with no existing water management systems.

Major components of the remedy protection actions include the following:

• Culvert replacements, drainage ditches, channel improvements, diversion structures, bypass
systems, and subsurface road drainage systems, identified in the eight primary Upper Basin
communities, four of which are located with OU 1 (Pinehurst, Smelterville, Kellogg, and
Wardner); and

• Identification of generalized actions that are expected to be needed in Upper Basin side
gulches outside OU 1.

Key benefits of these remedy protection actions include the following:

• Greater long-term protection of human health and the environment in Upper Basin
community areas, achieved through improvements to existing water conveyance systems
(e.g., culvert replacements, drainage ditches) and installation of new drainage systems.

3-19

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

• A proactive approach to addressing recontamination issues associated with potential
erosion or recontamination of existing barriers after a storm event. A proactive approach
decreases the risk of human exposure to contaminated materials.

Prior to construction of remedy protection infrastructure projects, local residents and elected
officials engage in a public information or participation process with the agencies. Local
jurisdictions responsible for infrastructure, along with IDEQ, sign an Interagency Cooperative
Agreement (ICA). The ICA requires local governmental entities holding jurisdiction or
ownership of the project to assume responsibility for performing and funding ongoing O&M of
the project.

Remedy protection actions in the Box do not include protection against flooding of the SFCDR
and Pine Creek. Protection against flooding of the SFCDR and Pine Creek is a complex, system-
wide problem that will require substantial involvement and investment on the part of
numerous local, state, and federal entities. USEPA and IDEQ are committed to participating in
efforts to understand more fully the SFCDR system, including Pine Creek, and ways in which
various entities can contribute to the management of flooding problems.

Operations and Maintenance and Actions since the Last Five-Year Review

As described earlier, the remedy protection actions were selected in the 2012 Interim ROD
amendment. Since then, four remedy protection projects (see Figure 3-3) have been constructed
in OU 1 in 2013 and 2014 and are summarized in the following subsections. Construction of
three additional remedy protection projects are planned in OU 1 in 2015 including Jackass
Creek in Kellogg, Silver Creek in Page, and Slaughterhouse Gulch in Wardner.

Wardner Projects

Sierra Nevada Road

The Sierra Nevada Road Remedy Protection Project was constructed in 2013. The major features
of the installed remedy include the following:

• Enlarging approximately 300 feet of existing ditch and armoring with riprap.

• Installing catch basins and approximately 60 linear feet of 12-inch corrugated high-density
polyethylene (CHDPE) storm drainpipe.

• Installing approximately 90 linear feet of 30-inch diameter CHDPE storm drainpipe tied into
the west wall of the Milo Creek intake structure.

• Constructing 85 linear feet of curb and gutter and grading and resurfacing the road to
promote drainage to the installed features.

O&M of the Sierra Nevada Road project is conducted in accordance with the Sierra Nevada Road
Operation and Maintenance Manual (TerraGraphics, 2013a). Inspections and maintenance of the
Sierra Nevada Road remedy protection remedial action are conducted by the City of Wardner
in accordance with an ICA (IDEQ and City of Wardner, 2012). The Sierra Nevada Road project
has required no maintenance during this review period.

3-20

-------
River

South Fo^

Smelterville

Pinehurst

Portland
Avenue

m-M

Jackass
Creek

Kellogg

»ffi: ¦ '.

Little nv
Fy, Pine 'jit

l 'Itt&rSi!

¦> nine
Creek

Page

Silver

Creek

m>X>xnifl

Slaughterhouse

I u

Gulch I

tE4\

Wardner

Sierra
Nevada ^

Road

Bk A fc • .¦. v

•ssSOBmS

jource: Esri, DigitalGlobe, GeoEye, i-cubed, Earthstar Geographies, CNES/Airbus

S, AEX, Getmapping, Aerogrid, IGN, IGP, swisstopo, and the GIS User Community

1 Miles

interstate 90

Streams and Tributaries

South Fork Coeurd'Alene River

Remedy Protection Areas
C3 South Fork Coeurd'Alene River

FIGURE 3-3

Box Remedy Protection Project Areas

2015 Five-Year Review
BUNKER HILL SUPERFUND SITE

TerraGraphics Environmental Engineering, Inc. 2010_5_Year / Figure1_2_box.mxd 2/25/2010

-------
-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Slaughterhouse Gulch

Plans for the Slaughterhouse Gulch remedy protection project involve construction of two
rolling dips and swale to direct overland drainage from Slaughterhouse Road to Slaughterhouse
Creek. Construction is planned for 2015.

Smelterville Project

Grouse Creek

The Grouse Creek Remedy Protection Project was constructed in 2013. The major features of the
installed remedy include:

• Excavating approximately 1,530 cy along 1,660 feet of the existing Grouse Creek stream
channel to increase the channel capacity and constructed a typical two-stage trapezoidal
channel with a low-flow section designed for the 2-year event.

• Replaced an existing jersey barrier wall with 153 linear feet of 7-foot-tall reinforced concrete
cantilever retaining wall.

• Installed 137 linear feet of 7-foot-tall and 225 linear feet of 4-foot-tall reinforced concrete
cantilever retaining wall along portions of the channel where a vertical channel wall was
required to meet the design capacity.

• Replaced two culverts under Main Street and Breeden Street with a single 100-foot-long
realigned 14-foot by 6-foot, 3-sided concrete bridge culvert.

• Installed a catch basin and 18-inch-diameter CHDPE pipe tied into the installed bridge
culvert wingwall.

• Armored select stream banks with riprap and reinforced the constructed channel benches
and stream banks with erosion mats and prescribed vegetation.

O&M of the Grouse Creek project is conducted in accordance with the Grouse Creek Operation
and Maintenance Manual (TerraGraphics, 2013b). Inspections and maintenance of the Grouse
Creek remedy protection remedial action are conducted by the City of Smelterville in
accordance with an ICA (IDEQ and City of Smelterville, 2013). The city repaired the fence along
one of the channel walls in February of 2015. No other maintenance has been required on the
project.

Pinehurst Project

Little Pine Creek

The majority of the Little Pine Creek Remedy Protection Project was constructed in 2014. Final
completion of the project occurred during the summer of 2015. The major features of the
designed remedy include:

• Installation of four concrete bridge culverts, two in the north reach and two in the south
reach.

• Four concrete box culverts were installed in the south reach along D Street, replacing
existing bridges that provided access to the residences.

3-23

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

• Four existing metal or wood bridges were replaced with new timber bridges in the south
reach.

• A large portion of the existing stream channel was dredged, widened, and cleared of debris.
The new banks were reinforced with riprap or vegetation and the bottom remained natural
stream substrate. Berms were constructed along some sections of the stream channel where
it was more feasible than dredging.

• Installation of new concrete retaining walls at select reaches of the creek.

O&M of the Little Pine Creek project will be conducted by the City of Pinehurst and Shoshone
County following construction closeout (IDEQ and Shoshone County, 2014; IDEQ and City of
Pinehurst 2014). A draft O&M manual was prepared during the design of the project, which
will be revised once construction is complete to incorporate the final project as constructed.

Kellogg Projects

Portland Avenue

The Portland Avenue Remedy Protection Project was constructed in 2014. The major features of
the installed remedy include:

• Approximately 1,150 linear feet of Portland Avenue gravel roadway was resurfaced and a
riprap channel was constructed to convey stormwater to the riprap rundown.

• Installation of a culvert to convey stormwater from the roadside ditch to the riprap
rundown. The riprap rundown will convey stormwater to the storm drain system.

• Installation of a storm drain catch basin and storm drain curb inlet that routes the
stormwater on the project site to the storm drain system. Approximately 425 linear feet of
subsurface storm drainpipe, including three manholes, were installed.

• Construction of a stilling basin that reduces the velocity of the stormwater runoff before
entering the storm drainpipe system. Construction of approximately 50 linear feet of new
curb and gutter to convey surface runoff water to curb inlets.

O&M of the Portland Avenue project will be conducted by the City of Kellogg in accordance
with an Intergovernmental Cooperative Agreement (IDEQ and City of Kellogg, 2014). A draft
O&M manual was prepared during the design of the project, and is currently being finalized.

Jackass Creek

Plans for the Jackass Creek remedy protection project involve installation of a subsurface bypass
pipe and culvert upgrade along the Creek. Construction is planned for 2015.

Page Area Project
Silver Creek

Plans for the Silver Creek remedy protection project involve replacement of a damaged culvert.
Construction is planned for 2015.

Remedy Status

The OU 1 remedy protection projects installed during this review period were constructed
between 2013 and 2014. Maintenance personnel at the cities of Smelterville, Wardner, and
Kellogg were contacted in March 2015 to provide feedback on the project performance and to

3-24

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

summarize any maintenance activities. To date, minor storms have occurred, and the systems
have performed as designed according to discussion with city maintenance staff.

In the relatively short time that these projects have been in place, they have required minimal
O&M efforts. Channel side slopes and channel inverts have remained stable. Based on these
observations, the remedy protection projects appear to be functioning as designed to protect
existing human health remedies against stormwater runoff, tributary flooding, and heavy rain.

3.2.1.6 Institutional Controls Program
Background and Description

Institutional controls were identified as a key component to the Selected Remedy in order to
manage contaminants left in place into perpetuity. The ICP was adopted for OU 1 and OU 2 as
part of the PHD environmental health code in April 1995 and was expanded to include OU 3 in
2007. Implementation and execution of the ICP follows the requirements and standards
described in the Code itself (IDAPA 41.01.01.500 through 41.01.01.543 and 41.01.01.900 through
41.01.01.902).

The ICP was established to 1) protect public health by controlling human exposure to metals,
especially children's exposures; 2) ensure that barriers remain protective, are adequately
maintained, and are appropriately installed in new developments and during redevelopment
activities; and 3) ensure clean materials are used and provide appropriate disposal options for
the local communities. The ICP regulates construction and land use changes on all properties
within the ICP boundary; it is designed to facilitate community development and commerce.

The program provides a number of free services to local residents, including education,
sampling assistance, clean soils for small projects (less than 1 cubic yard of material), collection
of soil removed in small projects, and permanent disposal sites for contaminated soils generated
within the ICP administrative area. The ICP also regulates and provides information for interior
construction and renovation projects that involve ceiling or insulation removal, as well as dirt
basements and crawl spaces. The ICP's permitting process is linked to existing local building
departments and land use planning activities. Educational materials are made available
primarily through permitting, contractor training, and property disclosures to owners, lenders,
and realtors. Pamphlets and flyers with information about the ICP are available at the ICP office
and online. The PHD records ICP activities and summarizes them in quarterly reports that are
provided to IDEQ and USEPA.

The historical context of the ICP, including detailed ICP-related documents, is provided in the
2010 Five-Year Review (USEPA, 2010c). Information specific to OU 2 and OU 3 is discussed in
Section 4.2.12 and Section 5.2.1.6 of this report, respectively.

Operations and Maintenance and Actions since the Last Five-Year Review

All permits and records of compliance are maintained in hard copy and electronic form. PHD
also maintains contractor licenses, logs of samples collected and results, logs of disposal
volumes and counts, and logs of clean soil and gravel provided to homeowners. Since the last
Five-Year Review, PHD completed the following activities under the ICP:

• Issued 2,597 permits in OU 1, most of which were for large exterior excavation projects
(>1 cubic yard) (Table 3-6). Photographs are taken for every permitted project.

3-25

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

• Issued 1,260 licenses to contracting companies and 152 licenses to government entities and
utility companies for all OUs (licenses are not tracked by OU).

• Provided 918 property disclosures in OU 1 and OU 2.

• Recorded and followed-up with 3,096 One-Call system calls in OU 1 and OU 2.

• Scanned all current and historical permits and records of compliance into electronic files
that are maintained on PHD's local server in Kellogg, Idaho and backed-up following
PHD's information technology procedures.

TABLE 3-6

Number of ICP Permits Issued in OU 1, 2010-2014
2015 Five-Year Review, Bunker Hill Superfund Site

Permit Type

Calendar Year

Cumulative
5-Year Total

Annual
Average

2010

2011

2012

2013

2014

Large Exterior
Projects - Excavation3

1,035

241

273

286

378

2,213

443

Large Exterior
Projects - Demolition

Interiors Total

113

Records of
Compliance

224

Total

1,097

308

350

363

479

2,597

519

Notes:

a Includes subdivision/planned unit development totals.

An estimated total of 80,562 cubic yards of soil from permitted projects in OU 1 and OU 2 were
directed to the Page Repository or community fill locations since the last Five-Year Review
(Table 3-7). In addition, an estimated total of 642 cubic yards of building demolition debris
(including insulation), 230 bags of insulation, and 34,430 square yards of carpets and padding
were directed to the Page Repository. As part of the ICP permitting process, waste disposal
volumes are reported by the permittee. For this reason, the reported waste volumes from ICP
permitted projects are estimates and will not match those presented in Section 3.2.2, which are
based on year-end engineering surveys for all remedial action and ICP waste volumes placed
and compacted.

From 2010 through 2014, a total of 237 cubic yards of clean soil and gravel were delivered to
Box properties and a total of 13 vouchers were issued for homeowners to pick up clean soil and
gravel (Table 3-8).

3-26

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TABLE 3-7

OU 1 and OU 2 ICP Waste Disposal Volumes
2015 Five-Year Review, Bunker Hill Superfund Site

Waste
Category

Disposal Site

Materials
Disposed or
Source of
Materials

Units

Calendar Year

Cumulative
5-yr Total

Annual
Average

2010

2011

2012

2013

2014

Building
Demolition

Page Repository

Demolition Debris

350

469

Insulation

Bags

198

230

Insulation

168

173

Carpets and Pads

479

1,068

1,016

19,162

12,705

34,430

6,886

Soil

Disposal

Page Repository

Soil

17,592

14,000

9,125

8,087

18,089

66,893

13,379

Shoshone County Airport

Soil

1,335a

4,744a

370a

6,449

1,290

Transfer Station

Soil

7,220

1,444

Notes:

Data provided by PHD based on permittee estimates,
sy = square yard

a Includes Basin soils disposed at Shoshone County Airport.

3-27

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TABLE 3-8

OU 1 and OU 2 ICP Clean Material Volumes
2015 Five-Year Review, Bunker Hill Superfund Site

Calendar Year

Cumulative
5-yr Total

Annual
Average

Delivery Method

Units

2010

2011

2012

2013

2014

Clean soil and gravel
delivery

237

Clean soil and gravel
delivery

Buckets

Soil and gravel
voucher issued
(homeowner pickup)

No. of
vouchers

The ICP rule gives PHD the authority to undertake enforcement action for noncompliance with
ICP requirements. No enforcement proceedings have been initiated in the Box since the last
Five-Year Review. Letters urging compliance with the ICP are required infrequently.

The 2010 Five-Year Review recommended the following specifically to OU 1, and discussions of
each recommendation and actions taken since 2010 are presented in the following list.

• Recommendation: Secure permanent funding for the ICP, including consideration of
adequate staff and information management support to manage the program, as required
by the 1994 Consent Decree.

Discussion: Funding for the OU 1 ICP has been secured through settlements with Hecla
Mining Company and Asarco. The funds are in the State of Idaho's Bunker Hill Consent
Decree Trust Fund and are invested in interest-bearing accounts of the State of Idaho
Treasurer's Office. Based on cost estimates for the ICP administration and disposal
management these funds are expected to be able to provide secure funding for the near
future (currently estimated for approximately 30 more years). PHD adopted the rule based
on the premise of external funding and as such, IDEQ continues to monitor ICP costs and
available funding, and make adjustments as necessary to meet long-term ICP funding
obligations. Additionally, PHD evaluates staffing needs and adjusts when necessary. This
recommendation is complete.

• Recommendation: Complete the Community Fill Policy (CFP) currently being developed by
USEPA and IDEQ for all three OUs.

Discussion: The CFP for using metals-impacted materials within the ICP administrative
boundary was finalized by IDEQ and USEPA in December 2013 (USEPA and IDEQ, 2013).
Subsequently, in 2014, IDEQ began evaluating possible CFP sites based on the established
criteria. This recommendation is repeated for all three OUs and is complete for all three
OUS.

3-28

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

• Recommendation: Continue offering ICP programs, including the vacuum loan program.
Secure permanent funding the ICP as required by the 1994 Consent Decree (an ongoing 2005
Five-Year Review recommendation).

Discussion: ICP funding is addressed above. PHD continues to offer the HEPA vacuum
loan program as part of the LHIP and will continue to do so. This recommendation will not
be retained in the table of issues and recommendations, because it is an ongoing element of
the ICP. This recommendation is complete.

• Recommendation: Continue offering services, including blood lead screening services and
follow-up nurse visits, to help identify and mitigate potential exposure pathways (an
ongoing 2005 Five-Year Review recommendation).

Discussion: Blood lead screening is an important component of the LHIP. PHD has
maintained the blood lead screening program and follow-up consultations throughout the
Site and will continue to do so. This recommendation will not be retained in the table of
issues and recommendations, because it is an ongoing element of the Remedial Action LHIP
component. This recommendation is complete.

• Recommendation: Address long-term disposal needs as part of the permanent funding for
ICP, as required by the 1994 Consent Decree. Evaluate the need for snow disposal areas (an
ongoing 2005 Five-Year Review recommendation).

Discussion: Long-term waste estimates have been developed and planning for additional
Box repository space is ongoing (TerraGraphics, 2014a). Expansion of the Page Repository is
discussed in Section 3.2.2. The long-term disposal needs portion of the recommendation is
complete because this task has been initiated and is underway. Snow disposal is still an
issue of concern identified by ICP inspectors. As snow melts, sediment is left behind, and
past samples for some years have averaged more than 1,000 mg/kg lead (see
Section 3.2.1.1). If contaminated sediment left behind as snow piles melt is of a significant
quantity and lead concentration, these sediments may contribute to recontamination
because most of the snow piles are located on remediated properties with gravel/ soil
barriers. The snow disposal portion of the recommendation will not be retained in the table
of issues and recommendations, because it does not directly affect protectiveness. It will
instead be included in the table of planned action items.

• Recommendation: Continue working with the BEIPC and other stakeholders to evaluate
and plan actions relative to addressing SFCDR and Pine Creek flooding that may affect
cleanups.

Discussion: IDEQ, USEPA, and the BEIPC have requested assistance from federal and state
flood control agencies to address the threat of large-scale flooding to the remedy (such as
flooding from the SFCDR and Pine Creek). The Silver Jackets, an interagency coordinating
group, identified local actions that could be taken to help protect against flooding. However,
funding has not yet been found to perform the required flooding study and subsequent
flood control projects. The BEIPC Executive Director continues to work with local flood
control entities to identify sources of assistance. This recommendation is complete. This
recommendation is repeated for all three OUs.

3-29

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

• Recommendation: Continue working to develop an approach for addressing roads as long-
term barriers in collaboration with state, county, and local entities.

Discussion: Approximately 28 miles of Box and Basin roads that were underlain by
contaminated soils were rebuilt, patched, or chip sealed in 2013 and 2014. The Paved Roads
program is expected to last several more years in the Box and Basin. Local authorities are
responsible for long-term maintenance and eventual replacement of roads within their
jurisdictions. This recommendation is repeated for all three OUs and is complete for all
three OUs.

• Recommendation: Develop appropriate institutions and funding mechanisms to finance
and oversee stewardship activities.

Discussion: In 2013 and 2014, USEPA and the Coeur d'Alene Trust have invested
approximately $11.5M in paved road surface remediation and $6.4M in flood management
infrastructure work throughout the Upper Basin. These "Paved Roads" and "Remedy
Protection" projects are on-going. In addition to the Selected Remedy Protection projects
identified in the 2012 ROD Amendment (USEPA, 2012b), IDEQ, USEPA, and the BEIPC
have requested assistance from federal and state flood control agencies to address the threat
of large-scale flooding to the remedy (such as flooding from the South Fork of the Coeur
d'Alene River and Pine Creek). The Silver Jackets, an interagency coordinating group,
identified local actions that could be taken to help protect against flooding. However,
funding has not yet been found to perform the required flooding study and subsequent
flood control projects. The BEIPC Executive Director continues to work with local flood
control entities to identify sources of assistance. Since the last Five-Year Review, Remedy
Protection projects have been constructed. In addition, associated environmental covenants
and O&M agreements have been developed to ensure long-term maintenance of the
constructed infrastructure. These assist in addressing the institutional elements of the
recommendation. Additionally, IDEQ has developed an inventory of flood control
structures in the communities, including those that were installed as part of the remedy.
IDEQ plans to create a coordination cooperative that will work together to track
maintenance and repair work for the structures. This effort is in the initial planning stage.
This recommendation will not be retained in the table of issues and recommendations,
because much work has been completed and additional actions are underway to oversee
stewardship activities. It will instead be included in the table of planned action items. This
recommendation is repeated for all three OUs.

• Recommendation: Repair and regularly maintain existing infrastructure (e.g. failing roads).
Identify funding and other resources for infrastructure maintenance and improvement to
protect the remedy, such as stormwater controls (an ongoing 2005 Five-Year Review
recommendation).

Discussion: In 2013 and 2014, USEPA and the Coeur d'Alene Trust have invested
approximately $11.5M in paved roads surface remediation and $6.4M in flood management
infrastructure work throughout the Upper Basin including OU1. These "Paved Roads" and
"Remedy Protection" projects are ongoing. Local jurisdictions and IDEQ have entered into
Interagency Cooperative Agreements in which the jurisdictions have accepted responsibility
for O&M of Paved Roads and Remedy Protection structures. In addition, since the last Five-
Year Review, IDEQ has developed an inventory of flood control structures in the

3-30

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

communities, including those that were installed as part of the remedy. IDEQ plans to create
a coordination cooperative consisting of local jurisdictions and IDEQ that will work together
to track maintenance and repair work for the structures. This effort is in the initial planning
stage. Because this effort will be pursued in response to the recommendation directly above,
this recommendation is complete.

Remedy Status

As part of this Five-Year Review, ICP activity reports and special reports concerning recreation,
storm, fire, and flood events were reviewed and discussions with PHD personnel were
completed. Several issues were identified that pose challenges to the ICP.

In the last five years, localized flooding was previously noted to be an issue with destroying
barriers, and was noted again in the winter of 2010-2011 and 2012 (PHD, 2011a and 2013a).
Erosion from hillsides may potentially affect adjacent remediated properties. In August 2011, a
fire on the hillsides around Kellogg and Wardner burned more than 17 acres. The area is steep
and the vegetative barrier that was controlling erosion and soil movement was compromised
(PHD, 2011b). Damaged barriers have the potential to release contaminants back into the public
domain where children can again be exposed. To begin to address these issues, the 2012 ROD
Amendment selected projects to assist with protecting the remedy (see Section 3.2.1.5).
Additionally, USEPA and the State of Idaho requested assistance from federal and state flood
control agencies to address the threat of large-scale flooding to the remedy. The Silver Jackets,
an interagency coordinating group, identified local actions that could be taken to help protect
against flooding.

Managing recontamination or release of contamination because of localized instances of runoff
has been a challenge for the ICP. For example, contaminated runoff from the Bunker Hill Mine
complex in Kellogg was identified after high precipitation in spring of 2014, and has not yet
been comprehensively addressed. USEPA and IDEQ subsequently took actions to clean out a
drainage ditch that was previously constructed to direct water to a storm drain off Mine Road
from the Bunker Hill Mine.

PHD personnel indicate that adequate documentation is a key component for the ICP to issue
permits and disclose appropriately. In the past and at times, the ICP has been unable to acquire
or locate documentation from entities performing work that affects properties on the Site. As
remediation continues, it is imperative that the Coeur d'Alene Trust, USEPA, IDEQ, U.S. Army
Corps of Engineers (USACE), and any other entity conducting earthwork provide the ICP with
documentation of completed work to ensure PHD's database remains up to date.

Community and contractor acceptance and compliance with the ICP remains high. PHD
routinely requests feedback from those acquiring permits and licenses on the quality of ICP
services. From 2010 to 2014, nearly 28 percent of questionnaires sent to Box and Basin
contractors, utility companies, and government agencies were returned; very few
questionnaires were returned by homeowners. A large majority of responses rated the ICP as
good or excellent (> 96 percent). Based on community-wide acceptance, no enforcement actions
have been required. ICP users indicated a very high level of satisfaction with the program. The
main concerns voiced relate to increased costs incurred on large projects for labor, gravel,
cleanup (dependent on weather and time of year), drainage issues, and access to disposal sites.

3-31

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Based on record and report reviews and discussions with personnel, PHD continues to
implement the ICP according to its rule (IDAPA 41.01.01). PHD continues to implement the ICP
in a manner that maintains the 350 mg/kg residential community-wide lead average in soils by
directing contaminated soils to a repository, enforcing the use of clean import soils, and
permitting and inspecting new property development. Clean barriers that were disrupted
through excavation have been repaired in response to ICP permitting and inspection activities.
The ICP inspectors are continually in the field to ensure that barriers are installed consistent
with the remedy defined in the ROD and in compliance with the ICP rule. PHD has also
continued to evaluate and ensure the appropriate level of staffing for the ICP and maintain
adequate information management support that is critical to ensure the long-term sustainability
and protectiveness of installed remedies. Funding to implement the ICP into perpetuity is
critical.

3.2.2 Box Repository

This section presents information for the Bunker Hill Box Repository Program with respect to
disposal of waste from ICP-permitted activities and Remedial Actions. Background, remedial
actions, and remedy evaluation of the Page Pond area in OU 2 are presented in Section 4.2.12.

3.2.2.1 Background and Description

Primary disposal operations for waste generated in the Bunker Hill Box occur at the Page
Repository in the Page Pond area, located near the west end of OU 2 (Figure 3-4). The areas
immediately to the east and west of the Page Ponds Wastewater Treatment Plant (PPWTP) were
used as designated repository areas for contaminated soils removed during implementation of
remedial actions within OU 1 and OU 2 and are identified as East Page Repository and Page
Repository, respectively. The East Page Repository was filled and has been closed since the mid-
1990s. In 2010, expansion of the Page Repository (the Wedge expansion) into West Page Swamp
started to address the need for additional repository space within the Box. A much larger
expansion, planned in phases or cells to the west of the Wedge, began in 2013 and is known as
the Westward Expansion (TerraGraphics, 2013c).

A long-term repository system in the Box is necessary to meet the needs of local residents,
contractors, utilities, and the government, while protecting the remedial actions implemented
pursuant to the ROD. The Page Repository, currently managed by IDEQ, has been used as the
primary repository for waste materials generated under ICP permits. In 2013 and 2014, it was
also used to dispose of remedial action wastes from remedy protection and paved roadway
remediation projects.

The historical context of the Page Repository, including disposal volumes, is provided in the
2010 Five-Year Review (USEPA, 2010c). Additionally, the Page Repository Westward Expansion
2013 Annual Water Quality Report (IDEQ and TerraGraphics, 2014) provides a comprehensive
conceptual site model that includes a summary of the historical Site activities, past remedial
actions, repository use and expansion, site-specific conditions, hydrogeology, and surface
water-groundwater interactions.

3-32

-------
SMELTERVILLE FLATS

INTERSTATE 90

WEST PAGE
SWAMP

TRA'L OF the

D'^LENES

/ PAGE
/ REPOSITORY

PAGE WASTEWATER
TREATMENT PLANT

EXPANSION BOUNDARY WITH
CONSTRUCTION PHASE-BOUNDARIES

EAST PAGE 1
REPOSITORY

SMELTERVILLE

EAST PAGE*
SWAMP

WEDGE PAGE REPOSITORY
EXTENSION

WEST BENCH EXTENSION

jKUiJ);

Repository Boundary

Repository Extensions

Surface Water

WENI Wetland Area

0
L

375

750

1,500 Feet

J I

TerraGraphics Environmental Engineering, Inc. Five_Year_2015 / Page_Area.mxd 3/13/2015

FIGURE 3-4

Page Ponds Repository and Vicinity

2015 Five-Year Review
BUNKER HILL SUPERFUND SITE

v>EPA

-------
-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

3.2.2.2 Operations and Maintenance and Actions since the Last Five-Year Review

Several upgrades and operational changes have been completed to allow for greater efficiencies
and expanded repository capacity since the last Five-Year Review.

Upgrades completed during the 2010 summer construction season included a woody debris
stockpile area and associated composting bins for the use of compost as a soil amendment in
revegetation efforts. The access routes and traffic patterns were also rearranged and a one-way
loop was added to allow for continuous traffic flow, more efficient operations, and ease of use.
Asphalt regrinds covered these new routes to provide a passive barrier against the spread of
contamination from tracking and fugitive dust emissions. A newly established ICP stockpile
area began providing a designated area for residents to dispose of their waste materials
(generated from ICP-permitted projects) easily and safely outside the areas where heavy
construction equipment is operated. The apron of asphalt regrinds that underlies the ICP
stockpile area is routinely washed off to minimize 1) exposure of ICP customers to
contaminants in the disposal area and 2) offsite tracking. The ICP area is continuously accessible
through PHD-managed key-card access. The final upgrade completed in 2010 was the
designation of an area to contain petroleum-contaminated soils (PCS) that may be generated
from accidents or spills within the ICP administrative boundary. A berm constructed around
this designated area allows it to be used for emergency disposal of PCS, if needed in the future.
It is the only designated PCS disposal and treatment location within the Silver Valley.

Westward expansion of Page Repository was selected as the preferred alternative for additional
repository space (TerraCraphics, 2011a). The Westward Expansion is expected to hold a total of
665,000 cubic yards of waste soil and is planned in phases. The foundation consists of coarse
durable cobble-sized material, designed to segregate contaminated waste from West Page
Swamp surface water, and riprap side-slope armoring to prevent scour.

Based on this design layout, construction of the foundation for Cell 1 of the expansion began in
fall 2012. Foundation construction continued in May 2013 and waste placement commenced in
Cell 1. The Final Design Report was completed in September 2013 (TerraGraphics, 2013c). In
May 2014, foundation materials were stockpiled on the western edge of Cell 1 for Cell 2 site
preparation and construction, which began shortly thereafter. The foundation for Cell 2 was
completed in November 2014.

To mitigate for wetland losses associated with the Westward Expansion, a 14-acre wetland was
constructed in 2012 in the 18-acre WENI area, located north of West Page Swamp. An additional
45-acre wetland mitigation project at Robinson Creek in the Lower Coeur d'Alene Basin began
in 2014 to complete USEPA and IDEQ obligations for mitigating wetland losses due to the
expansion. Construction of the Robinson Creek mitigation project is scheduled to be completed
in 2015.

As part of the O&M of Page Repository, annual topographic surveys to estimate waste
placement volume have been completed beginning in 2012. Table 3-9 presents estimated
volumes for the years 2012-2014 based on in-place, compacted cubic yards of ICP and remedial
action waste and Panhandle Health estimated ICP waste volumes for 2010 and 2011.

Section 3.2.1.6 includes a description of estimated ICP waste volumes.

3-35

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TABLE 3-9

Estimated Waste Volumes Placed at Page Repository 2010-2014
2015 Five-Year Review, Bunker Hill Superfund Site

Year

Foundation
(cy)

Westward
Expansion
Waste Soils
(cy)

Wedge Waste
Soils (cy)

Total Waste Soil
Volume Placed,

Excluding
Foundation (cy)

Total Volume
Placed (cy)

2010

17,470

2011

11,500

2012

9,975

26,200

36,175

2013

4,400

11,525

7,500

19,025

23,425

2014

21,800

52,000

1,650

53,650

75,450

Totals

36,175

63,525

46,850

110,375

146,550

The Paved Road program implemented in the Box began generating significant waste volumes
in 2014. The waste from this program is in the form of inert asphaltic concrete and generally
low-level contaminated base materials excavated with the asphalt. To prioritize repository
space for more contaminated ICP and remedial action wastes, a Limited Use Repository (LUR)
was sited and developed in the Government Gulch area south of Smelterville, in accordance
with the LUR policy memo, (IDEQ and USEPA, 2015). The Government Gulch LUR will operate
for approximately 2 years to receive Box road waste. It will then be completed into an area
ready for redevelopment, following the ICP capping requirements. It has a design capacity of
82,000 cy.

The 2010 Five-Year Review included the following recommendations. Any actions taken since
2010 follow each recommendation.

• Recommendation: Continue to develop a comprehensive O&M and Site Closure Plan for
the Page Repository.

Discussion: An interim O&M plan for the Page Repository was developed as part of the
Repository expansion design. Although closure criteria for soils cap and cover, use of
stormwater best management practices (BMPs), and Site access controls are stipulated in the
final designs for the Westward Expansion, a final closure plan will not be completed until
the final repository footprint has been developed. At that time, plans are to update the Page
Repository O&M plan based on current operating practices and to incorporate Page Pond
Area O&M requirements into a comprehensive plan. This activity will not be retained in the
table of issues and recommendations, because it does not directly affect protectiveness. It
will instead be included in the table of planned action items.

• Recommendation: Evaluate appropriate decontamination improvements and put measures
in place to reduce the potential for recontamination (an ongoing recommendation from the
2005 Five-Year Review).

Discussion: Construction of a water production well for a complete decontamination
facility began in the spring of 2014. The facility was fully functional for the 2014 construction
season. The facility is used for decontamination of all vehicles entering and leaving the
Exclusion Zone of the repository, for filling water trucks used in fugitive dust abatement, to

3-36

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

promote composting on wood chip piles, and to prevent spontaneous combustion of
composting piles. This recommendation is complete.

• Recommendation: Evaluate biological monitoring results and impacts related to the Page
Repository expansion (an ongoing recommendation from the 2005 Five-Year Review).

Discussion: The WENI Wetland was constructed in 2012 as part of the wetland mitigation
for the Westward Expansion of Page Repository. In keeping with the design goal to improve
wetland habitat, approximately 14 acres of wetlands were constructed or improved within
the 18-acre WENI area. Construction included removing more than 50,000 cubic yards of
rock and soil material, which was taken to Page Repository where it was screened and
sorted for re-use or disposal. As part of the mitigation process, the monitoring, evaluation,
and maintenance of the constructed wetlands are vital to document the wetland condition,
progress, and status over time. Specific post-construction requirements, a monitoring and
evaluation plan, guidance for O&M, adaptive management of the WENI wetland, and a
comprehensive method for determining wetland mitigation credits was developed in 2014
(TerraGraphics, 2014b). Mitigation credits for the expansion of West Page Swamp will be
determined over a period of approximately five years and will be based on the MDT
Montana Wetland Assessment Method (Bergland, 1999).

IDEQ started a monitoring and maintenance program at the WENI wetland immediately
following construction (TerraGraphics, 2013d and 2014b) and two monitoring events have
been conducted at the Site in 2013 and 2014 (TerraGraphics, 2014b and 2015b). IDEQ has
assessed the potential for mitigation credits and anticipates 14.3 acres of 1-to-l credit from
the WENI Wetland (TerraGraphics, 2014c). IDEQ anticipates that the mitigation credits
derived from the Robinson Creek Project will exceed USEPA and IDEQ obligations for the
Westward Expansion and will be banked to offset other site-wide remedial actions requiring
mitigation under Section 404 of the CWA. Additionally, USFWS continues to conduct
biological monitoring of the Page Pond area annually; the results are summarized in
Section 2.5.3. This recommendation is complete.

3.2.2.3 Remedy Status

Reviews of existing documents, Site evaluations, and water quality data all indicate the Page
Repository is currently functioning as designed. Repository expansion and associated actions
are ongoing to provide continuous ICP and remedial action waste disposal capacity. IDEQ
predicts a need for additional repository space (beyond the Westward Expansion) for future
remedial actions and ICP projects in the Box, which may generate more than 2.4 million cubic
yards of waste. IDEQ and USEPA continue to work on alternative waste reuse and disposal
technologies to provide for this need. This includes recycling and reuse of asphalt and concrete,
use of community fill sites, and the development of limited use repositories for specific
purposes or projects.

3-37

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Weekly, monthly, and annual reports for construction progress and remedy performance are
developed and IDEQ applies corrective actions as needed. O&M activities at the Page
Repository have occurred based on those outlined in the Page Repository Westward Expansion
Design Report (TerraCraphics, 2013c) and a draft O&M Plan. Maintenance and modification of
stormwater BMPs occur routinely. All BMPs are inspected weekly and after major stormwater
events. The results of those inspections are documented in weekly reports. BMPs are
maintained or modified based on the results of those inspections. There have been no
unauthorized releases through the stormwater management system and no catastrophic failures
observed.

The potential for tracking contaminated materials has been reduced with the addition of the
permanent decontamination facility in full operation during daytime hours throughout the
construction season. For ICP users, a road surfaced with gravel and asphalt regrind leads to the
designated disposal area on top of the historical repository where they can dispose of soil and
exit the repository while traveling on designated clean roads. Because the hardened roadways
are easy to clean and have proven to be an asset in controlling contaminant tracking, all
roadways, off-loading aprons, equipment, and materials stockpile areas that are underlain by
asphalt regrinds are routinely inspected, washed clean of dirt and litter, and rebuilt to optimize
their use as a clean barrier in the work area.

As Page Repository expansion continues, revegetation efforts keep pace with the earthwork to
minimize the area exposed to erosion by wind and water, and to begin closure of those portions
of the repository that have reached final grade. Repository side slopes are covered with a
mixture of clean soil and composted woodchips, hydroseeded, and watered annually as the
repository expands. Revegetation efforts have provided a robust vegetative community that
also reduces fine sediment on the face of the repository where cap and cover activities are not
yet completed. Minimizing exposed earthworks eliminates excessive fugitive dust, as observed
and reported in the last Five-Year Review.

The primary goal of groundwater and surface water quality monitoring at and near the Page
Repository is to monitor for potential impacts from the Westward Expansion. Monitoring began
in 2009 for the Page Repository Westward Expansion, prior to waste placement in the expended
repository footprint, and continues to-date. Dissolved metals are considered indicators of
contamination under base-flow conditions for surface water and for all groundwater conditions.
Total metals, especially lead, are indicators of contamination in surface water under high-flow
conditions. Historical impacts on water quality at the Page Ponds area, prior to the Page
Repository, resulted from the Page Pond Tailings Impoundment, which was used to contain
flotation tailings and reprocessed jig tailings stored within this vicinity (IDEQ and
TerraGraphics, 2014 and 2015). Prior to the Westward Expansion, historical exceedances of the
regulatory thresholds include dissolved arsenic, cadmium, lead, and zinc in groundwater, and
dissolved cadmium, mercury, and zinc and total arsenic, cadmium, and zinc in surface water.
Six monitoring events have been conducted since the start of waste placement in May 2013, and
results show exceedances for the same contaminants at similar levels. Although historical
impacts to water quality are present, the 2013-2014 data collected after waste placement
provide no immediate indications that placement of repository waste in the Westward
Expansion is adversely affecting water quality. However, only limited data are available (six
sampling events over 18 months) and insufficient data exist to conduct statistical trend analyses.
Statistical analysis is planned following collection of the 2015 data.

3-38

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

3.3 Technical Assessment for Operable Unit 1

3.3.1 Is the Remedy Functioning as Intended by the Decision Documents?

The implemented risk management strategies outlined in the Selected Remedy have been
successful in reducing OU 1 children's lead exposure and subsequent lead absorption. The
Human Health Selected Remedy aimed to protect residents from exposure to lead and other
metals by removing and replacing contaminated surface soil and waste as well as establishing
barriers in residential yards, commercial properties, and ROWs that contain subsurface
contamination.

The community mean soil lead target of 350 mg/kg was achieved in all communities by 2008
(USEPA, 2010c) and is assumed to remain similar today because ongoing ICP activities have
been successful in maintaining barriers. In addition to the ongoing ICP, the Paved Roads
program and Remedy Protection projects have been implemented since 2013 to ensure materials
greater than or equal to 1,000 mg/kg lead remain below a barrier. Under the Paved Roads
program, to date approximately 14 miles of Box roads have been rebuilt, patched, or chip sealed
by the end of 2014 and now provide effective barriers to contaminants. Approximately 25 miles
of Box roads remain to be addressed by the Paved Roads program. Four remedy protection
projects have been completed by the end of 2014, all of which are performing as designed. Three
more Remedy Protection projects remain to be constructed in OU 1.

Remedial actions at OU 2 areas that contributed to fugitive dusts in OU 1 were largely
implemented prior to 2002. O&M activities continue to maintain the remedies (see Section 4.3).

Remedial action waste and contaminated materials generated from ICP-permitted projects
continue to be disposed of at the Page Repository. Reviews of construction and on-going
operations reports and water quality data indicate the Page Repository is functioning as
designed. Repository expansion and associated actions are ongoing to provide capacity for ICP
and remedial action waste in the Box into the future. IDEQ recognizes the perpetual need for
additional repository space (beyond the expansions to the Page Repository) to support future
ICP projects in the Box.

Interior mean dust lead concentrations in Box communities remain below the community-wide
risk-based goal of 500 mg/kg, even though the one-time interior cleaning component of the
Selected Remedy has not been implemented. Approximately 5 percent of homes still have house
dust lead concentrations above 1,000 mg/kg, the criterion for the one-time cleaning remedy
specified in the ROD. Elevated lead levels in some homes may be attributed to multiple
potential sources of contamination such as the following:

• Soil and sediment from hillsides, the Coeur d'Alene River Basin, and Upper Basin mine and
mill sites where many residents recreate;

• Erosion from hillsides surrounding OU 1, especially those abutting residential properties;

• Occupational sources;

• Lead-based paint;

• Interior legacy reservoirs such as attics, basements, and crawl spaces; and

• Personal activities, occupations, or hobbies.

3-39

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

The Selected Remedy only addresses mining- and smelter-related lead sources and cannot
change personal choices and activities. The efficacy of a one-time interior cleaning of homes
with dust lead concentrations greater than or equal to 1,000 mg/kg versus other methods of
reducing a typical child's risk of elevated blood lead levels in those homes has yet to be
resolved. Additional work to determine a risk management strategy for OU 1 homes with dust
lead concentrations greater than or equal to 1,000 mg/kg is ongoing (TerraCraphics, 2015a).

The Selected Remedy also included the prevention of contaminated groundwater consumption.
Private groundwater wells used for drinking were closed during the years that yard soil
remedial actions were ongoing; however, the current potable or nonpotable status of 13 wells
whose owners refused closure is currently unknown. The IDWR continues to designate the
upper and lower zones of the main valley groundwater system within OU 1 and OU 2 as an
"area of drilling concern" to protect public health and further minimize aquifer contamination.

The LHIP provides voluntary blood lead screening, environmental health follow-up for
children with blood lead levels greater than or equal to 5 jug/dL, education and awareness
programs, and the vacuum loan program. Participation rates for blood lead monitoring in the
Box have been highly dependent on door-to-door recruitment and monetary incentives,
resulting in low participation in years when they are not provided. The vacuum loan program
continues to be utilized by area residents.

The success of the ICP has been demonstrated for almost 20 years in the Box, as it continues to
accomplish the following:

• Ensure that barriers are installed and maintained to prevent recontamination and
consequent exposure;

• Provide clean materials and appropriate disposal options for the local communities; and

• Minimize the impact of residual subsurface contamination on community development and
the conduct of commerce.

PHD issued 2,597 ICP permits in OU 1 in the last 5 years, and observations by PHD personnel
inspecting these ICP-permitted projects indicate that owners (or their representatives) are
maintaining installed barriers. Soil and sediment samples collected since 2010 for ICP
monitoring and permitting purposes show substantial subsurface contamination remains in
OU 1, with lead levels greater than 40,000 mg/kg. These results reinforce the continued need for
an ICP to protect public health. PHD personnel have indicated that tracking and permitting of
interior projects, which are often not permitted through the local building authorities, is
difficult because interior work is not seen as easily as exterior projects. While estimates indicate
funding for the ICP is expected to cover the near future, long-term funding mechanisms will be
necessary to ensure success of the Selected Remedy and ultimately maintain public health and
the environment.

3-40

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Approximately half of the estimated childhood population participated in the 2013 LHIP blood
lead screening because of door-to-door recruitment and monetary incentives. The observed
mean blood lead level was 2.2 (ig/ dL, ranging from 1 to 20 (ig/ dL, and 1 percent (2 of 276 tested
children) exhibited blood lead levels greater than or equal to 10 (ig/ dL. Sustained blood lead
reductions indicate that the risk management strategies outlined in the Selected Remedy are
functioning as intended.

Successful implementation of the remedial strategy has required a comprehensive approach to
reduce soil and dust lead exposures throughout the communities. Remedial actions
simultaneously produced reductions in soil exposure and sources of lead in house dust, both of
which are essential to meeting and maintaining achievement of the blood lead RAOs (discussed
in Section 3.2.1.4). Observed blood lead levels and IEUBK Modeling results (discussed in
Section 3.2.1.2) indicate that the remedial actions continue to operate and function as designed.

3.3.2 Are the Exposure Assumptions, Toxicity Data, Cleanup Levels, and Remedial
Action Objectives Used at the Time of Remedy Selection Still Valid?

No changes or new applicable or relevant and appropriate requirements (ARARs) since the last
Five-Year Review.

The Box RAOs were selected based on the residential scenario for risk assessment (i.e., chronic
and sub-chronic residential exposure through the air, diet, drinking water, and soil/ dust
pathways). The following summarizes the OU1 RAOs.

• No more than 5 percent of children in the community have a blood lead level of 10 (ig/ dL or
greater.

• Less than 1 percent of children exceed 15 (ig/ dL.

The Box RAOs are community-based, which differs from current USEPA lead health risk policy
(USEPA, 1994a and 1998b). The current guidance advises that the risk of a typical child exceeding
10 (ig/ dL be less than 5 percent (USEPA, 1994b and 1998b) and uses the individual residence as
the primary exposure unit of concern, as opposed to the community. As noted in previous Five-
Year Reviews, the original OU 1 RAOs are considered to be protective of children living in the
Box (USEPA, 2000a, 2000b, 2005, and 2010c). There are likely individual homes in OU 1 where a
child living at that residence would have more than a 5 percent chance of experiencing a blood
lead level of 10 (ig/ dL or greater. These exceedances are often associated with high house dust
lead levels in combination with residual soil concentrations exceeding 700 mg/kg (USEPA,
2010c) and recreation occurring in non-remediated areas. To address the subset of individual
OU 1 homes with estimated exceedances, USEPA, PHD, and IDEQ will continue to assess the
sources of lead in house dust and the need for implementing the interior cleaning remedy.

Since the last Five-Year Review, CDC has recognized that adverse health effects occur even with
low lead levels in the blood, and in 2012 began utilizing a reference value of 5 (ig/ dL (CDC,
2012). In response to this recommendation, PHD lowered the LHIP follow-up criterion to
5 (ig/dL in 2012. USEPA is currently considering this CDC recommendation and its
implications for current lead health risk management policies at Superfund Sites at the national
level.

3-41

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

The cleanup strategy developed for the Box was based on site-specific dose-response analyses
of the blood to soil/ dust relationship. The cleanup levels were developed using an early version
of the model later released as the IEUBK Model for Lead in Children. The dose-response
relationship at the Bunker Hill site was evaluated extensively using site-specific soil, dust, and
blood lead data amassed through 1990. At that time, the default IEUBK model over-predicted
observed blood lead levels, and quantitative analyses identified a number of Bunker Hill site-
specific parameters that improved the IEUBK model's ability to predict blood lead levels in
resident children. Previously, it was not possible to determine whether the reduced dose-
response relationship was due to lower soil/ dust ingestion rates, lower bioavailability, or a
combination thereof. Consequently, the original risk analysis used a combination of reduced
soil/ dust ingestion rates (a nominal average of 70 mg/ day) and reduced bioavailability
(20 percent) (TerraGraphics, 1990). The dose-response relationship, particularly soil and dust
lead uptake (ingestion rate x bioavailability), was monitored throughout the cleanup, and the
uptake parameters were adjusted periodically to reflect the accumulating data. These
adjustments, in addition to modifications in the IEUBK model, resulted in what is now referred
to as the "Box Model," which used default IEUBK soil/dust ingestion rates (nominal average of
109 mg/ day) and a reduced bioavailability of 18 percent. The other assumptions and
parameters used for the lead risk modeling are described in the original documents (Jacobs
Engineering Group [J EG] et al., 1989 and TerraGraphics, 1990).

New information related to the risk parameters used at the time of remedy selection is now
available. In 2012, a USEPA-funded research project analyzed archived property soil and house
dust samples for analysis of in vitro lead bioavailability (IVBA) (USEPA, 2007a and 2012c).
Archived soil and house dust samples originally obtained, respectively, from the top 1 inch of
73 yards and from 193 homes in Box communities were sieved using a No. 80 mesh and
analyzed for IVBA. The objective of the project was to estimate children's soil and dust
ingestion rates through re-evaluation of the dose-response relationship using the new
bioavailability data. Mean soil bioavailability ranged from 30 to 39 percent by community,
averaging 33 percent (standard deviation ±4.0 percent), and dust bioavailability ranged from
27 to 30 percent, averaging 28 percent (standard deviation ±5.5 percent) (von Lindern et al.,
2015). Use of the new bioavailability results provided age-specific soil/dust ingestion rate
estimates ranging from 86 to 94 mg/ day for 6-month to 2-year-old children and 51 to
67 mg/ day for 2- to 6-year-old children.

This new information suggests that a nominal soil and dust and ingestion rate of 65 mg/ day
and 30 percent bioavailability (near the IEUBK default value) is a more appropriate combination
than those used in the original risk assessment. While this differs from the combination of soil
and dust ingestion rates and bioavailability parameters employed, use of the new values results
in nearly the same post-remedial blood lead estimates and cleanup levels (using a blood lead
criterion of 10 \ig/ dL) and ultimately has little effect on the validity of the OU 1 blood lead
RAOs. EPA will continue to evaluate the protectiveness of the remedy in future Five Year
Reviews taking into account any changes to the Superfund lead health risk management
policies.

3-42

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Toxicity data for a few nonlead chemicals of concern have changed since the time of remedy
selection, including arsenic and cadmium cancer slope factors and arsenic, zinc, and copper
reference doses (RfD) for noncarcinogenic effects. The arsenic and cadmium inhalation cancer
slope factors are outdated because guidance for estimating risk from the inhalation pathway has
changed since the time of the risk assessment (USEPA, 2009a). The impact of these changes on
baseline risk is unknown without further calculations. Zinc's oral RfD has increased slightly
since the time of the original risk assessment, resulting in a decreased risk. The RfD for copper
used in the risk assessment is outdated and the consequential change in risk is unknown
without further calculations. The noncancer baseline and incremental risk from both zinc and
copper was negligible (TerraGraphics, 1990). The oral RfD for arsenic has decreased since the
time of the risk assessment, resulting in an underestimation of risk for noncancer effects.
However, noncarcinogenic risk from arsenic was already considered excessive. Although these
changes in toxicity factors have been identified, the Selected Remedy remains valid because
subchronic lead was the most significant health risk and was used to determine the cleanup
strategies.

No major changes in OU 1 land use have occurred since the last Five-Year Review.

3.3.3 Has any Other Information Come to Light that Could Call into Question the
Protectiveness of the Remedy?

The 2015 Five-Year Review did not find new information that calls into questions the
protectiveness of the OU 1 remedies.

3.4 Summary of Operable Unit 11ssues, Recommendations, and
Follow-Up Actions

Issues, recommendations, and follow-up actions that were identified during this fourth, or
previous, Five-Year Reviews and affect protectiveness are summarized in Table 3-10. Action
items that were identified during this fourth Five-Year Review and do not affect protectiveness,
but are expected to require future action, are summarized in Table 3-11. These
recommendations are summarized herein to allow USEPA to track this information, as
suggested by Five-Year Review guidance (USEPA, 2001a).

3-43

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TABLE 3-10

OU 1 Summary of Issues and Recommendations
2015 Five-Year Review, Bunker Hill Superfund Site

Remedial
Action
(e.g., Human
Health
Barriers,
ICP)

Issue

Recommendations

Party
Responsible

Oversight
Agency

Planned
Completion
Date

Affects
Protectiveness?

(YIN)

Current

Future

House Dust

Results of two pilot studies
indicate that house dust lead
concentrations return to pre-
cleaning levels within one year
of cleaning, regardless of the
cleaning method. Recent data
confirm that house dust lead
concentrations have achieved
the community mean of
500 mg/kg and the number of
homes exceeding 1,000 mg/kg
lead in house dust is declining.

Evaluate the need for
implementation of the interior
cleaning component of the remedy
based in part on information on
alternative dust lead sources.
Determine additional data and
monitoring needs to support one-
time cleaning evaluation.

IDEQ, USEPA

IDEQ,
USEPA

December 31,
2017

Drinking
Water

Owners of 13 wells that
exceeded federal drinking water
standards refused closure. At
the time of refusal, all wells
were dedicated to non-potable
uses.

Review current use of the 13 wells
whose owners refused closure to
identify those being used for potable
purposes, if any.

IDEQ, USEPA

IDEQ,
USEPA

December 31,
2016

3-44

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TABLE 3-11

OU 1 Action Items that Do Not Affect Remedy Protectiveness
2015 Five-Year Review, Bunker Hill Superfund Site

Remedial Action
(e.g., Human Health
Barriers, ICP)

Action Item

Responsible
Party

Oversight
Agency

Human Health Barriers

Develop an approach (or program) that defines how barrier integrity for all remediated
properties would be monitored overtime. Repeated in OU 3.

IDEQ, PHD,
USEPA

IDEQ, USEPA

Page Repository

Continue to develop a comprehensive O&M and Site Closure Plan for the Page
Repository. Repeated in OU 2.

IDEQ

USEPA

LHIP

Continue to evaluate options for increasing participation in the annual blood lead
screening program. Repeated in OU 3.

IDEQ, PHD,
USEPA

IDEQ

ICP

Infrastructure Maintenance Funding: Develop appropriate institutions and funding
mechanisms to finance and oversee stewardship activities and support local
governments in their efforts to identify funding for large-scale flood control. Establish
infrastructure O&M cooperative involving local jurisdictions and IDEQ. This action item
applies to all three OUs, but is listed only once, here in OU 1.

BEIPC

IDEQ, USEPA

ICP

Formalize a process to be implemented after catastrophic events occur for the purpose
of evaluating barrier performance, barrier repairs, responsibility, and funding sources.
This action item applies to all three OUs, but is listed only once, here in OU 1.

IDEQ, PHD,
USEPA

IDEQ, USEPA

ICP

Evaluate the need for snow disposal areas.

ICP, IDEQ

IDEQ

ICP

As required by the ICP, ensure all entities conducting earthwork and remedial actions
provide documentation of these activities to Panhandle Health for inclusion in the ICP
property database. This action item applies to all three OUs, but is listed only once, here
in OU 1.

PHD, IDEQ,
USEPA

IDEQ, USEPA

3-45

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

3.5 Performance Evaluation of the Operable Unit 1 Remedy

The 2012 Upper Basin ROD Amendment (USEPA, 2012a) selected additional OU 1 actions to
protect in place remedies from localized flooding. Four remedy protection actions have been
implemented through the end of 2014, and all are projected to be completed by the end of 2015.
Approximately 14 miles of Bunker Hill Box roads underlain by contaminated soils were rebuilt,
patched, or chip-sealed in 2013 and 2014.

There are some homes where interior house dust lead concentrations remain high. Based, in
part, on information related to alternative lead sources, a determination will be made regarding
the advisability of implementing the interior cleaning component of the OU 1 remedy.

Continued maintenance of the clean barriers to underlying contamination is essential to ensure
long-term protectiveness of the remedy. In addition, continued funding and state and local
support of the ICP is necessary to ensure barrier maintenance occurs in the long-term.

See Section 6.1 for the OU 1 protectiveness statement.

3-46

-------
4 Review of Selected Remedies for
Operable Unit 2

This section summarizes the protectiveness evaluation of the OU 2 remedial actions conducted
to date. The individual remedial actions presented and discussed are part of the overall OU 2
Selected Remedy as documented in the initial 1992 OU 2 ROD (USEPA, 1992) and its
subsequent decision documents (ROD Amendments [USEPA, 1996a, 2001b, and 2012a] and ESD
documents [USEPA, 1996b and 1998a]). The information in this section is organized as follows:

• 4.1 Overview of the Selected Remedy

• 4.2 Review of Operable Unit Remedial Actions

• 4.3 Technical Assessment

• 4.4 Issues and Recommendations

• 4.5 Performance Evaluation of the Selected Remedy

A review of actions taken since the last FYR and progress on Issues and Recommendations is
included in the review of each remedial action in Section 4.2 as appropriate.

4.1 Overview of Selected Remedies

OU 2 comprises areas in the Bunker Hill Box that were nonpopulated, nonresidential areas at
the time of the 1992 OU 2 ROD. These areas (shown on Figure 4-1) are the former Industrial
Complex and Mine Operations Area (MOA), Smelterville Flats (floodplain of the SFCDR in the
western half of OU 2), hillsides, various creeks and gulches, Central Impoundment Area (CIA),
and Bunker Hill Mine and associated acid mine drainage (AMD). The SFCDR within OU 2 and
the nonpopulated areas of the Pine Creek drainage are both addressed as part of Operable
Unit 3 (OU 3).

Cleanup actions identified in the 1992 OU 2 ROD included a series of source removals, surface
capping, reestablishment of stable creek channels, demolition of abandoned milling and
processing facilities, engineered closures for waste consolidated onsite, revegetation efforts, and
treatment of contaminated water collected from various Site sources. The specific ROD
requirements and remediation goals and remedial action objectives for the OU 2 Selected
Remedy are described later in this section as the individual remedial actions are discussed and
evaluated.

The bankruptcy of the major PRP for the Site (i.e., Gulf Resources) resulted in shifting
responsibility for OU 2 remedy implementation from a PRP to USEPA and the State of Idaho.
Pursuant to CERCLA requirements for fund-led remedy implementation, USEPA and the IDEQ
entered into a State Superfund Contract (SSC) to implement the OU 2 Selected Remedy (USEPA
and IDHW, 1995). The SSC comprises various supporting documents, including the Support
Agency Cooperative Agreement (SACA) for Cost-Share, the Comprehensive Cleanup Plan
(CCP), and the Remedial Action Management Plan (RAMP).

4-1

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

After the PRP bankruptcy, the IDEQ determined that the PRP-proposed remedy
implementation strategy for OU 2 was unacceptable under the statutory constraints of CERCLA
because the State would be responsible for 100 percent of O&M costs after the remedy is
complete. As a result, the State and USEPA negotiated an alternative approach to OU 2 ROD
implementation that focused more on permanent remedial techniques such as source control
and containment and less on long-term treatment remedial approaches originally developed by
the PRP. This led to a two-phased remedy implementation approach presented in the CCP for
OU 2.

Phase I of remedy implementation includes extensive source removal and stabilization efforts,
all demolition activities, all community development initiatives, development and initiation of
an ICP, future land use development support, and public health response actions. Also included
in Phase I are additional investigations to provide the necessary information to resolve long-
term water quality issues, including technology assessments and pilot studies, evaluation of the
success of source control efforts, development of Site-specific water quality and effluent-
limiting performance standards, and development of a defined O&M plan and implementation
schedule. Interim control and treatment of contaminated water and AMD is also included in
Phase I of remedy implementation. Phase I remediation began in 1995, and source control and
removal activities are nearly complete.

Phase II of remedy implementation will address long-term water quality, ecological, and
environmental management issues. Phase II remedial actions are identified in the 2001 OU 2
ROD Amendment and the 2012 Upper Basin ROD Amendment. Implementation of the Phase II
remedy is estimated to begin in 2016. The initial Phase II actions will consist of upgrading and
expanding the CTP and a GWCS located between the CIA and the SFCDR. A detailed
discussion of these initial Phase II actions are presented in Sections 4.2.8 and 4.2.9.

There have been three ROD Amendments (USEPA, 1996a, 2001b, and 2012a) and two ESDs
(USEPA, 1996b and 1998a) since the 1992 OU 2 ROD was issued. The ESDs clarified
implementation aspects of portions of the Selected Remedy for OU 2 consistent with Phase I
objectives and did not change the Selected Remedy. The ROD Amendments added additional
requirements and actions to the overall OU 2 Selected Remedy and are discussed in more detail
in Section 2.2.2.

4.2 Review of Operable Unit Remedial Actions

4.2.1 Hillsides

4.2.1.1 Background and Description

The hillsides include the steep portions of OU 2 that slope upward from the floor of the SFCDR
valley and from the gulches (Figure 4-1). This section describes the remedial actions associated
with the hillsides and the two industrial landfills located between Deadwood and Railroad
Gulches.

4-2

-------
•" # " a " J#

• V*' '¦•¦•'¦ ' f •. .^n *?•

^ •% v , - V

[LffiionlBacificTRailroad

Smejterville Flats

Central :lmpoundment:Area

. wl4QjmoniRacific

[Afe'a1! 4

, " •.. "
SMELTERVILLE

Raqe:Ponds

Smelter.
Elosure

KELLOGG

Bcfrrowi
IwfreaB

JM0TAtand^":
Boulevaraffyrt&i

PINEHURST

IKosslRancn

lirlillsideTA'reasi

rWARDNER

Remedial Action Areas

0.25

0.5

1 Miles

FIGURE 4-1

OU 2 Remedial Action Areas

2015 Five-Year Review
BUNKER HILL SUPERFUND SITE

&EPA

-------
-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

The hillsides have been affected by 100 years of mining and metals-refining related activities,
including logging and clearing, mine waste rock dumping, and emissions and fugitive dust
from processing operations. Natural events such as forest fires, wind, and flooding have
increased the impacts to the hillsides leading to severe erosion and reduced vegetation in many
areas. The erosion of the contaminated soils from the hillsides has resulted in contaminants
being conveyed to the streams, gulches, and other areas.

A review of hillsides remedial action requirements described in the 1992 OU 2 ROD and the
1998 OU 2 ESD is presented in the 2010 Five-Year Review Report (USEPA, 2010c). RAOs for the
Hillsides consist of the following:

• Minimizing soil erosion

• Reducing suspended sediment and/ or contaminant loading in surface runoff to SFCDR.

Information related to the interim and final performance standards (IPSs and PSs) used for
monitoring hillside performance is also summarized in the 2010 Five-Year Review Report
(USEPA, 2010c).

The hillsides remedial action was fully implemented by 2002. The general components of this
action consist of the following:

• The hillsides were revegetated and reforested between 1975 and 2002 by the PRP, USEPA,
and the IDEQ. Soil amendments were added prior to select plantings.

• The hillsides were stabilized with bench terraces for erosion control, and slopes were
stabilized in Wardner and Smelterville.

• Check dams were installed to minimize erosion in gullied areas, and erosion control
measures were implemented at select mine waste dumps.

• Solid waste from the lower industrial landfill located between Deadwood and Railroad
Gulch was removed.

Additional detail, including a complete listing and description of remedial actions, is provided
in the 2010 Five-Year Review Report (USEPA, 2010c).

In 2006, the IDEQ transferred a portion of the hillsides, located above the Smelter Closure Area
(SCA) and Borrow Area Landfill (BAL), to a third party. Large-scale development of a golf
course community has been ongoing in the lower hillsides, including residences, and associated
infrastructure. As part of development, portions of the hillsides remedy were graded or altered
to allow the golf course fairways to be placed. Along with the major undeveloped portions of
the hillside areas, redeveloped portions are evaluated as part of regular O&M and ICP
inspections. A long-term O&M manual was prepared for the hillsides remedial action in 2010
(TerraGraphics, 2010a), which describes the RAOs and O&M requirements in more detail. The
Selected Remedial Action is intended to accomplish the following (TerraGraphics, 2010a):

• Minimize erosion

• Reduce suspended sediment and contaminant loading in surface runoff to the SFCDR

4-5

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

4.2.1.2 Operations and Maintenance and Actions since the Last Five-Year Review

Semiannual inspections of the hillsides remedial action are conducted by the IDEQ in
accordance with the hillsides O&M manual (TerraCraphics, 2010a).

All IDEQ inspections, including the latest conducted in fall 2014, noted that hillsides areas
appear to be functioning with adequate vegetation cover and no active erosion (IDEQ, 2014a).
During this review period, the hillsides remedial action has required the following maintenance
activities:

• Erosion and all-terrain vehicle damage was repaired at Silver King knob and included
revegetation and placing rocks to restrict access in September 2012 (IDEQ, 2012c).

• Galena Ridge repaired and reseeded eroded areas on hillside slopes within the Galena
Ridge Golf Course (IDEQ, 2011a, and IDEQ, 2013a).

• A fire occurred in August 2011 on the hillsides above Kellogg. The burned area was outside
of the limits of the remedial action area depicted in Figure 4-1. IDEQ and PHD participated
in discussions with Shoshone County Fire District 2 regarding mitigation following the fire
with the understanding that increased stormwater runoff and erosion resulting from the
vegetation loss in the area could potentially transport contaminated sediment from the
burned area to the downgradient residential areas. The Fire District has implemented a
mitigation plan in the area, and vegetation appears to be recovering. The Fire District has
also conducted tree thinning and cutting as a fire mitigation measure in several other areas
of the hillsides during this review period (IDEQ, 2011a and 2011b).

4.2.1.3 Remedy Performance

According to the O&M inspections of the hillsides conducted by IDEQ, check dam performance
has been acceptable. Major findings include the following:

• Check dams are controlling gully erosion.

• Terraces are functioning as intended.

• Minimal slope erosion is occurring.

Although the hillsides remedy is functioning as intended and achieving the RAOs, the hillsides
are accessible through the development of Upper Magnet Gulch and Deadwood Gulch, as well
as through Grouse Gulch. IDEQ has observed some localized evidence of increased public
access and recreational use on the hillsides during this review period. Significant increases in
off-road vehicle use by the public could lead to additional adverse effects to re-established
vegetation, as well as a potential human health risk in those areas of the hillsides where residual
contamination is known to exist. At this time, most public use does not appear to be causing
significant damage to vegetation, with the exception of all-terrain vehicle use at Silver King
knob. IDEQ completed repair work in this area and placed a rock barricade to restrict access.
Currently, IDEQ repair work is performing as intended. Logging can affect hillsides by causing
erosion, if not done properly. Ongoing O&M inspections will continue to monitor this area.

4.2.2 Gulches

The gulches include the flat portions of the tributary gulches and not the sloping hillsides
addressed in Section 4.2.1. The seven gulches of primary concern cited in the 1992 OU 2 ROD

4-6

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

for remedial actions are, from west to east, Grouse, Government, Magnet, Deadwood, Railroad,
Portal, and Milo (Figure 4-1). Milo Gulch is discussed in Section 4.2.8 because its remedial
action is substantially different from the Phase I remedial actions conducted in the remainder of
the gulches. The 1992 OU 2 ROD-required actions for Portal Gulch focus on mine water
treatment from the Bunker Mine, whose portal (Kellogg Tunnel) is located in Portal Gulch.

Mine water pumped from the Bunker Mine is conveyed to the CTP for treatment. See
Section 4.2.9 for a discussion of the CTP and the treatment-related actions performed in the
Portal Gulch area. Additional detail for these differences is described in the 2010 Five-Year
Review Report (USEPA, 2010c). A review of remedial action requirements common to all
gulches described in the 1992 OU 2 ROD and 2001 OU 2 ROD Amendment is presented in the
2010 Five-Year Review Report (USEPA, 2010c). The RAOs associated with the Gulches remedy
are intended to accomplish the following:

• Minimize risk of direct contact with contaminants.

• Minimize soil erosion.

• Reduce suspended sediment and/or contaminant loading in surface runoff to the SFCDR.

For most OU 2 source removal actions, a chemical-specific soil excavation goal of 1,000 mg/kg
lead was used. The exceptions included Government and Magnet Gulches, for which the 1998
OU 2 ESD (USEPA, 1998a) provided separate upland and stream bed excavation goals.
Additional detail is provided in the 2010 Five-Year Review Report (USEPA, 2010c).

4.2.2.1 Grouse Gulch
Background

Grouse Gulch is a small watershed located west of Government Gulch with a perennial creek
(Grouse Creek) that passes through the Smelterville city limits. Past smelting and mining
activities resulted in surface contamination of the soils in the gulch area. Contamination sources
and the unstable and eroding creek contributed to contaminated sediment being carried
downstream, especially during high-flow runoff events.

The 1992 OU 2 ROD remedy for Grouse Gulch was not changed as a result of subsequent ROD
Amendments or ESDs issued for OU 2. The 1992 OU 2 ROD remedial action is consistent with
the goals and objectives of the Phase I remedy implementation.

The Grouse Gulch Phase I remedial action was fully implemented in 1997. The components of
this action consist of the following:

• Approximately 1,200 cy of tailings above the uppermost of the three existing gabion
structures were removed. Sediment accumulation was removed from other existing gabion
dams.

• A new gabion dam was constructed in the lower reaches of the gulch.

• The Wyoming mine dump located near the creek was buttressed at its base. Approximately
2,000 cy of mine dump material was removed.

4-7

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

• Accumulated sediment and alluvium was removed from downstream portions of the creek
within the Smelterville city limits.

• Access roads up through the gulch were improved to enable easier O&M of the gabion
dams.

Additional detail, including a listing and description of remedial actions, is provided in the 2010
Five-Year Review Report (USEPA, 2010c).

Operations and Maintenance and Actions since the Last Five-Year Review

The Grouse Gulch Phase I remedial action was fully implemented in 1997, and no actions have
been implemented since. Although a formal O&M plan for the Grouse Gulch gabion dams and
Wyoming Mine dump does not exist, Shoshone County, City of Kellogg, and City of
Smelterville are responsible for sediment removal from behind the three gabion dams to help
control flooding in Smelterville associated with Grouse Creek. Sediment was removed from
behind the three gabion dams in December of 2011 by the County and the City of Kellogg.
Ninety-six loads of contaminated material were hauled to the Page Repository. A remedy
protection project selected in the 2012 Upper Basin RODA was constructed downstream of
Grouse Gulch in Grouse Creek through Smelterville in 2013 to reduce the risk of flooding. The
remedy protection project is discussed in Section 3.2.1.5.

IDEQ conducts informal inspections of Grouse Creek semiannually along with the OU 2 O&M
inspections. In 2014, IDEQ identified orange water overtopping the road along Grouse Creek in
the upper portion of Grouse Gulch (IDEQ, 2014a and 2014b). The water is believed to come
from a collapsed adit in the area, but the source has not been confirmed. The surface water in
Grouse Creek remains orange for approximately 1,000 feet downstream of this source.
Precipitates appear to settle out and accumulate behind the gabion dams.

Remedy Status

Surface water quality monitoring at the mouth of Grouse Creek (BH-GC-0001) indicates that no
AWQC exceedances have occurred after Phase I remedial action. Concentrations of dissolved
cadmium, lead and zinc showed a significant decrease in concentration during the period of
2002 through 2014. Concentrations and trend data are presented in Section 2.5.

4.2.2.2 Government Gulch
Background

Government Gulch is the historical location of several ore processing and acid/fertilizer
producing facilities. Much of the subsurface soils were found to be highly contaminated to
about 10 feet below ground surface (bgs), especially in the industrial parts of the gulch.
Government Creek, which historically flowed down the center of the gulch in a meandering
pattern, was modified during the time of active ore processing, and specifically in the area
between the Zinc Plant and the Phosphoric Acid Plant.

A review of remedial action requirements specific to Government Gulch described in the 1992
OU 2 ROD, 1996 and 1998 OU 2 ESDs, and 2001 OU 2 ROD Amendment is presented in the
2010 Five-Year Review Report (USEPA, 2010c). The RAOs for the Government Gulch remedy
consist of the RAOs listed in Section 4.2.2 and the following:

• Reduce contamination of surface water and groundwater.

4-8

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

The Government Gulch Phase I remedial action was fully implemented in 2001. The general
components of this action consist of the following:

• Nearly 400,000 cy of contaminated materials (tailings, waste rock, and PTMs) were removed
from the gulch extending from the upper reaches of Government Gulch down to McKinley
Avenue.

• Specific segments of Government Creek were reconstructed.

• The aboveground structures associated with the Phosphoric Acid/Fertilizer Plant and Zinc
Plant were demolished.

• Gulch areas received a 6-inch clean soil ICP barrier cap, including hydroseeding and
riparian plantings.

Additional details, including a complete listing and description of remedial actions, are
provided in the 2010 Five-Year Review Report (USEPA, 2010c).

In 2006 and 2010, the IDEQ transferred several parcels in Government Gulch to third parties, as
described in the 2010 Five-Year Review Report (USEPA, 2010c).

A long-term O&M manual was finalized for the Government Gulch remedial action in 2010
(TerraGraphics, 2010b), which describes the RAOs and O&M requirements in more detail. The
RAOs associated with the Government Gulch remedy include the following (TerraGraphics,
2010b):

• Minimize direct contact with contaminated material.

• Minimize erosion.

• Reduce suspended sediment/contaminant loading in surface runoff to the SFCDR.

• Reduce contamination of surface water and groundwater.

Operations and Maintenance and Actions since the Last Five-Year Review

Semiannual inspections of the Government Gulch remedial action are conducted by the IDEQ in
accordance with the Government Gulch O&M Manual (TerraGraphics, 2010b). During this
review period, the Government Gulch remedial action has required no maintenance to sustain
the integrity of the action. The fall 2014 IDEQ inspection confirmed that the channel, gabion
dam, and culverts are all functioning as designed (IDEQ, 2014a).

Remedy Status

Based on the above RAOs, the Site inspections conducted for the IDEQ O&M program focus on
the stability of soil caps and constructed stream channel and condition of installed culverts. The
inspections conducted during 2010-2015 indicated that the capped areas of Government Gulch
are stable and provide effective barriers for underlying contaminated material. The stream
channel and associated culverts are in good condition.

Surface water data collected from Government Gulch (BH-GG-0001, BH-GG-0004, and BH-GG-
0008) continue to show significant decreasing trends for cadmium and zinc. However, median
dissolved zinc and cadmium concentrations for the period from 2009 to 2013 continue to exceed
AWQC. Concentrations and trend data are presented in Section 2.5.

4-9

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

4.2.2.3 Upper Magnet Gulch
Background

Magnet Gulch, located to the east of Government Gulch, was used for various material storage
and handling processes. Much of Magnet Gulch was filled to construct the A-l Gypsum Pond, a
railroad embankment and materials storage area. The lower portion of Magnet Gulch was filled
by the A-4 Gypsum Pond, discussed in Section 4.2.13. In the portion of Magnet Gulch
immediately south of McKinley Avenue, approximately 20,000 tons of copper dross flue dust
was stockpiled. This material contained significant amounts of lead, arsenic, zinc, and indium
and was designated as a PTM during the OU 2 RI/FS phase. Magnet Creek stabilization work,
primarily a sediment retention gabion dam, was constructed in 1992 as part of USEPA's 1990
Administrative Order on Consent with Gulf Resources and the Hecla Mining Company.

A review of remedial action requirements specific to Upper Magnet Gulch described in the 1992
OU 2 ROD, and 1996 and 1998 OU 2 ESDs is presented in the 2010 Five-Year Review Report
(USEPA, 2010c). The Phase I remedial actions for Upper Magnet Gulch did not differ from the
remedial actions identified in the 1992 OU 2 ROD.

The Upper Magnet Gulch Phase I remedial action was fully implemented in 1999. The general
components of this action consist of the following:

• The copper dross flue dust pile was relocated from Magnet Gulch.

• The A-l Gypsum Pond and mid-Gulch fill materials were removed.

• Magnet Creek was reconstructed and revegetated.

Additional details, including a complete listing and description of remedial actions, are
provided in the 2010 Five-Year Review Report (USEPA, 2010c).

A long-term O&M manual was finalized for the Gulches, including Magnet Gulch remedial
action in 2010 (TerraGraphics, 2010c), which describes the RAOs and O&M requirements in
more detail. The RAOs associated with the Gulches include the following (TerraGraphics,
2010c):

• Minimize direct contact with contaminated material

• Minimize erosion

• Reduce suspended sediment/contaminant loading in surface runoff to the SFCDR

• Reduce contamination of surface water and groundwater

Operations and Maintenance and Actions since the Last Five-Year Review

O&M of Magnet Gulch is conducted in accordance with the gulches O&M manual
(TerraGraphics, 2010c). Semiannual inspections of the Magnet Gulch remedial action are
conducted by the IDEQ for features of the original action that remain intact. The property
owner, Galena Ridge, is responsible for O&M of features that have been modified by
construction of the Galena Ridge Golf Course. During this review period, the Magnet Gulch
action has required no maintenance to sustain the integrity of the action.

IDEQ inspections, including the most recent fall 2014 inspection, confirmed that the lower
sedimentation basin is functioning as designed. The Hilfiker retaining wall installed by Galena
Ridge is sagging and has weeds growing in some areas. This has been under observation, but is
not a structural concern and no further action is planned by Galena Ridge. The remedial action

4-10

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

features on Galena Ridge property are in compliance with the performance standards of the
O&M manual (IDEQ, 2014a).

Remedy Status

Based on the above RAOs, the Site inspections conducted by the IDEQ O&M program focus on
the stability of soil caps and constructed stream channel, and condition of installed culverts. The
inspections conducted during 2010-2015 indicated that the capped areas of Magnet Gulch are
stable and provide effective barriers for underlying contaminated material. The stream channel
and associated culverts are in good condition.

Surface water data collected from Magnet Gulch (BH-MG-0001)) continue to show decreasing
trends for dissolved cadmium and zinc. Median dissolved zinc and cadmium concentrations for
the period 2009 to 2013 continue to exceed AWQC.

4.2.2.4 Deadwood Gulch
Background

Deadwood Gulch is located immediately east of Magnet Gulch. The Arizona Mine Dump filled
the narrow valley of Deadwood Gulch in its upper reaches. Various mine adits/portals were
present in Deadwood Gulch, many of which occasionally discharged water from underground
mine workings to the surface water in Deadwood Creek. Other than these point sources of
contamination, Deadwood Gulch contamination was primarily from the erosion of adjacent
hillside soils that had become contaminated with smelter emissions and the Sierra Nevada and
Arizona Mine Dumps. In the early 1990s, two gabion dams were built across Deadwood Creek
for sediment retention.

A review of remedial action requirements specific to Deadwood Gulch described in the 1992
OU 2 ROD is presented in the 2010 Five-Year Review Report (USEPA, 2010c).

The Deadwood Gulch Phase I remedial action was conducted beginning in 1995 and fully
implemented in 2001. The general components of this action consist of the following:

• Sediment that had collected behind the gabion dams was removed.

• Creek stabilization work consisted of constructing small cobble and boulder grade check
dams.

• The Arizona Mine Dump was removed and the streambed was reconstructed.

• Lower Deadwood Creek was reconstructed.

• Deadwood creek riparian corridor was planted.

Additional detail, including a complete listing and description of remedial actions, is provided
in the 2010 Five-Year Review Report (USEPA, 2010c).

A long-term O&M manual was finalized for the Gulches, including Deadwood Gulch remedial
action in 2010 (TerraGraphics, 2010c), which describes the RAOs and O&M requirements in
more detail. The RAOs associated with the Deadwood Gulch are the same as those listed in
Section 4.2.2.3 for Upper Magnet Gulch.

4-11

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Operations and Maintenance and Actions since the Last Five-Year Review

O&M of Deadwood Gulch is conducted in accordance with the gulches O&M manual
(TerraGraphics 2010c). Semiannual inspections of the Deadwood Gulch remedial action are
conducted by the IDEQ for features of the original action that remain intact. Private property
owner, Galena Ridge, is responsible for O&M of features that have been modified by
development activities. Development work is coordinated with ICP. During this review period,
the Deadwood Gulch action has required no maintenance to sustain the integrity of the action.

The fall 2014 IDEQ inspection noted the following (IDEQ, 2014a):

• Sediment basins, culverts, and the reconstructed channel are in good condition and function
as designed.

• The lower gabion dam is in poor condition, but has served its purpose and no further action
is necessary.

Remedy Status

The Deadwood Gulch Phase I remedial action has been in place for about 18 years. No O&M
has been necessary for the Deadwood Gulch Phase I remedy during this Five-Year Review
period.

The inspections conducted during 2010-2015 indicated that the remedial actions in Deadwood
Gulch are stable and provide effective barriers for underlying contaminated material. All of the
design features are meeting the performance standards listed in the gulches O&M manual
(TerraGraphics, 2010c). Based on Site inspections and lack of O&M needed for this remedial
action, this Five-Year Review documents that no issues currently exist with the performance of
the Deadwood Gulch Phase I remedy (USEPA, 2010c).

Surface water data collected from Deadwood Gulch (BH-DW-0001) continue to show
decreasing trends for the dissolved cadmium and zinc. Median dissolved zinc and cadmium
concentrations for the period 2009 to 2013 continue to exceed AWQC.

4.2.2.5 Railroad Gulch
Background

Railroad Gulch is east of Deadwood Gulch and south of the Boulevard Area. The lower portion
of the creek channel was undersized and routinely flooded during high flow spring runoff onto
the Boulevard Area (a flat area that historically stored piles of highly concentrated ore material,
"concentrates"). This localized flooding spread contamination that existed in the Boulevard
Area. Erosion of the channel also occurred during high runoff owing to the steep channel
gradient between McKinley Avenue and Bunker Creek.

The Railroad Gulch Phase I remedial action was fully implemented in 1997. The general
components of this action consist of the following:

• A portion of the Railroad Gulch surface water channel was reconstructed.

• Culverts beneath McKinley Avenue were increased in size to handle the estimated spring
runoff flows.

• Areas adjacent to the channel that were disturbed during construction capped with at least
6 inches of clean fill and were revegetated.

4-12

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Additional detail, including a listing and description of remedial actions, is provided in the 2010
Five-Year Review Report (USEPA, 2010c).

A long-term O&M manual was finalized for the gulches, including Railroad Gulch remedial
action in 2010 (TerraCraphics, 2010c), which describes the RAOs and O&M requirements in
more detail. The RAOs associated with the Railroad Gulch are the same as those listed in
Section 4.2.2.3 for Upper Magnet Gulch.

Operations and Maintenance and Actions Since the Last Five-Year Review

Semiannual inspections of the Railroad Gulch remedial action are conducted by the IDEQ in
accordance with the gulches O&M manual (TerraGraphics 2010c). During the 2012 spring O&M
inspection it was discovered that some of the western bank armor had sloughed into the
channel, barrier fabric was exposed, and the bank was compromised. IDEQ completed repairs
by replacing the channel armoring with large rip-rap rock in August of 2012 (IDEQ, 2012c).The
Railroad Gulch remedy has required no other maintenance to sustain the integrity of the action.

The fall 2014 IDEQ inspection noted the sediment basin, culverts, and the reconstructed channel
are in good condition and function as designed (IDEQ, 2014a).

Remedy Status

The Railroad Gulch remedial action has been in place for about 16 years. O&M inspections
conducted during this review period indicated that the Railroad Gulch Creek channel is stable
and revegetation in the gulch is established and minimizing erosion.

4.2.3 Smelterville Flats
4.2.3.1 Background and Description

The boundaries of the Smelterville Flats area are the northern bank of the SFCDR floodplain,
Pinehurst Narrows to the west, the city of Smelterville to the south, and the 1-90 West Kellogg
interchange to the east (Figure 4-1). The Shoshone County Airport and runway are located in
the Smelterville Flats area north of 1-90.

In 1910, mining companies in the Silver Valley constructed a series of plank and pile dams on
the SFCDR, including one in the Pinehurst Narrows area, to mitigate downstream transport of
tailings. The Pinehurst Narrows plank and pile dam impounded tailings in the SFCDR
floodplain in the Smelterville Flats area from OU 2 and upstream sources. Additional detail on
chronological events is provided in the 2010 Five-Year Review Report (USEPA, 2010c).

A review of Smelterville Flats remedial action requirements described in the 1992 OU 2 ROD,
the 1998 OU 2 ESD, and the 2001 OU 2 ROD Amendment is presented in the 2010 Five-Year
Review Report (USEPA, 2010c). The 1992 OU 2 ROD requirements for the SFCDR removal and
stabilization work are the same as those cited for Smelterville Flats. The 1992 OU 2 ROD and the
1998 OU 2 ESD requirements for the miscellaneous Box projects are the same as those cited for
Smelterville Flats. The RAOs associated with the Smelterville Flats remedy are intended to
accomplish the following:

• Minimize direct contact with contaminated material.

• Minimize surface water erosion and wind dispersion of contaminants.

• Minimize migration of contaminants to surface and groundwater.

• Minimize surface water infiltration into the underlying contaminants.

4-13

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

The Smelterville Flats Phase I remedial action was fully implemented in 2001. The general
components of this action consist of the following:

• Tailings were extensively removed in Smelterville Flats north of 1-90 to achieve Site-specific
removal goals of 3,000 mg/kg lead and 3,000 mg/kg zinc, as well as south of 1-90 and with a
removal goal of 1,000 mg/kg lead. The tailings removed were transported to the CIA for
disposal.

• The area was capped and revegetated, including riparian plantings of trees and shrubs, to
prevent direct contact with underlying contaminants by humans and animals and to
stabilize the floodplain and minimize erosion.

• Floodway work was conducted for the SFCDR to improve groundwater and surface water
quality.

• Surface water runoff control was improved.

Additional detail, including a listing and description of remedial actions, is provided in the 2010
Five-Year Review Report (USEPA, 2010c).

A long-term O&M manual was prepared for the Smelterville Flats remedial action in 2010
(TerraGraphics, 2010d), which describes the RAOs and O&M requirements in more detail.
Regular O&M inspections have been conducted by the IDEQ since the initial inspection of
Smelterville Flats in September 2009.

Following the Phase I remedial action, SFCDR surface water quality appears to have improved
with respect to dissolved zinc concentrations, AWQC ratios, and loading. The findings of the
Phase I remedial action assessment, with respect to water quality and performance standards,
are summarized in the 2010 Five-Year Review Report (USEPA, 2010c). The biological resource
effectiveness monitoring conducted on Smelterville Flats by the USFWS for USEPA is discussed
in Section 2.5.3 of this document and in monitoring reports prepared by USFWS.

4.2.3.2 Operations and Maintenance and Actions since the Last Five-Year Review

Semiannual inspections of the Smelterville Flats remedial action are conducted by the IDEQ in
accordance with the Smelterville Flats O&M manual (TerraGraphics, 2010d). During this review
period, the Smelterville Flats action has required no maintenance to sustain the integrity of the
action.

The fall 2014 IDEQ inspection noted the following (IDEQ, 2014a):

• The wetlands are thriving.

• Floodplain features (e.g., spillways, berms) are functioning as designed with the exception
of the three pairs of sills that failed twice to control the river channel route and were
abandoned in 2000.

• Weeds are growing aggressively in the area.

The 2010 Five-Year Review included the following recommendations for Smelterville Flats:

• Recommendation: Complete the CFP currently being developed by USEPA and IDEQ for
all three OUs.

4-14

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Discussion: See Section 3.2.1.6 for discussion. This recommendation is complete. This
recommendation is repeated for all three OUs and is complete for all three OUS.

• Recommendation: Continue informal observational monitoring of SFCDR removal and
stabilization project sites, especially after flood events. Will also include as part of
Smelterville Flats Phase I Remedial Effectiveness Monitoring (an ongoing recommendation
from the 2005 Five-Year Review).

Discussion: Informal observation of SFCDR removal and stabilization project areas and
Phase I Remedial Effectiveness Monitoring near Smelterville Flats have been conducted as
recommended. The 2012 ROD Amendment Selected Remedy does not include additional
actions along the SFCDR in the Smelterville Flats area. This recommendation is complete.

4.2.3.3 Remedy Status

Remedy performance of the Smelterville Flats Phase I remedy was evaluated by reviewing
IDEQ O&M inspections of the various remedial components completed to achieve the RAOs
cited above. The Site inspections conducted by the IDEQ O&M program focus on the stability of
soil caps and reconstructed stream banks and the health of the revegetation efforts. The
inspections conducted during 2010-2015 indicated that the capped areas of Smelterville Flats are
stable and provide effective barriers for underlying contaminated material. The vegetation at
Smelterville Flats was healthy and has been regenerating yearly without maintenance efforts.
Some noxious weed spraying has been conducted in the flats by Shoshone County on the
airport property during this review period, but Site inspections continue to identify noxious
weeds growing aggressively within the flats. Previous IDEQ O&M inspections have noted that
stream bank erosion is occurring along sections that were not subject to remedial action (IDEQ,
2014b). Long-term surface water monitoring down gradient from Smelterville Flats at Pinehurst
has displayed a decreasing trend in lead concentrations since the Phase I remedial actions were
conducted and is an indicator that the area is acting as a lead sink and remains stable. The
reconstructed stream banks of the SFCDR in the Flats area are stable and performing adequately
to minimize sediment entering into the river.

As discussed in Section 2.5, the effectiveness of the Smelterville Flats Phase I remedy can be
inferred by long-term decreasing trends in the SFCDR surface water station near Pinehurst.
Concentrations of total lead and total zinc at this station showed a significant decrease over the
period between 1990 and 2013, reflecting the remedial actions that occurred during Phase I.
However, this decreasing trend levels off at SFCDR near Pinehurst after 2003.

4.2.4 Central Impoundment Area
4.2.4.1 Background and Description

The CIA was constructed in 1928 as a repository for flotation tailings from Bunker Hill ore
concentration mills. Over time, the CIA developed into an impoundment for tailings, mine
waste, gypsum, other process waste and water, and AMD from the Bunker Hill Mine. The
current configuration of the CIA is shown in Figure 4-1 and covers approximately 260 acres
with embankments ranging in height from 30 to 70 feet above the valley floor. The evolution of
the CIA from its construction in 1928 through 1977, including detailed chronological events, is
presented in the 2010 Five-Year Review Report (USEPA, 2010c). After 1977, no significant
changes occurred to the CIA until its use as a waste repository during remedial actions in the

4-15

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

mid to late 1990s and its eventual closure with an impermeable cap in 2000. Since 2000, the
discharge rates measured at seepage locations on the southern bank of the SFCDR have been
reduced an order of magnitude. Groundwater elevations in the shallow aquifer in the area
suggest that the current discharge associated with the discrete seepage location are associated
with the shallow groundwater in the area and not direct seepage from the CIA.

A review of the CIA remedial action requirements described in the 1992 OU 2 ROD, the 1998
OU 2 ESD, and the 2001 OU 2 ROD Amendment is presented in the 2010 Five-Year Review
Report (USEPA, 2010c).

The CIA Phase I remedial action was fully implemented in 2000. The components of this action
consist of the following:

• Mine wastes and materials within the CIA were consolidated between 1995 and 1999.

• A geomembrane cover system was installed on the surface of the CIA.

A long-term O&M manual was finalized for the CIA remedial action in 2009 (TerraCraphics,
2009a), which describes the RAOs and O&M requirements in more detail. The RAOs associated
with the CIA remedy are intended to (TerraCraphics, 2009a):

• Minimize risk of direct contact with contaminated material.

• Minimize infiltration through contaminated media.

• Control erosion.

• Maximize efficient interception of contaminated groundwater from the CIA seeps.

• Provide location for CTP sludge disposal.

Additional detail, including a listing and description of remedial actions, is provided in the 2010
Five-Year Review Report (USEPA, 2010c).

4.2.4.2 Operations and Maintenance and Actions since the Last Five-Year Review

Semiannual inspections of the CIA remedial action are conducted by the IDEQ in accordance
with the CIA O&M manual (TerraGraphics, 2009a).

The fall 2014 IDEQ inspection noted the following (IDEQ, 2014a):

• No major deficiencies were found in the CIA performance.

• The vegetation on the cover is flourishing.

• The weed population is under control.

• A section of the fence along the north side had been damaged by snow plowing of the
adjacent parking lot.

During this review period, the CIA action has required the following maintenance activities:

• Weed spraying was conducted in October 2013 (IDEQ, 2013b).

• Disconnected drain system cleanout was repaired and area was reseeded in July 2012
(IDEQ, 2012c).

• Temporary fence was repaired in June 2014. Permanent repair of the access control in this
area will be evaluated pending the installation of the groundwater cutoff wall along the
north side of the CIA (IDEQ, 2014a).

4-16

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

4.2.4.3 Remedy Status

The Phase I CIA remedy is functioning as intended. To date, the first three objectives of the
Phase I CIA remedy have been achieved. The interception of groundwater was deferred to the
Phase II remedy, and the replacement of the unlined sludge pond will not be implemented until
the existing pond reaches capacity. Therefore, this assessment focuses on the Phase I CIA
remedies.

O&M inspections during this review period showed that the capped area of the CIA was stable
and provided an effective barrier to the underlying consolidated waste materials. No evidence
of adverse settlement was found. Vegetation on the capped area was healthy and regenerating
yearly without maintenance efforts. Noxious weeds have been under control since spraying
efforts took place in 2013. Weed control is not an element of the remedial action, but rather a
property owner obligation.

The runoff control berms and swales were stable and provide effective means to channel runoff
of the CIA and into rock-lined perimeter discharge points. The rock-lined surface water
discharge channels were stable and showed no signs of rock displacement. No remedy issues
were found in the CIA remedial action features.

The SFCDR reach adjacent to the CIA continues to be the highest source of dissolved metals
loading from groundwater to the SFCDR in the Upper Basin. As discussed in Section 2.5,
contaminant concentrations near the CIA, in both surface water and groundwater, continue to
exceed AWQC at most sampling locations. To measure the effectiveness of the planned Phase II
remedial action (groundwater collection and treatment adjacent to the CIA), USEPA will be
monitoring selected groundwater and surface water locations in comparison to baseline
conditions as part of a remedial action effectiveness monitoring program. The construction of
this remedy is scheduled to begin implementation in 2016.

4.2.5 Bunker Creek

4.2.5.1 Background and Description

Bunker Creek is located at the southern toe of the CIA and north of the Trail of the Coeur
d'Alenes. The combined flow of Bunker Creek is primarily made up of discharges from the CTP
effluent, drainage from the SCA and BAL, and surface water flows from Portal Gulch, Railroad
Gulch, the Boulevard Area, Deadwood Gulch, Magnet Gulch, and two CIA outfalls. Historical
records show that uncontrolled dumping of coarse tailings, fine-grained tailings (slimes), mine
waste rock, and granulated smelter slag occurred in the Bunker Creek corridor.

A review of Bunker Creek remedial action requirements described in the 1992 OU 2 ROD and
the 2001 OU 2 ROD Amendment is presented in the 2010 Five-Year Review Report (USEPA,
2010c). The RAOs associated with the Bunker Creek remedy are intended to accomplish the
following:

• Minimize the risk of direct contact with contaminants.

• Reduce suspended sediment and/or contaminant loading in surface runoff to the SFCDR.

• Minimize infiltration through contaminated material.

Bunker Creek Phase I remedial action was fully implemented by 2001. The general components
of this action consist of the following:

4-17

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

• Approximately 7,600 linear feet of the creek channel was reconstructed, including a low
flow channel and floodplain.

• Flotation slimes exposed at the surface of channel excavations were removed to a depth of
2 feet below the slimes and backfilled to stream grade with clean compacted backfill
material.

• Culverts and riprap headwalls were installed for three road crossings to maintain Site access
over Bunker Creek.

• Minimum 6-inch ICP barriers were placed at the surface of all disturbed areas in the Bunker
Creek corridor and hydroseeded.

• Trees and shrubs were planted along the creek corridor in 2001.

Additional detail, including a listing and description of remedial actions, is provided in the 2010
Five-Year Review Report (USEPA, 2010c).

A long-term O&M manual was finalized for Bunker Creek remedial action in 2010
(TerraGraphics, 2010e), which describes the RAOs and O&M requirements in more detail.

4.2.5.2 Operations and Maintenance and Actions since the Last Five-Year Review

Semiannual inspections of the Bunker Creek remedial action are conducted by the IDEQ in
accordance with the Bunker Creek O&M manual (TerraGraphics, 2010e). The fall 2014 IDEQ
inspection confirmed that the channel and barriers are performing as designed.

Beaver activity was observed during the 2010, 2012, and 2014 O&M inspections. IDEQ has
trapped six beavers and removed ten beaver dams and two beaver lodges since 2010. Beaver
activity will continue to be monitored through the IDEQ O&M program for potential impacts
on the remedy of Bunker Creek and adjacent areas.

During this review period, the Bunker Creek action has required the following maintenance
activities:

• Weeds were sprayed regularly by hand, with commercial spraying conducted in 2013
(IDEQ, 2014b)

• Beaver trapping and dam removal in 2010, 2012, and 2014 (IDEQ, 2011a, 2012b, and 2014a)

• Fence repair in July 2011 and June 2013. (IDEQ, 2011b and 2013a)

The 2010 Five-Year Review included the following recommendations for Bunker Creek.

• Recommendation: Regarding the Bunker Creek Culverts, continue working with the BEIPC
and other stakeholders to evaluate and plan actions relative to addressing SFCDR and Pine
Creek flooding issues.

4-18

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

flood control projects. The BEIPC Executive Director continues to work with local flood
control entities to identify sources of assistance. This recommendation is complete. This
recommendation is repeated for all three OUs.

• Recommendation: SSC for 2001 OU 2 ROD Amendment to continue, with the assistance of
the IDEQ, to pursue viable solutions to the SSC impasse. Once a solution is achieved,
continue with implementation of the 2001 OU 2 ROD Amendment (an ongoing
recommendation from the 2005 Five-Year Review).

Discussion: Because of an inability to reach agreement on the State's obligations for the
OU 2 Mine Water ROD amendment actions, phase II remedial actions have generally not
been implemented to date. Due to the settlement with Hecla, non-federal funds are now
available to implement some of the phase 2 actions, including the CTP and groundwater
collection system. Long-term O&M obligations for these actions is addressed in a 2014
memorandum of agreement whereby the IDEQ agreed to conduct long-term O&M activities
as long as the funds placed in the State Endowment Fund from the Hecla settlement last.
This recommendation is complete.

4.2.5.3 Remedy Status

The Bunker Creek Phase I remedy is functioning as intended by the decision documents.
Specific aspects of the Phase I remedy performance evaluation are described in the following
paragraphs.

The 1992 ROD required Bunker Creek to be lined in order to meet the RAO described above.
However, the 2012 ROD Amendment superseded this requirement with a selected remedy to
divert CTP effluent away from Bunker Creek to minimize infiltration through contaminated
materials. Planning for diversion of CTP flows away from Bunker Creek is underway. Site
inspections indicate that the Bunker Creek channel is stable, with soil caps remaining intact and
serving to prevent direct contact with underlying contaminated soils. The vegetation on both
the channel and adjacent areas is well established and is regenerating yearly without any
maintenance. Culverts are free of sediment and debris.

The 2005 Five-Year Review Report identified recontamination processes and contributing
factors in certain segments of Bunker Creek. Samples collected from the Bunker Creek channel
confirmed the presence of contaminated sediments. For this Five-Year Review, site inspections
confirmed that fencing installed between the creek and the Trail of the Coeur d'Alenes is intact
and functioning as intended, with the exception of occasional damage to the from wildlife
crossing requiring repairs. Repairs are completed as needed.

Based on the Phase I remedy goal of preventing direct contact by humans with underlying
contaminants, the Phase I remedy for Bunker Creek is performing adequately.

The water quality of Bunker Creek is significantly influenced by the water quality of tributary
creeks and other discharges (Portal, Railroad, Deadwood, and Magnet Creeks; CTP discharge;
stormwater runoff from the city of Kellogg, Bunker Hill Mine yard, and the SCA). As discussed
in Section 2.5, base flows in Bunker Creek do not meet the AWQC. With the completion of the
Phase II groundwater collection system, CTP effluent that is currently discharged to Bunker
Creek will be diverted to a discharge location in the SFCDR.

4-19

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

4.2.6 Industrial Complex

As defined by the 1992 OU 2 ROD, the Industrial Complex consisted of three main areas: the
Lead Smelter (now the Smelter Closure Area, SCA), the Zinc Plant (including the Phosphoric
Acid Plant), and the Mine Operations Area (MOA) (Figure 4-1). The highest concentrations of
contaminant metals within OU 2 were found in the Lead Smelter area. Risk assessments
conducted during the remedial investigation resulted in a subset of Site process materials that
were designated as Principle Threat Materials (PTMs) based on their higher level of
contamination. This section focuses on the remedy implemented for the SCA and PTM Cell, the
BAL, and Area 14. The MOA is discussed separately in Section 4.2.7.

A review of the Industrial Complex remedial action requirements described in the 1992 OU 2
ROD, the 1996 and 1998 OU 2 ESDs, and the 1996 and 2001 OU 2 ROD Amendments is
presented in the 2010 Five-Year Review Report (USEPA, 2010c). Individual remedial actions
and RAOs are discussed in the below sections.

The 2010 Five-Year Review included the following recommendation for the Industrial Complex.

4.2.6.1 Smelter Closure Area and Principal Threat Material Cell
Background

The Industrial Complex remedial action consolidated highly contaminated soil and material
accumulations from Site removal actions and debris resulting from demolition of the Industrial
Complex structures into an engineered closure with a low-permeability geomembrane cap. This
30-acre SCA (Figure 4-1) was designed to accommodate up to 420,000 cy of material. The RAOs
associated with the SCA remedy are intended to accomplish the following:

• Minimize risk of direct contact with contaminants.

• Minimize surface water infiltration through contaminants.

• Minimize soil erosion.

• Minimize the potential for contamination of surface water and groundwater.

The SCA Phase I remedial action was implemented between 1995 and 1998. The general
components of this action consist of the following:

• Demolition debris from the Lead Smelter, Phosphoric Acid, and Zinc Plants, and boneyard
soil, larger wood, and metal debris was consolidated in the SCA.

4-20

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

• Slag and contaminated soil from various Site removals was used as in-fill material to
minimize void spaces and the potential for future settlement.

• The PTM Cell (geomembrane-lined mono-cell) was constructed within the boundary of the
SCA. Approximately 80,000 to 100,000 cy of PTM, including copper dross flue dust, was
placed in the cell.

• A seep collection system and toe drain was constructed that conveys water to the lined
pond and to the CTP for treatment.

• The SCA was capped with a geomembrane liner, a drainage layer, growth media and
revegetated with a native plant seed mix.

• A surface water management system prevents run-on onto the closure cap. A separate
surface water system conveys precipitation off the closure cap using a series of berms and
ditches. Collected surface water is conveyed to Magnet and Bunker Creeks.

Additional detail, including a complete listing and description of remedial actions, is provided
in the 2010 Five-Year Review Report (USEPA, 2010c).

As described in previous sections, large-scale development of a golf course community has been
occurring in the upper Magnet Gulch and lower hillsides area, including residences and
associated infrastructure. As part of development, a portion of the SCA remedy was altered,
consisting of the removal and replacement of a portion of the West Canyon surface water
diversion and conversion of the unlined West Canyon sedimentation basins to a lined detention
pond (lake). Additional detail related to the development activities, including groundwater
quality and elevation monitoring at the SCA, is provided in the 2010 Five-Year Review (USEPA,
2010c).

A long-term O&M manual was finalized for the SCA Phase I remedial action in 2008
(TerraGraphics, 2008b), which describes the RAOs and O&M requirements in more detail. By
mutual agreement, the third-party property owner agreed to perform maintenance of those
features and areas that have been altered as part of development activities. IDEQ continues to
be responsible for ensuring appropriate O&M of these features occurs and for O&M of
unaltered features of the RA. The ICP oversees human health barriers installed outside the SCA
fence.

Operations and Maintenance and Actions since the Last Five-Year Review

Semiannual inspections of the SCA remedial action are conducted by the IDEQ in accordance
with the SCA Operation and Maintenance Manual (TerraGraphics, 2008b).

The fall 2014 IDEQ inspection noted the following (IDEQ, 2014a):

• The overall cover and drainage system is performing the intended function;

• Two strip-drain collection pipes, which had been repaired previously, have become
disconnected again and are not conveying stormwater as designed.

• Seven conifers and five woody plants were beginning to establish on the cap;

• Cottonwood trees are growing in the North Perimeter ditch but do not appear to be
obstructing flow in the ditch.

4-21

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

• Two isolated areas on the north and west ends were being invaded by spotted knapweed
and hawkweed.

• The overall vegetation on the cover system is well established responding well to weed
spraying.

• A section of the fence along the north side had been taken down and replaced by the third
party with temporary fencing.

During this review period, the SCA has required the following maintenance activities:

• A large cottonwood tree was removed that was obstructing the intake to a culvert near
McKinley Avenue in spring 2012.

• Woody vegetation found within the limits of the cover system was sprayed and removed
routinely during semiannual inspections, including 38 deciduous trees and 40 conifers.

• Noxious weeds were sprayed by hand routinely during semiannual inspections.

• Temporary repair to disconnected surface water strip drain collection pipes in July 2012
(IDEQ, 2012c). This was found during the fall 2014 inspection to have disconnected again,
and will require a permanent repair (IDEQ, 2014a).

Remedy Status

Inspections conducted through the IDEQ O&M program showed that the capped area of the
SCA is stable and provides an effective barrier to the underlying consolidated waste materials.
No evidence of settlement was found. Vegetation on the capped area is healthy and
regenerating yearly. The closure runoff control berms and swales are stable and provide
effective means to channel runoff off the closure area and into perimeter ditches. The rock-lined
perimeter ditch systems are stable and show no signs of rock displacement. Permanent repair of
the surface water strip drain collection pipes is planned for 2015.

As discussed in Section 2.5, the effectiveness of the SCA remedy can be inferred by long-term
decreasing trends in the SFCDR surface water station near Pinehurst. Concentrations of total
lead and total zinc at this station showed a significant decrease between 1990 and 2013,
reflecting the remedial actions that occurred during Phase I. However, this decreasing trend is
not observed in data collected at SFCDR near Pinehurst post 2003 and concentrations remain
above AWQC for lead, cadmium, and zinc. Groundwater quality in near the SCA is discussed
in Section 2.5.

4.2.6.2 Borrow Area Landfill
Background

The BAL (Figure 4-1) was developed in 1997 and 1998 to provide "clean" fill for several of the
Site remediation projects (CH2M HILL, 2002a). A portion of the BAL was subsequently used to
dispose of lower-level contaminated soil and solid waste from the upper industrial landfill
located in Railroad Gulch. With the closure of the OU 2's primary waste consolidation areas (the
Smelter Closure in 1997 and the CIA in 2000), a disposal area within the borrow area, the BAL,
was constructed in 2000 to accept contaminated soil and waste generated by the remaining
remedial actions at the Site. The RAOs associated with the BAL remedy are provided in
Section 4.2.6.1.

4-22

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

The following BAL activities were completed by 2002:

• Approximately 190,000 cy of waste materials were placed in the BAL in 2000 and 2001.

• The BAL was closed in 2002 and closure activities consisted of grading, surface water
management, placement of a soil cover, hydroseeding, and establishing settlement
monitoring points.

In 2006, the IDEQ transferred the BAL property to a third party. As described in previous
sections, large-scale development activities have been occurring near the BAL that include
construction of a golf course community and associated infrastructure. The BAL was converted
to a golf course and an associated pond.

Additional detail, including a listing and description of remedial actions, is provided in the 2010
Five-Year Review Report (USEPA, 2010c). A long-term O&M manual was finalized for the BAL
in 2007 (CH2M HILL, 2007b). By mutual agreement, the third-party property owner agreed to
perform maintenance of those features and areas that have been altered as part of development
activities. The ICP oversees the soil cover barrier at the BAL.

Operations and Maintenance and Actions since the Last Five-Year Review

O&M of the BAL during this review period has been conducted by property owner, Galena
Ridge, LLC, as a component of the Galena Ridge Golf Course. IDEQ monitors the performance
of the remedy at the BAL through coordination with ICP and notes potential issues in
semiannual O&M reports. The fall 2014 O&M report concluded that all of the features of the
BAL remedy are functioning as designed and in compliance with the ICP and performance
standards of the O&M Manual.

Remedy Status

Observations of the BAL development by IDEQ and PHD personnel indicate that the barriers
installed as part of the Galena Ridge Golf Course development are stable and well maintained.
Based on these observations, the BAL remedy is performing as designed and in accordance with
the decision documents.

4.2.6.3 Area 14
Background

Area 14 is approximately 8 acres located between McKinley Avenue and the SCA. Area 14 has
been defined as the West Slag Dumps of the Smelter Complex due to blast furnace slag piles
that were staged on the eastern portion of the subarea. The western portion of the area contains
the former Sweeney Mill and an area currently leased to Avista Utilities and Williams Gas. Area
14 is currently designated for industrial use.

The following Area 14 activities were completed:

• Two former sedimentation ponds (Gilges Pond and Sweeney Pond) and known PTM were
excavated and backfilled in 1997 and 1999.

• In 2006, the former Sweeney Mill area was graded to drain and a 6-inch ICP barrier placed.
Approximately 120 cy of contaminated material was removed from the adjacent hillside and
disposed in the Page Repository. The hillside was graded, capped, and revegetated.

4-23

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

In 2006, the IDEQ transferred Area 14 property to a third party, as described in the 2010 Five-
Year Review Report (USEPA, 2010c). An ICP barrier has not yet been installed within the
eastern portion of Area 14 pending development.

Operations and Maintenance and Actions since the Last Five-Year Review

No activity has occurred in Area 14 during this review period.

The 2010 Five-Year Review included the following recommendation.

• Recommendation: Initiate phased site characterization, remedial design, and remedial
action at Area 14 (an ongoing recommendation from the 2005 Five-Year Review).

Discussion: Area 14 is currently fenced and owned by Galena Ridge. Further cleanup of
Area 14 will occur in accordance with the ICP during development of the property. This
recommendation is complete.

Remedy Status

Other than an ICP cap over the Sweeney Mill portion and subsurface removal of contaminated
material, the remedy for Area 14 has not yet been installed, pending development by the
property owner.

4.2.7 Mine Operations and Boulevard Areas
4.2.7.1 Background and Description

Figure 4-1 shows the historical location of the MOA and Boulevard Area. Historically, the MOA
consisted of land and ore processing structures consisting of the powerhouse, the concentrator
silo and conveyor system, the concentrator building and trestle system to the CIA, the mill
settling pond, and two small ancillary office buildings west of the concentrator building. When
initial ore processing was conducted at the MOA facilities, the Boulevard Area was used as a
staging area for concentrates prior to being loaded into rail cars and transported to the Lead
Smelter. The MOA facilities operated until the early 1980s. The RI (McCulley, Frick, and Gilman
[MFG], 1992) indicated that the Boulevard Area soils were contaminated to levels exceeding
principal threat levels.

A review of the Mine Operations and Boulevard Areas remedial action requirements described
in the 1992 OU 2 ROD and the 1996 OU 2 ROD Amendment, and a summary of performance
standards for the remedies, are presented in the 2010 Five-Year Review Report (USEPA, 2010c).
The RAOs associated with the MOA remedy are intended to accomplish the following:

• Minimize risk of direct contact with contaminants.

• Minimize surface water infiltration through contaminants.

The MOA remedial action was completed in 1995. The components of this action consist of the
following:

• Hazardous materials located within buildings were characterized and removed.

• Contaminated soil, concentrates, and ores were removed for reprocessing.

• Buildings were demolished, and debris was disposed of on top of the CIA. Asbestos was
abated and disposed offsite.

4-24

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

• The Site was graded and revegetated and ICP barriers were put into place.

The Boulevard Area remedial action was completed in 1997. The components of this action
consist of the following:

• PTMs and contaminated soil were removed and transported to the SCA and disposed in the
geomembrane-lined PTM Cell. Non-PTM-level (84,600 mg/kg) materials were disposed in
the general SCA.

• Soil was replaced with clean soil and surface water control measures constructed.

Additional detail, including a complete listing and description of remedial actions, is provided
in the 2010 Five-Year Review Report (USEPA, 2010c). Long-term O&M of the Boulevard Area is
addressed in the Gulches O&M Manual (TerraCraphics, 2010c).

4.2.7.2 Operations and Maintenance and Actions since the Last Five-Year Review

Semiannual inspections of the MOA and Boulevard Area remedial action are conducted by the
IDEQ in accordance with the Railroad Gulch/Boulevard Area portion of the Gulches
Operations and Maintenance Manual (TerraCraphics, 2010c).

The fall 2014 IDEQ inspection (IDEQ, 2014a) confirmed that the remedy is functioning as
intended. Soil barriers are intact, drainage ditches are functioning, and culverts are in good
condition.

During this review period, the Boulevard Area action has required the following maintenance
activities:

• A small cottonwood tree was obstructing the intake to one of the culverts along McKinley
Avenue and was removed by IDEQ in fall 2011 (IDEQ, 2011b).

• A bare area was identified near the sediment basin during the fall 2010 O&M inspection
(IDEQ, 2011a). Subsequent sampling indicated lead levels below 1,000 parts per million. No
follow on action was necessary.

4.2.7.3 Remedy Status

The MOA remedy is functioning as intended by the decision documents.

O&M inspections conducted through the IDEQ O&M program indicated that the soil caps in
the MOA and Boulevard Areas remain intact and prevent direct contact with underlying
contaminated soils. The vegetation on both the MOA and Boulevard Areas is well established
and is regenerating yearly without any maintenance. In addition, surface water runoff ditches
and culverts are performing as necessary to channel flow to Bunker Creek.

4.2.8 Milo Gulch

4.2.8.1 Background and Description

Milo Creek drains an approximately 4-square-mile watershed located above and within
Wardner and Kellogg and eventually discharges into the SFCDR (Figure 4-1). The Milo Creek
watershed is discussed in this section in three segments: the upper Milo Creek watershed, the

4-25

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

lower Milo Creek piping system, and Reed Landing. Additional detail for each segment is
provided in the 2010 Five-Year Review Report (USEPA, 2010c).

The upper Milo Creek watershed has an area of about 2 square miles and consists of forested
and clear-cut areas, the Silver Mountain Ski Resort, mine dumps, and some industrial mining
areas (Reed Landing). Mine dumps, portals, access roads, hoists, and other industrial mining
features are located throughout this area and have affected Milo Creek's water quality and
discharge over the years.

The lower Milo Creek piping system consists of a concrete sediment basin upgradient of
Wardner and an underground high-density polyethylene conveyance system.

Reed Landing consists of a mine tailings dump obstructing the Milo Creek flow path, located
midway up the watershed, which was filled in the early days of the Bunker Hill Mine Complex
operations. Prior to 1998, a 4 x 4 culvert conveyed Milo Creek through the dump or "landing."

A review of Milo Gulch remedial action requirements described in the 1992 OU 2 ROD, the 1998
OU 2 ESD, and the 2001 OU 2 ROD Amendment is presented in the 2010 Five-Year Review
Report (USEPA, 2010c). The RAOs associated with the Milo Gulch remedy are intended to
accomplish the following:

• Reduce suspended sediment and/or contaminant loading in surface runoff to SFCDR.

• Minimize surface water infiltration through contaminants.

• Minimize surface water infiltration into the underlying Bunker Hill Mine workings.

• Minimize the potential for recontamination of previously remediated residential yards.

• Reduce the quantity of AMD created in the Bunker Hill Mine.

Milo Gulch and Reed Landing remedial action was conducted between 1995 and 2000. The
general components of this action consist of the following:

• About 30,000 cy of mine waste rock and tailings removed from creek banks above Reed
Landing and placed in Guy Caves area by Bunker Hill Mine owner.

• Milo Creek and Reed Landing conveyance systems were installed to convey flow
unimpeded and to minimize contact between Milo Creek and underlying tailings/mine
waste and to protect downstream residences from recontamination during floods. The
conveyance system was constructed with a capacity to convey a 100-year recurrence interval
storm event.

• The failing timber crib retaining walls were removed and the nearly vertical face of the
landing was regraded.

Additional detail, including a listing and description of remedial actions, is provided in the 2010
Five-Year Review Report (USEPA, 2010c).

There are additional remedial actions called for in the 2001 OU 2 ROD Amendment (USEPA,
2001b) to address the infiltration into the underground mine workings. Remedial design for the
West Milo Diversion project was conducted by USACE for USEPA. The design was completed
to the 95 percent level in 2008. Construction is pending remedial action funding. In addition to
the West Milo Diversion project, other remedial actions called for in the 2001 OU 2 ROD
Amendment that have not be implemented include rehabilitating the Phil Sheridan Raise and

4-26

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

plugging in-mine drill holes to reduce the quantity of surface water entering the mine and AMD
creation within the mine.

A watershed district was formally established in 1998 for maintaining the Milo structures. A
long-term O&M manual was prepared for Milo Creek (TerraCraphics, 2001) and the Reed
Landing structures (USACE, 2000) that describe the O&M requirements in more detail. USEPA
remains responsible for Reed Landing elements of the Milo conveyance system until O&M
responsibilities are formally transferred from USEPA to the IDEQ. The Milo Creek Watershed
District has the responsibility of conducting regular O&M activities for the lower Milo Creek
piping system.

4.2.8.2 Operations and Maintenance and Actions since the Last Five-Year Review

The Milo Watershed District Commissioner was consulted and confirmed that the District
conducts regular inspections semiannually and inspects the intake structures daily during high
flow events to prevent excessive sediment and debris buildup. Maintenance activity during this
review period has been limited to regular sediment and debris removal and a concrete patch
after a hole was found in the structure during the July 2015 inspection.

The Reed Landing flood control project is inspected semiannually by IDEQ (on behalf of
USEPA) in accordance with the Reed Landing O&M manual (USACE, 2000). USEPA funded
sediment and debris removal from the Reed Landing structure in October of 2011.

IDEQ removed debris from the structure by hand during the fall 2014 O&M Inspection (IDEQ,
2014a). No other maintenance has been required during this review period to sustain the
integrity of the remedial action.

The 2010 Five-Year Review introduced the following recommendations for Milo Gulch.

• Recommendation: Regarding AMD discharge at Reed and Russell adits, continue
discussions and negotiations with the mine owner to redirect the adit flows in the Milo
drainage to the CTP for treatment. Subsequent to redirection of the adit flows, evaluate
stability of the 4-foot by 4-foot structure (the first portion of this recommendation is also an
ongoing recommendation from the 2005 Five-Year Review).

Discussion: USEPA continues to be eager to coordinate this issue with the mine owner and
operator. USEPA selected a remedy in the Upper Basin ROD Amendment to address this
issue. This recommendation is complete.

• Recommendation: Secure permanent access for system maintenance (an ongoing
recommendation from the 2005 Five-Year Review).

Discussion: USEPA continues to work with the mine owner and operator to secure
permanent access to Reed Landing for long-term O&M. This recommendation will not be
retained on the table of issues and recommendations, because it does not directly affect
protectiveness. It will instead be included on the table of planned action items.

4-27

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Discussion: Because of an inability to reach agreement on the State's obligations for the
OU 2 Mine Water ROD amendment actions, phase II remedial actions have generally not
been implemented to date. Due to the settlement with Heel a, non-federal funds are now
available to implement some of the phase 2 actions, including the CTP and groundwater
collection system. Long-term O&M obligations for these actions is addressed in a 2014
memorandum of agreement whereby the IDEQ agreed to conduct long-term O&M activities
as long as the funds placed in the State Endowment Fund from the Hecla settlement last.
This recommendation is complete.

4.2.8.3 Remedy Status

The Milo Gulch remedies have been in place for 15 years. The drainage system continues to
function as designed, providing protection to downstream residences from recontamination
due to flooding. Based on IDEQ O&M inspections and discussion with the Milo Creek
Watershed District Staff in March of 2015, the hydraulic systems, including pipes and open
channels, have required regular O&M efforts to keep structures free from debris during high
flow, but the system appears to be functioning as designed.

As discussed in Section 2.5, surface water quality monitoring at the mouth of Milo Creek since
the last five-year review shows a significant decreasing trend in particulate and dissolved lead
as well as dissolved cadmium and zinc. All metals continue to exceed AWQC.

4.2.9 Central Treatment Plant
4.2.9.1 Background

The CTP was constructed in 1974 to treat metals-laden AMD from the Bunker Hill Mine and
process water from various Industrial Complex facilities using a lime precipitation process. The
CTP is located at the base of the southeast corner of the CIA (Figure 4-1). Historically, mine
water flowed by gravity to the top of the CIA into an unlined holding pond prior to being
conveyed to the CTP for treatment. Additional metals-contaminated water from other Site
sources (runoff from the Zinc Plant, Phosphoric Acid Plant, and the Lead Smelter) was pumped
to the CTP for treatment beginning in the mid-1970s.

To continue treatment of the Bunker Hill mine water and other contaminated Site flows,
operational efficiency of the CTP has been improved, and more routine maintenance and
equipment upgrades have been conducted since 1995. In addition, the historical practice of
placing acidic mine water in unlined ponds on top of the CIA was ceased after construction of a
lined holding pond in 1995.

Currently, the overall Bunker Hill mine water collection and treatment system consists of the
Kellogg Tunnel Portal system, the mine water pipelines, the Lined Mine Water Storage Pond
(Lined Pond), the Sweeney Area pipeline, the CTP, and the unlined Sludge Disposal Cell on the
CIA. AMD flows from the Kellogg Tunnel Portal into a concrete channel and passes through a
Parshall flume where the flow is measured. AMD then enters a buried high-density
polyethylene pipeline (Mine Water Pipelines - Main Line), which conveys it either directly to
the CTP (via the Direct Feed Branch) or to the Lined Pond (via the Lined Pond Branch),
depending on the pipeline valve settings.

4-28

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

The Bunker Hill CTP is a lime treatment system configured for the high-density sludge (HDS)
process. The HDS process is a modification of conventional lime precipitation designed to
density the sludge, reduce the volume of sludge requiring management, and improve sludge
dewatering and water filterability. The CTP is currently operated in low-density sludge (LDS)
mode with insufficient sludge recycling and sludge inventory in the Thickener to produce a
high degree of sludge densification. Operating in LDS mode results in lower effluent total
suspended solids (TSS) and particulate metals concentrations, enabling compliance with current
discharge requirements. However, the LDS process generates significantly more sludge volume
(approximately three times) than the volume if the CTP were operated in HDS mode. Currently,
treated effluent is discharged directly to Bunker Creek, and waste sludge is pumped to the
unlined Sludge Disposal Cell on the CIA, for dewatering and disposal in-place. Additional
detail, including CTP configuration and operation, is provided in the following documents:

• Design Considerations for Phase 1 and 2 CTP Upgrades (also known as the 2013 CTP Master
Plan Update; CH2M HILL, 2013b);

• Phase 1 Central Treatment Plant Upgrades Project Design Definition Report (DDR;
CH2M HILL, 2013a); and

• Revised Draft Phase 1 Central Treatment Plant Upgrades and Central Impoundment Area
Groundwater Collection System Schematic Design Report (CH2M HILL, 2014a).

4.2.9.2 Review of Record of Decision and Record of Decision Amendment Requirements

A review of the CTP remedial action requirements described in the 1992 OU 2 ROD and the
2001 OU 2 ROD Amendment (also known as the 2001 Mine Water ROD Amendment) is
presented in the 2010 Five-Year Review Report (USEPA, 2010c). The 1992 OU 2 ROD identified
Phase I source control actions for OU 2, which have largely been completed. The 2001 Mine
Water ROD Amendment (USEPA, 2001b) and the 2012 Upper Basin ROD Amendment
(USEPA, 2012a) identified Phase II remedial actions for collecting and treating select metals-
contaminated source waters within OU 2 and the Upper Basin portion of OU 3 of the Site. Some
remedial actions included in previous decision documents for OU 2 have not yet been
implemented and are not modified by the Selected Remedy in the 2012 Upper Basin ROD
Amendment. The RAOs associated with the CTP remedy are intended to accomplish the
following:

• Reduce metal concentration in AMD to levels treatable using constructed wetland.

• Reduce the flow of mine water from the Bunker Hill Mine.

• Prevent AMD from discharging at locations other than the Kellogg Tunnel.

• Provide a cost-effective way to convey mine water from the Kellogg Tunnel to the CTP and
Lined Pond.

• Provide storage for AMD to prevent flows greater than treatment capacity under high flow
conditions.

• Meet effluent requirements for the CTP and prevent CTP upsets.

4-29

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

• Provide a lined storage facility for CTP sludge.

• Provide an alternate location for treatment of contaminated water.

The 2001 Mine Water ROD Amendment added remedial actions to the Selected Remedy for
OU 2 (USEPA, 1992) to address the management of AMD from the Bunker Hill Mine. This was
necessary, in part, because the CTP, which had not been significantly upgraded since it was
built in 1974, could not consistently meet current water quality standards, and the existing
sludge disposal area was approaching capacity. The OU 2 Selected Remedy also includes source
control actions to reduce the amount of surface water flow into, and AMD flowing out of, the
mine. The 2000 CTP Master Plan (CH2M HILL, 2000a), included as an appendix in the 2001
Bunker Hill Mine Water RI/FS (USEPA, 2001c), provided technical guidance on the phased
implementation of the actions included in the 2001 Mine Water ROD Amendment.

Time-critical components of the 2001 Mine Water ROD Amendment were implemented
between 2002 and 2006 as emergency actions to avoid potential catastrophic failure of the aging
CTP and to provide for emergency mine water storage (USEPA and IDEQ, 2003; CH2M HILL,
2013a).

As noted in Section 2.2.2 of this report, USEPA, the IDEQ, and the Coeur d'Alene Tribe signed a
memorandum of agreement in 2014 to provide funds set aside in a Court Registry Fund from
the Consent Decree with Hecla Limited (U.S. v. Hecla Ltd., 2014) with the State's Endowment
fund Investment Board. The memorandum of agreement stipulates that the funds set aside for
the IDEQ must be used for collection and treatment, including O&M of facilities, of OU 2
contaminated waters.

The 2012 Upper Basin ROD Amendment clarified and modified some of the OU 2 and OU 3
water collection and treatment actions that had previously been selected in prior RODs for OU 2
and OU 3 (USEPA, 1992 and 2002a). Overall, the water collection actions focus on intercepting
metals-contaminated groundwater, and adit discharges emanating from abandoned mining-
impacted Sites before the flows enter surface waters. Some adit discharges, primarily those in
relatively remote locations, have been designated for onsite passive or semi-passive treatment.
The collected groundwater and adit seeps not treated onsite have been designated for
collection, conveyance to, and active treatment at the CTP. The current treatment capacity of the
CTP is insufficient to accommodate those additional OU 2 and OU 3 flows designated for active
treatment; therefore, actions to increase the capacity of the CTP were selected as part of the 2012
Upper Basin ROD Amendment. In addition to increasing the capacity, the CTP upgrades are
needed to comply with NPDES requirements. Based on additional flows that were planned to
be treated as part of implementing the Selected Remedy in the 2012 Upper Basin ROD
Amendment, the CTP Master Plan was updated in the fall of 2013 (CH2M HILL, 2013b) to
document the CTP upgrades that had been conducted since 2000 as well as to revise future
upgrade approaches.

4.2.9.3 O&M and Actions since Last Five-Year Review (2010-2015)

Additional remedial actions at the CTP were not completed during this Five-Year Review
period. Activities performed at the CTP consisted of routine O&M of the treatment plant.

USACE, under an Interagency Agreement with USEPA, currently administers an O&M contract
for the CTP and associated mine water infrastructure components external to the mine. The

4-30

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

New Bunker Hill Mining Corporation has not actively mined for several years. USEPA does not
have regular access to the interior of the mine to verify that the maintenance of internal
infrastructure is being conducted by the mine owner regularly; however, observations by
USEPA, its contractors, and the CTP O&M contractor indicate that at least some of the needed
maintenance activities are occurring. Such indications include regular pumping from the mine
and visible flows in the ditch leading to the mine water line intake flume.

A long-term O&M manual was prepared for the CTP remedial action in 2004 (CH2M HILL,
2004). Regular O&M activities are conducted by the USACE O&M contractor that operates and
maintains the CTP.

The 2010 Five-Year Review included the following recommendations for the CTP.

• Recommendation: Regarding the AMD discharge from Reed and Russell, work with mine
owner to address AMD conveyance issues resulting in discharge of AMD at these locations
(an ongoing recommendation from the 2005 Five-Year Review).

4.2.9.4 Central Treatment Plant Upgrades/Groundwater Collection System Remedial Design (2013-
2015)

As part of the Phase II remedial actions identified in the 2001 Mine Water ROD Amendment
and the 2012 Upper Basin ROD Amendment for collecting and treating select metals-
contaminated source water within OU 2 and the Upper Basin portion of OU 3, upgrade and
expansion of the CTP is expected to occur in two phases. The first phase (Phase 1) would
include upgrades to the existing systems to improve efficiency and effectiveness, and would
provide expanded treatment capacity to accommodate contaminated groundwater collected in
OU 2 prior to its discharge to the SFCDR, in addition to the Bunker Hill Mine water currently
treated at the CTP. The second phase (Phase 2) of CTP upgrade and expansion would provide
additional treatment capacity for waters collected in OU 3 and conveyed to the CTP.

As one of the first of several water collection and treatment actions included in the Selected
Remedy in the 2012 Upper Basin ROD Amendment, a remedial design (RD) project was
initiated in 2013. An SDR was prepared (through approximately 30 percent design completion)

4-31

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

to document the RD basis for the Phase 1 CTP Upgrades and CIA GWCS Remedial Action (also
known as the 2014 CTP Upgrades/GWCS SDR; CH2M HILL, 2014a). The RD was conducted in
accordance with the 2001 Mine Water ROD Amendment, the 2012 Upper Basin Interim ROD
Amendment, the 2013 CTP Master Plan Update, and Remedial Design/Remedial Action
Handbook (USEPA, 1995). The RD, as documented in the 2014 CTP Upgrades/GWCS SDR,
includes the following elements:

• A GWCS located primarily between the CIA and the SFCDR

• Phase 1 CTP upgrades and expansion

• An effluent discharge pipeline from the CTP to the SFCDR

Based on analysis produced by CH2M HILL (2014a) it was apparent that the remaining capacity
of the existing sludge disposal facility would likely be exhausted during the design and
construction of the upgrades to the CTP. Therefore, USEPA directed CH2M HILL to include the
provisions for a new sludge disposal cell on top of the CIA for dewatering and disposal in-place
of waste sludge from the CTP. The new disposal cell will be included in the Phase 1 CTP
upgrades and expansion.

The upgraded and expanded CTP will include replacement of the existing facility components
that have reached their useful life and the construction of new components to meet discharge
water quality standards. The power supply for the CTP and GWCS will be from existing
substations and power lines and will terminate at a new transformer near the CTP, and at
service transformers at the extraction wells.

The CTP Upgrades/GWCS will be implemented under an Operations/Design/Build/Operate
(ODBO) contract. Procurement will be administered by the USACE on behalf of USEPA. The
construction is estimated to start mid-2016 and to be complete in 2020, which includes a one-
year O&M period after the upgrades are completed.

4.2.9.5 Upgraded Central Treatment Plant Effluent Discharge Limits Evaluation (2014-2015)

The CTP currently operates under discharge limitations established by a NPDES permit that
was issued in 1986 and expired in 1991. Expected future discharge limits were evaluated for
USEPA in 2002, and the evaluation was revised in 2007 (CH2M HILL, 2002b and 2007b). These
expected future limits, as evaluated in 2007, were lower than the current expired CTP effluent
limits. However, these evaluations were never formalized into permit documentation. The
evaluations are being superseded by the most recent evaluations, described as follows.

The 2012 Upper Basin ROD Amendment selected the discharge point of the upgraded CTP to be
the SFCDR (whereas it previously discharged into Bunker Creek). In February 2015, USEPA
established new surface water quality discharge requirements consistent with the substantive
requirements of the NPDES permit program. The statutory and regulatory basis for the
technology and water quality-based effluent limits and a list of the current and future CTP
effluent discharge limits, are provided in the CTP Discharge Requirements Technical Memorandum
(USEPA, 2015b). Based on these future limits, a filtration system will be a necessary component
of the upgraded CTP to achieve the discharge limits.

4.2.9.6 Groundwater Collection System

The GWCS is part of the OU 2 groundwater collection remedial action and is intended to collect
the metals-contaminated groundwater from the CIA (Section 4.2.4) and convey it to the CTP for

4-32

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

treatment (Section 4.2.9) or the Lined Pond for temporary storage. The GWCS is currently in the
early stages of remedial design. Once constructed, the GWCS will be located between the CIA
and the SFCDR. The GWCS will primarily consist of a cutoff wall and 10 to 12 extraction wells

4.2.9.7 Review of Record of Decision, Record of Decision Amendment, and Explanation of
Significant Differences Requirements

The 2001 Mine Water ROD Amendment and the 2012 Upper Basin ROD Amendment identified
Phase II remedial actions for collecting and treating select metals-contaminated source waters
within OU 2 and the Upper Basin portion of OU 3 of the Site. The 2012 Upper Basin ROD
Amendment clarified and modified some of the OU 2 and OU 3 water collection and treatment
actions that had previously been selected in prior RODs for OU 2 and OU 3 (USEPA, 1992 and
2002). Overall, the water collection actions focus on intercepting metals-contaminated
groundwater, and adit discharges emanating from abandoned mining-impacted sites before the
flows entering into surface water creek and river systems. The collected groundwater and adit
seeps not treated onsite have been designated for active treatment at the CTP.

As part of USEPA's remedy implementation planning, the OU 2 groundwater collection and
treatment remedial action was selected for design and construction in the first 10-year phase of
cleanups in the Upper Basin (USEPA, 2013). Collecting and treating OU 3-contaminated
groundwater and adit seepage was identified as a potential cleanup project in the latter part of
the first 10-year implementation plan. The GWCS described in this section focuses solely on the
OU 2 groundwater collection remedial action associated with the CIA. As described in
Section 4.2.9, Phase 1 design of the CTP upgrades is currently ongoing to accommodate the
OU 2 waters, in addition to the Bunker Hill Mine water that is currently treated at the CTP.

There has been a change in approach to collect the contaminated groundwater as described in
the Final FFS (USEPA, 2012a) and the 2012 Upper Basin ROD Amendment. Initially, the GWCS
within OU 2 was assumed to be a 4,225-foot-long drain constructed along the northern edge of
the CIA with a single pump station and conveyance piping back to the CTP. The groundwater
collector drain would be used to collect contaminated groundwater near the CIA before it enters
the SFCDR. As part of the design definition phase of the GWCS, the groundwater collection
approach was evaluated in greater detail from the perspective of groundwater and surface
water interaction, geochemical and geotechnical conditions, constructability, and screening
level costs. This optimization phase is documented in the Central Impoundment Area Groundwater
Collection System Design Definition Report (2013 GWCS DDR; CH2M HILL, 2013c). The
groundwater collection approach was modified to include a cutoff wall (likely a slurry wall)
constructed north of the toe of the CIA to block groundwater flow and to minimize oxygenated
river water from entering the collection system. A series of pumping wells behind (to the south)
of the cutoff wall that would connect to a force main to convey collected groundwater back to
the CTP for treatment or temporary storage in the Lined Pond. This change in approach
constitutes a "significant change" to the Selected Remedy, as defined by CERCLA. USEPA
plans to prepare and publish an ESD describing the reasons for the change while the project
design and construction activities are underway.

4.2.9.8 Groundwater Collection System Design Activities (2013 - 2015)

A Design Definition Report (DDR) was prepared in 2013 (CH2M HILL, 2013c), which
documented the design basis for the GWCS to collect the metals-contaminated groundwater

4-33

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

from the CIA and convey it to the CTP. The design objectives included reducing contaminant
loading to surface water (SFCDR; Bunker Creek), minimizing system maintenance and fouling
to the extent practicable, preventing contaminated groundwater surface ponding, minimizing
the flow to be treated at the CTP, and minimizing system capital and O&M costs.

The groundwater collection approach included a cutoff wall (likely a slurry wall) constructed
north of the toe of the CIA to block groundwater flow and to minimize oxygenated river water
from entering the collection system. A series of pumping wells behind (to the south) of the
cutoff wall would connect to a force main to convey collected groundwater back to the CTP for
treatment or temporary storage in the Lined Pond.

The CTP Upgrades/GWCS will be implemented under an ODBO contract. Procurement will be
administered by the USACE on behalf of USEPA. The construction is estimated to start mid-
2016 and to be complete in 2020, which includes a one-year O&M period after the upgrades are
completed.

4.2.10 Union Pacific Railroad Right-of-Way Remedial Action in the Box
4.2.10.1 Background and Description

Two separate remedial actions have been implemented by Union Pacific Railroad (UPRR) in its
ROW, which stretches more than 71.5 miles between Plummer and Mullan, Idaho. The initial
action was conducted in the Box in 1997 and 1998 and is briefly described in this section. The
second action was conducted between 2000 and 2004 and focused on the ROW portions outside
the Box. Additional information can be found in Section 5.2.5, Trail of the Coeur d'Alenes
Removal Action, on the latter.

The ROW in the Box runs east-west and is approximately 7.75 miles long and 60 to 200 feet
wide (Figure 4-1). The rail line was originally constructed in the late 1800s and used to transport
mining and milling products to and from the Silver Valley. In portions of the UPRR ROW, lead-
bearing materials were used in the construction of the original rail bed. In 1991, UPRR
commenced proceedings to abandon the Wallace and Mullan Branches; cessation of rail service
was authorized in 1994 (USEPA, 1999a). The line is being maintained by UPRR as part of the
larger Trail of the Coeur d'Alenes rails-to-trails recreational facility. Oversight and management
of the ROW within the Box is under the State and USEPA and is subject to the ICP.

The Box UPRR ROW remedial action requirements are described in the 1991 OU 1 ROD and the
1992 OU 2 ROD. A review of these actions is presented in the 2010 Five-Year Review Report
(USEPA, 2010c). The RAO associated with the UPRR ROW remedy is intended to minimize risk
of direct contact with contaminants.

The UPRR-funded remediation of the UPRR ROW in the Box was conducted between 1997 and
1998. For additional details on these actions, refer to the 2010 Five-Year Review (USEPA,

2010c).1 A long-term O&M manual prepared in 2001 for the UPRR ROW remedial action
describes the post-closure O&M requirements in more detail (MFG, 2001).

1 The 2010 Five-Year Review Report is available online at http://ao.usa.aov/39vTA.

4-34

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

4.2.10.2 Operations and Maintenance and Actions since the Last Five-Year Review

The Idaho Department of Parks and Recreation (IDPR) manages the trail within the Box
boundary. UPRR conducts O&M activities under the oversight of the IDEQ. Transect surveys
were conducted every year (2010-2014) to determine if any barrier settlement or loss had
occurred. No significant barrier loss problems were documented based on the transect surveys
(ARCADIS, 2011a, 2012a, 2013a, 2014a, 2015a).

Routine monitoring, maintenance and repair (M&R) of the trail is documented in more detail in
annual reports (ARCADIS, 2011a, 2012a, 2013a, 2014a, 2015a, Coeur d'Alene Tribe and IDEQ,
2010, 2011, 2012, 2013, 2014). The following summary of actions have occurred since the last
Five-Year Review.

• Asphalt was repaired in 2011 and 2013 near the trail on the north side of the A-4 Gypsum
Pond and the Magnet Gulch bridge, because of subgrade settlement.

• Fences damaged by humans and game animals were repaired in 2011 throughout
Smelterville and the corridor between the A-4 Gypsum Pond and Kellogg.

• Asphalt damage, as a result of tree roots, was routinely repaired in areas where the asphalt
cracked. Tree seedlings were also removed.

• In 2014, trail asphalt and gravel barriers were damaged due to bridge construction at the
Pinehurst 1-90 overpass. Final repairs will occur in 2015, when the project is complete.

• The steep gravel bank between the paved trail and the area below the Pine Creek bridge,
located west of the Pinehurst trailhead, was temporarily repaired because of damage caused
by human foot traffic. This area is used for access to a popular summer swimming location.

• The access control fence located in Smelterville between the trailer court and the Wal-Mart
store was damaged by vandals and repaired several times.

• The access control fence between Smelterville and Kellogg was damaged by large game
animals and subsequently repaired.

• Several sink holes appeared in the trail below the Smelter Complex and were repaired. The
steep hillside slope in this same area was severely eroded and subsequently repaired.

The 2010 Five-Year Review included the following recommendation:

• Recommendation: Regarding UPRR barrier protectiveness, ensure that O&M obligations
defined in the CD are met to protect the integrity of the installed barriers.

Discussion: UPRR is meeting their O&M obligations under the oversight of IDEQ, USEPA,
the Coeur d'Alene Tribe, and the ICP. This recommendation is complete.

4.2.10.3 Remedy Status

Continued M&R activities conducted is critical to the preservation of the barriers. Regularly
scheduled M&R activities, conducted by UPRR, have address those issues identified as a result
of inspection activities conducted by IDEQ, IDPR, and the ICP along with the UPRR's
contractor. The integrity of the asphalt and gravel barriers is maintained by O&M activities
conducted by UPRR. Such activities address damage to the barriers caused by flooding, tree

4-35

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

root intrusion, and unauthorized use by motor vehicles. Transect surveys conducted as part of
barrier monitoring showed no significant barrier loss.

4.2.11 Page Pond Area

4.2.11.1 Background and Description

The Page Pond area is located near the west end of OU 2 and is bounded on the east by the city
of Smelterville, on the south and west by Highway 10, and on the north by the UPRR ROW
(Figure 3-7). The area covers approximately 170 acres, including roughly 70 acres of tailings
repository and 100 acres of wetlands and riparian habitat. The Page Pond Tailings Repository
was used between 1926 and 1969 to contain flotation tailings produced at the Page Mill in
Humboldt Gulch. Approximately 30 acres in the central portion of the inactive 70-acre tailings
repository now serves as the Site of the Page Ponds Wastewater Treatment Plant. The areas
immediately to the east and west of the Page Ponds Wastewater Treatment Plant were used as
designated repository areas for contaminated soils and are identified as "East Page Repository"
and "Page Repository/' respectively. The East Page Repository has been closed since the mid-
1990s.

The 2010 Five-Year Review Report (USEPA, 2010c) provides a review of the Page Pond area
remedial action requirements described in the 1992 OU 2 ROD. The previous five-year report
provided specific remedial actions outlined in the Bunker Hill Superfund Site, Page Pond
Closure Final Remedial Design Report (RDR; MFG, 1995), and remedial actions completed by
UMG during the 2000 construction season and between 2005 and 2010.

The RAO associated with the Page Pond remedy are intended to accomplish the following:

• Minimize risk of direct contact with contaminants.

• Minimize surface water infiltration through contaminants.

• Minimize habitat destruction.

The Page Pond area remedial action components completed through 2010 consist of the
following:

• Tailings excavation and removal, and disposal in the Page Repository.

• Exposed tailings in the eastern portion of the North Channel were graded, capped, and
vegetated.

• Outlet control weirs were installed at the East and West Swamp discharge locations.

• Isolation of Humboldt and Grouse Creeks.

• The surface of the original Page Repository was graded and vegetated.

A detailed discussion of the remedial actions listed above can be found in the 2010 Five-Year
Review Report (USEPA, 2010c).

4.2.11.2 Operations and Maintenance and Actions since the Last Five-Year Review

UMG worked with USEPA and IDEQ to review and complete all work prescribed in the RDR
(MFG, 1995) since the last Five-Year Review. UMG submitted its remedial action certification

4-36

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

report on April 11, 2011 (Hydrometrics Inc., 2011). After consultation with IDEQ, USEPA
certified completion of work on April 18, 2011.

The last Five-Year Review recommended the following items for the Page Pond area, and a
discussion of the recommendation or actions taken since 2010 are presented as follows.

• Recommendation: Continue to work with the Site-wide water quality monitoring program
(i.e., forthcoming revised BEMP) to integrate special considerations at the Page Pond.

Discussion: Historically, water quality monitoring was conducted in the Page Ponds area as
part of the BEMP (CH2M HILL, 2006). In preparation for the Page Repository Westward
Expansion, a water quality program specific to the repository expansion was developed and
implemented in July 2013. Beginning in the fall of 2014, select monitoring sites (that are
included in the repository expansion monitoring program) were removed from the BEMP to
eliminate redundancy. This recommendation is complete.

• Recommendation: Evaluate possible issues in existing Page Pond monitoring program.
Review recommendations in 1999 monitoring program memorandum (CH2M HILL, 1999).
Finalize monitoring program elements (ongoing recommendation from the 2005 Five-Year
Review).

Discussion: See discussion for 2010 recommendation, above. This recommendation is
complete.

• Recommendation: Evaluate biological monitoring results and impacts related to Page
Repository expansion (ongoing recommendation from the 2005 Five-Year Review).

Discussion: Mitigation wetlands have been constructed in the WENI area and a design for
further wetland mitigation at Robinson Creek is being developed. These projects are in
response to the loss of existing wetlands in the West Page Swamp due to repository
expansion. Refer to Section 3.2.2 for the complete discussion on mitigation wetlands.
Additionally, USFWS continues to conduct biological monitoring of the Page Pond area
annually; the results are summarized in Section 2.5.3. This recommendation is complete.

• Recommendation: Complete Page Pond remedial actions (ongoing recommendation from
the 2005 Five-Year Review).

Discussion: As discussed above, UMG worked with USEPA and IDEQ to review and
complete all work prescribed in the RDR (MFG, 1995). After consultation with IDEQ,

USEPA certified completion of work on April 18, 2011. This recommendation is complete.

• Recommendation: Mitigative measures should be considered for wetland loss at West Page
Swamp due to expansion of Page Repository (an ongoing recommendation from the 2005
Five-Year Review).

4-37

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

(TerraCraphics, 2014b). Mitigation credits for the expansion of West Page Swamp will be
determined over a period of approximately five years and will be based on the MDT

Montana Wetland Assessment Method (Bergland, 1999).

IDEQ has assessed the potential for mitigation credits and anticipates 14.3 acres of 1-to-l
credit from the WENI Wetland (TerraCraphics, 2014c). Additionally, IDEQ anticipates that
the mitigation credits derived from the Robinson Creek Project will exceed USEPA and
IDEQ obligations for the Westward Expansion and will be banked to offset other site-wide
remedial actions requiring mitigation under Section 404 of the CWA. This recommendation
is complete.

The status of other ongoing items is presented as follows.

• Routine O&M activities are being conducted as part of the Page Repository, such as
maintenance of stormwater and dust controls (see Section 3.2.2 for more information on the
Page Repository). UMG developed a draft O&M Plan that is not yet approved by the
Agencies or finalized by UMG (Hydrometrics Inc., 2010). The Agencies plan to incorporate
Page Pond Area O&M requirements into the Page Repository O&M Manual, as appropriate

• An upgraded broad-crest step weir was installed at the West Page Swamp outlet in
December 2014. This structure replaced the existing flume to maintain swamp water levels
and allow larger spring peak flow events to pass with less risk to the repository expansion
side slopes.

4.2.11.3 Remedy Status

Completion and certification of the remedial actions associated with the Page Pond area
indicate that releases of metals from tailings and the potential for direct contact has been
reduced (see Section 3.2.2). The west outlet control weir has been replaced with an upgraded
design that more effectively limits downgradient flooding and maintains minimum water levels
over contaminated wetland sediments. Long-term O&M required to maintain the remedial
action should be formalized in an overall manual for the Page Repository and Page Pond Area.

The graded and seeded surface of the original Page Repository has been maintained or is
actively being used as part of the current repository operations, and the open footprint area has
been kept to a minimum to aid in reduction of contaminated dust. Additionally, stormwater
best management practices are employed at the Page Repository to limit releases to the Page
Pond area. No unauthorized releases through the stormwater management system and no
catastrophic failures have been observed at the Page Repository (see Section 3.2.2 for additional
information).

A remedial effectiveness monitoring program now exists as part of the Page Repository
Westward Expansion monitoring. Refer to Sections 3.2.2 and 2.5.2 of this report for additional
information on water quality monitoring results.

4.2.12 A-4 Gypsum Pond Closure
4.2.12.1 Background and Description

The A-4 Gypsum Pond is located in the central region of OU 2 near the mouth of Magnet Gulch
(Figure 4-1). The gypsum contained in the A-4 Gypsum Pond was produced between 1964 and

4-38

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

1970 as a waste byproduct during production of phosphoric acid at the Phosphoric
Acid/Fertilizer Plant in Government Gulch. The material is predominantly calcium sulfate
(CaS04) with traces of impurities.

The 2010 Five-Year Review Report (USEPA, 2010c) provides a review of the A-4 Gypsum Pond
remedial action requirements described in the 1992 OU 2 ROD, and specific remedial actions
outlined in the RDR (MFG, 1996). The RAO associated with the A-4 Gypsum Pond remedy are
intended to accomplish the following:

• Reduce or prevent direct contact with gypsum.

• Control migration of gypsum o surface water, groundwater, and air.

• Reduce surface water infiltration through the gypsum.

The Stauffer Management Company (SMC) initiated remedial actions in 1996. The general
components of this remedial action consist of the following:

• Ditches were constructed to manage run on and runoff at the Site, and surface water
management improvements for Magnet and Deadwood Creeks.

• Approximately 13 acres of the closure surface area were capped and vegetated.

• The upper portion of the existing north perimeter embankment was removed, and the
downstream face of the embankment was regraded, to achieve a slope of 2 horizontal to 1
vertical and reduce erosion.

• A seepage barrier was installed along the north perimeter of McKinley Pond (south of
McKinley Avenue), as was a new culvert under McKinley Avenue from McKinley Pond.

• A French drain was installed on the eastern side of the mouth of Magnet Gulch channel
along the toe of the north dike to intercept groundwater seeps and supplement lowering of
groundwater levels beneath the impounded gypsum.

Additional detail of remedial actions is provided in the 2010 Five-Year Review Report (USEPA,
2010c).

A long-term O&M manual was prepared for the A-4 Gypsum Pond remedial action in 2004
(MFG, 2004), which describes the post-closure O&M requirements in more detail. Semiannual
O&M inspections and repair work have been conducted by SMC since the initial inspection of
the A-4 Gypsum Pond in 2005.

4.2.12.2 Operations and Maintenance and Actions since the Last Five-Year Review

Inspection details, records of repair work, and water quality results from the semiannual
inspections and water quality monitoring of the A-4 Gypsum Pond are documented in the
O&M and annual water quality reports (ARCADIS 2011b, 2012b, 2012c, 2013b, and 2013c; LFR
2010 and 2011; Maul Foster & Alongi, Inc. [MFA] 2014, 2015a, and 2015b).

The following summarizes the 2010 through 2014 O&M inspections findings (ARCADIS, 2011a,
2012a, 2012b, 2013b, and 2013c; LFR, 2010 and 2011; MFA, 2014a and 2015b):

4-39

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

• Sink holes were observed during all inspections conducted for the last five years. Sink holes
are associated with embankments, dikes, and drainage features along the north edge of the
pond and Magnet Gulch channel, and eastern surface diversion ditch vicinities.

• In 2011, SMC conducted a geophysical survey using electrical resistivity to compare
previous survey work and evaluate solution cavity activity (ARCADIS, 2011c). No
conclusive evidence was found concerning solution cavity development.

• Sink holes and settlement impacted three monitoring wells (A4-4, A4-5, and A4-6). These
wells were either repaired or abandoned and replaced.

• Several instances of riprap/channel failure were observed on the western side of the Magnet
Gulch channel due to dissolution of underlying gypsum.

• Perimeter fence damage as a result of game animal activity was observed during all
inspections. Repairs to the fence occurred.

• Other observations included areas of thinning vegetation, erosion rills, cracks, cap
sloughing, brush growth in drainages, and the presence of noxious weeds.

The 2010 Five-Year Review included the following recommendation for the A-4 Gypsum Pond.

• Recommendation: Regarding A-4 contaminant release, determine whether additional
measures should be undertaken to reduce the potential for contaminant migration from the
gypsum to groundwater in accordance with the remedy objective as described in the RDR
(MFG, 1995).

Discussion: RDR performance standards include "reduction or prevention of contaminant
migration from the gypsum to groundwater, surface water and air." Groundwater
monitoring near the A-4 Gypsum Pond is ongoing and will continue at least through
implementation of the CIA GWCS, which is expected to capture and treat significant
volumes of groundwater near the CIA and adjacent areas, including the A-4 Gypsum Pond.
IDEQ and USEPA will continue to evaluate SMC's groundwater monitoring results.
Recommendation is complete.

4.2.12.3 Remedy Status

The O&M inspection findings and maintenance actions show that gypsum continues to
dissolve. Maintenance of the pond cover and monitoring wells will always be necessary.
Perimeter fencing repair will continue due to big game animal activity in the area. Vegetation
and capping is sufficient to reduce wind-blown dust from the facility. Noxious weed control
will continue to be necessary.

Water quality results indicate that elevated cadmium and zinc in groundwater is likely due to
the underlying jig tailings beneath the pond, and surface water may be periodically impacted
by the dissolution of gypsum. Water quality results documented in the latest annual report
include the following (MFA, 2015a):

• Groundwater dissolved cadmium and zinc concentrations remain generally stable, except
closure well A4-2 that shows appreciable concentration fluctuations in the past three to four
years.

4-40

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

• Long-term trends of dissolved cadmium and zinc at the mouth of Magnet Gulch (BH-MG-
0001) have shown a significant decrease since 2002. Concentrations of these metals continue
to exceed AWQC and detections in both upstream and downstream surface water
monitoring sites have fluctuated over the years.

• Lower concentrations of cadmium and zinc in Magnet Gulch surface water compared to
higher concentrations of cadmium and zinc in closure wells A4-2 and A4-12 indicate that the
aquifer is likely influenced by the underlying tailings.

• Concentration of fluoride, phosphate, and sulfate observed during October 2014, indicate
possible gypsum dissolution. Fluctuation of fluoride and phosphate levels between closure
wells and surface water sites indicate that surface water is not consistently impacted.

• Distinct rises in sulfate were observed in upgradient and closure wells, and upstream and
downstream surface water Sites.

4.2.13 Institutional Controls Program

4.2.13.1 Background and Description

Institutional controls were identified as a key component to the Selected Remedy in order to
protect public health by managing contaminants left in place into perpetuity (USEPA, 1992).
The ICP in OU 2 is the same as the ICP implemented in OU 1, discussed in Section 3.2.1.6. The
ICP in OU 2 focuses on future development. Development in OU 2 is managed by local
jurisdictional planning and zoning ordinances requiring adherence to the ICP administrative
rules. The IDEQ provides funding for the OU 2 ICP as part of its match and O&M obligations at
the site, including costs for Page Repository operations associated with disposal from the non-
populated areas of the Box, discussed in Section 3.2.2.

4.2.13.2 Operations and Maintenance and Actions since the Last Five-Year Review

Since the last Five-Year Review, the ICP has issued a total of 92 permits in OU 2, almost all of
which were for large excavation projects (Table 4-1). Other ICP activities and functions, such as
contractor licensing, disclosures, disposal, and clean fill material handling, are tracked with
OU 1 activities and are presented in Section 3.2.1.6. Due to the economic downturn, no new
subdivisions or planned unit developments were proposed in OU 2 since the last Five-Year
Review.

TABLE 4-1

Number of ICP Permits Issued in OU 2, 2010-2014
2015 Five-Year Review, Bunker Hill Superfund Site

Calendar Year

Cumulative
5-Year Total

Annual
Average

Permit Type

2010

2011

2012

2013

2014

Large Exterior
Projects -
Excavation Total3

Large Exterior
Projects -
Demolition Total

Interiors Total

4-41

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TABLE 4-1

Number of ICP Permits Issued in OU 2, 2010-2014
2015 Five-Year Review, Bunker Hill Superfund Site

Calendar Year

Cumulative
5-Year Total

Annual
Average

Permit Type

2010

2011

2012

2013

2014

Records of
Compliance Total

Totals

Notes:

Data provided by PHD.

a Includes subdivision/planned unit development (PUD) totals.

The last Five-Year Review recommended the following, specifically to OU 2, and discussions of

each recommendation and actions taken since 2010 are presented as follows.

• Recommendation: Secure permanent funding for the ICP, including consideration of
adequate staff and information management support to ensure long-term effectiveness of
the program.

Discussion: Funding for the OU 2 ICP is held in the Box Bunker Hill Environmental
Remediation Fund. Idaho Statute 39-3606c establishes the Environmental Remediation Fund
for the purpose of meeting match and O&M requirements at environmental cleanup and
remediation and restoration Sites. The Fund was established in the state treasury under 39-
3605c and is interest-bearing. The Box Fund was established in 1995 to meet OU 2 match
and O&M obligations. Based on cost estimates for the ICP administration and disposal
management these funds are expected to be able to provide secure funding for the
foreseeable future (currently estimated for approximately 30 more years). PHD adopted the
rule based on the premise of external funding and as such, IDEQ continues to monitor ICP
costs and available funding, and make adjustments as necessary to meet long-term ICP
funding obligations. Additionally, PHD evaluates staffing needs and adjusts when
necessary. This recommendation is complete.

• Recommendation: Create irrevocable trust to provide consistent cash flow for the ICP
operation into perpetuity (an ongoing 2005 Five-Year Review recommendation).

Discussion: The State of Idaho has not established an irrevocable trust and will work with
USEPA to determine if such a Trust is required beyond the commitment embodied in a SSC.
This activity will not be retained in the table of issues and recommendations, because it does
not directly affect protectiveness. It will instead be included in the table of planned action
items.

• Recommendation: Establish a long-term disposal plan for ICP-generated wastes (an
ongoing 2005 Five-Year Review recommendation).

4-42

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

• Recommendation: Collect information for an ICP property database (an ongoing 2005 Five-
Year Review recommendation).

Discussion: Documentation of some past remedial actions affecting property in the Box has
not yet been located and creates challenges for PHD to issue ICP permits and provide
disclosure. To date, IDEQ has provided PHD with documentation when information is
located. As work continues, PHD needs the timely receipt of documentation from the Coeur
d'Alene Trust, USEPA, and IDEQ and any other entities conducting remedial action work.
This activity will not be retained in the table of issues and recommendations, because it does
not directly affect protectiveness. It will instead be included in the table of planned action
items. This is a site-wide task and as such has been listed only once in the OU 1 table of
action items.

• Recommendation: Identify funding and other resources for infrastructure maintenance and
improvements to protect the remedy, such as stormwater controls (an ongoing 2005 Five-
Year Review recommendation).

Discussion: In 2013 and 2014, USEPA and the Coeur d'Alene Trust have invested $6.4M in
flood management infrastructure work throughout the Upper Basin including OU2. These
"Remedy Protection" projects will continue until the ROD Amendment Selected Remedy is
complete. In addition to the Selected Remedy Protection projects identified in the 2012 ROD
Amendment (USEPA, 2012a), IDEQ, USEPA, and the BEIPC have requested assistance from
federal and state flood control agencies to address the threat of large-scale flooding to the
remedy (such as flooding from the SFCDR and Pine Creek). The Silver Jackets, an
interagency coordinating group, identified local actions that could be taken to help protect
against flooding. However, funding has not yet been found to perform the required
flooding study and subsequent flood control projects. Since the last Five-Year Review,
Environmental Covenants and Interagency Cooperative Agreements have been finalized for
completed Remedy Protection projects to ensure long-term maintenance of the constructed
infrastructure. These assist in addressing the institutional elements of the recommendation.
Additionally, IDEQ has developed an inventory of flood control structures in the
communities, including those that were installed as part of the remedy. IDEQ plans to create
a coordination cooperative consisting of local jurisdictions and IDEQ that will work together
to track O&M work for the structures. This effort is in the initial planning stage and is the
same effort developed in response to issue and recommendation "Infrastructure
Maintenance Funding: Develop appropriate institutions and funding mechanisms to finance
and oversee stewardship activities". This recommendation is complete.

• Recommendation: State of Idaho should continue to work with the different entities to
ensure the appropriate O&M is conducted. Investigate development and designation of a
central O&M coordinating entity for all remedy-specific O&M. Develop dedicated funding
sources to ensure responsible implementing of O&M.

Discussion: Since the last Five-Year Review, IDEQ has developed an inventory of flood
control structures in the communities, including those that were installed as part of the
remedy. IDEQ plans to create a coordination cooperative consisting of local jurisdictions
and IDEQ that will work together to track O&M work for the structures. This effort is in the
initial planning stage. This activity will not be retained in the table of issues and

4-43

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

recommendations, because it does not directly affect protectiveness. It will instead be
included in the table of planned action items.

• Recommendation: Regarding flood control, continue working with the BEIPC and other
stakeholders to evaluate and plan actions relative to addressing SFCDR and Pine Creek
flooding that may affect cleanups.

Discussion: This recommendation is repeated for all three OUs. See Section 3.2.1.6 for
discussion. This recommendation is complete.

• Recommendation: Continue working to develop an approach for addressing roads as long-
term barriers in collaboration with state, county, and local entities.

Discussion: This recommendation is repeated for all three OUs. See Section 3.2.1.6 for
discussion. This recommendation is complete.

• Recommendation: Develop appropriate institutions and funding mechanisms to finance
and oversee infrastructure maintenance activities.

Discussion: This recommendation is repeated for all three OUs. See Section 3.2.1.6 for
discussion. This activity will not be retained in the table of issues and recommendations,
because it does not directly affect protectiveness. It will instead be included in the table of
planned action items. This is a site-wide task and as such has been listed only once in the
OU 1 table of action items.

4.2.13.3 Remedy Status

Section 3.2.1.6 discusses the performance and status of the Box ICP in detail. The ICP in OU 2
faces challenges similar to those in OU 1. The ICP is being implemented according to its rule
(IDAPA 41.01.01) and in a manner that maintains the 350 mg/kg residential community-wide
lead average in soils. Funding to implement the ICP into perpetuity is critical to the success of
the Selected Remedy.

4.3 Technical Assessment for OU 2

4.3.1 Is the Remedy Functioning as Intended by the Decision Documents?

To the extent remedial actions selected in decisions documents have been implemented, they
are functioning as intended.

Construction of the remedial actions listed in the 1992 ROD (Phase I) are complete, except at
Area 14, which was postponed pending development by the property owner.

Continued implementation of O&M, in accordance with O&M plans, is integral to the long-term
effectiveness of completed remedial actions and the Selected Remedy. O&M of completed
remedial actions is ongoing as scheduled, and potential repairs and maintenance are identified
during inspections. The IDEQ and USEPA entered into a Memorandum of Agreement that
designated settlement dollars to be invested by the State for purpose of operating the CTP until
funds are exhausted (USEPA and IDEQ, 2014).

4-44

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Inspection findings over the last five years show that capped areas, constructed stream
channels, culverts, sedimentation basins, and gabion dams are generally in good condition and
functioning as intended. If IDEQ finds any engineered feature not functioning properly, they
either repair the feature (e.g., Railroad Gulch) or in coordination with USEPA decide it is no
longer needed (e.g., the lower gabion dam in Deadwood Gulch). Hillsides are generally stable,
vegetation is thriving in most areas, and check dam performance is acceptable. Beaver activity
in Bunker Creek is recurring, and beaver removal is needed to prevent negative impacts to the
reconstructed creek channel and culverts. The CIA cap shows no evidence of settlement, and
vegetation is regenerating. The reconstructed stream banks of the SFCDR in the Smelterville
Flats area are stable and performing adequately to minimize sediment entering the river. Many
areas require noxious weed control. However, weed control is a property owner obligation and
is not an O&M responsibility under Superfund.

Monitoring and Maintenance &Repair of the Trail has proven effective in the long-term
protectiveness of the remedy. Based on the findings of the M&R reports and regular
monitoring, the remedy is performing as intended and remains protective of human health and
the environment.

IDPR is closely monitoring the adequacy of the settlement cash-out they received to manage the
Trail of the Coeur d'Alenes. Incurred costs to date have exceeded the revenues generated from
interest earned on the principal plus encroachment and other special use fees, resulting in the
utilization of base funds.

Galena Ridge Golf Course, Milo Watershed District, and SMC are third-party entities also
responsible for implementing O&M of OU 2 remedial actions. IDPR and UPRR are responsible
for maintaining the remedy on the Trail of the Coeur d'Alenes.

Long-term ICP waste estimates for OU 2 have been developed. Although the current Page
Repository offers sufficient capacity for years to come, planning for additional Box repository
space is ongoing.

O&M costs for State maintained actions have been less than expected. However, there has not
been a significant storm or flood event in OU 2 since IDEQ took over O&M responsibilities.
Such an event would likely cause a large expenditure of O&M dollars, offsetting the low annual
costs experienced so far.

The ICP is administered, implemented, and enforced by PHD according to the rule (IDAPA
41.01.01), with funding from the State. Funding to implement the ICP into perpetuity is critical
to protect public health and maintain protectiveness of the Selected Remedy. Current estimates
indicate funding for the ICP is expected to cover the foreseeable future, or approximately
30 more years. Longer-term funding mechanisms will be necessary.

The various remedial actions implemented at the CTP to date are functioning as designed and
as intended by the decision documents. However, the overall CTP and mine water remedy is
not yet complete. Therefore, only the completed portions of the remedy are addressed in this
Five-Year Review Report. The CTP is currently required to meet the discharge requirements of
its expired NPDES permit (USEPA, 1986). This permit expired on October 30,1991; however, its
discharge requirements have continued to be used by USEPA until the remaining CTP
upgrades are implemented. This is because the existing CTP is not capable of consistently
meeting modern Idaho water quality standards without the upgrades. The CTP consistently

4-45

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

meets its current discharge requirements with only occasional minor deviations from the
effluent requirements, which are primarily attributable to the lack of a filtration system and the
condition of dilapidated equipment that are planned to be replaced as part of the plant
upgrades. When deviations occur, standard procedures are to adjust the treatment plant
operations as needed and re-sample and re-test effluent quality to ensure compliance. As
previously discussed in Section 4.2.9.6, CTP upgrades and expansion are schedule to begin in
2016. Specific actions on the CTP and groundwater collection system are being implemented
under a memorandum of agreement that provides for long-term O&M as long as the funds
placed in the State Endowment Fund from the Hecla settlement last.

Both remedial action effectiveness and long-term water quality monitoring for OU 2 is ongoing
(discussed in Section 2.5). Trend results indicate that remedial efforts in the SFCDR valley and
its tributaries since the early 1990s have been successful in reducing concentrations of trace
metals. Statistically significant downward trends were noted during water years 1990-2013 for
all constituents evaluated in the SFCDR at Elizabeth Park and for zinc and lead in the SFCDR
near Pinehurst, reflecting the effectiveness of Phase I remedial actions. During water years
2003-13, the SFCDR at Elizabeth Park continued to indicate significant downward trends in
total cadmium and zinc concentrations, but no significant trends were observed for this period
in the SFCDR near Pinehurst (USGS, 2015 ) However, significant decreasing trends in cadmium
and zinc concentrations were observed in monitored tributaries that feed SFCDR between 2002
and 2014, with the exception of Bunker Creek for which no trend was observed.

Further significant reductions in cadmium and zinc concentrations in the SFCDR necessitates
reducing loads entering the SFCDR from cadmium- and zinc-enriched groundwater near the
CIA. The SFCDR reach adjacent to the CIA continues to be the highest source of dissolved
metals loading from groundwater to the SFCDR in the Upper Basin (USGS, 2015). Contaminant
concentrations near the CIA, in both surface water and groundwater, continue to exceed ARARs
at most sampling locations. As discussed in Section 2.5, most groundwater monitoring sites
(40 of 62 sites) are located near or downgradient of the CIA, near the SCA, and near
Government Gulch. The highest MCL ratios for cadmium and zinc are also found in these areas.
Across OU 2, 77 percent of the sites exceed the MCL for cadmium and 61 percent exceed the
MCL for zinc. For the period between 2002 and 2014, results for zinc across OU 2 show
39 percent of sites as not improving, 21 percent improving, 8 percent caution (concentrations
increasing), and 32 percent stable. Overall results for cadmium across all of OU 2 show
29 percent of sites as not improving, 37 percent improving, 13 percent caution, and 21 percent
stable. The groundwater collection and treatment remedial action (Phase II) currently under
design is expected to intercept metals-contaminated groundwater and reduce loading to the
SFCDR from groundwater by over 60 percent, resulting in significantly decreasing trends in
cadmium and zinc following installation of the remedy.

The effectiveness evaluation of Phase I source control and removal activities to meet water
quality improvement objectives, including drinking water requirements, indicates that Safe
Drinking Water Act (SDWA) groundwater MCLs identified as ARARs in the 1992 OU 2 ROD
have not been met for areas within the Box. As the 2012 FFS for the Upper Basin explains, given
the pervasive nature of the subsurface contamination under communities, roadways and
infrastructure in the Box (and elsewhere in the Upper Basin), achieving the MCLs in the
groundwater is expected to be challenging. The Selected Remedy in the 2012 Upper Basin ROD
Amendment will address many significant sources of contamination in the Upper Basin and

4-46

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

will protect human health and the environment commensurate with its scope. However, as an
interim measure, achieving certain water quality criteria standards for all locations, are outside
the scope of, and need not be attained by, the Selected Remedy. As determined to be
appropriate, USEPA will evaluate future monitoring data and completed actions to determine
whether a technical impracticability waiver may be warranted at locations where achievement
of drinking water standards in groundwater cannot be achieved.

4.3.2 Are the Exposure Assumptions, Toxicity Data, Cleanup Levels, and Remedial
Action Objectives Used at the Time of Remedy Selection Still Valid?

The ARARs identified in the 1992 OU 2 ROD, 2001 OU 2 ROD Amendment, subsequent
changes identified in the 2010 Five-Year Review Report (USEPA, 2010c), and the ARARs
identified in the 2012 Upper Basin ROD Amendment continue to be protective.

The RAOs outlined in the ROD, ROD Amendments, and O&M plans are generally intended to
reduce human and ecological exposure to chemicals of concern and reduce impacts on surface
water and groundwater quality.

The following RAOs were addressed:

• Minimize direct contact with contaminated material

• Minimize erosion and wind dispersion of contaminants

• Minimize migration of contaminants to surface water and groundwater

• Minimize water infiltration through underlying contaminated media

No major changes in land use have occurred since the last Five-Year Review. However, the Trail
of the Coeur d'Alenes, the SFCDR, and hillsides are typically used by recreationalists in OU 2,
and the frequency of access appears to be increasing in localized areas. New, informal
pedestrian paths leading down the riverbank to the SFCDR have been observed by IDPR, IDEQ,
and PHD in various places along the Trail of the Coeur d'Alenes and likely result in barrier
erosion and increased risk of exposure to trail users. PHD has also observed several informal,
undeveloped (or "impromptu") Sites where children created swimming holes on the banks of
the SFCDR and its tributaries. As noted in the last Five-Year Review, development of Upper
Magnet Gulch, Deadwood Gulch, and Grouse Gulch has made areas of the hillsides more
readily accessible.

The recreational scenario evaluated in the original OU 2 risk assessment suggested that a soil
concentration from about 1,200 to 3,500 mg/kg could be considered acceptable for short-term
exposures involving children 6 years of age and older (SAIC, 1991). Consequently, a
recreational cleanup number was not selected at the time of the 1992 ROD. New information
about bioavailability and ingestion rates suggests that these levels may not be protective and
consideration should be given to re-evaluation if a recreational cleanup standard is needed for
future cleanup decisions in OU 2. Incremental risk for OU 2 areas was estimated by projecting
post-remediation blood lead levels for children living in the residential areas of OU 1 and
calculating potential incremental exposures (or increased blood lead levels) for children that
might undertake recreational activities in OU 2. Post-remediation blood lead levels for children
residing in OU 1 were estimated using Site-specific parameters in the USEPA IEUBK model,
described in the original documents (SAIC, 1991, JEG et al., 1989). Incremental intake rates were
calculated using a soil and dust ingestion rate of 100 mg/day for a typical 6-year-old child

4-47

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

engaging in more dirt-intensive recreational activities, coupled with a 20 percent bioavailability
estimate and a number of other Site-specific input parameters (SAIC, 1991; JEG et al., 1989).

As discussed in Section 3.3, a USEPA-funded research project analyzed archived yard soil and
house dust samples for IVBA in 2012, which was not available at the time of the original risk
assessment (USEPA, 2007a, 2012c). Results from that project suggest that a lower residential soil
and dust ingestion rate and higher soil bioavailability are more appropriate than those used in
the Site-specific model (von Lindern et al., 2015). The new bioavailability information indicates
the risk assessment for child recreational scenarios should employ a higher value, closer to the
IEUBK default value of 30 percent, or as high as the 39 percent observed in Smelterville, which
may reflect smelter emissions deposited on nearby hillsides. Many factors are involved in
calculating risk and it is unknown how this new information might impact the original
recreational risk-based soil values (i.e., over or underestimated). Current information regarding
recreational areas (PHD findings on high blood levels associated with recreational exposures)
and risk assessment assumptions suggest recreational risk was likely underestimated, but may
be somewhat offset by the better than anticipated post-remediation blood lead levels observed
in the residential areas. The 2013 mean blood lead levels were slightly lower than those
estimated in the risk assessment (2.2 jug/dL compared to 3.2 jug/dL), likely due to lower than
anticipated diet and drinking water intakes and projected post-remediation soil/ dust lead
concentrations. There is no new information to suggest recreational soil and dust ingestion rates
should be modified.

In addition to lead, incremental carcinogenic risks for arsenic and cadmium were estimated for
the various OU 2 locations and the cancer slope factors used in the original risk assessment have
changed. Risk was negligibly underestimated for arsenic ingestion because the slope factor used
was slightly higher (1.75 (mg/kg-day)-1) than the current slope factor in the Integrated Risk
Information System (IRIS; 1.5 (mg/kg-day)1). The inhalation slope factors are outdated as
newer guidance for estimating risk from the inhalation pathway has changed since the time of
the risk assessment (USEPA, 2009a). The impact of these changes on incremental risk from the
recreational and occupational scenarios is unknown without further calculations. However, the
impacts are likely inconsequential because most of the remedial actions at the OU 2 locations
have barriers and/or access controls, or the inhalation pathway was not applicable.

4.3.3 Has any Other Information Come to Light that Could Call into Question the
Protectiveness of the Remedy?

The 2015 Five-Year Review did not find any other new information that calls into question the
protectiveness of the OU 2 remedies.

4.4 Summary of OU 2 Issues, Recommendations, and Follow-Up
Actions

No issues, recommendations, and follow-up actions that directly affect protectiveness were
identified during this fourth Five-Year Review. Action items identified during this fourth Five-
Year Review that are expected to require future action, but do not affect protectiveness are
summarized in Table 4-2. These recommendations are summarized herein to allow USEPA to
track this information, as suggested by Five-Year Review guidance (USEPA, 2001a).

4-48

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TABLE 4-2

OU 2 Action Items that Do Not Affect Remedy Protectiveness
2015 Five-Year Review, Bunker Hill Superfund Site

Remedial
Action

Action Item

Responsible
Party

Oversight
Agency

Page Pond
Area

Continue to develop a comprehensive O&M and Site Closure Plan
for the Page Repository. Repeated in OU 1.

IDEQ

USEPA

ICP

Create irrevocable trust to provide consistent cash flow for the ICP
operation into perpetuity

IDEQ, PHD,
USEPA

IDEQ,
USEPA

ICP

IDEQ should continue to work with the different entities to ensure
the appropriate O&M is conducted. Investigate development and
designation of a central O&M coordinating entity for all remedy-
specific O&M. Develop dedicated funding sources to ensure
responsible implementing of O&M.

IDEQ, PHD

IDEQ,
USEPA

Milo Gulch

Secure permanent access for system maintenance.

USEPA, IDEQ

USEPA

4.5 Performance Evaluation

In 1995, with the bankruptcy of the Site's major PRP, USEPA and the State of Idaho defined a
path forward for phased remedy implementation in OU 2. Phase I of remedy implementation
included extensive source removal and stabilization efforts, demolition activities, community
development initiatives, ICP development and implementation, land use development support,
and public health response actions. Phase I also included investigations to provide the
necessary information to resolve long-term water quality issues, including technology
assessments and pilot studies, and evaluation of the success of source control efforts. Interim
control and treatment of contaminated water and AMD was also included in Phase I of remedy
implementation.

Phase I remedies have removed and consolidated more than 2.8 million cy of contaminated
waste onsite in engineered closure areas (the Smelter and CIA closures). Using geomembrane
cover systems on these closure areas effectively removed these contaminated wastes from direct
contact by humans and biological receptors. Consolidating these wastes in engineered closures
also substantially reduced the exposure pathway to the surface water and groundwater
environment in comparison with pre-remediation Site conditions.

In addition, more than 800 acres of property within OU 2 have been capped to eliminate direct
contact with residual contamination that remains in place within some areas of OU 2. In
addition, the revegetation work conducted as part of the Phase I remedial actions has
substantially controlled erosion and significantly improved the visual aesthetics of OU 2. The
success of the Phase I revegetation efforts involved providing improved habitat for wildlife that
was largely absent for decades in many areas of the hillsides and Smelterville Flats.

All of these efforts have reduced or eliminated the potential for humans to have direct contact
with soil and source contaminants, have reduced opportunities for contaminants to be
transported by surface water and air, and are expected to provide surface and groundwater
quality improvements over time throughout the Site. Responsibility for O&M of OU 2 Phase I

4-49

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

remedial actions has been transferred to the IDEQ upon completion of the remedies and
development of area-specific O&M manuals.

Phase II of remedy implementation will address long-term water quality, ecological, and
environmental management issues. Phase II remedial actions are identified in the 2001 OU 2
ROD Amendment and the 2012 Upper Basin ROD Amendment. Implementation of the Phase II
remedy is estimated to begin in 2016. Initial Phase II work will consist of upgrading and
expanding the CTP and a GWCS located between the CIA and the SFCDR.

USEPA and the IDEQ signed a memorandum of agreement in June 2014 to provide long-term
O&M of the CTP, the new sludge disposal cell, and the GWCS located primarily between the
CIA and the SFCDR. IDEQ's obligation under this Agreement for O&M of the facilities used to
collect and treat contaminated waters exists only as long as the Endowment Fund Account
(from the Hecla settlement) contains sufficient funds to pay for those operations.

The OU 2 remedy currently protects human health and the environment where remedial actions
have been taken. However, continued maintenance of the clean barriers to underlying
contamination is essential to ensure long-term protectiveness of the remedy. In addition,
continued funding and state and local support of the ICP is necessary to ensure barrier
maintenance occurs in the long term.

4-50

-------
5 Review of Selected Remedies for
Operable Unit 3

This section documents the remedial actions completed in OU 3. The information in this section
is organized as follows:

• 5.1 Overview of the Selected Remedies

• 5.2 Review of Operable Unit Remedial Actions

• 5.3 Technical Assessment

• 5.4 Issues and Recommendations

• 5.5 Performance Evaluation of the OU 3 Remedy

A review of actions taken since the last Five-Year-Re view and progress on Issues and
Recommendations is included in the review of each remedial action in Section 5.2 as
appropriate. A protectiveness statement for OU 3 is provided in Section 6.1 of this report.

Figure 5-1 is a site map for the Upper Basin of OU 3. Figure 5-2 is a site map for the Lower Basin
of OU 3. A timeline of key events associated with OU 3 may be found in the 2010 Five-Year
Review Report (USEPA, 2010c).

5.1 Overview of Selected Remedies

On September 12, 2002, USEPA issued an interim ROD (the 2002 OU 3 ROD) to address mining
contamination in the broader Coeur d'Alene Basin (OU 3) (USEPA, 2002a). The 2002 OU 3 ROD
describes the specific cleanup work, called the interim Selected Remedy (the remedy), that will
occur in the Basin. Letters of support for the 2002 OU 3 ROD were signed by the State of Idaho,
the Coeur d'Alene Tribe, the Spokane Tribe, the State of Washington, the BLM, the USFWS, and
the U.S. Forest Service (USFS).

In 2012, USEPA issued a ROD Amendment for the Upper Basin, which included the eastern
portion of OU 3 upgradient of the Bunker Hill Box (USEPA, 2012a). The Selected Remedy in the
2012 Upper Basin ROD Amendment is an interim remedy that will be finalized in the future as
additional knowledge is gained about conditions at specific locations within the Upper Basin
and the effectiveness of remedial actions. The Selected Remedy for the Upper Basin builds upon
the remedies identified in the 2002 ROD and incorporates additional information obtained since
the ROD for OU 3 was issued in 2002. Specific elements of the interim remedy for OU 3 are
presented in Sections 2.2 and 2.2.3.

The 2010 Five-Year Review included the following recommendations.

• Recommendation: USEPA Region 10 has received funding for implementation of the OU 3
human health remedy. The Region will continue to work with USEPA Headquarters and
other parties to secure funding for full implementation of the 2002 OU 3 ROD (an ongoing
2005 Five-Year Review recommendation).

5-1

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Discussion: Because of the settlements with Hecla and ASARCO, USEPA Region 10 has
received only limited amounts of pipeline funds from Headquarters. Most of the work
under the OU 3 ROD is being conducted by the Coeur d'Alene Work Trust using funds
from the Asarco settlement. The Trust cannot conduct work in the Box, as stipulated in the
ASARCO settlement so funds from the Hecla settlement are being used to conduct actions
in OU 1 and OU 2. The Hecla funds have also been used for the Basin Property Remediation
Program (BPRP), but this work is also being transitioned to the Trust in 2015. USEPA is
continuing to seek funds from Headquarters in order to complete actions in OU 1 and OU 2,
because the Hecla funds may not last beyond 2017. This recommendation does not impact
protectiveness and will not be retained in the table of issues and recommendations.

• Recommendation: Continue successful implementation of safety programs as evidenced by
no lost time or injuries reported (an ongoing 2005 Five-Year Review recommendation).

Discussion: USEPA agrees continued safe implementation of remedial actions is very
important. However, this recommendation does not impact protectiveness and will not be
retained in the table of issues and recommendations.

Although the sediments at the bottom of Coeur d'Alene Lake contain mining contaminants, a
remedy for Coeur d'Alene Lake was not selected in the 2002 OU 3 ROD. State, Tribal, federal,
and local governments committed to developing a revised Lake Management Plan (LMP)
outside of the Superfund process using separate regulatory authorities. Appendix A of this
Five-Year Review Report provides additional details of the LMP.

The 2010 Five-Year Review included the following recommendations relative to Coeur D'Alene
Lake.

• Recommendation: Continue LMP implementation activities and lake monitoring efforts.

Discussion: The 2002 OU 3 ROD did not select a remedy for the lake, but relies on the
effective implementation of the LMP by IDEQ, the Coeur d'Alene Tribe, and other
jurisdictions. This recommendation will not be retained in the table of issues and
recommendations, because the LMP is not a CERCLA action.

• Recommendation: Evaluate the need for additional fish tissue sampling and testing in
Coeur d'Alene Lake to assess the applicability of the current fish consumption advisory (an
ongoing 2005 Five-Year Review recommendation).

Discussion: Planning for collection of additional fish samples within the waterbodies of the
Lower Basin is underway. The sampling program will follow the fish advisory guidelines
from USEPA (USEPA, 1994b, 1995a, 1996c, and 1999b) as implemented by the Idaho Fish
Consumption Advisory Project (IFCAP). The goal of the IFCAP is to protect the public from
adverse health risks associated with consuming contaminated fish from Idaho and Tribal
waters.

USEPA has identified the need to evaluate potential data gaps on fish tissue concentrations and
consumption in the Lower Basin and in particular the chain of lakes. Further evaluation of this
issue is identified as an action item as discussed in Section 5.1.1.1. This activity will not be
retained in the table of issues and recommendations, but will instead be included in the table of
planned action items.

5-2

-------
Upper Basin,
Coeur d'Alene
River, North Fork

Lower Basin,
Coeur

SMELTERVILLE

Big Creek
Repository Annex

(Big Creek
Repository

Upper Basin,
, Coeur d'Aiene
River, South Fork

Lower Burk Repository

Goiconda Mine and Mill Site

MULLAN

Constitution Mine and Mill Site

Upper Basin,
Coeur d'Alene
River, South Fork

9 Mine and Mill Sites
River/Creek
Wiaterbody
Repository
l~~T City Limit

~ County Boundary
State Boundary

~ Coeur d'Alene Subbasin
The Bunker Hill Box

Base Map Data:
NHDPIus (Hydrography, 2005);
ESRI (Roads, Jurisdictional Boundaries, 2006).

0.5

2 Miles

Figure 5-1
Site Map - Upper Basin
2015 Five Year Review
BUNKER HILL SUPERFUND SITE

6EPA

BCRISSING 10/5/2015 8:40:12 AM

-------
-------
East Mission Flats
Repository

West Field

Lower Basin,

Coeur
d'Alene River

Upper Basin,
Coeur d'Alene
River, South Fork

River/Creek
W3terbody

~ Coeur d'Alene Subbasin
l~*T City Limit

~ County Boundary
State Boundary

Repository

Agriculture to Wetland Conversion Site

ll ] East Field
West Field

Base Map Data:
NHDPIus (Hydrography, 2005);
ESRI (Roads, Jurisdictional Boundaries, 2006).

0.5

2 Miles

Figure 5-2
Site Map - Lower Basin
2015 Five Year Review
BUNKER HILL SUPERFUND SITE

6EPA

ISSING 10/5/2015 8:56:42 AM

-------
-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

USEPA's highest priority for implementation of the 2002 OU 3 ROD has been and continues to
be the remediation of residential and community areas and recreational areas that pose direct
human health risks. Additional actions include cleanup of areas that pose ecological risks.

A more detailed overview of the OU 3 selected remedies can be found in the third Five-Year
Review (USEPA, 2010c)1.

5.1.1 Upper and Lower Basins
5.1.1.1 Human Health Actions

The primary goal of the human health cleanup is to prevent people (particularly young children
and pregnant women) from coming into contact with unhealthy levels of metals. Children
under 3 years of age and pregnant women are the most at risk from exposure to lead and other
metals; however, the goal applies to all children under 7. The 2002 OU 3 ROD describes the
actions needed to reduce children's exposure to lead through soil and dust exposure pathways.
The lead health risk goal defined in the 2002 OU 3 ROD states that "the selected remedy will
reduce exposure to lead in soil and house dust.. .such that there is a five percent or less
probability of a typical child having a blood lead level greater than 10 (ig/ dL and a one percent
or less probability of a typical child having a blood lead level greater than 15 (ig/ dL" (USEPA,
2002a). The 2002 OU 3 ROD also describes actions to reduce human exposure to other metals in
soil and private drinking water sources.

Residential and Community Area Remedies

The OU 3 community and residential area cleanup program includes:

• Testing of residential soils and informing property owners of their sample results;

• Remediation of residential and commercial properties, common-use areas, and ROWs;

• Partial removal and replacement of surface soils that have metal levels greater than
1,000 mg/kg lead or 100 mg/kg arsenic, and enhancement of barriers, such as vegetation,
for soils between 700 and 1,000 mg/kg lead. No cleanup is required for soils below

700 mg/kg lead and 100 mg/kg arsenic;

• Evaluation of the need for interior cleaning for homes after completion of exterior soil
cleanup;

• Testing of private drinking water wells and provision of safe drinking water for homes with
contamination above 2002 OU 3 ROD action levels; and

• Implementation of a lead health education and intervention program to provide health and
hygiene information to families as well as a free HEPA vacuum cleaner loan program to
limit exposure to household dust. In addition, an annual blood lead screening program is
being implemented in the Basin.

Remedies in Recreational Areas on the Coeur d'Alene River

The 2002 OU 3 ROD identifies recreational areas near the Coeur d'Alene River (campgrounds,
picnic areas, and boat ramps) that have been prioritized for cleanup. The contaminated soils at

1 The third Five-Year Review is available online at http://ao.usa.aov/39vTA.

5-7

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

these areas are to be either capped or removed, depending on the area. In addition, lead health
information and signs are to be placed at several recreational use areas in the Basin.

Information for Anglers

The 2002 OU 3 ROD calls for education and information, including health advisories, to be
provided to anglers to advise them of the potential risks associated with eating fish from areas
of concern. The advisories will be provided in alternative language formats, as required. While
there is currently a fish consumption advisory for Coeur d'Alene Lake, it does not apply to
other portions of the Lower Basin including the lateral lakes. To address this potential gap,
information being collected by other federal and state agencies has been reviewed to determine
if fish advisories are necessary in the SFCDR, the chain lakes and Coeur d'Alene River. Based on
this review, additional data will need to be collected on fish tissue concentrations and
consumption rates in these areas in order to make this determination. This activity has been
included in the table of action items (Table 5-17).

Institutional Controls Program

The 2003 OU 3 ROD indicates that Institutional Controls (ICs) are required to protect the
remedy over time when contaminants are left in place. The ROD states that an ICP for the Basin
is to be established, modeled on the existing ICP in OU 1 and OU 2. The Basin ICP, which is
implemented by the PHD, was established and first implemented in 2007.

5.1.1.2 Ecological Actions

The remedial actions selected for environmental protection in the Upper and Lower Basins are
described in the 2002 OU 3 ROD and 2012 Upper Basin Rod Amendment. For protection of the
environment, USEPA, working with Basin stakeholders, identified three environmental
priorities in the 2002 OU 3 ROD:

• Dissolved metals in surface water (particularly zinc and cadmium): High concentrations of
these metals have harmful effects on fish and other aquatic life.

• Lead in soil and sediment: Existing elevated lead concentrations in the beds, banks, and
floodplains of the river system have harmful effects on waterfowl and other wildlife.

• Particulate lead in surface water: Lead transported downstream is a continuing source of
contamination for the Coeur d'Alene River, Coeur d'Alene Lake, and the Spokane River.
Lead transported in particulate form in the river has contaminated recreational areas in the
Lower Basin and the Spokane River. The Panhandle and Spokane Health Districts have
posted health advisory signs at beaches and swimming areas. During flood events, lead
transported by the river also affects wetlands, floodplains, waterfowl, and other wildlife.

The Selected Ecological Remedy for OU 3 is an interim remedy based upon a subset of the
numerous actions included as part this remedy. For protection of ecological receptors, the
Selected Remedy includes excavation and disposal, containment, bioengineering, and water
treatment actions to reduce dissolved metals in rivers and streams. Waste dumps and stream
banks that are major sources of particulate metals will be stabilized to reduce erosion.

Upper Basin

USEPA issued a ROD Amendment in 2012 updating the Upper Basin cleanup plan that builds
upon the remedies identified in the previous ROD and incorporates additional information
obtained since the ROD for OU 3 was issued in 2002. The Selected Remedy will be implemented

5-8

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

through an adaptive management approach, which will involve prioritizing activities and
identifying and evaluating remedy modifications where necessary based on information gained
as this interim remedy is implemented. Remedial actions are currently underway in the
Ninemile Creek Watershed discussed in Section 5.2.2.3.

Remedial actions completed prior to the 2010 Five-Year Review Report in the Upper Basin that
are expected to result in some ecological benefit were primarily conducted at the mine and mill
sites that posed the greatest human health risk. The 2002 OU 3 ROD identified specific actions
for the mine and mills sites, which are further discussed in Section 5.2.2.

Lower Basin

The 2002 OU 3 ROD defines the Lower Basin as the Coeur d'Alene River west of Cataldo to
Harrison at the mouth of the Coeur d'Alene River and identifies remedial actions such as pilot-
scale dredging, bank stabilization, capping, remediation of select water fowl feeding habitat and
increasing clean waterfowl feeding habitat through the conversion of agricultural lands,
construction of contaminated sediment traps, and measures to prevent recontamination. While
the ROD selected a broad range of actions to be taken in the Lower Basin it acknowledged that
the data upon which they were based were limited. Should additional Lower Basin remedies
beyond those selected become necessary, an additional decision document would be necessary
in the future. This approach allowed critical source control measures to proceed in the Upper
Basin, where contaminant sources and pathways are better defined, while allowing more time
to refine the understanding of the complex Lower Basin system further and to develop specific
details of remedial actions."

Remedial actions completed to date in the Lower Basin include a pilot-scale agriculture-to-
wetlands conversion project that involved soil inversion and hydraulic controls to minimize
recontamination and riverbank bio-stabilization demonstration project at a commercial
campground in Cataldo. Early actions have also have included paving boat ramps and
installing engineered bank isolation structures.

Detailed planning for future remedial action in the Lower Basin requires more comprehensive
knowledge of the complex mechanisms by which lead and other metals in sediment is
mobilized, transported, and deposited. As a first step in expanding the working hypothesis for
the Lower Basin, the 2000 conceptual site model for the Coeur d'Alene Basin (CH2M HILL,
2000b) was updated for the Lower Basin in 2010. The ECSM summarized existing data and
knowledge regarding river system dynamics, sediment characteristics, key data gaps, and
related information (CH2M HILL, 2010).

USEPA will use this information to establish baseline data against which to evaluate the
effectiveness of Lower Basin remedies previously selected in the 2002 OU 3 ROD and future
actions that may be selected. USEPA will use available information coupled with computational
hydraulic and sediment transport models to examine Lower Basin remedies previously selected
in the OU 3 ROD and determine whether the selected actions should be modified or
supplemented. The Lower Basin work may include reviews of select remedial actions identified
in the 2001 FS Report (USEPA, 2001e), with recognition that a ROD Amendment or other
decision document for the Lower Basin may be appropriate at a future date.

5-9

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

5.1.2 Spokane River

The 2002 OU 3 ROD did not identify any areas needing cleanup on the Idaho State portion of
the Spokane River. The Washington State portion of the Spokane River, however, has a number
of sediment and soil areas in and adjacent to the Spokane River that have been identified for
further investigation and possible cleanup on the basis of potential human and ecological risks.
These areas are located along a 16-mile reach of the river between the Idaho/Washington state
line and Upriver Dam, upstream from Spokane. The identified areas include 10 shoreline areas
and one subaqueous area where contaminated sediments have accumulated directly behind
Upriver Dam.

5.2 Review of Operable Unit 3 Remedial Actions

5.2.1 Residential and Community Areas

5.2.1.1 Human Health Barriers
Background and Description

Remedial Action Objectives (RAOs) in the OU 3 ROD include the reduction of movement of soil
and sediments containing unacceptable levels of contaminants into residential areas and
structures, and the reduction of human exposure to soils (including residential garden soils)
and sediments that have concentrations of contaminants of concern greater than selected risk-
based levels (USEPA, 2002a). The long-term strategy to achieve these objectives is to clean up
contaminated soils on residential and commercial properties, common use areas, and ROWs,
and establish a network of barriers to contain subsurface contamination and protect residents
from exposure to lead and other metals in soil and dust. Actions to address human exposure to
metals contamination include the following:

• Testing of residential soils;

• Informing property owners of their sample results;

• Education;

• Access controls;

• Partial removal and replacement of surface soils that have metal concentrations greater than
or equal to 1,000 mg/kg lead or 100 mg/kg arsenic; and

• Barrier enhancement (such as vegetation) of soils with lead concentrations between 700 and
999 mg/kg.

In 2013, IDEQ and USEPA clarified how specific remedial actions shall be applied on a
property-specific basis in the Basin (IDEQ and USEPA, 2013). Clarifications included guidance
on which areas of large rural Basin properties may need to be remediated and what can
realistically be done to address a property that is flood-prone and subject to recontamination.

5-10

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Detailed discussions of the historical context of the remedy, including the soil lead and arsenic
concentration data, and property sampling and remediation progress are provided in the 2005
and 2010 Five-Year Reviews (USEPA, 2005 and 2010c).

As a component of the human health barriers Selected Remedy, the Paved Roadway Surface
Remediation Program began in 2013 to address the need for paved roads to serve as protective
barriers to underlying contaminants. The program is described in more detail in Section 5.2.1.1.

O&M and Actions since the Last Five-Year Review
Residential and Commercial Properties

Since the 2010 Five-Year Review (from 2010 through 2014), a total of 1,014 properties were
remediated, 53 of which housed children younger than seven years of age or pregnant women
at the time of remediation (Table 5-1). Refer to annual construction completion reports for a
more detailed description of remediation efforts in the last 5 years (North Wind, Inc. [North
Wind], 2011 and 2012; North Wind Construction Services, LLC [North Wind Construction],
2013, 2014, and 2015a). An estimated 260,195 cy of contaminated soil were removed and placed
in designated repositories. Through 2014, up to 17 percent of sampled properties did not
require remedial action and 83 percent require remedial action (Table 5-2).

TABLE 5-1

Summary of OU 3 Property Remediation
2015 Five-Year Review, Bunker Hill Superfund Site

Year3

2010

2011

2012

2013

2014

Number of Remediated Properties'3

316

243

223

137

Remediated Properties with Resident Young Children
(less than 7 years of age) or Pregnant Women

Cubic Yards of Contaminated Soil Removed

76,000

57,815

56,463

40,917

29,176

Notes:

a Remediation of schools, daycares, recreational, and common use areas have not been tracked separately from other
properties since 2005.

b Data provided by IDEQ. A property may have discrete areas, such as a ROW, driveway, play area, etc. in addition to
a yard. If discrete areas of a property were remediated (and not the yard), that property is included in this count. City or
County ROWs and private gravel roads are also included in this count.

5-11

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TABLE 5-2

OU 3 Properties by Remedial Action Category, through 2014
2015 Five-Year Review, Bunker Hill Superfund Site

Remedial

Action
Category3

Lower Basin

Kingston

Side
Gulches

Osburn

Silverton

Wallace

Burke/Ninemile

Mullan

All Areas

No.

No Action

392

66%

145

19%

13%

706

17%

Barrier
Enhancement
Only, No
Removal

Combination,
Removal and
Barrier
Enhancement

129

17%

111

24%

154

20%

23%

19%

119

21%

752

18%

Removal
Only, No
Barrier
Enhancement

159

27%

460

60%

273

60%

551

70%

175

74%

306

73%

259

78%

423

74%

2606

63%

Total Number
of Properties
Sampled

597

762

457

788

235

420

330

573

4162

Note:

a Remedial actions occur on at least one or more portions of a property due to exceedances of either the lead or arsenic criteria. No action means all sampled areas on a
property tested below remedial action criteria for both lead and arsenic.

5-12

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Of those properties that require remedial action, the majority only require action on a portion of
the property (as opposed to all sampled areas of a property, Figure 5-3). The Lower Basin has a
larger proportion of properties that require no remediation when compared to the Upper Basin.
The Wallace, Burke/Ninemile, and Mullan geographic areas have a larger proportion of
properties that require remedial action on all sampled areas of the property (Figure 5-3).

As the soil remedy has progressed, IDEQ and USEPA have continued to revise the total number
of parcels requiring remediation in OU 3 (IDEQ and USEPA, 2013; IDEQ and TerraGraphics,
2012; TerraGraphics, 2008c). An estimated 5,200 parcels in OU 3 were eligible for sampling and
potential remediation. To date, sampling of those eligible parcels is estimated at 91 percent
complete, and remediation is 85 percent complete. Approximately 4 percent of the eligible
parcels have owners that are unable to be contacted or have refused sampling or remediation.

In 2012, IDEQ and USEPA implemented an inventory to track completion of the Basin
residential and commercial property sampling and remediation (IDEQ and TerraGraphics,
2012). A status summary is completed annually and contains additional details on property
status counts (TerraGraphics, 2015c; IDEQ and TerraGraphics, 2012).

The 2010 Five-Year Review included the following recommendations.

• Recommendation: Develop an approach (or program) that defines how barrier integrity for
all remediated properties would be maintained and monitored over time.

Discussion: An O&M approach or program separate from the ICP has not been developed.
However, the main purpose of the ICP is to have an approach or program to monitor and
maintain barriers into perpetuity. Widespread evaluation of the property barriers has not
been completed since the PRP certification of remedial activities in OU 1. This activity will
not be retained in the table of issues and recommendations, because it does not directly
affect protectiveness. It will instead be included in the table of planned action items. This
recommendation is repeated for OU 1.

• Recommendation: Continue to implement residential and community area remedial
actions.

Discussion: This recommendation will not be retained in the table of issues and
recommendations, because completion of the BPRP is the highest priority for USEPA and
IDEQ at the Bunker Hill Site and will continue through completion.

• Recommendation: Evaluate findings of follow-up study and, as appropriate, conduct
further evaluations of technical feasibility of soil amendments (an ongoing 2005 Five-Year
Review recommendation).

Discussion: IDEQ evaluated the feasibility of soil amendments and found that over time
compaction rates for amended or unamended soils reached a nearly identical 83 percent,
which is an acceptable density for soils that may be manually worked by property owners.
In order to provide garden soils with workable densities in the short term, the BPRP
determined that soils used to backfill garden areas will be amended with composted
material. In addition, throughout areas to be backfilled, work practices such as soil delivery,
spreading, and traffic patterns were to be modified when possible to reduce compaction
rates. This recommendation is complete.

5-13

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

FIGURE 5-3

Summary of Remediation in OU 3 by Property Proportions and Geographic Area, through 2014
2015 Five-Year Review, Bunker Hill Superfund Site

00
rs

ft)
0.

100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%

191

392

574

145

320

178

550

192

-v>

254

155

JUL

160

166

V
&

257

289

~ All Sampled Areas are Below Remedial Action Criteria

~ All Sampled Areas Require Remedial Action

~ Part of Property Requires Remedial Action

5-14

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Gravel Roads

The OU 3 ROD recognized that roads are barriers to underlying contamination, and the 2010
Five-Year Review recommended that a collaborative approach be developed to address roads as
a long-term barrier. Beginning in 2011, sampling/ remediating publicly owned unpaved gravel
roads became a priority and unpaved gravel roads were categorized according to the entity that
owned or maintained it (public or private) (TerraCraphics, 2011b, 2012, 2013e, and 2014d).
Criteria for remediation of publicly owned gravel roads has a maximum removal depth of six
inches and depends on proximity to residences and traffic use (IDEQ and USEPA, 2013).
Alternatively, privately owned gravel roads are remediated using the same criteria as a
residential property (IDEQ, 2014c).

Through 2014, a total of 64.3 miles of publicly owned (includes county and local jurisdictions)
gravel roads have been sampled (Table 5-3). A total of 7.5 miles of those gravel roads required
remediation according to criteria developed by the agencies (IDEQ and USEPA, 2013), and
7.25 miles have been remediated to date. Some public gravel roads are scheduled to be
remediated under a different program, such as the Paved Roads Program.

A total of 27.8 miles of privately owned gravel roads have been sampled to date, and 6.7 miles
of those exceed remedial action criteria (Table 5-3). Through 2014, approximately 2 miles of
private gravel roadways have been remediated.

Paved Roads Program

Approximately 13.5 miles of Basin roads (6 percent) were rebuilt, overlaid, patched, or chip
sealed in 2013 and 2014. Completion or remedial action reports are not yet available because
many of these projects were completed in 2014. This is an ongoing program based on the paved
roadway surface remediation strategy (IDEQ and USEPA, 2013). A joint IDEQ/USEPA Paved
Roads Board was established which reviews and approves paved road remediation proposals
from the local cities and counties in the Box and Basin. The local road jurisdictions are
responsible for implementing the remediation according to approved plans and following
board guidelines. The jurisdictions are also responsible for O&M of the remediated roads,
which serve as barriers to contamination.

Remedy Status

To date, a total of 3,603 properties have been remediated, 734 of which were considered high
risk (residences with young children or pregnant women) at the time of sampling or
remediation, and nearly 820,000 cy of contaminated soil have been removed and placed in
designated repositories. The OU 3 ROD underestimated the number of properties that would
require cleanup because it was based on yard samples only (USEPA, 2002a). The 83 percent of
properties in the Basin that require remedial action is based on samples collected from the entire
property (e.g., a vegetable garden or gravel driveway).

Substantial reductions have occurred in community mean soil lead concentrations since the
large-scale property remediation began in 2002 (Figure 5-4). The earliest community reductions
for lead were observed in Upper Basin communities, corresponding to the prioritization of the
remediation efforts. As of 2014, community mean soil lead concentrations were near or below
200 mg/kg for all geographic areas. Community mean soil arsenic concentrations have
remained generally stable below the clean soil criteria of 35 mg/kg since the 2010 Five-Year
Review because remedial actions on property soils are typically due to elevated lead
concentrations (as opposed to elevated arsenic concentrations).

5-15

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TABLE 5-3

Summary of Gravel Roads Sampled and Remediated in the Basin, through 2014
2015 Five-Year Review, Bunker Hill Superfund Site

Publicly Owned/Maintained Roads

Privately Owned/Maintained Roads

GeoArea

Length of Sampled
Road (miles)

Length
Requiring
Remediation
(miles)3

Percent of Length
Remediated that
Required Remediation

Length of
Sampled Road
(miles)

Length
Requiring
Remediation
(miles)

Percent of Length
Remediated that
Required Remediationb

Lower Basin

46.7

2.0

100%

15.8

2.4

12%

Kingston

7.0

0.4

100%

8.0

2.1

32%

Side Gulches

3.7

1.2

100%

1.7

1.2

54%

Osburn

0.8

0.6

100%

0.2

Silverton

0.3

0.1

100%

0.0

N/A

Wallace

0.2

0.1

100%

0.1

100%

Burke/Ninemile

1.9

1.6

100%

0.1

48%

Mullan

3.7

1.4

84%

1.8

0.6

26%

Total for All
Geographic
Areas

64.3

7.5

97%

27.8

6.7

29%

Notes:

a Based on criteria set forth in IDEQ and USEPA, 2013.

b Percent of remediated gravel roads is an estimate because not all 2014 remediation records were finalized at the time of drafting this report.

5-16

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

FIGURE 5-4

OU 3 Area-Weighted Geometric Mean Lead Concentration by Geographic Area and Year
2015 Five-Year Review, Bunker Hill Superfurid Site

M Mullan —Burke/Ninemile Wallace ~ Silverton # Osburn —(—Side Gulches —A—Kingston )( Lower Basin

5-17

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Through 2014, a total of 7.25 miles of gravel roads have been remediated. Operations and
maintenance of remediated publicly owned gravel and paved roads are the responsibility of the
governmental jurisdiction that maintains each road. Unpaved gravel road remediation was
completed as designed in 2014. Performance of the unpaved gravel roads will be evaluated in
future years and reported in the next Five-Year Review.

The performance of the soil barriers is dependent on long-term maintenance and the ICP.

Barrier enhancement may have involved adding grass or other vegetation, or in some cases
when vegetation was considered sufficient, no additional barrier was installed. Maintenance of
these barrier enhancement areas relies on the residents and monitoring of these areas is not
conducted by the agencies. Consequently, the performance of the barriers may be degraded if
vegetation is not being maintained.

Additionally, flooding can affect the integrity of installed barriers. In January 2011, the
Highway 3 culvert at Rose Creek failed and the Idaho Department of Transportation installed a
new culvert and repaired the highway, but was unable to connect the old flood control gate to
the new culvert. High water that spring resulted in the Coeur d'Alene River backwashing
through the culvert and flooding the Rose Lake community. By fall of 2011, the BEIPC and
IDEQ installed a new flood control gate using IDEQ funds. The Rose Lake Water Board is
responsible for future O&M of the gate (BEIPC, 2012). It is unknown if this flood event
recontaminated any of the previously remediated properties in the Rose Lake community.

As part of the ICP, opportunistic sampling is conducted on projects by PHD, offering additional
data to evaluate remedy performance (Table 5-4). Snow pile sediment samples were collected
from various areas previously remediated in Osburn and Wallace between 2011 and 2014. Snow
sediment samples resulted in average lead concentrations of 300 to 500 mg/kg and average
arsenic concentration of approximately 20 mg/kg (Table 5-4). Two samples were collected from
basements in 2010: one with a lead concentration greater than 1,000 mg/kg and an arsenic
concentration greater than 100 mg/kg and the other below 1,000 mg/kg and 100 mg/kg,
respectively. Sediment samples from runoff and/ or erosion depositional areas were collected in
2014 in Silverton and Kingston and averaged 113 mg/kg lead and 8 mg/kg arsenic. Regrinds
and "other soil" samples were collected for ICP monitoring and permitting purposes, and
results from these samples indicate the need for an ICP to protect public health and manage
barriers into perpetuity.

Approximately 13.5 miles of Basin roads (6 percent) were rebuilt, overlaid, patched, or chip
sealed in 2013 and 2014. Paved road maintenance and performance is the responsibility of each
local jurisdiction. Therefore, funding for the Paved Roads Program does not include
maintenance, future site inspections, or data collection and analysis to determine if the paved
roads continue to function as a barrier. While implementation of this program is expected to
address a significant number of paved roads in the Site, it is not intended to address all road
problems and conditions. All roads within the ICP administrative boundary are subject to ICP
rules.

5-18

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TABLE 5-4

ICP Samples Collected in OU 3, 2010-2014
2015 Five-Year Review, Bunker Hill Superfund Site

Type

Year

Lead3

Arsenic3

No. of
Samples

Min
Cone,
(mg/kg)

Max
Cone,
(mg/kg)

Average
Cone,
(mg/kg)

Standard
Deviation

%of
Samples
>350
mg/kgb

No. of
Samples

Min
Cone,
(mg/kg)

Max
Cone,
(mg/kg)

Average
Cone,
(mg/kg)

Standard
Deviation

%of
Samples
> 100
mg/kg

Snow Pile

2010

2011

1,145

487

574

33%

2012

317

939

448

219

86%

2013

109

1,080

381

351

17%

6.8

22.9

2014

174

382

282

104

33%

7.7

25.2

Basement

2010

50%

2011

2012

2013

2014

Runoff

2010

2011

2012

2013

2014

24.9

285

113

4.7

10.1

14%

5-19

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TABLE 5-4

ICP Samples Collected in OU 3, 2010-2014
2015 Five-Year Review, Bunker Hill Superfund Site

Lead3

Arsenic3

Type

Year

No. of
Samples

Min
Cone,
(mg/kg)

Max
Cone,
(mg/kg)

Average
Cone,
(mg/kg)

Standard
Deviation

%of
Samples
>350
mg/kgb

No. of
Samples

Min
Cone,
(mg/kg)

Max
Cone,
(mg/kg)

Average
Cone,
(mg/kg)

Standard
Deviation

%of
Samples
> 100
mg/kg

2010

545

4,866

100%

2.5

247

17%

2011

895

2226

100%

Reg rinds0

2012

2013

100%

50%

2014

11.1

342

3.7

22.7

17%

2010

8,879

41%

2.5

496

2011

13,300

68%

2.5

479

17%

Other
Soils0

2012

20.7

68,200

78%

4.4

1,590

27%

2013

7.24

8,620

29%

2.5

187

35%

2014

24.9

4,090

18%

3.7

12%

Notes:

Data Provided by the Panhandle Health District.

- When the No. of Samples is less than three, data are not displayed in order to protect participant confidentiality.

Cone. = concentration.

a If a sample was below detection limits, the reported result was divided in half prior to data summary.
b ICP soil disposal lead level, discussed in Section 5.2.1.6.

c These samples were collected during ICP inspections of permitted projects, projects undertaken by the utilities or government, or to monitor erosion and/or tracking.
Soils that test greater than ICP criteria are directed to the repositories or capped under barriers. For this reason, averages and standard deviations were not calculated.

5-20

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

5.2.1.2 House Dust
Background and Description

Similar to OU 1, the OU 3 long-term human health cleanup strategy includes remediation of
contaminated soils and placement of clean soil barriers throughout the Site to reduce house dust
lead levels. The house dust RAO is to .. reduce human exposure to lead in house dust via
tracking from areas outside the home and air pathways, exceeding health risk goals" (USEPA,
2002a). Health risk goals, defined in USEPA's Office of Solid Waste and Emergency Response
(OSWER) Directive, are intended "to reduce risk to a typical or individual child receiving
exposures at the residence to meet Agency guidelines (i.e., no greater than a 5 percent chance of
exceeding a 10 (ig/ dL blood-lead level for a full-time child resident)" (USEPA, 1998b). The
Selected Remedy to achieve the dust RAO includes a vacuum loan program and information
and intervention with the LHIP (discussed in Section 5.2.1.4), and monitoring to ensure that
RAOs continue to be achieved after the Selected Remedy is implemented (USEPA, 2002a). In
addition, a contingency of interior cleaning (including consideration of crawl spaces, attics, and
basements) and paint abatement (via a state program) would address significant sources of
recontamination within residences that require interior cleaning after yard cleanups are
complete (USEPA, 2002a).

USEPA and the State of Idaho continue to monitor house dust concentrations as residential soil
remediation is completed to assess progress towards meeting the house dust RAO. Two
methods are used to track house dust lead concentration: vacuum bags and dust mats. Vacuum
bag data have been used in dose-response analyses relating children's blood lead levels with
environmental lead concentrations and are used in lead exposure modeling to assess
achievement of the OU 3 house dust RAO. Dust mat data are used to assess remedy
performance in reducing the tracking of soil lead into house dust.

Detailed discussions of the historical context of the remedy and evaluation of the house dust
lead concentration data through 2009 are provided in the 2005 and 2010 Five-Year Reviews
(USEPA, 2005 and 2010c).

O&M and Actions since the Last Five-Year Review

Basin house dust surveys were conducted in 2010, 2011, and 2013. In 2012, USEPA decided to
monitor Basin house dust every other year instead of annually, because this was considered
adequate for helping to assess the progress of the BPRP. Homes were targeted for sampling if
they included children less than 7 years old and/ or pregnant women based on prior house dust
sampling efforts, through property remediation tracking, and/ or through the annual LHIP
blood lead screening. Vacuum and dust mat samples were collected from 368 homes in 2010,
356 homes in 2011, and 360 homes in 2013 during the house dust surveys. From 2010 through
2014, vacuum bag samples were also collected opportunistically from 166 properties that
participated in the Basin residential property remediation program. Few vacuum samples were
collected in 2014 and are not used to evaluate trends discussed in the subsequent section.

The dust mat used for monitoring from 2002 through 2011 was no longer available in 2012, and
IDEQ selected a replacement dust mat based on similar dust and lead recovery results
(TerraGraphics, 2013f).

5-21

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Remedy Status
Dust Lead Concentration

Throughout the OU 3 communities, mean vacuum and dust mat lead concentrations have
generally decreased since monitoring began (Figures 5-5 and 5-6, respectively; TerraCraphics,
2014e). Since the 2010 Five-Year Review, geometric mean vacuum concentrations decreased in
all communities, with the largest decrease (67 percent) observed in Burke/Ninemile. Geometric
mean dust mat lead concentrations fluctuated since 2010, with the largest decrease of 24 percent
in Burke/Ninemile and the largest increase of 39 percent in the Side Gulches. In 2013, geometric
mean lead concentrations in all Basin communities were below 500 mg/kg (Tables 5-5 and 5-6).
Dust mat lead concentrations in the Lower Basin and Kingston geographic areas cannot be
evaluated because of the limited data collected since 2007.

In addition to observed decreases in house dust lead concentrations, the number and
percentage of homes that may be eligible for interior cleaning (i.e., greater than or equal to
1,000 mg/kg lead) have also generally declined since monitoring began in 1996 (Figures 5-7 and
5-8). However, the percentage of dust mat samples greater than or equal to 1,000 mg/kg lead
has fluctuated at similar levels in each community since 2004 (Figure 5-8). The ROD cost
estimates for house dust assumed up to 4 percent of Basin homes would require interior source
removal or more extensive cleaning after yard remediation was complete, using a threshold of
1,000 mg/kg lead (USEPA, 2001b and 2002a). In 2013, 5 percent of vacuum dust samples and
9 percent of dust mat samples were equal to or greater than 1,000 mg/kg lead
(Tables 5-5 and 5-6).

Historically, Wallace and Burke/Ninemile consistently had the highest house dust lead
concentrations and greatest percentage of homes with lead levels above 1,000 mg/kg compared
with other geographic areas (TerraGraphics, 2014e). Recent data indicated a substantial
reduction in house dust concentrations in Burke/Ninemile since the last Five-Year Review. The
community-mean vacuum and mat lead concentrations decreased by 67 and 24 percent,
respectively, and no vacuum samples and only 3 percent of dust mat samples were
> 1,000 mg/kg lead (Tables 5-5 and 5-6).

Dust and Lead Loading Rates

Dust and lead loading rates provide data to evaluate tracking of exterior dust and lead into the
home. For most OU 3 communities, geometric mean dust loading rates decreased substantially
from 1996 when they were at their highest (Figure 5-9). Dust loading rates have generally
fluctuated at similar levels in each community since 2004, although since 2007, not enough
samples have been collected from the Lower Basin and Kingston areas to assess trends
(Figure 5-9 and Table 5-7). Substantial decreases were also observed in dust lead content
between 1996 and 2004, with generally constant lead loading rates since 2004 (Figure 5-10).
Mullan and Wallace have continued to show higher lead loading rates than other geographic
areas (Table 5-7).

It is not clear what caused the substantial reduction in dustiness and lead loading rates between
1996 and 2004 (USEPA, 2005). Most of the pre-ROD data was collected in the aftermath of the
1996 floods when dusty conditions were likely exacerbated, which may have contributed to
higher lead loading rates.

5-22

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

FIGURE 5-5

Mean Vacuum Lead Concentrations by Year and Area for OU 3,1996-2013
2015 Five-Year Review, Bunker Hill Superfurid Site

2,500

5-23

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

FIGURE 5-6

Mean Dust Mat Lead Concentrations by Year and Area tor OU 3,1996-2013
2015 Five-Year Review, Bunker Hill Superfund Site

2,500

5-24

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TABLE 5-5

Vacuum Dust Summary Statistics by Year and Area for OU 3, 2010-2014
2015 Five-Year Review, Bunker Hill Superfund Site

Number

of
Vacuum
Samples3

Vacuum Samples
> 1,000 mg/kg
Lead

Vacuum Samples
> 1,500 mg/kg
Lead

Lead Concentration
Range
(mg/kg)

Mean Vacuum Dust Lead
Concentration
(mg/kg)

Year

Geographic
Area

Number

Percent

Number

Percent

Minimum

Maximum

Arithmetic
Mean

Arithmetic
Standard
Deviation

Geometric
Mean

Geometric

Standard

Deviation

Lower Basin

1,570

173

303

100

2.43

Kingston

4,200

508

1,067

253

2.52

Side Gulches

675

263

172

206

2.13

Osburn

749

276

171

231

1.84

2010

Silverton

17%

2,530

580

594

394

2.47

Wallace

25%

16%

5,660

994

1,157

620

2.70

Burke/Ninemile

13%

4,700

701

996

425

2.54

Mullan

8,670

698

1,321

429

2.33

Basin-wide

273

8,670

513

860

293

2.68

Lower Basin

1,040

125

164

2.29

Kingston

20%

1,040

401

377

280

2.69

Side Gulches

952

262

237

186

2.33

Osburn

1,640

326

282

251

2.02

2011

Silverton

10%

145

1,230

422

305

358

1.76

Wallace

26%

21%

46,200

3,640

10,716

552

5.95

Burke/Ninemile

13%

2,790

556

684

305

3.14

Mullan

14%

160

1,870

566

429

472

1.81

Basin-wide

210

46,200

620

3,306

219

3.03

5-25

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TABLE 5-5

Vacuum Dust Summary Statistics by Year and Area for OU 3, 2010-2014
2015 Five-Year Review, Bunker Hill Superfund Site

Number

of
Vacuum
Samples3

Vacuum Samples
> 1,000 mg/kg
Lead

Vacuum Samples
> 1,500 mg/kg
Lead

Lead Concentration
Range
(mg/kg)

Mean Vacuum Dust Lead
Concentration
(mg/kg)

Year

Geographic
Area

Number

Percent

Number

Percent

Minimum

Maximum

Arithmetic
Mean

Arithmetic
Standard
Deviation

Geometric
Mean

Geometric

Standard

Deviation

Lower Basin

627

120

145

2.69

Kingston

241

109

2.27

Side Gulches

Osburn

2012

Silverton

Wallace

Burke/Ninemile

Mullan

Basin-wide

627

125

141

2.62

Lower Basin

187

1.62

Kingston

310

181

111

147

2.12

Side Gulches

748

201

179

145

2.30

Osburn

820

233

157

191

1.93

2013

Silverton

4,540

421

937

207

2.59

Wallace

22%

7,140

904

1,384

499

3.01

Burke/Ninemile

622

190

130

154

2.00

Mullan

2,100

415

425

268

2.76

Basin-wide

196

7,140

357

671

205

2.60

5-26

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TABLE 5-5

Vacuum Dust Summary Statistics by Year and Area for OU 3, 2010-2014
2015 Five-Year Review, Bunker Hill Superfund Site

Number

of
Vacuum
Samples3

Vacuum Samples
> 1,000 mg/kg
Lead

Vacuum Samples
> 1,500 mg/kg
Lead

Lead Concentration
Range
(mg/kg)

Mean Vacuum Dust Lead
Concentration
(mg/kg)

Year

Geographic
Area

Number

Percent

Number

Percent

Minimum

Maximum

Arithmetic
Mean

Arithmetic
Standard
Deviation

Geometric
Mean

Geometric

Standard

Deviation

Lower Basin

213

140

122

1.87

Kingston

Side Gulches

Osburn

2014

Silverton

Wallace

Burke/
Ninemile

Mullan

Basin-wide

383

127

153

2.11

Notes:

Vacuum samples were collected through both the House Dust Survey and BPRP in 2010, 2011, and 2013 and the property remediation program in 2012 and 2014.
a When the number of samples is 2 or less, the results are not shown in order to maintain confidentiality.

5-27

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TABLE 5-6

Dust Mat Summary Statistics by Year and Area for OU 3, 2010-2013
2015 Five-Year Review, Bunker Hill Superfund Site

Number
of Dust
Mat
Samples3

Dust Mat Results
> 1,000 mg/kg
Lead

Dust Mat Results
> 1,500 mg/kg
Lead

Lead Concentration
Range (mg/kg)

Dust Mat Lead Concentration (mg/kg)

Year

Geographic
Area

Number

Percent

Number

Percent

Minimum

Maximum

Arithmetic
Mean

Arithmetic
Standard
Deviation

Geometric
Mean

Geometric
Standard
Deviation

Lower Basin

148

2.0

Kingston

315

162

144

1.7

Side Gulches

18,900

587

2,458

199

3.0

Osburn

2,850

298

358

203

2.3

2010

Silverton

10%

5,040

696

1,248

342

2.8

Wallace

21%

13%

20,800

1,207

2,984

477

3.1

Burke/Ninemile

15%

10%

4,700

639

888

358

2.9

Mullan

4,310

480

694

312

2.3

Basin-wide

366

10%

20,800

619

1761

281

2.8

Lower Basin

292

137

103

111

2.1

Kingston

17%

13,600

2,386

5,494

231

9.0

Side Gulches

1,010

210

205

146

2.3

Osburn

2,050

274

322

182

2.4

2011

Silverton

1,380

283

260

213

2.2

Wallace

13%

4,640

527

678

328

2.6

Burke/Ninemile

13%

1,940

376

457

222

2.8

Mullan

1,140

370

257

291

2.1

Basin-Wide

355

13,600

379

819

223

2.6

5-28

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TABLE 5-6

Dust Mat Summary Statistics by Year and Area for OU 3, 2010-2013
2015 Five-Year Review, Bunker Hill Superfund Site

Number
of Dust
Mat
Samples3

Dust Mat Results
> 1,000 mg/kg
Lead

Dust Mat Results
> 1,500 mg/kg
Lead

Lead Concentration
Range (mg/kg)

Dust Mat Lead Concentration (mg/kg)

Year

Geographic
Area

Number

Percent

Number

Percent

Minimum

Maximum

Arithmetic
Mean

Arithmetic
Standard
Deviation

Geometric
Mean

Geometric
Standard
Deviation

Lower Basin

Kingston

145

178

163

1.1

Side Gulches

10%

2,500

397

536

218

2.9

Osburn

30,000

697

3,216

256

2.8

2013

Silverton

3,230

376

555

238

2.5

Wallace

23%

11%

29,400

1,320

3,883

493

3.2

Burke/Ninemile

1,260

305

268

226

2.2

Mullan

2,560

503

405

396

2.0

Basin-wide

333

30,000

650

2367

299

2.7

Note:

a Indicates the number of homes where a mat sample was collected; if both an original and split sample were collected, the higher result was used for data summary.
When the number of samples is 2 or less, the results are not shown in order to maintain confidentiality.

5-29

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

FIGURE 5-7

Percentage of OU 3 Vacuum Samples > 1,000 mg/kg Lead, 1996-2013
2015 Five-Year Review, Bunker Hill Superfund Site

100%

90%

¦o 80%

OJ
_0>

*3)

£
o
o

° 60%

70%

(A
O

ra
W

o
ra
>

a>
D)
ra

a)
Q.

50%

40%

30%

20%

10%

¦Burke/Ninemile —B-Kingston —A— Lower Basin

-Mullan

Osburn

Side Gulches

Silverton

Wallace

Note:

When the number of samples is 2 or less, the results are not shown in order to maintain confidentiality. Refer to USER A, 2010c and Table 5-5 for the number of
samples collected.

5-30

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

FIGURE 5-8

Percentage of OU 3 Mat Samples > 1,000 mg/kg Lead, 1996-2013
2015 Five-Year Review, Bunker Hill Superfund Site

100%

90%

80%

g 70%
O)

E
o

§ 60%

50%

ro
CO

J 40%

2 30%
£

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

FIGURE 5-9

Mean Dust Loading Rates by Year and Area for OU 3,1996-2013
2015 Five-Year Review, Bunker Hill Superfund Site

ra
¦u

3,000

2,500

2,000

0)
ro
CH
ui

'S 1,500

E
o
o
O

1,000

500

-+-

% "S % V

<•£>

-Burke/Ninemile

-Kingston

Lower Basin

¦*—Mullan

Osburn

Side Gulches

7? V V
-4—Silverton —¦-Wallace

Note:

When the number of samples is 2 or less, the results are not shown in order to maintain confidentiality. Refer to USEPA, 2010c and Table 5-7 for the number of
samples collected.

5-32

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TABLE 5-7

Dust and Lead Loading Summary Statistics by Year and Area for OU 3, 2010-2013
2015 Five-Year Review, Bunker Hill Superfund Site

Dust Loading Rate (mg/m2/day)

Lead Loading Rate (mg/m2/day)

Year

Geographic
Area

Number
of Dust
Mat
Samples3

Arithmetic
Mean

Arithmetic
Standard
Deviation

Geometric
Mean

Geometric

Standard

Deviation

Arithmetic
Mean

Arithmetic
Standard
Deviation

Geometric
Mean

Geometric
Standard
Deviation

Lower Basin

4,040

3,171

2,852

2.8

0.312

0.388

0.193

2.77

Kingston

2,660

1,556

2,202

2.1

0.426

0.368

0.317

2.37

Side Gulches

1,990

3,472

879

3.3

0.737

1.85

0.173

5.31

Osburn

727

698

519

2.2

0.218

0.314

0.104

3.61

2010

Silverton

746

548

560

2.2

0.562

1.08

0.191

4.51

Wallace

818

956

497

2.7

0.705

1.40

0.235

4.72

Burke/Ninemile

959

859

643

2.7

0.564

0.778

0.209

5.00

Mullan

569

546

397

2.4

0.286

0.469

0.119

3.87

Basin-wide

366

1,015

1,690

573

2.7

0.477

1.09

0.157

4.43

Lower Basin

746

270

693

1.6

0.100

0.098

0.077

2.05

Kingston

952

1,055

555

3.2

0.713

1.18

0.128

12.2

Side Gulches

1,411

2,456

730

2.9

0.242

0.399

0.107

3.74

Osburn

702

755

491

2.3

0.189

0.312

0.089

3.60

2011

Silverton

602

537

434

2.3

0.185

0.230

0.092

3.93

Wallace

667

712

454

2.3

0.355

0.531

0.148

3.91

Burke/Ninemile

851

793

583

2.5

0.357

0.602

0.129

4.69

Mullan

587

603

403

2.3

0.291

0.511

0.117

3.90

Basin-wide

355

790

1,158

502

2.4

0.275

0.471

0.112

3.96

5-33

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TABLE 5-7

Dust and Lead Loading Summary Statistics by Year and Area for OU 3, 2010-2013
2015 Five-Year Review, Bunker Hill Superfund Site

Dust Loading Rate (mg/m2/day)

Lead Loading Rate (mg/m2/day)

Year

Geographic
Area

Number
of Dust
Mat
Samples3

Arithmetic
Mean

Arithmetic
Standard
Deviation

Geometric
Mean

Geometric

Standard

Deviation

Arithmetic
Mean

Arithmetic
Standard
Deviation

Geometric
Mean

Geometric
Standard
Deviation

Lower Basin

Kingston

2,607

2,455

1,236

6.7

0.444

0.412

0.201

7.35

Side Gulches

1,305

1,665

740

3.1

0.669

1.76

0.161

5.31

Osburn

786

1,189

398

3.4

0.374

1.07

0.102

5.81

2013

Silverton

1,005

1,358

587

2.7

0.391

0.777

0.140

4.31

Wallace

696

1,566

311

3.3

0.650

1.74

0.153

5.83

Burke/Ninemile

980

1,309

537

3.1

0.265

0.377

0.121

3.86

Mullan

789

1,061

464

2.7

0.501

1.13

0.183

3.97

Basin-wide

333

910

1,374

468

3.2

0.485

1.28

0.140

5.01

Note:

a Indicates the number of homes where a mat sample was collected; if both an original and split sample were collected, the higher result was used for data
summary. When the number of samples is 2 or less, the results are not shown in order to maintain confidentiality.

5-34

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

FIGURE 5-10

Mean Lead Loading Rates by Year and Area for OU 3,1996-2013
2015 Five-Year Review, Bunker Hill Superfund Site

>.
73

C0
U)

-G
(V
-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

House Dust RAO and Lead Health Risk

In order to assess if the most current exposure data achieve the OU 3 house dust RAO, an
analysis was conducted using the IEUBK Model (IEUBKwin version 1.1, build 11) to predict
childhood residential lead health risk (USEPA, 1998b). The 2011 and 2013 house dust data and
most recent property and community mean soil data were input into the IEUBK Model. The
same assumptions and methods used in previous site-specific analyses were applied
(TerraGraphics 2004, 2010f; TerraCraphics, et. al, 2001).

The probability that a hypothetical child exceeds a blood lead level of 10 |a,g/ dL was estimated
for each home and summarized by community. The results indicate that 13 percent of homes in
the Basin do not currently meet lead health risk goals for a typical child between 6 months and
6 years of age (Table 5-8; USEPA, 1994a, 1998b, 2002a). Soil remediation is nearly complete in
some residential areas of the Basin, particularly in the Upper Basin (TerraGraphics, 2015c).
Although the overall trends show reductions in average dust lead concentrations, and dust and
lead loading rates, the OU 3 dust RAO has not yet been achieved in all homes. Based on past
projections and analyses, the remedy is expected to be protective and achieve the RAO only
after dust lead concentrations in individual homes have been substantially reduced to final
post-remedial community soil lead means.

Elevated dust lead concentrations in homes throughout the Basin could be related to the
patchwork of remaining contaminated soils (i.e., un-remediated property soils, recreational
areas, or mine dumps), or may be due to sources unrelated to the current remedies. The large
number of discrete remediation activities in OU 3 leaves areas with soil lead levels less than
100 mg/kg among areas with soil lead concentrations ranging from 100 mg/kg to 999 mg/kg
(USEPA, 2010c). This variation can exist both within individual properties and within
communities due to the spatial distribution of contaminant concentrations. Other possible lead
sources in Basin homes include lead-based paint and residual dusts in building structures.

Prior to 2012, PHD conducted follow-ups with participants in homes with dust lead
concentrations exceeding 5,000 mg/kg, and they continue to offer follow-up services if a house
dust lead concentration exceeds 1,500 mg/kg (see Section 5.2.1.4 for details). There has been
some success in identifying lead sources in homes with dust lead concentrations above
5,000 mg/kg and providing guidance to the family to reduce exposures. However, there is less
understanding of the specific sources of lead in homes with dust lead concentrations less than
5,000 mg/kg, likely resulting in less effective intervention efforts. Similar to OU 1, past analyses
conducted to identify the sources and co-factors influencing persistent high dust lead levels in
some OU 3 households concluded that in most cases, the cause of elevated lead levels could not
be definitively determined (TerraGraphics, 2008d).

5-36

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TABLE 5-8

OU 3 Dust RAO Summary, Probabilities to Exceed Lead Health Risk Criteria using Recent House Dust and Soil Data
2015 Five-Year Review, Bunker Hill Superfund Site

Geographic
Area

No. of Homes
with Recent
Environment
al Data3

No. of Homes With

a Hypothetical
Childb Predicted to
Exceed Health
Criteria0

% of Homes With a
Hypothetical Childb
Predicted to Exceed
Health Criteria0

Minimum Soil
Concentration
(mg/kg)d

Maximum Soil
Concentration
(mg/kg)d

Minimum Dust
Concentration
(mg/kg)

Maximum Dust
Concentration
(mg/kg)

Lower Basin

310

21.5

1,040

Kingston

988

49.1

1,040

Side Gulches

10%

111

486

16.5

952

Osburn

164

524

36.6

1,640

Silverton

11%

141

331

65.9

4,540

Wallace

42%

137

416

29.1

46,200

Burke/Ninemile

13%

158

821

32.5

2,790

Mullan

14%

123

540

19.9

2,100

Basin-wide

350

13%

988

16.5

46,200

Notes:

a Homes with house dust data from 2011 and 2013. If a home was sampled in both years, datum from 2013 was used.

b A child aged from six months through seven years old. An exceedance of risk criteria at an individual home may occur with one age group or multiple age groups.
c Greater than 5% chance of a blood lead level exceeding 10 [jg/dL, using the Box Model

dThe Box Model assumes 30% property soil and 30% community soils contribute to children's exposure. The values shown are the average of the area-weighted
community mean and property soil concentration used as input to the IEUBK Model.

5-37

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

The cumulative nature of lead exposure and the lack of media-specific concentration RAOs in
OU 3 require that risk analyses be conducted to measure the effectiveness of the cleanup
strategy, which necessitates dust and soil exposure data. USEPA and IDEQ have continued to
monitor OU 3 house dust biennial as remedial actions are completed, and this information is
used by PHD to proactively identify and offer health intervention activities, in light of low
participation in the annual LHIP blood-lead screening (discussed in Section 5.2.1.4). The
vacuum loan program continues to be offered to residents through the LHIP. Evaluation of the
implementation of the interior cleaning component of the OU 3 Selected Remedy has not been
completed to date.

5.2.1.3 Drinking Water
Background and Description

The human health remedy in the 2002 OU 3 ROD includes testing private drinking water
sources and providing safe drinking water for homes with contamination above action levels
defined in the ROD (USEPA, 2002a). If a drinking water source exceeds a drinking water action
level for arsenic, cadmium, or lead, filtration or an alternative drinking water source is
provided, and the well is capped, if necessary. A detailed discussion of the historical context of
the drinking water remedy is provided in the 2005 and 2010 Five-Year Reviews (USEPA, 2005
and 2010c). Drinking water data from 1996 through 1999 were discussed in the Human Health
Risk Assessment (HHRA) (TerraGraphics et al., 2001). The 2010 Five-Year Review summarized
data from 2000 through 2009 (USEPA, 2010c).

O&M and Actions since the Last Five-Year Review

Drinking water samples were collected from 257 homes from 2010 through 2014.

Approximately 93 percent of those homes were in the Lower Basin and Kingston areas. Thirteen
properties were identified between 2010 and 2014 that require alternative drinking water
sources based on purged water sample results. No properties received municipal water hookup,
water treatment, or bottled water services since the previous Five-Year Review.

In addition to drinking water sources, irrigation water samples from privately owned wells and
surface water sources were collected from 22 properties that used the water sources to irrigate
soil areas surrounding the homes from 2010 through 2014.

The 2002 OU 3 ROD estimated that 7 percent of properties in the Upper Basin and 10 percent of
properties in the Lower Basin would exceed drinking water standards, for a total of
171 properties (USEPA, 2002a). Sampling results from 2000 through 2014 indicate that 5 percent
of properties in the Basin exceed drinking water standards based on purged sample results. The
current estimated number of homes eligible for the drinking water remedy is 65 (Table 5-9),
which is less than that estimated in the ROD due to additional data collected regarding the
number of residences that utilize private drinking water sources, as well as the slightly lower
percentage of homes that exceed drinking water standards.

5-38

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TABLE 5-9

Estimated Number of Residences with Drinking Water MCL Exceedances in the Upper Basin and Lower Basin
2015 Five-Year Review, Bunker Hill Superfund Site

ROD Estimates3

Current Estimates

Area

No. of
Residences'3

Assumed
Number of

Private,
Unregulated
Sources0

Estimated
Frequency of

MCL
Exceedancesd

Estimated
Number of
Residences
with MCL
Exceedances

No. of
Residences®

Assumed
Number of

Private,
Unregulated
Sources0

Estimated
Frequency of

MCL
Exceedances'

Estimated
Number of
Residences
with MCL
Exceedances

Upper Basin

4,633

1,216

2,894

515

Lower
Basin9

1,642

800

10%

1,355

765

Total

6,275

2,016

171

4,249

1,280

Notes:

a Source: USEPA, 2002a

b Based on site reconnaissance and demographic data from the human health risk assessment (TerraGraphics et al., 2001).
c Assumes 100 percent of residences outside water district service boundaries have private, unregulated sources.

d See Table 4-6 of the FS Report Part 2 (USEPA, 2001 e) for actual observed MCL exceedances. Lower Basin value applied to Kingston area because of small
Kingston dataset.

e Based on field observations and GIS analysis conducted in 2014.

'Based on purged drinking water results from sampling conducted between 2000 and 2014.
g Lower Basin Area includes Kingston geographic area.

5-39

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Remedy Status

Private drinking water sources continue to be sampled to identify homes that require
alternative drinking water supply or filtration. A total of 39 properties with high purged
drinking water results have been identified since 2000. Approximately 35 properties may
require an alternative drinking water supply or filtration system, which IDEQ and USEPA are
planning to provide. As sampling continues in the Lower Basin, where many homes use private
drinking water systems, additional homes may be identified that exceed drinking water
standards and would require alternative drinking water sources or treatment.

5.2.1.4 Lead Health Intervention Program
Background and Description

The LHIP, described in Section 3.2.1.4, was extended to OU 3 in 1996. As in OU 1, PHD is the
lead agency for implementing the LHIP in OU 3, with funding from IDEQ. Detailed discussions
of the historical context of the LHIP, including blood lead data and educational and awareness
programs, are provided in the 2005 and 2010 Five-Year Reviews (USEPA, 2005 and 2010c).

Annual voluntary blood lead screening of children between 6 months and 6 years of age and
follow-up with those exhibiting high lead levels has been offered each year from 1996 to the
present (prior to 2001, children through 9 years of age were included in the screening; USEPA
2005 and 2010c). The 1996 survey used the door-to-door solicitation method employed in the
Box. All other years used fixed-site voluntary blood draws with monetary incentive offered to
the family of each participating child, paid at the time of the blood draw. Participation rates
have historically been much lower than those seen in OU 1, with between 2 and 29 percent of
the estimated OU 3 child population tested each year from 1996 through 2009. Because of the
low participation in the OU 3 annual blood lead screening, the OU 3 ROD identified an LHIP
dust intervention protocol that used house dust monitoring techniques to identify families
proactively that may need health intervention activities while remediation is ongoing (USEPA,
2002a). The protocol was not implemented due to logistical and resource challenges (USEPA,
2010c). Alternatively, PHD offered follow-up services to families residing in homes showing
elevated dust lead concentrations when sampled during annual dust surveys.

The HHRA provides a thorough evaluation of blood lead levels from 1996 through 1999
(TerraGraphics et al., 2001). OU 3 blood lead levels from 1996 through 2005 are summarized in
the 2005 Five-Year Review and the Final Coeur d'Alene Basin Blood Lead Absorption and Exposure
Report (USEPA, 2005; TerraGraphics, 2006). The LHIP and blood lead levels through 2009 are
discussed in the 2010 Five-Year Review (USEPA, 2010c).

O&M and Actions since the Last Five-Year Review

Since the 2010 Five-Year Review, the LHIP continued to offer the same services previously
described in detail (USEPA, 2010c). Each year from 2010 through 2014, between 75 and
108 children participated in the blood lead screening (Table 5-10). The total number of children
living in the Basin was estimated using 2014 school district enrollment data and verified with
2010 census data, using a similar methodology as previously employed (TerraGraphics et al.,
2001). Basin-wide participation rates since the last Five-Year Review are estimated at 16 to
20 percent (Table 5-11).

5-40

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TABLE 5-10

Summary of Blood Lead Levels for Children Participating in the LHIP by Geographic Area in OU 3, 2010-2014
2015 Five-Year Review, Bunker Hill Superfund Site

No. (%) of Children With Blood Lead
Levels

Blood Lead Level
Range (|jg/dL)

Mean Blood Lead Level (|jg/dL)

Year

Geographic
Area

No. of
Children

Below
Detection
Limits

>5
|jg/dL

> 10
|jg/dL

> 15
|jg/dL

Minimum

Maximum

Arithmetic
Mean

Arithmetic
Standard
Deviation

Geometric
Mean

Geometric

Standard

Deviation

Lower Basin

1 (9%)

0 (0%)

1.4

4.2

2.0

0.9

1.9

1.4

Kingston

4 (17%)

5 (21%)

2 (8%)

1 (4%)

1.4

20.0

3.7

4.5

2.6

2.1

Side Gulches

4 (21%)

1 (5%)

0 (0%)

1.4

6.9

2.8

1.5

2.5

1.7

Osburn

6 (20%)

0 (0%)

1.4

4.1

2.0

0.7

1.9

1.4

2010

Silverton

3 (60%)

0 (0%)

1.4

2.0

1.5

0.3

1.5

1.2

Wallace

0 (0%)

1.4

4.0

2.2

1.0

2.1

1.5

Burke/Ninemile

2 (29%)

0 (0%)

1.4

2.8

1.8

0.5

1.8

1.3

Mullan

4 (36%)

1 (9%)

0 (0%)

1.4

5.6

2.2

1.2

2.0

1.5

Basin-wide

108

24 (22%)

7(6%)

2(2%)

1 (1%)

1.4

20.0

2.5

2.3

2.1

1.6

Lower Basin

1 (13%)

3 (38%)

0 (0%)

1.4

7.0

3.8

2.3

3.2

2.0

Kingston

7 (37%)

4 (21%)

1 (5%)

0 (0%)

1.4

12.0

3.4

2.9

2.7

2.0

Side Gulches

0 (0%)

1 (11%)

0 (0%)

2.5

6.5

3.8

1.2

3.7

1.4

Osburn

4 (17%)

2 (8%)

0 (0%)

1.4

5.8

2.6

1.3

2.4

1.6

2011

Silverton

1 (20%)

0 (0%)

1.4

2.9

2.2

0.6

2.2

1.3

Wallace

Burke/Ninemile

0 (0%)

1.4

4.4

3.4

1.3

3.2

1.6

Mullan

0 (0%)

1.5

2.6

2.1

0.5

2.1

1.3

Basin-wide

14 (19%)

10(13%)

1 (1%)

0(0%)

1.4

3.1

1.9

2.6

1.7

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TABLE 5-10

Summary of Blood Lead Levels for Children Participating in the LHIP by Geographic Area in OU 3, 2010-2014
2015 Five-Year Review, Bunker Hill Superfund Site

No. (%) of Children With Blood Lead
Levels

Blood Lead Level
Range (|jg/dL)

Mean Blood Lead Level (|jg/dL)

Year

Geographic
Area

No. of
Children

Below
Detection
Limits

>5
|jg/dL

> 10
|jg/dL

> 15
|jg/dL

Minimum

Maximum

Arithmetic
Mean

Arithmetic
Standard
Deviation

Geometric
Mean

Geometric

Standard

Deviation

Lower Basin

0 (0%)

1.7

2.3

2.1

0.3

2.0

1.2

Kingston

0 (0%)

1.0

4.9

2.8

1.2

2.6

1.6

Side Gulches

0 (0%)

2.1

4.6

3.5

0.9

3.4

1.3

Osburn

0 (0%)

1.8

4.5

3.1

0.7

3.0

1.3

2012

Silverton

0 (0%)

3.2

4.6

3.9

0.5

3.8

1.2

Wallace

0 (0%)

4 (21%)

0 (0%)

2.2

7.0

3.8

1.4

3.6

1.4

Burke/Ninemile

1 (9%)

0 (0%)

1.0

8.0

3.4

1.8

3.0

1.7

Mullan

0 (0%)

1.6

4.5

3.0

1.5

2.8

1.7

Basin-wide

1 (1%)

5(6%)

0(0%)

1.0

8.0

3.3

1.2

3.1

1.4

Lower Basin

Kingston

7 (33%)

4 (19%)

2 (10%)

1 (5%)

1.4

16.0

3.7

3.6

2.8

2.0

Side Gulches

2 (12%)

0 (0%)

1.4

3.9

2.3

0.7

2.3

1.3

Osburn

5 (17%)

0 (0%)

1.4

4.8

2.5

0.9

2.3

1.4

2013

Silverton

1 (8%)

0 (0%)

1.4

4.9

2.9

1.0

2.7

1.4

Wallace

Burke/Ninemile

0 (0%)

2.2

4.4

3.0

0.8

2.9

1.3

Mullan

Basin-wide

15(16%)

5(5%)

2(2%)

1 (1%)

1.4

16.0

2.8

1.9

2.5

1.6

5-42

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TABLE 5-10

Summary of Blood Lead Levels for Children Participating in the LHIP by Geographic Area in OU 3, 2010-2014
2015 Five-Year Review, Bunker Hill Superfund Site

No. (%) of Children With Blood Lead
Levels

Blood Lead Level
Range (|jg/dL)

Mean Blood Lead Level (|jg/dL)

Year

Geographic
Area

No. of
Children

Below
Detection
Limits

>5
|jg/dL

> 10
|jg/dL

> 15
|jg/dL

Minimum

Maximum

Arithmetic
Mean

Arithmetic
Standard
Deviation

Geometric
Mean

Geometric

Standard

Deviation

Lower Basin

0 (0%)

2.1

4.1

3.2

1.0

3.1

1.4

Kingston

1 (6%)

0 (0%)

1.0

5.0

2.7

0.9

2.5

1.4

Side Gulches

1 (10%)

0 (0%)

1.4

4.4

2.6

0.8

2.5

1.4

2014

Osburn

0 (0%)

1 (4%)

0 (0%)

1.6

5.0

3.0

0.9

2.8

1.3

Silverton

0 (0%)

1.6

4.4

3.2

0.9

3.0

1.4

Burke/Ninemile

0 (0%)

3 (21%)

1 (7%)

0 (0%)

2.3

11.0

4.1

2.3

3.7

1.5

Mullan

Basin-wide

2(3%)

5(6%)

1 (1%)

0(0%)

1.0

11.0

1.1

1.3

2.9

1.4

5-43

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TABLE 5-11

Summary of OU 3 Participation Rates in the LHIP, 2010-2014
2015 Five-Year Review, Bunker Hill Superfund Site

Year

Estimated Eligible
Population3

Total No. of Eligible
Population Providing
Samples3

Percentage of Population
Providing Samples

2010

555

108

19%

2011

517

15%

2012

455

18%

2013

469

20%

2014

483

16%

Notes:

Assumes 6% of children are not enrolled in school (2010 Census) and an even distribution in each age group.

a Eligible population is from 6 months through 6 years old and is based on annual enrollment data for School Districts
392, 393, and 274 and 2014 enrollment data for School District 391.

5-44

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

In response to CDC recommendations, discussed in Section 3.2.1.4, PHD began offering
follow-up services in 2012 to the parents of all children exhibiting a blood lead level of 5 pg/ dL
or greater (as opposed to 10 pg/dL prior to 2012). Since the last Five-Year Review, PHD offered
follow-up services to 18 families, and 7 families accepted these services. In addition to the LHIP
services, PHD also responded to doctor's referrals and conducted follow-up education for
additional children with elevated blood lead levels. In general, follow-up information indicated
that children with elevated blood lead levels were likely exposed during recreational activities.
In 2013, PHD documented a variety of recreational uses throughout the Basin, many of which
occurred at undeveloped sites (e.g., privately owned property used for camping and fishing
throughout the summer months and "impromptu" sites along the river and streams used for
playing and swimming; PHD, 2013b). PHD and IDEQ are updating educational materials to
increase public health education and awareness for recreational users (see Section 5.2.4).
Additionally, IDEQ is now funding and PHD is offering free blood lead screening to children
who recreate in the Basin but live outside the site.

The 2010 Five-Year Review recommended the following, and a discussion of actions taken since
2010 is presented after each recommendation.

• Recommendation: Determine whether an alternative approach to the 2002 OU 3 ROD's dust
intervention protocol could be established and implemented.

Discussion: In 2012, an alternative to the LHIP dust intervention protocol outlined in the
ROD was formally adopted to proactively identify additional families that may benefit from
lead health education and intervention while remediation is ongoing (IDEQ and USEPA,
2012). The alternative approach retains the intent outlined in the ROD, is simpler to apply,
and would not significantly affect PHD's staffing levels.

Each year, PHD offers follow-up services to families residing in homes with dust lead
concentrations greater than or equal to 1,500 mg/kg that were sampled during annual dust
surveys or as part of the BPRP (see Tables 5-5 and 5-6 of Section 5.2.1.2). The purpose of the
follow-up phone call or home visit is to discuss sampling results, home hygiene, and general
techniques to reduce dust lead concentrations in the home and to encourage parents to have
their children's blood lead tested. From 2010 through 2014, 29 follow-ups were completed in
response to elevated house dust lead concentrations at 71 homes. Twenty additional
participants living at homes with dust lead concentrations less than 1,500 mg/kg called
PHD to discuss their results from 2010 through 2014. This recommendation is retained on
the table of issues and recommendations.

5-45

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

• Recommendation: Identify additional funding sources for the LHIP. Continue to evaluate
options for increasing participation in the annual blood lead screening program (an ongoing
recommendation from the 2005 Five-Year Review).

Discussion: Additional funding sources for the LHIP have not yet been identified.

However, State funding has not been a problem over the last 5 years. Participation in annual
blood lead screenings seems to be associated with monetary incentives, and additional
options to increase participation continue to be discussed among the agencies. This
recommendation is not retained on the table of issues and recommendations, because it does
not directly affect protectiveness. It will instead be included in the table of planned action
items.

Details about the HEPA vacuum loan program and outreach and educational activities
conducted from 2010 through 2014 are discussed in Sections 3.2.1.4 and 5.2.4.

Remedy Status

The LHIP supports public health through voluntary blood lead screening services,
environmental health follow-up for children with blood lead levels >5 jug/ dL, and education
programs. Participation in the annual Basin blood lead monitoring continues to be less than a
quarter of the estimated child population and could be improved to identify more children who
require intervention.

To supplement the low participation rates, an intervention program using house dust sample
results was adopted in 2012. This alternative approach has identified a number of households
for follow-up lead health intervention services, but only a fraction of residents have returned
PHD's contact attempts. If activities that contribute to increased house dust lead levels were
identified at the time of follow-up, PHD staff provided specific instructions to help reduce the
impacts of these activities on house dust lead levels. To date, the reasons for elevated house
dust lead concentrations in most homes have not been definitively determined.

In general, mean blood lead levels in all geographic areas and age groups have declined both
nationally and at Bunker Hill since the late 1990s (Figures 5-11 and 5-12). Due to the small
sample size, particularly for some age groups and geographic areas, it is difficult to evaluate
trends in observed blood lead levels. However, an assessment of lead health risk based on
current soil and house dust exposures is described in Section 5.2.1.2.

Education and outreach continues to occur at the schools, and PHD personnel have noted that
children recall and reiterate what was taught from the previous year. In addition, IDEQ's
outreach and education efforts at community events have reached more than 2,500 people in
attendance at these events and 600 children at schools per year.

The HEPA vacuum loan program continues to be used by local residents and is presented in
Section 3.2.1.4.

5-46

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

FIGURE 5-11

OU 3 Geometric Mean Blood Lead Levels by Geographic Area, 1996-2014
2015 Five-Year Review, Bunker Hill Superfurid Site

Year

¦ Burke/Ninemile
Kingston
Lower Basin
Mullan

¦ Osburn

¦ Side Gulches
Silverton
Wallace
Basin wide

5-47

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

FIGURE 5-12

OU 3 Geometric Mean Blood Lead Levels by Age, 1996-2014
2015 Five-Year Review, Bunker Hill Superfund Site

9.0

8.0

^ 7.0

DO
=L

> 6.0
a>

¦c

> ^ <$y> ^

Age 1
Age 2
Age 3
Age 4
Age 5
Age 6
Age 7
Age 8
Age 9

Year

5-48

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

5.2.1.5 Remedy Protection
Background and Description

See Section 3.2.1.4 for a discussion of Remedy Protection background description.
Implementation of remedy protection, as selected in the 2012 Interim ROD amendment, began
in 2013.

O&M and Actions since the Last Five-Year Review

In 2013 and 2014, five remedy protection projects were constructed in OU 3, as summarized in
the following text. Construction of five remedy protection projects are planned for OU 3 in 2015:
Mill Road, South 2nd Street, Revenue Gulch, Blackcloud Creek, and McCarthy Creek. The
following projects have been completed or are planned to be constructed in 2015:

Mullan Projects (see Figure 5-13)

• Dewey Street—Construction of the Dewey Street remedy protection project was completed
between July and October 2013. The project involved installation of a new stormwater
system and reconstruction of a portion of Hunter Street. Additional information can be
found in the memorandum of completion (MFA, 2014b).

• Third Street—Construction of the Third Street remedy protection project was completed
between August and October 2013. The Third Street project involved replacement of
existing culverts and roadside ditches with a corrugated, high-density polyethylene pipe
network. It also included roadway reconstruction and curbing on Oregon, California, and
Montana streets to direct stormwater toward Third Street. Additional information can be
found in the memorandum of completion (MFA, 2014b).

• Mill Road — Construction of the Mill Road remedy protection project will begin in the
summer of 2015 and will consist of the installation of a new stormwater system to convey
water from various points along Mill Road and the upgradient catchment to the SFCDR. The
project includes 20 catch basins and approximately 2,100 lineal feet of storm pipe. A
perforated drainage pipe with fabric filter is included under both edges of Mill Road and
along a portion of Daisy Loop to collect and drain subsurface flow beneath the roadway.
The project also includes reconstruction of the roadway with curb and gutter and
approximately 1,400 lineal feet of paving. Additional information about the project is
available in the final design report (TerraGraphics, 2014f).

• South 2nd Street—Construction of the South 2nd Street remedy protection project is
planned for the summer of 2015. The project will involve the installation of a new storm
drain system to provide drainage to an area that experiences regular flooding and sediment
buildup.

Silverton Projects (See Figure 5-13)

• Unnamed Gulch—Construction at the Unnamed Gulch remedy protection project was
completed between October and November 2013. The project involved the removal of an
existing culvert, installation of a pipe-arch culvert, channel modifications upstream and
downstream from the new culvert, reshaping/ restoration of Anderson Way and a private
drive, and additional surface restoration. Additional information can be found in the
memorandum of completion (MFA, 2014c).

5-49

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

• Revenue Gulch—Construction of the Revenue Gulch remedy protection project is scheduled
for the summer of 2015. The project will involve the replacement of five existing culverts
and one existing bridge with new concrete box culverts or equivalently sized aluminum
plate culverts. The project includes installation of a high-flow diversion structure to divert a
portion of large-volume storm flows from Revenue Gulch into a stormwater collection and
conveyance system running parallel to the Revenue Gulch Channel. This will allow large
storms to bypass the existing channel constrictions without going over the bank and
damaging existing barriers. In addition, stormwater collection laterals will be installed along
four side streets (Sixth through Ninth streets). The laterals will drain through the bypass
system. The planned drainage area improvements will reduce the risk of flooding along the
Revenue Gulch channel. Additional information can be found in the final design
(TerraGraphics, 2015e).

Osburn Projects (see Figure 5-13)

• Meyer Creek—Construction of the Meyer Creek remedy protection project was completed
between May and October 2014. The project included the installation of a new stormwater
drainage system that conveys Meyer Creek through the town of Osburn. The project
provided increased flow capacity and located the piping system largely within the public
ROW. The project included the installation of an inlet structure for the new storm drain, and
modifications to the existing storm pipe inlet structure to restrict flow to the existing system.
In addition, modifications were made to the water and sanitary sewer systems to mitigate
conflicts with the new storm drain system. Additional information can be found in the
construction summary memorandum (MFA, 2015c).

• Shields Gulch—The Shields Gulch remedy protection project was constructed over two
construction seasons, starting in October 2013 and ending in August 2014. The project
involved construction of a new stream channel designed to provide adequate flow capacity
for the selected design storm and to reroute stormwater to bypass existing undersized
ditches near the elementary school. The bypass will reduce flooding at the school entry area.
In addition to construction of the new channel, four existing culverts were replaced by
concrete box culverts in order to provide adequate channel flow capacity. Additional
information can be found in the construction summary memorandum (MFA, 2015d).

Ninemile Watershed Projects (See Figure 5-13)

• Blackcloud Creek - Replacement of undersized drainage culverts and channel
improvements to increase flow capacity are planned for 2015.

• McCarthy Creek - Replacement of undersized drainage culverts and channel improvements
to increase flow capacity are planned for 2015.

5-50

-------
OSBURN

SIDE GULCHES

MULLAN

MEYER CREEK
PROJECTAREA"

iNjenue

9th Si

OSBURN

REVENUE GULCH
"PROJECTAREA

6», st

5fh St

Fir Aye

SI OVERTON

UNNAMED GULCH_
PROJECTAREA

2nd Si

SHIELDS GULCH
PROJECTAREA

BLACKCLOUD CREEK
"PROJECTAREA

Hunter Ave

MULLAN

Earte Ave

Fisher

SOUTH 2ND STREET

PROJECT AREA

MILL ROAD
PROJECT AREA \

Hat

Park St

Idaho St

MCCARTHY
PROJECTAREA

Cemetery Rd .

3RD STREET
"PROJECTAREA

[Cmek _

xNihen.

Source: Aerial photograph obtained from Esri ArcGIS
Oniing; roads dataset obtained from Esri; river dataset
obtained from Idaho Department of Water Resources.

500

1,000

2,000
I Feet

River
Interstate

Remedy Protection Project Area

Figure 5-13

OU 3 Remedy Protection Project Areas

2015 Five Year Review
Bunker Hill Superfund Site

oEPA

-------
-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

For each of the constructed remedy protection projects listed above, the Trust has prepared
O&M plans that describe regular inspection and maintenance activities. O&M is the
responsibility of the following local governments:

• Dewey Street: City of Mullan

• Third Street: City of Mullan

• Unnamed Gulch: Shoshone County

• Meyer Creek: City of Osburn

• Shields Gulch: City of Osburn

The Coeur d'Alene Trust completed a Five-Year Review inspection of the completed remedy
protection projects on February 12, 2015. No deficiencies in the function of the constructed
remedy protection projects were identified during the inspection.

Remedy Status

Based on the Five-Year Review visual inspections completed by the Coeur d'Alene Trust, the
constructed remedy protection projects are functioning as intended and are protective of the
previously completed remedies (i.e. yard remediation).

5.2.1.6 Institutional Controls Program
Background and Description

The purpose of the ICP established for the Basin is to protect public health by managing
contaminated soil left in place into perpetuity. The Basin ICP rule, which is based on the Box
ICP rule, was adopted by PHD in November 2006. The rule was accepted by the Idaho State
Legislature in March 2007, and became effective in July 2007. Implementation of the Basin ICP
commenced in September 2007. The ICP was adopted as part of the PHD environmental health
code. Implementation and execution of the ICP follows the requirements and standards
described in the Code itself (IDAPA 41.01.01.500 through 41.01.01.543 and 41.01.01.900 through
41.01.01.902).

The Basin ICP established a locally enforced set of rules and regulations to maintain the
integrity of installed barriers and to ensure that new barriers are installed as part of excavation
and grading. The ICP also regulates and provides information for interior construction and
renovation projects within the administrative boundary of the ICP. The general features of the
Basin ICP are the same as the Box ICP, which are described in Section 3.2.1.6 of this report and
in the 2005 and 2010 Five-Year Reviews (USEPA, 2005 and 2010c).

O&M and Actions since the Last Five-Year Review

Since the last Five-Year Review, PHD completed the following activities under the ICP:

• Issued 3,122 permits in OU 3, most of which were for large exterior excavation projects
(>1 cy) (Table 5-12).

• Issued 1,260 licenses to contracting companies and 152 licenses to government entities and
utility companies for all OUs (licenses are not tracked by OU).

• Provided 1,014 property disclosures in OU 3.

• Recorded and followed-up on 3,904 One-Call system (intent to excavate - locate utilities)
calls in OU 3.

5-53

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

• Scanned all hard copy permits and records of compliance into electronic files, maintained on
PHD's local server in Kellogg, Idaho and backed-up following PHD's information
technology procedures. The identification of parcels that will not be addressed under the
BPRP, as determined by IDEQ and USEPA, began since the last Five-Year Review and will
assist the ICP in issuing permits and directing installation of protective barriers.

TABLE 5-12

Number of ICP Permits Issued in OU 3, 2010-2014
2015 Five-Year Review, Bunker Hill Superfund Site

Permit Type

Calendar Year

Cumulative
5-Year Total

Annual
Average

2010

2011

2012

2013

2014

Large Exterior
Projects -
Excavation3

715

339

446

598

548

2,646

529

Large Exterior
Projects -
Demolition

Interiors

Records of
Compliance

356

Totals

815

434

533

693

647

3,122

624

Note:

Data provided by PHD.

a Includes subdivision/planned unit development totals.

The amount of waste managed through permitted projects is presented in Table 5-13 (refer to
Section 3.2.1.6 for an explanation of waste estimations from ICP permits). An estimated
90,000 cubic yards of OU 3 waste soil were directed to Basin Repositories or other community
fill locations since the last Five-Year Review. In addition, an estimated total of 1,100 cubic yards
of building demolition debris, 120 bags of insulation and 10,000 square yards of carpets and
padding were directed to the Big Creek Repository.

One hundred-twenty two (122) cubic yards and 5 buckets of clean soil/ gravel were delivered to
Basin properties, and a total of 21 vouchers were issued to homeowners for pick up
clean/ gravel since the last Five-Year Review (Table 5-14).

The ICP rule gives PHD the authority to undertake enforcement action for noncompliance with
ICP requirements. No enforcement proceedings have been initiated in the Basin since the last
Five-Year Review. Letters urging compliance with the ICP are required infrequently.

5-54

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TABLE 5-13

OU 3ICP Waste Disposal Volumes

2015 Five-Year Review, Bunker Hill Superfund Site

Waste
Category

Disposal Site

Materials
Disposed or
Source of
Materials

Units

Calendar Year

Cumulative
5-year
Total

Annual
Average

2010

2011

2012

2013

2014

Building
Demolition

Big Creek Repository

Demolition Debris

1,000

1,087

217

Insulation

Bags

120

Carpets and Pads

1,856

3,760

3,425

351

318

9,710

1,942

Soil

Disposal

Big Creek Repository

Soil

3,255

3,940

2,914

10,360

21,966

42,435

8,487

Mullan ICP Disposal Site

Soil

22,515

582

2,735

931

1,057

27,820

5,564

East Mission Flats

Soil

2,686

1,387

1,439

6,566

1,337

13,415

2,683

Shoshone County Airport

Soil

722

369

370

1,461

292

Other community fill sites3

Soil

1,314

1,401

2,337

1,211

265

6,528

1,306

Note:

a Other areas include County landfill-Polaris Peak, Osburn Fire Hall, and Mullan Fire Hall.

5-55

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TABLE 5-14

OU 3 ICP Clean Material Volumes

2015 Five-Year Review, Bunker Hill Superfund Site

Calendar Year

Cumulative
5-year Total

Delivery Method

Units

2010

2011

2012

2013

2014

Annual Average

Clean soil/gravel delivery

122

Clean soil/gravel delivery

Buckets

Soil/gravel voucher issued
(homeowner pickup)

No. of
vouchers

5-56

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

The 2010 Five-Year Review recommended the following, specifically to OU 3, and a discussion

of the recommendation or actions taken since 2010 are presented in the following list.

• Recommendation: Secure adequate funding of the ICP to ensure success of the remedy,
including consideration of sufficient staff and information management support to ensure
the long-term effectiveness of the program.

Discussion: Funding for the OU 3 ICP is currently being provided by USEPA and IDEQ,
and is based on an agreement among USEPA, IDEQ, and the PHD (2007). IDEQ is currently
receiving $1.5 million per year from the Water Pollution Control Account (as established by
the Idaho Statute) and placed in the Basin Bunker Hill Environmental Remediation Fund to
create a principle balance amount that will cover future match and O&M costs for the State.
Costs for the OU 3 ICP are considered to be match or O&M, depending on the activity. The
Basin Environmental Remediation Fund was created under Idaho Statute 39-3606c that
establishes the Environmental Remediation Fund for meeting match and O&M
requirements at environmental cleanup and remediation and restoration sites. The Fund is
held by the Treasurer's Office under 39-3605c and is interest-bearing. USEPA and IDEQ will
continue to work together to ensure that adequate funding exists for the ICP. This
recommendation is complete.

• Recommendation: Complete the CFP currently being developed by USEPA and IDEQ for
all three OUs.

Discussion: See Section 3.2.1.6 for discussion. This recommendation is complete. This
recommendation is repeated for all three OUs and is complete for all three OUS.

• Recommendation: Regarding the long-term disposal need from ICP, establish a process
with community planners to identify timing and quantity of waste soils to be hauled to
repositories from ICP-regulated activities.

Discussion: This activity should be undertaken for planning and repository capacity
management. It is not retained in the table of issues and recommendations, because it does
not directly affect protectiveness. It will instead be included in the table of planned action
items (Table 5-17).

• Recommendation: Determine whether a community-wide soil lead level is needed for the
Basin. If so, determine the appropriate level and how it would be used.

Discussion: In 2012, IDEQ and USEPA agreed to an ICP soil disposal lead level of
350 mg/kg, for consistency with the Box (USEPA and IDEQ, 2012). This will assist PHD
with disposal decisions that help achieve the objective of reducing exposures of young
children and pregnant women to lead-contaminated soils.

A Basin community-wide soil lead level has yet to be determined, because the only way to
develop a health-protective community mean soil level in the Basin is to evaluate house
dust lead levels and the distribution of soil lead levels at the completion of property
remediation. This recommendation is not retained in the table of issues and
recommendations, because while it does give the agencies a gauge of how protective the
cleanup is, it does not directly affect protectiveness. It will instead be included in the table of
planned action items (Table 5-17). The action item will be addressed once the BPRP is
completed and a Basin community-wide soil lead level is determined.

5-57

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

• Recommendation: Flood Control: Continue working with the BEIPC and other stakeholders
to evaluate and plan actions relative to addressing SFCDR and Pine Creek flooding that may
affect cleanups.

Discussion: This recommendation is repeated for all three OUs and is complete for all three
OUs. See Section 3.2.1.6 for discussion.

• Recommendation: Continue working to develop an approach for addressing roads as long-
term protective barriers in collaboration with state, county, and local entities.

Discussion: This recommendation is repeated for all three OUs and is complete for all three
OUs. See Section 3.2.1.6 for discussion.

• Recommendation: Develop appropriate institutions and funding mechanisms to finance
and oversee infrastructure maintenance.

Discussion: This recommendation is repeated for all three OUs. See Section 3.2.1.6 for
discussion. This recommendation will not be retained in the table of issues and
recommendations, because it does not directly affect protectiveness. It will instead be
included in the table of planned action items. This is a site-wide task and, as such, has been
listed only once in the OU 1 table of action items.

• Recommendation: Work with Basin communities and state and federal agencies on an
infrastructure plan to ensure remedy success.

Discussion: In 2013 and 2014, USEPA and the Coeur d'Alene Trust have invested $11.5M in
paved road repairs and/or replacement and $6.4M in flood management infrastructure
work throughout the Upper Basin. These "Paved Roads" and "Remedy Protection" projects
will continue until the ROD Amendment Selected Remedy is complete. Since the last Five-
Year Review, IDEQ has developed an inventory of flood control structures in the
communities, including those that were installed as part of the remedy. IDEQ plans to create
a coordination cooperative that will work together to track maintenance and repair work for
the structures. This effort is in the initial planning stage. This recommendation will not be
retained in the table of issues and recommendations, because it is similar to other ongoing
recommendations that are included in the table of action items.

Remedy Status

As part of this Five-Year Review, the ICP activity reports and special reports concerning
recreation, storm, fire, and flood events were reviewed, and discussions with PHD personnel
were completed. PHD continues to implement the ICP according to its rule (IDAPA 41.01.01).
Clean barriers that have been disrupted through excavation have been repaired in response to
ICP permitting and inspection activities. The ICP inspectors are continuously in the field to
ensure that barriers are installed consistent with the remedy defined in the ROD and in
compliance with the ICP rule.

Similar to the Box, runoff, localized flooding, and documentation are challenges faced during
everyday implementation of the ICP (refer to Section 3.2.1.6 for discussion of these topics). As
identified in the feedback from contractors acquiring permits and licenses, acceptance and
compliance with the program appears to be high. ICP users responding to the survey indicate a
very high level of satisfaction with the program.

5-58

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

5.2.2 Mine and Mill Sites

The 2010 Five-Year Review recommended the following for OU 3 Mine and Mill Sites in
general:

• Recommendation: Mine and Mill Site O&M: Coordinate with responsible entities to
formally implement O&M at mine and mill site with completed remedial actions.

• Discussion: O&M of work completed on Mine and Mill sites is being conducted as follows:
Constitution Site - BLM and Marmon Group, Golconda - Heel a, Rex - BLM and CDA Trust,
Sisters - IDEQ, USBM - CDA Trust. This recommendation is complete. The need for further
actions at previous Mine and Mill removal sites conducted by USEPA was considered
during the ROD Amendment process and no additional actions were identified at that time.
This recommendation for previous removal action follow-up is complete.

• Recommendation: Moon Creek, Silver Crescent, and Charles Dickens: Ongoing monitoring
(an ongoing 2005 Five-Year Review recommendation).

• Discussion: A Removal Action was conducted by the USFS at the Silver Crescent and
Charles Dickens Mines along Moon Creek in 1998-2000. Restoration was completed by the
USFS in 2008. Monitoring by the USFS is ongoing. This recommendation is complete.

• Recommendation: Upper SFCDA Morning Mine No. 6: Routine monitoring (an ongoing
2005 Five-Year Review recommendation).

Discussion: Hecla Mining Company conducted a Removal Action at the Morning Mine No
6 in 1989 and is responsible for on-going O&M of the site. This recommendation is complete.

• Recommendation: Upper Basin Mine and Mill Sites: Identify additional Mine and Mill sites
to begin RD (an ongoing 2005 Five-Year Review recommendation).

Discussion: Mine and Mill sites identified in the ROD Amendment are being prioritized by
USEPA for action by the CDA Work Trust. For several years, this work is focused on
Ninemile Creek and then moving over to Canyon Creek. In addition, IDEQ and USEPA are
evaluating Mine and Mill sites that may pose a human health exposure and/ or
recontamination concern to aid in further prioritization for action. This recommendation is
complete.

5.2.2.1 South Fork Coeur d'Alene River - Golconda
Background and Description

The Golconda Mine and Mill Site is located along the north banks of the Upper SFCDR below
Trowbridge Gulch (Figure 5-1). This subarea included a small tailings impoundment as well as
stream bank tailings and contaminated soils. The stream bank tailings were within and adjacent
to the SFCDR and were subject to ongoing erosion. The site was easily accessed and was
routinely used for recreational purposes.

5-59

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

The Golconda Mine and Mill Site remedial action was conducted in 2006 and 2007 to prevent
direct human contact with metals from recreational exposure and to prevent further erosion of
the source areas into the SFCDR. The components of these actions were as follows:

• Excavation and consolidation of mine wastes;

• Construction of riprap revetments along the SFCDR;

• Completion of final grading, construction of surface water control features, placement of soil
cover systems, and hydro-seeding; and

• Conveyance of adit flow into a pipeline to bypass the waste rock pile.

Remedial action effectiveness monitoring at the Golconda Mine and Mill Site was conducted
between 2007 and 2012 in accordance with the Golconda O&M Plan (USEPA, 2007b). Additional
technical and background information for the site and groundwater and surface water
monitoring data interpretation and evaluation through 2009 were presented in the 2010 Five-
Year Review (USEPA, 2010c).

O&M and Actions since the Last Five-Year Review

The last Five-Year Review made a recommendation to coordinate with responsible entities to
implement O&M formally at mine and mill sites with completed remedial actions. An
Environmental Covenant was executed by Hecla Silver Valley, Inc ("Heela SV"), USEPA, and
IDEQ on February 19, 2013 to ensure that Hecla SV and subsequent property owners will carry
out the O&M Plan (USEPA, 2009b) and that activities on the property will not interfere with the
remedial actions.

A site inspection was performed by IDEQ in February 2015 for the purpose of this Five-Year
Review. That inspection indicated the earthen cover, vegetation, and riprap revetments were
functioning as intended. Culverts and drainage ditches were functional, and the barrier was
intact. There was a healthy stand of grass and the site had signs of deer and elk. No
anthropogenic activity or adverse impacts on the remedy were observed at the time of the site
inspection. The site is accessible by foot from the east corner of the site after crossing the bike
path bridge.

July 17, 2014, Hecla conducted an inspection of the Golconda site. Hecla verbally reported to
USEPA that there were no indications of movement or delivery of new sediment, breaching of
sediment ditches and overflows. No leached oxidized rock materials were noted in contact with
surface waters, only the placed rip rap boulders from remediation. No areas of concern were
observed.

In addition to the IDEQ site inspection, PHD indicated that no ICP permits have been issued for
this section of Golconda, and ICP staff has not seen any evidence of change.

5-60

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Remedy Status

The evaluation of monitoring data from 2007 through 2012 indicates that some ARARs have not
been met, based on the median AWQC ratios (for additional detail see Data Summary Report
[2007-2012] and Adaptive Management Recommendations for the Upper Coeur d 'Alene Basin Remedial
Action Monitoring Program, CH2M HILL, 2012b). However, surface water concentrations in the
reach of the SFCDR adjacent to the site do not appear to be adversely affected by adit discharge,
overland flow, or groundwater discharge from the site based on differences in the AWQC ratio
calculated between upstream and downstream locations (CH2M HILL, 2012b). The
groundwater and surface water monitoring was discontinued in July 2012. The Environmental
Covenant signed by Hecla SV, USEPA, and IDEQ and recorded with the County in February
2013 ensures that O&M occurs and property use restrictions are applied at the site into the
future.

5.2.2.2 Wallace Yard Removal
Background and Description

The Wallace Yard, Hercules Mill, and Spur Lines are located near Wallace, Idaho (Figure 5-14).
In the early 1890s, railroad companies used the area known as the Wallace Yard for railcar
storage, switching, and other operations. The Hercules Mill, located within Wallace Yard,
processed ore from the nearby mines to produce concentrates for shipment to smelters. Over the
past decades, several portions of the Wallace Yard and Hercules Mill were abandoned and/ or
removed (USEPA, 2008b). The two historical spur lines that ran along Canyon Creek and a
single line along Ninemile Creek served the mines and communities in these side gulches for
many years; the lines have been abandoned for decades.

Mine waste found at various locations within the Wallace Yard, Hercules Mill, and Spur Lines
contained elevated concentrations of lead and other heavy metals above human health and
environmental risk-based action levels (USEPA, 2008b, ARCADIS, 2009). Several documents
provide additional background and technical information regarding the history and selected
cleanup within the Wallace Yard (USEPA, 2001b, 2002a, and 2008b).

In 2009, USEPA and IDEQ entered into a Consent Decree with the UPRR and the Burlington
Northern Santa Fe (BNSF) Railway Company to clean up the Wallace Yard, Hercules Mill, and
Canyon and Ninemile Creek Spur Lines, which was approved in federal court in 2010 (USEPA
and IDEQ, 2010). The following RAOs were identified:

• Reduce human exposure to soils, including residential garden soils, that have
concentrations of lead greater than or equal to 700 mg/kg or arsenic greater than or equal to
100 mg/kg for portions of Wallace Yard or the Spur Lines that either are or may be
reasonably anticipated to become residential use areas.

• Reduce human exposure to soils with lead concentrations at or above 700 mg/kg within
readily accessible common use areas of Wallace Yard or the Spur Lines (USEPA, 2008b).

The RAOs were to be achieved through installation of protective asphalt, gravel, or vegetative
barriers; removal and disposal of contaminated materials; and access controls (USEPA, 2008b).

O&M and Actions since the Last Five-Year Review

The remedial actions for Wallace Yard and the Ninemile and Canyon Creek spur lines were
implemented in 2010 and 2011 (ARCADIS, 2013d, 2013e, and 2013f). Remedial actions at the

5-61

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Hercules Mill were implemented in 2012 by UPRR and BNSF, and overseen by USEPA and
IDEQ (ARCADIS, 2013g). The work was certified complete on January 21, 2014 (USEPA, 2014).

Remedial actions included:

• Removal and replacement or capping of contaminated soils greater than or equal to

700 mg/kg lead or 100 mg/kg arsenic that were within 1,000 feet of residences or accessed
by the public;

• Installation of access controls to prevent barrier damage due to vehicle traffic;

• Asphalt capping of sections of the West Fork Ninemile Road, Yellow Dog Road, and some
parking areas in the Wallace Yard;

• Placement of large riprap on embankments to prevent erosion; and

• Full soil removal to bedrock on the rock face at the Hercules Mill site.

The excavated soils were disposed of at the Big Creek Repository. Additional details are
provided in the Completion of Element of Work reports (ARCADIS, 2013d, 2013e, 2013f, and
2013g).

The last Five-Year Review recommended that responsible entities should formally implement
O&M at Mine and Mill Sites with completed remedial actions (USEPA, 2010c). A long-term
Maintenance and Repair (M&R) Plan was finalized in 2013 for the Wallace Yard and the
Hercules Mill remedial actions (ARCADIS, 2013h). The spur lines are not subject to the M&R
Plan because the railroads had abandoned the spur lines and ownership is now subject to real
estate ownership regulations. It is anticipated that the railroad ROW along the spur lines will or
has been adopted by adjacent landowners and is therefore subject to the ICP which is
administered by PHD.

UPRR and BNSF conducted quarterly inspections of the Wallace Yard and Hercules Mill sites
and reported results to USEPA and IDEQ in accordance with the M&R Plan (ARCADIS, 2014b,
2014c, 2014d, and 2015b). During this review period, the Wallace Yard and Hercules Mill Site
remedy required the following maintenance activities:

• Regrading of erosion rills and barriers that had been damaged due to snow plowing
activities;

• Reorientation of traffic exclusion boulders that had been moved due to snowplowing
activities;

• Grading out areas and adding gravel to small potholes due to traffic use; and

• Removal of sediment from culvert discharge.

In addition, barrier disturbance was observed in the lawn area at the Wallace Visitor Center due
to the City of Wallace's construction activities (permitted by the ICP). The barrier will be
repaired when the work is complete.

5-62

-------
Spur Lines
Major Streets
Interstate 90
Streams

0 0.25 0.5 Miles

1 i I i I

FIGURE 5-14

Wallace Yard Including Hercules Millsite and Spur Lines

2015 Five-Year Review
BUNKER HILL SUPERFUND SITE

&EPA

TerraGraphics Environmental Engineering. Inc. 2010_5_Year/ wallace_yard.mxd 3/23/2015

-------
-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Remedy Status

The cleanup that occurred between 2010 and 2014 fulfilled the RAOs. An environmental
covenant executed and recorded in November 2011 by USEPA, IDEQ, and UPRR set forth
activity and land use limitations at the Wallace Yard property, including restrictions on
residential use and use of groundwater as drinking water, as well as other protections for
human health regardless of future ownership changes (USEPA et al., 2011).

The inspections conducted in 2013 and 2014 indicated several minor issues with barrier
integrity. Repairs were completed or are pending, as discussed in the previous subsection.

Snow removal and unauthorized vehicular access is expected to result in the continued need for
regular M&R by UPRR. The capped areas continue to provide effective barriers to the
underlying contaminated soils, access controls are still in place to prevent barrier disturbance,
and continued M&R is required by the Consent Decree (USEPA and IDEQ, 2010), which is
expected to continue to provide continued achievement of the RAOs. Clean barriers on the Spur
Line are not subject to long-term UPRR and BNSF maintenance obligations. Similar to all
human health barriers, continued performance of the barriers on the Spur Lines fall under the
jurisdiction of the ICP.

5.2.2.3 Osburn U.S. Bureau of Mines Impoundment Site
Background and Description

The Osburn USBM Impoundment Site is located between the southern bank of the SFCDR and
1-90 just west of Osburn, Idaho. The site is adjacent to North Frontage Road and Terror Gulch
Road. Mine tailing impoundment cells were constructed on the site in the late 1970s and early
1980s to evaluate the use of mill tailings for filling and reclaiming areas in the river floodplain.
Because of erosion and off-road vehicles activities, mill tailings with high concentrations of lead
and arsenic are exposed.

The remedial action selected for the site by the USEPA involved capping an impoundment area
of approximately 2.8 acres with 6 inches of 4-inch minus pit run material and quarry spall
windrows to deter vehicular access to the site. Barrier boulders, a barrier fence, ecology blocks,
and warning signs were placed around the perimeter of the site to limit access to the central
portion of the impoundment area. A cap of pit run material was also placed along a roadway on
the south side of the site to provide a designated route around the impoundment area to create
a long-term barrier between contaminated solids and human receptors. The remedial action
construction was completed in October 2011, as documented in the Remedial Action
Completion Report (MFA, 2012a).

O&M and Actions since the Last Five-Year Review

The Coeur d'Alene Trust has assumed responsibility for O&M at the Osburn USBM
Impoundment Site in accordance with site O&M plans (Parametrix, 2011; MFA, 2014d).
Inspections were completed at least annually between 2012 and 2014, with results documented
in annual reports (MFA, 2013, 2014e). Additional visual inspections are completed periodically
throughout the year, and following high-flow events in the SFCDR. Periodic maintenance has
involved replacing exterior barrier boulders that had been moved to allow recreational
vehicular access to the site (MFA, 2013 and 2014d).

5-65

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Remedy Status

The inspections indicate that the remedy is protective and functioning as intended. No evidence
of cap erosion, quarry spall windrow deterioration, or flood damage has been observed. During
the 2013 and 2014 inspections, barrier boulders had been moved to allow recreational vehicular
access to the site. One-inch-deep tire ruts were observed in areas where barrier boulders had
been moved, but the tire ruts were insignificant with respect to the integrity of the cap (MFA,
2013). The Coeur d'Alene Trust replaced the barrier boulders. If recreational vehicle users
continue to move the boulders, then larger boulders will be installed.

5.2.2.4 Canyon Creek Watershed: Sisters
Background and Description

The Sisters Mine is a small site located within the Canyon Creek Watershed adjacent to the
community of Woodland Park near Wallace, Idaho (Figure 5-1). Major features of the site
include waste rock piles, an adit (overgrown with vegetation), a former access road, two
unvegetated and slightly eroded escarpments, remnant mining track rails, and a refuse pile.

The remedial objective is to limit potential exposures of area residents and recreational users to
arsenic and lead-contaminated soils (USEPA, 2002a). The remedial activities included a
combination of site recontouring, installation of clean soil and native vegetative cover, and
eliminating access points. The remedy was constructed by IDEQ in July/August 2005.
Additional technical and background information for the Sisters Mine and Mill Site is provided
in the 2010 Five-Year Review (USEPA, 2010c).

O&M and Actions since the Last Five-Year Review

The 2010 Five-Year Review recommended that responsible entities should coordinate to
formally implement O&M at OU 3 mine and mill sites with completed remedial actions. No
formal O&M plan exists for the Sisters Mine.

A site inspection was conducted by IDEQ on February 18, 2015 in support of this Five-Year
Review. The terraces and vegetation were observed to be functioning as intended. Surface water
was shedding off the site as intended in the drainage ditches. There was evidence of deer and
elk crossing this site. Noxious weeds were present. No public use of this area was observed;
however, the "Private Property" signs at the base of this site near Dairy Road have faded.

Remedy Status

Since completion of the remedy, IDEQ inspected the Sisters Mine site and it appears to remain
stable. No maintenance has occurred since the last Five-Year Review, although updating
signage and conducting future O&M is necessary.

5-66

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

5.2.2.5 Ninemile Watershed

Waste Consolidation Area
Background and Description

The EFNM Waste Consolidation Area (WCA) site (Figure 5-15) is located approximately 6 miles
northeast of Wallace, Idaho in the upper reach of the EFNM Creek Watershed. It is located
approximately 250 feet above EFNM Creek outside of the alluvial valley and in an area that is
relatively isolated from groundwater. The site provides a location for long-term consolidation of
mine waste materials, including waste rock and tailings, from sites located throughout the
Ninemile Creek Watershed. Mine wastes will be consolidated into the EFNM WCA to reduce
metals loading into the watershed. Additional information on the EFNM WCA can be found in
the Final Remedial Design Basis of Design Report (CDM Smith, 2013).

The WCA was designed to be constructed in phases: construction of the initial 19 acres of the
EFNM WCA was completed in 2014. Upon completion, the WCA will be approximately
33 acres, with a capacity of up to 1.9 million cy. It is anticipated that wastes will be placed in the
WCA for at least 10 years, although the timeline is subject to change based on funding and work
execution progress in the Ninemile Creek Watershed.

O&M and Actions since the Last Five-Year Review

Initial construction of the EFNM WCA began in July 2013 and was completed in August 2014. A
winter shutdown of construction occurred from November 2013 through May 2014. A detailed
description of construction activities is provided in the Final Remedial Action Completion Report
(CDM Smith, 2014a). Construction activities associated with the EFNM WCA initial
development included:

• Clearing and grubbing

• Soil salvaging (excavation, screening, hauling, and stockpiling of growth media [cover soil]
and oversize material for future work)

• Developing and operating a rock quarry (excavation, crushing, screening, hauling and
stockpiling of rock materials to meet the requirements of the project)

• Installing two buttresses constructed from quarry rock and installing a buttress drainage
system consisting of drainage pipes and surface water drainage channels along the
perimeter of the buttresses

• Installing stormwater channels

• Installing a base drainage system consisting of a drainage layer (2-foot-thick layer of
drainage rock overlying a 16-ounce geotextile that separates the drainage rock from the
underlying subsoil)

• Installing two permanent access gates

The Coeur d'Alene Trust began operating the EFNM WCA (i.e. placing waste rock) in July 2014,
as the initial development of the WCA was being completed. The first waste materials placed at
the EFNM WCA were generated from the remedial action completed at the Interstate-Callahan
Rock Dumps. Placement of wastes from the Interstate-Callahan Rock Dumps site is scheduled
to be complete during the 2015 construction season. An expansion of the WCA will also be
designed in 2015 that will accommodate placement of waste materials from the Success

5-67

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Complex site. Periodic site inspections are completed by the Coeur d'Alene Trust as part of
operations.

A water monitoring program was initiated at the WCA in 2013 prior to waste placement. The
objectives of the initial water monitoring at the EFNM WCA were to understand the hydrology
of the area better and to evaluate surface water and groundwater baseline conditions prior to
waste placement. Additional information on the monitoring points is summarized in the Coeur
d'Alene Trust annual water monitoring reports (MFA, 2014f; 2015e). Monitoring will be
completed throughout the operation of the WCA (i.e. during waste placement) to help
understand effects of waste placement, if any, on surrounding surface water and groundwater.

After initial waste placement in the WCA, two rounds of monitoring were completed in October
and November of 2014. Dissolved metals concentrations in groundwater samples were
generally consistent with background samples with two exceptions: cadmium and lead
concentrations were somewhat elevated relative to background conditions in the October 2014
sampling event in one well, located southwest of the WCA. However, the November sample
results for these metals were non-detect. As a result, it is inferred that the elevated cadmium
and lead concentrations at this location may not be indicative of impacts associated with waste
placement. As additional monitoring is completed, the trends and conclusions will be
reevaluated.

Surface water samples collected after waste placement did not contain detectable dissolved
metals concentrations above AWQC, except for dissolved mercury in EFNM 018 in the
November 2014 event. EFNM-018 is upstream of all construction activities and mercury was
detected only slightly above the method reporting limit (see MFA, 2015e for additional
information).

During the monitoring of the drainage layer pipe outlets, flow was observed only in BRM-228
in the southwest corner of the EFNM WCA in July 2014. Metals were not detected above
AWQC.

Remedy Status

The EFNM WCA has been operational since July 2014. Inspection and monitoring data collected
through December 2014 indicate that the remedy is protective and functioning as intended.

5-68

-------
¦BUR053
INTERSTATE-CALLAHAN

INTERSTATE-CALL.AHAN
LOWER ROCK DUMPS

WASTE

CONSOLIDATION
AREA

¦SUCCESS MINE
ROCK DUMP

BURKE

BUR054
REX NO. 2 /
SIXTEEN-TO-ONE MINE

WALLACE

Source: Aerial photograph obtained from Esri ArcGIS
Online; rivers dataset obtained from Idaho Department
of Water Resources: roads dataset obtained from Esri.

C8 WCA Full Construction Boundary C3 Mine and [
C3 Ninemile Creek Basin Boundary Interstate

Stream /' River

0 750 1.500 3,000 Feet

Source Site

Figure 5-15

Ninemile Creek Watershed
Mine and Mill Sites

2015 Five-Year Review
BUNKER HILL SUPERFUND SITE

oEPA

Path: X:\CdA\0442\07.01_2015 5 Five-Year Review\Projects\Figure_Ninemile Watershed Mine and Mill Sites.mxd

Print Date: 3/11/2015

-------
-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Interstate-Callahan Rock Dumps
Background and Description

The Interstate-Callahan Rock Dumps Site (Figure 5-15) is located in the upper reaches of the
EFNM Creek Watershed approximately 6 miles northeast of Wallace, Idaho. Prior to
implementation of the remedial action, the site consisted of two mine waste rock dumps, the
Interstate-Callahan Mine/Rock Dumps (BUR053) and the Interstate-Callahan Lower Rock
Dumps sites (BUR160), located within two steep unnamed tributaries to EFNM Creek.

The rock dumps impeded the flow of surface water and a significant portion of the tributaries
flow infiltrated through the waste piles, contacting contaminated materials and resulting in
transport of dissolved metals.

The remedial action for the Interstate-Callahan Rock Dumps site is described in detail in the
100 percent Basis of Design report (North Wind/Pioneer, 2014a). In general, the project includes
the following components:

• Excavation of approximately 220,000 cubic yards of waste rock and placement in the EFNM
WCA;

• Closure of up to three adits, if they are exposed during waste excavation;

• Placement of cover soil and revegetation of the excavated areas (approximately 17 acres);

• Reconstruction of approximately 1,700 linear feet of EFNM Creek and 1,320 linear feet of
tributary channels, utilizing a temporary stream diversion for the EFNM Creek;

• Reconstruction of support roads and related culvert installation to provide continued access
through the area once the waste rock is removed; and

• Construction of 5,050 linear feet of stormwater control channels and other erosion control
BMPs

O&M and Actions since the Last Five-Year Review

Predesign investigation activities were completed at the Interstate Callahan Rock Dumps in
2011 and 2012. Results of the investigation are summarized in the 2012 EFNM Creek Predesign
Investigation Results Report (MFA, 2012b).

The remedial action was initiated during 2014. Work completed included excavation of
approximately 159,000 cy of mine waste and installation of cover soils over the corresponding
excavation area. Excavated materials were placed in the EFNM WCA. In addition, the two
tributary stream channels were reconstructed. An interim construction report provides
additional details on the 2014 construction (Pioneer, 2015).

The remedial action will be completed in 2015. Additional anticipated work includes excavation
and disposal of an additional 60,000 cy of mine waste and reconstruction of 1,700 linear feet of
EFNM Creek.

Once the Interstate-Callahan Rock Dumps project is fully constructed in the fall of 2015, the
Coeur d'Alene Trust will assume O&M responsibilities for the remedy. An O&M plan has been
prepared to guide these activities (North Wind/Pioneer, 2014b). Inspections will occur at least
annually beginning in 2016, and will evaluate vegetation, noxious weeds, cover soil and
erosion, reconstructed stream and tributary channels, and stormwater controls.

5-71

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

In addition, the Coeur d'Alene Trust will implement remedial action effectiveness monitoring,
including surface water monitoring in EFNM Creek above and below the completed remedy.
The Coeur d'Alene Trust will work with USEPA to develop the monitoring plan for this work
prior to completion of the project.

Remedy Status

Implementation of the Interstate-Callahan Rock Dumps remedy is on-going and will not be
fully constructed until late summer or fall of 2015. It is anticipated that upon completion the
remedy will be protective and will function as intended in the decision documents, because all
mine waste is expected to be removed from the site.

Rex Mine and Mill Complex
Background and Description

The Rex Mine and Mill Complex (Figure 5-15) is located in the EFNM Creek Watershed
approximately 5 miles northeast of Wallace, Idaho. The complex includes the Rex
No. 2/Sixteen-to-One site (BUR054) and the Rex No. 1 site (BUR139), which is located
approximately 500 feet upslope to the north of BUR054. The Rex No. 1 site includes the Rex
No. 1 adit and a mine waste dump. The 2012 Upper Basin ROD Amendment (USEPA, 2012)
specifies additional remedial action at Rex No. 1 (excavation and consolidation of waste rock).

The Rex No. 2/Sixteen-to-One site includes the Rex No. 2 adit and a consolidated mine waste
pile covering approximately 4 acres. A remedial action was conducted at the Rex No. 2 site in
2007. Prior to the remedial action, the tailings completely filled the small drainage area with
which it is associated, thus impounding the small creek that previously occupied the drainage
area. The tailings dam at the downgradient end of the site was determined to be unstable
because of the height and slope of the dam and the nature of the tailings. The remedial action
components consisted of the following:

• Removal and offsite disposal of miscellaneous debris from the former mill building area;

• Excavation and consolidation of contaminated materials (mine tailings and waste rock) into
the waste rock pile and the two tailings impoundments;

• Modifications to surface water management including routing the combined Rex No. 2 Adit
discharge and the Rex Creek discharge through an unlined reconstructed channel to
minimize contact of water with the tailings pile;

• Completion of final grading, placement of an earthen cover, and hydroseeding;

• Stabilization of the tailings dam; and

• Installation of a bat gate at the adit opening.

Additional detail is provided in the 2010 Five-Year Review (USEPA, 2010c) and in the
Construction Completion Report (USACE, 2010).

O&M and Actions since the Last Five-Year Review

Remedial action effectiveness monitoring at the Rex Mine and Mill Site was initiated in fall 2007
and continued through 2012 at the following monitoring locations:

• One upgradient and one downgradient surface water monitoring location (REX-SWU and
Rex-SWD-FLUME, respectively);

5-72

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

• Rex Adit (NM-361); and

• Two groundwater monitoring wells (one upgradient [REX-02] and two downgradient
[REX-09 and REX-04]). Note that REX-04 was eliminated from the monitoring beginning in
fall 2010.

Water monitoring data interpretation and evaluation are presented in the draft Data Summary
Report (2007-2012) and Adaptive Management Recommendations for the Upper Coeur d'Alene Basin
Remedial Action Monitoring Program (CH2M HILL, 2012b). Significant surface water loads and
AWQC ratio differences were observed for arsenic and zinc between upgradient and
downgradient stations (CH2M HILL, 2012b). The report concluded that trends are not changing
because of the remedial actions completed in 2006 and 2007, further contaminant metal
reduction from the completed RAs is expected to be relatively low, and additional RAs are
needed to reduce the contaminant metal releases occurring from the residual tailings pile
significantly (CH2M HILL, 2012b). Because of these findings, further action was conducted in
2014 to address continued infiltration into the tailings impoundment from the unlined portion
of Rex Creek that crosses the site. Observational information during the spring indicates the Rex
Creek lining has been effective and most water is bypassing the tailings impoundment.
Additional monitoring will be conducted to evaluate the long-term effectiveness of this action
in reducing surface water impacts downstream of the impoundment.

The Coeur d'Alene Trust completed water monitoring at Rex No. 2 at the following locations:

• Rex Adit (NM-361) (2013, 2014)

• REX-SWU (upstream location, 2014)

• NM-SWD-FLUME (flume located at the base of the dam, 2013)

• EFNM-020 and EFNM-021 (seeps identified downgradient of the waste pile during peak
flow event in 2014)

• EFNM-015 (downstream location at base of Rex tributary, 2014)

Analytical results for dissolved surface water samples at the Rex Adit and REX-SWU locations
generally exceed AWQC for cadmium, lead, and zinc. Dissolved cadmium and zinc exceed the
AWQC at EFNM-015, located at the base of the Rex drainage (MFA, 2013; 2015e).

The Rex Mine and Mill remedial action has been periodically inspected by BLM and USEPA
since completion of the remedy. The earthen cover and vegetation are functioning as intended.
However, as discussed in the 2010 Five-Year Review (USEPA, 2010c), the Rex Creek and Rex
Adit flows had been observed to completely infiltrate into the waste pile and then re-emerge at
the toe of the waste pile. It was recommended that the infiltration be mitigated because the
infiltrating water could be contacting contaminated materials and transporting dissolved metals
into Rex Creek (USEPA, 2010c). Accordingly, the USEPA directed the Coeur d'Alene Trust to
implement improvements to the existing remedial action that involved lining the existing
surface water channels to reduce infiltration.

The Coeur d'Alene Trust reconstructed vegetated and riprap channels using a low-permeability
geosynthetic liner between September and November 2014. Weir stations will be constructed
above and below the tailings impoundment in 2015 to evaluate the effectiveness of the lined

5-73

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

channels. The weirs will allow accurate flow measurements at the creek inlet/ outlet; any
difference in flow may be indicative of leaks within the channel lining system and potential
stormwater infiltration into the consolidated mine waste. Additional details regarding the
improvements constructed in 2014 are provided in the Final Basis of Design Report (CDM Smith,
2015a).

Beginning in 2015, the Coeur d'Alene Trust will complete remedial action effectiveness
monitoring at the Rex No. 2 site, including flow measurement at the weirs.

The 2010 Five-Year Review recommended the following specifically to the Rex Site.

• Recommendation: Regarding Rex Site contaminant release, mitigate the infiltration of Rex
Creek and the Rex Adit flow upgradient form the remedial action.

Discussion: This recommendation is complete.

Remedy Status

The inspections at the Rex No. 2 site indicate that the 2007 remedial action has adequately
protected against direct contact with contaminated tailings. However, the remedy was not
functioning as intended with respect to maintaining separation between surface water and mine
waste material. It is anticipated that the additional 2014 action to line the surface water channels
will prevent surface water contact with the waste and that the remedy will function as intended
in the future.

Success Mine and Mill Site
Background and Description

The Success Mine and Mill Site Complex (Figure 5-15) is located in the EFNM Creek Watershed
approximately 4 miles northeast of Wallace, Idaho, directly adjacent to EFNM Creek. The
Success Complex includes the following four sites that have been selected for remediation in the
Upper Basin ROD Amendment (USEPA, 2012a): Success Mine Rock Dump (OSB044), the
Success No. 3 adit (OSB089), the American Mine (OSB048), and the Alameda Mine adit
(OSB088). Success No. 3 and the Alameda Mine adits are located east and upgradient of the
Success Mine Rock Dump. A former mill was located within the Success Mine Rock Dump and
a steep, unnamed tributary (informally referred to as the Alameda Tributary) flows into the
rock dump.

The American Mine site is located across EFNM Creek from the Success Mine Rock Dump, but
is included as part of the Success Complex remedial action due to its proximity.

Although the intent of the previous removal actions completed by USEPA and the Silver Valley
Natural Resource Trustees at the Success Complex was to reduce metals loading in the SFCDR,
the Success Complex continues to be a significant contributor of metals loading into the SFCDR
from the Ninemile Creek Watershed (MFA, 2015g). Cleanup of the Success Complex is
scheduled to begin in 2016.

O&M and Actions since the Last Five-Year Review

Monitoring was completed between 2007 and 2012, as part of the Remedial Action Monitoring
Program, to assess the status and trends of mining-related contamination in surface water and
shallow groundwater and to evaluate the effectiveness of interim remedial actions with respect
to ecological conditions (CH2M HILL, 2012).

5-74

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

The Success Complex has been prioritized because it is a large source of metals to Ninemile
Creek and the SFCDR. Predesign investigation activities were completed at the Success
Complex in 2011, 2012, and 2014. Results of the investigation are summarized in the Success
Complex Remedial Design Investigation Report (MFA, 2015f). Remedial action design was initiated
by the Coeur d'Alene Trust in 2014. The design will be completed in 2015 and construction is
scheduled to begin in 2016.

The remedial action will include excavation of mine waste materials in the Success Mine Rock
Dump such that the remaining concentrations in the native soils are less than or equal to
530 mg/kg for lead. Based on the current understanding of site conditions, some excavation of
saturated waste materials below the groundwater table is expected and dewatering efforts will
be necessary. Native soils with elevated zinc concentrations within the floodplain that are
hydraulically connected to groundwater will be excavated to the extent feasible.

The American Mine remediation will include excavation of mine waste to a slope of 2 horizontal
to 1 vertical (2H:1V). There is a potential to expose four adits during the excavation of waste
materials, in which case the adits will be closed using a bat-friendly closure structure that will
restrict public access. Slopes that are 2.5H:1V or flatter following excavation will be covered
using 12 inches of amended soil generated from the EFNM WCA. Slopes steeper than 2.5H:1V
will be covered using 12 inches of a combination of amended cover soil and 12-inch minus
riprap, to protect the slope from erosion and to ensure long-term stability. The reclaimed slopes
will be re vegetated using an upland seed mix and the steep slopes will be planted with conifer
tubelings.

Excavated materials will be placed in the EFNM WCA. Haul roads will be developed to
accommodate transfer of the waste to the EFNM WCA. As the waste materials are excavated,
the existing Alameda Tributary, Success No. 3 adit discharge, Alameda adit discharge, and a
section of the EFNM Creek adjacent to the Success Complex will be realigned and
reconstructed. The access road that parallels the EFNM Creek will also be excavated and
realigned as part of the reconstruction.

Remedy Status

The additional remedial actions selected in the 2012 ROD Amendment (USEPA, 2012a) are
expected to significantly reduce future contaminant metal releases from the Success Complex,
which will significantly reduce the metals load from the Ninemile Basin into the SFCDR.

5.2.2.6 Pine Creek Watershed - Constitution Mine and Mill Site
Background and Description

The Constitution Mine and Mill Site is on the East Fork of Pine Creek approximately 8 miles
south of Pinehurst (Figure 5-1). The site is an abandoned lead, silver, and zinc mine and mill site
with two large fine-grain tailings piles totaling approximately 36,000 cy. The tailings piles were
uncontained and subject to extensive sediment loading into the East Fork of Pine Creek via
direct stream channel erosion of the toe of the tailings piles, as well as overland runoff of
sediment from the top of the piles into the stream.

5-75

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Remedial actions were designed to prevent direct human contact with metals from recreational
exposure and to prevent further erosion into Pine Creek. The remedial action was implemented
in 2006 and consisted of the following:

• Excavation and consolidation of mine wastes to the Upper Constitution site;

• Completion of final grading, construction of surface water control features, placement of a
soil/rock cap, and revegetation; and

• Conveying nearby adit flow into a pilot bioreactor project for treatment prior to discharging
into the East Fork of Pine Creek.

Additional technical and background information for the Constitution Mine and Mill Site is
provided in the 2010 Five-Year Review Report (USEPA, 2010c).

O&M and Actions since the Last Five-Year Review

The site has been inspected and the BLM performed O&M of the pilot bioreactor. Remedial
action effectiveness monitoring at the Constitution Mine and Mill Site has been ongoing since
the remedy was completed.

In 2013, the BLM decommissioned the pilot bioreactor. This involved removal of physical
hazards, fencing and concrete, as well as site reclamation including grading and application of
topsoil.

The 2010 Five-Year Review included the following recommendation for the Constitution Mine
and Mill Site.

• Recommendation: Post-remedial action monitoring required as follow-up. Continue to
monitor and operate the pilot water treatment unit (an on-going 2005 Five-Year Review
rec ommendation).

Discussion: With the decommissioning of the pilot reactor, no further monitoring is being
conducted and this recommendation is complete.

Remedy Status

The integrity of the cap has been maintained and the repository is performing well. There are no
signs of vandalism, surface erosion, or stream scour. Monitoring wells are intact. Weeds have
been an issue and will continue to be treated and monitored by BLM.

5.2.3 Washington Recreation Areas along the Spokane River
5.2.3.1 Background and Description

In 1998,1999, and 2000, Spokane River sediments were sampled to evaluate metals
concentrations in the Spokane River recreational areas. Lead concentrations at these recreational
areas exceeded the human health action level of 700 mg/kg. Arsenic, cadmium, and zinc were
also detected.

The Selected Remedy for the Washington recreation areas along the Spokane River identified in
the 2002 OU 3 ROD includes access controls, capping, and removal of metals-contaminated soil
and sediment. The remedy monitors water quality, aquatic life, and sediments and includes
contingencies for additional or follow-up cleanups for the recreational areas.

5-76

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Ten shoreline recreation areas and one subaqueous area have been identified for investigation
and remedial action. USEPA established a sediment lead cleanup level for the Washington
recreation areas along the Spokane River as 700 mg/kg for recreational use (USEPA, 2002a). The
20 mg/kg arsenic cleanup level used by USEPA is based on Model Toxics Control Act method
A. Implementation of the remedy, as defined by the 2002 OU 3 ROD, will reduce the potential
for exposure to metals at the beaches and shoreline recreational areas and will enhance human
uses of ecological resources.

The 2002 OU 3 ROD also states that additional cleanup of critical habitat areas identified by the
Washington State Department of Ecology (Ecology) will reduce risks to waterfowl and other
ecological receptors to generally safe levels. The critical habitat areas along the Spokane River in
Washington have been identified by Ecology to include Starr Road, Island Complex, Murray
Road, and Harvard Road.

A health advisory currently exists for ingestion of beach and shoreline sediment, and a fish
consumption health advisory currently exists for the Spokane River from the state line to
Ninemile Dam. These advisories include signs that have been posted along this portion of the
river to alert the public to elevated levels of lead in the beach soils and describe ways the public
can minimize the risk of lead exposure.

5.2.3.2 Description of Remedial Actions

Remedial actions have been implemented at eight of the ten Spokane River shoreline
recreational areas. The following provides a brief summary of these actions.

Starr Road

Removal and replacement of impacted shoreline soils was completed in 2006. A cap was placed
over upland areas. A pull-out parking area and footpath to the cleaned shoreline area was also
created. In the summer of 2007, Ecology added additional materials to the cap to enhance
identified trout spawning areas.

Island Complex

In 2007, a multi-layered soil cap was placed over contaminated sediments at the Island Complex
area, and native trees and shrubs were planted to stabilize the eroding bank in the backwater
area. River gravels were placed below the ordinary high water mark to enhance trout habitat
and limit erosion. Irrigation lines were installed and operated for two seasons to help establish
the plantings.

Murray Road

In 2007, an extensive sand and gravel cap was placed over impacted sediments at the Murray
Road area. Public access trail improvements and signage were built at both locations to assist
with foot traffic management and cap protection.

Harvard Road

In 2008, contaminated sediments along the upper portion of the riverbank were removed and
sent to an appropriate landfill. The area was backfilled with clean sand and gravel. A protective
cap of clean sand and gravel trout spawning mix was placed over the lower portion of the
riverbank to enhance existing habitat. An adjacent graveled boat launch was also installed, in
conjunction with fencing and boulder placement, to facilitate recreational river access while
prohibiting vehicle access to the cap.

5-77

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Flora Road

In 2012, contaminated sediments along the riverbank were removed and sent to an appropriate
landfill. Filter rock and capping rock were placed over the excavated area.

Barker Road North Shore

In 2012, contaminated sediments along the riverbank were removed and sent to an appropriate
landfill. Filter rock and capping rock were placed over the excavated area and native riparian
vegetation was planted.

Barker Road South Shore

Remedial actions were not conducted at the Barker Road south shore area because metal
concentrations were below cleanup levels, although signage was installed to limit recreational
human exposure to sediments.

Myrtle Point

In 2012, contaminated sediments along the riverbank were removed and hauled to a landfill.
Filter rock and capping rock were placed over the excavated area and native riparian vegetation
was planted.

Islands Lagoon

In 2012, filter rock and capping rock were installed
Donkey Island

Remedial actions were not conducted at the Donkey Island area because metal concentrations
are below cleanup levels.

Upriver Dam

Remedial actions to address metals contamination related to the Bunker Hill Superfund Site
have not yet been conducted. However, Ecology implemented remedial actions to address
polychlorinated biphenyls (PCBs). Co-located metal-contaminated sediments, related to Bunker
Hill were likely also addressed. USEPA will investigate the remaining contamination at the
Upriver Dam and determine whether further remedial action is warranted.

5.2.3.3 Remedy Status

Ecology monitors the Spokane River recreational areas to evaluate remedy performance and
detect potential recontamination. Depositional sediment samples were collected in 2013 at Starr
Road, Island Complex, Murray Road, and Harvard Road beach sites. Remedy inspections were
conducted in 2014 at Flora Road, Barker Road North, Myrtle Point, and Islands Lagoon beach
sites.

The results are provided in the Spokane River Shoreline Sediment Sites Monitoring, Sampling and
Analysis Report (Ecology, 2015). Lead concentrations were below the 700 mg/kg cleanup level
except for two samples collected at the Island Complex. These data suggest that
recontamination may be occurring at the site.

The locations not sampled as a part of the 2013 sampling event (Barker Road North, Flora Road,
Myrtle Point, and Islands Lagoon) were inspected for sediment accumulation and remedy
performance. It was generally observed that, at each of the locations, the remedy was intact and
little to no additional sediment accumulation had occurred (Ecology, 2015).

5-78

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

The remedies implemented at the Spokane River recreational areas are functioning as intended
by the OU 3 ROD (USEPA, 2002a), based on follow-up inspections and sampling. Two
exceedances above cleanup action levels (for lead) were found at Island Complex in 2013.
Additional monitoring will be needed to measure accurately the impacts of the remedial actions
with respect to sediment quality.

5.2.4 Lower Coeur d'Alene River Basin Recreation Sites (including Black Rock,

Thompson, Anderson, Rose Lake, Medimont, and Rainy Hill)

Background and Description

The Selected Remedy in the OU 3 ROD includes remediation of recreational areas to reduce
human exposure to lead and other metals. The ROD identified 31 recreational areas and
recognized that other recreational sites may be evaluated for cleanup (USEPA, 2002a). Beaches
along the Coeur d'Alene River pose special challenges for active remediation because of high
recontamination potential due to flooding, private ownership, and access issues (USEPA, 2005).
For these beach areas, an "information and education" program was implemented to inform
recreational users of area risks and safe-use practices. In addition to remediation, information,
and education, the Lower Basin Project Focus Team recommended the development of a Lower
Basin recreational management plan/policy. This policy would be to establish a coordinated
effort among the numerous agencies (i.e., BLM, IDFG, Coeur d'Alene Tribe, IDPR, USFS, and
PHD) that own and/or manage recreational sites (BEIPC, 2003). This has not occurred to date.

Remedial actions occurred at six recreational areas, and health warning signs were installed at
nine other locations. Detailed descriptions of the response actions accomplished through 2009
are provided in the 2005 and 2010 Five-Year Review Reports (USEPA, 2005 and 2010c).

Because of contaminated sediment deposition observed by PHD almost annually at public
recreation sites along the Coeur d'Alene River, guidelines to address sediment deposition from
high-water events were developed in 2008 by IDFG, IDPR, IDEQ, USEPA, Kootenai County,
USFS, BLM, Coeur d'Alene Tribe, Spokane Tribe, and PHD. The guidelines address:

• When a recreation site should be closed due to sediment deposition;

• What sites/ areas are to be cleaned or remediated;

• How sites are to be cleaned or remediated; and

• Coordination and communication among participating agencies.

Agencies that own and/or manage recreation sites are responsible to implement the guidelines.
O&M and Actions since the Last Five-Year Review

PHD inspects eight sites annually or after significant flood events, and makes recommendations
to the responsible entities regarding cleanup or closure. The agencies usually respond to PHD's
recommendations, and annual cleanup of recreational sites has occurred when necessary. The
eight sites include the six previously remediated areas plus a few others more commonly
accessed by the public: Medimont Boat Launch, Rainy Hill Boat Launch, Thompson Lake Boat
Ramp, Anderson Lake Boat Ramp, Bull Run Boat Launch, Killarney Lake Boat Launch, Black
Rock Slough Trailhead/ Highway 3 Crossing, and the Cataldo Mission and Boat Ramp
(monitored as one site).

5-79

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Active remediation at Lower Basin recreation sites has been limited because of high potential
for flooding and recontamination. Three main actions have occurred since the last Five-Year
Review:

• In 2013, USFS made improvements (USFS, 2015) to the Medimont Boat Launch to enhance
site access, stabilize ri verbanks, and mitigate health concerns associated with contaminants
(see Table 5-15).

• In 2013, USEPA selected a river bank/ recreation remediation pilot project based on
community input provided at Pilot Project Idea Forums, with the objective to reduce human
exposure to lead and other contaminated materials in banks and beaches where recreational
use is common. The project at Kahnderosa Campground was completed in December 2014
in a manner that is intended to support recreational use and ecological habitat (MFA, 2014g)
(see Table 5-15).

• IDEQ and PHD increased public outreach and education beginning in 2013 with two public
service announcements that provide health tips to recreationists. These were aired on the
radio during the summer months in 2013 and 2014 (BEIPC, 2014 and 2015). Additionally, in
2014, PHD and IDEQ inventoried many of the human health signs at recreation sites and
made necessary improvements and repairs to the existing signs.

TABLE 5-15

Summary of Actions Completed Since the Last Five-Year Review at Identified Recreational Sites, 2010-2014
2015 Five-Year Review, Bunker Hill Superfund Site

Recreation Site (CUA
No. when applicable)

Year(s)
Remedial
Actions
Completed

Management
Agency or
Owner

Actions Since the 2010 Five-Year Review

Black Rock Slough
Trailhead/Highway 3
Crossing

2001-2002,
2004, and
2005

IDPR

Routine monitoring and maintenance.

Medimont Boat Launch
(CUA045)

1999 and
2013

USFS

In 2013, USFS reconstructed and paved the access
road and parking area, reconstructed the existing ramp,
installed a concrete vault toilet, placed boulders to
control motorized vehicle use, and decommissioned
unauthorized access routes. In January 2013,
approximately 450 feet of riverbank was stabilized
utilizing encapsulated soil lifts with coir fabric; no hard
rock riprap was used. In February 2013, USFS staff
along with other stakeholders installed vegetative
plantings along the riverbank.

Rainy Hill Boat Launch
(CUA046&47)

1999 and
2006

USFS

Routine monitoring and maintenance.

Thompson Lake Boat
Ramp (CUA038)

1999-2000

IDFG

Routine monitoring and maintenance.

Anderson Lake Boat
Ramp (CUA033)

1999 and
2008

IDFG

Routine monitoring and maintenance.

Bull Run Boat Launch
(CUA059&60)

2004

USFS/IDPR

Routine monitoring and maintenance.

5-80

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TABLE 5-15

Summary of Actions Completed Since the Last Five-Year Review at Identified Recreational Sites, 2010-2014
2015 Five-Year Review, Bunker Hill Superfund Site

Recreation Site (CUA
No. when applicable)

Year(s)
Remedial
Actions
Completed

Management
Agency or
Owner

Actions Since the 2010 Five-Year Review

Kahnderosa
Campground Pilot
Project

2014

Private

USEPA remediated/restored a 300-foot section of
riverbank used as a beach. Work included the
construction of fiber-encapsulated soil lifts laid on
willow mattresses and affixed to the water's edge to
help stabilize the bank. The work was coordinated with
the BPRP that had selected this property to include
hardening the camping pads and roads at this site so
that they can be easily cleaned of sediments. The latter
was conducted under the oversight of IDEQ and is
scheduled to be completed in 2015.

CUA = common use area

The 2010 Five-Year Review included the following recommendations that were ongoing from
the 2005 Five-Year Review. Discussions and any actions taken since 2010 follow each
recommendation.

• Recommendation: Conduct post-flood monitoring at the Cataldo Mission.

Discussion: PHD routinely inspects the Cataldo Mission recreational area after flood events.
This recommendation is complete.

• Recommendation: Incorporate the Cataldo Boat Ramp into the remedial action program
and ongoing monitoring.

Discussion: PHD inspects the Cataldo Boat Ramp area, which consists of a hardened boat
launch and parking lot, after flood events. In addition, a new human health sign was placed
at this site in the fall of 2014. This recommendation is complete.

• Recommendation: Continue to monitor the stream bank at the Black Rock Slough
Trailhead/Highway 3 Crossing.

Discussion: PHD monitors this site periodically and after any substantial flooding. In spring
2015, PHD noted that the site was intact and clean. This recommendation will not be
retained in the table of issues and recommendations, because it is an ongoing element of
O&M. This recommendation is complete.

• Recommendation: Evaluate removal action in context of the 2002 OU 3 ROD and, if
warranted, incorporate Dudley Bank Stabilization into the remedial action program.

Discussion: In July 2015, IDEQ inspected the 1999 pilot bank stabilization work conducted
by Silver Valley Natural Resource Trustees and determined it remains in good condition.
No further action is necessary. This recommendation is complete.

5-81

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

• Recommendation: Evaluate removal action in context of the 2002 OU 3 ROD, and if
warranted, incorporate Medimont Bank Stabilization into the remedial action program.

Discussion: The banks at the boat launch were stabilized in 2014 by USFS. PHD monitors
this site annually and has noted that the vegetation is growing well and the remedy is intact.
This recommendation is complete.

• Recommendation: Recommend that USFS consider paving existing boat launch area at
Medimont Boat Launch and establish a paved picnic site near the restrooms on the north
side of the site. Continue day-use-only limitation. Address bank stabilization issues.
Consider establishment of overnight recreational vehicle parking area.

Discussion: USFS completed remediation and rehabilitation in 2013 (see Table 5-15). This
recommendation is complete.

• Recommendation: Pending completion of designs for the Highway 97 bridge replacement,
USEPA, IDFC, and the Recreational Area Project Focus Team will evaluate the potential
need for additional cleanup work at the Anderson Lake Boat Launch.

Discussion: The Highway 97 bridge replacement was completed by Idaho Transportation
Department and the remedy at the boat launch was not compromised by the construction
activities. PHD continues to monitor this site annually and after flooding events. This
recommendation is complete.

• Recommendation: Informational Signage: Replace damaged as needed.

Discussion: In 2014, IDEQ and PHD inventoried signage along the river between Bull Run
and Cave Lake. Two signs were removed because they were on private land and were
obstructed from view. One of the signs was installed at the Cataldo Boat Ramp in fall 2014.
PHD is holding the other sign to place at another more visible location in 2015. This
recommendation is complete.

• Recommendation: Additional Areas: Identify and evaluate additional Lower Basin
recreational areas that may require cleanup.

Discussion: During the past 5 years, a number of private or informal recreational sites have
been identified that may present a heavy metal exposure risk to recreationalists. Although a
comprehensive survey was not completed, PHD identified a number of privately owned
recreational sites and informal, undeveloped sites in 2013 that may pose a risk to
recreationalists (PHD, 2013b). Additional privately owned recreational sites along the
floodplain and the banks of the Coeur d'Alene River have been identified through the Basin
Property Sampling and Remediation Program in the last 5 years. Many of these sites are in
the floodplain or adjacent to the riverbank. Many sites are contaminated with lead and other
metals, and flood events likely deposit additional contaminated sediment.

In 2015, IDEQ, PHD, and USEPA evaluated options for reducing exposure to lead and other
heavy metals at a range of recreation sites in Upper and Lower Basin areas. This
recommendation will be retained in the table of issues and recommendations (see
Table 5-16) and expanded to include Upper Basin recreation sites and efforts to reduce
exposure to lead and other heavy metals at those sites. Much of the work needed to

5-82

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

complete the original recommendation has been performed and creating a new, broader
action item is a more proactive way to address sites throughout the Basin.

Remedy Status

Sediment with lead concentrations ranging from approximately 1,000 to 5,000 mg/kg and
arsenic concentrations ranging from 40 to 130 mg/kg is commonly observed at recreational sites
along the lower Coeur d'Alene River after high-water events (personal communication, PHD to
IDFG, July 16, 2008). From 2010 through 2014, PHD's annual monitoring and inspections of the
eight recreation sites indicate that, in general, removal of contaminated sediment at the public
recreation areas continues to help reduce the public's exposure to contaminated sediment.
However, PHD has documented on multiple occasions that contaminants are often left at the
eight monitored sites for prolonged periods throughout the spring before being cleaned up. The
agencies that own and/ or manage these sites state this is because of the risk of additional high-
water events and lack of funding. Formal adoption of the guidelines developed in 2008 and
additional criteria addressing barrier restoration after floods and other damage are necessary to
ensure these sites remain protective of public health. Timely O&M (e.g., washing off
contaminated sediment after flooding) carried out by the various agencies at these sites is
important from a human health exposure and risk reduction standpoint.

Remedial actions at the Kahnderosa Campground were completed in fall 2014 (MFA, 2014g).
No subsequent monitoring data are available, but USEPA plans to monitor the stability of the
riverbank and metals concentrations on the beach at this site because of the potential for erosion
or deposition from flooding.

Families recreate along the Coeur d'Alene River and are exposed to contaminated sediment
(PHD, 2013b). A number of impromptu sites where children swim and play along the banks of
the river were observed in 2013 (PHD, 2013b). Additionally, private property owners are
establishing private campgrounds or other frequently used recreational areas, many of which
are in the Coeur d'Alene River floodplain, are currently contaminated, and would become
recontaminated with lead and other heavy metals during flood events. To better understand
sediment transport and recontamination, USEPA has continued to develop a MIKE 21C (DHI)
sediment transport model (CH2M HILL, 2010) to evaluate contaminated sediment transport
and deposition in the river channel and across wetlands and floodplains. The model will assist
with prioritizing and evaluating remedial options.

Although active remediation of the 31 recreational sites identified in the ROD and other private
or impromptu sites is not complete or may not occur, signage, education, and outreach continue
to inform river users about recreational risks and safer-use practices. Signage condition and
visibility is being monitored, and the LHIP now offers free blood lead screening to recreational
users (see Section 5.2.1.4). Some of the recreational sites identified in the 2002 ROD now have
limited use or access and are lower priority for remediation. Meanwhile, use on other sites that
have not been previously identified has evolved over time and are now being used more
frequently. Those sites that fall into the latter may warrant further monitoring and evaluation.

In 2015, a recreation sites working group was established consisting of IDEQ, PHD, and USEPA
staff to evaluate options for reducing exposure to lead and other heavy metals at a range of
recreation sites in Upper and Lower Basin areas.

5-83

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

5.2.5 Trail of the Coeur d'Alenes Removal Action
Background and Description

UPRR performed the CERCLA removal action for its Wallace-Mullan Branch ROW located in
OU 3 beginning in 2000 and ending in 2004. Similar work took place in OU 2 (see
Section 4.2.10), but only the action conducted in OU 3 is presented in this section. The goal of
the UPRR removal action was to contain mine-waste-related contamination within the ROW in
a manner that was protective of human health and the environment (USEPA, 1999). The
removal action addressed the main line and related sidings of the Wallace-Mullan Branch ROW.

A brief description of the work elements follows:

• Removal, decontamination, and salvage of useable railroad ties and rail. Non-salvageable
material was decontaminated and disposed of at properly permitted offsite facilities.

• Repair of flood and scour damaged rail bed embankment, and removal of flood debris
impinging on bridge structures. This work was completed to maintain the integrity of the
railroad grade for use as a recreational trail and to mitigate the future migration of
contaminants from the ROW.

• Removal and disposal of mine waste materials and placement of protective barriers.

• Conversion of the ROW to a recreational trail.

• Removal of and/ or barrier installation over mine waste found within those ROW portions
that were associated with a residential type of use.

• Installation of access controls to protect barriers and prevent access to areas of
contamination such as tailings impoundments directly adjacent to the trail.

The remedial action was certified complete in 2005. UPRR retains responsibility for M&R of
protective barriers (including the asphalt barrier and trail within the Coeur d'Alene
Reservation), rail bed embankments that provide a foundation for the trail portion of the ROW,
and certain aspects of the Chatcolet Bridge. The State of Idaho is the owner and primary
manager of the Mullan through Harrison section of the ROW, which encompasses about
57.1 miles of asphalt trail. For this portion of the ROW, IDEQ is responsible for protecting
human health and the environment, and IDPR is responsible for general management and
operation. The Coeur d'Alene Tribe owns and is the primary manager of the Harrison through
Plummer section of the ROW, which entails about 14.4 miles of asphalt trail. For this portion of
the ROW, the Tribe Hazardous Waste Management Program is responsible for protecting
human health and the environment, and the Tribe Recreation Management Program is
responsible for general management and operation. The approximately 3-mile portion of ROW
passing through Heyburn State Park is jointly owned and managed by the Tribe and the State.

As part of its obligations under the Consent Decree, UPRR has provided a lump-sum cash
payment to support the trail maintenance activities conducted by the State and the Coeur
d'Alene Tribe. ICs implemented include the installation and management of signage and the
use of access controls as part of the removal action construction, as well as education and
awareness for residents of both incorporated and unincorporated communities along the ROW
and visitors to the area. UPRR is responsible for monitoring and repair of the barriers, including
the trail surface, in accordance with the Response Action Maintenance Plan (Coeur d'Alene Tribe
and State of Idaho, 2010; Coeur d'Alene Tribe et al., 2008) and Section VII of the Consent Decree

5-84

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

(U.S. District Court for the District of Idaho, 2000) Additional detail, including historical and
removal action context, is provided in the 2010 Five-Year Review Report and the Response Action
Maintenance Plan.

O&M and Actions since the Last Five-Year Review

Since the 2010 Five-Year Review, UPRR and IDPR conducted routine maintenance and repair
activities, with oversight by IDEQ, IDPR, and the Coeur d'Alene Tribe as described by the
Response Action Maintenance Plan (Coeur d'Alene Tribe et al., 2008). UPRR completed monthly
trail inspections, and IDPR and Coeur d'Alene Tribe staff regularly patrolled the trail. Routine
monitoring and maintenance of the trail is documented in detail in annual reports (ARCADIS,
2010, 201Id, 2012d, 2013i, and 2014e; Coeur d'Alene Tribe and State of Idaho, 2010, 2011, 2012,
2013, and 2014). The following summarizes the barrier and access maintenance actions
undertaken in the last 5 years.

• Bollards at Springston Trailhead, Pine Creek Trailhead, Cataldo (near Kahnderosa), Big
Creek near Shoshone Golf Course Road, Osburn, Enaville, and Wallace were replaced after
being vandalized or damaged during separate incidents.

• The post and chains were replaced along the trail at CCC Road in Cataldo, K Street in
Smelterville, and the Wallace Trailhead and repaired at Johnson Street in Osburn because of
damage by motorists, snow removal equipment, and vandalism.

• A rock barrier between the grassy area and county road was extended near Leisure Acres,
Osburn to stop unauthorized motorized vehicle access and preserve the protective barrier.

• Regular asphalt concrete pavement monitoring tests and assessments were conducted to
determine the integrity of the asphalt.

• Fog Coat® was applied on the segment from Plummer to Harrison.

• IDPR and the Coeur d'Alene Tribe regularly conduct noxious weed control along the entire
trail.

• Cracks, potholes, sinkholes, rills, and depressions were repaired to address roots, settling,
and flooding damage. In some locations, tree roots were cut at the edge of asphalt and
barricaded using steel flashing, after the application of herbicide.

• Damaged, disturbed, or eroded shoulder gravel was repaired along the length of the trail.

• Culverts and their grates were cleared to remove vegetation, rocks, and other debris.

• Eroded gravel barrier/rock armoring at the culvert at STA 50+00 was repaired.

• Damaged, stolen, or faded signs were replaced.

• PHD and IDEQ have increased their public outreach and education efforts (Section 5.2.4).

• Issuances of authorization to parties that intend to breach or cross the barriers and
follow-up with parties that failed to obtain authorization.

• Annual sampling of sand at Harrison beach was below 100 mg/kg lead in all samples.
The 2010 Five-Year Review included the following recommendation.

• Recommendation: Continue monitoring the UPRR barrier protectiveness and conduct
maintenance as needed.

5-85

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Discussion: UPRR, I DPR, IDEQ, and Coeur d'Alene Tribe have been implementing the
Response Action Maintenance Plan since 2008 and will continue to do so. This
recommendation will not be retained in the table of issues and recommendations, because it
is an ongoing element of the O&M program required by the Consent Decree. This
recommendation is complete.

• Recommendation: Continue to monitor performance of Harrison Beach sand (an ongoing
2005 Five-Year Review recommendation).

Discussion: Monitoring of the lead concentrations in the Harrison Beach Sand are part of
the ongoing M&R obligations that UPRR conducts. This recommendation is complete.

• Recommendation: Continue monitoring Trail of the Coeur d'Alenes unauthorized use
patterns (an ongoing 2005 Five-Year Review recommendation).

Discussion: Monitoring of unauthorized access along the Trail of the Coeur d'Alenes
corridor is part of the ongoing M&R obligations that UPRR conducts. This recommendation
is complete.

Remedy Status

Monitoring, maintenance, and repair is essential to the long-term protectiveness of the remedy
and is being conducted by the USEPA, State of Idaho, Coeur d'Alene Tribe, and UPRR, also
discussed in Section 4.2.10. Regularly scheduled M&R activities conducted by UPRR address
ongoing issues and those identified as a result of inspection activities conducted by IDEQ,

IDPR, PHD, and the Coeur d'Alene Tribe along with the UPRR's contractor. The integrity of the
asphalt and gravel barriers is maintained by M&R activities conducted by UPRR to repair
damage to the barriers caused by flooding, tree roots intrusion, and unauthorized use by motor
vehicles, snowmobiles, and all-terrain vehicles. Responsibility for control of unauthorized use
and access of the trail system rests with the trail management entities.

Overall, the protective barriers and access controls are maintained and remain protective.

5.2.6 Repositories

Cleanup in the Basin will require construction of repositories for disposal of metals-
contaminated soils, sediments, source materials, treatment residuals, and contaminated soils
moved by residents or their contractors. The number and size of repositories to accommodate
the estimated volumes will be determined as remedial actions proceed in OU 3.

Potential repository locations have been and will continue to be evaluated using criteria
provided in the 2002 OU 3 ROD, which include proximity to cleanup areas, background
environmental conditions, site conditions, impacts on groundwater, and other considerations.
Repositories will require long-term ICs and monitoring. Public involvement processes are one
of the primary components for the siting and design of all repositories.

Current and long-term disposal needs were estimated in the Repository Waste Management and
Planning Strategy 2014 Update (TerraGraphics, 2014a). The OU 3 repositories currently operating
or that are currently being constructed are discussed in the following subsections. Although the
Osburn Tailings Impoundment Repository located east of Osburn is currently designed to
30 percent, additional work will be held until additional repository capacity is needed. The
agencies continue to find additional or optimal repository capacity by waste segregation and

5-86

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

re-use, identification and development of Limited Use Repositories, and minimizing ICP
disposal at Repositories by promoting the use of Community Fill Projects. Appropriate disposal
of remedial action wastes is an important factor in remedial action implementation.

The Paved Road program implemented in the Basin began generating significant waste
volumes in 2014. The waste from this program is in the form of inert asphaltic concrete and
generally low-level contaminant-containing base materials excavated with the asphalt. To
prioritize repository space for more contaminated ICP and remedial action wastes, a Limited
Use Repository (LUR) was sited and developed in Osburn in accordance with LUR policy
memo, (IDEQ and USEPA, 2015). The East Osburn LUR will operate for 1 to 2 years to receive
Basin road waste and then be completed following the ICP capping requirements into an area
ready for redevelopment. It has a design capacity of approximately 32,000 cy.

The 2010 Five-Year Review recommended the following specific to OU 3 repositories.

• Recommendation: Regarding long-term disposal need from remedial actions, establish
process with remedial design teams and long-term planners to identify waste quantities and
timing associate with remedial actions.

Discussion: This activity is a planning function that is ongoing but will be tracked as an
action item because of the need to plan far enough in advance for waste streams and
quantities. This recommendation will not be retained on the table of issues and
recommendations, because it does not affect protectiveness. It will instead be included in the
table of planned action items (Table 5-17).

• Recommendation: Continue search and evaluation of potential new repository sites (an
ongoing 2005 Five-Year Review recommendation).

5.2.6.1 Lower Burke Canyon Repository
Background and Description

The Lower Burke Canyon Repository (LBCR) site is located approximately 2.25 miles northeast
of Wallace and immediately to the northeast of the community of Woodland Park (Figure 5-1).
The 40-acre LBCR site was formerly used for the impoundment of tailings, as part of the Star
Tailings Impoundment (STI). A summary of the public involvement process for siting of the
repository at the STI is provided in a response to comments document (BEIPC, 2010). The Coeur
d'Alene Trust began design of the LBCR in 2012. Initial construction work at the repository,
including necessary infrastructure and facilities, was initiated in 2014. The work will be
completed in 2015. Additional information on the initial design of the repository is provided in
the basis of design report (CDM Smith, 2014b).

The LBCR will provide a location for consolidating mine waste materials, including mine waste
rock and tailings that are located at sites throughout the Canyon Creek Watershed and waste
from Bunker Hill Superfund Site programs such as the BPRP and the ICP. These wastes will be
consolidated in the LBCR to reduce metals loading into the watershed. Current design

5-87

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

calculations indicate the LBCR will be capable of containing up to 1,150,000 cy of waste (CDM
Smith, 2014b). Wastes could be placed in the LBCR as early as 2015 if necessary, based on the
amount and location of wastes generated in the Upper Basin.

O&M and Actions since the Last Five-Year Review

No waste was placed at the LBCR through the end of 2014. As discussed above, waste could be
accepted as soon as 2015. O&M will be completed by the Coeur d'Alene Trust's repository
operations contractor for the LBCR. Prior to the placement of waste, the contractor will prepare
an operations plan that will guide O&M activities throughout waste placement.

The Coeur d'Alene Trust completed water monitoring at the LBCR from 2012 through 2014 to
support the repository design, to understand the hydrology of the area better, and to establish
baseline conditions prior to waste placement. The monitoring included 21 locations, including
20 monitoring wells and one stilling well adjacent to Canyon Creek. Twelve of the monitoring
wells were installed in 2012 by the Coeur d'Alene Trust. Additional information on the
monitoring points is summarized in the Coeur d'Alene Trust annual water monitoring reports
(MFA, 2014f and 2015e). Results indicate that a portion of the tailings in the northern STI ponds
3 and 4 are in contact with groundwater and that concentrations of metals are greatest
upgradient (north) and crossgradient (east) of the ponds (MFA, 2015e). The design concluded
that no additional groundwater monitoring is necessary for the LBCR (CDM Smith, 2014b).

Remedy Status

As of June 2015, the LBCR is now available to receive waste. Construction of the LBCR on top of
the STI and ultimate capping will reduce infiltration.

5.2.6.2 Big Creek Repository
Background and Description

The Big Creek Repository (BCR) is located approximately 4 miles east of Kellogg adjacent to the
Trail of the Coeur d'Alenes, near the confluence of Big Creek and the SFCDR (Figure 5-1). The
repository was constructed on a former 22 acre tailings impoundment that was used from 1968
to 1979. It is rectangular in shape approximately 100 feet above the valley floor (North Wind
Construction, 2015b). IDEQ has owned the BCR parcel since July 2003. Previous assessments of
the site indicate that the historical tailings are likely in contact with groundwater during part or
all of the year (TerraGraphics, 2015f). Additional information on the BCR site setting and
history are provided in the 2010 Five-Year Review (USEPA, 2010c).

The repository has been open since 2002. The BCR accepts waste materials from the ICP, BPRP,
Remedy Protection Program, and Paved Roads Program as well as wood waste material and
oversize concrete debris. Waste acceptance criteria are specified in the Final Bunker Hill Mining
and Metallurgical Complex Waste Acceptance Criteria (IDEQ and USEPA, 2011). Annual reports for
the BCR document the source and volume of waste materials placed at the repository.

The original design capacity of the BCR was 250,000 cy. In 2007, the capacity was increased to
450,000 cy, and then in 2011 the capacity was again increased to 576,000 cy (TerraGraphics,
2015f). At the completion of the 2014 operating season, the remaining capacity of the BCR was
approximately 24,000 cy, subject to change based on final repository closure and cover design
(North Wind Construction, 2015b).

5-88

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

In 2015, the repository will be expanded again as the Big Creek Repository Annex (BCRA),
located directly west of and across Big Creek from the BCR. Predesign investigation activities
and design of the BCRA were completed in 2014. A new bridge across Big Creek was
constructed in 2014 to connect BCR to BCRA. Necessary utility modifications were also initiated
in 2014. The modifications will be completed during the first half of 2015 and construction of the
BCRA repository completed in 2015. It is anticipated that the BCRA will be available for waste
placement during late summer 2015. The design capacity of the BCRA is 190,000 cy, for a total
projected remaining capacity of 214,000 cy between both the BCR and BCRA. Additional
information on the BCRA is included in the Basis of Design Report (CDM Smith, 2015b).

O&M and Actions since the Last Five-Year Review

As described above, the BCR has operated since 2002. The repository was originally operated by
IDEQ until May 2013 when operations were transferred to the Coeur d'Alene Trust. During
waste placement, O&M are guided by an operations plan (North Wind Construction, 2015c).
Operations include:

• Completing annual start-up activities each spring;

• Providing year-round access for users at the ICP transfer station;

• Inspecting and segregating incoming materials according to approved waste acceptance
criteria to prevent unsuitable material from being placed in the repository;

• Placing and compacting waste materials;

• Removing wastes that do not meet the waste acceptance criteria;

• Operating the decontamination station;

• Final grading of external slopes in accordance with the design plans and in accordance with
the requirements of the site stormwater plan;

• Managing stormwater BMPs including a stormwater retention pond at the top of the
repository;

• Completing end of season shut-down activities in late fall or early winter; and

• Preparing annual surveys, as-builts, and operations reports.

The repository operations contractor prepares weekly, monthly, and annual reports. As part of
operations, inspections are completed by the repository operations contractor and additional
monthly inspections are completed by the Coeur d'Alene Trust. Long-term O&M activities will
begin following the closure of the repository.

IDEQ contractors have completed monitoring of groundwater, porewater pressure in
piezometers, settlement monuments, and surface water on a quarterly basis at the BCR since
July 2004. Groundwater samples are currently collected from a network of five monitoring
wells. Two monitoring wells are located within the footprint of the northern expansion cell.
Groundwater monitoring results to date indicate that the tailings impoundment has contributed
to groundwater metals loading. However, since placement of repository waste at the site,
statistically significant decreasing concentrations of antimony and arsenic have occurred in the
downgradient monitoring wells and no other trends have been identified (TerraGraphics,
2015h). Four piezometers within the BCR footprint appeared to be compromised and were

5-89

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

decommissioned in 2014. Two piezometers remain. Surface water samples are collected at three
locations in Big Creek and in two locations in the SFCDR. Surface water monitoring results
through 2012 indicate no significant change in water quality in the previous 5 years
(TerraCraphics, 2014g).

The Coeur d'Alene Trust monitored six groundwater and two surface water stations at the
BCRA site from 2013 through 2014 prior to waste placement to establish baseline conditions and
chemical trends. Water monitoring will continue in 2015 at three groundwater and the two
surface water stations during operation of the BCRA to evaluate any effects from the BCRA on
water quality.

The 2010 Five-Year Review included the following recommendation.

• Recommendation: Continue to implement remedial actions at Big Creek Repository (an
ongoing 2005 Five-Year Review recommendations).

Discussion: This activity continues to be performed as a matter of waste disposal in the
Basin and will continue until closure (BCR anticipated after 2015 season and BCRA several
years later depending on waste volumes) and commencement of long-term O&M.

Therefore, this recommendation is complete.

Remedy Status

Based on the inspections and monitoring completed to date, the BCR is protective and
functioning as intended. Construction of the BCRA is on-going and it is anticipated that it will
also be protective.

5.2.6.3 East Mission Flats Repository
Background and Description

The East Mission Flats Repository (EMFR) is located on a 23-acre parcel of land owned by
IDEQ. It is located north of the Coeur d'Alene River, north of 1-90, across the freeway from the
Old Mission State Park and Cataldo Mission (Figure 5-2). The site is within a floodplain in an
area that has existing contamination from deposition of mining-impacted sediments. The EMFR
was constructed and began receiving waste in 2009. Additional background details for the
EMFR are provided in the 2010 Five-Year Review (USEPA, 2010c).

The EMFR accepts waste materials from the ICP, BPRP, Remedy Protection Program, and
Paved Roads Program. Waste acceptance criteria are specified in the Final Bunker Hill Mining
and Metallurgical Complex Waste Acceptance Criteria (IDEQ and USEPA, 2011). Annual operations
reports for the EMFR are generated, which document the source and volume of waste materials
placed at the repository.

The 14-acre repository footprint is roughly triangular, with a capacity of approximately
445,000 cy. Repository design details are available in the East Mission Flats Repository 90% Design
Report (TerraGraphics, 2009b). As of the 2014, the remaining capacity of the EMFR was
approximately 226,000 cy (North Wind Construction, 2015d).

O&M and Actions since the Last Five-Year Review

EMFR has operated since 2009. The repository was operated by IDEQ until May 2013 when
operations were transferred to the Coeur d'Alene Trust. During waste placement, O&M are
guided by the East Mission Flats Repository Operations Plan (North Wind Construction, 2015e).

5-90

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Operations include:

• Completing annual start-up activities each spring

• Providing year-round access for users at the ICP transfer station

• Inspecting and segregating incoming materials according to approved waste acceptance
criteria to prevent unsuitable material from being placed in the repository

• Placing and compacting waste materials

• Removing wastes that do not meet the waste acceptance criteria

• Operating the decontamination station

• Final grading of external slopes in accordance with the design plans and in accordance with
the requirements of the site stormwater plan

• Managing stormwater BMPs including a stormwater retention pond at the top of the
repository

• Completing end of season shut-down activities in late fall or early winter

• Preparing annual surveys, as-builts, and operations reports

Groundwater monitoring has been conducted at the EMFR by IDEQ contractors since 2007.
Groundwater monitoring at the EMFR site is conducted quarterly to evaluate groundwater
quality and hydraulic conditions. Groundwater monitoring results indicate that arsenic,
cadmium, lead, and zinc are below regulatory thresholds at five wells on and downgradient
from the EMFR site. No trends indicating significant increasing or decreasing concentrations
have been detected. Additional information and specific results of monitoring through 2012 can
be found in the 2013 Annual Water Quality Report (IDEQ, 2014d). The report concludes that
EMFR is not negatively affecting dissolved metals concentrations in groundwater and
recommends continued monitoring.

Floodwater sampling was conducted during flooding that occurred in May 2011, April 2012,
and March 2014 at the EMFR. The purpose of the sampling was to measure the quality of the
floodwater entering and leaving the area surrounding the repository. In general, lower metals
concentrations are measured as the floodwater recedes from the area surrounding the
repository. No results conclusively confirm that the EMFR is adversely affecting surface water
metals concentrations during flood events. Based on the many factors potentially contributing
to metals concentration in the receding floodwater, such as the surrounding historical
contamination, continued monitoring of floodwater metals concentrations is not recommended
(IDEQ, 2014d). Continued visual inspection to identify surface erosion or deficiencies in
sediment controls is recommended on a weekly basis.

Remedy Status

Based on the inspections and monitoring completed to date, the EMFR is protective and
functioning as intended. The operation of the repository has prevented the release of

5-91

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

contaminants to surface water, groundwater, or air in concentrations that would exceed state
and/ or federal standards.

5.2.7 Clean Waterfowl Habitat (Agriculture-to-Wetland Conversion Project)
5.2.7.1 Background and Description

A pilot project converted nearly 400 acres of farmland to clean wetland bird feeding habitat in
the Lower Basin was established by USEPA in coordination with the Coeur d'Alene Basin
Natural Resource Trustees led by USFWS and in coordination with Ducks Unlimited.
Significant numbers of waterfowl deaths have been recorded in the Basin for decades due to the
lead-contaminated sediment; this project will reduce waterfowl exposure to these contaminants
by providing clean wetland feeding habitat for migratory and resident swans, ducks, and other
wetland bird species.

USEPA used settlement monies to purchase a conservation easement from the property owner
and converted farmland (USEPA, 2012d) to healthy wetland habitat following actions described
in the 2002 OU 3 ROD (USEPA, 2002a). The conservation easement area, a 396-acre site located
near Medimont, Idaho, is divided into two units: the East Field and the West Field (Figure 5-2).
Approximately 295 acres are located in the East Field, and 100 acres are located in the West
Field.

Cleanup and conversion of agricultural lands to clean wetlands was identified in the 2002 OU 3
ROD as a measure to provide clean feeding areas for waterfowl. The 2002 OU 3 Interim ROD
identifies a soil cleanup level of 530 mg/kg lead in sediment for protection of waterfowl. A goal
of this agriculture-to-wetland conversion project is that soils in the conservation easement be
characterized with an overall average lead concentration less than 530 mg/kg lead.

Remedial activities were phased to allow for adaptive management of the remedial action.
Remediation began in 2006 and was completed in 2011. The East Field remedial activities
included:

• Remediation of a limited area with elevated soil lead concentrations;

• Abandonment of existing linear drainage ditches and creation of sinuous drainage swales;

• Rehabilitation of a portion of the levee between the East Field and both Robinson and
Canary Creeks; and

• Construction of water control structures.

The West Field remedial activities included:

• Hydraulic control improvements consisting of installation of water control structures,
abandonment of existing pump stations, and a new portable pump station; and

• Remediation of contaminated sediments using shallow soil removal and selective handling
methodology.

Following implementation of remedial actions, the Coeur d'Alene Basin Natural Resource
Trustees, led by USFWS in cooperation with Ducks Unlimited, began restoration activities
including upland grass seeding, planting shrubs and trees along the riparian corridor, and
restoration of the wetland vegetative community through control of reed canary grass, invasive
species control, and water management.

5-92

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

5.2.7.2 O&M and Actions since the Last Five-Year Review

Remedial actions in the East Field were completed prior to this 2015 Five-Year Review period.
Remedial actions in the West Field began prior to this 2015 Five-Year Review Period, but were
completed during this review period in November 2011. Remedial actions completed at the
West Field in 2010 and 2011 included:

• Soil remediation using the selective handling technique to address those limited areas with
elevated soil lead values following the 2009 remedial work.

• Installation of the West Field portable pump and electrical improvements.

• Demolition of existing pump structure

The final remedy inspection was conducted in November 2011 following full implementation of
the West Field remedy.

In 2006, the USEPA entered into a Memorandum of Agreement with the U.S. Department of
Interior, the State of Idaho, and the Coeur d'Alene Tribe regarding the Schlepp conservation
easement and wetland project. In the memorandum, the U.S. Department of Interior, on behalf
of the Natural Resource Trustees agreed to perform restoration work on the easement property
and provide for the long-term O&M of the easement interest consisting of maintenance of
habitats and O&M of infrastructure, including water intake and outlet structures, pumps,
levees, and the west field soil disposal area. USFWS and others are currently drafting a 10-Year
Operation and Maintenance Plan that is intended to provide the necessary activities to be
conducted at the easement. Recent O&M activities conducted at the easement are described in
the following paragraphs.

East Field

Vegetation monitoring and maintenance to ensure habitat diversity and water management
were the primary activities in the East Field. A new access ramp on the Canary Creek levee has
been established to reach and manage a concentrated area of reed canary grass that was
previously non-accessible. In 2013, Idaho Department of Transportation replaced two
undersized culverts (Canary Creek and Robinson Creek) adjacent to the easement allowing for
improved flow and reduced overflow of water onto the easement.

West Field

Poor establishment and growth of vegetation in the West Field following remediation and
subsequent soil testing indicated an imbalance of nutrients in the soil. In 2013, a series of
treatments were completed in the West Field to remedy nutrient, pH, and organic matter
deficiencies identified.

During water drawdown of the West Field for soil amendment work, earthwork was conducted
to create a new cross berm with a control structure to allow for improved water management.
Additionally, three islands to increase habitat diversity and provide loafing areas for birds were
constructed.

The 2010 Five-Year Review recommended the following specifically for the Clean Waterfowl
Feeding Area/ Agriculture-to-Wetland Conversion.

5-93

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

• Recommendation: Transfer the easement interest to the State of Idaho. The State will accept
the transfer, without cost to Idaho, to a third-party conservation organization (Ducks
Unlimited, Inc.).

Discussion: This continues to be an open item but USEPA is meeting with USFWS and
interested parties to seek agreement on final easement holder. This recommendation will
not be retained on the table of issues and recommendations, because it does not directly
affect protectiveness. It will instead be included on the table of planned action items.

• Recommendation: Identify landowners interested in agricultural to wetland conversion (an
ongoing 2005 Five-Year Review recommendation).

Discussion: Agricultural to wetland conversion is an important element of providing
uncontaminated Lower Basin waterfowl habitat and as such, this activity will continue in
support of new remedial actions. This recommendation is complete.

5.2.7.3 Remedy Status

The East Field agriculture-to-wetland conversion is functioning as intended by the ROD. The
East Field remedy was fully implemented in 2008, and to date, has achieved the RAOs. In 2007,
lead concentrations in confirmation samples from the East Field were below the 530 mg/kg
cleanup goal (CH2M HILL, 2007c), which indicates the presence of clean feeding areas for
waterfowl. Periodic site visits indicate that the wetland surface water elevation has been
maintained as designed, and the source of the water, Robinson Creek, does not provide
recontamination potential. Basin Environmental Monitoring Plan biological resource
monitoring conducted in 2014 indicated significantly higher waterfowl use than in previous
years. A 20-fold increase in tundra swan abundance was observed in 2014 compared to the
2008-2013 average. Additionally, there was a 99 percent reduction in tundra swan moralities.
(USFWS, 2010)

The West Field remedy was completed in 2011; however, poor establishment and growth of
vegetation required additional soil treatments. In 2014, there was high water fowl usage of both
fields. Further monitoring will be required to determine whether the West Field will attract high
waterfowl usage frequently or if additional restoration efforts may be necessary.

5.3 Technical Assessment for OU 3

5.3.1 Is the Remedy Functioning as Intended by the Decision Documents?
5.3.1.1 Selected Remedy for Protection of Human Health

The Human Health Selected Remedy in the community and residential areas of the Upper and
Lower Basin is not yet complete. Sampling of eligible parcels is estimated at 91 percent
complete, and remediation is up to 85 percent complete. Approximately 13.5 miles of paved
roads in the Basin have been rebuilt, overlaid, patched, or chip sealed through the Paved Roads
Program. Approximately 97 percent (or 7.25 miles) of publicly owned gravel roads that require
remediation have been completed; the remainder are scheduled to be remediated under a
different program, such as the Paved Roads Program.

Although the Selected Remedy is expected to result in significant improvements to
groundwater quality, it is not intended to achieve groundwater MCL ARARs under the SDWA

5-94

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

throughout the Upper Basin. Approximately 35 homes with private drinking water sources
have been identified as having elevated lead, arsenic, or cadmium concentrations, and have not
yet been provided an alternative drinking water supply or filtration system.

The Human Health Selected Remedy is functioning as intended by the OU 3 ROD and ROD
Amendment, although it has not yet been fully implemented. Community mean soil lead
concentrations are near or below 200 mg/kg lead for all geographic areas as of 2014. These
community means have decreased by an average of 34 percent in the Upper Basin and
18 percent in the Lower Basin since the last Five-Year Review, and by an average of 69 percent
and 23 percent, respectively, since the ROD. Community mean soil arsenic concentrations
continue to remain below the clean soil criteria of 35 mg/kg. Geometric mean dust lead
concentrations in all sampled Basin communities were below 500 mg/kg in 2013. The largest
reductions in both vacuum and mat dust lead concentrations since the last Five-Year Review
were observed in Burke/Ninemile. Since the last Five-Year Review, community mean vacuum
dust lead concentrations have decreased by an average of 40 percent in Upper Basin
communities and 30 percent in the Lower Basin communities. Upper Basin community mean
mat lead concentrations have remained relatively similar to means presented in the 2010 Five-
Year Review. Little to no dust mat data exist for the Lower Basin and Kingston geographic areas
in recent years.

Based on recent soil and house dust data, approximately 13 percent of homes in the Basin
currently do not meet childhood lead health risk goals, even though property remediation is
nearing completion in some communities. These exceedances for a typical (or hypothetical)
child between the ages of 6 months and 6 years are due to elevated soil or dust lead
concentrations, or a combination thereof. The voluntary nature of the residential yards program
may limit the protectiveness of the remedy when owners refuse to participate. An estimated
4 percent of eligible parcels refuse sampling and/ or remediation (approximately 200 properties)
increasing the potential of exposure to lead or arsenic in soil and increases the potential
recontamination of adjacent properties. In recent years, elevated dust lead concentrations in
homes throughout the Basin could be related to the patchwork of remaining contaminated soils
(e.g., un-remediated property soils, recreational areas, or mine dumps). Additionally, the
elevated dust lead concentrations may be due to sources unrelated to the current remedies that
have not yet been addressed, including lead-based paint and residual dusts in building
structures. Success depends on completing remediation of eligible properties and a better
understanding of the spatial distribution of remaining soil concentrations, source sites, and
elevated dust lead concentrations.

Interior house dust cleaning was a contingent remedial action identified in the ROD and has not
yet been evaluated or implemented in OU 3. The need for interior cleaning will be evaluated
after residential soil remediation is completed, taking into consideration ease of
implementation, sustainability, ongoing OU 3 house dust monitoring results, and lessons
learned in OU 1, which suggest that interior cleaning is not effective beyond the very
short term.

The LHIP continues to provide a valuable public health service through voluntary blood lead
screening to i) identify at-risk children, ii) provide environmental health follow-up for children
with blood lead levels > 5 jug/dL, and iii) implement education and awareness programs. The
HEPA vacuum loan program continues to be used by local residents. The low level of
participation in the annual Basin blood lead monitoring program remains a concern because it

5-95

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

limits the identification of children who might benefit from intervention. An alternative
approach using house dust data has identified a number of households for follow-up lead
health intervention services; however, house dust monitoring does not occur every year, and
only a fraction of residents take advantage of the follow-up services. For these reasons, the
success of this alternative approach is limited and difficult to quantify with the amount of
available blood and house dust data.

Remedial actions have been conducted at the Trail of the Coeur d'Alenes and seven recreational
sites along the Coeur d'Alene River where action was warranted. In 2015, a recreation sites
working group was established consisting of IDEQ, PHD, and USEPA staff to evaluate
recreational uses and make recommendations on whether further actions are appropriate as
recreational use evolves. Additional efforts to reach people through signage, education, and
outreach provide trail and river users with information about recreational risks and safer-use
practices. Semi-annual and post-flood monitoring of eight public recreational sites has indicated
that, in general, removal of contaminated sediment at these areas continues to help reduce the
public's exposure to sediments contaminated with mine wastes. Recreational boat launches are
owned and maintained by state and federal agencies and they are responsible for removing
contaminated sediments that are deposited on them. Resource constraints often result in
optimizing removal efforts, which can result in sediments being left at the boat launches until
the high runoff period has receded. Timely removal of contaminated sediments is critical to
completely prevent potential exposure. As continued development of private recreational sites
occurs along the SFCDR and mainstem of the Coeur d'Alene River, in addition to the public or
developed recreational areas, several private or informal recreational sites have been identified
in the last 5 years that may present a heavy metal exposure risk to recreationalists. These sites
were not in use and therefore not identified for remediation as part of the OU 3 ROD. USEPA
continues to develop a sediment transport model that, when complete, may be a useful tool for
prioritizing and evaluating options to address contaminated sediment transport or deposition
in the Lower Basin.

Based upon the trail inspections and transect measurements, the M&R activities performed on
the Trail of the Coeur d'Alenes have been effective in preserving the integrity of the protective
barriers, preserving the effectiveness of constructed access control measures, and maintaining
controls that prevent erosion or slope destabilization in inspected work areas. Transect station
measurements show that barrier losses are insignificant in relation to Response Action
Maintenance Plan (Coeur d'Alene Tribe et al., 2008) specifications. In addition, the asphalt
concrete pavement assessment inspection reports indicate the asphalt concrete pavement barrier
was observed to be functioning as intended as both a barrier and recreational corridor.
Monitoring, maintenance, and repair of the trail has proven effective in the long-term
protectiveness of the remedy. Based on the findings of the M&R reports and monitoring, the
remedy is performing as intended and remains protective of human health and the
environment.

Similarly, continued implementation of the ICP is a key element to the long-term functionality
and success of the human health selected remedy. PHD has implemented the ICP as described
in IDAPA 41.01.01, issuing 3,122 permits in OU 3 since the last Five-Year Review, performing
inspections, directing contaminated soils to designated repositories, receiving documentation of
samples for clean fill, and visually observing barrier depth. Runoff, flooding, natural disasters,
and documentation are challenges faced during everyday implementation of the ICP.
Community acceptance and compliance with the ICP remains high.

5-96

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

The long-term performance of the soil remedy is dependent on both the ICP and maintenance
by property owners, including free and convenient disposal locations for local users. Residents
are responsible for the maintenance of barriers on their properties. The performance of barriers,
especially barrier enhancements such as vegetation or gravel cover, may be compromised if
they are not maintained. Maintenance of publicly owned gravel and paved roads is the
responsibility of the governmental jurisdiction that maintains each road. Funding allotted for
the Paved Roads Program assists local jurisdictions by funding one-time reconstruction of the
paved roads as caps to underlying contamination. While implementation of this program is
expected to address a significant number of paved roads in the Site, it is not intended to address
all road problems and conditions and does not address privately owned paved roads. For this
Five-Year Review there was no physical assessment conducted to evaluate the condition of
remediated barriers on residential properties, publicly owned unpaved roads, and completed
paved road projects.

Remedy protection actions are improvements to existing water conveyance systems that are
being implemented to reduce the potential for erosion and recontamination of existing, clean
barriers that have been installed. Remedy protection projects include specific actions such as
culvert replacements, channel improvements, small diversion structures, and asphalt ditches.
Five remedy protection projects identified in the ROD Amendment were completed in OU 3 by
2014. O&M is the responsibility of the local governments within which the projects are located.
Based on the Five-Year Review inspections completed by the Coeur d'Alene Trust, the
constructed remedy protection projects are protective of the previously established remedies.
The projects are functioning as intended. The projects, along with future O&M, help alleviate
threats of localized flooding and migration of contaminated media.

The Human Health Selected Remedy also called for education, intervention, and monitoring to
reduce human exposure to contaminants in aquatic food sources. The IDHW has set forth fish
consumption guidelines for Coeur d'Alene Lake, but does not include the Coeur d'Alene River
or chain lakes, and are based on data collected in the mid-1990s. USEPA has identified fish
tissue metals concentrations in the chain of lakes as a potential data gap. Further evaluation,
through coordination with IFCAP, of fish consumption and concentrations has been identified
as an action item along with coordination with IDHW and IDFG.

5.3.1.2 Environmental Protection

Completed remedies at mine and mill sites in the Upper Basin are generally functioning as
intended and limit potential exposures of area residents and recreational users to contaminated
soils. The remedies completed and in process at mine and mill sites are anticipated to provide
ecological benefits, including protection of plants and animals from the effects of heavy metals
and improvements to water quality in the SFCDR and its tributaries. However, it is too early to
determine the full ecological improvements of completed remedies through monitoring
activities.

O&M is an integral part of the remedy at these sites for long-term remedy protectiveness. O&M
plans have been adopted for most sites, although there is no formal O&M plan for the Sisters
Mine and Mill site. The Canyon Creek and Ninemile Spur lines were capped as part of the
Wallace Yard and Spur Lines Response Action. Responsibility for long-term maintenance of the
barrier on the Spur Lines rest to the landowner because the lines have been abandoned by the
railroads as of 2014.

5-97

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

The Selected Remedy is expected to result in significant improvements to surface water quality
in the Upper Basin and may achieve AWQC2 ARARs under the Clean Water Act at many
locations; however, the remedy may not achieve these ARARs at all locations.

Although the Selected Remedy is expected to provide additional safe habitat for special-status
species and is intended to achieve ARARs under the Migratory Bird Treaty Act and the
Endangered Species Act where remedial actions are taken, it will not achieve these ARARs at all
locations.

5.3.1.3 Repositories

The repositories that are currently operational have been designed, constructed, and operated
pursuant to the 2002 OU 3 ROD to safely contain waste material and prevent the release of
contaminants to surface water, groundwater, or air in concentrations that would exceed state
and/or federal standards. The Burke Canyon Repository (BCR) has been in operation since
2002. Groundwater and surface water monitoring at BCR indicate that metals concentrations are
either stable or trending downward (TerraGraphics, 2014g and 2015f) and that the BCR design
has reliably contained waste material from remedial actions, as well as wastes generated by
citizens, communities, and development activities. EMFR has been in operation since 2009. No
trends indicating significant increasing or decreasing concentrations of metals have been
detected in groundwater at EMFR through the 2013 season (IDEQ, 2014d). Based on these
monitoring results, the operation of BCR and EMFR has prevented the release of contaminants
to surface water, groundwater, or air in concentrations that would exceed state and/ or federal
standards, and these repositories are functioning as intended. LBCR is operational, and
continued monitoring will be conducted to ensure the protectiveness of the remedy.

In addition to the two repositories, the East Fork Ninemile (EFNM) Waste Consolidation Area
(WCA), which is located in the upper reach of the EFNM Creek Watershed, was constructed
approximately 250 feet above EFNM Creek outside of the alluvial valley and in an area that is
relatively isolated from groundwater. The site provides a location for long-term consolidation of
mine waste materials, including waste rock and tailings, from sites located throughout the
Ninemile Creek Watershed. Mine wastes will be consolidated into the EFNM WCA to reduce
metals loading into the watershed. Additional information on the EFNM WCA can be found in
the Final Remedial Design Basis of Design Report (CDM Smith, 2013). The WCA was completed
in 2014 and began receiving waste from the Interstate Callahan Rock Dump. It is expected to be
operational for approximately 10 years and expanded to accommodate all the waste from
cleanup in EFNM.

5.3.1.4 Spokane River

The remedies implemented at the Spokane River recreational areas were certified as complete in
September 2013 for the 10 Spokane River shoreline areas and are functioning as intended by the
OU 3 ROD (USEPA, 2002a). Follow-up inspections and sampling indicate that the remedies are
functioning as intended. Two exceedances above cleanup action levels (for lead) were found at

2 The AWQC that apply to the Selected Remedy are a combination of State of Idaho AWQC and Site-specific AWQC developed by
the State of Idaho for the SFCDR Watershed. For a COC for which a Site-specific AWQC exists, the Site-specific AWQC is the
ARAR. For some COCs, Site-specific AWQC were not developed and, in these cases, the AWQC used are the State of Idaho
AWQC. The Site-specific AWQC were proposed by the State of Idaho and approved by USEPA as protective of ecological receptors
in the SFCDR.

5-98

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

the Island Complex in 2013. Additional monitoring will be completed as part of O&M activities
by Ecology before the next Five Year Review. Based on sampling results, Ecology in
coordination with USEPA, will determine if additional cleanup is warranted.

5.3.1.5 Clean Waterfowl Habitat

The East Field agriculture-to-wetland conversion is functioning as intended by the decision
documents. The East Field remedy was fully implemented in 2008, and to date, has achieved the
RAOs. Basin Environmental Monitoring Plan biological resource monitoring conducted in 2014
indicated significantly higher waterfowl use than in previous years. A 20-fold increase in tundra
swan abundance was observed in 2014 compared to the 2008-2013 average. Additionally, there
was a 99 percent reduction in tundra swan moralities. (USFWS, 2010)

The West Field remedy was completed in 2011; however, poor establishment and growth of
vegetation required additional soil treatments for site restoration. Further monitoring will be
required to determine whether an increase in waterfowl abundance and frequency of the West
Field occurs because of continued restoration activities and site operations by the Natural
Resource Trustees.

5.3.2 Are the Exposure Assumptions, Toxicity Data, Cleanup Levels, and RAOs
Used at the Time of Remedy Selection Still Valid?

The exposure assumptions, toxicity data, cleanup levels, and RAOs used at the time of remedy
selection remain valid. Since the HHRA was completed, minor changes in the reference doses
for several chemicals of potential concern have been adopted and no modifications to the cancer
slope factors were found in USEPA's Integrated Risk Information System. The changes either
decreased risk or would not effectively change risk and would not result in re-evaluation of the
cleanup levels for the protection of human health. Promulgated standards affecting the
protectiveness of the OU 3 Selected Remedy have remained unchanged.

As discussed in Section 3.3, new information is available on soil and house dust bioavailability
and estimated baseline soil/dust ingestion rates. Findings from the recent Regional Applied
Research Effort study affect the assumptions used at the time of remedy selection, but do not
affect the protectiveness of the remedy based on 10 pg/dL as the blood lead reference value.
Since the last Five-Year Review, CDC has recognized that adverse health effects occur even with
low lead levels in the blood, and in 2012 began utilizing a reference value of 5 pg/dL (CDC,
2012). In response to this recommendation, PHD lowered the LHIP follow-up criterion to
5 pg/dL in 2012. USEPA is currently considering this CDC recommendation and its
implications for current lead health risk management policies at Superfund sites at the national
level. USEPA will continue to evaluate the protectiveness of the remedy in future Five-Year
Reviews taking into account any changes to the Superfund lead health risk management
policies.

5.3.3 Has Any Other Information Come to Light that could call into question the
Protectiveness of the Remedy?

The Trail of the Coeur d'Alenes and the natural beauty of the river and mountains attract
numerous outdoor enthusiasts to the Silver Valley and Coeur d'Alene River. Land use along the
banks of the Coeur d'Alene River has continued to change in recent years. Property owners are
establishing private campgrounds on which multiple users set up seasonal campsites.

5-99

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Significant portions of these properties are in the floodplain, which is likely presently
contaminated with lead and other metals and may be recontaminated during flood events. The
HHRA identified certain exposures that cause potentially significant incremental risk to
children and pregnant women, including recreational activities at upland parks, public beaches,
and neighborhood streams and activities that cause contact with waste piles. Observations from
blood lead monitoring follow-ups conducted as part of the LHIP have indicated that in some
Basin children excess absorption is associated with recreational activities in the river or lateral
lake areas. Many formal recreational areas with contaminated soils and sediment exist,
although signage has been placed to alert recreationalists to the hazards associated with the
Site, and surfaces have been hardened at boat launches along the river. Recreational exposures
outside the Trail of the Coeur d'Alenes and its oases appear to be increasing as indicated by
new, informal pedestrian paths leading down the riverbank to the SFCDR and Coeur d'Alene
River in various locations. This unauthorized access may result in minor barrier erosion and
increased risk of exposure to trail users; however, the Response Action Maintenance Plan (Coeur
d'Alene Tribe et al., 2008) helps to ensure that such issues are addressed as part of regular
maintenance activities conducted by UPRR, with oversight conducted by IDEQ and the Coeur
d'Alene Tribe. PHD has also observed several informal, undeveloped (or impromptu) sites
where children created access on the banks or swimming holes in the channel of the SFCDR and
Coeur d'Alene River. In 2015, a recreation sites working group was established consisting of
IDEQ, PHD, and USEPA staff to evaluated options for reducing exposure to lead and other
heavy metals at a range of recreation sites in Upper and Lower Basin areas.

Potentially contaminated soils exist on properties where homeowners have refused sampling or
remediation. In addition, discrete remediation has left large areas in OU 3 with soil lead
concentrations ranging from 100 to 999 mg/kg. Soils with lead levels between 700 and
999 mg/kg receive a one-time surface enhancement (e.g., sod, stepping stones) that if not
maintained also becomes a possible source of lead exposure. In combination with current
interior dust lead concentrations, homes with soils in the 700 to 999 mg/kg range do not meet
current USEPA risk goals. Protectiveness of the remedy relies on completing property
remediation and long-term maintenance, as well as controlling tracking of contaminated soils
and sediments from source sites into the home environment.

5.4 Summary of OU 3 Issues, Recommendations, and Follow-Up
Actions

Issues, recommendations, and follow-up actions that were identified during this fourth, or
previous, Five-Year Reviews and affect protectiveness are summarized in Table 5-16. Action
items that were identified during this fourth Five-Year Review and do not affect protectiveness,
but are expected to require future action, are summarized in Table 5-17. These
recommendations are summarized herein to allow USEPA to track this information, as
suggested by Five-Year Review guidance (USEPA, 2001)

5-100

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TABLE 5-16

OU 3 Summary of Issues and Recommendations
2015 Five-Year Review, Bunker Hill Superfund Site

Remedial
Action
(e.g. Human
Health
Barriers,
ICP)

Issue

Recommendations

Party
Responsible

Oversight
Agency

Planned
Completion
Date

Affects
Protectiveness?
(Y/N)

Current

Future

LHIP

House dust monitoring currently
only occurs every other year
while remediation is ongoing.
Therefore, other strategies are
needed to help identify at-risk
children annually.

Consider additional alternative
approaches to the 2002 OU 3 ROD's
dust intervention protocol to identify
at-risk children.

IDEQ, PHD,
USEPA

IDEQ,
USEPA

March 2016

Basin

Recreation

Sites

There are numerous
contaminated sites used for
recreation throughout the Basin
that span the spectrum from
informally used to fairly highly
developed. These sites don't fit
into established cleanup
programs such as the BPRP.
Many have recontamination
potential from recurring flood
deposition.

Identify and evaluate Basin
recreational sites for possible
exposure reduction or educational
outreach measures. Identify and
evaluate cost effective exposure
reduction and educational outreach
measures (where appropriate)
geared towards various types of
recreational sites.

IDEQ, PHD,
USEPA

IDEQ,
USEPA

March 2019

5-101

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TABLE 5-17

OU 3 Action Items that Do Not Affect Remedy Protectiveness
2015 Five-Year Review, Bunker Hill Superfund Site

Remedial Action (e.g.,
Human Health Barriers, ICP)

Action Item

Responsible
Party

Oversight
Agency

Human Health Barriers

Develop an approach (or program) that defines how barrier integrity for all remediated
properties would be monitored overtime. Repeated in OU 1.

IDEQ, PHD,
USEPA

IDEQ, USEPA

Human Health

Determine whether a community-wide soil lead level is needed for the Basin. If so, determine
what the appropriate level is and how it would be used. If deemed necessary, the level would
be calculated once the BPRP is completed.

IDEQ, USEPA

LHIP

Continue to evaluate options for increasing participation in the annual blood lead screening
program. Repeated in OU 1.

IDEQ, PHD,
USEPA

IDEQ

ICP and waste disposal

Regarding a long-term disposal need from ICP, establish process with community planners
to identify timing and quantity of waste soils to be hauled to repositories from ICP-regulated
activities.

IDEQ, PHD,
USEPA

IDEQ, USEPA

Waste disposal from various
remedial actions

Regarding long-term disposal need from remedial actions, establish process with remedial
design teams and long-term planners to identify waste quantities and timing associated with
remedial actions.

IDEQ, PHD,
USEPA

IDEQ, USEPA

Waste disposal from various
remedial actions

Continue search and evaluation of potential new repository sites, as needed.

IDEQ, PHD,
USEPA

IDEQ, USEPA

Trail of the Coeur d'Alenes

Develop management and use strategies to prevent further unauthorized uses of the Trail of
the Coeur d'Alenes, which increase the risk of exposure to trail users.

IDEQ, PHD,
IDPR, Coeur
d'Alene Tribe,
UPRR

IDEQ, USEPA

Trail of the Coeur d'Alenes

Continue to monitor the slow moving slope next to the trail between Latour Creek and
Cataldo and work with adjacent private landowners. The clay soil is moving at a slow rate,
and trees located on private property continue to fall across the trail. Monitor trees near the
trail as they help to stabilize the slope.

IDEQ, PHD,
IDPR, Coeur
d'Alene Tribe,
UPRR

IDEQ, USEPA

Clean Waterfowl Habitat

Transfer the easement interest in the ag-to-wetland pilot project to the State of Idaho. The
State will accept the transfer, without cost to Idaho, to a third-party conservation organization
(Ducks Unlimited, Inc.)

IDEQ, USEPA

Fish Consumption in Lower
Basin (Chain of Lakes)

Planning for collection of additional fish samples within the waterbodies of the Lower Basin is
underway. The sampling program will follow the fish advisory guidelines from USEPA
(USEPA 1994b, 1995a, 1996c, and 1999b) as implemented by the Idaho Fish Consumption
Advisory Project (IFCAP). The goal of the IFCAP is to protect the public from adverse health
risks associated with consuming contaminated fish from Idaho and Tribal waters.

IDHW, IDFG,
Coeur d'Alene
Tribe

IDEQ, USEPA

5-102

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

5.5 Performance Evaluation of the OU 3 Remedy

The remedy included in the 2002 OU 3 ROD and subsequent 2012 Upper Basin ROD
Amendment is an interim remedy. The interim remedy is not expected to be completely
protective of the human health and the environment when fully implemented because
additional actions will be needed to protect human and environmental resources fully.

In the interim, most exposure pathways that could result in unacceptable risks are being
controlled or addressed in locations where remedial work has been completed. There are some
locations where interior house dust lead concentrations remain high. Monitoring of these areas
will continue in order to determine whether these levels decrease as anticipated as exterior
cleanup actions progress toward completion.

Although the human health selected remedy has not been fully implemented, the remedy is
functioning as intended by the OU 3 ROD and Upper Basin ROD Amendment where it has
been implemented. Community mean soil lead concentrations are near or below 200 mg/kg
lead for all geographic areas as of 2014. Geometric mean dust lead concentrations in all sampled
Basin communities were below 500 mg/kg in 2013. To date, a total of 3,603 properties have been
remediated, 734 of which were considered high risk at the time of sampling or remediation, and
nearly 820,000 cy of contaminated soil have been removed and placed in designated
repositories. Substantial reductions have occurred in community mean soil lead concentrations
since the large-scale property remediation began in 2002. Overall trends show reductions in
interior dust and lead concentrations and loading rates, but there are still residences where
interior lead levels remain high (greater than 1,000 mg/kg). House dust sampling will continue
in OU 3 to monitor dust trends in homes as remedial actions continue. This sampling effort will
aid in determining whether overall interior dust trends continue to decline in Basin
communities and whether the occurrences of residences with high lead levels decline in
response to the remedial actions implemented. Blood-lead screening will continue to be offered
annually to identify at-risk children and provide feedback on the effectiveness of cleanup
efforts.

Sediment contaminated by mine waste continues to be transported throughout the SFCDR,
including some of its tributaries, and the mainstem of the Coeur d'Alene River. Exposure to
these contaminated sediments poses health risks to people recreating in the Lower Basin as well
as waterfowl in the Lower Basin. Because of the significant recontamination potential in the
Lower Basin due to flooding and other issues, USEPA is conducting studies to evaluate Lower
Basin contaminated sediment transport issues prior to making or implementing additional
remedy decisions in the Lower Basin. The focus of USEPA's ongoing work in the Lower Basin is
to fill data gaps and to refine the ECSM (CH2M HILL, 2010), including sediment transport
modeling that will help guide effective decision-making regarding future remedial actions in
the Lower Basin.

In addition to cleanup work in the residential and community areas of OU 3, remedial work has
also been completed at a number of mine and mill sites in the Upper Basin as well as at
recreational sites along the Coeur d'Alene and Spokane Rivers. These remedial actions were
undertaken primarily to reduce human exposures to site contaminants from people accessing
mine and mill sites for recreational purposes (all-terrain-vehicle and motorcycle riding) and
those camping or accessing the rivers on or through contaminated areas.

5-103

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

The remedial actions at the mine and mill sites have included barriers or deterrents to all-terrain
vehicle and motorcycle use, which have reduced exposures and are functioning as designed.
Although the remedial actions at the mine and mill sites were undertaken primarily to reduce
human exposures, the work performed is also expected to provide some ecological benefits,
though it is too early to determine such effects through monitoring activities. Remedies at mine
and mill sites in the Upper Basin are functioning as intended.

Remedial work at the recreational sites along the Coeur d'Alene River have largely involved
grading and capping contaminated materials, installation of site access controls, and
stabilization of adjacent eroded riverbank. Remedial actions at the Spokane River sites have
involved a combination of removing contaminated materials, capping, and installing deterrents
to recreational users. In general, the remedies constructed at recreational sites along both the
Coeur d'Alene and Spokane Rivers are functioning as designed.

Three repositories and a waste consolidation area in Ninemile Creek have been designed,
constructed, and operated pursuant to the 2002 OU 3 ROD to safely contain waste material and
prevent the release of contaminants to surface water, groundwater, or air in concentrations that
would exceed state and/ or federal standards. Based on monitoring results in the last 5 years,
the operation of these repositories has prevented the release of contaminants to surface water,
groundwater, or air in concentrations that would exceed state and/ or federal standards, and
these repositories are functioning as intended.

The clean waterfowl habitat pilot study project establishing nearly 400 acres of clean feeding
habitat for migratory and resident swans, ducks, and other wetland bird species was completed
in the Lower Basin. The overall intent of this action is to provide clean waterfowl feeding
habitat to reduce their exposure to lead-contaminated sediment. The East Field was completed
in 2007; it is functioning as intended by the ROD. The West Field was completed in 2011, but
required additional work to establish vegetation suitable for waterfowl habitat. Sustained
increased waterfowl usage in both fields remains an objective. Continued restoration activities
coupled with water level management at the site may lead to the desired increase. Continued
monitoring of waterfowl usage will be important in the determination of that success. The
remedy provides clean waterfowl feeding habitat as intended but increased usage by swans and
some other species is desired.

The Trail of the Coeur d'Alenes was created by a CERCLA-negotiated settlement with UPRR.
The goals of this response action were to contain mine-waste-related contamination within the
ROW in a manner that was protective of human health and the environment and in compliance
with ARARs. Numerous entities routinely assess and inspect the functionality of the trail as
both a recreational facility and a protective barrier. The installed barriers are being maintained
by UPRR; they are functioning as designed. IDPR is closely monitoring the adequacy of the
settlement cash-out they received to manage the Trail of the Coeur d'Alenes. Incurred costs to
date have exceeded the revenues generated from interest earned on the principal plus
encroachment and other special use fees, resulting in the utilization of base funds.

The OU 3 remedy is currently protective of human health and the environment in areas where
remedial actions have been completed. However, continued maintenance of the clean barriers to
underlying contamination is essential to ensure long-term protectiveness of the remedy. In
addition, continued funding and state and local support of the ICP is necessary to ensure barrier
maintenance occurs in the long term.

5-104

-------
6 Statement of Protectiveness

6.1 Operable Unit 1

Although the selected remedy has not been fully implemented, it is nearly complete and data
indicate that the remedy is functioning as intended by the 1991 OU 1 ROD (USEPA, 1991). As
remediation nears completion, soil and house dust lead concentrations have declined, lead
intake rates have been substantially reduced, blood lead levels have achieved their RAOs, and
the ICP has been established and is operating. Continued operation of a robust ICP is essential
to the long-term performance of the installed human health barriers. House dust lead levels
have declined to below the 500 mg/kg site-wide average RAO. However, further evaluation is
necessary to inform ongoing implementation of the interior cleaning remedy.

Private groundwater wells used for drinking were closed during the years that yard soil
remedial actions were ongoing. Owners of 13 wells that exceeded federal drinking water
standards refused closure. None of these 13 wells was used for drinking water purposes at the
time; however, the current potable or nonpotable status of 13 wells whose owners refused
closure is currently unknown.

6.2 Operable Unit 2

Implementation of Phase I of remedy as selected in the 1992 ROD, ROD Amendments (1996,
2001, and 2012), and ESDs (1996 and 1998) includes extensive source removal and stabilization
efforts, demolition activities, development and implementation of the ICP, land use
development support, and public health response actions. Phase I includes monitoring and
evaluation of the success of source control efforts. Interim control and treatment of
contaminated water and AMD were also included in Phase I of remedy implementation.

Phase I remedies have removed and consolidated over 2.8 million cy of contaminated waste
onsite in engineered closure areas (the Smelter and CIA closures; see Section 4, Table 4-1). The
use of geomembrane cover systems on these closure areas effectively removes these
contaminated wastes from direct contact by humans and biological receptors. Consolidating
these wastes in engineered closures also substantially reduces the exposure pathway to the
surface water and groundwater environment in comparison to pre-remediation Site conditions.

6-1

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Over 800 acres of property within OU 2 have been capped to eliminate direct contact with
residual contamination that remains in place within some areas of OU 2. In addition, the
revegetation work conducted as part of the Phase I remedial actions has substantially controlled
erosion and has significantly improved the visual aesthetics of OU 2. The success of the Phase I
revegetation efforts is providing improved habitat for wildlife that was largely absent for
decades in many areas of the hillsides and Smelterville Flats.

All of these efforts have reduced or eliminated the potential for humans to have direct contact
with soil/ source contaminants, have reduced opportunities for transport of contaminants by
surface water and air, and are expected to provide surface and groundwater quality
improvements over time throughout the Site. Responsibility for O&M of OU 2 Phase I remedial
actions has been transferred to the State of Idaho upon completion of the remedies.

6.3 Operable Unit 3

The remedy at OU 3 is expected to be protective of human health and the environment upon
completion. In the interim, where remedial activities have been completed to date, they have
adequately addressed exposure pathways that could result in unacceptable risks in these areas.
However, the ecological remedy included in the OU 3 ROD (USEPA, 2002a) and ROD
Amendment (USEPA, 2012a) is an interim remedy and therefore a final remedy will need to be
selected to fully address groundwater and surface water contamination. Implementation of
cleanup activities is presented in the Superfund Cleanup Implementation Plan (USEPA, 2013).
Although the Implementation Plan focuses on cleanup actions selected in the ROD
Amendment, it also identifies additional actions identified in other decision documents and
additional studies that EPA plans to conduct at the site, including the Lower Basin. EPA
continues to pursue data collection efforts in the Lower Basin to support the evaluation of
remedial alternatives for subsequent decision documents.

The Selected Remedy is designed to provide significant improvements to soil, sediments,
surface water, and groundwater, and to greatly reduce the risks posed to human health and the
environment within the Upper and Lower Basin. It is also expected to reduce the movement of
contaminated sediments downstream in the Lower Basin.

Although the remedial action in Basin residential and community areas has not been fully
implemented, environmental data indicate that the remedy is, in general, functioning as
intended by the 2002 OU 3 ROD. As property remediation progresses, soil and house dust lead
concentrations are declining, lead intake rates have been substantially reduced, and blood lead
levels have declined to levels that meet the RAOs. The low level of participation in the annual
Basin blood lead monitoring program remains a concern because it limits the identification of
children who might benefit from intervention.

In addition to cleanup work in the residential and community areas of OU 3, remedial work has
also been completed at a number of mine and mill sites in the Upper Basin as well as at
recreational sites along the Coeur d'Alene and Spokane rivers. In addition to consolidating
mine waste to reduce contaminant loading to surface water and groundwater, the remedial
actions at the mine and mill sites have included barriers or deterrents to all-terrain vehicle and
motorcycle use, which have reduced exposures and are functioning as designed.

6-2

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Remedial work at the recreational sites along the Coeur d'Alene River have largely involved
grading and capping contaminated materials, installation of site access controls, and
stabilization of adjacent eroded riverbank. Remedial actions at the Spokane River sites have
involved a combination of removing contaminated materials, capping, and installing deterrents
to recreational users. The remedies constructed at recreational sites along both the
Coeur d'Alene and Spokane Rivers are, in general, functioning as designed. A number of
additional privately owned recreational sites and informal, undeveloped sites have been
identified that may present a heavy metal exposure risk to recreationalists.

Three repositories have been designed, constructed, and operated pursuant to the 2002 OU 3
ROD to safely contain waste material and prevent the release of contaminants to surface water,
groundwater, or air in concentrations that would exceed state and/or federal standards. Based
on monitoring results in the last 5 years, the operation of these repositories has prevented the
release of contaminants to surface water, groundwater, or air in concentrations that would
exceed state and/ or federal standards.

In addition to the three repositories, the EFNM WCA, which is located in the upper reach of the
EFNM Creek Watershed, was constructed approximately 250 feet above EFNM Creek outside of
the alluvial valley and in an area that is relatively isolated from groundwater. The WCA was
completed in 2014 and began receiving waste from the Interstate Callahan Rock Dump. It is
expected to be operational for approximately 10 years and expanded to accommodate all the
waste from cleanup in EFNM.

USEPA, working with the USFWS and Ducks Unlimited, completed a cleanup and pilot study
project establishing nearly 400 acres of clean feeding habitat for migratory and resident swans,
ducks, and other wetland bird species in the Lower Basin. The agriculture to wetland
conversion project has demonstrated high water fowl usage on the East Field and an increasing
activity in the West Field as a result of restoration activities conducted by the Natural Resource
Trustees.

The 2002 OU 3 ROD did not identify any remedial actions for Coeur d'Alene Lake, where large
quantities of contaminated mining wastes have been deposited in lakebed sediments. The ROD
indicated that a management plan for the lake would be developed by the State of Idaho and
the Coeur d'Alene Tribe, with input from local, other state, and federal agencies to focus on
controlling riverine inputs of metals and nutrients that continue to contribute to contamination
of the Lake and Spokane River. An important milestone was achieved in March 2009 when the
State of Idaho and the Coeur d'Alene Tribe completed a significant revision to the Lake
Management Plan (LMP; IDEQ and Coeur d'Alene Tribe, 2009). Implementation of initial LMP
actions has begun and lake monitoring efforts are underway.

6-3

-------
-------
7 Next Five-Year Review

The CERCLA Section 121(c) requires the USEPA to perform a review of remedial actions that
result in hazardous substances, pollutants, or contaminants remaining at the Bunker Hill
Superfund Site at least every 5 years. The purpose of the review is to determine whether the
remedial actions, upon implementation, are protective of human health and the environment.
The trigger date for completion of these reviews is 5 years after initiation of the first remedial
action at the Site. The first remedial action at the Site started in 1995. Because onsite
containment of hazardous substances is part of the Site's Selected Remedy, the first Five-Year
Review was completed on September 27, 2000. The second Five-Year Review was completed on
October 24, 2005. The third Five-Year Review was completed on November 18, 2010.

The next review (the fifth Five-Year Review) of the Bunker Hill Superfund Site will be
conducted within 5 years of the completion date of this fourth Five-Year Review Report. The
fifth Five-Year Review Report will cover all remedial work, monitoring, and O&M activities
conducted at the Site. In addition, as stated in the 2002 OU 3 ROD, USEPA will continue to
evaluate implementation of the Coeur d'Alene Lake Management Plan (IDEQ and Coeur d'Alene
Tribe, 2009) in the next and future Five-Year Reviews to help determine whether CERCLA
remedial actions in the lake are necessary to protect human health and the environment.

7-1

-------
-------
8 References

ARCADIS. November 2009. BNSF UPRR Response Action Work Plan.

ARCADIS. October 14, 2010. Wallace-Mullan Branch Response Annual Maintenance and Repair
Summary Report for 2010. Prepared for Union Pacific Railroad.

ARCADIS. January 2, 2011 (2011a). Bunker Hill Superfund Site 2010 Annual Status Report for the
Union Pacific Area Operations and Maintenance Program. Prepared for Union Pacific Railroad
Company.

ARCADIS. August 9, 2011 (2011b). Spring 2011 Operations and Maintenance Inspection, Gypsum
Pond A-4 Closure Area. Prepared for Idaho Department of Environmental Quality.

ARCADIS. December 22, 2011 (2011c). 2011 Geophysical Survey Report, Gypsum Pond A-4 Closure.
Prepared for Stauffer Management Company LLC.

ARCADIS. October 14, 2011 (2011d). Wallace-Mullan Branch Response Annual Maintenance and
Repair Summary Report for 2011. Prepared for Union Pacific Railroad.

ARCADIS. January 10, 2012 (2012a). 2011 Annual Status Report Post-Closure Operations and
Maintenance Activities. Prepared for Union Pacific Railroad Company.

ARCADIS. March 5, 2012 (2012b). 2011 O&M Report, Gypsum Pond A-4 Closure. Prepared for
Stauffer Management Company LLC.

ARCADIS. July 6, 2012 (2012c). Spring 2012 Operations and Maintenance Inspection, Gypsum Pond
A-4 Closure Area. Prepared for Idaho Department of Environmental Quality.

ARCADIS. October 14, 2012 (2012d). Wallace-Mullan Branch Response Annual Maintenance and
Repair Summary Report for 2012. Prepared for Union Pacific Railroad.

ARCADIS. January 10, 2013 (2013a). 2012 Annual Status Report Post-Closure Operations and
Maintenance Activities. Prepared for Union Pacific Railroad Company.

ARCADIS U.S., Inc. January 28, 2013 (2013b). Fall 2012 Operations and Maintenance Inspection,
Gypsum Pond A-4 Closure Area. Prepared for Idaho Department of Environmental Quality.

ARCADIS. September 10, 2013 (2013c). Spring 2013 Operations and Maintenance Inspection,
Gypsum Pond A-4 Closure Area. Prepared for Idaho Department of Environmental Quality.

ARCADIS. May 9, 2013 (2013d). Union Pacific Railroad and BNSF Railway Company, Completion of
Element of Work Report: Wallace Yard Element of Work.

ARCADIS. May 9, 2013 (2013e). Union Pacific Railroad and BNSF Railway Company, Completion of
Element of Work Report: Canyon Creek Element of Work.

ARCADIS. May 9, 2013 (2013f). Union Pacific Railroad and BNSF Railway Company, Completion of
Element of Work Report: Ninemile Element of Work.

8-1

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

ARCADIS. July 10, 2013 (2013g). Union Pacific Railroad and BNSF Railway Company, Completion of
Element of Work Report: Hercules Hill Element of Work.

ARCADIS. September 17, 2013 (2013h). Maintenance and Repair Plan and Maintenance and Repair
Plan Addendum. Wallace Yard and Spur Lines. Hercules Mill Element of Work.

ARCADIS. October 14, 2013 (2013i). Wallace-Mullan Branch Response Annual Maintenance and
Repair Summary Report, October 2012 to September 2013. Prepared for Union Pacific Railroad.

ARCADIS. January 10, 2014 (2014a). 2013 Annual Status Report Post-Closure Operations and
Maintenance Activities. Prepared for Union Pacific Railroad Company.

ARCADIS. April 23, 2014 (2014b). Summary Report Union Pacific Railroad Wallace Yard and
Hercules Mill First Quarter 2014.

ARCADIS. July 3, 2014 (2014c). Summary Report Union Pacific Railroad Wallace Yard and Hercules
Mill Second Quarter 2014.

ARCADIS. October 23, 2014 (2014d). Summary Report Union Pacific Railroad Wallace Yard and
Hercules Mill Third Quarter 2014.

ARCADIS. October 14, 2014 (2014e). Wallace-Mullan Branch Response Annual Maintenance and
Repair Summary Report, for October 2013 to September 2014. Prepared for Union Pacific Railroad.

ARCADIS. January 9, 2015 (2015a). 2014 Annual Status Report Post-Closure Operations and
Maintenance Activities. Prepared for Union Pacific Railroad Company.

ARCADIS. February 2015 (2015b). Summary Report Union Pacific Railroad Wallace Yard and
Hercules Mill Fourth Quarter 2014.

Basin Environmental Improvement Project Commission (BEIPC). February 2003. Coeur d'Alene
Basin 5-Year (2004-2008) Recommended Work Plan. Prepared by Basin Commission Technical
Leadership Group for the Coeur d'Alene Basin Improvement Project Commission Board.

Basin Environmental Improvement Project Commission (BEIPC). May 17, 2010. Response to
Comments Upper Basin Repository Locations Osburn and Star Tailings Impoundments,
Shoshone County, Idaho.

Basin Environmental Improvement Project Commission (BEIPC). February 2012. 2011 Annual
Report.

Basin Environmental Improvement Project Commission (BEIPC). February 2014. 2013 Annual
Report.

Basin Environmental Improvement Project Commission (BEIPC). February 2015. 2014 Annual
Report.

Bergland, Jeff. May 25,1999. MDT Montana Wetland Assessment Method, Prepared for Montana
Department of Transportation and Morrison-Maierle, Inc.

Bureau of Land Management (BLM). 1999. GIS Coverage of Sources in the Coeur d'Alene River
Basin.

8-2

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

CDM/Parametrix. October 2007. Rex Mine and Mill Site Remedial Action and Reclamation Project,
Final Basis of Design Report. Prepared for USEPA Region 10.

CDM Smith. May 2013. Final Remedial Design Basis of Design Report; East Fork Ninemile Creek
Basin, Waste Consolidation Area; Bunker Hill Mining and Metallurgical Complex Superfund Site,
Operable Unit 3. Prepared for Successor Coeur d'Alene Custodial and Work Trust.

CDM Smith. September 25, 2014 (2014a). Final Remedial Action Completion Report; EFNM WCA
and Infrastructure. Prepared for Successor Coeur d'Alene Custodial and Work Trust.

CDM Smith. August 2014 (2014b). Final Remedial Design, Basis of Design Report, Lower Burke
Canyon Repository, Bunker Hill Mining and Metallurgical Complex Superfund Site, Operable Unit 3.

CDM Smith. January 23, 2015 (2015a). Final Basis of Design Report, Rex Mine and Mill Site
Stormwater Control Channel Lining Project. Submitted to: Successor Coeur d'Alene Custodial and
Work Trust.

CDM Smith. February 2015 (2015b). Final Remedial Design Basis of Design Report, Big Creek
Repository Annex, Bunker Hill Mining and Metallurgical Complex Superfund Site, Operable Unit 3.
Submitted to Successor Coeur d'Alene Custodial and Work Trust.

Centers for Disease Control and Prevention (CDC). January 2012. Low Level Lead Exposure Harms
Children: A Renewed Call for Primary Prevention. Report of the Advisory Committee on Childhood
Lead Poisoning Prevention.

CH2M HILL. 1991. Residential Soil Feasibility Study for the Bunker Hill CERCLA Site Populated
Areas RI/FS (2 Vols.). Boise, ID, Prepared for Idaho Department of Health and Welfare.

CH2M HILL. December 16,1999. Bunker Hill Hillsides Revegetation Conceptual Plan and
Monitoring Plan, Final, Bunker Hill Superfund Site, Kellogg, Idaho. Work Assignment No. 31-68-
0NX9, USEPA Contract No. 68-W9-0031, CH2M HILL Project No. 150981.FD.04. Prepared for
USEPA.

CH2M HILL. (2000a). CTP Master Plan. Central Treatment Plant Master Plan for Improvements.
Prepared for USEPA Region 10. December 2000.

CH2M HILL. August 31, 2000 (2000b). Technical Memorandum: Draft Final Conceptual Site Model
Summary and Update. Prepared for USEPA Region 10 and URS Corp.

CH2M HILL. November 6, 2002. (2002a) Technical Memorandum: Bunker Hill Superfund Site
Borrow Area Landfill Development and Closure, A Design, Operation, and Maintenance Summary.
Prepared for USEPA and IDEQ.

CH2M HILL. April 2002. (2002b) Bunker Hill CTP Discharge Quality and Monitoring Plan.

Prepared for USEPA Region 10.

CH2M HILL. 2004. Bunker Hill Mine Water Collection and Treatment System O&M Manual. Server-
based manual, prepared for U.S. EPA Region 10.

CH2M HILL. December 2006. Coeur d'Alene Riparian Songbird Ecological Risk Assessment.

Prepared for U.S. Environmental Protection Agency Region 10.

8-3

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

CH2M HILL. October 2007 (2007a). Phase I Remedial Action Assessment Report, Operable Unit 2,
Bunker Hill Mining and Metallurgical Complex Superjund Site. Prepared for USEPA Region 10.

CH2M HILL. June 2007 (2007b). Bunker Hill CTP Discharge Quality and Monitoring Plan. Prepared
for USEPA Region 10.

CH2M HILL. December 10, 2007 (2007c). Technical Memorandum. Post Remediation Subunit 7
Average Soil Lead Concentration: Schlepp Agriculture to Wetland Conversion, East Field. Prepared for
USEPA.

CH2M HILL. November 25, 2008. 2008 Post-Flood Opportunistic Sediment Sampling Lower Basin of
the Coeur d'Alene River.

CH2M HILL. August 2010. Enhanced Conceptual Site Model for the Lower Basin Coeur d'Alene River.
Prepared for USEPA Region 10.

CH2M HILL. March 23, 2012 (2012a). Statistical Analysis of Groundwater Monitoring Data for
Operable Unit 2. Technical Memorandum.

CH2M HILL. 2012b. Data Summary Report (2007-2012) and Adaptive Management Recommendations
for the Upper Coeur d'Alene Basin Remedial Action Monitoring Program, Shoshone County, Idaho.
Prepared for U.S. Environmental Protection Agency Region 10.

CH2M HILL. 2013a. Phase 1 Central Treatment Plant Upgrades Project Design Definition Report.

CH2M HILL. October 2013 (2013b). Design Considerations for Phase 1 and Phase 2 CTP Upgrades.
Prepared for USEPA Region 10.

CH2M HILL. 2013c. Central Impoundment Area Groundwater Collection System Design Definition
Report.

CH2M HILL. January 10, 2014 (2014a). Volume I: Schematic Design Report, Phase 1 Central
Treatment Plant Upgrades and Central Impoundment Area Groundwater Collection System. Revised
Draft. Bunker Hill Mining and Metallurgical Complex Superfund Site. Prepared for USEPA
Region 10.

CH2M HILL April 22, 2014 (2014b). Draft Technical Memorandum D-3, Sediment and Lead Budgets.
Prepared for U.S. Environmental Protection Agency Region 10.

CH2M HILL. September 9, 2014 (2014c). Data Gap Evaluation, Unpublished side deck. Prepared
for U.S. Environmental Protection Agency Region 10.

CH2M HILL. May 2015. Five-Year Data Summary, BEMP Sediment Monitoring Program, Water
Years 2010-2014. Draft. Prepared for USEPA.

Clark, G.M., and C.A. Mebane. 2014. Sources, Transport, and Trends for Selected Trace Metals and
Nutrients in the Coeur d'Alene and Spokane River Basins, Northern Idaho, 1990-2013. U.S. Geological
Survey Scientific Investigations Report 2014-5204, 62 p. http://pubs.usgs.gov/sir/2014/5204/.

Coeur d'Alene Tribe, Idaho Department of Environmental Quality (IDEQ), U.S. Environmental
Protection Agency (USEPA), and Union Pacific Railroad (UPRR). January 22, 2008. Response
Action Maintenance Plan (RAMP).

8-4

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Coeur d'Alene Tribe and State of Idaho. October 2010. Response Action Maintenance Plan, 2010
Annual Report.

Coeur d'Alene Tribe and State of Idaho. October 2011. Response Action Maintenance Plan, 2011
Annual Report.

Coeur d'Alene Tribe and State of Idaho. October 2012. Response Action Maintenance Plan, 2012
Annual Report.

Coeur d'Alene Tribe and State of Idaho. October 2013. Response Action Maintenance Plan, 2013
Annual Report.

Coeur d'Alene Tribe and State of Idaho. October 2014. Response Action Maintenance Plan, 2014
Annual Report.

Franson, J.C. and D. Pain. 2011. "Lead in birds." In: Beyer W.N., Meador J.P., editors,
Environmental contaminants in biota: Interpreting tissue concentrations, 2nd. Ed. Boca Raton, FL:
Taylor and Francis, pp 563-594.

Hansen, James A. August 30, 2007. Songbird Exposure to Lead-Contaminated Soils in the Coeur
d'Alene Basin. Prepared for U.S. Fish and Wildlife Service.

Hydrometrics, Inc. October 2010. Final Post Closure Operations and Maintenance Plan Page Pond
Area.

Hydrometrics, Inc. April 11, 2011. Bunker Hill Superfund Site Page Pond Reasonably Segregable Area
- Completion of Remedial Action Certification Report. Prepared for Upstream Mining Group.

Idaho Department of Environmental Quality (IDEQ). January 12, 2011 (2011a). Memorandum:
Bunker Hill Superfund Site Operations and Maintenance Fall 2010. Prepared for U.S. Environmental
Protection Agency Region 10.

Idaho Department of Environmental Quality (IDEQ). November 2, 2011 (2011b). Memorandum:
Bunker Hill Superfund Site Operations and Maintenance Fall 2011. Prepared for U.S. Environmental
Protection Agency Region 10.

Idaho Department of Environmental Quality (IDEQ). 2012a. Beneficial Use Reconnaissance
Program Field Manual for Streams.

Idaho Department of Environmental Quality (IDEQ). July 8, 2012b. Roadway Surface Remediation
Strategy for the Bunker Hill Mining and Metallurgical Complex Superfund Site. Prepared for USEPA
Region 10.

Idaho Department of Environmental Quality (IDEQ). November 19, 2012c. Memorandum: Bunker
Hill Superfund Site Operations and Maintenance Fall 2012. Prepared for U.S. Environmental
Protection Agency Region 10.

Idaho Department of Environmental Quality (IDEQ). June 19, 2013 (2013a). Memorandum:

Bunker Hill Superfund Site Operations and Maintenance Spring 2013. Prepared for U.S.
Environmental Protection Agency Region 10.

8-5

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Idaho Department of Environmental Quality (IDEQ). November 6, 2013 (2013b). Memorandum:
Bunker Hill Superfund Site Operations and Maintenance Fall 2013. Prepared for U.S. Environmental
Protection Agency Region 10.

Idaho Department of Environmental Quality (IDEQ). December 11, 2014 (2014a). Memorandum:
Bunker Hill Superfund Site Operations and Maintenance Fall 2014. Prepared for U.S. Environmental
Protection Agency Region 10.

Idaho Department of Environmental Quality (IDEQ). July 18, 2014 (2014b). Memorandum: Bunker
Hill Superfund Site Operations and Maintenance Spring 2014. Prepared for U.S. Environmental
Protection Agency Region 10.

Idaho Department of Environmental Quality (IDEQ). July 2014. (2014c) 2014 Remedial Design
Report - Bunker Hill Mining and Metallurgical Complex Superfund Site Operable Unit 3, Human
Health Response, Coeur d'Alene Basin Project Residential, Commercial and Rights-of-Way.

Idaho Department of Environmental Quality (IDEQ). September 2014. (2014d) East Mission Flats
Repository 2013 Annual Water Quality Report.

Idaho Department of Environmental Quality (IDEQ). 2015. Operable Unit 2 Groundwater Annual
Data Summary Report for Calendar Year 2014.

Idaho Department of Environmental Quality (IDEQ) and City of Kellogg. July 23, 2014.

Interagency Cooperative Agreement, Remedy Protection Projects.

Idaho Department of Environmental Quality (IDEQ) and City of Pinehurst. May 12, 2014.

Interagency Cooperative Agreement, Remedy Protection Projects.

Idaho Department of Environmental Quality (IDEQ) and City of Smelterville. April 25, 2013.

Interagency Cooperative Agreement, Remedy Protection Projects.

Idaho Department of Environmental Quality (IDEQ) and City of Wardner. October 2, 2012.

Interagency Cooperative Agreement, Remedy Protection Projects.

Idaho Department of Environmental Quality (IDEQ) and Coeur d'Alene Tribe. March 2009. Lake
Management Plan.

Idaho Department of Environmental Quality (IDEQ) and Shoshone County. May 14, 2014.

Interagency Cooperative Agreement, Remedy Protection Projects.

Idaho Department of Environmental Quality (IDEQ) and TerraGraphics Environmental
Engineering (TerraGraphics). August 29, 2012. Basin Property Remediation Program Completion
Plan.

Idaho Department of Environmental Quality (IDEQ) and TerraGraphics Environmental
Engineering, Inc. (TerraGraphics). June 2014. Page Repository Westward Expansion 2013 Annual
Water Quality Report.

Idaho Department of Environmental Quality (IDEQ) and TerraGraphics Environmental
Engineering, Inc. (TerraGraphics). April 2015. Page Repository Westward Expansion 2014 Annual
Water Quality Report. Draft

8-6

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Idaho Department of Environmental Quality (IDEQ) and U.S. Environmental Protection Agency
(USEPA). December 2011. Final Bunker Hill Mining and Metallurgical Complex Waste Acceptance
Criteria.

Idaho Department of Environmental Quality (IDEQ) and U. S. Environmental Protection
Agency (USEPA). April 27, 2012. Revision to the House Dust Intervention Protocol in the Record of
Decision for Operable Unit 3 of the Bunker Hill Superfund Site.

Idaho Department of Environmental Quality (IDEQ) and U. S. Environmental Protection
Agency (USEPA). December 10, 2013. Analysis of Remedial Actions and Recommended Risk
Management Approaches for Public Unpaved Roads, Large and/or Flood-prone Properties, and
Recreational Areas Covered by the OU 3 Record of Decision.

Idaho Department of Environmental Quality (IDEQ) and U. S. Environmental Protection
Agency (USEPA). March 2015. Policy Statements and Technical Specifications for Development and
Construction of Limited Use Repositories in the Bunker Hill Superfund Site.

Jacobs Engineering Group (JEC), ICAIR, Life Systems Inc., and TerraGraphics Environmental
Engineering. 1989. Human Health Risk Assessment Protocol for the Populated Areas of the Bunker Hill
Superfund Site. Prepared for USEPA Region 10.

Laidlaw, M.A., H.W. Mielke, G.M. Filippelli, D.L. Johnson, and C.R. Gonzales. 2005.

"Seasonality and children's blood lead levels: developing a predictive model using climatic
variables and blood lead data from Indianapolis, Indiana, Syracuse, New York, and New
Orleans, Louisiana (USA)." Environmental Health Perspectives 113(6): 793-800.
http:/ / www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation
Mist uids=15929906.

Lanphear, B.P., and K.J. Roghmann. 1997. "Pathways of lead exposure in urban children."
Environmental Research, 74, 67-73. http://www.ncbi.nlm.nih.gov/pubmed/9339217.

Lanphear, B.P., R. Hornung, M. Ho, C.R. Howard, S. Eberle, and K. Knauf. 2002.

"Environmental lead exposure during early childhood." Journal of Pediatrics, 140,40-47.

Lanphear, B.P., P. Succop, S. Roda, and G. Henningsen. 2003. "The effect of soil abatement on
blood lead levels in children living near a former smelting and milling operation." Public Health
Report, 118, 83-91.

LFR, Inc. 2008a. Completion of Remedial Action Certification Report for Elizabeth Park - Montgomery
Gulch - Ross Ranch Reasonably Segregable Area. Prepared for Upstream Mining Group, Kellogg,
ID.

LFR, Inc. 2008b. Completion of Remedial Action Certification Report for Kellogg South of 1-90
Reasonably Segregable Area. Liberty Lake, WA. Prepared for Upstream Mining Group, Kellogg,

ID.

LFR, Inc. 2008c. Completion of Remedial Action Certification Report for Page Reasonably Segregable
Area. Prepared for Upstream Mining Group, Kellogg, ID.

LFR, Inc. 2008d. Completion of Remedial Action Certification Report for Pinehurst Reasonably
Segregable Area. Prepared for Upstream Mining Group, Kellogg, ID.

8-7

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

LFR, Inc. 2008e. Completion of Remedial Action Certification Report for Wardner Reasonably
Segregable Area. Prepared for Upstream Mining Group, Kellogg, ID.

LFR, Inc. July 21, 2010. Spring 2010 Operations and Maintenance Inspection, Gypsum Pond A-4
Closure Area. Prepared for Idaho Department of Environmental Quality.

LFR, Inc. January 13, 2011. Fall 2010 Operations and Maintenance Inspection, Gypsum Pond A-4
Closure Area. Prepared for Idaho Department of Environmental Quality.

Mack, D.E., and W. Yong. 2000. "Swainson's Thrush (Catharus ustulatus)." Account 540 in A.
Poole and F. Gill editors. The Birds of North America. The Birds of North America, Inc.,
Philadelphia, Pennsylvania, USA.

Manton, W.I., C.R. Angle, K.L. Stanek, Y.R. Reese, and T.J. Kuehnemann. 2000. "Acquisition and
retention of lead by young children." Environmental Research, 82, 60-80.

Maul Foster & Alongi, Inc. (MFA). March 13, 2012 (2012a). Osburn USBM Impoundment Site
Remedial Action Completion Report. Prepared for Coeur d'Alene Trust.

Maul Foster & Alongi, Inc. (MFA). December 20, 2012 (2012b). 2012 East Fork Ninemile Creek
Predesign Investigation Results Report. Prepared for the Coeur d'Alene Trust.

Maul Foster & Alongi, Inc. (MFA). September 20, 2013. Letter: 2012 and 2013 Osburn USBM Site
Evaluation and Maintenance Report. Prepared for Coeur d'Alene Custodial Trust.

Maul Foster & Alongi, Inc. (MFA). August 15, 2014 (2014a). Spring 2014 Operations and
Maintenance Inspection, Gypsum Pond A-4 Closure Area. Prepared for Idaho Department of
Environmental Quality.

Maul Foster & Alongi, Inc. (MFA). January 17, 2014 (2014b). Memorandum: Remedial Action
Memorandum of Completion for Dewey Street and Third Street Remedy Protection Projects. To Anne
McCauley, U.S. Environmental Protection Agency.

Maul Foster & Alongi, Inc. (MFA). January 16, 2014 (2014c). Memorandum: Remedial Action
Memorandum of Completion for Unnamed Gulch Remedy Protection Project. To Anne McCauley, U.S.
Environmental Protection Agency.

Maul Foster & Alongi, Inc. (MFA). November 21, 2014 (2014d). Operations and Maintenance
Manual; US Bureau of Mines Impoundment Site; Osburn, Idaho. Prepared for Successor Coeur
d'Alene Custodial and Work Trust.

Maul Foster & Alongi, Inc. (MFA). November 24, 2014 (2014e). Letter: 2014 Site Evaluation Report.
Prepared for Coeur d'Alene Custodial Trust.

Maul Foster & Alongi, Inc. (MFA). January 22, 2014 (2014f). 2013 Trust Water Monitoring Report.
Prepared for Coeur d'Alene Trust.

Maul Foster & Alongi, Inc. (MFA). December 24, 2014 (2014g). Memorandum: Construction
Summary Memorandum for the Kahnderosa Bank Remediation Pilot Project. To Ed Moreen, U.S.
Environmental Protection Agency.

8-8

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Maul Foster & Alongi, Inc. (MFA). February 23, 2015 (2015a). 2014 Fall Water Quality Report,
Gypsum Pond A-4 Closure Area, Bunker Hill Superfund Site, Kellogg, Idaho. Prepared for Stauffer
Management Company LLC.

Maul Foster & Alongi, Inc. (MFA). February 23, 2015 (2015b). Fall 2014 Operations and
Maintenance Inspection, Gypsum Pond A-4 Closure Area. Prepared for Idaho Department of
Environmental Quality.

Maul Foster & Alongi, Inc. (MFA). February 12, 2015 (2015c). Memorandum: Remedial Action
Construction Summary Memorandum for the Meyer Creek Remedy Protection project. To Anne
McCauley, US Environmental Protection Agency.

Maul Foster & Alongi, Inc. (MFA). January 19, 2015 (2015d/). Memorandum: Remedial Action
Construction Summary Memorandum for the Shields Gulch Remedy Protection Project. To Anne
McCauley, US Environmental Protection Agency.

Maul Foster & Alongi, Inc. (MFA). March 16, 2015 (2015e). 2014 Coeur d'Alene Trust Water
Monitoring Report. Prepared for Successor Coeur d'Alene Custodial and Work Trust.

Maul Foster & Alongi, Inc. (MFA). January 15, 2015 (2015f). Success Complex Remedial Design
Investigation Report. Prepared for Successor Coeur d'Alene Custodial and Work Trust.

Maul Foster & Alongi, Inc. (MFA). March 2015 (2015g). Memorandum: 2014 Ninemile Creek Basin
Mass Load Assessment. To Dan Meyer, Coeur d'Alene Trust.

McCulley, Frick, and Gilman (MFG). 1992. Bunker Hill Superfund Site, Remedial Investigation
Report.

McCulley, Frick, and Gilman (MFG). 1995. Page Pond Closure Final Remedial Design Report.

McCulley, Frick, and Gilman (MFG). April 1996. Bunker Hill Superfund Site, Gypsum A-4 Closure,
Final Remedial Design Report. Prepared for Stauffer Management Company.

McCulley, Frick, and Gilman (MFG). 1997. Completion of Remedial Action Certification Report for
Smelterville Reasonably Segregable Area. Prepared for Upstream Mining Group, Kellogg, ID.

McCulley, Frick, and Gilman (MFG). 1999. Completion of Remedial Action Certification Report for
Kellogg North of 1-90 Reasonably Segregable Area. Prepared for Upstream Mining Group, Kellogg,
ID.

McCulley, Frick, and Gilman (MFG). 2001. UPRR Corridor Post-Closure Operations and
Maintenance Plan.

McCulley, Frick, and Gilman (MFG). September 2004. Bunker Hill Superfund Site, Gypsum Pond
A-4 Closure, Final Operations and Maintenance Plan. Prepared for Stauffer Management Company,
LLC.

North Wind, Inc. (North Wind). March 2011. Coeur d'Alene River Basin Remediation Program 2010
Completion Report.

North Wind, Inc. (North Wind). April 2012. Coeur d'Alene River Basin Property Remediation
Project: Remedial Construction Oversight and Quality Assurance 2011 Annual Completion Report.

8-9

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

North Wind Construction Services, LLC (North Wind Construction). March 2013. Coeur d'Alene
River Basin Property Remediation Project: Remedial Construction Oversight and Quality Assurance

2012 Annual Completion Report.

North Wind Construction Services, LLC (North Wind Construction). March 2014. Coeur d'Alene
River Basin Property Remediation Project: Remedial Construction Oversight and Quality Assurance

2013 Annual Completion Report.

North Wind Construction Services, LLC (North Wind Construction). March 2015 (2015a). Coeur
d'Alene River Basin Property Remediation Project: Remedial Construction Oversight and Quality
Assurance 2014 Annual Completion Report.

North Wind Construction Services, LLC (North Wind Construction). February 2015 (2015b).
Draft. 2014 Big Creek Repository Annual Operations Report. Prepared for Coeur d'Alene Trust.

North Wind Construction Services, LLC (North Wind Construction). March 2015 (2015c). Big
Creek Repository Operations Plan. Prepared for Coeur d'Alene Trust.

North Wind Construction Services, LLC (North Wind Construction). March 2015 (2015d). Draft.

2014 East Mission Flats Repository Annual Operations Report. Prepared for Coeur d'Alene Trust.

North Wind Construction Services, LLC (North Wind Construction). March 2015 (2015e). East
Mission Flats Repository Operations Plan. Prepared for Coeur d'Alene Trust.

North Wind, Inc./Pioneer Technical Services, Inc. (North Wind/Pioneer). March 14, 2014
(2014a). Upper Basin of the Bunker Hill Mining and Metallurgical Complex Superfund Site; East Fork
Ninemile Creek Basin; 100% Interstate-Callahan Upper and Lower Rock Dumps Basis of Design Report.
Prepared for Successor Coeur d'Alene Custodial and Work Trust.

North Wind, Inc./Pioneer Technical Services. (North Wind/Pioneer). March 14, 2014 (2014b).

Upper Basin of the Bunker Hill Mining and Metallurgical Complex Superfund Site, East Fork Ninemile
Creek Basin, Appendix E, Final 100% Interstate-Callahan Upper and Lower Rock Dumps Operation and
Maintenance (O&M) Plan. Prepared by Successor Coeur d'Alene Custodial and Work Trust.

Nur, N., S.L. Jones, and G.R. Geupel. 1999. A statistical guide to data analysis of avian monitoring
programs. U.S. Department of the Interior; Fish and Wildlife Service, BTP-R6001-1999,
Washington, D.C.

Panhandle Health District (PHD). May 1986. Kellogg Revisited - 1983: Childhood Blood Lead and
Environmental Status Report. Kellogg, ID.

Panhandle Health District (PHD). March 25,1999. Overview of the Silver Valley Lead Health
Intervention Program, Bunker Hill Superfund Site.

Panhandle Health District (PHD). December 15, 2011 (2011a). Flood Report 2010-2011.

Panhandle Health District (PHD). August 17, 2011 (2011b). City of Kellogg Hillside Fire.

Panhandle Health District (PHD). April 2013 (2013a). Flood Report 2012.

Panhandle Health District (PHD). October 2013 (2013b). Coeur d'Alene River System Recreation
Sites.

8-10

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Panhandle Health Department (PHD) and TerraGraphics Environmental Engineering
(TerraGraphics). March 20, 2006. Final Performance and Closeout Report for Comparison of HUD
Risk Assessment Methodology to Methods Used at the Bunker Hill Superjund Site in Idaho for the
Identification of Risk from Lead in House Dust. Grant # IDLTS0096-03. Prepared for
U.S. Department of Housing and Urban Development.

Parametrix. December 15, 2011. Operations and Maintenance Manual; US Bureau of Mines
Impoundment Site; Osburn, Idaho. Prepared for USEPA Region 10, Seattle, Washington.

Pioneer Technical Services, Inc. (Pioneer). January 2015. Upper Basin of the Bunker Hill Mining and
Metallurgical Complex Superfund Site - East Fork Ninemile Creek Basin; Final Interstate-Callahan
Upper and Lower Rock Dumps Interim Construction Report. Prepared for Successor Coeur d'Alene
Custodial and Work Trust.

SAIC. November 1991. Ecological Risk Assessment for the Bunker Hill Superfund Site. Prepared for
USEPA.

Spalinger, S.M., M.C. von Braun, V. Petrosyan and I.H. von Lindern. 2007. "Northern Idaho
House Dust and Soil Lead Levels Compared to the Bunker Hill Superfund Site." Environmental
Monitoring and Assessment, Vols. 130, pp 57-72.

Succop, P., R. Bornschein, K. Brown, and C.Y. Tseng. 1998. "An empirical comparison of lead

exposure pathway models." Environmental Health Perspectives, 106 Suppl 6,1577-83.

http:/ / www.ncbi.nlm.nih.eov/pubmed/?term=An+empirical+comparison+of+lead+exposure

+pathwav+models.

TerraGraphics Environmental Engineering (TerraGraphics). 1990. Risk Assessment Data
Evaluation Report (RADER) for the Populated Areas of the Bunker Hill Superfund Site. USEPA Region
10 and Idaho Department of Health and Welfare Division of Environmental Quality.

TerraGraphics Environmental Engineering (TerraGraphics). 2001. Operations and Maintenance
Plan, Milo Creek Structures and Outfall. October 2, 2001.

TerraGraphics Environmental Engineering (TerraGraphics). 2002. 2001 Interior House Dust Data
Summary Report. Prepared for Idaho Department of Environmental Quality (IDEQ).

TerraGraphics Environmental Engineering (TerraGraphics). March 2004. Final Human Health
Remedial Evaluation Report (HHRE) for the Bunker Hill Superfund Site Box. Prepared for USEPA
Region 10 and Idaho Department of Health and Welfare Division of Environmental Quality.

TerraGraphics Environmental Engineering (TerraGraphics). 2005. Bunker Hill Superfund Site
OU1 House Dust Status and Rights-of-Way Recontamination Report. Prepared for Idaho
Department of Environmental Quality. October 31, 2005.

TerraGraphics Environmental Engineering (TerraGraphics). 2006. Final Coeur d'Alene Basin Blood
Lead Absorption and Exposure Report.

TerraGraphics Environmental Engineering (TerraGraphics). 2008 (2008a). Background and
Rationale for Proposed Modifications to the Bunker Hill Superfund Site OU 1 House Dust Remedial
Action Objectives.

8-11

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TerraGraphics Environmental Engineering (TerraGraphics). February 22, 2008 (2008b). Smelter
Closure Area Final Operation and Maintenance Manual. Prepared for Idaho Department of
Environmental Quality and Panhandle Health District.

TerraGraphics Environmental Engineering, Inc. September 23, 2008 (2008c) . Sampling Decision
Tree and "Large" Property Sampling Approach - Rev. 5, Final.

TerraGraphics Environmental Engineering (TerraGraphics). May 12, 2008 (2008d). 2006 Draft
Basin House Dust Data Evaluation Technical Memorandum. Prepared for Idaho Department of
Environmental Quality and U.S. Environmental Protection Agency.

TerraGraphics Environmental Engineering (TerraGraphics). March 17, 2009 (2009a). Central
Impoundment Area Final Operation and Maintenance Manual. Prepared for Idaho Department of
Environmental Quality (IDEQ).

TerraGraphics Environmental Engineering (TerraGraphics). June 5, 2009 (2009b). East Mission
Flats Repository 90% Design Report. Prepared for Idaho Department of Environmental Quality.

TerraGraphics Environmental Engineering (TerraGraphics). 2010a. The Hillsides Operation and
Maintenance Manual. Prepared for Idaho Department of Environmental Quality (IDEQ).

TerraGraphics Environmental Engineering (TerraGraphics). 2010b. Government Gulch Operation
and Maintenance Manual. Prepared for Idaho Department of Environmental Quality (IDEQ).

TerraGraphics Environmental Engineering (TerraGraphics). 2010c. The Gulches - Including
Deadwood Gulch, Magnet Gulch, and Railroad Gulch/Boulevard Area - Operation and Maintenance
Manual. Prepared for Idaho Department of Environmental Quality (IDEQ).

TerraGraphics Environmental Engineering (TerraGraphics). 2010d. Smelterville Flats Operation
and Maintenance Manual. Prepared for Idaho Department of Environmental Quality (IDEQ).

TerraGraphics Environmental Engineering (TerraGraphics). 2010e. Bunker Creek Operation and
Maintenance Manual. Prepared for Idaho Department of Environmental Quality (IDEQ).

TerraGraphics Environmental Engineering (TerraGraphics). November 5, 2010. (2010f) Draft
Assessment of Residential and Community Mean Soil Exposure Indices in Operational Unit 3, Bunker
Hill Superfund Site: Revision 1.

TerraGraphics Environmental Engineering (TerraGraphics). June 9, 2011 (2011a). Substantive
Compliance with the Clean Water Act Section 404 Page Repository Expansion Wetland Impact
Evaluation Bunker Hill Box, Operable Unit 2.

TerraGraphics Environmental Engineering (TerraGraphics). August 25, 2011 (2011b). Addendum
to the Sampling and Analysis Plan (SAP)/ Quality Assurance Project Plan (QAPP) for the 2011
Property Sampling in the Coeur d'Alene River Basin of Idaho.

TerraGraphics Environmental Engineering (TerraGraphics). April 10, 2012. Sampling and
Analysis Plan (SAP)/Quality Assurance Project Plan (QAPP) for the 2012 Property Sampling in the
Bunker Hill Mining and Metallurgical Complex Superfund Site.

TerraGraphics Environmental Engineering (TerraGraphics). 2013a. Sierra Nevada Road Operation
and Maintenance Manual.

8-12

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TerraGraphics Environmental Engineering (TerraGraphics). 2013b. Grouse Creek Operation and
Maintenance Manual.

TerraGraphics Environmental Engineering (TerraGraphics). September 2013 (2013c). Bunker Hill
Mining and Metallurgical Complex Superjund Site Operable Units 1 and 2 Page Repository Westward
Expansion Final Design Report.

TerraGraphics Environmental Engineering (TerraGraphics). April 18, 2013 (2013d). West End
Natural Infiltration Wetland Monitoring, Evaluation, and Maintenance Plan. Prepared for Idaho
Department of Environmental Quality.

TerraGraphics Environmental Engineering (TerraGraphics). April 11, 2013 (2013e). Sampling and
Analysis Plan (SAP)/Quality Assurance Project Plan (QAPP) for the 2013 Property Sampling in the
Bunker Hill Mining and Metallurgical Complex Superjund Site.

TerraGraphics Environmental Engineering (TerraGraphics). 2013f. 2012 and 2013 New Dust Mat
Testing Results. Memorandum to IDEQ.

TerraGraphics Environmental Engineering (TerraGraphics). September 8, 2014 (2014a). Technical
Memorandum: Repository Waste Management and Planning Strategy 2014 Update. Prepared for D.
Carpenter, Idaho Department of Environmental Quality.

TerraGraphics Environmental Engineering (TerraGraphics). May 23, 2014 (2014b). West End
Natural Infiltration Wetland Annual Monitoring Report - 2013. Prepared for Idaho Department of
Environmental Quality.

TerraGraphics Environmental Engineering (TerraGraphics). June 27, 2014 (2014c). West End
Natural Infiltration Wetland Monitoring, Evaluation, and Maintenance Plan Update 1. Prepared for
Idaho Department of Environmental Quality.

TerraGraphics Environmental Engineering (TerraGraphics). March 20, 2014 (2014d). Sampling
and Analysis Plan (SAP)/Quality Assurance Project Plan (QAPP) for the 2014 Property Sampling in
the Bunker Hill Mining and Metallurgical Complex Superjund Site.

TerraGraphics Environmental Engineering (TerraGraphics). June 2014 (2014e). Draft 2013 House
Dust Data Summary Report for the Bunker Hill Mining and Metallurgical Complex Superjund Site.

TerraGraphics Environmental Engineering (TerraGraphics). November 14, 2014 (2014f). Bunker
Hill Mining and Metallurgical Complex Superjund Site Operable Unit 3 Mill Road Remedy Protection
Project Final Design Report, Mullan, ID. Prepared for Coeur d'Alene Trust.

TerraGraphics Environmental Engineering (TerraGraphics). March 7, 2014 (2014g). Big Creek
Repository 2012 Water Monitoring Annual Report. Prepared for Idaho Department of
Environmental Quality.

TerraGraphics Environmental Engineering (TerraGraphics). 2015. (2015a) Bunker Hill Mining
and Metallurgical Complex Superjund Site OU 1 2013 House Dust and Blood Lead Data Evaluation and
Risk Management Evaluation. Prepared for Idaho Department of Environmental Quality (IDEQ).

TerraGraphics Environmental Engineering (TerraGraphics). March 20, 2015 (2015b). Draft 2014
West End Natural Infiltration Wetland Annual Monitoring Report. Prepared for Idaho Department
of Environmental Quality.

8-13

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

TerraGraphics Environmental Engineering (TerraGraphics). February 28, 2015 (2015c). Basin
Property Remediation Program Completion Status Report.

TerraGraphics Environmental Engineering (TerraGraphics). February 2015 (2015e). Bunker Hill
Mining and Metallurgical Complex Superjund Site Operable Unit 3 Revenue Gulch Remedy Protection
Project Final Design Report, Silverton, ID. Prepared for Coeur d'Alene Trust.

TerraGraphics Environmental Engineering (TerraGraphics). January 9, 2015. (2015f) Repository
Closure Design Assessment. Prepared for Idaho Department of Environmental Quality.

TerraGraphics Environmental Engineering (TerraGraphics), URS Greiner, and CH2M HILL.

July 2001. Final Baseline Human Health Risk Assessment for the Coeur d'Alene Basin Extending from
Harrison to Mullan on the Coeur d'Alene River and Tributaries, Remedial Investigation/Feasibility
Study. Prepared for IDH W, Division of Health; IDEQ; and USEPA Region 10.

Upstream Mining Group (UMG). July 1,1998. Addendum to the Completion of Remedial Action
Certification Report for the Reasonably Segregable Area of Smelterville.

United States v. Hecla Limited. Amended July 9, 2014. Case number 3:96 cv-001422-EJL.

U.S. Army Corps of Engineers (USACE). December 20, 2000. Reed Landing Flood Control Project
Operations and Maintenance Manual.

U.S. Army Corps of Engineers (USACE). March 5, 2010. Construction Completion Report Rex Mine
& Mill Site Shoshone County, Wallace, ID. Bunker Hill Mine and Metallurgical Complex Operable
Unit 03 Coeur d'Alene Basin, Idaho.

U.S. Environmental Protection Agency (USEPA). August 1986. Interim Site Characterization
Report for the Bunker Hill Site. Prepared by Woodward-Clyde Consultants and TerraGraphics.

U.S. Environmental Protection Agency (USEPA). August 1991. Record of Decision, Bunker Hill
Mining and Metallurgical Complex Residential Soils Operable Unit, Shoshone County, Idaho.
http:/ / www.epa.gov/superfund/sites/rods/fulltext/rl091028.pdf.

U.S. Environmental Protection Agency (USEPA). 1992. Record of Decision, Bunker Hill Mining and
Metallurgical Complex [Non-Populated Area], Shoshone County, Idaho. September 1992. (Although
not in the title, this ROD addressed the non-populated areas of the site, as well as aspects of the
populated areas that were not addressed in the 1991 OU 1 ROD.)
http:/ / www.epa.gov/superfund/sites/rods/fulltext/rl092041.pdf.

U.S. Environmental Protection Agency (USEPA). 1994a. Revised Interim Soil Lead Guidance for
CERCLA Sites and RCRA Corrective Action Facilities. USEPA 540/F-94/043. OSWER Directive
No. 9355.4-12. Washington, D.C.

U.S. Environmental Protection Agency (USEPA). 1994b. Guidance for Assessing Chemical
Contaminant Data for Use in Fish Advisories. Volume II: Risk Assessment and Fish Consumption
Limits. Office of Water EPA823-B-94-004.

U.S. Environmental Protection Agency (USEPA). 1995a. Guidance for Assessing Chemical
Contamination Data for Use in Fish Advisories. Volume IV: Risk Communication. Office of Water
EPA823-R-95-001.

8-14

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

U.S. Environmental Protection Agency (USEPA). 1995b. Remedial Design/Remedial Action
Handbook. Publication Number: EPA 540/R-95/059. June 1995.

U.S. Environmental Protection Agency (USEPA). September 3,1996 (1996a). Amendment to the
Record of Decision for the Bunker Hill Mining and Metallurgical Complex (Non-Populated Areas)
Superfund Site. USEPA/AMD/R10-96/146. USEPA ID: IDD048340921.

U.S. Environmental Protection Agency (USEPA). January 1996 (1996b). Explanation of Significant
Differences for Revised Remedial Actions at the Bunker Hill Superfund Site, Shoshone County, Idaho.

U.S. Environmental Protection Agency (USEPA). 1996c. Guidance for Assessing Chemical
Contamination Data for Use in Fish Advisories. Volume III: Risk Management. Office of Water
EPA823-R-95-00x.

U.S. Environmental Protection Agency (USEPA). April 1998 (1998a). Explanation of Significant
Differences for Revised Remedial Actions at the Bunker Hill Superfund Site OU 2, Shoshone County,
Idaho. USEPA/ESD/R10-98/037. USEPA ID: IDD048340921.

U.S. Environmental Protection Agency (USEPA). August 1998 (1998b). Clarification to the 1994
Revised Interim Soil Lead Guidance for CERCLA Sites and RCRA Corrective Action Facilities. USEPA
540-F-98/030. OSWER Directive No. 9200.4-2P. Washington, D.C.

U.S. Environmental Protection Agency (USEPA). January 1999a. Engineering Evaluation/Cost
Analysis Response Action under the Comprehensive Environmental Response Compensation and
Liability Act Union Pacific Railroad Wallace-Mullan Branch. USEPA Region 10.

U.S. Environmental Protection Agency (USEPA). 1999b. Guidance for Assessing Chemical
Contaminant Data for Use in Fish Advisories. Volume I: Fish Sampling and Analysis. 3rd edition -
Draft. Office of Water EPA823-R-99-007.

U.S. Environmental Protection Agency (USEPA). September 27, 2000 (2000a). Bunker Hill
Populated Areas Operable Unit First Five Year Review Report. Seattle, WA. USEPA Region 10.

U.S. Environmental Protection Agency (USEPA). September 28, 2000 (2000b). First 5-Year Review
of the Non-Populated Area Operable Unit, Bunker Hill Mining and Metallurgical Complex, Shoshone
County, Idaho. USEPA Report.

U.S. Environmental Protection Agency (USEPA). June 2001 (2001a). Comprehensive Five-Year
Review Guidance. USEPA 540-R-01-007.

U.S. Environmental Protection Agency (USEPA). December 10, 2001 (2001b). Record of Decision
Amendment: Bunker Hill Mining and Metallurgical Complex Acid Mine Drainage, Smelterville, Idaho,
United States Environmental Protection Agency. USEPA/541/R-02/105. USEPA ID:
IDD048340921. http://www.epa.gov/superfund/sites/rods/fulltext/al002604.pdf.

U.S. Environmental Protection Agency (USEPA). April 2001 (2001c). Bunker Hill Mine Water
Management Remedial Investigation/Feasibility Study. Prepared by CH2M HILL.

U.S. Environmental Protection Agency (USEPA) October 2001 (2001d). Coeur d'Alene Basin
Remedial Investigation/Feasibility Study, Remedial Investigation, Final (Revision 2). Prepared by URS
Greiner Inc. and CH2M HILL.

8-15

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

U.S. Environmental Protection Agency (USEPA). October 2001 (2001e). Coeur d'Alene Basin
Remedial Investigation/Feasibility Study, Feasibility Study Report, Final. Prepared by URS-Greiner
Inc. and CH2M HILL.

U.S. Environmental Protection Agency (USEPA). September 12, 2002 (2002a). Record of Decision,
Bunker Hill Mining and Metallurgical Complex Operable Unit 3 (Coeur d'Alene Basin), Shoshone
County, Idaho. USEPA DCN: 2.9.

U.S. Environmental Protection Agency (USEPA). April 2002 (2002b). Fish Investigation Plan,
Coeur d'Alene Basin. U.S. Environmental Protection Agency, Region 10. Prepared by URS
Greiner, Seattle, WA.

U.S. Environmental Protection Agency (USEPA). March 2004. Basin Environmental Monitoring
Plan - Bunker Hill Mining and Metallurgical Complex, OU 3.

U.S. Environmental Protection Agency (USEPA). October 2005. Five-Year Review Report: Second
Five-Year Review for the Bunker Hill Mining and Metallurgical Complex Superfund Site, Operable
Units 1, 2, and 3, Idaho and Washington.

U.S. Environmental Protection Agency (USEPA). January 2006. Environmental Monitoring Plan
Operable Unit 2. Bunker Hill Mining and Metallurgical Complex Superfund Site. Prepared for
USEPA.

U.S. Environmental Protection Agency (USEPA). 2007a. Technical Support Document: Estimation
of Relative Bioavailability of Lead in Soil and Soil-Like Materials Using In Vivo and In Vitro Methods.
Report no. OSWER 9285.7-77.

U. S. Environmental Protection Agency (USEPA). September 2007b. Golconda Mine and Mill Site
Shoshone County, Idaho Coeur d'Alene Basin Operable Unit No. 3 Operations and Maintenance Plan.

U.S. Environmental Protection Agency (USEPA). June 2008 (2008a). Certification of Completion for
the Reasonably Segregable Area, Kellogg North of Interstate 90. Letter from Daniel D. Opalski,
Director, Environmental Cleanup Office to A1 Czarnowsky, Upstream Mining Group.

U.S. Environmental Protection Agency (USEPA). March 2008 (2008b). Engineering
Evaluation/Cost Analysis Wallace Yard and Spur Lines Response Action Under the Comprehensive
Environmental Response Compensation and Liability Act.

U.S. Environmental Protection Agency (USEPA). January 2009 (2009a). Risk Assessment Guidance
for Superfund Volume I: Human Health Evaluation Manual (Part F, Supplemental Guidance for
Inhalation Risk Assessment). Report no. OSWER 9285.7-82.

U. S. Environmental Protection Agency (USEPA). October 6, 2009 (2009b). Golconda Mine and
Mill Site Shoshone County, Idaho Coeur d'Alene Basin Operable Unit No. 3 DRAFT Operations and
Maintenance Plan.

U.S. Environmental Protection Agency (USEPA). July 12, 2010 (2010a). Proposed Plan, Upper
Basin of the Coeur d'Alene River, Bunker Hill Mining and Metallurgical Complex
Superfund Site.

U.S. Environmental Protection Agency (USEPA). February 2010 (2010b). Draft Focused Feasibility
Study Report, Upper Basin of the Coeur d'Alene River, Bunker Hill Mining and Metallurgical Complex
Superfund Site. Prepared by CH2M HILL for U.S. Environmental Protection Agency Region 10.

8-16

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

U.S. Environmental Protection Agency (USEPA). November 2010 (2010c). Five-Year Review
Report: 2010 Five-Year Review for the Bunker Hill Mining and Metallurgical Complex Superfund Site,
Operable Units 1, 2 and 3, Idaho and Washington.

U.S. Environmental Protection Agency (USEPA). August 2012 (2012a). Interim Record of Decision
(ROD) Amendment, Upper Basin of the Coeur d'Alene River, Bunker Hill Mining and Metallurgical
Complex Superfund Site, http:/ /vosemite.epa.gov/rlO/cleanup.nsf/sites/bh+rod+amendment.

U.S. Environmental Protection Agency (USEPA). August 2012 (2012b). Focused Feasibility Study
Report Upper Basin of the Coeur d'Alene River, Bunker Hill Mining and Metallurgical Complex
Superfund Site. Final. Prepared by CH2M HILL.

U.S. Environmental Protection Agency (USEPA). 2012c. Standard Operating Procedure for an In
Vitro Bioaccessibility Assay for Lead in Soil. USEPA Report no. 9200.2-86.

U.S. Environmental Protection Agency (USEPA). June 2012 (2012d). Remedial Action Summary
Report. Prepared by USEPA Region 10.

U.S. Environmental Protection Agency (USEPA). February 2013. Superfund Cleanup
Implementation Plan, 2012 - 2022, Bunker Hill Mining and Metallurgic Complex Superfund Site.

U.S. Environmental Protection Agency (USEPA). January 21, 2014. Certification for Completion of
Work, Wallace Yard and Spur Lines Site, Civil Action No. 10-2009-0082.

U.S. Environmental Protection Agency (USEPA). July 22, 2015 (2015a). Modifications to Surface
Water Monitoring Program under the Basin Environmental Monitoring Program (BEMP).
Memorandum from Kim Prestbo/USEPA to file.

U.S. Environmental Protection Agency (USEPA). 2015b. CTP Discharge Requirements Technical
Memorandum.

U.S. Environmental Protection Agency (USEPA) and Idaho Department of Environmental
Quality (IDEQ). April 2003. State Superfund Contract Amendment for Time-Critical Acid Mine
Drainage Removal Activities.

U.S. Environmental Protection Agency (USEPA) and Idaho Department of Environmental
Quality (IDEQ). April 20, 2010. Consent Decree, UPRR (Union Pacific Railroad Company) and the
BNSF Railway Company v. United States of America and the State of Idaho. Civil Action, 04-20-2010,
available as 10-2009-0082, 75FR1412:

http://www.epa.gov/regionlO/pdf/sites/bunker hill/consent decree 042010.pdf.

U.S. Environmental Protection Agency (USEPA) and Idaho Department of Environmental
Quality (IDEQ). June 7, 2012. Memorandum for Agency Policy for Residential and Community Mean
Soil Lead Levels for Operable Unit 3, Bunker Hill Superfund Site. From Bill Ryan, USEPA and Rob
Hanson, IDEQ, To File.

U.S. Environmental Protection Agency (USEPA) and Idaho Department of Environmental
Quality (IDEQ). December 30, 2013. Community Fill Plan Using Metals-Impacted Materials with the
ICP Boundary.

8-17

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

U.S. Environmental Protection Agency (USEPA), Idaho Department of Environmental Quality
(IDEQ), Panhandle Health Department (PHD). 2007. Memorandum of Agreement among the US
Environmental Protection Agency Region X, the Idaho Department of Environmental Quality, and the
Panhandle Health District for the Bunker Hill Superfund Site OU3 Institutional Controls Program.

U.S. Environmental Protection Agency (USEPA), Idaho Department of Environmental Quality
(IDEQ), and Union Pacific Railroad Company (UPRR). November 2011. Environmental Covenant
for the Wallace Yard and Hercules Mill Site.

U.S. Environmental Protection Agency (USEPA) and Idaho Department of Health and Welfare
(IDHW). May 10,1994. Consent Decree; Bunker Hill; United States of America and State of
Idaho v. ASARCO Incorporated, Coeur d'Alene Mines Corporation, Callahan Mining
Corporation, Hecla Mining Company, Sunshine Precious Metals, Sunshine Mining Company;
Civil Action No. 94-0206-N-HLR.

U.S. Environmental Protection Agency (USEPA) and Idaho Department of Health and Welfare
(IDHW). April 1995. State Superfund Contract (SSC) and Corresponding Documents.

U.S. Fish and Wildlife Service (USFWS). 2010. Draft Schlepp Easement Management Guidance.

U.S. Fish and Wildlife Service (USFWS). 2014. Coeur d'Alene Basin Biological Monitoring, 2010-
2012 Annual Report, Bunker Hill Mining and Metallurgical Complex Superfund Site, Operable Units 2
and 3. Prepared for USEPA.

U.S. Fish and Wildlife Service (USFWS). 2015 in progress. Coeur d'Alene Basin Biological
Monitoring, 2013/2014 Annual Report, Bunker Hill Mining and Metallurgical Complex Superfund Site,
Operable Units 2 and 3. Prepared for USEPA.

U.S. Forest Service (USFS). May 27, 2015. Medimont Boat Launch Site Rehabilitation Construction
Report.

U.S. Geological Survey (USGS). 2005. Stream-Sediment Geochemistry in Mining-Impacted Streams:
Sediment Mobilized by Floods in the Coeur d'Alene-Spokane River System, Idaho and Washington.
Scientific Investigations Report 2005-5011.

U.S. Geological Survey (USGS). 2014. Sources, Transport, and Trends for Selected Trace Metals and
Nutrients in the Coeur d'Alene and Spokane River Basins, Northern Idaho, 1990-2013.

Von Lindern, I.H., Spalinger, S.M., Bero, B.N., Petrosyan, V. & von Braun, M.C. 2003a. "The
influence of soil remediation on lead in house dust." The Science of The Total Environment, 303,
59-78.

Von Lindern, I., Spalinger, S., Petroysan, V. and von Braun, M. 2003b. "Assessing remedial
effectiveness through the blood lead: Soil/ dust lead relationship at the Bunker Hill Superfund
Site in the Silver Valley of Idaho." The Science of The Total Environment, Vol. 303, Nos. 1-2, pp.
139-170.

Von Lindern, I., S. Spalinger, M. Stifelman, L. Wichers Stanek, and C. Bartrem. April 2015, in
progress. "Estimating Children's Soil/Dust Ingestion Rates Through Retrospective Analyses of
Blood Lead Biomonitoring from the Bunker Hill Superfund Site in Idaho." To be submitted to

Environmental Health Perspectives.

8-18

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

Washington State Department of Ecology (Ecology). April 2015. Monitoring, Sampling and
Analysis Report, Spokane River Shoreline Sediment Sites.

Yankel, A. J., I. H. von Lindern, and S. D. Walter. 1977. "The Silver Valley lead study: the
relationship between childhood blood lead levels and environmental exposure." Journal of the
Air Pollution Control Association, Vol. 27, No. 8. Pp. 763-767.

http:/ / www.ncbi.nlm.nih.gov/entrez / query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation
Mist uids=886085.

Zahran, S., M.A. La id law, S.P. McElmurry, G.M. Filippelli and M. Taylor (2013). "Linking source
and effect: resuspended soil lead, air lead, and children's blood lead levels in Detroit,

Michigan." Environ Sci Technol 47(6): 2839-2845.
http: / / www.ncbi.nlm.nih.eov/pubmed/23428083.

Zahran, S., H.W. Mielke, S.P. McElmurry, G.M. Filippelli, M.A. Laidlaw and M.P. Taylor (2013).
"Determining the relative importance of soil sample locations to predict risk of child lead
exposure." Environ Int 60: 7-14. http: / /www.ncbi.nlm.nih.gov/pubmed/23973618.

8-19

-------
-------
Appendix A

Coeur d'Alene Lake Management Plan

Introduction

Although Coeur d'Alene Lake is within the Bunker Hill Mining and Metallurgical Complex
Superfund Site (Bunker Hill Superfund Site), remedial actions for the lake were not selected in
the 2002 Interim Record of Decision (ROD). The U.S. Environmental Protection Agency
(USEPA) deferred a decision on whether to select remedial actions for the lake pending the
development and effective implementation of a revised Coeur d'Alene Lake Management Plan
(LMP), which was to be a revision of the 1996 LMP. USEPA concluded that "...an effective LMP
created outside of the CERCLA defined process, using separate regulatory authorities, would
reduce riverine inputs of nutrients and metals that continue to contribute to contamination of
the lake and the Spokane River" (Idaho Department of Environmental Quality [IDEQ] and
Coeur d'Alene Tribe, 2009). The ROD also addressed the possibility of future actions. One effect
of USEPA's decision was to limit its use of funds from the Superfund accounts created under
the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) to
address mining related water quality conditions in the lake.

The Coeur d'Alene Tribe (Tribe) and the Idaho Department of Environmental Quality (IDEQ)
share responsibility for water quality in Coeur d'Alene Lake under Clean Water Act (CWA)
authority. The Tribe and IDEQ collaboratively developed the 2009 LMP with the goal "to
protect and improve lake water quality by limiting Basin-wide nutrient inputs that impair lake
water quality conditions, which in turn influence the solubility of mining-related metals
contamination contained in lake sediments" (IDEQ and Coeur d'Alene Tribe, 2009) USEPA
assisted the Tribe and IDEQ by convening and participating in an Alternative Dispute
Resolution (ADR) process. USEPA includes lake management in its regular Five-Year Reviews
of ROD implementation progress, most recently in 2010. However, the 2009 LMP was not far
enough along to draw any conclusions at that time.

The LMP identifies objectives and strategies to accomplish the overall goal through ongoing
science, coordination with Coeur d'Alene River Basin (Basin) stakeholders, public outreach and
education, project implementation, and identification of potential funding sources. The status of
each of the objectives outlined in the LMP is summarized in the following section.

Status of Lake Management Plan Objectives

LMP Objective 1 - Improve Scientific Understanding of Lake Conditions through
Monitoring, Modeling, and Special Studies

The LMP highlights the need for an ongoing science program to understand water quality
trends better and to ensure management actions are efficient and effective. Monitoring,

A-1

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

modeling, and special studies are identified as strategies to achieve this objective. Progress in
these arenas is summarized in the following sections.

Monitoring

The LMP calls for consistent descriptions of water quality conditions from various sources. This
was identified during the ADR that IDEQ and the Tribe participated in to develop the LMP.

This section provides an update of Section 2.2 of the LMP based on monitoring conducted by
the Tribe and IDEQ (Lake Management Team or the Team).

Water quality data collected during 2008 to 2012 have been analyzed, with the following key
findings. All of the following findings are based on annual averages. There can be significant
seasonal deviations at specific locations throughout the lake. These variations will be addressed
in the subsequent synthesis.

• The data show a trend of increasing concentrations in the northern lake of total phosphorus
concentrations. Concentrations in the southern lake do not show a trend between the dataset
from 2003 to 2007 and the current dataset, but levels are higher than those observed in 1991
to 1992 are.

• Microscopic algae (phytoplankton), as measured by chlorophyll a, has increased lake-wide
since both the 1991 to 1992 dataset and the 2003 to 2007 dataset.

• Microscopic blue-green algae, as measured by the proportion of total bionumber, have
increased since the 1991-1992 dataset. Small blooms of potentially toxin-producing blue-
green algae have been observed at multiple locations within the lake during 2008 to 2012.

• Water clarity is greater now in the northern lake than it was in 1991 to 1992. There has been
no significant change since 2003 to 2007.

• Dissolved oxygen approaches zero in deeper (hypolimnetic) waters in the southern lake in
summer months. This is consistent with patterns observed in 1975,1991 to 1992, and 2003 to
2007. Dissolved oxygen in deeper waters of the northern lake typically stays above

6 milligrams per liter (mg/L). However, the current dataset shows levels dropping below
this level at times during summer months in the northern end of the lake.

• Dissolved zinc concentrations have steadily declined within upper waters of the lake, but
continue to exceed water quality standards consistently.

• Dissolved lead concentrations are higher than was observed in 2003 to 2007. However, total
(suspended) lead concentrations are lower than was observed in 1991 to 1992 at all locations
except the University Point monitoring site. Dissolved lead concentrations exceed water
quality standards during peak runoff months.

• Dissolved cadmium concentrations have not changed significantly since 2003 to 2007.

• Lakebed sediments remain contaminated with antimony, arsenic, cadmium, zinc, lead,
copper, silver, and mercury in much of the lake.

• Eurasian watermilfoil is established in the southern portion of the lake and has been
identified in shallow northern bays.

A-2

-------
APPENDIX A

COEUR D'ALENE LAKE MANAGEMENT PLAN

Based on current review of the available data, changes in a number of parameters have occurred
over time. It appears that there is a measured increase in phosphorus and microscopic algae,
which indicates a trend away from the state desired. This change warrants further investigation
to identify causes and help identify possible management solutions.

Overall, the data show that total metals concentrations are either stable or have generally
declined since the early 1990s. Except for total lead, the trends are continual. Trends in total
metals (based on annual averages) are summarized in the following list.

1. Total zinc levels have declined by approximately 40 percent since the early 1990s across all
sections of the lake. Relative to 1991 to 1992, these declines are significant to within

95 percent confidence.

2. Total cadmium levels are generally unchanged. However, in the northern pelagic zone, total
cadmium may have declined by around 5 percent since 2003 to 2007. This apparent decline
in the northern pelagic zone is significant to within 90 percent confidence.

3. Total lead levels in the northern and southern pelagic zones are variable, but have declined
by approximately 30 to 40 percent since the 1990s. Total lead levels in the central pelagic are
equivalent to their 1990s level. All observed declines relative to 1991 to 1992 are significant
to within 95 percent confidence.

Long-term Trends for Dissolved Metals

The dissolved metals dataset is less complete than that for total metals. However, the trends are
comparable for the period for which data are available. Overall, these data show that dissolved
zinc levels declined since 2003 to 2007 and that dissolved cadmium levels have remained
unchanged. Dissolved lead levels are higher than in 2003 to 2007 at all sampling locations.

Idaho Water Quality Standards are based upon dissolved fraction of metals and the state has
adopted site-specific criteria for certain dissolved metals on portions of the SFCDA River. The
Lake Management Plan developed "Triggers" for a variety of chemical and biological criteria,
which is referenced below. Trends in dissolved metals (based on annual averages) are
summarized in the following list.

1. Dissolved zinc levels have declined by 5 to 10 percent since the mid-2000s across all regions
of the lake. These declines are significant to within 95 percent confidence in the main lake
(pelagic) and to within 80 percent confidence within the northern bays (littoral).

2. Dissolved cadmium levels are unchanged across all regions of the lake.

3. Dissolved lead levels have increased in the northern lake between 2003 to 2007 and 2008 to
2012. These increases are significant to within 95 percent confidence in the northern bays
(littoral) and to within 85 percent confidence within the main lake (pelagic). Note that this
increase has only had a minimal impact on the frequency of trigger exceedance.

4. The dissolved lead trigger is intermittently exceeded in the southern pelagic region of the
lake.

5. Dissolved zinc trigger criteria are continuously exceeded in the northern and central regions
of the lake, but intermittently exceeded in the southern lake.

A-3

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

6. Dissolved cadmium and lead triggers are intermittently exceeded in the northern and
central regions of the lake, but not exceeded in the southern lake.

7. Trigger exceedances are most common in the central lake, closest to the Coeur d'Alene
River.

Long-term Trends for Dissolved Oxygen

Long-term trends in hypolimnetic dissolved oxygen vary according to water depth and location
within the lake. Dissolved oxygen levels are lowest in the southern lake with anoxic conditions
at the most southern site during summer months. However, annual minimum values do not
show a clear long-term trend since the early 1990s. Summer dissolved oxygen levels are higher
in the northern lake, but have declined since the early 1990s. These trends (based on annual
averages) are summarized in the following list.

1. Minimum summer oxygen levels are lower than they were in the early 1990s in the northern
and central pelagic zones, but are stable in the shallower regions of the southern pelagic
zone. Minimum oxygen levels are unchanged in the northern bays and southern littoral
zone.

2. Average summer oxygen levels in the overall hypolimnion are unchanged since the 1990s.

3. Average summer oxygen levels in the deepest portions of the hypolimnion that are more
sensitive to the lake's internal oxygen dynamics are lower than in the early 1990s in the
northern and central pelagic zones. This trend is larger and more continuous in the northern
pelagic zone than in the central pelagic zone.

4. Trigger exceedances are most common in the southern lake, where minimum summer
oxygen levels are consistently less than 4.0 mg/L and drop to 0 mg/L in the southern
littoral zone.

Long-term Trends for Trophic State Indicators

Phosphorus and chlorophyll a levels in the lake are increasing at all sampling locations. Water
clarity is generally greater than was observed in the early 1990s. Though the northern portion of
the lake is generally within the parameters of the preferred oligotrophic state (i.e., reduced
productivity, higher oxygen, clearer waters), these data suggest the lake is trending away from
this state. The southern portion of the lake has been mesotrophic since monitoring in 2003
began. These trends (based on annual averages) are summarized in the following list.

1. Total phosphorus levels have increased by about 1.5 to 2.5 times since the early 1990s across
all lake regions. This trend is consistent across the entire lake.

2. Maximum chlorophyll a values have increased by approximately 3 to 5 times since the early
1990s across all lake regions. This trend is consistent across the entire lake.

3. Geomean chlorophyll a values have increased by around 1.5 to 2.5 times since the early
1990s across all lake regions. This trend is consistent across the entire lake.

4. Water clarity has improved by approximately 15 percent since the early 1990s in the
northern lake.

A-4

-------
APPENDIX A

COEUR D'ALENE LAKE MANAGEMENT PLAN

Note that water clarity measures do stand in contrast to the other trophic state indicators, and
indicate that the lake's aesthetics have improved since the early 1990s. However, this
observation should be tempered by two factors:

• Water clarity is impacted by both sediment loading and phytoplankton productivity.

• This parameter is limited to the summer months when nutrient and chlorophyll a levels in
the lake are at their lowest.

Consequently, this clarity measure may reflect changes in sediment loading rather than lake
productivity and oxygen dynamics.

Long-term Trends for Biologic Indicators

Cyanobacteria are becoming more prevalent and Eurasian watermilfoil appears to be spreading
northward. Nitrogen to phosphorus ratio (TN:TP) data indicate that the lake is becoming more
nitrogen limited which could favor higher production of nitrogen-fixing cyanobacteria. The
technical literature suggests that the lake can be considered nitrogen-limiting if the TN/TP ratio
drops below 10. Such a condition would significantly increase the risk of blue-green algae
blooms. The bioindicator data indicate that cyanobacteria are becoming more prevalent and that
Eurasian watermilfoil appears to be spreading northward. Blooms of potentially toxin-
producing cyanobacteria have also been observed, though they appear to be sporadic. Blooms
that are more regular may occur in isolated bays, but current data are insufficient to assess this
possibility. These trends in biologic indicators and their relation to the TN/TP ratio are
summarized in the following list.

1. Since the early 1990s, cyanobacteria prevalence has increased to the point where total
cyanobacteria now consistently comprise around 35 to 40 percent of the phytoplankton
population throughout the lake. They now appear to be co-dominant with diatoms and
microflagellates.

2. Blooms of potentially toxin-producing cyanobacteria are common. These blooms were
thought to be absent or rare in the early 1990s.

3. Nitrogen to phosphorus ratios are steadily decreasing in a manner that is consistent with the
cyanobacteria trends. Total nitrogen to total phosphorus ratios at C5 (Blue Point) and C6
(Chatcolet) have dropped below 10 every year since 2004.

Modeling

The Estuary, Lake and Coastal Ocean Model - Computational Aquatic Ecosystem Dynamics
Model (ELCOM-CAEDYM) was identified as a model that would be used by the LMP team to
simulate Coeur d'Alene Lake system process, such as the following:

• Inflow loading of metals and nutrients and river plume flow through the lake;

• Sediment-water interactions;

• Primary production; and

• Organic matter cycling within the water column.

The model will enhance understanding of the complex dynamics of the lake system, and may
produce predictive results based on future land use changes within the Basin.

A-5

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

ELCOM-CAEDYM has been consistently improved since the initial model validation by
Dallimore et al. 2007 and Hipsey et al. 2007. The initial model validation relied on only one
meteorological station mounted on a buoy at mid-lake. Since 2011, the Tribe and IDEQ have
maintained four meteorological stations spanning the north/ south axis of Coeur d'Alene Lake.
Each station measures all meteorological variables in high temporal resolution required by
ELCOM-CAEDYM. The initial model validation did not use any zooplankton, so five
zooplankton groups were added, representing several trophic levels from predatory copepods
and herbivorous cladocerans, to early life stages of copepods and rotifers that are important
grazers on the microbial loop component of the lake's food web. A critical component of
modeling Coeur d'Alene Lake is the inflow and outflow of water temperature and chemical
constituents. The Tribe and IDEQ use the Basin Environmental Monitoring Plan (BEMP) water
quality data and U.S. Geological Survey (USGS) discharge data to estimate daily loading and
export of nutrients and metals in Coeur d'Alene Lake. The estimated daily loading and export
time series are input into ELCOM-CAEDYM as boundary conditions.

Current emphasis on model calibration includes the following:

• Temperature sensitivity analysis and tuning the model to optimize model accuracy to
predict the thermal structure of Coeur d'Alene Lake

• Calibrating the sediment diagenesis sub model in CAEDYM using parameters from past
sediment geochemistry studies of Coeur d'Alene Lake and the lower Coeur d'Alene River

Very limited phytoplankton data were available to the University of Western Australia Center
for Water Research team during the initial validation of ELCOM-CAEDYM to Coeur d'Alene
Lake. The next step in model refinement will be using the large phytoplankton database that
has been collected consistently from sites CI, C3, C4, C5, and C6 since 2007 to adjust
phytoplankton parameters in CAEDYM.

Special Studies

The LMP identified a need to improve knowledge and understanding of internal nutrient
cycling, metals release from sediments, food web toxicity, subsurface sewage systems impacts,
and other factors. Since 2009, the Team has collected data on aquatic macrophytes, benthic
macroinvertebrates, adjacent lakebed sediments, phytoplankton, picoplankton in bays, and
metals concentrations in size classes of zooplankton. Collection of data for these special studies
is a multi-year process. Analyses and reporting will be forthcoming once data collection is
complete in 2015. The LMP also began collecting data on the impact of anoxia on metals,
nutrients, and bioindicators at one site in the northern portion of the lake in 2013. Monitoring is
ongoing.

LMP Objective 2 - Establish and Strengthen Partnerships to Maximize Benefits of
Actions under Existing Regulatory Frameworks

The LMP relies on stakeholders to use existing tools and management actions to address
sediment and nutrient inputs to Coeur d'Alene Lake. The Management Action Tables (MATs)
included in the LMP document the jurisdictions of agencies, existing programs, best
management practices, and regulations that influence water quality. These MATs have been
used to coordinate partnerships in implementing the LMP. The MATs are currently undergoing
an audit process to determine the extent to which actions identified in them are being

A-6

-------
APPENDIX A

COEUR D'ALENE LAKE MANAGEMENT PLAN

implemented, evaluate the effectiveness of actions, identify items not being fully implemented,
evaluate resources needed to accomplish actions, and assess the commitment to continuing
actions identified (or develop new actions and strategies). The audit process is scheduled for
completion in 2015.

The audit has preliminarily identified the following completed actions:

• Kootenai County Parks and Waterways - upgrades of waterfront restroom facilities at
14 sites around Coeur d'Alene Lake, replacement of six antiquated sewage pump-out
stations on Coeur d'Alene Lake, and stormwater/erosion management improvements at
two boat launch ramps

• Kootenai County Community Development - Kootenai County adopted an updated
Comprehensive Plan since 2009. Subsequent efforts to revise land use code have resulted in
an amended site disturbance ordinance. Efforts to establish a land use code that aligns with
the comprehensive plan have been slowed by staff changes and changes in direction as new
county commissioners determine how to move forward. There is ongoing debate around the
protection of private property rights versus protection of shared public resources.
Waterfront protection has been especially contentious.

• Coeur d'Alene Tribe - The Tribe received approval in 2014 from USEPA for its water quality
standards.

The Team has been successful in utilizing partnerships to develop collaborative projects. An
example includes partnerships with the City of Coeur d'Alene, the University of Idaho (UI), and
the Panhandle Stormwater and Erosion Education Program (SEEP), to identify potential
waterfront and stormwater demonstration projects that will serve to both improve water quality
and provide community outreach opportunities to increase awareness of water quality impacts.
The Team has developed a partnership with the Watershed Advisory Group (WAG) in
tributaries to Coeur d'Alene Lake to work together on planning and implementation activities.
The Team has also been successful in collaborating with stakeholders in Washington to address
regional stormwater issues and further develop education and outreach opportunities. The
Team works with county natural resource advisory groups and county commissioners to
coordinate and exchange feedback on activities each entity is undertaking. This enhances
efficiency in connecting potential related efforts.

LMP Objective 3 - Develop and Implement a Nutrient Reduction Action Plan

In order to identify the magnitude and locations of nutrient sources, and in order to develop
priorities for addressing these sources in the Coeur d'Alene Lake Basin, the LMP identified
development of a nutrient reduction action plan as a major objective. The strategy identified to
develop the action plan included the following:

• Conducting a Basin-wide nutrient source inventory;

• Using the inventory to identify specific projects for implementation with management
agencies and other partners; and

A-7

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

• Incorporating the total maximum daily load (TMDL) process under the CWA, as well as
mitigation measures required by the Federal Energy Regulatory Commission (FERC) for
relicensing of the Avista hydroelectric project into the plan.

• Progress has been made in each of these components towards compiling the action plan.
Nutrient Inventory Status

The LMP identified a 3-year Basin-wide nutrient source inventory as a major action item. Since
adoption of the LMP, the Team identified existing nutrient source data (TMDLs and USGS
BEMP data) in the Basin and identified major data gaps. The largest data gap included the
St. Maries/St. Joe River Watershed. Subsequently, the Team conducted a 3-year nutrient source
inventory in this watershed, which focused on identifying the largest sources of nutrients
within its sub-water sheds. The resulting information is currently being used to help calibrate
GIS-based calculations. These calculations will help estimate nutrient loading from areas where
monitoring data are unavailable or incomplete, in order to help guide nutrient reduction
implementation. The Team will also use this information to determine whether additional
inventory work is needed in these other watersheds.

Nutrient Reduction Projects

The Team has worked with partners in the Basin to identify, plan, and fund on-the-ground
nutrient and sediment reduction projects. In the Wolf Lodge Creek Watershed at the northeast
end of the lake, the Team participated in the Coeur d'Alene Lake Tributaries WAG to plan
watershed assessment activities, applied for funding to implement watershed assessment
activities, and ultimately provided matching funds to implement bank stabilization activities on
Wolf Lodge Creek. The Team has also collaborated with the WAG and IDEQ TMDL staff to
apply for funding to develop a watershed-scale conceptual restoration plan. The Team recently
learned that funding for this effort has been approved by USEPA.

The Team has worked with Avista Corporation to help focus wetland enhancement and bank
stabilization mitigation efforts in the Basin. To date, approximately a mile of St. Joe River bank
erosion has been stabilized, and approximately 5,000 linear feet of the Coeur d'Alene River has
been stabilized using Avista funding. In addition, 124 acres of wetland enhancement along the
St. Joe River has been implemented using Avista mitigation funding provided under their FERC
license.

Other nutrient reduction activities include:

• Riverbank stabilization totaling 12.7 river miles in Kootenai and Shoshone Counties and
11.4 miles in Benewah County completed through partnerships between conservation
districts, the Natural Resource Conservation Service, and private landowners

• Upgrades to, or replacement of, four wastewater treatment systems throughout the Basin

• Meetings with the St. Joe/St. Maries River WAG to discuss nutrient inventory results and
potential future implementation projects

A-8

-------
APPENDIX A

COEUR D'ALENE LAKE MANAGEMENT PLAN

• Identification of erosion control and stormwater treatment project potentials with partners,
including the City of Coeur d'Alene, UI, Worley Highway District, Kootenai-Shoshone Soil
and Water Conservation District, and others

• Participation in the Panhandle SEEP
Nutrient Reduction Action Planning Timeline

Work on developing the action plan has been ongoing. The Team plans to finalize an approach
for filling data gaps, through either GIS-based modeling and/ or tributary monitoring, by the
end of 2015. Coordination with USEPA on BEMP nutrient monitoring in the Coeur d'Alene
Basin will have an influence on completion of the inventory effort. The Team has relied on
BEMP data to characterize nutrients in the Coeur d'Alene River Watershed as well as loading
from the mouths of the Coeur d'Alene and St. Joe Rivers and nutrient concentrations at the
outflow to the Spokane River. Next steps will be completing the modeling, planning
monitoring, compiling existing monitoring data, and placing this all in an action plan that can
be shared with land management entities throughout the Basin and other stakeholders. The
final plan is expected to be completed by the end of 2017, with project implementation activities
ongoing.

LMP Objective 4 - Increase Public Awareness of Lake Conditions and Influences on
Water Quality

The establishment of an education and outreach program to achieve Objective 4 has been one of
the most successful components of the Team's work. Through informal presentations at
community groups, working with K12 educators, development of educational materials and
tools, and partnership with UI and regional nonprofits, the Team has increased awareness of
the LMP's objectives. This has resulted in opportunities for community stewardship and
protection of water quality. Progress on strategies outlined in the LMP, as well as additional
outreach and education, is summarized in the following text.

Conduct a Public Education and Outreach Needs Assessment

As a first step towards building an education and outreach program, the State and Tribe
contracted Robinson Research to conduct a needs assessment, which included a telephone
survey, web survey, and focus groups. Three hundred telephone surveys were conducted. Of
the survey participants, 87 percent were year-round residents, and average age was 61 years
old. Respondents were surveyed about their opinions regarding Coeur d'Alene Lake water
quality, what they regarded as the biggest threat to water quality, which agencies they saw as
both trustworthy and having jurisdiction over water quality, and their
agreement/ disagreement with statements regarding various aspects of cleanup. Most
respondents felt that Coeur d'Alene Lake water quality was above average. Only one in four
respondents saw metals as the biggest threat to water quality. Conversely, most respondents
saw invasive plants as the most serious threat. Respondents saw local and state entities as more
trustworthy than federal agencies.

One weakness of the survey was the reliance on landlines, which may have skewed results
towards an older audience, as a majority of young adults now uses only cell phones.
Nevertheless, the needs assessment results helped identify gaps in information and
understanding of Coeur d'Alene Lake water quality issues that have informed the development

A-9

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

of the Team's educational and outreach strategy. The full report is available through the IDEQ
Coeur d'Alene Regional Office or the Tribe's Lake Management Department - Hazardous
Waste Management Program Office.

Lake Stewardship Center

The 2010 Needs Assessment found that there was little public support for the use of LMP funds
to establish an independent water resource educational center. However, at the same time, UI-
Coeur d'Alene (UI-CDA) invited the Team and other stakeholders to explore the possibility of a
joint water center to be housed at their facility on the Spokane River. Since 2010, both the State
and Tribe have worked with UI-CDA to establish educational priorities for the Community
Water Resource Center (Center). The Center houses a new water quality extension program that
provides training and volunteer opportunities for citizen water quality monitoring, laboratory
facilities, and a resource library. The Idaho Water Resource Research Institute has also
established a staff position at the center to work with the Team and other stakeholders to
identify and procure resources for both research and education. Most recently, a National
Science Foundation (NSF) Experimental Program to Stimulate Competitive Research (EPSCoR)
grant has provided funding for a UI-CDA-based coordinator as part of their "Managing Idaho
Landscapes for Ecosystem Services" program. The 5-year program is providing faculty
resources for teacher workshops, public outreach, and research related to Basin water quality
issues. The program has greatly strengthened the capacity of UI faculty to work in partnership
with the Team. The compilation of a science and resource library at the Center has begun, but
the bulk of work still needs to be completed.

Coordination with Schools and Youth Organizations

The Team has established partnerships with both formal and informal educators to provide
water quality education around the Basin. For 4 years, the Team has been providing training
and equipment to camp counselors at Camp Cross, a summer camp located on Loff's Bay, and
the Girl Scout facility, Camp Four Echoes, on Windy Bay. The counselors are then able to
integrate the material into their summer camp programming.

The Team leads classroom activities, such as the Enviroscape™ and zooplankton/foodweb
activities, at a number of venues, including science education days at Ramsey and Fernan
Elementary schools in Coeur d'Alene, the North Idaho GEAR-UP STEM (science, technology,
engineering, and math) Expo, and the Ul-coordinated Women in Science event. The Team has
also collaborated with UI-CDA to host water quality field days for Hayden Meadows
Elementary. Most recently, the Team has teamed up with UI and the Lands Council on the
"Confluence Project," a unique project that provides graduate students who teach and
coordinate field experiences for three local high schools, Post Falls, St. Maries and Lake City.
The Team has presented an environmental history of the Basin to each of the schools for the last
2 years. In addition, the Team has coordinated and assisted on various field trips.

Tribal LMP staff is also in partnership with the UI College of Education NSF-funded, "Back to
the Earth" project, a 4-year informal indigenous STEM project that engages Coeur d'Alene and
Spokane Tribal youth ages 9 to 16 in exploring water quality in their homelands. The project has
allowed LMP staff to participate in extensive professional development opportunities related to
STEM and experiential learning.

A-10

-------
APPENDIX A

COEUR D'ALENE LAKE MANAGEMENT PLAN

Education and Outreach Services Plan including a Lake*A*Syst Program

In 2013, the Team completed the Coeur d'Alene Basin Lake*A*Syst (Lakeshore Assessment
System) manual, a 12-chapter manual for Basin landowners that provides information on land
management strategies that can reduce negative impacts on water quality. Each chapter
provides risk assessment worksheets that can be used by the landowner to identify areas or
practices of concern, as well as resource directories for local technical assistance providers. The
manual is available in print, as well as on the LMP website, www.ourgem.org. The Team has
conducted pilot workshops with homeowners in the Fernan Lake Watershed, a tributary of
Coeur d'Alene Lake. Based on public feedback, the Team is making small revisions to the
manual. The Team will begin more targeted outreach in 2015.

Additional Outreach

The Team revised and reprinted the "Our Gem" map in 2010 and 2014. This map, initially
created with CWA funds through the Basin Environmental Improvement Project Commission
(BEIPC), provides information on recreational access to Coeur d'Alene Lake, as well as specific
best management practices related to the recreation community, such as aquatic invasive
species management, wake erosion prevention, and boater regulations. The map has been a
successful tool for outreach and is in wide demand at commercial and tourist venues around
the region.

In 2014, the Team established the "Our Gem" website (www.ourgem.org), as a means to
provide general background and information on the LMP. The website provides links to
partners, maps, the LMP itself, as well as the Lake*A*Syst materials. The Team also maintains
an active Facebook page (www.facebook.com/CdA.LMP) as an avenue for providing updates
and information to the public.

The LMP staff have presented to numerous community groups, including, but not limited to the
following:

• Coeur d'Alene and Hayden Rotary

• Kiwanis

• Coeur d'Alene Chamber of Commerce

• Coeur d'Alene Lakeshore Property Owners Association

• Leadership Coeur d'Alene

• Kootenai Environmental Alliance's "Lunch and Learn"

• Annual Osprey Cruise (a U.S. Bureau of Land Management and Coeur d'Alene Chamber of
Commerce event)

• Kootenai County Planning and Zoning Technical Advisory Group

• Various bay homeowners' associations

LMP coordinators actively participate in, and are instructors for, the Panhandle SEEP, a
certification course on best management practices for regional contractors, developers, and
planners. The SEEP committee recently helped initiate the formation of a stormwater working
group, currently identifying and developing broader outreach and demonstration projects in

A-11

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

the Coeur d'Alene-Spokane region. This effort led to a partnership with the Spokane River
Forum in hosting a "Stormwater Breakfast" in Spokane that engaged public policy makers and
agency representatives in discussions about innovative approaches to regional stormwater
management.

As a result of the stormwater partnership, LMP coordinators were able to collaborate again with
the Spokane River Forum in planning and hosting a one-day, "Our Gem" Coeur d'Alene Lake
Symposium for the Basin public, held in November 2014. The symposium included
presentations on the value of Coeur d'Alene Lake, in both economic and social/cultural terms,
by local and Tribal elected officials, USEPA and BEIPC staff, representatives of the business
community, and homeowners. LMP staff provided updates on monitoring and overall LMP
implementation. About 200 community members participated in both the presentations and
afternoon "Community Cafe" sessions. LMP staff received enthusiastic feedback on the
symposium, which also saw new partnerships with the Coeur d'Alene Chamber of Commerce;
local engineering firms; and CDA Vision 2030, a new community organization that
encompasses multiple stakeholders in a visioning project that includes goals of lake and river
enhancement and protection. LMP staff plan to work with these partners to host a 2016
symposium.

LMP Objective 5 - Establish Funding Mechanisms to Support the LMP Goals,
Objectives, and Strategies

Core program activities and related budget needs were identified in the LMP. Since its
adoption, funding commitments were made by IDEQ and the Tribe to fund a limited level of
staffing and operating expenses. However, neither government has been able to fund the LMP
at the level identified in the plan. The State of Idaho has funded the State's side of LMP
implementation at approximately $300,000 to $400,000 per year since adoption of the LMP. The
Tribe has funded their side of LMP implementation at similar levels. Other funding sources
include, or have included, the following:

• Laboratory support from USEPA's Manchester Lab for metals analyses in water samples
from Coeur d'Alene Lake

• Avista mitigation funding for water quality monitoring (not to include any metals analyses)

• Avista mitigation funding for erosion control (administered by Avista with input from
IDEQ and the Tribe)

• Avista mitigation funding for wetlands enhancement (administered by Avista with input
from IDEQ and the Tribe, among others)

• CWA Section 319 funding for TMDL-related implementation projects

Securing funding for LMP implementation has proved to be challenging, which affects the
ability of the Team to perform action items identified under Objectives 1 to 4. Challenges
include the following:

• USEPA has asked that the Team reduce the support in the number of samples sent to the
Manchester Lab due to funding constraints. They have also indicated they would eventually
like to discontinue any lab support soon. This puts an additional $30,000 to $50,000 burden

A-12

-------
APPENDIX A

COEUR D'ALENE LAKE MANAGEMENT PLAN

on the State of Idaho, and $20,000 for the Tribe to pick up analysis of the metals and
hardness samples (in 2013 dollars). It will be critical to maintain support for lab analyses, at
a minimum.

• The source the State of Idaho has utilized to fund the LMP is finite. The latest projections
indicate this funding source is likely adequate to provide the current level of support
through State Fiscal Year 2019 or 2020. Securing alternative, supplemental and, ultimately,
permanent funding sources is a priority.

• The Tribe also relies on a finite source of funding from mining settlements to fund the LMP,
and anticipates this funding being significantly drained over the next 3 to 5 years.

• The Tribe applied for funding from USEPA Environmental Justice grants, but was
unsuccessful in its application (2013). Additionally, the Tribe has twice been invited to
collaborate with UI for USEPA Environmental Education grants, but due to restrictions
within USEPA's request for proposal that explicitly excluded tribal environmental agencies
or governments from applying, was unable to apply for funding to support its outreach and
education efforts (2014 and 2015).

Conclusions

Lake Management Plan Effectiveness

The LMP is functioning as intended, albeit at a lower level of intensity than originally intended
due to funding constraints and other factors. This has resulted in a slower rate of progress. The
science program has continued to gather data that are useful in identifying trends in water
quality. These data have also been utilized to calibrate the ELCOM-CAEDYM, which will
eventually be used for predictive purposes and to reduce the level of staff hours necessary for
monitoring activities.

Partnerships with Basin stakeholders have been maintained, and, in some cases, improved
through collaboration and outreach. The first "Our Gem" Coeur d'Alene Lake Symposium
brought nearly 200 participants from throughout the Basin to learn about Coeur d'Alene Lake
and the challenges faced as a community in protecting it. The Team received feedback that the
LMP implementation needs to continue in order to protect Coeur d'Alene Lake and local
communities that rely upon it. The community was particularly emphatic about the need for the
following:

• Overall funding of the LMP

• Increased outreach and marketing

• Continued monitoring and research

• Increased integration with K-12 education

A more comprehensive summary is included in the Summary Report: Our Gem Symposium
Community Cafe, compiled by IDEQ and the Tribe (2015).

The nutrient reduction action plan is well under way in its development. In the meantime,
information gathered through monitoring and coordination with other efforts is being used to
prioritize nutrient reduction efforts. Nutrient reduction projects have been implemented and
future projects are being identified and planned. This effort has been slow moving due to the

A-13

-------
2015 FIVE-YEAR REVIEW, BUNKER HILL SUPERFUND SITE

critical need to work closely with stakeholders through outreach and their direct project
participation. Working with stakeholders also requires identifying and pursuing project funds
through resources such as CWA Section 319 funds. This process can take over a year, and
necessitates substantial staff time and investment.

Recommendations

Although it is too early to determine the effectiveness of the LMP in protecting Lake Coeur
d'Alene from nutrient loading, analysis of data collected from 2008-2012 by the LMP team does
point to some potential trends that need further tracking over time. While the data show total
and dissolved zinc levels are declining, dissolved cadmium and lead levels are not. This may be
expected because remediation in the Upper Basin is primarily focused on removal of zinc from
surface water while specific actions and timing for cleanup in the lower basin have yet to be
identified. However, a trend in increased productivity is beginning to emerge from the analysis
of the data collected over the past 5 years. More information needs to be gathered to verify this
trend and identify the primary causes for this increase (e.g., increased population, temperature,
or other sources of eutrophication pressure). This information then needs to be communicated
to Basin stakeholders to identify actions that may reverse any adverse trends. Finally, USEPA's
Superfund Program, along with USEPA's Water Program, will continue to evaluate available
data. USEPA is committed to working with the State and Tribe to develop evaluation criteria for
determining effectiveness of the LMP as well as benefits to the Lake from upgradient cleanup
actions. In combination, this information will be used to determine if CERCLA response actions
or other administrative controls will be necessary for the Lake in the long-term. Establishment
of these evaluation criteria will be partially dependent on the progress of the upgradient
cleanup actions and realized effects on Lake water quality.

Future funding of LMP implementation is a serious challenge. Sources of funding that have
been used to date for basic operating costs are limited. Alternative sources for implementation,
with the exception of Avista mitigation funding, are intermittent and require staff to seek them
out and secure them. Commitments for funding the LMP into the future will be critical to future
success.

References

Dallimore, C.J., Hipsey, M.R., Alexander, R. and Morillo, S. 2007. "Simulation Model to
Evaluate Coeur d'Alene Lake's Response to Watershed Remediation." Volume 1: Hydrodynamic
modeling using ELCOM. The University of Western Australia, Center for Water Research.

Hipsey, M.R., Alexander, R. and Dallimore, C.J. 2007. "Simulation Model to Evaluate Coeur
d'Alene Lake's Response to Watershed Remediation." Volume 2: Water quality modeling using
ELCOM-CAEDYM. The University of Western Australia, Center for Water Research.

A-14

-------