EPA 910/9-81 -084 United States Region 10
Environmental Protection 1200 6th Avenue
Agency Seattle, WA 98101
August 1981 EPA-10-ID-Boise/Eagle-Ada-WWTW-81
Environmental Final
Impact Statement
Wastewater Management for
Boise, Eagle, and Ada County,
Idaho
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U.S. ENVIRONMENTAL PROTECTION AGENCY
^eo st,^ R E G I O N X
1 200 SIXTH AV EN
SEATTLE, WASHINGTON 9 B 1 0 1
*
^ 1200 SIXTH AVENUE
ft"9ust 1A' 1981
BRi'ffi IV S 443
TO: All Interested Agencies, Public Groups and Citizens
Enclosed for your review and comment is the Final Environmental Impact
Statement (EIS) for wastewater management for Boise, Eagle and Ada
County, Idaho.
This EIS was prepared in compliance with the National Environmental
Policy Act and implementing Agency regulations (40 CFR Part 6,
November 6, 1979). Availability of the EIS will be announced in the
Federal Register on August 14, 1981, beginning a 30-day comment period
which will close on September 14, 1981. This agency will take no ad-
ministrative action on this project until the close of the comment
period.
We will appreciate your review of this document and any comment you
may have. Please send all comments to Norma Young, M/S 443 at the
above address.
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Final
Environmental Impact Statement
Wastewater Management for
Boise, Eagle and Ada County, Idaho
Boise Project No. C-16-0305
Eagle Project No. C-16-0288
U. S. Environmental Protection Agency
Region 10
Seattle, Washington 98101
With technical assistance from:
Jones & Stokes Associates, Inc.
2321 P Street
Sacramento, California 95816
U.S. EPA UBRMY REGION 10 MATEIWLS
¦IIIIIIIIIH
RXODDDOnS?
Prepared by:
Responsible Official:
L. Edwin Coate
Deputy Regional Administrator
Date: July 6, 1981
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TABLE OF CONTENTS
Page
EXECUTIVE SUMMARY i
Background ^
EPA's Recommended Action i
Proposed Projects iii
City of Boise Facilities iii
Eagle Sewer District Facilities vii
Southwest Area Wastewater Management ix
Summary of Impacts and Mitigation Measures ix
Surface Water Quality ix
Groundwater Quality x
Air Quality x
Vegetation and Wildlife x
Growth-Related Impacts x
No-Action Alternative xi
CHAPTER 1 - INTRODUCTION 1
The EIS Process 1
Grant Programs Under the Clean Water Act 1
Background to Development of This EIS 1
Report Format 3
CHAPTER 2 - WATER QUALITY MANAGEMENT ITS ADA COUNTY 5
Locational Setting 5
Existing Wastewater Treatment Facilities 5
City of Boise Facilities 5
Eagle Sewer District 11
Southwest Community Wastewater Management
Study 11
Facilities Problems 11
Gowen Field Treatment Plant 14
Lander Street Treatment Plant 14
West Boise Treatment Plant 14
Eagle Sewer District Facilities 14
Southwest Community Area 15
CHAPTER 3 - PROJECTS PROPOSED FOR CONSTRUCTION 17
Introduction 17
City of Boise Facilities 17
Facility Expansions and Service Area
Changes 17
Lander Street Treatment Plant Modification 21
West Boise Treatment Plant Modifications 21
Sludge Disposal 22
Interceptor Systems 22
Estimated Costs 24
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Pacre
Eagle Sewer District Facilities 28
Southwest Area Wastewater Management 31
CHAPTER 4 - WASTEWATER TREATMENT ALTERNATIVES 3 5
Introduction 35
City of Boise Facilities 35
Discharge Requirements 35
Staging and Capacity Considerations 37
Development of Project Alternatives 43
Energy Requirements 51
No-Action Alternative 55
Eagle Sewer District Facilities 55
Treatment Alternatives 57
Interceptor Systems 58
Energy Requirements 58
No-Action Alternative 58
Southwest Community Wastewater Management Study 58
Operations and Maintenance Program
Alternatives 61
CHAPTER 5 - POPULATION PROJECTIONS AND GROWTH
INDUCEMENT 65
Description of Facility Planning Population
Projections 67
Boise Planning Area 67
Southwest Planning Area 67
Eagle Planning Area 67
Growth Inducement Role of the Proposed Project 68
Relationship of Sewer Facilities to Growth 68
Growth Under the No-Action Alternatives 6 8
Growth Accommodated by the Proposed Projects 69
CHAPTER 6 - LAND USE IMPACTS 71
Introduction 71
Existing Land Use 71
Boise Planning Area 71
Southwest Planning Area 73
Eagle Planning Area 73
Land Use Plans and Policies 73
Ada County 76
Boise Planning Area 76
Southwest Planning Area 78
Eagle Planning Area 7 9
Consistency of Wastewater Facility Plans with
Local Land Use Plans and Policies 79
Boise Planning Area 81
Southwest Planning Area 82
Eagle Planning Area 82
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Page
CHAPTER 7 - URBANIZATION OF AGRICULTURAL LANDS 8 5
Introduction 85
Agricultural Land Resources 86
Definition of Agricultural Lands 86
Location of Important Farmland 87
Current Agricultural Production in the Planning
Areas 8 7
Boise Planning Area 87
Southwest Planning Area 89
Eagle Planning Area 89
Ada County Agricultural Land Policies 89
Urbanization of Agricultural Lands From the
Proposed Projects 90
Boise Planning Area 90
Southwest Planning Area 91
Eagle Planning Area 91
Mitigation Measures 91
CHAPTER 8 - PUBLIC SERVICES AND FACILITIES 93
Introduction 93
Provision of Community Services 93
Current Capabilities of Community Services 94
Drainage 94
Water Supply 95
Gas and Electricity 97
Solid Waste Management 97
Transportation 97
Schools 98
Police Protection 100
Fire Protection 100
Recreation 101
Summary of Community Services Capabilities and
Potential Impacts of Growth 101
Mitigation Measures 102
Organization of Local Government Finance 103
Fiscal Prospects: The Short-Run Picture 106
Fiscal Prospects: The Long-Run Picture 110
Area Summary 114
Conclusions 116
CHAPTER 9 - AIR QUALITY 117
Introduction 117
Terminology 117
Meteorological Factors 118
Temperature Inversions in the Boise Area 121
Existing Air Quality Problems 123
Summary 123
ESL/CH2M Hill Study 124
EPA Study 124
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Paqe
Idaho Air Quality Bureau Study 127
Permanent Monitoring Station Data 129
Idaho Transportation Department Monitoring
Data 134
Earth Metrics Ozone Study 135
Air Quality Management Considerations 13 5
Institutional Framework 13 5
Emissions Inventories and Forecasts 138
Future Air Pollution Potential in Ada County 150
Effects of Altered Population Distributions 155
Required Emission Reductions 157
State Implementation Plan Consistency 163
CHAPTER 10 - GROUNDWATER RESOURCES 16 5
Geology 16 5
Regional Geology 16 5
Geology of Study Area 16 5
Groundwater Hydrology 16 9
Boise Valley Aquifers 169
Groundwater Occurrence and Flow 170
Groundwater Quality 171
Nonpoint Source Waste Loadings of the Groundwater 17 6
Summary of Existing Nonpoint Source Dis-
charges to Groundwater in Ada County 176
Impact on On-Site Wastewater Disposal Systems on
Groundwater Resources 17 8
Groundwater Conditions and Land Use Changes 17 9
Mitigation Measures 180
Impacts of Sludge Disposal on Groundwater Resources 180
Boise Sludge Disposal Site 180
Mitigation Measures 181
Eagle Sewer District Disposal Site 182
CHAPTER 11 - THE BOISE RIVER ECOSYSTEM 183
Introduction 183
Summary of Impacts 183
Existing Conditions 184
Hydrology 184
Water Quality 192
Fishery Resources 200
Impacts of the Proposed Project 209
Hydrologic Changes 209
Water Quality Changes 20 9
Direct Impacts on Fisheries 216
Indirect Impacts on Fisheries 218
Mitigation Measures 218
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Page
CHAPTER 12 - VEGETATION AND WILDLIFE 219
Environmental Setting 219
Vegetation and Wildlife Habitats 219
Wildlife 221
Impact Analysis 230
Direct Impacts 233
Indirect Impacts 235
Impact Summary 236
CHAPTER 13 - ARCHEOLOGICAL AND CULTURAL RESOURCES 23 7
Introduction 237
Impacts 237
CHAPTER 14 - SUMMARY OF SIGNIFICANT PROJECT-RELATED
IMPACTS 241
Wastewater Treatment and Disposal Impacts 241
Boise River 241
Growth-Related Impacts 241
Air Quality 241
Conversion of Agricultural Land to Urban Uses 243
Public Services and Facilities 243
Vegetation, Wildlife and Fisheries 243
Drainage 244
Resource and Energy Use 244
Traffic Congestion 245
Water Resources 24 5
Construction-Related Impacts 246
Noise, Dust and Erosion 246
Traffic Disruption 248
Vegetation and Wildlife 248
Fisheries 250
Archeological and Cultural Resources 251
Disruption of Effluent Flow 252
Resources and Materials 252
No-Action Alternative 252
Boise 252
Eagle 253
CHAPTER 15 - RESPONSES TO COMMENTS ON THE DRAFT EIS 255
Introduction 255
Comments and Responses 255
Michael D. Giltzow 256
Boise City Planning Department 260
Boise City Public Works Department 264
Eagle Sewer District 268
City of Eagle 272
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Pacje
LIST OF REPORT PREPARERS 313
ACRONYMS AND ABBREVIATIONS 317
EIS DISTRIBUTION LIST 319
BIBLIOGRAPHY 321
Reference Documents 321
Personal Communications 329
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LIST OF TABLES
Table
Pa9e
3-1 Summary Cost Estimate for Recommended
Alternatives - Stage One Expansions 26
3-2 Summary Cost Estimate for Recommended
Alternatives - Stage Two Expansions 27
3-3 Cost and Funding Estimate for the Eagle Sewer
District Project 30
3-4 Southwest Community Wastewater Management Plan
Recommendations 32
4-1 Boise Treatment Plant Effluent Limitations Future
and Historical 36
4-2 Sewage Generation Rates Used for the Boise Area 38
4-3 Existing and Projected Sewage Flows from Sewer
Service Areas in Boise 39
4-4 Population Projections for Sewer Service Areas
Served by the Lander Street and West Boise
Treatment Plant 40
4-5 Projected Commercial and Industrial Acreage in
Boise Area 41
4-6 Projected Sewage Flows and BOD Loads at the
Lander Street and West Boise Sewage Treatment
Plants 42
4-7 Sludge Processing Alternatives Evaluated for the
West Boise Treatment Plant 45
4-8 Year 2000 Projections of Digested Sludge Volume
from the Lander Street and West Boise Treat-
ment Plants 46
4-9 Sludge Management Alternatives 47
4-10 Capital Costs of Alternative Plans - North Boise
Interceptor 50
4-11 Ammonia Limitations 52
4-12 Process Energy Consumption for West Boise
Alternatives 53
4-13 Energy Consumption for Sludge Transportation
Alternatives 54
4-14 Sewage Flow Projections for the Eagle Sewer
District 56
4-15 Primary Energy Consumption for Alternative Eagle
Sewer District Projects 59
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Table Page
4-16 Estimated Project Costs and Monthly User Charges
for Alternative Eagle Sewer District Projects 60
5-1 Summary of DED Planning Area Population Pro-
jections 66
6-1 Allocation of Developed Acres, Vacant Acres,
and Developable Acres by Boise Planning
Subareas 74
6-2 Land Use in Eagle's Area of City Impact in 1977 75
8-1 Property Taxes as Proportion of Local Budget in
Selected Ada County Jurisdictions 103
8-2 Revenue Sources in Boise and Eagle 104
9-1 Summary of Vertical Stability from Tethersonde
Study 122
9-2 Summary of Carbon Monoxide Emission Forecasts for
Northern Ada County 14 2
9-3 Carbon Monoxide Emission Densities in Northern
Ada County 145
9-4 Community Planning Area Characteristics Reflected
in the Emission Inventories and Forecasts 151
9-5 Summary of Average Weekday Vehicle Trip Char-
acteristics from the Boise Traffic Model 153
9-6 Forecasts of Air Pollution Potential 154
9-7 Base Year (1977) Air Quality Values Used for
Rollback Analyses 156
9-8 Reductions from Projected CPA Emissions Required
to Indicate Attainment of 8-Hour CO Standard 158
10-1 Chemical Analyses of Deep and Shallow Groundwater,
Boise River Water and Agricultural Drainage
Waters in Boise Valley, Idaho 17 3
10-2 Summary of Estimated Nitrogen and Total Salt
Loadings to Groundwater from Irrigated Crop-
lands, Animal Husbandry, and On-Site Waste
Disposal in Ada County, 1980 177
10-3 Summary of Estimated Nitrogen and Salt Loadings
to Groundwater Resulting from Irrigated
Agriculture, On-Site Waste Disposal and
Animal Husbandry in the Southwest Study Area,
1980 177
11-1 Principal Reservoirs in the Boise River Basin 186
11-2 Lucky Peak Reservoir Storage Allocation 187
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Table Page
11-3 Protected Beneficial Uses of Waters of the Boise
River Basin below Lucky Peak Dam 193
11-4 Summary of Idaho State Water Quality Standards
for Designated Beneficial Uses 195
11-5 Average Water Quality Conditions of the Boise
River Main Stem 196
11-6 Fishes of the Boise River Between Lucky Peak Dam
and the River Mouth 201
11-7 Recommended Low Flow Regime in cfs for the Boise
River from Lucky Peak Dam to Snake River 207
11-8 Present and Future Effects of Boise and Eagle
Effluent Flows on Boise River l-in-10 Year,
7-Day Low Flows below the Outfalls 210
11-9 Average Water Quality Data Above and Below Lander
Street and West Boise Sewage Treatment Plant
Outfalls, October 1975-April 1980 212
11-10 Estimated Nitrogen Loadings to Boise River, Year
2000 l-in-10 Year Low Flow Conditions 214
11-11 Annual Average Loadings of Total Phosphorus to
the Boise River under Present and Future
Conditions 215
11-12 Estimated Instream Concentrations of Trace
Inorganic Toxins below West Boise, Year 2000
l-in-10 Year, 7-Day Low Flow Conditions 217
12-1 Vegetation - Candidate Threatened or Endangered
Plant Species 222
12-2 Terrestrial Wildlife - Endangered and Threatened
Species and Species of Special Concern 226
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LIST OF FIGURES
Figure Page
1 Regional Setting iv
2 Existing Sewer Service Areas v
3 Facility Planning Areas for the Eagle Water
and Sewer District viii
2-1 Regional Setting 6
2-2 Sewer Service Areas in the Boise Metropolitan
Area 7
2-3 Lander Street Treatment Plant Site Plan 9
2-4 West Boise Treatment Plant Site Plan 10
2-5 Eagle Water and Sewer District Facilities 12
2-6 Southwest Community Wastewater Management
Study Area 13
3-1 Existing Sewer Service Areas 18
3-2 Proposed Sewer Service Areas, Stage 1
Construction 19
3-3 Proposed Sewer Service Areas, Stage 2
Construction 20
3-4 Sludge Pipeline Routing and Land Application
Site 23
3-5 Alternative South Boise Interceptor Routes 25
3-6 Eagle Water and Sewer District Study Area 29
4-1 North Boise Interceptor Alternatives 48
4-2 Area Considered for Centralized Sewer Service
during Southwest Community Wastewater
Management Study 62
6-1 Boise Planning Subareas 72
6-2 Incorporated Areas, Urban Service Planning
Areas and "Areas of City Impact" in Northern
Ada County 77
6-3 Southwest Community Comprehensive Land Use Plan 80
7-1 Distribution (approximate) of SCS-Designated
Prime Farmlands within the Facility Planning
Areas 88
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Figure Page
9-1 Relationship Between Atmospheric Stability
and Inversion Conditions 120
9-2 Monitoring Sites Used in the ESL/CH2M Hill
Study 125
9-3 Monitoring Sites Used in the EPA Carbon
Monoxide Study 126
9-4 Monitoring Sites Used During the Idaho Air
Quality Bureau CO Study 128
9-5 Average Winter Carbon Monoxide Levels at
the Boise Odd Fellows Hall Monitoring Site 130
9-6 Average Winter Carbon Monoxide Levels at
the Central District Health Department
Monitoring Station 131
9-7 Time Periods with 8-Hour CO Levels >9.0 ppm
at the Boise Odd Fellows Hall Monitoring
Station 132
9-8 Time Periods with 8-Hour CO Levels >9.0 ppm
at the Central District Health Department
Monitoring Station 133
9-9 Community Planning Areas Outside the Boise
Metropolitan Area 140
9-10 Community Planning Areas in the Metropolitan
Boise Area 141
9-11 1980 Emission Source Density Index Values
(daily basis) for the Boise Metropolitan Area 147
9-12 1987 Emission Source Density Index Values
(daily basis) for the Boise Metropolitan Area 148
9-13 2000 Emission Source Density Index Values
(daily basis) for the Boise Metropolitan Area 149
9-14 Emission Reductions Needed to Achieve the
8-Hour CO Standard in 1987 160
9-15 Emission Reductions Needed to Achieve the
8-Hour CO Standard in 2000 161
10-1 Generalized Geologic Cross Sections of Boise
Valley 166
10-2 Generalized Geologic Map of the Boise-Nampa
Area 16 7
11-1 Boise River Watershed 185
11-2 Average Monthly Flow at Four Locations on
Boise River 189
11-3 Boise River Diversions and Drains 190
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Figure Page
11-4 Hydrologic Characteristics of the Boise
River below Lucky Peak Dam and at Boise 191
11-5 Nitrate Conditions in Boise River 198
11-6 Total Phosphorus Conditions, Boise River 199
11-7 Percentage Composition for Total Fish, Game
Fish, and Nongame Fish in Electrofishing
Sample from the Boise River 11 July to
2 August 1974 202
11-8 Distribution of 13 Fish Species in the Boise
River from Barber Dam Downstream to the
Mouth as Determined by Electrofishing during
January-February, July-August and October
1974 204
11-9 Comparison of Trout and White Fish Life
History, Stream Flow, in the Boise River
and Recommended Maintenance Flows 20 8
11-10 Boise River Dissolved Oxygen Profile, Year
2000 l-in-10 Year, 7-Day Low Flow Conditions 213
12-1 Species of Special Concern Habitat 224
12-2 Deer and Elk Habitat 224
12-3 Waterfowl Habitat 231
12-4 Quail and Grouse Habitat 231
12-5 Partridge Habitat 232
12-6 Pheasant and Dove Habitat 232
14-1 Noise from Construction Equipment 247
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EXECUTIVE SUMMARY
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EXECUTIVE SUMMARY
( ) Draft Environmental Impact Statement
(X) Final Environmental Impact Statement
Type of Action: Administrative
Background
On March 27, 1981 the U.S. Environmental Protection Agency
(EPA) released for public review and comment a Draft Environmental
Impact Statement (EIS) which evaluated the environmental impacts
associated with proposed wastewater treatment facilities for the
City of Boise, Idaho and the Eagle Sewer District (ESD). The
decision to prepare an EIS on the proposed facilities was based
on grant applications from the City and the ESD for construction
grant assistance to plan, design and construct the needed facili-
ties. The Draft EIS was prepared concurrently with the City of
Boise and the ESD's detailed facilities plans. In addition, the
Ada Planning Association (APA) requested Section 208 grant funds
to evaluate wastewater management alternatives in the rural portions
of Ada County. Attention was focused on the area southwest of
Boise.
As a result of the three separate grant applications and the
extensive environmental analysis that would need to be performed
for each of the many alternatives, EPA decided to evaluate the
environmental impacts from an areawide or cumulative perspective
in a single EIS. EPA's Draft EIS, therefore, includes detailed
analysis of each of the alternatives presented in the Boise and
Eagle facilities plans as well as a number of wastewater manage-
ment alternatives for the rural areas of southwest Boise. A
public hearing on the Draft EIS was held in the City of Boise
on April 30, 1981.
EPA's Recommended Action
EPA concurs with the City and the ESD's proposed construction
of wastewater facilities and recommends that grant assistance be
awarded for those portions of the facilities determined to be grant
eligible by the Idaho Department of Health and Welfare (IDHW) and
EPA. EPA has also concluded that the proposed projects are cost
effective and environmentally preferable to the many alternatives
evaluated. There are, however, two issues which remain to be
resolved. They concern low flow requirements in the Boise River
and potential habitat impacts associated with the new ESD treatment
i
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facility site. EPA recommends that the City of Boise continue to
work with the Corps of Engineers to insure a 1 in 10 year minimum
resource maintenance flow of 80 cfs (Lucky Peak outlet) in the
Boise River. We intend to request the grantee to submit a
summary and schedule of actions to be taken along with an annual
progress report to meet this end. EPA will also request the ESD
to consult with the Idaho Department of Fish and Game and the U.S.
Pish and Wildlife Service during the pre-design phase to ensure
that mitigation measures deemed necessary by these agencies are
incorporated into the design. Certain types of development within
the proposed site may be limited according to this consultation.
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Proposed Projects
The proposed projects encompass the Cities of Boise and
Eagle, and the southwest community area. The projects, as
proposed in the various planning documents, include expansion
of the West Boise treatment plant, upgrading the existing
Lander Street plant, and building a new treatment plant about
1 mile downstream of the plant which now serves the Eagle Sewer
District. In addition staged construction for interceptors to
serve South and North Boise and sludge handling for the City of
Boise are proposed. Finally, septic tank systems for wastewater
management are considered to be the most appropriate way to meet
the "rural lifestyle" designation in the land use plan for the
Southwest Area.
The regional setting of the planning area can be found on
the following page in Figure 1.
City of Boise Facilities
The City of Boise is currently served by three wastewater
treatment plants: Gowen Field, Lander Street, and West Boise
(Figure 2). The Gowen Field plant is operating below capacity
with no operating problems. No facility improvements are
being considered for the Gowen Field plant. The Lander Street
and West Boise plants provide service to most of the City
of Boise. The Lander Street plant is currently operating
near capacity, both hydraulically and organically. The plant
is not designed to remove ammonia. The West Boise treatment
plant is currently overloaded hydraulically during the summer
months due to high amounts of infiltration/inflow (I/I).
Its organic load is far below capacity. It is designed to
remove ammonia throughout the year.
A major element of the facility plan for the City of
Boise involves providing sewage treatment plant capacity for
future growth. The proposed project will involve major new
construction at the West Boise treatment plant and only minor
facility changes at the Lander Street plant. The facility
plan also proposes the staged construction of a South Boise
interceptor. Following Stage 1 construction, sewage flows
from the Bench Sewer District, currently treated at the
iii
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_r
_j~
GEM CO
r \«0/
C0\^o
MILES
\
iv:'-1- *'
EAGLE
CALDWE
MERIDIAN
VALL
OWELL
LUCKY
PEAK
index map
LEGEND-
BOISE VALLEY BOUNDARY
g§ SOUTHWEST COMMUNITY
STUDY AREA
ADAPTED FROM NACE,19B3
BASE MAP: USGS 1:250,000 "BOISE",
REVISED 1978
FIGURE 1- REGIONAL SETTING
IV
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FIGURE 2.
EXISTING SEWER SERVICE AREAS
-LEGEND-
~ WEST BOISE
LANDER STREET
0 GOWEhl FIELD
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Lander Street plant, will be treated at tho expanded West
Boise plant. Following Stage 2 construction, sewage flows
from the Table Rock and South Boise sewer service areas would
be diverted from the Lander Street plant to West Boise. These
shifts in sewer service areas contributing to the different
treatment plants will free existing capacity at the Lander
Street plant to handle future growth in the Central Boise
and Northwest Boise Sewer District service areas.
Stage 1 modifications at the Lander Street plant will
involve installation of dechlorination and postaeration
facilities and a variety of measures to increase the use
of digester gas from the anaerobic sludge digesters.
Stage 1 expansion at West Boise will involve an addi-
tional influent pump, grit chambers, an additional comminutor,
two primary clarifiers, two additional secondary clarifiers,
additional aeration at the existing aeration basins, de-
chlorination facilities, a new flotation thickener, new
primary and secondary anaerobic sludge digesters, various
sludge and grit pumps, and a digester control building. A
significant aspect of the proposed West Boise plant modifi-
cation involves replacing the existing aerobic sludge digestion
system with an anaerobic digestion system. The peak month
average daily flow capacity of the West Boise plant would
be increased by 10.7 MGD (million gallons per day), to a
total of 17 MGD.
Stage 2 expansion would essentially involve construction
of a duplicate treatment facility adjacent to the Stage 1
facilities. Stage 2 construction would involve a new influent
pump station, headworks facilities (grit chambers, comminutors,
etc.), primary clarifiers, aeration basins, secondary clarifiers,
chlorine contact chambers, postaeration facilities, primary
and secondary sludge pumping, sludge thickeners, and anaerobic
sludge digesters.
As outlined in the draft facilities plan (CH2M Hill
1980c), the West Boise plant would have a hydraulic capacity
of 34 MGD (peak month average daily flow basis) following
Stage 2 construction. The Idaho Department of Health and
Welfare (IDHW) has indicated that state and federal grant
funding will probably be based on a 20-year sewage flow of
23.5 MGD (Korpalski 1981); additional capacity would be
locally funded.
Conversion at the West Boise plant to anaerobic sludge
digestion will allow agricultural use of sludge from both
the Lander Street and West Boise plants. Current plans involve
transporting digested sludge by pipeline to the Idaho State
Prison area for use as soil conditioner on the prison farm.
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Two interceptor system expansions were evaluated as
part of the facility planning process. The South Boise
interceptor would shift sewage flows from the Lander Street
plant to the West Boise plant, as discussed previously.
Stage 1 construction would allow the Bench Sewer District
to be served by the West Boise plant. Stage 2 expansion
would connect the South Boise and Table Rock sewer service
areas.
The North Boise interceptor would provide sewer service
to currently unsewered portions of the North Boise sewer
service area. The interceptor would be sized to accommodate
11,000 connections from a 2,400-acre area. The North Boise
interceptor would also provide up to 5.6 MGD of additional
capacity for sewage flows from the State Street service area.
It is at present uncertain whether the North Boise interceptor
will receive state and federal funding for Stage 1 construction
In addition to the interceptor projects identified above,
Stage 1 construction would include rehabilitation of existing
interceptors in the Garden City area. The Garden City inter-
ceptor system is subject to considerable infiltration of
groundwater during the summer, apparently from the Thurman
Mill Ditch. The proposed rehabilitation program is expected
to eliminate 30 percent (1.04 MGD) of the present summer
infiltration.
EPA has awarded a limited Step 2 grant to allow early
design work for certain elements of the West Boise plant
modifications. The facility elements involved (a comminutor,
one return activated sludge pump, and one secondary clarifier)
are needed to alleviate existing hydraulic overloads at the
plant.
Eagle Sewer District Facilities
The ESD is proposing to abandon the existing facility
site. A new facility would be constructed on a 65-acre site
adjacent to the north channel of the Boise River, about 1 mile
west (downstream) of the present site (Figure 3). The pre-
ferred project involves construction of a gravity flow inter-
ceptor from the existing site to the new site, pretreatment
and lift station facilities, two aerated lagoons, an equali-
zation lagoon, and an effluent pump station.
Effluent disposal is expected to involve a 35-acre rapid
infiltration site about 0.4 mile east of Palmer Road and
0.3 mile south of Beacon Road. An underdrain system will
collect the percolate and discharge it to an adjacent drainage
ditch which eventually discharges to the Boise River. Effluent
would be transported from the treatment plant site to the
infiltration area by a 4-mile-long force main.
vii
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EAGLE FACILITY PLAN STUDY AREA
EAGLE FACILITY PLANNING AREAS (A. B.C)
CORPORATE CITY LIMITS
EXISTING FACILITY SITE
PROPOSED FACILITY SITE
RAPID INFILTRATION SITE
EFFLUENT FORCE MAIN
INTERCEPTOR
MILES (APPROX.)
fe* . 1
¦'>!» H
FIGURE 3. FACILITY PLANNING AREAS FOR THE EAGLE
SEWER DISTRICT
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The overall ESD project would' be staged, with the second
aeration lagoon and three of the seven infiltration basins
to be constructed in 1990. Initial project construction
would provide 0.75 MGD of capacity (peak month average daily
flow basis); this would be adequate to serve about 8,000
residents in the service area. Second-stage construction
would bring treatment capacity to 1.31 MGD, sufficient for
about 13,300 residents.
If the preferred rapid infiltration project proves to
be infeasible, an oxidation ditch system would be constructed
at the new treatment plant site. This treatment system would
involve pretreatment and lift station facilities, an oxida-
tion ditch with brush aerators, two secondary clarifiers,
chlorination facilities, and a sludge basin. Treated effluent
would be discharged to the north channel of the Boise River.
Sludge from the clarifiers would be used as soil conditioner.
Southwest Area Wastewater Management
The Southwest community wastewater management study
was performed in conjunction with revisions to the Ada County
comprehensive plan. Adoption of a "rural lifestyle" land
use plan for the Southwest area dictates continued reliance
on septic tank systems for wastewater management. The adopted
Southwest area wastewater management plan (APA 1981) involves
a countywide voluntary septic tank maintenance program, a
public information and education program, and recommenda-
tions for various other measures.
Summary of Impacts and Mitigation Measures
Surface Water Quality
The proposed facility improvements at the West Boise
and Lander Street plants will result in generally improved
effluent quality. Nutrient loadings to the Boise River and
downstream reservoirs will, however, increase as wastewater
flow volumes increase. Avoidance of potential problems with
ammonia levels in the treatment plant effluent depends on
maintenance of minimal water flows in the Boise River.
EPA will request the City to continue to pursue a guaranteed
l-in-10 year minimum flow release of 80 cubic feet per second
from Lucky Peak Reservoir.
Return flows from the ESD rapid infiltration site are
not expected to have any adverse impacts on the Boise River.
ix
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Groundwater Quality
Percolation of septic tank effluent into local groundwater
systems will be reduced as currently unsewered areas become
connected to the Boise treatment system. The decision not to
provide central sewer systems in the Southwest area will continue
current septic tank use patterns and associated waste loadings
to local groundwater systems.
The proposed sludge disposal operation at the Idaho State
Prison area will require monitoring of groundwater conditions
to ensure that groundwater pollution problems will not develop.
The rapid infiltration site for the ESD facilities needs more
detailed soils and groundwater evaluations to verify the feasi-
bility of the proposed project.
Air Quality
A major problem in the Boise/Ada County area is a high level
of carbon monoxide (CO) in the atmosphere. Available monitoring
data indicates that the high CO levels occur primarily along
major traffic corridors. With the additional growth that is
projected for the area, impacts to the ambient air quality will
likely worsen unless effective mitigative measures can be imple-
mented. In accordance with the Clean Air Act of 1970 and the
1977 Clean Air Act amendments, EPA has designated Ada County as
a "nonattainment area" for CO. Efforts have been made by the
County to develop a State Implementation Plan for achieving the
federal primary standards as quickly as possible.
Vegetation and wildlife
Riparian habitat along the Boise River will be disturbed
or destroyed by construction of the new ESD facilities and by
various City of Boise interceptors and sludge pipelines. The
ESD facility site involves removal of 15 acres of riparian
habitat from one of the larger riparian areas remaining along
the Boise River. EPA will request both the Eagel Sewer District
and the City of Boise to consult with the Idaho Department of
Fish and Game and the U.S. Fish and Wildlife Service during pre-
design of the proposed projects and location of interceptors to
mitigate these impacts to the maximum extent possible.
Growth-Related Impacts
Population growth will be accommodated by increased
treatment capacity at the City of Boise and ESD facilities.
Continued development will involve several areawide types
of impacts. Major areawide concerns include traffic and air
quality impacts, urbanization of prime farmlands, and problems
with timely provision of urban services. Local agencies are
currently attempting to deal with these issues through a variety
of ongoing planning programs.
x
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No-Action Alternative
Federal regulation (40 CFR, Part 6) requires that all
EISs consider the impacts of continued use of the wastewater
treatment and disposal methods currently serving area residents.
This is the no-action alternative.
For Boise this would mean that the existing Lander Street
and West Boise plants would continue to operate as is, with the
potential for ammonia toxicity, residual chlorine toxicity and
reduced oxygen levels during low river flows. There is no
capacity to handle additional population growth in the area.
Most of the Boise area residents using septic tanks would continue
to do so with potential surface and groundwater contamination.
The city would have to finance any extensions of central waste-
water service to new residential, commercial or industrial
development.
For the Eagle Sewer District the no-action alternative would
mean continuing violation of the District's NPDES discharge
permit and would not provide for any improvement in the quality
of effluent being discharged into the Boise River. New develop-
ment would have to rely on the use of septic tanks.
These alternatives were determined to be unacceptable for
Boise and the ESD and therefore were dropped from further con-
sideration.
xi
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Chapter 1
Introduction
-------
Chapter 1
INTRODUCTION
The EIS Process
National Environmental Policy Act of 1969 (NEPA) requires
that all agencies of the federal government must evaluate
the environmental consequences of actions they undertake
or sponsor. Consistent with other essential considerations
of national policy, agencies are directed to avoid or mini-
mize possible adverse effects of their actions on the quality
of the human environment. The major implementation tool
of NEPA is the Environmental Impact Statement (EIS). An
EIS serves as a decision-making document which describes
and analyzes alternative actions or projects. The EIS process
serves as a means of obtaining input into agency decisions
from other federal agencies, state and local agencies, and
the general public.
The EIS process also provides a means for ensuring that
project planning considers the requirements of applicable
laws and policies. Examples of broadly applicable federal
legislation include the Clean Water Act, the Clean Air Act,
the Safe Drinking Water Act, the Endangered Species Act,
the Fish and Wildlife Coordination Act, and the National
Historic Preservation Act. Various Executive Orders and
agency policies also must be considered in connection with
the protection of floodplains, wetlands, and prime farmland.
Grant Programs Under the Clean Water Act
The federal Clean Water Act establishes a basic goal
of achieving "fishable, swimmable" surface waters throughout
the country by 1983, and the elimination of pollutant dis-
charges by 1985. The act establishes a permit system (National
Pollutant Discharge Elimination System [NPDES]) to regulate
the discharge of pollutants to waters of the United States.
The various provisions of the Clean Water Act are administered
by the U. S. Environmental Protection Agency (EPA).
1
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Section 201 of the Clean Water Act provides a program
to help meet the costs of upgrading publicly-owned wastewater
treatment systems. These "clean water grants" administered
by EPA provide up to 75 percent (or up to 85 percent for
innovative treatment/disposal systems) of the planning and
construction costs for eligible facility improvements. In
order to receive this funding assistance, local wastewater
management projects must be planned and designed in accor-
dance with various EPA requirements.
Section 20 8 of the Clean Water Act provides a separate
grant program to fund studies of "areawide" water quality
problems.
Background to Development of This EIS
A number of public wastewater treatment systems in Ada
County have received EPA grant funds in recent years, in-
cluding facilities for the City of Meridian and the City
of Kuna. Recently, the City of Boise and the Eagle Sewer
and Water District also initiated facility planning programs
under the Section 201 grant program. In addition, the Ada
Planning Association requested Section 208 grant funds to
evaluate wastewater management alternatives in the rural
portions of Ada County. Particular attention was focused
on the area southwest of Boise.
EPA decided that a single EIS should be prepared to
evaluate proposed wastewater management projects in the Boise
area. While the individual projects can be analyzed separately,
the significance of project-specific impacts is best determined
from an areawide or cumulative perspective. The individual
projects under consideration include those of the City of
Boise, the Eagle Sewer District, and the Ada Planning Asso-
ciation's Southwest Area study.
A Draft EIS evaluating these projects was issued on
March 16, 1981. A public hearing on the Draft EIS was held
in Boise, Idaho on April 30, 1981. The Draft EIS has been
revised in response to oral and written comments received
prior to, during or subsequent to that public hearing. Written
comments on the Draft EIS are presented in Chapter 15 of
this Final EIS.
Section 201 grants under the Clean Water Act are issued
in three stages. Step 1 grants cover initial feasibility
and planning studies, resulting in the preparation of draft
2
-------
facility plans. Stage 2 grants cover detailed facility design
work. Step 3 grants cover actual project construction. Step 2
grants normally are not awarded until the completion of all
environmental reviews. Because of current facility overloading
and associated water quality problems, an accelerated Step 2
grant has been given to the City of Boise. This Step 2 grant
allows design work to proceed for three items in the overall
facility plan: a comminutor, a return activated sludge pump,
and one secondary clarifier.
Report Format
This EIS is organized into chapters which discuss general
topic areas investigated during report preparation. The
initial chapters provide information on the wastewater manage-
ment programs planned for the area. Subsequent chapters
discuss major topic areas related to potential impacts. Each
such chapter includes discussion of essential background
information, relevant project details, impact analyses, and
potential mitigation measures. Some of the chapters in this
EIS are based on special studies described in more detail
by separate study reports or appendix documents. Appendix
documents released with the Draft EIS have not been reprinted
for this Final EIS. All appendix references in this report
are to the appendices printed and distributed with the Draft
EIS.
Several reports have been prepared specifically for
this project, and represent a considerable amount of supple-
mental technical information which may be useful to those
reviewing this Draft EIS. These reports include:
o Ground Water Resources of Boise Valley, Idaho,
H. Esmaili & Associates, Inc. June 1980.
o Nonpoint Source Waste Loadings in Ada County
and Southwest Community Study Area, H. Esmaili &
Associates, December 1980.
o Drainage Task Report - Drainage Planning and
Institutional Evaluations, Jones & Stokes
Associates, Inc. February 1980.
o A Tethersonde Field Study Examining Low Level
Stability in the Boise Valley, North American
Weather Consultants. April 1980.
3
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° Ozone Data for Ozone Special Study, Boise, Idaho,
Earth Metrics, Incorporated. November 1979.
These reports are available for review in the EPA Boise
office. If a strong need is identified by a reviewer, a
copy of the required report will be provided. The appendix
to the Draft EIS is also available in the EPA Boise office.
4
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Chapter 2
Water Quality Management in
Ada County
-------
Chapter 2
WATER QUALITY MANAGEMENT
IN ADA COUNTY
Locational Setting
Ada County, Idaho is located north of the Snake River
in the southwestern part of the state (Figure 2-1). Encom-
passing 673,000 acres, most of the county is between 2,500
and 3,300 feet elevation. The northeastern portion of the
county includes the slopes of the Boise Front, which rises
to elevations of about 5,900 feet. The southern part of
the county is primarily desert, with urban and agricultural
areas concentrated in the northern half of the county. The
northern half of the county is drained by the Boise River,
which joins the Snake River along the border between Idaho
and Oregon.
The City of Boise straddles the Boise River, with the
northern portions of the city against the lower slopes of
the Boise Front. The southern part of the city occupies a
series of river terraces (benches) rising south of the Boise
River. The City of Eagle is also located along the Boise
River, about 9 miles northwest (downstream) from downtown
Boise. The City of Meridian is located about 9 miles due
west of downtown Boise, while the small Town of Kuna is
13 miles southwest of Boise. The Cities of Nampa and
Caldwell in neighboring Canyon County are about 18 and 24
miles west of Boise.
Existing Wastewater Treatment Facilities
Each of the municipal wastewater management facilities
in Ada County consists of two basic components — a collection
system and facilities for treatment and disposal of the
collected sewage. The wastewater collection systems involve
networks of pipelines and pump stations which collect sewage
from individual homes, businesses, and industries, and carry
it to the wastewater treatment plant.
City of Boise Facilities
The City of Boise is served by three wastewater treatment
plants (Figure 2-2). The Gowen Field plant serves the area
5
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CANYON CO.
MILES
STAR
EAGLE
CALDWELL
\ VALL EY
\
NAMPA
LAKE
OWELL
INDEX MAP
-LEGEND-
miiim BOISE VALLEY BOUNDARV
SOUTHWEST COMMUNITY
STUDY AREA
ADAPTED FROM NACE,1983
BASE MAP: USOS 1:200,000 "BOISE",
REVISED 1970
FIGURE 2-1. REGIONAL
SETTING
-------
FIGURE 2-2. SEWER SERVICE
AREAS IN THE BOISE
7
METROPOLITAN AREA
STATE
STREET
-KST
• ae/sf
PLAHT
EWEr DISTRICT
SEWER
CLO rERDALE
DISTRICT
DISTRICT
SOUTH
BOISE
SOWEM
PLANT
-------
around the Boise municipal airport. The recently completed
West Boise plant serves the western portion of the Boise
area, including Garden City. The Lander Street plant, serves
most of the City of Boise.
Gowen Field Treatment Facilities. The Gowen Field treat-
ment plant was built during World War II (1942) by U. S.
Army Engineers. The original plant, a high-rate trickling
filter, discharged to the upper part of Five Mile Creek.
Due to overloading during the summer caused by training of
National Guard units, however, the tricking filter system
was abandoned and a lagoon system was constructed in 1976.
Treated effluent is stored during the winter. During the
summer, the effluent is used to irrigate 47 acres of alfalfa.
The Gowen Field system currently serves the Gowen Field National
Guard facilities, the airport, the Boise Industrial Park,
the Bureau of Land Management Fire Control Center, and the
commercial facilities by the airport and interstate highway.
The treatment system has a design capacity of 0.512 MGD
(million gallons per day). The storage at the treatment
plant is ample to accommodate 0.5 MGD throughout the year,
and at these flows, irrigation would have to occur approxi-
mately 7 months out of the year. Because effluent is stored
during the winter, plant capacity is lower during that period.
Lander Street Treatment Plant. The Lander Street plant
is located on the north side of the Boise River in the north-
western part of Boise. Following chlorination, secondary
treated wastewater is discharged directly into the Boise
River at approximately River Mile 49.7. The plant was built
in 1950 as a conventional activated sludge plant with anaerobic
sludge digestion. The plant was subsequently modified in
1960-1961, 1968-1969, 1971, 1973, and again in 1975. The
existing plant layout is shown in Figure 2-3. The peak month
average daily flow design capacity of the facility is 15.0 MGD
of flow and 23,000 pounds per day biological oxygen demand (BOD)
and total suspended solids (TSS) removal. The Lander Street
plant had a peak month discharge of 13.1 MGD in 1978 (CH2M
Hill 1979b) and 14.6 MGD in 1979 (CH2M Hill 1980a). These
peak month flows occurred during the summer.
West Boise Treatment Plant. The West Boise treatment
plant, built in 1975, is located south of the Boise River
near the north end of Cloverdale Road. The West Boise treat-
ment plant uses an activated sludge secondary treatment process.
Treated effluent is discharged to the Boise River at approxi-
mately River Mile 45. The existing treatment plant layout
is shown in Figure 2-4. The treatment facilities are rated
at 6.3 MGD hydraulic capacity, 15,000 pounds per day BOD
removal, and 15,000 pounds per day TSS removal (peak month
flow basis). The West Boise plant had a peak month discharge
of 5.28 MGD in 1978 (CH2M Hill 1979b) and 7.4 MGD in 1979
(CH2M Hill 1980a). Peak flows occurred during the summer.
8
-------
Figure 2-3. Lander Street Treatment Plant Site Plan
I INFLUENT
DfVf&ON
STfiUCTUAE
DlCiB&ft*.
\KOJ_
J !
p DtC,E&Ttfl c
asjr
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cawmx.bujuxhci—
•CHLOKJNZ mUfLCHt
DKY1NQ &££>
/&
ctrr of aotse facilities
SOURCE: CH2M Hill 1979a,
-------
Figure 2-4. West Boise Treatment Plant Site Plan
QYtXfLQW
ZTKUCTUZZ
fUtlr
¦ AOMfNlG TKATIQN
BU/L/DINC* ^
rtUMAKY
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rowD no. t
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ASAATION
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CLAJZJFtZ*. INFLUENT
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OiLDUNATtOM
BUILDING
%gr5TQtf«v ,
ClAJUF/Ee. NOl t
HUMUS,
rONO NO. Z
HUMUS,
SLuooe ruMP/NCi r
&UfLOtNQ
/txo&ic
facility
•joru*r
srwww
ClTT Of BOISE FACILITIES
B12430
lOfcMi
jKHILL
SOURCE: CH2M Hill 1979a.
-------
Eagle Sewer District
The existing sewage treatment facilities of the Eagle
Sewer District (ESD) were constructed in 1965 and modified
in 1975 and 1978. The plant site is located north of the
Boise River, west of Eagle Road (Figure 2-5). The existing
treatment system consists of two sewage lagoons and two sand
filters.
Sewage is pumped into the first pond (1.2 acres) which
is aerated by a perforated plastic pipe system. Effluent
from the aerated lagoon flows into a second lagoon (1.8 acres)
which does not have any special aeration system. The effluent
flows by gravity to the sand filters (0.41 acre each). After
percolating through 2 feet of sand, the effluent is collected
by an underdrain system and discharged to the Boise River
at river mile 42.5.
The existing facilities have a design capacity of 0.3 MGD
for winter and 0.5 MGD for summer. Summer flows have averaged
0.35 MGD (peak summer flows of 0.425 MGD) with an average
winter flow of 0.17 MGD (J-U-B Engineers 1980).
Southwest Community Wastewater Management Study
The rural area southwest of Boise (Figure 2-6) contains
a mixture of agricultural and large lot residential develop-
ments. The area currently has a population of about 16,700.
Most residents currently rely on individual septic tanks
for wastewater disposal. The Owyhee Sewer District operates
a small treatment plant which serves the Indian Lakes sub-
division. This facility employs lagoon treatment with land
disposal of the effluent. About 920 dischargers are currently
connected to this system. The Owyhee plant has a design
capacity of 0.35 MGD (APA 1979a). In addition there is one
small package plant (extended aeration and drainfield disposal)
serving a truck stop development. One community septic tank
system has also been constructed recently.
Concern over the nature of development and associated
wastewater disposal practices prompted the APA to initiate
an areawide wastewater management study funded under Section
208 of the Clean Water Act. The major objective of the study
was to determine whether a centralized sewer and wastewater
treatment system was needed for this area.
Facility Problems
Wastewater management projects and studies have been
initiated by the City of Boise, ESD, and APA. These studies
are intended to resolve the problems discussed below.
11
-------
Figure 2-5. Eagle Sewer District Facilities
FLOATING
FEATHER s . ROAD
Q
LEGEND
KISTING TREA
FACILITY
TMENT
Eagle Sewer District
Boundary
Existing Collection
System
SOURCE: J-U-B Engineers 1980,
-------
Figure 2-6. Southwest Community Wastewater
Management Study Area
OWYHEE 5EWEI
OtST 1ICT
STUDY AREA
BOUNDARY
SOURCE: Ada Planning Association 1979a
13
-------
Gowen Field Treatment Plant
The Gowen Field treatment plant is currently operating
at an annual average of 40 percent of capacity. No signifi-
cant problems have been identified at this plant. The avail-
able capacity is expected to serve development in the treat-
ment plant service area until about 1995 (CH2M Hill 1980a).
No facility improvements have been proposed for this treat-
ment plant.
Lander Street Treatment Plant
During 1979 peak month sewage flows reached 97 percent
of the facility design capacity while BOD loadings reached
94 percent of design capacity and TSS loadings exceeded design
capacity by 2 percent (CH2M Hill 1980a). Continued growth
in the service area for the Lander Street plant will increase
flows and organic loadings above plant capacity.
The existing Lander Street discharge contains an ex-
cessive concentration of chlorine (used for disinfection).
Excessive concentrations of ammonia are also discharged at
some periods of the year. Both chlorine and ammonia can
be toxic to aquatic organisms.
West Boise Treatment Plant
During 1979 peak month sewage flows exceeded treatment
plant design capacity by 18 percent, while BOD and TSS loadings
were less than 40 percent of design capcity (CH2M Hill 1980a).
The excessive hydraulic loading at the West Boise plant appears
to be due to very high groundwater infiltration in the Garden
City sewer system (CH2M Hill 1979a). Continued growth in
the area served by the West Boise plant will cause further
overloading of the existing capacity. As at the Lander Street
plant, treated effluent contains levels of chlorine which
may be toxic to aquatic organisms. Industrial wastes received
at the West Boise plant have led to some concerns about the
combined effects of heavy metals and ammonia in the plant
effluent.
Eagle Sewer District Facilities
With the recent construction of sand filters at the existing
plant, effluent quality has improved significantly. These
sand filters, however, are designed for only a few years
of use. Thus future effluent quality problems are expected.
Future development in the area served by the existing plant
could also create an excessive load on the facilities.
14
-------
Southwest Community Area
The Southwest Community Sewer Feasibility Study undertaken
by APA was initiated primarily due to concerns about possible
groundwater pollution from septic tanks. The major concern
focused on nitrate and nitrite levels in the local groundwater
systems. In addition, there was growing concern for growth
impacts upon other public service needs in the area. The
feasibility study provided a mechanism to coordinate the
areawide land use planning and the planning for key public
services for the Southwest area.
15
-------
Chapter 3
Projects Proposed for
Construction
-------
Chapter 3
PROJECTS PROPOSED FOR CONSTRUCTION
Introduction
Wastewater treatment alternatives have been evaluated
for three areas: the City of Boise, the Eagle Sewer District,
and the unincorporated Southwest Area of Ada County. These
alternatives are discussed in Chapter 4. The recommended
projects are described below.
City of Boise Facilities
The proposed project for the City of Boise includes
several elements affecting both the Lander Street and West
Boise treatment plants. No changes would be made at the
Gowen Field treatment plant. The facility plan for Boise
envisions a two-stage program of construction. Clean Water
Act grant funds being requested at this time would be used for
"Stage 1" construction. Major aspects of the proposed project
are discussed below.
Facility Expansions and Service Area Changes
A major element of the facility plan for the City of
Boise involves providing sewage treatment plant capacity for
future growth. The proposed project will involve major new
construction at the West Boise treatment plant and only minor
facility changes at the Lander Street plant. The facility
plan also proposes the staged construction of a South Boise
Interceptor. Following Stage 1 construction, sewage flows
from the Bench Sewer District, currently treated at the
Lander Street plant , will be treated at the expanded West Boise
plant. Following Stage 2 construction, sewage flows from the
Table Rock and South Boise sewer service areas would be
diverted from the Lander Street Plant to West Boise. These
shifts in sewer service areas contributing to the different
treatment plants will free existing capacity at the Lander Street
plant to handle future growth in the Central Boise and
Northwest Boise Sewer District service areas (Figures 3-1, 3-2,
and 3-3).
17
-------
FI6URE 3-1
EXISTING SEWER SERVICE AREAS
LEGEND-
G *EST BOISE
LJNDER STREET
~ GOWEN FIELD
NORTH
BOISE
STATE
STREET
~*EST
• BOISE
PIAHT
ISTRICT
BOISE
CLOfCRDALE
DISTRICT
BOISE
-------
FIGURE 3-2
PROPOSED SEWER SERVICE ARE
STAGE 1 CONSTRUCTION
-LEGEND-
~ WEST BOISE
H LANDER STREET
~ GOWEN FIELD
77
STATE
STREET
WEST
BOISE
PLAMT
CENTRAL
EWEB^DISTRICT
WEST
BOISE
SEW|ER
CLOTERDALE
TABLE
ROCK
DISTRICT
BENCH
! SEWER
i
DISTRICT
BOISE
-------
FIGURE 3-3
PROPOSED SEWER SERVICE AREAS
STA6E 2 CONSTRUCTION
7
BOISE
STATE
STREET
WEST
BOISE
PLMT
-LEGEND-
~ WEST BOISE
LANDER STREET
EO 60WEN FIELD
;;??A?rJrSEWEI STRICT
PLAN
BOISE
CLOfERDALE
TABLE
ROCK
DISIItlCT
I ^
SEWER
BOISE
-------
Lander Street Treatment Plant Modification
Stage 1 modifications at the Lander Street plant will
involve installation of dechlorination and postaeration
facilities and a variety of measures to increase the use of
digester gas from the anaerobic sludge digesters.
Dechlorination facilities will involve the use of sulfur
dioxide (S02) gas dissolved in water. The resulting sulfurous
acid solution will be mixed into the treated and disinfected
sewage effluent. Residual chlorine in the disinfected effluent
will be rapidly reduced to nontoxic forms such as chloride ions.
Treated sewage effluent generally has little dissolved
oxygen. The dechlorination process will further reduce dissolved
oxygen levels. A postaeration process will be installed to
increase oxygen levels in the treated effluent prior to dis-
charge to the Boise River. The facility plan recommends
converting chlorine contact basin No. 3 into a postaeration basin
using static tube aerators.
Following these modifications, the Lander Street treatment
plant capacity will remain essentially unchanged from present
conditions.
Methane gas produced by the anaerobic sludge digesters
is currently used as fuel for raw sewage pumps, aeration
system blowers, and winter heating of sludge digesters.
Currently about 72 percent of digester gas production is
utilized at the Lander Street plant. The remaining gas pro-
duction is lost through leaks or intentional flairing of
excess gas production. Several options to the existing pattern
of digester gas use are being evaluated, and specific
recommendations are presented in the draft facility plan.
West Boise Treatment Plant Modifications
A major expansion program is recommended for the West
Boise plant. This expansion will accommodate future growth
in the Boise area as well as the shifting of various existing
sewage flows from the Lander Street plant as the South Boise
Interceptor is built. Capacity expansion will be phased,
with the Stage 1 expansion adding 10.7 MGD of capacity (peak
month average daily flow basis) to the existing 6.3 MGD system.
It is anticipated that a second expansion stage would occur
in about 1988, adding an additional 17 MGD of capacity.
Stage 1 expansion at West Boise will involve an additional
influent pump, grit chambers, an additional comminuter, two
primary clarifiers, two additional secondary clarifiers,
21
-------
additional aeration at the existing aeration basins,
dechlorination facilities, a new flotation thickener, new
primary and secondary anaerobic sludge digesters, various
sludge and grit pumps, and a digester control building.
A significant aspect of the proposed West Boise plant modi-
fication involves replacing the existing aerobic sludge digestion
system with an anaerobic digestion system.
Stage 2 expansion would essentially involve construction
of a duplicate treatment facility adjacent to the Stage 1
facilities. Stage 2 construction would involve a new influent
pump station, headworks facilities (grit chambers, comminuters,
etc.), primary clarifiers, aeration basins, secondary clarifiers,
chlorine contact chambers, postaeration facilities, primary
and secondary sludge pumping, sludge thickeners, and anaerobic
sludge digesters.
As outlined in the draft Facilities Plan (CH2M Hill 1980b),
the West Boise plant would have a hydraulic capacity of 34
MGD (peak month average daily flow basis) following Stage
2 construction. The Idaho Department of Health and Welfare
has indicated that state and federal grant funding will
probably be based on a 20-year sewage flow of 23.5 MGD
(Korpalski, 1981); additional capacity would be locally
funded.
Sludge Disposal
Digested sludge from the Lander Street plant is currently
used as soil conditioner. The liquid digested sludge from
the Lander Street plant is presently trucked to agricultural
areas near Eagle and the Idaho State Prison (south of Boise).
The aerobically digested sludge from the West Boise plant is
presently stored and dried in humus ponds at the plant site.
Conversion at the West Boise plant to anaerobic sludge
digestion will allow agricultural use of sludge from both
the Lander Street and West Boise plants. Current plans involve
transporting digested sludge by pipeline to the Idaho State
Prison area for use as soil conditioner on the prison farm.
Alternative pipeline routes are shown in Figure 3-4. The
recommended routing involves the Phillippi alignment.
Interceptor Systems
Two interceptor system expansions were evaluated as
part of the facility planning process. The South Boise
Interceptor would shift sewage flows from the Lander Street
22
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WEST BOISE TREATMENT PLANT
PUMP STATION NO.1
4.ANDER STREET TREATMENT PLANT
PUMP STATION N0.2
PUMP STATION NO. 3 x
ALTERNATIVE .A : v
PUMP STATION N07 3"
ALTERNATIVE B
f ••••
i PUMP STATION NO.^
ALTERNATIVE C
i - r
. ^
• V
~ /;<|ssp^csiQRwliUa-
. i ' *-s>*
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CURTIS ROUTE
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PUMP STATION NO. 4
¦: -t
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PRISON AREA AGRICULTURAL
LAND APPLICATION SITE STORAGE
AND PUMP STATION LOCATION
PRISON FARM BOUNDARY-
¦;¦ V-
. f *
,.. ^
PLEASANT VALLEY ROAD
\
A
H
l-
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-4 ~
FIGURE 3-4. SLUDGE PIPELINE ROUTING
& LAND APPLICATION SITE
23
-------
plant to the West Boise plant, as discussed previously.
Stage 1 construction would allow the Bench Sewer District
to be served by the West Boise plant. Stage 2 expansion
would connect the South Boise and Table Rock Sever Service
Areas. Alternative routings for the Stage 1 construction
are shown in Figure 3-5. The preferred routing is the
Inland East - River West route combination. Stage 1
construction of the South Boise Interceptor will be sized
in anticipation of Stage 2 construction. Final sizing
for the South Boise Interceptor will be based on additional
studies of the overall Boise sewer system.
The North Boise Interceptor would provide sewer service
to currently unsewered portions of the North Boise sewer
service area (Figure 3-1). The interceptor would be sized
to accommodate 11,000 connections from a 2,400-acre area.
The North Boise Interceptor would also provide up to 5.6
MGD of additional capacity for sewage flows from the State
Street service area. It is at present uncertain whether
the North Boise Interceptor will receive state and federal
funding for Stage 1 construction.
In addition to the interceptor projects identified above,
Stage 1 construction would include rehabilitation of existing
interceptors in the Garden City area. The Garden City inter-
ceptor system is subject to considerable infiltration of
groundwater during the summer, apparently from the Thurman
Mill Ditch. The proposed rehabilitation program is expected
to eliminate 30 percent (1.04 MGD) of the present summer
infiltration.
Estimated Costs
Estimated costs for Stage 1 construction of the Boise
facilities are presented in Table 3-1. It should be noted
that the North Boise and miscellaneous interceptors listed
in the table may not receive state and federal funding.
Cost estimates for Stage 2 construction are shown in Table
3-2. The Stage 2 facilities are not included in the present
Clean Water Act grant application.
User charges for the Stage 1 and Stage 2 expansions
have been estimated for City of Boise residents. The current
user charge will probably increase by 11-12 percent following
Stage 1 construction (from an average of $7.70/month to
$8.60/month) with a further 7 percent increase after Stage
2 construction ($8.60 to $9.20 per month). Connection fees
will probably increase about 34 percent after Stage 1 con-
struction (from $165.00 to $221.00) with an additional minor
24
-------
(Existing
—-r *
~>J' ;X
in W'-^.
A \ J*
\ !>v!
L'.L ¦ »'•1
i; ^ From Garden City/
Lander Street <
Wastewater
Treatment Plant
.yVADAMS
\-r ;
-LEGEND-
— ALTERNATIVE INTERCEPTOR ROUTES
— — FUTURE INTERCEPTOR EXTENSION
PRELIMINARY FLOODWAY
v , <-y . ¦>.
N. . •
v«« , / * *
FiOISf]
-t. " V j i From Bench'
3 • ril r/Aswwj,ric,^\. r^
' ¦ -7*%: •:&, i hf»^jkk -.-i'
•'• v.:-- * ' \ L - ]%; ~H
*?• "A 1 . V - i-
• : •
- *v ^ *>
• «¦».••• •
¦RIVER WEST ,
i"-:: f- -^ V
- l i
''I
H
¦ft
W-r S
CHINDEN*
• t *¦ .v
-RIVER jNORTH i
MAIN
\i • fAlftVII-','J
3,
/ "
AVE
1 o
1 hi
1
' I .Wf.i ikni«- i
1 ,6< . .. Jr n.Kh s^'Si '"|a-.
4oooii UfZ j: I
• f%?«r ,' inf..
i 1 I !/•;
•» —T > INLAND EAST# „ . . .
v ,--I _ \ • / Beginning
0 m ' , 1 . ' RIVER' EASt . ^T>X Point
'..'J A , 1 V -/yrr'i I V
7 _ _ _ _ ' _ _
-| /• Ky-.-. .
fee| ' !' ' I-
V- • s?\ 1 v
¦ * m *;¦'! - 'v- •* -r.
i- "- - . "i" 1,- ' i J,n" •!("'•* i».h '
..., -I ; j, v
1 v Future Extension'
i South Boise
1 Interceptor ^
. . ,1 ...-¦ /
FIGURE 3-5. ALTERNATIVE SOUTH BOISE INTERCEPTOR ROUTES
-------
a
Table 3-1. Summary Cost Estimate for Recommended Alternatives
STAGE ONE EXPANSIONS
-1983
Capital
Annual
Salvage
Total Present
Alternative
Cost
O&M Cost
Value
Worth'5
West Boise Expansion
$ 8,295,000
$585,000/yr
$4,125,000
$ 9,620,000
Lander Street
196,000
41,000
118,000
518,000
Improvements
Sludge Pipeline
3,463,000
66,000
1,795,000
3,660,000
Agricultural Application
584,000
39,000
378,000
839,000
South Boise Interceptor^
2,989,000
12,000
—
3,115,000
*North Boise Interceptor
4,151,000
16,000
—
4,319,000
*MiscelIaneous Interceptors
2,461,000
10,000
—
2,566,000
Flow Augmentation
—
100,000°
—
1,049,000
TOTAL
$22,139,000
$869,000
$6,416,000
$25,686,000
a All estimates are In December 1980 dollars.
''Present worth estimates are based on a 20-year design period and a 7-1/8 percent discount rate.
"-Estimate is preliminary and may change depending upon availability of unallocated storage in Lucky Peak Reser-
voir.
^Extension to Americana Boulevard (Construction may be staged with completion to intercept with Bench Sewer
District by 1 983, and remainder perhaps in Stage 2).
*May not be funded by state and federal Clean Water Act grant funds.
SOURCE: CH2M HILL 1980a.
-------
Table 3-2. Summary Cost Estimate For Recommended Alternatives3
Total Present
Worthb
$14,585,000
2,231,000
$16,816,000
aA!l estimates are in December 1980 dollars.
^Present worth estimates are based on a 20-year design period and a 7-1/8 percent discount rate.
cExtensions east of Americana Boulevard.
SOURCE: CH2M Hill 1980a.
STAGE TWO EXPANSIONS - LATE 1980's
Capital Annual Salvage
Alternative Cost O&M Cost Value
West Boise Expansion $13,700,000 $1,135,000/yr $6,350,000
South Boise Interceptor0 2,147,000 8,000 —
TOTAL $15,847,000 $1,143,000 $6,350,000
-------
increase after Stage 2 construction (from ($221.00 to
$224.00). These user charges are preliminary estimates
only, and do not apply to residents served by the Bench
Sewer District or the Northwest Boise Sewer District.
Eagle Sewer District Facilities
The Eagle Sewer District (ESD) is proposing to abandon
the existing facility site. A new facility would be con-
structed on a 65-acre site adjacent to the north channel of
the Boise River, about 1 mile west (downstream) of the
present site (Figure 3-6). The preferred project involves
construction of a gravity flow interceptor from the existing
site to the new site, pretreatment and lift station
facilities, two aerated lagoons, an eguali2ation lagoon,
and an effluent pump station.
Effluent disposal is expected to involve a 35-acre rapid
infiltration site about 0.4 mile east of Palmer Road and 0.3
mile south of Beacon Road. An underdrain system will collect
the percolate and discharge it to an adjacent drainage ditch
which eventually discharges to the Boise River. Effluent
would be transported from the treatment plant site to the
infiltration area by a 4-mile-long force main.
The overall ESD project would be staged, with the second
aeration lagoon and three of the seven infiltration basins to be
constructed in 1990. Initial project construction would provide
0.75 MGD of capacity (peak month average daily flow basis);
this would be adequate to serve about 8,000 residents in the
service area. Second-stage construction would bring treatment
capacity to 1.31 MGD» sufficient for about 13,300 residents.
If the preferred rapid infiltration project proves to be
infeasible, an oxidation ditch system would be constructed
at the new treatment plant site. This treatment system would
involve pretreatment and lift station facilities, an oxida-
tion ditch with brush aerators, two secondary clarifiers,
chlorination facilities, and a sludge basin. Treated effluent
would be discharged to the north channel of the Boise River.
Sludge from the clarifiers would be used as soil conditioner.
The cost estimate and funding procedures for the rapid
infiltration alternative are shown in Table 3-3.
28
-------
EASLE FACILITY PLAN STUDY AREA
EASLC FACILITY PLANNMS AREAS {A. B,C)
CORPORATE CITY LIMITS
EH EXISTING FACILITY SITE
¦ PROPOSED FACILITY SITE
g RAPID INFILTRATION SITE
..... erFLUENT FORCE NAIN
INTERCEPTOR
MILES (APPROX.)
FIGURE 3-6. FACILITY PLANNING AREAS FOR THE EAGLE
SEWER DISTRICT
-------
TABLE 3-3
COST AND FUNDING ESTIMATE FOR THE
EAGLE SEWER DISTRICT PROJECT
Agency Participation
Amount
E?r. (75% of eligible cost)
State (15% of eligible cost)
2,893,815.00
578,763.00
Eagle Sever District (10% of eligible cost)
(ineligible cost)
Sub Total
385,842.00
25,000.00
410,842.00
TOTAL
3,883,420.00
SOURCE OF LOCAL FUNDS
Recommended Bonding Level
Yearly Bond Retirement @ 7 1/3%
Annual 0 & M Estimate (1st year)
Yearly Tax Revenues
411,000 .00
39,168.00
71,500.00
-12,000.00
Total Estimated Annual Cost
Estimated User Charge (based on S00 users)
98,663.00
$10.2S/Ho.
SOURCE: JUB Engineers, 1980
30
-------
Southwest Area Wastewater Management
The Southwest Community Wastewater Management Study
was performed in conjunction with revisions to the Ada
County Comprehensive Plan. Adoption of a "rural lifestyle"
land use plan for the Southwest Area dictates continued
reliance on septic tank systems for wastewater management.
The adopted Southwest Area Wastewater Management Plan
(APA 1981) involves a county-wide voluntary septic tank
maintenance program, a public information and education
program, and recommendations for various other measures
(Table 3-4).
31
-------
Table 3-4. Southwest Community Wastewater
Management Plan Recommendations
Tasks
Activities
Responsible
Agencie(s)
Estimated
Cost
Funding Sources
Installer's registration
permit examination and
training program
Occupancy Permit Program
Central sewer system
expansion mapping
Septic tank pumping
report procedures
Revise and develop a more compre-
hensive exam for obtaining an
installer's registration permit.
Hold annual training workshops for
local area installers and pumpers
covering installation and O&M.
Ada County Building Department(ACBD)
initiate a program of issuing oc-
cupancy permits on all structures
prior to allowing occupancy; and
establish a system of CDHD notifica-
tion of Building Department of septic
system installation approval prior to
Building Department issuing occupancy
permit.
Notifying of APA by municipalities
and sewer districts when areas pre-
viously served by on-site systems
are connected to central sewers.
APA maintain and update map of cen-
tral sewer and on-site system areas.
CDHD develop, print and distribute
septic tank pumping reporting forms
with input from pumpers and APA.
Municipalities (Meridian, Boise and
Nampa) coordinate in administration
of form collection and distribution
to CDHD
CDHD
-0-
Existing
Program
APA
CDHD
ACBD
$6000
Ordinance
Preparation
Phase II Grant
APA*
CDHD
Municipalities
Sewer Districts
CDHD*
Boise City
Meridian
Nampa
APA
-0-
Existing 201/208
Programs
Existing
Programs**
-------
Table 3-4 (cont'd.)
Tasks
Activities
Responsible
Agencie(s)
Estimated
Cost
Funding Sources
Septic tank pumping
and installation
computer data base
Public information
leaflet
Homeowner"s Hanual
Develop system for APA
input of log data provided
by CDHD on septic tank pumping,
installations and reinstallations
into APA computer data bank.
Prepare, print and distribute
semi-annual reports.
Initial preparation, printing
and distribution; and on-going
reprinting and distribution
Initial preparation, distribu-
tion & printing
Reprinting and on-going distri-
bution
APA*
CDHD
CDHD*
APA
APA*
CDHD
CDHD*
$6000-$7000
Initial
Startup
$5500/yr
On-Going
-0-
$5000-$6000
$1000-$1500/yr
Phase II Grant
APA/CDHD exist-
ing 208 program,
Ada County fund-
ing to APA/CDHD,
pursue 201/208
grant funds
Existing CDHD
0&M Program
Phase II Grant
Fee for manuals,
contribution to
program from in-
stallers and
pumpers, 208
Sewage Ordinance
Fees, CDHD exist-
ing program
*Lead Agency
**As mandated by the Ada County 208 Sewage Ordinance, the Central District Health
Department (CDHD) has the responsibility to develop and implement the septic tank
pumping reporting procedures.
SOURCE: APA 1981.
-------
Chapter 4
Wastewater Treatment Alternatives
-------
Chapter 4
WASTEWATER TREATMENT ALTERNATIVES
Introduction
The wastewater treatment projects discussed in Chapter 3
were selected from a larger number of alternatives evaluated
during project planning. This chapter summarizes the alterna-
tives identified in the various facility planning documents.
Discharge requirements and sewage flow projections used for
facility planning purposes are also discussed.
City of Boise Facilities
The facilities planning effort for the City of Boise
has been focused on a number of aspects: 1) expansion of
treatment facilities at the existing Lander Street or West
Boise wastewater treatment plants, 2) modification of treat-
ment processes (i.e., nitrification and organics removal),
3) infiltration and inflow studies of Garden City and Boise
City, 4) interceptor systems, 5) sewage sludge management,
and 6) augmentation of stream flows in the Boise River.
In the preliminary draft facilities plan prepared by
CH2M Hill, it was assumed that the unincorporated Southwest
community would be served by the West Boise treatment plant;
however, during development of the Southwest Community Waste-
water Management Study by APA, a decision was made not to
provide central sewers to this area. Data from the Boise
facilities plan have been adjusted in this EIS to reflect
that decision. Additionally, alternatives for the South-
west community are discussed separately herein.
The development of facilities alternatives is typically
influenced by two major considerations: required levels
of wastewater treatment (discharge requirements) and required
facility capacity.
Discharge Requirements
The Idaho Department of Health and Welfare has estab-
lished water quality standards for the Boise River. These
standards (discussed in Chapter 11) are intended to protect
a variety of beneficial uses in the Boise River. These<
water quality standards have in turn been used to set require-
ments for the level of treatment at the Lander Street and
West Boise wastewater treatment plants. These discharge
requirements are shown in Table 4-1.
35
-------
Table 4-1. Boise Treatment Plan Effluent Limitations Future and Historical
Historical Limitations
Parameter
BOD
TSS
Dissolved Oxygen
Fecal Coliform
Irrigation (Recre-
ation) Season
Non-Irrigation
Season
Chlorine Residual
Ammonia Nitrogen
Future
Limitation
Both Lander St.
& West Boise
20 mg/l
30 mg/l
6 mg/l or
75%
50/100 ml
100/100 ml
0.1 mg/l
Varies
West Boise
Lander St.
20 mg/l
30 mg/l
50/100 ml
50/100 ml
0.6 mg/l
18 mg/l
Boise River
Less than 120 cfsa
20 mg/l
30 mg/l
90%
50/100 ml
0.4 mg/l
3.4 mg/l
Boise River Boise River
Less than 170 cfsa Greater than 170 cfsa
30 mg/l
30 mg/l
90%
100/100 ml
0.6 mg/l
3.4 mg/l
30 mg/l
30 mg/l
80%
200/100 ml
200/100 ml
0.6 mg/l
3.4 mg/l
aBoise River flow measured at Capitol Boulevard
SOURCE: CH2M Hill 1980c.
-------
Staging and Capacity Considerations
EPA regulations (U. S. EPA 1978a) provide basic guidance for
estimating future wastewater facility needs. Overall planning
is based on a 20-year planning period. In many cases, however,
actual facility construction will occur in stages during
this 20-year period. Facility planning for the City of Boise
involved projecting future sewage flows and waste loads for
the year 2000. Separate projections were made for different
subareas of the Boise area. Population forecasts for these
subareas were taken from the forecasts used by the APA (1978a).
Existing sewage flows and sewage generation rates were
determined from water usage data and special studies of sew-
age flows in major trunk sewers. Separate estimates were
made for residential, commercial, industrial, and infiltration
flow components. Projections for the year 2000 assumed that
there would be an increase in per capita or per acre sewage
generation rates for most flow components in most subareas.
These sewage generation rates (Table 4-2) do not incorporate
any water conservation measures, but do reflect programs
to control infiltration in the Garden City area.
Existing and projected sewage flows are shown in Table 4-3.
The projected residential flows are based on the population
projections shown in Table 4-4. These projections assume
that all new development will be sewered and that all existing
unsewered development will be connected during the next 20
years. While the total population of the Boise area is pro-
jected to increase by 68.6 percent between 1978 and 2000,
the facility plan anticipates a 120 percent increase in the
number of residents actually connected to the treatment plants.
Projected wastewater flows from commercial and industrial
development were based on projections of commercial and indus-
trial acreage for the year 2000 (Table 4-5) . Existing commercial
and industrial acreages were derived from the 1978 zoning
plan for the City of Boise (CH2M Hill 1980c). Commercial
acreage was projected to increase in direct proportion to
population growth while future industrial acreage was esti-
mated from the Boise Metropolitan Planning Area map (CH2M
Hill 1980c) .
Future infiltration flows were projected using the infil-
tration rates shown in Table 4-3. In general, increased
infiltration rates are projected for all areas. A program
to eliminate 1.0 MGD of infiltration from the Garden City
area is assumed in the infiltration rates shown in Table 4-3.
Chapter 3 discussed the shifting of sewage flows from
the Lander Street to the West Boise treatment plant. Pro-
jected sewage flows and waste loadings at these two plants
are shown in Table 4-6.
37
-------
Table 4-2. Sewage Generation Rates Used for the Boise Area
Residential
Commercial
Industrial
Infiltration/Inflow
Rates
Flows
(qped)
Flows
(qpad)
Flows
(qpad)
Average Month
(qpad)
p
G .k. Month
(qpad)
Subaraa
1979
2000
1979 2000
1979
2000
1979
20 00
1979
20 Ob
Weot Boise Sewer District
62
65
BOO
800
1,000
1,000
25
150
50
250
Garden City
60
65
715
800
1,000
1,000
1,285
1,625
2,585
2,500
North Boise, State Street,
West Chinden, Cloverdale,
and Five Mile Sewer Service
Areas
60
65
650
BOO
625
1,000
100
150
200
250
Bench Sewer District
61
65
900
900
1,200
1,200
55
150
165
250
Americana Blvd. Sewer
Service Area
54
55
NA
900
NA
NA
55
150
165
250
South Boise Sewer Service
Area
64
70
520
800
1,000
1,000
175
200 (150)1
250
iuj US'J)1
Table Rock Sewer Service
Area
59
65
800
800
1,000
1,000
230
250 (150)1
400
1,000 (250) 1
Central Boise Sewer
Service Area
60
65
885
900
1,200
1,200
300
400
500
1,000
Northwest Boise Sewer
District
55
60
670
800
NA
NA
100
150
250
500 (250) 1
NOTES:
See Figure 2-2 for boundaries of sewer districts and sewer service areas; Americana Blvd. Sewer Service Area is part of the Bench
Sewer District.
NA = not applicable
gpccl = gallons per capita per day
qpad = qalions per acre per day
'VaJ-ui- in *.ipu] ieel only to now dove 1 opmcnt after 3 979.
¦. r.io.M nm nsoc.
-------
Table 4-3. Existing and Projected Sewage Flows from Sewer Service Areas in Boise
Wastewater Flow Component
Residential
Commercial
Industrial
Infiltration
Total
Sewer Service Areas
North Boise; State Street; West
Chinden; Cloverdale; Five Mile;
fiardon City; West Boise Sewer
District
Bench Sewer District
Table Rock; South Boise
Central Boise; Northwest Boise
Sewer District
TOTAL
North Boise; State Street; West
Chinden; Cloverdale; Five Mile;
Cardiri City; West Boise Sewer
District
Bench Sewer District
Table Rock; South Boise
CoiiLr.il Uuiuo; Norlliwost Boise
Sewer District
TOTAL
NOTES:
MGD = million qnllons per day
.* 1<>i lHtiuitl.il it-::
1978
0. 93
1.71
0.74
2. 38
5.76
0.93
1.71
0.74
2. 38
5.76
2000
4.35
2.30
3. 65
3.65
13.95
4. 35
2. 30
3.65
3.65
13.95
1978
0. 38
0.47
0.11
1.00
1.96
0.38
0.54
0.11
1.02
2.05
2000
0. 80
0. 55
0. 60
1. 15
3. 10
0.80
0.55
0.60
1.15
3.10
1978
2000
1978
Annual Average Flows (MGD)
0.17
0.30
0. 30
0.56
3.00 1.95
0.30 0.27
1.50 0.55
0.60
2.13
1.33 5.40 4.90
Peak Month Flows (MGD)
0.17
0. 30
0. 30
0. 58
1. 35
3.00
0.30
1.50
0.60
5.40
3.90
0. 81
0.90
3.62
9.23
2000
3.50
0.75
2. 35
3.25
9.85
5.60
1.25
5.05
7.60
19.50
1978
3.43
2.75
1.70
6.07
13.95
5.38
3. 36
2.05
7.60
18.39
2GOO
1 i. G5
J . vO
8. 10
8.65
32. 30
13.75
4.40
i 0. :10
13. U0
41. <#5
»f iit'W'r tlirll rii'l .ilitl nt-W'-l
DATA .'JOUHCHs CI12M Hill 1980r.
-------
Table 4-4. Population Projections for Sewer Service Areas Served by the
Lander Street and West Boise Treatment Plants
Sever Service Area
North Boise; State Street; West
Chindon; Cloverdale; Five Mile;
Garden City; West Boise Sewer
District
Bench Sewer District
Table Rock, South Boise
Central Boise; Northwest Boise
Sewer District
TOTAL
1978
Total Severed
35,010 15,250
31,410 28,700
17,000 12,000
42,390 40,500
125,810 96,450
1985
Total Sewered
46,090 30,580
33,060 31,125
27,580 24,020
46,420 45,035
153,150 130,760
1990
Total Sewered
54,145 40,205
33,270 31,980
38,275 35,870
49,285 48,300
174,975 156,355
1995
Total Sewered
61,950 53,625
34,110 33,465
47,700 46,490
52,560 52,040
196,320 185,620
20LQ
Total Sewered
66,790 66,790
35,805 35,805
53,840 53,840
55,710 55,710
212,145 212,145
See Figure 2-2 for boundaries of sewer service areas.
DATA SOURCE: CH2M Hill 1980c .
-------
Table 4-5. Projected Ccrmercial and Industrial Acreage in the Boise Area
Commercial Area Industrial Area
(acres) (acres)
Sewer Service Area 1978 2000 1978 2000
North Boise; State Street; West
Chinden; Cloverdale; Five Mile;
Garden City; West Boise Sewer
District
565
800
215
1,360
Bench Sewer District
520
600
250
250
Table Rock, South Boise
190
750
265
1,430
Central Boise; Northwest Boise
Sewer District
930
1,250
330
370
TOTAL
2,205
3,400
1,060
3,410
See Figure 2-2 for boundaries of sewer service area.
DATA SOURCE: CH2M Hill 1980c.
-------
Table 4-6. Projected Sewage Flows and BOD Loads at the
Lander Street and West Boise Sewage Treatment Plants
Treatment Plant
Sewage Flows (MGD)
1978
1985
1990
2000
1978
BOD Loads (lbs/day)
1985
1990
2000
Lander Street
West Boise
TOTAL
Lander Street
West Boise
TOTAL
Annual Average
10.50 10.30 7.40 8.65 16,900 15,370 11,885 13,775
3.45 10.10 16.95 23.65 2,600 10,705 19,175 28,270
13.95 20.40 24.35 32.30 19,500 26,075 31,060 42,045
Peak Month Average
13.00 13.35 10.20 13.00 21,640 19,675 15,215 17,635
5.40 11.65 20.55 28.95 3,325 13,700 24,545 36,190
18.40 25.00 30.75 41.95 24,965 33,375 39,760 53,825
Notes: MGD = million gallons per day
BOD = biochemical oxygen demand
DATA SOURCE: CH2M Hill 1980c.
-------
Development of Project Alternatives
Initial facility planning for the City of Boise evaluated
several treatment process and expansion options at the various
city facilities. Identification of alternative projects recog-
nized the following major considerations:
o The Gowen Field treatment plant will remain as is,
and continue to serve only the present service area,
o There is limited space available at the Lander
Street plant; the actual expansion limitations are
governed by the level of treatment required,
o The existing West Boise plant was designed with
expansion in mind and a parallel treatment plant
could be constructed at the existing plant site
to handle higher flows,
o There are certain effluent limitations governed by
seasonal flows in the Boise River.
Treatment Plant Expansion and Modification. Alternative
treatment plant modifications are dependent on whether or
not the capacity of the Lander Street plant is significantly
expanded. Expanded capacity at Lander Street would require
nitrification of the effluent (bacterial conversion of ammonia
to nitrate) or physical/chemical removal of ammonia. The
following processes were considered for the Lander Street
plant (the first five being biological nitrification processes,
the last four being physical/chemical treatments):
o single-stage nitrification
o two-stage nitrification
o activated biofilter tower
o rotating biological contactors
o pure oxygen modifications
o breakpoint chlorination
o ion exchange
o powdered activated carbon
o ammonia stripping towers
With the decision to provide major capacity expansion
at the West Boise plant rather than Lander Street, only the
minor facility improvements discussed in Chapter 3 are neces-
sary at Lander Street.
The West Boise plant currently provides nitrification
using an extended aeration process (single-stage nitrification).
Process alternatives considered for the West Boise plant all
retained this existing nitrification process. Alternatives
considered for West Boise focused on changes to the aeration
equipment and changes in the sludge digestion process. The
four alternatives investigated at West Boise involved:
43
-------
o expansion of existing processes
o expansion of the existing processes with conversion
to subsurface aeration
o expansion of the existing processes with conversion
to anaerobic digestion and addition of grit removal
and primary clarification
o expansion of the existing processes with conversion
to subsurface aeration and anaerobic digestion,
and the addition of grit removal and primary
clarification
The recommended project represents a mix of the third
and fourth alternatives. The surface aerators at the
existing aeration basins would be retained, with subsurface
aerators used at the new aeration basins. Expansion would
occur in two stages, as discussed in Chapter 3.
Sludge Management. A wide variety of sludge processing,
transport, storage, and disposal options were evaluated in the
draft facilities plan. Table 4-7 summarizes the sludge pro-
cessing alternatives evaluated for the West Boise plant. The
recommended sludge processing alternative for West Boise
involves flotation thickening and anaerobic digestion. No
dewatering or drying is recommended because of the selected
disposal method (agricultural use, with landfill disposal
as a back-up method). Projected sludge volumes for the year
2000 are shown in Table 4-8.
Alternative sludge transport, storage, and use options
evaluated in the facility plan are summarized in Table 4-9.
The recommended alternative would involve a combination of
Alternatives B-2 and B-3. Sludge storage at the prison farm
would involve one (or possibly two) 190,000-gallon storage
tanks plus a lagoon for emergency storage in the event of
storage tank problems (CH2M Hill 1980c).
Interceptor System. Two technical memoranda were prepared
by CH2M Hill which dealt with interceptor needs in the Boise
area. The two studies include Location Study - North Boise
Interceptor Technical Memorandum and the South Boise Interceptor
Route Selection Technical Memorandum. The studies focused
on three distinct needs: wastewater collection needs in
northwest Boise, routing analysis of the South Boise interceptor
through Garden City, and an analysis of need for sewer rehabi-
litation in Garden City and Boise.
North Boise Interoeptor. Four alternative interceptor
alignment plans were identified in the North Boise Interceptor
Technical Memorandum to serve North Boise, an area now served
by septic tank-drainfield systems and projected as an area
for rapid development (see Figure 4-1). Conclusions of
that memo were:
44
-------
Table 4-7. Sludge Processing Alternatives Evaluated
for the West Boise Treatment Plant
Thickening
Gravity thickening
(primary sludge)
Flotation thickening
{secondary sludge)
Centrifugal thickening
(secondary sludge)
Alternatives Considered for Various Sludge Processing Elements
Drying and
Stabilization
Anaerobic digestion
Aerobic digestion
Heat treatment
Composting
Chemical
Stabilization
Dewatering
Drying beds
Vacuum filtration
Pressure filtration
Belt filter press
Centrifugal
Dewatering
Reduction
Heat drying
Extractive
treatment
Oil emersion
Dehydration
Incineration
Pyrolysis
SOURCE: CH2M Hill 1980c.
-------
Table 4-8. Year 2000 Projections of Digested Sludge Volume from
the Lander Street and West Boise Treatment Plants
Treatment Plant
Lander Street
West Boise
TOTAL
Digested Solids
(lb/day)
Annual
Average
12,240
21,030
33,270
Peak
Month
16,910
28,630
45,540
Total Volume
(gallons/day)
Annual
Average
Peak
Month
62,160 84,895
87,040 116,725
149,200 201,620
Solids Concentration
(% solids)
Annual
Average
2.36
2.90
2.67
Peak
Month
2. 39
2. 94
2.71
SOURCE: CH2M Hill 1980c.
-------
Table 4-9. Sludge Management Alternatives3
Alternative
Deuaterinq
Transport
Storage
Disposal/Use
A
Not included
Tanker truck liquid
Al:
Covered concrete
Agricultural use at
sludge at 2.3% solids
at each plant site
Prison site.
A2:
Covered concrete
Assumes big gun
at Prison site
spi ii
tkler application
A3:
Lagoons at
Prison site
U
Hot included
Pipeline pimip/sta-
Bl:
Covered concrete
Agricultural use
tations at 2.3% solids
at each plant site
at Prison site.
B2:
Covered concrete
Assumes big gun
at Prison site
Sprinkler application
B3:
Lagoons at
Prison site
c
Filter belt press
Truck dewatered
CI:
Stockpile
CI:
Agricultural Use
at each plant site.
sludge at 17.5% solids
C2:
No storage
at Prison site
Output at 17.5% solids
C3:
Stockpile
via truck spread
C2:
Landfill
C3 :
Cowpust
1)
Drying beds dt
Truck dewatered
Dl:
Stockpile
Dl :
Agricultural use
each plant site.
sludge at b()% solids
D2:
No storage
at Pi i son si 1e
Output al 50% solids
via truck spread
D2:
Landfill
E
Drying beds at
Pipeline/pimp staLions
El:
Stockpile
El:
Agricultural use
Prison site.
at 2.3% solids
E2:
Ho storage
at Prison Site
Output at 50% solids
via truck spread
EZ:
Laud till
aAJ L alternatives
-------
14
16
15
13
MAIN F
SERVICE, ARE A
BOUNDARY
MAIN B
•ft*
00
MAIN A
STATE STREET A
SERVICE AREA a
MAINC
22
' glenwckSd STREET I:
f INTERCEPTOR _j ¦<£_ ¦_ _ _
'I'OINT OF'fr_OVtf DIVERSION TO NORTH
BOISE INTERCEPTOR
MAIN E
MAIN A
v
WEST BOISE
TREATMENT PLANT
SOUTH BOISE
INTERCEPTOR
FIGURE 4-1. NORTH BOISE INTERCEPTOR ALTERNATIVES
-------
o The North Boise interceptor service area would total
2,400 acres and up to 11,000 connections, depending
on the alignment plans selected,
o The North Boise interceptor should be sized to
handle excess flows of 5.6 MGD from the existing
Glenwood pump station,
o Extensive rights-of-way would be required under all
alignment plans,
o The location of the floodway boundary of the Boise
River affects the choice of an interceptor plan and
the area likely to be serviced by the sewer,
o Estimated capital costs appear in Table 4-10.
o Operation and maintenance costs are comparable among
alternatives.
o Plan 4 offers the maximum flexibility for staged
construction.
As noted in Chapter 3, the North Boise Interceptor is
not part of the current grant application for Stage 1
construction.
South Boise Interoeptor. The existing South Boise inter-
ceptor carries wastewater flows from the Garden City area
to the West Boise treatment plant. The proposal is to extend
the interceptor Southwest to relieve existing trunk and
interceptor lines flowing near capacity. A detailed analysis
of the routes and the advantages and disadvantages of each
was presented in the South Boise Interceptor Technical
Memorandum prepared by CH2M Hill.
The existing interceptor now terminates at the inter-
section of Field and Bradley Streets. The four alternative
routings were evaluated between the terminus at Field Street
and Main Street, approximately 11,000 feet to the southeast.
Portions of two of those alignments, River North and River
West, would be located within or fringing on the floodway
of the Boise River. In addition, the South Boise interceptor
east of Americana Boulevard would cross the Boise River to
join the future Table Rock interceptor. Two alternative
routes were evaluated from Main Street to Americana Boulevard,
a distance of approximately 4,000 feet (see Chapter 3,
Figure 3-5). The recommended routing for Stage 1 construc-
tion involves the Inland East-River West alignment.
Flow Augmentation. Under present conditions, flows
in the Boise River during the summer months (irrigation season)
are sufficient to provide proper dilution of effluent from
the Lander Street and West Boise treatment facilities. Winter
flows (nonirrigation season), however, are significantly
less than summer flows. Reservoir operation studies that
may result in greater flow releases from Lucky Peak Reservoir
are being developed by the Idaho Department of Water Resources,
49
-------
Table 4-10. Capital Costs of Alternative Plans -
North Boise Interceptor
Plan
Capital Costs
Capital Cost/Acre Served
1
$3,465,000
$599
2
$3,372,000
$583
3
$3,450,000
$574
4
$3,509,000
$584
SOURCE: CH2M Hill 1980c.
-------
U. S. Army Corps of Engineers, and U. S. Bureau of Reclamation.
Proposed hydropower facilities in Lucky Peak Dam would also
decrease the likelihood of low flow situations.
The U. S. Fish and Wildlife Service has recommended
stream resource maintenance flows (SRMF) of 225 cfs in
October and November and 150 cfs during January through
March. A l-in-10-year low river flow of 80 cfs was used
by the Idaho Department of Health and Welfare to determine
treatment plant effluent limitations at the West Boise and
Lander Street plants. Table 4-11 shows the percent of time
that the Lander Street and West Boise plants would have ammonia
limitations.
Energy Requirements
Treatment Plant Expansion and Modification. In the
Boise facilities plan, CH2M Hill explored six options and
several suboptions for the utilization of methane (digester)
gas at the Lander Street treatment plant. Primary use of
the gas would be to operate raw sewage pumps and air blowers;
however, two options for generating electricity for sell-
back to the Idaho Power Company (IPCo) were also evaluated.
Digester gas generation would vary from approximately 90,000
cubic feet per day during the winter to 140,000 cubic feet
per day during the summer. The quantity of natural gas or
electrical power needed to supplement the use of digester
gas at the facilities would vary with the option. The total
average energy cost would depend on: (1) the equipment needed,
(2) whether natural gas or electricity was used to supplement
digester gas and the future projected cost of each, and (3)
the credit price allowed for electrical energy generated
and fed back to IPCo. CH2M Hill recommended that the City
of Boise choose the preferred option after negotiations for
sale of generated electricity to IPCo are finalized.
Energy requirements for the various modification alterna-
tives at the West Boise plant are presented in Table 4-12.
The alternative of converting to anaerobic sludge digestion
was determined to be the most cost-efficient of the three
alternatives (CH2M Hill 1980c).
Sludge Management. An energy use comparison of the
various sludge transport alternatives is presented in
Table 4-13. The liquid sludge pipeline transport alternative
was determined to require the least amount of energy. In
addition to sludge transport, approximately 5,700 gallons
of diesel fuel and 52,200 kilowatt hours of electricity would
be required per year to apply sludge to agricultural land
(CH2M Hill 1980).
51
-------
Table 4-11. Ammonia Limitations
Treatment
Plant
Percent
of Time Ammonia
Discharge is Limited
Fall
Winter
Spring
Summer
Lander Street
15
0
0
0
West Boise*
100
75
25
75
limitations are based on projected year 2000 wastewater flows at West Boise.
SOURCE: CH2M Hill 1980c.
-------
Table 4-12. Process Energy Consumption
for West Boise Alternatives
EMESGY REQUIREMENTS (horsepower)3
Alternative Mo. 1 Alternative No. 2 Alternative Mo. 3
Aerobic Diaestion
With Primary
Clarification and
Aerobic Diaestion Anaerobic Diaestion Flotation Thicl'.er.ir.c
1990 2060 1990 iOOO 1990 20 JO
Effluent Pumping
130
290
180
290
180
290
Grit Removal
—
—
7
14
—
--
Screening and Grinding
4
8
4
8
4
3
Primary Clarification
—
—
4
8
4
3
Aeration Basins
670
1,140
520
890
520
390
Secondary Clarification
8
16
3
14
8
•_ 4
Postaeration
50
80
50
80
50
80
Cavity Thickening
—
—
1
1
—
—
Flotation Thickening
—
—
55
55
55
55
Sludge Pumping
75
120
65
115
70
115
Aerobic Digestion
430
850
—
--
450
750
Anaerobic Digestion
Total Energy Required (hp)
_ _
100° 145
—
—
1,417
2, 5 C 4
994
1,620
1,341
2,210
Digester Gas Heating Value
(therms /year)
0
0
202,000
370,000
0
1
Digester Heating Require-
ments (therms/year)
0
0
95,000
139,000
0
0
Electrical Energy
Generation (hp)c
0
0
195
360
0
0
Net Electrical Energy
Required
o Horsepower
o Kilowatt-hours/MGD
X, 417
1,691
2,504
1,830
799
953
1,260
920
1,341
1,601
2,210
1,615
aBased on average annual flew rates
of 15.0 MGD in 1990
and 24.5 MGD in 2000.
^Excludes digester sludge heating requirements.
°Based on the following assumptions: Gas engine availability = 85 percent.
Engine generator efficiency = 25 percent.
Gas engine heat recovery efficiency = 50 percent.
Boiler efficiency = 80 percent.
SOURCE: CH2M Hill October 1980c. 53
-------
Table 4-13. Energy Consumption for
Sludge Transportation Alternatives3
Liquid Sludge
Liquid Sludge Liquid Sludge Dewatered Sludge Pipeline/Truck
Item Pipeline Transport Truck Transport Truck Transport Transport
Electrical Energy (kWh/yr) 330,300 — 1,143,000 219,900
Diesel Fuel (gal/yr) — 42,000 6,480 15,050
Total Annual Cost ($/yr)b 8,000 48,000 35,000 22,900
aElectrical energy and diesel fuel quantities are based on average annual quantities
in the year 19 90.
^Annual costs are in December 1980 dollars: Electrical energy cost = $0.01915/kWh
+ $2.60/kW-month demand. Diesel fuel cost = $1.15/gal.
SOURCE: CH2M Hill October 1980c.
-------
No-Action Alternative
The no-action alternative would involve the continued
operation of the Lander Street and West Boise treatment
plants at their present capacities. The Lander Street plant
would, in the near future, become overloaded from both a
hydraulic and a waste load standpoint. The West Boise plant
is presently overloaded from a hydraulic standpoint. Increased
overloading would result in reduced effluent quality and
increased water quality impacts on the Boise River. Such
problems could lead to restrictions on future connections
to these systems or locally funded facility modifications
and expansions.
Eagle Sewer District Facilities
The existing Eagle sewage wastewater plant is considered
to be an interim treatment facility. A capacity limit equi-
valent to 790 dwelling units (population of 2,370) has been
imposed by the Idaho Department of Health and Welfare. With
the understanding that future facilities would be needed,
the Eagle Sewer District (ESD) purchased a 65-acre site
approximately 1 mile downstream from the existing facilities.
J-U-B Engineers, Inc., prepared a facilities plan for
the ESD which presented regionalization, land application,
and on-site disposal options. Facility site alternatives
were not considered in the draft facility plan. The existing
and proposed facility sites were shown in Chapter 3 (Figure 3-6).
The proposed facility site is shown as being within a
"special flood hazard area" on the 1977 flood hazard boundary
map produced by the Federal Insurance Administration.
The U. S. Army Corps of Engineers has completed a ground
control survey and is currently developing new cross sections
in the area which will aid in the development of detailed
floodplain boundaries (Fintel pers. comm.). A request has
been submitted to the District Engineer in Walla Walla, Washing-
ton for floodplain information as soon as it is available.
No information had been received at the time this Final EIS
was prepared.
Wastewater flow projections used for initial facility
planning are shown in Table 4-14. Refined flow and waste
load projections will be developed during more detailed design
studies.
55
-------
Table 4-14. Sewage Flow Projections for the Eagle Sewer District
War
Arc-j
I'upul .itlon
Service*
Popnlat ion
Fopul at ion
Increase
Change
In K1ou
60 gal/cap/day
Base Flaw
Existing
Removable T/I
Inf11tration
Existing
Non-Removable I/I
Inf 111 ra lion
Change In
A1lovable I/I
250 gal/hc/day
A11 ouaii 1 e I/I
Flow Less
Rein iv.ih 1 e I/I
Tc-ial
f i ou
i y 79
45S1
2370
—
—
0.1415
0.155
0.0535
—
0.0535
0. 1950
0".3i""
19S5
6210
4552
2182
0.1309
0.2724
0.155
0.0535
0.0606
0.1141
0.3865
0. 5 1 5
1900
8002
6897
2345
0.1407
0.4131
0.155
0.0535
0.0651
0.1792
0.5923
0.7;73
1995
JO,31 1
9759
2862
0.1717
0.5848
0.155
0.0535
0.0795
0.2587
O.B'<35
0. 9;jh5
2000
1'), 286
13,286
3527
0.2117
0.7965
0.155
0.0535
0.0980
0.3567
1.I 532
1.3uS2
*lt is
u SSUTS'.t*d
lut the present population
in the
service area slot
sewered, w11\
be sewered at a rate
of 5% per yea
r or 1J0 persons
per ye.ir.
SOURCE: 0-U-B Engineers 1980
-------
Treatment Alternatives
Five project alternatives were analyzed by J-U-B Engineers.
These are summarized below.
Alternative A - Oxidation Ditch. This alternative would
consist of pumping, pretreatment, oxidation ditch with rotating
aerators, secondary clarifiers, disinfection and sludge handling
facilities located at the new 65-acre site owned by ESD.
Construction of the facility would be staged according to
population growth.
Effluent from the disinfection facility (chlorine contact
chamber) would be discharged through a diffuser into the
North Channel of the Boise River. Sludge from the clarifiers
would be held in an equalization basin until applied to land
by injector truck. The sludge disposal site has not yet
been determined.
Alternative B - Pump to West Boise Treatment Plant.
This alternative would require pretreatment (screening grit
removal and flow measurement), a pumping station and 19,000
feet of pressurized pipeline from the new treatment plant
site to the West Boise treatment plant. The pipeline would
require two river crossings.
Alternative C - Land Application by Irrigation. The
alternative of applying wastewater by slow rate disposal
method would have the following project components: pre-
treatment (screening)j pumping station; aerated lagoons;
45 acres of storage lagoons (for storage of approximately 125
days of wastewater flows); disinfection; application system;
and 250-325 acres of land.
Alternative D - Rapid Infiltration. Rapid infiltration
was the second land disposal option evaluated. The components
of the alternative would include pretreatment, a lift station,
aerated lagoon, equalization lagoons, pump stations and rapid
infiltration basins. Observation wells would be constructed
to monitor groundwater quality.
Alternative E - On-Site Disposal. This alternative
would represent a combination of on-site community septic
systems and construction of a new 0.55 MGD treatment plant
to treat sewage from presently sewered areas (J-U-B Engineers
1980).
Ada County presently requires a 1-acre minimum lot size
for an on-site disposal system and a well. If central water
is provided, the minimum lot size required is .5 acre. Within
the planning area, approximately 400 homes are presently
being served by individual on-site systems and another 500
57
-------
units would likely be developed utilizing subsurface disposal.
Since the existing sewage treatment facilities are "at capacity"
(equivalent of 790 dwelling units), any future on-site systems
or a community septic system.
The community septic system would allow connection of
a maximum of 7 0 dwelling units to a compartmentalized septic
tank and parallel drainfield. Septic tanks would be pumped
once every 2 years and septage disposed of at the new
ESD treatment facility.
Interceptor Systems
The proposed interceptor (Figure 3-6) would be common
to all alternatives except no-action and Alternative E (on-
site disposal). Sizing of the interceptor will depend on
whether it is designed for a 20-year flow projection or (as
recommended in the facility plan) a 40- to 50-year planning
period.
Energy Requirements
Energy requirements for the four centralized treatment
alternatives are shown in Table 4-15. The recommended project
(rapid infiltration) has the lowest primary energy requirement.
The oxidation ditch alternative (recommended if the rapid
infiltration site proves unusable) has a primary energy require-
ment close to that of the proposed project.
Project Costs
Estimated project costs and user charges are summarized
in Table 4-16. The proposed project (rapid infiltration)
is the least costly alternative.
No-Action Alternative
The no-action alternative would be represented by the
continued operation of the present treatment system. The sand
filter treatment is operating within secondary treatment stan-
dards and would probably continue to do so under present
loading levels (population equivalent of 2,370). While no
additional hookups to the sewer system would occur, some
residential development would occur utilizing individual
subsurface disposal systems.
Southwest Community Wastewater Management Study
Rapid population growth in the Southwest community during
the period from 1970-1978 resulted in a number of steps
designed to provide orderly future development of the area:
58
-------
Table 4-15. Primary Energy Consumption for Alternative
Eagle Sewer District Projects
Project Alternatives
Energy Units
Horsepower1
Kilowatt hours/day2
Kilowatt hours/MGD2
Oxidation
Ditch
90
1,611
1,230
Pump to
West Boise
77*
1,379*
1,052*
Agricultural
Irrigation
121
2,166
1,654
Rapid
Infiltration
85
1,522
1,162
On-Site
Systems
70
1,253
2,279
Notes:
1From J-U-B Engineers 1980.
2Jones & Stokes Associates calculation of energy equivalencies; 1.31 MGD assumed for all
but the on-site systems alternative (0.55 MGD).
~Does not include energy requirements at the West Boise treatment plant (an additional
67 horsepower = 1,617 kilowatt hours/day = 1,234 kilowatt hours/MGD based on data in
Table 4-12).
Installed horsepower and equivalent kilowatt hours may be somewhat in excess of actual
facility energy demand due to standardized sizing of electric motors.
-------
Table 4-16. Estimated Project Costs and Monthly User Charges for
Alternative Eagle Sewer District Projects
Project Alternative
Cost Element
Capital Cost
Annual O&M Cost
Total Annual Cost
Monthly User Charge1
Oxidation
Ditch
$2,849,000
62,000
334,000
$7.43
Pump to
West Boise
$2,683,000
98,000
354,000
$10.30
Agricultural
Irrigation*
$2,797,000
71,000
338,000
$8.14
Rapid
Infiltration
$2,402,000
63,000
291,000
$7.16
On-Site
Systems
$3,584,000
58,000
$7.68
Notes:
*Cost of effluent pipeline system not included.
1Based on 1,000 connections; interceptor cost will add $0.49 to the monthly user charge.
SOURCE: J-U-B Engineers 1980.
-------
o 1978 - Board of Ada County Commissioners passed
a moratorium on additional platting and residential
rezoning in the Southwest community,
o February 197 9 - The County Commissioners adopted
the Southwest Interim Development District Ordinance
to guide development until revision of the compre-
hensive plan.
o 1979 - The Ada Planning Association (APA) initiated
preparation of the Southwest Community Wastewater
Management Plan.
During early APA planning efforts, 39 wastewater treatment
and disposal alternatives were evaluated and reduced to 10
warranting further consideration. Based on public input
and decisions regarding development density, the 10 alternatives
were narrowed to three structural alternatives and the no-
action option. Those alternatives were:
o Central wastewater collection system and treatment
at the West Boise treatment plant,
o Central wastewater collection and treatment at a
Southwest community wastewater treatment plant with
land disposal of effluent,
o Wastewater collection and treatment at community
lagoons with land disposal of effluent at separate
sites or a common site,
o On-site systems.
Centralized wastewater facility alternatives were
developed assuming that future development in the proposed
20-year service area (Figure 4-2) would occur at four units
per acre. The alternative of continued reliance on individual
on-site systems assumed that future development throughout
the Southwest area would generally involve densities of one
unit per 5 acres.
Public workshops and hearings on the wastewater manage-
ment alternatives and comprehensive plan revisions resulted
in adoption of a "rural lifestyle" land use plan for the
Southwest area.
As a result of that decision, the use of individual
on-site subsurface disposal systems became the only feasible
wastewater management alternative for the Southwest community
(APA 1980). In order to ensure some level of proper operation
and maintenance of septic systems, the Southwest Community
Wastewater Management Study set forth a number of maintenance
program alternatives.
Operations and Maintenance Program Alternatives
Three broad programs and a number of options within
each were analyzed. As discussed in Chapter 3, the vol-
untary operation and maintenance program was adopted as
a countywide program.
-------
Figure 4-2. Area Considered for Centralized Sewe*-
Service During Southwest Community Wastewater
Management Study.
APA 1980b.
62
-------
Mandatory Operation and Maintenance Program.
Case I. With this alternative an advisory agency would
be given authority to issue renewable use permits for subsurface
systems. Inspection would be conducted every 3 years and
any needed repairs made by the homeowner. A permit fee would
be levied to finance operational costs of the program. Licensed
contractors would do the inspection, repairs and any necessary
pumping.
Case II. The Case II mandatory operation and maintenance
program would include all inspection maintenance and repairs
conducted by the public agency, with homeowners charged an
annual fee plus costs of system repairs. Easements through
private property would be necessary for maintenance and repair.
Case III. The Case III option would involve ownership,
maintenance, and repair of septic systems. An annual fee
would be levied to finance inspection and repair, with all
users charged the same fee, no matter what the needed repair
and maintenance.
Volunteer/Mandatory Operation and Maintenance Program.
This combination program would involve a volunteer or optional
mandatory program for all homeowners now on septic systems,
with mandatory participation by homeowners with failing septic
systems, and those constructing homes after implementation
of the maintenance program.
Volunteer Operation and Maintenance Program. The volunteer
program would include the establishment of a public education
program and the mailing of notices to remind homeowners to
inspect their systems.
No-Action Program. The no-action alternative would
represent a continuation of the present system of allowing
all maintenance to be the responsibility of homeowners.
63
-------
Chapter 5
Population Projections and
Growth Inducement
-------
Chapter 5
POPULATION PROJECTIONS AND GROWTH INDUCEMENT
Introduction
Population projections prepared in conjunction with
wastewater facility planning are used to determine projected
wastewater flows. The projected flows provide the basis
for the sizing of wastewater treatment facilities. In
addition, population projections are used in environmental
impact assessments to assess potential indirect impacts
of growth accommodated by wastewater plans and to develop
possible mitigation measures.
EPA's policy for population projections to be used
for facilities planning is presented in Appendix A of the
agency's cost-effectiveness analysis guidelines (U. S. EPA
1978a). The policy requires wastewater facilities plans
to use population projections developed by states or appearing
in approved 208 plans, provided that state projections do
not exceed Bureau of Economic Analysis (BEA) projections
by more than 5 percent, and that 20 8 plan projections do
not exceed state projections by more than 10 percent. New
BEA projections are currently being developed in con-
junction with the federal Office of Management and Budget
(OMB). These new projections are not expected to be completed
until late 1981.
The state baseline population projection for facilities
planning was developed by the Bureau of Water Quality (BWQ)
and approved by EPA in January 1980. The BWQ projection
for Ada County in the year 2000 was 26 8,622. This projection
was subsequently revised to 289,000, and approved by EPA in
March 1980.
In August 1978, Ada Planning Association (APA) adopted
the report Demographic and Employment Distribution (DED)
to Year 2000. This report presents population and employ-
ment allocations in 5-year intervals for Ada County and for
smaller statistical areas. The DED allocations were adopted
as the population baseline for all APA regional planning
programs, including 208 areawide waste treatment management
planning. A summary of the DED population allocations is
presented in Table 5-1.
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Table 5-1. Summary of DED Planning Area
Population Projections
Year 2 0 0 0
1-975 Additional 2000 (- of Total)
Southeast
11,425
42,100
53,525
18.5
North River
35,650
34 , 300
6 9,9 50
2 4.2
City Center
2,940
3,715
6,655
2 . 3
North End
17, 180
930
18 ,110
6 . 3
Northwest
5, 310
19,145
24,4 55
8 . 5
FoothilIs
6,725
8 ,431
15,156
5 . 2
Warm Springs
3,495
2,079
5 ,574
] .'J
West Bench*
28,700
16,415
45,115
15.6
Central Bench
36 ,105
7,250
43 ,355
15.0
aSouthv;est
9,080
13,300
(9,905) 22,380
(18,985)
7.7
(6.6)
Total Metro
120,960
113,365
(109,970) 234 ,325 (230 ,930)
81.1
(79.9)
Meridian
a
6,349
18,801
25 ,150
8 . 7
Eagle
2 ,720
7,50 5
(10,566) 10,225
(13,286)
3 . 5
(4.6)
Kuna
a
1 ,308
5,517
6,825
2 . A
Kural Area**
8,063
4,412
(4,746) 12,4 75
(12,809)
4 . 3
(4.4)
Total Nonmetro
18,440
36,235(39,630) 54,675
(58,070)
18.9
(20.1)
Total Ada County
139 , 400
149,600
289,000
100.0
* Includes Garden City
**Includes Star
SOURCE: Ada Planning Association, 1978. Demographic and Employment Distribution
to the Year 2000: Ada County, Idaho.
d
Numbers shown in parentheses reflect APA reallocation of 3,395 from the Southwest
Area to the Eagle service and rural areas.
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Description of Facility Planning
Population Projections
Boise Planning Area
The Boise planning area corresponds to the Boise Metro-
politan Area with the exception of the Southwest area (see
Figure 4-6). The population projections prepared by the
facilities plan consultants were based on the DED allocations.
The population projection in the Boise facilities plan for
year 2000 is 212,145 (Table 4-4). This compares with 211,945
in the DED study for the year 2000.
Southwest Planning Area
A comprehensive land use plan was adopted for the South-
west planning area in August 1980. This land use plan,
referred to as Plan "C" - rural lifestyle, allows a maximum
density allowance of one unit per 5 acres for all new develop-
ment in areas designated "rural residential". Based on the
adopted land use plan, the population allocated by APA for
the year 2000 is 18,985.
As shown in Table 5-1, the adopted 20 8 (DED) allocation
for the Southwest area in the year 2000 is 22,380. The
difference between the DED distribution and the most recent
APA projection is 3,395 persons. Most of this additional
population allocated to the Southwest planning area has been
re-allocated by APA to the Eagle sewer service area (Area B
in Figure 3-6) for 20-year projections of wastewater treatment
capacity (Minter pers. comm.).
Eagle Planning Area
The DED original allocation for Eagle in the year 2000
was 10,225. Although this projection had been adopted as
the official 208 plan projection, APA has acknowledged that
it is probably low (Minter pers. comm.). With the addition
of 3,061 persons formerly allocated to the Southwest area,
the revised APA allocation for the Eagle planning area is
13,286. The population projection in the Eagle facilities
plan is 13,286 for the year 2000 and corresponds with APA's
revised allocation for Eagle. This projection covers only
Eagle planning area B. Provision of sewer service to planning
area C would need approval of residential zoning by Ada
County (Figure 3-6).
67
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Growth lnducemont Ro1e_of
the Proposed Projects
EPA policy requires that environmental impact statements
on wastewater treatment projects receiving federal construction
grant funds consider the growth-related impacts of the projects.
These impacts are typically indirect impacts because they
are primarily caused by the growth in part accommodated by
expansion of wastewater treatment facilities. The growth-
related impacts are discussed in Chapters 6 through 12. The
following section examines the relationship between sewer
facilities and growth; assesses growth under the no-action
alternative; and discusses the growth accommodated by the
proposed projects.
Relationship of Sewer Facilities to Growth
Although many factors contribute to the growth of an
area, the availability of sewer facilities can be and
often is an important influence on the rate of growth.
Extension of sewer facilities to a previously unserviced
area may induce or accelerate growth. Conversely, failure
to provide facilities may limit or restrict growth. The
extension of sewers is important not only in terms of
servicing areas but also in planning for future development
of areas. Providing sewer facilities to an area prematurely
can subvert local land use planning efforts.
The important relationship between sewer availability
and growth has been formally recognized in local land use
plans, policies and ordinances in Ada County. Both the City
of Boise and Ada County have adopted sewer wetline policies
which restrict growth to areas where sewer service is
available. In addition, the City of Boise has encouraged
development in the Southeast area through increased city
participation in funding for local collection systems.
These sewer policies are effective tools in accomplishing
related land use objectives.
Growth Under the No-Action Alternative
This section examines growth that would occur in the
area if the project were not built. It is not possible to
estimate exactly the extent of growth attributable to the
proposed projects. However, some generalizations can be
drawn. Without this project, the level of growth in the
Boise planning area would not reach projected levels. This
68
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is primarily due to the development restrictions of the
existing sewer wetline ordinance. Boise is the economic
center of the region- The significant decrease in the
current allocation to the Boise area that would result
from the No-Action alternative would likely cause growth
in other local areas to exceed what is currently projected.
However, it is very unlikely that other urban areas in
the region could attract or accommodate all the growth
presently allocated to Boise. Therefore, it is expected
that the overall regional growth would decline.
The impact of the No-Action alternative on growth in
Eagle is less certain. Eagle probably would absorb some
of the regional population growth, but it would be at
lower densities than projected with expanded wastewater
facilities.
Growth Accommodated by the Proposed Projects
Boise Planning Area. Expansion of wastewater treatment
facilities in the Boise planning area would accommodate a
population increase to 212,145 by the year 2000. This
represents an increase of 86,335 persons over the 197 8
estimate of 125,810 projected to occur over the 22-year
period (1978-2000). There are currently 29,360 Boise
area residents who are not on sewers. The planned expansion
of wastewater facilities will provide capacity to sewer
these residents and all projected new population by the
year 2000.
Wastewater facilities planning for Boise stages
implementation of the project. Stage 1 includes minor
modifications at the Lander Street treatment plant to meet
effluent discharge requirements. The present capacity of
the Lander Street plant is 15 MGD and no additional
hydraulic capacity is planned. Diversion of some of the
existing flow at the Lander Street plant to the West Boise
plant will provide capacity at Lander Street for some
future growth. Based on projected flows, capacity at the
Lander Street plant will be reached sometime after the year
2000.
In addition to the Lander Street modifications,
Stage 1 includes expansion of the West Boise treatment
plant from the current peak capacity of 6.3 MGD to 17 MGD.
Based on projected flows, the West Boise treatment plant
will reach its Stage 1 capacity of 17 MGD about 1987 and
will provide service to approximately 94,657 residents
{extrapolated from Table 4-4).
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Stage 2 involves construction of an additional 17
MGD capacity treatment plant adjacent to the existing
West Boise treatment facilities. This expansion should
have sufficient capacity to serve the 212,145 population
projected for the year 2000 as well as needs beyond year
2000. Total capacity of the West Boise and Lander Street
treatment plants will be 49 MGD by the year 2000.
Eagle Planning Area. Expansion of wastewater facilities
in the Eagle planning area would accommodate a population
increase from over 4,581 persons (estimated in 1979) to
13,286 in the year 2000 (Table 4-16). This represents an
increase of 8,705 persons over the 21-year period. In
addition, an estimated 1,550 persons could be served if
residential zoning is approved by Ada County for planning
area C (Figure 3-6). This additional population is not
included, however, in the current grant application.
Facilities planning in Eagle involves two 10-year
stages for design of treatment facilities. It is estimated
by the facility planning consultants (J-U-B Engineers 1980)
that, as of 1979, 2,370 persons out of a total population
of 4,581 in planning area B were provided sewer service.
By 1990, it is projected by J-U-B that 8,002 persons will
reside in planning Area B, with 6,897 persons on sewers
(Table 4-16). This represents an increase in sewered
population of 4,527 persons during the initial 10-year
planning period. By the year 2000, it is projected by
J-U-B that the total projected population (13,286) within
the Eagle planning area would be provided sewer service.
It appears there is some inconsistency between the
projected population to be serviced (13,286) by the year
2000 and the density of development in the Eagle planning
area slated for sewering. It is recognized by J-U-B
Engineers that not all areas will be of sufficient density
in the year 2000 to warrant sewer service. However, the
total population projected for the year 2000 has been
used to estimate flows and includes extending sewer service
to the total planning area.
70
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Chapter 6
Land Use Conditions and Trends
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Chapter 6
LAND USE IMPACTS
Introduction
A rapid increase in population is expected in Ada County
over the next 20 years. As a result, significant land use
changes are likely to occur. Although comprehensive plans
have been prepared to provide guidance for directing this
growth, the effectiveness of local plans to guide growth
will be determined by the extent to which the plans are
implemented. An important issue in this EIS is the impact
which implementation of the wastewater facility plans will
have on influencing future land use conditions.
This chapter examines the existing land use in the three
planning areas; reviews local land use plans and development
policies; and assesses the consistency of the wastewater
facility plans with local land use plans.
Existing Land Use
Information on existing land use conditions in the three
planning areas is limited. In the Boise planning area, the
most comprehensive analysis of existing land use was prepared
in 1970 by the Ada Council of Governments (ACOG) (Johnson pers.
comm.). For the Southwest planning area, more recent informa-
tion is available as a result of the current wastewater and
comprehensive land use planning efforts. For the Eagle planning
area, limited land use information is available from the pre-
paration in 1977 of the Eagle Comprehensive Plan.
Boise Planning Area
The existing land use pattern in the Boise planning
area is characterized by relatively dense concentration of
commercial and residential uses in the central region changing
to more scattered developments in the outlying areas.
For planning purposes, the Boise metropolitan area is
divided into five major planning subareas {Figure 6-1). These
planning subareas are the Southeast area; the North River
area; the West Bench area; the Central Bench area; and the
Southwest area.
71
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FIGURE 6-1. BOISE PLANNING
SUB-AREAS
SOUTHWEST
-------
As shown in Table 6-1, the Boise planning area had a
slightly higher percentage of vacant acres (53%) than
developed acres (47%) in 1978. The Central Bench area was
the most developed (83%) and the Southeast area was the
least developed (22%). Although 53% pf the Boise planning
area consisted of vacant land, only 84% of this vacant land
was considered developable.
Southwest Planning Area
The existing land use in the Southwest planning area
consists primarily of a mixture of residential, suburban
and agricultural uses. Approximately 42 percent of the
10,506 total gross acres has been subdivided for residential
use at an average gross density of 1.19 dwelling units per
acre (APA 1979a). Fifty-two percent of the Southwest
planning area is used for agricultural/grazing purposes or
is undeveloped. Industrial development in the Southwest
planning area is located primarily in the Boise airport
influence area at the eastern extreme of the area. Major
commercial uses include a community shopping center at Over-
land Road and Five-Mile Road, a neighborhood shopping center at
Five-Mile Road and Lake Hazel Road, and a mixture of commercial
and industrial uses at the Interstate 80/Overland Road interchange.
Eagle Planning Area
Much of the Eagle planning area is sparsely populated,
consisting of farmland, undeveloped open space, and flood-
plain. Urban land uses are centered around the City of
Eagle, with agricultural, rural residential and undeveloped
open space accounting for the bulk of the land uses in the
planning area. Table 6-2 presents a summary of land use
in the Eagle area as of 1977.
The existing residential development pattern consists
of 3-4 lots-per-acre subdivisions in the city and large lot
(1-5 acres) subdivisions in the rural areas. The commercial
and industrial uses are located in the immediate vicinity
of Eagle.
Land Use Plans and Policies
The Idaho Local Planning Act of 1975 establishes the
framework for local government comprehensive planning.
The law requires all cities and counties to prepare general plans,
requires certain elements to be included in local plans,
and requires zoning to be consistent with local plans. The
Idaho Local Planning Act also requires that local plans
designate "areas of city impact". The "areas of city impact"
are to be negotiated between the county and the incorporated
cities. The purpose in defining "areas of city impact" is
to identify areas surrounding the cities where land use and
other policies are important for successful implementation of
73
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Table 6-1. Allocation of Developed Acres, Vacant Acres
and Developable Acres by Boise Planning Subareas
Total
Acres
Developed
Acres
Developed
Acres as
% of
Total
Acres
Vacant
Acres
Vacant
Acres as
% of
Total
Acres
Developable
Acres
Developable
Acres as
% of Total
Vacant Acres
Southeast
Planning
Subarea
8,494
1,852
22
6,642 78
4,262
64
North River
Planning
Subarea
18,675
7,974
43
10,701
57
9,591
90
West Bench
Planning
Subarea
11,182
6,051
54
5,131
46
4,934
96
Central Bench
Planning
Subarea
6,198
5,136
83
1,062 17
986
93
Totals - all
Planning
Subareas
44,549 21,013
47
23,536 53
19,773
84
SOURCE: Derived frcm APA "Demographic and Employment Distribution to the Year 2000" 1978.
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Table 6-2. Land Use in the Eagle's Area of City Impact in 1977
Acres
Lots/Units
Residential
Less than 10,000 square feet
More than 10,000 square feet
Five acres or more
Multifamily
Rural housing
Commercial
Industrial
Public/Government
Ins ti tutional/School
Open Space/Parks
Vacant
More than 10,000 square feet
Five acres or more
Agriculture
(1,877.3)
15
741.2
797. 5
11.6
312.0
526.2
616.5
12,668.3
116.4
112.7
74.9
20.7
68
(13,811.0)
77
472
115
56
(720)
TOTAL
16,081.0
SOURCE: Eagle Planning and Zoning Commission 1979.
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both county and city goals (Ada County Planning Commission
1977). Figure 6-2 presents adopted and proposed "area of
city impact" designations in northern Ada County.
Ada County
In compliance with the Idaho Local Planning Act, Ada
County adopted a comprehensive plan in June 1977. This
plan uses the "urban service planning area" (USPA) approach
to encourage future growth in urban areas. The USPA is
defined as the area which each city intends to provide with
sewer and other "urban-type" services. A development
objective in Ada County's Comprehensive Plan is to accommo-
date between 92 and 95 percent of new growth within USPAs.
The USPAs within the study area are identified in Figure
6-2. As shown in Figure 6-2, the USPA is generally smaller
than the area of city impact.
In unincorporated Ada County, the county has implemented
the urban service planning area concept by adoption of a
"planned development" ordinance. This ordinance requires
that all proposed residential developments in the county have
central water and sewer service before a building permit is
issued. Because the county's policy over the past four
years has been to approve only subdivisions within USPAs,
the "planned development" review process has been used
effectively to require residential development to locate
within the USPAs.
Boise Planning Area
In October 1978 the Boise City Council adopted a Policy
Plan for the Boise Metropolitan Area. This plan shows the
Southwest area as part of the Boise Area of City Impact and
it suggests a population goal for the area. However, a
separate Southwest Community Comprehensive Plan has been
adopted by Ada County. Garden City, which is part of the
metropolitan area, is excluded from the Boise Policy Plan
because it has its own comprehensive plan.
In projecting a development pattern for the Boise
Metropolitan Area, the Boise Policy Plan's steering committee
suggested a development theme of centrality and compactness.
The central city area is to serve as the major employment
center for the area. Population growth is encouraged to
locate in the Southeast and Northwest subareas. Improved
access from these areas to the central city area is also
76
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EGEND-
^ INCORPORATED AREA
Durban service plannin6 area
AREA OF Cirr IMPACT
J. PROPOSED
| 1 ADOPTED
EAGLE
M/Jf
U STICK
MERIDIAN
OtSE
SOURCE: ADA COUNTY C0*Pi.Eli£N5IVE ?tl«
1977, AS AMENDED
\
\/l
FIGURE 6-2. INCORPORATED AREAS, URBAN SERVICE PLANNING
AREAS & "AREAS OF CITY IMPACT" IN NORTHERN ADA COUNTY
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recommended. Infilling of vacant developable acres within
the city is especially encouraged. The city intends to slow
the rate of growth in the West Bench subarea.
The Boise Policy Plan relies upon an incentive/dis-
incentive approach to implementation as opposed to a program
based upon strong growth controls. To encourage development
in the priority areas, a sewer financing formula provides an
incentive to developers through increased city participation
in funding (Stacy, pers. comm.). Also, improved access in
the priority areas has been provided by the city to stimulate
growth in those areas.
To discourage development in environmentally sensitive
areas (e.g., foothills and floodplains), the City of Boise
has enacted regulations for foothills development and is
currently preparing a comprehensive floodplain ordinance.
In addition, development in the airport influence area is
regulated by the city.
In 1978, the City of Boise adopted a sewer wetline
policy to regulate the location of development. This policy
requires all new development to be hooked up to the central
sewer system. Since adoption, however, several commercial
and industrial developments have been exempted from this
ordinance.
Southwest Planning Area
Until recently, growth in the Southwest area had been
guided by development policies from the 196 8 Ada County
Comprehensive Plan. Because of a rapidly increasing popu-
lation, the Southwest area experienced some growth-related
problems. As a result, the Ada County Commissioners imposed
a zoning and platting moratorium on the Southwest area in 1977.
The moratorium was replaced in February 197 9 by the Southwest
Interim Development District (SWIDD) ordinance. The interim
ordinances established density limitations on various types
of development while a Southwest Community Comprehensive Plan
was being prepared.
A final draft of the Southwest Community Comprehensive
Plan was submitted to the Ada County Commissioners in May
1980 for consideration. The residential density guidelines
recommended in the comprehensive plan were adopted by
resolution of the commissioners. These guidelines established
a high density and a low density infill plan, dependent on the
outcome of the central sewer feasibility study. The high
density plan allowed four dwelling units per acre on central
78
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sowers in the designated residential part of the Southwest
area. The low density plan allowed for two dwelling units
per acre on community wastewater systems in the residential
part of the area. A density level of one unit per 5 acres
would have been permitted on individual wastewatrr systems.
As a result of public hearings on the comprehensive plan,
and of workshops on wastewater alternatives, the Board of Ada
County Commissioners adopted a land use plan for the South-
west community in August 1980. This land use plan, referred
to as the "rural lifestyle alternative", contains a maximum
density allowance of one unit per 5 acres for all new develop-
ments in areas designated "rural residential". Although
higher densities could be permitted at some future time, the
anticipated population for the Southwest in the year 2000
is 18,985. When complete infilling has occurred, the popula-
tion is expected to increase to 20,385. The plan's land use
map is shown in Figure 6-3.
Eagle Planning Area
In 1976, the Eagle City Council adopted the Eagle Compre-
hensive Plan. In general, this plan recognizes Eagle as a
rural, suburban bedroom community of the Boise metropolitan
area and encourages the continuance of its rural character.
Recommended densities in the Eagle Comprehensive Plan permit
a maximum of 5 units per acre in the core area and 3 units
per acre outside the core area. The plan also encourages
growth to occur first within the city limits so that public
services can be planned for in an orderly manner.
Currently, efforts are under way to amend the Eagle
Comprehensive Plan. Although the exact nature of the
amendments is uncertain, it is believed that the compre-
hensive plan amendments would provide for the accommodation
of growth south of the Boise River.
Consistency of Wastewater Facility Plans with
Local Land Use Plans and Policies
EPA requires that wastewater facility plans be consistent
with applicable land use plans and policies. This is to ensure
that the facility planning area (or 20-year sewer service area)
is consistent with the area which local land use plans have
designated for extension of sewer service and other urban-type
services. It is recognized that the location an
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PRINCIPAL ARTERIAL
— MINOR ARTERIAL
COLLECTOR
EXISTING FIRE STATION
A
A
PROPOSED FIRE STATION
RELOCATION SITE
V $ V PARK AREA
¦ EXISTING SCHOOL
PROPOSED SCHOOL SITES
u (ONLY ONE TO BE BUILT)
1 I COMMUNITY SHOPPING CENTER
~ NEIGHBORHOOD SHOPPING CENTER
• CONVENIENCE CENTER
AIRPORT INDUSTRIAL
I 1 RURAL RESIDENTIAL/
I 1 URBAN RESERVE
I . 1 RANGELAND
Figure 6-3
SOUTHWEST COMMUNITY
COMPREHENSIVE LAND USE PLAN
-------
wastewater facility plans be consistent with local land use
and development policies. The following section evaluates
the potential impact of facility plans on local land use
plans and policies.
Boise Planning Area
The facility planning area in the Boise facilities plan
roughly corresponds to the city's urban service planning
area (USPA). As previously discussed, the USPA is the area
which each city intends to provide with sewer and other
"urban-type" services. Because the intent of the Boise
facility plan is to provide sewer service to all residents
within the facility planning area over the 20-year planning
period, a general consistency exists between the Boise
facility plan sewer service area and the sewer service area
as designated in local land use plans.
A second important issue is whether the Boise facility
plan provides for sewer availability in areas and, at a time
which is supportive of local growth policies. The Boise
Policy Plan recognizes the Southeast and Northwest areas
as high priority development areas. Because the exact
location and phasing of interceptors is uncertain, it is
difficult to determine the impact of wastewater facility
planning on land use. Some generalizations, however, can
be made.
Stage 1 in the Boise facilities plan involves the
extension of the South Boise Interceptor to provide
additional sewer service to the Southeast area, a high
priority development area. The other high priority area,
the Northwest, is, however, not a part of the current EPA
grant request but would be funded with local funds at
a later date. With the city's sewer wetline policy in
effect, it appears that sewer service in the Southeast area
would be a somewhat higher priority than sewer service in
the Northwest area.
Because of recent changing conditions (i.e., slower
growth, fiscal constraints), the city is re-examining its growth
policies related to priority development areas. Consequently,
proposed developments in the Northwest and Southeast areas
have been more closely evaluated and, in many cases, denied
for lack of available or planned public services. The
effect on land use has been to shift most developments to
the West Bench area where public service capacity is available
(Dopper, pers. comm.). The long-term implications of these
development conditions on wastewater facility needs are uncertain.
81
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Southwest Planning Area
The adoption of the Southwest Community Comprehensive
Plan precludes, for the present, consideration of central
or community wastewater treatment facilities for develop-
ment in the Southwest area. As a result, individual on-site
subsurface disposal systems will continue to be used for
wastewater management.
The adopted land use plan for the Southwest area would
essentially maintain the existing rural lifestyle which
characterizes most of the area. Future development at
higher densities, however, was not precluded by adoption of
the comprehensive plan. Provisions to re-subdivide into
higher densities could be implemented at some future date,
if coupled with sewer service and other public services.
In the meantime, the 5-acre minimum lot size requirement
can be expected to significantly reduce new development in
the Southwest area (APA 1980).
The preliminary 1980 census population of the Southwest
Community is approximately 16,700. With a projected popula-
tion of 18,895 persons in the year 2000, the Southwest area would
increase by approximately 2,200 persons over the 20-year
period. According to APA (Gross, pers. comm.), this growth
will occur primarily on lots which had been approved for
subdivision prior to adoption of the present density
requirements (one unit per 5 acres). Because of the
current high cost for land in the Southwest area ($6,000
to $10,000 per acre of unimproved land), there has been little
demand for 5-acre lots (Gross, pers. comm.). As a result,
it is assumed by APA (Gross, pers. comm.), that most of the
growth projected for the Southwest area will occur on
previously subdivided lots which are concentrated in the
northern portion of the area.
Eagle Planning Area
The Eagle Facilities Plan discusses the potential need
for wastewater facilities for Eagle planning areas A, B and
C. Only planning area B, however, is slated for sewer service
in the Eagle Sewer District proposed project. It appears that
planning area B roughly corresponds with the city's designated
urban service planning area and is consistent with the sewer
service area shown in local land use plans.
Development has been encouraged to the east of Eagle.
Whether it will be encouraged to the west of town is uncertain.
It is expected that local planning objectives will be clarified
at the conclusion of current efforts to amend the Eagle
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Comprehensive Plan. It is assumed that future serviceable
residential development will occur either within the existing
city limits or in areas annexed and zoned by Eagle in accordance
with the comprehensive plan. The county's wetline policy will
be the determining factor. It is likely that sewer service
will be provided to new development wherever development
densities are sufficient to warrant service.
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Chapter 7
Agricultural Lands In Ada County
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Chapter 7
URBANIZATION OF AGRICULTURAL LANDS
Introduction
Prime farmland is a nonrenewable resource; its con-
version to urban uses is essentially an irreversible process.
In recent years, the urbanization of agricultural land,
especially prime farmland, has become a growing national
concern. As a result, the U. S. Council on Environmental
Quality (CEQ) issued the following directive concerning
highly productive farmlands. "...efforts should be made
to assure that such farmlands are not irreversibly converted
to other uses unless other national interests override the
importance of preservation or otherwise outweigh the environ-
mental benefits derived from their protection (CEQ 1976).
National policies to slow the conversion of prime
farmland have been developed for several reasons. Some
of the more important reasons include:
o It is increasingly important to preserve those
lands best able to produce crops because the
rate of farm productivity growth has been
decreasing and export demands are increasing.
o Farmland preservation provides open space,
aesthetic, and environmental benefits.
o Agricultural production provides important
benefits to many local economies.
Because of these and other factors, EPA_in 1978 established
an agency-wide policy to assure that its actions, regulations,
and programs reinforce the retention of environmentally
significant agricultural land (EPA 1978d).
This chapter examines the agricultural land resources
within the three planning areas; discusses county preserva-
tion policies to protect agricultural land; assesses the impact
on agricultural lands from the proposed projects and recommends
measures to mitigate adverse impacts on important agricultural
lands.
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Agricultural Land Resources
Although Ada County has historically been viewed as
the center for business and government in Idaho, agriculture
has also played an important role in the local economy.
In 1974, the total market value of all agricultural crops
from Ada County surpassed $34 million, a significant portion
of which was harvested in northern Ada County. Principal
farm products include wheat, barley, alfalfa, corn, livestock
and livestock-related products.
Definition of Agricultural Lands
The terms prime farmland, cropland, and important
farmland are important to distinguish for purposes of this
analysis. The following definitions will be used:
° Prime farmland;
Land suitable for farming or silviculture with
"soil quality, growing season, and moisture
supply needed to economically produce sustained
high yields of crops when treated and managed,
including water management, according to acceptable
farming methods" (Lee, 1978). Prime farmlands
are the "most efficient, energy conserving,
environmentally stable lands available for meeting
food needs" (CEQ, 1978).
° Cropland:
Land in cropland use. Not all cropland is prime
farmland.
o Important farmland:
Important farmland is that farmland being mapped
by the U. S. Soil Conservation Service (SCS) under
its current (LIM-3) mapping program. It consists
of the following categories: prime farmland,
unique farmland (additional farmland used for the
production of specific high value crops), additional
farmland of statewide importance (to be determined
by state agencies), and additional farmland of
local importance (where appropriate, to be
determined by local agencies).
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Location of Important Farmland
The SCS has recently completed a soils survey for Ada
County. In addition, as part of their LIM mapping program,
SCS has identified prime farmlands in Ada County. Figure
7-1 presents the distribution of prime farmland within the
three planning areas.
Current Agricultural Production
in the Planning Areas
Although a significant amount of SCS-designated prime
farmland exists within the three planning areas (as shown
in Figure 7-1), a considerable portion of these lands is
not currently under intensive agricultural production. The
following section summarizes current agricultural activities
within the planning areas.
Boise Planning Areas
Agricultural production within the Boise facility
planning area is diverse. As a result of Boise's urbaniza-
tion, most of the significant agricultural production
occurs at the periphery of the planning area.
The northern section of the planning area is character-
ized by older agricultural operations of relatively small
scale (5-20 acres). Much of the area is grassland and
pastureland with scattered residences. Some cow operations
occur in this area. The eastern portion of the northern
section primarily consists of rolling hills with some
agricultural production in the valleys.
To the west of the City of Boise, scattered pastures
predominate. Considerable cropland exists toward the
western edge of the facility planning area. This area
between Boise and Meridian is primarily open farmland
with soils considered "probably as good as anywhere
around" (Walker pers. comm.). The primary agricultural
products are corn, grain, alfalfa and some dairy operations.
The South and Southeast areas of the Boise planning
area are mainly pastureland and grazing areas. The
pastureland primarily exists in the area directly south
of Boise. The Southeast area, although generally level
with available water, is characterized by sandy soils with
gravel beds interspersed. Although some alfalfa is
produced, the area is generally dry.
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FIGURE 7-1. DISTRIBUTION (APPROXIMATE)
OF SCS-DESIGNATED PRIME FARMLANDS
WITHIN THE FACILITY PLANNING AREAS
LEGEND-
Q PRIME FARMLANDS
SOURCE US SO!L CONSERVATION
SERVICE FILE DATA
'(MUl/i
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Southwest Planning Area
Because of a high water table, the Southwest area
is not considered exceptionally good for large-scale
agricultural production (Walker pers. comm.). In addition,
some hardpan sites are scattered throughout the
Southwest area. The Southwest area is characterized by
a considerable number of local, subsistance-type (3-10
acres) farming operations.
Eagle Planning Area
The Eagle facility planning area is characterized by
numerous "gentleman farms" (5-10 acres) and several larger-
scale operations. Some feed lot operations occur in the
northern portion of the planning area. On the higher
benches, some potatoes are grown. Many retired farmers
are located on the eastern edge of the planning area
(Walker pers. comm.).
Ada County Agricultural Land Policies
The preservation of agricultural land has received
considerable attention within Ada County. Preservation
of agricultural resources was formally recognized as an
important public issue in Ada County with the formulation
of goals, objectives and policies in the 1974 Ada County
Concept Plan (ACOG 1975b). Since the concept plan was
formulated, numerous preservation programs have been
recommended.
Of primary importance to Ada County's efforts to
preserve agricultural lands was the adoption of the Ada
County Comprehensive Plan. For rural areas, this plan
provides for agricultural preservation with development
policies which maintain large agricultural parcels.
Implementation of the policies has been provided by adoption
of an amended zoning and subdivision ordinance.
In areas where potential conflicts between urban and
agricultural uses are expected to occur, future urban
areas are defined by Urban Service Planning Area (USPA)
designations. These USPAs are areas "where municipal
sewer facilities and most other services and utilities
are available or planned". In effect, the USPA designa-
tion encourages development to occur within existing or
planned urbanized areas. One important implementation
measure of the USPA concept is the sewer wetline ordinance.
This policy restricts development to areas where sewer
service is available.
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Policies to protect agricultural lands within the
municipal boundaries of Eagle and Boise are limited.
Although the Eagle Comprehensive Plan recognizes the
importance of minimizing disruption to agricultural lands,
the comprehensive plan policies only address the areas
located outside of the facility planning area. These lands
are currently within the County's zoning jurisdiction.
The preservation of agricultural lands within the
Boise City limits was not discussed in the Boise Policy
Plan. Currently no zoning classification exists speci-
fically for agricultural lands within the City of Boise.
Urbanization of Agricultural Lands from
the Proposed Projects
Boise Planning Areas
Based on development policies expressed in the Boise
Policy Plan, future growth is encouraged in the Southeast
and Northwest areas. As shown on Figure 7-1, both the
Southeast and Northwest areas consist primarily of SCS-
designated prime farmland. The impact of growth in these
areas would be to convert a significant amount of SCS-
designated prime farmland to urban uses.
Although a major portion of the Southeast and North-
west areas are SCS-designated prime farmland, current
agricultural production in these areas is limited. At
present, the Northwest area consists primarily of grassland
with residences scattered throughout most of the area.
Although some lands are currently under agricultural
production, these are generally older gentleman-type farms,
projected growth for the Northwest would likely reduce
considerably the number of existing agricultural operations
in the area.
Current agricultural production in the Southeast area
is limited primarily to grazing land. Although the South-
east area is flat and is mostly designated prime farmland,
the area has relatively sandy soils and is generally dry.
The impact of growth projected in the Southeast would be to
significantly reduce grazing areas considered to be of
marginal agricultural value from a current production
standpoint.
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Although the Northwest and Southeast areas are
considered high priority development areas, most of the
current development is occurring in the West Bench area.
This area contains some significant agricultural land
resources in terms of both designated prime farmland
and current cropland production. Continued westward
expansion of development toward Meridian would
significantly affect current agricultural operations
in the area.
In summary, most of the growth projected for the Boise
planning area is expected to locate in the Southeast and
Northwest areas. Although the major portion of these areas
is designated prime farmland by the SCS, current agricultural
production is limited. Therefore, while the impact of growth
on the conversion of SCS-designated prime farmland is
considered significant, the impact of growth on current agri-
cultural production is considered marginal. If growth,
however, continues in the West Bench area, the impact on
current agricultural operations in that area would be
significant.
Southwest Planning Area
Future development in the Southwest planning area is
expected to be concentrated in the northern section of the
area. This northern section contains considerable SCS-
designated prime farmland (See Figure 7-1) but is not currently
under intensive agricultural production. Two important
limitations on larger-scale agricultural production are the
relatively high water table and scattered hardpan sites.
Because the Southwest area consists primarily of local
subsistence farming and because of density restrictions
on future development (one unit per 5 acres), the impact
of growth on current agricultural production is not expected
to be significant.
Eagle Planning Area
The Eagle facility planning area is almost entirely
SCS-designated prime farmland. The impact of projected
growth on designated prime farmland would be significant.
Although much of the Eagle facility planning area is
currently under agricultural production, most use involves
"gentleman farms" of relatively small scale (5-10 acres).
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Because it is uncertain in which locations growth
is likely to occur, it is difficult to assess the impact
of growth on current agricultural production. If
development is concentrated in relatively few areas, the
impact on current agricultural production could be
minimized. If, however, considerable numbers of annexa-
tions occur and developments are dispersed throughout the
planning area, the impact on current agricultural production
would be more significant.
Mitigation Measures
Because the facility planning areas are consistent
with local urban services planning area boundaries, EPA
is not recommending any grant conditions concerning agri-
cultural lands. However, in accordance with EPA and CEQ
policies which recognize the importance of prime farm-
lands, EPA recommends the following measures:
o Local agencies identify "farmlands of local
importance" which would supplement SCS's current
mapping program of important farmlands.
Evaluation criteria would likely include: soil
characteristics, location of farmlands to urban
development, parcel size, and current economic
productivity.
o Restrict future development in areas designated
as "farmlands of local importance" through
adoption of a local ordinance which prohibits
the extension of utility infrastructure to
these areas.
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Chapter 8
Public Services and Facilities
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Chapter 8
PUBLIC SERVICES AND FACILITIES
Introduction
Wastewater planning for Boise, the Southwest area, and
Eagle is based on 20-year population growth projections.
Growth within the three areas will increase demands on key
community services in addition to wastewater management.
This chapter examines the following community services:
drainage, water supply, electricity and gas, transportation,
solid waste management, schools, police protection, fire
protection, and recreation. Measures are identified which
could mitigate the impacts of growth on community service
delivery. In addition, because the provision of community
services will depend on the ability of local service agencies
to pay for growth, the fiscal structure and capabilities
of service agencies within the planning areas are discussed.
Provision of Community Services
There is a wide variation in the specific pattern of
responsibility for service provision in the greater Boise
area. First, certain services are provided by public agencies
in some areas and by private entities or individuals them-
selves in other areas. For example, while urban populations
of Boise are provided sewer service by the city, in less
densely settled portions of Ada County on-site wastewater
systems are frequently installed and maintained by indivi-
dual property owners.
Second, certain services are provided by local general
purpose government in some areas (particularly in Boise)
and by special purpose districts in others. In the City
of Eagle, virtually all services except general government
are provided by independent agencies: sewer, water, schools,
fire. Throughout the county, public education is provided
by school districts rather than by general purpose govern-
ment .
These variations suggest the difficulty of generalizing
about the provision of community services. Depending on
where a residence or business is located, it may receive
a different package of community services from a different
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set of service providers, and these differences result
in further differences in the quality/quantity of service
provided and its cost. Altogether, there are 50 different
public agencies in Ada County with service responsibilities
and taxing authority.
Current Capabilities of Coimnunity Service System
Most public service agencies within the planning areas
are experiencing difficulties in meeting the service
requirements of existing populations. Rapid population
growth during the 1970s is one of the primary causes of
these service shortfalls. In addition, recent fiscal
constraints, coupled with high inflation, have further
hindered the delivery of historic levels of service. This
section reviews the current capabilities of the community
service system.
Drainage
Among the public services provided to the cities and
communities of Ada County, drainage is probably the most
deficient. Further, the county faces a worsening drainage
p£oblsn\ in unincorporated areas due primarily to lack of
effective mechanism to plan, construct and maintain
adequate urban drainage facilities. The problem is parti-
cularly noticeable in the developing fringe areas, and
is likely to respond adversely to continuing growth.
Similar problems exist in the incorporated cities, including
Boise.
The problem stems from: 1) the lack of an adopted area-
wide drainage plan, 2) the lack of consistent areawide
drainage criteria, 3) the lack of consistent enforcement
of drainage requirements concurrent with development, and
4) the absence of agencies funded to maintain existing
drainage facilities.
The problems are currently manifested by flooding with
property damage during heavy storms; overflow of the irrigation
canals and ditches which intercept runoff from urbanizing
rural areas; concern by irrigation districts regarding urban
pollutants in runoff water; varying quality and effectiveness
of drainage facilities installed by developers; damage to,
failure of, and nuisance conditions from unmaintained drainage
facilities; and vocal concern about present and future drainage
problems by local government officials.
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Within the City of Boise, many of the older drainage
facilities are undersized and/or deteriorated, and even new
facilities tend to become overloaded from increased runoff
from developing tributary areas. Inadequate records of the
location, sizing and existence of storm drains further com-
plicates the problem.
There are many small subdivision areas along the Boise
Front and in the Southwest area that have been developed
with retention pond facilities in the last few years. Most
of these ponds are not maintained; they exhibit this lack
of maintenance in erosion, decreased capacity, furtively
dumped solid waste, and weeds and brush that constitute a
fire hazard.
In the Southwest area relatively flat conditions prevail
and the ponds tend to be continuously wet from surplus lawn
irrigation, car washing and other outdoor water uses Weed
growth and mosquitos tend to be problems associated "^h
these ponds. Silts and sediments, as well as organic debris
from vegetative growth tend to fill the ponds and decrease storage
capacity. Wet ponds with aquatic growth may support some wild-
otherwise would be absent from the urban fringe areas.
The ponds tend to be an attractive nuisance and could attract
children. The potential for drownings and injuries related
to pond use does exist, even when the ponds are fenced.^ Many
fences are improperly designed, constructed, and maintained.
Access to ponds for maintenance is often difficult, and pond
construction itself may make maintenance difficult.
Appendix D of the Draft EIS presents additional dis-
cussion of drainage problems. A February 1980 Drainage Task
Report is available at EPA's Boise operations office, and
has been widely circulated to relevant public agencies.
Water Supply
Boise. Boise's source of domestic water supply is
groundwater. Both shallow and deep aquifers are used, with
the shallow aquifer supplying individual wells and the deep
aquifer supplying the community system. The Boise Water
Corporation is the largest water purveyor in the Boise area,
supplying some 90 percent of the total water supply ^*;OG 1973b).
Annual water demand in the Boise area in 1972 was 5,865
million gallons. Demand was projected to increase to 12,800
million gallons by 1992 (ACOG 1973b). Groundwater supplies
appear adequate to meet the demands which will be generated
by projected growth; the Boise planning area population is
projected to increase to about 212,000 by the year 2000
(APA 1978). Additional wells, water storage facilities,
and water distribution facilities will be necessary to meet
future demands.
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Southwest Area. The Southwest area depends on shallow
groundwater for individual wells and deeper groundwater for
community supply. About one-half of the 4,350 residential
lots in the Southwest area receive domestic water from a
community system; the other one-half rely on inaividual wells.
The Boise Water Corporation supplies about 7,000 Southwest
area residents, almost half the area's population. Small
portions of the Southwest area are also served by the Ash
Park Water Company and the South County Water Company.
Irrigation water is provided by the New York Canal
which transports about 900,000 acre-feet annually (ACOG 1973b).
Three irrigation districts supply irrigation water to the
Southwest area, the New York district (serving 5,500 acres),
the Nampa and Meridian District (serving 1,500 acres), and
the Boise-Kuna District (serving 300 acres) (APA 1980).
Implementation of the "rural lifestyle" alternative
for the Southwest area would increase the area's population
to 18,985 (APA 1980). The Boise Water Corporation has not
projected any major problems in serving this growth, but
cautions that continued development using on-site systems
should include a long-term operation and maintenance program
to reduce the risks of groundwater contamination (APA 1980).
Policies in the Southwest Community Comprehensive Plan (APA
1980) encourage existing residential developments with gross
densities greater than one dwelling per five acres served
by individual systems to connect to community systems.
Eagle. Eagle uses groundwater for domestic water supply
and surface water for irrigation. Domestic water is supplied
by individual wells and by the Eagle Ranch Water Company,
which in 1977 provided well water to 300 customers (Eagle
Planning and Zoning Commission [PZC] 1978). Irrigation water
is provided by the Boise River and the Dry Creek Canal.
The Eagle area is expected to reach a population of
13,286 by the year 2000. As the population increases, new
wells and new water storage and distribution facilities will
be needed. The study plan for the Eagle Water and Sewer
district (J-U-B Engineers 1978) has policies to coor-
dinate future growth with water supply provision, and to
assure that expansion of water district boundaries is con-
sistent with the boundaries delineated in the Eagle Sewer
and Water Plan (Eagle PZC 1978).
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Gas and Electricity
The Intermountain Gas Company supplies natural gas
to all of Ada County. Natural gas in 197 9 was distributed
to 32,450 customers countywide through 821 miles of gas
mains (McKinney pers. comm.). Growth in Boise, the South-
west area, and Eagle will generate additional demands for
natural gas; natural gas supplies appear adequate to meet
these demands.
The Idaho Power Company supplies electricity to all
of Ada County; its service area is 20,000 square miles in
southern Idaho, eastern Oregon, and northern Nevada.
The company mainly relies on hydropower for electricity
generation, operating 16 hydro plants, in addition to a
combustion turbine and sharing ownership in a coal-fired
plant. Idaho power is currently developing an energy
conservation program to slow growth in demand. Population
growth in Boise, the Southwest area, and Eagle will create
additional electricity demands. The long-term supply and
demand outlook for electricity is uncertain.
Solid Waste Management
Most of Ada County's solid waste is disposed of in Hidden
Hallows sanitary landfill, located about 5 miles north of
the Boise City limit. Solid waste in Ada County is collected
by private firms. Browning and Ferris Industries collects
solid waste in Boise and Eagle; solid wastes in the unincor-
porated Southwest area are collected by Boise-Ada Disposal
Company.
In 1979, the landfill was receiving about 400 tons per
day; capacity is expected to be reached in 1985. At present,
three options are under consideration to provide future
management of solid wastes. They include: expand the present
landfill site; move to a new landfill site south of Boise;
or construct a waste-to-energy plant (Neil pers. comm.).
Transportation
The Ada County Highway District (ACHD) is responsible
for the construction and maintenance of local streets and
highways in Ada County. The City of Boise provides transit
service through the Boise Urban Stages bus system, with
operation of the system provided by contract with Transit
West Services, Inc. Service is provided within the City
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of Boise and Garden City, Monday through Saturday.
In general, buses operate between 6:30 a.m. and 6:30 p.m.
Various intercity and commuter bus lines provide additional
transit service to and from Boise. Carpool and vanpool
programs in the Boise area are coordinated by ACHD. Short-
range and long-range transportation planning is provided
by the Ada Planning Association.
Several streets in the downtown area of Boise
experience significant traffic congestion during rush hour
periods. Access into the downtown area from the south and
west is provided by four roadways. Two of these (the Fairview/
Main couplet and Capitol Boulevard) experience peak hour
congestion problems. Continued growth in the Boise area
will result in increased travel demand on local highways.
Completion of redevelopment projects in the downtown Boise
area will add a major new trip attractor to that area.
Current transportation planning focuses on a variety
of highway improvement projects, transit system improve-
ments, and ridesharing programs to accommodate future travel
demands on existing and planned roadways. A number of
specific highway improvement projects anticipated for the
1980-1987 and 1987-2000 time periods were identified in
Appendix A of the Draft EIS. Current transit system planning
is oriented toward a goal of capturing 20 percent of the
1990 commuter trips to the downtown area, while expanding
off-peak ridership to equal 50 percent of total daily
ridership. Accomplishing these transit goals will require
the purchase of 44 new buses during the 1981-1986 period.
The 1987 transit plan (APA 1980c) estimates total capital
costs for this fleet expansion (plus associated maintenance
facilities, bus shelters, etc.) at $11,170,000, with annual
operating costs of $5,840,000. Actual implementation of
these plans will be highly dependent on the availability
of funding.
Schools
Boise. The Boise School District currently operates
26 elementary schools, 5 junior high schools and 4 senior
high schools. At the junior and senior high school levels,
there is currently no significant overcrowding conditions
within the City of Boise (Boise School District, pers. comm.).
At the elementary level, "closed enrollment" conditions
currently exist in the Southeast area. A bond issue which
would provide funds for construction of a new elementary
school in the Southeast will likely be voted on in Spring 1982.
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As a result of attrition and the One Percent Initiative,
the Boise School District has had slight reductions in
personnel. Because of legislation enacted subsequent to
the one percent Initiative, however, the impact on the
school district has not been as severe as anticipated.
Population growth in Boise will increase the need for
additional schools. In addition to the Southeast area, the
Northwest area has been identified as the next area where
additional schools will need to be constructed. At the present
time, some students are bussed to schools in the central
area.
Southwest Area. Most of the Southwest area is served
by the Meridian and Boise School Districts, which together
operate four elementary schools and one junior high. Presently,
all schools in the Southwest area have enrollments in excess
of their capacity (APA 1979a).
Under the Southwest Community Comprehensive Plan "rural
lifestyle" alternative, it is projected that one additional
elementary school would be needed, but that the existing
junior high would be sufficient to accommodate projected
growth (APA 1980). Policies in the plan provide for developer
dedication of land or payment of fees for the acquisition
and development of school sites, but the feasibility of
implementing these policies is questionable (APA 1980).
Eagle. Students from the Eagle area attend schools
operated by the Meridian School District. At the elementary
levels, students from Eagle attend one of two schools.
Both elementary schools have projected additional capacity
for the 1982 school year (Hind pers. comm.). At the junior
high level/ additional capacity is projected for the 1982
school year at the Lowell Scott Junior High School where
students from Eagle would attend. Enrollment at the senior
high school is projected to be in excess of its recommended
capacity. A bond issue, which would provide funds to
construct a second high school, is expected to be voted on
in Spring 1982.
Growth projected for the Eagle area would contribute
to the need for additional schools in the Meridian School
District. A new elementary school in the Eagle area and
a new junior high school will be needed in probably 5 or
6 years (Hind pers. comm.).
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Police Protection
Boise. Police protection in Boise is provided by the
Boise Police Department. The current ratio between police
officers and the city's population is 1.17 officers per
1,000 population; this ratio is well below the state and
national average of 2.1 officers per 1,000 population.
As a result of primarily the One Percent Initiative, the
Boise Police Department has been reduced by 23 officers. To
compensate for these reductions on personnel, adjustments
in the scheduling of officers has become necessary. In
addition, prioritization of calls for police response has
been implemented.
Projected growth for Boise will further reduce the
officer-to-population ratio unless additional funding is
provided. The effect will likely be to increase the
response time to lower priority police calls.
Southwest Area. Police protection in the Southwest
area is provided by the Ada County Sheriff's Department.
The current officer-to-population ratio is below the ratio
of 0.67 officers per 1,000 population recommended in the
Southwest Community Comprehensive Plan (APA 1980). Because
of recent changes in fiscal conditions, the Ada County
Sheriff's Department has been reduced by 15 officers.
Similar to the Boise Police Department, the Sheriff's
Department has adjusted schedules and prioritized response
call to compensate for reduced personnel (Taylor pers comm.).
Additional growth will likely increase the response time
to lower priority calls.
Eagle. Police protection in Eagle is provided by the
Ada County Sheriff's Department. Because of recent cutbacks
in personnel, the Sheriff's Department is re-examining the
police protection needs within their service area. It appears
that urban areas such as Eagle which currently contract for
Sheriff services will be required to provide additional
funding in the future to maintain their current level of
service (Taylor pers. comm.).
Fire Protection
Boise. The Boise Fire Department operates a number
of fire stations, each intended to serve a 1.5-square-mile
area. There is currently adequate fire flow within the city
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and response time is considered generally adequate
(Boros pers. comm.). Additional fire stations may be
needed to meet the fire protection needs of the growth
projected for Boise.
Southwest Area. The Southwest area is provided fire
protection by the Whitney Fire District which operates one
fire station on Overland Road. Many portions of the area
currently experience water supply or water pressure problems.
The limited growth projected for the Southwest area under
the "rural lifestyle alternative" probably will not require
the construction of a new fire station (APA 1980). Policies
in the Southwest Community Comprehensive Plan encourage
provision of adequate fire flows in the future (APA 1980).
Eagle. Eagle is provided with fire protection by the
Eagle Fire District, which is staffed by volunteers. Future
growth to 13,286 would require at least one additional fire
station to be built and the acquisition of additional
equipment (Eagle PZC 1978).
Recreation
Boise. Two large community parks along the Boise River
(Ann Morrison and Julia Davis Parks) provide regional recrea-
tion opportunities for Boise residents. Boise also has
numerous smaller neighborhood and community parks. In the
future, the Boise River "greenbelt" will continue to be the
major focus of recreation in Boise, and additional parks
will continue to be provided as Boise's population grows
(Boise Planning and Zoning Department 1979).
Southwest Area. Currently* recreation facilities in
the Southwest area are limited to a 5-acre neighborhood park.
The Southwest area has mainly relied on county and City of
Boise park facilities and on school playgrounds to satisfy
recreational needs. Under the "rural lifestyle" alternative,
an additional 31 acres of neighborhood parks would be needed
but a new community park may not be needed (APA 1980).
Eagle. Eagle presently has one neighborhood park with
one other park under construction. The population increase
projected for Eagle will generate the need for more and
larger parks in the future.
Summary of Community Service Capabilities and
Potential Impacts of Growth
The growth projected in the facility planning areas
will increase the demands on local community services. Some
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services appear to be more capable of accommodating the pro-
jected growth than other services.
In general, the community services most likely to be
significantly impacted in the near term are pol :.ce and fire
protection. Because these services have already been signi-
ficantly impacted by recent fiscal conditions, additional
near-term growth will likely aggravate existing deficiencies.
If near-term growth consists of a significant number of school-
age children, schools could also be significantly affected.
The longer-term growth impacts will impinge on community
services which need costly investments for infrastructure
expansion. This includes primarily drainage, water supply,
and transportation improvements.
In conclusion, the impact of projected growth on the
community service system will depend on the ability of local
service entities to finance expansion of service and needed
capital improvements. This will likely require new and
innovative approaches to the financing and structure of com-
munity services delivery. The following section summarizes
some of the measures which could potentially be implemented.
Mitigation Measures
In an effort to coordinate growth and the provision
of community services, local agencies have developed policies
related to community services extension. Both the City of
Boise and Ada County review proposed developments for avail-
ability of all community services and for consistency with
urban service planning area (USPA) boundaries. If all ser-
vices cannot be provided within the USPA, the proposed develop-
ment is subject to denial. To the extent that these growth
policies are followed, the potential adverse impacts on growth
on public services will be mitigated.
If local community service policies are not followed,
local service deficiencies are likely to occur. As part
of the fiscal assessment developed for this study, a number
of measures have been identified which could help mitigate
the adverse impacts of growth on local service agencies.
Some of the measures include:
o district consolidation
o more private responsibility for delivery of services
o increase growth management fees
o establish local option taxes
o more financing through bonds
o obtain more state and federal funds
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These measures are discussed in more detail in the fol-
lowing section. In addition, Ada Planning Association has
prepared a study on the growth management fees approach to
financing community service needs (Business Economics, Inc.
1979) .
Organization of Local Government Finance
Certain of the features of local government finance in
Idaho are common to the various entities empowered to provide
services and to tax, and these similarities arise from state
legislation regulating the operations of local governments.
Some of the most important aspects of the finance system are
described below.
Balanced Budgets. The State of Idaho requires that the
budget for any given year must be in balance. As a prac-
tical matter, this means that local agencies typically under-
state their revenue anticipation so as to ensure that they
will not find themselves with a revenue shortfall at the
close of the fiscal year.
An exception to the rule is Boise, which operates on
a tax anticipation basis rather than a cash basis, a prac-
tice predating the state's 1977 balanced budget requirement.
Revenue Sources. Property taxes have long been the
mainstay of local government finance in Idaho. Table 8-1
shows the extent to which local governments in Ada County
have depended on property taxes in the past. This dependence
has been declining throughout the 1970s, and the One Percent
Initiative seems likely to further reduce local agencies'
reliance on the property tax.
Table 8-1. PROPERTY TAXES AS PROPORTION OF
LOCAL BUDGET IN SELECTED ADA COUNTY JURISDICTIONS
Ada
County
Ada
County
Highway
District
City of
Boise
Boise
School
District
1971
4 2.1%
39.3%*
36.2%
51.4%
1976
33. 4%
37 . 5%
19.01%
4 8.6%
1979-80
43.7%
31.6%
15.09%
43.6%
*1972.
Source: Boise City, 1979-80. Boise City Budget.
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Other taxes may be imposed at local option if authorized
by state legislative action. Examples of such taxes now in
effect are taxes on liquor-by-the-drink in McCall and Sun Val-
ley (both major visitor areas). The sales tax, which is an
important local tax in some other states, is a trivial element
in the local tax structure in Idaho, although a local sales
tax could be tacked onto the state's three-percent rate as a
local option (again, state approval would be a prerequisite).
Other current revenue sources include federal and state
grants and revenue sharing; fees, fines, reimbursements for
services, licenses and permits; interest; rents; and miscel-
laneous other sources. Table 8-2 sets forth the distribution
of revenues in the Cities of Boise and Eagle in their 1979-80
budgets.
Table 8-2. REVENUE SOURCES IN BOISE AND EAGLE
Ci ty
of Boise
City
of Eagle
Annual
Proportion
2nd Quarter
Proportion
Revenue
from That
Revenue
from That
Source
(Thousands)
Source
(Thousands)
Source
General/
Property Taxes
10,100.0
15.1%
18.3
55.0%
State Shared
Sales Tax and
1,300.0
1.9%
3.6
10.8%
Liquor Tax
Federal and
State Grants
27,000.0
40.5%
0.2
0. 6%
Revenue Sharing
1,700.0
2.5%
3.2
9.6%
Fees, Fines and
Reimbursements
12,700.0
19.0%
6.6
19.8%
for Services
Licenses and
Permits
800.0
1.2%
0.5
1.5%
Interest Income
400.0
0.6?.
0.9
2.7%
Rents
2,000.0
3.0%
-
-
All Other
10,800.0
16. 2%
-
-
TOTAL
66,700.0
100.0%
33.3
100.0%
Source: Boise City, 1979-80. Boise City Budget, p. xvii. Eagle City, 1980.
Statement of Revenue for the Quarter Ended March 31, 1980. Note that
Eagle's revenue statement is for the second quarter of the fiscal year
while Boise's is an estimate for the entire fiscal year. Comparable
data for the county are not available.
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Administrative Structure for Property Tax Collection.
Each local taxing entity sets its own tax rate. Because the
jurisdictional boundaries of these entities differ, neighboring
properties can have different composite tax rates if their pro-
perties lie in different taxing districts. Each possible com-
bination of taxing districts is called a tax code area and in
Ada County there are over 200 different tax code areas, which
is to say areas within which the combination of service-providing
entities (and therefore the composite tax rate) is different
from all other areas of the county.
While the One Percent Initiative and related state legis-
lation limited the basic property tax take to one percent of
market value, it did not revise the administrative structure,
and that has made the impact of the Initiative more severe.
Since state law provides that each taxing entity must have
a uniform rate of property taxation throughout its jurisdic-
tion, each tax code area within that jurisdiction shows the
same tax rate for that particular service. But since in no
tax code area may the composite rate exceed the one percent
of market value level, the tax code area in which the maximum
tax burden is imposed is the highest tax code area in the
county, and the rates in all tax code areas with service en-
tities overlapping the one percent area must reduce the var-
ious service entities' tax rates in order to maintain the
same rates throughout each service jurisdiction.
Thus, the one percent upper limit is not achievable
throughout the county: most tax code areas must have lower
rates in order to observe the requirement of rate consistency
within jurisdictions, and as a result the reduction in pro-
perty tax revenues effected by the One Percent Initiative has
been considerable. A recent study (Business Economics, Inc.,
1979) estimates Boise City's reduction in property tax revenues
as 55.36 percent, and every taxing entity whose jurisdiction
overlaps the City of Boise (for example, Ada County and the
Boise School District) has had to absorb the same reduction.
Market Values and Property Taxes. Property taxes generally
are calculated as the rate (determined by the taxing entity)
times the value of the property, which in most parts of the
United States is the assessed valuation as determined by
the county assessor's office.
It is typically the case that state law mandates or guides
the manner in which local officials value property. Idaho law
requires that by 1982 assessed valuations must be a uniform 20
percent of fair market value. In the past, there has been con-
siderable variation in local valuation practice, and a more
typical ratio of assessed valuation to market value was prob-
ably 10 percent. While certain local governments (such as
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Boise) moved rapidly in response to the legislation to bring
their valuations up to the 20 percent level, others moved
more slowly, and when Initiative Petition No. 1 passed, pro-
perty in those jurisdictions was still undervalued. These
governments have been able to revalue property to the 20 per-
cent level since the Initiative passed, and this has cushioned
somewhat the immediate impact of the Initiative in those juris-
dictions .
Under the provisions of the One Percent Initiative, pro-
perty may be revalued but the revaluation is limited to an in-
crease of two percent per year from a 197 8 base. Over time,
assuming recent inflation rates persist, the property tax
base will represent an ever decreasing portion of total mar-
ket values as a result of this limitation. Only new improve-
ments and properties that change hands are excluded from this
limitation.
Bonding. It is common practice throughout the nation
for the capital facilities requirements of public services to
be financed through bonds. Such government bonds may be either
general obligation bonds (repaid from the jurisdictions' gen-
eral revenues, such as property taxes) or revenue bonds (re-
paid through charges imposed for the specific service provided
by the facility financed via bonds).
These kinds of public finance instruments have not been
used as extensively in Idaho as they have in more urban states
and as a result none of the local jurisdictions - Boise, Eagle
or Ada County - has reached the limit of its bonding capacity
(ten percent of assessed valuation). This finance tool must
be mentioned, however, because it represents one of several
possible ways of financing public improvements independently
of restrictions on property taxes (bonded indebtedness is
specifically excluded from the one-percent property tax limi-
tation) . On the other hand, financing via bonds is not par-
ticularly popular in Idaho, where there is a strong tradition
of pay-as-you-go financing. School bonds have failed to re-
ceive the required two-thirds approval in the past, and every
bond measure - such as the $7,000,000 airport bond measure ap-
proved by Boise voters in November 1979 - must be fully ex-
plained to and understood by the voters in order to obtain ap-
proval.
Fiscal Prospects: The Short-Run Picture
In the short run, all three local general purpose govern-
ments - Boise, Eagle and Ada County - are experiencing similar
conditions: a sharp decline in revenue relative to three years
ago, and consequently pressure to accommodate this change by
altering the revenue structure and/or the volume of service
delivered.
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Declining Revenues. Initiative 1, as implemented by
the Idaho Legislature on an interim basis, froze local bud-
gets for a 3-year period at their 1978 levels. In antici-
pation of the passage of the Initiative, some local govern-
ments have already begun to trim budgets prior -to June 1978,
and it is those governments (Boise is one) that have been
hit hardest by the across-the-board budget freeze.
With budgets frozen during an inflationary period, the
actual fiscal impact has been more severe than simply a
frozen budget may suggest. The costs of providing govern-
ment services, like the costs of other goods and services
in the economy, continue to rise with inflation. Just as
households have to spend more to maintain their historic
standard of living, governments have to spend more to main-
tain their historic levels of service delivery. That simply
cannot be done on a frozen budget.
In March of this year, the Legislature enacted a bill
which provides some relief to the frozen budget situation
of local governments. The enactment of HB389 allows for
a 5 percent increase in the ad valorem budget of local
governments. Under certain rapid growth conditions, local
budgets can be increased by more than 5 percent.
Property taxes are not the only revenues that have de-
clined. With the rising mortgage interest rates of the last
two years, the downturn in housing construction and the current
recession, development-related fees have also declined, which
has hit Ada County particularly hard since much of the revenue
supporting the Growth Management Department derives from fees.
Fee levels have been increased, but total collections still
appear to be falling short of the level normally needed to
support past levels of planning and land development regula-
tion activities.
Uncertain Direction of Future Implementation of
Initiative No. 1. The passage of the Initiative did not
specify the means of implementation, and the State of idaho
(lacking the kind of surplus that California had when the
similar Proposition 13 was passed in that state) has taken
only interim measures to date to remedy some of the problems
posed by the property tax limitation. An important step
has been the earmarking of certain revenues from the three
percent state sales tax to relieve the fiscal plight of the
school district.
However, further measures appear in doubt. The apportion-
ment question (how to allocate tax rates or total tax revenues
among taxing districts) poses a particularly difficult problem
for whoever decides to address it, whether at the state level
or at the county level. And with this question unresolved,
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local agencies, particularly those in the faster-growth areas,
are left not only poorer but without official guidance on
their future fiscal organization. On the other hand, their
straitened circumstances have required immediate action.
The Current Fiscal Response. Cities and the county
are taking a number of steps to bring their costs into line
with their current revenue streams. Among these are the
following.
Annexation Policies. The City of Boise is looking much
harder at annexations before proceeding with them, this
caution stemming from the city's limited ability to extend
services to new areas. While Eagle is still considering an-
nexations (the Middlebrook annexation in particular), the de-
velopment process is to be structured in phases to permit the
city flexibility to adjust later phases in the event circum-
stances (such as service capacities) alter in the meantime.
Ada County, for its part, is giving increasing weight to the
desirability of ensuring that new urban scale development take
place within municipal contexts rather than in unincorporated
areas - a step which should reduce the county's service re-
sponsibilities to such areas over time.
Cost Reductions. The most common cost reduction stra-
tegies, which all three agencies are pursuing to some ex-
tent, are (1) reducing personnel costs, (2) eliminating capital
facilities expenditures to those financed wholly by federal
funds and (3) reducing maintenance expenditures. Boise of-
fered several specific examples. The city's permanent staff
has dropped from 1,100 to about 700. (This drop has been
accomplished both by attrition and by a layoff of 258 staff
members, including 22 firemen.) Certain services are being
spread more thinly or discontinued altogether. Some examples:
grass cutting in public green spaces is being reduced, the
smaller contribution to the Humane Society is increasing the
dog population of the city (and concomitantly reduced animal
enforcement is reducing dog license revenues), the diets of the
zoo animals are being reviewed to determine what cost savings
are possible, and the weed control ordinance has been repealed.
Not all of these reduced services meet public approval, but the
city feels it must make these and comparable changes to keep
costs and revenues balanced. The representatives of each of
the three governments generally echo the view that the voters
seem to want cuts only in those services which do not affect
them - but as every service benefits somebody, no cuts can be
completely painless.
The maintenance reduction is particularly worrisome to
public finance personnel, who feel that this strategy simply
builds up major public facility expenditure needs sooner than
would be required if ongoing maintenance could be kept at
its past levels.
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Re-examination of Local Government's Public Sevvioe
Bole. The irony of Initiative No. 1 is that it cuts back
on the resources of that level of government which had been
thought to be most readily responsive to the electorate, while
it does nothing to reduce the spending or the cbtrusiveness
of the state and federal governments. But local governments
must respond to the mandate to limit their roles, and one
likely target for reduction is services not mandated (or re-
imbursed) by federal or state requirements. Emergency medical
services provides a good example in Ada County. Public trans-
portation, too, is a service Boise provides (partly under
pressure from the federal government stemming from air quality
considerations) which is presently not mandated and is heavily
subsidized.
Hidden Costs. One of the concerns local governments
express is that of being able to cope with sudden expenses,
or with long-term costs of public improvements not now being
undertaken. The recent problems faced by many Pacific North-
west communities in cleaning up in the aftermath of Mount
St. Helens ash fallout provides an excellent example of public
costs that cannot readily be foreseen but must be dealt with
on a crisis basis. An example of the second kind of problem
is surface water drainage, a need not being addressed on
a coordinated basis in Ada County at present. Costs of coping
with this problem, which is particularly acute in the area
to the southwest of the City of Boise, may well exceed the
$20,000,000 level. Such costs of "new" services will be
difficult for existing governments to absorb under current
strapped fiscal conditions.
Need for Action. Public officials of all three juris-
dictions - Boise, Eagle, and Ada County - agree on the impor-
tance of responding to the property tax limitation initiative
in a manner that will permit restoration of adequate levels
of public services. Although the approaches which at present
seem most appealing differ among jurisdictions, there is
agreement on the desirability of coping responsibly with
future needs so as to allow a resumption of regional growth
along the lines desired in each community.
Local governments are particularly concerned about some
of the adverse impacts that may result from Initiative No. 1.
Among these are the loss to public agencies of good staff
people who may resign if they feel long term opportunities
are better elsewhere. Another is the concern that a decline
in public service levels could prove a disincentive to firms
to locate in the region. In particular, high technology firms
that consider a number of regions when locating a new plant
are known to be particularly sensitive to the quality of
the educational system locally, as their highly-trained pro-
fessional and technical people insist upon this feature In
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deciding whether to accept assignment to new locations. So
if the Boise area is to continue to move in the direction of di-
versifying and strengthening its economic base by adding clean
industry of this kind, there is a limit to the extent of cost-
cutting in public services that can be accommodated consistent
with economic development objectives.
These kinds of concerns have motivated local government
to look beyond the current problems of coping with the Ini-
tiative One aftermath to future questions of efficiency and
productivity in service delivery and long run solutions to
revenue problems.
Fiscal Prospects: The Long-Run Picture
Although public service finance in the Boise region
faces definite current difficulties, most observers from
all three jurisdictions see some positive outcomes of Initia-
tive One and point to a number of future actions to relieve
the current crisis and put local general purpose governments
on a firmer footing.
Stabilizing Revenues. Although, unless there is a two-
thirds override of the property tax limitation, it appears
that public revenues from that source will provide a decreasing
proportion of local government revenues as time goes on,
other sources of revenue have been identified and will even-
tually be tapped. Among those specifically mentioned by
local agencies are general obligation bonds (exempt from
the provisions of the Initiative), special purpose bonds/
such as for industrial development and housing finance
(require state enabling legislation but are common in other
states), local option taxes and state payments in lieu of
taxes. The latter revenue source would be of particular
assistance to the City of Boise, which hosts the state
government and has within its municipal boundaries a con-
siderable amount of state property not subject to property
tax though eligible for city services.
All jurisdictions are looking to imposition of user charges
(authorized by state legislation) and imposition or increases
in fees wherever possible. Ada County in particular has been
considering growth management fees in line with a study the
Ada Planning Association Board commissioned with funds from
the Pacific Northwest Regional Commission. Although the
methodology of that study has been criticized by some readers,
there is general agreement that under current fiscal conditions
some residential development probably does not "pay its own
way"; the main arguments lie in (1) whether a growth manage-
ment fee - a fee to cover the capital costs of future public
services - is the proper response to this situation, and (2)
how to allocate capital costs among various types of land use.
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Using other states' experience as an indicator, certain fees
(such as for school site dedication and park dedication) have
been upheld by the courts and are in widespread use, and the
principle is certainly readily applicable to such other ser-
vices as fire and police. Even its advocates recognize, how-
ever, that this approach covers only capital facilities, leav-
ing open the question of the ongoing financing of operating
costs. And if payment of such fees is required to precede
issuance of permits, the magnitude of the charges may well be
sufficient to deter some development.
Administrative Remedies.
Solving the Apportionment Problem. A problem dis-
cuss ed—earTierr3sthFt_^_Tmpo¥Tng-_EEe maximum one percent pro-
perty tax rate in all tax code areas, which is not possible
currently due to discontiguity among taxing districts. This
problem could be solved (as California has solved it) by im-
posing the one percent tax on a county-wide basis and then
apportioning the revenues among taxing districts. Thus far,
the legislature has not proposed this approach, and county
commissioners (who are familiar with county budgets but are
certainly much less familiar with the problems of the special
districts) have not been willing to take aggressive action
in this direction. Although the situation appears currently
to be at an impasse, most observers feel that a solution to
the problem will eventually be hammered out - if only because,
in the interim, tax revenues are going to fall far short of
the permitted one percent level in most areas of most counties.
So there is a powerful impetus for solving this problem.
District Consolidation. The apportionment problem
has called public attention to the number of special purpose
taxing districts in Ada County, and the general feeling is
that the number (around 50) is excessive. Economies of opera-
tion may well be possible if certain districts are consolidated.
Such consolidation can take place either on a functional basis
(i.e., several fire districts merging into one) or on a geo-
graphic basis (fire, open space, wastewater service to a given
area provided by a single district - just as city governments
generally operate). Both of these kinds of consolidation are
being widely studied in California for the same reasons (econ-
omy and increased efficiency) they are being proposed in Idaho.
The chief impediment seems to be that the special districts,
with elected boards, do offer valuable opportunities to area
residents for public involvement which would be reduced if
the number of such districts were cut back. But the benefits
of the approach are such that movement in this direction is
a realistic expectation.
Ill
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In the meantime, an interim measure cou Lei be the dis-
couragement of new district formation. This appears to be
the point of view of Ada County at present. The Middlebrook
controversy has drawn attention to the potential problems that
may arise when a city is empowered to approve an annexation
and subsequent development project the principal services to
which are the responsibility of other entities.
More Comprehensive Financial Planning. The current
fiscal crisis has drawn attention to the need for more
thorough-going and long-run analysis of public finance
requirements, which has spurred Boise in particular to begin
to look at long-term financial planning as an important aspect
of municipal finance. This kind of planning is seen as inte-
grated with long-term development planning in a coordinated
package to make public actions more efficient and consistent.
Boise has also been working with a group of private-sector
financial experts to improve the operation of financial
planning and reporting systems, and is establishing data
processing techniques to improve the capability, speed and
accuracy of financial reporting systems.
Going Private. As mentioned earlier, there are a number
of utilities or services that can be (and frequently are)
performed by private entities rather than by public agencies.
These include water (which in rural Ada County is generally
provided by on-site wells or private services) and solid
waste disposal (where householders may be individually
responsible for hauling their own refuse to a dump site or
for contracting with a private firm to provide this service -
the City of Boise recently made mandatory household trash
collection by a private service).
If the costs of providing a public service system appeared
prohibitive, it might be possible in some cases simply to put
the responsibility for providing that service on the individual
householder. There are a number of kinds of arrangements for
accomplishing this approach. Often, homeowners' associations
in new subdivisions can take responsibility for such functions
as landscape maintenance and weed control, pest control (func-
tioning as mosquito abatement districts), surface water drain-
age, street and street lighting maintenance, and so forth.
This approach relieves the public sector of financial respon-
sibilities, and gives the appearance of making new development
less costly to the public.
However, the approach doesn't make development less ex-
pensive for the new home buyer, who is paying the homeowners'
association for the same services he might otherwise have been
paying some public entity for, and the resident may actually
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end up paying more to the extent that public agencies can fi-
nance long term improvements in a less costly manner (i.e.,
through bonds) than private developers can. Furthermore, there
has been concern expressed in other states where this approach
is more widespread that these "private" responsibilities would
devolve upon the public in any case should a homeowners' asso-
ciation go into default.
Less structured private systems, such as on-site wells
and on-site septic systems, are often possible where densities
are low and these approaches, too, initially look less costly
from the point of view of the public treasury. But cost savings
of this kind may well be offset by cost increases in other
functions: more miles of roads are needed to serve dispersed
development, more travel by school buses to bring children to
schools, and so forth. Thus, private service provision must
be thoroughly analyzed before it can be concluded, on balance,
to be cheaper than the public alternative.
Land Use Planning Responses.
Tying New Development to Existing Infrastruotuve. The
high cost of new service extensions has called attention to the
advantages of utilizing existing infrastructure to accommodate
new development. Such an approach reduces the commitment of
capital required to serve new growth while it offers the ad-
vantage of reducing average costs of those already served by
an existing system that is operating at less than capacity.
Contiguous Development. A second way in which fiscal
constraints can alter land use planning is by pointing up the
advantages of contiguous development. If new development abuts
existing development, costs of service extension are generally
less than they would be if the newly-developing area were sepa-
rated from the urban boundary by vacant or undeveloped land.
Cautious Approach to Annexation. Recognizing the
lower level of, financial resources available, cities may well
resist annexation proposals that in the past would have been
almost routinely approved. The property tax limitation initia-
tive, in Idaho as in California, has tended to change the out-
look toward annexation of both annexors and annexees. Before
the initiatives, unincorporated areas often resisted annexa-
tion because their tax rates would rise; now, with tax rates
more or less equalized between incorporated and unincorporated
areas, this source of resistance has been greatly reduced or
altogether eliminated. On the other hand, cities which in pre-
initiative days considered annexations desirable because of
additions to the property tax base have found that benefit
much reduced, and are often legitimately concerned that the
increase in property tax revenues resulting from annexation
will not compensate for additions to service costs. It is for
these reasons that Boise is currently discouraging "annexation
proposaIs.
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Development Phasing. The fiscal constraints local
governments are now experiencing also make them more cautious
about giving approvals to long-term development projects,
because the service and fiscal conditions that apply when such
projects begin may no longer obtain by the time, of their com-
pletion. Furthermore, there are clear advantages in maintaining
ongoing approval authority of large projects in the event of
delays in completion, changes in ownership or management, or
other conditions that might result in an alteration in the
developer's intentions or objectives.
An example of the kind of project expected to be subject
to approval by phases is Midalebrook. Phased approvals have
been used by the City of Eagle on earlier projects, and this
approach can be expected to be used more extensively by Idaho
jurisdictions generally as long as the current fiscal crisis
lasts.
Area Summary
City of Boise. Boise has felt the impact of Initiative
One more severely than other jurisdictions because it operates
on an accrual basis and because its property had already
been revalued up to near the state-mandated limit at the
time the Initiative passed. That the reduction in revenues
has caused severe short-term problems is unquestioned. However,
the long-term outlook is not bleak. Certain additional sources
of revenues seem likely to be tapped in the future and Boise
will likely continue to receive more state and federal funds,
as a proportion of its budget, than do the other general
purpose governments reviewed.
The fiscal crunch has underlined the practicality of some
of Boise's planning policies, particularly the preference for
infill development in the southeast and (to a lesser extent)
the northwest. This growth corridor is the most easily ser-
viced by municipal agencies and in many cases the infrastruc-
ture to support new development in these areas is already in
place. Growth in the outlying areas will be more closely
scrutinized in the future, with fewer annexations, preference
given to contiguous development, and a close tie-in between
long-term physical development planning and capital improve-
ment planning to assure efficiency and minimum public cost.
City of Eagle. Eagle is still a comparatively small
town, with a preliminary 1980 population of approximately
2,600 (a substantial increase over the population at 1971
incorporation of less than 400). The urban service planning
area of the town, which is delineated in the Ada County Com-
prehensive Plan, is expected to see steady growth over the
next decades, bringing the future population of the community
to over 13,000 as indicated in APA Board-adopted subarea
population allocation.
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The growth of the community is not expected to abate much
as a result of current fiscal problems because the current scale
of operation of the City of Eagle is quite modest and no immediate
change in this characteristic is expected. One of the city's
sources of appeal for new residents is reportedly its small
town character and the direct accessibility of its government.
While this can be expected eventually to change as the local
population increases, the present structure of urban service
provision - most services are provided by special districts -
insulates the city somewhat from the more severe effect of
Initiative One noted elsewhere. The concern about Eagle's
growth often expressed in the region relates more to regional
planning questions than directly to fiscal capacity, although
the special districts providing services to parts of Eagle
City may encounter their own fiscal problems in extending
services, and that has not been explored in the course of
this qualitative review.
County of Ada. Ada County revenues have fallen short
of earlier expectations because of Initiative One and lower
construction activity (which has reduced fee revenues). The
county has responded by trimming staff and services where
possible. If the current crisis is prolonged, a reduction
in nonmandated services is a reasonable expectation.
Looking beyond the immediate future, it appears that the
county, like the City of 3oise, will be affected by fiscal
constraints in terms of its future development policies. This
has already been happening to some extent, but the revenue re-
duction has given this direction greater impetus. There will
be a reluctance to permit discontiguous development, a closer
evaluation of the public costs of new development, and more
assiduous observation of a policy to encourage new development
to annex to existing municipalities and to obtain city - rather
than special district - services. In general terms, the philo-
sophy of the county will increasingly be to support municipal
growth while unincorporated lands would be retained in rural
uses. The implications of this approach in terms of the spa-
tial distribution of growth are plain. Whether such a policy
would also serve to inhibit growth is less clear.
The Southwest Area. Initiative One has been one impor-
tant factor influencing the recent reassessment of future
growth in the Southwest area. The cost of providing urban
services to the dispersed developments that currently char-
acterize the area, has proven to be higher than anticipated.
These costs have contributed to the community's resistance
to construction of public wastewater facilities.
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The Southwest area is located in the unincorporated
county and is served by a number of special service dis-
tricts. As a result, the fiscal outlook for the Southwest
area is difficult to assess. It does appear, however, that
the combination of lower property tax revenues and an increasing
awareness of the cost of urban services will result in slower
growth than anticipated, at least in the near term.
Conclusions
Although this investigation has been qualitative and no
forecast of long-term public costs or revenues has been under-
taken, it seems clear from the review completed that current
fiscal problems are causing a reassessment of growth and plan-
ning policies in many of Ada County's jurisdictions.
While local officials believe the resources will be
available to accommodate future growth, that growth is probably
more likely to be concentrated in or adjacent to existing ur-
ban communities than might have been expected a few years ago,
with this pattern of concentration helping to assure efficiency
in urban service delivery and minimum average cost. The cur-
rent recession in the economy, which has been evidenced in part
by the downturn in new construction, has given local communities
some breathing time to adjust their planning, development and
fiscal policies in response to the new fiscal constraints they
f ace.
An unanswered question is whether the mechanisms for
guiding growth are strong and consistent enough to achieve
the stated policies of Ada County and the City of Boise.
Development of outlying areas is limited under county zoning
to essentially agricultural use (1 unit per 80 acres in agri-
cultural use areas and 1 unit per 160 acres in rangeland
areas) except that smaller parcels are allowed where there
is no water available for irrigation (1 unit per 40 acres)
or in approved subdivisions. How many undeveloped parcels
exist in the latter is not known, but no new subdivisions
in the rural areas have been authorized since 1977. Given
this zoning pattern it does not presently appear likely that
more restrictive development policies within and at the edges
of urban areas would cause much rural spillover development
outside the Southwest area.
However, a more substantial issue is the resilience of
the regional economy itself if housing prices continue to
rise in response to scarcity, and housing price, type and
locational availability pose disincentives to people consider-
ing moving into the region. If events take that direction,
there will be more pressure on local public agencies to facili-
tate development through both fiscal and planning policies.
116
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Chapter 9
ummmmammmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm
Air Quality
-------
Chapter 9
AIR QUALITY
Introduction
Terminology
Any discussion of air pollution issues requires an under-
standing of terms and phrases which have a technical meaning
in the context of air pollution discussions. It is especially
important to understand the distinction between air pollutant
emissions and ambient air quality. The term "pollutant
emissions" refers to the amount (usually stated as a weight)
of one or more specific compounds introduced into the atmos-
phere by a given source or group of sources. The term
"ambient air quality" refers to the atmospheric concentration
(amount in a specified volume of air) of a specific compound
actually experienced at a particular geographic location
(which may be well removed from the location of relevant
emission sources). Measured ambient air quality levels are
determined by: the location of emission sources; the types
and amounts of pollutants emitted; the physical processes
(meteorology) affecting the distribution, dilution, and
removal of these pollutants from the area of concern; and
chemical reactions which transform pollutant emissions into
other chemical substances and sometimes generate other pollu-
tants from normal atmospheric constituents.
Air pollutants are often characterized as being "primary"
or "secondary" pollutants. Primary pollutants are those
which are emitted directly into the atmosphere (e.g., carbon
monoxide, nitric oxide, hydrogen sulfide, sulfur dioxide,
many types of particulates, and many types of organic compounds,
etc). Secondary pollutants are those which are formed through
chemical reactions in the atmosphere (e.g., ozone, nitrogen
dioxide, sulfuric acid, sulfate and nitrate particulates,
etc.). These chemical reactions usually involve primary
pollutants, normal constituents of the atmosphere, and some-
times other secondary pollutants.
The distinction between primary and secondary pollutants
is more than a matter of semantics; important air quality
management implications are also involved. The ambient con-
centration of primary pollutants depends on the concentration
and strength of emission sources, and the degree to which
117
-------
emissions are dispersed or removed from the atmosphere between
the emission source and the ambient air quality monitoring
instrument. Thus, air quality problems involving primary
pollutants can usually be traced to a single pollutant source
(or concentrated group of sources) emitting large quantities
of the pollutant of concern. When an air quality problem
involves a secondary pollutant, however, the relationship
of emission sources to air quality problems becomes much
more complicated. Because secondary pollutants are not emitted
directly into the atmosphere, observed ambient concentrations
may not show much correlation with the concentration of pre-
cursor emission sources. The time factor involved in the
chemical reactions producing secondary pollutants allows
emissions from numerous sources to become dispersed and mixed
together. As a result, the observed ambient pollutant con-
centrations are due more to the cumulative areawide mass
emissions of precursors than to the spatial concentration
of emission sources.
Meteorological Factors
Meteorological factors are important to consider from
several perspectives when evaluating air quality issues.
Factors such as temperature, humidity, and the intensity
and duration of sunlight play important roles in governing
the nature and rate of chemical reactions in the atmosphere.
Atmospheric turbulence, wind patterns and vertical temperature
gradients are important factors governing the distribution
and dispersion of pollutants. Atmospheric turbulence, wind
patterns and precipitation processes affect the rate at which
pollutants are removed from the atmosphere.
Topographic Effects. Topographic conditions exert con-
siderable influence over local meteorological conditions.
Surface winds are deflected and channeled by terrain features,
resulting in air flow patterns at ground level which may
be quite different from the prevailing winds at higher
altitudes. In areas of rugged terrain, slope and exposure
greatly influence microclimatic conditions. In such areas,
daytime heating of mountain slopes can lead to a gentle upslope
breeze. Conversely, nighttime radiational cooling of the
slope will produce a layer of cold air next to the ground,
resulting in a downslope drainage flow of cold air. These
localized upslope and downslope flows are sometimes called
valley and mountain winds.
Atmospheric Stability and Temperature Inversions. The
topic of atmospheric stability centers on processes which
118
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produce or resist vertical motions in the atmosphere. On
a microscale level, vertical motions are predominantly a
result of mechanical turbulence due to wind flow across non-
uniform surface features. On a larger scale, vertical tempera-
ture differences within an air column become the major con-
sideration. Because atmospheric pressure decreases with
altitude, there is also a natural tendency in the lower
atmosphere for temperature to decrease with altitude.
An air parcel can be heated by contact with a warmer
surface, absorption of sunlight or infrared radiation, or
through heat released by condensation of liquids within the
air mass. If the air near ground level is heated sufficiently,
a pocket or "cell" of warmed air will expand and rise, being
displaced by cooler, denser air from above. As it rises,
the cell of warm air will expand further due to decreasing
atmospheric pressure, causing the temperature of the air
cell to drop. The air cell will continue to rise, expand
in volume, and cool until it reaches an altitude where it
is at the same temperature and pressure as surrounding air
masses. This rising of warmed air and replacement of cooler
air from above results in vertical mixing of the air column.
This type of vertical instability occurs when air at ground
level is significantly warmer than the air aloft. If the
air at ground level is only a little warmer than the air
aloft, air parcels will neither rise nor sink, and "neutral
stability" conditions will exist.
Stable atmospheric conditions occur when the air near
ground level has essentially the same temperature as the
air aloft, or when the air aloft is actually warmer than the
air at ground level. This latter situation, where air
temperature actually increases with altitude, is called a
temperature inversion.
Figure 9-1 illustrates the relationship between vertical
temperature changes and the various atmospheric stability
conditions discussed above. As can be seen from this figure,
unstable conditions are more sensitive to changes in vertical
temperature gradients than are stable conditions.
Temperature inversions can form under a wide variety
of circumstances. Radiation inversions often form during
clear nights when the land surface cools faster than the
air above it. Air at ground level thus cools more rapidly
than air at higher altitudes, creating a temperature in-
version. In mountainous areas, downslope movements of dense,
cold air from higher elevations can create an inversion
condition in valley areas. An influx of a shallow layer
of cold air under a larger warm air mass will also create
an inversion condition. A warm air mass moving into an area
119
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FIGURE 9-1
RELATIONSHIP BETWEEN ATMOSPHERIC STABILITY
AND INVERSION CONDITIONS
500 -i
NJ
O
(O
Od
UJ
O
ac.
o
>
o
00
-------
above a cold air mass at ground level can also create inversion
conditions. A subsidence inversion forms when a large mass
of air within a stagnant high pressure system sinks down
over an area and is warmed by compression to a temperature
higher than that of the surface air mass. This occurs because,
as air from the center of a high pressure area spreads outward,
it is replaced by a sinking air mass from above.
Radiation inversions and inversions formed by cold air
drainage usually occur at or near ground level. Subsidence
inversions usually form at higher altitudes above the ground.
Both surface and elevated inversion layers may be present
simultaneously. Surface inversions tend to break with normal
daytime heating of the land while inversions aloft tend to
be more persistent.
It should also be noted that cloud cover reduces daytime
heating of the ground and traps nighttime heat radiation
from the ground, thus favoring neutral stability conditions.
Strong winds result in turbulent mixing of the lower atmosphere,
thus suppressing both the heating and cooling of surface
air parcels; this again promotes neutral stability conditions
(though adding mechanical turbulence).
The presence of snow cover or frozen ground conditions
can greatly influence the persistence of ground level inver-
sions. Snow cover reflects sunlight, resulting in reduced
heating of land surfaces. Frozen ground will absorb sunlight
and warm when temperatures are below freezing. As the ground
temperature approaches 32°F, the heat energy in sunlight
will be expended in thawing the soil with little actual change
in soil temperature. Thus, both snow cover and frozen ground
conditions can inhibit the processes which weaken and destroy
ground level inversions.
Temperature Inversions in the Boise Area
The intensity of low level temperature inversions in
Boise was investigated during the early part of 1980. The
full report from this study (North American Weather Consultants
1980) is available in EPA's Boise operations office. An
instrumented balloon attached to a wire cable was used to
determine vertical temperature profiles at Ann Morrison Park.
Over half of the attempted balloon launchings had to be can-
celled due to high winds and storms. Data from 8 days with
successful operations are summarized in Table 9-1.
The North American Weather Service study compared data
collected at Ann Morrison Park with data from the Boise muni-
cipal airport. Wind speeds and directions at Ann Morrison
121
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Table 9-1. Sunmary of Vertical Stability Fran Tethersonde Study
Monday Tuesday Wednesday Friday Saturday Sunday Monday Tuesdav
1-21-80 1-22-80 1-23-80 2-8-80 2-9-80 2-10-80 2-11-80* 2-12-80
Height 11:16 4:15 9:15 12:45 10:00 3:50 9:51 1:00 9:00 Noon 4:12 8:45 Noon 4:15 8:45 Noon 4:15 8:45 Neon 4:15
Interval AM PM AM PM AM PM AM PM AM PM AM PM AM PM AM FM
Surface -
100'
A
A
D
B
D
A
E
A
A
F
E
G
F
A
F
F
A
A
A
A
100"-200'
F
E
D
A
E
B
E
F
A
A
A
C
A
A
E
A
A
E
D
A
200'-300*
F
G
D
D
D
E
E
A
G
F
B
F
B
A
D
A
A
E
k
E
300'-400"
G
A
E
B
E
C
E
G
F
E
A
A
F
A
D
F
A
G
G
E
400'-500'
G
D
D
D
D
F
D
G
A
E
B
A
E
D
E
B
B
G
A
A
500'-600'
E
E
F
E
B
D
E
E
A
A
E
D
E
A
B
600"-700*
A
A
E
E
E
D
G
B
D
700'-800'
A
TV
r\
800'-900"
A
Surface
Usrnperature
37.5°
39.
2°
23.
.9°
32.0°
32.0°
37.0°
31.
.0°
45.0°
28.0°
43.0°
48.5°
26.0°
41.0°
43.0°
27.0°
42.0°
45.0°
26.0°
37.0°
40
Surface Wind
Speed (irph)
2.0
0.
.5
1.
.0
2.0
3.0
4.0
4.
.0
8.0
1.5
6.0
5.0
1.0
2.0
3.0
1.5
4.0
5.0
2.0
4.0
6
Stability Class A = Extremely Unstable
B = Moderately Unstable
C = Slightly Unstable
D = Neutral
E = Slightly Stable
F = Moderately Stable
G = Extremely Stable
*8-hour carton monoxide level at 9th Street monitor was 9.6 ppm for 6 am-2 pm period.
DATA SOURCE: North American Weather Consultants 1980.
-------
Park were not well correlated with' those at the airport.
Data on atmospheric stability at Ann Morrison Park were much
more detailed than available data from the airport. The
special study data show a complex pattern of low level
stability conditions not detectable from data collected at
the airport.
Existing Air Quality Problems
Initial air quality monitoring in 1974 identified carbon
monoxide (CO) as the major urban source pollutant of concern
in the Boise area. The Idaho Air Quality Bureau operates
two permanent CO monitoring stations which provide continuous
monitoring data. The Idaho Transportation Department operates
a third continuous monitoring station at its State Street
offices. There have also been three special CO monitoring
programs which provide additional data on the nature and
extent of CO problems. There has been a limited amount of
monitoring for other pollutants. Since data are limited
for other pollutants, the focus of this chapter will be on
CO.
EPA has established two sets of ambient air quality
standards for CO. The standard for 1-hour exposures is
currently 3 5 ppm (parts per million), to be exceeded no more
than once per year at any air quality monitoring site. An
additional standard has been set for 8-hour exposures. This
standard (9 ppm averaged over a consecutive 8-hour period)
is also to be exceeded no more than once per year. In
practice, the 8-hour standard is more stringent than the
current 1-hour standard. EPA has proposed changing the
1-hour standard to 25 ppm, but no final action has yet
been taken.
Summary
Available monitoring data from several sources indicate
that the Boise area experiences a geographically extensive
pattern of high CO levels. These high CO levels are concen-
trated primarily along major traffic corridors. Under appro-
priate meteorological conditions (light winds and low level
temperature inversions), air masses containing high CO levels
can be transported more or less intact over distances of
up to 1 mile. Thus, much of the Boise area is susceptible
to episodes of high CO levels which originate primarily from
major roadway corridors.
123
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Episodes of high CO levels show a rather strong seasonal
pattern, with most episodes occurring during the winter
(November-February). There have, however, been instances
of 8-hour CO levels above the federal standard during every
month of the year and almost every possible 8-hour period
of the day. The seasonality, frequency, and magnitude of
CO episodes show significant yearly variation.
The valley and bench areas in Boise both experience
severe CO episodes. The hourly patterns of high CO episodes
in these two areas are rather distinctive. The bench area
experiences a pattern of late night and early morning CO episodes
seldom observed in the valley area. While differences in
traffic patterns may play some role, meteorological factors
appear to be a dominant influence. Topographic features
suggest that nighttime ground level radiation inversions are
frequent on the bench. The valley area, however, appears
to experience cold air drainage flows which mix with or flush
polluted air from the downtown area.
Appendix G provides a discussion of CO data collected
by the various special studies and the permanent monitoring
stations. These various data sources are briefly discussed
below.
ESL/CH2M Hill Study
The first significant air quality monitoring program
in the Boise area was conducted from January through May
1974. Monitoring site locations are shown in Figure 9-2.
In addition to these monitoring stations, short-term bag
sampling was conducted at street intersections near four
of the five fixed stations. The federal 8-hour CO standard
was exceeded at three of the five sites. The Eastman Building
site regularly recorded monthly peak 8-hour average CO values
of 12-20 ppm. None of the short-term bag sampling identified
any violation of the federal 1-hour standard.
This study concluded that CO problems existed in the
downtown Boise area, and at some more outlying areas. It
was also concluded that areas on the first bench or higher
locations generally comply with the federal CO standards.
EPA Study
EPA sponsored a special CO monitoring study during late
1977. Four-hour bag samples were collected twice a day on
weekdays between 10:00 a.m. and 6:00 p.m. Monitoring sites
used in this study are shown in Figure 9-3. Site 13 was
located adjacent to the Idaho Air Quality Bureau's downtown
monitoring station. The peak 8-hour CO level measured during
this study was 17.2 ppm at site 32.
124
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FIGURE 9-2. MONITORING SITES
USED IN THE ESL / CH2M HILL
STUDY
-LEGEND-
IT] fire STATION No.8
0 FIRE STATION No. 6
~] ITD BUILDING
B EASTMAN BUILDING
0 CH2M HILL BUILDING
-{tj-SITES RECORDING AT LEAST 1
" 8 HOUR CO VALUE » 9ppm
source: redrawn from ESL incorporated
AND CH2M HILL, 1974
I
N-
t
\
\
V
-------
(3081
[288]
~1
[2 SB]
'Z7B
»]
318
A
m
J0JU
=LEGEND=
(n) SITES USED FOR 20 OAYS
SOURCE REDRAWN FROM EPA 1978B
fa*) SITES USED FOR FIRST TEN OATS ONLY
298) SITES USED FOR SECOND TEN DArS ONLY
SITES RECORDING AT LEAST ONE 10 AM-6 PM
AVERAGE CC LEVEL GREATER THAN 9pj»«
FIGURE 9-3. MONITORING SITES USED DURING
THE EPA CARBON MONOXIDE STUDY
-------
This study concluded that the state's permanent monitoring
station on Ninth Street is generally representative of CO
concentrations in downtown Boise, although the station under-
estimated the magnitude and frequency of elevated CO levels.
For example, the permanent station recorded exceedences of
the federal 8-hour CO standard on 47 percent of the study
days. This is in contrast to one or more of the study sites
recording exceedences on 95 percent of the days. The state's
downtown monitoring station recorded an 8-hour CO level of
13.7 ppm at the time that EPA's site 32 station recorded
the 17.2 ppm average noted above. On 19 of the 20 days in
the study at least one of the EPA study sites had a 10:00 a.m.
to 6:00 p.m. average CO level greater than the simultaneous
reading at the state's Ninth Street monitoring station.
Idaho Air Quality Bureau Study
In an attempt to better characterize the spatial extent
of the carbon monoxide problem in Boise, the Idaho Air Quality
Bureau conducted a special monitoring program between November 7,
1977 and March 6, 1978. The major purpose of the study was
to assess carbon monoxide levels in areas outside the central
business district of Boise. The bench areas southwest of
the Boise River received special attention. Three portable
CO monitors were used to collect data for 1-week time periods
at a total of 46 sites. Traffic counts were made at most
of the monitoring sites. Monitoring sites were classified
by location as either valley or bench sites, and by proximity
to major roadways as either traffic corridor or neighborhood
sites.
Figure 9-4 shows the locations of the 46 monitoring
sites. Despite the limited duration of monitoring at any
one site, 20 of the 46 sites recorded at least one 8-hour
average CO value above the 9 ppm standard. The highest 8-
hour CO values were monitored at traffic corridor sites on
the bench. Eight of 10 stations reporting peak 8-hour CO
values of 12 ppm or more were bench sites. The highest 8-
hour CO value recorded during the study (25.0 ppm) occurred
on a day when the permanent downtown monitoring station did
not record any violations of the 8-hour standard. This value
also exceeded the peak 8-hour CO value recorded by the Ninth
Street monitoring station during all of 1978. The only neighbor-
hood site to record an 8-hour CO value above 9 PPm recorded
an 11.1 ppm 8-hour average at this time.
The results of the Air Quality Bureau study clearly
indicated that high CO levels occurred near major traffic
arteries on the bench as well as in valley areas. The results
also confirmed the observations of the EPA study regarding
the occurrence of high CO levels even when the Ninth Street
monitoring station shows no violation of the federal 8-hour
standard.
127
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FIGURE 9-4. MONITORING SITES
USED DURING THE IDAHO AIR
QUALITY BUREAU CO STUDY
LEGE ND-
ffl BENCH SITE
® VALLEV SITE
-<4>o* -(*)¦ SITES RECORDING AT LEAST
1 • HOUR CO VALUE > 9pp*
SOURCE: REDRAWN FROM IOAKO AtR
QUALITY BUREAU,1978
-------
Permanent: Monitoring Station Data
The Idaho Air Quality Bureau currently operates two
permanent monitoring stations in Boise. The downtown
station (at the Odd Fellows Hall on Ninth Street, south-
west of Idaho Street) has operated since July 1975. The
Orchard Street station (south of Highway 55) has operated
since May 1978.
Monitoring data from these two stations are presented
in Appendix G. The downtown station has recorded 8-hour
CO values as high as 20.4 ppm (in 1978) and 1-hour CO values
as high as 40.9 ppm (1977). Violations of the federal 8-
hour CO standard have been recorded on as many as 87 days
during a single year (1976) at the downtown station. Peak
CO values at the Orchard site are much lower (8-hour average
of 12.8 ppm and 1-hour average of 29.5 ppm, both in 1979).
Complete data for 1980 have not yet been reviewed.
The hourly pattern of CO levels in the downtown area
is illustrated by Figure 9-5. Both the morning and evening
commute periods are evident from the monitoring data. The
evening commute period shows a higher average CO value than
the morning commute period. This is partially a reflection
of the station location (near the intersection of two "out-
bound" streets). A more significant factor, however, involves
the operating condition of cars in the location traffic flows.
The evening commute period involves cars which are generally
beginning a trip in a "cold" operating mode (with high emission
rates). A significant portion of the morning commute traffic
will arrive in the downtown area in a warmed-up operating
mode (with lower emission rates).
An interesting contrast to the downtown station is pro-
vided by the Orchard Street station. The pattern of hourly
CO levels at this site (Figure 9-6) shows a predominance
of the morning commute pattern. A major factor here, as
at the downtown site, is probably the cold vs. warmed-up
conditions of vehicles in the local traffic flow.
The downtown and Orchard monitoring stations show dis-
tinctive patterns in the occurrence of 8-hour CO values
exceeding the 9 ppm standard. Data from the downtown station
are summarized in Figure 9-7. Most episodes occur during
time periods which include the mid-afternoon and early evening
periods. The Orchard site shows a pattern (Figure 9-8) which
has two distinct periods of episode conditions. High CO
levels tend to occur during the morning to early afternoon
period and again during the evening to late nighttime period.
129
-------
FIGURE 9-5
AVERAGE WINTER CARBON MONOXIDE LEVELS
AT THE BOISE ODD FELLOWS HALL
MONITORING STATION
O
o
UJ
o
<1
a:
UJ
>
<5
TIME PERIOD
NOTE BASED ON OCTOBER THROUGH FEBRUARY DATA
DATA SOURCE OCTOBER 1975 - FEBRUARY 1980 HOURLY
CO DATA FROM fDAHO AIR QUALITY
BUREAU.
130
-------
FIGURE 9-6
AVERAGE WINTER CARBON MONOXIDE LEVELS
AT THE CENTRAL DISTRICT HEALTH
DEPARTMENT MONITORING STATION
7.0
CL
a.
o
o
o
<
a:
UJ
>
«t
6.5'
6.0-
5.5-1
5.0-
4.5-
4.0-
3.5-
3.0-
2.5-
2.0-
1.5-
10-
0.5-
0.0-
*
< 3E
t
b-
OD
<7>
I
x
X
X
X
X
X
X
X
rL
CL
a!
CL
CL'
CL
CL
CL
CVJ
tf)
<£)
r*-
00
CL
©
o
x
i
TIME PERIOD
NOTE- BASED ON OCTOBER THROUGH FEBRUARY DATA.
DATA SOURCE^ OCTOBER 1976- FEBRUARY 1900 HOURLY CO DATA
FROM IDAHO AIR QUALITY BUREAU.
131
-------
FIGURE 9-7
TIME PERIODS WITH 8-HOUR CO LEVELS » 9.0 PPM
AT THE BOISE ODD FELLOWS HALL MONITORING STATION
JULY-DECEMBER 1975
181 TOTAL OCCURRENCES
'iiiiiui'iiiiiiiiiuiiii.
u>
M
1976
618 TOTAL OCCURRENCES
iiuttii
n
i *
1977
374 TOTAL OCCURRENCES
; : s = * : t
i ! : i : i : i ' : : : : :
6-HOW TlUt PERJOO
I-hour time period
8-HOUfl Time PERIOD
1978
374 TOTAL OCCURRENCES
1979
287 TOTAL OCCURRENCES
1975-1979 COMPOSITE
1,834 TOTAL OCCURRENCES
-------
FIGURE 9-8
TIME PERIODS WITH 8-HOUR CO LEVELS >9.0 PPM
AT CENTRAL DISTRICT HEALTH
DEPARTMENT MONITORING STATION
MAY-DECEMBER 1978
20 OCCURRENCES
ill—i—rvr-T~r
1979
92 OCCURRENCES
0 - HOUR TIME PERIOD
8-HOUR TIME PERIOD
1978-1979 COMPOSITE
112 OCCURRENCES
0-HOUR TIME PERIOD
NOTE' VALUES WOVE fHtQUCNC* GRAPH INDICATE NUMBER OF OCCURRENCES
FOR SPECIFIED TIME PEhtOD
DATA SOURCE HOURLY CO DAT A FROM IDAHO AIR yUALlTY flUhfAU
— 133
-------
It should be noted that Figures 9-7 and 9-8 represent all
individual 8-hour periods with CO values greater than 9.0 ppm.
The federal 8-hour CO standard, however, is applied only
to discrete, nonoverlapping 8-hour time intervals. Thus
the number of "occurrences" indicated in Figures 9-7 and 9-8
greatly exceed the number of violations of the federal stan-
dard .
The different patterns in high CO levels at the downtown
and Orchard sites involve both traffic and meteorological
factors. Traffic volumes near the downtown area shows morning
and afternoon peaks associated with commute patterns. Traffic
volumes on the bench tend to show a single broad peak period
from 11 am to 6 pm; this reflects shopping trips during the
mid-day period and the home-bound evening commute. Both
the bench and downtown areas exhibit low traffic volumes
during the night and early morning hours.
The high frequency of elevated CO levels on the bench
during the evening to early morning hours (Figure 9-8) cor-
responds with declining 8-hour average traffic volumes. The
evening to early morning time period, however, is typically
associated with the formation of ground level temperature
inversions (radiation inversions). Reduced pollutant dis-
persion associated with such inversion conditions can produce
"increasing pollutant concentrations even if total pollutant
emissions are declining. The 1978 Idaho Air Quality Bureau
special study and the Orchard Street monitoring station data
both suggest that this situation occurs frequently on the
bench area. The lack of such patterns in the downtown area
probably reflects a flushing of polluted air by cold air
drainage from the Boise Front into the Boise River Valley.
Idaho Transportation Department Monitoring Data
The Idaho Transportation Department operates a continuous
CO monitor at its laboratory building off of State Street.
Data have been collected since December 1975. No statistical
data summaries are available. A preliminary review of the
hourly data indicate five episodes of 8-hour CO levels above
the federal standard (1 in 1976 and 4 in 1979). The highest
8-hour CO value appears to be a 10.6 ppm average on November 16#
1979 (7:00 a.m. to 3:00 p.m.) . All of these episodes occurred
during the early morning to early afternoon time period.
The highest 1-hour CO level reported was 30 ppm on February 17 #
1976 at 8:00 a.m. to 9:00 a.m. The pattern of hourly CO
levels strongly suggests the influence of local vehicle
parking activities plus some pollutant transport from other
areas.
134
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Earth Metrics Ozone Study
During late summer and fall of 1979, the Idaho Air Quality
Bureau conducted a meteorological study t° ^ate sites for
future ozone monitoring stations. A coope n„nn(a monitorina
arranged between EPA and the state to provide ozone monitoring
instruments to supplement the available
results of this ozone study (Earth Metrics 1979) are available
in EPA's Boise operations office.
Two monitoring sites southeast of Boise were used during
this Studv one near Mayfield and the other west of Mountain
Home. No violations of the federal ozone ietected
during the period that valid data were co monitoring
15 through September 28, 19/y;. R„rpa,5)
closer to Boise during 1980 (by the IdJh°Lone
also failed to detect any violations of the federal
standard.
Air Quality Management Considerations
Institutional Framework
Federal and state activities related to air quality
have been authorized by several pieces o 9
most important of which are the 1970 an amendments
to the Clean Air Act. The 1970 Clean Air Act amendment
set the basic structure for federal and state air po
control programs. This basic structure has
under the 1977 Clean Air Act amendments.
The 1970 Clean Air Act amendments required each state
to develop and adopt a plan (implementation plan) to aohxeve,
maintain and enforce the national primary and secondary ambient
air quality standards in all portions of iPmlntation
1970 amendments further required that these a^°n
plans provide the means for , 1 -> na+-ional
national primary standards by July 19 a
secondary standards "within a reasonab e ' . nians
granted the authority to approve or disapprove these P^ns,
and to promulgate an acceptable plan if al P
of the submitted plan was disapproved. EPA was also
the authority to grant time extensions of up to 2 V®"® for
the attainment of a national Prima?Y reaion
standard in any particular air quality control region.
135
-------
The 1977 Clean Air Act amendments recognized the fact
that most of the major urban regions of the country failed
to attain the national primary air quality standards within
the deadlines set by the 1970 Clean Air Act amendments. The
new amendments required the states and EPA to identify areas
which meet all federal air quality standards; areas which
exceed any of the federal standards; and areas where adequate
ambient air quality monitoring data are lacking. Ada County
has been designated a "nonattainment area" for carbon monoxide,
as an "attainment area" for suspended particulate matter
and sulfur dioxide, and as an "unclassifiable area" (areas
where data are nonexistent or insufficient to determine
attainment or nonattainment status) for ozone and nitrogen
dioxide.
The 1977 amendments to the Clean Air Act establish
numerous criteria for determining the adequacy of state
implementation plans. Some of the more significant of these
include the following requirements:
o The implementation plan must include special pro-
visions for areas designated as nonattainment areas.
Plans for nonattainment areas must provide a means
of achieving the federal primary standards as ex-
peditiously as possible, but not later than December 31i
1982.
o If an area is designated as a nonattainment area
with respect to ozone or carbon monoxide, EPA can
extend the deadline for achieving the federal air
quality standard by up to 5 years (to December 31,
1987) provided a number of specified conditions are
met.
o The implementation plan must include schedules and
timetables for implementing emission limitations,
transportation controls, air quality maintenance
plans, preconstruction review of direct sources of
pollution, and other measures necessary to ensure
attainment and maintenance of the federal primary
and secondary air quality standards.
o State implementation plans for nonattainment areas
must provide for installation of "reasonably available
control technology" on existing stationary sources.
o Plans for nonattainment areas must provide a means
of achieving annual incremental reductions in the
emissions of relevant pollutants so as to attain
the federal air quality standards by the target date
identified in the plan ("reasonable further progress"
requirement).
1 36
-------
o Plans for nonattainment areas must expressly identify
and quantify pollutant emissions which will be allowed
to result from the construction and operation of
major new or modified stationary sources in the non-
attainment area.
o The implementation plan must prohibit construction
or modification of major stationary sources in non-
attainment areas after June 30, 1979 if the state
has failed to submit to EPA acceptable implementation
plan revisions pertaining to that nonattainment area.
The 1977 Clean Air Act amendments indicate that implemen-
tation plan provisions for ozone and carbon monoxide nonattain-
ment areas should be prepared by an appropriate organization
of local government officials, as designated by the state.
The Ada Planning Association (APA) has been designated as
the lead agency for developing air quality management programs
for Ada County.
The 1977 Clean Air Act amendments contain several pro-
visions regarding federal permit activities or financial
assistance programs. These provisions can be summarized
as follows:
o After July 1, 1979 EPA is prohibited from awarding
any grants authorized under the Clean Air Act, except
for air quality improvement or maintenance purposes,
if the agency applying for the grant is in an air
quality control region where the following three
conditions apply: one or more federal primary stan-
dards have not been attained; transportation control
measures are necessary to achieve the standard being
violated; and an appropriate state implementation
plan has not been submitted (or reasonable efforts
toward developing such a plan are not being made).
This funding prohibition also applies if an approved
plan is not being implemented.
o After July 1, 1979 the U. S. Department of Trans-
portation is prohibited from awarding grants of
approving projects under Title 23, United States
Code, except for safety, mass transit, or trans-
portation projects which improve air quality, if
the agency applying for the grant funds or project
approval is in an air quality control region where
the three conditions cited above apply. This funding
prohibition also applies if an approved plan is not
being implemented.
\ 37
-------
o No federal agency can engage in, license, permit,
approve, or support in any way any activity which
does not conform to the approved or promulgated state
implementation plan for the relevant^area.
o EPA is authorized to withhold, condition, or restrict
any grant for construction of sewage treatment faci-
lities if it is determined that: a) such sewage
treatment facilities will not comply with Clean Air
Act provisions relating to new source performance
standards or emission standards for hazardous air
pollutants; b) the state does not have, or is not
implementing, an approved state implementation plan
which expressly quantifies and provides necessary
management programs to deal with the air pollutant
emissions which may reasonably be anticipated to
result directly or indirectly from the new sewage
treatment capacity to be created by such construction;
c) the construction of such treatment works would
create new sewage treatment capacity which may
reasonably be anticipated to cause or contribute
to, directly or indirectly, a larger increase in
pollutant emissions than has been provided for
under the applicable state implementation plan; or
d) the construction of such treatment works would
create new sewage treatment capacity which would
cause or contribute to, directly or indirectly, an
increase in pollutant emissions which will interfere
with or be inconsistent with the applicable implemen-
tation plan of any other state.
Emissions Inventories and Forecasts
CO emissions have been estimated for several groups
of emission sources in northern Ada County. The greatest
attention has been devoted to sources in the Boise metro-
politan area, since air quality monitoring data have docu-
mented serious CO problems throughout the Boise area.
Emission estimates have been structured to reflect historical
conditions for 1977 and 1980, and expected conditions for
1987 and 2000. Three broad categories of emission sources
have been evaluated: vehicle traffic on major roadways,
on- and off-street vehicle parking activity, and residen-
tial fuel combustion for space heating or appliance operation.
Commercial and industrial fuel combustion emissions have
not been estimated. Data for residential fuel combustion
suggest that commercial and industrial sources are probably
insignificant. Drive-up window facilities have not been
directly evaluated for the emission inventories and fore-
casts discussed here. Data for parking facilities suggest
that drive-up facilities may be significant localized emission
sources. Hourly emission inventory and forecast results
for the three major source categories are presented in
Appendix F.
138
-------
Procedures used to produce the emission inventories
and forecasts are discussed in detail in Appendix A. All
forecasts were based primarily on the same population and
employment forecasts (APA 1978). Emissions from highway
traffic were based on traffic volumes projected by the
Boise area traffic model. Parking emissions were developed
using a variety of parking surveys from the Boise area.
Residential fuel combustion emissions were developed using
data from a recent survey of energy usage patterns (Elrick
and Lavidge 1980). All emission inventories and forecasts
were prepared in a manner allowing results to be summarized
by community planning area. The boundaries of community
planning areas as used for the Boise area traffic model and
the emission forecasting work are shown in Figures 9-9 and
9-10.
Results of. the emission inventory
Sn of^wood^toves and fireplaces results
contribution to total c0„e™"f(i.e. , emitted directly
Because CO is a "primary" Pollu?anJ ' actions) , the
rather than being formed trough chemical
total emissions burden xn a regio lutant levels,
indicator of c0ntributi°ns^o^ien Pcentration Qf a primary
Source contributions to the a®?*® t d by emission density,
pollutant are more accurately xndica y ±c Qf fche
the amount of pollutants em^ted p (pounds of CO emis-
source. Relative emission dens:ity ented in Table 9-3.
sions per source category a<^e) a P within different
The relative potential for CO pro indicated by a corn-
community planning areas ^ genera y (ESDI) values. The
parison of emission source ^nsity lative emission density
ESDI value is obtained by adding the re planning
values for each source.category « */^ticular HomewLt
area or group of planning areas • density values (pounds
artificial number, since ^ e™-S each SQUrce category.
per acre) relate to dif:E'eren* approach provides a
Nevertheless, this emission densi y ce of different
useful evaluation of the relative P
emission sources.
/^ncHtv values in Table 9-3 indicate
The emission scarce dem81 Jra£*ic and parking activities)
that vehicle activity (highway traffic an P problems.
is clearly the dominant factor ^ ^^ourc! density
Current and projected ^P°sJarious community planning
index (ESDI) values fo , n in Figures 9-11, 9-12, and ?
areas in the Boise area are sh emissions is also apparent
The dominant influence of velhie d&ta discussed pre-
from the ambient aJr.
-------
A
N
I
9FACON
BOIS*
USTICK
FAmvtiw ' Ave
KM 202
-------
FI6URE9-10. COMMUNITY PLANNING
AREAS IN THE METROPOLITAN BOISE
AREA
LEGEND-
(22) CPA NUMBER
CENTRAL
ml
-------
Table 9-2.
Summary of Carbon Monoxide Emission Forecasts tor
Northern Ada County
percent Contribution to Emissions
Ccnmtnity
plHvnint
ATf-f CCPA>7
goutKvist Arc*
I5W
OiV
to
W«r»t Spring*
£ubere*
(23>
Foothill* ««M»*
<24t
Motrthend SiA»rea
<2Jr>
IT i' nhwnY TTA'fiC
J£?Vof4-St*e«t ?«**«?
P-n»¦*«»»»«i«» ?»**»«*
Hood Stove*
Other ideati«l
total
tfiah**V Traffic
O*- * Qff-CCteet P*r«a9
MHwti'l Nrkin?
Wood Stovea
FirepJ*c«* , ,
Other Residential f»*l*
Ibtal
RiahMV tr»Wic
Ob- * UffStr^et r«r*i*9
fe»»i4er>ti*l r#rfcin^
Hood Stoves
HreplWW . , ,
Other Residential P««l*
Total
Highway Traffic
Orr- t ©Parting
pe*iod Stow**
Other Pe«ide«tl»l r»%3»
TOt*l
Biobway Traffic
cw- i 9»xkia*
metiOeotial 3»arfci»9
HcKnS SW*e»
Ot))«r He*i*«ituli >*1»
TrtlJ
, «»««. W "f""" ""
10 »«-« p*
Pexiod
20,926
I.U2
1,434
3.464
313
mm
11,812
591
439
1,4M
135
X05F
44.004
5,598
606
1,4*9
132
5I3H
4.988
157
421.
1,M7
92
X?B
LC.M?
~&.7«
<4S
4.JT9
19.0W
2,02*
1»83
10 Mr-* F* faily
rerioa toUl
25,€35
2,061
2,876
4,244
383
1
U7555
»*,6S>
«,1«
1,382
«.W
<4?
1TOB5
£1^57
*,3*6
13?
498
1,11%
102
943
«.L«
441
rnni -via
• .421
5,0<11
1,777
7.927
19,538
8.4 *t
45.753
27.121
4,481
2,372
19.7C2
1.1D3
10 w-6 P*
Period
23,910
1,422
1,173
7,5®7
sv»
lOil
u,»m
142
0*9
3,56*
J22
rr^i
ji»oas
5,371
511
Z,C49
185
4,en
220
J2S
I.J05
119
TT^fs TiTai?
},S4<
1,352
11, iM
3. Ml
23/555
9,999
Itf.03#
1,-372
20.254
S.W2
TC?25
42,003
7,781
910
f.MI
901
7,905
29l
590
4. 804
5iC
25.02$
912
1 ,*oi
13,09?
1,182
417908
9,5*0
317
768
«,aia
5«6
n;w5 «3i?
35,653
2.137
362
I.Ml
267
n,«i
S.0TS
77
205
l,«7S
151
^7H5
Zl«
4c 73'
428
359
S.16B
655
54?
31,429
1,952
Tf,5B9 29,57V
«9J
5,6*2
5U
:t> **-6 P«
Peritffl
74.9
t.i
5-1
12-*
85.0
10.9
1.2
2*B
0.3
5 9.3
3.3
10.«
75-1
0-«
*.?
16.0
1.5
27.4
2.9
42.«
3.0
9.2
•0.9
4.3
ti.fc
1,0
ft.4
39.6
3.0
P«ii ly
10 a*-4 P»
Baity
L0 am-6 P»
pefiod
TOtd 1
Peciod
T
77.4
1.7
i.O
13.7
1.2
59.&
2-fc
13.1
*5.0
2.3
6.7
15-1
1.4
69.2
3. »
4.7
20.9
2.2
84.2
e.o
1.3
5.9
4.6
65.1
1.4
5.7
25.1
2.7
43.6
2.5
9.2
~O. «
4.3
62.e
1.0
6.2
27.1
2.9
66.3
4.3
5.1
92.0
11.9
1. J
4.5
0.4
71.0
3-2
4-B
15.2
1- ?
5*. 1
1-2
7.6
30.4
2.8
««.* "**'• '
-------
Table 9-2 (cont'd.)
Cocmmity
Planninq
Area 1CPM>
fMt Bench Area
<30)
Central Bench
Ar*a
(40)
Southwest Area
(50)
U>
Boise Metropolitan
Area Subtotal
Meridian Xr«a
(60)
Eagle Are*
1701
Emission
Source
Category
Highway Traffic
On- t Off-street Parking
Residential Parking
Mood Stoves
fireplaces
Other Residential Fuels
Total
Highway Traffic
On- t Off-street Parking
Residential Perking
Wood Stoves
Fireplaces
Other Residential Fuels
Total
Highway Traffic
On- fc Off-street Parking
Residential Parking
Wood Stoves
Fireplaces
Other Residential Foals
Total
Highway Traffic
On— t Off-street Parking
Besidential Parking
Wood Stoves
Fireplaces
Other Residential Fuels
Total
Bighway Traffic
On- t Off-street Parking
Residential Parking
Mood Stoves
Fireplaces
Other Residential Fuels
Total
Highway Traffic
On- » Off-street Parking
Residential Parking
Mood Stoves
Fireplaces
Other Residential Fuels
Total
Carbon Monoxide Emissions (pounds) for Indicated Tiae Periods
1980 1997
Percent Contribution to Emissions
10 aa-6 pa
Daily
71,383
120,752
5,5*5
8.226
2,95s
7,137
26,279
2.792
163,945
87,658
65,153
4.397
3,859
9,311
842
112,101
7,691
34.310
83,571
164,626
38,691
66,143
2.843
1,835
8.187
870
2
1,797
79,879
285.236
484,907
31,441
27,299
121,789
12,940
20.368
13,698
33,077
2,988
355,375
678,40
17,156
28,667
1,457
1, *34
19,688
5,623
MC
273
790
71
37,190
629
2,908
309
13^51
10 an-6 p«
Period
84,349
5.843
3,458
7,823
707
Daily
Total
142,637
8,743
6,542
28,805
3,061
102,182 189,794
122,987
8.008
8.141
35,846
3,809
71,419
5,148
4,303
9,735
879
$1,486
44.348
1,814
1,182
2,673
241
1
50.259
328,813
22,163
16.204
36,660
3,311
407,160 774.000
178,798
75,707
2,937
2,235
9,843
1,046
2
91,769
559,291
34,677
30,655
134,984
14,342
29
19,306
MC
794
2,006
181
1
22,288
366
951
86
32,296
MC
1,693
7,387
785
457163
10,677
MC
785
3,503
372
1
15,338
10 aa-6 pa
Period
58,206
3,757
2,290
9,182
829
54,115
2,675
2.581
10.351
935
Daily
Total
96,139
S, 512
4,080
33,808
3.592
20 aa-6 pa Daily
74,266 143,138
90,442
4,128
4.600
38,113
4,049
70,669 141,349
35,530
1,507
859
3,447
311
1
41,655
247,332
15.983
11,458
45,948
4.150
11
324,882
10,276
NC
672
3,006
272
14.229
6,085
MC
320
1.427
129
"T5ST
58,648
2.377
1,532
12,691
1.348
3
76,799
410,271
24.738
20,419
169,180
17,975
36
642,619
1,334
11,076
1,177
30.41?
9,941
MC
633
5,254
556
TOiT
Period
Total
Period
51,443
81,944
81.4
2,246
3,192
6.3
1,409
2,469
3.4
11,517
42,407
8.1
1,040
4,506
0.7
3
9
67,658
134,526
37,428
60,702
78.0
1,243
1,094
5.3
1,455
2,548
4.6
11,886
43,765
11.1
1,074
4,650
1.0
3
9
53,089
113.569
36,138
56,346
88. 3
1.171
1.823
4.1
681
1,193
2.1
5,5*6
20,495
5.1
503
2,178
0.5
1
4
44,060
82,039
219,636
347,424
80.3
8,945
13,SIS
5.7
7,460
13,US
3.9
63,358
233,285
9.3
5,723
24,787
0.8
16
50
305,138
632,17S "
10,516
16,440
87.2
NC
NC
MC
626
1,204
3.2
5.606
20,643
8.8
506
2,193
0.8
1
4
l7,2SS
40,484
5,293
8,278
83.2
NC
NC
NC
293
562
4.0
2,591
9.540
11.7
234
1,014
1.1
8,412
2
19,395
Daily
Total
73.7
5.0
3.6
16.0
1.7
68.1
4.2
4.7
20.8
2.2
62.8
3.6
2.3
10.2
1.1
71.5
4.6
4.0
18.0
1.9
77.1
MC
3.9
17.2
1.8
4.7
22.0
2.3
10 aa-6 pB
Period
82.5
5.7
3.4
7.7
0.7
78.1
1.6
4.7
10.6
1.0
88.2
3.6
80.8
5.4
4.0
9.0
0.8
3.6
9.0
0.8
4.7
12.2
1.1
Daily
Total
75.2
4.6
3.4
68.8
4.5
4.6
20.0
2.1
82.5
3.2
2.4
10.7
1.1
72.3
4.5
4.0
17.4
1.9
76.6
NC
4.0
17.5
1.9
5.1
22.8
2.4
10 an-6 p» Daily
Pcnoi Tota I
78.4
5.1
3.1
12.4
1.1
3.7
14.6
1. 3
85. 3
3.6
2. 1
8. 3
0.7
3.5
14.1
1.3
4.7
21.1
1.9
4.0
17.9
1.6
67.2
3.9
2.9
23.6
2.5
2.9
3.3
27.0
2.0
16.5
1.8
63. B
3.8
3.2
26.3
2.8
2.1
17.0
1.5
70.5
2.3
2.7
22.4
2.0
1.5
12.6
1.1
72.0
2.9
2.4
20.8
1.9
3.6
32.5
2.9
3.9
32.1
3.4
Caily
Total
<0.9
2.4
1.8
31.5
3.3
53.4
1.7
2.2
38.5
4.1
68.7
2.2
l.S
25.0
2.7
55.0
2.1
2.1
36.9
3.9
3.0
51.0
5.4
2.9
49.2
5.2
-------
Table 9-2 (cont'd.)
PUnninq
Are* tCfMI
M-U A
-------
Table 9-3. Carbon Monoxide Emission Densities in Northern Ada County
tcetkli
SnitlMUt Ar«a
lltl
Kif* Springs
Stairu
1231
foothill* SdMnu
f24l
Mortem* SdtHffe*
t25)
8a«c«
Ui^taMy Traffic
0®- * Off-itmt tarkiag
teiWMtUV FuUii
Bavidaatial ruel Bst
Blqhwy ttifflc
Co- B Of f~9treet Yaxfciwi
RctidmtJjil Ricklaq
IMAmcUI h»l tea
BSOI-
RlftMay TtiHit
On- c Ofl-Bcmt hzUaj
Ms*4wtl«a Ptrklai
»—tifcmi ui rwi tfMt
liftany Traffic
Or* 4 Off«sirMt huftliig
ittidMtui p*rfciim
RMiJMttat rtael Dm
lljlwiy Teaffie
Oft- 4 RKfctm
^sideatltl firUmi
roe I Om
fis»t3
Rlgtway Traffic
Q(f V OCf-Sknat Autinq
BwiteatUl Partis?
^•idAtial fatl VW
Mfc«rtw«Y Traffic
Ok- * Wt-Stft^st Padtlt*9
Miilmbl diking
ReaUk«tk4l tvul tls«
i AdiaioB fiM
19*0
•* for aotirca- Armmw
_ 1M7
Ipotud* p«r Kttti
»»**««
iaji
D.1C
1.23
xl.»
IK.I1
126.56
IS. 52
l.N
bHI
LK.T4
41.2«
1.26
U?.»
31.19
1.26 -
X.U
».a
8.31
O.ti
190.20
n.«
L2t
_ _l.ll
21C.«
14T.60
30. H
U<1
2.83
!•*.«
' ,,i.3i ia.3»
HI755 MijS
"sfefl lrftfj
io ««-( p»
—-!««*
137.33
H.M
1.31
-3.M
lll.ib
UT.Cl
K.M
l.M
_3.M
iU.M
«.ti
100.45
33. W
1.34
<$.)}
2«.W
«.»
Tfit
2L].4»
22.85
1.34
3.31
240.59
365.69
39.13
I.IS
, I.t3
3W.M
tally
Total
232.60
59.55
2.41
12.07
305.14
24C.lt
50.55
;.5i
12-30
31»ItS
404.21
5*. S3
.54
314.8*
50.55
2.54
12.30
3W.3}
1C.il
50.55
o.cc
i-qa
13575?
359.49
50.55
2.54
12.37
432.95
200.it
50.55
*.3*
10.54
ssras
10 at-C pm
fcrlni
05. 36
1C.03
0.14
_ 3. 23
105.36
116.69
20.*9
0.H
3.31
rn?7$
301.00
22.11
0.76
nfe& ifeft afc
141.93
24.22
o.ie
3.11
i?0.^2
140.05
32.03
1.32
12.01
10C.27
100.30
32.03
1.3*
12. 3*
iU.ii
32.03
3.35
13.30
350.24
232.04
32.03
1.35
06.5*
22.0)
0.3)
nHf
240.00
32.0)
1.«
12.30
206.5«
185.7$
32.01
1.14
10.5«
1297*5
Ds.ily
09.30
1.16
0.36
3.21
ioo.ii
139.16
13.62
0.64
32.07
165.49
93.50
147.07
13.42
0.4S
12. 37
106.05
173.31
L32.il
271.34
». 53
13.(2
0.31
12.37
07.90
231.06
11.20
13.42
0.37
12.30
1«4.49
JsTTTI
55.02
87.56
13.51
13.62
0,09
7.30
104.2
125.00
197.09
13.62
0.05
1.31
12.31
135714
223.73
99. 39
$50.1>
9. SO
13.62
10.57
112.12
183.07
70.6
18.6
0.8
2.1
75.9
21.3
79.7
17.0
0.7
1.8
56.1
42.2
0.5
1.2
07.9
10.0
0.6
1.5
77.0
20.1
0*6
1.5
0.9
4.3
74.7
20.0
0.9
<.<
34.9
12.0
8.5
2.6
77.«
17.7
50.5
46.3
0-5
a.&
01.0
14.4
0.6
3.2
78.3
17.7
07
B0.1
17.3
0.8
1.9
10.1
19.4
0.7
£.8
15.4
33.1
0.4
1.Q
03.1
14.0
0.C
0.5
1.1
09.6
9.5
0.6
1.4
79.4
J 8. 7
0.6
1.4
. Contrlbuti.cn to 6SDI*
uej
16.1
19.2
0.0
3.9
77-0
18.3
0.8
3.9
U.5
2-3
81.2
15.0
55.1
42.2
0.S
2.2
03.0
13.5
0.6
1.9
79.7
J6.7
3.0
02. 3
14. 8
0.5
2.3
81.4
LD.G
1.4
1.6
03.4
14.2
0.4
i.i
71. 9
20. 7
0. 3
1.2
89.2
0. %
O.S
2.0
91.6
i'j. ft
&.S
2.1
Dally
Totu )_
75,6
17.2
0.7
0-S
13.6
0.6
5.2
86.9
0.4
1.5
64.0
11.2
d. 5
4,3
*-J. J
7.2
0.J
J. J
!¦.]
. J
1.2
5>3. i
4. 1
j.;
84.1
t.i
3-4
7.3
e
-------
Table 9-3 (cont'd.
Relative emission Densities' lor Source Kr«4s ({«gndi pec acrcl
fltfitete?
Ar?* |q*Mi
Source
Category
10 M>6 pn
Period
Daily
Total
10 an-6 pa
Period
Daily
Total
10 W*i (*
Period
Daily
Total
10 an-6 pa
Period
Oaily
Total
Central Benctt
Aree
<«•»
Highway Traffic
0»>- t Off-Rrcet Parfcln;
Metideotiai Parking
Residential Fuel Qse
ESDI*
170.64
36.19
0.98
2.5t
218.40
293.60
56.56
1.96
9.66
361.78
187.05
37.64
1.95
2.59
228.33
122.11
58.55
1.98
, *.-«*
492.30
138.65
20.76
0.59
2.59
162.59
231.72
32.03
1.0S
9.66
274.46
95.89
8.94
0.29
2.59
107.71
155.53
13.62
0.51
9.66
vrrts
Area
(SOI
fficrtiway traffic
On- t off-street Parking
Residential Parking
Residential fuel Oe*
BS&l*
66.09
35.75
0.4O
isjrfi
112.96
56.56
0.80
TS.7S
36.16
8.83
1.05
U J. 39
U9. tl
58.55
0.81
i?H§
60.69
20.31
0.24
-ifc*
100.52
32.03
0.4)
3.92
T5T55
61.73
8.75
0.12
Tfcfi
96.24
13.62
0.21
T
113.99
K«*ree*r Soiee
Mtopelitw
Area
NigJway Traffic
On- 6 Off-street Parking
Residential Parking
Residential fuel Ow
ES8I*
131.31
36.64
0.88
2.32
T3Toi
223.24
56.56
1.75
sHi
148.48
37.42
0.93
»¦«
U4.il
752.5S
58.55
1.15
J4J
106.00
20.70
0.52
tiHI
175.83
32.03
0.92
8.43
iTf.il
94.13
9.02
0.24
2.19
105.58
148.90
13.62
0.42
8.20
lit.14
Meridian Area
Ittl
Highway Traffic
On- * Off-Street Psrfciog
Residential Parking
Residential fwl Oee
KOI*
72.21
NC
0.81
120.66
NC
1.87
nfcff
81.26
NC
8.88
2.42
84.56
135.94
NC
1.87
9.05
146.86
48.44
HC
0.50
2.42
51.36
79.34
NC
0.99
9.06
89.39
49.58
NC
0.25
2.42
1315
77.50
HC
0.48
9.06
87.04
£*gle Area
<*9i
Bighway Traffic
On- 6 Off-Street Parking
Residential Parking
Residential Ibel Qse
ESDI1
73.63
NC
0.77
122.93
NC
1.77
xiHt
83.69
¦C
0.86
2.42
W.97
139.82
NC
1.83
*.06
150.71
59.76
NC
0.50
2.42
62.68
97.63
NC
0.99
9.05
107.67
51.98
NC
0.25
2.42
5?^S
81.30
NC
0.4*
9.05
90.63
Kgna Area
ttot
Highway Traffic
On- t Off-street Perking
Residential Parking
Residential Peel One
SS0I*
11.26
PC
0.71
2.42
14.39
16.74
NC
1.59
2». 37
13.57
NC
0.76
2.42
16.75
22.67
NC
l.«
9.04
Si.13
11. 31
NC
0.46
2.42
14.19
18.45
NC
D. 90
9.0S
28.40
19.40
NC
9.23
2.43
13.05
16.46
NC
0.43
9.06
25.95
fc*ral Ma Cotmty
•'*ree
<991
Higti«rair Traffic
On- 6 Off-Street Parking
Residential Parking
Residential feet Use
ESDI4
28.42
NC
0.25
0.81
29.47
~7.35
NC
6.57
3.02
50.94
32.05
NC
0.27
0.81
33.13
53.45
NC
0.58
3.02
57.05
23.36
NC
0.16
0.61
24.33
38.13
NC
0.31
3.02
41.46
18.67
NC
0.08
0.81
19.56
29.51
NC
0.15
3.02
32.68
Jteeraee* NortHern
Me County
Highway Traffic
On- & Off-Street Parking
Residential Parking
Residential Pnel Use
ESDI*
*0.32
36.64
0.79
.a.i?
lit.87
134.72
56.SC
1.59
7.91
206.70
91.32
37.42
0.83
2.09
159.29
154.70
58.55
1,60
222.67
66.81
20.70
0.47
2.07
90.05
110.49
32.03
0.84
torvn
58.76
9.02
0.22
2.04
70.04
92.88
33.62
0.39
__?>**
114.51
NO - Jiot calculated dee to lack of ptrfciag survey data.
E*is*ioa^Dea;ity " 9max>e category amissions frem Table 9-2 divided by MtiMtad Mr»m of «ai»»io» aonrce utMorv
Highway «cm9es baaed on roadway *ilaa {Table 9-4) and assunnd average roadway widtb of 70 feet. On- and off-street
t""r**af «eti»ated e*>r Ro**e Metropolitan Area as a whole using Hand tabulation of parking facility data files and
assayed average o. 4.20 square feet p*te parting space. Average eooree density for Metropolitan area used aa daily total value
^f??0~at CTAf- J* «¦•-* P--^ value* for each CPA calculated fro* ratio of 8-hour^ daUy^EsIiow il ££e 1-2
Residential Acreage* froa table 9-4 used for residential parking and residential foci use categories.
*ESM * B^iaaion Source Density Index, itic index calculated as the •« of source category relative ealuiea densities.
Percent Contribution Lo ESDI'
19Bp 19B7
10 an-6 pat DAily 10 n«-< pm Doily lo an-6 [M
Period Total Period Total Period
01.1 82.2 81.9 82.1 85.3 94.4 89.Q Bf. 7
11.2 1S.S 16.5 14.9 12.8 11.1 8.3 7.6
0.5 0.5 0.5 0.5 0.4 0.4 0.3 0.]
1.2 2.7 1.1 2.5 i.6 3.5 2.4 5.4
€4.8 64.8 £6.8 67.1 73.8 73.4 86.2 84.4
34.6 32.5 31.9 30.4 24.7 23.4 12.2 11.9
0.4 0.5 0-4 0.4 0.3 0.3 0.2 0.2
1.0 2.3 0.9 2.0 1.3 2.9 1.5 3.4
70.1 76.9 78.5 78.6 81.9 80.9 89.2 87.0
26.9 19.S 19.8 18.2 16.0 14.7 8.5 8.0
0.6 0.6 O.S 0.5 0.4 0.4 0.2 0.2
1.7 3.0 1.2 2.7 1.7 3.9 2.1 4.8
95.7 91.7 96.1 92.6 94.3 88.8 94.9 89.0
MC NC NC NC NC NC NC NC
1.1 1.4 1.0 1.3 1.0 1.1 0.5 0.6
3.2 6.9 2.9 6.2 4.7 10.1 4.6 10.4
95.8 91.9 96.2 92.8 95.3 90.7 95.2 89.5
NCNCNCNCMCNCNCNC
1.0 1.3 1.0 1.2 0.8 0.9 0.5 0.5
3.2 6.8 2.8 6.0 3.9 8.4 4.4 10.0
78.2 63.8 81.0 68.0 79.7 65.0 79.7 63.4
NC NC NC NC NC NC NC MC
4.9 5.4 4.5 4.9 3.2 3.2 1.7 1.7
16.8 30.• 14.4 27.1 17.1 31.9 18.6 34.9
67.0 67.1 SI.3 69.5 74.? 62.2 83.9 81,1
30.6 28.2 36.8 26.3 23.0 29.8 12.9 11.9
0.7 0.8 1.0 0.7 0.5 0.8 0.3 0.3
1.8 3.9 4.9 3.5 2.3 7.2 2.9 6.7
-------
FIGURE 9-11. 1910 EMISSION SOURCE
DENSITY INDEX VALUES (DAILY BASIS]
FOR THE BOISE METROPOLITAN AREA
-LEGEND
~ 100-150
150-200
300-350
350-400
400-450
500 +
SOUTHWEST
-------
FIGURE 9-12. 1987 EMISSION SOURCE
DENSITY INDEX VALUES (DAILY BASIS)
FOR THE BOISE METROPOLITAN AREA
-LEGEND-
CD 100-i5o
150 - 200
200-250
250-500
350 +
¦ acs
-------
FIGURE 9-13. 2000 EMISSION SOURCE
DENSITY INDEX VALUES (DAILY
BASIS) FOR THE BOISE METROPOLITAN
-LEGEND-
~ lOO-150
S3 150-200
¦ 200-250
S3 250-300
-N-
-------
other pertinent characteristics of'each community planning
area, are summarized in Table 9-4. Table 9-5 summarizes
vehicle trip data from the Boise area traffic model.
The significance of different emission source categories
cannot be fully evaluated solely from the percent contribution
columns of Table 9-2 or 9-3. The percent contribution of
any source category is, to a major extent, a reflection of
the significance of other sources in a particular community
planning area. For example, 1980 on- and off-street parking
emissions in the Foothills subarea contribute substantially
to the ESDI value (Table 9-3). This is largely a reflection
of the minimal amount of vehicle traffic in that area, rather
than an indication of massive amounts of parking-related
emissions (compare Tables 9-2 and 9-3).
Future Air Pollution Potential
in Ada County
The implications of projected emission levels have been
evaluated using simple proportionality ("rollback") techni-
ques (see Appendix H). Each community planning area has
been analyzed as a discrete subarea, without considering
the possibility of pollutant transport between areas. The
use of such procedures requires selection of a base year
from which to extrapolate potential pollution levels. The
ambient monitoring data summarized previously show that the
1976-1977 period experienced the most frequent and severe
CO episodes yet reported. The 1977-1980 emission increases
noted in Table 9-2 are largely attributed to highway traffic.
As shown in Tables 9-4 and 9-5, the Boise area traffic model
projected a 14.2 percent increase in vehicle trips and a
15.4 percent increase in vehicle miles traveled during the 1977-
1980 period. Actual traffic count data do not seem to show
such increases during this time period. It remains to be
seen whether this recent reduction in per capita vehicle
travel will continue significantly into the future. In any
event, 1977 data have been used in this EIS as representative
of potential CO levels under unfavorable weather conditions.
The procedures used for this analysis have not dealt
with the possibility of significant pollutant transport
between community planning areas. As discussed in Appendix G,
available monitoring data demonstrate only neighborhood scale
transport events.
Estimates of future air pollution potential are pre-
sented in Table 9-6. Potential CO levels were analyzed as
two components: a "background" increment related to total
emissions in each planning area, and a roadway corridor
150
-------
Table 9-4. Community Planning Area Characteristics Reflected in the Emission Inventories and Forecasts
Daily Vehicle Daily Home-
Dwelling Total Residential Roadway Miles Based Vehicle
Community Planning Area (CPA #) Year Population1 Units1 Acreage1 Acreage2 Miles3 Traveled3 Trips'
it
Southeast Area (10)
1977
13,578
4,675
8,503
1,169
20
118,241
34
556
1980
16,808
5,728
8,503
1,432
22
147,878
43
266
1987
29,702
10,132
8,503
2,533
33
270,901
80
827
2000
49,831
17,661
8,503
4,415
33
495,573
148
887
Northwest Subarea (21)
1977
6,327
2,016
3,880
492
11
78,560
14
902
1980
7,853
2,580
3,880
629
11
92,402
19
488
1987
14,411
4,810
3,880
1,173
12
153,431
38
371
2000
24,455
8,465
3,880
2,065
12
229,285
71
362
CBD Subarea (22)
1977
3,178
1,974
1,084
481
22
221,750
14
591
1980
3,534
2,231
1,084
544
22
257,537
16
852
1987
4,366
2,765
1,084
674
24
360,418
22
058
2000
6,655
3,996
1,084
975
24
596,172
33
687
Harm Springs Subarea (23)
1977
3,698
1,372
1,090
335
4
30,569
10
141
1980
4,003
1,522
1,090
371
4
40,043
11
496
1987
4,553
1,761
1,090
430
4
57,951
14
048
2000
5,574
2,261
1,090
551
4
100,696
19
061
Foothills Subarea (24)
1977
7,603
2,400
14,021
2,400
13
24,645
17
740
1980
8,921
2,869
14,021
2,869
13
31,026
21
671
1987
12,529
4,105
14,021
4,105
13
71,089
32
747
2000
18,850
6,389
14,021
6,389
13
143,629
53
861
Northend Subarea (25)
1977
17,458
6,997
2,141
1,707
15
142,791
51
720
1980
17,874
7,244
2.-141
1,767
15
161,512
54
717
1987
17,957
7,426
2,141
1,811
13
178,029
59
240
2000
18,110
7,642
2,141
1,864
13
260,063
64
424
West Bench Area (30)
1977
30,276
9,633
11,182
2,752
57
462,544
71
204
1980
32,640
10,559
11,182
3,017
60
538,089
79
757
1987
37,565
12,393
11,182
3,541
61
699,132
98
864
2000
45,115
15,545
11,182
4,441
61
1,102,625
131
049
Contral Bench Area (40)
1977
36,749
12,577
6,198
3,930
45
411,511
52
965
1980
37,716
13,140
6,198
4,106
45
456,62-3
99
253
1987
39,248
13,971
6,198
4,366
46
637,459
1 11
453
2000
43,355
16,043
6,198
5,013
46
843,049
135
247
Southwosl Aroa (50)
1977
10,277
3,001
18,383
2,308
69
271,411
22
182
1980
12,072
3,608
18,383
2,775
69
313,706
27
253
1987
3 4,914
4,652
38,383
3,578
69
472,042
37
11 1
2000
22,380
7,513
18,383
5,779
69
800,122
63
337
Suhlnl.tl, Boise
J977
129,144
44,644
66,482
15,574
25G
1 ,702,022
''.'A')
0'Jrj
Metropolitan Aroa
1980
141,427
49,481
66,482
17,510
261
2,038,816
373
753
1987
175,244
62,016
66,482
22,211
275
2,900,452
494
728
2000
234,050
85,516
66,482
31,492
275
4,571,214
720
925
-------
Table 9-4 (cont'd.)
Daily Vehicle
Daily Homo-
Dwelling
Total
Residential
Roadway
Miles
Based Vehic
;ommunity Planning Area (CPA #) Year
Population 1
Units 1
Acreage1
Acreage 2
Miles 3
Traveled 3
Trips
Meridian Area (60) 1977
7,295
2,341
10,560
780
28
111,456
17 ,304
1980
8,593
2,708
10,560
903
28
127,620
20,394
1987
12,639
4,060
10,560
1,353
25
129,427
32,388
2000
22,122
7,567
10,560
2,522
25
235,621
63,792
Eagle Area (70) 1977
3,152
1,066
9,728
355
9
36,810
7,880
1980
3,800
1,284
9,728
428
9
42,199
9,699
1987
5,696
1,926
9,728
642
12
77,992
15,365
2000
10,225
3,497
9,728
1,166
12
122,956
29,481
Kuna Area (80) 1977
1,626
494
3,520
165
9
5,791
3,651
1980
2,004
608
3,520
203
9
7,082
4 ,593
1987
3,301
1,025
3,520
342
9
11,296
8,177
2000
6,415
2,101
3,520
700
9
20,265
29,675
Rural Ada County Area (90) 1977
8,507
2,668
335,598
2,668
234
379,333
19,721
1980
9,393
2,988
335,598
2,988
234
433,013
22,570
1987
11,794
3,819
335,598
3,819
224
533,280
30 ,466
2000
15,913
5,278
335,598
5,278
224
837,644
44,4 95
Total, Northern Ada County 1977
149,724
51,213
425,888
19,542
536
2,295,412
378,551
1980
165,211
57,069
425,888
22,032
541
2,648,730
431,069
1987
208,674
72,847
425,888
28,367
545
3,652,447
581,132
2000
289,000
103,958
425,888
41,158
545
5,787,700
876,396
Notes and Sources:
'Tabulated from data in APA 1978, reflecting traffic
zone aggregations as used in the Boise traffic
model.
Calculated from dwelling unit values assuming 4.0 units per acre
in CPA 10
; 4.1 units
per acre in
CPAs 21, 22, 23,
and 25;
1.0 unit per acre in CPAs 24 and 90; 3.5 units per acre in CPA 30; 3.2 units per acre in CPA 40; 1.3 units per acre in CPA 50;
and 3.0 units per acre in CPAs 60, 70, and 80. Dwelling unit per acre values selected by Jones & Stokes Associates staff
based mi duLJ in APA 1978.
3From Boise traffic model output; computer runs made in November 1980.
""Calculated for each CPA using areuwi.de average trip generation rates; areawide trip generation rates calculated separately lroi
each forecast year from traffic model output of total home-based vehicle trips and total dwelling units listed above. All vehicle
trip numbers represent sura of trips in both directions. Values are preliminary estimates, subject to revision when spociI i a
CPA summaries become available directly from the traffic model.
-------
Table 9-5. Summary of Average Weedkay Vehicle Trip Characteristics
From the Boise Traffic Model
Vehicle Trips
Percent of Total Trips
Average Trip Duration
(minutes)
Percent of Trips Completed
Within 7 Minutes
Percent of Total Travel
Time Within 7 Minutes of
Trip start
Mean Vehicle Trips per
Household
TriP TVPe Total
HBW HBO NHB PI-AX PX-AI Trips
1977
102,213
18.6
12. 07
269,247
49.0
10.15
143,357
26.1
8.62
7,090
1. 3
29. 94
27,790
5.1
32.49
549,697
100.1
11.82
18.2
36.6
49.2
0.2
0.0
33.6
66.2
75.8
82.6
28.6
22.9
71.7
2.00
5.26
2.80
0.14
0.54
10.74
1980
Vehicle Trips
116,844
307,126
165,045
8,099
30,624
627,738
Percent of Total Trips
18.6
48.9
26.3
1.3
4.9
100.0
Average Trip Duration
12.24
10.23
8.64
29.91
32.44
11.84
(minutes)
Percent of Trips Completed
17.6
36.3
49,7
0.2
0.0
33.6
Within 7 Minutes
Percent of Total Travel
65.4
75.4
82.6
28.8
23.1
71.5
Time Within 7 Minutes of
Trip Start
Mean Vehicle Trips per
2.05
5.39
2.89
0.14
0.54
11.01
Household
1987
Vehicle Trips
Percent of Total Trips
Average Trip Duration
(minutes)
Percent of Trips Completed
Within 7 Minutes
Percent of Total Travel
Time Within 7 Minutes of
Trip Start
Mean Vehicle Trips per
Household
159,293 410,837 228,699
18.8 48.4 27.0
12.81 10.57 8.76
16.1 34.5 50.6
63.1 73.9 82.2
2.19 5.64 3.14
11,002 38,423 848,254
1.3 4.5 100.0
29.89 32.46 12.04
0.3 0.0 32.9
28.9 23.2 70.5
0.15 0.53 11.65
2000
Vehicle Trips 243,157 616,480 357,011 16,757 53,022 1,286,427
Percent of Total Trips 18.9 47.9 27.8 1.3 4.1 100.0
Average Trip Duration 13,38 10.96 8.76 29.6 9 32.39 12.21
(minutes)
Percent of Trips Completed 14.7 32.8 52.3 0.3 0.0 32.6
Within 7 Minutes
Percent of Total Travel 61,0 72.1 82.2 29.1 23.2 69.7
Time Within 7 Minutes of
Trip start
Mean Vehicle Trips per 2.35> 5.96 3.45 0.16 0.50 12.43
Household
Notes; Based on traffic model runs made in December 1980. Vehicle occupancy
assumptions: HBW, HBO, and NHB f 1.33? Pl-AX and PX-AI 1 1.67.
"Trips" represent "1-way travel events"? a "round trip" counts as two trips.
Trip type definitions:
HBW m home-based work trips
HBO - home-based other trips
Nhb - nonhome-based trips
PI-AX ¦ production internal, attraction external (to northern Ada County)
PX-AI ¦ production external, attraction internal (to northern Ada County)
153
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Table 9-6. Forecasts of Air Pollution Potential
Emission
Potential 8-
-Hour Carbon
Community Planning
Forecast
Monoxide Levels
(ppm)
Area (CPA # )
Basis
1977
1980
1987
2000
Southeast Area (10)
10 am-6 pm
10.2
12.4
11. 5
12.0
Daily Total
10.2
12.5
11. 4
11. 4
Northwest Subarea (21)
10 am-6 pm
10.8
12. 7
11.2
8.2
Daily Total
10.8
12.7
11.1
8.9
CBD Subarea (22)
10 am-6 pm
18.3
21.0
15.7
14.1
Daily Total
18.3
21.0
15.5
13.3
Warm Springs Subarea (23)
10 am-6 pm
12.0
15.2
11. 8
12.1
Daily Total
12.0
15.1
11.5
11.3
Foothills Subarea (24)
10 am-6 pm
4.3
5. 2
6.0
6.3
Daily Total
4.3
5.3
5.8
6.0
Northend Subarea (25)
10 am-6 pm
14.1
15.8
9.5
8.2
Daily Total
14.1
15.8
9.4
7.8
West Bench Area (30)
10 am-6 pm
18.9
22.1
15.3
13.3
Daily Total
18.9
22.2
15.0
12.7
Central Bench Area (40)
10 am-6 pm
21.0
23.1
17.2
11.8
Daily Total
21.0
23.1
16.8
11.4
Southwest Area (50)
10 am-6 pm
10.3
11. 7
9.5
9. 6
Daily Total
10.3
11. 8
9.2
8. 9
Meridian Area (60)
10 am-6 pm
7.5
8.4
4.6
4.7
Daily Total
7.5
8.5
4.5
4.6
Eagle Area (70)
10 am-6 pm
5.0
5. 7
5.5
4.9
Daily Total
5.0
5.7
5.4
4.7
Kuna Area (80)
10 am-6 pm
1.4
1.7
1.4
1.4
Daily Total
1.4
1.7
1.4
1.4
Rural Ada County Area (90)
10 am-6 pm
2.9
3.3
2.3
1.8
Daily Total
2.9
3.3
2.2
1.7
NOTES AND SOURCES:
Forecasts prepared using simple proportionality ("rollback") proce-
dures, with "background" CO increment proportional to change in total
CPA emissions and "corridor" CO increment proportional to change in
highway plus nonresidential parking emissions for CPA. Each CPA
treated separately (no pollutant transport between CPAs).
1977 used as a uniform base year, since that year showed the highest
ratios of observed CO levels to estimated emissions.
"Background" and base year ambient CO values for each CPA shown in
Table 9-7. Emission estimates and forecasts shown in Table 9-2.
ppm = parts per million, by volume.
154
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increment related to highway traffic and nonresidential
parking emissions. Table 9-6 makes it clear that CO prob-
lems can be expected to persist at least to the year 2000
in several portions of the Boise metropolitan area. The
effects of existing vehicle emission control requirements
are accounted for in the emission forecasts used for this
analysis.
Table 9-7 summarizes the assumptions used in this
analysis regarding 1977 background CO increments and overall
8-hour CO levels. Background CO values for the CBD area
were selected after reviewing the hourly CO data for the
downtown monitoring station. Background CO values for other
planning areas were selected on the basis of other monitoring
data and the emission source density index values for 1977.
Base year ambient CO values for each planning area were developed
separately for valley and bench areas. Data from the downtown
monitoring station were used for valley areas. The second-
highest 8-hour CO episode for 1977 (18.3 ppm) was assigned
to the CBD area. Base year CO values for other planning
areas were extrapolated from this on the basis of emission
source density index values. A similar procedure was used
for the bench areas. The second highest 8-hour CO event
reported from the Idaho Air Quality Bureau special CO study
(21.0 ppm) was assigned to the central bench planning area.
Emission source density index values were used to extrapolate
base year CO values for other planning areas.
The Southeast area (CPA 10) deserves some special dis-
cussion. The Idaho Air Quality Bureau special study reported
an 8-hour CO value of 17.7 ppm from a site along Broadway
Avenue. This is substantially higher than the 10.2 ppm CO
value assigned to this planning area in Table 9-8. The 10.2 ppm
value seems quite reasonable for most of the Southeast area.
Interpretation of the analyses presented in this chapter
should recognize that the portion of the Southeast area near
Broadway Avenue may have a more serious air quality problem
than indicated. Except for this one situation, the base
year CO values assigned in Table 9-7 are in agreement with
all available ambient monitoring data.
Effects of Altered Population Distributions
The analyses presented above are based on the population
distributions incorporated into the Boise area traffic model
and the 1978 Demographic and Employment Distribution report
(APa 1978). Recent wastewater management planning has been
based on lower population growth in the Southwest area and
higher growth in the Eagle area (see Chapter 5). The air
quality implications of this altered population distribution
have been evaluated using trip origin-destination data from
the Boise area traffic model.
155
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Table 9-7. Base Year (1977) Air Quality Values
Used for Rollback Analyses
Community Planning
Area (CPA #)
Background
CO (ppm)
Total Ambient
CO (ppm)
Emission Source
Density Index
Southeast Area (10)
1.0
10. 2
156.93
Northwest Subarea (21)
1.0
10. 8
166.65
CBD Subarea (22)
2.0
18.3
281.58
Warms Springs Subarea (23)
1.5
12.0
184.72
Foothills Subarea (24)
0.5
4.3
65.62
Northend Subarea (25)
2.0
14.1
216.40
West Bench Area (30)
1.5
18.9
189.63
Central Bench Area (40)
2.0
21.0
210.40
Southwest Area (50)
1.0
10.3
103.29
Meridian Area (60)
0.5
7.5
75. 44
Eagle Area (70)
0.5
5.0
76. 83
Kuna Area (80)
0.1
1.4
14. 39
Rural Ada County Area (90)
0.1
2.9
29. 47
NOTES AND SOURCES:
10 am-6 pm Emission Source Density Index (ESDI) values from Table 9-3.
Total ambient CO value for CPA 22 is second high 8-hour average for
1977 as reported by the Ninth Street monitoring station.
Total ambient CO value for CPA 40 is the second high 8-hour average
reported by the Idaho Air Quality Bureau special study in 1977-1978
(Idaho Air Quality Bureau 1978).
Ambient CO values for CPAs 10, 21, 23, 24, 25 and 70 calculated from
value for CPA 22, based on relative ESDI values.
Ambient CO values for CPAs 30, 50, 60, 80, and 90 calculated from
value for CPA 40, based on relative ESDI values.
Background CO values assigned on a judgmental basis following inspec-
tion of hourly CO values at the Ninth Street monitoring station and
comparison of ESDI values by CPA.
156
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Traffic model output was obtained summarizing the des-
tination patterns for all trips originating in each community
planning area. The trip patterns for the Southwest and Eagle
areas were then adjusted, assuming that adjusted trip numbers
would be proportional to the change in planning area popu-
lation. Results for 1987 show a 6.3 percent reduction
(3,937 trips) for the Southwest area and a 27.1 percent
increase (4,114 trips) for the Eagle area. The net change
in travel patterns is minimal for most planning areas. Total
trip arrivals (trip destinations) increase by 9.8 percent
for the Eagle area, 0.75 percent for the Northwest area,
and 0.35 percent for rural Ada County. Trip arrivals de-
crease by 1.4 percent for the Southwest area, 0.4 2 percent
for the Southeast area, 0.40 percent for the Central Bench,
and 0.17 percent for the Kuna area. All other community
planning areas show virtually no change in 1987 trip patterns.
None of these changes are likely to produce significant air
quality effects.
Results for the year 2000 are generally similar. Trips
originating in the Southwest area decrease by 14.5 percent
(14,917 trips) while trips originating in the Eagle area
increase by 29.6 percent (8,808 trips). Trip arrivals in-
crease by 11.2 percent for the Eagle area and by 0.73 percent
for the Northwest area. All other community planning areas
show a net reduction in trip arrivals (3.9 percent for the
Southwest area, 1.2 percent for the Central Bench, 1.1 percent
for the Southeast area, etc.).
Required Emission Reductions
The procedures used to develop Table 9-6 have also been
used to estimate the extent of emission reduction which
would be necessary to predict attainment of the federal
/mhour co standard in each of the four analysis years
^"¦able 9-8) . To meet the 1987 deadline established by
the Clean Air Act, projected 1987 emissions must be reduced
~y as much as 53 percent in some community planning areas.
The greatest emission reduction requirements for the 1987
Period apply to the Central Bench, CBD, and West Bench
community planning areas. The extent of emission reduction
requirements for 1987 and 2000 are shown in Figures 9-14
an<* 9-15.
Emission reduction requirements have been estimated
®eParately for each community planning area because of the
Patially limited nature of CO problems (relatively close
major roadways and parking areas). Measures to achieve
squired emission reductions, however, will not always be
° restricted in geographic scope. The traffic producing
157
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Table 9-8. Reductions From Projected CPA Emissions Required
To Indicate Attainment of 8-Hour CO Standard
Community
Planning
Area (CPA#)
Emission
Forecast
Basis
Required Percent
From Projected
: Reduction
Emissions
1977
1980
1987
2000
Southeast Area (10)
10 am-6 pm
Daily Total
13.04
13.04
30.64
30.82
24.55
23.70
28.53
24.57
Northwest Subarea (21)
10 am-6 pm
Daily Total
18.37
18.37
32.33
32.47
21.67
21.17
0.0
0.0
CBD Subarea (22)
10 am-6 pm
Daily Total
57.06
57.06
64.50
64.19
47.92
47.47
40.57
36. 83
Warm Springs Subarea (23)
10 am-6 pm
Daily Total
28.57
28.57
46.30
46.11
27.12
25.03
29. 59
23.74
Foothills Subarea (24)
10 am-6 pm
Daily Total
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Northend Subarea (25)
10 am-6 pm
Daily Total
42.15
42.15
49.90
49.75
6.04
5.47
0.0
0.0
West Bench Area (30)
10 am-6 pm
Daily Total
56.90
56.90
64.45
64.43
44.85
43.92
35.42
32.36
Central Bench Area (40)
10 am-6 pm
Daily Total
63.16
63.16
67.44
67.36
52.89
51.78
26. 83
23.77
Southwest Area (50)
10 am-6 pm
Daily Total
13.98
13.98
25. 93
25.95
5.38
2.61
6.71
0.0
Meridian Area (60)
10 am-6 pm
Daily Total
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Eagle Area (70)
10 am-6 pm
Daily Total
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
-------
Table 9-8 (cont'd.)
Community
Planning
Emission
Forecast
Required Percent Reduction
From Projected Emissions
Area (CPA#)
Basis
1977
1980
1987
2000
Kuna Area (80)
10 am-6 pm
0.0
0.0
0.0
0.0
Daily Total
0.0
0.0
0.0
0.0
Rural Ada County (90)
10 am-6 pm
0.0
0.0
0.0
0.0
Daily Total
0.0
0.0
0.0
0.0
Notes and Sources:
Based on proportionality (rollback) procedures discussed in text.
Supporting emission forecasts presented in Table 9-2.
-------
CTl
o
FIGURE 9-14. EMISSION REDUCTIONS
NEEDED TO ACHIEVE THE 1-HOUR
CO STANDARD IN 1917
LEGiND-
~ NONE
5-10 •/.
20-30V.
40-50V.
50+ V.
I
=WEST
BENCHK30
-------
FIGURE 9-14. EMISSION REDUCTIONS
NEEDED TO ACHIEYE THE 8-HOUR
CO STANDARD IN 1917
-LEGEND
~ NONE
5-10 V
20-J0*/.
40 -50 V.
50 + V.
BENCH=( 30)
\
OUTHWEST
-------
FIGURE 9-15. EMISSION REDUCTIONS
NEEDED TO ACHIEVE THE 1-HOUR
CO STANDARD IN 2000
-LEGEND-
~ NOME
AD s-io%
_ 20-J0V.
30 - 40*/.
40 + */.
i
tHI£Jfr(30)
-WiST
iOVTNWE
-------
CO problems in a local area will include vehicles originating
from all areas of Ada County as well as from outside the
county. Air quality management actions which focus on altering
vehicle travel patterns or vehicle operating characteristics
must necessarily apply to broad geographic areas. Those measures
focusing on local traffic flow improvements can be much more
localized in application.
The analyses presented above have not included the
effects of any vehicle inspection and maintenance program
for Ada County. If such a program were implemented, pro-
jected vehicle emissions would be reduced by about 20-25
percent. This level of emission reduction would still be
insufficient to provide for attainment of the 8-hour CO
standard in the Central Bench, CBD, West Bench, and Warm
Springs areas.
The APA is currently reviewing a number of air quality
measures which could be implemented to help achieve air
quality standards throughout Ada County. Measures currently
under consideration include:
o Implementation of a countywide vehicle inspection
and maintenance program, with special consideration
given to "cold start" emissions.
o Improved public transit (short-term and long-term
programs).
o Carpool/vanpool programs.
o Park and ride facilities.
o Traffic flow improvements through signalization
programs, intersection design changes, added road
lanes; many specific roadway and intersection
improvements are already accounted for in the
emission forecasts (see Appendix A).
o Exclusive bus and carpool lanes.
o Parking management programs (controls on the loca-
tion and duration of on- and off-street parking?
parking costs; supporting park and ride programs;
facility design and operation; etc.).
o Controls on extended vehicle idling at drive-in
facilities.
o Pedestrian malls.
162
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o Improved bicycle facilities.
o Employer actions to support transit, carpool/van-
pool programs, bicycle usage, flexible work
schedules, etc.
o Planning programs to assist in implementing measures
on an individual development project basis.
State Implementation Plan Consistency
Expanded wastewater treatment plant capacity for the
City of Boise and the ESD will accommodate additional urban
development. As mentioned previously, the federal Clean
Air Act requires that federal funding programs not be.used
to support projects which are inconsistent with air quality
management programs identified in State Implementation Plans.
(SIP). The SIP provides the framework for achieving and
maintaining federal air quality standards.
SIP revisions for Ada County were submitted to EPA in
¦January and July 1980. In October 1980 EPA approved three
aspects of the revised SIP:
o The 1979 transportation control plan portion of the
carbon monoxide attainment plan,
o A variance from state indirect source review require-
ments for the Boise Redevelopment Agency's City
Center Project.
o An extension of the CO attainment deadline from
December 31/ 1982 to December 31» 1987.
EPA also required that an additional SIP revision for
Ada County be submitted by July 1,. 1981. This SIP revision
is to provide commitments to, and a schedule for establishing,
an effective vehicle inspection and maintenance program.
In addition, the normal updating of the SIP (in 1982) must
include revised emission inventories and forecasts, revised
analyses of required emission reductions, and a demonstration
that "reasonable further progress" is being made toward achieving
tne federal CO standards. The revised emission inventories
and forecasts must incorporate anticipated highway and redevelop-
ment projects.
The emission inventory and forecasting procedures described
in Appendix A have been developed to meet the types of require-
ments noted above. The initial application of these procedures
has been discussed previously in this chapter. These emission
forecasts were prepared using the same population forecasts
Vfiich served as a basis for the Boise wastewater treatment
facility plan.
163
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The facility plan for the ESD has been based on a popu-
lation forecast which is about 30 percent greater than the
forecast incorporated into the emission projections. The
analysis presented elsewhere in this chapter, however, indi-
cates that such additional development in the Ea^jle area
would probably not lead to new or aggravated CO problems
in northern Ada County.
164
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Chapter 10
Groundwater Resources
-------
Chapter 10
GROUNDWATER RESOURCES
Geology
A brief discussion on geology and groundwater hydrology
is presented in this section. More detailed information
on these topics is included in groundwater and nonpoint
source waste loading reports (H. Esmaili & Associates 1980)
available in the EPA office in Boise.
Regional Geology
The regional geology of the Boise Valley is depicted in
Figure 10-1A which shows a generalized geologic cross section of
the western Snake River Plain. The western Snake River Plain
is underlain by a wide, structural trough in the granitic
Idaho batholith. This basin contains a section of upper
Cenozoic strata several thousand feet thick, composed pri-
marily of sediment and volcanics of the Idaho Group. The
stratigraphy of the Idaho Group has been classified by Malde
and Powers (1962). Overlying the eroded surface of the Idaho
Group is a relatively recent and thin sequence of basalt and
sediments into which the Boise Valley has cut. A generalized
section of the shallow geology beneath the Boise Valley is
shown in Figure 10-1B.
Geology of Study Area
Figure 10-2 is a map of the study area geology as shown by
Dion. Following is a brief description of the geologic units
exposed in the study area.
The Idaho batholith outcrops at the upper elevations of
the Northern Highland and extensively in the Eastern Upland.
The granitic batholith is generally regarded as being essen-
tially impermeable, although considerable volumes of water
are contained locally and discontinuously in fractures and
weathered zones. The fault-bounded batholith plunges deeply
beneath the Boise Valley to the southwest, forming the lower
limit of the groundwater system.
The unit of the Idaho Group which underlies the Boise Valley
is the Glenns Ferry Formation of late Pliocene and early Pleisto-
cene age. It has a thickness of about 2,000 feet beneath the
Boise Valley, outcrops extensively along the Boise Front, and
underlies much of the valley at relatively shallow depths.
Its stratigraphic subunits range in texture from clay to fine
m^61, include some volcanic ash and lava flows, and are of
highly variable thickness and extent. Bedding of the Glenns
165
-------
GENERAL
IZ
FIGURE 10-1
ED GEOLOGIC CROSS SECTIONS
OF BOISE VALLEY
6000'
UNDIFERERENTIATED
2000'
' NE
6000'
-4000'
2000'
4000'
0 10 20
1 1 >
Approximate Horizontal Scats
Vertical Scat* Exaggerated Approximately 15*
OS ( A)
(AFTER MALDE AND POWERS, 1962 )
Esmoli 1960
Tenni le Tcrroce
E ightmil• Terroct
kv>
Gowen Terrace
Whittle/ Terrace o ®°'
\ Brood»oy Terroce
2800'
0 1 2 3 4 5 6 MILES
1 l t 1 1 1 1
Datum i t Mean S«a L«v«l
N
3200'
3000'
3000'
2600'
2600'
{
(B)
(AFTER NACE Etol , 1957)
— LEGEND— F?| Ootfl -early terrace gravel - chiefly coarse gravel
~ ^ W/SOME SAND
Qol-ALLUVIUM-CLAY, SILT, SAND & GRAVEL
M Ota - GLENNS FERRY FORMATION
W\ Oft^-LATE TERRACE GRAVEL-CHIEFLY MEDIUM-GRAINED TO COARSE GRAVEL W/SOME SAND, SILT C CLAY
—. Klui- GRANITE OF IDAHO BATHOLITH
Qtb- SNAKE RVVEB BASALT - TO BLACK VESICULAR BASALT 1—1
-------
-QUATERNARY
Pt'J
V// A
Tounger lerroce grower
STAR
Eos'*
Basalt of the Snake River Group
Qotg
Older terrace gravel
Otg
ARDEN CITY
MERIDIAN
UPM'
and
Lo*er
Crttoctout
.
Gienns Ferry Formotion
of the Idaho Group
Ter
Basalt of the Columoia River Sroup
Ki
Idaho Batholith
Contact
Appro* inately located
Dashed where approiimately located
Although numerous faults occur in
the Boise-Nampo area , especially
in the Boise front, only those
referred to in this report are shown.
Line of hydrologic section
FIGURE 10-2. GENERALIZED GEOLOGIC MAP OF
THE BOISE - NAMPA AREA
-------
Ferry Formation is inclined to the west, southwest, and south
at angles of up to five degrees in the Boise Valley region.
The formation is relatively coarser near the Idaho batholith
along the Boise Front; where exposed, it is an important ground-
water recharge area. Permeable sand and gravel beds in the
saturated Glenns Ferry Formation beneath the Boise Valley act
as an important deep, regional aquifer which is semi-confined
by the interbedded clay.
Unconformably overlying the Glenns Ferry Formation are
the deposits of terrace gravels presently exposed at the sur-
face (Figure 10-1B). Where saturated, these gravels form what is
generally referred to as the shallow aquifer of the Boise
Valley. Dion subdivided the terrace gravel deposits into
older and younger units. The older unit is described as "a
thick sheet of unconsolidated silt, sand, and well-sorted
gravel of Pleistocene age." This unit is actually a grouping
of the deposits forming the valley's upper terraces, namely
Tenmile Bench and Meridian, Gowen, and Sunrise terraces.
Deposition of these gravels appears to have occurred by streams
flowing to the southwest. The older terrace gravels range in
thickness from over 100 feet on Tenmile Bench to less than
80 feet on Meridian Terrace and generally less than 50 feet
on Gowen and Sunrise terraces.
Pleistocene to Holocene-age basalt flows of the Snake River
Group are interbedded within the older terrace gravels as well
as occurring directly over the Glenns Ferry Formation. The
basalt flow exposed on Eightmile Terrace is as much as 100
feet thick. It overlies approximately 40 feet of the older
terrace gravel. Basalt is exposed most extensively in the
study area south of Tenmile Bench and Meridian Terrace. Maxi-
mum thickness of basalt in these areas is about 150 feet.
Where saturated, the basalt has variable aquifer character-
istics. Snake River basalt is exposed over nearly the entire
Mountain Home Plateau.
Underlying the surface of Whitney and Star terraces are
the younger terrace gravels of Pleistocene and Holocene age.
These deposits of unconsolidated clay, silt, sand, and gravel,
are generally finer grained than the older terrace gravels,
and appear to have been deposited by streams flowing to the
northwest. This unit forms a thin veneer over basalt of the
Snake River Group in a large area south of Meridian Terrace.
The younger terrace gravels directly overlie the Glenns Ferry
Formation on Whitney and Star terraces where they are up to
50 feet thick.
Broadway Terrace and the tributaries of the Boise River
are underlain by unconsolidated Holocene alluvium, the young-
est geologic unit in the study area. The alluvium is composed
of silt, sand, and coarse, well-sorted gravel; these deposits
168
-------
directly overlie the Glenns Ferry Formation, and have a maximum
thickness of 50 feet. Extensive caliche development has occurred
in the alluvium and both of the terrace gravel units, as much as
10 feet thick in some areas.
Groundwater Hydrology
Thp Boise valley has a unique and plentiful groundwater
resource due to the large Potential storage capacity of^the
recent sediments, the annual availability 01 * b ^
surface water from the Eastern Up , , tion system and
this water lor recharge £
the occurrence ox 2, uuu ieet uj.
ation at depth.
Boise Valley Aquifers
^ j- Kot-o rifscsrribed the Boise Valley as gen-
Previous studies have deep and shallow. The
erally having two groundwater systems a P he Glenns
deep groundwater system occurs comp f the gnake
Ferry Formation. The terrace gavels,basalts of the
River Group, Holocene alluvium, and upper portions oi
Glenns Ferry Formation comprise th
j. j onuifpr within the Glenns Ferry
The existence of a deep aq fro_ +v,e shallow, water-
Formation that is relatively separ difference in water
table aquifer is made evident ^ the difterenc^inja^^^
levels in wells perforated at vary g P n observed
in the relatively deep wells of the Bo se vauey
to be both above and below the leve sediments and basalt
table. The saturated thickness ol recent laments usu
in the study area range from as little as
not more than 50 feet.
The boundary between the ^^^poorl^defined one.
the Glenns Ferry Formation is a ^adual^ occurrence of inter-
Nevertheless, the cumulative . Glenns Ferry Forma-
bedded fine-grained materials within theGlenns re^y
tion is a significant reduction ^ . p within the Glenns
ductivity. In other words, gr°un?w^e^n^ILiiy with the
Ferry Formation although ^P£y®^harged and discharged in
shallower groundwater, x%keing r«g face groundwater,
quite a different manner from the near
Wells with static water levels ^J^^^^aquifer^re^
ent from those tapping the s^11^'Jlcess'of 300 feet, although
ordinarily perforated at dept^® * e not uncommon. Artesian
similar wells with shallower depths are Broadway, Star
or free-flowing wells are generally l°=a"l?nthe?e are free-
and Meridian Terraces. Along the Boise River there are ire
flowing wells as shallow as 100 feet.
169
-------
Deep wells exhibiting water levels below the shallow ground-
water table occur primarily in the area of the upper terraces
where seasonal, irrigation-related recharge has raised the
water table to exceptionally high levels.
The saturated shallow aquifer of the Boise Valley formed
artificially as the result of agricultural development. Because
irrigation with Boise River water is not conducted south
and east of the study area, the level of the shallow ground-
water body rapidly drops to that of the deep groundwater
system. Within the study area, the shallow aquifer contains
a principal shallow groundwater system as well as several
bodies of perched groundwater.
The shallow groundwater system is made up of five aquifer
units: the older terrace gravels, basalts of the Snake River
Group, younger terrace gravels, Holocene alluvium, and upper
portions of the Glenns Ferry Formation. With the exception of
the Glenns Ferry Formation, the components of the shallow
groundwater system act as a single hydrologic unit because
groundwater flow in this system is not significantly altered
at formation interfaces. However, each aquifer unit has a
differing range of hydraulic characteristics.
Groundwater Occurrence and Flow
The configuration of the groundwater surface in the Boise
Valley is unusually complex, reflecting the high rate of re-
charge into the shallow aquifer by diverted Boise River ir-
rigation water. The primary factors affecting the flow and
occurrence of groundwater in the Boise-Ada County Study Area
include: (1) the exceptionally high volume of recharge re-
sulting from leakage along the New York Canal, (2) the near
uniform distribution of groundwater recharge elsewhere in the
study area due to irrigation and conveyance losses, and (3) the
irregular surface of the relatively less permeable Glenns Ferry
Formation buried beneath the Boise Valley. Additionally,
groundwater is significantly influenced by bodies of buried
basalt and the system of artificial drains on the lower terraces.
The configuration of the groundwater-elevation contours
in the southwest Boise area is dominated by the influence of
recharge from the New York Canal. The highest groundwater
elevation in the study area, 2,750 feet above sea level, occurs
beneath the New York Canal on Eightmile Terrace. The New York
Canal and other irrigation-related sources of recharge to the
west combine to produce a broad, high mound of shallow ground-
water throughout the Boise Valley. East of the New York Canal,
recharging groundwater descends quickly to the level of the deep
groundwater system.
170
-------
Within the Southwest Boise study area, high shallow
groundwater levels occur primarily beneath Broadway, Star
Whitnev Gowen Sunrise, and Eightmile terraces. This area
is heavily irrigated and criss-crossed with leaky irrigation
canals and laterals. The resulting recharge saturates a
significant depth of the terrace gravels and alluvium The
unusually intricate groundwater-level contours on '
and Broadway terraces indicate the intersection o t
seasonal-hiEh water table with the network of drainage canals
SS l"erSif ?o the extent that these drains are e"ective,
they serve to flatten the peak of the seasonal rise
shallow, near-surface water table.
The surface of the shallow groundwater
beneath Meridian Terrace at elevations similar to *$fhgIesSect
water of the lower terraces but at greater
to the land surface. Beneath and south . declines
south of Meridian Terrace, the groundwater surface declines
to the level of the deep groundwater system.
The manner and extent to which .bodies* ¦
water in the study area become c°ntinuoJ} zones of
deeper groundwater system is unclear. Ho , broadly
perched groundwater appear to roughly groundwater
spaced water-level contours of the P«n"Pal jrou,Qdwate:r
system In both the upper and ^.SE^rSSS^iStS
gests an eventual merging 01 tne perci *=,
the main system.
Groundwater flow. Groundwater
for the shallow and deep aquifers. The P ^ Bolse Front,
system flows from its source of recharg g th nd
Boise River, and Boise Valley in general to the south and
southwest where it discharges to the Snake Kiver.
. The flow of the Boise Valley shallow groundwater^system^
originates esserltially along the nigh r vnrk Canal
with the New York Canal. To the east of the New York Canal,
the shallow groundwater descends rapidly , ,, eround-
deep groundwater system. West of the £an ' din~ to tfte
water flow is to the west and nort1^™a?ion
gradient of the eroded surface of the tprrace cravels.
as well as the direction of deposition of the terrace gravels.
Groundwater Quality
The quality of Boise f f XS'SsU™
SunTiJ of°highest°quality, shallow and ae»-
cultural drain waters have the poorest quality, and deep Erou
water is of relatively intermediate quality. The intermixing
of surface wlter and shallow and deep groundwater influences
their relative qualities.
171
-------
The quality of the deep groundwater in the study area is
indicated in Table 10-1 which contains analyses of samples
obtained from 17 deep wells of the Boise Water Corporation.
When compared to the quality of the Boise River near Boise,
the deep well samples are higher in sodium (15-72 mg/1) and
dissolved solids (147 mg/1) content suggesting the impact of
recharge from irrigation return flows and wastewater disposal
operation. Nitrate concentrations (as NO3-N) range up to 10
mg/1.
Shallow groundwater in the Boise Valley is almost entirely
derived from recharge of Boise River water through irrigation
and conveyance networks. The waters immediately beneath irri-
gated agricultural lands have markedly different quality char-
acteristics than the applied water (see the analysis of the
Boise River water near Boise). Dissolved solids increase from
a range of 43 to 125 mg/1 measured in Boise River below Lucky
Peak Dam to a range of 100 to 1,240 mg/1 measured in shallow
wells. Significant increases occur in all constituents, most
notably nitrate (up to 88 mg/1 as NO3-N), sodium (up to 184 mg/1),
and chloride (up to 86 mg/1). Continual monitoring of these
shallow wells would be a prerequisite to establishing the extent
of impacts upon groundwater from irrigation, and to establishing
specific mitigation measures.
Agricultural drains exhibit water quality similar to
shallow groundwater, especially during the nonirrigation
season when no dilution occurs with irrigation return flows,
as indicated by the November analysis of Fivemile Creek drain
at Star Road (Table 10-1). Whereas the effect of agricultural
return flow is to dilute the mineral concentration of drain
water during the irrigation season, excess applied irrigation
water tends to increase mineral concentrations of shallow
groundwater due to increased leaching.
Dion (1972) investigated a possible deterioration of shal-
low groundwater quality due to land use change since the time
of the previous study by Nace, West, and Mower (1957). In-
creasingly widespread use of septic tank wastewater disposal
method was suspected to lead to a rise in nitrate concentra-
tions. However, no significant change in shallow groundwater
quality was identified. Sampling also did not reveal high
concentrations of fecal coliform bacteria in areas of septic
tank use nor a buildup of pesticides from agricultural prac-
t ices.
Other investigators have continued to evaluate the possible
changes in shallow groundwater quality in the Boise Valley, again
particularly with emphasis on nitrate concentrations. A study
by the Central District Health Department (1979) showed that a
172
-------
Table 10-1. Chemical Analyses of Deep and Shallow Groundwaters,
Boise River Water, and Agricultural Drainage Waters in Boise
Valley, Idaho (in mg/1 unless otherwise indicated)
Deep Groundwater
Shallow Groundwater
Ab
Bb
I!. S.
Bureau of Reclamation
Boise
Water Corporation a
Shorman Oaks
We stgate
OiPtiical
Constituents
Mean
Variance
Range
Mean
Range
Mean
Range
Mean
Ran
ge
Mean
Range
spec. Cond.
(UBihos/cm)
970
250
-5300
320
20
-950
678
255
901
748
100
-1240
Diss. Solids
245
98
147 -500
-
-
-
-
425
315
577
418
191
- 616
nh3-n
-
-
-
0.11
0
1.6
0.04
0
- 0.75
0.007
0
0.1
0.19
0
3.3
N02~N
-
-
-
0.03
0
0.78
0.003
0
- 0.11
0.007
0
0.07
0.01
1
0.36
no3-n
2.1
3.2
0.08- 10
11.2
0
60- 88
5.5
0
40- 32
3.2
0.04-
6.5
5.8
0
01- 24
Organic N
-
-
-
0.72
0
2.5
0. 50
0
- 1.8
0.27
0.04-
0.88
0.29
0
02- 2.6
Total P
0.09
0.07
0.02- 0.
22
0.41
0
.06- 1.7
0.41
0
10- 0.95
0.14
0.02-
1.1
0.71
0
14- 6.0
Ca
31
11
18 - 55
-
-
-
-
59.4
42
73
59
28
- 85
Mg
11
8.3
2.0 - 32
-
-
-
-
24
17
35
25
13
- 36
Na
34
17
15 - 72
-
-
-
-
61
7
117
70
4
- 184
K
-
-
-
-
-
-
-
2.0
1.2 -
2.7
3.6
2
0 - 5.1
CI
9.7
5.7
2.7 - 25
15
0
- 86
4.0
0
- 15
14
2.1 -
38
27
0
- 63
so4
28
22
3.2 - 87
-
-
-
-
59
41
73
59
28
- 85
r
0.56
0.16
0.39- 0
75
-
-
-
-
0.97
0.82-
1.1
0.68
0
44- 1.1
si°2
8.0
30
17 - 49
-
-
-
-
50
35
58
42
30
- 50
Tot. Hardness
121
60
57 -268
-
-
-
-
-
-
-
-
Tot. Alkalinity
284
95
198 -548
-
-
-
-
-
-
-
-
Total Coliforw
-
-
-
-
-
-
-
318
2 -10200
72
2
-1020
Fecal Coliform
-
-
-
-
-
-
-
34
0
3000
42
0
-6000
Fecal Strep
-
-
-
-
-
-
-
16
0
220
35
0
- 80O
HCO,h
co3h
-
-
-
-
-
-
-
333
273
395
175
25
- 331
-
-
-
-
-
~
0
0
0
0
0
0
-------
Table 10-1. Cont'd.
Chemical
Constituents
Shallow Groundwater
Boise
River and Agricultural Drains
Boise-Nampa Area**
DWRe
Boise R.
near
Boisef
Boise R.
at
Star
Road^
Tivemilc
Creek
at
Star Road^
Eaqle
drain
near
Eaglef
Purdaw
drain
near Ada
Canyon^1
Mosey
Creek
near Ada
Canyon9
Mean
Range
Mean
Variance
Range
Spec. Cond,
(urahos/cw)
596
104-1210
605
199
116 -86
93
326
624
330
460
540
Diss. Solids
-
-
-
-
-
60
219
448
222
-
-
-
-
-
-
-
-
-
-
-
0.07
0.08
MO ,-N
_
_
_
_
-
-
-
_
_
0.01
0
*
0.53-11
}0.13
}2 .7
ttOyfi
2.7
0- 13
3.1
2.2
-
-
3.0
3.2
Organic W
-
-
-
-
-
-
-
"
0.3R
0.36
Tot_al P
0.24
0- 1.8
-
-
-
0.07
-
0.41
-
o.?o
o
00
Ca
-
-
-
-
-
1?
-
56
-
-
_
-
-
-
-
-
1.5
-
18
-
-
Va
-
-
-
-
-
4.5
-
70
"
-
-
K
-
-
-
-
-
0.8
-
3.5
-
-
-
CI
16
0- 63
14
9.8
2.4-36
1.5
3.6
14
5.2
8.5
9.4
SO4
-
-
-
-
-
0
-
62
-
-
-
F
-
-
-
-
-
0.3
-
0.7
-
-
-
Sx02
-
-
-
-
-
13
-
41
-
-
-
Fecal Col i fori*
-
-
-
-
-
-
-
50
-
-
.
iico3h
-
-
-
-
-
52
-
322
-
-
-
0
11
-------
Footnotes for Table 10-1
a
Average analyses from 17 wells in study area drawing from
deep groundwater system. Range is for mean ananyses of each
well, (Boise Water Corporation, 1980).
^Area "A" north of I-faO south of Boise River and over Ada Canyon
County line. (9 wells). Area "B" along Mason creek feeder from
Hubbard Reservoir Northwest to Ada-Caynon County line.
(5 wells). Samples taken monthly 1973-1975 (Lewis et al.,
1978)--specially constructed shallow test wells.
CSamples taken 7/77 to 9/79 (U. S. Bureau Reclamation, 1979)
Sherman Oaks: 3N1E sec. 23: 5 wells
Westgate: 3N1E sec. 1: 8 wells
--specially constructed shallow test wells.
d
Samples taken 6, 7, 8/70 from nearly 200 wells in Boise-
Nampa area (Ada and Canyon counties) (Dion, 1972)
e
21 wells from Idaho Department of Water Resources "Boise
Valley Monitoring Newwork" in Ada County study area.
Sampled 4/78-9/79 (Leach, 1980).
^Boise River and drain. Analyses 11/71 (Thomas and Dion, 1972).
g
Purdam Drain sampled 1971-1975. Mason Creek sampled 1974-1975.
(Lewis et al., 1978).
has CaCO-j
175
-------
74 percent increase in nitrate concentrations had occurred since
the time of measurements made by l>ion , from an average of 2.02
mpr/1 NO3-N in June to August of 1970 to an average of 3.53 mg/1
during an undisclosed period in 1979. Preliminary results of
the Idaho Department of Water Resources' Boise Valley Monitoring
Network (Leach, 1980), however, show this increase to be well
within the range of annual fluctuations of nitrate concentra-
tions, commonly fluctuating 3 mg/1 and up to 10 mg/1 during the
year within a given well. Sampling by the U. S. Bureau of
Reclamation (1979) indicates annual fluctuations of nitrate
concentrations in wells to be commonly over 6 mg/1 and as much
as 17 mg/1. If the Idaho Department of Water Resources' data
of July 1979 is compared to Dion's data of July 1970, little
change is observed in any quality parameters (Table 10-1).
Nonpoint Source Waste Loadings of the Groundwater
Summary of Existing Nonpoint Source Discharges to Groundwater
in Ada County
Tables 10-2 and 10-3 summarize the estimated nonpoint source
loadings for Ada County and the Southwest Study Area, re-
spectively under existing land use conditions. On a county-
wide basis irrigated agriculture contributes a significant
portion of both salt (88 percent) and nitrogen (75 percent)
loadings to local groundwaters. The disposal of wastes from
feedlots and dairies in the county represents the second major
source of mineral contamination, responsible for the generation
of about 11 percent of the salt and 20 percent of the total
nitrogen discharged annually. On-site waste disposal practices
contribute relatively minor quantities of these constituents,
amounting to about 4.5 percent for nitrogen and 1 percent for
total salts.
In the Southwest Study Area irrigated agriculture is
again the major source of salt and nitrogen loadings to the
aquifer. In this case irrigation return flows contribute
84 percent of the salts and 58 percent of the total nitrogen
discharged from the three sources investigated in this study.
On-site waste disposal is responsible for approximately 11
percent of the salt load and 35 percent of the nitrogen load.
The two operating dairies generate the remaining 7 percent
of the nitrogen and 5 percent of the total salt emissions.
The figures cited in the summary tables are expressed
as total mass emissions of pollutants. As such, the values
do not reflect differences that may exist in either the con-
centration or spatial distribution of discharges. These
additional consideration^ may, however, have a substantial
effect upon interpretation of the results. For example, highly
concentrated wastes from a dairy or feedlot may severely impact
176
-------
Table 10-2. Summary of Estimated Nitrogen and
Total Salt Loadings to Groundwater
from Irrigated Croplands, Animal
Husbandry and On-site Waste
Disposal in Ada County, 1980
Waste Source
Nitrogen
tons/yr %
Salts
tons/yr
%
On-site waste disposal
122
4.5
608
1.1
Animal husbandry
547
20.1
6143
11.0
Irrigated cropland
2058
75.4
49334
87.9
Total
2727
100
56085
100
Table 10-3. Summary of Estimated Nitrogen and Salt Loadings
to Groundwater Resulting from Irrigated Agri-
culture, On-site Waste Disposal and Animal
Husbandry in the Southwest Study Area, 1980
Waste Source
Nitrogen
tons/yr %
On-site waste disposal
46.4
35.3
233
10.7
Animal husbandry
8.8
6.7
109
5.0
Irrigated cropland
76.4
58.0
1828
84.3
Total
131.6
100
2180
100
Salts
tons/yr %
177
-------
the quality of a downstream well,' while the emission of a far
greater total mass of pollutants from cropland may have no
measureable impact because of the low initial strength of these
return flows and their large areal dispersion. Interpretation
of the data presented in this report should, therefore, be
made with an awareness of local factors which may have a sig-
nificant bearing on the relationships between pollutant dis-
charge and groundwater quality.
Impact of On-Site Wastewater Disposal Systems on
Groundwater Resources
The Southwest Boise region is a major area of concentration
of septic tank leachfield systems in Ada County. This area is
expected to remain unsewered for the foreseeable future under
established land use plans. The major impact of septic tanks
on groundwater resources of the study area would be manifested
by high levels of nitrates and possibly total dissolved salts
and pathogenic bacteria and viruses in the shallow groundwater
bodies.
The presence of nitrate in groundwater is primarily a
result of the leaching of fertilizers from the unsaturated
soil and nitrification of organic nitrogen contributed by on-
site wastewater disposal systems and other sources. Nitrifi-
cation is an aerobic process dependent on optimal temperature
and pH conditions as well as the availability of sufficient
oxygen levels. Low concentrations of ammonia-nitrogen in shal-
low groundwater measured by the Bureau of Reclamation (1979)
(generally less than 1.0 mg/1) indicate that nitrification or
denitrification of effluent from septic tanks is occurring
primarily in the unsaturated zone. Nitrate production in the
Boise Valley is probably limited seasonally by the repeated shifts
between aerobic and anaerobic conditions due to the fluctuating
near-surface water table and by the cold winter-month soil
temperatures. The leaching of nitrate into Boise Valley ground-
water most likely occurs as the result of heavy rains, spring
snow melt and soil thaw, and the application of excess irriga-
tion water. Groundwater recharge from the infiltration of ex-
cess irrigation water not only results in the leaching of nitrate
but may also significantly dilute nitrate concentrations. Thus,
seasonal peaks in groundwater nitrate concentration can be
justified theoretically at several times throughout the year
depending on a variety of complex environmental conditions.
Mink, et al. (1975) found high levels of ammonia and coliform
bacteria in the immediate vicinity of septic tank leachfields
constructed in areas with exceptionally high water tables at
several study sites in the Boise Valley. The low values of
nitrate and nitrite concentrations were believed to be due to
the inhibition of the nitrification process by high water
table conditions.
178
-------
Nitrogen emissions in the Boise Valley are most likely
increasing as a result of septic tank wastewater disposal prac-
tices. However, annual recharge of conveyance losses and excess
applied irrigation water has the effect of diluting mineral con-
centrations to near-normal levels, particularly during the summer
and early fall months. Widespread dilution by rather uniformly
distributed excess applied irrigation water perhaps explains
the lack of well-defined high nitrate zones in the study area.
Nitrate levels may remain unchanged until the present practice
of applying an average of 3.00 acre-feet per acre per year of
excess-irrigation water of low nitrate concentration is sig-
nificantly altered. It is also probable that there exists a
trend of increasing peak-annual nitrate concentrations in
groundwater during the non-irrigation season which has gone
undetected due to infrequent sampling. An ongoing sampling
program undertaken by the Idaho Department of Water Resources
will provide the much-needed data in future years.
Groundwater Conditions and Land Use Change
Some of the previous investigations on groundwater con-
ditions in the Boise Valley were aimed at evaluating the
impact of land use changes on groundwater level and quality
characteristics. Land disposal of domestic and other waste-
waters has offset some of the losses in the historical sources
of recharge. The decline of irrigated acreage due to sub-
urbanization may have diminished the rate of recharge to
the shallow-groundwater body and caused a lowering in the
water table. Increasingly widespread use of septic tanks
as well as long-term effects of agriculture have been
expected to result in groundwater quality degradation.
No significant changes in groundwater quantity and quality
conditions were observed in the Boise-Nampa area between 1953
and 1970. The explanation given for a lack of change in shallow
groundwater levels were as follows: (1) the magnitude of change
in recharge and discharge were relatively small, (2) seasonal
and year-to-year fluctuations in water-supply conditions over-
shadowed any progressive changes in groundwater conditions
with time, and (3) small changes in the level of near-surface
water tables were moderated by the influence of artificial
drains.
Results of the present study tend to indicate the existence
of a correlation between the quality of shallow groundwater
body and the volume of recharge from irrigation water distri-
bution network and cropped land areas. It appears that recharge
from these sources helps to dilute the waste loadings derived
from agricultural, residential and commercial land use practices.
As additional agricultural lands are converted to nonagricultural
uses, the ^alance between nitrogen and salts loadings and the
volume of water recharged to the aquifers will be-adversely
affected.
179
-------
Even alter suburbanization changes, significant, volumes
of Boise River irrigation water are being recharged to the
groundwater by irrigation of landscaped areas. On the other
hand, the continued trend of lining the irrigation canals and
laterals wil 1 significantly reduce shallow groundwater recharge.
Reduced shallow groundwater recharge will undoubtedly result
in lower water tables and a shift in the shallow groundwater
divide, possibly to the west away from the New York Canal.
Lowering of the water table will place groundwater of rela-
tively poorer quality nearer to the zone in which the main
water supply wells are located. Additional long-term moni-
toring of groundwater levels and quality conditions must be
carried out to provide adequate data for evaluating the impact
of land use changes in the study area.
Mitigation Measures
Under land use Plan C, Rural Life Style, it is expected
that the Southwest Boise area will retain its rural charac-
teristics for the foreseeable future. Although some popula-
tion growth is expected to occur in this area over the next
20 years, it is improbable that the anticipated growth will
create a major change in groundwater quality and quantity
conditions, barring any significant unforeseen changes in
other land use practices or in the irrigation practices of
local farmers.
Based on the above discussion, no specific mitigation
measure is deemed necessary to alleviate the adverse impact
of septic tank discharge on groundwater quality in the study
area. Regular monitoring of shallow and deep groundwater
quality, preferably on a seasonal basis, should, however, be
carried out by an appropriate government agency to provide
needed data for future planning and decision-making purposes.
Also, adequate controls should be maintained on siting, design,
installation and maintenance of septic tank and leachfield
systems to assure the protection of public health and safety.
The adopted operation and maintenance; program and related
measures are described in Chapter 3.
Impacts of Sludge Disposal
on Groundwater Resources
Boise Sludge Disposal Site
Land at the Idaho State Penitentiary is considered to
be the preferred site for sludge disposal. Soils mapping
of the site was conducted by the SCS and soil suitability
ratings for sludge application were identified.
180
-------
The surveys showed that much of the area was underlain
by a hardpan layer, ranging from 13-34 inches below the surface.
The water table is located below the hardpan layer, at an
unknown depth. The SCS survey indicated a depth to ground-
water of 72 inches, while other SCS data indicated depths
to the seasonal high water,table ranging from 24-60 inches
(CH2M Hill 1980c). An irrigation well on the site is known
to draw water from a depth of 550 feet.
The presence of the hardpan layer between the surface
and the groundwater should prevent the movement of leachate
downward. Because it is unlikely that the hardpan layer
occurs uniformly throughout the area, leachate could travel
downward toward the water table wherever cracks or breaks
in the hardpan occur.
During the rainy season water may perch above the hard-
pan and move laterally downslope. Much of the sludge appli-
cation site is flat or has slopes of 3 percent or less.
The migration of heavy metal ions into the groundwater
should not occur so long as the soil and sludge pH is main-
tained above 6.5 (U. S. EPA 1977a).
Surface ponding of liquid sludge may increase mosquito
populations. Pathogens from the sludge may be transmitted
by insect or rodent vectors or by aerosols. Sludge has the
potential to cause odors in the area of application.
Sludge has the potential benefit of fertilizing crop
lands with a product otherwise buried in landfill or unavail-
able. This also has potential benefits of possible revenue
to the City of Boise through sale of sludge, and of reduced
costs to the farmer.
Mitigation Measures
The IDHW has prepared Guidelines for Land Application
of Municipal Sewage Sludge which include a number of features
designed to protect groundwater resources:
Site approval requires demonstration that the
proposed project will not result in violation of
water quality standards applicable to ground and
surface water (Idaho Department of Environmental
and Community Services, 1973). Factors that will
be considered in granting approval include:
- Proximity to water supply wells.
- Existing quality and use of groundwater.
- Geohydrological characteristics of the site; the
minimum groundwater depth should not be .less
than 4 feet.
181
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Monitoring wells should be installed as indicated
by a geohydrological study of the site. The wells
and surface streams in the areas should be analyzed
for nitrogen, heavy metals, organic and fecal
coliforms before sludge disposal at the site and
during the life of the project.
Mosquito population may be limited by reducing surface
ponding and by using mosquito control measures as necessary.
Pathogens in the sludge are not expected to be signifi-
cant, however opportunities for exposure to humans should
be reduced by limiting access such as by fencing and by "buffer
zones". The site is already on prison land and public access
reduced accordingly.
Spraying should be avoided on windy days in order to
eliminate drift of liquid or aerosols from the application
area.
Odors may be mitigated by "buffer zones" between the
treated area and human use areas. Additional measures such
as working the sludge into the soil may be required as
necessary.
Eagle Sewer District Disposal Site
Analysis of potential impacts of the ESD rapid infiltra-
tion project will require additional soils testing and a
study of vertical and lateral groundwater movements. The
lack of industrial discharges to the ESD system and the prob-
able requirement for underdrains at the infiltration site
suggest that there should be few significant impacts.
182
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Chapter 11
The Boise River Ecosystem
-------
Chapter 11
THE BOISE RIVER ECOSYSTEM
Introduction
The Boise River has many roles in Ada County. Once
a prolific producer of anadromous fish, the river's prin-
cipal functions are now irrigation water supply, recrea-
tional boating and floating, freshwater fisheries, drainage,
and reception and transport of treated sewage effluent from
urban areas in the Boise Valley. This chapter focuses on
the effects of the new and enlarged Boise and Eagle waste-
water treatment and disposal facilities on the hydrology,
water quality, and fisheries of the Boise River.
Summary of Impacts
The proposed wastewater facilities will cause or contri-
bute to the following impacts:
o 23 percent of the total nitrogen load in the river
o 47 percent of the total phosphorus load in the
river
o possible algal growth increases downstream
o higher peak flows and nonpoint pollutant loads from
urbanized areas
o short-term increases in sediment load from facilities
construction activities
o long-term degradation of fishery habitat
Boise and Eagle wastewater facilities will contribute
about 2 3 percent of the total nitrogen load and about 4 7
percent of the total phosphorus load to the Boise River in
the year 2000. Nutrient removal may be a future option to
decrease excessive algal growth levels in Snake River
reservoirs.
Urban growth using the expanded sewage facilities will
contribute to increased runoff rates including higher peak
flows during storms and increased nonpoint source pollutant
loads in the Boise River. These changes are expected to
lower the quality of habitat for trout and whitefish in the
Boise River. Implementation of a master drainage and nonpoint
source pollution reduction program could reduce these impacts.
183
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The construction of the sewage treatment and outfall
facilities may have temporary construction impacts on water
quality and fisheries. Special care needs to be taken to
protect and preserve riparian habitat in construction areas.
Existing Conditions
Hydrology
The Boise River flows westerly for about 200 miles from
its headwaters in the Sawtooth Mountains to its confluence
with the Snake River, draining a watershed area of 4,234
square miles (Figure 11-1).
Peak flows in the Boise River occur during the spring
snowmelt period between April and June, although high flows
of short duration also occur due to summer thundershowers.
Minimum flows occur during winter months. During the winter
when there is no demand for irrigation water, runoff is
generally stored in reservoirs.
River Regulation. Boise River flow is regulated by
three on-stream reservoirs (Lucky Peak, Arrowrock, and
Anderson Ranch) and one off-stream reservoir (Lake Lowell).
Various direct diversions along the Boise River also regulate
the flow. The four reservoirs and their storage characteristics
are shown in Table 11-1.
Lucky Peak was the most recent dam to be constructed.
It is operated in conjunction with Arrowrock and Anderson
Ranch to maximize irrigation, flood control, power production
and recreation benefits. Storage capacity in Lucky Peak
has been allocated (Table 11-2) to irrigation and to the
Idaho Department of Fish and Game for minimum stream flow
maintenance during the nonirrigation season. Unallocated
storage in Lucky Peak (Table 11-2) was set aside for future
irrigation needs. Demand for this capacity from newly irri-
gated lands, however, has not occurred. Irrigation districts
have the right to purchase some of the capacity on a year-
to-year basis if their supply falls short.
A cooperative study of the effects of reservoir opera-
tions on the Boise River system is currently being conducted
by the Idaho Department of Water Resources, the U. S. Army
Corps of Engineers, and the U. S. Bureau of Reclamation (USBR).
A second study, which will assess the possible fate of the
unallocated capacity in Lucky Peak Reservoir, is being con-
ducted by USBR (CH2M Hill 1980b). The results of these studies
may have significant bearing on the amount of Boise River
flow available to dilute Boise sewage effluent. The USBR
study is not expected to be complete until 1982.
184
-------
r
CO
U1
PAYETTE .
CAMAS
CANYDNX
Rtmrvotr
DIVE*S>
A
V*
! u
MILES
UTAH
SOURCE: IDAHO WATER RESOURCES BOARD, 1974
LOCATION MAP
FIGURE 11-1. BOISE RIVER WATERSHED
-------
Table 11-1- Principal Reservoirs
in the Boise River Basin
Reservoir
Capacity (AF)1
Gross Active
Year Constructed
Agency
Water Source
Anderson
Arrowrock
Lucky Peak
Lake Lowell
493,200
286,600
307,040
190,100
423,200
286,600
266,200*
169,000
1945-USBR 2
1915; raised 5 ft.
in 1937- USBR
1954-USCE
1908-USBR
South Fork,
Boise River
Boise River
Boise River
New York Canal
(Boise River)
NOTES:
XAF: acre-feet.
2USBR: U. S. Bureau of Reclamation.
3USCE: U. S. Army Corps of Engineers.
^278,200 AF available (top 4 feet of storage not used).
SOURCE CH2M Hill 1980b.
-------
Table 11-2. Lucky Peak Reservoir Storage Allocation
Use
Total Capacity
(AF)
Usable Capacity
(AF)
Irrigation
111,750
107,200
Idaho Department of
Fish and Game
50,000
47,800
Unallocated
116,250
111,200
TOTAL
278,000
266,200
SOURCE: CH2M Hill 1980b.
187
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Flooding. Flooding has historically occurred on the
Boise River during spring runoff and thunderstorms. The
frequency of flooding, however, has decreased as the degree
of river regulation has increased. The highest recorded
flood flow occurred in 1896 when 35,500 cubic feet per second
(cfs) was measured at Boise. The largest rainfall-related
flood was recorded in 1909 at 15,200 cfs.
The Boise River is currently regulated so as not to
exceed a flow of 6,500 cfs in Boise. Flooding occurs within
the Boise Metropolitan area at flows exceeding channel capa-
city of 6,500 cfs. Major flooding generally occurs at flows
over 10,000 cfs.
Flood control operations at the reservoirs begin in
January and usually continue through May, when storage
begins to fill the empty flood control capacity.
Irrigation. The greatest use of surface water in the
Boise River watershed is for irrigation. Irrigation in the
Boise Valley dates from the late 1800s. Currently, there
are 31 major irrigation diversions from the Boise River.
These canals have a total capacity of 6,700 cfs (Idaho Water
Resources Board [IWRB] 1974). A transbasin diversion from
the South Fork of the Boise River occurs at Little Camas
Reservoir. This diversion, averaging 10,500 acre-feet per
year, is used for irrigation of lands in the Mountain Home
Irrigation District, outside of the Boise River watershed.
Flow Conditions. The flows of the Boise River vary
significantly between Lucky Peak Dam and the mouth of the
river. Hydrographs representing the flow in the Boise River
at various locations are shown in Figure 11-2. During the
irrigation season significant flow reductions occur between
Lucky Peak Dam and Capitol Street Bridge. Between Capitol
Street and Star, the flow is reduced even more due to addi-
tional diversions. At Parma, agricultural return flows add
to the river and increase the flow. Figure 11-3 is a sche-
matic of the major diversions and drains.
Calculated natural annual flow (with no dams or diversions)
and impaired flow (with existing dams and diversions) below
Lucky Peak Reservoir, and l-in-2 year and l-in-10 year flows
at Boise are shown in Figure 11-4. As a result of regulation
and diversion, flows are much lower than natural, especially
during the nonirrigation season (November-March). The 1-
in-10 year low flow at Boise during the nonirrigation season
is lower than the l-in-2 year flow by about a factor of 10,
while the difference during the irrigation season is much
less. The greater difference during the nonirrigation season
is partially due to periodic maintenance shutdowns of the
Lucky Peak outlet structure.
188
-------
f
CO
VP
4600
4200
3800
3400
3000
2600
2200
1800
1400
1000
600
200
AU6 SEP OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG
1972 1973
SOURC: AC06 1975 & IDWR DATA
FIGURE 11-2. AVERAGE MONTHLY FLOW AT FOUR LOCATIONS ON BOISE RIVER
(AUGUST 1972 THROUGH JULY 1973)
o
o
tli
UI
ui
ao
=3
O
-- BELOW LUCKY PEAK
— CAPITOL (BOISE)
STAR
PARMA
-------
Penitentiary Canal-*---
58.3^=
63.6
Lucky Peak Reservoir
58.3
Boise City Canal
^Boise River near Boise
—rf°ISE ^roject ^in ^ ^0RK^ ^ANAL
Barber Dam
—*-Ridenbaugh Canal
^Burb, ft eves #1 8 # 2,
1-3
!.0
51.0
Farmers Union & Boise Valley Canals-*--
Boise Sewer
fossi Mill Canals
< Boise River at Boise
—Settlers Canal
-» Drainage District ft z
—Davis Ditch
¦Th
50.4
4G.4
Fhurman Mill Canal
Uew Dry Creek £ New Union Canals*-
3allentyne Canal-
entyne
-ague Drain-
ilDDLETQN CANAL-*—-
Eagle Island
9 Eagle
ISLAND-*-—
CANALS
jttle Pioneer Canal-*
Canyon County Canal-*
North & South Middleton Drain
.6
— ^Caldwell Highline Canal
Fivemile Creek
11 EC
Willow Creek
Hartley Drain and Gulch
Sebree, Campbell & Siebenberg Canals
21.2
Conway Gulch
Baxter and Boone Canals-*—
Andrews Canal-*
fVm)N Pumps-*
Parma Canal-*-
19.7
M
M
river mile-
•••Thurman Drain
-•-Eureka # 1 and Phyllis Canal
¦8
hson Creek and Drain w
iverside and Pioneer Dixie Canals
'Caldwell Bridge
^•••Indian Creek
-~flcmNus and Teater Canals
--•-iurekaJ1 2 Canal
-+-JPPER Center Point
-~-jowman and Swisher
jower Center Point _
< Boise River at Notus
~•••Dixie Slough
•-Haas Canal
-•-Island Highline Canal
—hjcConnel Island Canal
<1 Boise River near Parma
Snake River
Figure 11-3. Boise River Diversions and Drains.
SOURCE: USBR 1977.
190
-------
10,000
5,000-
8
Ui
t/>
Q:
Uj
a.
UJ
UI
u.
CO
U
o
-J
u.
1,000
500-
1 IN 2 YEAR MONTHLY AVERAGE
NATURAL FLOW BELOW LUCKY PEAK
1 IN 2 YEAR MONTHLY
AVERA6E IMPAIRED FLOW
BELOW LUCKY PEAK
1 IN 2 YEAR MONTHLY
AVERAGE IMPAIRED FLOW
AT BOISE
\'
1 IN 10 YEAR MONTHLY AVERAGE
IMPAIRED FLOW AT BOISE
/
JAN FEB MAR APR MAY UUN JUL AUG SEP OCT NOV DEC
MONTH
(US«S OATA, U S. ARMY CORPS Or ENSINEERS DATA) YEARS OP RECORO 18M-19T9
FIGURE 11-4. HYDROLOGIC CHARACTERISTICS OF THE BOISE
RIVER BELOW LUCKY PEAK DAM AND AT BOISE
191
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Regulation of the Boise River by the dams now in
place began in 1955, but the operation of those reservoirs,
especially Lucky Peak, has changed recently. The current
regulation scheme, begun in 1977, balances water allocations
so that any shortages in storage in Lucky Peak Reservoir
will be taken in the unallocated storage rather than the
allocated irrigation or fish and game storage. That is,
if Lucky Peak fails to fill, the deficit will be assigned
to the unallocated capacity first. Past practice was to
distribute the shortfall over all three storages.
Existing Treatment Plant Flows. Two of the three Boise
treatment plants (Lander Street and West Boise) discharge
treated effluent directly to the Boise River. Other treat-
ment plants which discharge directly or indirectly to the
Boise River include those at Eagle, Star, Middleton, Meridian,
Caldwell, Nampa, Notus, and Parma. The Lander Street and
West Boise plants have peak month average discharges of 14.6
MGD (22.6 cfs) and 7.4 MGD (11.4 cfs), respectively. The
combined flows from the Meridian, Nampa, and Caldwell facili-
ties are comparable to those from the two Boise plants. The
other treatment facilities are small plants (less than 1
MGD capacity each).
Water Quality
Water Quality Standards. Designated beneficial uses,
water quality standards, and wastewater treatment requirements
in Idaho are promulgated by the State of Idaho in Title 1,
Chapter 2 of the Rules and Regulations of the Idaho Department
of Health and Welfare. These rules and regulations are formu-
lated by department staff, and adopted by the Board of Health
and Welfare pursuant to authority vested by the Idaho code.
Within 1 year of adoption by the board, the Idaho State
Legislature may modify or reject new or revised rules and
regulations by concurrent (majority) resolution of both houses.
The EPA may approve standards set by the state, or not
approve them and promulgate its own standards. EPA formulates
National Pollutant Discharge Elimination System (NPDES) permit
requirements (i.e., waste discharge permit requirements) to
comply with state standards it approves, or its own standards.
EPA may take enforcement action against dischargers in vio-
lation of NPDES permit requirements.
Idaho Designated Beneficial Uses. Beneficial uses desig-
nated for the Boise River basin b61ow Lucky Peak Dam are
shown in Table 11-3. Above river mile 50 (the location of
the Lander Street sewage treatment plant discharge) the river
is protected for all uses, and is designated a "Special Re-
source Water". Below river mile 50, domestic water supply
and Special Resource Water designations are dropped..
192
-------
Table 11-3. Protected Beneficial Uses of Waters of the
Boise River Basin Below Lucky Peak Dam
Beneficial Uses
River Reach
Domestic
Water
Supply
Agricultural
Water
Supply
Cold
Water
Biota
Warm
Water
Biota
Salmonid
Spawning
Primary
Contact
Recreation
Secondary
Contact
Recreation
Special
Resource
Water
Boise River - Lucky Peak
to River Mile 50 (through
Veterans State Park)
•
•
•
•
•
•
Boise River - River Mile
50 (Veterans State Park)
to Caldwell
•
•
*
•
•
Ten Mile Creek
•
*
*
•
Five Mile Creek
•
*
*
•
Boise River - Caldwell
to mouth
•
*
*
•
9
Indian Creek - Above
Sugar Avenue, Nanpa
•
•
•
•
•
Indian Creek - Below
Sugar Avenue, Nampa
•
*
*
•
• Protected for present use.
* Protected for future use.
1 Except Lucky Peak Dam to Diversion Dam.
SOURCE: Title 1, Chapter 2, Rules and Regulations of the Idaho Department of Health and Welfare.
-------
The rules and regulations state that protected uses
are not limited to those listed; and that "in all cases,
existing beneficial uses of the waters of the state shall
be protected" (Section 1-2050.026).
Idaho Standards for Protection of Beneficial Uses. The
water quality standards for protection of beneficial uses
are shown in Table 11-4. The standards for a given use apply
to waters protected for that use, unless superseded elsewhere
in the regulations. For example, the dissolved oxygen standard
for salmonid spawning in the Boise River below river mile
50 (the Lander Street discharge) is lowered to 6 mg/1 or
75 percent of saturation, whichever is greater, by Section
1-2278 of the regulations.
In late March 1980, the Idaho legislature revised the
un-ionized ammonia standard for Indian Creek below Nampa
to 1.0 mg/1. The legislature has also lowered the dissolved
oxygen standards below reservoirs from 6 mg/1 to 5 mg/1.
Existing Water Quality Conditions. The water quality
conditions of the Boise River and its tributaries have been
extensively studied since the early 1970s. Sampling has
included dissolved and suspended constituents, bacteria and
the biotic communities. Sampling agencies have included:
o Ada Planning Association
o U. S. Bureau of Reclamation
o City of Boise
o Boise State University
o Idaho Department of Health and Welfare
o U. S. Army Corps of Engineers
o Idaho Department of Fish and Game
o U. S. Environmental Protection Agency
o U. S. Fish and Wildlife Service
Water quality conditions are governed by various point
source discharges, by agricultural return flows and by river
flow available to dilute pollutant loads. During the winter
nonirrigation season, flow in the river below Lucky Peak
is often insufficient to provide adequate dilution of wastes
discharged to the river. In the irrigation season, diversion
of flow for agricultural usage may create low flow conditions
in the vicinity of Star. Below Star flows again increase
due to agricultural return flows.
Existing water quality conditions for the Boise River
are summarized in Table 11-5. Generally, the water quality
of the Boise River worsens downstream of Boise. This de-
gradation is due to the various point and nonpoint source
pollutant loads entering the river. Several industrial dis-
charges, in addition to the municipal waste load, add signi-
ficant pollutant loads. Agricultural drains also account
for a portion of the total pollutant load in the river. De-
tailed conditions are given below.
194
-------
Table 11-4. Summary of Idaho State Water Quality Standards
For Designated Beneficial Uses
Use
Parameter
Standard
Primary Contact
Recreation
Secondary Contact
Recreation
Cold Water Biota
Salmonid Spawning
(During Spawning
an 6 mg/1 at all times
6.5-9.0
<22°C instantaneous; < I9°C daily average
<110 percent of saturation
<0.04 mg/1 30-day mean if water quality
characteristics near cotir.al, <0.02 r.g/1
otherwise
>6 mg/1 or 90 percent saturation, whichever greater
6.5-9.0
<13°C instantaneous;
-------
Table 11-5. Average Water Quality Conditions
of the Boise River Main Stem
Boise River
Below
Lucky Peak
Boise River
Below
Barber Dam
Boise River Boise River Boise River
At At at Highway 30
Glenwood Bridge Star Bridge, Caldwell
S*
W*
S
W
S
W
S
W
S
W
pH (units)
7.3
7.3
7.2
7.3
7.4
7.5
7.4
7.5
7.7
7.8
Temperature |°C)
11.9
7.3
12.0
7.2
12.7
7. 3
14.3
7.3
14.9
7.5
DO (mg/1)
10.1
11.6
9.6
11.8
9.4
11.2
9.5
11.1
8.7
11.4
BOD (mg/1)
1.1
1.2
1.2
1.1
1.4
2.7
1.9
2.5
1.8
2.2
Ammonia -N (mg/1)
.02
.02
.02
.02
.20
.43
.04
.20
. 03
. 10
Nitrite -N (mg/1)
< .01
.01
< .01
< .01
.02
.03
.02
.03
.02
.05
Nitrate -N (mg/1)
.12
.23
.12
.16
.19
. 32
.37
1.07
.86
1.60
Organic
Nitrogen -N (mg/1)
.28
.26
.28
.25
.29
. 36
. 38
.41
.50
.43
Total Phosphorus
-P (mg/1)
.04
.06
.04
.05
.19
.31
.17
.39
.26
.33
Ortho Phosphorus
.
-P (mg/1)
.01
.03
.01
.02
.23
.12
.30
.15
. 22
*S = summer, April-September
W = winter, October-March
SOURCE: STORET (data collected by U. S. Water and Power Resources Service, mainly from
1977-1979).
-------
Temvcvatuve. The temperature' of the Boise River in
creasimTdS^itream direction and is especially elevated
during the summer months. An increase in water temperature
occurs between Caldwell and Parma stations, which have average
summer temperatures of 14.9°C and 17.4°C, respectively. The
flows in this reach are governed by agricultural return flows.
Dissolved Oxygen. Adequate levels of dissolved oxygen
are necessary survival of fish and other aquatic
organisms. STORET (EPA computerized data base) data show
that dissolved oxygen concentrations in the Boise River
decrease in a downstream direction during the summer months.
During the winter the average dissolved oxygen is relatively
stable, with only a slight decrease downstream. The agricultural
drains usually have lower dissolved oxygen concentrations
than the Boise River.
Ada Council of Governments (ACOG 1975d) found dissolved
oxygen concentrations to decrease in a downstream direction.
The concentrations, however, were determined to be within
acceptable limits for the beneficial uses along the river.
At Star EPA (1971a) found minimum percentage dissolved
oxygen saturation. Star is the point in the river where
flows are greatly reduced, often approaching a no-flow
condition.
Nutrients. The major nutrients used by algae and other
aquatic plants include various nitrogen and phosphorus com-
pounds. Nitrogen released in sewage effluent is primarily
in the form of organic nitrogen or ammonia. Various bacteria
decompose the organic nitrogen to ammonia, while other bacteri
convert ammonia to nitrite and nitrate. Algae can use ammonia,
nitrite, or nitrate; the nitrate form, however,
used, while ammonia and nitrite can serve as Plant nutrients,
these two forms of nitrogen can also be toxic to fish.
Very little ammonia is found in the river ab°ve Boise
Ammonia concentrations reach a maximum (0.43 ™g/l in _winter)
at Glenwood Bridge. The increase is due to wasteloads,
especially treated municipal sewage, en'fc®5inf * ia COncen-
Boise, the river shows improvement with the ammonia
trations decreasing (EPA 1971a. ACOG 1975d). Nitrate increases
in a downstream direction, with the highest concentration
found at Parma (Figure 11-5). The large nitrate concentration
at Parma is due not only to upstream discharges of ammonia,
organic nitrogen and nitrite from wastewater effluent,
also due to runoff from agricultural lands.
Total phosphate and orthophosphate
stream direction. Orthophosphate averages 0.01 mg/1 b
Lucky Peak and 0.30 mg/1 at Star. The increase is
in response to runoff from agricultural ac^age ^cretio
from groundwater recharge from irrigation and treated sewage
affluent. Figure 11-6 shows total phosphorus conditions
ln the Boise River. ^
-------
NITRATE
LUCKY
PEAK
BARBER
DAM
GLENWOO
BRIDGE
STAR
BRIDGE
HIWAY 30
TJT-
)-D
63.8 (102.3)
48.0 <77.21 ,o WHUE
58.3 (93.8)
32.0 (52.9)
2 1.1 (33.9)
M A-J J-S
PERIOD
Figure 11-5. Nitrate conditions in Boise River.
SOURCE: USBR 1977.
-------
Soo«ce.
. «*«|
RtV** MILE
°SBH
197?
Pho
sPhQ
'•fus
cori(3
OiJS,
Bo
ise
Siv,
-------
Biochemical Oxygen Demand. Biochemical oxygen demand
(BOD) is an index of the oxygen-consuming organic substances
in water. High BOD levels can deplete the dissolved oxygen
necessary for survival of fish and other aquatic organisms.
The BOD in the Boise River does not show large increases
over upstream concentrations until the station at Parma.
During summer conditions, organic materials are readily oxi-
dized. Consequently, the effect of oxidizing BOD loads shows
up as lower oxygen concentrations rather than increased BOD
concentrations. In the winter, colder temperatures inhibit
the organisms that oxidize organic material, and BOD increases
at the downstream stations.
Fishery Resources
Aquatic habitats in Ada County include Lucky Peak, Indian
Creek, Blacks Creek, and Hubbard Reservoirs; numerous irriga-
tion canals and drains; the Boise River; the Snake River;
and numerous smaller streams, most of which flow only sea-
sonally. The Boise River is probably the most significant
aquatic habitat with regard to the potential for impacts
of Ada County wastewater management alternatives.
Historical Perspective. In the early 1800s, the Boise
River supported populations of white sturgeon, chinook salmon,
sockeye salmon, and steelhead rainbow trout (Caldwell and
Wells 1974). These fish are "anadromous" (i.e., they spawn
in fresh water and live a part of their life cycle in the
ocean). These fish populations migrated to and from the
Pacific Ocean via the Snake and Columbia Rivers. Salmon
were an important staple for the aboriginal Indian inhabi-
tants of the Boise River Valley.
Gold was discovered in the Boise River Basin in 1862,
and sedimentation due to placer mining activities soon severely
reduced salmon populations. The construction of Barber Dam
in 1906, New York Diversion Dam in 1908, "and Arrowrock Dam
in 1915 cut off the upper drainage areas to anadromous fish
migration (Ada Council of Governments 1973a). Subsequent
construction of impassable dams downstream on the Snake River
cut off the entire Boise River from anadromous fish migrations.
Present Day Fishes. Today the Boise River supports
a diverse fauna of native and introduced game and nongame
fishes (Table 11-6). Idaho Department of Fish and Game (IDFG)
data indicate that nongame fishes outnumber game fishes by
about 10 to 1 (Figure 11-7). The nongame-to-game fish biomass
ratio is probably considerably larger than 10 to 1 due to
the large size of the suckers. The more abundant nongame
fishes are suckers, redside shiner, carp, and chiselmouth;
the more abundant game fishes are mountain whitefish, large-
mouth bass, and bluegill.
200
-------
Table 11-6. Fishes of the Boise River Between
Lucky Peak Dam and the River Mouth
Common Name Scientific Name
Kokanee
Oncorhynchus nerka
Rainbow trout
Salmo qairdneri
Brown trout
S. trutta
Dolly Varden
Salvelinus malma
Mountain whitefish
Prosopium williamsoni
Chiselmouth
Acrocheilus alutaceus
Carp
Cyprinus carpio
Tui chub
Gila bicolor
Northern squawfish
Ptychocheilus oreqonensis
Longnose dace
Rhinichthys cataractae
Speckled dace
r. osculus
Redside shiner
Richardsonius balteatus
Bridgelip sucker
Catostomus columbianus
Largescale sucker
r. macrocheilus
Mountain sucker
c.. platvrhynchus
White catfish
Ictalurus catus
Brown bullhead
X. nebulosus
Channel catfish
I. ounctatus
Tadpole madtom
Noturus qyrinus
Pumpkinseed
Lepomis gibbosus
Warmouth
L. aulosus
Bluegill
Tj. macrochirus
Smallmouth bass
Micropterus dolomieui
Largemouth bass
M. salmoides
Black crappie
Pomoxis niqromaculatus
Yellow perch
Perca flavescens
Mottled sculpin
Cottus bairdi
/
SOURCES: Ada Council of Governments 1973a; Gibson 1978;
Idaho Department of Fish and Game pars. comm.
201
-------
TOTAL FISH
N: 6041
GAME FISH
N = 516
NONGAME FISH
N = 5525
N0N6AME FISH
'///, 91-5
GAME FISH
v 6.5%
WHITEFISH
46.1%
LAR6EM0UTH
BASS
BLUE6ILL'
1.17.2
WHITE CATFISH .2%
YELLOW PERCH .2%
BROWN TROUT .6%
RAINBOW TROUT (HATCHERY) 1.0%
RAINBOW TROUT (WILD) 1.2%
BROWN BULLHEAO 1.6%
BLACK CRAPPIE 2.3%
CHANNEL CATFISH 3.1%
PUMPKINSEED 4.0%
SMALLMOUTH BASS 4.2%
SUCKER
35.7 %
REOSIDE
SHINER
25.5%
lCHISELMOUTH
I \ 21-1% /
CARP
TUI CHUB .1%
DACE 1.2%
SCULPIN 1.4%
SQUAWFISH 3.6%
SOURCE: GIBSON, 1978
FIGURE 11-7. PERCENTAGE COMPOSITION FOR TOTAL FISH, GAME FISH AND NON-
GAME FISH IN ELECTROFISHING SAMPLE FROM THE BOISE RIVER (FROM THE MOUTH,
UPSTREAM TO BARBER DAM), 11 JULY TO 2 AUGUST, 1974
-------
Distribution of Fishes. The species composition of
fishes in the river changes as one proceeds downstream from
Barber Dam to the river mouth (Figure 11-8). Coldwater
species are generally limited to the river reach above Star,
and warrawater species to the reach below Star. Although
whitefish are found in the entire river, they are much more
abundant above Star. Species composition in the vicinity
of Boise State University is dominated by whitefish and trout
(Kelley pers. comm.). Largemouth bass, black crappie, and
bluegill are found mainly in backwater sloughs below Star.
Smallmouth bass and channel catfish are most abundant in
the river from Notus to the mouth. Redside shiner, suckers,
carp, chiselmouth, and squawfish are more evenly distributed
than other species (Gibson 1978).
Rainbow trout are probably the most sought after game
fish in the Boise River. Population levels are maintained
by natural reproduction and by stocking with hatchery fish.
IDFG annually stocks about 30,000 catchable size fish at
various locations between Barber Dam and Star. Rainbow trout
comprise about 0.3 percent by number of all fishes in the
river according to electroshocking data (Gibson 197 8). The
distribution of rainbow trout in the lower Boise River pre-
sently extends from approximately Star to Lucky Peak Reservoir.
Rainbow trout require good water quality and temperature
below about 70°F (21°C). For spawning, rainbow trout require
gravel abut 0.5-1 inch in diameter that is relatively free
°f fine sediments (sand and silt).
Brown trout are a popular non-native game fish species
found in the Boise River. Population levels are maintained
by natural reproduction and stocking of hatchery-bred fish.
The IDFG annually stocks about 25,000 fingerlings in fall
in various locations between Barber Dam and Star. Brown
trout comprise about 0.01 percent by number of the fishes
-J-n the Boise Riv^r, according to year-round electroshocking
d^ta of Gibson (1978). Spawning gravel requirements are
similar to those of rainbow trout.
Mountain whitefish are the most abundant game fish species
the Boise River. The population is maintained entirely
by natural reproduction. Whitefish comprise about 4 percent,
by number, of the fishes in the Boise River (Gibson 1978).
f-n the Boise River, mountain whitefish spawn in early November
through mid-December, and egg incubation extends through
March (Reid pers. comm.). Mountain whitefish spawn in gravelly
areas; there is no evidence that they excavate any nest and
there is little or no selection of gravel size (Brown 1952).
Gibson (1978) investigated the food habits of mountain white-
J^-sh in the Boise River. Immature aquatic insects were the
Q°roinant food items.
203
-------
MOUNTAIN WHITE FISH
RAINBOW TROUT (HATCHERY)
RAINBOW TROUT (WILD)
LA R6E MOUTH BASS
BLACK CRAPPIE
BROWN TROUT
BLUE6ILL
to
o
SMALLMOUTH BASS
Fairviw Strawberry
, Borber Dow , Bridge , 6lenn .Eagle
Star
i
Caldwell
¦
Notus
i
BOISE RIVER
10 Mi Its
mm
Parma
Mouth at
Snake R.
CHANNEL CATFISH
REDSIDE SHINER I 1
SUCKER £ ~|
CARP I 1
CHISEL MOUTH j 1
SQUAWFISH ^ . , " ' J
SOURCE: GIBSON, 1978
FIGURE 11-8. DISTRIBUTION OF 13 FISH SPECIES IN THE BOISE RIVER FROM BARBER
DAM DOWNSTREAM TO THE MOUTH AS DETERMINED BY ELECTROFISHING DURING
.UUCkRX-FEfcRUARX, 4VI- AUGUST AMD OCTOBER , A974
-------
Both trout and whitefish are characteristic of cool,
relatively pollution-free streams, and feed mainly on ter-
restrial and aquatic invertebrates. Although there is little
information on specific habitat requirements and relative
resistance to various kinds of pollution for whitefish and
trout, they are presumably about the same in habitat require-
ments and resistance to various types of pollutants.
The great difference in relative abundance between trout
and whitefish in the Boise River can be explained by a single
significant difference; trout bury their eggs, while whitefish
(and all other fish species in the Boise River) do not
(Brown 1952). Sediments hinder water circulation to the
buried eggs. Sediment characteristics thus appear to be
a factor limiting reproduction of rainbow and brown trout
in the Boise River. There is little gravel of the proper
sizze above Boise, and the suitable gravels below Boise are
rendered unusable by sedimentation. Other limiting or regula-
ting factors (e.g., lower winter flows and high pollutant
loads) during other fish life stages probably affect trout
and whitefish more equally.
Human Factors Affecting Aquatic Life. Human-induced
changes in the hydrology and sediment budget of the Boise
River greatly affects its aquatic life, as discussed below.
Hydro logy. The annual stream flow regime of the Boise
River has been greatly altered by dam operations and diver-
sions for agriculture and as a result the Boise River below
Lucky Peak Dam has: 1) lower winter base flows; 2) reduced
winter and spring flood peaks; 3) summer flows that are higher
than natural near the upper and lower parts of the river,
but lower in the middle near Star; and 4) drastic short-
term flow fluctuations. Urbanization, overgrazing, and off-
road vehicle use have probably increased flood peak flows
and sediment loads in undammed smaller tributary streams
such as Cottonwood Creek and Five Mile Creek.
These hydrologic changes have multiple effects on the
fish populations. Lower winter flows cause less pollutant
dilution and dispersion. They also promote formation of
ice cover which hinders oxygen transfer and which, in turn,
may increase the effects of waste discharges and occasional
Pollutant spills during winter. Periodic fish kills in the
river were more common in the past. Many'industrial waste
discharges have been eliminated or treated in recent years
(Ada Council of Governments 1973a). Short-term flow fluctua-
tions or complete flow shut-off for maintenance of the outlet
structure of Lucky Peak Reservoir strands fish and aquatic
invertebrates in pools and makes them more vulnerable to
Pollution.
205
-------
These fidverse effects can be mitigated in part by revising
the flow regime through Lucky Peak Dam. The recommended
minimum flow regime published by the U. S. Fish and Wildlife
Service Cooperative Instream Flow Service Group for maintenance
of fishery resources is presented in Table 11-7. Comparison
of actual flow frequencies to the recommended flow (Figure 11-9)
indicates spawning flows for rainbow trout are generally
met, but spawning flows for brown trout are not met.
On June 10, 1980, the Federal Energy Regulatory Commission
(FERC) issued a license to the Boise Project Board of Control
for new hydropower facilities on Lucky Peak Dam. A con-
tinuous minimum flow release of 160 cfs was a condition
of the permit. This would have enhanced fishery habitat
in the river. However, on October 9, 1980, FERC issued an
order repealing the minimum flow release condition. The
repeal was based on difficulties with the integrated manage-
ment of Lucky Peak, Arrowrock, and Anderson Ranch Reservoirs.
The low-flow situation in the Boise River should improve
considerably if and when the hydropower project is completed;
there will be two outlets and flow shutdowns for tunnel main-
tenance will be unnecessary.
Sediment. Changes in the sediment budget of the Boise
River have resulted from the factors identified below:
o Arrowrock, Lucky Peak, Diversion, and Barber Dams
have blocked gravel recruitment from upstream areas.
Periodic high flows have flushed smaller gravels
downstream, leaving only large gravels and rocks.
This "armoring" of downstream areas leaves them
with gravels too large for trout spawning use.
Most suitable spawning gravels (about 0.5 inch
diameter) exist in higher side channel areas, and
flows greater than about 1,000 cfs are necessary
to provide suitable water depths and velocities over
them. Rainbow trout spawn in these gravels during
high flow periods of spring, but the nests become
exposed due to rapidly falling water levels during
summer, and the eggs die (Pruitt and Nadeau 1978).
Limited amounts of proper-size spawning gravels are
transported to the main stem of Boise River by
tributaries downstream of Boise area, such as
Indian Creek (Nadeau pers. comm.).
o The reach between Lucky Peak Dam and Barber Dam
has received extensive sand deposits from mining
operations in the More's Creek watershed in the
1930s and 1940s. These deposits stifle aquatic
insect productivity and are unsuitable for trout
spawning (Ada Council of Governments, 1973a).
206
-------
Table 11-7. Recommended Low Flow Regime in cfs, for the
Boise River from Lucky Peak Dam to Snake River
Spec1es/L1fe Stage
JAN
FEB
MAR
APR
HAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
Rainbow Trout
Spawning
225
225
225
Incubation
151
151
151
151
151
Brown Trout
Spawning
225
225
Incubation
151
151
151
151
151
Dolly Varden
Spawning
150
150
Incubation
100
100
100
100
100
Rearing - All Species
150
150
150
150
150
150
150
150
150
150
150
150
Recommended Flow Regime
150
150
150
225
225
225
150
150
150
225
225
150
SOURCE: Pruitt and Nadeau 1978.
207
-------
RAINBOW TROUT
SPAWNING
INCUBATION
REARING
BROWN TROUT
SPAWNING
INCUBATION
REARING
MTN. WHITEFISH
SPAWNING
INCUBATION
REARING
10,000
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC _
v//s/s
Z7//77/
/7/7S7
*7722211 t
u
en
in
10
QC
Ui
to
o
CD
*
o
*
o
>-
Q
j
©
1,000-
tOO-u^V
10-
1IN t YEAR
LOW FLOW
SPAWN INS MAINTENANCE
FLOW
A
REAR I NO MAINTENANCE FLOW
1 IN tO YEAR
LOW FLOW
LEGEND-
BOISE RIVER BELOW
LUCKY PEAK
B0I8E RIVER AT BOISE
— — RECOMMENDED MAINTENANCE
FLOWS ( PRUITT & NADEAU, (978
SOURCES: PRUITT ft NADEAU, 1978, USSS FLOW DATA (FILE); REID (PER8. COMM.)
FIGURE 11-9. COMPARISON OF TROUT AND WH ITEFISH LIFE
HISTORY, STREAMFLOWS IN THE BOISE RIVER AND
RECOMMENDED MAINTENANCE FLOWS
208
-------
o Fine sediments from sites of overgrazing and con-
struction activities/ stream channel alterations,
and irrigation return flows are deposited in the
river. Urban development in the Boise foothills
and gravel crushing operations are especially dele-
terious (Ada Council of Governments 197 3b). Sedi-
mentation renders stream gravels unproductive of
aquatic insects and unsuitable for trout spawning
due to the clogging of gravel interstices and
blockage of water circulation and oxygen transfer.
These changes in sediment budget may affect fish species
composition. Boise River fish sampling data (Gibson 1978)
show that game fish were 9.5 percent of the total fish popula-
tion, and of the game fish, 46 percent were mountain white-
fish, 2.2 percent were rainbow trout, and 0.6 percent were
brown trout (see Figure 11-7).
Impacts of the Proposed Projects
Hydrologjc Changes
The Lander Street and West Boise sewage treatment plants
are projected to treat and dispose of an annual average of
32.3 MGD of wastewater by the year 2000. During the fall
and winter low flow period, the year 2000 Lander Street dis-
charge will be about 10 MGD (15.5 cfs) and the West Boise
discharge will be about 22 MGD (34.0 cfs). The Eagle Sewer
District plant will discharge about 1.3 MGD (2.0 cfs).
Table 11-8 summarizes the effects of these discharges during
l-in-10-year, 7-day low-flow periods. As shown in Table 11-8,
the West Boise discharge will have the greatest relative
effect on Boise River flows. It is presently uncertain where
the Eagle effluent will enter the river. However, the effects
of the Eagle effluent on total river flow will not be signifi-
cant.
Development accommodated by expanded sewage treatment
facilities in the Boise area will result in an increase in
storm runoff from impervious surfaces. Increased storm runoff
will result in somewhat higher river flows after significant
storms.
Hater Quality Changes
The following discussion focuses on the water quality
effects of the Lander Street and West Boise discharges.
Water quality data are not available for the vicinity of
present Eagle Sewer District plant. That facility has
NPDES permit requirements except for suspended solids
^r^hg algal blooms in the treatment ponds (J-U-B Engineers
J-980) . Construction of the proposed new treatment facilities
20 9
-------
Table 11-8. Present and Future Effects of Boise and Eagle Effluent
Flows on Boise River l-in-10-year, 7-Day Low Flows Below the Outfalls
{Lucky Peak Flow = 80 cfs)
Lander Street
West Boise
Eagle
Present Conditions
Upstream flow
100
65
67
Effluent flow
16
7
0.5
Downstream flow
116
72
67.5
(Percent local effluent flow)
14
10
1
(Percent cumulative effluent flow)
14
21
13
Year 2000 Conditions
Upstream flow (cfs)
100
65
67
Effluent flow (cfs)
16
34
2
Downstream flow (cfs)
116
99
69
(Percent local effluent flow)
14
34
3
(Percent cumulative effluent flow)
14
42
14
Notes: cfs = cubic feet per second
DATA SOURCE: Morrison pers. comm.; J-U-B Engineers 1980.
-------
at Eagle will alter the location of effluent discharge to
the river. If the recommended rapid infiltration project
is built, collected percolate from the infiltration site
will be mixed with agricultural drain water prior to eventual
discharge. If the alternative oxidation ditch system is
built, effluent discharge will occur about 1 mile west (down-
stream) of the current discharge. In either case, there
should not be any significant effects on overall river water
quality due to the low volume of effluent.
Present Effluent Effects. Water quality data are col-
lected above and below both the Lander Street and West Boise
outfalls. Average data are shown in Table 11-9. Increases
in ammonia and phosphate occur below the Lander Street outfall,
while dissolved oxygen concentrations decrease. Temperatures
increase slightly. The change in river quality due to the
West Boise discharge is not as pronounced for many consti-
tuents as at the Lander Street plant. Phosphate levels show
the greatest relative increase.
Dissolved Oxygen Changes. Figure 11-10 shows dissolved
oxygen levels projected to exist in the Boise River under
year 2000 conditions of effluent flow and quality. Dissolved
oxygen levels are projected to be above the 75 percent of
saturation standard at all locations. The minimum dissolved
oxygen saturation was 82 percent, which corresponds to 8.4
mg/1 at 15°C. This is a level sufficient to support a
healthy fish community.
Nutrients. Effluent loading of nitrogen and phosphorus
are of concern for potential stimulation of nuisance algal
growths in Snake River reservoirs downstream of the Boise
River, including Brownlee Reservoir. Nitrogen loadings to
the Boise River under l-in-10-year, 7-day low-flow conditions
were estimated when the river dissolved oxygen modeling was
Performed (Table 11-10). Lander Street, West Boise, and
Eagle will contribute about 10, 12, and 1 percent, respectively,
of the total nitrogen load. The present contributions are
about 10, 4, 0.3 percent, respectively. Total phosphorus
loadings to the Boise River under present and future conditions
are estimated in Table 11-11. Phosphorus loadings from the
Boise and Eagle effluents will about double. The percentage
-------
Table 11-9. Average Water Quality Data Above and Below
Lander Street and West Boise Sewage Treatment
Plant Outfalls, October 1975-April 1980
Above
Below
Above
Below
Lander St.
Lander St.
W. Boise
W. Boise
Temp. ° C
I
10.6
10.8
11.8
11.5
N
6.0
6.7
6.4
6.6
pH
I
7.4
7.4
7.5
7.5
N
7.5
7.5
7.6
7.6
Dissolved 09 mq/1
I
9.9
9.3
9.0
8.9
N
10.2
9.5
8.7
9.5
NH-.-N mg/1
I
0.12
0.34
0.12
0.09
J
N
0.22
0.94
0. 50
0.43
PO, mg/1
I
0.22
0.47
.34
.43
N
0. 23
0.85
.72
1.04
NOTES:
I = Irrigation season (April-September)
N = Nonirrigation season (October-March)
SOURCE: City of Boise (Lander Street Wastewater Treatment Plant file
data).
212
-------
55
O
K
<
CC
o
to
U>
x
o
a
NORTH
CHANNEL
SOUTH
CHANNEL
BOISE RIVER ESTIMATED DISSOLVED OXYGEN PROFILE '
(MINIMUM OISSOLVEO OXYGEN LEVEL « 82% SATURATION)
BOISE RIVER MINIMUM ALLOWABLE
DISSOLVED OXYGEN LEVEL * 7»r. SATURATION
ASSUMPTIONS USED TO COMPUTE OISSOLVEO OXYGEN PROFILE
« FALL CONDITIONS
• BOISE RIVER: FLOW -80 CFS AT LUCKY PEAK RESERVOIR
TEMPERATURE - 12°C
DISSOLVED OXYGEN » 80* SATURATION
60
LANDER STREET EFFLUENT: FLOW-IOMGD
ULTIMATE BOD - 35 MG/L iBODg - 20 MG/L)
AMMONIA - 18 MG/L
TEMPERATURE - 20°C
OISSOLVEO OXYGEN - 75%
WEST BOISE EFFLUENT: FLOW-25MGO
ULTIMATE BOO - 35 MG/L
-------
Table 11-10. Estimated Nitrogen Loadings to Boise River,
Year 2000 l-in-10-Year Low-Flow Conditions
Pounds per Day
Percent of
Source
Nitrogen
Total Load
Headwaters and groundwater seepage
385
2
Lander Street treatment plant
1,507
10
West Boise treatment plant
1,909
12
Eagle treatment plant
100
1
Other treatment plants
1,294
8
Indian Creek
9,590
61
Other tributaries and drains
879
6
DATA SOURCES: Morrison pers. comm.; STORET data.
-------
Table 11-11. Annual Average Loadings of Total Phosphorus to the
Boise River under Present and Future Conditions
Present P Load to River Year 2000 P Load to River
Tributaries and Drain lb/day
I sham 4
Ridenbaugh 8
Baxter 2
Davis 35
Eagle 35
Dry Creek 25
Thurman 18
Fish Hatchery 2
Mason Creek North 6
Mason Creek South 6
Mason Drain 239
North Middleton 51
South Middleton 167
Willow Creek 45
Hartley Drain 92
Hartley Gulch 42
Conway 106
Dixie 4 36
Wilder 16
Indian Creek 333
Tenmile Creek 184
Sewage Treatment Plants
Lander Street 500
West Boise 275
Eagle 25
Percent lb/day Percent
19
500
14
10
1,100
31
1
65
2
DATA SOURCES: USBR 1977; STORET data.
-------
is concern for future heavy metals concentrations below West
Boise due to the new Hewlett-Packard plant. Effluent limita-
tions for metals and other inorganic toxins from the West
Boise plant have been formulated by IDHW. Table 11-12 shows
estimated instream concentrations of these substances during
a 1-in-iO year, 7-day low flow event in the year 2000. No
constituent would be greatly increased, and some would be
decreased by the effluent discharge. No EPA (1976) water
quality criteria for freshwater aquatic life would be exceeded.
Construction Impacts. Construction of expanded sewage
treatment facilities and interceptor lines in Boise and Eagle
will result in short-term local increases in erosion and
sedimentation in the vicinity of the construction sites.
The Eagle interceptor will cross several watercourses. The
south Boise interceptor route alternatives that run along
the Boise River appear to have greater sedimentation impact
potential than the inland east route (CH2M Hill 1980c).
Direct Impacts On Fisheries
Expansion of the Boise and Eagle wastewater treatment
facilities is not expected to have any significant adverse
effects on the fish populations of the Boise River as long
as the water quality standards are met. The facilities plan
(CH2M Hill 1980c) indicates that receiving water quality
standards can be met as long as flow releases from Lucky
Peak Dam equal or exceed 80 cfs, which is the anticipated
l-in-10 year low flow. However, additional assurance is
needed that 80 cfs will continue to be available during the
20-year life of the project, since part of that supply has
already been appropriated to the U. S. Bureau of Reclamation
and is subject to sale to irrigators. If the l-in-10-year
flow of 80 cfs is assured, then no significant effects on
fish populations will occur in 90 percent of all years. In
the other 10 percent of all years (the lowest 10 percent
in terms of water flow) some adverse fisheries impacts may
occur, depending on how far below 80 cfs releases from Lucky
Peak go. The potential for adverse effects on fishes due
to residual chlorine will decrease with the installation
of dechlorination facilities at the Boise wastewater treat-
ment plants.
Construction will have short-term effects on fisheries
due to sedimentation and disturbance of riparian vegetation.
Fisheries may be permanently affected if riparian vegetation
is removed, particularly at the Eagle site where riparian
vegetation is abundant.
216
-------
Table 11-12. Estimated Instream Concentrations of Trace Inorganic Toxins
Below West Boise, Year 2000 l-in-10-Year, 7-Day Low-Flow Conditions*
EPA (1976)
Effluent
Upstream
Downstream
Aquatic Life
Limitation
Concentration
Concentration
Criterion
Constituent
(mg /1)
(mg/1)
(mg/1)
(mg/1)
Arsenic
0.01
<0.01
<0.01
_
Aluminum
0.1
0.28
0.22
-
Baron
0.3
0.15
0.20
-
Cadmium
0.001
<0.01
<0.01
0.004
Chromium,
Total
0.01
<0.01
<0.01
0.1
Chromium,
Hexavalent
0.01
<0.01
<0.01
-
Copper
0.02
<0.01
<0.013
0.1 of
lc50
Cyanide
0.01
no data
-
0.005
Fluoride
0.5
0.43
0.45
-
Iron
0.3
0.36
0.34
1.0
Nickel
0.05
<0.50
<0.5
0.01 of
lc50
Zinc
0.06
0.005
0.024
0.01 of
lc50
*River flow = 65 cfs; Effluent flow = 34 cfs
DATA SOURCES: STORET AND IDHW data.
-------
Indirect Impacts on Fisheries
Indirect impacts on fish and wildlife resources will
result from the population growth and attendant land use
changes associated with provision of new or expended sewer-
age facilities. The principal indirect impacts on fisheries
accompanying provision of sewerage facilities in Ada County
will be nonpoint source pollution resulting from urban expan-
sion. Nonpoint source pollution includes sediment, oil and
grease, rubber particles, metals, and a host of other toxic
or oxygen-demanding substances. Many of these pollutants
are generated through urban storm runoff. There is no co-
ordinated implementation of a master storm drainage plan
in Ada County at the present time. Increased fishing pressure
may also affect populations.
Sedimentation is a major water quality problem in the
Boise River, especially below Boise. Fine sediments that
clog spawning gravels limit the natural reproduction of rain-
bow and brown trout in the river reach below Boise. Con-
struction associated with population growth may worsen the
problem. Insufficient data exist at this time to quantify
the present nonpoint source problem or to quantify future
loads and their effects.
Mitigation Measures
The l-in-10-year low flow of 80 cfs from Lucky Peak
is not assured, i.e., flows lower than 80 cfs may occur.
The City of Boise should continue its efforts to assure
reliable flows from Lucky Peak Dam.
Construction impacts should be minimized by using earth-
moving practices which minimize land disturbance and movement
of sediment toward watercourses. Riparian habitat along
the Boise River should be preserved to the maximum possible
extent during construction. The Boise facility planners
have already met with Idaho Department of Fish and Game
regarding minimization of construction impacts {CH2M Hill
1980c).
A master storm drainage plan for Ada County is needed
to help control urban runoff and nonpoint source pollution.
Provisions for nutrient removal from sewage effluent
may be desirable in the future to help control algal growth
in downstream Snake River reservoirs.
218
-------
Chapter 12
Vegetation and Wildlife Resources
-------
Chapter 12
VEGETATION AND WILDLIFE RESOURCES
Environmental Setting
In the following section describing the plant and animal
communities of the study area, special attention is given
to; 1) habitats of major importance to wildlife, 2) habitats
and wildlife that may be impacted by the proposed projects,
and 3) plant and animal species of special concern (e.g.,
endangered species, recreation species). Representative
plant and animal species of Ada County are listed by common
and scientific name in Appendix E.
Vegetation and Wildlife Habitats
Wildlife Habitat Types. Nine general plant community
r wildlife habitat types occur in northern Ada County:
j Riparian, 2) big sagebrush, 3) bitterbrush shrub steppe,
f irrigated agricultural, 5) nonirrigated agriculture,
iL°pen.water' 7* grassland, 8) Douglas-fir, and 9) urban-
naustrial (Idaho Department of Pish and Game 1977).
sur, Riparian habitat is densely wooded* typically
ta?P°rtln25 . ar®as, the riparian community is seldom very wide
vegeiJJ,* uPstream from Eagle? in many cases the riparian
Veqet r«n is afc>s®nt or only a few trees wide. Riparian
JWer k°n formerly extended further inland from the active
indust* • ?ne1' but has been replaced by agricultural or urban-
the Sfc^ta USes' Downstream from the Eagleare* to Caldwell,
Motia lh °f riParian vegetation is usually wider than th#t
aiong ™ river near Boise. Riparian habitat also occurs
some of the tributary creeks draining the Sfcise Front.
219
-------
Sagebrush , Sitterbrush, and. Grass lands. Prior to urbani-
zation and agricultural development in Ada County, most of
the county was brushland or grassland. Riparian habitat
occurred along the rivers, and forests were found in the high
mountains.
Bitterbrush-dominated shrubland presently occurs at
midelevations of the foothills north and east of Boise. Sage-
brush-dominated shrubland occurs in the foothills above and
below the bitterbrush communities, as well as comprising
most of the vegetation of southern Ada County. Grasslands
occur north of the Boise River and southeast of Boise, and
in small, scattered locations elsewhere in the county. In
addition, various grasses form part of the understory for
the forests and shrublands. Cheatgrass, crested wheatgrass,
bluebunch wheatgrass, Idaho fescue, and Indian ricegrass
are among the county's common grasses.
Agriculture. Large tracts of irrigated farmland lie
west of Boise and Eagle. Other scattered irrigated and non-
irrigated agricultural lands lie in eastern Ada County and
in southwestern Ada County near the Snake River. In the
last 10 years, large parcels of agricultural land southwest
of Boise have been converted to housing and other urban uses.
Corn is the primary row crop in the county. Alfalfa,
grains, sugar beets, and mint are among the other crops.
Irrigation is accomplished through furrow and large moving
sprinkler systems. Livestock production and dairies are
additional agricultural activities.
Open Water. Open water habitats are the surface waters
of lakes, reservoirs, and streams. Riparian habitat often
occurs around the edges of such areas. Lucky Peak Reservoir,
Lake Lowell, Indian Creek Reservoir, and the Boise River
are examples of open water habitat. Large sewage treatment
ponds also serve as open water wildife habitat.
Douglas-Fir. Along the upper crest of the Boise Front
in northeastern Ada County, Douglas-fir and ponderosa pine
are the dominant plants. The forest community formerly extended
farther downslope and into some lower drainages; fires and
timber harvest have limited the forest to the higher slopes
Urban-Industrial. Boise, Garden City, Eagle, Meridian,
Star, and Kuna, as well as development in unincorporated
areas, comprise the urban-industrial habitats of Ada County.
220
-------
Within the Boise River floodplain, many areas support rela-
tively large trees. Parks, golf courses, and various open
space areas provide a combination of natural and artificial
(e.g., landscaping) vegetation within the urban complex.
Threatened and Endangered Plant Species. Two plant
species are listed as candidates for threatened or endangered
status by the U. S. Fish and Wildlife Service (Table 12-1).
Mulford' s milk, vetch and Hannah aase' s onion are currently under
going evaluation to identify locations of populations, number
of plants, degree of endangerment, and other parameters which
will help to determine the status of these plants. The U. S.
Pish and Wildlife Service (Merhoff pers. comm.) expects to
officially propose these species for threatened or endangered
listing in the near future.
Both plant species are closely associated with soils
of sedimentary origin; locally these soils are found in a
narrow band at the base of the foothills north and east of
Boise (Steele pers. comm.; U. S. Soil Conservation Service
1979). Because these plants are closely associated with
a specific limited soil type, it is unlikely that further
surveys will discover numerous additional populations or
broaden their known distributions.
Mulford's milk vetch historically has been identified
on 10 sites; but, only two populations have been recently
verified (Kennison 1980). Threats to this species are con-
version of native habitat to agriculture, excessive grazing
pressure, and urban development.
Hannah aase's onion has 10-12 known populations. Its means
°f reproduction is by bulb division. A sexual reproduction
(bulb division) in this species has promoted uniformity
among plants within individual populations and notable dif-
ferences among populations. Maintenance of different popu-
lations is crucial to maintenance of the genetic variation
°f the species. The total range of this plant is approxi-
mately 5 miles by 20 miles. Threats to the continued exis-
tence of this species are urban development and gravel ex-
traction (Packard 1979).
ffildlife
A variety of wildlife species utilize the habitats of
Ada County, either seasonally or year-round. Many species
are migratory, occurring in the county primarily during one
season or passing through the county briefly in spring or
fall. Deer, for example, summer in the high mountains, and
winter at lower foothills (because snow excludes them from
221
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Table 12-1. Vegetation - Candidate Threatened or Endangered Plant Species1'2'3'
Plant Nane
(Scientific/Corneal)
Proposed
Status1-
Known locations
Plant Comnunity
Elevation, Slope, Soils
ComtentE
Astragalus mulfordiae
Mulford's ntxlkvetch
KUins aaseaa
Harrna Aage 's Onion
Foothills east of
Boise; Owyhee, Wash-
ington Counties in
Idaho; Malheur Coun-
ty, Oregon; 5 sites.
Known only from the
foothills in the vici-
nity of Boise and
Bnnett; 10-12 sites.
Steppe, shrub-steppe
desert shrub, sage-
brush-grass. Plant
associates include
sagebrush, bitter-
brush, fescue, wheat-
grass.
Immediate habitat
bare, bordered by
bitterbrush and
buckwheat; surroun-
ding ccrmunity is
sagebrush-grass.
2,000-0,000 feet;
level to moderate
slope; sandy soils,
particularly along
old river deposits.
2,850-4,400 feet;
slope usually steep,
nest often on eroding
faces of river ter-
races; gravelly and sandy
soils, sedimentary
in origin.
Seldom aLujiddnt
where it occurs, and
sites usually very
snail.
Plants us-jally
abundant on prcper
habitat, but such
sites very restric-
ted. Narrow habi-
tat suitability in-
dicates irost of
potential habitat
is probably occu-
pied; no potential
alternate range,
*See Table 10-3 for definition of threatened or endangered
2A toted of 23 and 45 plant species in Idaho have been previously proposed for endangered or threatened status, respectively, by the U. S. Fish aid Wildlife
Service, Office of Endangered Species (Federal Register: June 16, 1976; July 1, 1975). The list of proposed species expired Decarber 10, 1979. Species
that had rot either been officially designated threatened/endangered or deleted frcm the proposed list remained candidate species. Status of candidate; spe-
cies are continuing to be reviewed; as a result some species have been officially reproposed (and officially listed in sate cases). The two candidate spe-
cies listed above are undergoing evaluation and will be officially proposed for threatened or endangered listing in the near future. Two other species in-
cluded in the initial proposals (Draba douglasii and Primula cusickiana) have been reccratended for deletion frcm further threatened or endangered considera-
tion pars, octroi.).
3Data Sources: Henderson et al. (1977); Packard (1979); Kennison (1980).
'"Status listed in expired proposals (see note 2 above). T = threatened; E = endangered.
sHomk'i.-san ot al. (1977) reorimuraijd changing status to endangered.
-------
the higher elevations). Reptiles, on the other hand, are
year-round residents because of their restricted mobility.
Wildlife by Habitat Type. Some of the characteristic
or common wildlife species inhabiting each of tho county's
habitats are discussed below. Some wildlife species are
closely associated with a given habitat, whereas other species
occupy several habitats.
Riparian. Riparian habitat generally supports a more
diverse wildlife population than any other habitat type
because of the diversity of food and cover plants and the
availability of water.
Muskrats and beavers have been reported in the Barber
Pool area. Raccoons, deer, skunks, and foxes typically inhabit
riparian areas.
The most visible component of the wildlife community
in riparian areas is the various water**associated birds.
Great blue herons, Canada geese, mallards, green-winged-teals,
belted kingfishers, and killdeer are common on the water
and in the adjacent vegetation. Yellow-headed blackbirds,
red-winged blackbirds, and quail may be observed in the ad-
joining upland areas. Black-billed magpies construct their
stick nests in the trees. Great blue herons have established
rookeries near Eagle (Figure 12-1) and Star (Ada Council
of Governments 1973a). Birds of prey are commonly observed
in or near riparian habitat. Bald eagles, ospreys, marsh
hawks, and Swainson's hawks have been seen along the Boise
River.
Amphibians, such as the spotted frog, are common in
riparian areas due to abundant water supplies. Garter snakes
and other reptiles may also be observed.
Saqebr*u8h. Bitterbrushi and Gvaaslands. The arid foot-
hill and southern portion of the county support sagebrush,
bitterbrush or grassland habitats. Coyotes commonly occur
in these habitats, preying largely upon mice and other small
mammals. Deer migrate from the hxgher mountains into these
areas during winter, feeding on the shrubs and other plants
remaining uncovered by snow. Badgers, Ord kangaroo rats,
Townsend ground squirrels, and black-tailed jackrabbits are
among the other common mammals of these habitats.
Brushlands and grasslands are foraging habitats for
many birds of prey, such as golden eagles, prairie_falcons,
kestrels, burrowing owls, and ferruginous hawks. Other birds
characteristically inhabiting such areas are sage grouse,
long-billed curlews, ravens, horned larks, meadowlarks, and
savannah sparrows.
223
-------
tAtl-l
Chtnd»n
Lucky Pml
Dlvtrtlon
Don
Idaho
SOURCE: ACOO iSTSo, K«ot»«9
P»r». Comm.
M FIGURE 12-1. SPECIES OF SPECIAL CONCERN HABITAT
SOURCE• ACOO l«T»®
Idaho
P*ni»«n»iory
FIGURE 12-2. DEER AND ELK HABITAT
224
-------
Western fence lizards, western rattlesnakes, and sage-
brush lizards are typical reptiles in this habitat, Amphi-
bians are uncommon because of arid conditions.
Aariaulture. Farmland provides suitable habitat for
many wildlife species, as long as escape and breeding cover
is maintained between and around the fields. Ring-necked
pheasant, mourning doves, quail, and cottontail rabbits are
major species of agricultural areas. Waterfowl feed on stubble
and leftover grain in harvested fields.# Marsh hawks, burrowing
owls, and coyotes will forage for the mice and other small
mammals that live on farmlands. Amphibians occur m the
irrigation and drainage ditches.
Oven Water. Open water habitats serve as resting and
feeding areas for waterfowl and other water-associated birds.
Many species remain in the county year-round, breeding and
nesting in vegetation adjacent to the water. Barber Pool
is an excellent waterfowl breeding area, producing 125-150
Canada geese annually (Ada Council of Governments 1973a).
The greatest water-associated bird populations occur during
spring and fall migrations. Mallards, green-winged t®a '
shoveler, California gulls, white pelicans, American avocets,
and great blue herons are some of the species
and streams of Ada County. Osprey andcba^d.eajj®®
for fish and bald eagles prey on waterfowl in this habitat.
Douglas-Fir. Mammals inhabiting the Douglas-fir areas
include elk, deer, snowshoe rabbits, red squirrels,
mantled ground squirrels, porcupines, and b^s^ta^ ^Jain
Bird species include blue grouse, ruffed <3*ouse' /
chickadees, pine siskins, and red-breasted nuthatches. Spotted
frogs and garter snakes also occur in this habitat.
Urban-Industrial. Wildlife speciesinhabiting ^ban
areas are tolerant of human activity. Three of the ^os
common species (i.e., house mouse, house sparrow, _
are introduced. Other species include raccoons, night
hawks, black-billed magpies, cedar waxwmgs, and robins.
Threatened Species. Endangered sPfci^s; ,yfufPf
of Special Concern"Four mammal, ten bird and two reptile
species designated as endangered or known^to be of special
concern to governmental agencies or Pr*va*f
occasional seasonal or year-round inhabitants of the study
ar«a. Table 12-2 summarizes the status, habitat
food habits, distribution, and other inJ?rma^5naf®?^rf^9
these species. Of the listed species, the bald eagle and
long-billed curlew are the most likely to b®,*™Pajted
the current project; these two species are discussed below.
225
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'fable 12-2. Terrestrial Wildlife - Endangered and Threatened Species and Species of Special Concern5
Common Name
Status
Habitat and Special Requirements3
Food Habits
Distribution /Cements 3
Spotted bat
River otter
Kit fox
Bobcat
Ferruginous hawk
Southern bald eagle
Osprey
Prairie feilcon
Peregrine falcon
GolmJjicin tharp-
tailed grouse
Bolvrtii to
Sen, PT
Sen
Sen, Sp Con
Sen, Sp Con
Sen, Sp Con,
PT, BL
E, Sen
Sen, PT, BL
Sp Con, PT, BL
Er Sp Con
Son, Sp Cbn,
PC, BL
Sp Con
Usually arid open or scrub habitat; may
enter buildings and caves; highly selec-
tive of daily roost sites in cracks and
crevices of high cliffs and canyons.
Riparian habitats along streams and lakes
Vegetation arid land; open, level sandy
ground for burrcwing.
May occur in most wildlife habitats in
county; dens in rock crevices and
hollcw logs.
BIRDS
Arid sagebrush lands; grasslands, range-
lands, open country; nests built of
sticks {primarily big sagebrush) in
cliffs, in trees, or on the ground;
readily deserts nests if disturbed.
Roost near rivers, reservoirs, and
lakes providing sufficient food supply;
also forages in adjacent sagebrush,
grassland, and agriculture; scavenger
and predator.
Roost and forage near rivers, reser-
voirs and lakes.
Tall sagebrush and shrublands in Ada
County; plains, prairies, deserts;
nests on cliffs.
Wide ranging; open country; jiests on
cliffs usually near marshes and streams
providing adequate food.
Nonirrigated agriculture, grass-shrub
habitat, prairie.
Cottoiwnod-willow riparian; farmland;
brush open country; roadsides.
Primarily moths
Fish
Stall rodents
Small manuals,
birds, carrion
Jackrabbits,
cottontails,
and rodents
Fish, waterfcwl,
rabbits, rodents
Fish
Ground squirrels,
other srrvi 11
manna Is, birds
Birds
Seeds, buds,
berries
Seeds of leqimjs,
weedy herbs, and
cultivated qrains,
i I lUeeLs
Extremely unccmon; sunnier migrant.
Probably few (if any) in Boise River
belcw Lucky Peak Dam.
Very rare; confined to arid areas in
southern portions of the state.
Some populations have been considera-
bly reduced in recent years; probably
few (if any) in Boise River belcw
Lucky Peak Dam.
Restricted to the sagebrush areas of
the Snake River plains; populations
limited; observed occasionally.
Winter migrant; as many as 1.2 bald
eagles have been observed win; ¦bring
along lower Boise River; Barber Poei
primary wintering area.
Seasonal migrant in southern Idaho.
Snake River Birds of Prey Natural
Areas lias one of the world's 1 \rqes t:
nesting populations (i.e., £ ixjrctiii.
of world's total).
Very unccmnon seasonal migrant.
Low populations in Ada County.
JjCw, stable papulations in rr .¦-: ci ¦
habitat; along Boise River dewastr^.
of CVirdon City.
-------
Table 12-2. Cont'd.
Cartoon Name
Status
Habitat and Special Heguiremants
Food Habits3
Distribution/Ccrirnents 3
Mountain quail
Northern long-billed
curlew
Western burrowing owl
Sen, Sp Con Bitterbrush shrub steppe; brushy moun-
tain and forest slopes.
Sen, FT, BL Open short grass prairie; agriculture,
rangelands, sagebrush and bitterbrush
shrublands.
Sen, PT, BL Grasslands, sagebrush, desert, farms;
utilizes former rodent and badger
burrows.
Pine seeds, acorns
berries
Insects
Small manuals,
insects
Low population north of Lucky Peak
ervoir; and Along Crane, Hulls, WatTa
Springs, and Maynard Creeks.
Nest north of Barber Pool.
Populations: low in winter-scring;
mediutt in sunrcer-fall.
Western ground snake
Desert night snake
REPTILES
Sen, Sp Con Annual grasslands; tell sagebrush; sand
and subsurface moisture.
Sp Con Annual grasslands; tall sagebrush;
deserts.
Spiders, centi-
pedes, insects,
insect larvae
Frogs, lizards
Medium year-round population levels.
Median year-round population levels.
''Species of Special Concern: Species whose population numbers are known to be of concern to governmental agencies or scientific, educational, or publtc
interest groups.
'status:
E - Endangered Species; designated endangered under the Federal Endangered Species Act of 1973 (as amended through December 28, 1979). "Ttcz' term
'endangered species' means any species which is in danger of extinction throughout all or a significant portion of its range other than a species
of the Class Insecta determined by the Secretary to constitute a pest whose protection under the provisions of this Act would present an over-
whelming and overriding risk to man."
T - Threatened Spades: designated threatened under the Federal Endangered Species Act of 1973 (as amended through December 28, 1979). "The: terra
"threatened species' means any species which is likely to became an endangered species within the foreseeable future throughout all or a signifi-
cant portion of its range."
Sen - Sensitive Species: Designated as sensitive in a Master Memorandum of Understanding between the Idaho Department of Fish and Game and the. U. S.
Bureau of Land Management (1977). Sensitive species are those lacking official listing and: . . la] whose populations are consistently small
and widely dispersed, or whoso ranges are restricted to a few localities, such that any appreciable reduction in numbers, habitat availability, ov
habitat condition might lead toward extinction; and [b] whose numbers are declining so rapidly that official listing may becoma necessary as a
conservation nwasure."
Sp Con - Species of Special Concern: Listed as a species of special concern in the fish and wildlife "Policy Plan" of the Idaho Department of Fish ana
~"8i>ue.Ses of ai>x:i.jl coiK.t-Tti are thtxw species wliosc restricted range, specific lvtbit.it retjuivumints and/or luw population mwU i:; nuk tliew
vulnerable to elimination from the state if adverse impacts on populations or habitat occur."
FT
Potentially Threatened: included in the original identification of potentially threatened wildlife, the "Bed Book" (U. S. Fish and Wildlife Service
1973), but not now designated as endangared or threatened (0. S. Fish and Wildlife Service 1980); o: listed as sfcatus-urxV'ttrmined by Mrblor (1'O i),
-------
Table 12-2. Cont'd.
BL - Blue Listi Included in the National Audubon Society "Blue list"; an "annual 'early warning list" of declining, threatened, or vulnerable Ibixd]
species" (ftrbib 1979). Only those species having sane additional status designation ate listed above.
3Habitat requirements, life history, distribution, and other information taken frcm: Burt and Grossenheider 1976; Idaho Department of Fish and C-r,L.» 1977,
1978; Jensen 1980; Mohler 1974; National Fish and Wildlife Laboratory 1980; Peterson 1961; Snow 1972, 1973, 1974a, 1974b, 1974c; Stotbins 1966; U. S.
Bureau of Land Management 1980; U. S. Fish and Wildlife Service 1973; Zarn 1974a, 1974b.
-------
Bald. Eagle. The southern bald eagle is designated
"endangered" by the U. S. Fish and Wildlife Service. His-
torically and as late as the 1880s, bald eagles nested along
the Boise River near Eagle, feeding on the large steelhead
and salmon runs. Elimination of the fish runs by damming
the river and the urbanization of the Boise area has restricted
local bald eagle activity primarily to winter use of the
Barber Pool (Figure 12-1) l(Keating pers. comm.). One to
five bald eagles make incidental use of the Boise River ri-
parian habitats between Boise and Star (Howard pers. comm.).
Barber Pool is a large area of wooded riparian habitat,
islands, and braided river channels behind Barber Dam. An
abundant whitefish and salmonid fishery provides the primary
prey for the eagles; waterfowl, jackrabbits, and various
upland species comprise a smaller percentage of the prey.
Jensen (1980) surveyed the Boise River between Mores Creek
Bridge and Boise during the winter of 1979-1980. As many
as 12 bald eagles were observed along the river, 7 in Barber
Pool. Bald eagles occupied the area from late October to
early April. Eagles roost in taller cottonwoods and on cliffs
south of the river.
Northern Long-billed Curlew. The northern long-billed
curlew is one of 14 bird species designated as "sensitive"
under a memorandum of understanding between the Idaho Depart-
ment of Fish ahd Game and the U. S. Bureau of Land Management
(1977). The species has no official threatened or endangered
status, but was listed by the U. S. Fish and Wildlife Service
(1973) as a "status undetermined" species (i.e., possibly
threatened with extinction, yet sufficient information to
conclusively determine its status was lacking) . Mohler "(1974)
also listed this species as status undetermined.
The long bill and long legs of the curlew adapt it to
feeding on insects in short grass plains, rangelands, and
agricultural fields. Nesting occurs in open prairie and
is easily disturbed by human activity.
Curlews are largely spring and summer inhabitants of
Ada County, usually leaving Idaho to migrate to the south-
western United States by August. Curlews nest in suitable
upland habitat northeast of Barber Dam (Keating pers. comm.)
a^d in central and northwestern Ada County (Ada Council of
Governments 1973a) (Figure 12-1). The U. S. Bureau of Land
Management recently conducted a study of long-billed curlews
in Canyon County; analysis and publication of results have
not been completed.
Recreational Species. A variety of recreational wildlife
(i.e., game species) occur in Ada County. Ducks, ring-necked
229
-------
pheasant, mourning doves, chukar partridge, quail, and Hun-
garian partridge are the major birds harvested in the county;
blue grouse, ruffed grouse, geese, and sage grouse are also
taken. Elk, deer, and cottontails are the county's game
mammals. Figures 12-2 through 12-6 illustrate the distri-
bution of some of these species in Ada County.
Deer migrate to the lower foothills of the Boise Front
or south of Lucky Peak Reservoir from higher elevations during
winter when snow is deep or temperatures are severe. Deer
formerly migrated onto the Snake River Plain as far downstream
as Lake Lowell; urbanization has eliminated most such long
migrations.
Breeding areas for waterfowl are limited in Ada County,
although approximately 10,000 ducks are produced annually
from breeding areas in Barber Pool, along the Boise River
downstream of Garden City, along the Snake River, and at
the county's smaller reservoirs.
Quail occur in the riparian and brushy habitats along
several of the county's creeks and the Boise River. Chukar
and Hungarian partridge inhabit arid brushlands and some
agricultural fields. Blue grouse and ruffed grouse are
restricted to the timbered areas of the Boise Front; sage
grouse occur in sagebrush habitat south of Lucky Peak Reservoir.
Pheasant occur in most of the agricultural areas of
the county. Pheasant are well adapted to farmland habitat,
as long as sufficient cover exists along fencerows, between
fields, and along roads. Consolidation of small farms into
large farms, cultivation and mowing up to and directly adjacent
to the fenceline, and modern sprinkler irrigation techniques
reduce availability of suitable habitat to pheasants.
Mourning doves are widespread throughout most of Ada
County, Farms, grassland, brushland, riparian areas, and
woods all provide habitat for this species.
Impact Analysis
The projected direct and indirect impacts of the planned
facilities are discussed below. Direct impacts are those
resulting from facility construction or operation at the
plant sites, along the pipeline routes, or at the sludge
disposal sites. Indirect impacts are those resulting from
growth and urbanization that would not have occurred without
increased waste treatment capacity.
230
-------
TREATMENT PLANTS
© IMU
0 Will • Oil!
® LA NO IN IT.
0 tOWAN FIIUO
V -LEGEND-
13 MUCIN# »IM
<•>!«
\
«, Uueky Paak
SOURCE' ACOO 19730
FIGURE 12-3. WATERFOWL HABITAT
SOURCE* AC06 1»75o
FIGURE 12-4. QUAIL AND GROUSE HABITAT
: 231
-------
A
N
11
M8MMN
£2°32<«i3?
sHMHBMHw
Kw" »frAtAfra»3*fli
»VaVa Ml
mmmm
ldoho\ \\
. P«nl tuntiary
SOURCE:ACOO 1973a
Chtndin
Idohe
P«nlt«ntiary
SOURCE! ACOO 197 3 0
-------
Direct Impacts
Lander Street and West Boise. Expansion of the capacity
of the Lander Street and West Boise facilities will have
few direct impacts at the plant sites. Biotic communities
of the sites are currently highly disturbed. Most construction
will occur within the existing plant sites in areas formerly
used for waste treatment or in landscaped areas. Disturbance
of local wildlife during construction should be minor and
temporary. Disturbance caused by operation of the expanded
plant should not be significant.
Construction of the sludge pipeline will impact plant
communities slightly along the route, including riparian habitat
where the pipeline crosses the river. The vegetation should
recover following construction if no right-of-way maintenance
program is instituted.
Sludge disposal at the penitentiary should have little
or no effect on wildlife. If additional acreage is brought
under cultivation as part of the project, some of the native
species supported on the presently uncultivated land will
be lost. The cultivated fields, however, will provide forage
for agriculture-tolerant species.
Eagle. Construction of the new Eagle treatment facilities
will eliminate about 15 acres of riparian habitat along the
Boise River. The riparian habitat will be replaced by aerated
lagoons, an equalization basin, several small structures,
and dikes. The connecting pipeline between the new and old
facilities will lie almost totally outside riparian vegetation.
The proposed plant site is located in a floocLhazard
zone and is in one of the larger riparian comunlties alon^
the river. Because of its size and configuration (extending
over 100' yards inland from the edge of *1*® r*v®V.' ~*is
riparian community provides excellent habitat for dee »
raccoons, yellow-headed blackbirds, kingfishers,_great blue
herons, and many other species. Riparian areas Jhat
only a line of trees or a narrow band of vegetation along
the streamcourse do not support the great wildlife diversity
that such a large, deep parcel is able to support. The
riparian habitat at the Eagle site is of even_greater impor
tance because it is one of only three large riparian areas
in the reach of the river from Boise to Eagle (the ^her _
two ares 1) downstream of the Strawberry Glen Airport, and
2) at Barber Pool).
Loss of the riparian habitat will reduce the wildlife
populations inhabiting the site. Water-associated .
and mammals will be detrimentally affected. Available roosting
sites for raptors, including possibly an occasional bald
eagle, will be reduced.
233
-------
Executive Order 11990, Protection of Wetlands, "requires
Federal agencies conducting certain activities to avoid,
to the extent possible, the adverse impacts associated with
the destruction or loss of wetlands and to avoid support
of new construction in wetlands if a practicable alternative
exists" (40 CFR 6.302). As defined in this policy, "wetlands"
includes marshes, sloughs, river overflows, and similar areas.
In response to Executive Order 11990, and in consultation
with the U. S. Fish and Wildlife Service, EPA performed a
wetlands assessment of the Eagle site. The U. S. Fish and
Wildlife Service concluded that the site is not a natural
wetland (see Chapter 15, responses to comments).
Although construction of the Eagle facilities will cause
a direct loss of appproximately 15 acres of riparian habitat,
the remaining riparian habitat on the 65-acre, district-
owned site (if maintained in its present condition) may persist
longer than if the site had remained in private ownership.
Many acres of privately-owned riparian habitat have been
converted to urban and agricultural use in the past.
Specific plans have not been developed for the old
treatment plant site once the new plant is completed. The
facilities plan (J-U-B Engineers 1980) states that a possible
use could be park development. Loss of the open water habitat
provided by the old ponds will not be significant; the new
ponds and adjacent river will provide similar habitat. Develop-
ment of riparian habitat at the site could enhance its wildlife
value.
The pipeline from the ponds to the rapid infiltration
site is expected to run along existing rights-of-way. Such
areas are already highly disturbed, and construction impacts
on wildlife should be negligible.
The rapid infiltration site is currently under cultivation
and is immediately adjacent to a heavily stocked feedyard
that is completely lacking in vegetative cover. A wooded
canal that will carry infiltration effluent runs along the
south side of the site. No impacts are expected at the site
with the possible exception of some disturbance in the canal
when drainage pipes are being installed.
Southwest Area. Because the "rural lifestyle" land
use plan (APA 1980) for this area is currently the most
likely to be implemented, no direct impacts are foreseen.
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Indirect Impacts
Boise and Eagle. The major impacts of expansion of
the Boise and Eagle facilities will result from accommodating
urban growth. The habitats primarily impacted will be the
agricultural lands and the arid brushland-grasslands in the
foothills of the Boise Front and on the Snake River .
Many or all of the local populations of the two candidate
threatened or endangered plant species could be lost to ur-
banization if no provisions are made for protecting the popu-
lation. Developments impacting these endangered plants may
be proposed and approved without the facilities expansion.
Loss of the farmlands# brushlands, and grasslands will
reduce the populations of the species (e.g., pheasants and
mourning doves) inhabiting those areas. Foraging habitat
for raptors such as kestrels and marsh hawks will be reduced.
As urban areas extend into the foothills, deer winter
ranges will be detrimentally affected. Although most of
the crucial wintering areas of the Boise Front are in public
ownership (Parker pers. comm.), some important areas will
be lost, and the incremental losses of wintering areas of
lesser importance will continue. Increased recreation,
especially off-road vehicles and snowmobiles, will also
degrade the wildlife habitats along the Boise Front.
Urban growth will likely impact the feeding or nesting
areas of the long-billed curlew, through both direct habitat
loss and disturbance by increased human activity in adjacent
areas. Urbanization near Barber Pool will increase disturbance
and decrease secondary foraging habitat for bald eagles.
Higher local human populations will increase use of the Barber
Pool area for recreation. The majority of recreation use,
however, should occur in suaaner when eagles are absent. Bald
eagles are considered vulnerable to human disturbance ? the
precise level of nearby Jtunian activity that b#ld esfies will
tolerate, however, is unknown.
Southwest Area. The loss of agricultural and brushland-
grassland habitat to high density urban development will be
avoided by implementing the "rural lifestyle" alternative.
Urban growth will occur on larger lots suitable for septic
tank systems, however, taking some farmland out of production,
replacing existing vegetation with landscaping plants, and
increasing human activity. Pheasants and other farmland
wildlife will be detrimentally impacted, and raptor foraging
habitat will be reduced. These impacts will be less severe
than would be projected for higher density development.
231.
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Impact Summary
Few direct wildlife impacts will result from the proposed
projects. A major direct detrimental impact will be the loss
of a large area of Boise River riparian habitat at the proposed
Eagle plant site. Accommodated urban grwoth will cause the
greatest long-term impacts on wildlife. Conversion of open
spaces in the foothills and on the plain to housing and industry
will reduce the available habitat for many species. The bald
eagle and long-billed curlew are especially vulnerable to
disturbance.
EPA has concluded that no practical alternative site exists
for construction of the Eagle facilities. A major factor in the
acceptance of this site is the determination by the U. S. Pish
and Wildlife Service that the proposed site is not a natural
wetland. However, EPA recommends that the Eagle Sewer District
make every effort to minimize impacts to the riparian habitat at
the site. EPA has requested that the ESD consult with the Idaho
Department of Fish and Game and the U. S. Fish and Wildlife
Service during the pre-design phase to ensure that mitigation
measures deemed necessary by these agencies are incorporated
into the design.
A variety of mitigation measures may be incorporated into
the facilities design. Potential mitigation measures include:
° Retention of a 100-foot-wide buffer strip of riparian
vegetation between the river and the facility.
0 Dedication of the remaining riparian habitat within
the district-owned parcel to wildlife, and maintaining
the riparian vegetation.
Urbanization and recreation within or adjacent to Barber
Pool should be planned to minimize bald eagle disturbance.
Development, for example, should be discouraged near the cliffs
used as roosting sites, and winter recreation should be directed
toward the periphery of the pool, rather than through the middle
of it. Similarly, development should be directed away from
curlew nesting areas. Indirect impacts can be reduced through
local development impact review. Local land use plans and
ordinances currently indicate concern for wildlife resources
and provide for mitigation of development impacts.
236
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Chapter 13
Archaeological and Cultural
Resources
-------
Chapter 13
ARCHEOLOGICAL AND CULTURAL RESOURCES
Introduction
Section 106 of the National Historic Preservation Act
requires the head of any federal agency with jurisdiction
over a proposed federal or federally-assisted project to
consider the impact of the project on sites, districts or
structures included on, or eligible for inclusion on, the
National Register of Historic Places prior to taking action
on the project. The federal agency must also provide the
Advisory Council on Historic Preservation the opportunity
to review the cultural and historic implications of the pro-
posed project prior to action.
Regulations implementing Section 106 identify the pro-
cedure for evaluating potential impacts on properties on
or eligible for the National Register. This includes:
1) identifying properties within the project's area of impact
that are on or eligible for inclusion on the National Register
of Historic Places (this includes consulting the National
Register and the State Historic Preservation Officer [SHPO]);
2) determining whether properties on or eligible for the
National Register might be affected by the project; 3) deter-
mining if the effect is adverse; 4) notifying the Advisory
Council and the SHPO of the findings of the impact analysis;
and 5) proceeding with the consultation process if an adverse
effect is anticipated.
The annual listings of historic properties appearing
in the March 18# 1980 Federal Register and monthly supple-
ments have been reviewed and the Idaho State Historic Pre-
servation Officer (SHPO) has been contacted with respect
to possible historic and cultural resources which may be
affected by the wastewater treatment facilities proposed for
the Eagle Sewer District (ESD) and the City of Boise.
Impacts
As a result of consultation with the Idaho SHPO and
review of the annual listings of historic properties, EPA
has determined that none of the alternatives evaluated for
providing wastewater facilities for the ESD and the City
of Boise will affect any historic properties included in
the National Register of Historic Places. In addition, it
237
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has been determined that there are no properties within the
area of environmental impact that will be affected which
are eligible for inclusion in the National Register.
In further consultation with the Idaho SHPO, the state
archeologist has determined that there are no cultural
resources located within the ESD project area. This deter-
mination is based on an archeological field reconnaissance
of the proposed construction site.
The proposed City of Boise wastewater treatment facilities
have also been reviewed by the state archeological officer.
The primary area of concern appears to be along the Boise
River. Of the numerous archeological surveys conducted along
the river, the only site found to date is a large trash deposit
located in the Julia Davis and Ann Morrison Parks. Proposed
interceptor alternative alignments will, however, run near
the river; therefore, the state archeologist would like to
periodically inspect the open trenches and dirt removed from
them to record buried archeological sites and recover any
artifacts found (see letters at end of this chapter).
Based on this request, EPA will require the City of
Boise to provide access to Idaho SHPO representatives for
inspection of trenches and excavated materials. This require-
ment will be included in a Step III (construction) grant
condition. The state archeologist has concluded the proposed
sludge pipeline will have no effect on any sites.
If any changes in proposed construction location
associated with the proposed Eagle or Boise facilities
should occur, the state archeologist will be notified and
appropriate action taken to comply with Section 106.
238
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January 21» 1981
/j^\
"r. "nynr* ''•lb1 is
Project Planner
J-T;-r !*n«ineers, Inc.
250 ^coc'vv'ood Avenue, Tuite 1
noJ.if, Idaho >'3705
Re; '\t-1o "•¦'tnr mi.l ''waer "M^trfct
Vnr 'r. ^
An irc'.neolo * Jed ''
construction Mto in
han ii?pn conducted.
! ' ri'ronnnlsr-unci r>£ thn «ro«osr»tl
t'"'C ;>i"lr 'if.pr *ml Untrict
°frtce no cultural resources <-»<9rrolPCt h*v<» io effect or any ntc!\ae~*
olor;ccrcl",
T^ocflt J, ^jr.cpn
'¦it*to Arch.iool
State historic T'r'eoer/fltlon Office
cc: M,nl UoflRll, Jones w? Pto1-ar> Aa^oeintofi
239
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December 22, 1980
Ma. Margaret L. Ziimaerwan
ck2k mil
700 Clearwater Lane
Box 8748
Doiso, Idaho 83707
Dear Ma. Eiranermn:
We have finally reviewed tho irap*} you nent for
the iuoiae \'astw*ater Kacilitiea #lao. Our only
area of concern in nlon;- the Jioteo River. i*o
haw conducted .numerous archaeological surveys alonp:
the rivet a;:J l.-vo yet to Mm' any site* other than
the larj-.e historic tranh ucpasie* in Julia Davin
and Ann ."crrlnon parka.
"Die sludge pipelines *111 :>,tve no effect on any
archaeological or historic rjltes.
For the intercoptorn runniny; near the river we Uo
want to periodic?llv inspect.tho open trenches add
the dirt recoved Trow ther to racnrd burjo.v arch-
aeological si tea and recover any artifacts uncovered.
No arbhaeolo; ical excavation or nlov anvne of the
construction will be needed.
Sincerely,
Thomas J. CJreen
State Archaeologist
State Historic Preservation Office
240
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Chapter 14
Summary of Significant
Project Related Impacts
-------
Chapter 14
SUMMARY OF SIGNIFICANT PROJECT RELATED IMPACTS
In this chapter the alternatives proposed for the City
of Boise and the Eagle Sewer District (ESD) wastewater treat-
ment projects are reviewed and the significant impacts of
each are briefly discussed and summarized under a number
of environmentally important headings.
Wastewater Treatment and Disposal Impacts
Boise River
Impacts. There should be no significant adverse impacts
resulting to the Boise River from the proposed wastewater
treatment plant at the Cities of Boise and Eagle, provided
that the l-in-10 year low flows used in the Boise facilities
designs are actually implemented.
Residual chlorine levels in the Boise River will be
decreased due to installation of dechlorination. Increased
nutrient loadings to the Boise River may cause greater algal
growth levels and greater dissolved oxygen sags in the lower
river. The quantitative extent of the impact is not known.
Mitigation. The l-in-10 year low flow used in designing
facilities expansion needs to be assured in order that the
receiving water quality criteria can be met.
Growth-Related Impacts
The proposed projects will provide capacity to accom-
modate growth. This growth will cause indirect impacts upon
a number of environmental features. These impacts have been
described in previous chapters and are summarized under the
following environmental topic headings where relevant.
Air Quality
Impacts. Vehicle emissions from traffic associated
with growth accommodated by the proposed projects will
partially offset emission reductions which would otherwise
241
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occur (due to current vehicle emission control programs).
Violations of the federal carbon monoxide (CO) standard are
expected to continue beyond the year 2000 unless additional
air quality improvement measures are taken. Projected 1987
CO emissions from motor vehicles must be reduced by as much
as 53 percent to achieve air quality standards throughout
the Boise area,
Mitigation. The APA is currently reviewing a number
of measures which could be implemented to help achieve air
quality standards throughout Ada County. These measures
include:
o Implementation of a county-wide vehicle inspection
and maintenance program with special consideration
given to "cold start" emissions.
o Improved public transit (short-term and long-term
programs).
o Carpool/vanpool programs.
o Park and ride facilities.
o Traffic flow improvements through signalization
programs, intersection design changes, added road
lanes; many specific roadway and intersection
improvements are already accounted for in the
emission forecasts (see Appendix A).
o Exclusive bus and carpool lanes.
o Parking management programs (controls on the loca-
tion and duration of on- and off-street parking;
parking costs; supporting park and ride programs;
facility design and operation; etc.).
o Controls on extended vehicle idling at drive-in
facilities.
o Pedestrian malls.
o Improved bicycle facilities.
o Employer actions to support transit, carpool/van-
pool programs, bicycle usage, flexible work
schedules, etc.
These measures will require further study to determine
the effectiveness of each measure to aid in the achievement
of air quality maintenance standards.
242
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Conversion of Agricultural Land to Urban Uses
Impacts. Future development in the Boise, Eagle, and
Southwest areas will occur largely on lands identified by
the Soil Conservation Service as "prime farmlands". Most
of these areas have been shown for future urban development
on local comprehensive plans, and currently have minimal
crop production.
Public Services and Facilities
Impacts. The adverse impacts on public services from
growth accommodated by wastewater facilities will be most
significant in areas where the existing level of public
service is currently deficient. In the Boise metropolitan
area, the outlying areas are presently experiencing some
public service deficiencies, primarily in police and fire
protection and schools. In the Eagle area, adverse impacts
on most public services will result as growth extends beyond
the central city planning area. Additional medical care
and hospital facilities will be required.
Mitigation. Existing Ada County and Boise policies
should be implemented to avoid further compounding existing
public service deficiencies. These policies encourage con-
centrating future development in areas already provided with
public services, or in areas contiguous to serviced develop-
ments .
Urban service policies are implemented in part by desig-
nation of urban service planning areas in Ada County. Most
residential, commercial, and industrial development is
encouraged by the Ada County Comprehensive Plan to occur
in urban service planning areas.
The policy plan for the Boise Metropolitan Area also
uses the urban service planning area as a mechanism to co-
ordinate growth and the provision of urban services.
Vegetation, Wildlife and Fisheries
Impacts. Accommodated urban growth will cause variable
long-term impacts on wildlife. Conversion of open spaces
in the foothills and on the plain to housing and industry
will reduce the available habitat for many species. The
bald eagle and long-billed curlew are especially vulnerable
to disturbance.
Indirect impacts due to population growth will consist
of increased sediment load, and higher flood peak flows from
urbanized tributaries. Increased sedimentation of stream
gravels will lower habitat quality conditions for trout and
whitefish in the Boise River.
243
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Mitigation.
Vegetation and Wildlife. Urbanization and recreation
within or adjacent to Barber Pool should be planned to mini-
mize bald eagle disturbance. Development, for example, should
be discouraged near the cliffs used as roosting sites, and
winter recreation should be directed toward the periphery
of the pool, rather than through the middle of it. Similarly,
development should be directed away from curlew nesting areas.
Fisheries. Implement drainage and runoff control measures
to prevent sediments from growth-related development entering
the streams and rivers.
Drainage
Impacts. Existing problems of inadequate or poorly
maintained drainage facilities are likely to persist. These
problems include potential flooding and property damage from
inadequate storm drainage systems, overloading of irrigation
canals in some areas, and nuisance conditions at poorly main-
tained detention ponds.
Mitigation.
o Designate an agency to implement countywide drainage
planning, facility implementation, maintenance and
administration.
o Seek legislative clarification to provide full
drainage authority and funding.
o Develop, adopt and implement consistent drainage
criteria for storm drain design and flow routes from
100-year flood runoff.
o Prepare, adopt and implement drainage master plan,
specifying facilities or concepts, and providing
for funding and a consistent approach to storm drain
authorization with irrigation facilities.
Resource and Energy Use
Impacts. Population increases in the sewered area will
use energy in the residential and transportation sectors
and could stimulate consumption in the commercial and indus-
trial sectors. The principal energy sources are natural
gas, electricity, and petroleum fuels. Some geothermal energy
is used for space heating in Boise, and many residences use
wood as fuel.
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Future trends in the availability and consumption of
energy resources are difficult to predict. The local avail-
ability of energy will be closely related to regional and
global trends in energy sources and supplies.
Mitigation, Institute energy conservation measures.
Traffic Congestion
Impacts. Population growth supported by increased waste-
water treatment plant capacity will add traffic loads to
the existing roadway system of the area. Roadway elements
which currently experience significant congestion may be
further impacted by additional development.
Mitigation. Develop local traffic plan considering
air quality attainment standards.
Water Resources
Impacts. As additional agricultural lands in the Boise
Valley are converted to nonagricultural uses the balance
between nitrogen and salts loadings and the volume of Water
recharged to the aquifers will be adversely affected.
Under land use Plan C, rural lifestyle, it is expected
that the Southwest Boise area will retain its rural char-
acteristics for the foreseeable future. It is improbable
that the anticipated growth will cause a major change in
groundwater quality and quantity. However, further data
are needed to ensure protection of public health and safety as
growth occurs.
Mitigation. Regular monitoring of shallow and deep
groundwater quality, preferably on a seasonal basis, should
be carried out by an appropriate government agency to pro-
vide needed data for future planning arid decision-maXing
purposes. The Southwest Community Wastewater Management
Plan (APA 1981) identifies programs and recommendations which
will further protect groundwater supplies in rural areas.
Public Health, There should be no significant iragiact
upon groundwater or public health as a result of liquid
sludge disposal as proposed and deacribed in the Boise waste-
water treatment facilities plan*
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Construction-Related Impacts
There are many construction-related impacts which will
be common to all the alternatives at both Boise and Eagle.
These impacts relate to the general use of equipment and
are chiefly in the categories of noise, dust, sedimentation,
and traffic. Impacts may also include physical displacement
or destruction of resources such as vegetation and wildlife.
The proposed projects involve modification or construction
of facilities at several different locations in the Boise
and Eagle area. The significance of construction-related
impacts usually depends on site-specific conditions. Thus,
the following discussions are organized in terms of project
elements at different locations.
Noise, Dust and Erosion
Impacts. Figure 14-1 identifies noise levels by types
of equipment which are typically used for construction and
demolition. Most of this equipment will be necessary for
implementation of the primary treatment improvements and
pipeline construction. In addition to equipment used within
the primary plant sites, vehicles related to construction
operations will be entering and leaving the sites. Con-
struction-related vehicles will include passenger vehicles
for workers, materials transport trucks, and waste removal
vehicles.
Plant site grading and excavation of facility sites and
pipelines, demolition of abandoned facilities, vehicle movements
on unpaved roads and parking areas, and handling of debris
from construction or demolition will produce dust and expose
soil surfaces to erosion. Dust generated by construction
activities will undoubtedly be carried off-site on occasion.
South Boise Interceptors. Short-term adverse impacts
upon recreational, green belt, and park areas will occur
from the river north route, and upon a recreational area
from the river west route. Short-term adverse impacts will
result to residences along the Adams Street route, and to a
recreational vehicle park near the river east and inland
east routes.
North Boise Interaeptors. Short-term adverse impacts
will result to approximately the same extent from all four
proposed North Boise interceptor routes.
Eagle. No significant adverse impacts will result from
the proposed treatment plant facilities and interceptor.
246
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Figure 14-1
NOISE FROM CONSTRUCTION EQUIPMENT
NOISE LEVEL (dBA) AT 50 FT
60 70 80 90 100 lift
EQUIPMENT POWERED BY INTERNAL COMBUSTION ENGINES
1 EARTHMOVING
COMPACTERS (ROLLERS)
FRONT LOADERS
BACKHOES
TRACTORS
SCRAPERS, GRADERS
PAVERS
TRUCKS
H
1
j
1
—H
1—
1
—1
H
,
—I
MATERIALS HANDLING
CONCRETE MIXERS
CONCRETE PUMPS
CRANES (MOVABLE)
CRANES (OERRICK)
1
1
H
K
1
H
1 STATIONARY |
PUMPS
GENERATORS
COMPRESSORS
*
i
1 '
H "" ;
1—
1
1 IMPACT
' EQUIPMENT
PNEUMATIC WRENCHES
JACK HAMMERS AND ROCK DRILLS
t '<
h- -
— 1
PILE DRIVERS (PEAKS)
1
1
OTHER
VIBRATORS
>
1
SAWS
h——-
i
NOTE > Bastd on limittd available data wraplM
SOURCE: U. S. Environmental Protection Agency, 1971b.
247
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Mitigation. Noise can be minimized by requiring that
all internal combustion engines be equipped with mufflers
and baffles and be properly maintained. Construction opera-
tions should be limited to normal daylight working hours.
Vehicles should carry full loads of materials and passengers
to minimize trips.
Normal dust control measures should be followed during
construction (water sprinkling or chemical treatments such
as calcium chloride or light petroleum products for con-
struction and parking areas). Disposal areas on agricultural .
land should be replanted soon after disposal of soil. Exposed
areas and spoil piles should be watered down to prevent dust.
Exposed areas which will be incidental to construction and
not required for operations should be reseeded following
construction, preferably with natural vegetation.
Traffic Disruption
Impacts. Construction activities at the primary treat-
ment plants will not directly block or otherwise disrupt
traffic patterns on adjacent streets. Movement of construction
equipment, construction materials, new facility equipment,
and construction wastes could result in temporary reductions
in traffic flow on area roadways. This would be most likely
for trucks bringing over-sized loads to the plant sites (heavy
construction equipment and new facility equipment).
Excavation and placement of interceptors and sludge
pipelines will temporarily disrupt traffic. Trenching adja-
cent to or within agricultural areas will temporarily restrict
access and movement of agricultural equipment. Pipeline
routes will intersect roads, requiring an open cut across
pavement. Motor vehicle flow will be temporarily detoured
or restricted for jackhammer and trenching operations across
roadways.
Mitigation. Trucks with over-sized loads should be
routed to the construction site so as to avoid peak traf-
fic- periods and major local arterials. On-site parking
areas should be provided for construction employees.
Vegetation and Wildlife
Impacts.
Eagle. The proposed plant site is in one of the larger
riparian communities along the river. Construction of the
proposed Eagle facilities treatment ponds will eliminate
248
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a minimum of 15 acres of riparian habitat along the Boise
River. Loss of the riparian habitat will reduce the wildlife
population inhabiting the site, especially water-associated
birds and mammals.
Boise. Riparian habitat will be destroyed by certain
of the proposed interceptor and sludge line routes which
may be located near the river. The river west route for
the South Boise Interceptor would destroy more than 5 acres
of riparian vegetation in a narrow strip along the river
if located near the bank.
The proposed North Boise interceptor routes would have
significant impact only where Main A would cross Eagle Island
and the river, and where Main E crosses the river. There
would be fewer impacts from the other routes which generally
are located on irrigated farmlands.
The greatest impact would probably be the crossing of
Eagle Island which would disrupt vegetation and may disturb
an active great blue heron rookery. Impact would be greatest
during the heron and waterfowl nesting season (February
through June).
Construction could conflict with bird hunting seasons
in the fall.
The destruction of riparian habitat may generally be
regarded as a potentially significant short-term impact. Vege-
tation will be lost, and associated animal life will be lost
or disturbed.
The long-term impacts will not be significant if vege-
tation is reestablished.
However, if any of the corridor routes are used for
other land uses, such as bikeways, then there would be a
significant long-term adverse impact upon the wildlife due
to elimination of habitat and to disturbance by humans.
Mitigation. EPA recommends that both the Eagle Sewer
District and the City of Boise consult with the Idaho Department
of Fish and Game and the U. S. Fish and Wildlife Service during
pre-design of the proposed projects. Impacts to the riparian
habitat that will result from construction of the Eagle sewage
treatment plant and the probable location of interceptor and
sludge line routes for the Boise facilities should be mitigated
to the maximum extent possible. Consultation ydth state and
federal agencies will ensure that specific mitigation measures
deemed necessary by these agencies are incorporated into the
design.
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Interceptor and sludge lines'proposed for Boise should be
located to avoid riparian habitat where feasible and the
vegetation within the corridors should be restored.
Other land uses should not be established in areas where
significant wildlife use exists, such as the great blue heron
rookeries.
Fisheries
Impacts. There is some potential for fisheries impacts
resulting from river crossings by interceptors and sludge
pipelines. All of the Boise interceptor and sludge pipeline
alternatives would require at least one river crossing. River
crossings will result in temporary adverse effects on aquatic
biota. Fall spawning runs of anadromous fish species may
also be affected. Species will be displaced from the area
of equipment operations, and sedentary species or fish eggs
could be destroyed. Sedimentation from excavation and river
bottom disturbance will affect fish, causing avoidance of
silted waters and possible gill irritation. Insects which
serve as food for fish will also be affected. Siltation
will also cause smothering of fish eggs in downstream areas.
These adverse impacts are not expected to be significant
if stream crossings are conducted as advised by the Idaho
Department of Fish and Game and the U. S. Army Corps of Engi-
neers. All stream crossings will require appropriate permits
from the Idaho Department of Fish and Game and the U. S.
Army Corps of Engineers.
Mitigation. Specific mitigation measures should be
developed in consultation with the Idaho Department of Fish
and Game and the U. S. Army Corps of Engineers. The Corps
has issued a Nationwide General Permit for the placing of
dredged or fill material for backfill or bedding of utility
line crossings provided the following conditions are satisfied:
"a. The watercourse is returned to precon struct ion
bottom contours and all excess material is removed
to an upland disposal area.
b. That the discharge will not be located in the proxi-
mity of a public water supply intake.
c. That the discharge will not occur in areas of con-
centrated shellfish production.
d. That the discharge will not destroy a threatened
or endangered species as identified under the En-
dangered Species Act, or endanger the critical
habitat of such species.
250
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e. That the discharge will not disrupt the movement
of those species of aquatic life indigenous to
the water body.
f. That the discharge will consist of suitable material
free from toxic pollutants in other than trace -quan-
tities, •
g. That the discharge will not occur in a component
of the National Wild and Scenic River System or
in a component of a State Wild and Scenic River
System.
The following management practices should be followed
to the maximum extent practicable to minimize the adverse
effects of the discharge on the aquatic environment:
a. Discharges in spawning areas during spawning seasons
should be avoided.
b. Discharges in wetland areas should be avoided.
c. Heavy equipment working in wetlands should be
placed on mats.
d. Discharges into breeding and nesting areas for
migratory waterfowl should be avoided."
Archeological and Cultural Resources
Impacts. No cultural resources have been identified
at the proposed Eagle treatment site or along the proposed
Boise interceptor or sludge pipeline routes.
.Historic trash deposits have been found at Julia Davis
and Ann Morrison Parks but these parks will not be adversely
impacted by the project.
Excavations for proposed treatment facilities or pipelines
have the potential for disturbing previously unknown historical
or archeological sites.
Mitigation. Excavation iti areas designated by the state
archeological officer as potential sources of archeological
artifacts should be conducted according to advice fro® profes-
sional archeologists. The state archeologist should be kept
2$l
-------
informed of the progress of the proposed project, and the
opportunity provided for professional examination of excavated
sites and materials (see Chapter 13).
Disruption of Effluent Flow
Impact. Disposal of effluent during phases of new con-
struction of pipelines and other facilities could be impaired.
Mitigation. Adverse impacts may be avoided by retaining,
existing pipelines, pumping stations, etc., until new facilities
are put into operation.
New pump stations, for example, may be built separately
and tied into existing pipelines during periods of low flow
in the system. Temporary storage within the pipelines and
emergency holding ponds may be used as needed while the new
facilities are connected to the existing pipelines.
Resources and Materials
Impacts. All of the proposed alternatives will require
the irretrievable expenditure of energy and materials in
the construction and operation of the wastewater treatment
facilities and the interceptor and sludge lines.
Mitigation. Recovery of methane gas from anaerobic
digestion to aid in operating equipment in wastewater treatment
facility.
Reduce infiltration/inflow in sewer lines, and establish
water conservation program (reduce pumping loads).
No-Action Alternative
Boise
If the proposed wastewater treatment plans are not imple-
mented, the present water quality problems would continue,
and projected population growth would have no sewer service,
leading to possible additional water quality problems. In
turn this would lead to detrimental impacts upon fisheries
and recreational uses of the Boise River.
Increased growth without sewering could result in increased
waste discharge to septic tanks with significant threat of
pollution to area waters. A building moratorium may result
from this threat.
252
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Boise residents may be required to pay fines and suffer
the loss of federal funds for public projects if NPDES standards
are not met.
Eagle
If no action is taken to implement the proposed wastewater
treatment plan, conditions would remain as they are, resulting
in continuing violation of the District's NPDES discharge
permit, and with no provision for improvement in quality
of effluent being pumped into the Boise River.
With no plan implementation there would be no new impacts
at the proposed site. However, adverse impacts of the existing
system would continue, including those related to water quality
and community growth limitations. Any new growth would have
to rely upon on-site waste disposal systems, which would
increase risfc of water pollution and which would require
low density land use with possible adverse economic impacts
upon the community, and indirect adverse impacts upon fish
and wildlife habitat.
-------
Chapter 15
Responses to Comments
On the Draft EIS
-------
Chapter 15
RESPONSES TO COMMENTS ON THE DRAFT EIS
Introduction
Preparation of this EIS was initiated with three scoping
meetings in Boise, Idaho (March 23, April 24, and May 9,
1979). These meetings were attended by a variety of local,
state, and federal agencies. On June 7, 1979 EPA issued
a Notice of Intent to prepare an EIS covering the wastewater
management alternatives being considered by the City of Boise,
ESD and APA.
Development of the Draft EIS proceeded concurrently
with development of the various facility plans. During the
initial 6 months of this work, the coordinator for the EIS
preparation team was located in Boise.
Three public workshops were held in Boise on May 13
and 14, 1980. These workshops focused on air quality, ground-
water, and surface water issues. The workshops were followed
by an advertised public meeting on the evening of May 14,
1980. Publicity for this meeting included coverage in the
local newspaper and distribution of 150 flyers to a variety
of interested parties. The public did not respond to this
publicity, and only personnel from various agencies concerned
with the proposed projects appeared at the meeting.
The Draft EIS was released on March 16, 1981. A public
hearing on the Draft EIS was advertised for the evening of
April 30, 1981 in the Boise City Hall. Attendance ^t the
public hearing was low, with comments and presentations made
primarily by local agency staff. A transcript of the public
hearing is available from the EPA, Region 10 office in Seattle,
Washington.
Comments and Responses
Written comments received prior to, during, and after
the public hearing are presented on the following pages*
Responses to these comments are presented following each
letter. Responses are keyed to comment numbers coiit2iined
within each letter or shown in the margin of the letter".
¦lass-
-------
rliCi-iAEL D. GILTZOM
S8SS HAPLEUIEH CI ft
liuI'SE# i UAH1"'
U.S. tNUIRONMENTAL PROTEC
tc.ii H. WASHINGTON
I REGRET THAT i Ar-i UhABLE TO ATTENu "Ht Hi iS 11.\ sATtR MANAGEMENET
hEE'i iHb APRIL 30# 1981. I MOULD LIKE TO HAKE M NUMBER OF COMMENTS ON THE
PROPOSED OEIS. I MILL BE AS BRIEF AS POSSIBLE. i HOPE YOU HILL CONSIDER
nV COMMENTS BEFORE THE FINAL DRAFT COMES OUT.
I HILL CONFINE MY COMMENTS TO THE FOLLOWING FIUE SUBJECTS: <1) SEMER
UPDATE PLANS (2> ONSITE COMMUNITY SEPTIC TANK & DRAINFEILDS <3> TOXIC HASTE
DISCHARGE <4> SEMER ALTERNATIUES & <5> OIL & GREASE DRAINAGE.
Li.SEMER UPDATE PLANS: IN READING THE UPDATE PLAnS I FIND THAT I HAUE ft FEW
QUESTIONS CONCERNING THE FEASIBILITY OF THE PROJECTS FINANCIALLY. IN UIEH
OF THE PRESENT ADMINISTRATION'S BUDGET CUTTING MOOD; HILL THERE REALLY BE
,OmDS FOR THESE PROGRAMS IN THE FUTURE? IS IT REALISTIC TO SUPPOSE THAT
FUNDING THROUGH 7 1/8* BONDS HILL BE POSSIBLE:1 IF THE FUNDS HILL NOT BE
huhIlABLE , MHAT ALTERNATIVE FORMS OF SEHERING HILL BE IMPLEMENTED OR WHAT
hlTERNATIUE FORMS OF FINANAC1NG HILL BE TRIED'?
L^uNSITE COMMUNITY SEPTIC TANK & DRAINFIELDS: THESE SYSTEMS HAUE BEEN TRIED
IN SEUERAL LOCATIONS IN ADA COUNTY IN THE PAST. I SEE NO REAL PROBLEMS
Hi1H THE COMMUNITY DRAINFIELDS AS LONG AS ADEQUATE ROOM IS RESERUED FOR
H BACKUP DRA1NFIELD. I DO SEE SOME PROBLEMS H1TH ThE LARGE COMMUNITY SEPTIC
fHiir,. INITIAL COST IS UERY HIGH# MAINTENANCE COSTS ARE UERY HIGH AND SOLIDS
ARE CONCENTRATED IN TOO SHALL A SPACE FOR ADEQUATE BIOLOGICAL BREAK DOHN.
,.INSPECT SEUERAL SEPTIC SYSTEMS IN THE BOISE AREA FOR THEIR OMNERS. ONE
Of THESE SYSTEMS IS LOCATED AT FIUE MILE PLAZA AND CONSISTS OF SEUERAL SHOPS
.uNNECTEO TO A 9800 GALLON SEPTIC TANK. EUERY TIME I HAUE INSPECTED THIS
TANK IT HAS REQUIRED PUMPING. THERE IS A MASSIVE BUILD UP OF SLUDGE AND
256
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r'AGE THO
iCuM NEAR THE INLET. THE SCUM IS SO THICK AT THE INLET THAT SLUDGE MEASURE-'
MENT IS HOT POSSIBLE. THE TANK MUST BE PUMPED IN ORDER TO FUNCTION PROPERLY.
YE I' THE REMAINDER OF THE TANK IS HARDLY USED HT ALL. THE SAME TYPE OF SOLID
RETENTITOH COULD BE ACCOMPLISHED WITH A 1000 GALLON SEPTIC TANK IN SERIES
WITH SEUERAL OTHER TANKS. THE OTHER TANKS MOULD ACT AS SETTLING CHAMBERS
MUCH AS THE REST OF THE 9006 GALLON TANK DOES. WITH THE ALTERNATE SYSTEM
YOU MOULD HAVE TMO ADVANTAGES OVER THE LARGE SEPTIC TANK. ONE:INITIAL COST
MOULD BE LOWER AND TWO: WHEN PUMPING IS NECCESSARY THE PUMPER WOULD PUMP
A 1000 GALLON COR 1500 GALLON-1 TANK INSTEAD OF A 9000 GALLON TANK WHICH
WOULD BE A SAVINGS TO THE OWNER. IN SUBDIVISIONS WHERE A COMMUNITY SYSTEM
iS USED I BELIEVE HAVING INDIVIDUAL SEPTIC TANKS HOOKED INTO A COMMON
ORAINFIELD WOULD BE MORE EFFICIENT THAN ONE LARGE TANK BECAUSE THE SLUDGE
Hfio SCUM MOULD BE LESS CONCENTRATED AND BREAKDOWN WOULD OCCUR MORE RAPIDLY.
THUS PUMPING WOULD BE REQUIRED LESS OFTEN AND A REDUCED AMOUNT OF SLUDGE
MOULD BE TRANSPORTED TO THE SEWER PLANT FOR PROCESSING.
\ --'. TOXIC WASTE DISCHARGE: THO PROBLEMS SHOULD BE CONSIDERED HERE. ONE: AS
ME LEARNED SEVERAL YEARS AGO PUTTING OUR WAbTE IN THE OCEAN DOEb NOT ALWAYS
mean we have seen the last of it. i refer to the mercury in tuna fish
PROBLEM. MY CONCERN IS THAT WE ROUTINELY DISPOSE OF HOUSEHOLD POISONS AND
C-htMlCALS WHICH EVENTUALLY END UP IN OUR OCEANS. DO WE KNOW THAT THESE
CHEMICALS OR THEIR BREAK-DOWN PRODUCTS ARE SAFELY DIPOSED OF OR DO WE RUN
The POSSIBILITY OF FURTHER PROBLEMS LIKE THE MERCURY PROBLEM IN TUNA FISH?
SECONDLY CAN WE PUT OUR EFFLUENT AND/OR SLUDGE OH AGRICULTURAL LANDS WITHOUT
Kunming the same type of risks as dumping it im our oceans'?
lUSEHER ALTERNAT IUES. I BELIEVE THAT ALTERNATIVES TO CONVENTIONAL GRAVITY
itHERS SHOULD AT LEAST BE MENTIONED IN THE HASTEMATER MANAGEMENT EIS. I
MM SPECIFICALLY TALKING ABOUT PRESSURE SEHER SYSTEMS. I BELIEVE THAT THE
m« ****
BEHFUF.T^t TM^V" OMT
-------
r'Hbt fHREE
h.-iL-i i HE PROPER OFFICIALS SHOulO KNON OF THEIR ADVANTAGES FOR SOME PROJECTS.
IN SOME CASES A PRESSURE SEHER SYSTEM CAN EE RUN "iO AN EXISTING MIAN SEHER
LINE AND DUMP EFFLUENT AND-OR SOLIDS INTO THE LINE. THUS SAVING THE COST
OF A LARGE DIAMETER GRAVITY MAIN FROM THE DEVELOPMENT TO THE MAIN LINE.
OTHER ADVANTAGES ARE: WITH PRESSURE EFFLUENT SYSTEMS SOME PRETREATMENT OF
ut sludge is dome on site and therefore has llimpac r un the size of the
lEihRAL PLANT. ALSO WHEN SLUDGE IS TRUCKED IN TO THE PLANT A HOLDING TANK
CAN BE USED AND THE SLUDGE CAN BE PROCESSED THROUGH THE PLANT AT A TIME
UritN THE TOTAL CAPICITY OF THE PLANT IS HOT BEING UTILIZED (SUCH AS AT NIGHT).
JjJDIL & GREASE DRAINAGE: THE OIL ANDGREASE THAT DRAINS FROM OUR PARKING
-UiS, ROADS# SERVICE STATIONS AND RESTAURANT IS NOT MENTIONED IN THE EIS
AT ALL. IT IS A MAJOR PROBLEM. EVERY YEAR WE DUMP MORE GREASE AND OIL
ifnO OUR OCEANS FROM THE ABOVE SOURCES THAN ALL THE MAJOR OIL SPILLS EVER
RECORDED. SOME WORK IS BEING DONE HERE IN ADA COUNTY BY REQUIRING GREASE
h: ,J SAND TRAPS TO BE INSTALLED IN PARKING LOTS, RESTAURANTS, SERVICE STATIONS
Eli. BUT THAT IS THE END OF THE REQUIREMENT. WHEN THE TRAP FILLS UP IT
rU:,h£S OILS AND GREASES INTO OUR DRAINAGE SYSTEMS AND OUT INTO OUR STREAMS,
RIVERS, LAKES AND OCEANS. A MAINTENANCE SYSTEM FOR THESE TRAPS SHOULD BE
:¦ i UUlEO.
i THhHv.. VOU FOR YOUR TIME AND CONSIERATION. I HOPE THAT MY COMMENTS
WILL BE OF HELP TO YOU IN PREPARATION OF YOUR FINAL DRAFT.
MICHAEL OfT GILTZOH
258
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Response to Comments From Mr. Giltzow
1. These issues will be addressed during more detailed
facility planning stages.
2. These issues should be considered by the Ada Planning
Association and the Central District Health Department
when implementing the recommendations contained in the
Southwest Community Wastewater Management Plan (see
Chapter 3 of this EIS.
3. There is always some element of risk associated with
any method of waste disposal. Facility planning studies
conducted to date have not identified any special con-
cerns with either treated sewage effluent or digested
sludge. Sludge applications at the prison farm site
will involve areas used for fodder crops. A variety
of monitoring and testing programs will be used to
ensure that problems do not develop at this site.
Sludge application rates will be based on a combina-
tion of factors, including heavy metal content of the
sludge and relevant soil characteristics.
4. The use of pressure sewers was not addressed in the
City of Boise or Eagle Sewer District facility plans.
5. This topic should be considered by the city and county
agencies; the Ada Planning Association has primary
responsibility for overall "nonpoint source" water
quality management planning.
259
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'IDAHO
BOISE CITY PLANNING DEPARTMENT
150 NORTH CAPITOL BLVD.
2ND FLOOR
April 14, 1981
Ms. Norma Young (M/S 443)
% U.S. Environmental Protection Agency-
Region 10
1200 Sixth Avenue
Seattle, WA.
!j\i ^
16 I98i
RE: Draft EIS "Wastewater Management for Boise, Eagle and Ada
County, Idaho"
Dear Ms. Young:
It is a mark of civilized society when sanitary wastes are
collected and carried away from human settlements. It is a
superlative achievement when a society not only carries waste
away, but also treats it, makes useful products of it, and
protects the continued purity of earth and water.
The central questions of this EIS on wastewater management should
be: "What will happen if wastes are collected and treated? What
will happen if they are not?"
Believing this, I wish to challenge the logic (exemplified in
your first paragraph on page 236 and your summary beginning on
page XV) of identifying "growth" as an "area of impact". History
is full of evidence that the presence or absence of advanced (or
any) wastewater treatement neither directly or indirectly encour-
ages or discourages growth in a community. Rather, growth is the
result of economic forces primarily, with political and social
forces contributing somewhat. It would be a delusion of grandeur
for wastewater management analysts to believe that future popula-
tion growth in Ada County is going to be accellerated or retarded
merely because of the status of wastewater collection or treat-
ment .
What will be affected, however, is the ability of the community
to manage new population growth in a rational and flexible manner
in which a whole series of goals can be achieved by the com-
munity. We wish to have clean water, make more efficient use of
the land, protect the public health, provide an excellent transit
service as an alternative to the auto, provide land use patterns
which are convenient and satisfying for citizens, and provide an
orderly system of public services at costs that taxpayers can re-
cognize as reasonable.
POST OFFICE BOX SOO • BOISE, IDAHO 83701
AN EQUAL OPPORTUNITY EMPLOYER
260
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Page 2
If new growth has to be served on septic tanks, for example, then
we will very likely fail to attain any of the goals mentioned
above. But there will be new growth.
The purpose of these remarks is really to suggest that the con-
cept of "growth" as a result or impact of better wastewater
management is an example of fuzzy thinking.
Because of the way in which this issue is presented and discussed
in your report, it would appear logical to think: "Well, if the
sewer system can handle it, the community will grow; if the com-
munity grows, a lot of bad things will happen; (loss of agricul-
tural land, decreased air quality, loss of habitat, more flood-
ing) and therefore, we better think twice about improving the
sewer system."
I would rather have seen your matrix present the growth issue so
that the logic would be more like this: "The community will
grow; if it does, there will be a series of environmental protec-
tion problems for the community to have to deal with-either in
new ways or in more intensive ways; if they intensify efforts in
waste water management, they will be able to protect water qua-
lity of the Boise River, if they do not, water quality will be
threatened. Growth will present other problems with respect to
air quality, drainage, and habitat for wildlife. While waste-
water management is the focus of the present EIS, we recommend
continued efforts and attention be given to air quality, drain-
age, and the like".
The summary statement on page 83 presents a rather ominous tone
and, as a conclusion, is also not very accurate. Boise City has
enacted regulations for foothills development and drive-up
businesses (air quality), regulates building structures in the
floodplaln, is working on a more comprehensive floodplain or-
dinance, has enacted energy conservation goals, and regulates
development in the airport influence area. None of these things
is at all "uncertain".
Development policies now governing city development are very
likely to be adjusted and changed to accommodate new conditions
of the 1980's. Our growth management policy must and will be
responsive to public and private priority shifts. Low density
development will probably give way to higher densities, as
energy, service, and housing costs rise. If the development
policies of the 1970's are strictly followed and neve* adjusted,
our future in the 1980*a may not be the future we Will find
acceptable.
261
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Page 3
10.
Turning to another subject; air quality. On page 114, the report
states: "The emission inventories presented in Table 7-1 indi-
cate that recent reductions in the frequency and magnitude of
pollution episodes do not result from reductions in pollutant
emissions. Heterological conditions (inversion frequency and
intensity, wind conditions, etc.) appear to be the controlling
factors. Thus, 1977 represents an indicator of potential CO
levels under unfavorable weather conditions." I challenge this
conclusion for the following two reasons. First, you have pre-
sented absolutely no meterological data in the report or appendix
which demonstrates that Boise has had progressively milder condi-
tions every year since 1977. Secondly, we have been anticipating
some beneficial results of improved auto emission control tech-
nology as newer vehicles replace older ones. Connected with this
anticipation, we have observed a decline or stall in the rate of
traffic volume increases on major streets in Boise since gasoline
costs have risen.
If we were to assume that meteorological conditions were identi-
cal in 1980 and 1977, would it not be rational to conclude that
reduced traffic levels would result in lower emissions and im-
proved air quality?
11.
I am puzzled at your interest in separating the emissions burden
by neighborhoods and communities. (Table 7-1 and Table 7-2.) It
is "Northern Ada County," with its complex of economic, commer-
cial, social, and cultural interactions which result in our over-
burdening our air with more wastes than we can safely dispose of.
Solutions to the problem must be region wide, not focused on any
particular neighborhoods. That is why "Northern Ada County" is
the non-attainment area, not just our denser neighborhoods*
Thank you for this opportunity to comment on the Draft EIS
"Wastewater Management for Boise, Eagle and Ada County, Idaho."
It is my view that it will always be better to treat wastes in
such a way that neither ground nor surface water will be con-
taminated. I hope that the Environmental Protection Agency will
see it that way also.
Sincerely,
iytMjai/i.
Si san M. Stac r, A|CP
D RECTOR OP 1 i.A»'HIHG
SMS:vvv
262
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Response to Comments From Boise City Planning Department
1/ 4, 5. Refer to revised text (Chapter 5).
2. Refer to revised text (Chapter 5). City ani county
wetline sewer policies directly link new development
to the availability of wastewater treatment facilities.
3, 7. Comment noted.
6. The issue is not whether or not to have sewers, but
rather how to efficiently plan for them in conjunction
with other public services.
8, 9. Refer to revised text (Chapter 6).
10. Refer to revised text (Chapter 9). A comparison of
the relative change in peak 1-hour and peak 8-hour
CO levels (Appendix G of Draft EIS) clearly indicates
that meteorological conditions have not remained con-
stant from one year to the next. The various special
studies summarized in the text also provide data on
changing meteorological conditions. Air quality data
from the downtown station during 1980 were further
Influenced by rerouting of traffic flows due to major
construction work. The intent of the discussion on
this topic was to identify the year which best illu-
strated the highest ambient air quality increment likely
to result from a given increment of emissions. All
data point to 1977 being that year.
11. Refer to revised text (Chapter 11).
263
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PUBLIC WORKS DEPARTMENT
CITY" HALL - 4TH FLOOR
(200) 364-4292
rT'*- •
err? of tbees
BOISE CITY. IDAHO
RICHARD R EARDLEY
MAYOR
May 8, 1981
Ms. Norma Young
U.S. Environmental Protection Agency
Region X
M/S 443
1200 6th Avenue
Seattle, WA 98101
Subject: Draft EIS for Wastewater Management for
Eagle and Ada County, Idaho
COUNCIL MEMBERS
JOY BUERSMEYER. COUNCIL PRESIDENT
RALPH McADAMS. COUNCIL PRO-TEM
MARGE EWING
GLENN SELANDER
MIKE SILVA
KEITH A
¦iii«5
11 1981
ENVIRONMENTAL EVALUATION
Boise, W*™
Dear Ms. Young:
We have prepared the following comments with respect to the
draft Environmental Impact Statement. These comments are
general in nature and reflect our overall philosophy.
1. As stated when we presented oral testimony at the public
hearing, we cannot stress enough the importance to the
City of Boise that this EIS be completed prior to
September 15, 1981, as indicated in your proposed
schedule. Any delays could not only cost the City in
inflation costs that we have incurred because of past
delays, but also losing potential funding under
recommended new state policy if the project was not
ready for a grant offer before September 30. The City
must have its grant offer by that date for Step II work.
2. We would request that any item in our Facility Plan that
is indicated not to be controversial be pulled out and
the City would be able to proceed with Step II work for
those elements that appear to have no significant
impact. Your agency by letter of March 10, 1981, from
Don Dubois has indicated support for that procedure.
3. On page ii, the statement is made that to meet water
quality standards at Lander Street, the plant will
require construction of ammonia removal facilities, and
minimum stream flows in the Boise River will be needed
during the winter months or both. Our Facility Plan
indicated that ammonia removal facilities would not be
required if minimum instream flows in the Boise River
were provided.
POST
264
OFFICE BOX 500 - BOISE, IDAHO 83701
AN EQUAL. OPPORTUNITY EMPLOYER
-------
Ms. Norma Young
May 8, 1981
Page 2
4. On Page xv, on Table 1 under Costs of Direct Area of
Impacts, the comment is made, "Trunk transport of liquid
or dewatered sludge is four to six times as expensive as
pipe line transport." We concur with the recommendation
to construct the pipeline. However, our Facility Plan
indicated that the truck transport and sludge pipe line
were near the same cost. The costs being discussed
should be better defined. Also, the EIS has indicated
that the Boise user charge was an average increase of
$7.70 per month to approximately $8.60 per month for
Stage 1 improvements and to $9.20 per month for Stage 2
improvements. It must be noted that is only for Boise
City customers and not for our independent sewer
agencies.
5. On Page 168, third paragraph, it indicates that West
Boise is being designed to meet all water quality
standards and the low flows from Lucky Peak are not an
issue. Therefore, we do not understand why we cannot
proceed with the design of the West Boise Treatment
Facility, if in fact that we do not create a problem for
water quality in the Boise River as stated in the EIS.
6. On Page 169, under Mitigation Measures, the EIS
consultant recommends that the facility planners and the
EPA not proceed with too detailed planning for Lander
Street and West Boise until the flow issue is resolved,
but on the previous page indicated that it is not an
issue for the West Boise plant. We find this issue of
flow augmentation to be very inconsistent throughout the
document. We are building facilities which would be
compatible with any river flow regime. Therefore, we
fisel we should proceed with construction to alleviate or
minimize any potential water quality problem,
7. On Page 170, the Summary of Impacts, the last paragraph,
indicates the Boise River flows for the Lander Street
plant cannot be assured. The detailed planning of these
facilities should not commence until availability of
flows is assured. Our current plan is to provide for
dechlorination and postaeration which will improve the
water quality of the Boise River rather than damage that
quality, therefore, we should proceed with those design
and construction elements for Lander Street, If
additional facilities are required to operate the plant
to meet certain stream flow# then that problem needs to
be addressed at a later date. The dechlorination and
-------
Ms. Norma Young
May 8, 1981
Page 3
postaeration facilities are required whether there is
sufficient flows in the Boise River or not.
8. On Page 180, under Sediment, in reviewing the first
paragraph under Sediment, it indicates that the gravels
are not appropriate for trout spawning and that flows
greater than a 1000 cfs are necessary to provide
suitable water depths and velocity over the side
channels where those gravels are available. This
appears to say salmonid spawning is not physically
achievable in the Boise River. Why is the Boise River
protected for that designated use?
In summary, the City of Boise feels the most important issue
to be made is the EIS recommendation to resolve the flow in
the Boise River prior to proceeding with design and
construction of the facilities at Lander Street and West
Boise. The issue is that we are planning to provide
facilities which are compatable with any future expansion that
may be required due to low flow in the Boise River. The EIS
reiterates several times how removal of chlorine from our
Lander Street discharge will be advantageous to the fish
habitat, but then state that we should not proceed with that
developmental plan. Again we cannot stress importance to
Boise enough of how critical completing the EIS process as
soon as possible. If you have any questions, please contact
us.
Sincerely yours,
Carl B. Ellsworth, P.E
Environmental Engineer
CBEire
266
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Response to Comments From Boise Public Works Department
1. Comment noted.
2. Accelerated Step 2 grant items are discussed in the
revised EXECUTIVE SUMMARY and the revised Chapter 1.
4. See revised text (Chapter 3).
7. This discussion has been deleted from the revised text.
8. Some spawning undoubtedly occurs at lower flows. Flows
often exceed 1,000 cfs near Boise during the rainbow
trout spawning season (April-June).
-------
p o Bqx 368 9 EaglQi jD 83616 # ph 208/939-0132
April 13, 1981 1
U..c .Enviornmental Protection Agency
Region X _
1200 Fixth Avenue BRANCH
Seattle, Washington 98101
APR J7 jggj
WW£N[Al 0WALUAJION
1.
Attention: Ms. Norma Young (M/S M+3)
Re: Eagle Pew^r District Ccmments on the Ada County EIS
Dear Ms. Young:
We aporeciate the opportunity to review and comment on
the Draft Enviornmental Impact Statement (DEIP) for Wastewater
Management for Eoise, Eag^e, and Ada County, Idaho. Cur comments
are as follows:
Page ii, paragraph 2 - It is stated that large flows
occur in the Boise River during the summer and low flows during
the winter. While this may be true for various reaches of the
Boise River it is not accurate for all reachf?. Because of the
irrigation diversions into carols from the Boise River, flows in
some reaches are severly reduced during the summer months. As
this section relates to Boise, it aonears to to accurate. How-
ever, as this section relates to discharge- from Eaglr-, Meridian
and Star, it is not entirely accurate.
Pagexx, paragraph 2.
Page ?03, paragraphs *+, 5, and 6.
Page ?0*+, paragraphs 1 and 2.
Page ?05* paragraph 5.
268
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U.S. Enviornmental Protection W13-81
Agency - Region X
Page ?^5, paragraph 1? and pare ?!f6, paragraph 1.
These particular sections pertain to the loss of ri-
parian wildlife habitat and to what ha? been referred to as
"wetlands", as a result of constructing the Earle ^>wer Dist-
rict. treatment facility.
'We are in total disagreement with the classification
of the proposed treatwnt riant site as a wetland (pa^es xx,
20*+, and T05). We reference you to the lett r of February 25*
1981 by Kr. Dennis 0. P-u-chler of the U.P. Fish and Wildlife
Pervice where the determination was that "wf do not consider
this small stream-blocked area to be a natural w-tl'i^d.' We
assume that this determination would satisfy the requirements
of Executive Crder 119^«
While we agree that there will be some reduction of
riparian wildlife habitat, the DEir does not quantify the extent
of the impacts of the reduction. The DEIF appears to rel-y on
subjective ^valuations to justify a particular ^oint of view.
The DEIF also states that the impacts associated with construct-
ing the new treatment, facility are not mitirable. It is our
ot)ir.ion that the ap roxiirate 1? acres of the total 65 acre site
does not represent a "-i ?nific^.t" amount of rinarian wildlife
habitat alons! the Boise River, xt is our opinion that if the
riparian areas between Boise and '*Uden«tcm are closely examined
you will find contiguous riparian areas of a much greater size
than the proposed treatment plant site. The proposed treatment
plant site is not unioue.
269
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U.F. Fnviornmental Protection -3- *4-13-81
Agency - Rrficn X
a'g disagree with the statement on page xx that the im-
pacts of constructing the treatment, plant at the proposed site
are not n3tis>able. The imoacts are not only mitisable, but with
careful oneration the riparian wildlife habit-t can be enhanced.
This would include construction techniques to reduce the trans-
ient impacts and operation and maintenance techninu^s to encour-
age proliferation of wildlife habitat. The proposed treatment
plant is not an intensive operation and maintenance facility.
La ocn systems can be allowed t.c ore:\ate in a condition similar
to a marsh or pend and thereby provide habitat.
We do not feel that additional investigation into other
potential treatment plant sites is productive. The rrorosed
treatment plant site meets the requirements and the minor enviorn-
mental impacts will be mitigated.
Page 15, para?rarh 2 - The effluent from the lagoons
flows by gravity to the sand filters. The discharge roirt is lo-
cated at arnroximateIy Boi"e Riv r Kile Hr.5.
Pages 55, 56 and 57. Tables >+-17, I+-1&. if-19 and
*f-?0 have been revised.
Pa?e 67 - The treatment facility construction will be
phased for ten (10) years design neriod.
Page 158, paragraph - The desipn canacity fcr the ex-
isting Eagle Pew District Treatment is 0.3 MOD for winter and
0.5 W'D for surmer.
If you have any questions concerning the above comments
please contact fcirby D. Vickers at *+-67-525?.
4?—
f;DV:^CiC«i WAYNE CHOFBY, Chairman
-------
Response to Comments From Eagle Sewer District
1. Comment reflected in Chapter 11 discussion.
2, 3. Note revised text (Chapter 12).
4. Riparian habitat is widely considered by wildlife
biologists to possess a disproportionately high value
per acre for wildlife relative to other habitat types.
The juxtaposition of food, water, and cover, as well
as the diverse plant community structure, supports
unusually large and diverse wildlife populations. The
loss of any such productive habitat should be considered
significant, especially in light of previous riparian
habitat losses to agriculture and urbanization. Several
large areas of riparian habitat do exist downstream
of Eagle toward Middleton. Pew large riparian areas,
however, remain upstream of Eagle, where riparian
habitat is usually very narrow or nonexistent.
5. See revised text (Chapter 12). The lagoons at the
new facility will provide some open water wildlife
habitat. Such habitat, however, is already available
on the adjacent river, and some will be lost as the
old facility is taken out of service. It is unlikely
that the new facility will enhance existing riparian
habitat or encourage a proliferation of wildlife habitat.
6. Corrections made to revised text.
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P.O. BOX 477
EAGLE, IDAHO 83616
208 939-6813
Mayor: Jerry Deckard
Council: Floyd Decker
Carol Haley
Orval Krasen
LeRoy Pearman
April 30, 1981
Ms. Norma Young, M/S 443
US Environmental Protection Agency, Region 10
1200 Sixth Avenue
Seattle, Washington 98101
The following are the comments of the City of Eagle on the Draft
Environmental Impact Statement, Wastewater Management for Boise,
Eagle, and Ada County, Idaho, dated March 16, 1981.
Changes to the draft EIS which are deemed necessary by the City
of Eagle are attached as Enclosure 1.
Eagle's arguments on demographics are contained in Enclosure 2.
In our opinion, it would be unconscionable for any agency to ignore
true demographics and insist on adhering to those put forth by
the APA staff. Reference Section 4, page C-23, EIS Appendices,
the City of Eagle agrees with the conclusions of Gruen Gruen &
Associates, that APA did not property forecast employment, did
not take into consideration employment growth caused by Hewlett-
Packard, and did not consider employment growth of the Middlebrook
project. APA staff is well aware of the problems with their
population projections, but has pled lack of funds for not correcting
the 208 plan.
Since it is the prerogative^of EPA to either accept of reject the
poulation projections in the 208 plan, and since the 208 plan is obviously
flawed concerning the Eagle Area, it is requested that EPA use the year
2000 population figure of 12,775 for the City of Eagle.
I Also, your attention is directed to 67-6528, Idaho Code. It is expected
by the City of Eagle that this law will be adhered to by not only
agencies of the State of Idaho, but also of the Federal Government.
ncerely,
SGSSOW
Jerry Deckard 0\l "SS'
Mayor Mw T
272
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City of Eagle
April 30, 1981
Enclosure 1
CHANGES TO THE DRAFT EIS RECOMMENDED BY THE CITY OF EAGLE, IDAHO
1. All references in the EIS to the Eagle Water and Sewer District should
be corrected to reflect their proper title, "Eagle Sewer District."
2. Reference page 218, paragraph 2, the remark by Blake, "The Middlebrook
project, as proposed, would consume 540 acres of some of the country's
most productive agricultural lands," is not substantiated by facts.
According to the Soil Conservation Service Soil Survey, the 540 acres
includes some Class III-W (wetlands) which can hardly be considered as
"most productive agricultural lands;" therefore, it is requested that
this be deleted from the EIS. Further, since the City of Eagle has
not approved any development in this area, let alone the composition
of the development, the statement "This development would include
250 acres for industrial park and 290 acres for residential uses"
is conjectural and should be eliminated from the Draft EIS. It is
the policy of Eagle that any development in Middlebrook be done in
phases, with each phase being approved at the time it is proposed, so
as to allow those future elected offials to render their decisions on
the then current plans.
3. Reference page 225 on schools in Eagle, it is suggested that the
Meridian School District be contacted for current data on the schools
in Eagle. Also, Eagle's population projection (paragraph 5) is not
10,225 but 12,775. Another source which should have been used was
Eagle's Future Acquisitions Map and Capital Improvement Program and/or
the Meridian School District Future Acquisition Map.
4. Reference page 227, the statement that "Eagle presently has no public
park is not now true, nor was it true in the past. It is recommended that
this paragraph be deleted and the City of Eagle be contacted for correct
data.
273
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City of Eagle
April 30, 1981
Enclosure 2
EAGLE CITY'S COMMENTS ON DEMOGRAPHICS
Chapter 5, page 63, Draft EIS, outlines EPA's policy of using population
projections appearing in approved 208 plans. The city of Eagle under-
stands this policy; however, it is expected that EPA will also give due
consideration to the accuracy of such population projections. Federal
monies were used by APA to write the following three documents:
1. Demographic and Economic Base Study, Ada County, Idaho, prepared by
Wilbur Smith and Associates for APA, December 1976.
2. Eagle, Idaho, Comprehensive Plan, prepared by APA, January 1978.
3. Demographic and Employment Distribution to year 2000, Ada County,
Idaho, prepared by APA', August 1978.
The Wilbur Smith report assigns a year 2000 population of 13,825 to
Eagle; the Eagle Comprehensive Plan a population of 12,775; and the APA
report a population of 10,225.
The Draft EIS has adopted the APA population figure of 10,225; however, if
Ada County Demograph report prepared by APA is carefully examined, the only
conclusion that can be reached is that these figures were wrong at their
inception and there use can only cause a disservice to the City of Eagle
and to Ada County. The report states:
(1) "The projected population for Eagle was distributed based on the
Eagle Comprehensive Plan." This report then assigns a population of
10,225. On page 53 of the Eagle Comprehensive Plan, the population
for Eagle is shown as 12,775. This is a difference of 25% which the
APA staff has subsequently chosen to ignore.
(2) "Due to the liminted inventory of data for deriving specific acreages
of remaining developable land, a simplified method of distributing
projected population was used." If one turns to page 35 of the
Eagle Comprehensive Plan (which was published prior to the Ada County
Demographic report) one can see that the data on acreages of remaining
developable land was available to APA.
(3) "The percentage of residential growth planned for each traffic zone
was estimated from Eagle's Community Design Map." Page 61 of the
report shows that Traffic Zones 178, 179, 180, 183 and 184 were
used in arriving at the 10,225 population figure. If the Eagle
Community Design Map on page 77 of Eagle Comprehensive Plan was used,
who made the arbitrary and capricious decision to delete traffic
zones 173, 174, 187 and 1887? The City of Eagle did not and does not
agree with these deletions.
274
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City of Eagle
April 30, 1981
Enclosure 2
Page 2
(4) The Appendix Table for Ada County Residential Characteristics
and Employment, on page 1-91, assigns an estimated population
of 3800 to Eagle for the year 1980. The 1875 population (page 1-83)
is given as 2720. This is a growth factor of 40%. A special
census conducted in Eagle in 1977 showed a population figure of
1576. Without any further annexations, or changes in area size,
the 1980 census showed a population of 2620, a gain of 66%. Again,
as in (1) above, you can see a difference of 26% between APA staff
estaimates and the actual population figures.
-------
Response to Comments From City of Eagle
Cover Letter.
1. The Draft EIS did not adopt the population projection
of 10,225 for Eagle in the year 2000 but rather stated
that this number was the adopted 208 population projection.
Other population figures were also mentioned as under
consideration by the Eagle facility plan consultant
(J-U-B Engineers) for wastewater facility planning
purposes. The revised facility plan uses a population
projection of 13,286 for the year 2000 in the Eagle
facility planning area. Ada Planning Association, the
regional agency responsible for 208 planning, has con-
curred with this allocation (13,286) and has adopted
this allocation as the official 208 and 201 population
projection for Eagle.
2. Idaho code number 67-6528 is the 1975 Idaho Local Planning
Act. EPA policies require that wastewater facility
plans be in conformance with local land use plans. As
discussed, a general consistency now exists between
the adopted population projection for 201 planning
purposes and the wastewater facility plan. Other plan
consistency issues are discussed in Chapter 6 - LAND
USE IMPACTS.
Enclosure 1.
1. Text revisions made.
2. Because the area for the proposed Middlebrook development
(planning area A in the Eagle facility plan) is not
shown as a service area in the Eagle facility plan,
an analysis of the agricultural resources in this area
has not been prepared in the Final EIS. As a point
of interest, however, planning area A consists of
scattered areas of prime farmland but is predominately
nonpr ime farmland.
3. The revised text (Chapter 8) reflects information
provided by the Meridian School District. Population
issues are discussed in response to cover letter
comment 1,
4. Refer to revised text (Chapter 8).
Enclosure 2.
1, 2. Refer to response to cover letter comment 1.
276
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HUB OF TREASURE VALLEY
A Good Place to Live
OFFICIALS
LA WANA L. NIEMANN, City Claifc
M. KIEBERT, Traaaurar
ROGER SHERWIN, Chief of Polio*
BRUCE D. STUART, Water Work* 8upt.
JOHN 0. FITZGERALD, Attorney
ROGER WELKER, FlreChlal
EARL WARD, Waate Water Supt.
CITY OF MERIDIAN
728 Meridian Street
MERIDIAN, IDAHO
83642
Phone 888-4493
JOSEPH L.OLAISYER
Mayer
April 17, 1981
COUNCILMEN
RICHARD C. WILLIAMS
GRANT P. KINGSFORD
BILL BREWER
RICHARD F.ORTON, JR.
DONALD L. SHARP
Chairman Zoning & Planning
U. S. Environmental Protection Agency
Region 10
1200 6th Avenue
Seattle, Washington 98101
Dear Sir:
We have read your Draft of Environmental Impact Statement
EPA-10-ID-Boi se/Eagle-Ada-WWTW-81.
In this Draft you refer to Middlebrook Subdivision, Page 226
Fire Protection. You state that Eagle F1re District would
1. | give fire protection. This land is not in Eagle's District,
but is in the Meridian Rural Fire District and would put
undue hardship on our Department.
If you have any questions please feel free to contact us.
Phone (208) 888-1234.
Sincerely,
RogeirL. Welker
FIRE CHIEF
MERIDIAN RURAL FIRE DISTRICT
RW/RV/ln
cc: Mayor and City Council
File (2)
APR to
*wiima«w*w«tjwnoN
-------
Response to Comments From City of Meridian
1. Comment noted. The Middlebrook area is no longer
included in the service area for the Eagle Sewer
District project.
278
-------
T„ wv Poamft
Subject
Date
From
IQ^fce-LflcL """flsflL.
Co^vvvs61*^4 rK ^QC Tf*
Wilson Jonas Company
Signed
JSltfSgfl
MWI3 'U'
jWMWfWrv p«ujaiion
¦-—Bhrtrtbif
|3J79
-------
(Central District Health Department Comments)
DRAFT ENVIRONMENTAL IMPACT STATEMENT
WASTEWATER MANAGEMENT FOR BOISE, EAGLE, AND ADA COUNTY, IDAHO
EPA
Page Paragraph
V 14 "Most of Boise area residents using septic tanks
would continue to do so with potential surface
and groundwater contamination"
This statement misleads the reader in that it
implies ALL types of contamination to surface
and groundwater. The main concern is increase
in nitrates in the groundwaters and this fact
needs to be clarified to the reader. Our tests
have not revealed any concern for bacterial
contamination.
19 1 Again, it needs to be stressed that the concern
was about nutrient (nitrate) contamination.
145 1 "Nitrogen emissions in the Boise valley are most
likely increasing as a result of Septic Tank Waste-
water disposal practices"
This statement is a broad sweeping generalization and
there are no solid data to make such a statement.
Review of tables 8.2 and 8.3 discredits this statement.
145 1 IDWR now indicates they will not have funds to continue
sampling.
223 2 There is no mention of South County Water Company which
supplies domestic water to numerous subdivisions in the
area.
280
mmmi
MAY IS 1961
environmental evaujat
BRANCH
-------
Response to Comments From Central District Health Department
1. Comment noted. Even though bacterial contamination
has not been identified there is nonetheless a potential
for such problems.
2. Note revised text (Chapter 2).
3. This material reflects the opinion of the contractor
performing this aspect of the study. Tables 10-2 and
10-3 (formerly 8-2 and 8-3) do not provide any time
series data; thus, they do not directly support or
discredit the conclusions being questioned.
4. Comment noted.
5. The South County Water Company was mentioned in the
referenced paragraph.
m
-------
SOIL
CONSERVATION
SOCIETY
OF AMERICA
R.N. Irving Chapter
Rm. 345, 304 No. 8th St.
Boise, Idaho 83702
May 7, 1981
2.
3.
5.
Regional Administrator
U.S. Environmental Protection Agency
1200 6th Avenue
Seattle, Washington 98101
Dear Sir:
We have reviewed the draft Environmental Impact Statement for Wastewater Management
for Boise, Eagle and Ada County, Idaho, and offer the following conments.
The Statement is based on the assumption that zoning is not an effective agricul-
tural land preservation tool and that the transition of agriculturally zoned lands
from rural to urban use to accommodate projected growth in the Boise planning area
will likely occur. It addresses the high costs of sewage treatment plants, prob-
lems of air pollution, transportation, and mentions that prime agricultural land
is a non-renewable resource and its conversion to urban uses is irreversible.
The Statement does not consider or address the alternative of promoting urban
expansion to the dry rangelands southeast of Boise.
The area southeast of Boise parallel to or adjacent to Highway 80N is for the
most part presently classified as Vic with an irrigated potential of lis. Domestic
water is readily available from deep wells. Soils are suitable for home or condo-
minium construction. Drainage or floodplain problems common to Boise Valley do
not exist. Air Inversion or air pollution problems common to Boise Valley are
nonexistent. Sewage or wastewater treatment plants would be more economical
because lagoon systems could be used and high water table problems common to irri-
gated Boise Valley are not present.
The alternative of developing urban expansion to the southeast could result in
preservation of low energy cost prime agricultural lands and avoid further in-
creased pollution problems on the Boise River. Future housing development on
the Boise Valley floodplain could be avoided.
4.1 The area southeast of Boise is close to the downtown business district. Trans-
I portation energy costs to and from work could be kept at a reduced level.
The Statement does not address problems and concerns of Irrigation districts,
drainage districts, and canal companies. These districts and companies are
presently being adversely affected by urban expansion Into prime agricultural
lands.
Yours truly,
Sharon Norrls
Chapter President
ENVIRONMENTAL EVALUAIK*®
282
01©
MM It Ml
'UWWgffij-J?
To advance the science and art of good land use
-------
Response to Comments From Soil Conservation Society of America
1. The revised text discusses the impact of urban expansion
into the Southeast area. Although the area is pre-
dominately designated prime farmland (refer to Figure 7-1),
the impact of urbanization on current agricultural
production is not considered significant.
2f 3. Policies which encourage development to locate in the
Southeast area have been adopted in the Boise policy
plan. Although the Southeast area has been designated
as a priority development area in the policy plan,
development of the Southeast area would result in some
environmental problems. These problems have been
addressed in sections of the Draft EIS pertaining to
the specific subject areas.
4. Comment noted. The Southeast area has been designated
as a priority development area in the Boise policy plan
for a number of reasons; minimizing transportation energy
costs is recognized as one reason for promoting develop-
ment in that area.
5. We recognize that irrigation districts, drainage districts
and canal companies are concerned with urban expansion into
agricultural lands. As shown in Chapter 7, (Figure 7-1)
much of the facilities planning area is designated prime
farmland. It appears that the extent of future urban expansion
will be determined by local land use planning procedures
which establish Urban Service Planning Area (USPA) bounda-
ries.
283
-------
May 8, 1981
) ; ADA PLANNING ASSOCIATION
650 Main Street
Boise, Idaho 83702
(208) 344-7600
Ms. Norma Young
Region X
Environmental Protection Agency
1200 Sixth Avenue
Seattle, WA 98101
REFERENCE: Comments on Draft EIS for Wastewater Management
for Boise, Eagle and Ada County, Idaho
Dear Ms. Young:
As we indicated at your April 30, 1981, public hearing on the above-
referenced EIS, the Ada Planning Association is submitting the attached
comments for EPA's consideration in finalizing the report. Throughout
the past several months, APA staff has worked very closely with both the
Environmental Protection Agency and Jones & Stokes Associates, 1n an
effort to provide up-to-date information for the EIS. As an areawide
planning agency, we are attempting to provide a review perspective,
which considers all aspects and possible impacts of the proposed projects
under analysis.
Our various verbal and written comments and the guidance provided in
earlier memorandums have covered the issues of concern. Please accept
the attached written comments for further guidance in completing and
expediting the final Environmental Impact Statement, 1n order that the
affected projects may be initiated without any further delay.
Sincerely,
ADA PLANNING ASSOCIATION
Ri
Executive Director
Attachments
RM:RH:st/F1le 309
cc: Charlie Hazel - Jones & Stokes
M. Masarlk - EPA
Richard Eardley, Mayor - City of Boise
Bill Ancell - Boise City Public Works
Jerry Deckard, Mayor - City of Eagle
Wayne Crosby, Chairman - Eagle Water & Sewer District
environmental evaluation
BRANCH
EQUAL OPPORTUNITY/AFFIRMATIVE ACTION EMPLOYER
284
-------
Revised 05-08-81
ADA PLANNING ASSOCIATION COMMENTS ON FEBRUARY 1981 DRAFT ETS FOR WASTEWATER
MANAGEMENT FOR BOISE, EAGLE & ADA COUNTY, IDAHO, PREPARED BY EPA
EXECUTIVE SUMMARY
Page 11, third paragraph:
Paragraph mentions a requirement for construction of anmonla removal facilities
at the Boise Lander Street facility. Ihis is not covered in the Boise Facility
Plan Summary Information listed on page 32 of the draft EIS.
Page iv:
Figure needs correction on Lake Caldwell to Lake Lowell.
Page xv, Table 1, Growth:
The 1980 population, according the 1980 Census, for Eagle is 2,620.
Page xx, 2nd Paragraph:
The statement should reflect the loss of habitat, rather than wetlands and it is
felt that some of the facilities' expansion needs and their Impacts are
mltigable. These should be defined further resolved in the Eagle Step 2 grant.
Page xx, 2nd to last paragraph, 2nd sentence:
This is not a complete sentence and needs further correction.
Chapter 3 - WATER QUALITY MANAGEMENT IN ADA COUNTY
Page 10, Figure 3:
Change Lake Caldwell to Lake Lowell.
CHAPTER 4, WASTEWATER TREATMENT ALTERNATIVES
Page 24, Figure 4-2:
The legend for the service area, under the Lander Street Treatment Facility has
been omitted and needs correction on the figure.
285
-------
EES COMMENT
MAY 8, 1981
PAGE TWO
Page 30:
As with the conment on the Executive Surrmary section, the treatment plant expan-
sion and modification, under Boise, does not indicate any ammonia problem and
should be corrected to indicate that the river flow releases are being assumed
to reduce the need for ammonia treatment.
General Caiment - Chapter 4: EAGLE SEWER & WATER DISTRICT PLAN:
The draft EIS reflects, primarily, the Information that was presented in the
May, 1980 facility Plan, prepared by JUB Brgineers for the Eagle Sewer & Water
District. Since that time, a December 1980 draft and an errata sheet on the
December draft, have been issued by the District. Ihe entire draft EIS should
be updated to reflect the adjusted population, 20-Year Service Area, cost
estimates, impact assessment, etc., of the more recent draft and errata sheet.
This should include, among other things, the modification of Table 4-16, on page
51, which reflects different population projections that have since been
adjusted. The Facility Plan and EIS effort should analyze only the impacts of
13,286 population projection for the Year 2000 for Area B, thereby, dropping off
the costs and impact analysis for the lower population and facility flow projec-
tions on the tables reflecting the other projections.
CHAPTER 5, ANALYSIS OF FACILITY PLANNING POPULATION PROJECTIONS
Page 64, Southwest Comnunity Planning Area Population Projections:
Wherever the word "projections" is used in this paragraph and others which refer
to the 1978 Demographic and Employment Distribution Report prepared by APA, it
should be replaced with "allocations" or "distributions." The populations
"projections" for Ada County were prepared by the Idaho Department of Water
Resources in an IPEF model. APA does not make projections, but merely allocates
growth projections from the Department of Vfetter Resources into subareas, based
on comprehensive plans.
The allocation (18,985) currently used under the land use Plan C is correct.
The population for the Southwest area of 22,380 was the original allocation In
the APA DED Report. However, the 3,095 difference between those two allocations
has not been totally directed to the Eagle Sewer Facility Plan area. The
adjustment (for planning purposes) is not 13,600 for the Eagle Water and Sewer
District, but 13,286 as expressed an page 66.
Page 66, Table 4-4
The 44,548 additional persons number referred to as being provided central sewer
by 1987, on Table 4-4 cannot be found on that table.
If there is another source for this data, that source needs to be delineated.
286
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EES COMMENT
MAY 8, 1981
PAGE THREE
CHAPTER 6 - LAND USE CONDITIONS AND TRENDS
Page 69, 2nd Paragraph
• Add a final sentence that states, "The DED overall Ada County projection
taken from the 1976 BSU/DWR State of Idaho (IPEF 73) projection.
Page 69$ 3rd Paragraph, last sentence
An Area of City Impact Agreement between Eagle and Ada County was adopted on
September 23, 1980. The boundary is consistent with Figure 6-1 on Page 71,
except on the eastern side where it follows Horsehoe Bend Road (Highway 55) and
its alignment south to the north channel of the Boise River, then west along the
river to the alignment of doverdale Road. This agreement has the effect of
amending the Ada County Comprehensive Plan, which is the source of information
used in Figure 6-1.
Page 71, Figure 6-1
^ ^ * There is no such agency as the "Ada County Planning Department." The source
cited should be the "Ada County Comprehensive Plan 1977 as amended."
Page 75, 4th Paragraph, last sentence
The statement is Inaccurate and should be reworded as follows:
This policy plan shows the Southwest area as part of the Boise Area of City
15 Impact and it suggests a population goal for the area. However, a separate
Southwest Conmunity Comprehensive Plan has been adopted by Ada County. Garden
City, which is part of the metropolitan area, is excluded from the Boise Policj
Plan because it has its own comprehensive plan.
Page 85, Last Paragraph
This paragraph, dealing with the Eagle Sewer Service area south of the Boise
River, should be deleted as it is not reflected in any adopted ptL&n.
Page 86, 2nd Paragraph, 3«3 sentence
The statement seems to be question^ "the ooi^s,
Plan. "Ability" was a poor choice of wortts ardthe following wording should be
used as a substitute: "....depends en the county implementing the
provisions..."
287
-------
ECS COMMENT
MAY 8, 1981
PAGE POUR
CHAPTER 7 - AIR QUALITY
Existing Air Quality Problems
Page 91 (last paragraph, last sentence)
It should be initially stated that Ada County is a non-attainment area for car-
18 J bon monoxide. Pollutants which do not currently exceed federal health standards
should be identified.
Page 92 (First paragraph, second sentence)
"The standards for 1-hour exposures is currently 35 ppm (parts per million), to
19j be exceeded no more than once per year..." (recommend deleting remainder of sen-
tence).
Permanent Monitoring Station Data
Page 98 (first paragraph, last sentence)
Question the portion of morning traffic in the warm mode. Suggest deleting the
20 word "significant" from this sentence. "Tfy the time it arrives at its
destination," should be added at the end of the sentence.
Page 98 (third paragraph, last sentence)
21 Morning CO levels may well be a reflection of commute trips. Incorporate
thought into explanation.
Data (Figures)
Plages 101 and 102
22 Include a footnote at some point, explaining difference between occurrence,
exceedence and violation. This will reduce the likelihood of data misuse.
Institutional Framework
Page 105 (third paragraph, last sentence)
2 3J. A brief description of the areas special "designation" for particulates would be
appropriate here.
288
-------
EES COMMENT
MAY 8, 1981
PAGE FTVE
Page 104 (second point)
Include condition to implement a vehicle inspection and maintenance program.
Bnlssions Inventories
Pages 106, 108, 109
Reconrnend clarifying definition of ESDI in the text.
lUture Air Pollution Potential in Ma County
Page 114 (third paragraph, fifth sentence)
Correct sentence by inserting "totally" between "episodes do not result" and
"from reductions."
Page 114 (third paragraph)
It is a valuable planning tool to look at the pollution levels in the various
community planning areas. However, this paragraph should stress that the source
of pollution (automobiles) is an areavrt.de problem. Simply because a particular
planning area does not experience high levels within its boundaries, does not
mean that its residents do not contribute to the high air pollution levels in
another planning area.
page 127 (list of measures)
Include: . Coldtart considerations to be incorporated into an area vehicle
inspection and maintenance program.
gh'Stountya air quality prcblem JS ¦'*
the various potential facility expansions i^on the f&cilltiee sten
specifically addressed. The air quality ^icts of the proposea recipes
from the secondary impact of the growth ascorimcda ed - foliowiret tvoe of state-
emissions fron the actual facility. At a mlntaum, the following type at state-
ment should be included at the end of this section.
"The Boise sewer facilities merely accomodate one aervice need of the growth
Projected and assumed in the area plans."
A brief expression of the general air impact of
accorrmodatSd in the Eagle Sewer a*i Water JmIW JJg Session.
Included in the finalEXS as agreed on at the April 8, 1981 work session.
289
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EIS COMMENT
MAY 8, 1981
PAGE SIX
CHAPTER 10 - FISHERY RESOURCES
Page 187, Indirect Impacts on Fisheries
1st Paragraph
The 1980 population for Ada County is 173,036 according to advance Census
Reports. We would recorrmend deleting the range used and inserting the more
current figure.
CHAPTER 12 - AGRICULTURAL LANDS IN ADA COUNTY
Page 207 - General
Although this chapter is called Agricultural Land in Ada County, it confines its
analysis to the three wastewater study areas and does not describe how Ada
County has endeavored to preserve agricultural land in areas designated as Rural
Areas in the Ada County Comprehensive Plan. In addition, it does not address
the conflicts between urban and rural land uses which may exist in the study
areas. Consequently, it gives the impression that nothing is being done to pre-
serve agricultural lands and that in all instances agricultural uses in Urban
Service Planning Areas are viable, even though an agricultural parcel may be
surrounded by urban uses. It is felt that local comprehensive plans adequately
address this subject.
CHAPTER 13 - PUBLIC SERVICES AND FACILITIES
IMs section does not adequately address the problems that are currently facing
local governments and special districts within Ada County and its orientation is
so superficial as to be unusable in terms of analyzing the total impacts of
growth and its direct relationship with sewer service development. The Ada
Planning Association has exhaustively studied this subject under its Growth
Management Facility Fees Analysis. Such studies point ait the public service
and financial problems that face local government in Ada County.
Page A-15, 2nd Paragraph, 1st sentence
Change "parkiiTg" to "engine off."
Page A-l6, 4th Paragraph, last sentence
Insert "selected" between "other" and "portions."
290
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EIS COMMENT
MAY 8, 1981
PAGE SEVEN
APPENDIX B - FISCAL OVERVIEW
On the whole, the Fiscal Overview Analysis was very well done and f^rately
pointed out the many problems that local governments currently face as a result
of Inflationary pressures, growth demands and revenue limitations. As accurate
as this analysis is, there should be additional Information within the EIS,
which addresses itself to recent legislation that was passed by the 1981 Idaho
Legislature.
APPENDIX C - ISSUE PAPER POPULATION PROJECTIONS FOR ADA COUNTY ELS ANALYSIS
As discussed at the April 8, 1981 meeting, it would be advantageousi to d^ete
this discussion from the appendix since these population issues have been
resolved.
APPENDIX G
Page G-15, Chart
We request that the remainder of the 1980 CO data be included for the final
report.
291
-------
Response to Comments From Ada Planning Association
1-10. Corrections made to revised EIS sections.
11. See revised text (Chapter 5). This number was extra-
polated from data presented in Table 4-4.
12. This paragraph has been deleted from the revised text.
13-16. Corrections made in revised text.
17. This paragraph has been deleted from the revised text.
18. Note revised text (Chapter 9, Page 136).
19. The last phrase in this sentence reflects EPA guidelines
for interpreting federal air quality standards.
20. Note revised text and (new) Table 9-5.
21, 22. Note revised text (Chapter 9).
23. The Federal Register designation of attainment status
does not discuss the basis for individual subarea desig-
nations. The Boise area has recorded ambient particulate
values exceeding the federal primary standard. The
attainment status designation was granted under EPA's
"rural fugitive dust policy" due to the lack of industrial
particulate sources in the area.
24-29. Note revised text (Chapter 9).
30. This paragraph has been deleted from the Final EIS.
31. The focus of this chapter has been changed somewhat
to evaluate the impact of urbanization on agricultural
resources within the planning areas. Although it is
recognized that local land use plans and policies help
preserve agricultural resources in the rural areas,
the concern of this chapter is to examine the agricultural
resources (i.e., designated prime farmland and farmland
currently under production) which are expected to be
converted to urban uses as a result of future growth
in the facility planning areas. No attempt has been
made to determine the economic value of specific parcels
for either urban or agricultural use.
32. Note revised text (Chapter 8).
33,35,36. The appendix document has not been republished with
The Final EIS; thus, no changes have been made to the
appendices.
34. Much of this material has been incorporated (with some
updating) into the revised EIS text (Chapter 8).
292
-------
John V. Evans, Governor
Daniel T. Emborg, Administrator
State Capitol Building
Boise, Idaho 83720
DIVISION OF ECONOMIC AND COMMUNITY AFFAIRS
Ms. Norma Young
Environmental Protection Agency
Region X
Seattle, WA 98101
Dear Ms. Young:
The Idaho State Clearinghouse has completed its review on THE DRAFT
ENVIRONMENTAL IMPACT STATEMENT - WASTEWATER MANAGEMENT FOR BOISE,
EAGLE, AND ADA COUNTY, IDAHO - SAI #00315618. The following agencies
were contacted for their review and comment:
Ada Planning Association
Ida-Ore Regional Planning and Development Association
Department of Water Resources
Department of Health and Welfare/Division of Environment
Department of Transportation/Division of Highways
Department of Fish and Game
Division of Economic and Community Affairs
The Department of Health and Welfare/Division of Environment made extensive
comments - for complete details see comments attached. The Ada Planning
Association state formal comments are being made directly to your agency -
see comments attached. At the time of sign-off the other listed agencies
have not commented. All late comments will be forwarded to your agency.
Thank you for letting us be of assistance in the review of your Draft
Environmental Impact Statement, if you have any questions, do not hesitate
to contact myself or Lois Wade at 208-334-4718.
May 4, 1981
Sincerely,
Gloria Mabbutt, Coordinator
Idaho State Clearinghouse
GM/lw
WW 6 1981
ENViRQMMENTM. EVALUATION
BRANCH
293
I
-------
ADA PLANNING ASSOCIATION
650 Main Street
Boise. Idaho 83702
(208) 344-7600
AREAWIDE CLEARINGHOUSE
A-95 Project Sign-Off
PROJECT TITLE: DEIS Wastewater Mqmt. for Boise. Eagle & Ada County
STATE APPLICATION IDENTIFIER NUMBER: 00315618
CLEARINGHOUSE FINDING:
( ) Support Project
( ) Do Not Support Project
( ) Needs Attention
( ) No Comment
REVIEWING AGENCIES AND RESPONSES:
Support
Non-Support
No Comment
Comments
Attached
i No
Response
Ada Planning Association
X
Board of County Commissioners
X
Mayor Eardley - Boise City
X
Mayor Deckard - City of Eagle
X
COMMENTS: Formal comments are being made
directly to the Environmental Protection
Agency.
•
AREAWIDE CLEARINGHOUSE REPRESENTITIVE:
DATE: U.-S-o
EQUAL OPPORTUNITY/AFFIRMATIVE ACTION EMPLOYER
294
-------
STATE OF IDAHO
DEPARTMENT OF HEALTH
AND WELFARE
DIVISION OF ENVIRONMENT
Statehout*
Bote, Idaho 83720
April 24, 1981
Ms. Norma Young
Environmental Evaluation Branch
U. S. EPA
Region X - M/S 443
1200 Sixth Avenue
Seattle, Washington 98101
Dear Ms. Young:
The Division of Environment, Idaho Department of Health
and Welfare, has reviewed the draft EIS Wastewater Manage-
ment For Boise* Eagle, And Ada County, Idaho, and wishes
to submit the following comments!
1) Page A-46 of Appendix - BTU content of natural gas is
1000 BTU per cubic foot (not 106 cubic feet).
2) Page 148 - Our current water quality standards should
be referenced rather than our 1973 standards.
3) Page 158 - Why is Caldwell listed as having a discharge
to the Boise River when the other discharges in Canyon
County are not listed?
4) Page 6 - The workshops were held in 1980 rather than 1979,
5) Page 43 - Proposed Eagle Sewer District plant site is
not subject to wetlands policy.
6) Page 50 - EWSD population projections now have the
concurrence of APA.
7) Page 52 - Rapid infiltration site has now been defined.
8) Page 66 and 218 - The 16,000 population figure is not
included in the EWSD facilitr plan anymore.
m 1881
ENVIRONMENT*! ^valuation
i-f'V* • . ¦ * J
295 .
EQUAL OPPORTUNITY EMPLOYER
-------
Ms. Norma Young
April 24, 1981
Page 2
9) Page 85 - The Section on the Eagle planning area
needs to be redone to reflect new data on populations
and planning areas and costs on Pages 54 - 57.
10) Page 168 - What is the basis for the statement "Lander
Street plant does not have enough land available to
install nitrification processes that are economical"?
11) Page 169 and 170 - The proposed design and construction
at Lander Street and West Boise would be necessary for
a river discharge regardless of minimum in stream flows.
Therefore, the design of the J.-ander Street STP and West
Boise STP need not be delayed until U. S. Water and
Power Resource Services completes its operation studies
of flow releases in the Boise River.
12) Page 204 - Executive Order 1190, Protection of Wetlands,
does not apply to the Eagle site according to U. S. Fish
and Wildlife Service.
13) Page 229 - The reference to near term scale of operation
of City of Boise is unclear.
14) Page 235 - Reference is made to more complete analyses
of several issues for the final EIA. Who will do these
analyses and when will they do them?
15) The recommendation that detailed planning not proceed
until stream flow issue is resolved should be deleted.
16) We did not note any discussion in the groundwater section
on potential impacts of the EWSD proposed rapid infil-
tration alternative.
17) Which, if any, o£ tne growth impact mitigation measures
will be required? How are the measures implemented and
enforced?
18) Page 244 - What is basis for statement that EWSD alter-
native B pipeline will "destroy" habitat for 19,000 l.f.
and "significantly" impact a blue heron rookery. In
contrast Page 245 notes that North Boise interceptor
"may disturb" a blue heron rookery.
296
-------
Ms. Norma Young
April 24, 1981
Page 3
19) Page 246 - Will we still require consultation with
Fish and Wildlife on EWSD treatment construction
mitigation measures?
Thank you for the opportunity to comment on this Environmental
Impact Statement.
Administrator
LWS/b
297
-------
Response to Comments From Idaho Division of Environment
1. Correction noted. The appendices to the Draft EIS
have not been republished with the Final EIS. The
error noted is a typographical error only; all calcula-
tions were performed using the correct BTU value.
2. This material was excerpted from the Draft Facility
Plan (CH2M Hill 1980c).
3. Note revised text (Chapter 11).
4. Text corrections made.
5. Note revised text (Chapter 12).
6. Note revised text (Chapters 4 and 5).
7. Note revised text (Chapter 3).
8, 9. Text corrections made.
10, 11. Material deleted from revised text.
12. Note revised text (Chapter 12).
13. The reference should have been to the City of Eagle.
14. Note revised Chapters 5, 8, and 9.
15. Material deleted from revised text.
16. Note revised text (Chapter 10).
17. These measures have not yet been identified by EPA
as potential grant conditions. The Clean Air Act man-
dates actions such as those discussed in terms of air
quality.
18. Note revised text (Chapter 14).
19. Note discussion of the Eagle site in Chapter 12, page 236.
298
-------
STATE OF IDAHO
DEPARTMENT OF FISH AND GAME
REGION 3
109 WEST 44TH
GARDEN CITY, IDAHO 83704
Way 12, 1981
m
*MT) IS
Environmental Protection Agency
Region X
1200 Sixth Ave.
Seattle, WA 98101
?e.- Environmental Draft impact Statement Wastewater Management
for Boise, Eagle and Ada County, Idaho
Dear Sirs:
Personnel from the Idaho Department of Fish and Gam have reviewed the above
referenced document and offer the comments listed below.
Zn general, the document adequately covers the alternatives and associated
environmental problems. We are concerned with the loss of riparian vegetation^
issociated with the construction of the Eagle facilities. The document adeguately
itates the impacts to wildlife from loss of riparian cover. However, the document
Joes not state the adverse impacts to the river and the fishery. Not only does
riparian vegetation provide cover for wildlife, it also provides shading for the
rivers, maintianing cool water temperatures necessary for cold water fisheries.
Should the Eagle facility require construction at the site selected we recommend
i minimum 100-foot buffer between the river and the sewage treatment facility.
Specifically i
1. Page 171. Present Day Fishes - Although largewouth bass and bluegill may
be more popular in the Boise River, rainbow trout and brown trout are more
abundant and much more important in the study area.
2. Page 173. Table 10-1 - The Boise River between Lucky Peak dam and the river
mouth contains no coho salaon or cutthroat trout.
??9
EQUAL OPPORTUNITY EMPLOYEE
-------
Environmnetal Protection Agency
Page 2
May 12, 1981
3. The document does not state the adverse impact to the river or its fishes
due to the potential loss of riparian vegetation due to construction of the
Eagle facility.
4. Page 246. Fisheries - The Boise River does not support any anadromous
fish.
5. Page 246. The Idaho Department of Fish and Game does not issue permits
for river alteration — Water Resources is the proper department.
Sincerely,
Regional Supervisor
Region 3/Boise
cct Ada County Planning
300
-------
Response to Comments From Idaho Department of Fish and Game
1. The EIS states that species composition in the river
near Boise State University (and hence the City of
Boise proper) is dominated by whitefish and trout.
However, since the effects of the Boise discharges
could potentially affect areas far downstream, the
"study area" extended to the mouth of the Boise River.
4, 5. Note revised text (Chapter 11).
3. Note revised text (Chapter 11) and mitigation measures
in Chapter 12, page 236.
Ml.
-------
United States Department of the Interior
FISH AND WILDLIFE SERVICE
ECOLOGICAL SERVICES
4620 Overland Road, Room 209
Boise, Idaho 83705
FEB 2?
February
Mr. Mark T. Masarik, Urban Area Coordinator
U.S. Environmental Protection Agency
Idaho Operations Office
422 West Washington Street
Boise, ID 83702
^ MAR 4 19
Dear Mark:
ENVIRGNv
This responds to your recent request for our Service's opinion on a question-
able wetland area located approximately three miles west of Eagle, Idaho. The
area in question is the city-owned property (65 acres) that 1s designated for
a sewage lagoon site for the city of Eagle. By this letter, we are advising
your office and Mr. Kirby D. Yickers, P.E. of J-U-B Engineers, Inc., that we do
not consider this small stream-blocked area to be a natural wetland.
We appreciate being advised of this proposal. As discussed during the
January 30, 1981, field trip, we are available if additional imput 1s needed
for the possible Implementation of any waterfowl structures or wildlife plant-
ings associated with the development of this site. Please feel free to con-
tact our office at anytime. Thank you.
Sincerely yours,
Dennis G. Buechler
Field Supervisor
cc: J-U-B Engineers
(212 Tenth Avenue South, Nampa,
Attention: Mr. Kirby D. Vlckers
IDF&G, Boise/Region III
Nampa, ID 83651
302
-------
Response to Comments From U. S. Fish and Wildlife Service
1. Note revised text (Chapter 12).
-------
o.
REGION X
DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT
BOISE SERVICE OFFICE
419 NORTH CURTIS ROAD
BOISE. IDAHO 83704
March 23, 1981
Hugged?jjjj
IN REPLY REFER TO!
10.4HTV - S/D
Mr. Donald Dubois
U. S. Environmental Protection Agency ^ jijl
Region X 25 1981
1200 Sixth Avenue
Seattlej Washington 98101 EVALUATION
Dear Mr. Dubois:
Subject:
FHA/HUD Response Environmental Impact Statement
Boise, Eagle, and Ada County, Idaho
We agree with the mitigation measures for drainage listed on page 222 of
the subject report. It is the policy of this agency that street right-of-ways
in subdivision development must be accepted for maintenance by local authority
having jurisdiction. It is our position that acceptance of these right-of-ways
1. also constitutes acceptance of street drainage within these right-of-ways,
and we recognize the local authority's responsibilities for drainage.
It is the policy of this office not to accept holding or retention ponds
onsite unless they are owned and maintained by the local authority or other
acceptable public entity. Home Owner Associations that are a part of a
Planned Unit Development offering alternative use of retention or holding
ponds can be acceptable. Home Owner Assocations for drainage purposes only
will not be accepted.
Sincerely,
Reno Kramer
Supervisor
Boise Service Office
304
-------
Response to Comments From U. S. Department of Housing and
Urban Development
1. Comment noted.
-------
United States
Department of
Agriculture
Soil
Conservation
Service
Room 345
304 North 8th Street
Boise, Idaho 83702
April 23, 1981
Ms. Norma Young
U.S. Environmental Protection Agency
Region X, 1200 6th Ave.
Seattle, Washington 98101
Dear Ms. Young:
We have reviewed the Environmental Impact Statement draft for Waste Management
for Boise, Eagle and Ada County, Idaho and have the following comments:
1) Chapter 12, last paragraph, page 207, indicates an absence of a prime
farmland map for Ada County. At the time information requested from
SCS, there was not a prime farmland map or a published soil survey.
Prime soils had not been identified either. Information was provided
that land capability class I and II would probably be classified as
prime agricultural land.
Prime soils have been identified but a map has not been published.
Information is available from SCS for prime ag lands in Ada County.
2) The first sentence on page 208 states that "All lands designated
as Class I and II in figure 12-1 are considered prime farmland,"
is not quite correct. The following should be added to the state-
ment: "When irrigated". The (figure 12-1) information shows much
of south Ada County desert as prime farmland, including the Army
National Guard maneuvering area.
3) You may want to contact Leland Holstine, District Conservationist,
Meridian Field Office, P.O. Box 421, Meridian, Idaho 83642 - telephone
888-1890 for up-to-date information on prime agriculture land in Ada
County.
Thank you for the opportunity to review and comment on this draft EIS.
"Amos I. Garriso:
JT
State Conservationist
tr m
p/jq (MTIOH
The SoU Conservation Service
Is en agency of the
Department of Agriculture
306
SCS-AS-'
10-79
-------
Response to Comments From U. S. Soil Conservation Service
3. Note revised text (Chapter 7), especially Figure 7-1.
-------
RCPLY TO
ATTENTION OF:
DEPARTMENT OF THE ARMY
WALLA WALLA DISTRICT, CORPS OF ENGINEERS
BUILDING 602, CITY-COUNTY AIRPORT
WALLA WALLA, WASHINGTON 99362
NPWEN-PL
12 May 1981
Ms. Norma Young
Region X
Environmental Protection Agency
M/S 443
1200 Sixth Avenue
Seattle, Washington 98101
Dear Ms. Young:
We have reviewed the Draft Environmental Impact Statement for Wastewater
Management for Boise, Eagle, and Ada County, Idaho. Our review does not
reveal any effects on navigation, flood control, or hydropower development.
If you do any dredging or filling 1n rivers or wetlands, you will need a
404 permit under the Clean Water Act. A permit may be applied for by con-
tacting this section prior to construction:
We appreciate the opportunity to review this Draft Environmental Impact
Statement.
Regulatory Functions Section
Walla Walla District, Corps of Engineers
Bldg. 606, C1ty-County Airport
Walla Walla, Washington 99362
Sincerely
BRAMMER
W. 1. BRAMMER
Chief, Engineering Division
30 »
-------
Response to Comments From U. S. Army Corps of Engineers
1. Comments noted. Note U. S. Fish and Wildlife Service
letter regarding Eagle facility site.
-------
Advisory
Council On
Historic
Preservation
Reply to: Lake Plaza South, Suite 616
44 Union Boulevard
Lakewood, CO 80228
1522 K Street. NW
Washington, DC 20005
May 13, 1981
1.
Mr. Donald P. Dubois
Regional Administrator
U.S. Environmental Protection Agency
Region X
1200 Sixth Avenue
Seattle, Washington 98101
Dear Mr. Dubois:
Thank you for your request of March 16, 1981, for comments on the
environmental statement for Wastewater Management for Boise, Eagle,
and Ada County, Idaho. Pursuant to Section 102(2)(c) of the National
Environmental Policy Act of 1969 6111(1 Council's regulations,
"Protection of Historic and Cultural Properties" (36 CFR Part 800),
we have determined that your draft environmental statement appears
adequate concerning our area of interest, and we have no further
comments.
Sincerely,
_ w/V/wi,
Lou^sj^S. Wall
Chief, Western Division
of Project Review
dmowij]
m 18 1981
ENVIRONMENTAL ^AllJATlGN
BRANCH
310
-------
Response to Comments From Advisory'Council on Historic Preservation
1. Comments noted.
311
-------
LIST OF REPORT PREPARERS
U. S. Environmental Protection Agency - Region 10
Elizabeth Corbyn - Chief, Environmental Evaluation Branch;
Seattle, Washington.
Area of EIS Responsibility. Coordinates EIS preparation
efforts with other EPA Region 10 environmental evaluation
functions.
Roger Mochnick - EIS Preparation Coordinator, Environmental
Evaluation Branch; Seattle, Washington.
Area of EIS Responsibility. Oversees all EIS preparation
efforts for EPA Region 10.
Norma Young - Project Monitor, Environmental Evaluation
Branch; Seattle, Washington.
Area of EIS Responsibility. Principal monitor and
reviewer of Ada County/Boise EIS.
Mark Masarik - Urban Area Coordinator EPA Operations Office,
Boise.
Area of EIS Responsibility. Coordinates efforts of
EIS team with local government agencies and contractors.
Jones & Stokes Associates, Inc.,
Sacramento, California
Charles R. Hazel - B.S., M.S.# and PhD., Fisheries Biology.
Formerly with California Department of Fish and Game
as Director of Water Pollution .Control Laboratory.
As Vice President of Jones & Stokes Associates, Inc.,
has managed numerous environmental studies and reports
and served as expert consultant in fisheries and
water quality ecology.
Area of EIS Responsibility. Program director.
Harold p. Bissell - B. A*.•>. ..BiochemistryM.A., Zooiogy.
Formerly with California Department of Fish and Game
as wildlife biologist; leader of wildlife nutrition
laboratory; and assistant chief of coastal resources,
Also chairman of state power plant siting committee,
and former executive secretary of California Interagency
Council for Ocean Resources As environmental Scientist
313
-------
with Jones & Stokes Associates, Inc., contributor to,
and manager of, numerous environmental studies and
impact statements and reports.
Area of Responsibility. Project manager.
Robert D. Sculley - B.S., Zoology, M.S., Ecology. Staff
ecologist with special expertise in air quality analysis
including modeling, development of emission inventories
and projection of air quality changes. With Jones &
Stokes Associates, Inc., for 9 years with varying project
management, and resource planning and environmental
impact analysis experience.
Area of EIS Responsibility. Project coordinator,
air quality.
Douglas P. Albin - A.B., Zoology, M.S. Fisheries.
Area of EIS Responsibility. Fisheries and hydrology.
Nicholas Cimino - B.A., Political Science.
Area of EIS Responsibility. Project coordinator,
Boise, Idaho.
Jeffrey D. Civian - B.S., Renewable Natural Resources.
Area of EIS Responsibility. Air quality.
larol Cunningham - B.Sc., Geography.
Area of EIS Responsibility. Editing and coordinating.
Michael Durkin - B.A., Geography.
Area of EIS Responsibility. Air quality •
Patricia S. French - B.A., French, M.L.S., Library and
Information Studies
Area of EIS Responsibility. Preparation of reference
listing.
Slenn Gephart - B.A., Biological Sciences and Ecology,
M.S., Wildlife Science.
Area of EIS Responsibility. Vegetation and wildlife.
Albert Herson - AICP, B.A., Psychology, M.A., Psychology,
M.A., Urban Planning
Area of EIS Responsibility. Land use studies/ population
issues and community services.
314
-------
JoArtne Sorenson - B.A., Biology, M.A. , Biology.
Area of EIS Responsibility. Editing.
Curtis E. Spencer - P.E.
Area of EXS Responsibility. Drainage and hydrology.
Thomas C. Wegge - B.A., Urban Studies, M.S., Environmental
Economics.
Area of EIS Responsibility. Land use, growth implica-
tions and population projections.
Jones & Stokes Associates# Inc.,
Seattle, Washington
Jonathan H. Ives - B.B.A., Wildlife Management, M.S.,
Wildlife Biology.
Area of EIS Responsibility. Hydrology, wastewater
alternatives, and water quality management.
Culp-Wesner-Culp
Cameron Park, California
Robert Williams - B.S., Civil Engineer, M.S., Sanitary
Engineer.
Area of EIS Responsibility. Evaluation of facility
plans, description of existing facilities.
Justin Faisst - B.S., Civil Engineer, M.S., Environmental
Engineer.
Area of EIS Responsibility. Evaluation of facility
plans, description of existing facilities.
H_. Esmaill and Associates, inc.,
Berkeley, California
Houshang Esmaili - Doctor of Engineering, Water Resources
Engineering.
Area of EIS Responsibility. Overall coordination/
supervision of groundwater/water studies.
Nicholas Johnson - M.S., Hy$«@logy.
Area of EIS Responsibility; Hydrology and groundwater
quality.
MS
-------
Barry Hecht - PhD., Candidate in Geography.
Area of EIS Responsibility. Hydrogeology and ground-
water quality.
Roger Abraham - M.S., Soil Science.
Area of EIS Responsibility. Nonpoint source loadings.
Gruen Gruen + Associates
San Francisco, California
Roberta Mundie - Master of City Planning.
Area of EIS Responsibility. Population and fiscal
impacts analysis.
Suzanne Lampert - Master of Public Affairs and Urban Planning.
Area of EIS Responsibility. Population and fiscal impact
analysis.
Geological Drafting Service,
Sacramento, California
Steve Fleming - Extensive Cartographic Experience.
Area of EIS Responsibility. Report graphics.
316
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ACRONYMS AND ABBREVIATIONS
ACHD Ada County Highway District
AC0G Ada Council of Governments
APA Ada Planning Association
BEA Bureau of Economic Analysis
B0D biochemical oxygen demand
BWQ Bureau of Water Quality
CaC03 calcium carbonate
C°HD Central District Health Department
CEQ Council of Environmental Quality
c^s cubic feet per second
co carbon monoxide
DED Demographic and Employment Distribution
EI^ Environmental Impact Statement
EPA U. S. Environmental Protection Agency
ESD Eagle Sewer District
ESDI Emission Source Density Index
FEMA Federal Emergency Management Agency
FERC Federal Energy Regulatory Commission
Idaho Department of Fish and Game
IDHW Idaho Department of Health and Welfare
¦cp<-° Idaho Power Company
IWRB Idaho Water Resources Board
lbs/ac pounds per acre
MGD million gallons per day
m9/l milligrams per liter
mmhos/cm millimhos per centimeter
N nitrogen
NAAQS National Ambient Air Quality Standards
NEPA National Environmental Policy Act
nh3 ammonia
N01 Notice of Intent
no3~n nitrate measured as N
NPDES National Pollutant Discharge Elimination System
317
-------
OMB Office of Management and Budget
ppm parts per million
SHPO State Historic Preservation Officer
SRMF Stream Resource Maintenance Flow
SWIDD Southwest Interim Development District Ordinance
TSS total suspended solids
201 Section 201 of the Clean Water Act
208 Section 208 of the Clean Water Act
USGS U. S. Geological Survey
USSCS U. S. Soil Conservation Service
USPA Urban Service Planning Area
318
-------
EIS DISTRIBUTION LIST
Federal Agencies Advisory Council on Historic Preparation
U.S. Department of Agriculture
Farmers Home Administration
U.S. Department of Commerce
National Marine Fisheries Service
U.S. Department of Defense
Corps of Engineers, Seattle District
U.S. Department of Health and Human Services
U.S. Department of Housing and Urban Development
U.S. Department of the Interior
Fish and Wildlife Service
U.S. Bureau of Reclamation
U.S. Department of Transportation
Federal Highway Administration
Idaho State Agencies Central Health District
Division of Environment
Air Quality Bureau
Department of Fish and Game
Department of Planning ana tommunuy Artairs
Department of Transportation
Department of Water Resources
State Clearinghouse
Ada County Board of County Commissioners
Engineer
Highway District
Planning Association
Zoning Department
319
-------
City of Boise
City Counci I
Planning & Zoning Department
Public Works Department
Elected Officials Honorable John Evans
Governor of Idaho
Honorable Richard Eardley
Mayor, City of Boise
Honorable Jerry Deckard
Mayor, City of Eagle
Honorable Joseph Glaysier
Mayor, City of Meridian
Citizens Groups Ada County Conservation League
Ada County Medical Society
Idaho Citizen's Coalition
Idaho Historical Society
Idaho Lung Association
Idaho Water Users Association
Idaho Wildlife Society
League of Women Voters of Boise
League of Women Voters of Idaho
Soil Conservation Society of America
Wilderness Society
Others Bench Sewer District
Boise Public Library
Eagle Water & Sewer District
The Idaho Statesman
West Boise Sewer District
A local citizen mailing list is available upon request.
320
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BIBLIOGRAPHY
Reference Documents
ACHD see Ada County Highway District.
ACOG see Ada Council of Governments.
Ada Council of Governments. 1973a. Ada County ecology: a ^
reconnaissance survey with management implications. Environ-
mental rep. no. 9. Boise. 140 pp.
1973b. Background information for Ada County, Idaho.
Environmental rep. no. 3. Boise. 95 pp.
1975a. Land...nature's design for the future: a
background report for consideration of regional land use alter-
natives. Boise. 56 pp.
1975b. Agriculture in Ada County. Boise. 32 pp.
1975c. Boise metropolitan area: statistical analysis
of vacant land. Boise. 6 pp.
1975d. Boise River water quality monitoring. Environ-
mental rep. no. 10. Boise. 69 pp.
Ada County Highway District. 1979. Annual budget, 1979-80.
Ada County Planning Commission. 1977. Ada Cpunty comprehensive
plan. Boise. 16 pp. + maps.
Ada Data, Inc. 1979. Boise real estate research report of 1979.
Prepared for Boise Real Estate Research Committee, 177 pp.
Ada Planning Association. 1978. Demographic and employment
distribution to the year 2000. Boise. 19.8 pp.
1979a Southwest wastewater management study, chap-
tor 3: current Conditions and characteristics of study area.
Boise. 36 pp.
197 9b Ada county record subdivision report,: summary
points, July 1978 to December 1978. Memorandum frofti Robert
Hugenberg, Executive Director, and Harvey Gross, Comprehend
Planning Director.
311
-------
. 1980a. Southwest community wastewater management
study: operation and maintenance alternatives for on-
site subsurface wastewater disposal systems. Boise. 4 2 pp.
. 1980b. Southwest community wastewater management
study: summary.
. 1980c. 1987 transit plan for the metropolitan
Boise area.
APA see Ada Planning Association.
Arbib, R. 1979. The blue list for 1980. Am. Birds 33(6):830-835
Boise (City). 1979. Boise city budget, 1979-1980.
Boise Center for Urban Research. 1977. Analysis of alternatives
to refuse disposal. 97 pp.
Boise Planning and Zoning Department. 1979. Draft environmental
assessment of downtown redevelopment program.
Boise Project Board of Control. 1979. Annual report, 1978.
Brown, C. J. D. 1952. Spawning habits and early development of
the mountain whitefish (Prosopium williamsoni) in Montana.
Copeia 1952(2):109-113.
Burt, W. H., and R. P. Grossenheider. 1976. A field guide to
the mammals. 3rd ed. Houghton Mifflin Co., Boston. 289 pp.
Business Economics, Inc. 1979. An analysis of growth management
fees in Ada County, Idaho. Prepared for Ada Planning Association
Board and Idaho State Division of Budget Policy Planning and
Administration. Boise.
Business Economics, .Inc., and Benkendorf and Associates. 1978.
197 8 housing study. Prepared for Ada Planning Association.
Caldwell, H. H., and M. Wells. 1974. Economic and ecological
history support study for a case study of federal expenditures
on a water and related land resource project, Boise Project,
Idaho and Oregon. Idaho Water Resources Research Institute,
University of Idaho, Moscow. 180 pp.
Carlton, N. H. 1969. A history of the development of the Boise
Irrigation Project. M.A. thesis, Brigham Young University,
Provo, UT. 138 pp.
Central District Health Dept. 197 9. Southwest Boise water study,
Boise, Idaho. Boise. 8 pp.
CH2M Hill, Inc. 1977. Urban runoff control handbook for Ada
and Canyon Counties. Prepared for Ada/Canyon Waste Treatment
Management Committee. 46 pp. + tables.
322
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. 197 9a. Mechanical treatment alternatives, City of
Boise, Idaho, wastewater facilities plan. Prepared for the
City of Boise. Technical memorandum, Oct. 1979.
. 197 9b. Planning and design criteria, City of Boise
wastewater facilities plan. Prepared for the City of Boise.
Technical memorandum, May 1979.
. 1979c. South Boise interceptor extension route
selection, City of Boise wastewater facilities plan. Prepared
for the City of Boise. Technical memorandum, November 1979.
. 1979d. West Boise hydraulic capacity analysis, City
of Boise wastewater facilities plan. Prepared for the City of
Boise. Technical memorandum, September 197 9.
. 1979e. Sludge management. Prepared for the City of
Boise. Technical memorandum.
. 1979f. North Boise interceptor. Prepared for the
City of Boise. Technical memorandum, September 1979.
. 1980a. Boise wastewater facilities plan: summary.
Prepared for the.City of Boise.
. 198 0b. Flow augmentation and flow routing. Prepared
for the City of Boise. Technical memorandum.
. 198 0c. Wastewater facilities plan, Boise, Idaho,
parts I and II: preliminary draft. Prepared for the City of
Boise.
Costle, Douglas M. 1978. EPA policy to protect environmentally-
significant agricultural lands. Letter from the Administrator,
U.S. Environmental Protection Agency to Assistant Administrators,
Regional Administrators, and Office Directors.
Davis, J. C. 197 5. Minimal dissolved oxygen requirements of
aquatic life with emphasis on Canadian species: a review.
J. Fish Res. Board Canada ,32:2295-2332.
Davis, J. C., et al. 1979. Dissolved oxygen. Pp.169-174 in
R. V. Thurston7~et al., eds., A review of the EPA red boafc:
quality criteria^Ebr~wa ter. Water Quality Section, American
Fisheries Society, Bethesda, MI?,
Dion, M. p. 1972, Some effects of land-use changes on the shallow
groundwater system in the Boise-Nampa area, Idaho. Water info,
bull. no. 26. Idaho Dept. of Water Administration. 47 pp.
Eagle (City). 1980. Statement &€ revenue tor the guar tear ended
March 31, 1980.
333
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Eagle Planning and Zoning Commission. 1978. Eagle compre-
hensive plan.
Eagle PZC see Eagle Planning and Zoning Commission.
Earth Metrics Incorporated. 1979. Ozone data tor ozone
special study Boise, Idaho.
Elrick and Lavidge, Inc. 1980. The Pacific Northwest residential
energy survey, vol. I: executive summary. Bonneville Power.
Administration, Portland, OR. 81 pp.
ESL, Inc., and CH2M Hill, Inc. 1974. Ambient air quality measure-
ments in the Boise, Idaho, urban area. Prepared for Idaho
Transportation Dept. and Ada County Highway District.
European Island Fisheries Advisory Commission. 1979. Water
quality criteria for European freshwater fish: report on
ammonia and inland fisheries. EIFAC techn. pap. no. 11. 12 pp.
Gibson, H. R. 1978. Survey of fish populations and water quality
in the Boise River from its mouth upstream to Barber Dam.
Idaho Dept. of Fish and Game Snake River fisheries investiga-
tions job performance report, project no. F-63-R-4. 64 pp.
H. Esmaili & Associates, Inc. 198 0a. Groundwater resources of
Boise Valley, Idaho: preliminary draft. Prepared for Jones
& Stokes Associates, Inc.
1980. Non-point source waste loadings in Ada
County and southwest community study areas: preliminary draft.
Prepared for Jones & Stokes Associates, Inc.
Henderson, D. M., F. D. Johnson, P. Packard, and R. Steele. 1977.
Endangered and threatened plants of Idaho: a summary of current
knowledge. University of Idaho, College of Forestry;, Wildlife
and Range Science bull. no. 21. 72 pp.
Holmgren, Arther H. 1972. Handbook of the vascular plants of
the northern Wasatch. 4th ed. Intermountain Herbarium, Utah
State University, Logan. 202 pp.
Idaho Air Quality Bureau. 1978. Staff report, Boise carbon
monoxide study, winter 1977 - spring 1978, Boise,: Idaho.
Idaho. Dept. of Employment. 197 9. Selected Ada County employment
statistics.- Unpublished data from Research and Analysis Bureau,
Boise.
324
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Idaho. Dept. of Fish and Game. 1977. Habitat ana species report,
Ada County. Boise. 16 pp.
. 1978. A plan for the future management of Idaho's
fish and wildlife resources, vol. I: goals, objectives, and
policies, 1975-1990. Boise. 170 pp.
Idaho. Dept. of Fish and Game, and U.S. Bureau of Land Management.
1977. Sensitive species supplement to the master memorandum
of understanding between the Idaho Dept. of Fish and Game and
the U.S. Bureau of Land Management. Boise. 2 pp.
Idaho. Dept. of Health and Welfare, n.d. Rules and regulations
for the control of air pollution in Idaho. Boise.
Idaho. Dept. of Water Resources. 1978. Ada County, Idaho:
water-related land use. Boise.
Idaho. Division of Tourism and Industrial Development. 1977.
Idaho almanac. Boise. 447 pp.
Idaho. Water Resources Board. 1974. Hydrology support study
for a case study of federal expenditures on a water and related
land resource project, Boise project, Idaho and Oregon.
Idaho Water Resources Research Institute, University of Idaho,
Moscow. 157 pp.
Jensen, Scott W. 1980. Wintering bald eagles of the Lower
Boise River. U.S. Fish and Wildlife Service. Unpublished
report. 9 pp.
Jones & Stokes Associates, Inc. 1980. Draft drainage task report:
drainage planning and institutional evaluations. Prepared
,for U.S. Environmental Protection Agency. 51 pp.
J-U-B Engineers, Inc. 1978. Study plan for Eagle water and
sewer plan. Nampa, ID.
. 1980. Draft step 1 wastewater facility plan, Eagle
water and sewer district. Prepared for Eagle Water and Sewer
District. Nampa, ID. 95 pp. + appendices.
J-U-B Engineers, Inc., and Barton, Stoddard, Milhollin & Higgins.
1973. Boise metropolitan area storm sewer system general
plan. Prepared for Ada Council of Governments. Nampa, ID.
48 pp. + appendices.
Kennison, John A. 1980. (Status report of Astragalus mulfordaeT]
Oregon Natural Heritage Program, Portland. 16 pp. Mimeo.
Lee, L. K. 1978. A perspective on cropland availability,
USDA, Agricultural Economics Report 406. %^hfnjg.toii^;..,lDC
3SS
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Lewis, G. C., D. V. Naylor, J. R. Busch, and D. W. Fitzsimons.
1973. Groundwater quality study in the Boise Valley.
Idaho Agricultural Experiment Station res. bull. no. 105.
30 pp.
McAffee, W. R. 1966. Rainbow trout. Pp.192-2x5 in A. Calhoun,
ed., Inland fisheries management. Calif. Dept. of Fish & Game,
Sacramento.
iMald, H. E.f and H. A. Powers. 1962. Upper cenozoic stratigraphy
of Western Snake River plain, Idaho. Geol. Soc. Am. Bull. 73:
1197-1220.
Mathematical Sciences Northwest, Inc. 1979. Estimating energy
impacts of residential and commercial building development:
a manual (draft). Prepared for U.S. Dept. of Energy.
Mink, L. L., A. T. Wallace, and M. G. Lucky. 1975. Study on
the impact of subsurface sewage disposal in the Ada/Canyon
County area of southwest Idaho. U.S. Army Corps of Engineers
regional water management study. 61 pp.
Mohler, Levi L. 197 4. Threatened wildlife of Idaho. Idaho
Wildl. Rev. 26(5):3-5.
Moyle, P. B. 1976. Inland fishes of California. University of
California Press, Berkeley. 405 pp.
Nace, R. L., S. W. West, and R. W. Mower. 1957. Feasibility
of groundwater features of the alternate plan for the Mountain
Home project, Idaho. U.S. Geological Survey Water Supply Pap.
1376. 121 pp.
National Fish and Wildlife Laboratory. 1980. Selected vertebrate
endangered species of the seacoast of the United States. U.S.
Fish & Wildlife Service. FWS/OBS-80/01.
North American Weather Consultants. 1980. A tethersonde field
study examining low-level stability in the Boise Valley.
Packard, Patricia L. 1979. Status report Allium aaseae. College
of Idaho, Biology Dept., Caldwell, ID. 12 pp. Mimeo.
Peterson, R. T. 1961. A field guide to western birds. 2nd ed.
Houghton Mifflin Co., Boston. 309 pp.
Peterson, Russell W. 1976. Subject analysis of impacts on prime
and unique farmlands in environmental impact statements. U.S.
Council "on Environmental Quality, Washington, D.C. Memorandum.
Pruitt, T. A., and R. L. Nadeau. 1978. Recommended stream re-
source maintenance flows on seven southern Idaho streams.
Instrean Flow Infc, Pap. No. 8. U.S. Fish and Wildlife Service,
Ft. Collins, CO.
326
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Snow, Carol. 1972. American peregrine falcon (Falco perearinus
anaturn) and Arctic peregrine falcon (Falco peregrinus tundrius).
Habitat management series for endangered species rep"." no. 1.
U.S. Bureau of Land Management Techn. Note. 3 5 pp.
. 1973. Southern bald eagle (Haliaeetus leucocephalus
leucocephalus) and northern bald eagleTHaliaeetus leucocephalus
alascanus). Habitat management series for endangered species
rep. no. 5. U.S. Bureau of Land Management Techn. Note. 58 pp.
. 1974a. Spotted bat (Euderma maculatum). Habitat
management series for endangered species rep. no. 4. U.S.
Bureau of Land Management Techn. Note T-N-170. 13 pp.
. 1974b. Prairie falcon (Falco mexicanus). Habitat
management series for unique or endangered species rep. no. 8.
U.S. Bureau of Land Management Techn. Note T-N-240. 18 pp.
. 1974c. Ferruginous hawk (Buteo regalis). Habitat
management series for unique or endangered species rep. no. 13.
U.S. Bureau of Land Management Techn. Note T-N-255. 23 pp.
Staley, J. 1966. Brown trout. pp.233-242 in A. Calhoun, ed.,
Inland fisheries management. Calif. Dept. of Fish and Game,
Sacramento.
Stebbins, R. C. 1966. A field guide to western reptiles and
amphibians. Houghton Mifflin Co., Boston. 279 pp.
U.S. Bureau of Land Management. 1980. Snake River birds of
prey environmental assessment: final. Boise.
U.S. Bureau of Reclamation. 1977. Water quality study,
poise Valley.
___. 1979. Boise Valley shallow groundwater study,
first year review. 27 pp.
U.S. Bureau of the Census. 1977. 1974 census of agriculture.
U.S. Government Printing Office, Washington, DC.
U.S. Council on Environmental Quality. 1976. Untaxing open
space: an evaluation of the effectiveness of differential
assessment of farms and open space. Washington. DC.
401 pp.
1978. Environmental quality: the ninth annual
report of the CEQ. Washington, DC.
327
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U.S. Dept. of Labor. 1979. Employment and earnings, 1909-1978.
Prepared by Bureau of Labor Statistics.
U.S. Environmental Protection Agency. 1971a. Summary of water
quality conditions, pollution sources, water quality regulations,
Upper and Central Snake River Basins, Idaho-Oregon. Denver.
10 6 pp.
. 1971b. Noise from construction equipment and
operations, building equipment and home appliances. Prepared
by Bolt, Beranek and Newman.
. 197 6. Quality criteria for water. U.S. Environ-
mental Protection Agency, Washington, D.C. 256 pp.
. 1977a. Municipal sludge management: environmental
factors. EPA 430/9-77-004.
. 197 7b. Draft background paper on EPA programs and
environmentally-significant agricultural lands. Washington,
D.C. Memorandum from Office of Land Use Coordination,
December 5, 1977.
. 1977c. Guidelines for the interpretation of air
quality standards. Revised February 1977. EPA Office of
Air Quality Planning and Standards, OAQPS #1.2-008.
. 1978a. Municipal wastewater treatment works con-
struction grants program, state and local assistance, grants
for construction of treatment works (Title 40, pt. 35, subpart
E). Fed. Reg. 44022-22099 (Sept. 27, 1978).
. 1978b. Carbon monoxide study, Boise, Idaho, Nov.
25-Dec. 22, 1977, parts 1 and 2. Prepared by C. B. Wilson
and J. W. Schweiss.
. 1978c. Idaho environmental quality profile, 197 8.
. 1978d. EPA policy to protect environmentally
significant agricultural lands. Washington, DC
U.S. Fish and Wildlife Service. 1973. Threatened wildlife
of the United States. Washington, DC 289 pp.
. 1980a. List of endangered and threatened wildlife
and plants. 45 Fed Reg. 33768 (May 20, 1980), as amended
through July 14, 1980.
. 1980b. Handbook of interagency NEPA participation.
328
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U.S. Soil Conservation Service. 1979. Soil survey of the Ada
County area, Idaho. Boise. 327 pp. + maps.
Webb, D. 1958. Bioassay report, Boise River. Idaho Dept. of
Fish and Game, Boise. File report.
Wilbur Smith and Associates, Inc. 1976. Demographic and economic
base study, Ada County, Idaho.
Willingham, W. T., et al. 1979. Ammonia. Pp.6-18 in R. V.
Thurston, et al. , ecFs., A review of the EPA red Book; quality
criteria for water. Water Quality Section, American Fisheries
Society, Bethesda, MD.
Zarn, Mark. 197 4a. Burrowing owl (Speotyto cunicularia hypugaea).
Habitat management series for unique or endangered species
rep. no. 11. U.S. Bureau of Land Management Techn. Note T-N-250
25 pp.
. 1974b. Osprey (Pandion haliaetus carolinensis).
Habitat management series for unique or endangered species
rep. no. 12. U.S. Bureau of Land Management Techn. Note T-N-
254. 41 pp.
Personal Communications
Barker, L. S. December 18, 1979. CH2M Hill, Boise. Letter to
C. R. Mickelson, Boise City Engineer.
. April-May 1980. CH2M Hill, Boise. Telephone conversa
tions.
Berent, Mary. August 20, 1979. Data Technician, Ada Planning
Association, Boise. Memorandum on Ada County recorded subdi-
vision report and summary points.
Blake, Diane. May 1980. Ada Planning Association, Boise. Tele-
phone conversation.
Boise Water Corporation. 1980. Well log and well-water quality
data. Written and verbal unpublished data.
Boros, John. May 29, 1980. District Chief, Boise Fire Dept.
Telephone conversation.
Clough, Mr. May 29, 1981. Boise School District.
Dopper, Laura. May 21, 1981. Planner, City of Boise.
32$
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Federal Emergency Management Agency. January 1981. Telephone
conversation with map identification facility, Bethesda, MD.
Fintel, Robert. January 1981. U.S. Army Corps of Engineers,
Walla Walla, WA. Telephone conversation.
Gross, Harvey. May 21, 1981. Director, Comprehensive Planning.
Hind, Mr. May 29, 1981. Meridian School District.
Howard, Rich. October 7, 1980. Threatened and Endangered
Species ffice, U.S. Fish and Wildlife Service, Boise.
Telephone conversation.
Huffacre, Gene. May 29, 1981. Boise Police Department.
Johnson, Margaret, May 1980. Planner, Ada Planning Association.
Telephone conversation.
Keating, James. March 1980. Idaho Dept. of Fish and Game, Boise.
Telephone conversation.
. July 14, 1980. Letter to Jones & Stokes Associates,
Inc.
Kelley, Fenton. April 23, 1980. Professor of Ichthyology, Boise
State University. Telephone conversation.
Leach, C. 1980. Idaho Dept. of Water Resources. Telephone
conversation.
McKinney, ?. May 29, 1980. Vice-President of Marketing, Inter-
mountain Gas Company. Telephone conversation.
Merhoff, L. A. July 23, 1980. Area Manager, U.S. Fish and Wild-
life Service, Boise. Letter to Jones & Stokes Associates.
Minter, Bob. August 9, 1979. Environmental Planning Director,
Ada Planning Association. Memorandum on urban storm drainage
summary report.
. January 1981. Telephone conversation.
Murrey, A. E. 1980. Idaho Dept. of Health and Welfare, Boise.
Letter to Bill Ancell, Public Works Superintendent, City of
Boise.
Nadeau, Richard L. May 2, 1980. Fishery Biologist, U.S. Fish and
Wildlife Service, Washington-, D.C. Telephone conversation.
330
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Neal, Dave. August 29, 1979 and June 2, 1981. Ada County
Environmental Office. Telephone conversation.
Parker, Tom. October 1, 1980. Wildlife Biologist, Idaho Dept. of
Fish and Game, Boise. Telephone conversation.
Reid, Will. March 20, 1980. Fishery Biologist, Idaho Dept. of
Fish and Game, Boise. Telephone conversation.
. April 1980. Telephone conversation.
Stacy, Susan. May 1980. Boise Planning Dept. Telephone conversa-
tion.
Steele, Robert. October 1980. U.S. Forest Service Intermountain
Forest and Range Experiment Station, Boise. Telephone conversa-
tion.
Taylor, Captain Tom. June 1, 1981. Ada County Sheriff's
Department.
Vickers, Kirby. 1981. Engineer, J-U-B Engineers, Nampa, ID.
Telephone conversation.
Walker, Norman. May 27, 1981. Ada County University of
Idaho Cooperative Extension.
331
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