EPA-910/9-82-091
United States
Environmental Protection
Agency
Region 10 .
1200 Sixth Avenue
Seattle WA 98101 November, 1982
EPA/10 Anchorage AK WWTW 82
<&ER& Environmental
Impact
Statement
•
City of Anchorage, Alaska
Wastewater Facilities
p
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U. S. ENVIRONMENTAL PROTECTION AGENCY
R E'G I O N X
1200 SIXTH AVENUE
SEATTLE, WASHINGTON 98101
HEPUTO
AfTN Oft
TO: All Interested Government Agencies, Public Groups and Citizens
Enclosed for your review and comment is the Draft Environmental Impact
Statement (EIS) on the proposed City of Anchorage Wastewater Treatment
Plant Expansion and Interceptor facilities. The Environmental Protection
Agency (EPA) has given the grant for planning needed facilities for the
transmission and treatment of wastewater from developed areas in the City
of Anchorage. The City has an Environmental Protection Agency grant for
planning the proposed facility which includes treatment plant expansion
and interceptors under Section 201 of the Clean Water Act. The Environ-
mental Protection Agency has prepared this Draft Environmental Impact
Statement on its proposed approval of this action, pursuant to Section
102(2)(c) of the National Environmental Policy Act (NEPA) of 1969 and
implementing Federal- regulations.
EPA will announce the availability of this document in the Federal
Register an Friday, January 21, 1983, which will begin a 45-day review
period. .If you have any comments on the Draft Environmental Impact
Statement or wish to provide additional information for inclusion in the
Final Environmental Impact Statement, we would appreciate hearing from
you before the close of the comment period on March 7, 1983. All com-
ments will be used by the Environmental Protection Agency in evaluating
the effects of approving the proposed action.
Please send your comments to: Clark Smith
Environmental Evaluation Branch
Environmental Protection Agency, Region 10
1200 Sixth Avenue, M/S 443
Seattle, Washington 98101
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DRAFT
ENVIRONMENTAL IMPACT STATEMENT
MUNICIPALITY OF ANCHORAGE
SEWERAGE FACILITIES EXPANSION
Prepared by:
U. S. Environmental Protection Agency
Region 10
1200 Sixth Avenue
Seattle, WA 98101
Clark Smith, Project Officer
With Technical Assistance from:
Jones & Stokes Associates, Inc.
2321 P Street
Sacramento, CA 95816
November 1982
Responsible Official:
John R. Spencer
Regional Administrator
Environmental Protection Agency
Region 10
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DRAFT ENVIRONMENTAL IMPACT STATEMENT
City of Anchorage, Alaska
Wastewater Facilities
Prepared By
United States Environmental Protection Agency
Region 10
Seattle, Washington, 98101
with Technical Assistance From
Jones and Stokes Associates, Inc.
2321 P- Street
Sacramento, California 95816
ResponsiDle Official:
gionaq Administrator
Date
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TABLE OF CONTENTS
CHAPTER 1 - INTRODUCTION
Organization of DEIS I
Background and History of the Project 2
Objectives of the Facilities Plan 3
Necessity and Purpose of the Environmental
Impact Statement 3
Issues of Concern 4
Legal, Policy and Regulatory Constraints 5
Federal Laws, Policies and Regulations 5
State Laws, Regulations and Policies 9
Local Laws, Rules and Regulations 10
Public and Agency Participation 11
Study Area Characteristics 11
Physical Location 11
Population . 13
Past Growth 15
CHAPTER 2 - EFFLUENT LIMITATIONS, NPDES PERMIT,
EXISTING SEWERAGE SYSTEM 19
Collection and Interceptor System 21
Service Areas 21
Pump Stations 21
Point Woronzof Wastewater Treatment Plant 24
Liquid Process 24
Solids Processing 26
Auxiliary Facilities 26
Effluent Characteristics 26
CHAPTER 3 - ALTERNATIVES FOR WASTEWATER COLLECTION,
TREATMENT AND DISPOSAL 33
Introduction 33
Service Area 35
Planning Constraints 35
Recommended Plan 36
Solids Processing 39
Auxiliary Facilities 40
Ocean Outfall and Diffuser 41
West Bypass Interceptor Sewer 42
Southeast Interceptor 44
Interceptor Sizing 45
Hillside Wastewater Management Plan 50
Collection Sewer Improvement Projects 54
Range of Alternatives . 56
Screening of Alternatives 58
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Description of Alternatives 58
"No-Action" Alternative 58
Land Application Treatment 53
Wastewater Renovation and Reuse 60
Point Woronzof Treatment Alternatives 60
Alternatives for Ocean Outfall and Diffuser 64
West Interceptor Extension Alternatives 65
Rabbit Creek/Potter Creek Collection
and Treatment Alternatives 65
Individual Treatment Systems 66
Cost Summary 69
User Costs 69
CHAPTER 4 - WETLAND ISSUES 81
Legal, Regulatory and Policy Constraints 81
Issue Summary 83
Biological Setting of Nontidal Wetlands 84
Habitat Types 85
Aquatic Organisms 91
Birds 92
Mammals 96
Biological Setting of Potter Marsh 98
Biological Setting of Tidal Wetlands 100
Hydrologic Setting 1Q1
Hydrologic Cycle 101
Surface Runoff and Groundwater 101
Surface/Groundwater/Wetland Complex 103
Human Use Setting 105
Wetland Impacts 106
Pipe Emplacement Impacts 106
Mitigation of Pipe Emplacement Impacts 121
Hydrologic Impacts 122
Mitigation of Hydrologic Impacts 130
Secondary Biological Impacts 130
Mitigation of Secondary (Growth-Related)
Biological Impacts ]_3]_
Human Use Impacts j_3]_
Impacts on Potter Marsh j_32
Mitigation of Sedimentation Impacts
on Potter Marsh j_33
Pipe Emplacement Impacts on Tidal Wetlands 133
CHAPTER 5 - HILLSIDE ISSUES 135
Issue Summary j_35
Legal, Regulatory and Policy Constraints 137
Planning Guidelines ^37
On-Site Sewage System Inspections 137
On-Site Water Well Inspection ^33
Human Use Setting 138
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Hydrologic Setting 139
Surface Water 139
Groundwater 139
Domestic Water Supply 140
Impacts of Sewerage Decisions on Hillside Area 141
Impacts of Sewering Portions of
Hillside Area- 141
Impacts of Designating On-Site Sewerage
for Portions of Hillside Area 143
CHAPTER 6 - CULTURAL RESOURCE IMPACTS 153
Archeological Resources 153
Historic Places 153
CHAPTER 7 - SECONDARY IMPACTS 155
Growth Inducement 155
Consequences of Growth 158
Water Supply 159
Solid Waste Disposal 160
Energy Resources 161
Education 163
Police Protection 163
Fire Protection 164
Recreation 164
Air Quality 165
Hydrology, Erosion, Seismicity 166
Perceived Quality of Life 170
CHAPTER 8 - EFFLUENT TREATMENT AND DISPOSAL IMPACTS 173
Introduction 173
Physical Oceanography 174
Tides 174
Tidal Currents 178
Flushing Rates of Knik Arm and Cook Inlet 178
Waste Assimilation Ability of Knik Arm 180
Biological Oceanography of Knik Arm, Cook Inlet 182
Chemical Oceanography and Bacteriology of
Knik Arm, Cook Inlet 185
Alkalinity and pH 185
Dissolved Oxygen 185
Suspended Solids/Nutrients 186
Primary Pollutants 186
Coliform Bacteria ' 187
Conclusions 187
Wastewater .Treatment Impacts 188
CHAPTER 9 - SLUDGE PROCESSING AND DISPOSAL IMPACTS 189
Air Quality 189
Energy Consumption 191
Knik Arm Impacts 191
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Landfill Capacity Impacts 192
Landfill Leachate Impacts 192
Groundwater Impacts of Ash Lagoons 192
CHAPTER 10 - SHORT-TERM CONSTRUCTION IMPACTS 195
Impacts Common to Most Activities 195
Special Case Impacts 195
Alaska Railroad 195
CHAPTER 11 - IMPACTS OF ALTERNATIVES 199
Land Application of Effluent 199
Wastewater Renovation and Reuse 200
Alternative PA: Primary Clarification With
No Chlorination of Effluent 200
Secondary Treatment of Effluent 201
Sludge Disposal 202
West Bypass Interceptor 202
Rabbit Creek/Potter Creek Area 204
Rabbit Creek/Potter Creek Area Wastewater
'Collection Alternatives 205
No-Action Alternative 207
CHAPTER 12 - ISSUES UNRESOLVED BY ALTERNATIVES 209
CHAPTER 13 - COORDINATION 211
Scoping Meeting 211
Public Workshops and Meetings 211
In'teragency Workshop - September 9, 1981 211
Facilities Plan Public Meeting -
October 15, 1981 211
EIS Wetlands Workshop - October 16, 1982 213
Facilities Plan Public Meeting -
January 20, 1982 213
EIS Wetlands and Hillside Workshop -
April 14, 1982 213
Comments Received Through Distribution of the
Preliminary Draft EIS 213
CHAPTER 14 - REFERENCES . 215
Documents 215
Personal Communications 221
APPENDICES
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LIST OF TABLES
Table Page
1-1 Current and Projected Population: Munici-
pality of Anchorage 14
2-1 NPDES Effluent Limitations for Point Woronzof,
Based "on Secondary Requirements 20
2-2 NPDES Effluent Requirements for Point Woronzof
WWTP, Based on Primary Treatment 20
2-3 Summary of State of Alaska Water Quality
Standards Applicable to Knik Arm 22
2-4 Summary of Existing O&M Staff at Point
Woronzof WWTP 28
2-5 Yearly Average Effluent Concentrations 31
3-1 Peak Flow Projections Use for Interceptor '
Sizing - Subareas 48
3-2 Peak Flow Projections Used for West Bypass
Interceptor Sizing - Composite Flows 49
3-3 Present-Worth Component Criteria 71
3-4 Present Worth Summary - Point Woronzof
Primary Treatment Expansion Alternatives 72
3-5 Present Worth Summary - Point Woronzof
Secondary Treatment Expansion Alternatives 73
3-6 Present Worth Summary - Incinerator Ash
Disposal Alternatives 74
3-7 Present Worth Summary - West Bypass Interceptor
Extension Alternatives • 75
3-8 Present Worth Summary - Rabbit Creek/Potter
Creek Collection Alternatives 76
3-9 Present Worth Summary - Rabbit Creek Treatment
Alternatives 77
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Table
3-10 Present Worth Summary - Rabbit Creek/Potter
Creek Collection and Treatment Alternatives 78
3-11 Estimated Changes in Single-Family Monthly
Service Charge for Sewer Service 79
4-1 Habitats Identified in Inland Wetland Areas
of the Anchorage Bowl -86
4-2 Birds Sighted in Connors Lake Bog and Campbell-
Klatt Bog, September 10-17, 1981 93
4-3 Mammals Trapped by Specific Habitat Type and
General Habitat Category; Connors Lake Bog
and Campbell-Klatt Bog; September 10-17, 1981 97
4-4 Potential Impacts on Proposed Sewer Lines on
Biological and Recreational Re-sources 107
4-5 Sections of Proposed Sewerage Interceptor
Crossing Wetlands Undisturbed by Pipe
Emplacement HI
4-6 Sections of Proposed Sewer Interceptor Adja-
cent to Nontidal Wetland Areas 114
4-7 Section of Proposed Sewer Interceptors Which
Cross Streams or are in the Stream Flood-
plain 116
4-8 Precipitation (in inches) Summary for Periods
Preceding Aerial Photography of Connors
Lake Bog 129
, 5-1 Tabulation of Areas to be Served by Public
Sewers and by On-Site Sewerage Systems in
the Hillside Area 145
7-1 Residential Land Use Comparisons by Anchorage
Bowl Areas for Current (1980) and Future
(Saturation) Conditions 157
9-1 Average Daily Sludge Incinerator Emissions 190
10-1 Potential Short-Term Impacts Typically Associ-
ated With Construction Activities. Many .are
Relatively Minor in Effect and Magnitude and
can be Effectively Mitigated as Outlined 196
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LIST OF FIGURES
Figure Page
1-1 Location Map 12
1-2 Population Projections for Anchorage 17
2-1 Sewer Service Areas 23
2-2 Schematic of Point Woronzof WWTP Liquid Process 25
2-3 Schematic of Point Woronzof WWTP Solids Process 27
2-4 Comparison of Effluent Quality to NPDES Permit
Limits 30
3-1 Proposed Expansion of Point Woronzof WWTP -
Site Layout 37
3-2 Proposed Expansion of Point Woronzof WWTP -
Process Diagram 38
3-3 Proposed West Bypass and Southeast Interceptor
Sewers 43
3-4 Adopted Hillside Area Sewerage Designations 51
3-5 Hillside Area Septic Tank Suitability . 52
3-6 Proposed Sewer and Interceptor Sewer Construc-
tion, Repair and Rehabilitation Projects 55
3-7 Alternative Treatment Process Diagrams -
Liquid Process - Point Woronzof WWTP 61
3-8 Alternative Treatment Process Diagrams -
Solids Process - Point Woronzof WWTP 63
3-9 Rabbit Creek-Potter Creek Alternatives 67
3-10 Rabbit Creek-Potter Creek Alternative Treat-
ment Process Diagrams 68
4-1 Wetlands 82
4-2 Campbell Klatt Bog 87
4-3 Connors Lake Bog - 88
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Figure page
4-4 Moose Corridors 99
4-5 The Hydrologic Cycle Related to Anchorage 102
4-6 1981 Photo of Connors Lake Bog 108
4-7 Comparative Photographs of Baxter Bog 109
4-8 1964 Photo of Connors Lake Bog 124
4-9 1970 Photo of Connors Lake Bog 125
4-10 1975 Photo of Connors Lake Bog 126
4-11 1978 Photo of Connors Lake Bog 127
4-12 1980 Photomosaic of Connors Lake Bog 128
7-1 Residential Land Use Impacts of Urban Runoff 167
7-2 Measures to Control Erosion and Sedimentation. 171
7-3 Measures to Control Increases in Runoff and
Decreases in Infiltration 17'1
8-1 Generalized Bathymetry of Cook Inlet, Alaska 175
8-2 Bathymetry of Knik Arm 176
8-3 Current Speed Measured 500 Meters off Point
Woronzof Superimposed on Tide Heights for
the Same Period 177
8-4 Point Woronzof Current Directions, August 16,
1979. Bearings are Degrees True. ' 179
8-5 Estuarine Waste Assimilation Diagram 181
8-6 Water Quality, Intertidal and Subtidal
Sampling Stations in Knik Arm ]_g3
13-1 Issues Identified for EIS Coverage and
Priorities at July 9 and 10, 1982 Scoping
Meetings 212
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EXECUTIVE SUMMARY
ENVIRONMENTAL IMPACT STATEMENT
Draft (X)
Final ( )
Prepared by: U. S. Environmental Protection Agency
Region 10
1200 Sixth Avenue
Seattle, WA 98101
Type of Action: Administrative
Project Description
This Draft Environmental Impact Statement (DEIS) is
prepared by the U. S. Environmental Protection Agency (EPA)
to evaluate the impacts of expanding the Municipality of
Anchorage (MOA) wastewater collection, treatment and dis-
posal system. It emphasizes matters of particular concern,
including wetlands, Hillside area sewerage decisions, growth
inducement and impacts of growth, effects of disposing of
effluent in Cook Inlet, and the impacts of sludge disposal.
The DEIS specifically evaluates the MOA facilities plan
that proposes expansion of the sewerage system. That facili-
ties plan consists of two. related documents. The first is
entitled Wastewater Facilities Plan for Anchorage, Alaska
dated June 1982. This report was prepared for the MOA
by a joint venture of Ott Water Engineers, Inc., Quadra
Engineering, Inc., and Black and Veatch Consulting Engineers,
and it comprises the majority of the MOA Section 201 facili-
ties plan. The remainder of the Section 201 facilities plan
is the Hillside Wastewater Management Plan developed by the
MOA Planning Department, with contract assistance from Arctic
Environmental Engineers and adopted by MOA in May 1982.
The Hillside Wastewater Management Plan, funded under
Section 208 of the Clean Water Act, was prepared to address
sewerage needs of the Hillside area of the Anchorage Bowl
with an emphasis on continuing on-site sewage disposal and
preserving a rural lifestyle in the study area. The plan
identifies areas of the Hillside that are to be served by
on-site treatment and disposal systems (such as septic tanks
with drain fields), areas to be served by sewers, 'and areas
unsuitable for on-site systems where no sewer systems are
to be provided (although on-site systems may be allowed).
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The Wastewater Facilities Plan for Anchorage. Alaska
(MOA 1982) .recognizes the determinations for these Hillside
areas and proposes sewage collection, treatment and disposal
systems serving the areas designated for sewerage in the
Hillside plan. It also encompasses alternatives for expansion
of sewage collection, treatment and disposal facilities for
the rest of the Anchorage Bowl, outlined as follows:
o Alternatives for expansion of Point Woronzof waste-
water treatment plant (WWTP) from a current design
capacity of 34 MGD-58 MGD.
o Extension of the existing outfall by 1,500 feet.
o Adding a diffuser of undetermined length at the
end of the extended outfall.
o Alternatives for disposal of sludge solids from
the treatment process.
o Alternatives for construction of the West Bypass
Interceptor sewer.
o Construction of the Southeast Interceptor sewer,
including sewerage alternatives in the Rabbit Creek-
Potter Creek area.
o Provisions for on-site sewerage of a portion of the
Hillside area.
o Construction of about 70 sewer improvement projects
through- 1998 .
The facilities plan also sets forth a MOA-Recommended Plan,
suggesting implementation of specific alternatives.
For EIS purposes the above project alternatives, except
for the 70 sewer improvement projects, are evaluated in de-
tail in the EIS. The 70 sewer improvement projects are
addressed only with specific reference to wetland impacts
and in general terms relative to cumulative impacts.
Recommended Plan
The Point Woronzof WWTP would be expanded from its
current effective capacity of 22 MGD to 58 MGD (average annual
flow). Current design capacity is 34 MGD, although the plant
cannot meet discharge requirements at a design flow rate
over 22 MGD. This expansion would be achieved through con-
struction of three additional primary clarifiers, modification
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of other portions of the liquid processing to increase capa-
city, addition of another sludge incinerator to the solids
process, and consideration of-alternative disposal methods
for incinerator ash. The facilities plan indicates a pre-
ference for discharging the ash into the Knik Arm of Cook
Inlet through the outfall along with the effluent, although
discharge to a landfill or to lagoons or a gravel pit in
the area of Point Woronzof is also considered.
The facilities plan recommends that the outfall be ex-
tended by 1,500 feet, that an extensive design effort be
undertaken, and that the diffuser requirements be further
studied. Preliminary diffuser modeling prepared for a
Section 301(h) waiver application determined that a 1,000-
foot diffuser would enable the discharge of chlorinated
effluent to meet all existing water quality standards.
A diffuser study is underway to evaluate outfall and
diffuser requirements under the assumption that chlorination
would be discontinued. Preliminary results indicate that
a theoretical diffuser length of tens of miles would be needed
to meet coliform standards applicable to Cook Inlet if
chlorination is discontinued. All other standards, however,
apparently could be met with a minimal (100-foot) diffuser.
The study also is evaluating the diffuser requirements
under assumptions that certain state-designated beneficial
uses of the waters of Cook Inlet would be deleted. This
change would allow less strict Alaska state water quality
standards to apply. If fecal coliform standards of 200
FC/100 ml were to apply (compared to current standards of
14 FC/100 ml), a diffuser length of 6,100 feet would enable
the discharge to meet -this standard.- If designated uses
were further relaxed to eliminate all coliform standards
a minimal length (100-foot) diffuser would be adequate.
A major interceptor sewer, the West Bypass Interceptor,
is proposed to connect existing interceptor sewers at the
Alaska Railroad crossing over Campbell Creek to an existing
downstream section of the West Bypass Interceptor sewer near
the Minnesota Bypass-Raspberry Road intersection. The pro-
posed completion of the interceptor between these points
would bypass a deteriorated, undersized corrugated metal
pipe sewer paralleling Campbell Creek and an occasionally
overloaded pumping station at Campbell Creek. -A 25 MGD
pumping station and force main are recommended, with pro-
vision for future expansion to 60 MGD capacity.
The existing Southeast Interceptor is proposed to be
extended south to provide service to areas of the Hillside
that are designated for public sewerage in the Hillside plan,
including the south Hillside areas near Potter Creek and
Rabbit Creek.
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The Hillside Wastewater Management Plan (MCA 1982)
evaluated the suitability of the Hillside area of Anchorage
to accommodate on-site disposal systems, and delineated areas
for public sewers, unsewered areas for on-site systems and
unsewered areas generally unsuitable for on-site disposal
systems. It sets forth planning and design criteria, con-
struction guidelines and operation and maintenance require-
ments for on-site systems.
The Hillside plan does not preclude on-site systems
in generally unsuitable areas; rather it applies additional
restrictions, including soil tests for each lot in a sub-
division, requiring innovative systems unless conventional
systems are shown to be acceptable, and requiring more detailed
system reviews by MOA.
The existing Anchorage Bowl system of collector sewers
is in need of expansion, replacement and renovation in certain
areas. Additional capacity is required in some instances,
as well as replacement of several miles of corrugated'pipe.
About 70 sewer construction, rehabilitation and replacement
projects are recommended in the facilities plan.
Alternatives
The facilities planning process in Anchorage has evolved
over many years. A relatively broad range of investigations
has been completed, with many alternatives evaluated and
some rejected. The current facilities plan is intended as
the culmination of these, and it identifies most prior
evaluation efforts, although it does not document all of
the screening that went into the development of the current
Recommended Plan.
"No-Action" Alternative. The no-action alternative
assumes no'rehabilitation, improvement, or expansion of the
existing collection system, and no expansion of Point
Woronzof WWTP.
No action was rejected because the MOA would be in vio-
lation of federal and state laws. Pollution of local streams
would increase and be subject to local objections. Further,
the state could impose a moratorium on new sewerage connec-
tions, adversely affecting growth of "the Anchorage area.
No action would be inconsistent with MOA desires.
Land Application Alternatives. Land application alter-
natives were considered during development of an earlier
(1976) facilities plan. The potential of rapid infiltration
at the Point Campbell Military Reservation appeared cost
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effective at that time, due to the proximity of the lands to
Point Woronzof, the presence~of sand and gravel soils, and the
apparent groundwater flow direction away from areas of ground- .
water extraction and toward Cook Inlet. This alternative is
the land application a'1-ternative evaluated in th'e current
facilities plan.
The Point Campbell land application alternative was
rejected due to probable land use conflicts, lack of feasibil-
ity studies and probable adverse environmental impacts.
Wastewater Renovation and Reuse. Currently, little need
for treated effluent has been identified in the Anchorage area,
but the facilities plan recommends future review of this alter-
native. The economic benefits of reuse might outweigh the
costs of additional treatment, depending on a variety of
factors. The facilities plan concludes that this alternative
cannot be seriously analyzed until a market for the wastewater
is identified.
Point Woronzof Treatment Alternatives. The facilities plan
considers two primary treatment and two secondary treatment
alternatives. Alternative PA would be identical to the
Recommended Plan, described earlier, with the exception that no
chlorination would be employed in this alternative, and that
the diffuser length may be different. Diffuser length would
change as a function of fecal coliform limits at the perimeter
of the discharge -mixing zone. Changes in the designated uses
of the waters of upper Cook inlet would also be made as part of
this alternative. This would apply different water quality
standards, thus changing this coliform limit.
The MOA has sought to obtain a modification of NPDES
requirements under Section 301(h) of the Clean Water Act to
permit continued ocean discharge of less than secondary
effluent from the existing point Woronzof WWTP. EPA has tenta-
tively decided to issue a 5-year permit modification under
Section 301(h). Continued primary discharge beyond the expira-
tion dates of any such modification is not assured in the Clean
Water Act, and under the construction grant regulations, EPA
must restrict its funding to projects with a 20-year planning
horizon. Since EPA has no authority to consider an alternative
involving ocean discharge of less than secondary-treated ef-
fluent 20 years in the future, the selected alternative must
incorporate secondary treatment. Both secondary treatment
alternatives could be added to the primary treatment alterna-
tives, thus meeting this requirement. High-rate trickling
filters and a complete mix activated sludge process are the two
secondary treatment processes evaluated in the facilities plan.
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No alternatives to the recommended 1,500-foot extension
of the outfall are presented in the facilities plan. The
diffuser length could vary from about 100 feet to 6,100 feet
in length, depending on applicable water quality standards
and whether chlorination is continued
Sludge Processing and Disposal Alternatives. As an
alternative to incineration at the Point Woronzof WWTP, sludge
could be dewatered, digested and landfilled; it could also
be disposed of through co-incineration with municipal refuse,
with the residual ash being landfilled. In the digestion
alternative, either primary or secondary sludge would be
dewatered by gravity thickeners, and then pumped to an anaerobic
digester for stabilization. The stabilized dewatered sludge
would be hauled to a sanitary landfill.
Primary or secondary sludge can be incinerated in com-
bination with refuse, a process called co-incineration. Com-
bustion is easily accomplished because of the fuel value
of the refuse. The heat output can generate electricity,
produce steam, and be applied to drive mechanical dewatering
devices -or other treatment plant equipment and provide heat.
The ash would be landfilled. Total community solid waste
volume could be reduced if co-incineration were used.
Interceptor Sewer Alernatives. West Bypass Interceptor
sewer alternatives were considered, including a gravity in-
terceptor with open trench construction, gravity interceptor
with tunneling for deep excavation areas, and the recommended
pump station and force main. The gravity alternatives were
rejected due to potential significant adverse impacts from
dewatering the trench area. Potential ground subsidence
and loss of water from a high-yielding water supply well
were major considerations.
Rabbit Creek-Potter Creek Sewerage Alternatives. The
facilities plan presents a series of sewage collection, treat-
ment and disposal alternatives to serve the southerly portion
of the Hillside area designated for public sewers in the
Hillside plan. One set- of alternatives encompasses four
treatment options that would be independent of the Point
Woronzof plant and one pump station-force main option (the
Recommended Plan) that would connect to the Southeast Inter-
ceptor, flowing to Point Woronzof. In addition, other alter-
natives describe alternative collection system patterns in
the area.
Interceptor Sizing. Sizing of the West Bypass Interceptor
and Southeast Interceptor sewers, both of which would serve
the southeast area of Anchorage that encompasses the Hill-
side area, has been an identified issue due to controversy
over sewer capacity to be provided to the Hillside area.
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EPA has'also raised questions regarding the fundable capacity
^of the interceptors (Appendix A to DEIS). The DEIS summarizes
the flow computations of the facilities plan and explains
how the interceptor capacities were recommended.
Hillside Area Alternatives. 'The Hillside Wastewater
Management Plan element of the facilities plan does not evalu-
ate alternative public sewer systems or alternative public
sewer/on-site system area designations. The plan does allow
alternative types of on-site sewerage systems, depending
on individual needs on each parcel.
Environmental Impacts
The Recommended Plan as presented in the facilities
plan would result in environmental impacts on many areas
of the Anchorage Bowl. The DEIS addresses these impacts
in major topic areas, including cost, wetlands, the Hillside
area, cultural resources, secondary (growth-related) impacts,
treatment and disposal impacts, sludge processing and dis-
posal impacts, construction impacts, and impacts of alterna-
tives .
User Costs
Costs to individual MOA sewer customers' would increase
as a result of expansion of the wastewater facilities in
accordance with the Recommended Plan. Those customers served
by sewers would sustain a rate increase estimated at from
22-34 percent in 1985, and 30-40 percent in 1999, depending
on funding sources for construction.
The low range in these estimates assumes that EPA would
provide 75 percent construction funding for the Point Woronzof
WWTP improvements, and the state would provide an additional
12.5 percent; that the state would fund 50 percent of all
other expansion; and that local funds would comprise the
balance. The high range assumes no EPA funding, but rather
that all construction cost funding would be 50 percent state
and 50 percent local. Both ranges assume that user charges
would support all local costs. No comparable estimates of
user costs are available for the unsewered Hillside area.
Wetland Issues
The Anchorage Bowl contains numerous nontidal wetland
areas that comprise an estimated 9,400 acres, or 15 percent
of the 64,000-acre area of the Bowl bounded by the military
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reservations and Chugach State Park. An additional 2,300 acres
of tidal wetlands are incorporated into the Potter point State
Game Refuge. These wetlands provide fish and wildlife habitat,
open space and hydrologic benefits, and recreational opportuni-
ties. They are potentially susceptible to significant impacts
from sewerage facilities expansion, both directly from sewer
interceptor construction, and indirectly from facilitation of
urban growth through- the provisions of new sewerage facilities.
A primary characteristic of a wetland is, obviously, the
presence of water. The presence, characteristics, and movement
of this water are termed hydrology. Hydrologic values of wet-
lands include retention of rainfall and snowmelt, runoff,
augmentation of stream base flow, water quality benefits, and
groundwater recharge. Loss of wetlands could result in ele-
vated flood and erosion risks, and alteration of stream flow
and water quality.
The construction of facilities within and adjacent to the
wetlands may result in loss of more than half of all nontidal
wetlands in the Anchorage Bowl.
Construction of sewers within wetlands as proposed in the
facilities plan (about 26 sewer facilities in many of the area
wetlands) will result in destruction of vegetation and. loss of
wildlife habitat along pipe alignments. Heavy equipment
crushes or removes vegetation and compacts peat deposits.
Areas of bog wetlands stripped of vegetation generally do not
revert to the original habitat type, but instead are overgrown
by ruderal vegetation or are kept barren by foot or off-road
vehi-cle traffic. Long-term alteration of habitat is apparent
in aerial photographs taken long after emplacement of pipe. In
Campbell-Klatt Bog, for example, one sewer line is proposed to
pass through an area used by Canada geese and other waterfowl
as a nesting area..
Much more subtle, but perhaps more significant, is the
delayed impact on hydrologic features 'of wetlands. Most peat
bogs, such as those comprising the majority of wetlands in the
study area, are natural water-retaining basins. in some ways,
their character is analogous to a teacup filled with water and
cotton. If a buried pipe were placed through a wetland and if
a backfill material were used which did not impede water move-
ment, the action would be approximately analogous to chipping
the rim of the cup, allowing some of the water to drain away
To continue the analogy, water level in the cup (bog) will
probably sink below the level of the damaged area because the
cotton (peat) will act. as a wick bringing moisture to the
outlet area. This dewatering process will adversely change the
biological and hydrologic values of wetlands.
Vlll
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Additional hydrologic impacts may result from the use of
permeable material as backfill. Pipe corridors not only may
act as corridors for water movement into or out of wetlands,
but also may divert groundwater away from wetland areas when
the pipe corridor is adjacent to a wetland and perpendicular to
the path of groundwater movement. These impacts may be of
diminished.importance when the wetlands appear in a floodplain,
but may be very important to isolated bogs.
The facilities plan will remove a major constraint on
population growth in the Anchorage Bowl, particularly in the
area south of Tudor Road. If population saturation is reached
in 20 years and if all wetlands designated as developable by
the MOA wetlands management plan are developed then a loss of
about 55 percent of the remaining nontidal wetland habitat in
the Anchorage Bowl would result. The major consequences of
this overall loss are likely to be: 1) alternations in the
hydrologic regimes of streams, 2) changes in groundwater move-
ment, and 3) a major loss of bird nesting habitat including a
well-established Canada goose nesting area at Heather Meadows
(C Street and Tudor Road) and in southern Campbell-Klatt Bog.
Construction of sewers and growth in the Anchorage Bowl
could result in the loss of more than half of the Anchorage
Bowl wetlands and have adverse impacts on vegetation, wildlife
and hydrology in many of the remaining wetlands. There would
be a decrease in wildlife abundance (including moose and
especially nesting waterfowl) because of increased recreational
activities on remaining wetlands, and loss of wildlife and fish
habitat because of alterations in hydrologic regime.
These impacts may be partly mitigated through special
construction techniques to inhibit groundwater diversions
caused by pipe construction a-nd backfill; by rerouting sewers
away from wetland areas that are to be preserved; by timing
construction in strearnbeds to avoid sensitive times for migra-
ting and spawning fish; and by providing protection for
preservation of wetlands through the existing wetlands manage-
ment plan.
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Potter Marsh, a coastal wetland on lower Rabbit Creek
between Old Seward Highway and the Alaska Railroad, is part
of the Potter Point State Game Refuge. The facilities plan
proposes sewer construction adjacent to the marsh, and the
Hillside plan proposes development of the ajdacent .area.
Potter Marsh will be adversely affected by turbidity in
waters entering the marsh from Rabbit and Little Rabbit
Creeks as a result of sewer construction and development
activities. Some of the extra sediment burden may be trans-
ported out of the marsh at the next "breakup" or heavy storm
runoff, but a portion may remain permanently in the marsh.
Sewering of some tributary areas of the Hillside may
provide benefits to Potter Marsh by preventing on-site system
construction and thereby precluding water quality impacts
due to system failure. Other portions of the watershed that
will not be sewered may develop with on-site systems for
sewage disposal. These areas will increase the threat of
water quality standards violations in Rabbit Creek and in
Potter Marsh.
The presence of sewers in and adjacent to Potter Marsh
presents a threat of spills and seepage of untreated sewage
to the marsh. If the pump station or force main near Rabbit
Creek were to fail, sewage would overflow, reaching Potter
Marsh.
Seismic activity and frost heaving can separate pipe
joints, move manholes and allow infiltration as well as ex-
filtration, depending on groundwater depth as compared to
pipe depth. Seismic activity in particular can cause cata-
strophic damage, and could disable the sewerage system for
an extended period.
The potential impact of contamination of Potter Marsh
can be partly mitigated by providing standby pumping and
storage capacity at the Rabbit Creek pump station. Conserva-
tive design and construction practices can help reduce the
susceptibility of sewers to frost heaving and seismic- activity,
lessening infiltration and exfiltration.
It has been suggested that a new water supply for the
south Hillside would be developed from surface water in the
area, and that inflow to Potter Marsh would be reduced. Potter
Marsh is fed by Rabbit and Little Rabbit Creeks. The worst
case- impact that could occur would be for the entire wa-ter
supply to be developed from Rabbit and Little Rabbit Creeks.
If this occurs, water diversions could reduce inflow to Potter
Marsh by more than 50 percent at certain times of the year,
and by about 15 percent on an average annual basis. The
wildlife values of Potter Marsh could be adversely affected
by such a change in hydrologic regime. Fishery resources
of the creeks could also be adversely affected.
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Proposed sewer lines will cross streams throuyliout the
Anchorage Bowl. Construction activities may adversely affect
water quality and salmonid tish. Many species of fish use
Campbell Creek and other streams for spawning. Construction
may reduce spawniruj and rearing success.
Hi] Iside Impacts
The Hillside area lias been sparsely settled by residents
who wish to live in a less crowded area than exists elsewhere
in the Anchorage Howl, and who wish to retain some flavor of
rural Alaska in their residential setting. With the exception
ot a Lew areas close to New Seward Highway the Hillside does
not have public water or sewers. instead, the area relies on
individual domestic water supply welly and individual on-site
sewage disposal systems such as septic: tanks with drain fields.
The U. S. Geological Survey in 1975 prepared a report
documenting possible water quality and public health threats
that could result from increased Hillside area development
using on-site sewage disposal systems. They concluded that a
high risk of groundwater pollution, surface water pollution and
public health effects existed.
The MOA adopted the Hillside Wastewater Management Plan in
1982. The objectives in preparing the plan were to better
define physical constraints to on-site sewage disposal, deline-
ate a rear, that would be served by public sewers and areas that
would be served by on-site sewage system, and to provide tor
proper and safe management of on-site systems to protect public
health.
By aciopting the "recommended maximum perimeter ot public
sewerage" the Mun.icpality has excluded sewers from 79 pec cent
ot the Hillside area. In order to develop within this un-
sewered area each landowner must demonstrate that adequate land
is available.to support three drain fields and that other
conditions are met. If a property is located on areas desig-
nated as generally unsuitable for on-site treatment systems (30
percent of the Hillside is so classified), approval is more
difficult, but is still possible. Innovative (special technol-
ogy) on-site systems are required unless it can be shown that
the traditional system is acceptable.
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Water Availability impacts. The Hillside plan does not
address the-water supply issue. EIS analyses assume that
individual wells will continue to be the source of domestic water
for the Hillside. As U. S. Geological Survey points out, water
availability is very limited in localized portions of the
Hillside, even though sufficient water resources exist on an area-
wide basis to support full development. Some development may be
precluded by an inability to develop a well. it is also possible
that numerous wells tapping the same limited aquifer could exceed
the recharge of the aquifer, leaving upslope or shallower wells
without water.
This impact can be mitigated by providing a public water
supply system to the area, or by limiting development by water
availability based on evaluation of local groundwater supplies.
Surface Drainage Problems. The Hillside area has certain
unique surface drainage problems that may subject development to
risk of damage, and which complicate the use of on-site disposal
systems. With the exception of the major streams, much of the
area lacks defined natural drainage channels; wetland areas are
present on the Hilside, along with areas with shallow groundwater;
flood hazard areas adjoin the major creeks; and winter icing and
spring thaws complicate transportation and affect local drainage.
Development may increase total runoff and may inadvertently
channel it toward existing downstream residences. The Hillside
plan includes a requirement that surface water disposal plans be
prepared covering "...erosion and sediment controls, water quality
controls, surface water conveyance and disposal and on-site system
operation." This requirement will help mitigate some of the risks
to development related to the drainage problems of the Hillside.
XII
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Groundwater Quality and public Health Impacts. The poten-
tial for localized groundwater pollution in the Hillside is
relatively high, based on work by both U. S. Geological Survey
(1975) and Arctic Environmental Engineers (1981). This high
potential exists because most chemicals, detergents, and patho-
gens are not removed in the septic tank, but rather by contact
with unsaturated soil particles in the drain fields. If this
contact is inadequate, pollutants may remain untreated. in
addition, certain pollutants such as nitrates are not readily
removed, and may contaminate the underlying groundwater. in the
Hillside area, bedrock outcrops, shallow bedrock, shallow
groundwater, steep slopes, roadway excavations, building site
excavations and freezing conditions increase the risks of in-
adequate treatment.
The large number of on-site systems will increase the risk
of accumulations of conservative pollutants such as nitrates.
Cumulative impacts of substantial groundwater recharge from
nearly 9,000 on-site systems may be significant. Nitrate levels
could exceed the EPA drinking water standards in localized
areas, and could affect the artesian aquifer under the lower
hillside and within the Anchorage Bowl.
As the number of on-site systems on the Hillside increases
from 1,500 to nearly 9,000, the number of failures from all
causes is likely to increase, even considering tighter design
standards and pumping requirements. As existing systems age,
failures will increase. Septic systems do not last forever; new
drain fields will need to be provided as existing fields absorb
pollutants and suspended solids, and eventually fail to meet
adequacy testing "on resale or simply fail to accept discharged
wastes.
Surface Water Quality Impacts. Vvherever septic tank ef-
fluent is allowed to surface, or where shallow groundwater
recharges a surface water body, the potential for surface water
pollution exists. There are many ways in which septic tank
effluent can surface.
Xlll
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The growing number of roadway excavations and building site
excavations poses a risk of intercepting percolating effluent.
At a density of one unit per acre excavations frequently will
be in close proximity to on-site sewerage systems. The poten-
tial for public health impacts would be magnified substantially
by incompletely treated effluent surfacing and flowing in local
drainage courses and roadside ditches.
Mitigation Measures. Mitigating the potential groundwater
impacts on public health and water quality that result from the
decision to preclude public sewers and allow a substantial
increase in on-site systems in the Hillside presents many chal-
lenges. The Hillside Wastewater Management Plan incorporates
certain mitigation measures that are discussed in greater depth
in the DEIS. Additional mitigation methods could include
groundwater monitoring, periodic certification of domestic
wells, creation of a public septic system maintenance district,
providing capacity in downstream interceptor sewers, providing
a public water supply to the Hillside area, improving site
inspection criteria, monitoring surface water quality, pro-
hibiting the construction of drain fields upslope of
excavations, and prohibiting excavations downslope of existing
drain fields.
Cultural Resources
The Anchorage Bowl area is not noted for extensive use by
prehistoric populations. A known archeological site occurs at
point Woronzof one-half mile from the WWTP.
Impacts to known or newly-discovered archeological sites
can be minimized through avoidance where possible. The facili-
ties plan does not threaten the site in the Point Woronzof
area. A preconstruction survey of the expansion area at the
WWTP should be conducted as a precautionary measure. Since
watercourses are often places of high habitation probability, a
brief reconnaissance at all stream crossings is recommended.
During all construction activity, a localized work halt should
occur and the state Historic Preservation Officer should be
immediately notified if an archeological site is uncovered.
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Secondary Impacts
The facilities plan is judged to indirectly allow popu-
lation growth of about 134,500 persons as a consequence of
expanded sewerage facilities and on-site sewerage decisions
in the Hillside area. The facilities plan is also assumed to
be a direct inducer of growth in the south Hillside areas
from Little Rabbit Creek to Potter Creek, where development
will depend on the sewerage extensions included in the facili-
ties plan.
The most visible sign of population growth is the develop-
ment of land. Unless there is a high vacancy rate or unused
capacity in existing structures, residential, commercial
and industrial developments will occur to fulfill the needs
of the growing population.
The effects of growth, both beneficial and adverse,
may be observed in environmental and socioeconomic areas,
and may have regional and local consequences. Growth usually
affects the following:
o Services and utilities
- sewerage
- water supply
- solid waste disposal
- energy
- transportation
- education
- police and fire protection
- parks and recreation
- social services
o Resources
- air quality
- water quality
- hydrology, erosion, seismicity
- open space
- wetlands
- biological resources
- aesthetics
- noise
o Socioeconomic values
- development-related economic activity
- community cultural resources
- social structure
- fiscal strength
- perceived quality of life
xv
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Water supply is of substantial concern, since existing
supplies are currently barely able to meet demand in critical
periods. In the summers of 1976 and 1977, during an extended
dry period, both the Anchorage Water Utility 'and Central
Alaska Utilities publicly requested that their customers
curtail water use because demand exceeded production and
a drop in water pressure was experienced in various areas.
In 1980, the MOA retained a consultant to investigate the
feasibility of obtaining a 70 MGD water supply from Eklutna
Lake by pumping water from the tailrace below the Eklutna
powerhouse. If this project is undertaken, the water supply
will be adequate for the growth predicted by the 201 facilities
plan.
In the meantime the MOA is investigating the drilling
of additional wells to use groundwater supplies until the
Eklutna project is constructed.
A relationship between water supply and sewerage exists,
in that a portion of the water supply becomes wastewater.
If the water supply available to Anchorage is not increased,
water conservation and/or rationing could be imposed. This
would tend to keep sewage flows lower than projected by the
facilities plan. Lack of adequate water supplies could delay
the need for part of the proposed expansion of sewerage
facilities.
Solid waste is also o'f concern, since the MOA is running
short on capacity at the existing Merrill Field landfill,
and is expected to require a new landfill no later than mid-
1986. No new landfill has been identified, although the
Solid Waste Management Plan is expected to be updated in
1983.
The use of energy resources will increase with growth
and it is expected that supplies will keep pace.
The increased population and automobile use will place
additional demands on the existing roadway network and public
transportation services. Roadways and services will need
to be established in the new sewered residential and com-
mercial areas. Certain secondary impacts are also generated
by increased transportation use. These include increased
energy consumption and higher levels of air pollution, parti-
cularly carbon monoxide.
Most of the urbanized area of the Anchorage Bowl has
been formally designated as a carbon monoxide "nonattainment
area" due to violations of federal air quality standards.
The MOA is designated as being in attainment of other federal
air quality standards (ozone, nitrogen dioxide, sulfur dioxide
and suspended particulate matter).
xvi
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MOA has adopted.an air quality plan that focuses on attaining
the Federal carbon monoxide standard by 1987.- The facilities plan
is considered consistent with the growth assumptions of the air
quality plan since the facility plan does not accommodate growth
levels beyond those anticipated in the air quality plan.
Demands for educational services, police protection, fire
protection and other governmental services will increase.
Additional facilities and staff will be needed to meet these
demands.
The Anchorage Bowl has numerous and varied recreational
resources. Population gtowth will put increasing pressure on these
resources. Some existing resources may become more heavi-ly used
and seem overcrowded, particularly local and neighborhood park
facilities and bike trails in greenbelt areas. Although growth may
be accompanied by the provision of additional urban recreational
facilities, the expansion is not possible in the case of finite
resources such as beaches and greenbelt areas. Chugach State Park
and other open land areas in south-central Alaska will also get
heavier use.
Some benefits will also accrue from growth. Development will
bring economic activity, including construction and accompanying
employment. A larger population can support a greater diversity of
cultural resources, such as plays, ballet, symphonies, art
exhibits, popular entertainment, museums, ana libraries.
Urban construction has wide ranging effects on surface and
groundwater hydrology. Most of these impacts are caused by the
reduction of naturally permeable soil surfaces with impermeable
concrete, asphalt, and buildings. Percolation of rainwater ana
snowmelt to the groundwater is substantially reduced, and runoff to
stream channels may become inadequate to contain the man-altered
runoff regime.
xvn
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Other development-related impacts can be controlled by
proper land use planning and plan implementation, including
specific plans for transportation, air quality, recreation,
public services and facilities, and other elements.
Treatment and Disposal impacts
Effluent leaving the Point Woronzof WWTP is chlorinated and
discharged to the Knik Arm of Cook Inlet. The increase in dis-
charge and improvement in treatment capability is not expected
to noticeably affect the Inlet, even though discharge quality
will be improved.
Knik Arm is one of the most dynamic water bodies in the
world. The physical environment is so harsh, in fact, as to
hinder the establishment of a benthic biological community.
The only observable evidence that municipal wastes are injected
into Knik Arm via an outfall at Point Woronzof is the accumula-
tion of coliform bacteria on the beaches to the east of the
discharge. The bacteria are brought ashore on the flood tide
by an eddy along the north shore of Point Woronzof. The
lengthening of the outfall by an additional 1,500 feet will
ensure that wastes are injected outside of the system and thus
not returned to shore.
The provision of a 1,000-foot diffuser should ensure that
all water quality standards are met at the boundaries of the
state designated mixing zone around the discharge point.
xvin
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Treatment of additional quantities of wastewater at
an expanded Point Woronzbf WWTP will increase the use of
chemicals (particularly chlorine) and energy (pumping of
wastewater), will create about eight additional employment
positions, and may increase the potential for odors near
the plant.
Sludge Processing and Disposal Impacts
The Recommended Plan for sludge treatment and disposal
involves dewatering, incineration" and discharge of ash to
the Knik Arm of Cook Inlet via the outfall, landfilling the
ash, or discharging the ash to a lagoon or gravel pit near
the plant as a slurry blended with wastewater.
Incineration of increased volumes of sludge is not ex-
pected to create any significant air quality impacts. Energy
consumption will probably increase.
Discharge of sludge ash through the outfall pipe following
incineration will increase the suspended solids concentra-
tion in plant effluent. The ash alone would increase total
suspended solids by about 13 mg/1. Considering that the
plant currently has difficulty meeting discharge requirements
of TOO mg/1 (monthly average), the addition of ash will make
it increasingly difficult to avoid NPDES permit violations.
As a mitigation measure, the plant could be designed
to achieve a consistent effluent quality of 85 mg/1 suspended
solids in the clarifier overflow, allowing for an additional
13 mg/1 from incinerator ash.
There is a slight chance that discharge of ash in sus-
pension with treated effluent could introduce toxic materials,
such as heavy metals, to the Knik Arm of Cook Inlet. Without
an analysis of constituents of the ash, evaluation of solu-
bility of end products, particle size and volume of discharge,
no further analysis is possible.
Landfilling the ash will use landfill volume that would
otherwise be available for municipal refuse and other solid
waste. At a rate of 1.8 tons per day, the incinerator would
produce about 660 tons per.year, representing 0.33 percent
of total landfill volume. If. a new landfill site is chosen
that has a 20-year life, it would last 24 days longer without
the ash.
If toxic substances are present in landfilled sludge
ash, percolating rainwater could leach these substances into
the groundwater, adversely affecting water quality and bene-
ficial uses of the.water resource. The potential for such
impacts occurring is small.
xix
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There is a remote risk that discharging sludge ash to
lagoons or gravel pits near Point Woronzof (within 0.25 mile
of the WWTP) could lead to local pollution of groundwater,
depending on constituents in the ash. Evaluations of land
disposal of wastewater at nearby Point Campbell (U. S. Army
Corps of Engineers 1979) indicated that groundwater flow
was toward Cook Inlet in this general area. A more detailed
review of both shallow and deep aquifers in this area is
necessary to ascertain movement direction and potential inter-
change between aquifers.
Construction Impacts
Construction of wastewater facilities typically results
in an assortment of short-term nuisance impacts. This type
of impact typically lasts for the duration of the activity
in a particular local area. These impacts include noise,
dust, stream turbidity, access problems, traffic congestion,
potential safety hazards and visual "eyesores". These impacts
are usually judged insignificant unless someone is injured
or a stream is severely damaged. In most cases, these impacts
are readily mitigated to tolerable levels.
Impacts of Alternatives
The DEIS evaluates impacts of alternatives including
land application of effluent; eliminating chlorination of
the Point Woronzof effluent; sludge digestion rather than
incineration; alternative concepts for the West Bypass
Interceptor'sewer; various collection, local treatment, and
pumping alternatives for the Potter Creek area; and no action.
Land Application of Effluent. Land application of effluent
was evaluated for the Point Campbell Military Reservation
area. Land application would reduce or eliminate the discharge
from the outfall into Cook Inlet. While wastewater percolates
through soil, heavy metals, organic compounds, bacteria and
viruses can be filtered, biologically degraded or bound to
soil particles and probably not reach Cook Inlet in signifi-
cant amounts. The Point Campbell Military Reservation is
moose habitat, and nutrient enrichment of the Soils may
accelerate growth of forage species, particularly if appro-
priate forage management actions were undertaken.
Potential adverse environmental impacts relate to pro-
jected and existing human use of the disposal area. The
MOA plans to develop a park in the Point Campbell area
following transfer of the property from military to MOA
jurisdiction.
xx
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Groundwater impacts could also result from 'land dis-
posal of effluent in the Point Campbell area. As noted pre-
viously, prior .study (U. S. Army Corps of Engineers 1979)
indicated flow of groundwater was generally toward Cook Inlet.
A more detailed review is needed of shallow and deep aquifers
in this area to confirm movement direction and assess pos-
sible interchange between aquifers. Such an analysis should
include consideration of the effects of increased MOA ground-
water pumping on the direction of flow.
Treatment and Effluent Discharge Alternatives. Chlorina-
tion of effluent is a generally accepted technique for killing
viruses and-bacteria which may cause human disease. On the
other hand, chlorination is known to result in the formation
of potentially toxic halogenated organic compounds (e.g. ,
chloramines) and free chlorine which are toxic to salmonids
and other aquatic species. Partially in response to these
toxicants, the Alaska Department of Environmental Conservation
has recommended an extension of the outfall and elimination
of the chlorination process as measures to minimize the poten-
tial for adverse impacts on migrating salmon.
Actual benefits to the salmon resource are unknown,
primarily because the impact of the chlorinated effluent
on the Knik Arm is unknown. Elimination of chlorination
will result in elevated levels of bacteria and viruses- in
the discharge mixing zone, beyond the mixing zone, and in
nearshore areas.
Two alternative changes in state-designated beneficial
uses of the waters of upper Cook Inlet are proposed in studies
undertaken following publication of the facilities plan.
These changes would, in effect, ease or eliminate coliform
standards applicable to the Knik Arm. These recent studies
show that an unchlorinated effluent discharge would violate
current receiving water quality standards.
One alternative would ease coliform standards to 200 FC/100 ml
from the current 14 FC/100 ml, requiring a 6,100-foot diffuser
to meet the relaxed standard. Certain beneficial uses of
the waters of Cook Inlet, specifically, water supply for
seafood processing, water contact recreation, and harvesting
for consumption of raw mollusks or other raw aquatic life,
would be deleted as designated uses. This change in standards
would probably not significantly-affect any existing uses,
nor would it preclude any likely future uses. Water contact
recreation, however, does occur to a small degree on Cook
Inlet. Public use of the shoreline area occurs, and high
coliform counts have historically been of concern.
xxi
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The second alternative, with a minimal (about 100-foo.t)
diffuser, would require deletion of all beneficial uses except
growth and propagation of fish, shellfish, aquatic life, and
wildlife, including seabir-ds, waterfowl and furbearers. This
would result in no coliform standard being applicable, pursuant to
state water quality standards. In addition to the uses foregone
as described for the alternative above, water supply for aqua-
culture, water supply for industry, and secondary water recreation
would no longer be protected (designated) uses.
High natural turbidity levels in Knik Arm preclude most of
these uses as a practical matter. However, water quality
standards coliform levels could be exceeded.
Secondary treatment would require a greater capital invest-
ment, greater energy consumption, more land at the plant, and
would generate larger volumes of sludge.
Sludge Disposal Alternatives. An alternative to sludge
incineration, namely digestion of the sludge and subsequent
disposal in a landfill, is evaluated. This would hasten the
reduction in available landfill capacity.
Another alternative discussed in the facilities plan is
co-incineration of sludge and refuse. This alternative has the
environmental advantage of reducing the amount of solid waste
destined for a land fill and generating energy as a by-product.
Adverse impacts on air quality may occur If steps are not taken to
minimize the release of carbon monoxide and particulates.
West Bypass Interceptor Alternatives. Two alternatives for
the West BypassInterceptor,namely a gravity, flow interceptor
with open ditch construction, and a gravity flow option with a
combination of open ditch and tunneling construction, would have
potentially significant imapcts on the environment. A 50-foot
excavation would be required along much of the alignment in C
Street and the easterly portion in Raspberry Road. Shallow
groundwater is prevalent in this area, with sand and gravel
deposits predominating. Dewatering would be required in order to
allow construction of either the open trench alternative or the
tunnel alternative.
One of the highest yielding water wells in the Anchorage Bowl,
operated by Central Alaska Utilities, Inc., for domestic
water supply is located several hundred feet north of the
xxn
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interceptor's route. The dewatering could decrease the
Anchorage water supply for several months. Considering that
the Anchorage water supply is currently barely adequate to
meet demands at critical periods, loss of well production
could cause a water shortage in Anchorage.
Several commercial buildings and residences are located
near the interceptor alignment and could be affected by con-
struction activities, especially dewatering. Dewatering
may allow soil particles to compress, causing subsidence
of the land surface. This may affect utilities and structures,
particularly the Alaska Bank building and its sensitive com-
puter system.
Rabbit Creek/Potter Creek Area Alternatives. The facili-
ties plan describes a number of alternatives for providing
sewerage service to those portions of the lower Hillside
area requiring connection to the public system. Several
alternatives provide for a small WWTP at the north edge of
Potter Marsh that would discharge secondary treated effluent
into Rabbit Creek. This method of disposal is likely to
have adverse environmental impacts on Potter Marsh and the
fishery resources in Rabbit Creek. Of major concern are
the adverse impacts of an accidental discharge of raw or
inadequately treated sewage, elevated water temperatures
during winter, chlorine, and turbidity.
Alternatives in sewer alignments would have somewhat
different impacts. One alternative was determined to have
less potential impact on Potter Marsh.
No-Action Alternative. The long-term environmental
consequences of no action appear more adverse, than the long-
term consequences of any of the alternatives or the Recom-
mended Plan. The status quo would increasingly violate
federal and state water quality laws and could result in
a state-imposed moratorium on new sewer hookups in the
Anchorage Bowl. Failure to expand or renovate the existing
sewer system would increase the incidence of pollution of
local streams and of local groundwater supplies. This situ-
ation would place severe constraints on local growth and
the local economy, and sharply increase the hazard to public
health.
Consistency With Federal Laws, Policies, and Regulations
Clean Water .Act. -The EPA is charged with overall admini-
stration of the Clean Water Act, as amended (33 USC 1251
et seq.), with certain responsibilities delegated to those
states carrying out EPA-approved water quality programs.
xxm
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Section 201 of the Clean Water Act establishes a con-
struction grant funding program for publicly-owned municipal
wastewater facilities. In order to receive grants under
Section 201 of the Clean Water Act, the MOA must conduct
its planning according to guidelines promulgated by the EPA
a-nd administered by the State of- Alaska. The State of Alaska
has not determined whether the MOA facilities plan is con-
sistent with the state guidelines. EPA has raised several
questions regarding the plan's consistency (see Appendix A
to DEIS) .
Section 402 of the Clean Water Act requires a NPDES
permit for all discharges to waters of the United States.
In the State of Alaska, EPA submits the draft NPDES permit
to the Alaska Department of Environmental Conservation for
certification that the permit meets state water quality
criteria. The existing NPDES permit for the Point Woronzof
treatment plant expires on December 30, 1982« The permit,
AK-002255-1, actually refers to a discharge of secondary
treatment effluent. Permission was granted in a letter by
EPA to continue primary effluent discharge until July 1,
1982. The MOA has applied for a Section 301(h) waiver of
the requirement for secondary treatment of the wastewater
discharged to Knik Arm. Consistency between the facilities
plan and the requirements of Section 402 cannot be determined
until the new NPDES permit is issued.
Section 404 of the Clean Water Act establishes a permit
program, administered by the Secretary of the Army, acting
through the U. S. Army Corps of Engineers, to regulate the
discharge of dredged material (including backfill) into waters
of the United States. Interceptors and the outfall extension
called for by the facilities plan which cross streams and
wetlands may require 404 permits. Utility crossings of streams
and wetlands are allowed under a nationwide 404 permit subject
to certain criteria. Of these criteria, the following may
not be met by the proposed facilities as described in Chapter 4
of the DEIS.
o No change in preconstruction bottom contours is to
take place.
o Discharge (backfill) is not to. disrupt the movement
of indigenous aquatic species.
o Spawning, areas are to be avoided to the maximum
extent possible during spawning season.
o Discharge (backfill) is to be avoided to the maximum
extent possible in migratory waterfowl breeding areas.
xxiv
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Heavy equipment in wetlands is to be placed on mats to
the maximum extent possible.
Temporary fills are to.be removed.in their entirety.
If.any single criterion is not met by certain elements of the
proposed facility plan, those elements will require an indi-
vidual Section 404 permit issued by the U. S. Army Corps of
Engineers.
Coastal Zone Management Act. The act (16 USC 1451 et seq.)
requires Federal activities to be consistent to the maximum
extent practicable with approved state coastal zone management
plans. Certain elements of- the facilities plan may not be con-
sistent with the state-approved MOA coastal zone management
plan to the extent that they allow and encourage development in
the southern half of Campbell-Klatt Bog. Campbell-Klatt Bog is
a significant migratory waterfowl nesting area and is desig-
nated for preservation by the state-approved MOA coastal zone
management plan. A formal coastal zone management consistency
determination will be made by the State of Alaska.
Federal Policy on Floodplain and Wetlands Protection. The
EPA is required to assess the impacts of its action.on wetlands
and floodplains and to avoid or minimize unavoidable adverse
impacts. Insufficient information is available to adequately
describe indirect impacts on wetlands resulting from emplace-
ment of sewer pipes adjacent to wetland areas.
Endangered Species Act. The EPA is required by the
Endangered Species Act (16 USC 1536 et seq.) to ensure that
actions funded by the agency do not jeopardize the continued
existence of any endangered or threatened species or result in
the destruction or adverse modification of critical habitat for
these species. There are no known endangered or threatened
species in the study area, therefore te Endangered Species Act
requirements are not relevant to the facilities plan.
Clean Air act. The Clean Air Act requires that Federal
funding not support projects inconsistent with
locally-developed state air quality plans. Consistency between
the MOA facility plan and state air quality management plans is
determined by comparing population growth forecasts and treat-
ment activities such as sludge incineration which result
xxv.
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Chapter 1
INTRODUCTION
This Draft Environmental Impact Statement (DEIS) is pre-
pared by the U. S. Environmental Protection Agency (U. S. EPA)
to evaluate the impacts of expanding the Municipality of
Anchorage (MOA) wastewater collection, treatment and disposal
system. It emphasizes matters of particular concern, including
wetlands, Hillside area sewerage decisions, growth inducement
and impacts of growth, effects of disposing of effluent in Cook
Inlet, and the impacts of sludge disposal.
Organization of DEIS
This DEIS is organized in 14 chapters. Chapter 1 pro-
vides background detail; Chapter 2 describes the existing
sewerage situation; Chapter 3 describes the projects proposed
by the MOA as the Recommended Plan, and also describes alter-
natives to that plan; Chapters 4 through 10 .evaluate impacts
of the Recommended Plan; Chapter 11 evaluates impacts of alter-
natives to that plan; Chapter 12 describes issues unresolved
by alternatives; Chapter 13 describes coordination activities
and public input; and Chapter 14 is a list of references used
in compilation of the plan.
The text is set off into chapters, as noted above;
within chapters a consistent system of subheadings is used
to denote the relative rank of the discussions in outline
style. The following key to the appearance of headings in
terms of capitalization, centering, alignment with or inden-
tion from the left margin, underlining, and type face is pro-
vided to assist the reader.
Federal Laws
INTRODUCTION
Background
Clean Water Act.
Mitigation Measures.
Rank 1 (Chapter title:
Rank 2
Rank 3
Rank 4
Rank 5
In the case of Ranks 4 and 5 headings, text begins imme-
diately following and on the same line as the headings. The
Table of Contents provides additional assistance to the under-
standing of this system through Rank 3.
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Background and History of the "Project
The wastewater collection system in the Anchorage Bowl
was developed in an uncoordinated, patchwork fashion between
1917 and the mid-1960s. A comprehensive wastewater plan
was formulated in 1966, initiating the construction of the
Greater Anchorage Area Borough trunk and interceptor system
during the period 1970-1973. This period included develop-
ment of the Point Woronzof wastewater treatment plant (WWTP)
and an 84-inch ocean outfall extending 804 feet into the
Knik.Arm to a depth of 15 feet below MLLW. Since that time,
extensive population growth and associated development through-
out the Anchorage Bowl area resulted in overloading of the
existing wastewater collection and treatment system. The
Point Woronzof WWTP was designed as a primary treatment plant
and put into operation in 1972 with a rated average daily
flow capacity of 34 million gallons per day (MGD) for a design
population of 221,000. Based on historical performance, a
realized rating of 22 MGD is appropriate. Average flows
in 1980 and 1981 were 26.5 MGD and 28 MGD, respectively.
Under current National Pollutant Discharge Elimination
System (NPDES) limits, the WWTP is overloaded.
The U. S. Army Corps-of Engineers (U. S. COE) Alaska
District started a facilities planning process in 1976.
During preparation of the U. S. COE facilities plan, the
Anchorage Water and Sewer Utility (AWSU) proceeded with an
infiltration and inflow analysis, a sewer system evaluation
survey, and a wastewater collection system study. An in-
complete draft report was issued by the U. S. COE in 1979.
Completion of the report was not possible for a number of
reasons, including:
o The MOA had not adopted a wastewater collection
system study.
o The sewer system evaluation survey was incapable
of generating adequate wastewater flow projections.
o The issue of on-site disposal vs. sewerage in the
Hillside area remained unresolved.
o The comprehensive development planning process was
not completed, specifically the Hillside Wastewater
Management Plan, the Wetlands Management Plan and
the Comprehensive Development Plan were needed to
adequately project population growth and define
areas requiring new or additional service.
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The MOA postponed development of a facilities plan until a
revised community development program could be prepared.
On July 9, 1981, the MOA authorized a sanitary engineering
consultant to begin work preparing draft and final facilities
plans for expansion of sewage collection, treatment and disposal
facilities. The MOA intends to use the facilities plan to apply
for U. S. EPA construction funds under Section 201 of the Clean
Water Act. Facilities plan work was initiated with the assump-
tion that the Hillside Wastewater Management Plan and the Wet-
lands Management Plan would be sufficiently complete and not
significantly affect planning, e.g., changes in these documents
upon adoption would not have a major impact on the facilities
plan, and adoption of these management plans as elements of the
Comprehensive Development Plan would occur early in the 201 facili-
ties planning process. The Wetlands and Hillside plans were
adopted in the spring of 1982.
Objectives of the Facilities Plan
The facilities plan has the following objectives:
o Evaluate existing wastewater collection and treatment
systems and their abilities to meet current and anti-
cipated future sewage loads.
o Provide a long range plan for orderly development
of sewage collection and treatment facilities in
an environmentally-sound manner. Project wastewater
loads and flow for treatment facilities to 2005.
Design principal interceptors for peak flows expected
in 2025.
o Evaluate alternative collection and treatment systems
and recommend cost-effective improvement and expansion
programs.
o Meet the requirements of the MOA's application for
a grant of funds from U. S. EPA under Section 201
of the Clean Water Act.
Necessity and Purpose of the
Environmental Impact Statement
The MOA has requested a grant from U. S. EPA under
Section 201 of. the Clean Water Act. Under terms of Section
201, local facilities construction projects are eligible
to receive up to 75 percent federal funding for the planning,
design, and construction of municipal wastewater treatment
systems. Up to 85 percent funding can be received for innova-
tive techniques. Eligibility is based largely on EPA regula^-
tions and guidance memoranda. As the lead agency for the
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Clean Water Act, U. S. EPA is charged under terms of the
National Environmental Protection Act (NEPA) with assessing
the environmental impacts of proposed wastewater facility
projects built with federal funds. A review of planning
documents for the Anchorage area, meetings with U. S. EPA
Region 10 staff, a review of the projec-t area environment,
and discussions with local officials resulted in the deter-
mination that significant environmental impacts are potentially
associated with the Section 201-funded facilities plan.
The issues of concern are identified in the following section
of this chapter. If significant adverse impacts may occur
the U. S: EPA is required by NEPA to prepare an Environmental
Impact Statement (EIS).
The EIS is to be a "full disclosure" document and must
follow specific regulations of the Council on Environmental
Quality (CEQ), (as set forth in 40 CFR, Part 6 and published
in the Federal Register, Volume 43, Number 230, November 29,
1978), and of the U. S. EPA, (as set forth in the Federal
Register, Volume 44, Number 21-6, November 6, 1979). It is
the intent of NEPA that alternatives identified during the
scoping process be evaluated and a plan selected on the basis
of all environmental, engineering, and economic considerations,
not just monetary costs.
This EIS has been prepared to evaluate the environmental
impacts of the MOA wastewater facilities expansion and to
encourage public participation in the planning process through
local meetings, workshops, and public hearings. It also
provides input to the facilities planning firm and coordinates
feedback between the facilities plan and environmental assess-
ment during the EIS process.
Issues of Concern
Prior to and during the preparation of this EIS, a number
of key issues were identified that warrant discussion and,
if possible, resolution. The issues identified below are
described in detail and evaluated in Chapters 4-11. Those
issues that remain generally unresolved are identified and
discussed in Chapter 12, ISSUES UNRESOLVABLE BY THE ALTER-
NATIVES. The issues of general concern to this wastewater
collection, treatment, and disposal project are:
o The impacts of pipe emplacement through wetlands
on wetland resources, including biological resources,
hydrologic characteristics, and open space/aesthetic
values.
o The impacts of facilities on growth and development
in the Hillside area, and associated impacts on
water quality in the Hillside area..
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o Growth-indueing impacts, particularly effects of
population growth on wetlands and community services,
traffic and energy, and the perceived quality of
life. .
o The impacts- of effluent disposal on fishery resources
in Cook Inlet.
o The impacts of sludge disposal on the environment.
Legal, Policy and Regulatory Constraints
The following briefly discusses major federal, state
and local laws, regulations and policies that affect the
MOA's 201 facilities plan.
Federal Laws, Policies and Regulations
Clean Water Act. The U. S. EPA is charged with admini-
stration of the Clean Water Act, as amended (33 USC 1251
et seq.). The goals of the act are to achieve fishable,
swimmable surface waters throughout the nation by 1983 and
to achieve no discharge of pollutants by 1985. The act
requires that all 'discharges to the United States waters
be issued a permit under NPDES (Section 402). In the State
of Alaska, the U.. S. EPA submits the draft NPDES permit to
the Alaska Department of Environmental Conservation (ADEC)
for certification that the NPDES permit meets state water
quality criteria.
All alternatives being considered for the 20-year
facilities plan include a discharge to navigable surface
waters and, therefore, the discharge must comply with an
NPDES permit issued for the outfall. The existing permit
for the Point Woronzof WWTP was issued on November 30, 1977,
became effective on December 30, 1977, and is scheduled to
expire on December 30, 1982. The permit, AK-002255-1, actually
refers to a discharge of secondary treatment effluent. Per-
mission was granted in a letter by the U. S. EPA to continue
primary effluent discharge until July 1, 1982. The MOA has
applied for a new NPDES permit which would authorize a
continuation of the discharge of primary treated effluent
under Section 301 (h) of the Clean Water Act Amendments.
Section 201 establishes .a construction grant funding
program for publicly-owned municipal wastewater facilities
(a federal funding of 75 percent with a maximum of 85 percent
for "innovative" wastewater treatment and/or di-sposal concepts) .
In order to receive grants under Section 201 of the Clean
Water Act, the MOA must conduct its planning according to
strict guidelines administered by the State of Alaska and
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enforced by the U. S. EPA. In order to comply with these
mandates, the MOA prepared a facilities plan for the expansion
and upgrading of the wastewater collection, treatment and
disposal systems based on effluent quality limitations estab-
lished by the U. S. EPA and the State of Alaska.
Section 404 establishes a permit program, administered
by the Secretary of the Army, acting through the U. S. COE,
to regulate the discharge of dredged material (including
backfill) into waters of the" United States. This term has
been defined by regulations. (Federal Register Volume 42,
pages 37122-37164, July 19, 1977) such that all the streams
in the study area up to their headwaters and the adjacent
wetlands are subject to the 404 permit program. This com-
prises over 12 percent of the study area. Utility crossings
of these streams and wetlands are permitted under a nation-
wide 404 permit, subject to the following criteria:
o No change in preconstruction bottom contours will
occur.
o Discharge will not be located in the proximity of
a public water supply intake.
o Discharge will not occur in areas of concentrated
shellfish production.
o Discharge will not violate provisions of the Endangered
Species Act.
o Discharge will not disrupt the movement of indigenous
aquatic species.
o Discharge will be free of toxic pollutants in toxic
amounts.
o Discharge will be maintained to prevent erosion
and other nonpoint pollution.
o Discharge will not occur in a national or state
wild and scenic river element.
Toxic Substances Control Act. The U. S. EPA is charged
by the Toxic Substances Control Act (15 USC 2601 et seq.)
to protect public health and the environment from harmful
chemicals and mixtures. Among other provisions, the act
authorizes the U. S. EPA to adopt regulations governing
the manner of disposal of chemical substances. U. S. EPA
has promulgated regulations which require an analysis of
wastewater or effluent at the discharge to identify toxic
pollutants. If toxic pollutants are identified, the dis-
charger must develop a program for pretreatment of toxic
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pollutants entering the wastewater stream from industrial
sources, and must develop a nonindustrial source control
program. MOA has developed a plan and incorporated it into
its 301 (h') application.
Coastal Zone Management Act. The act (16 USC 1451 et
seq.) establishes funding and requirements for state coastal
zone management programs. Under U. S. EPA procedures for
implementing NEPA (40 CFR Part 6), a determination of con-
sistency with applicable coastal zone management programs
is required of U. S. EPA activities having significant coastal
zone impacts. U. Sv EPA has approved the Alaska Coastal
Management Program as established by the Alaska State Coastal
Zone Management Act of 1977. In Alaska, the state has desig-
nated specific local governments to implement coastal manage-
ment controls. Anchorage's Coastal Zone Management Plan
was certified by the Alaska Office of Coastal Zone Management.
The existing treatment plant, discharge, and portions of
the collection system fall within the area controlled by
the MOA.
» Potter.Marsh, all tidal flats and coastal wetlands,
Campbell-Klatt Bog, Turnagain Bog, and most of Potter, Little
Rabbit, Rabbit, Furrow, Campbell, Fish, Chester, and Ship
Creeks in the study area have been included in areas desig-
nated for preservation under the MOA Coastal Zone Management
Plan (MOA 1980, map 12). Development in these areas, parti-
cularly as approved in Campbell-Klatt Bog by the MOA's Wetlands
Management Plan, will require amendment of the coastal zone
management plan. The coastal zone management plan also states
that "public works activities . . . shall avoid or minimize
adverse impacts upon coastal marsh systems."
The Point Woronzof WWTP is located in the coastal zone
management area. The tidal area to the south of the treat-
ment plant is designated a wetland of special concern.
Extension of the outfall should not impact this area.
No marine or estuarine sanctuaries occur in the vicinity
of the proposed discharge or other facilities.
Resource Conservation and Recovery Act. As part of
its proposed nonindustrial source- control program, MOA pro-
poses to establish centrally located sites where the. public
may discard toxic pollutants or hazardous wastes, including
grease and oil. Under provisions of the Resource Conservation
and Recovery Act .(42 USC 6921 et seq.), the U. S. EPA has
authority to regulate this program.
Endangered Species Act. The central purpose of the
Endangered Species Act, as amended (16 USC 1536 et seq.)
is to halt and reverse the trend toward species extinction
through limitations on the actions'of federal agencies. By
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enacting the Endangered Species Act, Congress made a con-
scious decision to give endangered species priority over
the "primary missions" of federal agencies. The Endangered
Species Act states that each federal agency shall "...
ensure that any action authorized, funded or carried out
by such agency does not jeopardize the continued existence
of any endangered species or threatened species or result
in the destruction or adverse modification of habitat of
such species which is determined by the Secretary to be
critical, unless such agency has been granted by exemption
for such action by the Committee". The Endangered Species
Act (Section. 7) also requires that all federal agencies
consult with the Secretary to achieve these ends and the
Secretary must issue an opinion on how the agency action
will affect the species and how the impacts could be avoided.
If the opinion indicates that the agency action may jeopardize
a listed species or critical habitat, the agency must either
modify its action or apply for an exemption from the Endangered
Species Act.
Nonfederal entities contracting with a federal agency
may also be subject to the Endangered Species Act provisions
as well. Provisions of the Endangered Species Act may apply
even after a project has been built.
There are no known endangered or threatened species
in the study area (Alaska DFG 1976) . Arctic peregrine falcon
are classified rare and endangered by the federal government
and the State of Alaska. Any area in Cook Inle4- could receive
use by Arctic peregrines during spring and fal_ migration
periods', but such use in the study area would be uncommon
and has not yet been reported. There is a possibility that
the Aleutian Canada goose may occur in lower Cook Inlet,
but this use has not been verified either, and is highly
unlikely in the study area.
Critical habitat areas have not been identified in upper
Cook Inlet. Potter Marsh and the tide flats south of Campbell
Point to Chugach State Park are included in the Potter Point
State Game Refuge managed by Alaska DFG, but these areas
are not covered by Endangered Species Act jurisdiction.
U. S. EPA Policy on Floodplain and Wetlands Protection.
In January 1979, U. S. EPA issued a Statement of Procedures on
floodplain and wetlands protection pursuant t,o Executive
Order 11988 and Executive Order 11990. Under the procedures,
U. S. EPA is required to assess the impacts of its action
on wetlands and floodplains and to avoid or, if no practicable
alternative exists, minimize adverse impacts.
U. S. EPA, Region 10 has determined that 201 grants
may promote or support development in environmentally-sensitive
areas such as wetlands and floodplains. This effect occurs
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when facility designs provide capacity for a reasonable amount
of future growth, thereby influencing the amount or location
of future development within a planning area. Potential
adverse impacts of the MOA's proposed projects are described
in this EIS.
Clean Air Act. The Clean Air Act, as amended (42 USC
1857 et seq.) requires states to prepare plans to attain
national ambient air quality standards (NAAQS) in regions
where the standards are being violated. These standards
are designed to protect human health from the effects of
chronic air pollution. Any project that directly or indirectly
creates local air pollution conditions in excess of NAAQS,
or which conflicts with the strategy presented in an approved
State Implementation Plan (SIP), may have federal funding
withheld under Section 316 of the Clean Air Act. Because
federal standards for carbon monoxide are periodically vio-
lated in the Anchorage Bowl, an air quality plan has been
prepared and was adopted in June 1982 (MOA 1982) .
Safe Drinking Water Act. The Safe Drinking Water Act
(42 USC 30'0f et seq.) requires U. S. EPA to set standards
for drinking water quality and to establish guidelines for
state regulation and enforcement of these standards. It
als.o gives U. S. EPA the responsibility of protecting under-
ground sources of drinking water. National primary drinking
water regulations were established by U. S. EPA in 1977 and
secondary drinking water regulations were established in
1979. The facilities plan must be analyzed for its effects
on local drinking water-supplies.
Fish and Wildlife Coordination Act. Under this act
(16 USC 661 et seq.), federal agencies involved in projects
resulting in modifications of streams or other water bodies
are required to protect fish and wildlife resources which
may be affected by the project. U. S. EPA procedures for
implementing NEPA require consultation with the U. S. Fish
and Wildlife Service(USFWS) and appropriate state wildlife
agencies to develop mitigation measures for adverse impacts.
National Historic Preservation Act. Under the National
Historic Preservation Act (16 USC 470 et seq.), if federal
agencies undertake activities affecting sites of historic,
architectural, archeological, or cultural value that are
listed on the National Register of Historic Places, then
the Advisory Council on Historic Preservation must be con-
sulted and mitigation measures must be developed.
State Laws, Regulations and Policies
Alaska Water Quality Standards. U. S. EPA has granted
jurisdiction for preventing and abating water pollution in
the state to ADEC. ADEC is responsible for is-suing permits for
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the discharge-of liquid wastes into state waters and for the
disposal of nondomestic liquid wastes into publicly operated
sewer systems. ADEC has developed water quality standards
(18 AAC 70) under the Alaska Water Pollution Control Program
(ADEC 1979). It also has established mixing zone regulations
which determine the size of mixing zones in receiving waters.
The code requires that reports, plans and specifications for
all proposed modifications or construction of new sewer systems
must be submitted to ADEC and approved by ADEC in writing.
Alaska State Coastal Zone Management Act. See discussion
of Coastal Zone Management Act under Federal Laws, Policies
and Regulations
Local Laws, Rules and Regulations
Sewer Tariff. The MOA has a sewer tariff which prohibits
the discharge of toxic substances at concentrations hazardous
to humans or animals, which may interfere with the sewage
treatment process, or create any hazard in the receiving
waters. The sewer tariff also specifies upper limits of
certain heavy metals and phenol which may be discharged into
the sewer system.
Wetlands Management Plan. The MOA Wetlands Management
Plan, adopted in April 1982, has been enacted to provide
for the orderly control of development of wetland areas in
the Anchorage Bowl. Under the plan, most of the wetland
areas in greehbelt areas or adjacent to recreational sites
are designated as preservation areas. The remaining wetlands
are either available for complete urbanization and develop-
ment to satisfy growth needs, or are available for develop-
ment if identified resource values are maintained as,much
as practicable.
Hillside Wastewater Management Plan. Adopted in May
1982, the plan establishes guidelines for on-site sewerage
'in the Hillside area and identifies those areas unsuitable
for on-site disposal systems. The plan seeks to minimize
the public health hazards associated with on-site disposal
system failures and subsequent contamination of groundwater
and surface water, while minimizing the growth-inducement
impact that could result from installing a wastewater collec-
tion system tied to the MOA system.
Comprehensive Development Plan. The MOA has developed
a draft Comprehensive Development Plan (MOA 1982) to guide
community development. It addresses land use and supporting
services, including transportation, parks, trails, open space,
energy, land use, and phasing of urban development. An adop-
tion date is not currently scheduled. In the meantime the
1976 Comprehensive Development Plan Ordinance remains in
effect.
10
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Anchorage Coastal Management Plan. See discussion of
Coastal Zone Management Act under Federal Laws, Policies
and Regulations.
Public and Agency Participation
Data for this EIS were compiled from numerous existing
studies of the Anchorage Bowl, wastewater facilities docu-
ments, field reconnaissance, literature review, and numerous
contacts with governmental agencies and individuals. Some
of the agencies providing information and assistance in pre-
paration of this EIS include the U. S. EPA, USFWS, U. S. COE,
Alaska DFG, ADEC, Arctic Environmental Information and Data
Center, U. S. Geological Survey and various entities of the
MOA.
The EIS process encourages public input into the decision-
making process. Scoping meetings were held in Anchorage
on July 9 and 10, 1981; an interagency workshop was held
on September 9, 1981 regarding wetlands work; a 201 facilities
plan public meeting incorporating EIS topics was held on
October 15, 1981; an EIS workshop on wetland issues was held
on October 1-6, 1981; a 201 facilities plan public meeting,
incorporating EIS topics, was held on January 19, 1982; and
an EIS workshop emphasizing hillside and wetlands issues
was conducted on April 14, 1982. Many agencies, interest
groups and individuals were represented at the public meetings
and workshops.
The Draft EIS will be widely circulated by U. S. EPA
for public comment, and a public hearing will be held to
solicit public response. The results of the public meetings
and hearings and any written comments received will be pre-
sented in the Final EIS. Final U. S. EPA action concerning
the grant award to the MOA will be made following the comment
period on .the Final EIS.
Study Area Characteristics
Physical Location
Anchorage is located in south central Alaska, at the
head of Cook Inlet on a lowland shelf dividing the Khik Arm
and the Turnagain Arm (Figure 1-1). The City of Anchorage
and its immediate surrounding suburban area is referred to
in this EIS as the Anchorage Bowl area, due to the presence
of the Chugach Mountains on the east and marine waters on
the south, west and north. The area, comprising approximately
240. square miles, slopes gently downward from the Chugach
foothills immediately east of the city to a general elevation
of 80 feet above sea level. The entire lowland is separated
11
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KNIK
ARM
Figure 1-1. Location Map
12
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from the sea by steep bluffs, and only along the valley of
major streams does the land approach sea level with a gentle
gradient. This topography is consistent in the Bowl area,
except at the extreme west tip where a ridge of hills with
elevations reaching- 300 feet extends from Point Campbell
to Point Woronzof.
The study area for this EIS is bounded by the northern
limits of the military reservations (Elmendorf Air Force
Base and Fort Richardson), Chugach State Park and Cook Inlet.
Climate in the Cook Inlet region is transitional between
the maritime and continental regimes, and consequently is
variable. Weather conditions may also vary substantially from
point to point within the Anchorage Bowl area due to the many
geographic factors in the local area. Temperatures average
from 18°F during the winter to 65°F in summer, with occasional
periods of more extreme temperatures. The maximum temperature
ever recorded at Anchorage International Airport is 86°F; the
lowest ever recorded is -38°F (Environmental Atlas 1972).
Average annual precipitation at Anchorage International Airport
is 14.7 inches with an annual average snowfall of 75.1 inches.
The Anchorage Bowl area receives from 13-20 inches precipi-
tation annually. Heaviest precipitation is in July and August
when the wind direction is generally from the southwest.
Prevailing winds are from the north, with an average velocity
of 6.5 miles per hour.
Prior to the establishment of Anchorage in 1914 as a
railroad camp, the Anchorage Bowl was characterized by birch
forest and muskeg bogs around numerous small lakes and ponds.
Moose were common, especially in winter, and salmon were
abundant in Ship Creek., Fish Creek, Campbell Creek, and Rabbit
Creek.
Population
According to the 1980 census, the population of the
MOA was 174,431 (Table 1-1). Approximately 79 percent of
the population lives in the Anchorage Bowl area. The balance
of the population lives in Eagle River/Chugiak/Eklutna,
Turnagain Arm areas or on Elmendorf Air Force Base and Fort
Richardson Military Reservation. The Anchorage economy
depends on wholesale and retail trades; transportation,
construction and utility services; government employment;
oil production; service industries; and tourism. The con-
struction industry causes a seasonal flux in both the local
economy and population.
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Table 1-1
Current and Projected Population:
Municipality of Anchorage
1980 2000
Census Projection
Anchorage Bowl 143,451 258,501
(includes Hillside)
Military 17.499 17,499
Eagle River/Chugiak/Eklutna 12,835 36,066
Turnagain Arm 656 6, 300
Municipality of Anchorage 174,4311 318,3662
^Source: U.S. Bureau of Census
2Source: Institute of Social and Economic Research
SOURCE: Hillside Wastewater Management Plan Technical
Report . . ., MOA 1982.
14
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Past Growth
The MOA experienced rapid growth during the early and
mid-1970s. According to Anchorage School District figures,.
the population peaked around 181,500 in 1978 and then sharply
declined for a brief period during 1979 and' 1980. The popu-
lation is currently on the rise and is apparently at its
highest (182,429 in 1981) , based on school enrollment figures
(Schaedel pers. comm.). The rapid growth of the early and
mid-1970s reflected statewide growth trends, largely in
response to the trans-Alaska pipeline project; Once the
pipeline was completed many residents returned to the lower
48 states, causing the dip in population in the late 1970s.
Comprehensive development plans, zoning ordinances,
capital facilities programming and other factors have served
to direct and control past growth in the MOA to various degrees,
The 1976 Comprehensive Development Plan Ordinance remains
in effect, although a new Comprehensive Development Plan
is currently in the approval process.
The new Draft MOA Comprehensive Development Plan focuses
on the basic issue of growth: its pattern, density and quality
(MOA 1982). The plan is intended to guide urban growth,
while conserving natural resources and open spaces, reducing
potentially harmful environmental conditions, and minimizing
the overall costs of public services and facilities to the
community. The Draft Comprehensive Development Plan's land
use maps and the zoning ordinance will establish the use
that may be made of the land within the MOA's boundaries.
The uses designated reflect a general policy of concentrat-
ing urban growth in areas that have already seen some develop-
ment and limiting of population density in more rural areas.
The adopted Wetlands Management Plan and Hillside Waste-
water Management Plan also control growth. The wetlands
plan designates development and preservation categories for
most wetland areas of the Anchorage -Bowl. The Hillside waste-
water plan designates much of the Hillside area for on-site
sewage disposal systems, thereby limiting development densities.
Capital facilities programming also influences urban
growth patterns. The annual capital improvement program
is intended to be consistent with the Comprehensive Develop-
ment Plan. The latter identifies general areas of urban
growth and the capital improvement program schedules those
facilities and services necessary to support the land use
patterns.
Coastal zone regulations enacted pursuant to the federal
Coastal Zone Management Act of 1977 limit growth in the coastal
areas.
15
-------
Future Growth. The population of the MOA is projected to
increase to 318,366 by the year 2000 (Figure 1-2). The addi-
tional growth from 1980 to the end of this century is antici-
pated to be over 143,935 people, nearly a doubling of the popula-
tion. Most of this growth is predicated upon Anchorage's role as
the transportation and service center for outlying areas in
Alaska, especially as it relates to exploration and utilization
of natural resources. It is difficult to predict what additional
impact may result if the state capital and related services are
relocated from Juneau to Willow.
16
-------
400,000
350,000
300,000
250,000
200,000
150,000
100,000
50,000
318,400;
INSTITUTE FOR SOCIAL 8
ECONOMIC RESEARCH PROJECTION
MOA HISTORICAL
POPULATION
STUDY AREA SEWERED
POPULATION
STUDY AREA
PROJECTION
137,000
STUDY AREA HISTORICAL
POPULATION
• 0
1925 1935 1945 1955 1965 1975 1965 I99S 2OOS 20iS 2025
SOURC£:MOA, 1982
FIGURE 1-2. POPULATION PROJECTIONS
FOR ANCHORAGE
17
-------
Chapter 2
Effluent Limitation, the NPDES Permit, and the Existing
Sewerage System
• Collection and Interceptor System
• Pump Stations
• Treatment Plant
• Effluent Characteristic
-------
Chapter 2
EFFLUENT LIMITATIONS, THE NPDES PERMIT,
AND THE EXISTING SEWERAGE SYSTEM
Public Law 92-500, the Clean Water Act, requires that a
National Pollutant Discharge Elimination System (NPDES) permit
be issued for each waste treatment facility that discharges
to surface waters, fresh and marine. Effluent quality limita-
tions are established for each discharge in its NPDES permit.
The Clean Water Act also states that secondary treatment
of wastewater is to be implemented by July 1977. The NPDES
permit issued for the Point Woronzof Wastewater Treatment
Plant (WWTP) requires effluent to meet secondary quality at
the levels indicated in Table 2-1.
However, permission was granted by EPA by a letter attached
to the NPDES permit (AK-002255-1) to continue the discharge
of primary effluent. The allowed concentrations are presented
in Table 2-2. The letter of permission also requires that
discharge flow and pH limits be no- different than those set
forth in the original NPDES permit.
An amendment to the Clean Water Act (PL 95-217) was
passed in 1977 which allows, under Section 301 (h), a conditional
waiver of the secondary treatment requirement. Waiver approval
depends on the demonstration that: a) the existing receiving
waters are either ocean or saline, with currents of sufficient
strength to ensure rapid effluent dispersion; and b) the EPA
must be satisfied that the discharge has no significant environ-
mental impact. The MOA has applied for and received tentative
approval of a waiver under Section 301(h), but as of October 1982
it had not been issued.
The effluent must not cause the receiving water to exceed
the State water quality standards established in Chapter
70 of Title 18 (18 ACC70). These standards reflect known
or potential beneficial uses of the Knik Arm and impose strict
regulations on the quality of waters used publicly or privately.
The Alaska Department of Environmental Conservation (ADEC)
will allow criteria for effluent-receiving waters to be exceeded
within a prescribed boundary known as the "mixing zone."
However, these standards must be met outside the specified
mixing zone boundaries.
The waters of the Knik Arm are designated as marine
waters, supporting all protected marine uses. A summa'ry
of applicable water quality standards with requirements for
19
-------
Table 2-1. NPDES Effluent Limitations for Point
Woronzof, Based on Secondary Requirements1
Effluent Unit of Monthly Weekly
Characteristics Measurement Average Average
Effluent Concentrations
Biochemical Oxygen Demand mg/1 30 45
(5-day)
Suspended Solids mg/1 30 45
Effluent Loadings
Biochemical Oxygen Demand kg/day (Ib/day) 3,867 (8,500) 5,800 (12,760)
Suspended^olids kg/day (Ib/day) 3,867 (8,500) 5,800 (12,760)
1 Conditions waived by U. S. EPA letter. See text.
Table 202 applies.
Table 2-2. NPDES Effluent Requirements for Point
Woronzof WWTP, Based on Primary Treatment
Effluent Unit of Monthly Weekly Daily
Characteristics Measurement Average Average Maximum
Biochemical Oxygen Demand mg/1 120 130 140
(5-day)
Suspended Solids mg/1 100 115 130
Fecal Coliform Bacteria Number/100 ml 700 1,500
Source: MOA 1982
20
-------
selected constituents is presented in Table 2-3. The strictest
requirement in each column is 'the governing criterion. For
a complete listing of constituents and standards, the reader
is referred to the Alaska Water Quality Standards.
Collection and Interceptor System
The first sewers in Anchorage were constructed in 1917.
This system, centered in what is now the northern portion
of the business district, was expanded south to 16th Avenue
by 1948. The earthquake of 1964 severely damaged the collec-
tion system, especially the Knik Service Area sewer lines.
Two years later, area-wide sewerage authority was granted
to the former Greater Anchorage Borough, and by 1969, Sewer
Service Area No. 40 was established. Major interceptors
were constructed between 1967 and 1972 to collect the wastewater
and transport it to the present location of the Point Woronzof
WWTP. Prior to 1972, when the treatment plant became operational,
raw sewage was discharged into the Knik and Turnagain Arms
of the Cook Inlet.
When the City and Borough of Anchorage were consolidated
in 1975 to form the Municipality of Anchorage, the sewer
systems were consolidated under the new Anchorage Water and
Wastewater Utility (AWWU). The AWWU administers sewerage
system planning, construction, operation and maintenance
in the Municipality.
Service Areas
The sewerage system is divided into five major drainage
or service areas (Figure 2-1) that contain more than 400
miles of sanitary sewers, and 23 pumping stations that contribute
flow to Point Woronzof WWTP. Elmendorf AFB and Fort Richardson
are not included in these areas, but are tributary to them.
Elmendorf AFB contributes flow to the Municipality's
system in the Knik Service Area. Fort Richardson contributes
to the Northeast Service Area. Air Force Base flows reach
Point Woronzof via the downtown area and the Chester Creek
Pump Station, while Fort Richardson flows travel to the
Campbell Creek Pump Station near Campbell Lake and are then
pumped north to Point Woronzof WWTP.-
Pump Stations
The study area includes 23 pump stations. Only two
of these stations will be described in further detail.
21
-------
Table 2-3. Surrmary of State of Alaska Water Quality Standards Applicable to Knik Arm
WATE R
OUAlllY ~*"
PARAMtTli
II
MAKINt ~J
V\Al 1 R Uit i f
IAI W-U'. 5UMI,,y
III *uua«.ulluii.
IAI A ,1.-. i, y
IAI Wain Supply
eluding jny tvJtrf IOU
pi 'ft uu.l m dit.».>d
(in., lollirr ihjn loud
jKiKtu.mjl including
cni-fgv pioiliu lion 01
I. on
IB) Water Rfctealion
In) ierondd/y
iMteation
(Cl Giowiti and Pro
paqdiion of Fuh Shell
filh AyuJlit Life.
and Wildlife Includim
Scabiidi Waterfowl ani
Fuitb-aicrt
IDI Harkctniitf loi Con
tumiMiun of Ha*. Mul
luikt oi Other Raw
Aquatic Life
FECAL COL IF OHM BACIf RIA (FCI
ISe,- Note 1)
f
un a mmmiuni ol S lamulet taken in a pcnod ol
30 ddV* ihjl not e»c.-,-d 200 FC/lOO ml and
nui moie lh«n 10\ ol llic umuM ihjll e.cL-ed
400 FC/lOO nil For picKludt not noirnjlly
cnokfd the UK an bdt. d on a minimum of 5
t.mi|>l.i idk.n tn a pi- nod ol 30 d*yj ihall not
iht umul- 1 iitjll t .turd 40 FC 100 ml
j*i, .id ol 30 rl.yi iiujn ihjll nul e*cei-d 20
FC ' 100 ml jnd nui moCL-|H
whi-tr Hdluial conUiliont cjui* tlui value to be
ilcuicitcd In no cate thall DO k-»L-h abuve 17
mg 1 be pcrinilled The concentration ol luul
diiiulied yat ihall nul exceed 110'X. of t-iluration
at any pomt of i ample collet-tton
Same ai I2HAH.I
Sdme di |2)IAHil
pM
IVaiianon of pH for waleri naturally
ou tude Ihe tpecified range thai! be
lowafdi the range |
Shall not be leu than 6 S or, greater
than 8 S and ihall not *aiy more
than 0 1 pH umtt from natural con
dnion
Slijll nal be lui ihjn 6 0 01 gicjlti
llun 8 & Slull not vary moie ihjn
0 b pH umi Irom naiuut cundilion
Slull not be ktt llun & 0 or yiojlci
IhJii 9 0
Ihjn 85 If the njluul pH con
du ion n ouludc Hut range iobii.incei
water
Shall not be leu than 5 0 or greater
than 9 0
Shall noi be lets than & b or grcatei
than 8 5, jnd ihall nui vary more
than 0 1 pH unit from natural con
dition
Shall noi bu leu llun 6 0 or yrejle*
Hun 8 5 Slull not vjry more ilu,,
0 5 |>H unit Irom rijturdl condition
TURBIDITY
Shjll not CHcecd 25 NTU.
Shjll noi interlcre with diint
fection
Shdll not caitti! dctnnu-nidl
cflci.li on L-iUblnhcd leweli ol
Shall not cuceed 25 NTU
Shall not reduce ihe di-jtih of
ihe compenidlion point tor photo
tynihetic activity by more than
10%. In addition, thai) not re
duce the maximum n-cchi disk
depth by more llun 10%
Sj
-------
A
H
£
X
^-~ T- 1
KNIK SERVICE
AREA
NORTHEAST
SERVICE AREA
WEST SERVICE
AREA
TURNAGAIN
SERVICE AREA
LEGEND
PLANNING AREA BOUNDARY
SERVICE AREA BOUNDARY
ON -SITE DISPOSAL
SOURCE-MOA, 1982
FIGURE 2-1. SEWER SERVICE AREAS
23
-------
In 1-972, the Chester Creek and Campbell Creek Pump
Stations were put on-line. These stations, the largest in
the system, transport between 70 and 90 percent of the wastewater
flow received at the Point Woronzof WWTP. Sewage from nearly-
all of the Knik Arm Service Area, Elmendorf AFB, central
business district and the Spenard area discharges to the
Chester Creek Pump Station, located near the mouth of Chester
Creek at the Alaska Railroad. The force main discharging
from the Chester Creek Pump Station discharges to large-
diameter gravity sewers near Northern Lights Boulevard and
then flows west to Point Woronzof.
The Campbell Creek Pump Station serves the Northeast,
Southeast and much of the Turnagain service areas. Most flows
reach the pump station through an aging corrugated metal
pipe that parallels Campbell Creek. This interceptor is
overloaded, and occasionally spills raw sewage to Campbell
Creek near the Alaska Railroad. The pump station is located
near the mouth of Campbell Creek, and pumps sewage north
and east to gravity sewers near the Minnesota Bypass and
south of Raspberry Road. These gravity sewers flow north,
joining flows from the rest of Anchorage and flowing west
to the Point Woronzof WWTP -
Point Woronzof Wastewater Treatment Plant
The John M. Asplund Wastewater Treatment Plant, commonly
referred to as the Point Woronzof WWTP, has been in service
since July 1972. The facility operates as a primary treatment
plant and was designed for a population of approximately
221,000. Current population projections indicate that this
design population will be exceeded before the year 1995,
and evaluation of the plant operation indicates it is incapable
of adequately treating sewage from that population.
A brief description of the Point Woronzof WWTP plant, including
the improvements constructed in the summer of 1982, follows.
The treatment process is discussed; the liquid and solid
processes are discussed in separate subsections.
Liquid Process
A 96-inch influent pipeline enters the plant, and its flow
is divided between three Barminutors which cut up the solids
in the wastewater (Figure 2-2). These solids are then screened,
mechanically removed, and sent to the hammermill for grinding,
and then incinerated. The wastewater is cleaned of grit
(sand, gravel), prechlorinated and distributed to three primary
clarifiers. Here, the sludge is settled out, and the scum
(greases and oils) are skimmed off. The wastewater then
flows to a metering box, where flow amounts are recorded,
and on to a drop box.
24
-------
(SLUICE GATES, TYR)
SCREENING
(BARMINUTORS)
DIVERSION BOX
60 CLARIFIED LIQUID
EFFLUENT BOX
METERING BOX
DROP BOX
CHLORINE TOWER
CHLORINE. SOLUTION LINE
-84 OCEAN OUTFALL
SOURCE MO A, 1982
FIGURE 2-2. SCHEMATIC OF POINT
WORONZOF WWTP LIQUID PROCESS
25
-------
Chlorine, which destroys fecal coliform and other micro-
organisms, is automatically injected into the drop box. The
chlorinated effluent flows 3,200 feet through an 84-inch
pipe to the control tower. The flow is surcharged, slowing
the velocity and increasing contact time between the chlorine
and the effluent (about 38 minutes at 34 mgd). The effluent
is discharged into the Knik Arm of Cook Inlet through an
804-foot-long, 84-inch-diameter ocean-outfall pipe.
Solids Processing
The sludge and scum separated from the wastewater in
the clarifiers are transferred to two thickeners by raw sludge
pumps (Figure 2-3). Before entering the thickeners, grit
is removed by the classifier and hydrocyclone, and is trucked
off to the Merrill Field sanitary landfill. In the thickener,
further gravity settling separates sludge from excess water.
Sludge is then pumped to the dewatering facilities where
more water is removed by a belt filter press. Dewatered
sludge is conveyed into a multiple hearth incinerator and
is burned. Ash from the incinerator is transported to a
sanitary landfill. The water extracted from the sludge by
the thickener enters the wastewater stream at the diversion
box, while the wastewater from the dewatering process flows
back to the screening room at the head of the plant.
Scum from the clarifier can be pumped to the belt filter
press for dewatering or to a screen incinerator contained
in the incinerator building. Surplus is returned to the
liquid process at the screening room.
Auxiliary Facilities
At this time, 51 employees, including operators and
maintenance staff, oversee the operation of Point Woronzof
WWTP (Table 2-4). A lab located in the administration building,
a maintenance shop, and control room located in the solid
processing building complement the wastewater treatment facili-
ties .
Effluent Characteristics
The effluent flows through an 804-foot, 84-inch ocean
outfall and is discharged into the Knik Arm of the Cook Inlet.
Monthly characteristics of the effluent compared to current
26
-------
LEGEND
SP- SCUM PUMP
RSP-I- RAW SLUDGE PUMP
TSP-I- THICKENED SLUDGE PUMP
STP- SLUDGE TRANSFER PUMP
-O- - PLUG VALVE
•H*-- THREE-WAY PLUG VALVE
—«8>-- FOUR-WAY PLUG VALVE
—W CHECK VALVE
B3 - SLUICE GATE
NOTE: ALL PIPING 6" UNLESS OTHERWISE SHOWN
SLUDGE THICKENER DISTRIBUTION BOX
o"
10" f
1
n
8"
i
v' »• ORI
10"
'
—i
•r
h 10"
HYDROCYCLONE (GRIT REMOVAL)
GRIT TO LANDFILL
8' TO FUTURE HYDROCYCLONE
-SCUM TO CONCENTRATOR (SEE FIGURE IV-4)
TO DIVERSION BOX
DISTRIBUTION BOX SCUM
SCUM (TYR
SLUDGE HOLDING TANK
DEWATERING PUMP
THICKENER THICKENER
No. I No. 2
THICKENER DEWATERING
SLUDGE
THICKENER
DEWATERING PUMP
CLARIFIER SCUM
TSP-I SP-I
SLUDGE
CONDITIONING TANK
/ ,S\ (TYR)
CLARIFIER No. 2 CLARIFIER No. I
CLARIFIER No. 3
BELT FILTER PRESS
DEWATERED SLUG
TO INCINERATOR
-FILTRATE TO DRAIN LINE
TO VACUUM FILTER CONDITIONING
TANK (SEE FIGURE IV-4}
PLANT EFFLUENT WATER
SOURCE^ MOA, 1982
FIGURE 2-3. SCHEMATIC OF POINT
WORONZOF WWTP SOLIDS PROCESS
-------
Table 2-4. Summary of Existing O&M Staff
at Point Woronzof WWTP
CI ass i f i cation Number Employed
Superintendent 2
General Foreman 2
Maintenance Foreman ^
Operation Foreman k
Senior Operator k
Operator I I 8
Operator I 5
Instrument Electrician k
Machinist 1
Mechanic Welder 1
Mechanic Leadman l
Journeymen Craftsman 1
Mechanic 1
UtiIi ty Man I I 1*
Building Superintendent 1
Lab Supervisor l
Lab Ana Iyst 1
Lab Assistant l
W.Q. Tech. 1/2 2
Cleri caI 1
Exped i ter 1
Warehouseman _i^
TOTAL 51
28
-------
NPDES limits are shown in Figure 2-4. BODs, TSS, and fecal
coliform levels have at times exceeded NPDES limits. These
occurrences are generally linked to seasonal flows as well
as long-term increases in wastewater flows between 1978 and
1981. TSS concentrations typically exceed NPDES limits during
spring breakup, while higher BOD5 concentrations occur during
low flow periods. NPDES fecal coliform violations generally
occur when the residual chlorine content of the effluent falls
below 1.0 mg/1.
Table 2-5 depicts average yearly effluent concentrations
and "removal efficiencies for BOD5 and TSS. As wastewater
flows have increased, removal efficiencies have declined.
This is mostly due to the overloading of the clarifiers.
To determine the design requirements for future expansion,
extensive evaluation of the primary clarifiers was undertaken.
The clarifiers were designed for a maximum overflow rate
(the rate at which water is drawn from clarifiers) of 1,000
gallons per day per square foot (gpd/sf) yielding a design
flow of 34 million gallons per day (MGD). Past operation
records indicate that current NPDES effluent limits can only
be met if retention time of wastewater within the clarifiers
is increased; the flow rate must be reduced to 660 gpd/sf,
yielding a design flow on only 22.2 MGD.
It is apparent that violations will continue, depending
on seasonal flows and population growth. The frequency of
violations is expected to increase, although the 1982 modifica-
tions should provide some improvements in treatment. Obviously,
in the event that Section 301(h) is not granted and the secondary
treatment NPDES permit goes into effect, continual violations
of the permit will occur until expansion and upgrading .can
occur.
29
-------
o
o
s
I
*
o
_i
u.
30
20
10
o
120
110
^"°
§ 100
o
90
80
o
120
110
100
30
o
in
a
UJ
o
z
UJ
0.
in
80
60
WASTE WATER FLOW
1978
1979
1980
1981
i
Jl
NPOES PERMIT LIMITS
JT
re
Lr
EFFLUENT BOO
^
1978
1979
I960
1981
NPDES PERMIT LIMITS
EFFLUENT SUSPENDED SOLIDS
1978
1979 -
I960
1981
SOURCE MOA , 1982
FIGURE 2-4. COMPARISON OF EFFLUENT
QUALITY TO NPDES PERMIT LIMITS
30
-------
Table 2-5. Yearly Average Effluent Concentrations
Year
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
BOD5
Concentration
mg/1
110
72
58
68
98
107
113
105
112
110
Percent
Removed
30
48
41
29
20
21
25
17
20
21
TSS
Concentration
mg/1
78
74
69
70
62
77
77
80
83
89
Percent
Removed
60
62
53
38
45
45
47
39
39
42
Source: Wastewater Facilities Plan for Anchorage, Alaska AWWU, June 1982
-------
Chapter 3
Alternatives for Wastewater Collection, Treatment and
Disposal
Introduction
Recommended Plan
Range of Alternatives
Description of Alternatives
Cost Summary
X-.
-------
Chapter 3
ALTERNATIVES FOR WASTEWATER COLLECTION,
TREATMENT AND DISPOSAL
Introduction
The description and comparison of project alternatives
in the preparation of an EIS must follow specific regulations
of the CEQ as contained in 40 CFR, Part 6 as published in
the Federal Register, Vol. 43, November 29, 1978 and of the
EPA as contained in the Federal Register, Vol. 44, No. 216,
November 6, 1979. The comparative evaluation should include
an analysis of the environmental impacts, commitments of
resources, costs and societal risks associated with each
alternative. The reasons why a proposed alternative management
system is finally selected must also be explained in detail.
This section contains a description of the alternatives con-
sidered for. the MOA wastewater facilities expansion and evalua-
tions relative to cost and engineering considerations.
The information on which much of the following discussion
is based is contained in the document entitled Wastewater
Facilities Plan for Anchorage, Alaska dated June 1982. This
report was prepared for the MOA by a joint venture of Ott
Water Engineers, Inc., Quadra Engineering, Inc. and Black
and Veatch Consulting Engineers, and it comprises the majority
of the MOA Section 201 facilities plan. The remainder of
the section 201 facilities plan is the Hillside Wastewater
Management Plan developed by the MOA Planning Department,
with contract assistance from Arctic Environmental Engineers.
The two documents taken together comprise the combined facili-
ties plan that is the subject of this EIS.
There are important differences between components of
the plan. During initial planning, the service area was
divided into two portions: the Hillside area, and the remainder
of the Anchorage Bowl. The preparation of the Hillside Waste-
water Management Plan (MOA 1982) was undertaken with Section
208 funding to address sewerage needs of the Hillside area
with an emphasis on continuing on-site sewerage disposal
and preserving a rural lifestyle in the study area.
The plan identifies areas of the Hillside that are to
be served by on-site treatment and disposal systems (such
as septic tanks with drain fields), areas to be served by
sewers, and areas unsuitable for on-site systems where no
33
-------
sewer systems are to be provided (although on-site systems
may be allowed). The Wastewater Facilities-Plan for Anchorage,
Alaska (MOA, 1982) -recognizes the determinations for.these
areas and proposes sewage collection, treatment and disposal
systems serving the portion of the Hillside area designated
for sewerage in the Hillside plan. It also encompasses expan-
sion of sewage collection, treatment and disposal facilities
for the rest of the Anchorage Bowl.
The combined facilities plan describes an areawide sewerage
facilities expansion program serving the Anchorage Bowl and
extending over a 20-year period. It encompasses:
o Alternatives for expansion of Point Woronzof WWTP;
o Extension of the existing outfall by 1,500 feet;
o Study of adding a diffuser at the end of the extended
outfall;
o Alternatives for disposal of sludge solids from the
treatment process;
o Alternatives for construction of the West Bypass
interceptor sewer;
o Construction of the Southeast interceptor sewer, includ-
ing sewerage alternatives in the Rabbit Creek-Potter
Creek area;
o Provisions for on-site sewerage of a portion of the
Hillside area;
o Construction of about 70 sewer improvement projects
through 1998.
The facilities plan sets forth a MOA-recommended plan, suggest-
ing implementation of specific alternatives.
For EIS purposes the above project alternatives, except for
the 70 sewer improvement projects, are evaluated in detail in the
EIS. The 70 sewer improvement projects are addressed only with
specific reference to wetland impacts and in general terms
relative to cumulative impacts. The Recommended Plan is presented
and analyzed in greater depth, with alternatives analyzed in
sufficient detail to provide a full perspective of the consequences
of alternative actions.
Chapter 3 includes descriptions of the Recommended Plan and
alternatives as summarized from the facilities plan. The
Recommended Plan is described first; followed by a brief
34
-------
overview of the range of alternatives considered in the planning
proce-ss, a discussion of the screening of alternatives, and
a description of all alternatives evaluated in the facilities
plan. The chapter is concluded with cost-effectiveness evalua-
tions of all alternatives.
Service Area
The area to be served by facilities proposed in the
facilities plan consists of the Anchorage Bowl, including
lands west of Chugach State Park, Elmendorf Air Force Base,
and Fort Richardson (Figure 2-1). It excludes all portions
of the MOA outside of this area, such as Eagle River, Chugiak
and Eklutna. The area was selected as the area that can
logically be served by the Point Woronzof wastewater treatment
plant.
Planning Constraints
A variety of federal and state laws and regulations
and local conditions impose constraints on the facilities
planning process. Regulations promulgated by EPA pursuant
to the Clean Water Act of 1977 are primary constraints. These
regulations (40 CFR Part 35) set forth in detail requirements
for obtaining federal funding for WWTPs. Other regulations
and requirements in effect during development of the MOA
facilities plan are summarized in the EPA publication Facilities
Planning 1981, Municipal Wastewater Treatment.
EPA requires that the planning period for the facilities
plan be 20 years, meaning that the alternatives proposed
in the facilities plan must provide sufficient capacity to
meet the needs for 20 years following project inception,
although phased implementation is permissible. The alternatives
must include the no-action alternative, and evaluation of
all alternatives is required from economic, environmental,
reliability and public interest aspects. Many other requirements
apply and are outlined in the 1981 publication referenced
above.
State laws and regulations govern effluent quality and
discharge, establishing a minimum performance level for the
treatment plant and outfall. Other state and local constraints
described in Chapter 2 of this EIS influence the planning
process and the allowable range of alternatives evaluated
in the plan.
35
-------
Recommended Plan
The Wastewater Facilities Plan for Anchorage, Alaska (MOA
June 1982) and the Hillside Wastewater Management Plan (MOA
May 1982) together set forth an area-wide Recommended Plan for
wastewater collection, treatment and disposal in the Anchorage
Bowl. The Hillside plan, which designates areas for sewerage,
on-site sewage disposal systems, and no sewerage service
(generally unsuitable for on-site systems), was adopted by
the Municipal Assembly on May 18, 1982. This is considered
a Recommended Plan in the context of EIS'analyses. The
Wastewater Facilities Plan for Anchorage, Alaska acknowledged
the adopted Hillside plan and includes sewerage service to the
areas so designated in that plan. The wastewater facilities
plan also evaluates alternatives in the remainder of the
Anchorage Bowl and presents a Recommended Plan selected from
those alternatives.
The Recommended Plan for providing wastewater collection,
treatment and disposal is described in this section. The
expansion of the Point Woronzof treatment plant is described
first, followed by 'the outfall and diffuser, major interceptor
sewers, the Hillside sewerage plans, and the remaining sewer
improvement projects.
The Point Woronzof WWTP would be expanded from its current
effective capacity of 22 MGD annually to 58 MGD (average annual
flow). (Current design capacity is 34 MGD, although the plant
cannot meet discharge requirements at a design flow rate over
22 MGD.) This expansion would be achieved through construction.
of three additional primary clarifiexs, modification of other
portions of the liquid processing to increase capacity (Figure 3-1),
addition of another sludge incinerator to the solids process
(Figure 3-2), and consideration of alternative disposal methods for
incinerator ash. These improvements are described below in the
order of the treatment process.
Liquid Processing
Minor construction in the headworks will be necessary for
safe and efficient operation of the screen room. The door and
window opening into the solids processing building will be re-
placed with a solid wall. Special electrical fixtures will be
installed in areas where hazardous gasses accumulate, and the
existing fixtures will be inspected to ensure compliance with
the National Electrical Code.
During peak flow periods (usually spring breakup) grit
is washed from the collection system into the clarifiers.
The accumulated grit forms deposits on the sludge scraper
rotors, interferes with scraper operation, and must be cleaned
off manually. Clarifier effluent is adversely affected by
36
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LEGEND
:= = = = NEW PIPE
=^^.= ^= EXIST PIPE
NEW STRUCTURE
EXIST. STRUCTURE
.PLANT INFLUENT
WATCH TANK
PRIMARY SLUDGE Tip
" " %
PUMP ROOM_^^ ^
CHLORINE SOLUTION ^~^- II ,
/ID
A
H
I
SOURCE- MOA, 1982
FIGURE 3-1. PROPOSED EXPANSION OF POINT
WORONZOF WWTP - SITE LAYOUT
-------
UNTREATED WASTEWATER
i
SCREENING
GRIT REMOVAL
PRIMARY CLARIFIERS
CHLORINATION
OCEAN OUTFALL
AND DIFFUSER
T
EFFLUENT
SOURCE. MOA , 1982
FIGURE 3-2 PROPOSED
EXPANSION OF POINT
WORONZOF WWTP-
PROCESS DIAGRAM
SCREENINGS
TO GRINDER
& INCINERATION
>GRIT TO LANDFILL
PRIMARY
SLUDGE
GRAVITY
THICKENER
SLUDGE
HOLDING
BELT
FILTER PRESS
INCINERATOR
•ASH TO
LANDFILL,
OUTFALL,
LAGOONS
OR
GRAVEL
PITS
38
-------
excessive grit. A grit removal system will be installed prior
to clarification to eliminate this, problem. Three units
(two functioning, one standby) and a diversion box will be
installed.
As discussed in Chapter 2 and above, current effluent
limits cannot be met consistently unless the overflow rate
of the clarifier is limited to 660 gpd/sf. This overflow
rate would yield only 22 MGD processing capacity- Three
additional 150-foot clarifiers would provide an additional
35.5 MGD capacity. At this time, only two are necessary,
but by 1995, the third clarifier may be required. Alterations
in effluent-permit limits, wastewater strength, or variations
in the efficiency of treatment facilities may postpone or
accelerate the need for the third clarifier. Modifications
to the existing flow diversion box will be required to direct
influent to the proposed clarifiers.
The propeller meter control section at the metering
box may be enlarged to provide for increased flows. Replace-
ment or overhaul of the propeller meter would be accomplished
if necessary.
Four constant-speed raw sludge pumps will be added,
three for the proposed clarifiers, and one as a standby to
simplify sludge pumping and reduce costs.
Replacement of the existing chlorine feed system is
recommended by the facilities plan. Pre-chlorination would
require a 5,000 Ib/day feeder, while combined pre- and post-
chlorination require a 16,000 Ib/day system. The combined
feed system is recommended in the plan.
Solids Processing
Sludge thickener No. 1 will be renovated. The two thicken-
ers will have sufficient capacity until 2005. Two additional
belt filter presses for sludge dewatering would be installed
to provide adequate sludge dewatering capacity past 1990.
A larger multiple-hearth incinerator will be installed
to increase solids handling capacity and to provide needed
standby capacity. A heat recovery system will be installed
with the new incinerator that will be adapted to the present
hot -water recovery system. The system will provide heat
for the treatment plant.
Two new scum pumps and solids grinders will be added
to prevent plugging of scum processing equipment. Two scum
concentrators are also recommended in the facilities plan.
In both cases, one unit would serve as standby.. A system
to feed scum into the incinerator at a constant rate is required
3.9
-------
The facilities -plan presents no recommended project
for disposing of the residual ash following sludge incineration.
Instead, it describes three alternatives and suggests an order
of preference for their consideration. These alternatives
are described as follows:
Alternative 1 - Continue hauling ash to a sanitary landfill,
with an estimated haul distance of 20 miles per trip and
current disposal charges. Ash is now hauled by covered truck
approximately 7 miles to the landfill near Merrill Field.
This landfill, which currently is the only facility serving
civilian uses in the Anchorage Bowl, is expected to be filled
within three to four years. No replacement site has been
selected for the landfill, although it is recognized in the
facilities plan that a new site could double haul distances.
This alternative is incompletely described since no
site for the new landfill has been identified in the facilities
plan or in other MOA planning documents.
Alternative 2 - Blend ash with plant effluent and dispose
of through the ocean outfall. This alternative is identified
as preferred, unless significant adverse environmental impacts
are associated with the action.
Alternative 3 - Blend ash with plant effluent and discharge
to a lagoon or gravel pit within 0.25 mile of treatment plant.
This alternative is identified as the second choice if alternative
2 is not acceptable. If a lagoon is used, it would be drained
and covered when full, or the ash removed to a landfill at
that time, and the lagoon reused. If a gravel 'pit is used,
no draining, covering or removal would be involved.
Auxiliary Facilities
Enlargement of the existing buildings and additions to the
operational control centers are needed to properly handle the
expanded treatment facilities. Currently, space in the main-
tenance 'building is limited, and equipment and parts must be
stored elsewhere. A new, larger building, about 10,000 square.
feet in size, would be constructed to centralize maintenance
services.
The laboratory would be relocated from the administration
building to the existing maintenance building. Also, pretreat-
ment facilicies will require a sampling area complete with
a mud room, and a room for equipment storage and washing
equipment. Removal of the laboratory will free space in
the administration building, providing room for additional
office space and allowing expansion of the conference room
for use as a lecture facility for educational and community
services.
40
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,.?hx (602) 496-0025 * Kansas (913) 841-7641
)om would be expanded or extensively modified,
i control panel and increased control capabili-
led treatment plant.
'acilities would require up to eight or
: 'sonnel:
^ el for operation of added equipment and
i .tenance;
1 person to operate and maintain new pumping
not be needed if other proposed improvements
me existing stations;
v.-.i -Hi-fi ••'•—-'TO
u TWO operations personnel will be needed in the control
room.
Ocean Outfall and Diffuser
To prevent shoreward movement of effluent, studies con-
ducted by Kinnetic Laboratory, Inc. (1979) suggest that the
existing outfall be extended by about 1,500 feet, and that a
diffuser also may be necessary.
The facilities plan recommends that the outfall be exten-
ded by 1,500 feet, that an extensive design effort be under-
taken, and that the diffuser requirements be further studied.
Preliminary diffuser modeling prepared for the Section 301(h)
waiver application determined that a 1,000-foot diffuser would
enable the discharge of chlorinated effluent to meet all
existing water quality standards.
The MOA has entered into a contract with Ott Water Engi-
neers, Inc. to study the outfall and diffuser requirements
under the assumption that chlorination would be discontinued.
Preliminary results indicate that a theoretical diffuser length
of tens of miles would be needed to meet coliform standards
applicable to Cook Inlet. All other standards, however, appar-
ently could be met with a minimal (100-foot) diffuser.
The Ott study also is evaluating the diffuser requirements
under assumptions that certain beneficial users of the waters
of Cook I-nlet would no "longer be considered designated uses.
This change would allow less strict, standards to apply (see
Table 2-3). Assumptions are made by Ott whereby the only re-
maining designated uses would be industrial water supply;
secondary water recreation; and growth and propagation of fish,
shellfish, and wildlife, including seabirds, waterfowl and fur-
bearers. The uses of water supply for aquaculture, seafood
41
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^ssing and water-contact recreation would be deleted as
lated uses, leaving the most stringent applicable coliform
rd as 200 FC/100 ml. Under these assumptions a diffuser
of. 6,100 feet (1,860 meters) would meet water quality
\s.
notes that deleting all beneficial uses except
1 propagation of fish, shellfish, aquatic life,
o _fe including seabirds, waterfowl and furbearers
- that carries no fecal coliform standard) would permit
./ery short diffuser, perhaps only 100 feet in length.
The preliminary results of the Ott study also indicate
that the MOA should more accurately locate the limit of the
gyre that causes shoreward movement of effluent. They indi-
cate that a significantly shorter outfall extension than
indicated in the 301 (h) application may be possible.
The Recommended Plan for the ocean outfall and diffuser
is defined, for EIS purposes, as a 1,500-foot outfall exten-
sion with a diffuser about 1,000 feet in length, discharging
chlorinated effluent. It should be recognized that the on-
going studies may result in a different alternative becoming
the Recommended Plan.
Alternatives are: 1) the construction of a 1,500-foot
outfall extension with a 6,100-foot diffuser discharging un-
chlorinated effluent along with the deletion of water supply
for aquaculture, seafood processing, and water-contact recrea-
tion as designated uses of the waters of Cook Inlet; and
2) the construction of a 1,500-foot outfall extension with a
100-foot diffuser discharging unchlorinated effluent together
with the deletion of all designated uses of the waters of Cook
Inlet, except growth and propagation of fish, shellfish,
aquatic life, and wildlife including seabirds, waterfowl and
furbearers.
West Bypass Interceptor Sewer
A major interceptor sewer is proposed to connect existing
interceptor sewers at the Alaska Railroad crossing over Campbell
Creek to an existing downstream section of the West Bypass
interceptor sewer near the Minnesota Bypass - Raspberry Road
intersection. The proposed completion of the interceptor
between these points would bypass a deteriorated, undersized
corrugated metal pipe sewer paralleling Campbell Creek and
an occasionally overloaded pumping station at Campbell Creek.
(see Figure 3-3).
42
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Point
Woronzof ,'
WWTP — ''
I POTTER CREEK ,
| PROPOSED
3 ALTERNATIVE 1 !
LEGEND-
D Pump stations and force main
Existing major connecting sewers
— Direction of flow
Source: MOA,1982
r
FIGURE 3-3. PROPOSED WEST BYPASS
& SOUTHEAST INTERCEPTOR SEWERS
43
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A pumping station and force main are recommended (Alterna-
tive 3). A 25 MGD pumping station (complete with standby
electrical power) would be constructed immediately, followed
by an expansion to about 60 MGD capacity.
o The recommended location for the pumping station is
on the south bank of Campbell Creek, west of the Alaska
Railroad.
o A 36-inch force main would be constructed southwest
for about 270 feet, crossing Campbell Creek, and running
west approximately 1,400 feet to C Street. The force
main would turn north along C Street for 1,300 feet,
turning west again to follow Raspberry Road for 3,700
feet, joining the existing 78-inch interceptor near
the Minnesota Bypass.
The West Bypass Interceptor would serve a large portion
of Anchorage, including the areas generally east of Old Seward
Highway and south of Tudor Road, plus the area east of Goose
Lake between Glenn Highway and Tudor Road. The service area
includes all portions of the Hillside area that are to be
served by sanitary sewers.
Southeast Interceptor
The southeast interceptor is proposed to be extended
south to provide service to areas of the Hillside that are
designated for public sewerage in the Hillside plan. The
northerly terminus of the existing southeast interceptor
is at the Alaska Railroad crossing of Campbell Creek (also
the starting point for the West Bypass interceptor sewer).
The interceptor currently ends about 1,500 feet south of
Dimond Boulevard along the Alaska Railroad, and would be
extended south from this point to De Armoun Road. "Extension
of the southeast interceptor to Potter is also recommended
as the preferred plan for sewering the south Hillside areas
near Potter Creek and Rabbit Creek.
Approximately 1,700 feet of the Southeast Interceptor is
scheduled for construction from its terminus south of Dimond
Boulevard to De Armoun Road by the summer of 1984. If it is
decided to serve the Rabbit Creek/Potter Creek area -with the
Southeast Interceptor, certain portions of the existing pipe
will be inadequate to carry projected flows, and capacity
would be expanded as follows:
o A 600-foot section crossing Dimond Boulevard would be
paralleled by a 42-inch pipe.
44
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o Between 84th and 88th Avenues, approximately 12,000
feet of 36-inch pipe would be installed parallel to
the existing 36-inch pipe.
o A 15-inch pipe would parallel a 400-foot section of
interceptor north of 81st Avenue.
Southeast Interceptor and Force Main Extension to Rabbit
Creek-Potter Creek. The facilities plan evaluates several
alternatives for-providing sewerage service to the southerly
Hillside area near Little Rabbit and Potter Creeks. These
alternatives include various sewer alignments with the option
for a package treatment plant at either Rabbit Creek or Potter
Creek, or a force main with flow to Point Woronzof via the
Southeast Interceptor. This latter alternative has been
recommended in the facilities plan. It would include:
o Gravity collectors and force mains sized for satura-
tion population of the area designated to be sewered
in the Hillside plan.
o A 24"- to 30-inch gravity interceptor sewer with an
above-grade crossing of Little Rabbit Creek following
the bluff along Old Seward Highway from Potter Creek
to the pump station.
o Construction of a pumping station near Rabbit Creek
with a pumping head (lift) of about 20-0 feet. Two
possible locations are considered: a) between Old
and New Seward Highways, north of Potter Marsh; or
b) adjacent to Old -Seward Highway north of Rabbit Creek.
o A 14-inch force main along the New Seward Highway fron-
tage road from the pump station to the Southeast Inter-
ceptor.
o-Improvements to the existing interceptor sewer, which
serves a small area between Huffman and De Armoun Roads.
Interceptor Sizing
Sizing of interceptor sewers serving the southeast area
of Anchorage, including portions of the Hillside area, has been
an identified issue due to controversy over sewer capacity to
be provided to the Hillside area. The two proposed interceptor
sewers that serve these areas are the Southeast Interceptor and
the West Bypass Interceptor. This section describes the metho-
dology used to determine the sizing of these facilities as pro-
posed in the Recommended Plan.
45
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The assumptions used in the sizing are summarized as
follows:
o Population estimates: Planning Department estimates of
maximum and minimum saturation populations in the year
2025.
o Wastewater flows: 80 gallons per day per capita (gpcd).
o Peaking factors: Derived as a function of population
based on sanitary engineering literature (Fair and Geyer
1954, as reprinted in Committee of the Great Lakes and
Upper Mississippi River Board of State Sanitary Engineers
1978). Peaking factors are read from a chart based on
population and applied to average flows to determine peak
flows for pipe capacity. Factors vary inversely with
population.
o Infiltration/inflow: Data from Infiltration/Inflow
Analysis and Sewer Evaluation Survey (MOA 1979). This
study indicated that infiltration/inflow reduction was
only cost effective in reducing infiltration inflow
into the existing system to 4,000 gallons per inch di-
ameter per mile (gpdim) in 1979- It was assumed that a
similar level of infiltration/inflow would also be an
appropriate basis for design of new sewers.
o Commercial and industrial flow: Calculated separately
for Southeast service area; commercial and industrial
flows for the Northeast area are included in current
flow data used for projections.
Sizing of the West Bypass Interceptor is dependent on
flows from the Northeast as well as Southeast areas (Figure 3-3).
The Northeast area flow projections are discussed first, followed
by Southeast flow projections.
Northeast Service Area. Peak flow data from the 1979
Infiltration/Inflow Analysis and Sewer Evaluation Survey were
used to arrive at an average per capita peak flow of 300 gpcd
from a population of 53,700. Tne population is expected to
increase by 22,700-48,600 yielding a-n average peak flow increase
of 6.8-14.6 MGD. Table 3-4 shows this projected flow added to
the existing measured peak flow of 16 MGD. As mentioned above,
commercial and industrial flows are included with residential
peak flows.
Based on these calculations, the total projected peak flow
from the Northeast service area would be between 22.8 and
30.6 MGD. Available capacity in the existing 48-inch Northeast
Interceptor is 40.1 MGD, which should be adequate for saturation
conditions in 2025.
46
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Southeast Service Area. According to the Hillside Waste-
water Management Plan, the Hillside area will require collec-
tion systems to serve a projected population of between 70,400
and 86,800 persons in an area of approximately 5,9QO acres.
This includes the Rabbit Creek-Potter Creek area. Applying
the average flow of 80 gpcd yields a base flow of 5.6-6.9 MGD
(Table 3-1).
An infiltration/inflow allowance of 7.2 MGD was calcu-
lated by using a value of 4,000 gpdim and assuming 200 feet
of pipe per acre and 5,900 acres to be sewered.
The peaking factors were applied to the residential base
flow and the infiltration/inflow allowance. (U. S. EPA has
questioned the application of this peaking factor to the in-
filtration/inflow allowance. See Appendix A).
Flows for commercial and industrial lands identified in
the September 1981 Draft Comprehensive Development Plan repre-
sent peak flows and include infiltration/inflow allowances.
These flows, reflected in Table 3-1, total 10.9 MGD.
If the Potter Creek-Rabbit Creek area is not sewered to
the Southeast Interceptor, but rather is sewered to a new
treatment plant with a local discharge, then both the South^
east and West Bypass Interceptors could be designed for a
slightly lower flow. The residential base flow for the Rabbit
Creek-Potter Creek area was. estimated using a projected popu-
lation of 13,500 and per capita flows of 80 gpcd, plus assumed
infiltration of 1,200 gpd per acre for 2,000 acres. The flow
estimates, shown in Table 3-1, total 3.5 MGD from this portion
of the Hillside area, equivalent to about 250 gpcd, which is a
typical wastewater flow for low density developments.
Interceptor Sizing. The flow values at the bottom of
Figure 3-1 are used for sizing the Southeast Interceptor.
Separate calculations are necessary to estimate the sizing
for the West Bypass Interceptor. Table 3-2 presents, those
calculations. Lesser peaking factors computed from the com-
bined population of both service areas are used in this
instance. The maximum and minimum flows from the total tribu-
tary area, including the Rabbit Creek-Potter Creek area,
are estimated to average 91.2 cfs.
If the Rabbit-Creek-Potter Creek area were to be excluded
from service by these interceptors, flows would be as shown
in the bottom portion of Table 3-2.
The facilities plan presents sizing recommendations
based on gravity construction for the West Bypass Interceptor.
47
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Table 3-1. Peak Flow Projections Used for
Interceptor Sizing - Subareas
Maximum
Flow
(MGD)
Minimum
Flow
(MGD)
Northeast Service Area
Existing Peak Flow
Projected Peak Flow Increase
Total Projected Peak Flow
Rabbit Creek-Potter Creek at
Saturation Development
Residential Average Flow
Infiltration
Total Residential Average Flow
Southeast Service Area Including
Rabbit Creek-Potter Creek1
Residential Average Flow
Infiltration
Total Residential Average Flow
Peaking Factor
Residential Peak Flow
Commercial/Industrial Flow
Total
Equivalent Total
1.1
2.4
3.5
6.9
7.2
14.1
x2.0
28.2
10.9
39.1
(60.5 cfs)
16
6.8
22.8
1.1
2.4
3.5
10.9
37.8
;58.5 cfs)
1 Basis for sizing Southeast Interceptor.
SOURCE: .Municipality of Anchorage Wastewater Facilities Plan
for Anchorage, June 1982.
48
-------
Table 3-2. Peak Flow Projections Used for West
Bypass Interceptor Sizing - Composite Flows
Maximum Minimum
Flow Flow
(MGD) (MGD)
Northeast and Southeast Service
Areas Including Rabbit Creek-
Potter Creek Area
Northeast Service Area
Average Flow 15.3 11.4
Southeast Service Area
Average Flow 14.1 12.8
29.4 24.2
Peaking Factor xl. 76 xl.83
Residential Peak Flow 51.7 44.3
Southeast, Industrial/
Commercial 10.9 10.9
Total Peak Flow 62.6 55.2
Equivalent Total (96.9 cfs) (85.4 cfs)
The maximum and mini-mum flows average to 91.2 cfs.
Northeast and Southeast Service
Areas Excluding Rabbit Creek-
Potter Creek Area
Northeast Service Area
Average Flow 15.3. 12.4
Southeast Service Area
Average Flow 10.6 9.3
Total Average Flow 25.9 21.7
Peaking Factor xl.8 xl.9
Peak Flow 46.6 41.2
Southeast, Industrial/
Commercial 10.9 10.9
Total Peak Flow 57.5 52.1
Equivalent Total. (89.0 cfs) (80.7 cfs)
The maximum and minimum flows average to 84.9 cfs.
SOURCE: Municipality of Anchorage Wastewater Facilities Plan
for- Anchorage , June 1982.
49
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It should be noted that the Recommended Plan proposes
a pump station and force main,.which would involve several
smaller pipes under pressure that would discharge to the
ex-isting 78-inch interceptor sewer near Minnesota Drive.
Under the Recommended Plan, little if any large diameter
interceptor pipe would actually be constructed. The facili-
ties plan discussion of sizing is included here, however,
since gravity construction is an alternative.
Sewer pipe of the size required to handle large flows
at relatively flat grades is generally available in 6-inch-
diameter increments. The two candidate sizes for gravity
flow for the West Bypass Interceptor are 72 inches and
78 inches. Since a 72-inch interceptor at the maximum avail-
able slope of 0.00035 foot of drop per foot of distance pro-
vides capacity for 78 cfs, a 78-inch line with a 96 cfs capa-
city is recommended by the facilities plan. With the exclu-
sion of the Rabbit Creek-Potter Creek area, the West Bypass
Interceptor would receive an average peak flow of 84.9 cfs,
still above the 72-inch line capacity of 78 cfs.
Hillside Wastewater Management Plan
The Hillside Wastewater Management Plan (MOA 1982)
adopted by the Municipal Assembly on May 18, 1982, evaluated
the suitability of the Hillside area of Anchorage to accommo-
date on-site disposal systems, and delineated areas for public
sewers, unsewered areas for on-site systems and unsewered areas
generally unsuitable for on-site disposal systems. Figures 3-4
and 3-5 show the Hillside study area and the resulting desig-
nations. The areas suitable for on-site systems are classified.
as "generally suitable for individual on-site treatment systems'
or "generally unsuitable. . .". Some of the area is also indi-
cated as "marginal", and one area is classified as an "area
recommended for use of privately-owned cluster system sewers
(1 dwelling unit/acre)." A recommended maximum perimeter of
public sewerage is delineated that excludes most of the Hill-
side in the northern half of the plan's study area and includes
large areas in the southern half near Little Rabbit Creek and
Potter Creek.
The plan text indicates that the area is subdivided into
"1) areas suitable for on-site systems; 2) areas generally un-
suitable for on-site systems; and 3) areas marginally suitable
50
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•LEGEND-
12 Areas recommended for public sewerage
13 Areas recommended for cluster-
system sewers
~~ Hillside study area
Note : See Figure 3-5 for on-site sewerage suitability
FIGURE 3-4. ADOPTED HILLSIDE AREA
SEWERAGE DESIGNATIONS
51
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-LEGEND-
O Generally unsuitable (or on-site
treatment systems
til Known problem areas containing
both marginal and unsuitable
lands
— — Hillside study area
Source: MOA, 1982
FIGURE 3-5. HILLSIDE AREA
SEPTIC TANK SUITABILITY
52
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for on-site systems using alternative systems." This last
area is denoted on the map as "known problem areas containing
both marginal and unsuitable lands." Unsuitable designations are
delineated for portions of land within the shading for this
category. It appears to be the intent of the plan to allow
alternative systems within the marginal areas, including
those portions of the marginal areas shaded as unsuitable
for on-site systems, subject to "a more rigorous design and
review process." Likewise, for areas classified as unsuitable
for on-site systems, the plan states:
"The scale of the mapping did not permit site-by-site
investigations, so it must be emphasized that these areas
are considered generally unsuitable. Any given site could
have good conditions for on-site treatment, but if it lies
within a generally unsuitable area, it will be subject to
the same rigorous design and review process which will be
used to evaluate individual lots in the marginally suitable
areas. Even in the non-suitable areas, certain on-site
systems may be used, based on the attributes of the
particular site as well as certain developed lands.
"It should be reemphasized that these area designations
do not necessarily preclude the use of on-site system opera-
tion, but because of adverse environmental problems, requires
a more rigorous design1 and review process. The innovative
systems described earlier in this report may allow development
in these areas."
The plan sets forth planning and design criteria, construc-
tion guidelines and operation and maintenance requirements
for on-site systems.
Planning and design criteria encompass training for home-
owners, engineers, contractors, septic tank pumpers and site
evaluators, including an examination; review of drainfield
locations by the Municipality Department of Health and Environ-
mental Protection (DHEP); incorporation of a drainage plan with
new plats; surface water disposal plans for on-site areas of
the Hillside; testing of innovative on-site systems; and provi-
sion of four feet of insulating soil cover over all new drain-
fields.
Construction guidelines provide for training of contractors,
certification of the job site installer under the training
program, and insulation of septic tanks.
Operation and maintenance requirements include mandatory
pumping of septic tanks every two to three years, with MOA
recordkeeping and enforcement, and further training and MOA
supervision of pumpers.
53
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Additional restrictions are applied to marginal a.nd
unsuitable areas, including soil tests for each lot in a
subdivision; requiring innovative systems unless conventional
systems are shown to be acceptable; and more detailed system
reviews by DEEP.
Collection Sewer Improvement Projects
The existing collector system is in need of expansion,
replacement and renovation in certain areas. Additional
capacity is required in some instances, as well as replacement
of several miles of corrugated pipe. About 70 sewer construction,
rehabilitation and replacement projects (Figure 3-6) are recom-
mended in the facilities plan. The more significant of these
proposed projects are generally described in the following
section. For a complete listing, the reader is referred to
pages X-4 through X-12 and Figure IX-2 of the facilities plan.
Northeast Service Area.
° No replacement or development is recommended in this
area..
Knik Service Area.
o Two interceptors along the Alaska Railroad near Nulbay
Park are of corrugated metal pipe and are scheduled for
replacement.
o Trunks following Chester Creek exceed capacity during
peak flows. Enlargement of trunks is necessary.
o The trunk following Fish Creek overflows, and should
be replaced.
° An additional trunk located near Fish Creek will be
relocated to the Tudor Road right-of-way between the
Alaska Railroad and Wisconsin Street. An adjacent
trunk would also be reconstructed.
o Trunk B-2 needs improvement. Portions have already
been replaced.
P University and hospital area trunks require additional
capacity.
° The Chester Creek pumping station requires a fourth
pump and a 36-inch force main to correct inadequate
capacity.
54
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--LEGEND-
• PUMP STATIONS AND FORCE MAIN
PROPOSED SEWERS. LETTER DESIGNATIONS REFER TO
LISTINGS IN TABLES 4-4 THROUGH 4-7. NUMBER
DESIGNATION REFER TO PIPE DIAMETER IN INCHES.
FIGURE 3-6. PROPOSED SEWER AND INTERCEPTOR
SEWER CONSTRUCTION, REPAIR AND
REHABILITATION PROJECTS
55
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Southeast Service Area.
o Existing reserve capacity is sufficient, but potential
capacity increases in the northern portion of the service
area may require development of trunks and interceptors.
These facilities are not included in the facilities plan
at this time.
Turnagain Service Area.
o Extensive construction is required on the Campbell
Creek trunk. Internal inspection is recommended to
determine required rehabilitation. Installation of the
West Interceptor will allow inspection of the existing
line and enable accurate construction recommendations
for the Campbell Creek trunk.
o Trunks along 88th-Avenue and crossing the Dimond-Mears
High School grounds possibly need expansion. Construc-
tion of the West Bypass interceptor would postpone the
enlargement.
o Development of the Klatt Bog area would overload the
Turnagain interceptor; rigid inspection is required
to control infiltration and inflow in this wetland.
Range of Alternatives
The range of alternatives considered in. development
of the facilities plan is partially documented in the two
plan documents. The facilities planning process in Anchorage
has evolved over many years with intermediate reports such
as the incomplete Corps of Engineers facilities plan, the
URS-Bomhoff study and other work as discussed in Chapter 1
of this EIS. A relatively broad range of investigations
has been completed over the past several years, with many
alternatives evaluated and some rejected. While the current
facilities plan is intended as the culmination of these,
it does not identify all prior evaluation efforts, nor does
it document all of the screening that went into the development
of the current Recommended Plan.
The range of alternatives evaluated in the Wastewater
Facilities Plan for Anchorage, Alaska is outlined as follows:
o No action;
o Land application of treated wastewater;
o Wastewater renovation and reuse;.
o Point Woronzof alternatives:
56
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- Primary alternatives - expansion of primary clarifiers
with and without chlorination;
- Secondary alternatives - high rate trickling filters
or complete mix activated sludge process;
- Sludge treatment and disposal - incineration,
anaerobic digestion, coincineration, with suboptions
for incinerator ash disposal;
o Outfall and diffuser alternatives - outfall extension
of 1,500 feet with various diffuser lengths depending
on whether chlorination is employed and depending on
whether designated uses of Cook Inlet waters are
changed;
o West Interceptor alternatives - gravity with trench
or tunnel construction, or pump station-force main;
three alternative alignments are referenced, with
only the preferred alignment described;
o Southeast Interceptor - no alternatives, except as
influenced by Rabbit Creek-Potter Creek alternatives;
o Rabbit Creek-Potter Creek alternatives - various
collection sewer alignments combined with a small
treatment plant with alternative processes at one
of two alternative locations, or pump station-force
main to Southeast Interceptor.
The Hillside Wast.ewater Management PJan does not evaluate
alternative public sewer systems or alternative public sewer/
on-site system area designations. The plan does allow alterna-
tive types of on-site sewerage systems, depending on individual
needs on each parcel.
Other sewerage alternatives considered for the Anchorage
Bowl -in prior reports include the following:
o Alternative sewer alignments, including sewering of
major portions of the Hillside area (URS'-Bomhof f 1979) ;
o Flow and waste reduction, covered in Infiltration-Inflow
(MOA 1979) and Sewer System Evaluation Survey. Certain
identified cost-effective rehabilitation work is complete,
as addressed in the facilities plan;
o Point Woronzof treatment alternatives, including
aerated lagoons and facultative lagoons (primary),
and five additional variations of the activated sludge
process (secondary);
57
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o Advanced primary treatment alternatives considered in
the facilities planning process, but not documented in
the June 1982 draft facilities plan;
o Export of digested sludge to the Matanuska Valley,
considered in the facilities planning process but not
documented in the June 1982 draft facilities plan.
The foregoing list is not intended to be exhaustive, but
rather to be illustrative of the wider range of alternatives
considered by the MOA during the planning process.
The EIS description of alternatives and analysis of
viable alternatives is limited to the alternatives described
in the June 1982 facilities plan and in the Hillside Wastewater
Management Plan.
Screening of Alternatives
The facilities plan documents do not describe the screening
process used to identify the viable alternatives. It would
be speculation on the part of the EIS to attempt to describe
how the MOA and its facilities planners selected those alterna-
tives described in Chapter VII of the' Wastewater Facilities
Plan for Anchorage,. Alaska. That document does indicate
how the Recommended Plan was selected from among the viable
alternatives, and those reasons are given in the following
section along with the discussion of each alternative.
Description of Alternatives
"No-Action" Alternative
The no-action alternative assumes no rehabilitation,
improvement, or expansion of the existing collection system,
and no expansion of Point Woronzof WWTP.
No action was rejected because the MOA would be in viola-
tion of federal and state laws. Further, the state could
impose a moratorium on new sewerage connections, adversely
affecting growth of the Anchorage area. It would increase
pollution of local streams and be subject to local objec-
tions. No action would be inconsistent with MOA desires.
Land Application Treatment
Because land application satisfies the goals of "zero
discharge" and "resource recovery" as stated in the 1972
Clean Water Act and its 1977 amendments, EPA requires that
58
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land application be evaluated. The Act also allows preferential
federal funding covering up to 85 percent of the installation
cost of a land application system, compared to 75 percent
for - conventional facilities.
Land application wastewater treatment uses natural systems
(i.e., vegetation and soil) to control organic pollutants.
The nutrients contained in wastewater increase the fertility
and productivity of terrestrial systems, making this treatment
attractive to silvicultural and agricultural interests. The
level of treatment may be superior in some cases to conventional
treatment methods. Three methods of application are possible:
o Slow rate process - distribution of wastewater over
the receiving land by sprinklers or ridge and furrow
flooding. Rates range from 0.50-4 inches per week,
depending on soil characteristics.
o Rapid infiltration - distribution over sand or loam
soils. Rates range from 4-120 inches per week.
o Overland flow - wastewater is applied to the upper
margins of a relatively impermeable and gently sloping
watershed. Rates range from 6-16 inches per week.
Some treatment is necessary before land application.
For slow rate and rapid infiltration, primary treatment is
adequate. For overland flow, screening and grit removal
may be sufficient.
Land application alternatives were considered during
development of the 1976 facilities plan. The potential of
rapid infiltration at the Point Campbell Military Reservation
appeared cost effective at that time, due to the proximity
of the lands to Point Woronzof, the presence of sand and
gravels, and the apparent groundwater flow direction away
from areas of use and' towards Cook Inlet. The 1982 facilities
plan cites this alternative as the land application alternative
evaluated in the current -facilities plan.
The Point Campbell land application alternative was
rejected for the following reasons:
o The Point Campbell military reservation is being trans-
ferred to the MOA for park use.
o A pilot program to establish feasibility and design
criteria has never been funded.
o Environmental concerns, including loss of a potential
parkland resource, loss of existing public recreational
use of the area, loss of existing moose habitat, visual
impacts, the risk of groundwater contamination and
the potential for strong public objections are also
cited as reasons for rejection.
59
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Wastewater Renovation and Reuse
Reduction of effluent discharge may be accomplished
by reusing the treated wastewater for potable or nonpotable
consumption. Various treatment facilities elsewhere in the
United States have reclaimed wastewater for 1) crop irrigation;
2) cooling and boiler feed;- 3) golf course and park irrigation; and
4) nonpotable domestic use, among others. Secondary treatment
is generally the minimum required before wastewater can be
reused for nonpotable purposes.
Currently, "little need for this water has been identified
in the Anchorage area, but the facilities plan recommends
future review of this alternative. The economic benefits
of reuse might outweigh the costs of additional treatment,
depending on a variety of factors. The facilities plan concludes
that this alternative cannot be seriously analyzed until
a market for the wastewater is identified.
Point Woronzof Treatment Alternatives
The facilities plan considers two primary treatment
and two secondary treatment alternatives. Alternative PB,
one of the two primary treatment options, is the recommended
process and is described in an earlier section of this chapter.
The remaining primary alternative and the two secondary alterna-
tives are described in the following section.
Primary Treatment. In the event that MOA is granted
a waiver under Section 301(h) of the Clean Water Act, the
Point Woronzof plant could continue discharging primary treated
wastes to Cook Inlet. Expansion of the current primary clarifier
system to provide increased capacity is the basic concept
for both alternatives PA and PB. The Recommended Plan, alterna-
tive PB, retains effluent chlorination in the process.
Alternative PA would discontinue chlorination consistent
with the desires of ADEC.
Alternative PA would be identical to the Recommended
Plan, presented earlier in this chapter, with the exception that
no chlorination would be employed in this alternative,
and that the diffuser length may be different. Diffuser
length would change as a function of fecal coliform limits
at the perimeter of the discharge mixing zone. Suggested
changes in the designated uses of the waters of upper Cook
Inlet would apply different water quality standards, thus
changing this coliform limit.
A diagram of Alternative PA is shown in Figure 3-7.
60
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A1LT ERIN! A TO VE PA
PRIMARY EXPANSION
SCREENINGS
TO GRINDER ^
8 INCINERATION * —
GRIT TO LANDFILL «—
PRIMARY SLUDGE ^
TO PROCESSING
a DISPOSAL
UNTREATED WASTEWATER
1
SCREENING
i
p
GRIT REMOVAL
j
r
PRIMARY CLARIFIERS
i
r
OCEAN OUTFALL
AND DIFFUSER
I
EFFLUENT
AIL TERN AT II VIE SA
TRICKLING FILTER SECONDARY EXPANSION
AILTERMATO VE
ACTIVATED SLUDGE SECONDARY EXPANSION
UNTREATED WASTEWATER
SCREENINGS
TO GRINDER
a INCINERATOIN
GBITTO LANDFILL-
PRIMARY SLUDGE
TO PROCESSING
a DISPOSAL
1
SCREENING
GRIT REMOVAL
PRIMARY CLARIFIERS
INTERMEDIATE
LIFT STATION
HIGH RATE
TRICKLING FILTERS
FILTER HUMUS
TO PROCESSING
a DISPOSAL
RNAL CLARIFIERS
CHLORINATION
EFFLUENT
UNTREATED WASTEWATER
SCREENINGS
TO GRINDER
a INCINERATION
GRIT TO LANDFILL-
PRIMARY SLUDGE
TO PROCESSING
a DISPOSAL
RETURN ACTIVATED
SLUDGE
WASTE ACTIVATED
SLUDGE TO
PROCESSING
SCREENING
GRIT REMOVAL
PRIMARY CLARIFIERS
AERATION BASINS
FINAL CLARIFIERS
CHLORINATION
EFFLUENT
SOURCE^ MOA,1982
FIGURE 3-7. ALTERNATIVE TREATMENT
PROCESS DIAGRAMS-LIQUID PROCESS-
POINT WORONZOF WWTP
61
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Secondary Treatment. The MOA has sought to obtain a
modification of NPDES requirements under Section 301(h) of
the Clean Water Act to permit continued ocean discharge of
less than secondary effluent from the existing Point Woronzof
WWTP. Issuance of a 5-year permit modification under Section
301 (h) is expected in the fall of 1982. Continued primary
discharge beyond the expiration dates of any such modification
is not assured in the Clean Water Act, and under the construc-
tion grant regulations, EPA must restrict its funding to
projects with a 20-year planning horizon. Since EPA has
no authority to consider an alternative involving ocean discharge
of .less than secondary-treated effluent 20 years in the future,
the selected alternative must incorporate secondary treatment.
Both secondary treatment alternatives could be added to the
primary treatment alternatives, thus meeting this requirement.
Secondary treatment (biological treatment) utilizes
microorganisms to extract about 85 percent of the BOD and
TSS. The two secondary treatment options evaluated in the
facilities plan are described below. Both are practicable,
but are not-proposed for implementation due to pending approval
of the 301 (h) wa-iver.
Alternative SA - High-Rate Trickling Filters (Figure 3-2).
After primary clarification, wastewater is distributed evenly
over fixed redwood or plastic media. These trickling filters
utilize microorganisms growing on the media surface to assimilate
organic pollutants. A portion of the filtered effluent is
recycled to increase contact time with the microorganisms
on the substrate. Clusters of microorganisms sloughed off
of the media are settled out in final clarifiers.
Because of the cold climate, an enclosed heated structure
would be needed to provide for consistent micro-organism
growth and adquate treatment.
Alternative SB - Complete Mix Activated Sludge Process.
After primary treatment, wastewater enters an aeration
basin which contains microorganisms in a "mixed liquor."
The liquor is aerated by mechanical mixing or bubbling.
After biological activity removes organic solids, the micro-
organisms are removed in final clarifiers where they settle
as sludge. Portions of this activated sludge are pumped
back into the aeration basins to seed incoming sewage.
The liquid from the clari-fiers is discharged through the
outfall.
Alternatives for Sludge Solids Treatment and Disposal
Figure 3-8 presents the sludge treatment and disposal
alternatives. Sludge solids removed from either primary or
secondary treatment must be processed to ensure environmentally
safe disposal.
62
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ALTERNATIVE
PA-1 6 PB-1
ALTERNATIVE
PA-2
ALTERNATIVES
SA-1 6 SA-2
ALTERNATIVES
SB-1 & SB-2
SLUDGE PROCESSING
ALTERNATIVE 1
SLUDGE PROCESSING
ALTERNATIVE 2
PRIMARY
SLUDGE
1
p
GRAVITY
THICKENER
WASTE
ACTIVATED
SLUDGE
1
t
DISSOLVED
AIR
FLOTATION
SLUDGE PROCESSING
ALTERNATIVE 1
SLUDGE PROCESSING
ALTERNATIVE 2
FIGURE 3-8
DIAGRAMS
WWTP
ALTERNATIVE TREATMENT PROCESS
SOLIDS PROCESS-POINT WORONZOF
-------
Alternative 1; Incineration; Ash to Landfill, Outfall,
Lagoon's or Gravel Pits. Sludge would continue to be incinerated,
with three possible disposal options identified. Land
filling (the current method) could be continued; ash could
be mixed with effluent and discharged through the outfall;
or ash could be discharged as a slurry mixed with a small
quantity of plant effluent and discharged to a lagoon or
gravel pit near the Point Woronzof WWTP- The outfall discharge
is identified as preferred, although not firmly recommended,
in the facilities plan. The incineration alternative with
all three disposal options is considered as part of the
Recommended Plan, and the impacts are evaluated in Chapter 9. '
Alternative 2: Dewatering, Digestion and Landfilling.
In all- cases except Alternative SB-2 either primary or secondary
sludge would be dewatered by gravity thickeners, and then
pumped to an anaerobic digester for stabilization. In
Alternative SB-2, sludge would be dewatered by dissolved
air flotation units (solids are removed by air bubbles)
and then stabilized in the aerobic digester. The stabilized
dewatered sludge would be hauled to a sanitary landfill.
Co-Incineration. Primary or secondary sludge can be
incinerated in combination with refuse. Combustion is easily
accomplished because of the fuel value of the refuse. The
heat output can generate electricity, produce steam, and
be applied to drive mechanical dewatering devices or other
treatment plant equipment and provide heat. The ash would
be landfilled. Total community solid waste volume could
be reduced if co-incineration were used.
Alternatives for Ocean Outfall and Diffuser
Alternatives for the ocean outfall and diffuser are described
in depth earlier in this chapter in the Recommended Plan
discussions. The two alternatives for the Recommended Plan are
repeated below.
Alternative 1. The construction of a 1,500-foot outfall
extension with a 6,100-foot diffuser discharging unchlorinated
effluent along with the deletion of water supply for aquaculture,
seafood processing an.d water contact recreation as designated uses
of the waters of Cook Inlet.
Alternative 2. The construction of a 1,500-foot outfall
extension with a 100-foot diffuser discharging unchlorinated
effluent together with the deletion of all designated uses of
the waters of Cook Inlet, except growth and propagation of fish,
shellfish, aquatic life, and wildlife, including seabirds, water-
fowl and furbearers.
64
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West Interceptor Extension Alternatives
The West Interceptor extension will serve the eastern
portion of the Anchorage Bowl, north of Fort Richardson and
south to the east fringe of Potter Marsh. Extension of the
Interceptor will continue east along Raspberry Road to "C"
Street. From this point, three routes had been considered,
two of which were eliminated during preparation of the facilities
plan and are not documented in the plan. The alternatives
considered in this EIS are thus restricted to construction
options along'the recommended routing. The routing is described
in the foregoing section on the Recommended Plan.
o Alternative 1 - A gravity interceptor, with open
ditch construction;
o Alternative 2 - A gravity interceptor, constructed
by both tunneling and open ditch;
o Alternative 3 - Pump station and force main, described
in Recommended Plan.
The first two alternatives are not recommended in the
facilities plan due to extensive excavation (50-foot-deep
trenching), difficult dewatering requirements, a nearby shallow
well that provides a high yield of potable water, the potential
for conflict with the Bank of Alaska computer facility from
vibration and building settlement, and high construction
cost. These factors are addressed in further detail in
Chapter 11.
Rabbit Creek/Potter Creek Collection and Treatment Alternatives
The facilities plan presents a series of sewage collection,
treatment and disposal alternatives for the southerly portion
of the Hillside area designated for public sewers in the
Hillside plan. Lettered alternatives A through E encompass
four treatment options that would be independent of the Point
Woronzof plant and one pump station-force main option (Alterna-
tive D, the Recommended Plan) that would connect to the Southeast
Interceptor, flowing to Point Woronzof. In addition, numbered
Alternatives 1-4 describe alternative collection system patterns
in the area.
The Recommended Plan was selected from these alternatives
based on cost effectiveness, least land requirements and
environmental questions regarding a separate treatment plant
and discharge.
Alternative A. An extended aeration package treatment
plant would be located at Rabbit Creek, providing secondary-
treatment of wagtewater. Effluent would be discharged into
Rabbit Creek and the sludge hauled to Point Woronzof WWTP
and processed (Figure 3-10).
65
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Alternative B. An oxidation ditch wastewater treatment
plant, providing secondary"treatment, with effluent discharged
to Rabbit Creek.
Alternative C. An aerated lagoon wastewater treatment
plant', providing secondary treatment, with effluent discharged
to Rabbit Creek.
Alternative D. Pumping station and force main discharging
to the Southeast Interceptor as described in Recommended
Plan.
Alternative E. An extended aeration package treatment
plant identical to alternative A, but located at and discharging
to Potter Creek.
Once the pumping or treatment facility is chosen,
a system of interceptors, trunks and laterals must be selected.
The four alternatives are shown in Figure 3-9 and described
below:
Alternative 1: Gravity Flow Toward Rabbit Creek (Figure 3-9),
A 24-inch gravity interceptor flowing north, 13,000 feet long,
would roughly follow Old Seward Highway. Crossing Little
Rabbit Creek, it would then proceed northwest, cross Old
Seward Highway and flow into either the pumping station or
treatment plant at Rabbit Creek. Further discussion is contained
in the section on Recommended Plan.
Alternative 2: Pumping Station and Force Main Toward
Rabbit Creek. This alternative would consist of a pumping station
north of Potter Creek, and a 14-inch force main toward Rabbit
Creek along Old Seward Highway. A 12- to 18-inch interceptor
would parallel this main and transport wastewater by gravity flow
to the pumping station.
Alternative 3: Gravity Flow Toward Rabbit Creek. A
12- to 18-inch gravity interceptor would flow south to the Potter
Creek weigh station. A 30-inch interceptor would then convey flow
north toward Rabbit Creek on the west side of the Alaska Railroad
embankment.
Alternative 4: Gravity Flow to Potter Creek .
This alternative was designed specifically for treatment
Alternative E. A 12- to 18-inch interceptor would be laid
along Old Seward Highway, carrying the flow south to the
Potter Creek Package Treatment Plant.
Individual Treatment Systems
On-site wastewater dispoal units, studied by the MOA
Physical Planning Department and described in the Hillside
Wastewater Management Plan, will be discussed in Chapter 4.
66
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-PROPOSED SOUTHEAST
INTERCEPTOR
-PUMPIN8 STATION OR
WASTEWATER TREATMENT
PLANT
FORCE WAIN
AU-TERIN1ATOVE:
GRAVITY FLOW
TO RABBIT CREEK
PROPOSED SOUTHEAST
INTERCEPTOR
MOUTH
ONC *«L> _«!.(
PUMPINS STATION OR
WASTEWATER TREATMENT
PLANT
LEGEND
-^— SERVICE AREA
——• INTERCEPTOR
FORCE MAIN
ALTERNATIVE 2
GRAVITY FLOW TO POTTER, PUMP STATION
AND FORCE MAIN. TO RABBIT CREEK
-PROPOSED. SOUTHEAST
INTERCEPTOR
-PUMPIN8 STATION OR
WASTEWATER TREATMENT
PLANT
'•••• FORCE MAIN
ALTER INI AT QVE . 3
GRAVITY FLOW
TO RABBIT CREEK
AL.TERNATO VE
GRAVITY FLOW
TO POTTER CREEK
FIGURE 3-9. RABBIT CREEK-POTTER
CREEK ALTERNATIVES
67
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XC.TERIMATD VIES A & E
PACKAGE TREATMENT PLANT
AlLTIKKMAYOVBf.
OXIDATION DITCH
A( .-: LR iA V1., VI C
AERATED LAGOON
UNTREATED WASTEWATER
1
COMMINUTOR
1
r
COMPLETE MIX TANK
'
r
FINAL SETTLING
i
p
CHLORINATION B
DECHLORINATION
i
EFFLUENT TO
RABBIT CREEK
OR
POTTER CREEK
4BPTI IBM
SLUDGE
1 ^ SLUDGE TO
w HOLDING TANK
UNTREATED WASTEWATER
SCREENINGS
TO LANDFILL
GRIT TO LANDFILL
RETURN SLUDGED
SLUDGE TO
PROCESSING
a DISPOSAL
1
SCREENING
GRIT REMOVAL
OXIDATION DITCH
FINAL SETTLING
CHLORINATION a
DECHLORINATION
EFFLUENT TO
RABBIT CREEK
UNTREATED WASTEWATER
AERATED LAGOON
i
r
FINAL SETTLING
1
r
POLISHING POND
^
r
CHLORINATION ft
DECHLORINATION
EFFLUENT TO
RABBIT CREEK
«RFTI IRN c;i i innp
WASTE
1 SLUDGE TO
HOLDING TANK
SOURCE: MOA, 1982
FIGURE 3-10. RABBIT CREEK-POTTER CREEK ALTERNATIVE
TREATMENT PROCESS DIAGRAMS
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Cost Summary
Federal regulations require that a comprehensive cost
analysis of all wastewater treatment plans be undertaken.
The most cost-effective plan is defined as the lowest present-
worth alternative that meets water quality standards in the
absence of overriding non-monetary costs. Present-worth
evaluation is the method most commonly applied to evaluate
the cost of alternative facilities. Present-worth evaluations
include:
o Probable construction costs: engineering, legal and
administrative fees, contingencies and interest.
o Operation and maintenance: labor, materials, supplies,
spare parts, chemicals and power, usually on an annual
basis.
o Remaining value of improvements: Value of facilities
at the end of the planning period.
Table 3-3 shows the criteria used to determine the costs
of the above present-worth components. Tables 3-4 through 3-10
show present-worth alternatives described in this chapter.
Present-worth costs for the outfall extension and diffuser
are not included in the tables. A 1,500-foot outfall extension
is estimated to cost $5,660,000, and a 1,000-foot diffuser
is estimated to cost $3,770,000 (MOA 1982).
User Costs
Costs to individual MOA sewer customers would increase
as a result of expansion of the wastewater facilities
(Table 3-11). Those customers served by sewers would sustain
a rate increase estimated at from 22 percent to 34 percent
in 1985, and 30 percent to 40 percent in 1999 as a result
of the Recommended Plan, depending on funding sources for
construction.
The low range in these estimates assumes that U. S. EPA
would provide 75 percent construction funding.for the Point
Woronzof WWTP improvements, and the State would provide
an additional 12.5 percent; that the State would fund 50 percent
of all other expansion; and that local funds would comprise
the balance. The. high range assumes no U. S. EPA funding,
b'ut rather that all construction cost funding would be
50 percent State and 50 percent local. In both cases, all
repair and rehabilitation work, as well as maintenance and
operating costs, would be paid with 100 percent local funds.
69
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The above estimates also assume that the rates for sewer
service will be raised to reflect the actual local operating
costs by 1985.
Comparable cost data are not available for the Hillside -
area. '
Cost information has been excerpted from a preliminary
draft of the Executive Summary of the facilities plan.
U. S. EPA has expressed concerns that cost assumptions
be consistent with U. S. EPA requirements (see Appendix A).
It should be noted that U. S. EPA may participate
in funding certain interceptor sewers, depending on timing
of the projects. Section 10 (b) of PL 97-117 limits the
eligible reserve capacity in an interceptor to 40 years
if the interceptor was funded under a Step 3 grant awarded
prior to December 29, 1981. For all interceptors subsequently
funded under Step 3 grants awarded prior to October 1., 1984,
the eligible reserve capacity would be limited to 20 years.
After October 1, 1984, only that capacity for existing
needs would be grant eligible.
The May 12, 1982 interim final construction grant
regulations (40CFR 35.2123) reiterate the funding limitations
contained under Section 10 (b) . They also allow Step 3
grant participation in reserve capacity up to 40 years
for the remaining segments of an interceptor providing
that an initial segment of the interceptor had received
Step 3 funds prior to December 29, 1981. Where the first
segment was awarded after December 29, 1981, but before
October 1, 1984, the entire interceptor may be eligible
up to the 20-year capacity.
70
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Table 3-3. Present-Worth Component Criteria
• Planning Period 20 years/
(1985 - 2005)
• Service Life -
Structures 50 years
Pipelines 50 years
Equipment 20 years
Basins 30 years
Package Treatment Plants 10 years
Package Pump Stations 20 years
• Land Costs $75/000/acre
• Interest Rate 7.625%
• inflation. Rate 3% per year
(for land costs only)
• All Costs Adjusted to Dec. 1981 Price Levels
• Allowances for Engineering,
Legal & Administrative Costs 15%
• Contingencies 15%
• Interest during Construction O)(P/2)(C)
I = Interest Rate
P = Construction Period in Years
C = Total Capital Costs
Source: Wastewater Facilities Plan for Anchorage, Alaska
June 1982
71
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K)
Table 3-4. Present Worth Summary
Point Woronzof Primary Treatment
Expansion Alternatives
Probable Construction Cost
Engineering, Legal 6
Administrative Costs
Cont ingencies
Interest During Construction
TOTAL PROJECT COST
Present Worth Remaining Value (-)
Average Annual O&M Cost
Present Worth Average Annual
O&M Cost
TOTAL PRESENT WORTH
Average Annual Equivalent Cost
At ternati ve
PA-1
($ x 103)
20,720
3,108
3,57<*
l,0i*5
$28,** 47
-2,252
(2,1*22)
24, i*58
$50,653
($ 5,016)
Al ternati ve
PB-1
($ x 103)
20,605
3,091
3,55<*
1,039
$28,289
-2,106
(2,837)
28,659
$5^,8^2
($ 5,1*31)
Al ternati v.e
PA-2
($ x 103)
23,685
3,553
<*,086
1,194
$32,518
-2,870
(2,597)
26,226
$55,873
($ -5,533)
Source: Anchorage Wastewater Facilities Plan
June 1982
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Ul
Table .3-5. Present Worth Summary
Point Noronzof Secondary Treatment
Expansion Alternatives
Probable Construction Cost
Engineering, Legal £
Administrative Costs
Cont ingenci es
Interest During Construction
TOTAL PROJECT COST
Present Worth Remaining Value (-)
Average Annual O&M Cost
Present Worth Average Annual
O&M Cost
TOTAL PRESENT WORTH
Average Annual Equivalent Cost
Al ternative
SA-1
($ x 103)
47,927
7,189
8,267
4,833
$ 68,216
-1,257
(3,9V*)
39,828
$106,787
($ 10,575)
Al ternative
SA-2
($ x 103)
51,817
7,772
8,938
5,225
$ 73,752
-1,388
(4,548)
45,927
$118,291
($ 11,714)
Al ternat i ve
SB-1
($ x 103)
45,233
6,785
7,803
4,561
$ 64; 382
-1,006
(4/648)
46,937
$110,313
($ 10,924)
Source: Anchorage Wastewater Facilities.Plan, June 1982
-------
Table 3-6. Present Worth Summary
Incinerator Ash Disposal
Alternatives
Alternat ive 1
Ash to Landf iI I
Alternative 2
Ash to OutfalI
Alternat i ve 3
Ash to Lagoon
Probable Construction Cost
Engineering, Legal 6 Administrative
Costs
Cont ingenc i es
Interest During Construction
TOTAL PROJECT COST
Present Worth Remaining Value
Average Annual 0£M Cost
Present Worth Average Annual OEM Cost
TOTAL PRESENT WORTH
$287,800
1*3,200
1*9,700
7,300
$388,000
(80,300)
810,900
$1,198,900
$13^,100
20,100
23,100
3,400
$180,700
—
(39,000)
394,200
$574,900
$437,400
65,600
75,500
11,000
$589,500
(39,000)
394,200
$983,700
Source: Anchorage Wastewater Facilities Plan
June 1982
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Ul
Table 3-7. Present Worth Summary
West Bypass Interceptor Extension
Alternatives
Probable Construction Cost
Engineering, Legal 6
Administrative Costs
Contingencies
Interest During Construction
TOTAL PROJECT COST
Present Worth Remaining Value (-)
Average Annual OSM Cost
Present Worth Average Annual
OEM Cost
TOTAL PRESENT WORTH
Average Annual Equivalent Cost
78- inch Interceptor
Open Trench
($ x 103)
11,15^
1,673
1,924*
562
$15,313
-1,805
(10)
101
$13,609
($ 1,348)
78- inch Interceptor
Open Trench & Tunnel
($ x 103)
10,773
1,616
1,858
5*43
$14,790
-1,743
(10)
101
$13, 1^8
($ 1,302)
Pump Station
and Force Main
($ x 103)
6,234
935
1,075
314
$8,'558
-905
(128)
1,300
$8,953
($ 887)
Source: Anchorage Wastewater Facilities Plan
June 1982
-------
CTl
Table 3-8. Present Worth Summary
Rabbit Creek/Potter Creek
Collection Alternatives
A
Construction Cost
Engineering, Legal &
Administrative Costs
Cont ingenc i es
Interest, During Construction (6 mos.
Right-of-Way Costs
TOTAL PROJECT COST
Present Worth Remaining Value (-)
Average Annual OEM Cost
Present Worth OSM Cost
TOTAL PRESENT WORTH
Average Annual Equivalent Cost
Iternative 1
($ x 103)
1,838
276
317
) 93
1,100
$3,621*
-754
-
_
$2,870
($ 284)
Alternative 2
($ x 103)
2,327
349
401
117
-
$3,194
-377
(35)
353
$3,170
($ 314)
Alternative 3
($ x 103
2,599
390
448
131
-
$3,568
-421
-
-
$3,147
($ 312)
Al ternat i ve 4
($ x 103)
779
117
134
39
• —
$1,069
-126
—
—
$ 943
($ 93)
Source: Anchorage Wastewater Facilities Plan
June 1982
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Table 3-9. Present Worth Summary
Rabbit Creek Treatment
Alternatives
Alternative A
Package Unit
($ x 103)
Probable Construction Cost
Engineering, Legal £
Administrative Costs
Cont i ngenc i es
SUBTOTAL
Interest During Construction
TOTAL PROJECT COST
Present Worth of Expansion at 1995
Present Worth Remaining Value (-)
Average Annual O6M Cost.
Present Worth Average Annual
O£M Cost
TOTAL PRESENT WORTH
Average Annual Equivalent Cost
1,458
219
252
$1,929
74
$2,003
1,321
-0
(316)
3,196
$6,520
$ (646)
Alternative B
Oxidation Di tch
($ x 103)
2,452
368
423
$3,243
124
'$3,367
-219
(320)
3,236
$6,384
$ (632)
Al ternative C
Aerated Lagoon
($ x 103)
2,511
377
433
$3,321
127
$3,448
-222
(294)
2,969
$6,195
$ "(613)
Alternative D
Pump Station
& Force Main
($ x 103)
986
148
170
$1,304
50
$1,354
-122
(32)
323
$1,555
$ (154)
Source: Anchorage Wastewater Facilities Plan
June 1982
-------
Table 3-10. Present Worth Summary
Rabbit Creek/Potter Creek Collection
and Treatment Alternatives
Al ternati ves
A -
A -
A -
A -
B -
B -
B -
C -
C -
C -
D -
D -
D -
1
2
3
i*
1
2
3
1
2
3
1
2
3
Treatment
Cost
($ x 103)
6,520
6,520
6,520
6,520
6,384
6,384
6,384
6,213
6,213
6,213
1,320
1,320 '
1,320
Co 1 1 ect i on
Cost
($ x 103)
2,655
2,674
2,920
704
2,655
2,674
2,920
2,655
2,674
2,920
3,975
3,994
4,240
Total
Present
Worth
($ x 103)
9,175
9,174
9,440
7,224
9,039
9,058
9,304
8,868
8,887
9,133
3,975
3,994
4,240
Rank ing
3
1
1
2
Source: Anchorage Wastewater Facilities Plan, June 1982
78
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Table 3-11. Estimated Changes in Single-Family
Monthly Service Charge for Sewer Service
Scenario 22
Scenario 33
Current
Rates
$7.50
7.50
Required
1985 Rates
No Projects
$12.68
12.68
1985 Rates
with
Projects
$15.47
17.03
1990 Rates
with
Projects
$15.75
17.03
1995 Rates
with
Projects
$14.78
15.09
1999 Rates
with
Projects
$13.95
15.00
1 Additional revenues required to pay for status quo system.
2 75 percent, U. S. EPA, 12.5 percent funding of Point Woronzof; 50 percent funding of all other
projects; remainder from local funds.
3 50 percent state funding for all projects; 50 percent local funding.
-------
Chapter 4
Wetland Issues
Legal, Regulatory and Policy Constraints
Issue Summary
Habitat Types
Biological Setting of Potter's Marsh
Biological Setting of Tidal Wetlands
Hydrological Setting
Human Use Setting
Wetland Impacts
-------
Chapter 4
WETLAND ISSUES
The Anchorage Bowl contains numerous nontidal wetland
areas that comprise an estimated 9,400 acres, or 15 percent
of the 64,000-acre area of the Bowl bounded by the.military
reservations and state park. An additional 2,300 acres of
tidal wetlands are incorporated into the Potter Point State
Game Refuge. These wetlands provide fish and wildlife habitat,
open space and hydrologic benefits, and recreational oppor-
tunities. They are potentially susceptible to significant
impacts from sewerage facilities expansion, both directly
from sewer interceptor construction, and indirectly from
facilitation of urban growth through the provision of new
sewerage facilities. Wetlands are shown on Figure 4-1.
Legal, Regulatory and Policy Constraints
The nation's wetlands are of federal as well as local
concern, as evidenced by Presidential and Congressional actions,
U. .S. EPA's federal interest in the wetlands through the
EIS process stems from these federal statutes and policy
directives.
Executive Order No. 11990, "Protection of Wetlands",
issued May 24, 1977 directs that "Each agency shall provide
leadership and shall take action to minimize the destruction,
loss or degradation of wetlands and to preserve and enhance
the natural and beneficial values of wetlands". It requires
that "...each [federal] agency to the extent permitted by
law shall avoid undertaking or providing assistance for new
construction located in wetlands unless the head of the agency
finds: 1) that there is no practicable alternative to such
construction, and 2) that the proposed action includes all
practicable measures to minimize harm to wetlands which may
result from such use. In making this finding the head of
the agency may take into account economic, environmental
and other pertinent factors."
The U. S. COE has extensive responsibility for the pro-
tection of wetlands under Section 404 of the Clean Water
Act. Any excavation or filling conducted in a wetland must
be carried out under a permit issued by the U. S. COE. The
U. S. Department of Interior, USFWS, under authority from
Executive Order No. 11990, Migratory Bird Act, Fish and
81
-------
LEGEND-
Bi Wetlands
Source: MOA, 1982
FIGURE 4-1. WETLANDS
82
-------
Wildlife Coordination Act and 40 CFR 230, is given the re-
sponsibility for evaluating the impact a project will have on
wetlands and providing comments and recommendations -to
the U. S. COE. The U. S. COE takes these recommendations
and those of other agencies such as the Alaska DFG and
ADEC under consideration to determine if a 404 permit will
be granted.
Local concern about Municipality wetlands has been
expressed in the development of a wetlands management plan
by the MOA. The plan applies four classifications to the
wetland areas: 1) wetland areas classified as "preservation"
would be managed or protected in their natural conditions.
Activities that would enhance, restore or preserve the
natural character of wetlands would be allowed. (This
category covers about 3,800 acres of nontidal wetland,
or about 40 percent of the remaining nontidal wetland areas
in the Anchorage Bowl.) 2) Wetland areas classified as
"conservation" could be developed subject to conserving
"their natural functions and values to the maximum extent
practicable" (MOA 1982c). Development would be allowed
on fringes and in "less critical wetland areas." (This
category covers about 400 acres, or about 5 percent of
the remaining nontidal wetlands.) 3) Wetland areas classified
as "development" or "developable" could be urbanized. (This
category covers about 5,200 acres of nontidal wetland,
or about 55 percent of the remaining nontidal wetland areas
in the Anchorage Bowl.) A subcategory of developable wetlands
is the classification "mixed development'. " This refers
to developable wetlands in low density zoned areas, specifically
the Hillside area. 4) Wetland areas classified as "special
study" cover a few"areas, where more information is required
on environmental values. These would be studied and classified
in one of the three foregoing categories.
The Municipality's plan was adopted by the Assembly
on April 20, 1982. The plan constrains the use of wetlands
by landowners, developers, public agencies, and citizens.
Issue Summary
The sewerage facilities plan includes installation of
interceptor sewers that traverse wetland areas. The facilities
plan also may facilitate population growth, thereby accelerating
pressure to develop wetlands. These potential impacts of
the facilities plan on wetlands are of concern because wetlands
typically have hydrological, open space and biological values
beneficial- to the public at large. Wetland areas in Anchorage
are under increasing development pressure as the available
land supply decreases and population growth and urban develop-
ment continue.
83
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Hydrological values of wetlands include retention of
rainfall and snowmelt runoff, augmentation of stream base
flow, water quality benefits, and groundwater recharge. Loss
of wetlands could result in elevated flood and erosion risks,
and alteration of stream flow and water quality.
Wetlands are a valuable aesthetic and recreational resource
to many citizens of Anchorage. Loss of open space and natural
areas within the Municipality, including wetlands, will have
an impact on the perception of quality of life.
Biological resources associated with wetland areas in
Anchorage have not been studied or reported in detail. Concern
has been expressed that sewerage decisions may precipitate
losses of undefined wetland values, including the inadvertent
loss of biological resources dependent on wetland habitats.
Biological Setting of Nontidal Wetlands
This section of the EIS describes the biological setting
of freshwater wetlands within the Anchorage Bowl that are
analyzed and evaluated in the EIS. The study area, methods
of study, principal findings, and the biological resources
of these wetlands are described based on extant data and
1981 field work.
Study Area and Methods
Anchorage is located in an area whose climate is transi-
tional between maritime climatic and continental climatic
zones (Hartman and Johnson 1978). Although forested areas
in Anchorage are transitional, (i.e., contain some species
found only in the maritime forests and other species found
only in interior Alaska), open bog areas are generally similar
to those found in interior Alaska.
Two wetland areas in the Anchorage Bowl were selected
to receive special attention in describing existing conditions
of wetlands potentially impacted by the facilities plan.
Campbell-Klatt Bog, between Campbell Creek and Klatt Road,
was studied as a large, representative wetland with relatively
minimal impact by human activities. Connors Lake Bog, between
Campbell Creek•and International Airport Road, was studied
as a large, representative wetland surrounded by development
and currently crossed by sewer facilities and a road network.
Recent (1980) aerial photographs of these wetland areas
were obtained, and habitats identified using photo-interpre-
tation techniques. Preliminary maps of wetland habitats
were prepared by vegetation type, and were ground checked
as necessary. Field studies, were done during September
10-18, 1981 to survey small mammal occurrence by habitat
types. Sherman live traps (408 trap nights) were used
84
-------
to ascertain small mammal occurrence; in addition, mammal
signs (e.g., scat, evidence of feeding activity, tracks,
burrows) were noted to augment other data. Incidental
sightings of bird use by habitat type also were noted.
Based on available information, including the field
work conducted during preparation of this EIS, a general
description of the biological resources of wetland habitats
in the Anchorage Bowl is presented.
Habitat Types
Wetlands in the Anchorage Bowl include: tidal marshes
at the base of the bluffs along Turnagain Arm and Knik Arm;
Potter Marsh, located between Old Seward Highway and the
Alaska Railroad embankment and isolated from direct tidal
influence by tidal gates; and inland black spruce and treeless
bogs, which are not affected by tidal action. The vegetation
of Potter Marsh and the coastal marshes between Campbell
Point and Potter Marsh has been previously described (U. S.
COE 1978b; Batten et al. 1978; Macdonald 1980; Alaska DFG
1981a). The vegetation of inland bogs (black spruce bogs
and treeless bogs) in Anchorage has not been described prior
to the- current study.
A number of schemes have been devised to classify or
characterize various wetland habitats, (e.g., U. S. COE
1978a; Cowardin et al. 1979; Batten 1980; Viereck and Dyrness
1980; Viereck et al. 1981). Differences in these scheme's
are based on their purposes and levels of division of vege-
tation types into component habitats. The classification
scheme of Viereck et al. (1981) is used here, but an effort
also is made to relate this scheme -to the USFWS (Cowardin
et al. 1979) classification system.
This survey of inland wetlands in the Anchorage Bowl
identified 11 habitat types (Table 4-1) based on vegetation.
(Nomenclature used in this report for the habitat types is
that used at Level IV by Viereck et al. [1981].) Maps of
the wetland habitats as delineated in 1981 in Campbell-Klatt
Bog and Connors Lake Bog are presented (Figures 4-2 and 4-3).
Three of the habitats mapped in Figures 4-2 and 4-3 combine
certain of the habitat types identified in Table 4-1 for rea-
sons described below. The 11 habitat types are discussed below.
Open Water. This habitat category is broadly defined,
because it includes a range of open water habitat types in
the Anchorage wetlands. It is not identified at Level IV
of Viereck et al. (1981), but is nearly equivalent to pond
and lake habitat at Level III (Table 4-1). Waterlily (Nymphaea
spp.) and submerged forms of CeratophyHum, Po'tamogeton and
a few other aquatic plants grow in larger, deeper, more permanent
85
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Table 4-1. Habitats Identified in Inland Wetland Areas of the Anchorage Bowl.
Nomenclature of Habitats is that of Viereck et al. (1981).
The Equivalent USFWS Designation (Oowardin et al. 1979).
is also Presented.
Level I
Aquatic
Herbaceous
Shrublond
Shrubland
Forest
Forest
Forest
Forest
Forest
Herbaceous
Shrubland
Level II
Freshwater
Sedge-grass
Low shrub
Low shrub
Conifer forest
Conifer forest
Conifer forest
Mixed conifer and deciduous forest
Deciduous forest
Tall grass
Tall shrub
Level III
Ponds and lakes
Sedge-grass bog meadow
Open low shrub
Open low shrub
Conifer woodland
Open conifer forest
Closed conifer forest
Closed mixed forest
Closed deciduous forest
Blue joint-herb
Closed tall shrub
Level IV
Open water*
Subarctic lowland sedge bog meadow
Dwarf birch- ericaceous shrub- sphagnum bog
Sweetgale-sphagnum bog
Black spruce (woodland, canopy 10-25%)
Black spruce (open forest, canopy 25-60%)
Black spruce (closed forest, canopy 60-100%)
Spruce-birch (closed forest, canopy 60-100%)
Paper birch (closed forest)
Bluejoint-fireweed
Alder
USFWS
LIOWH or POWF or PEM5
PEM5
P SSI B
EMS
P SSI B
EMS
P SSI B
FO4
PFO4B
PFO4B
P FO4 B
roi '
Not classified
PEM5
PSS1
•Approximately equivalent to "ponds and lakes" habitat (Level III) of Viereck et al. (1981).
-------
5VEETGALE -SPHAGNUH BOC
DWARF BIRCH - ERICACEOUS SHRUB - SFHA6MUM
LICK SPBUCE IOPEII COKIfti FOIESI, CMOPf 25 60%l
HC« SPBUCE (CLOSED COWFEI) FOIESI, CUOP1 60 WO % I
PiUCE -BIRCH (CLOSED HIKED FOBE5T, CANOPY 60-100%)
APER BIRCH (CLOSED DECIDUOUS FOREST)
I5TURIEO AREAS:
BlUEJOINT GRASS
ALOIS
•ARREN
FRAILS OR DRAINAGE DITCHES
FIGURE 4-2. CAMPBELL KLATT BOG
-------
Lake bpenard
35;- '
aduu.-\\ ,'•! :y.
11 fO] '
-SU ;J •« ; If ir^7r-
L-EGEND-
OPEN WATER .
SUBARCTIC LOWLAND SEOGE 803 MEADOW
PI SWEETSALE- SPHASNUM BOO
DWARF BIRCH • ERICACEOUS SHRUB - SPHAGNUM 906
FIGURE 4-3. CONNORS
LAKE BOG
| BLACK SPRUCE (CONIFER WOODLAND, CANOPY 10-29%)
| SLACK SPRUCE (OPEN CONIFER FOREST, CANOPY 29-80%)
8LAC< SPRUCE (CLOSED CONIFER FOREST, CANOPY 60-100%)
^ SPRUCE - BIRCH (CLOSED MIXED FOREST, CANOPY 80-100%)
PAPER BIRCH (CLOSED DECIDUOUS FOREST)
DISTURBED AREAS:
8LUEJOINT GRASS
ALDER
BARREN
TRAILS OR DRAINAGE DITCHES
-------
bodies of water such as Connors Lake. Bladder wort (Utricularia
sp.) and sedges frequently are found in small, shallow ponds,
potholes and depressions. Cowardin et al. (1979) classify
the.former as permanent limnetic open water (L10WH), and
the latter as semipermanent palustrine open water (POWF)
or emergent, palustrine, persistent, harrow-leaved vegetation
(PEM5).
Subarctic Lowland Sedge Bog Meadow. This habitat type
is usually found on very wet sedge peat, often with standing
water present in areas of poor drainage. Sedge bog meadows
can be found on quaking mats on the margins of open standing
water. Carex spp. are very common; cottongrass (Eriophorum
spp.) frequently is found in stands near the drier margins
of the sedge meadow. Buckbean (Menyanthes trifoliata) and
arrowgrass (Triglochin maritimum) also are common in this
habitat. Cowardin et al. (1979) classify this habitat as
palustrine, persistent, narrow-leaved emergent vegetation
(PEM5).
Dwarf Birch-Ericaceous Shrub-Sphagnum Bog/Sweetgale-
Sptiagnum Bog. This habitat is a combination of two separate
Level IV open low shrub bog habitats recognized by Viereck
et al. (1981) . Because of the topographic patterns charac-
teristic of these bogs, i.e., linear peaty ridges separating
wetter, often sedgy basins, these two habitat types are not
easily distinguished or mapped at a scale of 1:12,000. Con-
sequently, these two similar habitats, recognizable in the
field, are combined on the vegetation maps of Connors Lake
Bog and Campbell-Klatt Bog. Sphagnum spp. and other mosses
form the ground cover and much of the peat, and often form
hummocks or linear ridges. Dwarf birch (Betula nana), bog-
rosemary (Andromeda polifolia), narrow-leaf Labrador-tea
(Ledum decumbens), and bush cinquefoil (Potentilla fruticosa)
account for much of the taller shrub species on hummocks
and ridges. Additional species frequently observed are:
crowberry (Empetrum nigrum); leatherleaf (Chamaedaphne
calyculata); mountain cranberry or lingenberry (Vaccinium)
vitis-idaea); bog blueberry (V. uliginosum); bog cranberry
(V. oxycoccos); cloudberry (Rubus chamaemorus); alpine blue-
berry (Arctostaphylos alpina); and scattered black spruce
(Picea mariana) displaying stunted growth forms less than
1 m high. Wetter sites have sweetgale (Myrica gale), marsh
five-finger (Potentilla palustris), horsetail (Equisetum
fluviatile), buckbean (Menyanthes trifoliata), and sedges.
Cowardin et al. (1979) classify these habitats as saturated,
palustrine, narrow-leaved, persistent emergent vegetation •
and broadleaved, deciduous shrub habitat
EM
89
-------
Black Spruce (Conifer Woodland, Canopy 10-25 Percent.
Many of the species in this habitat, also are associated with
the dwarf birch-ericaceous shrub- sphagnum bog habitat, but
in this habitat stunted black spruce (Picea mariana) less
than 2 m in height forms a distinct - third canopy layer above
the sphagnum moss and shrubs. Ericaceous shrubs are more
common, and sweetgale (Myrica gale) is less common relative
to the open low shrub bog habitat. Although stunted black
spruce trees can be found in the open low shrub bog, they
do not form a recognizable stand as they do in this habitat.
The stunted black spruce in this habitat type are usually
distinguishable from the taller growth forms of the open
and closed black spruce forest. Under the Cowardin et al.
(1979) classification system, this habitat is saturated,
palustrine broad-leaved deciduous shrub and needle-leaved
evergreen habitat _£,_
(pSSIB)
1 F04 '
Black Spruce (Open Forest, Canopy 25-60 Percent/Closed
Forest, Canopy 60-100 Percent). These two habitat types,
distinguished by Viereck et al. (1981), are not clearly de-
lineated from each other in the wetlands of the Anchorage
Bowl. Black spruce (Picca mariana) forms the overstory in
both habitats to a height of about 5-12 m. Paper birch
(Betula papyri f era) also may occur as part of the overstory.
Dwarf birch (Betula nana) and Labrador-tea (Ledum groenlandicum)
comprise a mid-level canopy over the moss understory. Addi-
tional species frequently observed are: bog blueberry (Vaccinium
uliginosum) , lingenberry (V. vitis-idaea) ; cloudberry (Rubus
chamaemorus) ; crowberry (Empetrum nigrum) ; and bog- rosemary
(Andromeda polifolia) . Generally, the shrub und'erstory displays
a taller and more lush growth form relative to the open low
shrub bog and black spruce woodland. These two habitats
are classified as saturated, palustrine needle-leaved ever-
green habitat (PF04B) under the Cowardin et al. (1979) system.
Spruce-Birch (Closed Mixed Forest) . In some areas of
the wetlands, black spruce and paper birch form mixed stands.
This habitat type is primarily a transition between the black
spruce forest, which is characterized by poorly drained organic
soils, and paper birch forest, which is characterized by
well-drained organic or mineral soils. Under the Cowardin
et al. (1979) classification, this habitat is a mixture of
broad- leaved deciduous and narrow-leaved evergreen palustrine
habitat on saturated soils
FOI
90
-------
Paper Birch (Closed Forest). Paper birch (Betula papyrifera
occupies well-drained areas and upland areas bordering the
bog. Paper birch'predominates, but quaking aspen (Populus
tremuloides) also occurs in thickets or small stands. Willows
(Salix spp.) and alder (Alnus spp.) also may be present,
particularly at edges of disturbed areas (e.g., along roads).
The understory is characterized by shrubs such as Labrador-
tea (Ledum groenlandicum), devilsclub (Oplopanax horridus),
prickly rose (Rosa acicularis), American red currant (Ribes
triste), and highbush cranberry (Viburnum edule). Woodland
horsetail (Equisetum sylvaticum) forms a dense ground cover
where the canopy is closed. Bluejoint grass (Calamagrostis
canadensis) and sedges can be found in small open depressions
where surface drainage is lacking. This habitat generally
is not considered wetland habitat, and is not classified
under the Cowardin et al. (1979) system.
Disturbed Areas (Bluejoint-Fireweed/Alder). Disturbed
wetland areas include drainage ditches, road cuts and similar
areas which have not been filled or developed. Bluejoint
grass (Calamagrostis canadensis) and fireweed (Epilobium
angustifolium) are common species in disturbed areas of the
open low shrub bog. Alder (Alnus spp.) also is commonly
associated with disturbed areas, especially in well drained
sites along roads and on higher ridges of the disturbed areas.
Roads and trails cut through the bogs and allowed to
lie fallow generally are colonized by bluejoint or alder.
Bluejoint grass grows under a wide array of edaphic (soil)
conditions, ranging from very wet to moderately dry and from
organic to mineral soils. Bluejoint grass in wet areas usually
indicates that the area experiences slow water movement.
Sedges may grow in deep ruts or in areas where water collects.
In most cases, peat excavated during construction of a drainage
ditch was deposited as a "spoils ridge" to one side of the
ditch. These "spoils ridges" generally remain barren at
the top for long periods of time, but may be colonized by
bluejoint grass near the base. "Prickly rose (Rosa acicularis)
and small shrubs occasionally grow on peat spoils. Shallowly
excavated drainage ditches may be colonized by sedges. Because
of the narrowly linear and patchy distribution of these dis-
turbed areas, these habitat types have been generally mapped
as disturbed areas in Figures 4-2 and 4-3.
Aquatic Organisms
No data are 'available which describe the kinds of aquatic
organisms found in the shallow ponds and water-filled depres-
sions of the nontidal wetlands in the Anchorage Bowl. Preliminary
data obtained by Fugro Northwest, Inc.1 et al. (1980) on the
91
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quality of surface water in several drainage ditches in Connors
Lake Bog and Campbell-Klatt Bog indicate that water quality
in many cases does not restrict the occurrence of aquatic
organisms. Mosquito larvae probably form a major component
of the aquatic invertebrates in bogs. Other insects, small
crustaceans, and representatives of other taxa also may occur.
The wood frog (Rana sylvaticus) occurs in wetlands in the
Anchorage Bowl.
Use of wetlands in the Anchorage Bowl by fish is not
well documented. Salmonid species use Campbell Creek, Rabbit
Creek, and Ship Creek as spawning and rearing areas (Alaska
DFG 1980), but the role of wetlands in these fisheries is
poorly understood. Chester Creek is no longer considered
a candidate stream for fishery management because of signi-
ficant negative impacts of stream alteration resulting from
development in the drainage basin (Alaska DFG 1974). Never-
theless, juvenile coho salmon have been found in the upper
reaches of South Fork Chester Creek during studies by the
USFWS (Nickles pers. comm.) and in field work for this EIS.
Threespine sticklebacks (Gasterosteus aculeatus) may
occur in some wetland ponds and ditches. Alaska blackfish
(Pallia pec'toralis) , not native to the Anchorage area, was
accidentally introduced to Lake Hood in 1948. Since then,
blackfish have appeared in Fish Creek and the city sewer
system, and are thought to occur in other areas in Anchorage
including possibly wetland ponds and ditches (Kubik Ipers.
comm. 1981). Several lakes in the Anchorage area are stocked
each year with catchable rainbow trout by the Alaska DFG
(1977b). Records exist on the number of fish planted and
the harvest and effort (Kubik pers. comm. 1981). Stocking
of some of the lakes in the Anchorage Bowl is done primarily
to establish a "put and take" fishery. Total harvest of
the year's fish plant is desirable because of high winter
mortality (Alaska DFG 1977). Experimental plants of grayling
occurred in Connors Lake in three successive years, but the
experiment was not successful and was discontinued (FAA 1976).
Birds
Wetlands in the Anchorage Bowl provide habitat for a
number of bird species. To the casual observer, birds probably
represent the most visible wildlife using wetland habitats.
Kessel et al. (1967) briefly discuss migration, breeding
and nesting activities of birds in the Anchorage area. Selkregg
(1972) lists birds potentially or known to be using Anchorage
area wetlands. A brief review of migratory activities is
presented by Alaska DFG (1977a). Field observations made
by Jones & Stokes Associates in September 1981 are summarized
in Table 4-2.
92
-------
Table 4-2. Birds Sighted in Conners Lake Bog and
Campbell-Klatt Bog, September 10-17, 1981
Location
Habitat Type
Species
(Common Name/
Scientific Name)
Remarks
Arctic Icon
Gavia arctica
Mallard
Anas platyrhynchos
American green-winged teal
Anas crecca carolinensis
Greater scaup
Aythya marila
Marsh hawk
Circus cyaneus
Spruce grouse
Canachites canadensis
Sandhill crane
Grus canadensis
Killdeer
Charadrius •-•pciferus
Cctnnnon snipe
Capella gallinago
Belted kingfisher
Megaceryle alcyon
Gray jay
Perisoreus canadensis
Black-billed magpie
Pica pica
Cannon raven
Corvus corax
Black-capped chickadee
Parus atricapillus
Boreal chickadee
Parus hudsonicus
Present in water-filled
ruts formed by heavy
equipment.
Present in water-filled
ruts formed by heavy
equipment.
Foraging over bog;
individual perched at
edge of spruce/birch
forest at south end of
Klatt Bog.
-------
Table 4-2. Cont'd.
Location
Habitat Type
Species
(Comon Name/
Scientific Name)
id's
4J CO
fti
Remarks
American robin
Turdus migratorius
Golden-crowned kinglet
Requlus satrapa
Ruby-crowned kinglet
Requlus calendula
Northern shrike
Larius excubitor
Ccmtion redpull
Carduelis flaimiea
Savannah sparrow
Passerculus sandwichensis
Dark-eyed junco
Junco hyemalis
Tree sparrow
Spizella arborea
Lapland longspur
Calcarius lapponicus
-------
Waterfowl represent the group of birds most dependent
on wetland habitats. Which species use inland wetland
habitats for nesting purposes depends a great deal on the
size and depth of open water habitat. For example, marsh
and pond ducks (dabblers) may make extensive use of potholes
in bog areas because they do not require large stretches
of open water when initiating flight and forage in shallow
water. Diving ducks (bay ducks and sea ducks) require larger
and deeper water bodies because they run and patter along
the surface when initiating flight and usually dive under
water while foraging. Common snipe and sandhill cranes may
require little open water habitat in a shrub bog.
Sellers (1979), Eldridge and Rosenberg (1981), and Ritchie
et al. (1981) have studied wetland habitat utilization in
the upper Cook Inlet area. A number of water birds, including
red-throated loon, red-necked grebe, Canada goose, pintail,
mallard, green-winged teal, sandhill crane, least sandpiper,
northern phalarope, greater and lesser yellowlegs, long-billed
dowitcher, common snipe, mew gull, and herring gulls, were
found to nest in inland bog habitats. Loons, grebes, diving
ducks and mergansers used deeper, larger ponds when these
were available in the bog; otherwise, these species were
more likely to occur in coastal marsh habitats or on marshes
along lakes and creeks.
Potter Point State Game Refuge, southwest Campbell-
K.latt Bog, lower Campbell Creek, Connors Lake Bog, Heather
Meadows, Lake Spenard, Hood Lake and Turnagain Bog are major
nesting and brood-rearing areas for waterfowl in the- Anchorage
area. Sandhill cranes utilize Campbell-Klatt Bog, and Canada
geese nest in Potter Marsh, Campbell—Klatt Bog, and Heather
Meadows (Nickles pers. comm.). Although concentrated in
only a few wetland areas, nesting and brood-rearing occurs
in many wetlands in the Anchorage Bowl. During field surveys
in early July 1982, numerous small bogs with little or no
open water habitat were noted for large numbers of white-
crowned sparrows (Zonotrichia leucophrys), least sandpipers
(Erolia minutilla) and yellowlegs (Totanus sp.p.). Although
a few pairs of birds nesting in various ponds and bogs may
seem insignificant relative to an area supporting many pairs
(e.g., Potter Marsh), in cumulative numbers the nontidal
wetlands of the Anchorage Bowl may support a significant
proportion of the waterfowl occurring and nesting in the
Anchorage area.
95
-------
Mammals
Selkregg (1972) has listed the mammal species most likely
to occur in the bogs and marshes of the Anchorage Bowl. Field
surveys conducted in September 1981 by Jones & Stokes Associates
have provided further information on the mammalian fauna
of Anchorage Bowl wetlands. Prior to this recent effort,
no studies had been undertaken either to verify the occurrence
of the species listed by Selkregg (1972) or to identify specific
wetland habitats used.
Field data collected by Jones & Stokes Associates in
September 1981 confirmed the presence of 10 species of mammals
in wetland habitats of the Anchorage Bowl. Redbacked vole
(Clethrionomys rutilus), masked shrew (Sorex cinereus), dusky
shrew (_S. obscurus), shorttailed weasel (Mustela erminea)
and house mouse (Mus musculus) were live-trapped in wetland
habitats (Table 4-3). Scats of coyotes (Canis latrans), snow
shoe hares (Lepus americanus), red fox (Vulpes fulva), and
moose (Alces alces) were frequently encountered in wetland
areas surveyed. A coyote was sighted in Campbell-Klatt Bog,
and red squirrels (Tamiasciurus hudsonicus) were observed
in birch forest and mixed birch-black spruce forest habitats.
Red-backed voles were trapped most often, and probably
were the most abundant small mammals in the wetland habitats.
Bangs (pers. comm.) found that red-backed voles and masked
shrews were the most abundant small mammals in lowland forests
of the Kenai National Wildlife Refuge, and that capture success
was greater in mature forest than in stands of black spruce
regrowth.
The field data collected during this study do not provide
a clear picture of Level IV habitat preference by red-backed
voles (Table 4-3). Many of the habitats as defined at Level
IV especially disturbed areas along drainage ditches and
sedge bog meadows, are very small and patchily distributed
within the wetland. Traps set in these habitats frequently
were within 1 m of an adjacent Level IV habitat type. A
study of Level IV habitat preference was impractical. If
all wetland habitat types were combined into four broad catego-
ries, as shown in the lower half of Table 4-3, the preliminary
data suggest that red-backed voles were more likely to be
trapped in forested areas than in open habitats (i.e., open
bog or black spruce woodland). Red-backed voles also were
present, however, in grassy areas along drainage ditches
(disturbed areas) in the study area (Table 4-3). Bangs (pers.
comm.) considers good cover from 1-12 inches above the moss
or ground layer to be crucial to voles. The summer diet
of voles at Kena'i National Wildlife Refuge is 50 percent
fungus and 30 percent low bush cranberry. A major fraction
of the fungus is hypogeoid fungus, which is associated with
underground tree roots (Bangs pers. comm.).
96
-------
Table 4-3. Manuals Trapped by Specific Habitat Type and General Habitat Category;
Connors Lake Bog and Carrpbell-Klatt Bog; September 10-17, 1981,
by Jones & Stokes Associates Staff.
Specific Habitat TyiJtiS 2
Subarctic lowland sedge
bog meadow
Open lew shrub bog
Black spruce woodland
Black spruce forest
Black spruce-birch mixed
forest
Paper birch forest
Disturbed areas
TOTAL
Ger,ere.l Habitat
Categories
Sedge
Open habitat
Forest
Disturbed
TOTAL
Total
Traps
Set
' 3
73
131
87
20
21
73
408
3
204
128
73
408
Traps Sprung,
No Sign of
Visit l
0
0
0
0
0
1
0
1
0
0
1
0
1
Red-Backed Voles
Traps 1
Visited
0
2
5
16
0
4
5
32
0
7
20
5
32
*
0
9
8
11
1
1
8
38
0
17
13
8
38
% of Traps
in Habitat
0%
12%
6%
13%
5%
5%
11%
-
0%
8%
10%
11%
-
Dusky
Shrews
*
0
0
1
0
0
1
0
2
0
1
1
0
2
Masked
Shrews
*
0
0
0
1
0
0
1
2
0
0
1
1
2
Snort-
Tail
Weasels
#
0
0
0
0
1
0
0
1
0
0
1
0
1
Total Visits
House
Mice
f
0
0
0
0
0
0
1
1
0
0
0
1
1
and Captures '
«
0
11
14
23
2
6
15
76
0
25
36
15
76
\ of Traps
in Habitat
0%
15%
11%
32%
10%
29%
21%
-
0%
12%
28%
21%
-
Footnote:
•'A "visit" was recorded if a trap did not contain an animal, yet fecal pellets were observed on top of or within the trap. The visited trap may or ney not
have been sprung.
2Generally defined at Level IV of Table 1.
-------
Prior to the urbanization of the Anchorage Bowl, moose
used the area as a winter refuge from deep snow in the Chugach
Range. In the late 1950s about 3,000 moose occurred in Game
Management Unit 14c, which incorporates the Anchorage area,
military bases north and east of Anchorage, and portions
of the Chugach Range. Approximately 1,000 moose are now
found in Game Management Unit 14c (Harkness pers. comm.).
The reduction in numbers apparently is primarily a function
of loss of winter habitat and forage in the Anchorage Bowl
(Harkness pers. comm.). Very few moose now winter in west
Anchorage because urbanization has reduced open space to
a few narrow corridors (Figure 4-4). Winter forage of moose
typically consists of shrub and deciduous tree communities
(Cushwa and Coady 1976). Extensive development of upland
habitats in the study area has greatly reduced the availa-
bility of winter forage.
Biological Setting of Potter Marsh
Potter Marsh is a coastal wetland situated on lower
Rabbit Creek and Little Rabbit Creek between Old Seward
Highway and the Alaska railroad embankment. It is part of
the Potter Point State Game Refuge, managed by Alaska DFG.
Although it is a coastal wetland, the railroad embankment
and the associated tidal gates on the Rabbit Creek outlet
have effectively removed tidal influences, leaving Rabbit
Creek and Little Rabbit Creek as the major hydrologic
influences.
Habitat types in Potter Marsh have been mapped by
Alaska DFG (1981a) as part of the Potter Point State Game
Refuge. A PuceineIlia/Triglochin community (alkali grass,
seaside arrowgrass) is located at the confluence of Rabbit
Creek and Little Rabbit Creek, at the outlet of Rabbit Creek.
A Carex community (sedge) surrounds it, and a Scirpus/Carex
community (bulrush, sedge) extends along New Seward Highway
south of the Rabbit Creek outlet. A deciduous tree forest
(paper birch, poplar, alder, willow) is located north of
Rabbit Creek and along Old Seward Highway on the east. A
large shrub/bog community extends south of Rabbit Creek
between the Scirpus/Carex community along New Seward Highway
and the deciduous forest along Old Seward Highway.
Threespine stickleback (Gasterosteus aculeatus) is the
most common resident fish in Potter Marsh (Wolf et al., in
press), ninespine stickleback (Pungitius pungitius).and
sculpins are also present. Rabbit Creek supports a small
salmon run (Selkregg 1972). Alaska DFG (1981b) reports up
to 500 pink salmon (Oncorhynchus gorbuscha), up to 100 coho
(Oncorhynchus kisutch), 5-15 chinook (Oncorhynchus tshawytscha),
98
-------
-LEGEND-
Moose Corridors
Source: Dave Harkness, ADFG
November 12,1982
r
FIGURE 4-4. MOOSE CORRIDORS
99
-------
500 Dolly Varden (Salvelinus malma), and about 100 whitefish
(Coregonus nelsoni) can be found in Rabbit Creek as spawning
adults.
Waterbird use of Potter Marsh during migration periods
and summer nesting periods is perhaps the most valuable aspect
of the marsh from the biological resource perspective. Potter
Marsh is among the more productive marshes in the state for
duck production (MOA undated). The nesting population of
lesser Canada goose (Branta canadensis parvipes) is a major
attraction for bird watching activity around Potter Marsh.
Shorebirds, grebes and gulls also nest in the marsh. Alaska
DFG (1976) lists the Potter Point State Game Refuge as a
very important wildlife habitat in the Cook Inlet area.
Muskrat (Ondatra zibethicus) and mink (Mustela vison)
are relatively common in Potter Marsh. Snowshoe hare (Lepus
americanus), red squirrel (Tamiasciurus hudsonicus), least
weasel (Mustela rixosa), red-backed vole (Clethrionomys
rutilus), and shrews (Sorex spp.) live in the deciduous
forest community. Beaver (Castor canadensis) are present
in small numbers in lower Rabbit Creek.
Biological Setting of Tidal Wetlands,
Extensive mudflats and marsh habitat are found at the
base of the bluff between Campbell Point and Potter Creek.
This area comprises the bulk of Potter Point State Game
Refuge. High marsh habitats are affected by tides only during
the lunar spring tide periods; tide pools are frozen over
during the winter months. Low marsh habitats (tidal flats)
are populated by algae in the summer months, and are subject to
ice floe scouring in the spring.
The tidal flats are either barren silt or occupied
by algae. Coastal marsh plant communities have been surveyed
by U. S. COE (1978), Batten et al. (1978), Macdonald (1980),
and Alaska DFG (1981a). The high marsh is comprised of a
seaward Puccinellia/Triglochin community (alkali grass, sea-
side arrow grass) and a landward Carex community (sedge).
A black spruce forest is also present at the base of the
bluff west of De Armoun Road.
Threespine stickleback (Gasterosteus aculeatus) is the
most common fish found in tide pools in the coastal marsh
(Wolf et al., in press). Campbell Creek and Rabbit Creek
have carved channels through the marsh, and Potter Creek
empties into a narrow stretch of marsh at the southern
terminus of the Potter Point State Game Refuge. Potter Creek
serves as spawning habitat for a few Dolly Varden (Salvelinus
100
-------
malma) and a small run of pink salmon (Oncorhynchus gorbuscha).
Fisheries of Rabbit Creek are summarized in the section on
Potter Marsh.
The extensive mudflats and marsh habitat'provide prime
habitat for migrating or nesting waterfowl and shorebirds.
At least 130 different species of birds have been sighted
in the refuge (Alaska DFG 1981b). Bald eagles frequently
forage in the area, especially in the spring. Lesser Canada
goose (Branta canadensis parvipes) and numerous species of
ducks and shorebirds nest on the coastal marsh habitat. Alaska
DFG (1981b) reports an average of 80 breeding ducks per square
mile, which is a very high density, demonstrating the great
value of this area to wildlife. Alaska DFG (1976) lists
the Potter Point State Game Refuge as a very important wild-
life habitat in the Cook Inlet area.
Mammal use of the coastal marsh is generally similar
to that reviewed in the section on Potter Marsh. Small mammal
populations are probably highest in the high marsh and forest
habitats at the toe of the bluff.
Hydrologic Setting
Hydrologic Cycle
Precipitation, in the form of rain and snow, falls onto
the west slopes of the Chugach Mountains. This water flows
toward the Cook Inlet either as groundwater (aquifer flow)
or surface runoff, diminished by evaporation and evapo-
transpiration (Figure 4-5). Average annual precipitation
in the Anchorage Bowl increases from 15 inches at the lowland
areas near the coast to about 30 inches at an elevation of
2,000 feet. Up to 160 inches of snow accumulates on the
highest mountain slopes*. Surface water is plentiful with
an average combined daily flow of 163 MGD from Chester Creek,
Ship Creek, Campbell Creek and Rabbit Creek (U. S. Geological
Survey 1978; MOA 1979) . Both surface runoff and groundwater
flow characteristics dictate the hydrology of streams, lakes
and wetlands in the Anchorage Bowl.
Surface Runoff and Groundwater
Depending upon soil permeability and the amount of water
contained in the upper soil layers, waiter flows either as
surface runoff or groundwater. Water percolates through
permeable soils to become groundwater. Impermeable and
saturated soils promote surface runoff.
101
-------
PRECIPITATION
:SNOW-'
PLANT TRANSPIRATION
- \\\\\\\x- - -----^
-A \ \\\\\\\\\\\~
X.- ?
; :•...-•. .v-:-.-:
i •:•"•.• vr-i^'J.V-
^r-^-^4- ,. ^i-^^;
SOURCE-'USGS, 1972
FIGURE 4-5. THE HYDROLOGIC CYCLE
RELATED TO ANCHORAGE
-------
Two major aquifer systems have been identified in the
Anchorage drainage. First, an upper level aquifer, known
as the unconfined aquifer, lies between 1.0 and 50 feet below
ground level, and is composed of peat, glacial sand and gravel.
In wetland areas, the aquifer is composed of peat, clay and
silt, and tends to be less permeable. Twenty to thirty feet
below this groundwater lies the artesian aquifer composed
of thin layers of sand and gravel. Confining clayey sediments
separate the two aquifer systems. Artesian groundwater,
50-300 feet below the surface, is the source of all municipal
groundwater and most of the domestic supplies, about 14 million
gallons of water per day (U. S. COE 1979) .
Surface water flowing in streams and rivers is also
important as a municipal water source and as a recreation
resource. Four major drainage basins in the study area con-
vey water toward their outlets at the Turnagain and Knik
Arms: 1) Ship Creek, 2) Campbell Creek, 3) Chester Creek,
and 4) Rabbit Creek watersheds. Surface water quality tends
be good (Fugro 1980). Throughout the study area, most
of the surface water is calcium bicarbonate type and some
measured chemical and physical parameters are typical of
unpolluted water. However, water analysis of the study
area streams by the MOA (1979) revealed that Campbell Creek,
Chester Creek, and Ship Creek have periodically exceeded
fecal coliform limits (20 FC/100 ml.) . For instance, coliform
levels of 138 FC/100 ml were measured in Campbell Creek,
and Chester Creek levels were several times higher. Ship
;Creek and Rabbit Creek have also exceeded coliform' limits.
Heavy metal limit violations have also occurred in some
of these streams. The study indicates that the metal sources
may be commercial and industrial runoff, roadway runoff,
peat bog drainage, and possibly groundwater inflow.
Most lakes in the area are small (usually less than
1 square mile) and shallow (less than 40 feet deep). In
general, the lakes, with the exception of Campbell Lake,
have little.inflow and outflow, and are adjacent to bogs.
Surface/Groundwater/Wetland Complex
Recent studies illuminate the interrelationships between
surface waters (lakes, streams) and wetlands with the ground-
water systems in the Anchorage Bowl. Man-made alterations
of groundwater, surface runoff and wetland hydrology have
occurred. Evidence suggests hydrologic interdependency between
these water systems, but quantitative data are generally
not available.
103
-------
One illustration of this interrelationship is the fluc-
tuating water level of Sand Lake (U. S. COE '1979). Develop-
ment within Sand Lake's drainage basin has possibly reduced
groundwater recharge to the lake by speeding the removal
of excess surface water with drainage channels and sewer
lines, and by prohibiting the vertical flow of surface water
to groundwater by covering permeable soils with impermeable
cement and asphalt. Permeable gravel fill material used
in storm drain construction may also encourage horizontal
flow along the drain pipe's path. Thus, part of the water
usually flowing into the groundwater and recharging the lake
is transported out of the drainage basin. The Sand Lake
system demonstrates the probable dependence of lake water
level on groundwater hydrology in most of the Anchorage Bowl
area.
Similarly, bogs within the Bowl possibly have many
hydrologic influences on surface runoff. Campbell/Klatt Bog
and Connors Lake Bog have been investigated and reports imply
these relationships. Although Campbell/Klatt Bog is minimally
fed by surface runoff, it has been suggested that it may
also be fed by upwelling groundwater (Fugro 1980) .
Connors Lake Bog and Campbell/Klatt Bog also may influence
runoff chemical composition. Organic processes, usually
high within peat bogs, may add dissolved nutrients such as
nitrates, nitrites, and phosphorus as well as suspended organic
matter to surface runoff. Heavy metals (iron, manganese,
and aluminum) are also believed to be introduced to runoff
by peat bogs and degrade stream receiving waters (MOA 1979).
Comparison of Connors Lake Bog drainage water quality to
its receiving water, Campbell Creek, indicates that such
a degradation may occur (Fugro 1980) '.
Bogs also have great water storage capacity and may
reduce flood hazards by attenuating peak surface flows. The
peat soils, vegetation, and ponded areas have significant
storage capacity. As a result, the bogs can release snow
melt or accumulated 'rainfall over days, weeks or months
following the initial event.
More complete evidence suggests relationships between
streams and aquifers. Research by Weeks (1970) showed a
sizeable interchange between the Anchorage artesian aquifer
and Ship Creek. Approximately 25 cfs seeps into the ground
water from Ship Creek. About half of this volume recharges
the aquifer, while about 11 cfs returns to Ship Creek down-
stream. The U. S. Geological Survey (1978) also conducted
seepage studies in North Fork Campbell Creek and determined
groundwater recharge to the stream was approximately 1.5 MGD
between November 17, 1970 and May 26, 1971. But because
of measurement inaccuracies, the U. S. Geological Survey
data may be substantially in error.
104
-------
It must be pointed out that the hydrologic links between
surface runoff/groundwater/wetland complexes has been only
partially studied; some data on surface runoff relationship's
exist, but groundwater flow data are negligible. Further
investigation is needed to properly assess the impact of
human induced alterations on Anchorage Bowl hydrology.
Human Use Setting
In addition to providing wildlife and fish habitat,
wetlands provide open space and recreational opportunities
for the citizens of Anchorage. For many citizens, parti-
cularly long-term residents, the open space and natural
areas and the incidental observations of moose, nesting
waterfowl, and migrating salmon within the Municipality are
a valuable aesthetic resource, whose loss would detract from
the perceived quality of life.
The wetlands are currently used by individuals with
a great range of interests. Birdwatching and wildlife
observation is locally important to naturalists and residents.
Waterfowl hunting is a major recreational activity occurring
in some of the larger wetlands. Primary species hunted include
dabbling ducks, especially mallards and pintails. Sport
fishing is also a popular pursuit in streams through greenbelt
areas. Potter Marsh, part of a 2,300-acre state game refuge,
is an area with a great wealth of wildlife.. The refuge
is an important nesting and feeding place for numerous ducks,
geese, swans, and shorebirds which migrate through Anchorage
during spring and fall. It is enjoyed throughout the year
by Anchorage residents and.visitors.
There are many opportunities for summer boating in the
Anchorage area including a wide array of small boats and
rubber rafts on the many lakes and creeks in Anchorage, most
of which are in wetland areas. Small boats and rubber rafts
are widely available. Throughout the wetlands there are
a number of trails used for hiking, horseback riding and
biking. Certain lakes are also used extensively by residents
for floatplane operations.
Winter recreation is of particular importance in the
wetland areas. When snow conditions permit, snowmachines
and cross-country skiers are active over most of the wetland
area. Campbell Creek and Chester Creek are frozen in winter
and serve as trails for snowmobiles and skiers. Four-wheel-
drive vehicles are used during winter months in some of the
larger wetland areas, e.g., Connors Lake Bog and Campbell/
Klatt Bog.
105
-------
Wetland Impacts
Wetland impacts are likely to occur when interceptors
cross or are laid adjacent to wetlands, streams, lakes or ponds,
Impacts of the expansion of sewerage facilities on wetlands
in the Anchorage Bowl can be classified as direct and indirect
impacts. Direct impacts result from emplacement of facilities
in or adjacent to wetland areas, and may be of short or long
duration. An example of an indirect impact is the inducement
of urban growth which may result from an expansion of waste-
water treatment facilities, thereby increasing development
of wetlands.
Pipe Emplacement Impacts
Emplacement of sewer interceptors generally involves
movement of heavy equipment at the site, excavation of a
trench, potential inclusion of a dewatering operation, and
backfilling of the trench with a stabilizing material. Gravel
is typically used in Alaska as a backfill in wetland areas
because peat .does not provide a suitable fill material for
holding the pipe in place.
Table 4-4 lists the interceptor pipes proposed in the
facilities plan and mapped in Figure 3-6, and identifies
those pipes likely to directly impact wetlands, streams,
coastal marshes, other b-iological resources or recreation
resources.
Wetland Crossings. A number of events occur which impact
wetlands when interceptor lines cross wetlands. The most
obvious event is destruction of the vegetation in the right-
of-way. Heavy equipment crushes or removes vegetation and
compacts peat deposits. Areas of bog wetlands stripped of
vegetation by heavy equipment or by excavation generally
do not revert to the original habitat type, but instead are
overgrown by ruderal vegetation or are kept barren by foot
or off-road vehicle traffic. Ruderal vegetation is composed
primarily of a bluejoint grass/alder community (Calamagrostis
canadensis/Alnus spp.). Long-term alteration of habitat
is apparent in aerial photographs taken as long as 16 years
after emplacement of pipe. For example, the alignments of
a sewer line emplaced in 1965 between West 80th Avenue and
Strawberry Road on the -proposed Northwood Drive alignment
(Figure 4-6), and a sewer-line emplaced in 1968 through Baxter
Bog south of Northern Lights Boulevard (Figure 4-7) are still
obvious in 1981 photos.
106
-------
Table 4-4. Potential Impacts on Proposed Sewer Lines
on Biological and Recreational Resources
0
c *
•H «
rH 4J
O
IH HI
0) •!->
3 0
Q) M
M a
T24
NS
NL18
NNL
SNL
MD14
US
U14
MFW
FAE
FAW
DB15
CCE
CC24
CC30
PA
SC
ARRN
CBDN
CBDM
CBDS
AC
BLN
FC18
FC24E
FC24W
FC30
FC36
FCF30
HC
WP
ARRS
IARE
IARW
D12
RWL
R78
LCCI
CCI
SLN
SLS
JL
JLN
JLE
JLS
CKBNE
CKBC
CKB
KR
SEI
HE
OSHN
OSHS
TL
RCF
RCI
4J
0> 4J rH
•O C C (0 T3
C -H C 4J
0) M -O O
-------
Figure 4-6. 1981 Photo of Connors Lake Bog
North is toward the top of the photo. Connors Lake is in the upper left comer, Blueberry
Lake is at right center, and Strawberry Lake is in the lower right corner. A sewer line was
constructed east of Connors Lake in a northwest-southeast alignment to Raspberry Road, in a
northeast-southwest alignment from Raspberry Road to West 72nd Avenue, and in a north-south
alignment south of West 72nd Avenue.
108
-------
Figure 4-7. Comparative Photographs of Baxter Bog
1967 photo of Baxter Bog prior to sewer construction.
margin of the page.
North is toward the right-hand
1981 photo of Baxter Bog.
of the pond.
A sewer has been constructed in the north-south direction, east
109
-------
A second major biological impact is less obvious and
is discussed in more detail in the hydrology impact section.
The hydrological characteristics of a wetland area are ex-
tremely important to the nature of the vegetation and there-
fore the type of wildlife habitat that occurs (Moore and
Bellamy 1974) . Alteration of the hydrological regime alters
the wetland biota.
To a certain extent, wetland areas already intersected
by interceptors have already been impacted, and replacement
of existing pipes or emplacement of additional pipe in
existing right-of-way will re-initiate the growth of ruderal
vegetation on the right-of-way. Examples of an existing sewer
facility right-of-way can be seen in Connors Lake Bog
(Figure 4-6) as the 84-inch West Interceptor passes north-
westerly from Raspberry Road to International Airport Road
at Jewel Lake Road, and in Baxter Bog (Figure 4-7). Replace-
ment or emplacement of additional pipe in the existing right-
of-way is unlikely to have a significant biological impact
since the damage to the wetland, if any, has already occurred.
Wetland areas not yet disturbed by utility rights-of-
way will be significantly impacted. Existing bog habitat
on the right-of-way will be replaced by bare areas or ruderal
vegetation. Impacts on hydrology may occur (see Hydrology
section), which alter the physical and habitat characteristics
of the site. A number of wetlands not yet impacted by sewer
interceptors will be crossed by the proposed facilities.
Table 4-5 identifies the interceptors that represent construc-
tion in wetland areas which have not yet been directly impacted
by pipe emplacement. Six sections of pipe listed in Table 4-5
cross wetlands designated for eventual development in the
Municipality Wetlands Management Plan. Of these six, line
FC24E crosses Heather Meadows wetland between B Street and
Old Seward Highway. This wetland has been identified as
a nesting area for Canada geese and other waterfowl, and
was in use in 1982 as a nesting area in spite of development
around and in part of the bog.
Two sections of pipe (CKB, KR) listed in Table 4-5
cross an area of Campbell-Klatt Bog which has been designated
for conservation in the Municipality Wetlands Management
Plan. Although the objective of the conservation designation
is to permit development while conserving natural resource
values of the area, the practicality of meeting this objective
in Campbell-Klatt Bog is questionable. Along with other
resource values (e.g., hydrologic values, value as wetland
habitat), Campbell-Klatt Bog is particularly noteworthy
as a nesting area for Canada geese and is the largest open
bog area in the Anchorage Bowl. Because of its large size,
moose utilize the area, and certain species of birds, e.g.,
sandhill cranes, use the bog for a foraging or resting
area during the migration periods.
110
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Table 4-5. Sections of Proposed Sewerage Interceptor Crossing
Wetlands Undisturbed by Pipe Emplacement
Pipe
Impacted Area
Wetland
Designation*
NL18
CC30
Northeast of Northern Lights and
Muldcon intersection
Westchester Lake (relocated
Muldoon Park
Westchester Creek
Development
Preservation
PC24E
PC24W
EWL
SLS
JL
CKBNE
CKBC
CKB
KR
HE
SEI
crossing of Chester Creek)
B Street to Old Seward Highway
Extension of Tudor Road west
Entire section
Extension of West 80th Avenue west
Qnerald Street to Gloralee Street
Campbell Creek greenbelt south bank
South of West 89th Avenue
Entire section
Entire Section
Entire Section
Entire Section
Dimond Boulevard to East 100th
Avenue
Heather Meadows complex
Fish Creek
Connors Lake Bog
Sand/Sundi/Jewel Lakes
Sand/Sundi/Jewal Lakes
Greenbelt Marsh
Campbell-Klatt Bog
Campbell-Klatt Bog
Campbell-Klatt Bog
Campbell-Klatt Bog
Furrow Creek
Campbell-Klatt Bog
Development
Preservation
Development
Preservation
Preservation
Preservation
Development
Development
Conservation
Conservation
Conservation
Development
* tfanicipality of Anchorage 1982. Designation refers to immediate area of impact.
Ill
-------
The line designated CKB in Figure 3-6 is routed through
an area rich in potholes and used by Canada geese and other
waterfowl as a nesting area. The USFWS Office of Ecological
Services conducted field work in Campbell-Klatt Bog during
the spring and summer of 1982 (Nickles,- pers. comm. ) . The
proposed routing of CKB is near a USFWS transect area which
contained two (possibly four) nesting pairs of Canada geese,
two mallard nests, one widgeon nest, and numerous pairs
of yellowlegs, snipe, greenwing teal, northern phalarope,
and gulls. A cow and calf moose were seen in early summer
along this route, and two bulls were spotted later in the
summer. Based on these and other observations, it is highly
probable that CKB is routed through the major waterfowl
nesting and wildlife area in Campbell-Klatt Bog. Even
limited development in the southern half of Campbell-Klatt
Bog is likely to significantly alter its value as a large
wetland area offering habitat for species such as sandhill
crane, which require minimal human intrusion.
Section HE also crosses a wetland (Furrow Creek) designated
for conservation. Major aspects of this wetland crossing
are likely to be related to hydrologic value of this wetland
along Furrow Creek.
Five sections of pipe listed in Table 4-5 cross wetlands
designated for preservation in the Municipality Wetlands
Management Plan. Three of these (CC 30, FC24W, part of CKBNE)
represent new construction in greenbelt areas (Chester Creek,
Fish Creek, Campbell Creek, respectively). The Chester Creek
interceptor currently crosses under Westchester Lake. In-
creasing the capacity of this line (CC30) may require reloca-
tion of the crossing of Chester Creek. Fish Creek from
its origin near Spenard Road and Chugach Way to its mouth
is paralleled by an interceptor sewer (FC24W).
New construction in a greenbelt area, e.g., the east-
west^leg of CKBNE, represents a unique case of construction
in a'wetland area. Unlike inland bogs, wetlands in the green-
belt areas depend on the hydrological regime of the creeks
or on the tides. Riparian vegetation along the streams
typically grows more rapidly than bog vegetation, therefore,
ruderal vegetation or barren ground is not likely to persist
in greenbelt areas. Most of the existing sewer lines in
greenbelt areas are overgrown by birch trees, alder, sedges,
and grasses.
Two interceptors cross an inland bog in an area desig-
nated for preservation by the Municipality wetlands management
plan. Lines SLS and JL cross the Sand/Sundi/Jewel Lakes Bog.
This lake/wetland complex is tributary to Campbell Creek
by way of an existing natural channel. Flow characteristics
of the outlet channel are apparently determined by precipi-
tation patterns and water levels in Sand Lake (Quadra Engineering,
112
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Inc. 1981). The bog is primarily open low shrub or black
spruce woodland habitat. Some waterfowl nesting may occur
along the lake shores. Jewel Lake is a popular fishing and
recreation area.
Construction of interceptor sewers may have a significant
impact on Sand Lake and Sand/Sundi/Jewel Lakes Bog. Sand
Lake historically displayed a pattern of fluctuating water
level corresponding to local precipitation patterns. Two
construction projects, including a 1966 sewer line east
of the lake at the margin of the wetland, may have caused
a subsequent long-term decline in water level which did not
correspond to precipitation patterns (Quadra Engineering,
Inc. 1981). If construction of the sewer line in 1966 caused
a drop in water level, construction of two additional inter-
ceptors across the bog may accelerate dewatering of the lake/
bog complex. The mechanism of this action is discussed in
the Hydrology section.
Pipes Adjacent to Nontidal Wetlands. Emplacement
impacts on wetlands may occur when pipes are laid adjacent
to wetland areas. If the backfill is permeable material,
the sewer line may intercept groundwater flow to or from
the wetland and conduct groundwater along the sewer line.
This may have a major, long-term impact on the wetland as
described in the Hydrology section.
Table 4-6 lists those sections of proposed interceptors
which would be emplaced adjacent to wetland areas. Of the
nine sections identified, seven are adjacent to wetland areas
which the Municipality has designated for eventual development
(MOA 1982). Construction of a sewer interceptor (RWL) through
Connors Lake Bog east of Minnesota Avenue could expedite
development of the area, which would lead to a loss of water-
fowl nesting habitat around Blueberry Lake. The remaining
two sections (U14 and DB15) are adjacent to the Chester Creek
greenbelt in the general vicinity of Lake Otis Parkway. Their
potential impact is'li'kely to be from sediment, which could
enter the streams during construction, and from interception
of groundwater in the greenbelt area. If groundwater is
intercepted and transported by the backfill material, it
would be transported to the greenbelt area where U14 and
DB15 enter the greenbelt.
Crossing or Adjacent to Streams. Significant short-
term impacts on stream flow, water quality, and fish migration
can be expected during the period of time an interceptor
is being laid across or adjacent to a stream, i.e., within
the floodplain. Long-term impacts to stream biota and water
quality may result as pipes age and deteriorate or if sections
of pipe are improperly connected or damaged during seismic
or freeze/thaw events. Additional•long-term damage to the
stream biota and water quality may occur if the interceptor
surcharges during spring thaw and raw sewage is spilled out
113
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Table 4-6. Sections of Proposed Sewer Interceptor
Adjacent to Nontidal Wetland Areas
Pipe
NS
NL18
U14
DB15
PCF30
D12
KWL
JLN
JLE
Impacted Area
Between Newell Street and Norman
Street
Northern Lights Boulevard west
of Patterson
Between Mallard Lane and Northern
Lights Boulevard
Along Sitka Street
Wisconsin Street south of West
31st Avenue
North of Dowling between Old and
New Seward
Entire section
Along Jewel Lake Road and West
84th Avenue
Along Birch Lake
Wetlahd*
North Russian Jack Springs
Baxter Bog
Chester Creek forks
Chester Creek
Turnagain Bog
Seward Highway
Connors Lake Bog
Sand-Sundi-Jewel Lake Bog
Connors Lake Bog
MCA Designation*
Development
Development
Preservation
Preservation
Development
Development
Development
Development
Development
FOOTNOTE:
*Municipality of Anchorage 1982. Designation refers to immediate area of impact.
114
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of manholes into the stream floodplain. This latter event
now occurs on the Campbell Creek interceptor. Construction
impacts on riparian habitat in creek floodplains appear
inconspicuous within a few years, particularly if the right-
of-way surface elevation is restored to its original contour.
As an example, the right-of-way for the existing Chester
Creek interceptor is now overgrown by a deciduous tree
community (paper birch, alder, and willow). The path of
the right-of-way is revealed only by the appearance of manhole
structures and the appearance of shallow trenches where the
fill has settled or slight mounds where the fill has not
settled. The changes in contour are probably noticed only
by those individuals looking for them and aware of their
approximate location. In lower Fish Creek the sewer line
right-of-way is overgrown by a sedge and grass community found
in the area, but is much more conspicuous because of the
dike-like effect of the backfill material.
Trenching and excavation activities during stream crossings
will result in the temporary destruction or displacement
of aquatic invertebrates in the project area, increase in
turbidity and siltation downstream from the project area,
and obstruction of fish passage.
Following completion of construction, turbidity will
decline precipitously. Silt that settled on the bottom, down-
stream of the project area will remain until increased flow
at the next "breakup" or rainstorm washes it away. Aquatic
invertebrates will re-establish themselves in disturbed areas
if clean gravel is available.
Some beneficial impacts may be realized in the long term.
Most of the sections of pipe identified in Table 4-7 are
located in existing right-of-way and will expand the capa-
bility of the existing sewer line. The existing lines carry
near capacity flows or already experience flow in excess
of capacity. As a result of capacity expansion, the existing
lines will be less likely to surcharge and overflow raw sewage
into the stream or floodplain. The Campbell Creek interceptor
also has deteriorated and is in need of rehabilitation. Eli-
mination of raw sewage discharge will improve long-term water
quality for aquatic bi'ota and human recreation and water-
related activity.
As noted in Table 4r7, the project facilities may impact
Ship Creek, Chester Creek, Fish Creek, Hood Creek, Campbell Creek,
Furrow Creek, Rabbit Creek, and Little Rabbit Creek. All project
areas occur below the U. S. COE designated headwaters point
except those on Fish Creek, Hood Creek, Furrow Creek, and possibly
North Fork Chester Creek and a small tributary to South Fork
Chester Creek (Table 4-7). Stream crossings by utility lines
below headwater points are usually classified under the nationwide
404 -permit according to Section 323-. 4-3 (a) (1) , (42 FR 37146
July 19, 1977), provided the following conditions, are satisfied:
115
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Table 4-7. Section of Proposed Sewer Interceptors Which Cross Streams or are in the Stream Floodplain
Pipe
NL18
NHL
MD 14
MD14
U14
U14
FAW
DB15
DB15
CCE
CCE
CC24
CC30
CC30
SC
SC
BNL
FC24W
FC24W
IC24W
FC21W
Crossi/ig Adjacent Approximate Location
x South of Ptarmigan Street
x Baxter Road near Northern
Lights
x South of College Gate Elemen-
tary School
x Wesleyan Drive near Pawn Place
x North of Gosling Circle
x North of Gosling Circle
x South of 15th Avenue
x South of Sitka Street
x Along Sitka Street
x Lake Otis Parkway
x Along most of length
x Sitka Street to Eagle Street;
C Street to West 18th Avenue
x Spenard Road
x Spenard Road to Knik Arm
x Downstream of fish hatchery
at Elmendorf Access Road
x Along most of length
x West terminus at Fish Creek
x Chugach Street near Wilson
Street
x Minnesota between West 39th
Street and West 41st Avenue
x Alo::kii TVii 1 ronr] near Rrxx'ievcl t
Drive
x V*j:jt of Tudor Road
Stream
South Fork Chester Creek
South Fork Chester Creek
Unnamed ditch
South Fork Chester Creek
South Fork Chester Creek
Middle Fork Chester Creek
Chester Creek
Chester Creek
North Fork Chester Creek
South Fork Chester Creek
Middle Fork Chester Creek
Chester Creek
Chester Creek
Chester Creek
Ship Creek
Ship Crock
Fish Creek
Fish Creek
Fish Creek
Fi.=;h Crook
Fish Creek
New
Fishery Value Right-of-Way
Moderate: remanant of f outer
coho and pink salmon runs;
Dolly Varden
Moderate: as above
Low: tributary (drainage
ditch) to South Fork Chester
Creek
Moderate: adequate flow and
gravels
Moderate: as above
Moderate: adequate flow and
gravels; instream litter and
debris cottmon
Moderate: adequate flow; serve
channelization
Moderate: adequate flow and
gravels
None: silted drainage ditch
with little flow, drains
landfill area
Moderate: adequate flow and
gravels
Moderate: adequate flow and
gravels; instream litter and
debris comtton
Moderate: adequate flow;
some channelization
Moderate: as above Yes
Moderate: as above
High: salmon migration and
spawning; Dolly Varden; rainbow
trout
High: as above
Low: blackfish; numerous
impediments to fish migration
Low: as above
Jnw: as at>ove
I
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Table 4-7. Conf d.
Pipe
FC24W
FC24W
PC30
FC30
FC30
PC36
PC36
FC36
FC36
PCF30
PCF30
PCF30
HC
HC
WP
ARRS
R78
CCI
CCI
CCI
JLN
JLE
JLS
Crossing Adjacent Approximate Location
x South of Spenard Road and
Turnagain Street
x Entire length
x South of Forest Road
x North of Spenard Road near
West 42nd Place
x Entire length
Northern Lights Boulevard near
Forest Park Drive
Forest Park Drive near Northern
Lights Boulevard
Alaska Railroad and Chester
Creek
x Entire length
x Alaska Railroad near Fish
Creek
x Alaska Railroad and Chester
Creek
x North of Northern Lights
Boulevard
x Telequana Drive and Katmai
Circle
x Entire length to Katmai Circle
x Near Wickersham Park
x Alaska Railroad north of Tudor
Road
x Alaska Railroad near 73rd
Avenue
x C Street near Campbell Creek
x Campbell Lake outlet
x Entire length
x Jewel Lake Road near West
88th Avenue
x I West 88th Avenue near Jewel
Lake Road
x ' Blackberry Street near West
Stream
Fish Creek
Fish Creek
Fish Creek
Fish Creek
Fish Creek
Fish Creek
Fish Creek
Chester Creek
Fish Creek
Fish Creek
Chester Creek
Fish Creek
Hood Creek
Hood Creek
Campbell Creek
Fish Creek
Campbell Creek
Campbell Creek
Campbell Creek
Campbell Creek
Unnamed stream
Unnamed stream
Unnamed stream
Mew
Fishery Value Right-of-Way
Low: as above Yes
Low: as above Partially
Low: as above
Low: as above
Low: as above
Low: as above
Low: as above
Moderate:
Low: as above
Low: as above
Moderate:
Low: as above
None: inadequate flow
None: inadequate flow
High: salmon migration and
spawning; Dolly Varden; rainbow
trout
Low: as above
High: salmon migration and
spawning; Dolly Varden;
rainbow trout
High: as above
High: as above
High: as above
None: drainage from Sand Lake
None: drainage from Sand Lake
None: drainage from Sand Lake
Below
Headwaters
No
No
No
No
No
No
No
Yes
No
No
Yes
No
No
No
Yes
No
,Yes
Yes
Yes
Yes
No
No
No
Dimond Boulevard
-------
Table 4-7. Cont'd.
Pipe
JLS
JLS
CKBNE
CKBNE
KR
HE
SEI
SEI
FCI
Crossing Mjacent Approximate Location
x West Dimond Boulevard near
Blackberry Street
x Entire length
x Campbell Creek at West Diirond
Boulevard
x Greenbelt Drive to Crystal
Drive
x Klatt Road and Victor Street
extended
x Huffman Road near New Seward
Highway
x Frontage road south of Huffman
Road
x Huffman Road
x Rabbit Creek west of Ptarmigan
Stream
Unnamed stream
Unnamed stream
Campbell Creek
Campbell Creek
Unnamed stream
Furrow Creek
Furrow Creek
Furrow Creek
Rabbit Creek
Fishery Value
None: drainage from Sand Lake
None: drainage from Sand Lake
High: Salmon migration and
spawning; Dolly Varden;
rainbow trout
High: as above
None: drainage from Campbell-
Klatt Bog
None: inadequate flow and
significant litter and debris
above Old Seward Hiahwav
None: inadequate flow and
significant litter and debris
above Old Seward Highway
None: as above
Moderate: small runs of Coho
New
Right-of-way
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Belcw
Headwaters
No
No
Yes
Yes
No
No
No
No
Yes
RCI
Iterrace
Little Rabbit Creek near Old
Seward Highway
Little Rabbit Creek
and pink salmon; Dolly Varden;
whitefish
Low: few salmon; Dolly Varden
Yes
Yes
-------
o No change in preconstruction bottom contour will
occur.
o Activity will not be located in proximity to a
public water supply intake.
o Activity will not destroy threatened or endangered
species.
o Backfill material will be -free from toxic pollutants
in toxic amounts.
o Activity will be maintained to prevent erosion and
other nonpoint sources of pollution.
o Activity will not occur in a component of a wild
and scenic river system.
o Best management practices listed in Section 330.6 of
the regulations are followed to the maximum extent
possible. These include:
- Avoiding or minimizing discharge into waters of
the United States and wetlands;
Avoiding, spawning areas during spawning season;
Avoiding the impediment of the movement of
indigenous aquatic species or high water;
Avoiding adverse impacts caused by changes in
water flow rate;
Placing heavy equipment on mats in wetlands;
- Avoiding discharge into migratory waterfowl
breeding areas;
Removing temporary fills in their entirety -
If any of these conditions are not met by the project facilities,
an individual 404 permit will be required for that part of the.
facilities plan.
Ship Creek. Ship Creek has high fishery values as one of
the two major streams for salmon rearing in the Anchorage area.
Migration of king, coho, pink, and sockeye salmon occurs June
through September; spawning occurs July through November. Fish
passage structures permit migrating salmon to reach spawning
grounds upstream of the dam- at Chugach Electric"s power
generation facility- The Alaska DFG maintains a fish hatchery
on Ship Creek near the Elmendorf bypass.
119
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The Mountain View area is served by an interceptor (SC in
Figure 3-6) paralleling Ship Creek on the south bank, and even-
tually crossing the creek just downstream of the fish hatchery.
Most of the route is through industrial development; however,
the crossing of Ship Creek just below the fish hatchery
is likely to adversely impact salmon during the construction
period. Improper timing of construction could impede the
movement of adults bound for spawning gravels upstream
of the construction site, or the deposition of fine sediments
in spawning redds downstream of the construction site.
An impediment to salmon migration or excessive sediment
deposition could reduce the number of adult salmon returning
to spawn in subsequent years. The extent of the impact
depends on the timing of construction and the mitigation
measures incorporated into the construction program.
Chester Creek, Chester Creek and South Fork Chester
Creek have moderate fishery value. Although much of the
stream is channelized, a few natural channel areas retain
spawning gravels and good fish habitat. Projects (as de-
scribed in Table 4-7) likely to adversely impact fish habitat
during the construction period include: NL18, U14 where
they cross South Fork Chester Creek, DB15 where it crosses
South Fork Chester Creek, and CC24 between Maplewood Street
and Latouche Street. The Middle Fork Chester Creek (draining
Russian Jack Springs area) has ample flow and gravel substrate
to support fish, but heavy algal growth suggests poor water
quality. Fish were spotted in July 1982 near 20th Avenue
and Sunrise ball diamond. The North Fork of Chester .Creek
(draining along Sitka Street) is now routed through a drainage
ditch, and is poor fish habitat.
Fish Creek. Fish Creek has low fishery value, particularly
upstream of West 35th Avenue. Fish migration has been sub-
stantially impacted by the placement of narrow culverts on
the Alaska Railroad crossing near the mouth and on almost
all road crossings upstream of that point. Projects (as
described in Table 4-7) likely to adversely impact fish
habitat during the construction period include: BNL and
FC36 downstream from the corner of Northern Lights Boulevard
and Forest Park Drive. The major impact of all projects on
Fish Creek (BNL, FC24W, FC30, FC36, FCF30, ARRS) probably will
be an increase in turbidity which may be noticed in lower
Fish Creek.
Hood Creek. Hood Creek has low flow and little
or no fishery value upstream of the area impacted by the
facilities plan (sewer line HC in Figure 3-6). One homeowner
has developed a pond on Hood Creek as part of the landscaping.
Campbell Creek. Campbell Cireek has high fishery value
as one of the two major streams for salmon rearing in the
Anchorage area. Pink salmon spawning occurs from Campbell
Lake upstream to the confluence of North and South Fork of
120
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Campbell Creek. Migration of king, coho, pink and sockeye
salmon occurs June through September; spawning occurs July
through November. The entire length of Campbell Creek provides
rearing habitat for king and coho salmon throughout the year.
Dolly Varden is a resident "species of Campbell Creek.
All projects on Campbell Creek or in the greenbelt (R78,
CCI, CKBNE) are likely to adversely impact salmon during
the construction period. Improper timing of construction
could impede the movement of adults bound for spawning gravels
upstream of the construction site, or cause the deposition of fine
sediments in spawning redds downstream of the construction
site. An impediment to salmon migration or excessive sediment
deposition could reduce the number of adult salmon returning
to spawn in subsequent years. The extent of the impact depends
on the timing of construction and the mitigation measures
incorporated into the construction program.
Furrow Creek. Furrow Creek has low flow and no fishery
value above Old Seward Highway and impacts on fishery resources
are not significant.
Rabbit. Creek. Rabbit Creek has moderate fishery value,
supporting small runs of coho and pink salmon and resident
populations of Dolly Varden and whitefish. Tidal" gates under
the Alaska Railroad embankment are a major obstacle to fish
migration. The Rabbit Creek interceptor is likely to adversely
impact salmon during the construction period. The project
area is close to Potter Marsh, and impacts from turbidity
may be noticed in Potter Marsh. This issue is addressed
in the Impacts on Potter Marsh section.
Little Rabbit Creek. Little Rabbit Creek has low fishery
value. Although impacts on fishery resources in Little Rabbit
Creek are not significant, the project area is close to Potter
Marsh, and impacts from turbidity may be noticed in Potter
Marsh. This issue is addressed in the Impacts on Potter
Marsh section.
Mitigation of Pipe Emplacement Impacts
A number of potential impacts associated with emplacement
of pipes across or adjacent to wetlands, streams, lakes or
ponds have been identified in the previous section. Most
of these impacts may be mitigated by appropriate actions
or techniques. These impacts and appropriate mitigation
measures are summarized below.
Loss or Alteration of Habitat in Wetland Areas by New
Sewer Right-of-Way in Wetlands Designated for Preservation
by the MOA. This impact can best be mitigated by not routing
121
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new sewer lines through wetlands designated for preservation
by the MOA. This measure in particular would be of great value at
Sand/Sundi/Jewel Lake Bog.
If a new right-of-way must be established in a wetland
slated for preservation, steps should be taken to minimize
the persistence of barren soil on the right-of-way. Few
guidelines are available for restoring the displaced bog
species (Alaska Agricultural Extension Service 1972; Johnson
and Van Cleve 1976), Efforts should be concentrated
on seeding the right-of-way as soon as possible with bluejoint
grass and fertilizing the stripped area with the appropriate
nutrients.
Loss of Waterfowl and Shorebird Nesting Habitat. Loss of
nesting habitat for bird species is an unavoidable adverse
impact resulting from direct and indirect impacts of the
facilities plan. This loss is particularly severe if lines
CKB and KR in southern Campbell-Klatt Bog encourage development
in this wetland area. The loss may be partially reduced by
blasting new potholes in wetland areas designated for pre-
servation by the MOA. This effort may encourage nesting
activity by certain ducks and geese.
Alteration of Groundwater Movement Into or Out of Wetlands.
This impact can be partially mitigated by the use of impervious
backfill material at strategic locations along the right-
of-way. For example, impervious material should be used
as backfill material at the boundaries of wetlands and at
regular intervals (e.g., 100 m intervals) along rights-of-
way through greenbelt areas. These measures would reduce
the amount of groundwater moving through the more porous
gravel typically used as backfill material.
Increased Sediment Load In Streams and Impediment to
Fish Migration. See mitigation for short-term construction
impacts, Chapter 10.
Hydrologic Impacts
The most obvious feature of wetlands is their wetness,
and any activity which permanently alters the hydrology of
a wetland area is likely to lead to permanent changes in
the biota of the wetland. This is particularly true of bog
habitats that are not directly fed by stream flow. The
obvious and immediate impact of pipe emplacement in wetlands
is the destruction of vegetation in the right-of-way and
the long-term alteration of habitat (see Pipe Emplacement
Impacts). Much more subtle, but perhaps more significant,
is the delayed impact on hydrologic features of the wetland.
Most peat bogs, such as those comprising the majority
of wetlands in the study area, are natural water-retaining
basins (Moore and Bellamy 1974). In some ways, their character
122
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is analogous to a teacup filled with- water and cotton. If
a buried pipe were placed through a wetland and if backfill
material were used which did not impede water movement, the
action would be approximately analogous to chipping the rim
of the cup, allowing some of the water to drain'away. To
continue the analogy, water level in the cup (bog) will probably
sink below the level of the damaged area because the cotton
(peat) will act as a wick bringing moisture to the outlet
area. This dewatering process will adversely change the
biological and hydrologic values of wetlands.
Two lines of evidence support the contention that the
dewatering process has occurred in the past in the Anchorage
Bowl. The first is the observation that water level in Sand
Lake declined following construction of a sewer line at the
margin of the Sand/Sundi/Jewel Lakes Bog, and water levels
no longer display the historical pattern of fluctuating with
local precipitation patterns (Quadra Engineering, Inc. 1981).
The second line of evidence is based on a series of
aerial photographs of Connors Lake Bog, beginning with a
1964 photograph (Figure 4-8) and including 1970 (Figure 4-9),
1975 (Figure 4-10), 1978 (Figure 4-11), 1980 (Figure 4-12),
and 1981 (Figure 4-6). Interceptor sewers were installed
in 1965 on the western boundary of the bog, between 1970
and 1972 angling through the bog (West Bypass Interceptor A),
and in 1979 along the Raspberry Road alignment (78-inch West
Bypass Interceptor. The series "of photographs, when correlated
with the precipitation patterns shown in Table 4-8, indicates
a gradual dewatering of Connors Lake Bog.
The June 1, 1964 photograph can be used as a reference
point because it precedes construction of interceptor lines
through Connors Lake Bog, follows a period of slightly below
normal winter precipitation and heavy spring precipitation
(Table 4-8), and also follows any tectonic changes in eleva-
tion associated with the 1964 earthquake.
The July 7, 1970 photograph is taken following a 15-
month period of below normal precipitation. As might be
expected, water levels in Connors Lake and Blueberry Lake
are lower, and the hollows in the bog show little sign of
flooding. On the other hand, the June 27, 1975 photograph
is taken at the end of a wet winter and spring. Although
the hollows in the bog are flooded and water level in Blueberry
Lake is similar to 1964, the water level in Connors Lake
has dropped further. The general dewatering trend is most
obvious in the September 10, 1980 photograph, which follows
a period of wet to very wet weather since the winter of 1978-
1979- Water levels in Connors Lake and Blueberry Lake remain
low relative to 1964, and the hollows in the bog show little
sign of flooding. Low water levels in the lakes and the
absence of open water in the hollows was still obvious as
of June 30, 1982.
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Figure 4-8. 1964 Photo of Connors Lake Bog
Connors Lake Bog prior to installation of the sewer as outline in Figure 4-6. North is
towards the top of the photo. Connors Lake is in the upper left corner, Blueberry Lake
is at right center, and Strawberry Lake is in the lower right corner. Note the drainage
ditch system in the lower half of the photo.
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Figure 4-9. 1970 Photo of Connors Lake Bog
Connors Lake Bog during installation of the sewer as outlined in Figure 4-6.
'access road for construction equipment' and small pond at upper center.
Note the
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Figure 4-10. 1975 Photo of Connors Lake Bog
Connors Lake Bog following construction of sewer as outlined in Figure 4-6. Water level in
Connors Lake remains low, although water level in Blueberry Lake has returned to that noted
in 1964 photo (Figure 4-8). Small pond at upper center has been filled by the Municipality
solid waste landfill.
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Figure 4-11. 1978 Photo of Connors Lake Bog
Note significant reduction in water levels in Connors Lake, Blueberry Lake, and Strawberry
Lake. Stockpiling of sewer pipe for the 78" West Interceptor along Raspberry Boad is
evident.
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Figure 4-12. 1980 Photonosaic of Connors Lake Bog
Note stockpiling of sewer pipe for 78" West Interceptor. Construction of Raspberry Road
and Minnesota Drive" is underway.
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Table 4-8. Precipitation (in inches) Surmery for Periods Preceding Aerial Photography of Connors Lake Bog
Previous Winter Mean Winter Total For Pre- Mean Total For Preceding
Date of Photo Precipitation1 Precipitation2 ceding 3 mos. Preceding 3 mos. 2 Month Total
June 1, 1964 5.19
July 7, 1970 4.40
June 27, 1975 7.38
September 17, 1978 5.17
September 10, 1980 9.22
September 22, 1981 6.26
6.00 2.93
6.00 1.55
6.00 2.65
6.00 5.41
6.00 8.06
6.00 10.18
1.80
2.28
1.80
5.27
5.27
5.27
0.97
0.85
0.40
0.54
3.06
4.96
Mean Total
Preceding Month2 SumiBry
0.57
1.14
0.57
2.20
2.20
2.20
Dry Winter; Wet
Spring
Dry
Wet
Dry Winter;
Normal Spring
Very Wet
Normal Winter;
Very Wet Summar
FOOTNOTES:
1October - March, inclusive
21943-1980 (NQAA 1980)
Source: NOAA 1981, 1982
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In all the photographs following 1964, water levels
in Strawberry Lake have dropped, probably because of the
construction of a drainage ditch system into and out of
Strawberry Lake. In general, the sequence of photographs
reveals that water levels have dropped in Connors Lake and
Blueberry Lake and hollows no longer contain open water,
even in very wet years such as 1980.
Additional hydrologic impacts may result because of a
loss of wetlands to development. Wetlands, particularly
those in floodplains, tend to display a water-retention
ability which reduces peak flood flows and maintains stream
flow and groundwater movement during low flow periods. It
is not clear how important wetlands are in moderating stream
flows or groundwater movement in the Anchorage area. The
impacts of growth-induced development of wetlands on loss
of hydrologic function cannot be assessed with the available
information. Most of the wetlands designated for preservation
by the MOA occur in greenbclt areas along major streams. There-
fore, the impacts on wetland hydrology are most likely to be
associated with effects on groundwater, because wetlands in the
floodplain are not as likely to be developed.
Additional indirect hydrologic impacts may result from
the use of permeable material as backfill. Pipe corridors not
only may act as corridors for water movement into or out
of wetlands, but also may divert groundwater away from wetland
areas when the pipe corridor is adjacent to a wetland and
perpendicular to the path of groundwater movement. These
impacts may be of diminished importance when- the wetlands
appear in a floodplain, but may be very important to isolated
bogs .
Mitigation of Hydrologic Impacts
Two major hydrologic impacts on wetlands and streams
have been identified in the previous section. These impacts
and appropriate mitigations are summarized below.
Alteration of Groundwater Movement Into or Out of Wetlands.
This impact and appropriate mitigation measures are discussed
following the section on pipe emplacement impacts.
Alteration of Stream Flow. No feasible mitigation measures
can be proposed until site-specific details are available
on the hydrologic function of the specific wetland and the
impact of the proposed project.
Secondary Biological Impacts
Secondary (indirect) biological impacts of the sewerage
facilities expansion relate primarily to induced growth in
the urban area. Urbanization of the Anchorage Bowl has already
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altered some wildlife values of the area. For example, the
moose population in the area (see Biological Setting) has
dropped to one-third the population of 30 years ago, primarily
because of a loss.of winter habitat in the Bowl (Harkness
pers. comm.). Additional urbanization will place additional
constraints on winter foraging by moose in the Anchorage
area. As another example, restrictions on sportfishing in
Campbell Creek and Rabbit Creek have been promulgated in
order to maintain a salmon fishery, forcing sportfishermen
to travel elsewhere for salmon fishing. The increased popu-
lation growth in Anchorage over the past 20 years has increased
pressure on resources such as salmon, waterfowl, and wilderness
habitats in areas within reasonable driving distance of the
Anchorage area.
The facilities plan will remove a major constraint on
population growth in the Anchorage Bowl, particularly in
the area south of Tudor Road. If population saturation is
reached in 20 years and if all wetlands designated as develop-
able by the wetlands management plan are developed, then
a loss of about 55 percent of the remaining nontidal wetland
habitat in the Anchorage Bowl would result. The major conse-
quences of .this overall loss are likely to be: 1) altera-
tions in the hydrologic regimes of streams, 2) changes in
groundwater movement, and 3) a major loss of bird nesting
habitat including a well-established Canada goose nesting
area at Heather Meadows (C Street and Tudor Road) and in
southern Campbell-Klatt Bog.
Mitigation of Secondary (Growth-Related) Biological Impacts
If appropriate mitigation measures mentioned elsewhere
in this chapter are adopted, losses of hydrologic and bio-
logical values may be reduced to a limited extent. Short
of restricting population growth, it does not seem practical
to offer mitigation measures for cumulative impacts. If
growth is to occur in the Anchorage Bowl, it may be preferable
to confine the losses to the already urbanized area, and not
attempt to expand growth to outlying, more pristine areas.
Human Use Impacts
The use of wetlands as open space and recreational areas
may be altered if sewer interceptors cross wetland areas
or if the improved sewer system encourages population growth
in the Anchorage Bowl. Adverse impacts include: loss of
wetlands because of development pressure; decrease in wildlife
abundance (especially nesting waterfowl) because of increased
recreational activities on remaining wetlands; and loss of
wildlife and fish habitat because of alterations in a hydrologic
regime and, subsequently, habitat. To many residents accustomed
to urban living, these impacts may be acceptable, but to
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many citizens, particularly long-term residents, the open
space and wildlife within the Anchorage Bowl area are a
valuable aesthetic resource.
Beneficial imparcts can be realized when sewer interceptors
cross wetlands. Although emplacement of a sewer pipe in
a wetland removes the existing shrub vegetation on the right-
of-way, the right-of-way can serve as a new recreational
trail, particularly during the winter when cross-country
skiing and snow vehicle use are popular.
Potentially impacted areas may be identified by-Table 4-5
(sewerage interceptors crossing wetlands) and by examining
the wetland areas 'scheduled for development by the Anchorage
1982 Wetlands Management Plan.
Impacts on Potter Marsh
Sewerage has been proposed by the Hillside Wastewater
Management Plan for about 3,600 acres (18 percent) of the
Hillside area. Two major areas proposed for sewerage are
lower elevation areas between Abbott Road and De Armoun Road
and the area south of Rabbit Creek Road. These areas would
be served by the southeast interceptor and a proposed trunk
sewer running east of the Old Seward Highway east of Potter
Marsh. The proposed trunk line near Potter Marsh would be
connected to the southeast interceptor by a proposed pumping
station and force main along the New Seward Highway. The
proposed pumping station would be located near the small
airstrip on the north edge of Potter Marsh.
Short-Term Construction Impacts on Potter Marsh. The
trunk line east of Potter Marsh will cross Little Rabbit
Creek and Rabbit Creek. Most of the construction impacts
on Potter Marsh will be communicated to the marsh by these
two streams. Trenching and excavation activities•for stream
crossings will result in temporary increases in siltation
in the marsh. Some of the extra sediment burden may be trans-
ported out of the marsh at the next "breakup" or heavy storm
runoff, but a portion may remain permanently in the marsh.
Long-Term and Secondary Impacts on Potter Marsh. Home
construction in some areas of the Rabbit Creek watershed
is partially impeded by problems with on-site disposal systems.
Sewering the problem areas, as proposed by the Hillside Waste-
water Management Plan and the 201 facilities plan, will eliminate
this constraint, but may have adverse impacts on Potter Marsh.
The construction of additional housing units may increase
the sediment load transported by Rabbit Creek and Little
Rabbit Creek into Potter Marsh. Additional housing units
will increase demands on groundwater supplies, potentially
altering the hydrologic regime tributary to Potter Marsh.
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The sewering may provide benefits to Potter Marsh by
preventing on-site system construction and thereby precluding
water quality impacts due to system failure. Other portions
of the watershed that will not be sewered may develop with
on-site systems for sewage disposal. These areas will
increase the threat of water quality standards violations
in Rabbit Creek and in Potter Marsh. These issues are also
discussed in Chapter 5.
Mitigation of Sedimentation Impacts on Potter Marsh
Short-term construction impacts on Potter Marsh relate
primarily to temporary increases in siltation. One possible
mitigation measure is to reroute the collection system to
run along the seaward side of the Alaska Railroad embankment,
as shown in Figure 3-9 (Alternative 3 of the facilities plan) .
Alternatively, the interceptor could be jacked under the
streambeds, thereby minimizing the disturbance of the streambed,
Mitigation for growth-induced impacts is discussed in Chapter 5,
Pipe Emplacement Impacts on Tidal Wetlands
The facilities plan proposes construction in tidal
wetlands along the Alaska Railroad embankment from the down-
town area to the lower 'Fish Creek wetland area. Construction
along the railroad embankment between the downtown area and
the mouth of Fish Creek is unlikely to result in significant
adverse impacts on the environment. This area is charac-
terized by thick silt deposits and tidal action. Construc-
tion will likely have to occur during neap tides. Crossing
the mouth of Hood Creek and Chester Creek may cause increased
turbidity in these areas, but it is unlikely that the turbidity
resulting from construction will exceed or be distinguished
from the usual turbidity of Knik Arm water.
Construction in lower Fish Creek upstream to the Alaska
Railroad crossing may temporarily denude the pipeline right-
of-way. The existing right-of-way is slightly elevated
relative to the surrounding wetland, causing minor impounding
of water upslope of the right-of-way and providing space
for a slightly different tidal wetland vegetation type.
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Chapter 5
Hillside Issues
• Issue Summary
• Legal, Regulatory and Policy Constraints
• Human Use Setting
• Impacts of Sewerage Decisions on Hillside
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Chapter 5
HILLSIDE ISSUES
The Hillside Wastewater Management Plan comprises one
element of the Section 201 facilities plan for Anchorage.
The plan encompasses the Hillside area south of Abbott Road,
East of New Seward Highway and west and north of Chugach State
Park. The purpose of the plan is "...to identify on-site and
alternative wastewater disposal techniques, the boundaries of
the areas where on-site disposal [is] not possible and those areas
in which some method of on-site alternative system should be
feasible, and to identify appropriate and supporting land use
recommendations" (MOA 1982).
The issues and potential environmental impacts of the
Hillside Wastewater Management Plan are distinct in many ways from
those related to the remainder of the Anchorage Bowl. This
chapter addresses these issues and evaluates the impacts of the
plan.
Issue Summary
The Hillside area has been sparsely settled by residents
who wish to live in a less crowded area than exists elsewhere
in the Anchorage Bowl, and who wish to retain some flavor of
rural Alaska in their residential setting. One- to five-acre
zoning is common, although some areas are platted with lots as
small as one-quarter acre. With the exception of a few areas
close to New Seward Highway the Hillside does not have public
water or sewers. Instead, the area relies on individual
domestic wells for water supply and individual on-site sewage
disposal systems such as septic tanks with drain fields.
In 1979 a study was completed for the MOA that proposed
sewer line extensions into the Hillside .area (URS-Bomhoff 1979).
Residents and groups objected, fearing that sewering would enable
dense development of the Hillside. They were also concerned
that the expense of public sewers would necessitate a more dense
development pattern to reduce to a reasonable amount the per lot
costs for bringing sewers to the Hillside.
Strong opposition to sewers continues today. The opposition
to sewers is apparently a direct reflection of the desire to
retain the rural character of the Hillside by allowing the
limited water supply and marginal suitability for on-site sewerage
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disposal on the Hillside to provide a practical limit to develop-
ment densities. The U. S. Geological Survey, in Hydrology for Land
Use Planning: The Hillside Area, Anchorage, Alaska »'U. S. Geolo-
gical Survey 1975), seriously questioned the ability of the
Hillside to support added development while protecting surface
water quality, groundwater quality, and individual water supply
wells. The U. S. Geological Survey concluded that:
"Dense development may result in the local depletion of aquifers
or increased surface drainage problems, or lead to ground and
surface water pollution unless community water and sewage facili-
ties are substituted for individual systems in the susceptible
areas...
"In numerous locations, steep slopes, swamps and shallow ground
water, and low permeability of surficial earth materials could
make the use of septic tank systems hazardous to public health,
and also cause critical drainage conditions. Septic tank effluent
must percolate into and be cleansed by surficial sediments; other-
wise, streams, lakes, aquifers, and even the land surface can be-
come contaminated. At this time, the total load of pollutants
that the sediments can absorb is not determinable, but onsite
waste disposal has the potential to cause pollution in much of
the Hillside area... Particularly where the land is not conducive
to cleansing liquid-waste discharge within critical distances,
the density of development will determine the degree of change in
water quality locally and downslope from development...
"Ground water in the Hillside area probably has not been polluted
by the current density of domestic sewage systems. However, the
probability of future aquifer pollution because of a much greater
density of onsite waste-disposal systems is relatively high in the
upper Hillside area..." (U. S. Geological Survey 1975).
Another influence is the limited supply of developable
land in the Anchorage Bowl. The confined geography of the Bowl
is likely to begin limiting growth several decades in the future,
and the Hillside will come under greater pressure to develop in
a more dense manner.
In response to these apparently conflicting concerns, the
MOA began preparation of the Hillside Wastewater Management
Plan in 1981. The objectives in preparing the plan were to
better define physical constraints to on-site sewage disposal,
delineate areas that would be served by public sewers and areas
that would be served by on-site sewage systems, and to provide
for proper and safe management of on-site systems to protect
public health.
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As described in Chapter 3, the plan delineates areas for
public sewerage and for on-site systems, and recommends land
use, construction, inspection, and maintenance practices to
help ensure successful operation of on-site sewerage systems
and protect public health.
Legal, Regulatory and Policy Constraints
The Hillside Wastewater Management Plan, adopted May 18, 1982,
is now a legal constraint on sewerage in the Hillside area. The
plan is described in Chapter 3, and certain specific features are
discussed later in this chapter. Other laws, regulations and
policies constrain on-site waste disposal, drilling of private
domestic wells, land division (platting) of unsewered areas, and
other activities relevant to the issues surrounding sewerage
options in the Hillside area.
Platting Guidelines
Municipal ordinances govern the minimum sizes of lots
allowed where development will utilize on-site sewage systems
in combination with individual wells or community water supplies.
Maximum density for on-site system lots using individual wells
is one residence per acre, while for lots using community water
supplies the limit is two residences per acre. Specific lot
square footage requirements vary.by soil type, and larger parcels
may be required where high groundwater or bedrock outcroppings
occur.
Each lot must be sized to provide one-half of its area at
a slope of less than 25 percent (14 degrees) available to provide
for three on-site disposal systems (one original system and two
replacements).
On-Site Sewage System Inspections
Prior to obtaining a building permit, an applicant must
provide evidence of suitability of the soils, location
(at least 100 feet from any stream, body of water or well), and
provide an acceptable system design. Minimum design standards
are prescribed and enforced by the MOA DHEP. Construction in-
spections are .performed by the Department to ensure conformance
with the requirements.
A second form of inspection occurs whenever a structure is
sold with financing through a commercial lending institution.
These lenders, as a protection of their investment in loans on
property, routinely require a reinspection of all on-site
sewerage systems and recertification of individual wells.
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Under this program septic systems two to four years old are
pumped, and systems over four years old are pumped and an
adequacy test performed on the leaching area. If the system
proves inadequate, it must be upgraded or funds for upgrading must
be placed in escrow before the lender will disburse "loan funds.
On-Site Water Well Inspection
The MOA enforces standards for water wells and requires
permits for drilling all wells. Municipal ordinances require
a sanitary seal and also set minimum casing depths of 40 feet
to prevent shallow infiltration into the well. Where bedrock
restricts this depth the casing must be seated in the bedrock.
A well log must be provided so that a permanent record is kept
of conditions encountered during drilling, and wells must be
tested and disinfected prior to use.
When property changes hands and is financed by a commercial
lender, laboratory water quality testing is required.
Human Use Setting
The Hillside area is one of the more desirable residential
areas in the Anchorage Bowl. In spite of difficult access
problems in upper parts of the Hillside during winter snow and
ice conditions, the area is attracting increasing large lot
development activity. Future development is an issue to those
residents already living in the area, as well as the rest of
the Anchorage Bowl residents who have an interest in the future
of their community.
The estimated population of the Hillside area was about
5,000 in 1973, and projections at that time suggested the
possibility of 15,000 people by 1985 (U. S. Geological Survey 1975)
Data in the Hillside Wastewater Management Plan suggest a 1980
population of about 11,200 persons with projections for saturated
development of 42,300 to 66,118, or from four to six times 1980
levels. It is projected that the Hillside may increase its
relative importance in providing Anchorage Bowl housing from the
present level of 7.2 percent of all dwelling units to 14.8 percent
(MOA 1982). These figures indicate that the MOA envisions growth
in the Hillside to levels much higher than the U. S. Geological
Survey assumed in conducting their 1975 study.
The western edge of the Hillside area has developed with
public sewers and water supplies. The balance of existing
development draws water from domestic wells and disposes of
wastes via on-site disposal systems. The Hillside plan proposes
that development continue in much of the area based on on-site
sewage disposal and individual wells, with public sewers provided
in certain areas (see Figures 3-4 and 3-5).
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Hydrologic Setting
The interrelationship of surface water, groundwater,
domestic wells and on-site sewerage systems is central to many
of the Hillside issues. This section describes the surface
water, groundwater and domestic water supply resources of the
Hillside area. In addition, Figure 4-5 provides a conceptual
view of the hydrologic cycle relative to Anchorage and helps
place some of the water resources relationships in perspective.
Surface Water
Five streams and numerous tributaries traverse the Hillside
area. The Little Campbell, Furrow, Rabbit, Little Rabbit, and
Potter Creeks rise in the Chugach mountains or in the eastern
Hillside and flow generally west. The south fork of Campbell
Creek also skirts the north and easterly boundaries of the
Hillside, but is not considered within the area covered by this
chapter.
Furrow Creek has relatively low flow much of the year,
and is not discussed further. Little Campbell Creek flows at
less than 2 cfs for most of the year, and almost stops during
severe winter icing. Rabbit Creek flows year around with an
annual average flow of 17 cfs. Little Rabbit Creek averages
about 6.2 cfs annually, with low flow of about 1 cfs (U. s.
Geological Survey 1975) . Average annual Potter Creek flows are
estimated at less than 3 cfs.
Water quality of these streams is generally good, although
some evidence of urban pollution is revealed in the limited .
testing that has been conducted. Little Campbell Creek evidences
occasional elevated coliform counts, minor amounts of lead and
nitrate that may be elevated above natural levels. Little Rabbit
Creek also has shown some high coliform levels. These pollutants
are typical of urbanized watersheds.
Groundwater
From Figure 4-5 it can be seen that the Hillside area serves
as a recharge area for part of the Anchorage Bowl, and is
therefore important to the Municipality's water sypply. Ground-
water is generally found in the Hillside area in sand and gravel .
lenses betweeen less permeable till layers, below confining hard-
pan layers, and to a limited extent in bedrock fractures. The
water-bearing deposits generally deepen and thicken with lower
elevation, and movement of groundwater occurs towards lower
elevations.
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Water budget estimates developed for the Hillside indicate
groundwater inflow to the area at the average rate of about 11 cfs
and outflow of about 8-13 cfs (U. S. Geological Survey 1975,
1982). Recharge, evapotranspiration, interchange between creek
flows and groundwater, precipitation, and data inaccuracies
affect these estimates. It is not known what proportion of
the estimated 8 to 13 cfs outflow discharges to Turnagain Arm
and how much recharges the confined aquifer under the Anchorage
metropolitan area. The U. S. Geological Survey estimates that
an annual average of about 116 cfs enters the confined aquifers
between the Little Rabbit Creek basin and the Ship Creek basin.
Groundwater quality is generally excellent for all beneficial
uses, including domestic water supply. In some locations well
water is treated to remove iron or reduce hardness.
Domestic Water Supply
Individual wells supply groundwater for domestic supply
in most of the Hillside area. Each residence has its own well
and pump, often a small hydropneumatic tank to maintain even
water pressure and, where wells yield at low rates, storage
tanks to provide for peak demand times. No treatment is -usually
required, unless iron is present, or it is desired to reduce
hardness.
Well testing is conducted regularly by the Municipality
for bacterial contamination. In 1981, the Municipality DHEP
tested over 1,200 wells at residences as part of resale inspections
and new well certification. The standard requires that no
coliform be present in the sample. A test failure-rate of less
than 1 per 1,000 wells tested is reported (Rasmussen pers. comm.
1982). The U. S. Geological Survey has occasionally tested wells
for chemical quality. Their 1975 Hillside report cited 12 wells
tested, with constituents within EPA water supply limitations.
Two wells reported nitrate levels of 7.8 and 9.0 mg/1, respectively,
close to the EPA standard of 10 mg/1. This standard is intended
to protect public health, specifically to prevent methemoglo-
binemia, a potentially fatal form of oxygen starvation in infants.
In March and May of 1982, u. S. Geological Survey sampled nine
additional wells for chemical constituents. A nitrate level of 6.5
was found in one shallow hand-dug well located south of Rabbit
Creek near Buffalo Street. The property has not changed hands
in many years, and the MOA retesting program has therefore-not
required upgrading. The nitrate contamination may be from shallow
septic tank seepage in the general area. No tests for bacterial
contamination were made (Brabetts pers. comm.).
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Impacts of Sewerage Decisions
on Hillside Area
The sewerage decisions relating to the Hillside area will
impact the resources and future residents of the area in various
ways. The impacts relate to whether or not public sewerage will
be provided, whether individual or cluster type on-site disposal
will be allowed on individual lots in the remaining area, and
whether these systems will function effectively over the long
term (at least for the EPA recommended 20-year planning period).
The areas to be sewered are evaluated first, followed by the
on-site system areas, incorporating the proposed cluster system
area.
Impacts of Sewering Portions of Hillside Area
Providing public sewers to the lower Hillside area between
Abbott Road and DeArmoun Road in accordance with the adopted
Hillside plan will allow development to occur at higher
density than could occur with on-site sewerage systems.
Densities of 3 dwelling units per acre and greater were proposed
in the plan.and discussed between the Planning Department and
"Hillside Advisory Committee during plan formulation. The
densities in these areas were often at issue, and objections were
apparently resolved by defining buffer areas and standards to
effect an acceptable transition between low density (on-site
sewerage) and higher density (public sewerage) areas. Transition
Area Standards were adopted as part of the Hillside plan.
Establishment of densities in the entire Hillside area now awaits
adoption of the Comprehensive Development Plan. The decision to
provide sewerage to this area has thereby removed a constraint
to growth.
If the sewers to be provided in this area have extra capacity
such as can occur through conservative design (that is, provision
for high infiltration flows, high peaking factors, or other
factors), future extension of sewerage service to adjacent por-
tions of the Hillside may be possible. The MOA Planning Department
indicated in Assembly hearings on the Hillside plan that a 25
percent oversizing was being incorporated into design of inter-
ceptors serving the Hillside area; Water and Sewer Utilities
representatives later questioned these statements. The facilities
plan does not indicate a 25 percent allowance in flow computations.
(See interceptor sizing discussions in Chapter 3).
If the area .of public sewerage is expanded in the future,
premised on extra downstream sewer capacity, the timing of
such an expansion would be an important factor in determining the
effects of oversizing. If oversizing occurs, but no new sewer
extensions are .authorized until rural density development patterns
are assured, then few development impacts would occur. There could
be some pressure to subdivide single lots into two or three
parcels in some cases. If authorization to extend the sewerage area
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were to occur early in the development process, however, the
availability of sewers may induce some landowners to seek the
greater profits' from development of their lands that can occur
at higher residential densities. Depending on the attitude of
approval agencies, the excess capacity could affect land use
density under these circumstances.
Higher densities than currently allowed would decrease the
rural character of the affected portion of the Hillside, lending
a more urban character to the area. This would be contrary to
the desires of many current residents of the area, and would be
contrary to.the implied objective of the Hillside plan to main-
tain low density development through exclusion of sewers.
Greater densities would accommodate a greater population in the
Anchorage Bowl and provide a greater total population holding
capacity.
Provision of extra capacity in downstream interceptor sewers
may provide a benefit in future years if on-site system failures
increase in frequency or water supply contamination occurs, and
residents press for public sewers. This is discussed in greater
depth later in this chapter.
Sewering the lower Hillside area south of Little Rabbit
Creek, as shown in the Hillside plan will enable development
at significantly higher densities than would otherwise occur
supported by on-site sewerage systems. The Golden View Drive
area and much of the Potter Creek watershed were judged generally
unsuitable for on-site treatment systems (Figure 3-5), and
portions of these areas may not be developable without sewers,
even with innovative (special technology) on-site systems. Thus,
sewering of this area can be considered growth-inducing. Chapter 7
provides additional information on the secondary impacts of growth.
If surplus capacity is provided in the Potter Creek-Rabbit
Creek collection system, pump station and force main, further
extension of the sewerage facilities could occur, with impacts
similar to those discussed above for the northern portion of
the Hillside area.
An additional issue relative to development of the south
Hillside area centers on water supply to Potter Marsh. It has
been suggested that a new water supply for the south Hillside
would be developed from surface water in the area, and that inflow
to Potter Marsh would be reduced. Potter Marsh is fed by Rabbit
and Little Rabbit Creeks. The worst case impact that could occut
would be for the entire water supply to be developed in Rabbit
and Little Rabbit Creeks. (Potter Creek does not flow to Potter
Marsh, and may have insufficient flow to provide a dependable
water supply.
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Total natural inflow to Potter Marsh from Rabbit and Little
Rabbit Creek is estimated at about 23 cfs (U. S. Geological Survey
1975). The quantity of sewage to be exported from the area in
the proposed pump station and force main is about 1.1 mgd or
1.7 cfs. In addition to this export,_some of the developed water
supply will become surface runoff due to car washing, lawn
watering and other activities, and some will be lost through
evaporation. An estimated water supply averaging 2 mgd or 3.1
cfs would be required, based on 145 gallons per capita per day,
the estimated consumption rate in the Anchorage Bowl. Thus
the maximum impact of developing a water supply for the sewered
area of the South Hillside area from Little Rabbit and Rabbit
Creeks would be to reduce Potter Marsh inflow from about 23 cfs
to as low as 20 cfs on an annual basis.
At some times of the year combined inflow from Rabbit and
Little Rabbit Creeks is less than 6 cfs. At such times water
diversions could reduce inflow to Potter Marsh by more than 50
percent. The wildlife values of Potter Marsh could be adversely
affected by such a change in hydrologic regime. Fishery resources
of the creeks could also be adversely affected.
The presence of sewers in and adjacent to Potter Marsh pre-
sents a threat of spills and seepage of untreated sewage to the
Marsh. If the pump station or force main near Rabbit Creek were
to fail, sewers would overflow at manholes once their' limited
storage capacity is filled.
Seismic activity and frost heaving can separate pipe joints,
move manholes and allow infiltration as well as exfiltration,
depending on groundwater depth as compared to pipe depth.
Seismic activity in particular can cause catastrophic damage,
and could disable the sewerage system for an extended period.
The potential impact of contamination of Potter Marsh can
be partly mitigated by providing standby pumping and storage
capacity at the Rabbit Creek Pump station. Conservative design
and construction practices can help reduce the susceptibility of
sewers to frost heaving and seismic activity, lessening infiltra-
tion and exfiltration.
Impacts of Designating On-Site Sewerage for Portions of Hillside
Area
By adopting the "Recommended Maximum Perimeter of Public
Sewerage" the Municipality has excluded sewers from a major
portion of the Hillside area. In order to develop within this
unsewered area each landowner must demonstrate that adequate land
is available to support three drain fields and that other conditions
are met. If a property is located on areas designated as generally
143
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unsuitable for on-site treatment systems, approval is more
difficult, but is still possible. Innovative (special technology)
on-site systems are required unless it can be shown that the
traditional system is acceptable.
The Hillside plan will keep maximum densities at or below
one dwelling unit per acre unless a community water supply is
provided, in which case maximum densities of 2 dwelling units
per acre would be allowed. In addition, where areas judged
generally unsuitable for on-site systems are designated, develop-
ment may, in some cases, be precluded. However, the plan does
provide that "...innovative systems as well as the conventional
deep trench system may be used in those areas identified as
generally unsuitable where it can be demonstrated that particular
site conditions allow for such on-site wastewater treatment".
The extent to which development would be precluded will depend on
the criteria applied by the Municipality in reviewing specific
lots and development proposals.
Table 5-1 provides a generalized indication of the areas
designated as suitable and unsuitable for on-site systems in the
Hillside area. It can be seen that approximately 5,840 acres
in the Hillside area, comprising 30 percent of the study area,
are judged unsuitable for on-site treatment. Of these unsuitable
acres only 1,560 or 27 percent are proposed to be served by
sewers. The recommended plan for wastewater treatment and dis-
posal on the Hillside does not appear to solve the problem of
waste disposal on lands judged unsuitable for on-site treatment
systems.
The potential for development of these generally unsuitable
areas may lead to higher failure rate and cumulative impacts on
the area's water resources. Enterprising landowners are likely
to exert strong efforts to demonstrate suitability of some type of
innovative system on their property. The economic and social
rewards of owning a home in the exclusive Hillside area will
provide a strong impetus for continued development, including the
generally unsuitable areas. This reasoning suggests that the
Hillside will experience significant infill largely independent
of suitability designations.
As noted earlier in this chapter, the U. S. Geological Survey
raised significant questions in 1975 as to the local depletion
of aquifers, increased surface drainage problems, groundwater
pollution and surface water pollution as a result of continued
development supported by individual wells and on-site sewage dis-
posal. The following sections discuss these issues and explore
potential impacts and mitigations.
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Table 5-1. Tabulation of Areas to be Served
by Public Sewers and by On-Site Sewerage
Systems in the Hillside Area
Total Study Area
Generally suitable for on-site treatment
Generally unsuitable for on-site treatment
Not evaluated
Areas to be Served by Public Sewers
Generally suitable for on-site treatment
Generally unsuitable for on-site treatment
Not evaluated
Area to be Excluded frcrn Public Sewerage
Generally suitable for on-site treatment
Generally unsuitable for on-site treatment
Not evaluated
Area In Acres
19,550
10,850
5,840
2,860
4,120
2,250
1,560
310
15,430
8,600
4,280
2,550
% of
Subarea
100%
55
30
15
100
55
38
7
100
56
28
16
% of
Study
Area
100%
55
30
15
21
11
8
2
79
44
22
13
Area in Acres
% of
Evaluated
Area
Area to be
Sewered,
Acres
Area not
to be
Sewered,
Acres
Total Evaluated Area* 16,690
Generally suitable
for on-site treatment 10,850
Generally unsuitable
for on-site treatment 5,840
100%
65%
35%
3., 810
2,250
1,560
100% 12,880 100%
59% 8,600 67%
41% 4,280
33%
* 19,550 acres less 2,860 acres in public ownership or otherwise excluded from suit-
ability analyses.
SOURCE: Jones & Stokes Associates, calculated from maps in Hillside Wastewater Manage-
ment Plan, MOA 1982.
145
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Water Availability Impacts. The Hillside plan does no't
address the water supply, issue. EIS analyses assume that indi-
vidual wells will continue to be the source of domestic water
for the Hillside. As U. S. Geological Survey points out, water
availability is very limited in localized portions of the Hill-
side, even though sufficient water resources exist on an area-
wide basis to support full development. Some development may
be precluded by an inability to develop a well. It is also
possible that numerous wells tapping the same limited aquifer
could exceed the recharge of the aquifer, leaving upslope or
shallower wells without water.
This impact can be mitigated by providing a public water
supply system to the area, or by limiting development by water
availability based on evaluation of local groundwater supplies.
Surface Drainage Problems. The Hillside area has certain
unique surface drainage problems that may subject development
to risk of damage, and which complicate the use of on-site
disposal systems. With the exception of the major streams, much
of the area lacks defined natural drainage channels; wetland
areas are present on the Hillside, along with areas with shallow
groundwater; flood hazard areas adjoin the major creeks; and
water icing and spring thaws complicate transportation and
affect local drainage.
Conflicts between these natural conditions and urban develop-
ment are likely to increase as residential infill occurs in
the Hillside. For example, development may increase total runoff
and may inadvertently channel it towards existing downstream
residences. The Hillside plan includes a requirement that surface
water disposal plans be prepared covering "...erosion and sediment
controls, water quality controls, surface water conveyance and
disposal, and on-site system operation". This requirement will
help mitigate some of the risks to development related to the
drainage problems of the Hillside. It may be difficult for an
individual property owner to evaluate .the total area tributary
to his property, and to plan for flow leaving his property if he
has to provide a plan for it to reach a distant watercourse.
Areawide drainage planning, similar to that being conducted
elsewhere in the Anchorage Bowl, combined with the requirement for
individual drainage plans, would provide a more unified approach.
Drainage planning should also recognize flood risks. Flood-
plains that are presently delineated should be maintained free
of development, and it may be desirable to develop floodplain
mapping for presently unmapped areas.
Wetland areas are protected under Section 404 of the Clean
Water act, locally administered by the Corps of Engineers.
Chapter 4 discusses wetland issues and impacts in. detail. It
146
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should be noted that the "waterlogged" areas defined by U. S.
Geological Survey•in 1975 differ in location and area from the
wetland areas shown in the Municipality's Wetlands Management
Plan.
Additional discussion of drainage concerns related to
development can be found in the 1975 U. S. Geological Survey
report.
Groundwater Quality and Public Health Impacts. The 1975
U. S. Geological Survey Hillside study provided strong indications
that increased development of the Hillside area with on-site
sewerage systems will significantly increase the risk of
groundwater pollution. The concerns and cautions of that report
remain valid. Further, the higher level of growth projected in
the Hillside plan as compared to in the U. S. Geological Survey
report intensifies these concerns.
It is estimated that the Hillside area population has
more than doubled from about 5,000 in 1975 to about 11,200
in 1980. The Hillside Wastewater Management Plan projects
a four- to six-fold population increase to a level between
42,300 and 66,118 at full build-out. About 23,000 of these
people would be served by some 9,000 on-site sewerage systems
(MOA 1982). In contrast, the U. S. Geological Survey report
expressed concerns based on a projected Hillside population
of only 15,000 by 1985. While the areas covered by the two
studies differ somewhat, these population projections both
appear to cover the Hillside area in total. In any event,
the population that is likely to be present in the Hillside
area in the year 2005 (EPA1s Section 201 planning period),
while not estimated in the Hillside Wastewater Management
Plan, is likely to be significantly larger than that which
triggered much of the U. S. Geological Survey concern.
The potential for localized groundwater pollution in
the Hillside is relatively high, based on work by both U. S.
Geological Survey (1975) and Arctic Environmental Engineers
(1981). This high potential exists because most chemicals,
detergents, and pathogens are not removed in the septic tank, but
rather by contact with unsaturated soil particles in the drain
fields. If this contact is inadequate, pollutants may remain
untreated. In addition, certain pollutants such as nitrates are
not readily removed, and may contaminate che underlying ground-
water. In the Hillside area, bedrock outcrops, shallow bedrock,
shallow groundwater, steep slopes, roadway excavations, building
site excavations and freezing conditions increase the risks of
inadequate treatment.
System failures are the vehicle by which much contamination
can occur. If a tank fills with solids, if a drain field refuses
to accept the volume of waste discharged to it or if a system
freezes, remedial work will be required. Most homeowners will
147
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probably be conscientious and will rapidly pursue upgrading
before a lengthy discharge of pollutants occurs. As the number
of on-site systems on the Hillside increases from 1,500 to nearly
9,000, the number of failures from all causes is likely to
increase, even considering tighter design standards and pumping
requirements. As existing systems age, failures will increase.
Septic systems do not last forever; new drain fields will need
to be provided as existing fields absorb pollutants and suspended
solids, and eventually fail to meet adequacy testing on resale
or simply fail to accept discharged wastes.
While the Hillside plan requires pumping of tanks every
two years, total adequacy tests are required only on resale,
and failures can occur and go undetected by the Municipality for
extended periods. Failures involving pollution of groundwater
may go undetected for many years if no surface evidence exists.
The following discussion, quoted from the U.S. Geological
Survey (1975) report, points up some of these aspects of the pollution
threat. Note that the U. S. Geological Survey cites "as many as
3,000 systems", contrasted to MOA's estimate of 3,500 on-site
systems existing in 1980 with 5,459 new systems projected by
build-out, resulting in a projected total of nearly 9,000
on-site systems.
"As septic system density in the study area increases, effluent
will increase the rate of recharge to the areal groundwater body.
A future population of 10,000 people in the study area may require
as many as 3,000 systems, or one system per 3 acres. The total
daily discharge of these systems probably would increase from
the current estimated 0.4 million gallons to about 1.2 million
gallons. This increase represents an average distribution of
about 130 gallons of septic wastes per day on each acre of the
study area. If the water supply continues to be obtained from
local wells, the supply will be in part recycled by the residents.
Analysis of the water budget indicates that groundwater recharge
from precipitation is between 300 and 700 gallons per acre. If
it is assumed that all effluent percolates to the groundwater body,
a density of one system per 3 acres will increase local recharge
by 19 to 43 percent. If development density reaches one system
per acre, local recharge will be increased 56 to 130 percent
and total septic system discharge may be as much as 3.6 Mgal/d in
the study area. Present land use trends indicate that these systems
will not be evenly distributed. Consequently, pollution problems may
result where high septic tank density coincides with areas where the
susceptibility of the physical environment to pollution is high"
(U. S. Geological Survey 1975).
148
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In effect, the Hillside plan would allow development densities
of one unit per acre. If an aquifer in a local area received all
of its recharge from local precipitation prior to development,
septic tank recharge of the aquifer could become the predominant
source of water serving individual wells in that area. Threats
to public health from high nitrate levels and waterborne diseases
would be magnified in such cases. If seasonal high groundwater
occurs in these areas, treatment of septic tank effluent in
drain fields could be inadequate, and direct contamination of
the water supply would occur.
"There is a high probability of ground water contamination where
either the water table or bedrock lies between 15 and 25 feet
below the surface. If septic tank systems are installed where
either the water table or bedrock surface is less than 15 feet
below the surface, ground water contamination is a strong pos-
sibility.
'VJhere a seepage pit is constructed in saturated material, the
effluent may overflow the pit and eventually rise to the surface.
This occurs where the capacity of the material to transmit water
is too small to allow the dispersion of septic tank discharge.
Contaminants in the effluent also mix with and pollute the
shallow ground water surrounding the seepage pit.
"Contaminated effluent probably will find its way into bedrock
fractures if seepage pits are constructed in sediments that are
only 15 feet thick or less. Where fractures in the bedrock con-
tain ground water, pollution may spread rapidly and wells tapping
fractures more than 1 mile away may pump contaminated water in a
relatively short time after the effluent reaches bedrock".
(U. S. Geological Survey 1975).
The Hillside Wastewater Management Plan does not prohibit
on-site systems in shallow bedrock areas, nor does it require
seasonal groundwater monitoring to detect seasonal fluctuations
that would affect the degree of treatment.
The large number of on-site systems will increase the
risk of accumulations of conservative pollutants such as nitrates
that are not readily treated in travel through the soil. The
contamination of the three wells with nitrate approaching EPA
standards cited earlier in this chapter may be an example.
Cumulative impacts of substantial groundwater recharge from
nearly 9,000 on-site systems may be significant. Nitrate levels
could exceed the EPA drinking water standards in localized-areas,
and could affect the artesian aquifer under the lower hillside
and within the Anchorage Bowl.
In areas where cluster systems are used the effects of
potential failures may be more severe. Whenever more than one
dwelling unit drains to a system, repair difficulties and
determination of financial responsibility tend to be greater
149
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problems. Homes served by a cluster system may be more
reluctant to curtail water use during failures than would be the
case with an individual system failure in a .person's own yard.
The quantity of discharge from a failed cluster system will
likely be greater than for a failed individual system, causing
potentially greater impacts on surface and groundwater quality
and on public health risks.
Mitigation Measures. Mitigating the potential groundwater
impacts on public health and water quality that result from the
decision to preclude public sewers and allow a substantial in-
crease in on-site systems in the Hillside presents many challenges.
Developing an adequate plan to drink from a limited groundwater
supply and discharge wastes back to that supply entails risks.
Implementing such a plan under the adverse soils, geologic and
climatic conditions of the Anchorage Hillside area magnifies
those risks. Attempting to mitigate the risks in a social
environment where there is a strong desire to minimize govern-
mental involvement further complicates the problem.
The Hillside Wastewater Management Plan incorporates certain
mitigation measures that are discussed earlier in this chapter.
They include training and certification of persons involved in
the design, construction, maintenance and administration of
on-site systems; review of drain field location and soil conditions;
requiring more rigorous design and a pilot program of innovative
systems for areas generally unsuitable for on-site systems;
pumping and insulation of septic tanks to reduce failures; and
requiring three drain fields for each building site.
These mitigations do not reduce the impacts to the lowest
possible level, however. The impacts described in this chapter
are likely to occur if the Hillside Wastewater Management Plan is
implemented as adopted. Additional mitigations could be employed
to further reduce risks to public health and water resources. They
include:
o Groundwater monitoring, including coliform and nitrate
as well as other substances of concern to public health.
Monitoring could be designed to regularly .sample shallow
and deep groundwater on the Hillside and in downslope
areas to determine whether on-site system loading is threat-
ening water supplies on the Hillside and in the Anchorage Bowl.
o Periodic certification of domestic wells. Data developed
for the Hillside plan showed that the "average resident
lives in his home for a period of 5.6 years, indicating
most wells are now tested on an infrequent basis. An
annual or biennial testing of wells would protect those
who have not financed their home and those who have lived
in the area more than 1-2 years. Periodic certifica-
tion would provide greater protection for visitors to
homes in the Hillside, who may be more sensitive to
contaminants in the water than residents who consume
it daily and who may have developed higher tolerance.
150
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o Operate a public septic tank maintenance district for
the enti-re Hillside on-site disposal area. The district
could be administered by the Municipality or a specially-
organized entity that would perform groundwater and
surface water monitoring. The agency could assume- respon-
sibility for all system operation, maintenance and
liability. Revenues could be derived from assessments
against properties or as service fees from residents.
Other variations of this approach are possible (EPA 1981).
o Provide public sewerage capacity as a mitigating option.
As development of the Hillside area proceeds and densities
increase, there are likely to be increased failures, and
some serious public health threats may be detected.
Future populations are likely to request public sewer
service in some cases. If the capacity is provided in
downstream interceptors to serve the Hillside, this
o option would be possible. If capacity is not provided,
the practical and economic burdens of providing sewerage
could be far greater. In either case, financing of
extensions into the upper Hillside area would likely
be difficult.
o Provide a public water supply to the Hillside area.
Potential health threats due to contamination of indivi-
dual wells could be eliminated by providing a public
water supply to the entire Hillside area. The supply
would be assumed to be drawn from areas free from sub-
stantial recharge by Hillside wastewater systems. The
proposed Eklutna project would be a potential source.
Provision of a water distribution system would be expensive
due to relatively low density and great variation in
elevation, requiring numerous separate pressure zones.
Financing might be difficult. It should also be noted
that a doubling of density of the Hillside could be
allowed with a public water supply system.
o Improvement of site inspection criteria. Tightening of
approvals for on-site systems may help prevent failures.
In addition to the methods set forth by MOA, seasonal
groundwater levels could be monitored to detect "worst
case" conditions on each site, and prevent construction
of on-site systems that may discharge inadequately
treated wastes during one-or several months of seasonal
high groundwater each year. Also, areas generally un-
suitable for on-site systems could be precluded from
development unless it is positively demonstrated by
pilot testing of innovative systems and site data that
on-site sewerage is appropriate for that site.
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Surface Water Quality Impacts. Wherever septic tank effluent
is allowed to surface, or where shallow groundwater recharges a
surface water body, the potential for surface water pollution
exists. There are many ways in which septic tank effluent can
surface. Shallow seasonal groundwater may interfere with in-
filtration and cause the effluent to pond to the surface; drain
fields can be plugged by improper tank maintenance; relatively
impermeable soils may refuse to accept the volume of discharge,
causing ponding; steep slopes (greater than 20 percent), roadway
excavations, or building site excavations can intercept lateral
flow of effluent; and deep frost can freeze shallow pipes.
The growing number of roadway excavations and building site
excavations poses a high risk of intercepting percolating effluent.
At a density of one unit per acre excavations frequently will be
in close proximity to on-site sewerage systems. The potential
for public health impacts would be magnified substantially by
incompletely treated effluent flowing in local drainage courses
and roadside ditches.
Mitigation Measures. A number of mitigation measures can
be employed to reduce impacts on surface water quality. They are:
o Surface water monitoring of quality of local streams to
detect effluent discharge to surface waters. The program
could be structured to detect pollutants and trace sources.
o Prohibition of drain fields upslope of existing and
proposed roadway excavations. The MOA could prohibit
the location of on-site treatment system drain fields
within 100 feet upslope of existing and proposed roadway
excavations. This would reduce the threat of surfacing
effluent reaching roadside ditches and watercourses.
o Prohibition of building site excavations downslope of
drain fields. A similar mitigation would be the pro-
hibition of excavation for home construction or other
related purposes within 100 feet downslope of an existing
or permitted drain field. This would also reduce the
threat of inadequately treated effluent reaching locations
where public contact can occur.
Economic Impacts. The Hillside Wastewater Management Plan
presents limited cost data that suggest sewering the Hillside
on a large-lot basis would cost $38,180 per unit, while on-site
systems would cost $4,390 per unit. However, no 20-year present
worth analysis is. developed to compare true life-cycle costs
of both systems through the planning period.
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Chapter 6
Cultural Resource Impacts
Archeological Resources
Historic Places
-------
Chapter 6
CULTURAL RESOURCE IMPACTS
Archeological Resources
The Anchorage Bowl area is not noted for extensive use
by prehistoric populations. A known archeological site occurs
at Point Woronzof one-half mile south of the WWTP (49-TYO-030).
The Tanaina were known to have fish camps at the mouth of Ship
Creek during early historic times. A more detailed description
of archeological resources is found in
Impacts to known or newly-discovered archeological sites
can be minimized through avoidance where possible. The faci-
lities plan does not threaten the site in the Point Woronzof
area. A preconstruction survey of the expansion area at the
WWTP should be conducted as a precautionary measure. Since
watercourses are often places of high habitation probability,
a brief reconnaissance at all stream crossings is recommended.
During all construction activity, a localized work halt should
occur and the State Historic Preservation Officer should be
immediately notified if ar\ archeological site is uncovered.
Historic Places
Although Anchorage is a comparatively young city, having
been established in 1915, it has a number of places of historic
value, including seven sites listed in the National Register
of Historic Places:
o the Oscar Anderson House on 4th Avenue
o the Old Federal Building and U.S. Courthouse at 601
W. 4th Avenue
o the Campus Center on Wesley Drive
o the Eklutna Power Plant northeast of Anchorage
o the Old St. Nicholas Russian Orthodox Church on
Eklutna Village Road
o the old Anchorage City Hall at 524 W. 4th Avenue
o the Pioneer School House at 3rd Avenue and Eagle St.
None of these sites is affected by the facilities plan.
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Chapter 7
Secondary Impacts
• Growth Inducement
• Consequences of Growth
• Perceived Quality of Life
•*&S!*v*4i%*
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Chapter 7
SECONDARY IMPACTS
The impacts of urban growth are often considered to
be secondary or consequential effects of the action that
induces or allows growth to occur. This chapter discusses
growth inducement related to the sewerage expansion and
presents the secondary impacts that would occur at 'the pro-
jected population growth rate, assuming adequate sewer faci-
lities are available and lack of facilities does not become
a constraint.
Growth Inducement
The normal growth inducement roles of utility facilities
can be summarized as follows. A capacity expansion of sewerage
facilities usually -increases the holding capacity but does
not stimulate growth in areas where the existing holding
capacity has not been reached. Holding capacity can be
defined .as the total amount of possible development in terms
of population or area. However, if the holding capacity
has been reached, and new hookups are prohibited because
of lack of sewerage capacity, then expansion of the facilities
may well stimulate development. Depending on specific
circumstances, decisions not to expand or to limit the
expansion of sewerage facilities may restrict growth by
delaying, limiting or preventing it. Extension of facilities
to a previously unserviced area may stimulate or accelerate
development.
The growth inducement potential of a proposed project
can be defined primarily by its influence on the holding
capacity and growth rate of an area. The analysis of growth-
related impacts involves identifying the role of the proposed
project in influencing economic and/or population growth
in an area and the identification and analysis of the
environmental impacts attributable to any growth produced
or accommodated by the project.
Lack of sewerage facilities is not now constraining
the rate of growth in the Anchorage area. There is no
moratorium on new sewer connections. The Point Woronzof
•treatment plant currently exceeds its capacity at times,
and some inadequate interceptor sewer and pump station
facilities occasionally allow spills of raw sewage to
Campbell Creek and Chester Creek. If no expansion of sewer
155
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facilities occurs, this situation is expected to worsen with
growth, probably to the extent that a moratorium on new sewerage
service could eventually be imposed. No estimate of the
amount of such new growth that would trigger a moratorium
is attempted in this EIS.
Although not a constraint on the areawide growth rate,
lack of existing sewerage service is probably a constraint
on the location of new growth. For example, areas south
of Little Rabbit Creek in the Hillside area cannot develop
until the southeast interceptor is extended and the Rabbit
Creek interceptor's pump station and force main are con-
structed as recommended in the facilities plan. Also, some
Hillside area lots may not be developable under provisions
of the Hillside Wastewater Management Plan.
The amount of growth that the facilities plan expansion
would induce or support can be considered as the sewer-
dependent portion of projected new population that could
not live in the Anchorage Bowl without those sewers. This
can be estimated as a population equivalent to the year
2005 sewered population (projected in the facilities plan
as 287,400 persons) less the 1985 sewered population, (esti-
mated to be 167,100 persons), and also less any growth beyond
the 167,100 persons that would otherwise be allowed in
the absence~of sewerage expansion. For ease of analysis
this EIS considers the facilities expansion to support
growth from the 1985 level to the 2005 level, or 120,300
persons. The Hillside Wastewater Management Plan is assumed
to provide for growth in the unsewered areas of the Hillside
from about 9,100 (1980 estimate) to 23,300, or an increase
of 14,200 persons (MOA 1982). Thus, total growth related
to these plans is about 134,500 persons.
The facilities plan is assumed to be a direct inducer
of growth in the south Hillside areas from Little Rabbit
Creek to Potter Creek, where development will depend on
the sewerage extensions included in the facilities plan.
The most visible sign of population growth is the develop-
ment of land. Unless there is a high vacancy rate or unused
capacity in existing structures, residential, commercial
and industrial developments will occur to fulfill the needs
of the growing population.
A major factor in the development of residential areas
is the amount of undeveloped land and unrestricted zoned
land. Eighty-six percent of the remaining undeveloped land
is in central and southern portions of the Anchorage Bowl.
Of the total undeveloped land in the Anchorage Bowl, the
Hillside area accounts for 61 percent (Arctic Environmental
Engineers and MOA Planning Department 1982) . The northern
portion of the Anchorage Bowl contains scattered undeveloped
land parcels that can support additional infill. Residential
land uses and undeveloped land acreages for various areas
of the Anchorage Bowl are shown in Table 7-1.
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Table 7-1. Residential Land Use Comparisons by Anchorage Bowl Areas
for Current (1980) and Future (Saturation) Conditions
01
Are*
[town town
Northwest
Northeast
Central
Southwest
Southeast
(llillsi.le)
Anchorage
bowl
Current
Dwelling
Units
(Oil's)
2.308
18.043
21. 000
9. 820
4, 254
4. 305
59. 730
% share
of total
DU'a
3.86
30.20
35.10
16.44
7.20
7. 20
100.00
Developed
Land
( acreage)
169
2. 196
3.789
2. 200
1, 210
3,940
13, 513
Density
(DU'a/Devel-
oped ac.)
13.7
8.2
5. 5
4. 5
3. 5
1. 1
4.4
Undeveloped %
Land Share
(acreage) ot Total
17 (0.01)
622 (3.2)
2,015 (10.4)
3,150 (16.1)
1,703 (8.8)
11.945 (61.4)
19,452 (100.0)
Future
Dwelling » Share
Units of Midpoint
(DU'a) Total
2. 595 -
2,718 (1.95)
25.315 -
29.267 (19.97)
33,425 -
41,414 (27.48)
28. 539 -
39.240 (24.89)
12,781 -
19,551 (11.87)
17,807- (14.83)
25, 430*
120,462 -
157,620 (100.0)
Density
(DU's/total
ac. )
14.0 - 14.6
a. a - 10. 2
5.8 - 7. 1
5.3 - 7.3
4.4 - 6.7
1.1- 1.6
3.6 - 4.8
"Uaseii upon recommendations of Hillside Wastewater Management Plan.
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The draft Comprehensive Development Plan (MOA 1982)
encourages multifamily residential units in the more central
areas of the Anchorage Bowl, particularly in Muldoon, Fairview,
Mountain View and Spenard. This development would be a mixture
of infilling undeveloped parcels and redevelopment of deter-
iorating structures. Upgrading the existing sewerage facilities
in these areas would facilitate higher density residential
growth.
Medium density single-family residential development
is encouraged by the plan for the southern portion of the
Anchorage Bowl, in western Sand Lake near Kincaid Park, Abbott-
O'Malley, Lake Otis, and sections of Campbell-Klatt. New
and upgraded sewer facilities would permit expanded resi-
dential growth and higher density levels.
The plan proposes to retain the majority of the Hillside
area in rural low-density residential development. The estab-
lishment of sewerage facilities in those areas of the Hillside
that have been identified as environmentally unsuitable for
any type of on-site disposal system , and that are geographically
feasible for sewerage, such as large undeveloped tracts,
would open up the area for residential development at various
densities, together with supporting uses.
Major commercial development would continue to be located
in the downtown and midtown areas with supporting community
commercial nodes in east, south and west Anchorage. Industrial
development would continue to grow in the Port/Ship Creek,
International Airport and Merrill Field areas. New industrial
development could also occur along the Alaska Railroad in
central and southern Anchorage. New and upgraded sewerage
facilities would facilitate expansion of commercial and
industrial uses in these areas.
Consequences of Growth
The effects of growth, both beneficial and adverse,
may be observed in environmental and socioeconomic areas,
and may have regional and local consequences. Growth usually
affects the following:
Services and utilities
- sewerage
- water supply
- solid waste disposal
- energy
- transportation
- education
- police and fire protection
158
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- parks and recreation
- social services
Resources
- air quality
- water quality
- hydrology, erosion, seismicity
- open space
- wetlands
- biological resources
- aesthetics
- noise
Socioeconomic values
- development-related economic activity
- community cultural resources
- social structure
- fiscal strength
- perceived quality of life
The above list is illustrative rather than exhaustive.
Several of the above topic areas were selected for analysis
in this EIS. based on results of the EIS scoping process and
EIS impact evaluations. These include water supply, solid
waste disposal, energy, transportation, education, police
and fire protection, recreation, air quality, hydrology,
erosion and sedimentation, and perceived quality of life.
Impacts on wetlands and biological resources are addressed
in detail in Chapter 4, including growth-related impacts.
Chapter 5 similarly addresses growth-related issues pertaining
to the Hillside area.
The impacts discussed in the remainder of this chapter
are independent of alternative, except for no action. If
no sewerage expansion is undertaken, growth-related secondary
impacts will occur only to the point where the lack of sewerage
facilities constrains growth. Among the other alternatives
evaluated in the facilities plan, no differences in the resulting
growth can be identified. Each would allow unconstrained
growth up to the capacity of planned facilities.
Water Supply
A detailed study of the existing water supply situation
and the critical need for additional water supplies for Anchorage
was published by .the U. S. COE (1979) . Currently, the MOA
water supply is provided by Ship Creek and groundwater sources
within the Anchorage Bowl. The following summary of the existing
system and projected need is derived from the above study.
159
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Water consumption in the Anchorage Bowl in 1977 averaged
26.2 MGD, of which 14.5 MGD came from groundwater and 11.7 MGD
from Ship Creek. Production capacity in 1977 was calculated
to be 29.7 MGD. Future water demand was forecast by presuming
a per capita use of 157 gallons per day. Part of this demand
occurs from residents allowing their water to run during
cold spells to prevent water lines from freezing. Assuming
a water service area population of 305,000 by the year 2005,
the calculated water demand would be 47.9 MGD.
It is immediately obvious that water problems will develop
in the short term if additional sources are not provided.
In the summers of 1976 and 1977, during an extended dry period,
both the Anchorage Water Utility and Central Alaska Utilities
publicly requested that their customers curtail water use
because demand exceeded production and a drop in water pressure
was experienced in various areas. In 1980, the MOA retained
a consultant to investigate the feasibility of obtaining
a 70 MGD water supply from Eklutna Lake by pumping water
from the tailrace below the Eklutna powerhouse. If this
project is undertaken, the water supply will be adequate
for the growth predicted by the 201 facilities plan.
In the meantime the MOA is investigating the drilling
of additional wells to use groundwater supplies until the
Eklutna project is constructed. A short-term threat of water
shortages in early summer and in winter will still exist
due to limited supplies.
A relationship between water supply and sewerage exists,
in that a portion of the water supply becomes wastewater.
If the water supply available to Anchorage is not increased,
water conservation and/or rationing could be imposed. This
would tend to keep sewage flows lower than projected by the
facilities plan. Lack of adequate water supplies could delay the
need for part of the proposed expansion of sewerage facilities.
Lack of adequate water supplies can also constrain growth,
particularly if a "wet" industry such as a cannery is prevented
from locating in the area due to water supply constraints.
Reduced growth would also reduce the need for sewerage facilities.
Solid Waste Disposal
The MOA is running short on capacity at the existing
Merrill Field landfill, and is expected to require a new
landfill no later than mid-1986. This projection was developed
in early 1981 based on annual solid waste loads of 160,000-
170,000 tons. Actual landfill volume in 1981 was 200,000
tons, up from a total of 160,000 tons in 1980. If the volume
160
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of waste continues at 200,000 tons per year, the landfill
would be full in mid-1985. If the tonnage increases with
accelerated development of urban growth, the landfill could
be full even sooner. Historically, solid waste volume has
increased on the o'rder of 10-15 percent annually (Niftier
pers. comm.).
The MOA Planning Department undertook site-specific
landfill location studies in 1980 as an update to the 1975
Solid Waste Management Plan. This planning effort, which
never culminated in a formally adopted report, noted that
the availability of sites for landfills was severely limited
and that environmental problems and/or community opposition
was likely to exist at those few remaining sites. The MOA
Planning Department study efforts were terminated and plans
laid to develop a new solid waste management plan. Informa-
tion obtained from the Solid Waste Division (Niftier pers.
comm.) reveals that the Solid Waste Management Plan will
be updated in 1983. Only three candidate landfill sites
remain in the Anchorage Bowl, and all are surrounded by
residential areas. Processing now costs $20-25 per ton at
the Merrill Field landfill and processing costs would double
if a disposal site were to be located outside the Bowl area.
The new study will also consider the feasibility of resource
recovery (i.e., recycling). Current processing does not
include resource recovery practices, although shredding does
occur.
Energy Resources
A fairly direct relationship exists between land use
patterns, transportation, and energy consumption. In a more
centralized, higher density land use area, the number of
vehicles required, miles traveled and the overall number
of trips taken decreases. This transportation decrease
results in less energy consumed. Higher density multifamily
residential areas generally consume less energy per capita
than single-family residential areas. This is because of
the space heat savings associated with common-wall multifamily
dwelling units and the more efficient use of public utilities.
The population increase associated with the new sewer
facilities will increase the amount of energy consumed in
the MOA substantially. Energy consumption need not increase
directly with population since some energy may be conserved
through higher density land use patterns, public transportation
usage, and building code conservation measures.
161
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Natural gas is supplied to the MOA by Alaska Gas and
Service Company (AG&S). AG&S serves the entire Bowl from
Eklutna River to Potter Creek. About 50 percent of the load
is consumed by power plants, which are fully interruptible.
Occasional peak load problems force the use of alternate
fuels by the power plants. Gas supply is primarily a contract
problem. Union Marathon Oil Company is the primary supplier,
with additional quantities produced by a small AG&S-owned
well or purchased from the state. Gas is readily available
in the area, but renegotiation of the contract with suppliers
usually results in a rate increase. The MOA has one of the
lowest gas billing rates in the nation, and it is presumed
that production and supplies will keep pace with population
growth (Sinclair 1982 pers. comm.).
Electric power is provided to the International Airport
area and the downtown core area (north of 36th Avenue, west
of Boniface Parkway and east of Minnesota Bypass) by Municipal
Light and Power (MLP). Chugach Electric supplies electricity
to the remainder of the Anchorage Bowl. Generation capacity
for MLP is currently 120 megawatts, compared to a 330-megawatt
capacity of Chugach Electric (Day pers. comm.). MLP is
expanding substation capacity in the Airport area from 7.5
megawatts to 25 megawatts. This expansion program and site-
specific expansion in the downtown area remains within the
framework of existing generation capacity, but it is uncertain
as to how much growth can be assimilated by MLP (Day pers.
comm.). Day (pers. comm.) reports the average annual resi-
dential use of electricity is around 750 kwh per month (i.e.,
9,000 kwh per year).
Chugach Electric has the largest service area in the
State of Alaska with over 54,000 retail customers, including
over 1,000 retail customers in the Kenai area. Wholesale
customers such as Seward are also supplied. Markley (pers.
comm.) reports an average annual retail customer use of
electricity around 15,000 kwh per year, including residential
and nonresidential customers. Although Chugach Electric
has some reserve generating capacity, substantial growth
in the Anchorage Bowl would require new generating facilities.
Planning is underway to expand facilities to accommodate
population growth (Markley pers. comm.).
Traffic and Transportation. The Anchorage Metropolitan
Area Transportation Study Long-Range Element Transportation
Plan proposes measures to help alleviate traffic problems
and accommodate the MOA transportation needs through 1995.
The plan proposes that by 2000, 10 percent of all person
trips will be made by public transportation, representing
approximately a ten-fold increase -in transit usage. The
plan recommends a major expansion of the number of buses
162
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and fixed route services, and the development of express
route services from outlying residential areas to close in
smployment areas.
Roadway improvements and new roadways will be phased
in response to incremental increases in traffic volume,
perceived need and funding availability. Much of the pro-
jected increased traffic volume should be funneled within
the three major corridors, the Glenn Highway, the Seward
Highway and the Minnesota Bypass. The plan.also proposes
deveToping an alternative transportation modes program for
pedestrians, bicyclists, and carpoolers.
The increased population and automobile use will place
additional demands on the existing roadway network and public
transportation services. Roadways and services will need
to be established in the new sewered residential and commer-
cial areas. Certain secondary impacts are also generated
by increased transportation use. These include increased
energy consumption and higher levels of air pollution,
particularly carbon monoxide.
Education
Demand for educational services is an important aspect
of growth. Unless exceptional conditions are present (e.g.,
migration of predominantly retirees or young married couples
with children), school enrollment is a reasonable barometer
of population trends. In the MOA, the school population
is approximately 20 percent of the total population (Schaedel
pers. comm.). Based on school enrollments, population growth
is now occurring in every part of the school system. Avail-
able space in the north area is rapidly disappearing and
school overcrowding currently exists in the Eagle River area
(experiencing the fastest growth) and south Anchorage. The
Anchorage School District anticipates continued expansion
and building programs over the next decade (Schaedel pers.
comm.).
Police Protection
The police department in the MOA currently employs 265
sworn officers to handle law enforcement (Ricketts pers.
comm.). Because the number of law enforcement officers is
largely population-dependent, police protection services
will need to expand essentially at the same rate as the
population increases. The number of law enforcement officers
necessary to adequately serve a given population can be
calculated using the national average of 1.5 officers per
163
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1,000 permanent residents. This standard varies according
to population density and per capita income. Based on this
ratio, the MOA would have to add 54 additional sworn officers
to achieve the national standard and would add approximately
200 additional law enforcement officers by the year 2000
to meet the projected population increase. Depending on
the character, income level and ethnic diversity of the new
population and the density of new developments, crime may
intensify in some urban areas, requiring additional law
enforcement effort. Additional jail, courtroom and other
facilities would also be needed to serve a growing popula-
tion .
Fire Protection
The fire department of the MOA has a full-time staff
of 275 fire fighters to handle required services (Grossman
pers. comnu ) . This present staffing level is considered
inadequate by the fire department at present, and a staff
increase of 11 percent is needed to cover population growth
in new areas. In addition to existing full-time staff, the
MOA provides equipment for three volunteer organizations
(Girdwood, Chugiak, and Southport/Eagle River Valley). The
MOA has a solid, well-enforced fire code for taller buildings,
which alleviates a major concern over fire protection in urban
areas.
Fire protection services are also population-related,
and the number of fire fighters and facilities will need
to expand as population increases. According to national
averages, about 1.2 fire fighters are necessary to adequately
serve every 1,000 permanent residents. Based on this ratio,
a total of 130 additional fire fighters would be needed by
the year 2000.
Recreation
The Anchorage Bowl has numerous and varied recreational
resources. Population growth will put increasing pressure
on these resources. Some existing resources may become
more heavily used and seem overcrowded, particularly local
and neighborhood park facilities and bike trails in greenbelt
areas. Although growth may be accompanied by the provision
of additional urban recreational facilities, the expansion
is not possible in the case of finite resources such as
beaches and greenbelt areas. Chugach State Park and other
open land areas in south-central Alaska will also get heavier
use, thus reducing the solitude and aesthetic values of
these areas.
164
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Air Quality
Existing Conditions. Urban development and meteorological
conditions in the Anchorage area have combined to produce
occasional air quality problems. The 8-hour federal ambient
air quality standard for carbon monoxide (9 ppm) has been
exceeded several times a year at various locations in the
urbanized Anchorage area. Peak 8-hour carbon monoxide levels
generally exceed 15 ppm at one or more monitoring stations
each year. The highest 8-hour.carbon monoxide level yet
monitored was 27.4 ppm in 1980 at the Sp'enard/Benson monitoring
station.
Most of the urbanized area of the Anchorage Bowl has
been formally designated as a carbon monoxide "nonattainment
area" due to these violations of federal air quality standards.
The MOA is designated as being in attainment of other federal
air quality standards (ozone, nitrogen dioxide, sulfur dioxide
and suspended particulate matter).
The federal Clean Air Act requires the development and
implementation of plans to achieve and maintain federal air
quality standards by certain deadlines. The plan for the
Anchorage area focuses on attaining the federal carbon monoxide
standard by .1987. Programs incorporated into the Anchorage
Air Quality Plan include:
o Roadway extension and widening projects;
o Intersection improvement projects;
o Ridesharing programs;
o Public 'transit system improvements;
o Mandatory vehicle inspection and maintenance for fleet
and government vehicles;
o Voluntary vehicle inspection and maintenance for
private vehicles.
In June 1982, the Anchorage Assembly formally adopted
the traffic improvements, ridesharing and transit improvement
elements of the air quality plan. The vehicle inspection
and maintenance elements of the air quality plan were approved
"in concept," but adoption of a specific program was deferred
until results from a research study in Fairbanks became avail-
able.
165
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Consistency Evaluation. The Clean Air Act requires
that federal funding programs, such as the Clean Water Grant
program, not be used to support projects which are inconsistent
with local air quality plans. Consistency between wastewater
and air quality management plans is determined primarily
by comparing the growth forecasts used in developing the
two plans.
The air quality plan assumes that the population of
the MOA will increase to 334,200 by 1995, with 263,700 people
in the Anchorage Bowl. The facility plan assumes a study
area population of 247,200 by 1995. The facility plan study
area is essentially the same as the Anchorage Bowl. The
facility plan can be considered consistent with the growth
assumptions of the air quality plan since the facility plan
does not accommodate growth levels beyond those anticipated
in the air quality plan.
The proposed expansion of sludge incineration capacity
at the Point Woronzof WWTP must also be considered in assessing
the consistency of the facility plan with the air quality
.plan. As discussed in Chapter 9, the increased sludge incinera-
tion at the treatment plant is expected to produce little
change in carbon monoxide emissions. It should also be noted
that the treatment plant site is outside the formal carbon
monoxide nonattainment area boundary. Thus, the facility
plan is consistent with the air quality plan in terms of
both direct facility emissions and indirect, growth-related
emissions.
Hydrology, Erosion, Seismicity
Urban construction has wide-ranging effects on surface
and groundwater hydrology (Figure 7-1). Most of these impacts
are caused by the reduction of naturally permeable soil surfaces
with impermeable concrete, asphalt, and buildings. Percolation
of rainwater and snowmelt to the groundwater is substantially
reduced, and runoff to stream channels is greatly hastened.
Larger flow volumes result, and stream channels, may become
inadequate to contain the man-altered runoff regime. Greater
flows and higher velocities can, in turn, increase erosion.
166
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REMOVAL OF VEGETATION. .....__.-_ ,„ ICE CONTROL CHEMICALS, SEWAGE AND
SOURCES EARTHMOVING DURING Sp«u?n,,I «. «»r»* L 1 TTER , VEH 1 CLE E XHAUS T __ *°»- ' ° WASTE
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\ T
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IL
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•
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EROSION BY
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STREAMS AND RIVERS "^
WILDLIFE. ENVIRONMENTAL
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SECONDARY
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.
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t 1 A
Figure 7-1. Residential Land Use Impacts of Urban Runoff.
SOURCE: Municipality of Anchorage, 208 Areawide Water Quality Management Plan,
January 1979.
-------
Groundwater recharge, which is most important along the Chugach
mountain front (Figure 4-5), may be reduced by increased
development. In turn, the portion of stream flow that is
attributable to upwelling groundwater would be reduced (see
Chapter 4') . Spring breakup flows may be especially affected
by urban expansion.
Erosion increases with urban expansion and development,
degrading water quality, destroying spawning habitat, and
filling lakes and wetlands with silt. Population growth in
the Anchorage basin will increase erosion and amplify its
consequences.
Knowledge of Anchorage Bowl soils and topography is
fundamental to sound land use planning and erosion control
and, as a result, has been rigorously studied and extensively
mapped. The study area consists of a complex mosaic of 23
soil types or series, described in detail in the U. S. COE's
Metropolitan Anchorage Urban Study, Volume 7 (1979).
Surficial deposits in the study area mostly originate
from glacial scour, and ocean and river sediment deposits.
Fragmented 'rock and gravels characteristic of scour are found
on the lower elevations of the Chugach Mountains and the
northern section of the Anchorage Bowl. River deposition
alluvium covers much of the central Anchorage area, and
ancient Cook Inlet marine deposits form what is referred to
as Bootlegger Cove clay. Because of the relative geologic
youth of the deposits and cool climate, soils are thin and
poorly developed.
Topography in the study area generally has low relief;
its highest points gently slope from 500-600 feet on its east-
ern boundary to an alluvial plain upon which most of Anchorage
is built. Over 90 percent of the study area has slopes of
less than 12 percent, but the western extremities (Point
Woronzof and Point Campbell) have hummocky terrain. Soils
on these points tend to be silty loam interspersed with
gravelly soils. Precipitous cliffs border the Cook Inlet.
Some slopes are also steep in the southeastern portion
of the study area. For instance, the Hillside area contains
moderate to steep slopes (5-45 percent). Elevations range
from 1,600 feet at the eastern border to about 400 feet near
Abbott Road. Homestead loam soil (silt, sand, and clay)
are abundant in this area, generally overlying alluvium in
lower elevations -with fragmented rock and sand in the upper
hillside.
Much vegetative cover is usually removed during develop-
ment of homes, roads, and utilities. Clearing the soil surface
allows rain splash, sheet erosion and ice accumulations to
163
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wash away topsoil. The sand, silt and clay soils which are
widespread in the Bowl are particularly susceptible to erosion;
especially subject are those soils exposed on moderate to
steep slope relief such as in the Hillside area. Road cuts
and fills are of special concern.
Erosion can also increase the likelihood of flooding.
The capacity of stream channels may be reduced in response
to erosion and subsequent sediment deposition, resulting
in bank overflow even during normal runoff events.
Increased urban development may also expose more people
and structures to potentially disastrous effects of seismic
activity. South-central Alaska has a long history of seismic
activity. Between 1899 and 1965 the vicinity of Anchorage
has experienced nine events that equaled or exceeded 8.0 on the
Richter Scale, and more than 60 that equaled or exceeded 7.0.
This intense seismic activity emanates from the circum Pacific
Belt extending from the Aleutian Chain to the southernmost
Alaska/Canada border. About 7 percent of annual global
seismic energy is released along this belt.
The Good Friday earthquake of March 27, 1964 (8.4 on the
Richter Scale) demonstrates the devastating effect of seismic
activity on urban areas. Much of the damage was attributed
to Bootlegger Cove clay which underlies much of the study
area. Water-saturated sand pockets within the Bootlegger
formation may have liquefied during the quake allowing con-
siderable land subsidence and greatly aggravating struc-
tural damage.
Statistical analysis of the frequency of past seismic
events indicates that earthquakes are likely to recur in
Alaska. It is predicted that quakes with the magnitude of
the Good Friday event will occur once every 10 years in the
circum Pacific Belt. Four large quakes have jolted Anchorage
from the 1964 epicenter in recent years, and the chance of
a "damaging" earthquake (7.0 centered near Anchorage or 8.0
in the general region) in any given year is estimated at
1 in 50 or 2 percent. If the statistics of past events prove
to be an accurate indication of future events, there is a
distinct likelihood of another strong quake in southern Alaska
within the next 35 years.
Growth from the 1964 population of about 100,000 persons •
to the 2005 projection of about 305,000 will expose triple
the number of persons to seismic activity. Logistical problems
such as evacuation and care for the homeless would be multi-
plied by the larger population.
169
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Mitigation Measures. Sound land use planning and erosion
control measures can reduce many undesirable effects of urban
expansion and development. Erosion can be controlled during
construction phases by leaving as much vegetation in place
as possible. Areas which are denuded "of vegetation can be
covered or reseeded (Figure 7-2).
Measures to control increases in runoff and decreases
in infiltration can be implemented. Stream impoundment,
meandering surface drainage, retention of natural stream
channels and retardation basins may be of substantial benefit
(Figure 7-3).
Seismic impacts may be reduced by adopting and enforcing
building codes and permits specifically designed for con-
struction on areas such as south-central Anchorage, which
are moderately susceptible to land failure. Mapping of areas
susceptible to ground failure has been completed for the
Anchorage Bowl area. Land use and structural controls in
such areas can be maintained at a stricter level to minimize
exposure to and damage from seismic events.
Perceived Quality of Life
Quality of life in the Anchorage Bowl will change as
the population grows and land develops. Open space will
decrease, the competition for available areas of leisure
pursuits will increase, and a more crowded feeling will pervade
the area. Highways leading toward the Kenai Peninsula and
Denali National Park will become more congested on weekends,
houses will be closer together in the Hillside area, and
the feeling of being a pioneer living on the fringes of a
wilderness will decrease.
Development will bring economic activity, including
construction and accompanying employment. This construction
will stimulate the local economy.
A larger population can support a greater diversity
of cultural resources, such as plays, ballet, symphonies,
art exhibits, popular entertainment, museums, and libraries.
The aesthetic impacts associated with population growth
include the elimination of open space and vegetation,, the
obstruction of vistas and scenic points and development near
streambanks and shorelines. Increased crime, noise, odors
and air pollution associated with growth also degrade the
aesthetic value.
173
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1
To prevent Construction
erosion lr'"ie- ""*•
parking, etc.
I
I'o reduce Sedimen
sediment filters
leaving site and traps
, , , r" ,
Slope
configurations
and modification
r
Ceding H
grass and Jn
grass + a
legumes
1
Management of construction sites
General |
1 , 1
Cultivation Cover crops
practices I""I»"V
r mulches
1 1
Sediment
basins and
filler screens
Grading [
1
Diversions
and diversion
techniques
1
Vegetation and seeding [
I „, I 1
,droseeding M«"<*
d chemical Sod
ibilization seede
areas
1 I 1
Erosion control
on very steep slopes
Temporary
divers ons
and chutes
1
1
es Mulches and
blankets to
d protect
seeded areas
|
FIGURE 7-2. MEASURES TO CONTROL
EROSION AND SEDIMENTATION
I Delay of runoff at source I
Infiltration of runoff at source
OVERFLOW
I
Increase time of concentration
by diversions and terraces
and runoff spreaders
Reduction of runoff and increase of infiltration |
Flood control by delaying discharge
I
Smal
"<"'
lmp
menls
1
e
earn
und-
s
upstream
impound-
ments
1 1
Dry
impound-
ments
sealing
Flood
in
sewers
Parking
lot
storage
Reduction of flood damage
I
ructural
res
I
Elevation of
structures
on stills,
Flood proofing
Dikes
levees
floodv
etc.
Recharge
of
excess
runoff
through '
injection
wells
SOURCE: Water resources protection technology. The urban land Institute, 1981
FIGURE 7-3. MEASURES TO CONTROL INCREASES
IN RUNOFF AND DECREASES IN INFILTRATION
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Although growth-related aesthetic impacts cannot be
eliminated, zoning restrictions and other land development
regulations can help ensure that the effects are minimized.
The Comprehensive Development Plan, the Coastal Zone Manage-
ment Plan, and the Wetland Management Plan contain policies
designed to minimize development impacts on aesthetics.
Noise can produce physiological effects on both man
and wildlife; it interferes with speech, sleep and walking,
reduces the aesthetic value of wilderness, rural areas, and
open space areas, and recreation activity and annoys the
general community.
A direct relationship exists between urbanization and
noise, thus noise levels will rise with increased development,
Although noise levels increase with development, measures
can be taken to reduce the noise impacts of growth. Noise
attenuation can be achieved through building and site design,
barriers, landscaping, and restrictions on the hours of opera-
tion of noise sources. Noises associated with the increase
in transportation levels can be reduced by limitations on
traffic volumes and routes. Noise levels can also be reduced
through zoning.
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Chapter 8
Effluent Treatment and Disposal Impacts
Introduction
Physical Oceanography
Chemical Oceanography and Bacteriology—Cook Inlet
Conclusions
Wastewater Treatment Impacts
-------
Chapter 9
Sludge Processing Disposal Impacts
• Air Quality
• Knik Arm Impacts
• Landfill Capacity Impacts
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Chapter 9
SLUDGE PROCESSING AND DISPOSAL IMPACTS
Impacts from solids processes at Point Woronzof WWTP
and disposal of residues from those processes are covered
in this chapter. The recommended plan for sludge treatment
and disposal involves dewatering, incineration and discharge
of ash to the Knik Arm of Cook Inlet via the outfall, landfill-
ing the ash, or discharging the ash to a lagoon or gravel
pit near the plant as a slurry blended with wastewater.
The impacts of potential concern that are addressed
in this chapter are air quality effects from expanded
incineration operations; energy consumption of incineration;
accumulation of toxic substances in Cook Inlet; use of landfill
capacity; and groundwater and land use impacts of lagoon
or gravel pit discharge, including leachates from the ash.
The evaluation of the impacts is hampered somewhat by the
solid waste situation in Anchorage, namely that the existing
Merrill Field landfill is expected to be full about the time
the projects being evaluated by 'this EIS come on line. A
further disadvantage is a lack of information on the composition
of the sludge ash. Further information is required before
full evaluation of sludge disposal can occur.
Air Quality
Direct air quality impacts of the proposed project are
primarily related to sludge incineration. The major air
pollutants associated with multiple hearth sludge incinerators
are particulate matter and nitrogen oxides. Carbon monoxide
emissions from sludge incineration are generally considered
to be negligible (EPA 1974). Particulate emissions can be
substantial unless appropriate emission control devices (usually
a wet scrubber) are used.
Projected average daily emissions from the existing and
proposed sludge incinerators are summarized in Table 9r-l.
Based on the available data, the propo-sed project would not
be considered a major stationary source subject to special
air quality review under EPA's "prevention of significant
deterioration" regulations.
189
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Table 9-1. Average Daily Sludge Incinerator Emissions
vo
o
POLLUTANT
Particulate Matter
Nitrogen Oxides
Volatile Organics
Sulfur Dioxide
Carbon Monoxide
Hydrogen Chloride
1985
32
58
11
9
3
.25
.75
.75
.40
ND
.53
Average Daily Emissions (Pounds)
'1990 1995 2000 2005
41
69
13
11
4
.85
.75
.95
.11
ND
.19
48.45
80.75
16.15
12.92
ND
4.85
55
91
18
14
5
.05
.75
.35
.68
ND
.51
61
102
20
16
6
.61
.68
.58
.43
ND
.16
CAPACITY
115
192
38
30
11
.20
.00
.40
.72
ND
.52
Notes: ND = no data; data source indicates "negligible" emissions.
Emission estimates by calendar year based on facility plan projections
of dry sludge generation and emission factors from EPA (1974), assuming
use of wet scrubbers for emission control
-------
Energy Consumption
Operation of the incinerators will require energy to
start up and maintain heat. It is unclear from the facilities
plan whether the incineration process is self-sustaining.
During the winter, waste heat from the incineration process
is used to meet heating requirements for the plant buildings.
The net heat input and savings from heat recovery systems
is not known.
Knik Arm Impacts
Discharge of sludge ash through the outfall pipe following
incineration will increase the suspended solids concentration
in plant effluent. The ash alone would increase total
suspended solids by about 13 mg/1. Considering that the
plant currently has difficulty meeting discharge requirements
of 100 mg/1 (monthly average), the addition of ash will
make it increasingly difficult to avoid NPDES permit violations.
As a mitigation measure, the plant could be designed
to achieve a consistent effluent quality of 85 mg/1 suspended
solids in the clarifier overflow, allowing for an additional
13 mg/1 from incinerator ash. This would increase the
cost of the treatment system, however, possibly requiring
additional clarifiers or new steps in the treatment process.
No feasibility analysis or cost estimates have been prepared
for this option.
The mean suspended solids concentration in the Knik
Arm during the critical summer period is estimated at 1,280 mg/L
(Arctic Environmental Engineers, et al. 1979). Wastewater
meeting the NPDES permit requirements contains one-tenth
the suspended solids of the receiving water. The discharge
of ash is expected to have no effect on suspended solids
concentrations in the receiving waters.
There is a slight chance that discharge of ash in suspen-
sion with treated effluent could introduce toxic materials,
such as heavy metals, to the Knik Arm of Cook Inlet. While
some of the ash could settle into the mud along the proposed
diffuser, most would probably remain in suspension and would
be widely distributed in the Inlet. Assuming a fine ash,
the ultimate fate of the ash'would probably be a minuscule
proportion of muds deposited on the Inlet floor over many
hundreds of square miles. No measurable effect on turbidity
would occur.
Without an analysis of constituents of the ash, evaluation
of__ solubility of end products, particle size and volume of
discharge, no further analysis is possible. With the exception
of discharge volumes, this information is not currently avail-
able .
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Federal law prohibits the discharge of sludge to fresh
or marine waters. A determination would have to be made
as to whether the ash from incineration of sludge would
be considered as sludge under the law. If it is, this
alternative would be prohibited.
Landfill Capacity Impacts
The incineration of sludge is expected to produce 1.8
tons of ash per day (3.9 cubic yards) in 1985, and 3.1 tons
per day (6.6 cubic yards) by 2005. The disposal of ash to
a landfill will use landfill volume that would otherwise
be available for municipal refuse and other solid waste.
As discussed in Chapter 7, the Merrill Field landfill
is expected to be full by about 1985 when the expanded sewerage
facilities come on line. No new site has been selected for
a landfill, although gravel pits in the Campbell Point area
are mentioned as potential sites. Site-specific impacts
on capacity cannot be estimated. However, current solid
waste volumes to the Merrill Field landfill are about 200,000
tons per year. At a rate of 1.8 tons per day, the incinerator
would produce about 660 tons per year, representing 0.33
percent of total landfill volume. This proportion would
likely remain constant as both solid waste and sludge volumes
increase in proportion to" population.
Another way of analyzing this impact is to assume a
landfill life based on its available volume, and compute
how much longer the landfill's life can be prolonged if it
does not receive sludge ash. If a new site is chosen that
has a 20-year life, a new landfill would last 24 days longer
without the ash.
Landfill Leachate Impacts
If toxic substances are present in landfilled sludge
ash, percolating rainwater could leach these substances into
the groundwater, adversely affecting water quality and bene-
ficial uses of the water resource. The potential for such
impacts occurring is unlikely, but a definitive answer depends
on constituents in the ash, location of the landfill, landfill
construction, the presence or absence of groundwater, direction
of groundwater flow, well locations and eventual fate of
the groundwater. Without an identified landfill site, no
further analysis is possible.
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Groundwater Impacts of Ash Lagoons
There is a remote risk that discharging sludge ash to
lagoons or gravel pits near Point Woronzof (within 0.25 mile
of the WWTP) could lead to local pollution of groundwater,
depending on constituents-in the ash. Evaluations of land
disposal of wastewater at nearby Point Campbell (USCOE 1979)
indicated that groundwater flow was toward Cook Inlet in
this general area. A more detailed review of both shallow
and deep aquifers in this area is necessary to ascertain
movement direction and potential interchange between aquifers.
The U. S. Geological Survey (1972) points up a potential
for saltwater intrusion in Anchorage if groundwater overdraft
occurs. The Municipality is currently considering increasing
pumping from groundwater to augment current supplies. The
relationship between this pumping, which could effect the
direction of groundwater flow, and percolation of water from
an ash-effluent slurry requires further evaluation before
impacts can be accurately predicted. The potential for adverse
impacts does exist.
Lagoons or gravel pits for ash disposal would require
10 to 15 acres of land. In addition, ash would be periodically
moved to another location or landfill. Total land requirements
for a 20-year lagoon system for ash disposal are unclear.
However, at least 10 to 15 acres of land would be lost to
other uses. No location for the lagoons or gravel pits is
given, so no identification of uses affected is possible.
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Chapter 10
Short-term Construction Impacts
Impacts Common to Most Construction Activities
Special Case Impacts
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Chapter 10
SHORT-TERM CONSTRUCTION IMPACTS
Impacts Common to Most Activities
Construction of wastewater facilities typically results
in an assortment of short-term nuisance impacts. This type
of impact typically lasts for the duration of the activity
in a particular local area. These impacts include noise,
dust, stream turbidity, access problems, traffic congestion,
potential safety hazards and visual "eye sores". These impacts
are usually judged insignificant unless someone is injured
or a stream is severely damaged. In most cases, these impacts
are readily mitigated to tolerable levels. When construction
is completed, the impact is relieved. Common short-term
impacts and their mitigation measures are presented in
Table 10-1. The short-term impact of greatest concern is
likely to be water quality degradation. This issue is dis-
cussed in more detail in Chapter 4, Wetland Impacts.
Special Case Impacts
A few short-term impacts are unique to only a few of
the proposed activities in the facilities plan. These are
discussed below.
Alaska Railroad
A number of existing and proposed sewer lines parallel
or cross .the Alaska Railroad right-of-way. Of particular
concern are sewer construction activities along the Alaska
Railroad right-of-way along Knik Arm between West Third
Avenue and Fish Creek, the crossing of CC30 at Chester Creek,
the crossing of FC36 along lower Fish Creek, the crossing
of FC30 on the West 30th Avenue alignment, and the crossing
of FC24W near the Tudor Road alignment. These sewer lines
either cross the Alaska Railroad right-of-way or parallel
the right-of-way in an area where the Alaska Railroad travels
on an embankment. Special construction techniques may be
necessary to prevent interference with rail operations and
maintain stability of the Alaska Railroad embankment, especially
along Knik Arm. When crossings are involved, a pit typically
is dug alongside the tracks and a steel or concrete casing
is forced beneath the tracks by hydraulic jacking and tunneling.
The sewer pipe would then be placed within the casing pipe.
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Table 10-1. Potential Short-Term Impacts Typically Associated With
Construction Activities. Many are Relatively Minor in Effect
and Magnitude and can be Effectively Mitigated as Outlined
Short-Term Impact
Recommended Mitigation Measures
Water quality degradation
Construction activities in streams and flood-
plains limited to periods of least sensitive
fish use. Care taken to not discharge petro-
leum or other pollutants into streams. Slope
stabilization and streambed protection should
be provided to reduce erosion potential.
Increased soil erosion and dust
Soil should be watered during construction.
After construction, exposed soil areas should
be reseeded with native species as soon as
possible.
Disruption of traffic, increased road
congestion, dust and noise from con-
struction vehicles.
Barricades and flagmen should be posted as
necessary to guide traffic through construction
zones and impacted street intersections.
Residents in area should be notified as to
location, nature, and duration of construction.
Construction traffic should avoid school and
hospital areas at all times to the extent
possible. Construction vehicle traffic should
be minimized on congested roads during peak
traffic volumes.
Safety hazards
Open trenches along back lots should be
covered at the end of each work day. All
open ends of emplaced pipe should be sealed
at the end of each working day to prevent
access by small children.
Vehicle emissions and noise from con-
struction vehicles.
All vehicles and equipment should be fitted
with appropriate and properly maintained
pollution- control devices and muffler.
Visual impact of construction
Equipment should be stored in a designated
area. Employees' vehicles should be parked
at designated locations. Trees slated for
removal from private property should be
offered to landowner, if practical, for use
as firewood.
Disruption of business activity
All businesses along construction rights-of-
way should be notified in advance of proposed
construction schedule. Meetings should be
held with owner/operators to determine
periods of minimal disruption to business
activity.
Spoil storage and disposal
Whenever possible, disposal of spoil material
should be coordinated with other ongoing
projects needing fill material.
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The southeast interceptor .parallels the Alaska Railroad
between East 78th Avenue and Huffman Road', but in an area
where the Alaska Railroad right-of-way is generally at ground
level. Construction of this interceptor should not interfere
with Alaska Railroad operations or stability of the track.
An additional area of potential concern is the construction
along the Alaska Railroad right-of-way between Tudor Road and
International Airport Road. The Minnesota Bypass crosses the
Alaska Railroad on an overpass structure in this area. The
construction activity will either take place through the exist-
ing overpass bridging area, in which case construction may impede
rail movement, or will require tunneling beneath the northern
approach to the overpass bridge. The latter course can be
mitigated by an engineering approach which will not disrupt
vehicle traffic on Minnesota Bypass.
Hospitals. Restricting access to hospitals can have a
severe impact during an emergency. The construction of inter-
ceptor DB15 along Debarr Road and DBWL across Airport Heights
Road at Penland Parkway may impede access to Alaska Hospital
and Medical .Center. Construction of these two lines may need
to be phased such that emergency vehicles will retain access
to the hospital. Additional provisions should be made such
that access from the north along Airport Heights Road is not
completely denied at any time.
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Chapter 11
Impacts of Alternatives
Land Application of Effluent
Primary Clarification with No Chlorination of Effluent
Secondary Treatment of Effluent
Sludge Disposal
West Interceptor Bypass
Rabbit-Potter Creek Areas
No Action Alternative
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Chapter 11
IMPACTS OF ALTERNATIVES
The recommended facilities plan and the alternatives
considered in recommending the plan are outlined in Chapter 3,
The following is a brief summary of the probable environ-
mental impacts of alternatives mentioned in the facilities
plan but not recommended by the MOA. In addition, a brief
discussion of the consequences of the no-action alternative
is presented.
Land Application of Effluent
The facilities plan refers to an earlier consideration
of applying wastewater effluent to land in the Point Campbell
Military Reservation. This area was considered because it
is near the Point Woronzof WWTP and is underlain by sand
and gravel deposits which are often suited for land disposal
of wastewater. Furthermore, groundwater flow in the area
is stated to be generally toward Cook Inlet, away from the
urbanized areas of the Anchorage Bowl (U. S. COE 1979).
Certain environmental impacts could accrue from this
technique. Land application would reduce or eliminate the
discharge from the outfall into Cook Inlet. While wastewater
percolates through soil, heavy metals, organic compounds,
bacteria and viruses can be filtered, biologically degraded
or bound to soil particles and probably not reach Cook Inlet
in significant amounts. The Point Campbell Military Reserva-
tion is moose habitat, and nutrient enrichment of the soils
may accelerate growth of forage species, particularly if
appropriate forage management actions were undertaken.
Potential adverse environmental impacts relate to
projected and existing human use of the disposal area.
The MOA plans to develop a park in the Point Campbell
area following transfer of the property from military to
MOA jurisdiction. Existing public recreational use includes
an offroad vehicle facility off Kincaid Road and cross-
country skiing during the winter.
Groundwater impacts could also result from land disposal
of effluent in the Point Campbell area. As noted in the
prior chapter, prior study (ASCOE 1979) indicated flow
of groundwater was generally toward Cook Inlet. A more
detailed review is needed of shallow and deep aquifers in
this area to confirm movement direction and assess possible
199
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interchange between aquifers. Such an analysis should
include consideration of the effects of increased MOA ground-
water pumping on the direction of flow.
Land area would be occupied by the disposal operation,
with other uses precluded. Accumulation of conservative
substances could permanently affect use of the land. Another
special problem with this alternative is feasibility of
application and percolation during the winter months.
Wastewater Renovation and Reuse
The environmental impacts of this technique cannot be
addressed because the facilities plan does not identify any
potential uses of reclaimed wastewater.
Alternative PA: Primary Clarification With
No Chlorination of Effluent
Chlorination of effluent is a generally accepted techni-
que for killing viruses and bacteria which may cause human
disease. Chlorination of wastewater, on the other hand,
is known to result in the formation of potentially toxic
halogenated organic compounds (e.g., chloramines) and-free
chlorine which are toxic to salmonids and other aquatic
species (Brungs 1973; Tsai 1973; Buckley 1977). Partially
in response to these toxicants, ADEC has recommended an ex-
tension of the outfall (to carry effluent further out from
shore) and elimination of the Chlorination process as mea-
sures to minimize the potential for adverse impacts on mi-
grating salmon. Actual benefits to the salmon resource are
unknown, primarily because the impact of the chlorinated
effluent on the Knik Arm is unknown. Elimination of Chlori-
nation will result in elevated levels of bacteria and viruses
in the discharge mixing zone, beyond the mixing zone, and
in near-shore areas. This impact is expected to be minimized
if the outfall is extended further into Knik Arm, and an
adequate diffuser is constructed.
Preliminary studies of the outfall and diffuser by
Ott Water Engineers indicate that current water quality
standards would be violated if Chlorination is discontinued.
As explained in discussions of the outfall and diffuser
in the Recommended Plan section of Chapter 3, two different
coliform standards were evaluated by Ott for their effect
on required diffuser length. Alternative 1, with a 6,100-foot
diffuser to meet a coliform standard of 200 FC/100 ml, would
delete certain designated beneficial uses for the waters
of Cook Inlet, specifically, water supply for seafood
processing, water contact recreation, and harvesting
for consumption of raw mollusks or other raw aquatic life.
200
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This change in standards would probably not affect
any existing uses, nor would it preclude any likely future
uses. High turbidity of the Knik Arm waters would prevent
the water from being used for seafood processing. The
population of raw mollusks is virtually nonexistent in
the study area (Chapter 8), and no such use is ever likely
to develop. Water contact recreation does occur to a small
degree on Cook Inlet, however. Public use of the shoreline
area occurs, and high coliform counts have historically
been of concern. Swimming, diving and other similar types
of contact recreation are virtually nonexistent, although
at least one water skier has been observed.
Alternative 2, with a minimal (about 100-foot) diffuser
would require deletion of all beneficial uses except growth
and propagation of fish, shellfish, aquatic life, and wildlife,
including seabirds, waterfowl and furbearers. This would
result in no coliform standard being applicable, pursuant
to State water quality standards. In addition to the uses
foregone as described for Alternative 1 above, water supply
for aquaculture, water supply for industry and secondary
water recreation would no longer be protected (designated)
uses.
High natural turbidity levels in Knik Arm would' be
serious problems for aquaculture or an industrial water
supply. Such uses are not currently established, nor do
they appear likely to develop in the future. Secondary
water recreation, including use of the shoreline and boating,
could result in public health threats from coliform levels
above state standards. The significance of this threat
is not presently quantified.
Secondary Treatment of Effluent
Two alternative alterations of 'Point Woronzof WWTP are
suggested in the facilities plan that would result in the
discharge of secondary treated effluent. No significant
adverse environmental impacts are anticipated with the dis-
charge of secondary effluent. However, it has not been
demonstrated that the discharge of less than secondary treated
effluent would harm Cook Inlet fishery resources or human
health (Murphy et al. 1972), although secondary treatment
would reduce suspended solids and BOD.
Secondary treatment would require a greater capital
investment, greater energy consumption, more land at the
plant, and would generate larger volumes of sludge.
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Sludge Disposal
The facilities plan recommends that incineration of
sludge continue and suggests three alternative methods of
ash disposal. The plan does not designate any one" of the
three ash disposal alternatives as part of the Recommended
Plan. Since these disposal options remain alternatives,
the impacts of the ash disposal methods are discussed in
Chapter 9, Sludge Disposal Impacts.
An alternative to incineration, namely digestion of
the sludge and subsequent disposal in a landfill, is not
preferred by MOA. A major environmental impact would be
the accelerated reduction in available landfill capacity.
The existing landfill will be full in the next 3-4 years,
and no alternate site has been selected. This impact is
discussed in more detail in Chapter 7.
Another alternative discussed in the facilities plan
is co-incineration of sludge and refuse. This alternative
has the environmental advantage of reducing the amount of
solid waste destined for a landfill and generating energy
as a byproduct. Adverse impacts on air quality may occur
if steps are not taken to minimize the release of carbon
monoxide and particulates.
West Interceptor Bypass
The impacts of the recommended alternative, a pump station
south of Campbell Creek and west of the Alaska Railroad, and
a force main from the pump station along C Street and
Raspberry Road to the existing West Interceptor Bypass, are
discussed in Chapter 4.
Two alternatives to the Recommended Plan, a gravity flow
interceptor with open ditch construction, and a combination
of open ditch and tunneling construction, have impacts on
the biological environment that are similar to the impacts
of the recommended alternative. All three cross Campbell
Creek and may temporarily impede movement of salmonids or
increase turbidity and sedimentation in the creek.
The potential physical impacts of the gravity flow alter-
natives are quite different than for the recommended force
main. Gravity flow alternatives require significantly deeper
excavations than the preferred alternative. In order for
the interceptor to be constructed to flow by gravity it must
be placed on a relatively flat grade connecting the existing
interceptor sewers at the Alaska" Railroad/Campbell Creek
location to the existing section of the west bypass interceptor
on Raspberry Road near Minnesota Bypass. The ground rises
202
-------
between these two points, and a 50-foot excavation would
be required along much of the alignment in C Street and
the easterly portion in Raspberry Road. Shallow groundwater
is prevalent in this area, with sand and gravel deposits
predominating. .Dewatering would be required in order to
allow construction of either the open trench alternative
or the tunnel alternative. In estimating construction
costs, Ott Water Engineers developed estimates of the extent
of dewatering that would be needed based on available soil
borings taken along the alignment. Ott estimated that
a series of about 36 temporary wells slightly deeper than
the excavation would be required for each 0.25 mile of
trench along the alignment. The wells would be spaced about
70 feet apart, and each would have to pump about 480 gallons
per minute to successfully dewater the excavation. Continuous
dewatering would be required for about 6 weeks for each
section of trench or tunnel. It was recognized that the
wells would have to discharge the pumped water, but no
acceptable discharge was readily located. This problem
was not resolved by the facilities planners, and became
a further reason for recommending the alternative of a
pump station with a much shallower force main.
One of. the highest yielding water wells in the Anchorage
Bowl, operated by Central Alaska Utilities, Inc., (CAU)
for domestic water supply, is located several hundred feet
east of C Street and a similar distance north of the inter-
ceptor's route from Campbell Creek to C Street. Dewatering
required for each nearby leg of the interceptor construction
was estimated by Ott Water Engineers to lower the water level
in the well by about 10-15 feet, or about 25 feet if both
legs are dewatered at once, temporarily lowering the well
yield by as much as 50 percent and increasing pumping costs.
This impact would last about 6 weeks to 3 months, depending
on the rate of construction. The impact would occur during
the summer construction season, possibly coinciding with
the early summer period when water supply is at a critically
low level.
While force main construction would not require dewatering,
it would leave a pressurized sewer near the surface of
the shallow groundwater table. Leakage from the force
main due to frost heaving or seismic action could pollute
the groundwater. A public health threat could exist through
use of the CAU well if leakage were to occur.
The dewatering could decrease the Anchorage water supply
for several months. Considering that the Anchorage water
supply is currently barely adequate to meet demands at critical
periods, loss of well production could cause a water shortage
in Anchorage.
Several commercial buildings and residences are located
near the interceptor alignment and could be affected by con-
struction activities, especially dewatering. When certain
types of soils are dewatered, the soil particles are allowed
203
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to compress more tightly together, allowing the land surface
to settle or subside slightly- Construction dewatering for
utilities and roadways has caused subsidence in many different
areas of the country, and the soils in the area of the west
bypass may be susceptible to subsidence if dewatering occurs.
The Alaska Bank maintains a large building with computer
facilities on Raspberry Road along the interceptor alignment.
If subsidence did occur, structural damage from differential
settlement would be likely. Any subsidence or vibration
from construction equipment could also interfere with the
operation of the computer system. Several weeks to several
months of construction activities in this area could sub-
stantially interfere with the operation of the bank computer
system and could leave the building unsuitable for that use.
Subsidence of soils in residential areas along the inter-
ceptor alignments can lead to cracks in walls, possible differen-
tial settlement of paving, and leakage of water and sewer
pipes.
Campbell Creek lies upslope from the project area and
may be a major source of recharge to local groundwater. The
dewatering could induce greater recharge from Campbell Creek,
reducing flow in the creek and adversely affecting salmon
runs in the creek.
In the event of seismic activity the interceptor could
separate at joints, allowing both infiltration and exfiltration.
Infiltration would increase the flow to the plant, decreasing
treatment capacity available for sewage. Exfiltration can
contaminate groundwater resources, including the CAU well.
Rabbit Creek/Potter Creek Area
The facilities plan describes a number of alternatives
for providing sewerage service to those portions of the lower
Hillside area requiring connection to the public system.
Five alternatives (A-E) dealt with the treatment of the
collected wastewater, and four alternative (1-4) were proposed
for the collection system.
Rabbit Creek/Potter Creek Area Wastewater Treatment Alternatives
Alternatives A through C generally provide for a small
WWTP at the north edge of Potter Marsh that would discharge
secondary treated effluent into Rabbit Creek. This method
of disposal is likely to have adverse environmental impacts
on Potter Marsh and the fishery resources in Rabbit Creek.
Of major concern are the adverse impacts of an accidental
discharge of raw or inadequately treated sewage, elevated
water temperatures during winter, chlorine, and turbidity.
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Recent studies by Sanville (1981) and Schwartz (1982) have
challenged the assumption that wetlands can act as a nutrient
sink or as a biotic nutrient filter. The Alaska DFG (1981a,
1981b) has expressed strong objections to the discharge of
sewage-into Rabbit Creek:
"Water quality and quantity in Potter Marsh must be
maintained at established levels to ensure the continued
health and productivity of the fish and wildlife which in-
habit the area. Disposal of sewage or industrial wastes,
whether treated or untreated, and the channeling of surface
runoff into Potter Marsh or any other portion of the Refuge
will be opposed by the Department".
Alternative E in the facilities plan provides for a
small WWTP discharging secondary treated effluent into Potter
Creek. Although Potter Creek does not drain into Potter
Marsh, it empties into Turnagain Arm just below the Potter
Point State Game Refuge. Alaska DFG may object to the dis-
charge of secondary effluent into Potter Creek. Potter Creek
has minimal numbers of Dolly Varden trout and a small run of
pink salmon (Alaska DFG 1981a). A small marsh has developed
in Potter Creek just upstream of the Seward Highway, probably
because of the restricted flow provided by the corrugated
steel culvert under the highway. The small marsh may be
adversely impacted by the proposed wastewater discharge,
particularly during the winter months when most water move-
ment in Potter Creek occurs under ice.
Alternative D is the Recommended Plan and is discussed
in Chapter 4. This alternative delivers the wastewater to
the southeast interceptor via a pump station and force main
for eventual treatment at Point Woronzof WWTP.
Rabbit Creek/Potter Creek Area Wastewater Collection
Alternatives
Four alternative routings were proposed for the sewage
collection system in the Rabbit Creek and Potter Creek areas
(Figure 3-9). Three of the alternative routings (Alterna-
tives 1-3) deliver sewage to either a small WWTP or a pumping
station at the north end of Potter Marsh, and are compatible
with Alternatives A-D described above. Alternative 4 is
compatible only with a small WWTP at Potter Creek (Alterna-
tive E above). Alternative 1 proposes a gravity interceptor
flowing north located east of the Old Seward Highway. This
route is the recommended alternative in the Facilities
Plan, and the impacts are discussed in Chapter 4.
205
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Alternative 2 (Figure 3-9) proposes gravity flow to
the south along Old Seward Highway, with a pumping station
located at the south end of Potter Marsh and a force main
carrying wastewater north along the Old Seward Highway to
the Rabbit Creek facility. The environmental impacts of
crossing Rabbit Creek and Little Rabbit Creek are essentially
similar to those of Alternative 1. The two major differences
are that the sewer right-of-way will be closer to Potter
Marsh in Alternative 2, and a pumping station will be built
at the south end of Potter Marsh near the weigh station.
Alternative 2 locates construction activity more closely
to Potter Marsh.
Alternative 3 proposes gravity flow to the south along
Old Seward Highway, as in Alternative 2, with gravity f^ow
turning to the north toward the Rabbit Creek area in an
interceptor placed west of the Alaska Railroad embankment.
Alternative 3 minimizes the amount of construction activity
along Old Seward Highway and eliminates the potential impacts
associated with a separate crossing of Little Rabbit Creek.
Alternative 3 would have only one stream crossing, on Rabbit
Creek below the tidegates. The interceptor would be located
in tidal mudflat habitat along most of the Alaska Railroad
right-of-way in an existing pipeline corridor. Tidal marsh
habitat would not be encountered until about the point that
the interceptor would cross Rabbit Creek. Placement of pipe
in the existing railroad-highway corridor is a preferred
alternative according to ADFG (1981b) as noted in the Potter
Point State Game Refuge Management Plan. The Alaska Railroad
would be crossed in two locations, one just north of Potter
Creek and the other just north of Rabbit Creek.
In some respects, the potential environmental impacts
of Alternative 3 are less adverse than those of the other
three routes, including the Recommended Plan. Some of
these are noted in the preceding paragraph, e.g., only
one stream crossing as compared to two. The interceptors
are potentially subject to failure, or leakage, such as
can occur following frost heaving and seismic events, and
it may be preferable to have raw sewage spilled along Turnagain
Arm rather than upslope of Potter Marsh. Alternative 3
reduces by half the length of the interceptor on the upstream
side of Potter Marsh and therefore reduces the risk of
sewage spills or exfiltration affecting Potter Marsh. MacDonald
(1980) has noted that the existing sewer berm along the Turnagain
Arm between Campbell Creek and Furrow Creek is occupied by
a unique, but trampled coastal marsh plant association. The
existing situation is somewhat different from the proposed
interceptor in that the existing berm travels through an
established coastal marsh area and is frequently used as
a convenient footpath, whereas the proposed berm would be
located in a muddy silt area and the railroad embankment"
is a more convenient "trail".
206
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Alternative 4 proposes a gravity flow interceptor
traveling south along Old Seward Highway to a small treat-
ment plant at Potter Creek. This alternative represents
the least amount of pipe emplacement around Potter Marsh,
and does not cross Rabbit Creek or Little Rabbit Creek. It
may cross Potter Creek, depending on the final location of
the small WWTP- The route and the route-specific impacts
are very similar to the corresponding portion of Alterna-
tives 2 and 3.
No-Action Alternative
The long-term environmental consequences of no action
appear more adverse than the long-term consequences of any
of the alternatives or the Recommended Plan. The status
quo would increasingly violate federal and state water
quality laws and could result in a state-imposed moratorium
on new sewer hookups in the Anchorage Bowl. Failure to
expand or renovate the existing sewer system would increase
the incidence of pollution of local streams and of local
groundwater supplies. This situation would place severe
constraints-on local growth and the local economy, and
sharply -increase the hazard to public health.
207
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Chapter 12
Issues Unresolved by Alternatives
-------
Chapter 12
ISSUES UNRESOLVED BY ALTERNATIVES
A number of issues have been raised during scoping and
preparation of this EIS that are related to the Recommended
Plan or alternatives, but that are not resolved by them.
This may occur because the issues are only peripherally affected
by the alternatives, because other factors determine the
outcome of the issues, or because the alternatives are not
directed toward resolution of the issues. Each relevant
issue that is unresolved by the alternatives is identified
below,
o Substantial wetland areas may be developed as a
result of sewerage expansion. While the EIS evaluates
wetlands and potential losses in depth and discusses
the relationship between sewerage expansion and this
issue, final resolution of wetland issues remains a
responsibility of the Municipality, the ADEC Office of
Coastal Zone Management, and the U. S. COE. The
U. S. COE permit authority under Section 404, the State
Coastal Zone Management Plan and the MOA Wetland
Management Plan will determine the fate of Anchorage's
wetlands.
o Sewerage options proposed for the Hillside area may
not provide a long-term (20-year) solution to waste-
water treatment and disposal needs. More than one-
quarter of the area is judged generally unsuitable for
outside treatment systems. The potential for one unit
per acre development throughout the portion of the
Hillside that is excluded from the public sewerage area
will lead to increased system failures and public
health risks as density increases, systems age and
groundwater recharge from on-site system effluent in-
creases. Should the Hillside Wastewater Management
Plan prove unable to provide for adequate sewerage
while protecting potable water supplies and minimizing
public health risks, additional action will be required.
The selection of such actions would be the responsibil-
ity of the MOA. These actions are undefined in MOA
201 planning, although possible mitigations are
addressed in the EIS.
o Anchorage is occasionally short of water during critical
periods. This problem will intensify as the Municipal-
ity gains population. Without an increase in water
supplies, Anchorage's growth may be adversely affected,
209
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and there may not be a sufficiently large increase
in sewage flows to justify the level of.sewerage
system expansion envisioned in the facilities plan.
This problem may be resolved by planning efforts
beyond the scope of the Section 201 facilities
planning, if the Ekluta water importation project
is implemented.
o Anchorage will fill its existing solid waste land-
fill by about 1985, and no new site is identified.
Disposal of sludge ash and other treatment byproducts
may require a landfill site; a new site is mandatory
for disposal of municipal trash. Planning for a new
site is beyond the scope of 201 planning.
o Location of development within the Anchorage Bowl.
The MOA Comprehensive Development Plan, currently
under review, will establish land use densities and
the location of future urbanization.
o Issues outside of the EIS study area, including in-
dustrial development on Fire Island, sewerage in
Eagle River or Girdwood, or urban development across
the Knik Arm are not addressed or resolved in the
EIS. Those areas are not tributary to the Point
Woronzof WWTP nor are they located in the Anchorage
Bowl.
210
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Chapter 13
Coordination
• Scoping Meetings
• Public Workshops and Meetings
• Comments Received through Preliminary-Draft EIS
-------
Chapter 13
COORDINATION
This chapter describes the public and agency contacts
that have occurred through workshops, meetings and reviews
of the preliminary Draft EIS. Detailed notes and minutes
are available for workshops and selected meetings from EPA
Region 10.-
Scoping Meetings
Pursuant to formal notice in the Federal Register, an
EIS scoping meeting was held in Anchorage on July 9, 1981,
followed by additional meetings on July 10. A list of
tentative issues was presented, discussed and expanded to
include additional concerns, and priorities were assigned.
A copy of the resulting issues and priorities that led to
the detailed EIS scope of study is reproduced as Figure 13-1.
Public Workshops and Meetings
Several public workshops and meetings were held in
Anchorage to discuss progress on EIS work and to refine its
scope. They are listed below.
Interagency Workshop - September 9, 1981
An interagency workshop was held at the Hill Building
in Anchorage on September 9, 1981 at the request of the MOA
Planning Department to discuss wetlands biology work for
the EIS. Representatives of EPA, USFWS, various MOA depart-
ments, the MOA Policy Advisory Committee and the ETS'team
attended. The EIS work scope was explained and the MOA's
needs for special study work on certain wetlands were described,
The possibility of coordinating EIS work with MOA's special
study work was discussed.
Facilities Plan Public Meeting - October 15, 1981
A 201 Facilities Plan public meeting was held on
October 15, 1981 at West High School. The meeting was
attended by about 40 people; Comments were received on
the EIS scope following a presentation of EIS issue areas
(Figure 13-1). Concerns about impacts of south Hillside
area urbanization on Potter Marsh were emphasized by attendees.
211
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Figure 13-1. Issues Identified for EIS Coverage and Priorities at
July 9 and 10, 1982 Scoping Meetings
• I I .,.! . I. I • I •!• I
Tentative EIS Topic Areas
Construction impacts
Growth-related issues
Hillside issues
Wetland issues
Socio-economics
Air quality
Physical factors
Effluent treatment and disposal impacts
Issues Presented and Discussed at EIS Scoping Meetings
Importance
Ranking
High
Low
Low
High
High
High
High
Controversial
Moderate
High
High
Moderate
Low
Low
Low
Moderate
Low
Moderate
Low
High
Moderate
High
Issue
Construction impacts
Wetlands
Transportation
Disturbances
Other
Hillside issues (growth related)
Surface water quality
Groundwater quality
Domestic water supply
Development densities
Wetland issues (growth related)
Biological values
Hydrological values
Development issues
Other growth-related issues
Socio-economic impacts
Air quality
Hydrology
Seismicity
Wind, water erosion
Effluent treatment and disposal impacts
Knik Arm discharge
O&M costs
Energy use
Odor potential
Other
Additional issues
Community-wide development issues
Air quality - sludge incineration
Sludge disposal to Knik Arm or land disposal
212
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EIS Wetlands Workshop - October 16, 1982
An EIS workshop emphasizing wetlands work was held in
the new Federal Building in Anchorage on October 16, 1982.
A major purpose was to identify a detailed scope of expanded
biological studies to satisfy both EIS needs and MOA special
study needs. Federal, state and local agency representatives
attending the workshop received handouts outlining a tentative
study scope and modifications were suggested by participants.
(The expanded biological studies were not funded for this
EIS.)
Facilities Plan Public Meeting - January 20, 1982
A 201 Facilities Plan public meeting was held on
January 20, 1982 at West High School, attended by about
25 people. Wastewater project alternatives were presented
and EIS issues discussed. Primary public attention was
focused on Hillside and Potter Marsh impacts that might
occur from sewering of the south Hillside.
EIS Wetlands and Hillside Workshop - April 14, 1982
A two-session EIS workshop was held in Anchorage on
April 14, 1982 to discuss wetlands and Hillside area issues.
The first session, attended by about 15 people, was held
in the Hill Building. The second session, attended by about
10 people, was held at Wendler Junior High School. Issues
discussed at the workshops included the outfall, Hillside
issues and specific wetland impacts.
Comments Received Through Distribution
of the Preliminary Draft EIS
The Preliminary Draft EIS was circulated for comments
on August 30, 1982 to certain public agencies and groups
that were active participants in EIS scoping. Comments
were received at a meeting in the MOA Telephone Utility
offices on September 15, 1982. Those comments have been
considered in completing this Draft EIS.
213
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Chapter 14
References
-------
Chapter 14
REFERENCES
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217
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221
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222
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APPENDICES
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U.S. ENVIRONMENTAL PROTECTION AGtNCY
REGION X
i
t> 1200 SIXTH AVENUE
% SEATTLE, WASHINGTON 98101
T
% <•<>
^PRO^° APPENDIX A
REPLY TO
AITNOF:
SEP 2 7 1982
Keith Kelton
Alaska Dept. of Env. Cons.
Pouch 0
Juneau, AK 99801
Dear Mr. Kelton:
In reviewing our consultant's preliminary Draft Environmental Impact
Statement, my staff has become aware of certain problems within the
Municipality of Anchorage's "Wastewater Facilities Plan for Anchorage,
Alaska." In the interest of avoiding lengthy delays in completing the
EIS and in initiating other activities that will follow the release of
the EIS, EPA intends that the draft EIS will identify these concerns and
indicate that additional information will be included in the0 final EIS.
i
Our concerns include: (1) flow projections used in sizing the treatment
works and the interceptor sewer; (2) reduced EPA eligibility for reserve
capacity; and (3) cost information that does not accurately reflect EPA
eligibilities and does not provide projections of annual cost to the
typical residential household.
More specifically, our concern related to flow projections and facility
sizing is based in part upon: (1) The attainment of saturation
populations ; (2) The inclusion of an I/I allowance of 4000 qpdim which
is the allowable I/ 1 component for existing rather than for new sewers;
and (3) The application of peaking factors to the I/I allowance.
Our concern on eligibility is based on the fact that the facility plan
does not reflect the recent amendments to the Clean Water Act which limit
or prohibit EPA grant participation in reserve capacity and in capacity
for serving industrial flows.
The facility plan does not include estimates of the annual costs that a
typical residential household can expect to pay. These costs must be
compared to the national standard and reported in the facility plan and
the EIS. We recognize that a precise estimate of such costs is
impossible because of the difficulty in predicting the availability of
EPA grant funding. We would expect, however, that the state priority
list which is based on assumed National levels of funding of $2.4 billion
per year would provide a reasonable approach for estimating the amount
and timing for future EPA funding of the Anchorage project. We also
believe that this projected level of EPA funding could be used in
developing the most likely scenario for project financing.
A-l
-------
It is also suggested that the facility plan incorporate an evaluation of
the financial capability of the MOA in proceeding with the project.
Although inclusion of this evaluation is not required to conclude the
facility planning or the EIS, it is a requirement for obtaining Step 3
grant funding and if accomplished at this time, could be considered as
within the scope of the Step 1 grant.
These items are being brought to
reducing delays in completing the
accordance with the provisions of
agency defers followup activities
your attention in the interest of
facility plan and the EIS. In
the EPA/ADEC delegation agreement, this
to ADEC. We must, however, clarify
these points for our final EIS, and therefore look forward to yoiur
assistance in their resolution..
Sincerely.
Reg
cc:
encer,
'Administrator
Ken Lauzen (MOA)
Ron Kreizenbeck (AGO)
John Jones & Stokes
A-2
-------
Appendix B
OCEANOGRAPHIC DESCRIPTION OF KNIK ARM, COOK INLET, ALASKA
IN REFERENCE TO THE"PROPOSED EXTENSION OF THE
POINT WORONZOF OUTFALL
By:
Kinnetic Laboratories, Inc.
519 W. Eighth Avenue, Suite 205
Anchorage, Alaska 95501
August 13, 1982
B-l
-------
LIST OF TABLES
Table Page
1 Net Mean Currents at Point Woronzof and B-13
Tidal Excursions
2 Salinity Values as a Function of Depth B-14
for Knik Arm
3 Cook Inlet Salinity Values for 1979 B-20
4 Cook Inlet Temperature Values for 1979 B-21
5 Volumes of Cook Inlet Cross-Sections B-22
6 Flushing Rates for Various Sections of B-23
Cook Inlet
7 Age and Size Distribution of Macoma B-31
b'althica Collected in the Point Woronzof
Area
.8 Water Quality Data at Proposed Outfall B-33
Site Collected August 1979
9 Selected Heavy Metal and Chlorinated B-36
Hydrocarbon Analysis of Sediment Samples
From the Beaches East of Point Woronzof
B-2
-------
LIST OF FIGURES
Figure page
1 Generalized Bathymetry of Cook Inlet, 3-6
Alaska
2 Bathymetry of Knik Arm B_7
3 Tidal Chart for the M2 Tide of Cook 3-8
Inlet, Alaska
4 Current Speed Measured 500 Meters Off B-10
Point Woronzof
5 Point Woronzof Current Directions, B-ll
August 16, 1979
6 Hansen and Rattray Classification B-16
Diagram
7 Salinity/Temperature Sampling Station B-18
Occupied by the U. S. S. Great Land During
1981
8 Estuarine Waste Assimilation Diagram B-25
9 Water Quality, Intertidal and Subtidal B-27
Sampling Stations in Knik Arm, Kinnetic
Laboratories, Inc. (1979)
B-3
-------
Oceanographic Conditions of Knik Arm
Introduction
The analysis of estuarine pollution is concerned with
the determination of the temporal and spatial distribution
of contaminants introduced into the system and with their
impacts on water quality and biological systems. This analy-
sis is important in predicting both the degree of treatment
required by a discharger and the maximum quantities o'f muni-
cipal and industrial wastes that can be assimilated by the
natural circulatory system of the estuary. Contaminants
normally enter the estuary via river flow and/or through
outfall structures. Outfalls provide varying amounts of
initial dilution through jet entrainment.
In addition to the effects of longitudinal and vertical
salinity gradient on waste dispersion, tidal velocity oscil-
lations also provide an important longitudinal dispersion
mechanism in estuaries. Although the velocity attributed
to freshwater discharge in an estuary is normally insigni-
ficant compared to tidal velocities, the net seaward flux
due to freshwater flow provides the important flushing action
in estuaries.
The following sections will discuss the physical, bio-
logical, and chemical oceanographic conditions of Knik Arm,
Cook Inlet, Alaska in relation to the present (August 1982)
maximum allowable discharge of 126,000 m3 per day from the
250 m long outfall located at Point Woronzof. This over-
view will then be employed to estimate what effects, if any,
would be observed in Knik Arm upon the extension of the Point
Woronzof outfall an additional 500 m, and upon increasing
the maximum allowable discharge to 219,000 m3 per day.
Physical Oceanography
Cook Inlet is an unique estuary in that it possesses
tidal ranges of 38 feet (26-foot mean height), tidal bores
B-4
-------
in the upper reaches, current 'of 4-5 knots, suspended glacial
silt of up to 2,000 mg/1 and, in winter, pancake ice of 1 m
thickness. The estuary is about 200 miles long and about
50 miles wide at the mouth (Figure 1). Generalized bathy-
metry (Figure 1) shows the inlet to be deep, approximately
20 fathoms (129 feet) north of the Forelands and about
90 fathoms at the mouth. A more detailed chart of the
region of the outfall at Point Woronzof indicates deep water
(30-170 feet) extending well past Anchorage up Knik Arm
(Figure 2).
Tides
The tide at Anchorage is one of the largest in the world.
It is a mixed tide whose diurnal inequality, i.e., the dif-
ference in heights of successive high waters or low water,
is somewhat obscured by the large tidal range. Although
the process'es which generate this tide are complex, the vari-
able boundary model of Mungall and Matthews (1970) provides
some useful insight. Figure 3 shows the M_ tide height ampli-
tudes calculated by these authors. The dashed lines are
corange lines, i.e., lines along which the range of tidal
displacements (cm) is equal. The solid lines are cotidal
lines, i.e., lines along which the maximum displacements
occur simultaneously. The cotidal lines indicate phases
of the tide and are expressed in degrees.
In Figure 3 the amplitudes are seen to double in magni-
tude as one moves north into the inlet, from 175 cm at the
entrance to 350 cm at Anchorage. It is important to note
that below the Forelands the corange lines run parallel to
the axis of the inlet. A difference in amplitude of approxi-
mately 40 cm is observed across the inlet. However, north
of the Forelands 'the corange lines tend to align with the
cotidal lines. These observations indicate that the tidal
regime of Cook Inlet is composed of two distinct regions
B-5
-------
w
GRAII1TE POINT J ' / , _ - -; POSSESSION
/-x' '
DEPTHS ARE IN
FATHOMS
v I ' \ 75--J
BARREN I SUNOS
Figure B-l. Generalized Bathymetry of Cook Inlet, Alaska.
B-6
-------
w
depths in feet below ML
Figure B-2. Bathymetry of Knik Arm.
-------
COOK INLET
Tidal Chart
for the M2 Tide
Amplitudes in cm
North Foreland*
West Foreland
Drift River
Figure B-3.
Cook Inlet: Tidal Chart for the M~ Tide.
(Amplitude in cm.)
B-8
-------
separated by the Forelands. In the south the tide shows
characteristics of a progressive Kelvin wave. Because the
maximum flood currents would occur at high water, the Coriolis
effect would be quite great and the tidal amplitude would
be greater on the east of the inlet than on the west. This
phenomenon is observed. Above the Forelands, however, the
tide behaves more like a conventional standing wave. The
corange and cotidal lines are no longer perpendicular, indi-
cating the frictional effects of shoaling. High and low
waterssand the time of slack water are nearly simultaneous
throughout this section. Thus the tidal amplitude is 90 degrees
out of phase with the current velocity. Figure 4 shows this
effect clearly for a current meter station off Point Woronzof
(Kinnetic Laboratories, Inc. 1979). In addition, since slack
water occurs at maximum tide, no Coriolis force exists at
that moment and no water level variations exist across the
inlet.
Tidal Currents
Although several investigators (Britch 1976; Marine
Advisors 1965) have measured the currents off Point Woronzof
for short periods of time, only Kinnetic Laboratories, Inc.
(1979) has generated data from moored current meters. The
moored data were taken at stations shown in Figure 5. Cur-
rent meters (General Oceanics Model 6011, tape recording)
were moored August 14-20, 1979 under a surface following
buoy at three stations along the alignment bearing of the
present outfall. The inshore meter was just offshore of the
present outfall (304 m off the chlorination tower on the
beach), the second meter was farther out at 495 m off the
tower, and the third meter was out in the region of the proposed
extension (705 m) -. The inner meters were at 6 feet below
the surface; the outer meter was at 16 feet below the surface.
Figure 5 shows the average velocities and directions for
the flood and ebb tides at the three stations for August 15.
B-9
-------
Knots
5 -
ft.(tide)
CO
M
O
1
30 4 H
20 3 -
10 2 -
0 I
tide
current
flood
flood
o
o
t-
o
o
CO
o
o
o>
o
o
w
o
o
o
o
W
M
o
o
ro
CO
o
o
o
o
o
o
o
o
ro
o
o
o
o
o
in
o
o
o
to
o
o
o
o
o
CO
o
o
o
O)
o
o
o
o
o
o
o
o
CVJ
hours (AST) 14 August 1979
Figure B —4 . Current Speed Measured 500 Meters off Point Woronzof Superimposed
on Tide Heights for the Same Period.
-------
61° ot 2.8 knots
245° at 3.1 knots
*
26O° at 3.8 knots
292° at 3.6 knots
700m 35 at LW
500'm 25 at LW
300m 18 at LW
250m
Pt.
Woronzof
1000
Figure B-5,
Point Woronzof Current Directions, 16 August 1979,
Bearings are Degrees True.
B-ll
-------
The shore effect on the two inside meters is quite noticeable
in the deflection of the water away from the shore at these
two stations during ebb and flood tide. Wastes from the
present outfall would be immediately carried away from the
shore on the flood, only to be returned to the beach as the
waters fill in behind Point Woronzof. Although the existence
of a gyre behind Point Woronzof has been documented by a
number of studies (Marine Advisors 1965; Britch 1976; Tetra
Tech 1977) , the seaward boundary of the gyre has not been
located accurately. Figure 5 indicates that only at 700 m
does the water movement appear to be unaffected by the shore.
For diffuser design purposes the lowest 10 percentile
current for these meter locations was calculated, then adjusted,
assuming a linear transfer function to the mean annual tidal
range (26 feet yearly mean as opposed to 23 feet mean during
the measurement period). The mean of the lowest 10 percentile
currents was 50-67 cm per second (1.0-1.3 kts); the maximum
of the 10 percentile range was 83-96 cm per second (1.7-
1.9 kts). Table 1 lists the average current velocities and
tidal excursions for each meter location over the study period.
In an estuarine system the salt balance and the dynamic
balance are parts of the same interlocking system. Hansen
and Rattray (1966) have developed a method of estuarine
classification based upon the ratios 6S/S (a stratification
parameter) and u /u (a circulation parameter). 6S is the
S u.
difference between surface and bottom salinity, S is the
mean cross-sectional salinity, uo is the mean surface current,
o
and u is the mean cross-sectional current velocity. From Table 1
u is found to be 15.5 cm per second and u. to be 12.9 cm
O t-
per second. Thus the ratio u /u equals 1.2.
S L.
Table 2 lists salinity values as a function of depth
for a station off Point Woronzof (61 degrees 13.3'N, 149 degrees
59.2'W) which was occupied in May 1968 by the R/V Acona of
the University-of Alaska. These data were abstracted from
B-12
-------
Table 1. Net Mean Currents at Point Woronzof and Tidal Excursions
to
1
Meter Location
(meters off Pt.
Woronzof)
300 (surface)
500 (surface)
700 (bottom)
•|~ Number of 15
§ cm/sec
FLOOD
§
// Time Intervals"*" Velocity Excursion
23.3 153.1 32.1 km
23.1 150.0 31.2 km
24.1 128.1 27.8 km
minute measurement intervals
EBB NET (on ebb)
§ §
// Time Intervals1" Velocity Excursion Velocity Excursion
26.9 154.2 37.3 km 11.7 5.2 km
27.0 164.5 39.9 km 19. A 8.7 km
26.4 131.4 31.3 km 7.8 3.5 km
-------
Table 2. Salinity Values as a Function of Depth for Knik Arm
Station CI 93 (61° 13.3'N, 149° 59.2'W) Occupied May 28, 1968
by the R/V Acona (Kinney et al. 1970)
Depth (meters) Salinity (ppt)
0 17.55
5 17.67
10
20 17.62
30 17.63
= 17.6]
o
t Miscellaneous information: time on station 1,812 hours.
Time of high water 1,930 hours (27 feet). Station depth,
50 meters.
B-14
-------
Kinney et al. (1970). The surface and bottom salinities
were 17.55 ppt and 17.63 ppt, respectively, and the mean water
column salinity, £JQ, 17.62 ppt. Thus &S/S equals 0.004.
Plotting the calculated values for the stratification and
circulation parameters on Figure 6 indicates that Knik Arm
falls in the classification group la, i.e., "the archetypical
well-mixed estuary in which the salinity stratification is
slight" and "the net flow is seaward at all depths and upstream
salt transfer is effected by diffusion."
Flushing Rates of Knik Arm and Cook Inlet
As mentioned previously, the net seaward flux due to
freshwater flow provides the important flushing action in
estuaries. The average length of time required to remove
1 day's contribution of water is defined as the ratio of
the quantity of river water accumulated in the estuary to
the quantity introduced daily by the river, and is termed
the flushing time, equation 1 (Ketchum and Keen 1953).
T = Q/R (I)
where Q is the total amount of river water accumulated
in the whole or section of the estuary, and R is the
river discharge.
There are a number of methods for calculating flushing
times. The Tidal Prism Method assumes the water entering
on the flood tide is fully mixed with that inside, and the
volume of seawater and river water introduced equals the
volume of the tidal prism (the volume between high and low
waters). On the ebb the same volume is removed and the fresh-
water content of it must equal the increment of the river
discharge. If V is the low tide volume and P the tidal prism,
then the flushing time in tidal cycles is:
p
B-15
-------
da
i
1
V s» 1
.01 __
.001
y///^U
''///////^^LL// //// ////////////////////////
lb /, /// 3b
/. //
/ o u ^
*,
\
la £ 2 a /x// 3 a
^
• ^~ Pt, Wor onzof Data
1 I
10
10
10
10
10'
Figure B-6. Hanson and Rattray Classification Diagram.
-------
Low water volume for Knik Arm has been determined by
Kinnetic Laboratories, Inc., from NOAA chart 16664 to be
7.2 x 10 m . The tidal prism was measured to be 2.75 x 10 . m .
This yields a flushing time of 1.26 tidal cycles or 15.6 hours.
Flushing times calculated by this method have been found
to give considerably lower estimates than those of other
methods. This is due to the erroneous assumption of complete
mixing of the estuarine waters, i.e., the fresher water near
the head of the estuary cannot reach the mouth during the
ebb. Also, some of the water which does escape during the
ebb returns on the following flood tide.
Another method of calculation is called the Fraction
of Fresh Water Method. The mean fractional freshwater con-
centration in any segment of estuary is:
S - ~S
where S is the salinity of the oceanic waters and S is
the mean salinity of a given segment of estuary. The total
volume Q is found by multiplying the fractional freshwater
concentration "f" by the volume of the estuary segment. This
basic technique has been used by both Gatto (1976) and Kinnetic
Laboratories, Inc. (1979), to determine the flushing rate
of Knik Arm. Since this method depends on river runoff,
Gatto' s low flushing time of 13.1 hours occurred in July
and has a high value of 205.3 hours in March. Kinnetic Labora-
tories, Inc. (1979) estimates for summer and winter flushing
rates were 5 days and 31 days, respectively.
Because a consistent set of salinity data was not avail-
able for Cook Inlet during winter, Kinnetic Laboratories, Inc.
arranged with Totem Ocean Trailer Express, Inc. for water
samples to be taken monthly by the U. S. S. Great Land at 10 sites
in Cook Inlet between Fire Island and the Barren Islands (Figure 7)
on its outward trip from Port of Anchorage to Tacoma , Washington.
The water samples were taken through the seawater intake at
B-17
-------
Figure B-7.
Salinity/Temperature Sampling Stations Occupied by
the S.S. GREAT LAND During 1981.
B-18
-------
a depth of approximately 15 feet below the water line. Tem-
peratures were immediately taken by the engineering staff,
the sampling time and station recorded, and the sample saved
for salinity determination. Samples were collected for a
8-month period beginning February 1981 and ending September 1981
These data are presented in Tables 3 and 4. Also included
in these tables are river discharge data for the Susitna
and Knik Rivers for the same time periods (USGS 1982).
Although the Susitna River is not located in Knik Arm, there
can be little doubt that its waters enter the Arm during
the flood tide and are thus available for mixing. Flushing
times of Knik Arm will be more optimistic when calculated
by these discharge data than those calculated using only
Knik and Matanuska Rivers runoff data. Table 5 lists the
cross-sectional areas delineated in Figure 7 for the salinity
sampling sites. Table 5 also presents the low water volumes
for Cook Inlet sections bounded by these transects. These
data are needed to employ equation 3 in the calculation of
flushing times. The flushing times so determined are listed
in Table 6.
Waste Assimilation Ability in Knik Arm
Officer and Ryther (1977) have developed a simplified
model to obtain order of magnitude classifications of dis-
charge situations in terms of biological oxygen demand and
potential eutrophication effects in the marine environment.
In the former case, the initial oxygen demand is averaged
over the volume of the receiving waters and corrected for
both first order waste decay and flushing time of the water
system.. This results in the calculation of the waste bio-
chemical oxygen demand (WBOD). A similar approach to the
potential utilization of the oxygen in the waste nutrients
by phytoplankton during respiration or decay results in the
calculation of the phytoplankton dissolved oxygen deficit
(PDOD).
B-19
-------
Table 3. Cook Inlet Salinity Values for 1979
tn
i
STATION
Feb(l-2) Mar(8-9) Apr(5-6) May (10-11) Jun(22-23) Jul(27-28) Aug(24-25) Sep(26-27)
[11,350] [7,100] [8,425] [103,900] [141,250] [188,500] [143,400], [45,570]
§ § § § §
§
§
Fire Island
Pt. Possession
Moose Point
Granite Point
Forelands
Upper Kalgin Is.
Ninilchik
Anchor Point
Seldovia
Barren Islands
17.00
19.47
19.97
21.78
24.59
25.41
29.21
29.70
30.03
30.03
22.35
25.36
22.05
26.68
25.65
28.90
28.96
31.40
31.46
31.66
24.26
24.44
24.46
25.18
26.33
28.31
30.03
32.16
31.78
31.78
20.37
20.88
23.36
26.95
28.24
29.10
30.33
31.74
31.97
31.97
13.12
13.33
13.78
16.82
20.61
23.94
27.55
30.84
31.44
32.20
7.04
7.53
9.40
13.98
20.67
18.45
24.12
27.26
28.04
30.76
5.33
5.72
7.58
10.34
16.19
19.20
23.38
26.86
29.12
28.67
9.56
11.84
14.30
17.47
21.58
23.13
27.83
29.80
30.99
30-. 09
[ ] indicates the average discharge of the Knik and-Susitna Rivers for the stated sampling days(cfs)
Data obtained from Water Resources Data for Alaska: Water Year 1981. U.S. Geological Survey (1982).
-------
STATION
Table 4. Cook Inlet Temperature Values (°C) for 1979
Feb(l-2) Mar(8-9) Apr(5-6) May(10-11) Jun(22-23) Jul(27-28) Aug(24-25) Sep(26-27)
[11,350], [7,100], [8,425], [103,900], [141,250], [188,500], [143,400]K [45,570]
993 33 3 99
w
1
M
h-1
Fire Island
Pt. Possession
Moose Point
Granite Point
Forelands
Upper Kalgin Is.
Ninilchik
Anchor Point
Seldovia
Barren Islands
4.0
3.0
2.8
1.1
3.0
0.5
4.4
6.1
6.6
5.6
4.0
2.5
2.0
4.1
4.0
4.0
5.5
5.6
5.0
5.5
4.0
4.5
4.0
3.5
3.5
3.0
3.0
3.0
8.0
7.5
indicates the average discharge (cfs)
listed .
Data obtained from Water Resources Data for
7
6
5
5
5
6
6
8
8
9
.5
.2
.5
.5
.5
.0
.5
.6
.9
.0
17.0
17.0
16.5
15.7
15.0
13.5
12.6
12.6
15.4
16.2
of the Knik and Susitna
Alaska: Water Year 198]
17.
17.
16.
17.
16.
15.
9.
16.
18.
14.
0
0
5
2
2
0
5
0
0
0
15.0
14.0
14.2
14.6
15.0
15.5
17.0
15.0
14.0
13.5
.10.5
11.0
11.5
11.5
12.0
11.5
12.0
11.5
11.5
13.0
Rivers for the time periods
. U.S. Geological Survey (1982).
-------
Table 5. Volumes of Cook Inlet Cross-Sections
Transect
Off Eagle River
Fire Is. (Knik Arm)
Point Possession
Moose Point
Granite Point
Forelands
Upper Kalgin Island
Ninilchik
Anchor Point
Seldovia
Barren Islands
Totals
Area
588.9
Volume
M x
0.
3.
14.
11.
11.
9.
47.
61.
144.
284.
io5
8
1
6
6
4
3
9
3
2
7
M3 x IO7
72.0
404.2
1459.8
1726.6
2271.3
2017.6
8180.6
9083.1
26960.6
38425.0
90600.8
t Areas and Volumes bounded by transects were calculated from
NOAA Charts 16640 and 16660. Data from Kinney et^ al. (1970)
B-22
-------
Table 6. Flushing Rates for Various Sections of Cook Inlet
Calculated by "Fraction of Freshwater Method" Using Data
of Tables 3 and 5
Flushing. Rates in Days
Transect
Off Eagle River
Fire Island
Pt. Possession
w Moose Point
I
u> Granite Point
Forelands
Upper Kalgin Is.
Ninilchik
Anchor Point
Seldovia
Fub(l-2) Mar (8-9) Apr(5-6) May(lO-ll) Jun(22-23)
11.2 12.2 8.2 1.0 1.2
62.6 58.3 53.5 6.5 8.1
239 312 216 21.9 32.3
410 468 389 32.6 56.1
559 714 578 43.1 79.8
670 815 684 50.2 94.8
760 1216 902 51.9 129
796
Jul(27-28) Aug(24-25) Sep(26-27)
1.2 1.7 4.4
7.8 10.8 26.5
30.6 41.4 95.5
50.9 72.9 160
67.1 101 218
84.6 120 260
123 162 315
Method of Calculation explained in text and in Dyer (1973).
-------
Figure 8 is a plot, after Officer and Ryther (1977) ,
of wasteloading (W/V or P/V against flushing time) for WDOD
and PDOD values of 10 and 1 mg/1. The waste assimilation
characteristics of the Houston Ship Channel, Delaware River,
Boston Harbor, and coastal waters have been plotted in addition
to those calculated for Knik. Arm using the salinity data
obtained by the U. £3. S_. Great Land. Both summer (S) and winter (W)
conditions are plotted. The wasteloading was calculated
assuming a maximum discharge of 120 mg/1 of BOD (NPDES permit
monthly allowable average), and flows of 126,000 m per day
(33.4 MGD) for the present discharge, and 218,000 m0 per day
(58 MGD) for the anticipated discharge in 2005 A.D.
Water Body Flushing Time Volume (10 m )
Houston Ship Channel 56 d 67
Delaware River 28 d 1,330
Boston Harbor 2 d 67
Knik Arm-
(S) 1-2 d 720
(W) 11-12 d 720
Officer and Ryther (1977) state that a wasteloading
of 400 x 10 g per day into a coastal environment of 4,000 x 10 m
which has a flushing time of 5 days would have negligible
effects on the dissolved oxygen concentration of the receiving
waters. From Figure 8, it is evident that BOD loading from
the Point Woronzof outfall would be even less a problem for
Knik Arm. It is also evident that this water body is not
endangered due to cultural eutrophication.
Departing from the more simplified classifications and
models, a sophisticated analysis of Cook Inlet water quality
was performed using a link node model (Tetra Tech 1977).
The model represents the system as a variable grid network
of "nodes" of discrete volume, characterized by surface area,
depth, and side slope. The nodes are interconnected by channels,
each having associated length, width, cross-sectional area,
B-24
-------
100
10mg/|_ wdod
10
M
•o
X
9
>
X .1
a. ~~
•a
c
a
>
2 -oil
Houston Ship
Channel
Delaware River
\
\
\
A
s* Knik Arm ^
\
wdod
10mg/| pdod
\
N
W
\ \
1 mg/i
.001
Present discharge
\7 proposed discharge
I
10
FLUSHING TIME IN DAYS
Figure B-8. Estuarine Waste Assimilation Diagram.
B-25
-------
hydraulic radius, side slope, and friction factor. Water
is restricted to flow from one node to another through these
channels. Assumptions pertinent to the model are: 1) the
estuarine system is well mixed vertically, 2) the law of
conservation of mass holds for constituents, and 3) chemical
reactions may be estimated via first order kinetics.
The chemical parameters modeled were BOD, volatile solids,
ammonia, nitrate, total and fecal coliform, heavy metals
and chlorinated hydrocarbons. The model was run for outfall
flows of 20, 60, 100, and 250 MGD. The results indicate
that even a 100 MGD discharge from primary treatment would
add very little of each constituent to the estuary. It was
found that a flow of 250 MGD primary treatment was required
before a water quality standard was violated. In that case,
the limit of 70 total coliform colonies per 100 ml was exceeded.
A flow of Z50 MGD corresponds to a population of 1.7 million
persons. The Municipality of Anchorage estimated the sewer
hookup population in 1979 to be 165,000. Tetra Tech modeling
substantiates the conclusions of the Officer and Ryther (1977)
models, i.e., that wasteloading to Knik Arm by the Point Woronzot
outfall is easily assimilated by that water body.
Biological Oceanography of Knik Arm, Cook Inlet
During August 1979, Kinnetic Laboratories, Inc. occupied
five principal intertidal transects in the vicinity of Point
Woronzof. These were located at Point Woronzof (Transect 1),
on the mudflats on each side of Point Woronzof (Transects 2
and 5), Cairn Point (Transect 3), and Race Point on Fire
Island (Transect 4) (Figure 9). Each transect consisted
of 4 or 5 stations each separated by a 2 m (vertical) interval.
A total of 8 random cores (15 cm x 18 cm) were taken at each
station.
In addition, two partial transects consisting of 1 or
2 stations of 7 replicates each were taken on the mudflats
B-26
-------
Figure B—9. Water Quality, Intertidal and Subtidal Sampling Stations in
Knik Arm. Kinnetic Laboratories Inc. (1979).
-------
adjacent to the north end of the Anchorage docks and on the
tidal flats between Fire Island and Point Woronzof (Pi and
P2 in Figure 9).
Three subtidal benthic stations (Figure 9) were occupied
in the vicinity of the Point Woronzof outfall by divers to
ensure that benthic fauna were not missed because of sampling
device errors. One of the stations was located within the
present outfall's Zone of Initial Dilution (247 m off the
chlorination tower), another outside the zone along the outfall
alignment (595 m off the tower), and a third in the general
area proposed for the extension (700 m off the tower).
Appendix Bl contains detailed physical descriptions
of the intertidal and subtidal transects and stations. Appendix B2
lists the density and standing stock biomass of the intertidal
transects and stations occupied.
The results of the Kinnetic Laboratories, Inc. biological
survey of the Point Woronzof vicinity can be summarized as
follows. Both qualitative and quantitative results indicate
a benthic marine fauna and flora of very low standing stock
and diversity. No benthic organisms were found in the subtidal
collections. Only three taxa of marine macrophyte algae
were found in the intertidal collections, and only 4 or
5 species of macrofaunal invertebrates which can be considered
truly marine (Macoma balthica, Eteona longa, Orchestia ochotensis,
Anisogammarus confervicolus, and a crangonid shrimp). Of
these taxa the crangonid consisted of only one fragmentary
collection and may not represent a resident intertidal popu-
lation. The amphipod O. ochotensis was found only in the
supralittoral zone of Fire Island, while the other amphipod,
A. confervicolus, is an epibenthic species which seems to
come and go over the mudflats with the movement of the tides.
This leaves only the bivalve M. balthica and the polychaete
E. longa as invertebrate species which can be considered
as resident marine intertidal populations in the study area.
B-28
-------
The populations of these two resident species are generally
so low and so patchy in distribution as to present difficulties
for any long-term monitoring.design which would have statistical
validity. This is especially true in that nothing is known
about seasonal and annual fluctuations of these populations
in the area.
The observed low diversity and standing stock is much
lower than would be expected in the North Pacific region.
This is thought to be the result of physical environmental
stresses. The main elements contributing to this stress
are the heavy suspended loads of glacial silt, low and fluc-
tuating salinity values, intertidal temperature fluctuation,
and mechanical disturbance of the substrate by strong tidal
currents and winter ice. On the rocky exposed beaches and
in the subtidal samples, this mechanical disturbance was
judged to be quite severe from the rounded and abraided appear-
ance of the cobbles.
Over the midtidal to upper intertidal range of the mudflat
beaches an algal mat (Vaucheria) appears to lend stability
to the substrate, permitting limited colonization by benthic
macrofaunal species, principally Macoma balthica and Eteona
longa. Populations of oligochaete worms and nematodes are
also found on all of the mudflat beaches. These taxa are
encountered primarily in the upper intertidal where freshwater
drainage and seepage may promote their existence. Both M.
balthica and 12. longa are considered pioneer species and
are known to tolerate broad salinity/temperature fluctuations.
They are probably the only marine benthic species which are
able to colonize these beaches with any degree of success.
In comparing the mudflat beaches of the Point Woronzof
area, there are some indications that Transect 2, located
southeast of the sewer outfall, may support a faunal diversity
and standing stock which is richer than that of Transect 5,
on the opposite side, or of Transect 3 located above the
B-29
-------
Anchorage docks. Even though the standing stock of Transect 2
2
is quite low (~3.9 g/m ), it appears to be an order of magnitude
2
greater than that observed at all other stations (0.1 g/m ).
Most of the biomass obtained from the beaches is generated
by Macoma balthica. From growth ring analysis of this species,
it appears that the Bootlegger Cove beach (Transect 2) supports
a higher proportion of mature clams than do the other beaches
(Table 7).
In addition to increased standing stock, the Transect 2
beach also supports at least one species not encountered
at the other transects, the large protozoan of the family
Gromidae. This occurrence in conjunction with the greater
biomass and apparent maturity of M. balthica, could indicate
organic enrichment of this locale. The genus Macoma, classed
as a selective detritus feeder, is known to feed on bacteria
in the surface sediments and near bottom waters. This enrichment
could be brought about by the transport of wastes from the
outfall to the shore by the gyre which develops to the east
of Point Woronzof on the flood tide. Caution must be exer-
cised in this comparison of faunal characteristics since,
with the exception of the Gromidae, there is no apparent
difference in species composition over the three mudflat
beaches sampled. Also, while the beaches were selected
according to similar physical characteristics, they were
by no means identical. The observed faunal differences
could easly be the result of physical factors rather than
organic enrichment.
Growth/size analysis of M. balthica recovered from the
quantitative samples indicates that its growth in this area
is relatively slow. -The oldest size class recorded (7+ years
from Transect 2) had attained a length of only 16.7 mm (Table 7).
The Kinnetic Laboratories, Inc. survey did not include
plankton species. However, a study performed by Tetra Tech
(1977) listed the results of two plankton tows in the
B-30
-------
Table 7. Age and Size Distributions of Macoma balthica
Recovered From Quantitative Samples in
the Anchorage Vicinity
Transect
2
2
5
2
2
5
2
2
2
Age
0+
1+
1+
2 +
3+
4 +
5+
6+
7+
Shell Length (mm) Sample Size (no. individuals)
1.
4.
6.
8.
14.
16.
0-1.7
1-6.8
5.8
5-8.7
1-8.8
11.8
12.4
1-15.4
6-16.7
11
4
1
5
2
1
1
5
2
B-31
-------
Point Woronzof area. The dominant components in the two
plankton samples were land plant debris and silt. The diatom
Coscinodiscus was the numerically dominant planktonic organism
followed by the diatom Ditylum. The presence of these organisms
in such highly turbid waters indicates that water turbulence
plays an important role in bringing them to the surface where
they may receive light. The plankton samples of Tetra Tech
(1977) contained very few zooplankton, and those were mostly copepods,
Chemical Oceanography and Bacteriology of Knik Arm, Cook
Inlet
Alkalinity and pH.
Little data are presently available concerning pH varia-
ations in Knik Arm. Murphy et al. (1972) reported the pH
ranged from approximately 7.7 in May to slightly greater
than 8.3 in- August of the same year. He stated that the
observed variation could be attributed to normal chemical
equilibrium processes. Kinnetic Laboratories, Inc. (1979)
measured the pH of waters at the outer current meter station
(700 m off the chlorination tower) as between 7.9 and 8.0
in mid-August. No significant variation was found either
in the water column or during the tidal cycle, Table 8. Al-
kalinities measured for the same samples ranged from 1.3-
1.4 meq per liter and appeared to be homogenous throughout
the water column at all stages of tide.
Dissolved Oxygen.
The dissolved .oxygen content of the water column at
the proposed outfall site was determined as between 8.20
and 8.55 ppm for slack high tide and between 8.28 and 8.49 ppm
for slack low water (Table 8), Kinnetic Laboratories, Inc.
(1979). During that study the waters off Point Woronzof
could be characterized as having an average salinity of 6.8 ppt
and an average temperature of 13.6°C. The oxygen saturation
B-32
-------
Table 8. Outfall Station No. 3 Water Quality Data Obtained
at the Proposed Outfall Site During August 1979t
High Slack Water:
Dissolved Dissolved
Suspended Phosphorous Silica
NO-
NO-
Depth
Surface
Middle
Bottom
Low Slack
Depth
Surface
Middle
Bottom
Time*
1455
1445
1430
Water:
Time*
2030
2015
2000
D0(mg/l)
8.20
8.20
8.55
D0{mg/l)
8.75
8.62
8.58
EH
7.9
7.9
7.9
PH -
8.0
7.9
8.0
ALK(meq/l)
1.34
1.34
1.40
ALK(meq/l)
1.30
1.30
1.30
Solids (mg/1)
660
1020
1040
Suspended
Solids (mg/1)
1490
1320
1330
(mg P/l)
0.112
0.155
0.096
Dissolved
Phosphorous
(mg P/l)
0.079
0.068
0.093
(mg/1)
1.60
1.61
1.61
Dissolved
Silica
(mg/1)
1.46
1.44
1.45
(mg N/l)
0.24
0.26
0.19
NO3~
(mg N/l)
0.25
0.18
0.35
(mg N/l
<0.01
< 0.01
< 0.01
NO 2"
(mg N/l)
< 0.01
< 0.01
< 0.01
*Note: Not instantaneous profiles.
-L
'Data from Kinnetic Laboratories, Inc. (1979)
-------
value for these conditions is 10.23 (Harvey 1960). Thus,
near saturation conditions existed in Knik Arm in August
1979. The data of Kinney et al. (1970) also indicate near
saturation to have existed in Knik Arm in May 1968. Murphy
et al. (1972) reported the dissolved oxygen of Knik Arm to
be 9.1 ppm in March 1970. The salinity and temperature values
recorded at that time were 20 ppt and -1.1°C, respectively.
Oxygen saturation for these, conditions is 13.2 ppm. Waste
BOD should not be a problem during the winter months.
Suspended Solids/Nutrients
The suspended solids content of Point Woronzof waters
is quite high (Table 8). The suspended sediment is derived
from glaciers at the headwaters of the Matanuska and Knik
Rivers. The materials range in size from colloidal to rather
large particles. The few samples collected in this study
do not indicate any relationship between suspended load and
tidal cycle, although one may exist. Kinney et al. (1970)
found that high suspended solids values tended to occur in
the well mixed region of strong tidal currents on the east
side of Cook Inlet.
Soluble phosphorus concentrations were found to be-between
0.155 and 0.068 mg P per liter. These values are in accord
with the 0.20-0-01 mg P per liter range reported by Tetra Tech
(1977) for the same time of year, but less than the 0.025 mg P
per liter value Kinney et al. (1970) found typified upper
Cook Inlet waters. However, during the Kinney cruise the
salinity measured 17 ppt. This value is much higher than
the 8 ppt recorded during the 1979 study, and indicates the
presence of a substantial quantity of seawater off Point
Woronzof during May 1968. Oceanic water has an average dis-
solved phosphorus concentration of 0.07 mg P per liter as
compared to the 0.59-1.1 mg P per liter measured in the
Matanuska River during the late summer (USGS 1977). Thus
the discrepancy between the above values can be attributed
to the greater freshwater input in the latter case.
B-34
-------
Dissolved silica concentrations were found to vary
between 1.44 and 1.61 mg per liter (Table 8). Silica concen-
tration has been found to be directly related to sediment
load in Cook Inlet (Kinney et al. 1970).
Nitrate values have been found to range from 0.35-0.19 mg N
per liter. Nitrite concentrations, however, are usually
less than 0.01 mg N per liter (Table 8).
Primary Pollutants
Appendix B3 contains the results of the Primary Pollutant
Analysis performed by Kinnetic Laboratories, Inc. (1979)
for Anchorage "wet and dry weather" effluents. Of the organic
members of the list, only toluene (36 ug per liter) and
tetrachloroethylene (22 yg per liter) were detected above
10 yg per liter. Dietyl phthalate was found at 10 yg per
liter concentration level. For the metallic elements, all
metals were below their detection limits with the exception
of copper (65 yg per liter) and lead (29 yg per liter).
Analysis of the "dry weather" effluent showed similarities
to the above with only methylene chloride (26 yg per liter),
tetrachloroethylene (44 yg per liter) and trichloroethylene
(14 yg per liter) being detected above 10 yg per liter. Metal
concentrations reported for the "dry weather" effluent to
be above their detection limits were chromium (46 yg per liter),
copper (68 yg per liter), lead (14 yg per liter), nickel
(15 yg per liter), and zinc (105 yg per liter).
Bioaccumulation of toxic materials was not investigated
by Kinnetic Laboratories, Inc. (1979) because of the extreme
difficulty in collecting for analysis enough specimens on
the beach east of Point Woronzof. Sediment samples from
beaches studied did not show significant concentration of
toxicants (Table 9).
B-35
-------
Table 9. Selected Heavy Metals and Chlorinated Hydrocarbon
Analysis of Sediment Samples From Beaches
East of Point Woronzof
Constituent Transect 2 Earthquake Chester
Park Creek
* Less than the number stated
t Data from Kinnetic Laboratories, Inc. (1979).
Antimony (Sb) 0.2 2.0 2.0
Arsenic (As) °-2* °-1 °-4
Beryllium (Be) 1.0* 1.0* 1.0*
Cadmium (Cd) 1.9 1.6 2.3
Chromium (Cr) 122 72 151
Copper (Cu) 24 21 54
Lead (Pb) 3.4 2.0 4.7
Mercury (Ilg) 1.7 2.1 1.3
Nickel (Ni) 70 47 90
Selenium (Se) 2.0* 2.0* 2.0*
Silver (Ag) 0.35 0.26 0.45
Thallium (Tl) 1.0* 1.0 1.0
Zinc (Zn) 64 49 108
Chlorinated Hydrocarbons
& Polychlorinated bi-
phenols 0.001* 0.001 0.001*
B-36
-------
Coliform Bacteria
Coliform sampling was accomplished at the three sites
at high tide (Transect 2, Earthquake Park', and Chester Creek)
by Kinnetic Laboratories, Inc. (1979). Fecal coliforms
averaged from 71-324 colonies per 100 ml in surface waters,
and from 31-2,310 colonies per 100 ml in surface muds. Total
coliforms were normally too numerous to count in these samples.
The bacterial studies clearly indicate the transport of muni-
cipal effluent to shore between Chester Creek and Point Woronzof
by the gyre present during the flood tide.
Conclusions
The discussions of the physical processes which occur
in upper Cook Inlet should convince the reader that Knik
Arm is one of the most dynamic water bodies in the world.
The physical environment is so harsh, in fact, as to hinder
the establishment of a benthic biological community.
The only observable evidence that municipal wastes are
injected into Knik Arm via an outfall at Point Woronzof is
the accumulation of coliform bacteria on the beaches to the
east of the discharge. The bacteria are brought ashore on
the flood tide by the previously described Point Woronzof
gyre. As discussed in the section on tidal currents, the
lengthening of the outfall by an additional 1,500 feet will
ensure that wastes are injected outside of the gyre system
and thus, not.returned to shore.
B-37
-------
References
Britch, R.P. (1976). Currents in Knik Arm, Cook Inlet, Alaska.
M.S. Thesis, University of Alaska, College, Alaska.
Gatto, L.W. (1976). Baseline data on the oceanography of Cook
Inlet. CRELL Report 76-25. USAE, Hanover, NH. 83pp.
Hansen, D.V. and M. Rattray (1966). New Dimensions in estuary
classification. Limnology and Oceanography: 11, 319-326.
Harvey, H.W. (1960). The chemistry and fertility of sea waters.
Cambridge University Press, Emgland.
Ketchum, B.H. and D.J. Keen (1953). The exchange of fresh and
salt waters in the Bay of Fundy and in Passamaquoddy Bay.
J. Fisheries Research Board of Canada; 10, 97 124.
Kinnetic Laboratories, Inc. (1979). Supplemental studies of
Anchorage discharge off Point Woronzof in Upper Cook Inlet.
KLI Report 79-13, September, 1979. Anchorage, Alaska.
Kinney, P.J., J. Groves, and D.K. Button (1970). Cook Inlet
environmental data: R/V Acona cruise 065, May 21 28,
1968. Institute of Marine Sciences, University of Alaska.
Marine Advisors, Inc. (1965). A study of the oceanographic
conditions in the Anchorage area relevant to sewage outfall
planning. Report to Tryck, Nyman, Hayes and Stevens and
Thompson, for the Greater Anchorage Area Sewage Study, 34pp
Mungall, J.C.H. and J.B. Matthews (1972). A numerical tidal
model and its application to Cook Inlet, Alaska. J. of
Marine Research: 30, 27-38.
Murphy, R.S., R.F. Carlson, D. Nuquist and R. Britch (1972).
Effect of waste discharges into a silt-laden estuary: A
case study of Cook Inlet, Alaska. Institute of Water
Resources, University of Alaska, College, Alaska.
Officer, C.B. and J.H. Ryther (1977). Secondary sewage treat-
ment versus ocean outfalls: an assessment. Science: 197,
1056-1060.
Tetra Tech (1977). Water quality study, Knik Arm and Upper
Cook Inlet, Alaska. Final report submitted to Alaska
District, USAE, September, 1977.
U.S. Geological Survey (1977). Water resources data for Alaska:
Water year 1977. USGS report AK-771.
B-38
-------
U.S. Geological Survey (1982). Water resources data for Alaska
Water year 1981. In press.
B-39
-------
Appendix Bl
B-40
-------
Physical Doseri pt i on of lutcrlidal Transects and
St. -it: ions
.1 : Point Woronz.f
Date Sampled: 15 August, 1979 Time Begun: 0740
Time of Low Tide: 0612 Low Tide- Height: +1.2 ft.
General site location and description: Exposed rocky beach
approximately 60 meterr, west of chlorination tower on Pt.
Woron;:of, fairly steep gradient, no apparent flora or fauna.
He. i.ti lit Above Substrate
St_a_tjcIH MLW (in) r>rsr:i'i pt i on_
1 0.8 :-.,-ind/cc>bbl c-'.s
2 2.0 sand/cobbles
3 A . 0 sand/gruvel/cobblcs
4 6.0 sand/cobbles
5 8.0 sand/cobbles
Tra n so ct 2 :_ _ Boo tlegqcr Cove
Date Sampled: 17 August, 1979 Time Begun: 1100
Time of Low Tide: 0949 Low Tide Height: +2.2 ft.
General site location and description: Low-profile mudflat covered,
over much of the tidal range, by filamentous algal mat
(Vaucheria sp.) approximately 1 mile southeast of Point Noronzof.
Height Above Substrate
Station MLW (m) Description
1 1.1 exposed blue clay
2 2.0 lower edge of algal mat;
thin silt over blue clay
3 4.0 inside algal mat; thick
silt over blue clay
4 6.0 inside algal mat; thick
silt over blue clay
5 8.0 above algal mat; loose,
coarse-grained sand
B-41
-------
Physical Description of Intertidal Transects and
Stations (cont.)
Transect 3: Cairn Point
Date Sampled: 16 August, 1979 Time Begun: 1005
Time of Low Tide: 0949 Low Tide Height: + 2.2 ft,
General site location and description: Exposed rocky beach
approximately 75 meters south of navigation/survey guadripod
on Cairn Point, fairly steep gradient, no apparent fauna or
flora.
Height Above Substrate
Station MLW (m) Description
1 2.0 coarse sand/angular
gravel/rounded cobble
2 4.0
3 6.0
4 8.0
Transect 4: Fire Island
Date Sampled: 16 August, 1979 Time Begun: 1530
Time of Low tide: 2052 Low Tide Height: +7.9 ft.
General site location and description: Exposed rocky beach on
Race Point, Fire Island; fairly steep gradient, no apparent
fauna, very sparse macroalgae (Fucus gardneri, Enteromorpha
linza) .
Height Above Substrate
Station MLW (m) Description
1 2.0 sand/cobble/boulder
2 4.0' sand/cobble/boulder
3 6.0 sand/cobble
4 8.0 sand/cobble
B-42
-------
Physical Description of Intertidal Transects and
Stations (cont.)
Transect 5: Woronzof-Camobell Cove
Date Sampled: 18 August, 1979
Time of Low Tide: 1102
Time Begun: 1100
Low Tide Height: +0.9 ft.
General site location and description: Low profile mud flat aboui
1 mile south of Point Woronzof; covered over mid-tide range
by algal mat (Vaucheria) and over upper tidal range by grasses
(primarily Puccinellia c.f P_. phryganodes, with pockets of
Car ex c.f C. r-amenskii and fringe of Trig loch in mari tima at
HHW line)." Ducks[unTdentified), and geese (lesser Canada
or white-fronted) seen on grass flats.
Station
1
2
3
Height Above
MLW (rr.)
0. 3
2.0
4.0
6. 0
8. 0
9- 0
Substrate
Description
pitted blue clay_
pitted blue clay
lower edge of algal zone;
thin silt over blue clay
upper algal zone; thick
silt over blue clay
matted grass (Puccinellia)
over thick silt
Triglochin fringe at HHW;
3 samples taken
Partial Transect: Municipal Flat
General site location and description: Low profile mud flat
approximately 100 meters north of north end of municipal
dock; coverd over much of tidal range by algal mat (Vaucheria)
Two stations of 8 samples each v.-ere completed, 16 August, 1979
Station
Height 7-,bove
MLW (:n)
2-4
4-6
Substrate
Description
lower 1/3 of algal zone;
thick silt over blue cJay
upper 1/3 of algal zone;
thick silt over blue clav
B-43
-------
Physical Description of Intertidal Transects and
Stations (cont.)
Sample Station: Turnagain Arm
General site location and description: Low profile sand flat
between Fire Island and Point Campbell at mouth of Turnagain
Arm, exposed only during low water. One station of 7 samples
was completed, 18 August, 1979.
Station
Height Above
MLW (m)
2.0
Substrate
Description
coarse sand with some
organic debris , apparently
terrestrial
B-44
-------
Appendix B2
B-45
-------
Density and Standing Stock Biomass on Stations
and Transects Sampled During August, 1979.
Transect 1
Station
Sie.ve
Size
1. 0 mm
Taxa
M. balthica
Mean
Density _,
(indiv/m )
Mean
Standing Stock
(g/m wet wt.)
1.0
No other flauna or flora apparent in Transect 1 samples. Only
1 K. balthica individual was recovered.
1
2
2
3
1 . 0 inm
1. 0 mm
0. 5 mm
1. C mm
3
4
0 . 5 mm
1. 0 mm
Transect 2
H_.__bal t h_ic_a
Va u ch c_r i_a s p.
M^ balthica
E. longa
Gammaridae
M. balthica
Gammaridae
Vaucheria sp
M. balthica
E. longa
A. conf ervi'colus
Ofigochaetes
E. longa
sp
Vaucheri a
M. balthica
E_. longa
Gammaridae
Oligochaetes
Nematodes
Crangonidae
18
24
6
4
26
2
16
20
4
26
56
30
16
16
44
2
2
0.605
2. 693
0.669
0.010
0.004
. 008
, 002
. 316
, 579
.050
. 024
,006
.242
.802
076
,151
, 038
0.
0.
31.
2.
0.
0.
0.
1.
68.
8.
0.
0.
0. 010
0. 001
fragment
only
Also found 1 unidentifed algae fragment. Possible Porphyra sp,
0 . 5 mm
Balthica
1 o n q a
No
:uru
?!_
Oligochaetes
Nematodes
Gaininar idae
Platyhclminth.
Gromidae
or flora in either sieve r, izo
108
10
V200
7300
4
6
- 200
0. 036
0. 121
0. 036
0. 006
0. 002
0. 002
0. 025
B-46
-------
Density and Standing Stock Biomass on Stations
and Transects sampled During August, 1979. (cont.)
Transect 2 (cont.)
Station
Taxa
Transect means (Station 5 excluded)
1 . 0 mm
1. 0 mm
0 . 5 mm
0. 5 mm
combined
M. _balthica
£. Longa
Gammaridae
Oligochaetes
Faunal x
Vaucheria sp
M. balthica
E. longa
Gammaridae
Oligochaetes
Nematodes
Platyhelminth
Gromidae_
Faunal x
Faunal x
Transect 3
Mean
Density2
(indiv/m )
22
11
7
M
58
34
17
2
50
75
2
5_0
230
288
Mean
Standing Stock
(g/m wet vt.)
2.
0.
0.
0.
3.
25.
0-
0.
0-
0.
0.
0.
0.
0.
3.
982
053
017
004
531
703
Oil
341
001
009
002
001
006
371
902
No fauna .or flora apparent in quantitative samples from
Transect 3.
Transect 4
No fauna or flora apparent in quantitative samples from
Transect 4. Qualitative samples from the vicinity yielded
the algae Fucus gardneri and Enteromorpha c.f. E. linza,
and the littoral amphipod Orchestia c.f. 0. ochotensis.
1
2
3
1. 0 mm
0 . 5 mm
1. 0 mm
Transect 5
M_._ balthica
M_._ Balthica
M. balthica
6
6
2
0.084
0. 006
•0. 270
B-47
-------
Station
Density and Standing Stock Biomass on Stations
and Transects Sampled During August, 1979. (cont.)
Transect 5 (cont.)
Si eve
Si zc
Taxa
Mean
Density2
(indiv/m )
1. 0
0. 5
mm
mm
1. 0 mm
0 . 5 mm
Vauchcria sp
Oligochaetes 72
Dolichopodidae 4
M. balthica 2
Oligochaetes 173
Nematodes 28
Anurida ,maritima_ 2
P_uc cTn cJJ_i a
Oligochaetes 117
Chironomidae 2
Nomatodes 2
Oligochaetes 52
Nematodes >400
Aphidae 135
Pupae 6
Unident. beetle 2
Unident. spider 2
Puccinellia -
Oligochaetes 10
Nematodes >250
Chironomidae 4
Dolichopodidae 4
Aphidae 84
Pupae 2
Oligochaetes 52
Chironomidae 2
Dolichopodidae 8
Aphidae 90
Ephydidae 2
Staphylinoidae 4
Unident. spider 2
Tranr.oct means (Stations 5 and 6 excluded)
1.0
nun
0 . 5 mm
1 . 0
mm
1 . 0 mm
0 . 5 irun
0 . 5 ran
Combined
-.
Oligochactcs
Dolichopo_didae
Faunal x
Vaucheria sp.
H . ba ] th.i ca
Cligoc'naetcs
Ncmatode s
A. maritima
Faunal
Faunal
x
X
2
18
.1
23
2
43
7
_!
53
76
Mean
Standing Stock
(g/m wet wt.)
130.500
0.008
0.010
0.002
0. 018
0-002
0. 002
550.000
0.010
0.002
0.002
0.014
0.012
0.046
0.004
0.002
0.002
170.000
0.002
0. 002
0.002
0.002
0.028
0.002
0.024
0.002
0.012
0.012
0.002
0. 002
0.002
0. 082
0. 002
0.003
0
32
0
0
0
0
087
625
002
005
•001
001
0. 008
0. 095
B-48
-------
Density and Standing Stock Biomass on Stations
and Transects Sampled During August, 1979. .(cont.)
M-Flat
Sieve
Station Size
1 1 . 0 ITUTI
1 0.5 :rim
2 1 . 0 ~jn
2 0.5 mm
Transect Means
1 . 0 mm
1 : 0 mm
0 . 5 mm
0 . 5 mm
Combined
1 1.0 mm
Mean
Density 2
Taxa • (indiv/m )
M. balthica
Vaucheria sp.
M. balthica
Cherinidae
Vaucheria sp.
M. balthica
Oligochaetes
A. conf ervicolus
M. balthica
M. balthica
Oligochaetes
A. conf ervicolus
Faunal x"
Vaucheria sp.
M. balthica
Chermidae
Faunal x
Faunal x
T-Flat
Oligochaetes
Gammarus sp-
8
257
2
94
6
2
22
51
3
1
55
140
1
141
196
8
2
Mean
Standing Stock
(g/m wet wt.)
0. 008
10.874
0.068
0. 002
141.203
0.076
0.002
0.002
0.016
0.042
0.001
0. 001
0
76
0
0
0
044
039
042
001
043
0.087
0.005
0.020
Also found 1 hydroid fragment, long dead
B-49
-------
Appendix B3
B-50
-------
Chemical Analysis of Effluent
Effluent Concentrations (ug/1)
Parameter
ACID COMPOUNDS
Dry Weather
Wet Weather
-2,4, 6-trichlorophenol
p-chloro-m-cresol
2-chlorophenol
2, 4-dichlorophenol
2, 4-dimethylphenol
2-nitrophenol
4-ni trophenol
2, 4-dinitrophenol
4 , 6-dini tro-o-cresol
pentachlorophenol
phenol
BASE/NEUTRAL COMPOUNDS
acenaphthene
benzidine
1,2, 3- trichlorobenzene
hexachlorobenzene
hexachloroe thane
bis (2-chloroethyl)ether
N/D
N/D
N/D
N/D
N/D
N/D
N/D
N/D
N/D
N/D
*
N/D
N/D
N/D
N/D
N/D
N/D
N/D
N/D
N/D
N/D
N/D
N/D
N/D
N/D
N/D
N/D
*
N/D
N/D
N/D
N/D
N/D
N/D
B-51
-------
(continued)
BASE/NEUTRAL COMPOUNDS (Cont'd)
2-chloronaphthalene N/D N/D
1, 2-dichlorobenzene * N/D
1,3-dichlorobenzene N/D *
1,4-dichlorobenzene * *
3,3'-dichlorobenzidine N/D N/D
2,4-dinitrotoluene N/D N/D
2, 6-dinitrotoluene N/D N/D
1, 2-diphenyIhydrazine
(as azobenzene) N/D N/D
fluoranthene N/D N/D
4-chlorophenyl phenyl ether N/D N/D
4-bromopheny1 phenyl ether N/D N/D
bis(2-chloroisopropyl) ether N/D N/D
bis(2-chloroethoxy) methane N/D N/D
hexachlorobutadiene N/D N/D
hexachlorocyclopentadiene N/D N/D
isophorone N/D N/D
naphthalene * *
nitrobenzene N/D N/D
N-nitrosodimethylamine N/D N/D
N-nitrosodiphenylamine N/D N/D
N-nitrosodi-n-propylamine N/D N/D
bis (2-ethylho:yl) ph thai ate * *
butvl benzyl phtihnlate * N/D
B-52
-------
(continued)
BASE/NEUTRAL COMPOUNDS (Cont'd)
di-n-butyl phthalate * *
di-n-octyl phthalate N/D N/D
diethyl phthalate 10 *
benzo(a)anthracene N/D N/D
benzo(a)pyrene N/D N/D
3, 4-benzofluoranthene N/D N/D
benzo(k)fluoranthene N/D N/D
chrysene N/D N/D
acenaphthylene N/D N/D
anthracene N/D N/D
benzo(ghi)perylene N/D N/D
fluorene N/D N/D
phenanthrene N/D N/D
dibenzo(a,h)anthracene N/D N/D
idenol(1,2,3-cd)pyrene N/D N/D
pyrene N/D N/D
2,3,7,8-tetrachlorodibenzo-
p-dioxin N/D N/D
VOLATILE5
acrolein N/D N/D
aerylonitrile N/D N/D
ben-one * *
carbon totrachloride N/D N/D
chlorobenzene N/D N/D
1,2-dichloroethane N/D *
B-53
-------
(continued)
VOLATlLg£ (Cont'd)
1,1/1-trichloroethane * *
1,1-dichloroethane N/D N/D
1,1,2-trichloroethane N/D N/D
1,1/2,2-tetrachloroethane N/D N/D
chloroethane N/D N/D
bis(chloromethyl) ether N/D N/D
2-chloroethylvinyl ether N/D N/D
chloroform * *
1,1-dichloroethylene N/D N/D
1,2-trans-dichloroethylene * *
1,2-dichloropropane N/D N/D
1,3-dichloropropylene N/D N/D
ethylbenzene N/D
methylene chloride 26
methyl chloride N/D N/D
methyl bromide N/D N/D
bromoform N/D N/D
dichlorobromomethane N/D N/D
trichlorofluoromethane N/D
dichlorodifluoromethane N/D N/D
chlorodibromomethane N/D N/D
tetrachloroethylene 44 3G
toluene * 22
trichloroethylene 14 *
vinyl chloride N/D 'N/D
B-54
-------
(continued)
PESTICIDES
aldrin N/D N/D
dieldrin N/D N/D
chlordane N/D N/D
4,4'-DDT N/D N/D
4,4'-DDE N/D N/D
4,4'-ODD N/D N/D
(Alpha) endosulfan N/D N/D
(Beta) endosulfan N/D N/D
endosulfan sulfate N/D N/D
endrin N/D N/D
endrin aldehyde N/D N/D
heptachlor N/D N/D
heptachlor epoxide N/D N/D
(Alpha) BHC N/D N/D
(Beta) BHC N/D N/D
(Gamma) BHC N/D N/D
(Delta) BHC N/D N/D
PCB-1242 N/D N/D
PCB-1254 N/D N/D
PCB-1221 N/D N/D
PCB-1232 N/D N/D
PCB-1248 N/D N/D
PCB-1260 N/D N/D
B-55
-------
PESTICIDES (Cont'd)
PCB-1016
toxaphene
Mi vex
Guthion
Methoxychlor
Parathion
Deme ton
Malathion
METALS
Sample 1
Antimony <100
Arsenic "^
Beryllium <5
Cadmium <^
Chromium ^4
7n
Copper /u
Lead , 16
<0 1
Mercury ^u
1 6
Nickel
Selenium
^ 5
Silver
<50
Th a 1 1 1 um
123
Zinc
N/D N/D
N/D N/D
N/D N/D
N/D N/D
N/D N/D
N/D N/D
N/D N/D
N/D N/D
Sample 2 Sample 1 Sample 2
<100 <100 <100
<5 <10 <10
<5 <5 <5
^.2 <2 <2
39 <5 <5
65 70 60
12 30 28
<0 .1 0.1 <0 .1
15 10 m 10
<10 <10 <10
<5 <3 <3
< 5 0 < 5 0 <5 0
•88 <3 <3
B-56
-------
(continued)
OTHER
pH, Units 7.1
BOD 114
Suspended Solids 66
Volatile Suspended Solids 51
Total Dissolved Solids 401
Ammonia Nitrogen 11.1
Total Kjadehl Nitrogen 4.4
Total Nitrogen 15.5
Nitrate Nitrogen 0.1
Nitrite Nitrogen 0.01
Total Phosphate (as P) 5.3
Cyanide -
Asbestos, million fibers 12.0 38.5
per liter
chrysotile; amphibole was below detection limit
* = Less than 10 ug/1
(Pesticides less than 5 ug/1)
N/D = Not Detected
0.5 ug/1
B-57
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