EPA 910/9 -77 -040
EPA - 10 - WA - SNOHOMISH - CITY OF LYNNWOOD - WWTW - 77
ENVIRONMENTAL IMPACT STATEMENT
FOR
WASTEWATER TREATMENT FACILITIES
C530688
CITY OF LYNNWOOD
&
ALDERWOOD WATER DISTRICT
SNOHOMISH COUNTY, WASHINGTON
- - uj
CD
g ^ ENVIRONMENTAL PROTECTION AGENCY
REGION X, SEATTLE, WA
-------
FINAL
ENVIRONMENTAL IMPACT STATEMENT
FOR
WASTEWATER TREATMENT FACILITIES
CITY OF LYNNWOOD
&
ALDERWOOD WATER DISTRICT
Snohomish County, Washington
EPA Project No. C-530688
prepared by
S. ENVIRONMENTAL PROTECTION AGENCY
REGION X
Seattle, Washington
with the assistance of
STRAAM ENGINEERS, INC.
700 Plaza 600 Building
Seattle, Washington 98101
JULY, 1978
ficial:
Donald P. Dubois
Regional Administrator
JUN 23 19ft
Date
-------
PREFACE
On September 16, 1977, the Environmental Protection Agency (EPA)
released to the public a Draft Environmental Impact Statement (EIS) for
proposed facilities to treat wastewaters from the City of Lynnwood and
the Alderwood Water District. A 45-day public review of the draft which
evaluates the environmental impacts associated with construction of a
secondary treatment plant for the City of Lynnwood and an interceptor to
serve the Swamp Creek basin followed. The EPA decision to prepare this
EIS was based on potentially significant environmental impacts associated
with an expected application from the City and the Alderwood Water Dis-
trict for construction grant funding in which EPA would provide 75% of
the funds required to plan, design, and construct the wastewater facil-
ities .
The EIS was prepared utilizing the "piggyback" approach, which
allows the Draft EIS and the Draft Facilities Plan to be prepared con-
currently. Under this method, a consultant is retained to prepare the
EIS who works independently from the consultant preparing the facilities
plan. EPA, in cooperation with the City of Lynnwood, has completed the
environmental impact evaluation and prepared this Final EIS.
A public hearing on the Draft EIS was held on October 18, 1977. A
summary of the hearing testimony, comments received, and EPA's responses
have been incorporated into this document and can be found in Chapter
VI.
Wastewater treatment facilities for the City of Lynnwood and the
Alderwood Water District were included within a common study area in
order to consider possible regional solutions to treating wastewater
from the Swamp Creek basin and the Lynnwood service area. Seven alter-
natives for solving existing wastewater problems in the study area and
the "no action" alternative were evaluated. At the conclusion of the
review process, EPA determined that wastewater within the study area can
be most cost-effectively managed by two separate systems. Accordingly,
EPA considers the most acceptable solution to be as indicated below:
o Expansion and upgrading to secondary treatment of the existing
plant on Browns Bay by the City of Lynnwood to treat wastewaters
from the McAleer and Scriber basins.
o Construction of the Swamp Creek interceptor by the Alderwood Water
District to convey Swamp Creek basin wastewaters to Seattle Metro
for treatment.
The principal concern prompting this EIS was potential degradation
of Swamp Creek by construction of a gravity interceptor to serve the
i
-------
Swamp Creek basin. Although EPA received only one letter from the local
community during the 45-day public comment period, several comments from
government agencies indicated serious concern for water quality and
aquatic life within the creek. Need for the interceptor was established
by a guided inspection of local conditions in the basin and correspon-
dence with the Snohomish County Health Department. It appears that sub-
stantial environmental and health problems that presently exist within
Swamp Creek basin can be best corrected by installing sewers. (Clarifi-
cation of these problems and documentation received by EPA can be found
in Appendix F.) Legitimate concern by the State Fisheries and Came
Departments and the U. S. Fish & Wildlife Service for potential impacts
to fish within Swamp Creek, however, prompted EPA to meet with these
agencies on April 20 and May 8, 1978 to define potential impacts and
enlist assistance in developing appropriate mitigation measures. Comment
letters received from these agencies following a site inspection on May 8
can be found in Chapter VI.
EPA believes that mitigative measures during construction are key
areas of concern and, therefore, considers the following grant conditions
to be necessary:
a) The final alignment should be designed to reduce the number of
crossings and provide, to the extent feasible, a buffer strip
between the pipe location and the stream alignment. This may
require the installation of pump stations.
b) When a stream crossing is necessary, the construction procedure
should be boring or jacking of the line under the stream. Open
cut methods will be allowed, however, through sections of stream
bed that are normally dried up.
c) Excavated material should not be placed on the downhill or stream-
ward side of the trench. Compliance with this measure may require
hauling of the excavated material from the site. Construction
access and haul roads should be placed on the uphill side of the
trench.
d) All swamp or bog areas should be avoided unless adequate means of
preventing siltation to the main stream can be incorporated within
the final design.
e) Any work within or that will affect Swamp Creek and its tributaries
must be restricted to the summer months only, i.e., June through
August.
f) Interceptor pipe shall be located a minimum of 25 feet from the
creek's edge (except when crossing the creek). Where houses are
within 25 feet of the creek, exceptions will be considered.
i i
-------
g) Erosion control devices should be continuously in place to prevent
erosion and trap sediment before it enters the stream. In addition,
reseeding, replanting, and mulching should be used in areas of
cleared ground and backfilled trenches.
h) To assure that the fishery production potential of Swamp Creek is
adequately protected, an environmental consultant shall be hired
to provide advice on fishery protection before and during construc-
tion.
EPA submits this Final EIS for a public review period of 30 days
during which time comments are invited. Following this review period,
the Regional Administrator of EPA will make a final determination con-
cerning approval of the Lynnwood/Alderwood Water District facilities
plan and eligibility of the proposed projects for design and construc-
tion grants.
iii
-------
TABLE OF CONTENTS
PREFACE i
SUMMARY xi
CHAPTER I: INTRODUCTION 1-1
FACILITIES PLANNING AND EIS PROCESS 1-1
Basic Concept 1-1
Piggyback Approach 1-2
DESCRIPTION OF STUDY AREA 1-2
PROGRAM DEVELOPMENT 1-5
Swamp Creek Trunk Sewer Feasibility Study 1-5
Lynnwood Sanitary Sewage Treatment Facilities Report 1-6
RIBCO Water Quality Management Report 1-7
Lynnwood Collection System Infiltration/Inflow Survey
Analysis 1-8
CHAPTER II: ENVIRONMENTAL SETTING II-l
PHYSICAL ENVIRONMENT II-l
Earth II-l
Air Conditions II-7
Water 11-17
Flora and Fauna 11-26
Noise 11-32
Natural Resources 11-33
Unique Physical Features 11-37
HUMAN ENVIRONMENT 11-39
Population 11-39
Land Use 11-51
Transportation 11-64
Public Services & Utilities 11-68
Sewerage System Description 11-75
Energy 11-83
Health 11-84
Historical & Archaeological 11-84
CHAPTER III: DEVELOPMENT OF ALTERNATIVES III-l
FORECAST OF FUTURE FLOWS III-l
Background III-l
Wastewater Characteristics III-6
ALTERNATIVE CONCEPTS III-ll
Description III-ll
Initial Screening 111-12
v
-------
DEFINITION OF VIABLE ALTERNATIVES 111-12
No Action 111-12
Secondary Treatment Only 111-14
Limited Service Extension 111-14
McAleer & Scriber Basins to Brown's Bay with Swamp
Basin to Metro ITI-17
McAleer Basin to Brown's Bay with Scriber & Swamp
Basins to Metro 111-17
McAleer, Scriber, & Swamp Basins to Metro TTI-17
New Plant at Scriber Creek with No Discharge to
Metro III—17
Treat at Brown's Bay & Scriber Creek with Lower
Swamp Basin to Metro TII-17
TREATMENT & INTERCEPTION ALTERNATIVE PROCESSES 111-23
Secondary Treatment 111-23
Sludge Processing 111-24
Swamp Creek Interception 111-27
CHAPTER IV: ENVIRONMENTAL IMPACTS OF ALTERNATIVES IV-1
EVALUATION OF PRIMARY ENVIRONMENTAL IMPACTS IV-1
Impacts at Treatment Facility Site IV-1
Air Changes Throughout Study Area IV-4
Water Impacts in Study Area IV-7
Noise Impacts IV-9
Natural Resources IV-10
Energy IV-11
Health IV-12
Archaeology & History IV-15
EVALUATION OF SECONDARY IMPACTS IV-15
Population IV-15
Land Use IV-19
Transportation IV-21
Public Services & Utilities IV-25
Natural Resources IV-27
Fiscal Impacts IV-30
Sewer Rates IV-32
COMPARISON OF ALTERNATIVES IV-34
Matrix Development IV-34
Ranking Alternatives IV-35
CHAPTER V: IMPACTS OF SELECTED ALTERNATE V-l
SELECTED ALTERNATIVE V-l
Facility Concept V-l
Treatment Concept V-l
vi
-------
UNAVOIDABLE IMPACTS AND MITIGATIVE MEASURES
Construction
Environmental Changes
V-l
V-l
V-4
SHORT-TERM ENVIRONMENTAL USE VERSUS MAINTENANCE AND ENHANCEMENT
OF LONG-TERM PRODUCTIVITY V-5
Potential Future Options V-5
Health and Safety V-7
Property Valuation V-8
Project Justification V-9
IRREVERSIBLE, IRRETRIEVABLE RESOURCE COMMITMENTS V-10
Project Implementation V-10
Land and Water Use V-ll
Malfunctions & Accidents V-12
CHAPTER VI: SOLICITED COMMUNICATION VI-1
PUBLIC PARTICIPATION VI-1
Citizens Advisory Committee VI-1
Public Meeting VI-1
Public Hearing VI-5
COMMENT PERIOD COMMUNICATION VI-14
SUBSEQUENT COMMENTS VI-57
BIBLIOGRAPHY 1
APPENDICES
A. Soils Investigation at Brown's Bay Site A-l
B. Water Quality B-l
C. Wildlife C-l
D. Noise Investigation at Brown's Bay Site D-l
E. Historical & Archeological Concerns E-l
F. Public Health & Septic Tank Considerations F-l
G. Population Forecast Acceptance G-l
vii
-------
LIST OF FIGURES
Number
Title
Page
1-1
Study Area
1-3
II-l
Soils & Drainfield Suitability
11-5
II-2
Browns Bay Site Soil Conditions
11-9
II-3
Suspended Particulates in Puget Sound Air
11-12
II-4
Current Study at Outfall - 85 ft. Depth
11-18
II-5
Current Study at Outfall - 50 ft. Depth
11-19
11-6
Current Study at Outfall - 10 ft. Depth
11-20
II-7
Drainage Basins and Hydrologic Features
11-21
II-8
Aerial Photograph of Study Area
II-29
II-9
Noise Contours for On-Site Stationary Source
11-34
11-10
Existing Noise Environment
11-36
11-11
Census Tracts and AAM Districts
11-41
11-12
Combined Land Use Plan
11-54
11-13
Lynnwood Comprehensive Plan
11-55
11-14
Lynnwood Zoning Map
11-59
11-15
Observed Traffic Volumes
11-65
11-16
Community Services
11-69
11-17
Existing Sewerage Systems
11-77
III-l
Population Forecasts
111-3
III-2
No Action Alternative
III-l3
III-3
Secondary Treatment Only
111-15
III-4
Limited Service Extension
111-16
III-5
McAleer and Scriber to Browns Bay with Swamp
Basin
111-18
to Metro
III-6
McAleer to Browns Bay with Scriber and Swamp
to
LII-19
Metro
III-7
McAleer, Scriber and Swamp Basins to Metro
111-20
III-8
New Plant at Scriber Creek - No Discharge to
111 - 21
Metro
111-22
III-9
New Plant at Scriber Creek - Lower Swamp Basin to
Metro
II1-25
111-10
Browns Bay Treatment Modification
III-ll
Scriber Creek Alternative - Site Layout
111-26
111-12
Swamp Creek Trunk Location
ILI-43
IV-1
Swamp Creek Impacts on Metro
IV-5
IV-2
No Action Population Forecasts
LV-16
IV-3
Forecasted Traffic Volumes
IV-23
V-l
Possible Appearance - Proposed Browns Bay
V-15
Secondary Treatment Plant
viii
-------
LIST OF TABLES
Number
Title
Page
II-l
Lake Volumes
11-23
II-2
Population Change in the Seattle-Everett SMSA
11-40
II-3
1970 to 1976 Building Permits and Population Trends
11-43
II-4
Population Trends in Study Area
11-45
11-5
Occupancy Characteristics of Housing Units
11-47
II-6
Housing Stock in Study Area
11-48
II-7
Seattle-Everett SMSA Resident Labor and Employment
11-49
II-8
Percent of Jobs by Employment Location and Census
Tract
11-50
II-9
Alderwood Planning Area Land Use
11-57
11-10
Lynnwood Residential Zoning Classifications
11-58
11-11
Lynnwood Postal Area Vacancy Survey
11-62
11-12
Housing Vacancy Rates
11-63
11-13
Annual Recorded Water Demands
11-73
11-14
Storage Facilities Within the Alderwood Water District
11-74
11-15
Lynnwood Sewer Service Area Summary
11-80
11-16
Basic Sewage Data Comparison
11-81
11-17
Typical Sewage Grab Samples
11-82
11-18
Detailed Analysis of 24 Hour Composite Sample
11-82
11-19
Present Energy Consumption
11-83
III-l
Employment Projections by Trade Area
III-5
III-2
Population Forecast by Drainage Basin
III-7
III-3
Sewage Design Flow Criteria
III-9
III-4
Drainage Basin Design Flows
111-10
III-5
Interceptor Design Flows
111-10
III-6
Costs of Interception Concepts
111-28
IV-1
Energy Consumption by Alternatives
IV-14
IV-2
No Service Extension - Population Forecast
IV-17
IV-3
Approximate Annual Precipitation Distribution
IV-29
IV-4
Typical Monthly Residential Sewer Charges
IV-33
IV-5
Primary Environmental Impact Matrix
IV-3 7
IV-6
Secondary Environmental Impact Matrix
IV-39
IV-7
Construction Impact Matrix
IV-41
VI-1
Highlights Summary - Draft EIS Comments Received
VI-15
ix
-------
SUMMARY
ENVIRONMENTAL IMPACT STATEMENT
WASTEWATER TREATMENT FACILITIES
City of Lynnwood & Alderwood Water District
Snohomish County, Washington
Environmental Protection Agency - Region X
1200 Sixth Avenue, Seattle, Washington 98101
1. Type of Statement: Draft ( ) Final ( X )
2. Type of Action:
( X ) Administrative Action
( ) Legislative Action
3. Description of action:
The EPA action that requires this Environmental Impact Statement is
the awarding of grant funds to provide secondary treatment facilities for
the existing sanitary sewerage system in the City of Lynnwood. The exist-
ing Lynnwood treatment plant at Brown's Bay affords only primary treatment.
Portions of the City of Edmonds are also served by the existing system.
The Alderwood Water District participation is the installation of new
gravity interceptors to extend sewer service to the Swamp Creek Basin.
All of these communities are in Snohomish County, Washington; however,
the proposed Swamp Creek interceptor would discharge to the Municipality
of Metropolitan Seattle (Metro) in King County for treatment.
4. Summary of environmental impacts and adverse environmental
effects.
Primary impacts. The existing Lynnwood treatment plant discharges pri-
mary treatment effluent by an outfall into Puget Sound. Discharge of
secondary effluent into Puget Sound will result in little direct change
in receiving water quality. Local noise and odors at the treatment
plant will be reduced. Installation of sewers within the Swamp Creek
basin will phase out the use of septic tank drain fields which release
xi
-------
poorly treated sewage to the surface drainage system due to inadequate
soil conditions, thus, the recognized extensive health risk of exposure
to sewage pathological organisms will be reduced.
Secondary impacts. Installation of sewers will allow the fore-
casted population within Swamp Creek Basin for the year 2000 to increase
from about 26,500 to about 41,800, in an area of approximately 9,600
acres. Present population is about 21,000. This will result in less
open space and some reduction in the available wildlife habitat. However,
densities will still be less than attained by most typical suburban
development so much of the rural character of the community will remain.
Urbanization may alter storm water runoff quantity and quality although
land development regulations have been proposed which could mitigate
these impacts on local surface waters. Within the City of Lynnwood, how-
ever, secondary impacts are expected to be negligible.
Construction impacts. For much of its length the new gravity trunk
for the Swamp Creek basin would be constructed roughly parallel to Swamp
Creek and its tributaries at a distance of at least 25 feet to prevent
excavated material and construction activity from disturbing the stream
water quality. Stream crossings would be constructed by pipe jacking when
required by State Fisheries or Game. Some traffic disruption, noise and
dust will be unavoidable as pipe is installed in spite of mitigating
controls in the vicinity of construction but working hours will be
restricted to minimize these impacts. Within the City of Lynnwood,
construction impacts would basically be limited to the treatment plant
site and outfall installation in Brown's Bay.
5. List of alternatives considered.
I Regional facility for total study area flow
A. At existing treatment site on Brown's Bay
B. New facility at new site located at Scriber Creek,
east of Brown's Bay, Alderwood plant site, or Edmonds plant site.
II Separate treatment facilities for various drainage basins
A. Improve Brown's Bay plant and other basins drained to
Metro
B. New plant at new location for Brown's Bay basin with
other basins drained to Metro
C. Separate treatment plants for each drainage basin
xii
-------
Ill Existing Brown's Bay facility abandoned
A. All flow treated at Edmonds
B. All flow treated at Alderwood
C. All flow treated at Metro
D. Combinations dividing flow between Edmonds, Alderwood,
and Metro
IV Treatment facility at Scriber Creek
A. Existing Brown's Bay plant abandoned with Swamp Creek
basin drained to Metro and remainder of study area treated at Scriber
Creek
B. Brown's Bay plant renovated, part or all of Swamp
Creek basin drained to Metro and remainder of study area treated at
Scriber Creek
C. No flow to Metro, all flow divided between Scriber
Creek and Brown's Bay plants
V Service less than entire study area
A. Secondary treatment provided at Brown's Bay for
existing service area only
B. Service extended to Martha Lake and the developed
part of Swamp Creek basin
VI No action
6. List of all federal, state, and local agencies plus other
entities from which comments have been requested:
Federal
Council on Environmental Quality
U.
S. Army Corps of Engineers
U.
S. Department of Agriculture
U.
S. Department of Defense
U.
S. Fish and Wildlife Service
U.
S. Department of Interior
u.
S. Department of Health, Education & Welfare
u.
S. Department of Housing & Urban Development
xiii
-------
U. S. Department of Transportation
Federal Energy Administration
National Marine Fisheries Service
Advisory Council on Historic Preservation
State
Department of Ecology
Department of Fisheries
Department of Game
Department of Social & Health Services
Parks and Recreation Commission
Local
City of Lynnwood
City of Edmonds
City of Brier
City of Mountlake Terrace
Municipality of Metropolitan Seattle
Northwest Air Pollution Control Agency
Snohomish County Health Department
Snohomish County Planning Department
Puget Sound Council of Governments
Alderwood Water District
Other
National Wildlife Federation
Lynnwood Chamber of Commerce
League of Women Voters
Sierra Club
7. Dates statements were made available to agencies and the public:
Draft September 16, 1977
Final September 18, 1978
xiv
-------
Chapter I
INTRODUCTION
-------
CHAPTER I
INTRODUCTION
Facilities Planning and EIS Process
Basic Concept
Section 201 of Title II of the Federal Water Pollution Control Act
Amendments of 1972 (Public Law 92-500), established the basic requirement
for waste treatment management plans. Key points are summarized below:
o Zero pollutant discharge has been established as a national goal to
be achieved by 1985.
o Best practicable wastewater treatment technology is to be applied
to any discharge to receiving water by July 1983.
o Secondary treatment is to be applied to all municipal wastewater
discharges to receiving waters by July 1977.
o Wastewater treatment is to be managed in the most cost-effective
manner for the region rather than merely by local political jurisdictions.
o Recycling and reuse of potential pollutants are to be encouraged
while ultimate disposal of unreclaimable waste shall not result in
environmental hazards.
Development of a sewerage facilities plan requires careful comparison
of all feasible alternatives to select the most cost-effective solution
for the community. Public participation during the planning period is
encouraged to insure that needs and concerns of the community are adequately
addressed. Once all aspects of the situation have been analysed, a
draft facilities plan is presented in a public hearing to receive comments
from all interested agencies and parties. All comments received are
incorporated into the final plan which is then forwarded to the U.S.
Environmental Protection Agency for review and approval.
Federal regulations prescribe a standard procedure for evaluating
environmental concerns in accordance with the National Environmental
Policy Act. When an Environmental Impact Statement (EIS) must be prepared,
a basic format is defined. The intent is for environmental concerns to
be an important element in the development of any major program rather
than merely an after-the-fact justification.
1-1
-------
Seven sections are specified to compose the body of every EIS.
Full attention must be given to long term effects as well as short term.
Primary impacts of the proposed action are to be identified as well as
secondary impacts caused indirectly. Beneficial results must be discussed
as well as adverse. Thus, the final document will allow an impartial
assessment of the entire project in terms of environmental consequences.
Piggyback Approach
Normally, preparation of a facilities plan includes an environmental
assessment to describe the environmental effects of the proposed action.
The assessment then provides a basis for the Environmental Protection
Agency to determine whether a negative declaration of significant impacts
can be issued or a formal EIS must be completed. Three to nine months
may otherwise be necessary to prepare an EIS which extends the project
planning time while delaying the program.
Some proposed actions will obviously have significant environmental
impacts. When these projects can be identified early in the planning
process, the EIS and the facilities plan can be developed concurrently.
This is defined by EPA as "piggybacking" and was determined to be the pro-
cedure used for this project.
As each step in the facilities plan is completed, piggybacking
provides a direct input of associated environmental concerns, thus
shaping the actual plan development. Defining plan alternatives allows
environmental impacts to be readily identified and mitigating measures
can then be incorporated as an integral element to the planning process.
Description of Study Area
The Department of Ecology has defined the study area for this
facilities plan to include the present service area for the City of
Lynnwood sewerage system (approximately 6,400 acres) plus the Swamp
Creek drainage basin (approximately 7,900 acres) within the Alderwood
Water District. Portions of the Cities of Brier and Edmonds are included
within the total study area of approximately 14,300 acres. Figure 1-1
delineates these boundaries.
1-2
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
A plan for sewerage facilities serving the entire study area has
been developed. Topography divides the Brown's Bay coastal zone where
the present Lynnwood plant is located from the Swamp Creek basin with a
ridge exceeding 400 feet elevation in places. Thus it is possible to
consider the study area as two separate aspects:
o The present sewerage collection and treatment facilities which
under PL92-500 must be upgraded to provide secondary treat-
ment .
o The Swamp Creek basin which presently is unsewered and could
remain so or sewers could be planned for all or part of the
area to connect either to an expanded Lynnwood system, the
Municipality of Metropolitan Seattle (Metro) system or another
new facility.
More than two dozen alternative configurations and combinations
were examined during the development of the facilities plan.
Program Development
A brief history of the project development contributes to an under-
standing of the proposed action. Thus, the following historical background
is provided.
Swamp Creek Trunk Sewer Feasibility Study, 1971
In mid-1964 there was considerable discussion concerning sewerage
problems in the unincorporated areas of southwest Snohomish County,
generated to a large extent by septic tank failures and property owners
who wanted sewer service. These discussions occurred among all local
government entities involved, and eventually evolved to the question of
which entity was logically situated to provide this service and could
and would accept the responsibility.
By February of 1965 the Alderwood Water District agreed to accept
this responsibility and initiated development of a Comprehensive Plan
for sewers in the major portion of the unincorporated areas of southwest
Snohomish County. Approval of the comprehensive plan by existing local
and county municipalities was completed in May, 1966, and adopted by the
District by Resolution No. 1422 on September 6, 1966. A public election
authorizing the District to construct, operate and maintain a sanitary
sewerage system and issue bonds to a maximum of $9,650,000 for this
purpose was approved by the electorate in November of 1966.
1-5
-------
The Department of Housing and Urban Development extended a loan to
the Alderwood Water District in March 1970 which funded a Feasibility
Study of the Swamp Creek Trunk Sewer. The purpose of this study was to:
1) Initiate advance planning needed for the preparation of plans in
sufficient detail to permit accurate cost estimating; 2) Compile and
evaluate those factors required for determining the advisability of con-
structing the Swamp Creek Trunk Sewer.
This study evaluated sites through aerial photography, property
descriptions, and field investigations to determine the most feasible
route for the proposed trunk sewer which would result in the least cost
and disturbance to existing use of the properties involved. Existing
reports, surveys, and field investigations were studied to determine the
extent of existing development of the area and the potentials of the
area for growth which could result from construction of the trunk sewer.
Based on the recommended location, a preliminary design was com-
pleted, together with preliminary plans and cost estimates. The ability
of the area to finance the project was investigated, as well as alternate
methods of financing. It was concluded that the Swamp Creek Trunk Sewer
was an economically feasible project which was needed to allow for
proper development and the elimination of existing pollution within the
Swamp Creek Drainage Basin. However, state and federal assistance was
not forthcoming so the project has not yet been implemented.
Lynnwood Sanitary Sewage Treatment Facilities Report 1972
As a result of the 1961 Comprehensive Sewerage Plan for Lynnwood,
Washington, a sewage treatment plant was constructed by the City in 1962
to provide primary treatment for a design flow of 2.2 million gallons of
sewage per day. Treatment consisted of comminution, clarification,
sludge conditioning, sludge burning, and chlorination. Ultimate disposal
of the liquid plant effluent is to Puget Sound through a deepwater
outfall. In 1967 a sludge disintegrator was installed at the plant to
improve sludge handling operations.
In later years there had been some discussion of the possibility of
rupture of the plant outfall under Puget Sound. Also, as a result of
the growth experienced in Lynnwood, the sewage loads, as recorded at the
plant, had increased to the point where design loads were equaled or
exceeded for periods of 14 hours or more and had peaked in excess of 4.0
million gallons per day (MGD)(maximum flow chart recording capability)
causing overloading of the clarifier. In addition, there had been
operational problems reported with the plant sludge conditioning and
burning facilities, causing plant shutdown.
1-6
-------
The high flows and reported operational difficulties, together with
increased emphasis on pollution control, caused the City of Lynnwood to
consider construction of improvements and expansion to the existing
sanitary sewage treatment plant.
An engineering report was prepared which analyzed the capabilities
of the existing treatment facilities to provide the required degree of
treatment to the sewage collected from the City and its contracted
parties. The report also determined the ways and means for complying
with current treatment standards through plant expansion and modifications.
The report first contemplated sewage loads imposed on the treatment
plant by the collection system service area. It then reviewed the
ability of the existing sewage treatment plant to produce a quality of
treatment commensurate with the facilities intent. It was found that
although minor modifications were desirable, the plant was well designed,
operated and maintained, and had been capable of adequately treating the
sewage loads experienced in the past. However, residential development
in the City of Lynnwood had overloaded the treatment facilities, and a
plant expansion was needed at that time.
The future system requirements were developed, based on current
standards and a projection of future treatment objectives. Several
alternative solutions were evaluated and the most feasible was selected
for preparation of preliminary plans and cost estimates.
A facility to treat the sewage from the total projected service
area would require additional site acquisition and result in substantial
site development costs. The report further recommended that in lieu of
servicing the total service area, the City, at some time in the future
when the Swamp Creek Trunk Sewer was constructed, could eliminate a
pumping station and divert a portion of the City's sewage to the Swamp
Creek Trunk Sewer, all in conformance with the past comprehensive plan-
ning which had been accomplished for the Lake Washington Drainage Basin.
The existing site would allow for the construction of a treatment
facility which would be adequate for the reduced service area consisting
of land located in the Puget Sound Drainage Basin.
The report concluded that the City of Lynnwood could not determine its
final course of action until regulatory agencies indicated quality of
treatment and nature and extent of background information required, or
until negotiations concerning cost distributions were completed.
RIBCO Water Quality Management Report 1974
The Water Quality Management Study, which began in 1971, was conducted
to define a basin-wide water quality management program in the Cedar and
I--7
-------
Greert River Basins, of which this study area is a part. The study was
part of a total environmental planning effort that included other studies
of water resource management, urban runoff and basin drainage, and solid
waste management. The environmental planning effort became known as the
RIBCO studies when the River Basin Coordinating Committee (RIBCO Committee)
was formed to guide the studies.
The study made an assessment of the quality of the waters in the basins
and the factors influencing that quality. Water quality was studied from
two basic approaches in accordance with the guidelines and standards estab-
lished by the U.S. Environmental Protection Agency and the Washington State
Department of Ecology. One approach involved an assessment of pollutant
sources such as municipal waste treatment discharges and the nonpoint
wastes from the human activities of urban development, agriculture,
recreation, construction and forestry. The other approach involved an
assessment of instream water quality of various contributary lakes and
streams.
The report provided a recommended regional sewerage plan for the
basins and made specific recommendations as to the location and con-
struction staging of sewage treatment plants and regional interceptor
facilities through the year 2000.
Specifically, for the southwest Snohomish County region, the ini-
tial analysis of sewage treatment plants dealt with 56 treatment plant
combinations with the service area boundaries as they now exist. The
four most cost-effective configurations were then reexamined to consider
modifying existing service boundaries at Lynnwood and Edmonds to allow
for the significant portions of the area which drain naturally toward
Lake Washington and the Metro treatment plants.
It became apparent that by altering existing sewage treatment plant
service areas to conform to natural drainage patterns, Lynnwood and
Edmonds had ten possible subalternatives that should be analyzed inde-
pendently. Four of the ten subalternatives were selected as final
alternatives for detailed analysis.
The cost-effective analysis performed in the study resulted in the
recommendation of an alternative which would maintain separate upgraded
treatment plants at Lynnwood and Edmonds; reduce the service areas;
abandon two pumping stations within the study area; and divert the
split-off portions, by gravity, through the McAleer trunk and a new
Swamp Creek Interceptor to Metro's West Point plant.
Lynnwood Collection System Infiltration/inflow Survey Analysis, 1976
The City of Lynnwood has filed for federal and state grant assist-
ance to improve and expand the Lynnwood sewage treatment plant. As part
1-8
-------
of the sewerage improvement program, the City of Lynnwood undertook an
investigation of its existing sewer system to determine if excessive
infiltration or inflow exists.
Infiltration is defined as the leakage of groundwater into sewers.
Inflow is defined as the entrance of any flows other than infiltration
or sewage from such sources as roof drains, storm drains, street wash
waters, basement drains, and cooling water discharges.
An Infiltration/inflow Analysis was completed by the City in
January of 1975 which concluded that Lynnwood's existing sanitary sewer
system is experiencing excessive infiltration and inflow.
The City of Lynnwood was authorized by the regulatory agencies to
proceed with a Sewer System Evaluation Survey. This Survey is a syste-
matic examination of the sewer system to determine the specific location,
magnitude, and type of infiltration/inflow into the Lynnwood system.
The Analysis summarized results of the Evaluation Survey to that
date, and recommended further investigation into areas containing
questionable sources of infiltration/inflow into the Lynnwood system.
The remainder of the Evaluation Survey was completed as a part of the
Facilities Plan.
1-9
-------
Chapter JT
ENVIROMENTAL
-------
CHAPTER II
ENVIRONMENTAL SETTING
Physical Environment
Earth
Geology. The study area lies within the Intercity Plateau, a
geologic region bounded on the west by Puget Sound, on the north and
east by the Snohomish and Snoqualmie Rivers, and on the south by Lake
Union, Lake Washington, and the Sammamish River. The entire plateau is
underlain by pre-Vashon Admiralty clay, which in some areas lies 1,000
feet thick, or greater, over Oligocene sedimentary rocks. At an eleva-
tion of approximately 200 feet, the Admiralty clay grades into Esperance
sand, a Vashon glacial drift advance outwash sand and gravel strata.
Admiralty clay is exposed along the Puget Sound shoreline below an
elevation of 150 to 200 feet. The thickness of Esperance sand is vari-
able, but in the project area it abruptly grades into Vashon ground
moraine till, commonly known as hardpan, at an elevation of 300 to 500
feet. In the Swamp Creek drainage, and also along the slopes to Puget
Sound, Esperance sand is exposed, or is the soil parent material, below
approximately 400 foot elevation. The glacial till hardpan forms the
surficial geology of the majority of the project area, and is generally
from 20 to 150 feet thick. It is composed of gravel and sand particles
cemented in a matrix of silt and clay. Except for erratic inclusions of
sand and gravel zones, it is only slightly permeable and often imperme-
able. Esperance sand is the only strata containing significant amounts
of groundwater.
Topography. The study area rises from Puget Sound and lies on a
rolling plateau at an elevation of 300 to 600 feet. Slopes along the
coast generally range between 10 and 25 percent with some locations
approaching 40 percent slope. Lunds Gulch, which enters Puget Sound
near the northwest corner of the project area as shown in Figure II-l,
is approximately 270 feet deep with canyon side slopes up to 50 percent.
Most of the rolling uplands of the project area have slopes in the range
of two to 13 percent, with some areas along Swamp Creek in the easterly
portions of the project area having slopes up to 25 percent.
Additional topographical features are discussed further in the
Unique Physical Features and Surface Water Movement Sections.
Erosion. Quantitative and/or geographical information regarding
soil erosion in the study area is lacking, but serious erosion is
II-l
-------
known to occur in the Swamp Creek drainage basin. Washington Department
of Game staff report turbidity in storm water runoff to be the most
damaging fisheries water quality problem in Swamp Creek, with resultant
sedimentation of salmonid spawning beds. The source of the sediment is
considered to be eroded soil from the more heavily urbanized areas of
the basin, and from soil erosion at construction sites.
Limited information regarding natural build-up (accretion) and
erosion along Puget Sound shorelines of the project area is available
from the Snohomish County Planning Department. At Norma Beach at the
northerly end of the study area, some marine shoreline accretion occurs.
The shorelines of Browns Bay are classified as marginal, a condition
midway between accretionary and erosional. Accretionary shorelines are
characterized as having dry usable beach at all states of the tide;
erosional beaches as having no usable backshore, and at high tide having
no dry beach. Erosional shoreline occurs in the study area south of
Browns Bay. Rates of accretion or erosion are not known.
Erosion occurs in Swamp Creek, and the RIBCO Water Quality Manage-
ment Report contains general recommendations for riprap stream bank
protection. No distinction was made between existing erosion and
anticipated possible future conditions, however.
Soils. The soils of the study area are a complex mixture of a
large variety of soil types, principally Alderwood and Everett soils,
most of them derived from glacial till which generally lies between two
to four feet below the surface. There are also significantly large
areas covered by peat-type and muck-type soils. These soil types
generally have severe limitations for use as septic tank filter fields
due to slow internal drainage, high seasonal perched aquifers, or a
shallow depth to impermeable glacial till parent material.
The Snohomish Health District classifies Snohomish County soils as
Class A, B, C, or D for purposes of describing their degree of accept-
ability for use as subsurface drainfields.
(a) Class A soil - porous soil, acceptable for septic tanks.
Example: 0 to 72 inch depth having a sandy loam characteristic.
(b) Class B soil - porous soil, may require sewage disposal systems to
be designed by a licensed Sewage Disposal Designer or Civil Engineer.
Example: 0 to 48 inch depth having a sandy loam with clay character-
istic overlaying a clay pan.
(c) Class C soil - marginal soil, may require sewage disposal site to
be checked and approved by Health Department before issuing permit.
Example: 0 to 18 inch depth having a sandy loam characteristic.
May be mixed with gravel, clay, and with water running over clay
pan.
II-2
-------
(d) Class D soil - Not acceptable for development by septic tanks under
present conditions. Example: plastic clay having fine silt. No
porous soil and generally water table close to top of the ground
indicating very poor drainage.
The Snohomish Health District has classified soils in portions of
the project area based on field inspections, soil tests, and records of
septic tank drain field failures. These classifications are discontinu-
ous over large sections of the project area and no systematic classification
has been attempted. In general, the soils of the project area may be
expected to be Class C with inclusions of Class D soils, generally along
lake shores and creek bottoms.
A composite soils map of the project area has been developed as
Figure II-l from the informal records of the Snohomish Health District.
The unshaded portion represents areas likely to be Class C under the
Snohomish Health District classification. The shaded portion represents:
1) areas with unusually severe limitations on the use of septic tank
drain fields (Class D soils),
2) areas having an unusually high incidence of drain field failures,
3) areas noted on the maps of the Snohomish Health District where no
septic tank permits will be issued for the area,
4) peat-type or muck-type soils are known to be present.
The Snohomish Health District is limited in its ability to survey
the soils of the entire district, so it is likely that there are additional
locations within the project area that should be classified as D soils.
These areas would most likely lie along Swamp Creek south of Stickney
Lake, Scriber Creek west of Swamp Creek, and along the stream that
drains south from Martha Lake.
None of the soils within the study area are classified as prime or
unique agricultural land by the Soil Conservation Service.
An investigation of soil stability and engineering characteristics
at the sewage treatment plant site was accomplished by Shannon & Wilson,
Inc., under contract to Gray & Osborne, Inc. during November and December,
1976. The resultant report of the soils investigation and analysis is
reproduced in part below.
The existing treatment plant site is located in a ravine which
exits into Puget Sound, about one-half mile south of Meadowdale,
Washington. The slopes are very steep, being greater than 40
degrees to the horizontal in places. Alder and dogwood trees,
blackberry vines and nettles cover most of the hillside.
A plan of the site showing the approximate locations of the
existing structures and the proposed new facilities is presented on
Figure II-2. It is understood that the construction of the new facil-
ities would require excavations into the toe of the south slope of the
ravine. Excavation heights of 8 to 10 feet are anticipated.
II- 3
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
Air Conditions
Climate. The climate of the Puget Sound area is predominantly a
midlatitude, west coast marine type with a dry season and pleasant
temperatures during the summer, rather mild but rainy winters, moist
air, and a small range in temperatures. Some of the factors influencing
the climate are terrain, distance and direction from the ocean, and the
position and intensity of the high and low pressure centers located over
the north Pacific.
During July and August, it is not unusual for 2 or 3 weeks to pass
without any measurable precipitation. On a typical summer day, afternoon
temperatures are in the upper 70s and the nighttime readings are in the
50s. Morning winds are often very light during the summer and a breeze
of 10 to 15 mph can be expected most afternoons. Air movement throughout
the year is generally sufficient to prevent any appreciable accumulation
of smoke or other air pollution materials.
The low pressure center near the Aleutian Islands intensifies and
moves southward in the fall and winter, and at this time the high pressure
area becomes smaller and also moves southward. The circulation of air
around these two pressure regions in the north Pacific brings a prevailing
flow of warm, moist air into Washington from a southwesterly direction.
This results in mild winter temperatures and a rainy season which begins
in October, reaches a peak in midwinter, then decreases in the spring.
On a typical winter day, the afternoon temperature is in the 40s,
and the typical nighttime reading is in the upper 20s or low 30s.
Minimum temperatures are nearly always above freezing during cloudy,
foggy» or rainy weather; thus, frost or ice rarely forms on the streets,
other than for brief periods following a snow. The prevailing wind
direction in the late fall and winter is from the south or southwest.
The highest wind velocities occur during this season as storm systems
from over the ocean move inland.
Air quality. The Lynnwood area consists generally of residential
and commercial establishments that service the residences of the surround-
ing area. As a result, the amount of air pollutants (mainly particulates
and sulfur oxides) generated by heavy or even light industrial establish-
ments is minimal. The main source of air pollutants is home heating and
unpaved roads for particulates, and vehicular traffic for oxides of
nitrogen, hydrocarbons, and carbon monoxide.
This assessment will be limited to the development of existing
levels of pollutants and anticipated levels that may occur when the area
has developed to its full potential. Currently, the area has had no air
pollution monitoring performed by any governmental agency. A review of
the Environmental Impact Statements in the Lynnwood area indicates that
the Alderwood Mall Shopping Center is the only impact statement with an
II-7
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
Air Quality Study. The results of that analysis (August 6-20, 1974)
indicated that in the mall vicinity, and adjacent to 1-5, the highest
1-hr CO concentration of 4 ppm occurred on August 19, the highest 8-hr
average value of 4 sampling sites for a given day was 2.3 ppm (from 1400
to 2200 hr on August 19), and the overall 8-hr average (1400 to 2200 hr)
for the 15 sampling days was 1.4 ppm. The site CO levels were well
within the EPA Standards of 35 ppm for the 1-hr value and 9 ppm for the
8-hr value (U.S. EPA 1973b).
Suspended particulates. The Puget Sound Air Pollution Control
Agency has estimated the levels of suspended particulates in the area.
As noted in the 1975 Annual Report, Pages 21 and 22, the 1974 and 1975
levels of particulates were 30 micrograms per cubic meter as compared
with the federal and local standard of 60 micrograms per cubic meter.
This value should be fairly uniform over the entire area, since partic-
ulate sources are limited and dispersed, as illustrated in Figure II-3.
Sulfur dioxide. The main source of Sulfur Dioxide in the area is
home heating. Since the maximum sulfur content of home heating fuel was
recently restricted to not over 2 percent by weight, it is not likely
that enough sulfur could be generated to exceed federal and local standards.
However, this standard represents no change in heating practice since heat-
ing oils used in the Puget Sound area have never exceeded 2 percent sulfur.
The current local standards are 0.02 ppm for annual average, 0.1 ppm for
a 24-hour average and 0.25 for a one-hour average in the exhaust gases.
Carbon monoxide. The main source of Carbon Monoxide (CO) is vehicu-
lar traffic and the values generally increase as the traffic increases.
There are 3 major areas in the study area that are significant sources
of CO. These are strips of land in which the three major arterials are
located, namely, 1-5, U.S. 99, and 196th Street SW and the Alderwood
Mall Shopping Center site. CO levels around these areas will range from
a high of 6-7 ppm to a low of 2 ppm depending on the weather conditions.
Areas away from these arterials will generally exceed the 2-5 ppm range
which is typical of rural and residential areas, but remain lower than the
commercial strips. These values are below the 9 ppm 8-hour average
federal and local standard.
Hydrocarbons and oxides of nitrogen. Although no monitoring data are
available for this area, it is anticipated that the levels are below
the .05 ppm oxides of nitrogen (NOx) standard and the .24 ppm hydro-
carbon standard (HC). This assumption is based on the fact that these
pollutants are vehicle-related, and when CO levels are low the HC and
NOx values are also anticipated to be below the standard.
11-11
-------
SUSPENDED PARTICULATES
1975 ANNUAL GEOMETRIC MEANS
(MICR0GRAMS/CU METER)
MORYSVIILE
JSlflNO CO
TSflP cfrs
SNOHOMISH
MONROE
SNOHOMISH CO
T KING CO
TOLT WRTER RES
SEPTTLE
BREMERTON
SNOQUflLMIE
RENTON
KITSAP CO
PIERCE CO
AUBURN
TflCOrifl
ENUMCLflW
PUYflLLUJ
PIERCE CO
Figure II-3
" SUSPENDED PARTICULATES
IN PUGET SOUND AIR
-------
Treatment plant incinerator. The existing incinerator is of the fluid-
ized bed type manufactured by Dorr-Oliver. No tests have been conducted on
emissions from the Lynnwood facility but a similar unit in Edmonds emits
about one pound of particulates per hour of operation. No measurements or
estimates of the gases are available. Some odor potential does exist though.
About 500 gallons per month of fuel oil are burned during operations.
Sulfur content has always been under 2 percent.
Odor. Odor may exist at four installations in the Lynnwood
sewerage system:
o Pump Station No. 10 on 204th Street S. W. north of Interstate
Highway 1-5
o Pump Station No. 12 on 216th Street S. W. east of U. S. 99
o Sewage Treatment facilities at the end of Brown's Point Road
o Manhole at Perrinville junction
Odors can be released from sewage handling and treatment facilities
in two ways:
o As part of stack gas such as is produced by the incinerator
o By transfer to air coming into contact with sewage, or with
odorous materials removed from the sewage, and then escaping
without being treated
There are no current regulations restricting or limiting the amount of
ambient odor since no accepted measurement standard exists.
Pumping Station No. 10 is a small, isolated unit which is well
built, maintained, and operated. Equipment consists of three pumps
controlled by a level controller in the wet well. Seal water is fresh
water maintained at a pressure about twice that of the sewage (40 psi
vs. 18 psi) so that all leaks are into the sewage. The standby electric
generator has enough capacity to operate all three pumps so that the
emergency overflow into a nearby creek is seldom used. This overflow is
capped by a heavy metal flap to prevent release of odorous materials.
The only odor source in this installation during normal operation involves
odors which escape from the wet well (normally covered) and are then
carried by air out the building ventilation vent. Odorous release
during abnormal operation (overflow from the wet well to the local
creek) is unlikely since installation of the third pump and the second
10-inch force main minimizes the likelihood of overflow.
Pumping Station No. 12 is similar to No. 10. Instead of three
pumps it has four of larger capacity. Standby diesel power is sufficient
to operate two pumps and emergency overflow is into the Edmonds sewage
system. Odorous release during normal operation occurs in the same
manner as described for Pumping Station No. 10. During abnormal opera-
tion odorous release is not increased because the sewage "overflow" does
not escape but is transferred to another sewage system.
11-13
-------
Sewage treatment plant odor problems are most severe during warm
weather, especially May through November. They are particularly notice-
able during and immediately following periods of calm, such as the
morning and evening calm, and when the sea breeze (warm days) or prevail-
ing northerlies (summer months) push the odors uphill. The main sewer
coming into the treatment plant is an important odor source. The
sewage, though cooler than the outside air, is warm enough to allow
biological action in the sewage as it travels from the Perrinville
junction to the main junction above the plant on 76th Avenue West (a
distance of about one mile). This produces odorous materials, particu-
larly if the sewage, or any part of it, goes anaerobic. The sewage then
travels down the main from the junction on 76th Avenue West into the
plant on a slope sufficient to thoroughly agitate the sewage, exposing
any odorous materials to the air in the main. At the same time the air
in the main, cooled and humidified by the sewage, also travels down the
main (the inverse chimney effect) and emerges at the outlet carrying all
of the odorous materials it received from the sewage. The released
odorous air is cooler than the atmosphere and will stay near the ground
and tend to build up until moved up the hill by the sea breeze or the
prevailing southwesterly wind, both of which are common during warm days
when the effect described is maximum.
The inlet junction at the plant headworks is covered, which mini-
mizes transfer of odor to the air, and one-third of the chlorinator
output is added to the sewage at this point to minimize odorous materials.
The grinder, bypass, and bar screen are completely open to the air which
maximizes the opportunity for air to contact the sewage, pick up odorous
materials, and carry them out into the environment.
Odor from the open clarifier will arise because transient air is
unhindered in entering, picking up odorous materials from the water
surface, and leaving, carrying the odorous materials with it. Two
aerators have been installed by plant personnel. During the summer
months these aerators may reduce odor somewhat by increasing aeration in
the surface layer, but the clarifier is still undoubtedly an odor source.
The degritter is an important continuous source of odor during
normal (24 hours per day) operation and a major source when the grit is
dumped daily into a tote box. These problems, particularly the second,
will be more severe during the summer months.
Odor may escape from the sludge thickener, particularly during the
summer months. Like the clarifier, transient air has substantially free
access to and exit from the odorous water in the thickener. As a source
of odor, the thickener is normally more important than the clarifier
because the sewage is more concentrated, it has been agitated in the
feed pumps and degritter, plus any beneficial effect of the inlet
11-14
-------
chlorination will be substantially gone. Two aerators installed by the
operating personnel are probably sufficient to prevent anaerobic conditions
from developing to the point where they disrupt the thickener operation
but their beneficial effect on odor release is probably small.
The sludge disintegrator is totally enclosed so it is not a source
of odor during "normal" operation. However, it is an old unit and
fitted with a stuffing box instead of mechanical seals so it develops
leaks requiring periodic repacking and bearing replacement. In practice,
therefore, it is a minor source of odor.
The sludge centrifuge creates few odor problems. However, centri-
fuge return line drops the centrifuge supernatant liquid onto the thickener
surface near the periphery. It then travels around the thickener edge
and is returned to the clarifier with the thickener effluent. This is
an important source of odor because this liquid:
o has a high concentration of sewage materials
o has been subjected to thorough agitation in the disintegrator
and centrifuge which maximizes the availability of odorous materials
o is warm which increases the tendency of the odorous materials to
leave the liquid
o has good access to transient air
The sludge conveyor, consisting of two screw-in-trough systems, is
adequate for handling nonvolatile, nonodorous materials where escape of
volatile materials (odors) and spillage of the material being conveyed
is not important. But it is not suitable when spillage and escape of
volatile (odorous) materials must be prevented.
The Dorr fluidized bed incinerator is probably not a major source
of odor. The present 10-11 hours per day, 7 days per week operating
schedule, combined with the new operating procedure which heats the bed
to about 1600°F. before shutting down, has largely eliminated the "cracked
diesel smell" previously encountered during startup when the bed tempera-
ture had dropped to 1200°F., or lower, on Monday mornings. The bed
temperature, 1400°F. , is high enough to substantially eliminate any
odorous materials present in the air fed to the bed or in the sludge.
The scrubber receives the incinerator stack gas at a high temperature
(1200°F. to 1600°F.), cools and saturates it with a co-current spray of
potable water, and "scrubs" it with raw sewage from the clarifier. The
scrubber is a major source of odor in the summer because it strips the
odorous material from about 25 gallons per minute of raw sewage, and
cools the stack gas from more than 1100°F. to less than 200°F. which
greatly reduces the buoyancy of the plume. In other words, it both
increases the amount of odorous materials in the gas and minimizes any
tendency of the gas to disperse.
11-15
-------
The operations building is capable of providing substantial odor
control benefits. But these potential benefits are substantially
reduced by the excessive opportunities provided for air to enter and
leave the building via:
o ventilation louvers near the main fluidizing blower intake
o open space in the roof around the incinerator stack
o open access hole to the roof
o tendency of plant personnel to tie the south door of the operations
building open.
The ventilation fan in the southeast corner of the operations
building, though presently not in use, can only serve to remove odorous
materials from the pump room and discharge them to the atmosphere.
Present tendencies to operate with half of the metering manhole cover
off allows release of some odor.
Major storms can change plant operating requirements by increasing
the sewage volume. If this occurs while the operators are present, they
can open the bypass gate at the influent structure and allow the excess
sewage to bypass the treatment facility directly into the outfall.
However, if this occurs while the plant is unattended, all the sewage
enters the headworks, overflows, and travels across treatment plant
grounds into Puget Sound via natural drainage. Sewage overflow is a
major odor source because air is provided free access to large sewage
volumes. A thorough washdown after the event will mitigate the problem
and shorten its duration, but it will still exist as a lingering odor
source.
Equipment failure can cause substantial odor problems. Plugged
pipelines in the summer will normally go anaerobic and removal of the
material in the line will produce an especially foul odor. The sludge
transfer line from the thickener to the disintegrator is the most
frequent problem.
Leakage at the disintegrator stuffing box is the next most frequent
equipment failure and is a minor source of odor.
Long, unscheduled shutdowns can result in odor problems when restarting
the sludge burner because:
o There will normally be some unburned sludge in the burner if the oper-
ator is unable to shut down the centrifuge and burn the in-process
sludge before the shutdown.
o The incinerator will be colder than design operating temperatures when
started up again, particularly if the operator is unable to heat it
(to about 1600°F.) before shutdown and/or if the shutdown is long.
11-16
-------
Odor complaints have been lodged only during the warm summer weather
on an irregular basis by a few affected individuals. It has not been pos-
sible to establish a definite odor pattern from the limited records and
data available.
Water
Surface water movement. Water movement studies were conducted in
Puget Sound in the vicinity of the existing Lynnwood sewage treatment
plant outfall on April 26, 1970 by Gray & Osborne. Three biplane
drogues with floats were used with the vanes set at 10, 50, and 85 feet
respectively below the surface float. The outfall discharges into Puget
Sound 750 feet from shore in 100 feet of water. Six series of observa-
tions were conducted between 10:15 a.m. and 3:50 p.m., with low tide
occurring at 12:30 p.m. Figures II-4, 5 and 6 illustrate observed
results. These water movement studies at the outfall were considered to
have confirmed general movements reported earlier by others that show
the normal movement of water at the point of discharge is parallel to
the shoreline, and that an onshore movement develops with the incoming
tide.
Generalized water budget studies of Puget Sound and its major
inlets have been performed. The flushing time of the Port Susan-Possession
Sound area northeast of the project area is approximately 21.9 tidal
cycles. The flushing time in the vicinity of Point No Point northwest
of the project area is approximately 19.5 tidal cycles. A flushing time
for Browns Bay, the location of the existing outfall, is then estimated
to be approximately 20 tidal cycles. However, flushing times do vary
widely, especially for shoreline indentations. It is possible the actual
flushing time greatly exceeds 20 tidal cycles.
Surface runoff generally follows the contours of the land with
considerable modification of flow routing by streets and drainage structures.
Drainage basin boundaries are shown in Figure II-7.
Surface water movement in year-round streams and runoff gullies of
the study area lie in two general drainage basins, the Puget Sound
drainage and the Swamp Creek drainage. Throughout the study area, urban
storm drainage channelization has produced minor rerouting of surface
water movement, but no major changes.
In the Puget Sound drainage area, natural surface water drainage
ways are intermittent runoff streams that run approximately northwesterly
into Puget Sound.
In the Swamp Creek drainage area, gross water flow is southerly out
of the study area to the Sammamish River which eventually flows into
±1-17
-------
SCALE: 1" - 100'
o
o
to
h-i
cb
Oh
APRIL 26.1971
LOW TIDE: 27', 12:30 P.M. (P.D.S.T.)
-------
O
OQ
LEGEND
APRIL 26,1971
LOW TIDE: 27', 12:30 P.M. (P.D.S.T.)
<3> TIME: 10:15 A.M.
<2> TIME: 11:00 A.M.
Q> TIME: 12:00 NOON
© TIME: 1:20 P.M.
-------
LEGEND
APRIL 26,1971
LOW TIDE: 27', 12:30 P.M. (P.D.S.T )
TIME:
<3> TIME:
<3> TIME:
<§> TIME:
© TIME:
10:15 A.M.
11:00 A.M.
12:00 NOON
1:20 P.M.
2:25 P.M.
3:15 P.M.
10:50 A.M.
11:50 A.M.
1:15 P.M.
20 P.M.
10 P.M.
50 P.M.
Figure H-6
CURRENT STUDY AT OUTFALL
Depth 10 ft.
II-20
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
Puget Sound via Lake Washington. Swamp Creek has a number of east and
west flowing tributaries. Scriber Creek, the major tributary of Swamp
Creek, flows westerly across the study area and has a number of southerly
flowing tributaries.
Runoff and absorption rates are highly variable throughout the
study area due to the mixture of low runoff/high absorption forested
areas with high runoff/low absorption urban impervious surfaces. The
Swamp Creek wetlands probably have minimal value as runoff flow attenu-
ators except for periods of heavy rains because the Swamp Creek water
course tends to flow directly through the swamps in a relatively well
defined channel.
Floods. The Snohomish County Planning Department does not report
any floodplain zoning in the study area. The Snohomish County Engineer
does not report any significant flooding in the study area. The RIBCO
Water Quality Management Study identified locations of flooding problems
along Swamp Creek and its tributaries, but did not distinguish between
existing problems and anticipated future problem areas, nor did it
delineate an actual floodplain.
In keeping with most creeks of similar size in the area, Swamp
Creek is shown on the U. S. Geological Survey "Open File Report for
Flood Hazards in the Seattle-Tacoma Urban Complex," 1975, as a potential
100-year floodplain less than 1/4 mile wide.
Surface water quantity. The volumes of four of the five lakes
within the project area are given in Table II-l. Part of Lake Serene is
shown within the study area, however this community is already completely
sewered and discharges to the Alderwood sewage treatment plant. Installa-
tion of a trunk sewer in the Swamp Creek basin would allow sewage flow to
follow topography and several pump stations could be abandoned. No environ-
mental impacts would therefore result in the Lake Serene area except for
the energy savings.
TABLE II-l
LAKE VOLUMES
Lake
Volume, Acre-feet
Source
Stickney
Martha
280
1346
1300
Bortleson, et_ al. , 1976
Wolcott, 1973
Bortleson, et «al. , 1976
Hall
Scriber
No Data
No Data
11-23
-------
The only regular stream flow records available are for Swamp Creek
outside the project area at the Bothell Way bridge (SR-522) in Kenmore
at river mile 0.5. Average discharge for the period 1972-73 and 1974-75
was 35.2 cubic feet per second (cfs) , or a yield of 20.69 inches per
year from the 23.1 square mile drainage basin upstream of the gaging
station. Maximum and minimum recorded discharges during this period
were 487 cfs and 2.7 cfs, respectively.
Surface water quality. The following terms are normally used to
describe the quality of freshwater lakes:
oligotrophic - clear with few nutrients and little organic matter
eutrophic - rich in nutrients and organic matter which will even-
tually settle out, filling the lake into a swamp
mesotrophic - a quality intermediate between oligotrophic and
eutrophic
Stickney lake was intensively studied by METRO during the spring,
summer, and autumn of 1972, and was classified as mesotrophic. Water
quality data on Stickney Lake obtained by the U.S. Geological Survey in
1973, falls in the same range reported by METRO. The lake is period-
ically tested for bacterial contamination by the Snohomish County Health
Department. Based on these data, Stickney Lake as a whole, meets the
applicable Washington State standards for lake class waters (WAC-173-
201-030).
METRO has classified Stickney Lake as mesotrophic with eutrophic
tendencies based primarily on low bottom dissolved oxygen conditions and
a high number of algae during summer blooms, and has designated the lake
for future intensive study.
Martha Lake was also intensively studied by METRO during the
spring, summer, and autumn of 1972. It has been classified as meso-
eutrophic. Water quality data on Martha Lake obtained by the U.S.
Geological Survey in 1973, falls in the same range reported by METRO.
The lake is periodically tested for bacterial contamination by the
Snohomish County Health Department. Based on these data, Martha Lake as
a whole meets the applicable Washington State standards for lake class
waters.
The only water quality studies known to have been conducted on Hall
Lake (6.1 acres, surface area) are periodic tests by the Snohomish
County Health Department for bacterial contamination. These data are
insufficient to properly evaluate whether Hall Lake meets Washington
State lake class standards.
Scriber Lake (Surface area 3.4 acres) does not meet the METRO or
USGS criteria for inclusion in their study programs. As the lake has no
11-24
-------
public access for recreational purpose, it has not been monitored by the
Snohomish County Health Department.
A reconnaissance study of lakes and streams in the Lake Washington
drainage basin was performed by METRO between July, 1971 and October,
1972 and included Swamp Creek. Among other things, that study concluded
that Swamp Creek and other streams in the Sammamish River drainage
basin, had generally poor water quality conditions. Solids concentra-
tions were high. Dissolved oxygen levels were occasionally low, but
this was attributed more to low flow conditions and shallow water during
this summer, than to a high biochemical oxygen demand. Coliform bacteria
levels were in excess of the applicable Washington State standards for
Class A streams (WAC-173-201-030; WAC-173-201-070). Stickney Lake, the
headwaters of Swamp Creek, had better water quality than did the stream,
so the source of the contaminants was presumed to be in the watershed
below the lake.
No oceanographic study is known to have been done in Browns Bay,
the location of the Lynnwood sewage treatment plant outfall into Puget
Sound. Water quality monitoring is carried out at a number of locations
in the general vicinity by METRO, the Washington Department of Ecology,
the University of 'Washington Oceanography Department, and others.
Gray and Osborne conducted a bacterial water quality study of
Browns Bay in the immediate vicinity of the Lynnwood outfall on August
4, 1971, at 8:00 a.m., on an ebb tide. Water samples collected within
750 feet of the outfall contained total coliform MPN concentrations of
43 per 100ml to 2,300 per 100ml (median: 230 per 100ml). Two samples
collected approximately 0.5 miles offshore of the outfall, and approxi-
mately 0.25 miles apart, had MPN bacterial concentrations of 43 per
100ml. The bacterial concentration in the effluent at the treatment
plant was 210,000 per 100ml at the time of the test. Browns Bay waters
are Class AA (WAC 173-201-080), and as such, bacterial concentrations
are not to exceed median values of 70 total coliform organisms per
100ml, with less than 10% of samples exceeding 230 per 100ml when
associated with any fecal sources. Studies to date indicate the high bac-
terial concentrations in Brown's Bay are due to the Lynnwood treatment
plant and the present treatment plant is apparently in violation of
required discharge standards.
Ground water movement. The ground water of the study area has been
surveyed by the U.S. Geological Survey as a part of a general geological
and ground water study of Snohomish County. No extensive ground water
movement through aquifers under the study area was noted.
Ground water quality. The ground waters of the area as a whole are
low in dissolved mineral matter, soft to moderately hard, and free from
color or odor. Waters from the strata which underlies the project area,
are moderately hard, averaging about 100 ppm hardness.
11-25
-------
Ground water supply. Ground water supply in the project area is
regionally variable and not entirely predictable. The area south of
Alderwood Manor to the Sammamish River is regarded, in general, as being
deficient in ground water because the silts and fine sands of that area
hold less water than the sands and gravels normally associated with the
Esperance member. Approximately one mile north of Alderwood Manor, the
Alderwood Water District has a standby well with a capacity of one
million gallons per day. Five wells in the Lynnwood area had draw-down
test discharges of 30,570, 400-800, 700 and 488 gallons per minute
according to well logs. Water table fluctuations are in conformance
with precipitation patterns.
Flora and Fauna
Terrestrial flora. The vegetation of the project area is made up
of a mosaic of natural and cultural plant communities. The natural
community consists primarily of native species that are the remains of
the original vegetation, or those which have reestablished themselves,
without the assistance of man, on disturbed sites. Natural communities
may contain introduced species. Cultural communities are those which
result from the more or less continuous activity of man and are typified
by, but not limited to, lawns, gardens, other landscaped areas, and
fields. Principal elements of these communities can be distinguished in
Figure II-8. Only natural communities are discussed here.
The exact composition of the natural communities and their species
diversity varies throughout the project area, and is dependent on the
severity and timing of disturbances, soil type and moisture, and exposure.
The upland forests are dominated by fir, hemlock, cedar, alder, and
maple. Other trees in the project area include pine, Cottonwood, yew,
birch, and spruce.
Understory shrubs exist in great diversity in the project area.
The most common species is salal. Vine maple, Oregon grape, red huckle-
berry, salmonberry, and red elderberry are common through the area.
Thimbleberry occurs along openings. Oceanspray and hazelnut are common
to drier areas, and Labrador tea, Douglas spirea, willow, devil's club
and red-osier dogwood are found in wet areas.
The variety and abundance of herbaceous species is highly variable
depending on soil moisture and shade. Irrespective of habitat, the most
common species and genera are sword fern, skunk cabbage, sedges, rushes,
horsetails, cattail, youth-on-age, buttercups, bleeding heart, fringe
cup, twinflower, bracken fern, and stinging nettle.
The marshy area along Swamp Creek above the intersection of Inter-
state Highways 5 and 405 is characterized by a discontinuous forest
coverage of primarily red alder with some western red cedar. The under-
story is made up of a dense, virtually impenetrable tangle of shrubs and
11-26
-------
herbaceous species dominated by willow, salmonberry, Douglas spirea, and
shrub-form red alder.
Aquatic flora. The larger lakes within the project area are reported
to have submersed and emergent aquatic macrophyte vegetation, particularly
along the shoreline and in adjacent wetlands, but species composition
has not been determined. Algae blooms exist in Stickney Lake and Martha
Lake.
Intertidal flora. The intertidal flora in the vicinity of the
outfall were surveyed on March 9, 1977 and consisted of fucoid algae
attached to the riprap around the outfall and on some rocks in the upper
intertidal. Since observations were made during the winter, several
species are not present. This area is reported to be one of the most
luxurious Intertidal beaches for several miles up or down the coast. It
is anticipated that several more species are present during the summer-
time. An eelgrass bed has been reported lying along the south shore of
Browns Bay which may project into the southerly 3,000 feet of the project
area shoreline.
Terrestrial and aerial fauna. A checklist of fauna likely to be
found within the project area has been assembled and is included in
Appendix C.
Aquatic fauna. Swamp Creek is utilized by coho, sockeye and chinook
salmon. Also found in Swamp Creek and its tributaries are cutthroat,
steelhead and rainbow trout, lampreys, sculpins, kokanee, and sticklebacks.
Martha Lake is regularly planted with legal size rainbow trout
prior to the opening of fishing season, and with fingerlings in May.
The lake will be restocked with rainbow trout and silver salmon next
year. Stickney Lake receives only a regular planting of legal size
rainbow trout prior to the opening of fishing season, and it also has a
natural population of bass, perch, crappie and bullhead catfish. Hall
Lake has not been planted with rainbow trout since 1970, and the Game
Department has no records of natural fish populations of either Hall
Lake or Scriber Lake.
Intertidal fauna. The intertidal fauna in the region of the out-
fall is typical of a sandy cobble beach. The intertidal life was
surveyed on March 9, 1977 and includes animals attaching to rocks and
piling stubs and burrowed into the beach. Observations by local resi-
dents were also solicited but no long-term studies were conducted as a
part of this project.
11-27
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
The marine life on the rocks consists primarily of mussels, bar-
nacles, snails, limpets, and associated species. The species found
burrowing in the beach were polychaete worms, and small shrimp-like
amphipods. No clams were observed in the intertidal between 0.5 and 10
feet above Mean Lower Low Water. A generalized survey of Puget Sound
shorelines indicates that geoduck (Panope generosa) occurs subtidally in
Browns Bay and that hardshell clams occur intertidally. Local residents
confirm that a substantial population of clams is present.
Marine fauna. A checklist of marine fishes likely to be found in
Browns Bay and adjacent waters has been assembled by listing species
reported in the Seattle-Central Puget Sound region ten or more times and
is included in Appendix C.
unique species. No threatened (rare or endangered) species are
known to inhabit the project area. Protected birds and wildlife likely
to be found in the project area include eagles, hawks, owls, songbirds,
Douglas squirrel and chipmunks.
Barriers and corridors. The existing patchwork urbanization of the
project area has long since destroyed any terrestrial wildlife corridors
that might have once existed. This urbanization has formed somewhat of
a barrier to free migration in and out of the wildlife habitat centered
around upper Swamp Creek.
Swamp Creek and its tributaries, as salmon spawning corridors, are
discussed in the fish and wildlife habitat section.
Agricultural crops. The Snohomish County Agricultural Extension
Service does not report any commercial farming or dairying in the project
area. No prime or unique farmlands have been identified within the study
area by the Soil Conservation Service.
Fish and wildlife habitat. The forested areas that remain scattered
throughout the patchwork urbanization of the project area provide food
resources and also cover and refuge for a variety of species which
inhabit the forest, the interface of the forest edge with fields and
urbanized areas, and the Swamp Creek and tributaries basins. The areas
immediately around Swamp Creek and its tributaries contain several
wildlife habitats including stream, marsh, forest, brush, and open
water. Several wildlife species of the project area have habitat needs
that can be satisfied only by wetlands areas. Examples of these species
include such animals as great blue herons, mallards and other waterfowl,
muskrats and other aquatic animals, and bullfrogs. The extensive brush
and forest cover created by the undeveloped nature of the creek bottoms
11-31
-------
probably provides a habitat for more wary wildlife species such as mink,
weasel, grouse, and piliated woodpecker.
Swamp Creek has been identified as a very important salmon-producing
tributary of the Sammamish River. The entire length of Swamp Creek is
utilized by chinook, coho, and sockeye salmon. In addition, coho salmon
also use Scriber Creek and two unnamed tributaries of Scriber Creek
(stream numbers 0062 and 0063, see Figure 11-7). The stream gradients
are very gradual in all utilized streams, and contain good pool-riffle
balance. The quality of gravel in the stream bottom is generally excel-
lent for spawning. In some areas stream channelization and landscaping
have seriously altered or destroyed the spawning value of these streams.
Other factors acting to limit the usefulness of these streams for spawn-
ing include low summer flows that preclude chinook salmon from ascending
the streams until mid-October and siltation from construction developments
altering stream bottom characteristics.
Noise
Existing Brown's Bay treatment plant site. The principal noise
sources in the vicinity are the existing treatment plant, Burlington
Northern and Amtrak trains, and vehicular traffic on local streets. Of
less significance is occasional noise from light aircraft, powered
residential maintenance equipment such as lawn mowers, and garbage
trucks.
Noise sources at the treatment plant include equipment within the
operations building plus a clarifier, a sludge thickener, a sewage grinder
and bar screen, and occasional trucks and automobiles. Of these, the
sources within the operations building produce the highest noise levels,
but are only operating during the daytime hours of 7:00 a.m. - 5:00 p.m.
Exterior steady-state noise contours from stationary on-site sources (the
operations building, sludge thickener, clarifier, sewage grinder, and bar
screen) are shown in Figure II-9 for the 7:00 a.m. - 5:00 p.m. hours when
all equipment is operating and for the 5:00 p.m. - 7:00 a.m. hours when
all equipment except that within the operations building (centrifuge, com-
pressor, and incinerator) is operating.
Noise sources within the operations building are the centrifuge,
two blowers, a pump, and the sludge incinerator. The door to the operations
building is normally left open during operating hours, thereby reducing
the effectiveness of the building as an acoustical enclosure. Acoustical
effectiveness is further reduced by the presence of slatted ventilation
openings.
11-32
-------
The remaining stationary on-site sources operate at night, and are
therefore significant because of the generally lower background noise
levels and greater noise sensitivity during nighttime hours. Except for
infrequent emergency repair vehicles and occasional autos using the site
as a secluded parking area during nighttime, vehicular traffic associated
with the facility occurs only during daytime.
Trains are a significant noise source affecting the residences west
of 76th Avenue. W. There are approximately 14 trains during daytime
(7:00 a.m. - 10:00 p.m.) averaging 39 cars per train and 8 trains during
nighttime (10:00 p.m. - 7:00 a.m.) averaging 42 cars per train.
Vehicular traffic occurs mainly on 76th Avenue W., 171st Street
S.W. and Talbot Road. Of these, 76th Avenue W. is most significant,
although it should be noted that traffic is very light on all streets in
the area. A traffic count at 76th Avenue W. on Monday, November 22,
1976, yielded only 70 autos and one school bus in the one-hour period
from 2:45 to 3:45 p.m., which is considered a representative daytime
traffic hour.
The occasional noise from aircraft, powered residential maintenance
equipment and garbage trucks was considered typical for a suburban resi-
dential area, and not of any unusual significance. Other typical
residential noise sources, such as dogs barking and children playing,
are also present. The 24-hour noise exposure in the community surround-
ing the treatment plant is shown in Figure 11-10. The levels are shown as
or day-night sound levels, which were computed on the basis of the
measured noise, operating hours of plant equipment, train schedules, topo-
graphic barrier effects, and estimated absorption due to vegetation.
Under State noise standards (WAC 173-60), the sewage treatment plant
would be a Class C noise source with the receiving residential property
designated Class A. Therefore the maximum permissible noise limits to the
residential properties would be 60 dBA. This level is presently being
exceeded as shown on Figure 11-10.
Natural Resources
Minerals. Huntting (1956) reviewed the metallic mineral resources
of Washington and describes no metallic mineral deposits in the project
area. Valentine & Huntting (1960) reviewed the nonmetallic mineral
resources of Washington and noted only peat and sand and gravel as being
present in the project area, but present no data on rate of use. The
entire project area is described as having a potential for supplying
sand and gravel, but the presence of the Vashon glacial till that covers
much of the area is a practical limitation on the commercial feasibility
of developing some sand and gravel deposits so covered. Rigg (1958)
11-33
-------
ROPERTY
LINE
1
SEWAGE GRINDER
& BAR SCREEN ?
60 dBA
CONTOURS FOR 5:00 P.M. • 7:00 A.M. ONLY
PROPERTY LINE-
Figure II-9
NOISE CONTOURS FOR ON-SITE STATIONARY SOURCE
11-34
-------
investigated peat resources in greater detail, and describes one peat
bog in the project area bordering the shores of Scriber Lake, and lying
in the Scriber Lake peat area (estimated at 20 acres). The peat bog
itself covers approximately 1.5 acres at the west end of the lake with a
smaller (0.5 acres) bog at the east end. The sphagnum peat lies two to
15 feet deep over lake sediments. Rigg gives no data on rate of use but
notes removal of peat from the last bog in 1953.
Fishing. As previously stated, Swamp Creek and its tributaries are
an important salmon-spawning stream system. The Washington Department
of Fisheries considers the Swamp Creek system to be one of the five
principal contributors to the Lake Washington coho salmon population.
The importance of Swamp Creek to regional fisheries has only recently
been appreciated; the first systematic salmon population tagging exercise
during spawning was conducted in 1976. However the yearly monetary
value of the Creek fish output is now estimated at $100,000.
Coho salmon utilize the entire length of Swamp Creek and some of
its tributaries, with most spawning occurring in the upper third of
Swamp Creek. From 1976 spawning tagging data, coho escapement is
estimated at 2,200 to 2,300 fish. The catch-escapement ratio for coho
is assumed to be at least 4:1 in Swamp Creek, so a total population of
coho in the Swamp Creek system is estimated at 10,000 fish. Production
is estimated by State Fisheries at 10 to 20 percent for the total Lake
Washington output and 2 percent of the Puget Sound total.
Chinook salmon use the deeper waters of lower Swamp Creek for
spawning. The 1976 escapement is estimated to be 50 to 60 fish, but
chinook runs are known to have been low in 1976 and a normal escapement
is estimated as approximately 100.
Sockeye escapement was estimated as 50 to 60 fish in 1976. Sockeye
runs are considered greatly depleted from the past and total population
is estimated at 50 to 60 fish.
Sport fish species such as cutthroat and steelhead trout and
kokanee also use Swamp Creek and its tributaries.
It must be understood that these population data are best estimates
based on a single season of population studies in the basin. Historical
data is not available. Population fluctuations should be expected from
year to year.
The Puget Sound waters offshore of the project area are noted for
concentrated sport salmon fishing, commercial salmon gillnet and purse
seine fishing and searun cutthroat sport fishing. Commercial outer
trawl bottom fishing is conducted in the far offshore waters. Subtidal
geoduck clams and intertidal hardshell clams are also reported present
as previously noted.
11-35
-------
rN
\
^6038
%
TALBOT RD.
r
Ldn < 55 dBA
Q- \
^ip
r1 & 2
IB
1 u
LU
C/5
CT
00
LU
Ldn > 65 dBA
Ldn < 55 dBA
^ NOISE MEASUREMENT POSITION
Figure n-10
EXISTING NOISE ENVIRONMENT
11-36
-------
Unique Physical Features
Stickney Lake. Stickney Lake is a natural lake of glacial origin
covering 19 acres at an elevation of 450 feet in the north portion of
the project area. It is relatively highly urbanized with 33 nearshore
homes on lots occupying 59 percent of the shoreline; public boat access
permits recreational use. The lake has a mean depth of 15 feet and a
maximum depth of 34 feet. The drainage basin area of 3.56 square miles
is large in relation to the size of the lake. Inflow is intermittent.
Outflow is via Swamp Creek. Stickney Lake constitutes a shoreline of
the state under the Shoreline Management Act of 1971 as it has an area
of approximately 20 acres.
Martha Lake. Martha Lake is a natural lake of glacial origin
covering 57 acres at an elevation of 455 feet in the northeast corner of
the project area. It is highly urbanized with 85 nearshore homes on
lots occupying 37 percent of the shoreline. Public boat access permits
heavy recreational use. The lake has a mean depth of 24 feet and a
maximum depth of 48 feet. The drainage basin area is only 0.80 square
miles. No inflow is visible. Outflow is poorly described but passes
through a swamp and unnamed creek, and then to Swamp Creek. Martha Lake
constitutes a shoreline of the state under the Shoreline Management Act
of 1971.
Hall Lake. Hall Lake is situated along the southwesterly project
area boundary at an elevation of 340 feet. It is a natural lake of
glacial origin, and is only six acres in area. Outflow is via Hall
Creek to Lake Ballinger. Public access is available. The 1973 Edmonds
East 7.5 minute USGS quadrangle map shows 17 nearshore residences and
other structures surrounding the lake. Due to its small surface area,
Hall Lake is not a shoreline of the state under the Shoreline Management
Act.
Scriber Lake. Scriber Lake is located one mile north of Hall Lake
at an elevation of 340 feet. It is a natural lake of glacial origin,
and covers only 3.4 acres. Outflow is via Scriber Creek to Swamp Creek.
The 1973 Edmonds East 7.5 minute USGS quadrangle map shows forest cover
surrounding the lake with marsh land lying to the north. Urbanized
areas lie within 250 feet of the lake shore. Due to its small surface
area, Scriber Lake is not a shoreline of the state under the Shoreline
Management Act.
Swamp Creek. Much of the study area lies within the Swamp Creek
drainage basin which includes one major tributary, Scriber Creek, and a
number of minor, unnamed tributaries. The basin is approximately ten
11-37
-------
miles long, extending from the vicinity of Paine Field on the north, to
Kenmore on the south. Its average width is approximately 2.5 miles and
its maximum width is approximately 4 miles in the center of the basin
where Scriber Creek branches to the west.
Swamp Creek is 10.9 miles long from its mouth at the Sammamish
River to its headwaters at Stickney Lake. The entire basin, including
all tributaries, contains 20.4 stream miles. Swamp Creek stream gradi-
ents generally range between 15 to 150 feet per mile, averaging approxi-
mately 40 feet per mile. The channel depression is small and often only
ten to twenty feet wide and two to five feet deep with a foot or so of
flowing water. Swamp Creek constitutes a shoreline of the state under
the Shoreline Management Act of 1971 from its mouth upstream to the
confluence of Swamp Creek and Scriber Creek.
Scriber Creek. Scriber Creek (Scriber Lake Creek) is the major
tributary of Swamp Creek. It joins Swamp Creek 4.5 miles above its
mouth. Three unnamed tributaries to Scriber Creek flow south joining it
at approximately river miles 1.7, 1.2, and 2.5. Scriber Creek is approxi-
mately 3.1 miles long, and drains about 6.5 square miles of the Lynnwood-
Alderwood Manor areas. Tts headwaters lie in Scriber Lake. Stream
gradients range from 20 to over 75 feet per mile, averaging approximately
50 feet per mile. The channel is generally small and narrow within a
deep gully. Scriber Creek is not designated a shoreline of the state
under the Shoreline Management Act.
Brown's Bay. The receiving water for the existing treatment plant is
a "Shoreline of Statewide Significance."
Peat bogs and wetlands. Probably the most important wildlife
habitat in the study area are the approximately 160 acres of red alder
swamp along Swamp Creek between Stickney Lake and the Interstate Highway
5 - 405 interchange. The wetlands definition stated in the Corps of Engi-
neers' rules and regulations as contained in the Federal Register, Volume
42, No. 138, Tuesday, July 19, 1977:
Those areas that are inundated or saturated by surface or ground
water at a frequency and duration sufficient to support, and that
under normal circumstances do support, a prevalence of vegetation
typically adapted for life in saturated soil conditions. Wetlands
generally include swamps, marshes, bogs, and similar areas.
South of Jefferson Way and Manor Road, a four-acre swamp lies 100
to 200 feet on each side of the stream for 0.2 to 0.3 miles. North of
148th Street S. W., a 20-acre swamp extends from Manor Road, east approxi-
mately 1,000 feet along 148th Street. South of 148th Street, the swamp
is restricted to a narrow band along the banks of Swamp Creek for a
length of approximately 1,500 feet, and covering approximately four
acres. A large, continuous swamp of approximately 132 acres, transected
by a number of slightly elevated roads and streets, begins in the vicinity
of 156th Street S. W., and continues downstream approximately two miles
to Interstate Highway 5. Below Interstate Highway 5, Swamp Creek enters
a low canyon and passes out of the study area with no additional wetlands.
II-351
-------
Human Environment
Population
Population. In the 1950's and 1960's Snohomish County experienced
a growth rate nearly twice that of King County to the south. In the
late 1960's, however, the rate of growth dropped precipitously. The
loss of aircraft industry related employment both in Seattle and Everett
areas was an important cause of this drop. Population has continued to
grow, although at a much slower pace than previously. Table II-2
illustrates trends through 1974.
On the whole, Snohomish County's incorporated and unincorporated
areas experienced a small 1.8 percent population gain between 1970 and
1976, rising from 265,236 to 270,100. Despite the natural increase of
13,531 during that period, there was a net out-migration of some 8,667
people.
The County's population now is nearly evenly divided between incor-
porated and unincorporated areas. Most of the incorporated areas were
either stabilized or lost population in the 1970-1976 period. Lynnwood
was the only city that consistently showed population gains every year,
growing from 16,919 to 20,150. Rates of new housing unit construction
dropped off in many of the unincorporated parts of the county, but all
census tracts in the Lynnwood study area showed net increases in the
number of dwelling units authorized during the 1970-1976 period. Figure
11-11 locates the census tracts within the study area together with the
Activity Allocation Model (AAM) districts established by the Puget Sound
Council of Governments (PSCOG). Table II-3 illustrates the trend, and
compares them to countywide trends.
The study area as a whole thus exceeded the countywide pace of
growth in dwelling units. Census Tracts 519 and 520, including a large
part of the Swamp Creek drainage area, showed especially high rates of
increase.
Population growth was not always proportional to the growth in
total numbers of dwelling units, however. Figures in the last two
columns of Table II-3 reveal that even though a net increase of dwelling
units occurred in all study area census tracts, population losses
occurred in four of them. These tracts are within or very near the
incorporated areas of Mountlake Terrace or Lynnwood. Apartment zoning
is located in those tracts, so that lower occupancy rates per unit would
help to account for the declines in population there.
The figures in Table II-3 reveal two other interesting patterns:
1. The census tracts that gained population were those tending to be
furthest from existing services - especially tracts 519 and 520 in
the Swamp Creek Drainage.
11-39
-------
TABLE II-2
POPULATION CHANGE IN THE SEATTLE-EVERETT
STANDARD METROPOLITAN STATISTICAL AREA
1950
1960
1970
1974
Avg. Annual Avg. Annual Avg. Annual
Change Change Change
1950 - 1960 1960 - 1970 1970 - 1974
No. % No. % No. %
Seattle-Everett
SMS A
of SMSA
844,572 1,107,213 1,424,611 1,413,300
King County Share 732,992
86.8%
Snohomish County 111,580
Share of SMSA 13.2%
935,014 1,159,375 1,146,200
84.4% 81.4% 81.1%
172,199 265,236 267,100
15.6% 18.6% 18.9%
26,764 2.7 31,740 2.6 -2,828 -0.2
20,202 2.5 22,436 2.2 -3,294 -0.3
6,062 4.4 9,804 4.4 466 0.2
City of Lynnwood Final EIS Alderwood Mall Shopping Center, 1975.
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
2. Population increases in the study area accounted for approximately
78 percent of the 1971-1976 population growth in all of Snohomish
County.
The first observation reflects known trends that apply to suburban
growth in most metropolitan areas, including availability of lower-cost
building sites than those found nearer to population centers, a desire
for rural surroundings within freeway reach of employment centers, the
assumption that urban services will eventually be available, etc.
The second observation verifies that the strategic location of the
Lynnwood study area, nearly midway between Seattle and Everett, with
ample freeway access to regional employment centers, is and will con-
tinue to be a powerful attraction for residential development as the
region's population grows.
Unincorporated portions of Snohomish County actually lost population
in the early 1970's, while most of the incorporated cities and towns con-
tinued to grow. The AAM districts in the study area, however, experienced
steady increases through 1975 as indicated in the selected statistics in
Table II-4.
TABLE II-4
POPULATION TRENDS IN STUDY AREA
AAM District
1961
1970
1975
7904
1440
2970
3240
7905
300
1200
1490
7906
680
1020
1350
7907
300
780
1230
7908
1630
3750
4080
7909
430
670
890
* Source: PSCG, Op. Cit.
Demographic characteristics of the population. 1970 Census figures
indicate that the study area's population is largely white and middle
class. Median family incomes in 1969 were above the countywide average
of $10,897 in all except three census tracts. The lowest median income
($9,441) occurred in Tract No. 419, located closest to Paine Field.
That tract also had the highest percent of nonwhite population (3.47
percent) of the census tracts in the Lynnwood Study Area. Nonwhite
population percentages in most of the other Study Area tracts were near
11-45
-------
or below the countywide level (1.68 percent). Educational levels,
measured by the Census in terms of median school years completed, were
near the countywide median (12.3 years) in all tracts.
Household characteristics. In the study area as a whole, a high
percentage of units are owner-occupied as shown in Table II-5. Four
census tracts, with substantial areas zoned for and developed with
apartments, showed high ratios of renter-occupancy relative to the rest
of the county. In all but three tracts, 1970 median values of housing
were higher than the countywide average, ranging from 4.9 to 26.0 per-
cent higher.
The amount of housing in apartment and mobile home units is an
indicator, although not an infallible one, of an area's transiency.
These housing tenure patterns also provide a basis for estimating future
densities and geographic distribution of development responsive to
future economic developments in the region. Table II-6 illustrates the
types of housing stock found in the study area in 1970.
There is a slightly higher proportion of apartment and mobile units
in the study area than in Snohomish County as a whole. Exceptionally
high percentages of apartments were found in Tracts 514 and 517, located
within or near Lynnwood's city limits and near the juncture of Interstate
Routes 5 and 405. Highest proportions of mobile homes were found in
tracts 418 and 419 nearest Paine Field, and in Tract 514 near Lynnwood
Center.
Economy. Economic trends of the Lynnwood study area and its sur-
rounding geographic areas are well summarized in the 1973 Snohomish
County Planning Department's Alderwood Area Plan as follows:
"The economic base of Snohomish County has shifted since 1950
from agriculture and extractive industries to service-oriented and
manufacturing industries. Lumbering, paper and allied products and
agriculture led the County in employment until the mid 1960's. The
subsequent establishment of the aerospace industry has radically
altered the economic function of the County, and has been the major
factor contributing to population growth. The County, once
economically independent of the Central Puget Sound Region, has now
become an integral part of the regional economy."
As described in the Alderwood Mall Shopping Center EIS, aerospace
industry employment fluctuated sharply in the past decade:
". . .A major factor in Snohomish County's recent growth was
the construction, in the mid-1960's, of the Boeing plant at Paine
Field for the production of 747 aircraft. The 747 assembly plant,
about 4 miles north of Lynnwood, began its buildup in 1967 and
reached its peak employemnt of about 25,000 workers in late 1969.
11-46
-------
TABLE II-5
OCCUPANCY CHARACTERISTICS OF STUDY AREA HOUSING UNITS - 1970
Census Tract
Percent
Owner
Occupied
Percent
Renter
Occupied
Percent
Vacant
Median Value
of
Owner Occupied
Units
418
73.2
23.1
3.7
19,900
419
40.3
42.0
17.7
18,500
501
76.8
16.9
6.3
22,800
502
90.6
7.7
1.7
30,000
503
87.1
9.4
3.5
29,300
504
69.6
24.0
6.4
23,400
513
86.9
10.4
2.7
21,800
514
30.0
51.3
18.7
19,500
515
61.8
30.2
8.0
22,000
516
74.8
21.9
3.3
22,500
517
51.9
30.3
17.8
23,200
518
69.7
24.8
5.5
22,200
519
82.0
13.7
4.3
22,200
520
76.8
13.2
10.0
23,200
STUDY AREA 69.4 22.8 7.8 22,900
TOTAL COUNTY 67.2 25.3 7.5 20,800
Source: U.S. Census 1970, as reported in Snohomish County Demographic Data,
Snohomish County Planning Department, 1977
Household size characteristics for the general study area are
available from the U.S. Census. In 1970 the average number of persons
per unit in owner-occupied housing was 3.6, while for renter-occupied
units, it was 2.8.
11-47
-------
Apa:
'erc<
;ing
33
33
33
10
2
4
20
4
63
28
15
41
23
13
12
23
21
TABLE I1-6
HOUSING STOCK IN STUDY AREA - 1970
Year-Round Single Family
Census Vacant Seasonal Dwelling Dwelling Mobile Multiple Family
Tract & Migratory Units Units Homes Dwelling Units
417
0
1,625
1,206
291
128
418
1
2,127
1,624
279
224
419
0
1,967
1,987
217
763
501
0
622
560
5
57
502
0
710
693
0
17
503
1
1,348
1,297
2
49
504
0
3,225
2,547
6
672
513
0
1,290
1,232
20
38
514
0
1,978
726
128
1,124
515
0
1,392
1,003
31
358
516
0
1,719
1,457
47
215
517
0
2,386
1,397
62
927
518
0
1,091
839
70
182
519
8
6,231
5,392
530
309
520
1
420
370
37
13
LYNNWOOD
STUDY AREA
11
28,131
22,330
1,725
5,076
TOTAL
COUNTY
1,381
88,056
69,769
3,954
14,333
Source: Department of Commerce, Bureau of Census, Puget Sound Governmental Conference
-------
After 1969, a combination of factors affecting the airline industry
led to substantial cutbacks in 747 production and a sharp drop in
local employment ..."
Unemployment peaked in the Seattle-Everett SMSA in 1971. Out-
migration of the labor force and gradually improving economic conditions
combined
to reduce the metropolitan area's
levels
of unemployment in
succeeding years, as shown
in Table II-7.
TABLE II-7
SEATTLE-EVERETT SMSA
RESIDENT
LABOR FORCE AND
EMPLOYMENT
(THOUSANDS)
Resident
Unemployment
Civilian
% of
Year
Labor Force
Employment
Total
Labor Force
1967
530
511
19
3.6
1968
570
546
24
4.2
1969
599
570
29
4.8
1970
629
568
61
9.7
1971
597
523
74
12.4
1972
610
544
66
10.8
1973
614
567
47
7.7
1974
647
603
44
6.8
1975
675
613
62
9.2
1976
701
638
63
9.0
(a) Adapted from State of Washington (1974b), by Larry Smith & Co., for
Alderwood Mall Shopping Center EIS, Op. Cit.
The economy of the study area is heavily dependent on commuting to
employment centers in Seattle and Everett. Table II-8 illustrates the
geographic distribution of jobs held by study area residents in 1970.
11-49
-------
Census
Tract
TABLE II-8
PERCENT OF JOBS
BY EMPLOYMENT LOCATION AND CENSUS TRACT, 1970
Employees*
Seattle
Other
King
County
Everett
Other
Sno.
County
Outside
Of SMSA**
417
1,780
30.1
10.1
31.6
25.6
2.6
418
2,330
16.7
8.7
51.0
23.0
. 6
419
1,637
12.8
7.6
55.1
21.7
2.8
501
668
27.4
21.6
23.5
27.5
0.0
502
957
33.5
13.7
14.0
38.1
.7
503
1,639
45.1
6.4
8.4
37.5
2.6
504
3,718
44.3
11.9
9.6
33.1
1.1
513
1,612
44.5
18.5
9.9
26.7
.4
514
1,778
34.2
8.7
21.6
33.6
1.9
515
1,462
46.2
12.8
10.4
28.7
1.9
516
2,096
37.1
14.3
17.0
29.7
1.9
517
2,398
34.8
11.5
16.4
34.2
3.1
518
1,130
41.6
7.7
18.2
30.6
1.9
519
7,251
43.5
18.1
10.0
25.8
2.6
520
352
29.5
15.3
31.0
22.2
2.0
TOTAL
COUNTY
88,515
23.7
8.7
34.8
30.6
2.2
*Total employees reporting place of work
**Standard metropolitan statistical area (Snohomish and King County)
SOURCE: Department of Commerce, Bureau of Census
Job commuting orientations illustrated in Table II-8 are quite
mixed throughout the study area, although two tendencies stand out
clearly. One is the higher-than-average Seattle-King County connection
of households in the southerly tracts, especially those close to Inter-
states 5 and 405 (Tracts 503, 504, 513, 515, 518, and 519). Another is
the strong Everett-Snohomish County orientation of the two northernmost
census tracts, 418 and 419. Very general conclusions from these obser-
vations suggest a tendency for population to locate in reasonable proximity
to jobs. This general maxim must be qualified, however, especially in
this part of the Seattle-Everett corridor; people employed at one or
another of the Boeing plants often seek compromise locations fairly
accessible to Paine Field, Renton, and Seattle's Boeing Field, so that
11-50
-------
in case of reassignment to a different work location, a household move
will not be necessary. With ready access to 1-5 and 1-405, most of the
study area would fall into this category. Attractiveness for residential
development therefore does not appear to depend solely upon employment
levels in the Everett or Seattle areas, but rather more generally upon
economic health of the metropolitan area as a whole.
Occupation and incomes. According to the employment profile
described in the Alderwood Mall Final EIS, 1970 Census figures revealed
that the general study area resembles the average profile for the Seattle-
Everett SMSA. There were lower proportions of people in professional
and technical, operative, laborer, and service worker occupations than
the SMSA averages. On the other hand, proportionally more managers,
administrators, sales persons, craftsmen and foremen lived in the study
area than in the SMSA as a whole. Median family incomes ($12,030 in
1969) were similar to the Seattle-Everett SMSA median ($11,676).
Land Use
Land use plans. Land use plans for the study area exist in varying
degrees of detail. The Lynnwood Comprehensive Plan map designates four
different kinds of residential use, four commercial, two industrial, and
various kinds of public facilities. The planning area extends outside
the present city limits of Lynnwood.
That portion of the study area in Snohomish County's land use plan-
ning jurisdiction is most subject to growth and change, since the commu-
nities of Lynnwood, Brier, and Mountlake Terrace area already are
approaching their probable growth saturation levels.
The following general planning goals adopted by the Snohomish Board
of County Commissioners in 1973 provide some indication of how the growth
and development of the unincorporated parts of the study area will be
guided:
1. Community character will remain primarily residential with
stress on single-family residential development in the unincor-
porated areas surrounding Lynnwood. Various densities of single-
family dwellings are encouraged, depending upon factors of
accessibility and natural site conditions. The most accessible
sites, in terms of both transportation and utilities, are expected
to be used for high-density single-family residences or low-density
multiple-family structures.
2. Commercial development is to be directed toward a scale
appropriate to the business opportunities in the Lynnwood area.
11-51
-------
Small agglomerations of commercial activities are encouraged,
particularly in areas serviced by utilities, but strip commercial
developments are expressly discouraged. A single, large, comparison-
goods facility (The Alderwood Mall) is also included in the area
plan. Convenience needs of the population and provision of a
limited employment base is desired.
3. Transportation facilities will support the interrelationship
between single-family residential development, convenience types of
retail and service establishments, and natural site conditions.
Pedestrian, bicycle, and horse trail would provide links to effi-
cient public and private vehicular transportation facilities.
4. Community facilities will be provided so future growth is
shaped in the most efficient, economical, and least disruptive
manner for the community.
5. Intrinsic landforms, watercourses, and vegetation conditions
within the planning area will be enhanced and maintained.
The Alderwood Area Plan further recommends that along Swamp Creek, all
connections to the interceptor be limited to locations in close proximity
to areas of substantial dwelling unit densities.
The combined land use plan for the study area is presented in
Figure 11-12. There are some discrepancies between this map and the
Lynnwood Comprehensive Plan Map, adopted June 9, 1975. These discrepan-
cies occur chiefly in the unincorporated area east of Lynnwood. Evidently
such interpretation variations reflect differences between the City of
Lynnwood's judgment about the best use for these presently-uncommitted
areas and opposing judgments of county officials at this time. Some alter-
ations in these land uses may result from developments envisioned by the
as yet incomplete Paine Field Airport Master Plan.
The State Department of Natural Resources' Water Resource Maps show
Brown's Bay as zoned for recreation and open space. The City of Edmonds'
Shoreline Management Plan covers that portion of Puget Sound which includes
the Lynnwood sewage treatment plant, however the plant is not specifically
mentioned therein and no other associated regulations are known to apply.
The community policy, as stated in the Shoreline Plan, is to avoid environ-
mental degradation and to encourage public access. A properly operating
sewage treatment plant would therefore be a compatible land use, however
the present plant does not always function within permitted effluent stan-
dards, therefore, it may occasionally cause minor environmental degradation.
The lower portion of Swamp Creek falls under the Snohomish County Shore-
line Management Plan which recognizes construction of the trunk sewer under
strict environmental controls as a compatible land use.
11-52
-------
Present land use trends. There are some lands, especially in the
lower part of the Swamp Creek study area, that are practically undevelop-
able. They are shown as "public use areas" along the creek, and occur in
large, wooded tracts elsewhere in the study area as a whole. Due to
commitment to preserve these areas as open space and the difficulty of
developing them due to steep slopes and soil conditions, only limited
urban growth may occur in these areas, as anticipated in the plan.
The unincorporated area known as the "Alderwood Planning Area"
within Snohomish County, bounded by 1-5, 1-405, and the King-Snohomish
County line is estimated to be 71 percent undeveloped.
11-53
-------
~ residential
multi-family
commercial
industrial
public use
1 water shed
T
Figure 11-12
COMBINED LAND USE PLAN
11-54
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
Table II-9 describes the Alderwood Planning Area land use.
TABLE II-9
ALDERWOOD PLANNING AREA LAND USE
Land Use
Alderwood
Planning Area(a)
% of Area
Approximate
Acres
Residential
12.00
660
Commercial
4.00
220
Industrial
1.00
55
Public
3.50
190
Streets
9.00
495
Undeveloped
64.50
3,550
Resources
6.00
330
Water
TOTAL
100.00
5,500
Snohomish County Planning Department (1973)•
The incorporated areas in Lynnwood, Mountlake Terrace, and Brier,
by contrast, are largely sewered and more fully developed, leaving only
about 30 percent of the areas undeveloped. It is expected that since
those incorporated communities are approaching their saturation points,
growth pressure will be directed increasingly toward the unsewered
Alderwood Planning Area and other parts of the Swamp Creek drainage
area. Areas most accessible to 1-405, 1-5, and SR-99 are likely to
develop soonest, since land access is difficult, and it is expensive to
develop many parts of the Swamp Creek Drainage Area.
The unincorporated, uncommitted portion of the study area (Swamp
Creek Drainage) is characterized by small scattered pockets of subdivisions
with access off the several arterial routes traversing it. Few of the
residential access streets connect with others to form a grid network,
so there are no large tracts of housing emerging at present.
Commercial activity is distributed notably in the Lynnwood retail
area on 196th near 1-5, and along SR-99. The Alderwood Mall site is
committed in the Lynnwood plan and zoning ordinance to major retail
development also. The amount of commercial space involved in these
three areas makes it unlikely that any other competing concentrations
will be proposed or allowed in the foreseeable future. The Alderwood
Mall site will undoubtedly become an intensively used commercial complex
regardless of whether the proposed shopping center configuration is
finally implemented by its private sponsors. The major commercial area
commitments in the study area appear to be well established and recognized
11-57
-------
in the official planning documents. The only other kind of commercial
establishment that can be anticipated is in the form of convenience
shopping areas, all of low intensity. Small centers of this kind,
featuring gas stations and food markets, are distributed throughout the
unincorporated area.
Acreages in the study area are used for suburban-estate style
housing, frequently with pasture for domestic livestock. Little of the
land could be called agricultural in the commercial sense of the term.
The future use of these small scattered pastures and woodlots depends
heavily on whether or not sewer service is introduced, to allow denser
development.
The existing zoning is consistent with the land use pattern. The
undeveloped, unincorporated portions of the study area are zoned rural
residential. The 1990 Land Use Plan indicates that the study area will
be permitted a higher density residential use than is presently permitted.
Zoning. The Lynnwood Zoning Code was adopted by ordinance in 1964
and has been amended by numerous ordinances since then. For utilities
planning, the most important aspect of the zoning ordinance is the
extent of various allowed uses and the gradations of allowed density
within each use. Table 11-10 is an excerpt from the Lynnwood Zoning
Ordinance text to show the wide range of densities accommodated in
various zones.
Table 11-10
LYNNWOOD RESIDENTIAL ZONING CLASSIFICATIONS
Minimum
Old
Essential Uses
Symbol
Description
Lot Size
Symbol
Single Family
RS-12
Suburban Residential
12,000 s.f.
*R-12
Residential
RS-9
Residential District
9,600 s.f.
*R-9
Districts
RS-8
Residential District
8,400 s.f.
*R-8
RS-7
Residential District
7,200 s.f.
R-7
Multi-Family
RD-8400
Duplex Residential-
Residential
Medium Density
8,400 s.f.
MR-1
Districts
RM-8400
Multiple Residential-
(RMM)
Medium Density
8,400 s.f.
IR-2
(RMH)
High Density
(None Specified)
(RMHR)
High Rise Multi-Family
(None Specified)
11-53
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
There is a substantial range of densities represented in these
classifications from three dwelling units per net acre (RS-12) up to
approximately 43 per net acre (RMHR).
The Lynnwood Zoning Map Figure 11-14, is essentially consistent
with its land use plan. Note that certain areas have been designated
as environmentally sensitive.
Housing. Lynnwood's zoning map corresponds rather closely with its
comprehensive plan map, but there is not enough detail on the actual
density of the city's single-family housing zones to determine zoned
holding capacity.
According to the existing Lynnwood zoning map, nearly 43 percent of
the city's total 3,515-acre area is set aside for single-family use. Of
these, approximately 62 percent or 942 acres were developed in 1973,
leaving approximately 570 net acres (streets, public use already deducted)
still available. Assuming that all of those acres were zoned at the RS-
8 density, some 2,955 additional units would theoretically be accommo-
dated in Lynnwood's single-family zones as of 1973. As for apartments,
its 236 acres of multi-family zone were 65 percent developed in 1973,
leaving 81 acres undeveloped. Since most of this appears on the zoning
map to be "medium-density" multi-family, the additional capacity of
those 81 acres is about 2,076 dwelling units.
Lynnwood's actual population growth between 1973 and 1975 was 547
people. The estimated population capacity of the two residential zones
described above is about 16,200 people. It appears that Lynnwood's
residential zoning allows some 15,650 additional population.
Building Department records. The value of this data is only to
indicate general trends of development investment, since there is little
geographical information to pinpoint where the development is occurring.
A comparison of October 1976 with earlier data is of interest
because it indicates a change of emphasis from single-family to multi-
family investment. From 1970 through the first six months of 1974,
approximately 80 percent of building permits issued were for single-
family units. From January to November 1975 approximately 74 percent of
the 84 residential permits issued were for single-family construction.
In the January through September period of the following year, 1976,
only 16 percent of the total 183 residential permits were for single-
family construction.
11-61
-------
The 1976 shift toward emphasis on multi-family construction is
dramatic, but it is too soon to tell if it was a unique year rather than
the start of a trend. The possibility of a long-term trend is there
because of low apartment vacancy rates in the region that tend to attract
investment. Associated with the strong market for apartments is the
trend toward more households formed per capita (more young people and
elderly people in independent households) and the increasing difficulty
of financing a single-family dwelling. If these factors remain valid in
coming years, pressure will mount to create more multi-family zones,
probably more concentrated than the past trend toward dispersed single-
family subdivisions.
Occupancy rates. Occupancy data is available from the Lynnwood
Postal Area, surveyed by HUD in 1974. The survey reported a vacancy
rate of 3.9 percent for apartments and 3.1 percent for owner-occupied
residences. Table 11-11 depicts these conditions.
TABLE 11-11
LYNNWOOD POSTAL AREA VACANCY SURVEY
FEBRUARY 21 - MARCH 7, 1974
Vacant
Structure
Total Units
Number
Percent
New
Residences
10,299
321
3.1
55
Apartments
3,034
118
3.9
0
Mobile Homes
972
74
7.6
NA
Units under
Construction
Residences
Apartments
57
0
-
-
-
From U.S. Department of Housing and Urban Development (1974).
Vacancy rates reported by the annual postal survey have exhibited a
steady decline in Lynnwood and most areas of the metropolitan community
over the past six years. Table 11-12 summarizes these rates.
11-62
-------
TABLE 11-12
HOUSING VACANCY RATES
POSTAL VACANCY SURVEY - SEATTLE, EVERETT, TACOMA
1971
1972
1973
1974
1975
1976
Everett
8.1%
8.1%
6.6%
6.4%
4.2%
2.2%
Lynnwood
9.8
6.3
4.1
3.6
2.5
1.5
Edmonds
5.2
4.1
3.5
3.1
2.0
1.7
Mountlake Terrace
5.0
6.0
8.0
5.7
1.8
2.5
Arlington
5.4
6.5
6.2
5.7
4.8
3.1
Marysville
6.0
7.8
8.2
5.1
3.8
2.2
Snohomish
3.0
3.6
3.9
3.4
3.0
2.0
Monroe
4.8
6.4
3.8
4.4
3.5
3.0
Snohomish County
6.9
6.5
5.6
4.3
3.3
2.1
King County
5.8
5.5
4.7
3.5
2.9
2.4
Pierce County
4.0
4.2
4.2
2.9
2.5
2.6
Table 11-12 shows Lynnwood with the lowest vacancy rate among
Snohomish County incorporated cities which suggests considerable poten-
tial for new residential construction within the study area, were
utility service available.
Aesthetics. Although a number of rating systems have been developed,
subjective evaluations like aesthetics are necessarily a matter of
opinion. Nevertheless, the rolling, wooded terrain within the study
area offers sufficient variety to provide what is usually considered an
acceptable natural setting. The presence of several substantial lakes
and small streams increases the appeal, as shown by the concentrations
of development at the localities. The rather hilly, rough terrain has
also contributed to the irregular street pattern, often with winding
alignments.
11-63
-------
Development within the sewered area has followed the course typical
within the northwest. Street patterns are basically rectangular. Com-
mercial areas tend to be in strips. Most construction is modern of the
usual functional, economical architecture. Residential areas have tended
to retain a substantial portion of the natural tree cover.
Unsewered areas have developed less uniformly. Lots are frequently
large with natural landscaping retained, though several tract developments
and mobile home parks do exist. Due in part to the undulating terrain
and dense forest native to the northwest, the Swamp Creek basin offers
many locations that seem remote and isolated from the urban world.
Transportation
Street and arterial systems. The street and arterial systems in
the study area are shown on Figure 11-15, which also summarizes the
weekday traffic volumes as provided by the Lynnwood Engineering Department
and the Washington State Highway Department.
Two major highways comprise the backbone of the road network in
this study area. SR5 provides the study area, as well as the greater
Seattle area, with a high capacity limited access facility. This route
serves commuter traffic, intercity and interstate motorists. Access to
SR 5 is provided at 196th Street S.W., 164th Street S.W., and Post Road.
To the west, SR 99 provides another north-south highway. SR 99 is not
access controlled and serves commuter traffic as well as local traffic.
Thirty-sixth, Forty-fourth and 76th Avenues West also provide city and
county north-south arterials for local traffic.
Primary east-west arterials are provided by 196th Street S.W.,
164th Street S.W., and Post Road. Southeast of the study area SR 405
provides a freeway link with the Bellevue-Renton area. To the west,
existing SR 525 connects the study area with Mukilteo and the Mukilteo
Ferry Terminal.
The following guidelines define the circulation system for this
area:
Snohomish County Transportation Plan
Lynnwood Comprehensive Plan
Urban Arterial Board Plan
The Snohomish County Transportation Plan is a coordinated regional
plan, which presents a recommended 1990 system for freeways and arterials.
As indicated, Interstate Highways 5 and 405 are the major freeway facili-
ties and traffic carriers serving the area.
11-64
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
The Urban Arterial Board Plan and the comprehensive plan for the
City of Lynnwood follows basically the same concept as the Snohomish
County Transportation Plan.
The Washington State Department of Highways is now developing a
traffic management and surveillance system for Interstate Highway 5
which would provide metered (controlled entry) ramps. This system will
provide controls and information to motorists to optimize the traffic
flow on Interstate Highway 5.
Airports. Paine Field Airport, located north of the study area,
provides Snohomish County with an all-purpose airport. It has the
capacity to serve the largest commercial aircraft. The Boeing 747 plant
leases this facility to deliver jumbo jets.
Ferry service. The Mukilteo Ferry Terminal in Mukilteo is located
approximately five miles northwest of the study area. This system
ferries passengers and autos to and from Whidbey Island.
Public transit. The 1975 Legislature authorized creation of a less
than countywide transit district, known as "Public Transportation Benefit
Area" (PTBA). The Snohomish County Public Transportation Benefit Area
encompasses Marysville, Snohomish, and all of the South Snohomish County
south of the City of Everett, and extends east to the Everett/Bothell
highway. This Benefit Area includes all the most heavily populated part
of Snohomish County and excludes Everett which has a transit system.
The Snohomish County Public Transportation Benefit Area Corporation,
owns and operates the system. This Corporation has been established and
consists of nine members: The Snohomish County Commissioners, the
Council members from Snohomish, Edmonds, Mountlake Terrace, Lynnwood,
Marysville and Brier.
Residents within the area will pay approximately 15% of the $10.4
million in capital costs that would be required between 1977 and 1980 to
implement the plan. Approximately 85% would be provided by state and
federal matching funds.
The Snohomish County Public Transportation Benefit Area Corporation
is authorized to levy a three-tenths of one percent sales tax in the
county to finance public transportation within the Benefit Area.
Matching money anticipated from the state and federal sources will
benefit the local economy and permit the majority of local dollars to be
spent for operations and improvement of the transit service and will
allow a low cost transit fare to be maintained which will benefit all
people.
11-67
-------
There are presently four routes in operation with intra-area and
King County transfer point facilities.
Under the proposed improved and expanded system, the following four
levels of service will be provided:
1. Local Service - meeting local travel needs within communities and
urbanized area.
2. Regional (Intra-County) Service - connecting cities and towns
within the PTBA together and to major employment, shopping, educational,
cultural and recreational opportunities.
3. Express (Inter-County) Service - connecting Snohomish and King
Counties.
4. Specialized Services.
a) Direct service to major centers like Boeing Plants and Universi
of Washington.
b) Events at the Kingdome, Monroe Fair and other places.
c) For handicapped persons in South Snohomish County.
d) Half-fares for Senior Citizens during off-peak, hours.
Proposed system facilities to be provided include additional routes,
100 bus shelters, 400 bus stop signs, 9 park and ride lots, 50 transit
coaches, maintenance and administrative facilities and a customer assist-
ance office. Figure 11-16 illustrates the principal routes within the
study area.
Public Services and Utilities
Education. Three school districts are located within the study area
The Edmonds School District No. 15 lies south of 148th Street S.W., and
Mukilteo School District No. 6 lies north of 148th Street S.W. Community
College District No. 5 (Edmonds Community College) also encompasses the
study area.
Edmonds School District No. 15 serves most of the Lynnwood study
area, with some students attending Northshore District Schools at the
Senior High level. Generally, these schools are newer than the average
for Snohomish County. The elementary schools are typically on 10-acre
sites, ample when compared with schools of comparable enrollment in
older cities such as Seattle. Most of the elementary schools have a
11-68
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
designed capacity of 600 students, which provides surplus space, con-
sidering the continually shrinking enrollments prevailing in most schools
since the 1969 peak year. There is enough surplus space in the district's
schools to afford room even for an increasing total population in the
study area. Bussing to even out enrollments in various schools is a
common practice in the suburban school districts serving low density
areas.
Junior high and high schools in the Edmonds District also are new
and built on large sites with ample capacity to expand if necessary.
Declining elementary school enrollments in the past decade indicate that
these higher-grade classrooms will also have surplus capacity by compari-
son with accepted standards.
For the Edmonds School District as a whole, enrollment is expected
to decline in the short run, from 23,572 in 1970 to 19,500 in 1980, then
increase again to 22,000 in 1985.
Figure 11-16 indicates the location of operating school facilities
in the planning area as of 1975. Many of these facilities in the unincor-
porated Swamp Creek area are new and evidently were built with the long-
term expectation that residential development in the surrounding area
would generate increasing enrollments.
Parks and recreation. The Combined Land Use Plan (Figure 11-12)
indicates substantial areas set aside for public use. Most notable of
the spaces with recreational open space potential is the linear area
shown along the course of Swamp Creek south of the I-5/I-405 junction,
and areas near the 1-5 right-of-way north of that junction. Apparently
the latter is designated as open space because of the buffer effect it
will provide between freeway and other uses. In the northwest (Meadow-
dale) part of the study area, in and near Lynnwood's corporate limits,
other large public open spaces are designated. These are presently
wooded and probably are difficult to develop because of the terrain and
soil conditions that typically exist in the highlands overlooking Puget
Sound.
Figure 11-16 shows curiously little dedicated park space in the
usual urban sense of the word. There is apparently a heavy investment
in school facilities and these all seem to have ample athletic area
associated with them. Public open space in the planning area may
eventually be located mostly in conjunction with school district proper-
ties and in the several natural resource-oriented areas previously
described. However, this possibility is complicated by budget problems
within the local schools which are beginning to sell unused real estate.
There are three main recreational facilities in the general area.
The Lake Serene public boat launch is located on the westerly shore of
Lake Serene. Lake Stickney and Martha Lake both have access for fishing
and general public use.
11-71
-------
Public water supply. The entire project area is served by the
Alderwood Water District of Lynnwood, Washington. The City of Lynnwood
purchases water from the Water District and sells directly to all customers
within the city limits. All supply, distribution, and service systems
are metered. The majority of services are residential, with some commer-
cial services. There are virtually no industrial users. Most water,
therefore, is used for household purposes and lawn irrigation. Highest
peak demands occur in the summer from lawn sprinkling. Table 11-13
shows average and maximum demands for the recent past and includes
projections for the near future. Table 11-14 shows storage facilities
within the entire water district, along with projected future facilities.
The two 28 million gallon storage reservoirs provide the reserves against
transmission failure from the supply and permit reduced sizing in the
supply transmission system. An additional terminal storage reservoir is
presently under construction.
Water supplies are purchased by the Alderwood Water District from
the City of Everett which has its sources in Spada Lake and Lake Champlain
(Sultan River drainage basin). Chlorinated water is pumped through two
30-inch mains from the Everett reservoir to the Alderwood Water District,
which rechlorinates all supplies entering and leaving its reservoirs.
Water is not presently filtered, but the City of Everett has begun
planning the construction of a filtration plant.
The pumping capacity of the Everett pumping station was measured at
21.5 million gallons per day with all four pumps running (July, 1970).
Two standby wells with a capacity of 2.5 million gallons per day provide
a total capacity of 24.0 million gallons per day (Erikson, 1970; Blunck,
1976).
The Alderwood water supply complies with the Interim Primary Drinking
Water Regulations. The Water District is participating with the City of
Everett in construction of a filtration plant so the system will comply
with the Final Regulations.
Emergency services. The study area is served by Snohomish County
Fire Protection District No. 1 and the City of Lynnwood Fire Department.
Police services are provided by the City of Lynnwood Police Department
and the Snohomish County Sheriff's Department, with a branch office in
Lynnwood. There are four hospitals in the general area, two in Everett,
one in Lynnwood, and one in Edmonds. Ambulance service is provided from
Lynnwood and Everett.
Utilities. Six utility companies serve the general study area.
Snohomish County PUD provides electrical service. Pacific Northwest
Bell and General Telephone provide telephone service. The Alderwood
Water District and the City of Lynnwood provide water and sanitary
sewers and the Washington Natural Gas Company provides natural gas for
household and industrial use.
11-72
-------
TABLE 11-13
ANNUAL RECORDED WATER DEMANDS
Average
Number
Meters
Persons
Daily Demand
Year
Per
Meter
Aver.
Day
*MGD
Peak
Day
MGD
Aver .
Meter
**GPD
Peak
Meter
GPD
Aver.
Per Cap.
GPD
Peak per
Capita
GPD
1957
9600
3.6
2.38
4.66
248
485
69
135
1958
10200
3.6
3.10
8.35
304
819
84
228
1959
10900
3.6
3.25
8.85
298
810
83
225 {
1960
12200
3.6
3.52
9.70
287
795
80
220 I
1961
13500
3.6
3.95
292
81
;
»
1962
14900
3.6
4.50
302
84
;
;
1963
16200
3.6
4.61
11.00
285
680
79
189
1964
17200
3.6
4.58
11.10
267
645
74
179 '
1965
18000
3.7
5.50
13.80
305
768
82
208 ;
1966
18800
3.7
5.62
14.60
299
778
81
210 ;
1967
19900
3.7
7.76
17.70
390
890
105
240 i
1968
21100
3.7
7.57
20.20
358
958
97
259 ;
1969
21900
3.7
8.43
19.00
385
870
104
235
1970
24370
3.7
9.22
25.20
390
1035
103
272
PREDICTED DEMANDS
1980
32400
3.8
14.50
34.00
448
1050
118
276
1990
38400
3.8
18.60
40.70
485
1060
128
279
2000
44500
3.8
23.40
47.60
525
1070
138
281
I
* MGD=Million gallons per day.
** GPD=Gallons per day.
11-73
-------
TABLE 11-14
STORAGE FACILITIES WITHIN THE ALDERWOOD WATER DISTRICT
Lochtion
1 Total Storage
Size Date TyPe of
MG Constr. Storage
Peak Demand
MG
Terminal
MG
35th Ave. W.
& 152nd SW
40th Ave. W.
& 185th SW
40th Ave. W.
& 185th SW
228th SW
& 4th Ave. W
35th Ave. W.
& 152nd SW
35th Ave. W.
& 152nd SW
2.0 1951
3.0
2.77
2.4
28.0
1957
1960
1961
.1962
2.0 1965
Terminal
Peak
Demand
Peak
Demand
Peak
Demand
Terminal
Peak
Demand
*0.5
3.5
6.27
8.67
8.67
*10.17
2.2
2.2
2.2
2.2
30.2
*30.0
35th Ave. W.
& 157th SW
28.0 1969
Terminal
FACILITIES UNDER CONSTRUCTION
10.17
58.0
35th Ave. W.
& 157th SW
20.0
1976
Terminal
10.17
78.0
PROJECTED FUTURE FACILITIES
r 224th S.E.
& 4 5th Ave. E.
' 228th S.E.
& 45th Ave. E.
j 156th St. S.E.
! & 73rd Ave. E.
2.0
3.0
28.0
1976
1978
1985
Peak
Demand
Peak
Demand
Terminal
**5.90
8.90
78.0
78.0
.90 106.0
* Six wooden water tanks constructed during 1940 to 1951 totaling
700,000 gallons capacity were removed from service and dismantled
prior to 1965.
>* Tanks at 40th Ave. W. & 185th S.W. to be sold to Lynnwood.
11-74
-------
Sewerage System Description
Service area. The City of Lytmwood sewerage system consists of a
primary sewage treatment plant, four pumping stations, and more than 100
miles of sewer pipe from 6 to 24 inches in inside diameter. The sewerage
system provides collection transportation and treatment facilities for
the sewage produced by a predominately residential population. The
collection system of the City of Lynnwood extends from 164th Street
Southwest to 216th Street Southwest, and from 76th Avenue West to 26th
Avenue West, comprising an area of 3,720 acres. In addition, the
collection system serves 1,000 acres outside the Lynnwood City Corporate
Limits from Edmonds and the Alderwood Water District. Thus, the present
service area covers approximately 4,720 acres, much of which is not yet
fully developed. The City of Brier is served by a sewerage system connected
to Metro through the Northeast Lake Washington Sewer District. However,
that portion of Brier within the study area is not presently sewered.
The current population of the City of Lynnwood is estimated at
20,150 persons and the estimated population within the boundaries of the
present collection system is 24,000 persons.
The collected sewage is transmitted through subtrunk sewers and
pumping stations to the major sewer trunk in 76th Avenue West, which
carries the collected sewage to the treatment plant. The system was
designed exclusively for sanitary sewage and is not a combined system.
Storm water is not intended to be intercepted by the system.
There are no industrial waste discharges to the system. The
system is designed to collect, transport, and provide primary treatment
for a domestic sanitary sewage. Commercial development is limited to
stores, shopping centers, filling stations, and schools normally associ-
ated with a residential community. Industrial development is minimal
and consists of manufacturing facilities which are not large water users
and do not produce industrial waste discharges.
Collection system. The treatment plant, four pumping stations, and
seventy-five percent of the trunk and collector system were constructed
in 1961 and 1962 with the remaining twenty-five percent of the collector
system being constructed in increments, in 1963, 1966, 1969, 1970, 1972
and 1976. The overall system, based on a 30-year plant life and 50-year
sewer line life, has an average remaining economic life of 35 years.
The gravity sewer system is constructed of concrete pipe with precast
concrete manholes and totals about 526,000 lineal feet. Pressure mains
are cast iron or ductile iron totaling about 12,300 lineal feet.
Figure 11-17 illustrates the sewerage piping systems serving the study
area.
11-75
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
Treatment plant. The existing primary treatment plant has a rated
capacity of about 2 mgd. It consists of a grinder, clarifier, degritter,
sludge thickener, sludge disintegrator, centrifuge, reactor for sludge
burning, odor control, and chlorination equipment, all of which have
been located so as to provide space for two additional clarifiers. The
plant layout is severely restricted on the north, south, and east by
steep hillsides of the available site. The west side of the plant site
is bordered by the Burlington Northern Railroad and Puget Sound.
The sewage grinder and bar screen are located at the plant headworks
where allowance for bypassing of the entire plant has been constructed.
The grinder is a comminutor with a rated capacity of 7.3 MGD.
The clarifier has a rated capacity of 2.2 MGD which occurs at an
overflow rate of 900 gallons per day per square foot. Detention time
at a 2.2 MGD flow rate, is 1,6 hours. Nominal detention times of from
1 to 2 hours are generally common for primary settling tanks.
The sludge thickener is of sufficient capacity; however, this unit
has experienced problems in the sludge and the scum drawoff lines,
causing buildup of scum and solids in the tank.
The centrifuge was replaced in 1974 with a new, more reliable unit.
During the period of time when this unit was inoperable, sludge was
stored in the thickener and the clarifier, which have a combined storage
capability of three weeks.
The incinerator reactor has a capacity of 220 pounds per hour of
dry solids and is operated an average of eight hours a day. Fuel
consumption averages 500 gallons per month.
The chlorinator is controlled from the flow recorder and auto-
matically distributes one-third of the chlorine solution to the plant
inlet and two-thirds of the solution to the plant effluent manhole.
However, there is no chlorine contact chamber. Disinfection is supposed
to occur in the outfall but there is no way to monitor effectiveness.
Tests conducted in 1971 Indicate the results are inadequate.
Outfall. The plant outfall was subjected to subsidence of the
foundation after initial construction and was reconstructed with new and
salvaged 36" diameter corrugated metal pipe. The outfall discharges to
Puget Sound at a point which is 750 feet from shore 100 feet below mean
lower low water with a capacity of 6.9 mgd.
General operations. In addition to the individual units, as previously
described, the plant contains a laboratory within the operations building,
and roof structures over the headworks, clarifier, and thickener.
11-79
-------
Presently the plant flows are continuously marked on a seven-day
chart by a recorder with a range from 0.0 MGD to 4.0 MGD. A record is
kept of the maximum, minimum, and total daily flows. Sewage temperature
is noted as well as the pH of the raw sewage and final effluent. Settleable
solids are measured daily and occasional dissolved oxygen tests are
reported on both the plant inlet and the final effluent. Daily measure-
ments are also provided for chlorine residual at the plant effluent and
the pounds of chlorine which are added to prechlorination and post-
chlorination application points.
Sewage volumes. Sewage flows are a composite result of construction
standards, population, per capita contribution, and size of the area
served. Ground water infiltration and storm water also enter the sewer
system. Infiltration tends to increase as the system becomes older.
Storm water inflows to the system through the ventilation holes in
manhole lids and the illegal connection of roof drains, subdrains, and
surface drains.
In 1974, the City of Lynnwood initiated an infiltration/inflow
analysis to determine the extent and source of such excessive infiltra-
tion and inflow experienced by the sewer system. A summary of the
results from this study and current data is shown in Table 11-15.
One major infiltration/inflow source was located during the Sewerage
System Evaluation Survey which has now been corrected. Utilizing the
observed flows, and adjusting for the expected inflow removal, the
current average daily domestic flow is estimated 58.3 gallons per capita
per day, the average wet weather infiltration is 305 gallons per acre
per day and the peak infiltration/inflow is 914 gallons per acre per
day.
Sanitary sewage analysis results. The City of Lynnwood tests daily
for temperature, dissolved oxygen, and pH. Weekly tests are also conducted
TABLE 11-15
LYNNWOOD SEWER SERVICE AREA SUMMARY
Service Area
Service Population
Average Annual Daily Flow (1976)
Average Daily Dry Weather Flow
Infiltration (Wet Weather)
Inflow (Peak)
24,000
2.4 MGD
1.4 MGD
1.2 MGD
2.4 MGD
3,940 acres
11-80
-------
for five-day BOD and suspended solids. The dissolved oxygen tests taken
on the plant influent is a constant 8.0 mg/1. Five-day BOD varies from
140 to 260 mg/1 and suspended solids vary from 100 to 180 mg/1.
Sewage analyses taken in 1972 have been supplemented by a composite
sample and four grab samples for dry weather flow in November of 1976.
Additional tests consisting of one composite and 4 grab samples were taken
for wet weather flow.
For purposes of comparison, Table 11-16 shows the results of the
testing in 1972, and 24-hour composite taken on November 15 and 16th,
1976, and the range of the results from the grab samples taken on
November 15th and 16th, 1976. The results of the current testing
generally conform to the earlier results.
TABLE 11-16
BASIC SEWAGE DATA COMPARISON
1972
11/15/76
Dry Weather Flow
24 Hr. Composite
11/15/76
Dry Weather Flow
Grab Samples
Five Day BOD
138 mg/1
160 mg/1
130 to 180 mg/1
Suspended Solids
180 mg/1
190 mg/1
88 to 400 mg/1
Dissolved Oxygen
8 to 10 mg/1
-
-
PH
7.4 to 7.8
6.9
7.0
Chemical Oxygen
Demand
340 mg/1
250 to 530 mg/1
The variation in sewage strength during the day was determined from
the grab samples. Grab samples were taken at four separate times to
indicate sewage strength during periods of high flows, low flows,
average flows and at a point in time when the system is receiving flows
from an unknown source. Results of the study of the daily flow curves
resulted in the selection of the grab samples to be taken at noon, 3:00
p.m., 1:30 a.m. and 5:00 a.m.
It is noted from Table 11-17 below, that the weakest sewage occurs
at 5:00 a.m. and that, although the suspended solids have decreased
considerably at that time, there is still a fairly high BOD. The
strongest sewage occurs at noon and at 1:30 a.m., due to the travel delays
from transit through the pipes. Both results are fairly consistent.
11-81
-------
TABLE 11-17
TYPICAL SEWAGE GRAB SAMPLES
Five Day BOD
Suspended Solids
pH
Chemical Oxygen
Demand
11/15/76 11/15/76 11/16/76 11/16/76 24-Hour
noon 3:00 p.m. 1:30 a.m. 5:00 a.m. Composite
180 mg/1
380 mg/1
7.0
420 mg/1
150 mg/1
250 mg/1
7.0
530 mg/1
180 mg/1
400 mg/1
7.0
320 mg/1
130 mg/1
88 mg/1
7.0
250 mg/1
160 mg/1
190 mg/1
6.9
340 mg/1
Tests were also run on the composite sample to determine the extent
of the presence of metals, oil and grease, and phenols in the sewage,
results of which are shown in Table 11-18.
TABLE 11-18
DETAILED ANALYSIS OF 24 HOUR COMPOSITE SAMPLE
mg/1
Zinc
0.21
Cadmium
0.13
Nickel
0.03
Iron
2.2
Mercury
0.001
Lead
2.5
Manganese
0.16
Copper
0.10
Chromium
0.01
Oil and Grease
10.00
Phenol
0.005
The results shown in Table 11-18 are, of course, not the concen-
tration found in receiving water at the outfall.
11-82
-------
At the present time there are no state or federal standards for the
maximum amounts of metallic pollutants allowed to enter the salt water
ecosystem. It is anticipated that some removals of these materials will
occur in the treatment plant process dependent upon the specific process
employed. The resulting concentrations are not sufficient to cause
environmental concerns in the absence of documented problems within the
receiving water. However, very little is known concerning the potential
hazards posed by such materials. Future research may well show addi-
tional treatment is necessary to prevent further environmental degradation.
Table 11-19 summarizes the existing energy consumption for the
total study area for 1976. The electrical power shown is required to
operate the sewage treatment plant, four pumping stations in Lynnwood,
three in Edmonds, and one in Alderwood Manor, all of which discharge
into the Lynnwood system.
Energy
TABLE 11-19
ENERGY CONSUMPTION
1976
Kilowatt Hours
Lynnwood
Pump Station No. 6
Pump Station No. 8
Pump Station No. 10
Pump Station No. 12
Sewage Treatment Plant
211,040
4,540
6,070
179,440
1,230,000
Edmonds
Pump Station No. 4
Pump Station No. 9
Pump Station No. 10
34,024
9,930
5,840
Alderwood
Alderdale Pump Station
Elberta Pump Station
Pump Station No. 1
Pump Station No. 2
Pump Station No. 3
Pump Station No. 7
14,080
20,320
35,520
32,470
7,830
3,070
Total
1,753,534
II-83
-------
Health
More than 650 septic tank drain field failures within the study area
have been recorded by the Snohomish County Health Department over the past
10 years or so and they regard the drain field problems within the study
area as about the worst in Snohomish County.
Although a number of potentially fatal diseases often originate
from inadequately treated sewage, little problem has yet been experienced
within the study area. This is probably because all potable water is
supplied by the Alderwood Water District rather than easily contaminated
individual wells. However, the risk for children and their pets playing
in contaminated local streams is of real concern to the county health
authorities.
Health standards within the United States are taken for granted by
today's population. It is difficult to draw a sharp distinction as to
when a potential health hazard becomes unacceptable. Occasionally, even
in the United States, the condition is not recognized by the public until
an epidemic occurs, perhaps involving a few deaths. Positive action can
then be easily enforced strictly for health reasons. Yet many examples
exist in less affluent nations to demonstrate the results of poor health
standards.
Concern for conditions within the Swamp Creek basin has been voiced
frequently by local residents and the County Health Department. In an
effort to control the septic tank problem, more than 300 land parcels
within the study area have been denied building permits due to inadequate
soil to support the necessary drain field. In a few isolated cases,
rental properties have been declared uninhabitable by the County Health
Department due to inadequate sewage disposal conditions. Yet without
the availability of sewers, health authorities lack the "teeth" to
compel corrections for private residences since the costs of individual
sewage treatment systems are prohibitive and no receiving water is
available for the discharge.
Historical and Archaeological
Historical. There are no sites listed on either the federal or
Washington State register of historic sites within the project area.
Four sites in the vicinity that are on the Washington State Inventory of
Historic Places are in Edmonds just outside the project area boundary.
The Edmonds-South Snohomish County Historical Society identifies
five sites of historic interest in the Alderwood Manor region of the
project area. Alderwood Manor was developed during the early 1920's
II-P-4
-------
into five-acre farm plots by the Pope & Talbot Company to promote
poultry raising and filbert nut farming. To assist in their sales
promotion, they constructed the following:
1. Experimental farm south of 196th Street, S.W. and west of 36th
Avenue W. No part of it now remains.
2. A brick and stucco office and store at 196th Street S.W., and 37th
Avenue W. presently occupied by a plumbing store.
3. The Manor Hardware Company store between 194th and 196th Streets,
S.W., facing 36th Avenue W. and still occupied by that firm.
4. A demonstration farm on the northwest corner of 180th Street, S.W.,
and 26th Avenue, W. The original house, garages, workshop and well
house remain.
Also of interest is the old Alderwood Manor School on 196th Street
5.W. which is now the Administration Headquarters for Edmonds School
District Number 15.
Settlement of the Meadowdale area dates from the last quarter of
the nineteenth century, with the first townsites being platted during
the first decade of the twentieth century. Caryl (I960) describes some
sites of historical and architectural interest in the Meadowdale area:
1. The old Cleveland store constructed in 1914 at 75th Place W. and N.
Meadowdale Road, since remodeled into a private residence.
2. The old Taylor residence at 5805 152nd Street S.W.
Archaeological. A review of the University of Washington Site
Survey Records lists one known archaeological site within the boundaries
of the facilities area. The site, formally designated 45SN9, was
discovered in the early 1950's. It consisted of a shell deposit approxi-
mately 1,000 feet long and 150 feet wide. The maximum depth of the
shell midden was one foot though the average depth was only three inches.
Revisited in 1958, the site was determined essentially destroyed. It had
been previously disturbed by the Pope and Talbot Lumber Company railroad
terminus and the remainder of the site had been destroyed by the then
recent housing development.
Pertinent ethnographic sources were consulted and though acknowledged
to be included in different aboriginal group territories, the Lynnwood
11-85
-------
area was riot specifically mentioned as containing historic Indian
villages or camp sites. T. T. Waterman lists three place names along
the Puget Sound shore within the facilities area. These place names
only indicate that the area was known by the Native American population
but not that the specific area was inhabited. T. T. Waterman (1922:190)
does list a village at the mouth of Swamp Creek (out of the facilities
area) and Swamp Creek itself.
According to Caryl (1960:141) artifacts were found near the Meadow-
dale Community Club building "many years ago." The topographic location
suggests that the site was an early man occupation.
The Fort Bellingham-Fort Steilacoom Military Road passed through
the facilities area and roughly followed an old Indian trail. The road
ran in a northeast orientation and was approximately a mile east and
roughly parallel to Highway 99 until it turned eastward to pass around
the northern end of Martha Lake. The road was generally located between
the four and five hundred foot contour in the Lynnwood area. Besides
the historical importance of this early historic road, the archaeological
significance of the earlier Indian trail that the road followed should
not be overlooked. Temporary camps and local hunting would be associated
with the trail. Thus, there is a high potential for archaeological
sites to occur along the road area.
The above trail was used historically, however, earlier trails and
habitation sites are unknown for the specific area. Based upon the
general settlement/subsistence pattern for early archaeological popu-
lations in other portions of Snohomish County, the upland areas in the
Lynnwood area can be considered to have high archaeological potential.
One archaeological site located outside of the study area provides an
example of what may be expected for the Swamp Creek area.
The site 45SN21 is approximately five miles east of the study area,
northwest of Woodinville. The topographic situation is similar to much
of Swamp Creek. The site is located on Bear Creek, near the four
hundred foot contour, on presently swampy ground. An early man site,
45SN21 reflects the difference between historic populations who concen-
trated near the present shorelines and the earlier populations that
utilized the upland areas. Similar archaeological sites can be expected
in the Swamp Creek area.
Based upon the historic utilization of the area, as indicated by
the above-mentioned trail, and the probable utilization by earlier
populations of the Swamp Creek area, it is recommended that an on-ground
reconnaissance be conducted by professional archaeologists when the
trunk line location is finalized. The Lynnwood Wastewater Treatment
Facility, as presently understood, is located on recent fill. The
construction of the present Burlington Northern Railroad and existing
treatment plant would have destroyed any cultural resources that may
have existed at one time. Thus, further consideration of archaeological
resources for the Lynnwood Treatment Facility is unwarranted at this time.
11-86
-------
Chapter JL I
DEVELOPMENT OF
-------
CHAPTER III
DEVELOPMENT OF ALTERNATIVES
Forecast of Future Flows
Background
Population. Official population forecasts for the study area are
based upon data extracted from the Interim Regional Development Plan
Activity Forecast prepared by the Puget Sound Council of Governments
(PSCOG), November 1976. The PSCOG forecasts are available for 1980 and
1990 and have been extended to the year 2020 when development, in
accordance with the adopted comprehensive plans for the various juris-
dictions within the study area, is expected to occur. As shown on Fig-
ure III-l, the present population for the study area is estimated to be
54,000 and the expected population for the year 2000 approaches 90,000.
The population forecasts for the various drainage areas were
determined by adjusting the available PSCOG forecasts to the proposed
study area boundaries and to a known population base. The PSCOG data
was available by Activity Allocation Model Districts (AAM) which correspond
to 1970 census tract boundaries or combinations of census tracts. These
are shown in Figure 11-11. A percentage of the AAM forecast was considered
attributable to the study area based upon the proportional amount of the
AAM district that was within the study area and was normalized to the
known 1970 population as determined from the 1970 census block data.
The forecasts for 1970, 1980, and 1990 were then extended to the year
2020, and compared to the expected population based upon the ultimate
holding capacity for the land use as currently shown on the combined
comprehensive land use plan for the planning area.
Employment. The economy of the study area is chiefly dependent on
commuting to employment centers in Seattle and Everett. As the economies
of those two centers have improved after the 1969 setback related to
Boeing's layoffs, the employment prospects for residents of the planning
area have improved. Trends and forecasts by trade area are presented in
Table III-l.
III-l
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
TABLE III-l
EMPLOYMENT PROJECTIONS BY TRADE AREA
1970
1980
1990
ALDERWOOD MALL PRIMARY TRADE AREA
Retail Trade
8,725
12,594
21,669
Services & Miscellaneous
6,627
8,621
16,028
Manufacturing
21,129
14,611
27,538
Wholesale, Trans., Comm. & Utilities
2,966
4,392
7,946
Government and Education
9,626
11,380
16,517
Total Employment
49,073
51,598
89,698
LYNNWOOD (SC71)
Retail Trade
1,456
2,232
5,743
Services & Miscellaneous
1,226
1,559
2,928
Manufacturing
413
558
671
Wholesale, Trans., Comm. & Utilities
603
936
1,403
Government and Education
1,892
2,307
3,057
Total Employment
5,590
7,592
13,802
Source: Alderwood Mall Shopping Center
EIS, Op.
Cit., pp.
3-53.
Population forecasts. The population forecasts presented are based
upon data extracted from the revised Interim Regional Development Plan
Activity Forecast prepared by the Puget Sound Council of Governments (PSCOG),
November 1976. These projections were specifically generated for Metro
for their use in current facilities planning. The PSCOG forecasts are
available for the years 1970, 1980, 1990, and 2000. The PSCOG, in its
capacity as a regional planning agency, developed a computer-based
Activity Allocation Model (AAM) to distribute regional forecasts to small
localized areas which correspond to census tract boundaries.
The current projections are considerably lower than those published
in earlier reports. In the intervening period, there have been major
economic and demographic changes which have resulted in a less accelerated
growth rate than was previously anticipated. In addition, there have
been changes in the regional assumptions regarding development policies
which have resulted in a greater concentration of the expected population
within the established urban areas. By the year 2000, the regional
forecasts of population are approximately 9% less than previously
anticipated and within the Lynnwood Facilities Planning Area the pro-
jections have been decreased approximately 20%.
III-5
-------
The significant changes in population characteristics included within
these forecasts are the continued tendency of the general population to
become more weighted toward middle and older age groups and the increased
forecast of one and two person households in both the young and older age
groups. Coupled with an expected increase in service employment oriented
to other than the immediate populace results in a more likely concentration
of the population in existing urban areas rather than a continual spread of
development.
The population for the study area is anticipated to exceed 86,000
in the design year 2000, which represents an annual increase of approximately
2-1/2 percent per year. The projections shown on Table III-2 represent
the expected population for the various drainage basins as can best be
determined from available data. These forecasts were developed by PSCOG
assuming sewer service would be available throughout the study area when
needed. Should this assumption not be valid, future population would be
significantly lower as addressed later in Chapter IV. It must be remem-
bered that the forecasts do not represent absolute numbers but reflect a
small range of numbers that can be used as to what is probable, given
the current set of regional forecasts and policy assumptions. Should
the regional development policies change, so will the forecast distrib-
utions .
The population forecasts for the various drainage areas were determined
by adjusting the available PSCOG forecasts to the proposed study area
boundaries and to a known population base. The PSCOG data was available
by Activity Allocation Model Districts (AAM) which correspond to 1970
census tracts. A percentage of the AAM forecast was considered attributable
to the study area based upon the proportional amount of the AAM district's
total population that was found within the study area when reviewing the
1970 census block data. The same proportionality was then applied to
each of the projections for the particular AAM district. Projections
for 2005 were determined by logically extending the forecasts generated
from the PSCOG data.
Wastewater Characteristics
Generation. Current concern for the preservation of natural resources,
utility rate expectations and technological improvements are expected to
cause the per capita water usage and its resultant sewage flow to increase
at a slower rate than was found appropriate by study of past trends and
future expectations. At an annual increase of approximately 3/4 percent
per year, the domestic flow rate is thus anticipated to rise from about
58 gallons per capita per day to about 70 gallons per capita per day in
2000. The amount of infiltration/inflow is also expected to increase
slightly once rehabilitation is complete due to the inevitable gradual
deterioration of the collection system as it becomes older and approaches
its expected life.
III-6
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
The size of the contributory area will affect the peak flow to be
expected at any point, at any one time. Within a small subbasin the
probability of simultaneous use of the sewer system is much greater due
to the fact that people tend to use water at common times of the day.
Sewage events occurring at one time within a small area tend to surcharge
that portion of the system, and therefore, require consideration of
larger flows per acre. However, in a long collection system, the time
of travel within the sewer system levels off the high peak flows. In
larger trunk systems, the length is such that the peak flow for the
upper end of the system arrives at the lower end of the system only
after the lower end has passed the peak flow; therefore, as the areas of
collection become larger, proportionately lower peak flows are expected.
Design peak flow ratios for typical communities have been found to vary
between five times the average daily flow for areas of one acre and
twice the average daily flow for areas of 1,000 acres or more.
The design flow criteria used to estimate the flows for the various
drainage basins for the design year 2000 were based on the observed
condition and the expected condition of the collection system as shown
in Table III-3.
TABLE II1-3
SEWAGE DESIGN FLOW CRITERIA
Year
Year
2000
2005
Design sewage, gallons per capita per day
70
75
Average infiltration, gallons per acre per day
300
300
Peak infiltration/inflow, gallons per acre per day
1,000
1,100
Peak flow ratios for sanitary sewerage collection areas
1,000 acres or more
2.00
2.00
400 acres
2.25
2.25
200 acres
2.50
2.50
50 acres
3.00
3.00
5 acres
4.00
4.00
1 acre
5.00
5.00
Forecast. Applying the design criteria to the various drainage areas
and their projected populations results in the expected design flows for
the design year 2000. Table III-4 is a summary of the design flows for
the various drainage areas within the study area to be used in the com-
parison of alternatives.
III-9
-------
TABLE II1-4
DRAINAGE BASIN DESIGN FLOWS
(Design Year 2000)
Popu-
Peak
Average
Basin
lation
Acreage
Flow
Flow
Brown's Bay
18,000
3,320
6.2 MGD
2.3 MGD
McAleer Creek
5,510
830
1.8 MGD
0.6 MGD
Scriber Creek
21,025
2,250
5.4 MGD
2.2 MGD
Lynnwood
Study Area
44,535
6,400
13.4 MGD
5.1 MGD
Swamp Creek
41,779
7,900
14.5 MGD
5.3 MGD
Total Study Area
86,314
14,300
27.9 MGD
10.4 MGD
To define the maximum trunk interceptor usable for the Swamp Creek
basin, ultimate development of the area must be considered. The population
resulting from full development in accordance with the current comprehensive
planning for the area is anticipated to approach 70,000 people, representing
an average density of 8.9 people/acre. The application of this saturation
population to the design criteria is shown in Table III-5 as is a similar
condition for the Lynnwood study area.
TABLE III-5
INTERCEPTOR DESIGN FLOWS
(At Ultimate Development)
Popu-
lation
Acreage
Peak
Flow
Average
Flow
Swamp Creek
Drainage Basin
70,000
7,900
19.2 MGD
7.6 MGD
Lynnwood
Study Area
64,300
6,400
17.5 MGD
7.2 MGD
111-10
-------
Alternative Concepts
Description
In formulating the Facilities Plan, more than two dozen variations in
facilities concepts were developed to intercept sewage throughout the
study area and deliver it to a variety of potential treatment sites. Basic
alternative concepts are briefly listed below in several categories:
I. Regional Facility for Total Study Area Flow
A. Existing Lynnwood treatment plant site
B. New treatment plant at new site
II. Subregional Treatment Facilities
A. Improve and expand existing plant
1. Process all flow from the Lynnwood area with
Swamp Creek basin to Metro
2. Swamp and Scriber Creek basins to Metro
3. Swamp and McAleer Creek basins to Metro
B. New plant at new location for the Browns Bay basin
1. Process all flow from the Lynnwood area with
Swamp Creek basin to Metro
2. Swamp and Scriber Creek basins to Metro
3. Swamp and McAleer Creek basins to Metro
C. Individual treatment plants for each drainage basin
III. Existing Lynnwood Treatment Facility Abandoned
A. All flow diverted to Edmonds
B. All flow diverted to Alderwood water district
C. All flow diverted to Metro
D. Combinations of the above
IV. Construct Subregional Facility at Scriber Creek
A. Abandon existing Lynnwood plant and intercept all flow
from Scriber and McAleer Creek basins with Swamp Creek
basin to Metro
B. Improve Lynnwood plant to process flow from Browns Bay
basin
III-ll
-------
1. Entire Swamp Creek basin to Metro
2. Swamp Creek basin east of 1-5 to Metro
C. Improve Lynnwood plant to process flow from Brown's Bay and
McAleer Creek basins while all other flow processed at Scriber
Creek facilities (no flow to Metro)
V. Service Extensions to High Development Areas Only
A. Improve and expand existing plant to process all flow except
Martha Lake which is routed to North Creek
B. Improve and expand existing plant to process all flow
except part of Swamp Creek, which is processed at a new
Scriber Creek plant, and Martha Lake, which is routed to
North Creek.
VI. No Action
A. Provide secondary treatment for existing service area only
B. No improvements at all
Initial Screening
The above-described facilities configurations of interceptors, pump
stations, force mains, and treatment plants were initially screened on
the basis of present worth (combined capital and operating costs over 20
years) and practicality to identify which concepts were most viable, based
totally on costs. No significant environmental benefits could be discerned
to justify the high costs of any discarded concept. Remaining concepts
were considered to warrant serious consideration.
Definition of Viable Alternatives
No Action
Strict application of "No Action" requires that the present sewerage
facilities remain unchanged through the year 2000. Violation of permitted
discharge standards would continue with the possibility of fines being
imposed on the City by regulatory agencies. All present pipes would
remain in service and any new structures erected within the service area
would be connected. However, the existing primary treatment facility
would not be expanded or upgraded, but would receive only such repairs
as to maintain all components operating at peak efficiency. Thus, any
flow increase could mean a drop in effluent quality since the present
load exceeds the design.
111-12
-------
-------
Sewerage facilities would not be extended beyond present limits to
serve the Swamp Creek basin. All presently unsewered areas would continue
to use septic tanks. Figure III-2 illustrates this concept.
Secondary Treatment Only
PL 92-500 requires all municipally owned treatment works to be upgraded
to provide secondary treatment. Therefore, to comply with federal law, the
present Lynnwood treatment plant on Brown's Bay would be modified to provide
secondary treatment. No additional service extensions would be provided to
Swamp Creek or other parts of the study area, however. New connections could
be allowed to the existing collection system, but all property outside this
limited service area would continue to be served only by septic tanks. This
alternate is shown in Figure III-3.
Since it presently is state policy to give higher priority to con-
structing treatment facilities rather than interceptors, it is quite pos-
sible that even should extension of sewer service throughout the study area
be recommended, it may not be funded or implemented. Construction of
"Secondary Treatment Only" facilities based on the population forecast for
the Lynnwood service area could then be an initial phase for a more
extensive service alternative of questionable implementation timing.
Limited Service Extension
The Scriber and McAleer Creek drainage basins would be intercepted to
Brown's Bay where the existing plant would be upgraded to achieve secondary
standards. A new secondary plant would be constructed near 44th Avenue West
and 1-5 to process the small portion of Swamp Creek proposed for sewer ser-
vice. Development at Martha Lake would be intercepted to North Creek for
treatment and disposal through Metro. This is shown on Figure III-4.
111-14
-------
-------
-------
McAleer & Scriber Basins to Brown's Bay with Swamp Basin to Metro
Sewer service would be extended throughout the Study Area as develop-
ment density warrants. The present Brown's Bay treatment site would be
expanded and upgraded to achieve secondary standards for all flows except
the Swamp Creek basin which would be routed to Metro as shown in Figure III-5.
McAleer Basin to Brown's Bay with Scriber & Swamp Basins to Metro
Secondary treatment would be provided to the Brown's Bay and McAleer
Creek basins at the present Lynnwood treatment plant site. Scriber Creek
and Swamp Creek basins would be intercepted to Metro. Figure III-6 illus-
trates this configuration. Service would be extended throughout these
areas as development density warrants.
McAleer, Scriber & Swamp Basins to Metro
Brown's Bay basin would continue to flow by gravity into the present
treatment plant site which would be upgraded to provide secondary treat-
ment. McAleer Creek, Scriber Creek, and Swamp Creek basins would be inter-
cepted to Metro as development density warrants. McAleer Creek could
require its own interceptor or could be pumped into Swamp Creek basin.
Figure III-7 shows this alternate.
New Plant at Scriber Creek with No Discharge to Metro
McAleer Creek would be pumped into the Brown's Bay basin for treatment
at the present site. A new treatment plant would be constructed near 44th
Avenue West and Interstate 5 for the Scriber Creek and Swamp Creek basins
as shown in Figure III-8. Pump stations would be necessary to intercept
Swamp Creek to this site. A pumped outfall would be constructed in
existing street right-of-way from the new site to Puget Sound.
Treat at Brown's Bay & Scriber Creek with Lower Swamp Basin to Metro
The existing treatment plant would be upgraded to provide secondary
treatment for the Brown's Bay basin. McAleer Creek and Scriber Creek basins
plus the northern part of Swamp Creek would be intercepted for treatment at a
new site near 44th Avenue West and Interstate 5. A pumped outfall would be
111-17
-------
Figure HE-5
TREAT MCALEER & SCRIBER BASINS AT
BROWNS BAY WITH SWAMP CREEK TO METRO
—Bj8vMGD PEAK FLOV\/\~
ij_ A V E RAG
-------
±
:A
1M.IH ST.!
J
"IS1"-[HW+'X-
f - ¦ v '^r- •
\
. K
Figure- IH-6
TREAT MC ALEER BASIN AT BROWNS BAY
WITH SCRIBER & SWAMP CREEK TO METRO
I '•«* r j
MGI) PEAK FLOW1 —
MGD AVE I
-------
Figure- IDL-7
MCALEER SCRIBER & SWAMP CREEK
BASINS TO METRO
^Q/VLJVTGD PEAK FLOW I-—
F^IGL) Average
—. <
-------
lis: \ 'r>d ~4l" -
1 ,-^mbs^ V ' - / • ¦'
A Y"V
:SS5%S5:S
A
V
~'tt.
¦/ y
mat ¦• • ¦
<*£*1 *Z>i;'r4
::x
y^j •
rr(L_ !• "
_^3r 4 Vu
PEAK FLt>W S;
\1( , IxAVE^AGE FLOV
LROWNS BATO?
r y ,
/\
*—¦- ^J^f^sTx^xTxXv:+:• :&: <::::::
• •* ''..V-ife • I •V'XOII^'•**#).• •'•**^
, ¦. 1.r..-.-.-v! -Tv-'._• _sr. . .-*?• • -y.
• iaj
¦j. i • >'•'%'f?y'. '.\ \ '.\\C--h*-
:¦: :'•': :n+jj
• • A' '.' , '*!•*'. . | . . | • ,»*»"** • "M •'
F[rv.i^. j* r*^
JU4
y -yh iA
~ ra\
¦ »»- -
: :•>& .':• >.:•:•:•:> :-:'x-
.V.V.; •,;,;.vvv.;.t.v.v
Figure H-8
NEW PLANT AT SCRIBER CREEK WITH
NO DISCHARGE TO METRO
-------
ICAIE
^GDPEAKXLOW
^-gjpVVNS BA
Figure HL-9
NEW PLANT AT SCRIBER CREEK WITH
LOWER SWAMP CREEK TO METRO
J,j7 MGD PEAK FLO
MGD AVERAGE RL
-------
constructed within present street right-of-way from this new site west to
Puget Sound. All of the Swamp Creek basin south of Interstate 5 would be
intercepted to Metro. Figure III-9 illustrates this concept.
Treatment & Interception Alternative Processes
Secondary Treatment
Processes considered. Wastewater reuse and land application were
briefly considered for wastewater management. No potential use for the
recycled wastewater could be identified and a suitable property with
acceptable soils is not reasonably available for land application of this
magnitude. Since no environmental justification could be found to support
extraordinary wastewater transportation costs to distant areas, reuse and
land application were not considered further.
Many processes have been proven capable of providing secondary treat-
ment. Few significant environmental differences can be detected among
most secondary processes so selection is usually based on costs and site
considerations. Those processes considered are listed below:
Stabilization Lagoon: Air mixed into large open pond by wind, not
likely to achieve secondary treatment.
Aerated Lagoon: Air mixed mechanically into open pond.
Trickling Filter: Sewage flows over shallow media covered by bio-
logical growth, suspended solids may not achieve secondary
treatment standard.
Rotating Biological Contactor: Biological growth rotated through
sewage as it flows in an enclosed channel.
Activated Biological Filter: Sewage flows through deep biological
media.
Activated Sludge - Conventional: Sewage thoroughly mixed with some
recycled solids in aeration tank.
Activated Sludge - Contact Stabilization: Sewage briefly in contact
with recycled solids, contact may not be sufficient for BOD to
achieve secondary treatment.
Activated Sludge - Extended Aeration: Sewage extensively mixed in
aerated tank with large volume of recycled solids.
Activated Sludge - Pure Oxygen: Identical to conventional activated
sludge except uses oxygen instead of air in smaller tank.
Physical-Chemical: Chemically assisted sedimentation and filtration.
Brown's Bay site. Due to the restricted space available at this site,
many proven methods of achieving secondary treatment were quickly discarded
as requiring too large an area. To accommodate the forecasted average day
111-23
-------
flow volume of 5.1 mgd, only activated biological filters could be readily
fitted to the site in a cost-effective manner. The suggested site layout
is shown in Figure 111-10. No environmental reasons could be found to
justify a more expensive process.
Scriber Creek site. The only basic restriction for treatment process
selection with respect to this site is the proximity to commercial and res-
idential property. Cost-effective analysis found rotating biological con-
tactors to be the preferred choice. Figure III-ll shows the recommended
site layout. Environmental impacts of this process are as low as any
proven treatment method so a more expensive system is unwarranted.
Sludge Processing
Methods available. Disposing of the waste sludge is the primary
problem in wastewater treatment. Cost-effective resolution is complicated
by the high water content and volatile nature of the sludge which renders
it unacceptable for disposal in raw form. Basic processing steps are
defined below:
Stabilization decomposes the putrescible organic matter which is most
liable to cause obnoxious odors. Some common methods include
aerobic digestion, anaerobic digestion, chemical addition, and
sludge lagoons.
Dewatering removes some of the water in the sludge so the bulk is less.
Open drying beds, vacuum filters, centrifuges, and pressure
filters are proven processes.
Reduction oxidizes volatile matter so the bulk is less and putrescible
matter is eliminated. Incineration and wet oxidation are accepted
methods.
Disposal of the residual solids is normally onto the land, either as
fertilizer or in a landfill.
Sludge processing is the major point of possible environmental concern
in the wastewater treatment operation. Past tendencies for low capital
cost systems resulted in many unsightly, malodorous facilities. With
adequate resources available, a variety of acceptable modern facilities
can be designed for any environment though.
Brown's Bay site. Limited land availability dictated that incinera-
tion is the only mode which can process the volumes of sludge forecast.
Pressure filters are recommended to thicken the sludge. Residual ash would
be trucked to the county landfill.
111-24
-------
SECONDARY CLARIFIERS
AERATIONS
BIO-FILTRATION CELLS
sludge THICKENING & INCINERATOR BUILDING_
f CHLORINE CONTACT CHAMBER
MODIFIED CLARIFIER
TEMPORARY HEADWORKS
STRUCTURE
GRIT REMOVAL UNIT
Figure H-10
BROWNS BAY TREATMENT MODIFICATION
111-25
-------
-------
Scriber Creek site. Space is available to consider a variety of sludge
processing methods. Two-stage anaerobic digestion followed by vacuum fil-
tration to dewater the stabilized sludge with disposal to the county sani-
tary landfill was found to be cost-effective.
Swamp Creek Interception
Interception concepts. There are three basic concepts to intercept
sewage within the Swamp Creek basin for treatment which are discussed below:
o Pump stations could inject all flow into a pressure interceptor so
the pipes could follow the ground contours. This would allow all pipes
to be placed in street right-of-ways and avoid the natural open
spaces which are wildlife habitats. However, even with standby
pumps and emergency power, pump stations can not be made completely
reliable. Failures will occur which would overflow raw sewage into
the surface drainage system. Overflows would thus present an
unpredictable health risk from sewage pathogens and water quality
degradation from the BOD. Blowoff and air release valves would be
operated periodically which could also allow untreated sewage to
escape. Capital costs, maintenance and operation expenses would be
high which would be reflected in local user charges.
o Lift stations could raise the flow at low points so gravity pipes could
be used along the street rights-of-way. This concept would also avoid
disturbing many of the natural areas but would still entail a substan-
tial risk of pump station failure and raw sewage overflow into the
surface drainage. Costs would be high and user rates would be set
accordingly.
o Gravity flow throughout the basin would be the most reliable system
with the least possibility for sewage overflow. Some natural habitats
would be disturbed at least temporarily by the construction along
the stream banks but strict specification enforcement can limit
these impacts to a narrow strip with little effect on water quality.
Capital, operation and maintenance expenses would be lower than
pumped concepts, so user rates would also be lower.
Cost analyses developed for the Facilities Plan showed the gravity
concept to be far more cost-effective than either the pump/pressure
interceptor or the lift/gravity interceptor. These costs are summarized
in Table II1-6.
111-27
-------
TABLE II1-6
COSTS OF INTERCEPTION CONCEPTS
Operation &
20 Year
Capital
Maintenance
Present
Costs
Costs
Worth
Pump Stations
and Force Mains
$15,032,000
$399,000
$19,562,000
Lift Stations
and Gravity Mains
$15,956,000
$122,000
$17,333,000
Gravity Mains
$11,527,000
$ 18,000
$17,731,000
Although local environmental impacts may be more severe during
construction of the gravity system, it would avoid the long-term risk of
overflow. No degree of standby power and telemetering equipment can prevent
occasional overflows. Power failures have occurred at about five per year
for the Alderwood Water District. The 5.3 mgd design sewage flow is over
20 percent of the average daily Swamp Creek flow. Since power outages are
unpredictable, the risk of substantial contamination would always be present
with a pump system. These possible environmental tradeoffs do not seem
to provide sufficient advantage to justify the higher expense of a pump
concept so the gravity concept was selected.
Interceptor alignment. The basic alignment of any gravity pipe system
is dictated by topography and will necessarily be in close proximity to the
local surface drainage. However, alignments must also consider property
lines to facilitate obtaining easements. The basic gravity interceptor
route developed for the Facilities Plan is shown in Figure 111-12.
Alternate pipe routes were considered at 29 separate locations ranging
from perhaps a hundred to several thousand feet in length. Final alignment
was chosen based on least cost with due allowance for mitigative measures
to protect the environment during construction.
Careful route reconnaissance and environmental investigation suggested
four of these locations should be examined in greater detail since it
appeared possible local impacts might be reduced. These alternate
locations are shown on Figure 111-12 and are discussed below:
1. Carter Road alternative is 2,900 lineal feet, mostly in public right-
of-way. Proposed route follows property lines for 2,200 lineal feet
through open space.
111-28
-------
2. Locust Road - 224th Street - 17th Place alternative is 4,300 lineal
feet primarily in public right-of-way. Proposed route is 4,000 lineal
feet through open space along Swamp Creek.
3. Ash Way alternative is about 6,000 lineal feet in public right-of-way
instead of 4,200 lineal feet through the largest wetlands within the
study area.
4. 22nd Avenue - Maple Road alternative is 4,800 lineal feet in mostly
street right-of-way. The proposed route 4,300 lineal feet through
open space.
All of the above alternative alignments are longer and involve sig-
nificantly deeper excavation with some increase in construction risks to
the workers. Costs of street pavement restoration roughly balance the
cost of environmental protection measures on a lineal foot basis so the
shortest routes are generally the most cost-effective. Only the Ash Way
alternative avoids disrupting a sufficiently large, undisturbed natural
habitat to justify the greater expense. In other alternatives, development
is already encroaching upon the open space and will, presumably, eventually
pervade the entire space. However, the wetlands north of the I-5/I-405
interchange are the largest within the study area. Development would be
expensive and shows no sign of commencing. Unfortunately, the proposed
State Route 525 freeway will skirt the south and west edges of this
wetland so the alternative alignment must be compatible with the future
state right-of-way. The estimated construction cost necessary to implement
the Ash Way alternative route were found to actually be less than proceeding
directly through the swamp where pile support of the pipe is necessary due to
poor soil condition. Routing the pipe around the wetlands is a desirable
investment towards preserving the local community character and wildlife
habitat.
Certain further route adjustments may also be warranted during .final
design. However, they are of far smaller scale and the accuracy of the
pipe alignment does not allow meaningful evaluation. Impacts in such
circumstances will be small in view of the strict environmental specifica-
tion which will be required for this project. Alignment shown in the
Facilities Plan is only approximate so the exact pipe location must be
established as a part of final design.
Much of the trunk will be installed in lowlands subject to flooding
during rainstorms. The design must consider prevention of inflow from
entering manholes when they become submerged.
Collector connections. Figure 111-12 also indicates approximate points
of connection to the trunk by the local collector system. Only conceptual
locations have been generalized for the development of the Facilities Plan
so the points shown must be recognized as only approximations.
111-29
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
Yet a potential impact is indicated by the number of connections, the
amount of open space penetrated by them, and the frequency of stream crossings.
It is not within the scope of the present Facilities Plan to develop a pre-
liminary plan for the collector network but it must be recognized that part
of final design will include establishment of tentative collector pipe
alignments. These alignments must be chosen with care or the number which
penetrate the natural areas will be sufficient to cause more disruption
than construction of the trunk itself.
During final design, consideration should be given to collecting sew-
age from some residences along the stream banks by individual grinder
pumps instead of insistence that all collection be by gravity. In this
way, pipe routes through the natural areas along the streams can be
minimized.
Stream crossings will also require careful planning. It is hardly sen-
sible to take special care in constructing trunk stream crossings by jacking
the interceptor beneath the stream bed if the collectors will be installed
by open cut across the same stream. Furthermore, collector construction,
with attendant potential disruption, will be spaced over a considerable
period of years instead of the two or three years necessary to place the
trunk. Unless the collectors are carefully constructed in accordance
with strict specifications similar to the trunk, the resulting prolonged
series of impacts from construction, disruption, debris and sediment
will seriously degrade the stream water quality. Spawning gravel beds
could then be destroyed by silt with possibly disastrous impacts on the
local fish population.
Installation of the Swamp Creek trunk will allow the existing small
pump stations east of Lake Serene to be abandoned so sewage can flow by
gravity to Metro.
Implementation. Under the present priority system for distributing
federal funds, treatment improvements are funded ahead of interception.
Thus it is not likely that any portion of the Swamp Creek interceptor can
be commenced before 1985 and it is questionable even then. Since current
development is concentrated towards the northern, upper reaches of the pro-
posed system, staged construction offers little scope to install the system
in pieces. Essentially, the entire interceptor must be installed before
any appreciable benefits can be realized by the community.
111-33
-------
Chapter HZ"
ENVIRONMENTAL
IMPACTS OF A
-------
CHAPTER IV
ENVIRONMENTAL IMPACTS OF ALTERNATIVES
Evaluation of Primary Environmental Impacts
Impacts at Treatment Facility Site
No action. Conditions at the existing treatment plant would remain
as they presently exist. Sewage effluent would continue to receive only
primary treatment prior to discharge into Browns Bay. No significant
environmental impacts can be proven to result from this discharge. Noise
and odor levels would stay at essentially the current levels, which are
low but still noticeable.
Secondary treatment only. Considerable new construction would be
required at the Browns Bay site with resulting temporary noise, traffic
congestion, dust, and disruption. An activated biological filtration
process would be erected by cutting into the canyon side slopes to obtain
sufficient construction space. A diffuser section would be added to the
existing outfall to insure adequate effluent dispersal. One accepted water
quality standard for diffuser design is to maintain a dissolved oxygen
concentration of at least 5 mg/1 which is the minimum level acceptable to
sensitive fish such as salmon. Sludge would be thickened, dewatered,
and incinerated by the fluidized bed process with residual ash hauled by
truck to the Snohomish County landfill.
All treatment components which are potential sources of odor would be
enclosed with the air exhausted through a scrubber system capable of reduc-
ing noticeable, objectionable smells to insignificant levels. Mechanical
equipment will be of modern design producing minimal noise and mounted within
sound-insulated enclosures to further reduce objectionable noise. The incin-
erator will meet the New Stationary Source Performance Standards of the
Environmental Protection Agency for air quality control.
Installation of an activated biological filter process does require
erection of filter towers about 20 feet tall. However, because the plant
site is located in a canyon, this height is not sufficient to obstruct any
views from private property. Other additional and larger components
will also be constructed on the site to achieve secondary treatment
resulting in some congestion due to the small land area available.
These structures will include architectural features to attain a pre-
sentable, aesthetic appearance. Canyon slopes will be landscaped to
screen the treatment components from view by private property residents.
IV-1
-------
Improved beach access will be offered by leaving the service road open
to the public. Recreation facilities to be provided as multiple use of the
treatment plant site may include limited public parking, restrooms,
picnic tables with fireplaces, and a walkway across the railroad tracks
with a ramp down to the beach. These facilities will be placed in an
attractively landscaped setting and maintained to encourage use.
Limited service extension. Impacts at the treatment site would be
similar to the Secondary Treatment Only alternative. The same treatment
processes would be employed, though modest additions to the Lynnwood
sewerage collection system will result in modestly higher flows, and
hence, slightly larger treatment components. These minor size increases
would not be readily apparent in magnitude. Aesthetic architecture and
landscaping will still render the plant visually unobtrusive. Noise and
odor levels are not expected to rise measurably. Thus local environmental
impacts are not expected to be detectably different than the Secondary
Treatment Only alternative.
Construction of the service extensions would create some temporary
degradation due to noise, dust, disruptions, and traffic. Once construc-
tion is complete and street surfaces restored, local conditions would equal,
or possibly better, present conditions along the pipe alignment.
Alternatives extending service throughout study area. Under these
five alternatives from 2.3 mgd up to 5.1 mgd of wastewater would receive
secondary treatment at the present Browns Bay site using activated
biological filters with sludge incineration. Local environmental impacts
would be similar to the Secondary Treatment Only alternative, though
marginally greater as the flow volume increases. Increased component
size would require considerable excavation into canyon side slopes with
retaining walls erected to insure slope stability.
Under the higher flow alternatives, an additional outfall would be
constructed parallel to the present outfall, which would still remain in
service. Studies conducted to date are not conclusive, yet there is no
reasonable indication that permanent, significant impacts will result due to
construction of the new outfall. However, a temporary turbidity increase
will be unavoidable. Long-term discharge of a higher volume of effluent
treated to secondary standards is not expected to have measurable impacts
other than in the immediate vicinity of the diffuser. Even those impacts
within a few feet are not expected to be of sufficient level to be
harmful to the local ecology.
However, some concern does exist for possible eventual contamination
entering the food chain due to heavy metals and PCBs in the effluent.
Studies released to date have not conclusively demonstrated this problem
exists so at present the question remains unanswered.
IV-2
-------
Additional treatment plant at Scriber Creek. Part of the service
area wastewater volume would be treated at an additional plant in the
Scriber Creek basin southeast of Interstate 5 and 44th Avenue West.
Average day flow volumes by the year 2000 considered for this plant were
5.0 mgd and 7.5 mgd. Rotating biological contactor was found to be the
cost-effective process for either flow volume. This site is presently
undeveloped and covered with brush and second-growth timber.
Construction traffic and dust would be noticeable in the vicinity but much
of the noise would blend into the freeway traffic. Sprinkling would miti-
gate some of the dust.
Because it is in the creek valley, the treatment components would
be at least somewhat visible to passing motorists on the freeway embankment
and, possibly, from existing or future home sites on higher elevations
to the east. Structural exteriors would be designed architecturally to
be aesthetically acceptable. Sufficient site property would be allocated
to landscaping to form a ground level visual screen of attractive vegetation.
Close proximity to Interstate 5 would render unnoticeable any noise
created by treatment plant operation. Odors could periodically be notice-
able, even against the background freeway smells and nearby commercial/
industrial activities. However, sludge disposal would involve two-stage
anaerobic digestion and trucking the dewatered solids to the Snohomish
County landfill. This process offers considerable odor potential on an
irregular basis. Therefore, all potentially odorous treatment com-
ponents would be enclosed and exhaust air would be scrubbed to control
odor emissions. The only present county landfill requirements call for
dewatered, stable sludge which should be satisfied by the recommended
process. Future requirements could be more stringent, of course, as the
County landfill is upgraded to comply with Land Disposal and Thermal Process-
ing Guidelines.
Neither of the two outfall route alternatives considered offers any
special environmental advantage over the other. Pipe lengths are not of
sufficient difference to be significant in terms of construction impacts
and, once installation was completed, all surfaces would be restored to
present conditions or better. A new outfall into the Sound would be required
for either route. Primary treated effluent is currently discharged in the
vicinity of both outfall terminuses so the addition of secondary treated
effluent is not expected to cause any appreciable long-term environmental
impacts. Outfall construction underwater will cause temporary local increases
in turbidity and some disruption of the local seabed. However, neither
vicinity encompasses a unique aquatic condition or habitat, such as a
commercial shellfish bed, requiring extraordinary construction precautions
beyond those normally imposed by the State. Some recreational shellfish
are harvested along the beaches of Brown's Bay, however.
IV-3
-------
Impacts on Metro. The volumes of wastewater forecast for any of
the alternatives for delivery to the Municipality of Metropolitan Seattle
for treatment are within the maximum planning levels developed by Metro.
Average Swamp Creek flows are forecast at 8 mgd while West Point flows
currently average 114 mgd. The Swamp Creek volume is too small to
significantly affect operation at the West Point treatment plant by
future presence or absence so the environmental impact is slight.
Capacities of the gravity interceptor to the Kenmore pumping station
and force main would be affected by the Swamp Creek interceptor volume.
Should Swamp Creek be connected to Metro, 4.8 miles of 60 inch pipe would
be required parallel to the Kenmore interceptor leading to the West Point
treatment plant. If Swamp Creek is not connected, the 1-1/2 miles of 36-
inch force main with two pump stations would be needed for the Redmond inter-
connection with flow diverted to the Renton treatment plant. These options
are illustrated in Figure IV-1.
The interceptor to West Point is now used by Seattle and has a poten-
tial overflow at the Lake Washington Ship Canal. It is the opinion of Metro
that adequate capacity exists in this interceptor to accommodate the Swamp
Creek basin but an overflow could have significant water quality effects in
the Ship Canal.
Air Changes Throughout Study Area
No service extensions. The No Action and Secondary Treatment Only
alternatives would show only small increases in population ranging from
20 percent in the study area to 16 percent in Lynnwood and 15 percent in
the Swamp Creek area. These increases in population would have little
effect on the existing air quality.
The suspended particulate levels would remain essentially unchanged
from the 30 ug/m^ level. Carbon monoxide would show the greatest reduc-
tion, falling approximately 50 percent to the 3 to 4 ppm level along major
arterials. Hydrocarbon levels would reduce along with carbon monoxide
levels while nitrogen dioxide levels would essentially remain the same as
it is anticipated that no new large sources of nitrogen dioxide will be
developed.
Limited service extension. Differences between limited service exten-
sions and no service extension are not sufficient to develop meaningful
air quality forecasts.
Service extended throughout study area. Throughout the study area,
the suspended particulate levels will remain constant at 30-40 ug/m^.
IV-4
-------
LEGEND
$$$« STUDY AREA
-------
Although the 70 percent increase in population density as well as light
industry growth through the year 2000 will tend to increase particulate
levels, the number of unpaved roads and open land will decrease and
should keep the net particulate loading constant. This has been true in
other areas with similar population densities, as indicated by the 1975
particulate loading estimates shown in Figure III-3. Higher population
density areas of North Seattle, Tacoma, and parts of Bellevue do not sig-
nificantly increase with large increases in population density. The levels
remain in the 30-40 ug/nP range with 20-30 ug/m particulate loading in
the less dense or rural areas. This 30-40 ug/nP loading is about one-half
of the ambient standard.
The sulfur dioxide levels in 2000 will remain at present levels or
will be reduced due to the change from petroleum heating fuels to lower
sulfur content energy sources for home heating. The current standard
should not be exceeded as a result of light industrial and residential
expansion.
The carbon monoxide levels in the study area should decrease by 2000
if current automotive emission standards for these pollutants are attained.
Current emission levels for 1977 automobiles without including hot and cold
start penalties is 48 grams per vehicle miles. This would be a 77 percent
reduction in emissions if we assume that the 1990 emission factor is con-
stant through 2000. The increase in population is a reasonable projection
of automobile activity in the region. In the study area, the population
change based on PSCOG data is 54,000 in 1977 to 91,000 in 2000, a 70 per-
cent increase.
Based on these projections, the existing travel routes, namely U. S.
99, 196th S. W. , and near 1-5 have existing CO levels in the 6-7 ppm range.
Reductions in petroleum usage as well as more efficient automobiles will
also reduce the CO levels. These values will decrease as the exhaust
emission reduction approaches 77 percent, but population increases in the
study area will restrain future CO levels in the 4-6 ppm range. It is
very unlikely that levels in the area will fall to the 1-2 ppm natural
level.
Hydrocarbon levels in 2000 will be reduced proportionately to the
CO levels. However, nitrogen dioxide levels will remain or will increase
with increasing automotive travel. This is mainly due to the proposed
policy relaxing NOx emission standards for automotive sources. The tighten-
ing of stationary N0X source emission standards will have minimal effect
on the study area.
IV-6
-------
Water Impacts in Study Area
Surface water movement. None of the alternatives will have any effect
on water movement within Puget Sound or Brown's Bay.
Swamp Creek water movement would be affected during construction of
the trunk. The proposed alignment lies only 25 feet away from the creek
bed for certain portions where the stream flows through narrow canyons
with limited space available for pipeline construction. Construction
activity will be restricted to minimize impacts on aquatic life, especially
fish spawning, but some temporary alteration in stream flow characteristics
will result. Significant permanent changes in the Swamp Creek flow
characteristics are not expected although minor channel modifications
will obviously result.
Runoff/absorption. Runoff may be temporarily interrupted and/or
diverted adjacent to the interceptor trench during construction. Runoff
will increase slightly after construction due to removal of vegetation.
This increase is not expected to be significant; however, significant
additional runoff may result from increased urbanization of the study area.
Flooding and flow volume. No significant changes are expected in
surface water quantities as a direct result of implementing any of the
alternatives, although some secondary changes could occur which are
addressed later. Some stream backup would occur temporarily during
construction of the Swamp Creek trunk but these volumes would be carefully
controlled to avoid property damage. Any silting due to ponding would
be of minor extent, no more than occurs naturally under adverse weather
conditions, and would not materially affect local wildlife habitats.
Fresh water quality. Lakes and streams in the Swamp Creek drain-
age basin receive considerable water as seepage from the perched aquifer.
Under the No Action and Secondary Treatment Only alternatives, continued
contamination of perched aquifer groundwater may result and adversely
influence surface water quality, particularly coliform bacteria, nitrate
nitrogen, and chloride concentrations. The Limited Service Extension alter-
native will reduce, but not eliminate, these contamination tendencies. Any
of the alternatives extending service throughout the study area offers the
potential to halt and eventually reverse this trend, leading to possible
future improvements in surface water quality.
Swamp Creek trunk construction will cause temporary increases in tur-
bidity and suspended solids concentration in some basin streams due to
erosion of bared surfaces, particularly if construction is conducted
through the winter rainy season. Impacts on water quality in Martha Lake
Creek and Swamp Creek above Interstate Highway 5 should be minimal due to
IV-7
-------
the generally flat terrain adjacent to the interceptor line. Swamp Creek
below 1-5 will be particularly subject to turbidity and suspended solids
increases during and immediately following rainfall runoff.
Removal of vegetation overhanging the stream for interceptor con-
struction could increase stream temperature, altering the aquatic habitat.
This may occur along about 5,000 feet of creek but is not expected to be
of sufficient magnitude to cause a significant ecological problem since
the pipe alignment is specified to be at least 25 feet from the stream
edge and construction disruption will be strictly controlled. Temperature
change under such conditions should be minimal.
Marine water quality. Present water quality in Brown's Bay is adversely
affected by the existing treatment plant effluent discharge to a slight
degree by excessive bacteriological discharge and occasionally high sus-
pended solids in the effluent. A slight worsening in this condition is
predicted for the No Action Alternative. However, Metro has conducted
extensive studies on primary effluent discharged from West Point without
finding any significant degradation due to BOD or suspended solids in far
larger quantities, though in lower concentrations. Data for metals is
insufficient to form any conclusions. It is unlikely that the far
smaller discharge at Brown's Bay could produce any more serious impacts.
Provision of secondary treatment will decrease the volume of oxygen-
demanding wastes entering Puget Sound and also the amount of coliform
bacteria. This may have a slight beneficial effect in the immediate
vicinity of the discharge point, even for the alternatives providing
increased flow quantities because the total volume of pollutants will be
less.
Secondary treated effluent should result in a chlorine residual in the
effluent below 0.5 mg/1. There presently are no State standards for either
maximum or minimum chlorine residual — only that the effluent must meet
the permit standards, which is a Most Probable Number (MPN) not exceeding
200 fecal coliform per 100 mg/1 for secondary treatment. The treatment
facility proposed for all alternates except No Action will achieve that
standard. Each alternate also proposes a diffuser achieving 500:1 dilution
so the resulting total coliform count on Brown's Bay near the outfall should
average about a MPN of 1 when compared to the present average MPN of 230.
Chlorine concentrations within Brown's Bay within the diffuser mixing
zone should average less than 0.001 mg/1, which is one-tenth of the current
EPA guideline of 0.01 mg/1. The most sensitive aquatic life with respect
to chlorine in Puget Sound are salmonids with a threshold toleration defined
by EPA as 2.0 micrograms per liter or 0.002 mg/1. Thus, even the proposed
mixing zone plume will not pose an appreciable risk to aquatic life. Chlorine
concentrations within the Brown's Bay vicinity of Puget Sound are considered
sufficiently low by the State Department of Ecology that dechlorination is
not required at Lynnwood. None of the available data refute this conclusion.
IV-8
-------
Groundwater. No change in groundwater quantity or movement is expected
to result from any of the alternatives. Groundwater quality may be altered,
however. In all developed portions of the service area not now served by
sanitary sewers, there are significant numbers of septic tanks with drain
fields. The groundwater of the perched aquifer is presently being contami-
nated by drain field effluents to some degree. Coliform bacteria, nitrate
nitrogen, and chloride are particular problem indicators. There are no
known significant domestic water supply sources in this perched aquifer so
this contamination has no major impact on water supply. Deep aquifers do
not appear to receive a direct recharge from the perched aquifer, so no
impact is predicted on deep aquifer groundwater. This contamination will
increase under the No Action and Secondary Treatment Only alternatives as
the population increases. This problem would be lessened under the Limited
Service Extension alternative but permanent improvement can not be expected
except by extending sewer service throughout the study area.
Noise Impacts
Treatment plant. One of the byproducts from enclosing the treatment
components at the Brown's Bay site to control odor will be some added capa-
bility to reduce the noise levels. The noisiest components of the present
treatment facility are located within the Operations Building. This will
continue to be true for any of the viable alternatives. However, construc-
tion of new facilities will include provision of an adequate ventilation
system which dampens the noise detected outside the building. This will,
in turn, reduce the noise associated with the plant heard at the nearby
residences to levels specified by State standards - 60 dBA during daytime.
Nighttime levels would be less since the incinerators would not normally
be operating. However, State standards allow exemption from the usually
required 10 dBA nighttime reduction for utilities.
The alternative which would provide treatment at the Scriber Creek
site would introduce a new source of low level noise into the community.
These treatment components would not be as completely enclosed as at Brown's
Bay so noise levels might be slightly higher. However, residences are not
within such close proximity so the impact will be less noticeable to local
inhabitants.
Construction. A certain volume of noise during construction activity
is unavoidable for a temporary time period. Noise standards now exist for
many classes of construction equipment and enforcement is relatively simple.
Project scheduling will be employed to limit activity to normal working
hours.
IV-9
-------
Natural Resources
Soils and other physical features. No potential impacts on physical
features can be identified which could be attributed to the No Action,
Secondary Treatment Only, or Limited Service Extensions alternatives.
Excavation for the Swamp Creek trunk and other interceptors under any
alternatives serving the entire study area will likely result in the mixing
of upper and lower soil layers with the glacial till material. When
this mixture is used to backfill trenches, the ground surface over the
filled trench will be less suitable for supporting vegetation. Poor vege-
tative cover could contribute to a greater rate of erosion, particularly
from sloped areas.
Some erosion during interceptor trenching is inevitable. The rate
of this erosion will be greater if construction occurs during the winter
rainy season, and will be directly caused by washoff from stockpiled
trench excavation material and ground disrupted by excavation activity.
Where the trench is constructed through flat, swampy areas, impact will
likely be restricted to the general vicinity of the trench due to low
flow rates through the swamps. Where erosion occurs on sloped land
adjacent to the creek, impact will be greatest, as eroded soil may be
washed into the stream. Two construction zones are particularly sensitive
in this regard: approximately 2,500 feet of line in a narrow, steep
canyon along Butternut Drive, and approximately 1,500 feet of line in
another steep-sided canyon along Locust Road. Canyon side slopes are
approximately 1:1 in these locations, with little or no floodplain
adjacent to the stream. Erosion is also likely to occur from ground
adjacent to the trench that has been cleared for equipment access.
Erosion will continue after the completion of construction if mitigative
measures are not implemented.
Aquatic life. The water quality parameters critical to salmonid fish-
eries in Swamp Creek and its tributaries are turbidity, suspended solids,
temperature, gravel composition, and dissolved oxygen. The first two of
these parameters are not measurably affected by septic tank effluents,
though dissolved oxygen can be lowered by the organic waste matter.
Therefore, direct impacts on fisheries resources from continued septic
tank effluent contamination of ground and surface waters as would occur
under the No Action, Secondary Only, or Limited Service Alternatives
would be limited.
Fish habitat in Scriber Creek and Swamp Creek could be disturbed
and possibly extensively damaged by stream sedimentation covering and/or
filling the spawning bed gravel due to erosion resulting from construc-
tion of the Swamp Creek trunk. Construction activity in or around stream
would be constrained during the spawning season which extends from late
IV-10
-------
August through June. Water turbidity and stream sedimentation are
the existing limiting conditions on salmonid populations in the Swamp
Creek system and increased erosion due to interceptor construction will
increase stress on these fish populations. Any increases in turbidity
and suspended solids in streams will have adverse effects on stream
fauna and bottom organisms in all life phases, and particularly on
salmonid eggs and larvae.
Where vegetation overhanging Swamp and Scriber Creeks is removed, the
fish habitat will be degraded. Overhanging vegetation provides necessary
shade and insulation to maintain cool water temperatures and also provides
a habitat for insects which drop into the stream, thus providing a food
source for the fish. This impact will be temporary until natural vegetation
has been reestablished by replanting. The areas most likely to be
affected by removal of overhanging vegetation are a 2,500 foot length of
Swamp Creek along Butternut Drive and another 2,500 foot length of Swamp
Creek between Cypress and Locust Roads. These areas are relatively
steep-sided canyons with little or no floodplain so the Facilities Plan
has located the interceptor only 25 feet from the stream bed.
Terrestrial flora and fauna. Trenching for placement of the inter-
ceptors to serve the entire study area will require clearing of all
vegetation from a moderate strip the length of the interceptors, except
where construction will occur along existing roadways and through cleared
fields. This vegetation removal is temporary for a few years duration,
and natural vegetation will be allowed to reseed after construction is
complete. Wildlife habitat along the interceptor construction corridor
will be disturbed during construction, and to a lesser degree after
construction until native vegetation has regrown. The most sensitive
areas are in the swamps and wetlands north of 1-5. This would be a
significant impact only if construction occurs during breeding season.
Due to the narrow vegetation corridor to be removed, and the lack of any
permanent above-ground structure, no identifiable long-term direct
impact on populations is predicted.
The construction of a sewage treatment plant at Scriber Creek will
result in the removal of several acres of vegetation dominated by red
alder, black cottonwood, and western red cedar. Most wildlife fauna
residing on the cleared acres will be eliminated.
Energy
No action and secondary treatment only. Since neither of these
alternatives would expand the size of the service area, long-term collec-
tion and transmission impacts would be limited to essentially existing
IV-11
-------
conditions. Electricity supplies power for system pumping plus lights
at the treatment plant. About 500 gallons per month of diesel oil as
auxiliary fuel for the sludge incinerator is needed. Although community
energy demands will increase over time, the increase will be outside the
control of the sewerage agencies and must be considered as the existing,
or background conditions.
The "No Action" alternative would result in no additional demands upon
energy resources when measured against background conditions. Energy con-
sumption rates forecasted for the existing system would be expected to
occur primarily for pumping lighting at the treatment plant and auxiliary
fuel for the incinerator. In 1976, the system consumed 1,631,000 kwh of
electricity. This quantity would increase with time as the served popu-
lation grows slightly.
"Secondary Treatment Only" would require additional energy to
operate new treatment components. Total system demands would increase
about 10 percent over No Action, but this is a relatively insignificant
amount when compared to energy consumption by all activities within the
service area.
Limited service extension. An estimated 0.4 mgd of sewage would be
collected from around Martha Lake by the year 2000. This volume would
be pumped to the North Creek interceptor for treatment at Metro's West
Point plant. It would pass through two additional pumping stations at
Kenmore and Lake City before treatment. An estimated 2.2 mgd would be
pumped approximately 100 vertical feet from the Scriber Creek service
area, and 0.6 mgd raised approximately 130 vertical feet from McAleer
Creek, then treated at the Brown's Bay site. An additional 2.1 mgd from
Swamp Basin would be treated at a new Scriber Creek site, then pumped 230
feet for discharge into Puget Sound. Energy impacts would be higher
than would occur under either No Action or Secondary Treatment Only since
the flow would be larger and facilities would be operated at two sites.
Extending service throughout study area. Each of the five full
service alternatives would provide sewers to the same population and
collect the same sewage volume. The major difference between the alter-
natives is the amount of pumping required. All of these alternates would
allow four small existing pump stations east of Lake Serene to be abandoned
so sewage would flow by gravity to Metro.
The "Swamp Basin to Metro" alternative would discharge an estimated 5.3
mgd from the Swamp Creek basin to Metro in the year 2000. Within the Metro
system, this sewage would pass through the Kenmore and Lake City pump stations
before reaching West Point. Transport within the Swamp Creek portion of the
system would be by gravity. The total pumping head within the Metro system
would be about 100 vertical feet. Sewage from the Scriber and McAleer
Creek basins would be pumped to the Brown's Bay plant in quantities
IV-12
-------
estimated at 2.2 mgd and 0.6 mgd respectively in the year 2000. Pumping
head requirements would be about 100 feet from the Scriber Creek basin
and 130 feet from McAleer Creek.
The "Swamp and Scriber Basins to Metro" alternative would discharge
the Scriber Creek basin to Metro along with sewage from the Swamp Creek
basin. Transport energy would be similar to "Swamp Creek to Metro."
Even though the Scriber Creek pump station would be eliminated and
sewage from Scriber Creek would flow by gravity to the Metro system,
total pumping requirements within the Metro system are comparable to
those between the Scriber Creek basin and Browns Bay. Sewage from
Scriber Creek is currently pumped about 100 vertical feet to reach
Browns Bay.
"Swamp, Scriber, and McAleer Basins to Metro" alternative adds the
McAleer Creek basin to the Metro system by pumping from the existing
McAleer Creek pump station to the Scriber Creek interceptor. Again,
transport energy differences would be slight. Sewage from McAleer Creek
would be transported through a total pumping head of about 100 feet.
Under the "Treat at Browns Bay and Scriber Creek with Lower Swamp
Basin to Metro" alternative, 3.1 mgd from the Lower Swamp Creek basin
would be discharged to Metro by the year 2000. This sewage would be
raised about 100 vertical feet between the basin and the West Point
treatment plant. A new 5 mgd plant would be constructed in the Scriber
Creek basin to receive 2.3 mgd by gravity from the Scriber Creek basin,
0.6 mgd pumped about 30 vertical feet from McAleer Creek, and 2.2 mgd
pumped about 90 vertical feet from the upper Swamp Creek basin. From
the Scriber Creek plant, the effluent would be pumped about 100 vertical
feet to Puget Sound.
The "Treat at Browns Bay and Scriber Creek" alternative requires all
of the sewage from the Swamp Creek basin to would be pumped to a 7.5 mgd
Scriber Creek plant, while McAleer Creek sewage would be pumped to
Browns Bay.
Total estimated treatment and transportation energy requirements are
summarized in Table IV-1.
IV-13
-------
TABLE IV-1
COMPARISON OF ALTERNATIVE ENERGY CONSUMPTION
Alternative
Annual Energy in KWH
No Action
Secondary Treatment Only
Limited Service Extension
Swamp Basin to Metro
Swamp & Scriber Basin to Metro
McAleer, Scriber & Swamp Basin to Metro
Treat at Scriber & Browns Bay with No Discharge
1,800,000
2,640,000
3,690,000
3,980,000
2,520,000
2,240,000
to Metro
Treat at Scriber & Browns Bay with Lower Swamp
4,580,000
to Metro
4,020,000
Health
Disease. The most important benefit from the Swamp Creek trunk will
be the elimination of the potentially serious hazard posed by inadequately
treated overflows from the septic tank drain fields. Health authorities
will have a practical solution which they can compel private residences
to employ in the many cases where soil conditions are simply inadequate
to accommodate present population densities.
With the increase in population forecast for the Swamp Creek basin even
under the No Action alternative, the risk of a critical disease outbreak
becomes more severe. Larger populations will result in substantially
more drain field overflows since the soil is often essentially saturated
now. Thus, the exposure to children playing in the local streams will
increase significantly if sewers are not installed.
Fish contamination. Although excessive solids now pass through the
existing Browns Bay treatment plant, disinfection is being accomplished
though not always in accordance with accepted standards. There seems to
be some risk of contaminating aquatic life within Browns Bay under present
conditions, yet improved treatment would reduce these possibilities.
Existing studies have shown primary plant suspended solids do
settle out within generally a mile or two of the outfall. Considerable
IV-14
-------
bottom life then accumulates to feed on this organic material and is in
turn eaten by fish. Thus, any heavy metals or PCBs present in the
effluent solids could eventually enter the human food chain. However,
the data analyzed to date are insufficient to clearly delineate the
actual hazards involved.
However, freshwater conditions are less acceptable. Overflows from
septic tank drain fields do present significant exposure of a migrating
salmon to pathological organisms. This contamination could enter the
human food chain. Only by installing sewers to the Swamp Creek trunk
can this exposure be reduced and eventually eliminated.
Archaeology & History
Historical. The only point where construction activity would impinge
on a site of possible historical interest is where the trunk crosses the
old military road in the alder swamp near the 1-5 right-of-way. It is
unlikely that excavation for the trunk sewer will disrupt any significant
historical features in this area.
Archaeological. No known archaeologic sites would be disturbed by
implementation of any of the viable alternatives. The probability of pre-
historic habitation in the swampy lowland is very unlikely. Archaeological
sites could possibly exist around Stickney Lake or along the lower 1.5 miles
of Swamp Creek which are typical of other areas where evidence of early
Native American habitation has been found. It is desirable that a profes-
sional archaeologist be engaged for the construction period to monitor
clearing and excavation.
Evaluation of Secondary Impacts
Population
Forecast variances. A population forecast for extending sewer ser-
vice throughout the study area was presented in Chapter III. That fore-
cast was developed to define maximum sewerage facilities required by the
period 2000 to 2005 based on Puget Sound Council of Government's November,
1976 calculations. Obviously, the population forecast would be quite
different if no service extensions were provided. Population forecasts
under the No Service Extension alternatives are shown in Figure IV-2,
based on the data presented in Table IV-2.
IV-15
-------
z
o
t-
<
-i
D
Q.
o
Q-
cn
<
o
LU
cc
o
20,000
[ SWAMP
CREEK
3ASIN
1
I
t
P.S.<
i>NOV
:.o.G.
.76 FORE
:ast
FORE
HAST FOF
j
A NO A<
Stion
-rrrrr^yy^,
1970
1975
1980
1985
1990
1995
YEAR
2000
2005
2010
2015
2020
110,000]
O
t-
<
_j
D
a.
O
CL
H
00
<
o
LU
ac
o
20,000
1970
SCRIB
ER CREf
:k, mca
LEER C
*EEK At
JD BROV
/NS BAY
BASINS
1
1
i
N(
S.C.U.Ci.
)V. 76 FOF
ECAST
•v".vv»vv"v'*'>v*
LFOREC>
^NO AC!
kST FOR
ION
1975
1980
1985
1990
1995
YEAR
2000
2005
2010
2015
2020
110,000
1970
1975
1980
1985
1990 1995
YEAR
2000
2005
2010
2015
2020
IV-16
Figure BE-2
POPULATION FORECAST NO ACTION
-------
TABLE IV-2
NO SERVICE EXTENSION - POPULATION FORECAST
Lynnwood Area
Swamp Creek Basin
Year
Lower Limit Upper Limit
Lower Limit Upper Limit
1970
1980
1990
2000
2020
29323
30910
32583
36205
38165
29323
32175
35304
42506
46640
20141
21613
23193
267Q7
28659
20141
22498
25131
31357
35027
These forecasts indicate that, over the 20-year study period, the
Lynnwood area would increase about 25 percent instead of the 52 percent if
sewer service were extended. The Swamp Creek basin would experience a 31
percent increase without sewers instead of 107 percent.
Household characteristics. Without sewer extensions, dwelling units
are expected to average one per acre in areas of soils classified as "C"
or "D" suitability for septic tank drain fields. More suitable soils may
support dwelling densities averaging above two dwelling units per acre.
Saturation at these densities would occur about the year 2020.
Dwelling unit trends in recent years have shown a continuously
increasing percentage of new construction to be mobile homes. Trends for
multiple family units are not so consistent, yet have also generally been
increasing their share of new homes at the expense of single family houses.
Both of these trends can be expected to continue regardless of which alter-
native is implemented, however drain fields restrictions relating to lot
size will tend to encourage single family house construction. Provision
of sewer service will allow the denser development caused by mobile home
parks and multiple family units.
Density of residential units can be forecast from land use and zoning
maps. However, area population is also related to average family size which
is more difficult to predict. Recent census data has shown general declines
in the number of children per household and increasing numbers of single
adults. Population forecasts for the Facilities Plan were based on an aver-
age of 3.2 persons per household. Lack of sewer service would encourage
single family houses and might result in slightly larger average households.
Sewer service allowing more mobile home and multiple unit development might
produce smaller households through fewer children.
IV-17
-------
Personal parameters. Population forecasts show significant growth
occurring regardless of which alternative is implemented. Many of these
families will be new to the study area and perhaps recent arrivals to the
metropolitan community or even the state. Provision of sewer service will
increase the proportion of new residents.
Average and median ages are generally rising throughout the United
States. It is possible that extension of sewer service will encourage
residences by more new and younger families, thus slowing the tendency
towards older average age. This could marginally increase the demand for
more active recreation opportunities such as tennis, golf, and swimming.
Densities. For the unsewered Swamp Creek basin, the No Action popu-
lation forecast was based on the assumption that medium density residential
development of 1.5 to 3.0 dwelling units per gross acre would occur in
those areas indicated for residential use on the comprehensive plan
which have soils suitable for septic tank development. Low density,
defined as 0.5-1.5 dwelling units per gross acre, would occur in areas
designated residential in land use plans where soils are limited in
suitability for use of septic tanks. The average household density
would be 3.2 people/unit in accordance with local census expectations.
Saturation development then would not occur until 2020.
The Swamp Creek basin under the above conditions would reach about
26,500 people in the design year 2Q00. Saturation population was
determined to be 31,843 which represents an overall density of 4.0
people/acre for the total Swamp Creek Study Area, an annual increase of
approximately 1% per year of the existing population. This is approxi-
mately 25% less than the 44,000 population level anticipated if sewer
service were fully extended throughout the study area. Further assuming
that zoned capacity in the sewered parts of the study area remained
unchanged, the design year 2000 population level in those areas might
reach a level of 36,500, or 8,0Q0 less than the 44,535 estimated with
sewerage improvements and extensions. This would result in an average
overall density of 5.7 people/acre and/or annual increase of approximately
3/4% per year of the present population.
The total study area population for the year 2000 might thus be approx-
imately 63,000, less than 3/4 of the 86,000 or so people who might reside
there if sewer service were fully extended.
This magnitude of difference would lower the total needs for parks,
schools, and other public services. However, some services are more econ-
omically provided for higher density populations - public transit, sewerage
and water services, for example - and these would cost more per customer.
The potential market for retail shopping would also be reduced. Since
fundamental regional trends of population growth would presumably continue,
the people not able to find homes or jobs in the study area would be
accommodated somewhere else in the Seattle region.
IV-18
-------
Land Use
Comprehensive plans. Land use plans for the study area assume that
sewer service will be made available when development is intensive
enough to make it financially feasible. In that context, timely extensions
of sewer service would not necessarily induce premature or unwanted
growth. Differences in the development patterns could occur between the
various service extension alternatives if the timing of service extensions
into subareas were varied, but construction schedules have not been
established at this stage of planning. The discussion that follows
therefore assumes that the proposed service extensions would all be made
within the same period of time.
Should the No Action, Secondary Treatment Only, or Limited Service
Extension alternatives be followed, existing comprehensive plans would be
substantially revised. The amount of land suitable for development at
greater than rural densities would be greatly reduced as reflected by the
lower population forecast. If regional and subregional population
growth estimates are correct, alternative living and working areas would
have to be found. In practical terms this would probably mean an increase
in density allowances within existing sewer service boundaries, combined
with a shift of development pressure to other parts of the metropolitan
Seattle area.
Another outlet for this growth pressure could be continued dispersal
of population in a low density pattern, further and further removed from
central services and employment. It appears that the alternatives extend-
ing sewer service to the entire study area are most consistent with existing
comprehensive plans. Since those plans were prepared through the normal
public hearing procedure, revision of their basic premises could encounter
considerable public opposition, essentially from property owners with perhaps
a vested interest.
The service extensions throughout the study area featured in all remain-
ing alternatives would eventually allow subdivisions and development of
land to fulfill the study area's market demand for housing and business
sites. Simply stated, sewerage capacity would make development of smaller
lots feasible.
All alternatives would discharge through outfalls to Puget Sound which
cross the City of Edmonds shoreline. These outfalls, and any necessary
improvements to the existing Lynnwood sewage treatment plant, would be con-
sistent with the Edmonds Shoreline Master Plan.
Development rate. The No Action Alternative obviously deters develop-
ment in the existing sewered area, while encouraging scattered low density
development on septic tanks elsewhere. Although not necessarily an adverse
IV-19
-------
impact, this would be at cross-purposes with all the explicit land use
plans for the area which encourage carefully managed growth rates through
zoning specific land parcels. Pressure would increase to develop some
land well beyond present growth areas.
The Secondary Treatment Only alternative would provide the greatest
influence toward high urban densities. The existing zoning and health
department constraints on development of unsewered areas would keep them
at relatively low densities, preserving some of their natural amenities.
If zoning were changed to allow greater densities in response to develop-
ment pressure in the existing service area, the character of the sewered
areas could become somewhat more urban than it is presently. However,
significant restriction of additional development within the study area is
most likely to result in the development occurring somewhere else in the
Seattle metropolian community.
The Limited Service Extension alternative would have much the same
effect as the Secondary Treatment Only alternative within Lynnwood only
to a lesser degree. However, pressure to develop near Martha Lake would
be increased due to availability of sewer service. Local aesthetics
would be improved by reduced odor and improved lake quality, thus adding
to the attractiveness of the area.
The alternatives extending service throughout the study area imply
some change from the present low density character for the currently
unsewered area. This would be within land use plan guidelines so that
much of the area's natural amenities can be preserved, although specific
parklands must be obtained by the local entities and local zoning/land use
controls must be enforced. The degree of change was judged acceptable
to those who participated in formulating the land use plans.
Housing market. The No Action alternative, by preventing further
growth in sewered areas and slowing it in unsewered areas, implies signifi-
cant increases in housing costs in the study area due to demand from the
increased population competing for a restricted housing market. Similar
results would occur with the Secondary Treatment Only and Limited Service
Extensions alternatives, unless rezoning to higher densities allowed a
new wave of housing construction to bring supply more nearly in line
with demand. Property values could increase significantly for these
three alternatives, both within and outside the service area boundaries,
since even the reduced population growth would provide additional potential
buyers competing for a limited number of individual parcels.
Increased property values in themselves need not necessarily cause
net increases of property taxes. If local legislators restrained public
expenditure increases, property taxes could be levied at a lower rate to
compensate for inflated property values. However, the cost of treatment
plant upgrading envisioned in the Secondary Treatment Only and Limited
IV-20
-------
Service Extension would be spread over a relatively small number of rate
payers, due to the smaller population forecasted for those alternatives and
the economics of scale would be less. The per capita expenditures from
taxes and/or user charges required to finance the local share of the
required treatment plant would likely be higher than for the alternatives
extending service throughout the study area.
Alternatives extending service would all make possible acquisition
of a wide variety of housing sites in the study area, thus diminishing
cost increases resulting from scarcity of such sites. Property tax revenues
in the entire study area would increase as land develops more intensively,
thus tax rates could rise at a slower rate, although many factors besides
sewers affect community tax rates.
Open space reduction. Development could be defined as preemption of space
that might have been used otherwise, perhaps even providing greater
community benefits. Three alternatives involve the utilization of existing
treatment sites and introduce little or no additional lengths of sewer
lines. They would, therefore, displace few other potential uses and
would consume no public open space, if the areas' land use plans are
followed.
However, considerations towards open space reduction must occur within
the context of conditions actually existing in the study area. As was shown
in Figure II-8, the aerial photograph, this is not pristine, virgin land.
Considerable development has already occurred through the study area and is
irreversible.
Alternatives extending service throughout the study area by stimulating
peripheral suburban development and some additional use of bypassed lands
within the present service area would commit those lands to human use.
The present amenity of privately owned open space and small pasturelands
would eventually be replaced by housing and possibly some publicly owned
recreation space. This tradeoff is deliberate and in accordance with
local land use plans. Even at the forecast population levels for the
year 2000, densities would still be well below accepted urban norms.
Yet there would be some change in the study area character which is
still significant, even though perhaps accepted or even desired by many
of the current residents.
Transportation
Streets and arterials. Several future traffic volume projections
are available for the study area. The primary sources are land use and
travel projections prepared by the Puget Sound Council of Governments (PSCOG,
1974) and the Washington State Highway Department. These projections
IV-21
-------
consider the "no build" and "build" alternatives for both the Alderwood
Mall Shopping Center and the SR-525 connection from the Swamp Creek
interchange to SR-99.
Future regional roadway improvement projects will exert a direct
influence on roadway traffic volumes. Freeway and expressway improvement
recommendations include land additions to 1-5 and 1-405 and the develop-
ment of a new segment of SR-525 from 1-405 to SR-99. Relevant arterial
plans include expanding the capacity of and improving SR-99, 196th
Street S. W. , Filbert Road, and SR-527.
Both Snohomish County and the City of Lynnwood have prepared 6-year
street and road construction improvement programs, the completion of which
will lessen the impact of increased traffic volumes on the roadway system.
PSCOG's 1990 Recommended Transportation Plan and the State Highway
proposed SR-525 route are shown on Figure IV-3. For the purposes of
this analysis, it is assumed that the Alderwood Mall Shopping Center and
the SR-525 connection will be constructed. It is further assumed that
all local and collector arterial streets will be constructed as required
when housing development occurs.
No action and secondary treatment only. Population increases of
approximately 15,000 within the study area are anticipated. The projected
traffic volumes represent an increase of approximately 25% to 80% over
existing volumes within the area. Traffic conditions for the design
year will result in continued heavy congestion along 196th Street S. W.
and 44th Avenue W. in the Lynnwood business district. The remainder of
the roadway system will accommodate anticipated traffic volumes with
implementation of the 6-year street improvement program.
Limited service extension. This alternative will have essentially the
same impact as No Action, though traffic volumes would be marginally higher.
Service extension throughout the study area. Application of any of
these alternatives will result in anticipated population increases of approx-
imately 36,000 over the present population of 50,000 and an increase of 23,000
or 36% over the No Action concept. This increase is comprised of 16,000 in
the Swamp Creek area and 7,000 in the Lynnwood study area. The resultant
increase in traffic volumes is directly proportional to the population
increase and the volumes are depicted in Figure IV-3 .
It is assumed that housing developments or subdivisions will be con-
structed according to the comprehensive plan and that related local streets
and collector arterials will be provided as required. A detailed analysis
of vehicle trip generation and distribution, roadway capacities and level
of service operating conditions within the Lynnwood study area is included
IV-2 2
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
in the Alderwood Mall Shopping Center EIS. With the implementation of the 6-
year street improvement programs and the SR-525 connection, the freeway/
roadway system within the study area, with the exception of the Lynnwood
business district, will accommodate anticipated traffic volumes. Increased
heavy congestion and delay will be realized in the Lynnwood business district
and along SR-99.
Airports. A slight increase in general aviation traffic can be
anticipated for all alternatives in proportion to population increases.
However, this will have no major impact on the Paine Field Airport which
has ample capacity. Aircraft use can generally be expected to parallel
population trends within the study area. Other than marginal noise
increases which are not readily established, no other impacts can be
identified.
Ferry service. A slight increase in demand for ferry service due
to increased work and/or recreational trips can be expected as popula-
tion increases. No appreciable impact can be anticipated during weekdays;
however, the increased demand on weekends will serve to increase existing
congestion and delays.
Public transit. Snohomish County Public Transit Benefit Area indi-
cates they will receive a UMTA grant which will enable them to acquire
new and additional rolling stock plus park-and-ride lots and shelters
between now and 1985. Their long-range development plan includes expan-
sion of routes and service throughout the study area. Their criteria
for development planning are also the PSCOG 1976 population forecasts.
Adequate capacity will exist to serve all levels of population envisioned
by these alternatives.
Public Services and Utilities
Fire protection. Snohomish County Fire District No. 1 perceives no
significant impact on their facilities or services under any of the alter-
natives. Fire stations currently are strategically located throughout the
study area. The City of Lynnwood and Fire District No. 1 provide supple-
mental backup services to each other as required. Equipment and facilities
appear adequate and the only impact to be realized is that possibly one or
two additional full-time fire fighters would be required to provide a 24-hour
manned operation.
Police protection. There would be no anticipated significant impact
by any alternative within the City of Lynnwood, since they are operating
IV-2 5
-------
very close to the recommended ratio of two officers per 1,000 population and
will probably continue to do so.
There will be a significant impact in unincorporated areas. The
Snohomish County Sheriff's Department indicates that it is operating at a
ratio of 0.7 men per 1,000 population and is currently understaffed based
on the above-recommended ratio. Any increase in population will require
additional officers or necessitate a lower level of service and increased
response time in emergencies.
Water supply. The Alderwood Water District indicated no anticipated
impact on their facilities for any alternative population level. Two
30-inch lines, with a 24-inch cross tie, traverse the study area. There
are 4-400 hp pumps with a capacity of 25 mgd feeding the district. One
additional pump is proposed and a 2Q-million gallon reservoir is currently
under construction. The resultant terminal storage capacity will be 76
million gallons and pumping capacity will be 31 mgd. Their facilities
are being designed to accommodate sewered development throughout the
study area.
Electrical power. The Snohomish County PUD indicated no anticipated
impact on their facilities by any alternative. A new substation is slated
for construction in the Mill Creek area, and when completed, the grid net-
work will easily service all anticipated growth in the study area. Any
development would be considered "natural growth."
Natural gas. No gas mains presently exist in the Swamp Creek area;
however, portions of the Lynnwood area are served by natural gas. It is
anticipated that the bulk of the energy load would be supplied by the
PUD in the Swamp Creek area since Washington Natural Gas Company does not
believe it would be economically feasible to install mains and distribution
systems and remain competitive with electrical energy. It should be
noted, however, that the Washington Natural Gas Company is franchised
throughout the study area. No problems are anticipated in the Lynnwood
study area where gas mains presently exist.
Education. For the most part, growth within the study area will
occur within the boundaries of the Edmonds School District. Even though
the population has been somewhat stable, or on a slight increase during
the past few years, school enrollment within the district has been
dropping. Within the study area, the school district owns five existing
closed schools; has four closed facilities up for possible sale; and
owns various sites intended for construction of new facilities. The
district would compensate for any increased enrollment by reopening
existing closed facilities and busing students thereto until any new
construction became economically justified.
IV-2 6
-------
Telephone. General Telephone indicates no anticipated impacts.
Their planning and population projections of approximately five percent
per year concur with those used in this study. All population increases
will be considered as normal growth.
Natural Resources
No action and secondary treatment only. Groundwater and surface
water quality in the Swamp Creek basin would continue to be increasingly
degraded by septic tank effluents from both existing facilities and new
construction in the area. The construction of new residences with
septic tank sewage disposal in the basin is restricted by the Snohomish
Health District to sites having soils with adequate percolation rates.
Extensive areas of the Swamp Creek basin have soils unsuitable for
septic tank - drain field sewage disposal or only marginally so. This
will temper the rate and amount of urbanization, and thus the extent of
water quality degradation. It is likely that coliform bacteria, nitrate
nitrogen, and chloride contamination of surface and groundwaters would
increase. From the information available, it is difficult to predict
whether this would have any detrimental effect on present uses of Swamp
Creek and its tributaries. Increased nutrient loadings to streams in
conjunction with low summer flows can promote abnormally high algal
growths to the detriment of general stream ecology and fisheries resources.
Limited service area extension. The extension of interceptor
service to a limited portion of the Swamp Creek basin along 196th Street
and the area south of Martha Lake will provide some relief to the
on-going contamination of surface and groundwaters in these areas as
service connections are made in the future. Certain water quality
parameters in Martha Lake may improve, although water quality in the
lake is presently generally good, so the effect may not be noticeable.
Use of the lake may well increase, however, along with lakeshore develop-
ment, with some resulting contamination due to oil and urban runoff.
On a basin-wide basis, there may be little overall change in
surface water quality in the lower reaches of Swamp Creek. Water quality
improvements in the limited service area will likely be countered by
increased urbanization in other, unsewered areas of the basin. The
limited service area is presently relatively urbanized already, so no
remarkable increase in the rate of urbanization and urban runoff
contamination of streams is predicted.
Service extension throughout study area. The extension of inter-
ceptor sewers to the Swamp Creek basin will result in gradual increases
in service connections in that ax;ea, and thus greater effluent flows
into Puget Sound. The design flow of the existing system of 2.0 million
gallons per day (MGD) will increase as new services are added to the
system.
IV-2 7
-------
Water quality in Brown's Bay is presently not known to be adversely
affected by the treatment plant effluents. Studies by Ebbesmeyer and
Helseth (1976) of the Metro sewage treatment plant at West Point, the
largest on Puget Sound (average discharge 114 MGD, peak discharge 320
MGD), have not shown measurable effects on nutrient concentration or
phytoplankton productivity (growth) in Puget Sound. Analysis of bottom
life has shown increased activity resulting from the discharge of primary
effluent rich in organics but risks due to heavy metals and PCBs have
yet to be documented.
The increased discharge from the Lynnwood-Swamp Creek system is
therefore not expected to have significant impact on Puget Sound waters.
As discharge flows increase, there will undoubtedly be greater salinity
dilution and higher concentrations of nutrients and contaminants in the
immediate vicinity of the outfall, but rapid dilution will localize the
effect. Diffuser specifications will be defined as a part of final design
but will achieve the standards set by regulatory agencies. Limiting con-
centration changes in the receiving waters outside the effluent plume to
not more than 0.005 mg/1 is commonly accepted for chlorine. The Facilities
Plan calculated the diffuser based on a 500:1 dilution, for a mixing
zone concentration of only 0.001 mg/1.
In time, existing septic tank sewage disposal systems in the
service extension area will be abandoned as connections to the
interceptor are made. This will effect a gradual improvement of surface
and groundwater quality throughout the basin, particularly regarding
coliform bacteria, nitrate nitrogen, and chloride concentrations. No
beneficial impact is predicted for the most critical water quality
problem in the Swamp Creek system, turbidity and suspended solids loads.
Water quality in the lakes of the service extension area should also
improve gradually as nearshore septic tank systems are abandoned for
sanitary sewer connections.
The provision of sewer service will make possible an increase in
extent and intensity of urbanization within the Swamp Creek basin with
attendant adverse impacts on groundwater recharge, water quality,
wildlife habitat, and fisheries resources. Many areas of the basin are
known to be presently undevelopable due to soils that are not suitable
for septic tank drain field sewage disposal according to Snohomish
Health District regulations.
It is likely that additional lands are also undevelopable for the
same reason. The availability of sewer lines will permit development of
those lands. The present population of the Swamp Creek area is approxi-
mately 21,000. The year 2005 population is estimated to be between
26,000 and 30,000 if no sewer extension is provided. However, if sewer
service is provided, population in 2005 is expected to reach approximately
44,000. Based on projected average urban densities developed by
Woolridge (1971) for the Puget Sound region in the year 1990, an
IV-2 8
-------
additional 3,500 acres of undeveloped land in the Swamp Creek area would
be urbanized to satisfy the residential and service needs of that
population increase.
The urbanization of an additional 3,500 acres in the Swamp Creek
area will destroy a significant amount of existing wildlife habitat and
eliminate those wildlife populations dependent on that habitat for food,
shelter, and breeding range. Wildlife species will likely be replaced
by a lesser population and diversity of species more adaptable to urban
environments.
The process of urbanization produces significant changes in runoff
hydrology and groundwater recharge. Significant portions of urbanized
lands are converted to impervious surface, up to 50 percent or more in
multifamily development densities. Infiltration to the groundwater
system is decreased, evapotranspiration decreases, total runoff, and
storm runoff are increased, and delayed runoff is decreased. Table IV-3
illustrates typical hydrologic changes.
TABLE IV-3
APPROXIMATE ANNUAL
PRECIPITATION DISTRIBUTION
Forests versus 50
Percent Impervious Cover
Precipitation in Inches
50 Percent
Forest
Impervious
Cover
Cover
Annual Precipitation
40
40
Interception
5
3
Infiltration
35
14
Evapotranspiration
-15
-10
Total Runoff
20
27
Storm Runoff
0
23
Delayed Runoff
20
4
Source: Woolridge, 1971
Urbanization in the Swamp Creek basin is expected to result in less
than 50 percent impervious cover in individual developments, yet substan-
tially more than exists presently. Thus, urban runoff will increase sig-
nificantly .
IV-2 9
-------
Increased storm runoff is accompanied by greatly increased peak
flow rates and decreased time to peak flow in streams below the site.
The Snohomish County Metropolitan Municipal Corporation - King County
208 Areawide Waste Management Planning Study has produced a Model Urban
Drainage Ordinance which, when adopted by Snohomish County and other
regional jurisdictions, will act to mitigate many of the worst effects
of increased runoff from impervious surfaces. The effects of increased
storm runoff will be restricted to the developed site by limiting runoff
discharge rates to 100 percent of the natural condition and requiring
detention ponds to store excess runoff water for delayed discharge. It
is still likely, however, that decreases in groundwater recharge will
occur in the Swamp Creek basin with increased urbanization, further
resulting in decreased low flow rates in streams.
Surface water quality degradation is an inevitable effect of urban-
ization. Street surface contaminants (oil and grease, heavy metals, and
solids), fecal wastes from pets, fertilizer and pesticides applied to
urban gardens, and suspended solids from erosion associated with construc-
tion activities and bared soils are major contributors to this degradation.
The combined effects of urban runoff contamination and the elimination
of septic tank effluents from groundwater are not predictable from
existing information. The surface water quality parameters most likely
to increase would be oil and grease, heavy metals, biochemical oxygen
demand, and chloride. The detention ponds to be required for peak flow
mitigation in the future may have some slight mitigating effect on water
quality also. Some contaminants are adsorbed onto sediment particles
and will settle out in still water. It is doubtful if detention will be
of a sufficient time to effect significant improvements in surface
runoff water quality due to sedimentation, however.
Some detrimental effect on salmonoid fisheries and general stream
quality is inevitable from the urbanization of the Swamp Creek basin.
Decreased low flow rates will make spawning migration more difficult.
Increased suspended solids loads in streams will promote stream erosion
and scouring in some areas and sedimentation in other areas. Spawning
gravel beds may be damaged. Runoff detention ponds to be required in
the future will have some mitigating effect on stream erosion and
scouring. Uncontrolled residential development along stream banks will
likely result in stream channelization and the removal of overhanging
vegetation. These are the types of problems addressed by the 208 program.
Fiscal Impacts
Development. The fiscal effects of all alternatives depend on
assumptions about annexation policy and the timing of service extensions.
If sewer trunk lines were extended to all areas as soon as the inter-
ceptor/treatment facilities became available, the fiscal impact would be
IV-30
-------
much more severe than in a "phased growth" situation. In the latter,
sewer and other services such as water, police and fire protection, and
storm drainage would be extended to selected areas, encouraging develop-
ment there to absorb a certain amount of study area growth pressure
before opening other districts for development.
No action. This alternative would entail no public expense, but
the lack of "growing room" could restrict business and industrial uses
resulting in lower sales and less commercial tax revenue which ordinarily
helps to keep residential property tax levels down.
Secondary treatment only. A relatively high per capita cost would
result from this alternative unless the zoned densities of existing
sewered areas will be substantially increased to allow more apartment
and/or dense single family development. This high cost results from
fewer residents paying for a complex facility of smaller, less economical
size.
Limited service extensions. Limited Service Extensions would have
basically the same kinds of fiscal effects as Secondary Treatment Only,
although not so pronounced since overall density could be somewhat less.
Service extension throughout study area. Fiscal impacts resulting
from these alternatives would be similar in most ways, although differences
could occur, depending on the type of financial assistance available to
supplement local taxes and revenues from users of the system for construction.
One major determinant of fiscal effects would be whether or not
annexation of unincorporated areas could be made a condition of sewer
service extensions. It appears that within the existing legal/institutional
framework, there would be no incentive for owners of land in the unincor-
porated areas to annex to existing municipalities if water and sewer
service can be obtained through the Alderwood Water District, and other
services such as education and fire protection are available through
existing special purpose districts. If there is no condition of annexa-
tion imposed, sewering and developing of unincorporated areas may prove
to be relatively expensive for residents of existing cities in Snohomish
County. None of the property tax revenue from those areas will be
available to support basic city services that are used in part to accommodate
suburbanites who use city streets, parks, and other facilities when they
go there to shop, work, or recreate. This fiscal impact could be remedied
by tying sewer services to strong annexation incentives.
IV-31
-------
Sewer Rates
Interceptor treatment costs. The Sewerage Facilities Plan developed
costs for the interceptor pipes and treatment plant, all of which are
eligible for federal and state grant assistance. Most of the alternatives
require some discharge to Metro facilities in King County, and therefore
incur a financial obligation to Metro.
Metro has developed a standard rate applicable to all King County
customers to finance new construction, maintenance and operations, plus
amortize the debt assumed from all the sewer districts which were merged
to create Metro. In the past, an arbitrary 25 percent surcharge has
been imposed on all customers outside King County. Recent court decisions
have required all charges be based on equitable, justified costs, however
Metro has maintained the surcharge with respect to Alderwood is based on
capital costs and, hence, not subject to the new provisions. Thus,
costs shown in the Facilities Plan incorporated figures provided by
Metro to represent the appropriate "fair share" for areas served by the
various alternatives.
Collector costs. Once the interception and treatment facilities have
been financed, extending pipes between individual properties and the
trunk is normally performed as a Utility Local Improvement District
(ULID) since these costs are not normally eligible for any state or
federal grant assistance. Charges for each land parcel are developed
from three elements:
o Frontage along the street containing the sewer pipe would be
assessed approximately $40 per front foot
o Property area would be assessed about $0.03 per square foot
o Sewer house connections to the street collector average about $250
At present development levels, land parcels average approximately one
acre with 200 feet of frontage. The collector sewer assessment would then
total about $9,600. This assessment could be paid in a lump sum but is
normally financed over perhaps as long as 20 years. At current interest
rates of 7 percent, this would require an annual payment of about $906 or
$75.50 per month in addition to the interception and treatment monthly
charge.
Availability of sewer service will promote division of land into
smaller lots. Quarter-acre lots would require an assessment of about $3,800
with an annual payment of $359 or $29.90 per month. Should lots be divided
as small as 7,000 square feet, the collector assessment would be about $3,300
with an annual payment of $312 or $26.00 per month.
Residential rates. Comparison of all costs from providing sewer ser-
vice to the study area for each of the alternatives is summarized in Table
IV-4 to include collector assessments as well as treatment costs.
IV-3 2
-------
TABLE IV-4
TYPICAL MONTHLY RESIDENTIAL SEWER CHARGES
Alternate
Browns Scriber McAleer Swamp Creek
Bay Creek Creek Upper Lower
No Action $5.50
Secondary Treatment 7.43
Limited Service
Extension 7.64
Swamp Basin to Metro 7.64
Scriber & Swamp Basin
to Metro 8.46
Scriber, McAleer &
Swamp Basin to Metro 8.25
Scriber Creek Plant &
Lower Swamp to Metro 8.43
Scriber Creek Plant 9.07
$ 5.50 $5.50
7.43 7.43
7.64 7.64 $26.00+$17.31 $26.00+$17.31
7.64 7.64 $26.00+$ 5.31 $26.00+$ 5.31
8.91 8.91 $26.00+$ 5.63 $26.00+$ 5.63
10.04 8.25 $26.00+$ 5.52 $26.00+$ 5.52
10.04 8.43 $26.00+$ 6.69 $26.00+$ 4.50
8.91 8.91 $26.00+$ 6.00 $26.00+$ 6.00
The rates shown in Table IV-4 for Browns Bay, Scriber Creek, and
McAleer Creek basins reflect the typical residential charge for a lot
presently served by the existing system. Upper and Lower Swamp Creek basins
are shown with an assessment to construct sewers for typical lots plus an
appropriate sewer rate.
Commercial rates would probably differ from residential rates in some
manner not yet defined. In most communities, commercial rates are based on
water consumption. Special allowance may be needed for establishments which
consume substantial water quantities yet return only a small portion to the
sewer, as could occur with irrigating a large lawn or a bottling plant.
Financing. Within the existing service area, the present rate struc-
ture can be readily amended to collect the appropriate rate necessary to
implement any selected alternative. However, this tool is not available
for the large unsewered area of Swamp Creek. Were trunk sewer construction
to be financed just by those residences initially connected, rates would be
exorbitant.
IV-33
-------
Another method of financing trunk sewer construction would be a ULID
embracing essentially all of the Swamp Creek basin. Costs would thus be
divided among property owners based on the size of land parcels. This
could appear excessive to some individuals with large land parcels which
could not be connected to the sewer for several years.
A revenue bond could possibly be financed by the Alderwood Water Dis-
trict based on some form of flat rate charge to each existing and potential
customer served by the sewer even though that parcel may not actually be
connected for several years.
Comparison of Alternatives
Matrix Development
Selection of the alternative offering the best tradeoff between
environmental benefits versus adverse impacts requires a means to com-
pare all pertinent factors among all alternatives. A matrix summarizes
these comparisons in a single page, or series of pages.
The basic listing of pertinent factors for such a matrix would
include all applicable entries from the "List of Elements of the
Environment," published in the Washington State Environmental Policy Act
Guidelines. A few additions are needed to adequately address all
federal EIS requirements. Taken together, these factors allow a summary
review of the environmental impacts described earlier in this chapter.
In fact, a paradox results. The more factors listed in the matrix,
and the more variables compiled for each, the more subjective becomes the
result because all the little inaccuracies, when multiplied together, add
up to a wide range of possible errors. Such a matrix can be readily skewed
to produce any desired result.
Meaningful comparisons can really be made only between like quantities—
such as evaluating the impacts of the various alternatives on only one fac-
tor. However, not all factors are of equal significance. Many are of only
marginal concern to the community so alternative selection must be based
just upon these few factors which are key to the project.
The accompanying matrix lists the factors pertinent to the Lynnwood-
Swamp Creek basin sewerage facilities which are mentioned in the federal
and state environmental guidelines. A numerical comparison among the
viable alternatives has been developed for each factor. However, only
the 15 factors marked with at least a single asterisk (*) are considered
of sufficient significance to be employed in selecting the most environ-
mentally desirable alternative. Four of these factors are marked with a
IV-34
-------
double asterisk (**) as having sufficient value to be counted double and
two factors - Health and User Charges - are counted triple (***) since
they are felt to be the truly key impacts.
Impacts require comparison in several ways:
o Importance, as affecting the entire study area environment
o Severity of effects or the amounts involved after mitigation
o Duration considers permanent, temporary, and variable changes
o Certainty should be gauged since some impacts are only potential
o Polarity of adverse impacts as opposed to benefits
Basic values assigned to each factor in the matrix are based on the
existing condition so No Action is valued at 0, or no change. Benefits
or improvements are then shown as + or positive while adverse impacts
are shown as - or negative. Each factor is valued in a comparison among
the alternatives with the most beneficial valued highest and the most
adverse valued least. Thus, the numerical value is essentially just a
ranking of alternatives for that specific factor and where little dis-
tinction can be drawn between alternatives they are shown as equal with
the same value.
Ideally, a matrix should provide a directly measured impact quantity —
estimated, precise, or a range — for each factor by each alternative.
Unfortunately, it is not often practical to develop a quantity which
accurately represents the severity or magnitude of the impact. Thus,
most factors must depend on subjective evaluation which may differ
significantly from person to person. An absolute determination is not
achievable in practice which will satisfy everyone. Tables IV-5, 6, and 7
show the environmental impacts as they are valued in this EIS.
Ranking Alternatives
Although more than 50 factors are shown in the matrices, attempts to
include all in any weighted evaluation results in a meaningless statistic.
Only the most important factor should be considered. Addition of the values
shown with an asterisk plus double asterisks counted twice and three
asterisks counted triple provides the results shown below:
Swamp Basin to Metro
+1
Secondary Treatment Only
0
No Action
0
Scriber & Swamp Basins to Metro
-1
McAleer, Scriber & Swamp Basin to Metro
-7
Limited Service Extension
-20
Scriber Plant - No Discharge to Metro
-22
Scriber Plant - Lower Swamp Basin to Metro
-26
IV-3 5
-------
While the above subjective results can hardly be considered as absolute
relative ratings, the indications generally agree with intuitive expecta-
tions. No Action does nothing to improve an existing poor situation. Second-
ary Only meets all needs of the presently sewered area while avoiding any dis-
ruption to the Swamp basin. Limited Service Extension solves some problems
at high cost but ignores others. Swamp Creek Basin to Metro provides the
most cost-effective solution for the entire study area. Remaining alterna-
tives are simply less efficient possibilities.
Thus, Swamp Basin to Metro was found the cost-effective alternative in
the Facilities Plan and also provides the most beneficial environmental
tradeoff. Should funding not be immediately available for the Swamp
Creek trunk, then the Secondary Treatment Only alternative is the second
choice—ideally as an initial stage for eventual funding of the Swamp
Creek trunk.
IV-3 6
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
Chapter 3ZT
IMPACTS OF SELECTED
-------
CHAPTER V
IMPACTS OF SELECTED ALTERNATIVE
Selected Alternative
Facility Concept
As developed through the Environmental Matrix, the most cost-effective
and environmentally acceptable alternative was found to be draining all of
the Swamp Creek basin to Metro with the McAleer, Scriber, and Brown's Bay
basins continuing to be served at the existing treatment facility site on
Brown's Bay. This concept was illustrated in Figure III-5 with the gravity
interceptor further shown in Figure 111-12.
Treatment Concept
The existing treatment facility on Brown's Bay would be upgraded to
achieve secondary quality effluent using the activated biological filtra-
tion process with sludge disposal by incineration on-site and disinfection
by chlorination. This process was schematically shown in Figure 111-10.
Unavoidable Impacts and Mitigative Measures
Construction
Trenching. Erosion during interceptor construction is unavoidable,
and serious erosion with subsequent water quality turbidity increases
and stream siltation is inevitable if interceptor trenching is carried
out during the winter rainy season. Water quality and stream siltation
effects will be greatest from construction activities on slopes that lie
adjacent to streams. Erosion from cleared ground and backfilled trenches
could continue after the completion of construction if reseeding,
replanting, and/or mulching is not practiced. It is particularly
important that interceptor construction on slopes draining directly into
a stream be conducted during the summer due to the extreme erosion-
siltation hazard from those sites. The effects of erosion can be some-
what restricted to the vicinity of the interceptor trench if excavated
material is stockpiled on the uphill side of the trench. Any haul roads
should also be placed on the uphill side of the trench.
V-l
-------
The mixing of near-surface soils with deeper glacial till should be
avoided when possible. During excavation, soil and till should be
stockpiled separately with till being used for initial backfill. However,
in some restricted areas, segregated stockpiles could disturb more land
with greater impacts than simply allowing the soils to be mixed.
Water quality degradation due to erosion-induced turbidity and
suspended solids increases will be a particular problem where trenching
must be done on steep slopes adjacent to streams. In some areas, stream
canyon slopes are approximately 1:1, and the canyon bottoms are narrow
with no floodplain in some locations. Water quality degradation and
stream siltation can be avoided only through attentive enforcement of
strict specifications. Construction in these areas should be restricted
to the low flow period in midsummer to avoid the worst effects of water
turbidity and stream siltation.
Treatment facility site. Truck traffic will increase along 76th
Avenue West due to transportation requirements of construction materials.
Excavation for treatment components will be performed by heavy equipment.
Dust, noise, and some odors will be generated during the construction
process.
Since the existing plant must remain in operation until the new
facility can commence treatment and the site area is limited, careful
construction scheduling is essential. Working hours and traffic patterns
should also be integrated into the construction schedule to minimize
disruption to the local residents. Key construction equipment items
must meet federal noise standards. Sprinkling exposed soil will reduce
dust generation.
Outfall. Installation of a diffuser section on the existing out-
fall and construction of a new, parallel outfall will require significant
underwater activity. Some disturbance of the seabed, turbidity, and
sedimentation is unavoidable. Sidecasting of soil should not be allowed.
Any dredgings should be removed from the site for disposal on land as
approved fill.
Stream crossings. Precise pipe locations have not been defined but
the total trunk length will approximate 13 miles. Available aerial
photographs and topographical maps are insufficient to accurately locate
all surface water bodies. However, preliminary plans indicate the Swamp
Creek trunk with the Martha Lake and Scriber Creek interceptors will
have about 30 stream crossings. Approximately 67 lateral connections
are planned and perhaps 25 of these must cross a stream to enter the
trunk. The only feasible alternatives to these lateral connections would
be a force main trunk or a lift station - gravity pipe trunk. Both of
V-2
-------
these alternatives were found to be too expensive for serious consider-
ation. Present intentions are to locate the pipe at least 25 feet away
from any stream. This proximity will occur in at least two lengthy
locations totalling several thousand feet where usable land is limited.
Disturbance of the stream bed with this frequency could create
turbidity and sufficient downstream sediment to cause significant damage
to the fish habitat that will adversely affect spawning. Removal of
large quantities of vegetation shading the streams could allow the water
temperature to exceed the desirable upper limit for salmon. Details of
trunk location are insufficient to establish more than preliminary
magnitudes of these impacts however.
Strict enforcement of carefully worded specifications can limit
chance or unnecessary entrance of construction equipment into the stream
bed. Should work within the stream bed be essential, it will be scheduled
to avoid periods when fish are incubating or spawning and those streams
when high flow volumes are expected. Some precipitation will undoubtedly
occur during construction however, so construction practices will limit
the area of barred soil to just what must be needed for a given time
period. Erosion control devices will be continuously emplaced to prevent
erosion and trap sediment before it enters the stream.
Actual stream crossings will be constructed in accordance with State
Fisheries and Game requirements. In most cases the technique will
involve diverting the stream flow through a culvert or stream isolation
by sheet piling. If so directed by Fisheries, construction will be by
jacking a casing underneath the stream bed and installing the trunk
sewer within the casing.
Wildlife habitat. The swampy area north of 1-5 bounded by Ash Way
and Alder Way is the largest undisturbed wetlands habitat within the
study area. The originally proposed trunk route was to pass right
through the middle of this area as the least costly alignment. However,
this was felt to be an unnecessarily severe impact on the habitat so a
more expensive alignment following Ash Way has been selected instead to
minimize the disruption to local wildlife.
Much of the proposed trunk route passes through natural areas along
the creek banks within the study area. These areas now provide an
attractive habitat for low densities of the smaller wildlife species.
However, spotty home construction over the years and recent tract resi-
dential developments have also found these areas attractive. As a
result, the remaining natural areas are restricted and small resulting
in limited value as wildlife habitats. The trunk can be constructed
under strict specifications to limit disruption and requiring attentive
surface restoration which will have only minimal impacts on the local
wildlife for a temporary duration.
V-3
-------
Environmental Changes
Water. Local groundwater quantity in the uppermost water-bearing
strata will be reduced by eliminating septic tank drain fields due to the
installation of sewerage collectors to the interceptor. Groundwater
tables above the elevations of gravity flow sewers will cause some
infiltration of groundwater into the sewers. This effect is minor and
will be minimized by using neoprene or plastic gaskets or seals at sewer
pipe joints. Of greater impact would be the drainage of local ground-
waters along the bed of the sewer pipe. The beds upon which sewer pipe
are placed and the backfill material are usually more porous than sur-
rounding undisturbed soils and will act as drains. All available
groundwaters in the vicinity of such drains and above the sewer pipe
elevation would be drained to the sewer pipe elevations. This impact
can be very substantially mitigated by the careful placement of imperme-
able clay dams at regular intervals along the sewers. These dams act as
a stop to the drainage of groundwaters.
Flora. The destruction of vegetation along the interceptor route
is unavoidable. The severity of the effects of this destruction and its
duration can be shortened. Appropriate measures would include reseeding
and replanting disturbed areas with native vegetation and short-term
stabilization of the soils surface with organic mulches. Straw has been
successfully used as a mulch and soil stabilizer for sloping embankments
along new highway construction.
All dry brush must be removed to aid control of wild fires. Native
vegetation will be reseeded to control erosion.
Seeding and fertilizing should be carried out. Particular attention
will be paid to pasture and meadow areas where natural reseeding would
be expected to be difficult. Additionally, reseeding would assure the
growth of desired plant species. Fertilization within forested areas
would also enhance revegetation of bare areas, although some controls may
be necessary to limit nutrient runoff to the local streams during rainfall.
Separate storage of upper soil layers and glacial till material
during construction and replacement of the upper natural soil layers
over the till backfill material would provide an improved environment
for the growth of new plants. However, additional area would be disturbed
which could create a more severe impact than soil mixing. These mitiga-
tive measures should be considered for application at all locations
where the sewers would deviate from roadside cuts.
Wildlife habitat. The removal of vegetation overhanging Swamp
Creek and Scriber Creek will have greater impact than general vegetation
V-4
-------
clearing as it will affect fisheries habitat in addition to vegetation
and wildlife habitat. When overhanging vegetation is removed, it may
eliminate needed shading of pools in the stream and will also eliminate
an insect habitat that is a source of fish food. In locations where the
interceptor alignment is closely parallel to Swamp Creek or Scriber
Creek, the alignment should be routed a sufficient distance away from
the stream to assure that no overhanging vegetation will need to be
cleared for construction. However, the removal of some overhanging
vegetation will probably be required along certain areas of Swamp Creek
where the stream flows through steep-sided canyons.
The temporary disturbance of wildlife populations during construc-
tion will occur. Once installation is complete and the interceptor
corridor is allowed to revegetate, these disturbances will gradually
fade away. However, increased development will, in time, cause permanent
habitat changes which will reduce present wildlife populations. New
wildlife patterns will gradually emerge, featuring fauna more compatible
with human development, though at a probably lower density and less
"wild" state.
Some erosion is inevitable, and it is likely that some stream
sedimentation will occur over salmonoid spawning beds. Mitigative
measures regarding erosion control, construction scheduling, and revege-
tatlon will minimize detrimental effects on the fisheries, but not
eliminate them.
Short-Term Environmental Use Versus Maintenance and
Enhancement of Long-Term Productivity
Potential Future Options
Land use. No significant short-term versus long-term tradeoffs are
involved through proposed improvements to the Lynnwood sewerage system.
Basic facilities have been installed for many years. Cost comparisons
developed during the Facilities Plan clearly showed relocation of the
treatment plant would be expensive and no compensating environmental
gain can be identified.
Construction of the Swamp Creek trunk will allow correction of the
environmental impact resulting from septic tank drain field failures.
However, the trunk will also allow property subdivision into smaller
lots supporting higher population densities. Over time, resulting
population growth may alter the character of the community signifi-
cantly. Less open space would be available to the public and wildlife.
V-5
-------
It is definitely not the intent of EPA-funded projects to encourage
commercial development and land speculation. Yet provision of sewers
will unavoidably promote a certain amount of such activity. However,
current population forecasts suggest that even 20 years of such growth
will still result in significantly lower densities than are common in
many suburban communities. In any event, substantial development is
occurring now and will continue even in the absence of sewer construction.
Furthermore, it is far from certain that the past growth trends upon
which forecasts must be based will continue very far into the future.
Rising construction costs of single-family housing have already altered
some residential tendencies. Future energy costs may force further
changes, especially in transportation where commuting to work is common.
A rather comprehensive park plan has been developed by Snohomish
County which would preserve much of the local natural open space. All
that is required is a community commitment to allocate sufficient funds
to secure certain key properties and trail rights-of-way. However,
funds are likely to be limited, so the resulting park system actually
attained will probably be less than the County plan suggests.
Among the elements of the County Park plan is a proposed Swamp Creek
trail which follows essentially the same alignment as the Swamp Creek
trunk from Lake Stickney south to the King County line. Construction of
the Swamp Creek trunk offers a unique opportunity to mitigate some of
the detrimental impacts which could result from constructing a large
sewer through natural open space. Trails for either bicycles, hiking,
horses or various combinations could be built within the trunk right-of-way
after installation of the pipe. An 8-foot wide asphalt bicycle path might
cost $3 per lineal foot and the total length is about 40,000 lineal feet.
Equestrian or foot trails would be less expensive.
Thus, some significant land use changes must be expected with con-
struction of the Swamp Creek trunk, but the basic community character
will continue to be rural residential for the foreseeable future.
Water use. Improved treatment levels are not expected to result in
noticeable changes to Puget Sound water quality, even within just the
Brown's Bay locality. Thus tradeoffs can not be identified.
Freshwater surface streams may experience some water quality trade-
offs, though. Provision of sewers should lower BOD and pathogen levels
resulting in higher dissolved oxygen and safer water. However, additional
development may promote changes in storm flow characteristics in spite
of intended corrective regulation. More rapid runoff could produce
greater flow volume, higher turbidity and more sediment which could
affect aquatic life—especially salmon and trout.
V-6
-------
Future uses. Sufficient development has already occurred within
the study area to form an irreversible commitment to rural residential
use. Individual and economic commitments are simply too great for a
return to lower development levels to be practical. The only question
is how dense future development will become. Based on data available,
investment potential is not present to generate sufficient densities to
achieve even the typical suburban levels of 8 or 9 persons per acre.
Instead, population levels are not expected to exceed perhaps 5 or 6
per acre, which though noticeably denser than at present, do not repre-
sent a drastic land use change.
Health and Safety
Disease. Raw or poorly treated sewage has long been recognized as a
serious source of disease. Septic tanks treat sewage basically by
allowing the organics to decompose and settle out. No disinfection is
provided to the effluent which is expected to percolate through the soil
from the drainfield. However, when the soil is insufficiently porous,
or becomes saturated by storm water or the drain field is overloaded,
the septic tank effluent may be forced to the ground surface and flow
overland. This condition commonly occurs in the Swamp Creek basin under
present conditions.
In addition to the offensive odor, the septic tank effluent flowing
on the ground surface poses considerable potential health risks. This
is especially true because of ready contact with pets and small children.
Some bacteria and virus pathogens can be destroyed by settling, however
detention times for septic tanks are often designed for about 24 hours
which is not sufficient to eliminate many of the potential disease-
causing organisms. Some of the more common diseases borne by sewage
are:
o Typhoid fever
o Infectious hepatitis
o Infant metlemoglobinemia (nitrate poisoning)
o Tetanus
o Gastrointestinal infections
Provision of sewers will practically eliminate exposure to these
hazards. Yet while current septic tank usage prevails the risk of a
disease outbreak with possibly fatal results is always present. Should
an outbreak occur, eliminating the pathological causes will be costly
and time consuming without adequate sewers. Elimination of this health
risk is the primary benefit and motivation to construct the Swamp Creek
trunk.
V-7
-------
Chlorine. Disinfection will be accomplished with chlorine dispensed
from ton cylinders. This is a highly corrosive and poisonous gas.
Chlorinators have been perfected and proven safe over many years of
operation. Accidents rarely occur. Yet the continual use within a
residential neighborhood of some 200 pounds per day of a deadly gas is a
risk which must be recognized and understood by the community. In
addition to storage and use at the Brown's Bay site, ton cylinders will
be transported by truck through the City of Lynnwood with consequent
exposure to traffic accidents. These risks are all present with the
existing treatment facility but at a lower level due to small quantities
of chlorine employed. However, the safety record of chlorine disinfection
nationwide is excellent. Accidents are extremely rare and injury or
death is almost unknown.
Chlorine disinfection does form some potentially harmful compounds
in the treated effluent and receiving waters. The significance of these
compounds is not yet clearly defined but is a matter of concern to
modern researchers. Future studies may demonstrate that the hazards
involved with these compounds are unacceptable, in which case dechlori-
nation of the effluent will be required. Provision should be retained
in the new treatment facilities for future installation of dechlori-
nation equipment should it eventually become necessary.
Property Valuation
Treatment plant site. Because a sewage treatment plant has existed
at Brown's Bay for many years, property values in its immediate vicinity
have long since adjusted to this basic condition. Expansion of the
facility through installation of additional, larger components is expected
to marginally depress local property values. Provision of public use
facilities in the form of beach access, rest rooms, picnic shelters, and
parking in an attractive setting may offset some depreciation due to
upgraded treatment. However, public facilities with parking may also
draw additional patrons from outside the immediate vicinity and may not
be viewed as a benefit by some local residents who already possess beach
access. Much of the value for any land parcel rests in the opinions of
owners or buyers. Impacts due to site upgrading are not really predict-
able but must be expected to at least marginally lower the value of
homes in the immediate vicinity.
Construction activity of any kind is usually a detriment to res-
idential property sales, should a home be on the market during that
period. The activity will continue for a year or more. Transient
fluctuations could be sufficient to cause a significant value loss to
certain residents.
V-8
-------
Existing sewer service area. The proposed action will have no
immediate effect on property presently connected to the sanitary sewer.
Any value accruing over a longer time period due solely to the possibly
higher level of commercial activity which could occur with development
in the Swamp Creek basin is likely to be slight and not readily identified.
Areas receiving sewer extensions. Availability of sewers will, of
course, result in some appreciation in local property values. The
local interceptor share and entire collector cost is basically a local
investment which is intended to improve local properties. Any apprecia-
tion in property value is a direct result of local investment and is not
likely to substantially exceed the present worth of the improvements, as
borne by the residents in annual assessments and service charges.
Some proposed developments and residential construction have been
disallowed in recent years due to the lack of adequate sewerage facilities.
Provision of acceptable facilities may allow some of these developments
to be implemented. In a few cases the valuation gains may be substantial.
Yet when the years of stifled improvements are considered too, such
gains may well be justified. There are no known large land parcels
where owners or developers stand to receive "windfall" benefits.
Project Justification
Lynnwood service area. PL 92-500 requires all municipal wastewater
treatment facilities to install and operate secondary treatment components.
The elements proposed by the Facilities Plan for the Lynnwood service
area represent the most cost-effective method of complying with this
legal requirement over the required 20-year design period.
Swamp Creek service area. There are no legal requirements which
mandate that any action needs to be taken within the Swamp Creek service
area. However, several justifications for the project exist which will
worsen with time.
1. Health risks exist throughout the area due to the failure of local
soils to support septic tank drain field operations. As a result,
poorly treated sewage flows in surface drainage channels exposing
children, adults, and pets to ready contact with potential disease-
causing pathogens.
2. Swamp Creek and tributaries receive some contamination from poorly
treated drain field effluents. Fish caught from these streams could
be contaminated by the pathogens present in this drain field dis-
charge. It is possible effluent organics could locally lower the
dissolved oxygen content and reduce the ability of the streams to
support aquatic life.
V-9
-------
3. Malodorous and visual nuisances are created by the surface flow
from inadequate drain fields. These conditions are especially
objectionable to the local residents during warm weather.
Irreversible, Irretrievable Resource Commitments
Project Implementation
Capital. Investment in fixed, permanent facilities has been esti-
mated in the Facilities Plan as summarized below:
Construction Cost Total Project Cost
Brown's Bay Treatment Plant
Swamp Creek Interceptor
Pump Station Improvements
Total
$ 9,430,000
9,550,000
720,000
$19,700,000
$11,780,000
11,530,000
880,000
$24,190,000
Presuming that essentially all of the above costs are found to be
grant-eligible and do, in fact, receive funding, cost would be divided
approximately as follows:
Federal share (75%)
State share (15%)
Lynnwood service area
Swamp Creek basin
$18,140,000
3,630,000
1,270,000
1,150,000
$24,190,000
In addition to the initial investment, annual operating and main-
tenance expenses for the Lynnwood system are estimated at about $210,000
and about $51,000 for the Swamp Creek service area including Metro
treatment costs.
Construction effort. The above-mentioned capital investment will
purchase labor, material, and equipment necessary to construct the
sewerage facilities. In the present Pacific Northwest market and the
United States in general, construction capacity exceeds the demand. As
a result, construction unemployment exceeds national and local averages.
A project of this magnitude would be welcomed by the industry.
None of the materials required for this project are currently in
critically short supply. There are no known items of material or equip-
ment proposed for these improvements whose use would prevent another,
possibly more desirable, project from being implemented.
V-10
-------
Design talent necessary to prepare the necessary detailed plans and
specifications is also readily available on the local market. Present
demands upon engineering capacity allow adequate efforts to be devoted
to this project without significant impediment to other activities
desired by the local community.
Land and Water Use
Direct commitments. Upgrading the present Brown's Bay treatment
plant will not require any additional land. Instead, careful development
of the existing site could provide increased public benefit through
construction of recreation facilities resulting in multiple use of the
property.
The Swamp Creek trunk will be installed primarily in easements on
private properties. Although little will be visible of the sewer once
in place, vegetation along this right-of-way will be altered, probably
permanently. Future placement of structure over or near the trunk will
be severely limited.
Little change will be observed in Puget Sound water quality as a
result of providing secondary treatment to the sewage effluent. Some
construction-related degradation of Swamp Creek will result from sedi-
mentation which may affect salmon spawning at least temporarily.
Elimination of septic tank drain fields with the resulting overflows may
eventually lower the coliform count in Swamp Creek and, possibly, raise
the dissolved oxygen level.
Indirect commitments. Installation of sewers will accelerate the
commitment of all property within the study area towards more intense
urban development. Provision of sewers will cause the present building
prohibition imposed on some 600 land parcels to be lifted and development
can commence. Increased population densities will reduce the open space
within the study area and restrict the range of wildlife. However,
forecasted population increases over the 20-year design period will
still result in a density considerably less than prevails in many
typical, modern suburban communities.
It is possible that increased real estate development will alter
the rate and volume of storm runoff which will affect Swamp Creek water
quality. Local planning and legislation is intended to limit alterations
to storm runoff characteristics; however, such intentions do not always
achieve desired results. These controls are aimed at larger developments
with dependence on plan checks and site inspection. Yet individual lots
may be developed under less stringent controls. But when the aggregate
V-ll
-------
of many individual lots is considered the alterations may be significant.
Shortened runoff times plus increased flow volumes could produce flooding
along Swamp Creek with some sedimentation which could affect salmon
spawning. Flooding may be sufficiently severe to cause property damage.
Malfunctions & Accidents
Chlorine. The most lethal potential malfunction within the sewerage
facilities involves the use of chlorine for effluent disinfection. In
spite of the deadly possibilities inherent with this highly toxic gas,
the safety record for its use over the past several decades in treatment
plants is excellent.
Chlorine will be dispensed from ton cylinders at a rate expected to
average about 5 mg/1 into the treated effluent. This could result in
chlorine use exceeding 200 pounds on an average day for the year 2000.
Chlorine gas leaks are rare but they do occur from time to time. However,
such leaks are almost invariably too slow to pose serious health risks
outside the chlorination structure. In the entire United States since
1945 only about a half dozen serious chlorine accidents resulting in a
total of 4 deaths have occurred among the thousands of operating treat-
ment facilities. This accident exposure rate is so small as to be
negligible.
Transportation of chlorine to treatment facilities is normally by
truck. There is no record of any truck accident within the United
States involving chlorine which resulted in a chlorine-related hos-
pitalization or death. Thus the transportation risk is nil.
Effluent standards exceeded. There are three basic situations
which could conceivably result in the treated effluent exceeding the
standards specified by the discharge permit:
o Failure of one or more treatment equipment components
o Operator mistakes in managing the treatment facility
o Introduction of toxic material by a customer into the sewage
However, the specified minimum standard of secondary treatment is
more than twice as stringent as the best effluent quality ever produced
by the existing treatment plant and no evidence has been found which
proves any significant deterioration has yet resulted in receiving water
quality. Since any failure to achieve the permitted effluent standard
will be temporary in duration, no significant impact on local water
quality is expected, should effluent standards be exceeded.
V-12
-------
Plant design will not permit the wastewater flow to bypass treatment.
Equipment failure possibilities will be minimized through provision of
redundant units, emergency power, and several piping options to allow
various flow configurations.
Personnel operating the plant will meet state licensing requirements
and adequate staff will be provided by the City. Yet manipulation of
living organisms is never a precise science. Changes occur constantly
in the organic metabolism which are not always readily apparent or
understood. Thus, operating errors do occur, but will be corrected as
efficiently as possible.
The City sewer use ordinance specifies objectionable materials
which are not acceptable for discharge to the sewer. Unfortunately
these requirements are often misunderstood, forgotten, or simply ignored.
When toxic wastes reach the treatment plant, biological activity in the
filters and aeration basins will be severely depressed resulting in
lower oxidation rates of organic matter and raising the BOD in the
effluent. In some cases the toxic material could pass through the plant
and be discharged into Puget Sound with possible impacts on the aquatic
environment. The plant has sufficient flexibility to adjust treatment
configuration and recirculation rates so toxic material will not destroy
the entire treatment capability for extended time periods. In the event
an undesirable material appears in the waste stream at regular intervals
plant personnel can eventually trace the origin of the material to the
offending customer and appropriate action implemented.
Activated biological filters are one of the most flexible treatment
processes yet developed and have extremely good resistance to upsets by
toxic material plus fast recovery when such upsets do occur. Piping
configurations allow treatment components to be managed to best accommodate
changing waste conditions. Recirculation rates can be altered to vary
the exposure of wastes to the treatment components and thereby minimize
the time period when effluent standards might be exceeded.
Pump stations. Although provision of a gravity trunk through the
Swamp Creek basin will allow several pump stations to be eliminated,
others will still be necessary. Failure at one of the remaining pump
stations will result in the overflow of raw, untreated sewage into the
surface drainage which will enter Swamp Creek through its tributaries.
Such overflows will lower stream dissolved oxygen, introduce patho-
logical organisms, and create an unsightly, malodorous mess.
All pump stations will incorporate modern design features including
a standby pump in addition to the design peak flow capacity and emergency
power during periods of electrical outages. However, pump stations can
not be made absolutely reliable. Electrical relays fail. Mechanical
components break and jam. Failures of this nature seem most likely to
occur during peak flow periods, especially under storm conditions.
V-13
-------
However, such conditions would not necessarily result in extreme environ-
mental impacts. Storm inflow to the sanitary sewers would dilute waste
concentrations and runoff would raise creek flows. Thus, impacts,
which are heavily dependent upon concentrations, may not be terribly
severe. In any case, pump station failures are expected to be infrequent
and of short duration.
Treatment equipment failure. There are no particular physical
dangers inherent with the potential failure of any treatment equipment
item, other than the previously mentioned chlorinators. Since all
treatment steps involve dual units, operations would continue even
should one unit fail.
Incineration is probably the treatment element most susceptible to
environmental impacts in the event of failure. Unstabilized sludge
would still be produced in the event the disposal system failed. How-
ever, the two incinerators are planned to operate only 12 hours per day,
five days per week. Failure of even the larger incinerator would simply
result in longer operation of the remaining unit. Nine days storage
capacity for dewatered sludge is provided in the hopper with an additional
two days provided ahead of the pressure filters. Since many pressure
filter cells will be needed, failure of one, two, or several will not
disrupt operations.
Pipe system. Explosion of sewer gas in long pipe system was a sig-
nificant risk when waterborne sewers were first developed many years
ago. Modern systems incorporating proven minimal flow velocities and
adequate ventilation have almost eliminated the potential for accumu-
lating sufficient methane to reach an explosive mixture. Risks of
explosion in modern systems like Lynnwood are considered negligible.
Pipe blockage due to foreign material or sediment in the pipe could
result in the backup of sewage into residences. Aggressive maintenance
will render such events infrequent yet they are a nuisance when they do
occur. However, correction is normally rapid with little or no permanent
effects.
V-14
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
Chapter ~2L
SOLICITED COMMUNICATION
-------
CHAPTER VI
SOLICITED COMMUNICATION
Public Participation
Citizens Advisory Committee
Early in the development of the Facilities Plan and the EIS a Citizens
Advisory Committee was formed from interested individuals residing within
the study area:
Kenneth Marvel, Chairman
Sam Eelton
Ed Sherman
George Ward
Ben Dunlap
John Rosebaugh
Paul Benthall
Dean Echelbarger
Howard Olds
The Committee met privately on a periodic basis and was regularly
consulted as the draft Facilities Plan and EIS documents were developed.
Public Meeting
The meeting was held from 7:30 to 10:00 p.m. on Thursday, February 17,
1977 in the Lynnwood City Council chambers. It was chaired by Mr. William
Nims, Director of Public Works for Lynnwood. The meeting had been announced
to the public by five newspaper articles appearing from December 29, 1976 to
February 17, 1977. About twenty-five (25) residents from the study area
were in attendance plus the staff and consultant personnel directly asso-
ciated with the project.
Each participant was given a handout containing the meeting agenda, a
description of the alternative plans to be given further study, a map of
the combined Lynnwood and Swamp Creek service areas, and a list of phone
numbers of the principals involved.
Mr. Bill Nims (Lynnwood) introduced all of the principals represent-
ing the public entities, consulting firms, and the Citizens Advisory
Committee. He traced the history of the present treatment system in Lynn-
wood which was begun in 1961 and referred to the federal law passed in
1972 requiring that treatment be upgraded from primary to secondary. He
explained that Lynnwood and the Swamp Creek areas are being studied together
in this planning phase at the direction of the State Department of Ecology,
but that any actual design and construction would be handled by the juris-
diction involved.
VI-1
-------
Mr. Blunck (Alderwood) described the Alderwood Water District as con-
taining about 58 square miles, including the Swamp Creek drainage basin.
It presently has about 3,800 sewer connections, only a handful of which
are in the Swamp Creek basin. The district applied in 1971 to DOE/EPA
for a grant on the trunk sewers required to serve the Swamp Creek basin,
but has not yet been assigned a position on the priority list. The
requirements to qualify for federal and state grants are now more compli-
cated and additional planning is needed, hence their involvement in this
project. Mr. Blunck confirmed that any design and construction in the
Swamp Creek basin would be handled by the district.
Mrs. Meyerson (EPA - Environmental) explained that EPA, during its
review of the Lynnwood planning grant application, determined that the
potential environmental impacts of the project were serious enough to
warrant a formal environmental impact statement. It was decided to pre-
pare the statement concurrently with the facility planning by the "piggy-
back" method. This method involves use of a consultant to prepare the
EIS independent from the one doing the facility planning. EPA held an
active role in the impact statement since it will be published as a fed-
eral report. Those interested in receiving a copy of the draft EIS were
invited to sign a register, and were told a copy would be mailed to them.
Mr. Marvel explained the function of the Citizens Advisory Committee
to represent the community and make certain that the views of the citizens
are presented and considered. The number on the committee, six, was not
frozen. Other interested residents were invited to join.
Mr. Nims stressed the need for comments, reaction, and suggestions
of citizens. At this point he made it clear that there is no intention
for Lynnwood to provide sewers in the Alderwood Water District. This will
be handled by the district. The planning being done now is for treatment
facilities and interceptors (trunk sewers) only.
Mr. Dowe (facilities planning consultant) described the boundaries
of the study area and discussed the population projections on which the
planning will be based. The figures are provided by the Puget Sound
Council of Governments which is responsible for overall planning in the
study area. He also discussed briefly two previous plans for Swamp Creek,
one in 1966 and one in 1971, and one for Lynnwood in 1972. Although the
federal act of 1972 calls for secondary treatment of Lynnwood's sewage by
1977, it is not expected that it will be accomplished before 1980. The
trunk lines in the Swamp Creek area will probably not be in place until
about 1985. He then presented 26 different possible plans for handling
the sewage from the combined service areas.
During his discussion he narrowed the choices down to five or six
plans which would be studied in detail and presented in the plan. Most
involved some treatment at Lynnwood with the remainder at Seattle Metro
or a new plant near 44th Avenue W. and 1-5.
VI-2
-------
(Since the meeting was informal and not a public hearing, identification
of those asking questions was not required.)
Q. What is secondary treatment?
A. Removal of 85% or more of biochemical oxygen demand (BOD) and suspended
solids; maintenance of pH (acidity) between 6 and 9 (7 is pure water);
and control of coliforms (bacteria which grow in the intestines of
animals, including humans).
Q. Is the County Health Department represented?
A. No. They will be asked to comment on the report but are not involved
in treatment plans. They must approve septic tanks.
Q. What is the "no action" alternative?
A. Leaving the Swamp Creek area to develop as it has, i.e., on septic
tanks; and leaving Lynnwood to develop on current codes without add-
ing capacity or increased treatment capability at the present plant.
Q. Is the University of Washington model of Puget Sound tidal flows and
the effect of various types of sewage being used?
A. There is not sufficient anticipated effect on Brown's Bay to warrant
further use of this model. There will be study of the outfall design
and it is anticipated that the outfall will be extended and a diffuser
added. The dispersal pattern at the present outfall has been observed
by submarine and a colored movie is available for those interested.
Q. Since the Swamp Creek area can't handle present sewage, how can we
project an increase in population from 20,000 now to 43,000 in 2005?
A. The projection assumes sewers will be installed.
Q. Is Martha Lake in the study area?
A. Yes.
Q. Where would a plant in the Scriber Creek area (44th and 1-5) discharge?
A. To Puget Sound through an outfall sewer.
VI-3
-------
Mr. Wilson (EIS consultant) discussed the physical nature of the
study area. Base line (current) environmental conditions were described.
Special concerns expressed by EPA were discussed including noise, odor,
and aesthetics at the present plant site in Lynnwood and the secondary
effects of putting sewers in Swamp Creek on the air, water, land, wild-
life, etc. The rural character of the Swamp Creek area was mentioned.
Over 600 septic tank failures in the area were reported in the past ten
years. There were probably many more unreported. Over 300 parcels of
land in the area have been refused building permits until sewers are avail-
able .
Q. Does the study consider the extension of Route 405?
A. It assumes it will be built. It will probably not have much effect
in the study area.
Q. Will the location of the outfall be studied?
A. Yes, as part of the design.
Q. How many people realize the Swamp Creek area will grow with sewers?
Some may want it to remain rural.
A. One purpose of the meeting is to solicit comment. There were five
news articles published in local papers.
A. (By another citizen): He moved out of Lynnwood to be in a rural area,
then found that sewers are needed. Has been in indignation meetings
on failing septic tanks. The area has been studied to death. They
need sewers in Swamp Creek now!
Q. Is it proposed to combine Lynnwood and Alderwood Water District for
sewers?
A. No.
Q. What if no grants are forthcoming?
A. DOE and EPA can't refuse Lynnwood since the law requires upgrading.
Swamp Creek is another question. Lynnwood can be handled separately.
There is real possibility of delay for Swamp Creek.
VI-4
-------
Q. Does combining areas for planning lend strength to Swamp Creek?
A. If the study shows that the most cost-effective plan is to send a
large part of Lynnwood's sewage through the Swamp Creek sewers, then
the Swamp Creek project would probably get a higher priority than it
now has.
Q. Shouldn't any trunk required be installed before Route 405 is extended?
A. The trunk would be under 1-5 slightly north of the interchange.
Q. What is the cost of this planning?
A. About $200,000, including the EIS.
Q. What is the effect on Swamp Creek as a fish hatchery?
A. That will be discussed in the EIS. Very difficult to assess because
of lack of historical data.
Mr. Nims advised that there will be a public hearing on the EIS and
facilities plan at a later date. All written comments on the draft EIS
will be answered in the Final EIS.
Public Hearing
Mr. Peter Haller (EPA hearing officer) opened the public hearing at
7:30 p.m. on October 18, 1977. Only one private citizen was present in
addition to staff, consultants, and citizen advisory personnel. Mr. Haller
described the hearing process and EPA procedures. He then introduced the
consultants to present the details of the facilities plan and the EIS.
Mr. Dowe (facilities planning consultant): A facility plan is an
engineering report to determine the best means, the most cost-effective
means, of providing sanitary sewer service to the area that's outlined in
red on the topographic map (illustration projected on screen) consisting
of the City of Lynnwood, portions of the Alderwood Water District known as
the Swamp Creek drainage basin, and a small portion of Mountlake Terrace,
a portion of Edmonds, and of Brier. All of which communities have been
involved in the production of the facility plan through involvement in
the technical review committee.
VI-5
-------
The facility plan consists of a number of elements; foremost is a
sewer system evaluation survey which is conducted at the same time that the
facility plan itself is being accomplished. The evaluation survey is
required where you have existing sanitary sewer system. The City of Edmonds,
Mountlake Terrace, and the City of Lynnwood all have existing sanitary san-
itary sewer systems, which flow to the drainage pattern in the study area.
As a result, the City of Edmonds did their evaluation survey and we did
the evaluation survey for the City of Lynnwood. The Sewer System Evalua-
tion Survey indicates the flow rates in the existing system, the status of
existing system structurally, and an inspection of those areas which are
anticipated to allow excessive infiltration of the system. This study
results in an indication of the type imd character of rehabilitation
required and an estimated cost in order to eliminate inflow. This data
is plugged into the facility plan at a point in time during which we are
evaluating the alternatives.
The facilities plan itself involves evaluation of population projec-
tions, which are a direct result of the Lynnwood waste water flows, and
characteristics of the sewage effluent limitations imposed, in this case
by the EPA, existing facilities of the system, alternative methods of
water waste treatment, facility concept alternatives - this is how many
plants, how big should they be, where should they be located, and the same
with the trunk sewers - and evaluation of those alternatives. During the
evaluation, we arrive at a desired process, location, and size. At that
time, we plug into our cost-effective analysis the results of this earlier
survey, arrive at a size facility. We develop some preliminary plans and
arrive at summary and recommendations.
The present population of the basin of the study area is in the range
of 52,000 people. We are designing for 20 years, from the time in which
the facility is expected to be in use. That would be in 1980. The Swamp
Creek populations at that time are anticipated to be in the vicinity of
88,000 persons.
The waste water flows in this case have been studied, as far as
existing flows and characteristics, are concerned and they are very sim-
ilar to other municipalities involved. Where there is domestic sewage
only, there is no industrial flow or industrial waste into the sanitary
sewer system, so that the characteristics and the flows do truly reflect
the domestic sanitary sewer system. The design will be based on dry
weather flows of 800 gallons per acre per day, and a total of 1,100 gallons
per acre per day wet weather flows. Individual contributions are expected
to be 70 gallons per capita per day for Lynnwood in the year 2000 and 75
in the year 2005.
Lynnwood has a sewage treatment plant on Browns Bay. There are no
existing sanitary sewage facilities in the Swamp Creek drainage basin.
Sewage treatment is managed in the basin through the use of septic tanks,
VI-6
-------
with the exception of some developments which do collect sewage and pump
it into the Lynnwood system and other areas which collect their sewage
and discharge it into the City of Everett system to the north.
We investigated approximately 11 alternative methods of sewage treat-
ment. We would meet the goal of 85 percent removal, which is secondary
treatment. We investigated a number of ways of handling the sludge
developed by the treatment system, and these methods are discussed in the
facility plan in detail.
Our facility concepts discussed treatment facilities: How many and
where they should be, should we have one at Lynnwood, should we have one
at Edmonds, one at Alderwood Manor, should we have one in Swamp Creek,
one at Scriber Creek, should we have one for each drainage basin? Of the
large number of alternatives which we developed, we reduced the number for
the evaluation itself to six different facilities concepts.
We investigated whether we should treat the sewage at Metro or at
Lynnwood, and whether we should have one or two treatment plants for the —
basically what would be the Lynnwood system — for the evaluation of
processes. We elected to evaluate in detail the RBC and the ABS methods
of treatment. The decision was that there should be a sewage treatment
plant at Browns Bay at the site of the existing Lynnwood treatment plant,
and it should treat all the sewage generated by what we call the Lynnwood
service area, which does include portions of Edmonds and a small portion
of Mountlake Terrace. There should also be a Swamp Creek trunk sewer
designed to flow generally along Swamp Creek, and extending northeasterly
to the westerly border of Swamp Creek drainage basin, all to drain to
Metro for treatment at the West Point treatment plant.
The ABS process with sludge disposal by incineration was found cost-
effective. We have some preliminary plans of the actual facility at the
Lynnwood treatment plant site. Sewage will flow into the inlet struc-
tures through the screens into biological filtration cells, then to the
aeration basins and then to the secondary clarifier. The existing waste
water clarifier would be modified to suit our purposes. It will dis-
charge to the Sound. We will use chlorination for a disinfectant. The
solids that are generated in this process will all be carried to the
existing sludge thickener, then to filter presses, and to the incinerator.
The existing incinerator will work in conjunction with a new incinerator
to dispose of the sludge and the residue will be in ash.
The results of our detailed cost estimates indicate that the rehab-
ilitation program will cost an estimated $18,425 to remove some of the
infiltration/inflow into the existing treatment system — that the treat-
ment system had a design flow rate of 5.48 MGD — with an estimated total
cost of $11,783,570. There will be some necessary upgrading to the existing
pumping stations that the City of Lynnwood now has at $880,880. And the
interceptor sewers, Swamp Creek, are estimated at $11,527,290, for a total
of $24,210,265.
VI-7
-------
Current EPA grants are for 75 percent of eligible costs and Depart-
ment of Ecology grants are for 15 percent. If Lynnwood and Alderwood are
successful in obtaining these grants, we anticipate the remaining amount
to be financed by the City of Lynnwood would total $1,268,299. The remain-
ing amount financed by the Alderwood Water District for the trunk sewers
will be $1,152,739. These figures do not include the cost of any changes
that might be imposed by Metro for the treatment of the sewage.
Mr. Haller: Thank you, Mr. Dowe. If you have any questions of
Mr. Dowe, I would ask you to save them for later. I would like to intro-
duce Mr. John Wilson to talk about the environmental impacts of the project.
Mr. Wilson: Thank you. The objective of the environmental impact
statement process itself is to consider the effect that this project is
going to have on the local environment, in terms of human and also of
the local ecology.
Public Law 92-500 requires that any municipal treatment works afford
secondary treatment, and EPA has defined this in specific terms. However,
the law does not require sewer service to be extended to large presently
unsewered areas such as the Swamp Creek drainage basin. The question of
whether or not such an action is desirable or required in this case was
determined to constitute a requirement for an environmental impact statement.
In preparing a statement, the environmental impacts and benefits are
considered, both on a primary level and a secondary level. Primary being
considered as those directly attributable to the action itself: a change
in the water quality, land use —such as a larger plant — putting the
pipe in a location. Secondary impacts are indirect effects — something
that happens as a result of the fact that you have a sewer system with
pipes in the ground, allows a larger population, allows more extensive
development of an area.
In the preparation of the impact statement itself, we were aided by
a citizen advisory committee which was formed early in the process. These
were local citizens who lived in the area that is affected by the project,
had extensive personal knowledge, and in some cases personal qualifications,
to consider the impacts and consider the area in which they live and the
process would affect.
The document that we prepared was built around existing information.
One of the constraints of this study was that no additional research would
be undertaken as a part of the project. The first element involved the
study of the environmental setting itself to document the existing physi-
cal and human conditions. A reasonable representation of those conditions
can be obtained by looking at the aerial photographs. The project boundary
is not outlined on it, but it generally encompasses the area shorn. The
treatment plant is located on Browns Bay. The existing service area of the
City of Lynnwood is roughly this area here. The remaining portion that is
vi-a
-------
shown in the photograph is essentially unsewered, but as you can see by
the photograph, the area is developed though to a lesser degree at this
time. It is not a virgin wilderness, in other words.
Based upon the existing conditions, we then developed alternatives
in the form of concepts. Meaning the size and location of treatment plants,
alignments of pipe, interceptors, various sites that the plants could be
located at, and methods in which the sewage could be collected and trans-
mitted—meaning does it flow by gravity or is it pumped? These alterna-
tives were then evaluated in the form of a matrix comparison to see which
were the most significant impacts, which alternatives were the ones of the
most concern to the community, and what the cost of each involved was.
Based on this study, the cost-effective solution arrived at collected
sewage from the existing City of Lynnwood, from the Scriber Creek drainage
basin, and the McAleer Creek area then delivered all of that to the site
on Browns Bay. The remaining portion of the study area, the Swamp Creek
basin, would be collected through a new pipe and delivered to Metro.
In looking at the impacts of this selected alternative, perhaps the
first and most significant one is the change in population within the
community. This graph (illustration) reflects the change in population
for the study area. This dotted line is an ultimate population density
which is developed in a comprehensive plan for this portion of the com-
munity. The total study area population is plotted here, and the point at
which the study concludes is 20 years after 1980. Population then reaches
about 88,000. The various subdivisions within this area are shown below.
Now, that population of 88,000 needs to be weighed against a figure of
about 66,000, which would be the population at the year 2000 if there
were no project.
We also considered some of the financial aspects, as indicated in the
cost estimates developed in the facilities plan. One of the first things
that was considered was the impacts that are going to occur on Metro.
Metro has an existing treatment plant at West Point which currently
handles most of the City of Seattle and a good portion of the population
within the King County area. In developing a system that will be served
by Metro, the Swamp Creek trunk would be extended down to the existing
interceptors system within Metro. However, these pipes do not always have
an even larger interceptor. However, if the system is not built, Metro's
current plan is that these pipes would remain the same size, but they
would built an alternate system on the other side of the lake in the
Bellevue area to connect down to the Renton plant. In any event, the
site at West Point is not greatly affected.
In looking at the costs that Metro provided, it was concluded that
the impact on the community of Lynnwood would change sewer rates from
about $5.50 per month presently to $7.64 per month. However, in the
Swamp Creek basin, since there is not an existing collection system there,
VI- 9
-------
the cost may be more pronounced. The Metro cost for treating and collecting
sewage is probably $5.31, based on the current estimates that we have.
However, the collection system for each one acre parcel would cost in
the neighborhood of $75 per month to build. Of course, that's going to
be paid off in a period of time, and then that cost ceases.
In looking at the Swamp Creek environment itself, one has to con-
sider that this is one of the five most important streams — as a fishery
resource — emptying into Lake Washington. Lake Washington is a significant
fisheries resource for the Puget Sound area. This trunk would be built
basically down the existing creeks, because on a gravity system, that's the
low point and that's the only really cost-effective way that you can locate
it. Construction of that trunk itself would cross the stream in the neigh-
borhood of 25 times, which means a certain disruption at each of these
crossings. This can be mitigated in accordance with Fisheries Department
regulations, but nevertheless it still has some impact.
Furthermore, as you connect laterals serving the various subdivisions,
houses, and blocks within this community, there would be additional stream
crossings totaling perhaps 20 to 25, depending upon the route alignment.
Again, each of these crossings can be done within the tolerance that the
Department has established but nevertheless there is an impact which has
to be considered.
Water quality within the surface waters of this area currently is
affected by the septic tank seepage. The soils within this community are
poor and to a large extent are already overloaded—according to the Health
Department in Snohomish County—by the present septic tank system. Some
improvement in certain water quality parameters may be noticed by install-
ing sewers. However, you have a trade-off which is the urban runoff from
storm water due to more paved surfaces and a higher development—more
houses and more people. Probably, in the long run on a subjective basis—
which is the only way it can be determined—the net effect on the water
quality is going to be a negative and not a positive one. But water qual-
ity may really decrease out of regular residential development regardless
of what was intended because the population will increase to some extent
regardless of whether this sewer system is instituted.
Browns Bay, where the treatment plant currently exists, was found
to be really the only feasible site in terms of economies and availability
of sites for building a new plant discharging into Puget Sound. Pres-
ently, their existing data on the plant indicates that the effluent dis-
charge into the Sound violates several conditions of th permit. In par-
ticular, the requirements on suspended solids, but more significantly the
bacteria counts—it is not adequately disinfected. Our evaluation of
environmental impacts of Puget Sound was based primarily on existing data,
which in relation to Browns Bay is quite limited. The data that has been
developed by Metro is interesting, but not conclusive. The indications
are that the impacts on water quality, other than meeting the discharge
VI-10
-------
requirements for the existing plant, are not likely to be large. The
Sound has adequate capacity for the permitted organic and suspended
solids discharge. However, provision of adequate suspended solids
removal equipment and disinfection is a necessity.
At the existing site, there is a current problem with respect to
noise and odor. The recommendations of the facility's consultant to
solve this is basically to enclose the plant. With that sort of a facil-
ity, noise can be reduced through insulation and soundproofing. The odor
can be controlled by an internal system. This is not to say that either
noise or odor will be eliminated by the system, but they will re reduced.
There are a few other sites within the existing collection system
which have an odor problem. Consideration has been given towards pro-
vision of treatment facilities at those manholes or pump stations through
injection of hydrogen peroxide or other elements which would minimize
the odors that are present there.
That concludes my remarks.
Mr. Haller: Thank you very much, Mr. Wilson.
At this time, I would like to call for any comments that we have
from the floor. I would like to take the comments as I said before in
the following order. Other federal agencies, other than EPA. State
agencies, any comments? Snohomish or King County agencies. The City of
Lynnwood or the Alderwood Water District. Okay. Is there anyone here
representing, in their own capacity, representing a citizens' group?
And lastly, individuals?
I do have one card indicating one person wishes to speak. Mr. Ken-
neth Marvel.
Mr. Marvel: That's correct. I believe I remarked that T would have
a written comment to submit.
Mr. Haller: You did, and you do not wish to speak?
Mr. Marvel: Right.
Mr. Haller: And you're aware that the comments should be submitted
by the 31st of this month?
Mr. Marvel: Yes.
Mr. Haller: At this time, with no comments per se having been made,
I would like to open the hearing up to any questions that people have.
I know I have one question. Are there any other people that have any
questions?
VI-11
-------
Mr. Marvel: I'd like to know what has been the xiinal decision on
the design of the diffuser; will there be any modifications to the exist-
ing outfall pipe?
Mr. Dowe: We haven't designed it, but the existing outfall consists
of an open pipe at the bottom of the Sound. As a part of the project,
we will install an additional pipeline parallel and adjacent to the exist
ing one, and both pipelines will be equipped with a properly designed
diffuser.
Mr. Marvel: They will not be designed further than the present
pipe?
Mr. Dowe: That design question has not been totally resolved.
Mr. Marvel: Do you have any guidelines by which you must adhere
in the design of a diffuser?
Mr. Dowe: Oh, yes. As a matter of information, we have one pre-
liminary calculation and all of our calculations indicate that with
diffusers at the existing location, we would more than adequately meet,
by many times, the outfall criteria being imposed upon us at that point.
Mr. Marvel: Thank you.
Mr. Haller: Do you have any more questions, Mr. Marvel?
Mr. Marvel: Not at the moment.
Mr. Haller: May I ask a question of Mr. Dowe. How far out into
the Sound is the present outfall?
Mr. Dowe: I simply don't recall — 700 feet.
Mr. Haller: And do we know what depth that is?
Mr. Dowe: 105 - between 105 and 108 feet.
Mr. Haller: Okay. Are there any more questions? Okay. I reserve
the right to ask one, I'm going to confront or address this chart over
here, which I see is Figure 111-12, which will be contained in Chapter II
of the draft EIS. I noticed this dark black line purports to be the pro-
posed interceptor, and at two points along its path, there are dotted
lines, or a little hyphenated line, which, according to the legend here,
if the interceptor were laid in that path, it would be lower in cost.
I asked myself why is the project designed in a different course. Could
someone answer that?
-------
Mr. Wilson: Yes, I can. The dotted line that you see here runs
through a swampy area, and just north of the freeway. That was the orig-
inal recommendation that the pipe be aligned on, and the initial studies
were based on that. And at the time it was presumed that would be the
lowest cost solution. And at the time this figure was prepared, it was
the lowest cost solution. Since that time, some studies have been done
in the neighborhood, and it appears that an alternative alignment—we
had recommended would actually be lower cost than the one that's shown
there. To my knowledge, that's the only place that a lower cost alter-
native is shown on this figure. And in that case, it's a significant
lower cost. Does that answer your question, sir?
Mr. Haller: Yes. I have no further questions.
Once again, —
Mr. Dowe: I have one more for those that are interested. We have
an honest rendition made of one of the forms of treatment plant. Might
take a look, for your information, if you would like to look at it after
the hearing is over.
Mr. Haller: Do we have any more questions, comments, statements,
whatever from the floor?
Mr. Nims: I'm Bill Nims. I'm the director of Public Works for the
City of Lynnwood. I don't believe, Jim, that our facility plan includes
accepting any new sewage from Mountlake Terrace.
Mr. Dowe: We have a small line on the south side of the city,
doesn't that take a few homes now from Mountlake Terrace?
Mr. Nims: Mountlake Terrace revised their system and they have taken
all of the 64 or so customers that they previously had off our system and
they have them all. Our agreement only covers now overflow from Pump Sta-
tion 12.
Mr. Dowe: Then my comments on that should be corrected on that part.
Mr. Haller: If there are no further comments or questions, I'm dis-
posed to adjourn the hearing at this point. The hearing is hereby
adjourned, it is 8:24.
VI-13
-------
COMMENTS PERIOD COMMUNICATION
During the 45-day comment period for the draft EIS, 13 written comments
were received by EPA. These are included herein, together with responses
to all questions raised by each letter.
Highlights of each comment letter are summarized in Table VI-1.
VI-14
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
Advisory Council on
Historic Preservation
1522 K Street N.W.
Washington, D.C. 20005
September 19, 1977
Ms. Alexandra B. Smith, Chief
Environmental Evaluation Branch, M/S 443
U.S. Environmental Protection Agency, Region X
1200 Sixth Avenue
Seattle, Washington 98101
Dear Ms. Smith:
This is in response to Donald P. Dubois' request of September 8, 1977,
for comments on the draft environmental statement (DES) on the wastewater
systems for the City of Lynnwood and Alderwood Water District, Snohomish
County, Washington.
The Council has reviewed the DES and notes that while cultural resource
studies to date indicate no properties included in or eligible for
inclusion in the National Register of Historic Places will be affected
by the proposed undertaking, additional cultural resource studies will
be undertaken prior to project implementation. Accordingly, we wish
to remind the Environmental Protection Agency that should those studies
identify such cultural resources eligible for inclusion in the National
Register which will be affected by the undertaking, it is required to
afford the Council an opportunity to comment pursuant to Section 106
of the National Historic Preservation Act of 1966 (16 U.S.C. 470f, as
amended, 90 Stat. 1320) prior to taking any further action with respect
to the undertaking which will affect the identified cultural resources.
Should you have questions or require additional assistance, please
contact Brit Allan Storey of the Council staff at P. 0. Box 25085,
Denver, Colorado 80225, or at (303) 234-4946, an FTS number. Your
continued cooperation is appreciated.
Sincerely yours,
?ricLi€ &
Louis S. Wall
Assistant Director, Office
of Review and Compliance
VI-17
The Council is an independent unit of the Executive Branch of the Federal Government charged by the Act of
October 1 5, 1966 to advise the President and Congress in the field of Historic Preservation.
-------
Advisory Council on His-
torical Preservation
RESPONSE
1. If cultural resources are identified which are eligible for the
National Register, no further action will be taken on the project until
EPA has fulfilled requirements of Section 106 of the National Historic
Preservation Act of 1966, as amended.
VI-13
-------
DEPARTMENT OF THE ARMY
SEATTLE DISTRICT. CORPS OF ENGINEERS
PO BOX C-3755
SEATTLE. WASHINGTON 98124
r
NPSEN-PL-ER
4 OCT £77
Alexandra B. Smith, Chief
Environmental Evaluation Branch, M/S 443
U.S. Environmental Protection Agency
Region X
1200 Sixth Avenue
Seattle, Washington 98101
Dear Ms. Smith:
We have reviewed the draft environmental impact statement for Wastewater
Treatment Facilities, City of Lynnwood and Alderwood Water District,
Snohomish County, Washington with respect to the U.S. Army Corps of
Engineers' areas of responsibility for flood control, navigation, hydro-
power, and the activity which is subject to Corps of Engineers permit
authority.
Under Section 404 of the Federal Water Pollution Control Act, a Department
of the Army permit may be required for dredging and fill material associated
with stream crossings and wetlands, and in lakes where fills will occur
below the ordinary high water line.
Thank you for the opportunity to comment on this statement.
Sincerely yours
R. P. 5ELLEVOLD, P.E.
Chief. Engineering Division
VI-19
-------
Corps of Engineers
RESPONSE
1. Upon decision to implement any portion of the project which may be
within the jurisdiction of the Corps of Engineers, coordination will be
effected to define permit requirements.
VI-20
-------
STATE OF
WASHINGTON
600 North Capitol Way/Olympia, Washington 98504 206/753-5700
DEPARTMENT OF GAME
RECEIVED
CCT J 1577
Dixy Lee Ray
Governor
£P.A-r;«
September 29, 1977
Environmental Protection Agency
Region X
1200 6th Avenue
Seattle, WA 98101
Your document was reviewed by our staff as requested; comments follow.
On page 11-95 you state that there are no state or federal standards for the
maximum amounts of metallic pollutants allowed to enter salt water. Water Quality
Criteria, edited by McKee and Wolf, might contain more information in that regard.
Also, several sections of the Revised Code of Washington, and the Washington
Administrative Code appear to regulate deleterious materials entering both salt
and fresh water.
Table 11-18 lists several metals which may be entering Puget Sound waters. Of
these metals the toxicity of chromium can vary widely. Fish are relatively
tolerant of this element, but lower forms of aquatic life are extremely sen-
sitive. Depending upon the chromium compound involved, lethal values for
Daphnia magna are as low as 0.016 mg/1. Toxicity levels for cadmium vary from
0.01 to 10mg/l. Concentrations of copper compounds varying from 0.015 to 3.0
mg/1 have been reported as toxic, particularly in soft water, to many kinds of
fish, Crustacea, mollusks, insects, phytoplankton and zooplankton. Lead con-
centrations as low as 0.1 mg/1 have been shown to be deleterious to fishlife in
general. Nickel appears to be less toxic to fish than copper, zinc, and iron;
however, the lethal limit for sticklebacks has been reported at 0.8 mg/1.
Phenol may affect fish by a direct toxic action and by imparting a taste to the
flesh of fish. Reported lethal concentrations vary widely with species, time
of contact, temperature, and dissolved oxygen and mineral content of the water.
Many phenolic compounds, as is the case with metals, can be more lethal in com-
pounds than in the pure form. Synergistic action, instances in which two or more
otherwise harmless materials' combined effect jis toxic, can occur. This is true
of many metals as well.
While most shellfish demonstrate higher tolerancy levels to various metallic
poisons, they tend to accumulate and concentrate sufficient amounts of these
toxic materials to become a hazardous link in the overall foodchain of the
marine environment. Also, such a process can render clams, oysters, etc.
unfit for human consumption.
We realize that the 24 hour composite sample on page 11-94 is not indicative of
VI-21
-------
page 2
Environmental Protection Agency
Region X
metal concentrations expected to be found in outfall samples. However, this
should demonstrate a need for concern about the potential adverse impact that
metals could have on a marine environment. Monitoring of outfalls and adjacent
waters might be helpful in determining future impacts. Measures could then be
taken to remove such pollutants before they are discharged into aquatic environ-
ments .
Our main concern, however, is for Swamp Creek. This is an important stream for
steelhead, cutthroat, and native trout as well as salmon. Your water quality
studies indicate that water degradation to Swamp Creek may be the result of
leaching from nearby septic drainfields. Improved sewage facilities would help
to remedy this problem. However, extreme impacts to riparian habitat and aquatic
life in the Swamp Creek drainage system could result. It appears that the pro-
posed trunk line of approximately 13 miles in length (P. V-4) , and its related
interceptors and lateral connectors will cross Swamp and Scriber Creek approximate-
ly 55 times. Stream crossing and the disturbance of riparian habitat (diverting
and culverting stream flows, removal of vegetation, soil removal, trenching,
etc.) could adversely impact wildlife associated with the Swamp Creek drainage
system. Spawning grounds for fish could be destroyed by silting and sedimentation
due to increased runoff and erosion. Fertilizers entering the stream during
reseeding can be detrimental to fishlife and cause algal blooms in pool and
swamp areas. Herbicides and pesticides, if involved, also can be harmful to
wildlife. Variations in turbidity, suspended solids, and dissolved oxygen re-
present temporary, but additional adverse impacts to salmonids.
The trout and salmon of Swamp Creek are an important natural resource. Re-
planting of fish may be necessary restorative measure. However, channel scouring
and destruction of spawning grounds may mean that existing fish populations
cannot be re-established. The stream would lose some of its supportive cap-
acities .
The disruption of 13 miles of riparian habitat could greatly impact waterfowl
and terrestrial wildlife. Although construction activities lasting several
years would be temporary, the impact would have long-term effects. Wildlife
may attempt to relocate, but surrounding habitats are usually filled to cap-
acity and cannot support additional numbers. The result is a net loss in
numbers and kinds of wildlife.
Considering the severity of impact to wildlife that could result from the
Swamp Basin to Metro proposal, we have difficulty in agreeing with the results
of your environmental impacts matrix and your statement on page IV-40 that
Swamp Basin to Metro "...provides the most beneficial environmental tradeoff".
Therefore, we urge that one of your alternate proposals be given more consideration.
Thank you for your document. We hope you find our comments helpful in protecting
important natural resources.
Sincerely,
THE DEPARTMENT OF GAME
Environmental Management Division
VI-22
FM:bj cc: Agencies, Regional Manager
-------
Game Department
RESPONSE
1. The references you have cited provide guideline criteria for receiv-
ing water quality. We agree that the statement at the top of Page 11-95
was poorly worded in that it referred to effluent standards but did not
specifically say so. Although no state or federal standards exist for
maximum metallic effluent discharges into marine waters, wastewater
effluent must meet receiving water quality standards as set forth in the
July, 1976 revision of EPA's Quality Criteria for Water when it leaves
the designated mixing zone. This EPA publication is often referred to
as the "Red Book." Using EPA's effluent guidelines, conditions are set
specifically for each individual discharge, based on chemical analysis
of the proposed effluent and receiving water standards. Metallic pollu-
tants generally have not been found significant at secondary treatment
plants treating only domestic wastes, as does the Lynnwood facility.
It is not expected, therefore, that metallic limitations will be imposed
for the Lynnwood plant.
2. See Response No. 3 to the Department of Interior comment letter of
November 4, 1977.
3. Pages V-3 and V-4 of the EIS address impacts to wildlife habitat
that would occur during construction. Restoration and revegetation would
allow habitat disturbances to fade away gradually. However, growth and
development in the study area would cause permanent habitat changes and
reduce present wildlife populations. (See EIS Page V-5.) Although it
appears no species would be endangered, we agree that some numbers would
be substantially reduced by construction of a gravity interceptor or by
implementation of any other alternative.
4. See Response No. 3 to the State Department of Fisheries letter of
October 31, 1977.
VI-23
-------
UNITED STATES DEPARTMENT OF AGRICULTURE
SOIL CONSERVATION SERVICE
Room 360 U.S. Courthouse, Spokane, Washington 99 201
October 13, 1977
Alexandra B. Smith, Chief
Environmental Evaluation Branch, M/S 443
U.S. Environmental Protection Agency, Region X
1200 Sixth Avenue
Seattle, Washington 98101
Dear Ms. Smith:
The Soil Conservation Service has reviewed the draft environmental impact
statement for Wastewater Treatment Facilities for the city of Lynnwood
and Alderwood Water District in Snohomish County, in accordance with
guidelines contained in 7CFR 650, subpart B of the Federal Register dated
August 8, 1977. In general, the concerns identified in subpart B have
been adequately addressed, with the following exceptions:
1. While page 11-39 indicates there is no commercial farming or dairying
located in the project area, the draft environmental impact statement
does not specifically address prime and unique farmlands as required
by the Council of Environmental Quality in their Memorandum for Heads
of Agencies dealing with "Analysis of Impacts on Prime and Unique
Farmland in Environmental Impact Statements," dated August 30, 1976.
An appropriate statement dealing with this requirement needs to be
added under Soils in Chapter II.
2. Similar statements need to be developed for Chapter IV under
(1) Evaluation of Primary Environmental Impacts (2) Evaluation of
Secondary Impacts and (3) Comparison of Alternatives.
Information on prime and unique lands for Snohomish County can be
obtained from our Lake Stevens field office, USDA Building, Frontier
Village, Lake Stevens, Washington 98258.
Thank you for the opportunity of reviewing this statement.
Sin
Galen a. Bridge
State Conservationist
VI-24
-------
Agriculture
RESPONSE
The following reply was received from the local Soil Conservation
Service field office:
VI-25
-------
UNITED STATES DEPARTMENT OF AGRICULTURE
SOIL CONSERVATION SERVICE
Frontier Village, Lake Stevens, Washington 98258
Stevens, Thompson & Runyan, Inc.
Engineers/Planners
700 Plaza 600
Seattle, Washington 98101
November 8, 1977
Dear Sir:
This is a reply to your letter of October 25, 1977. There is no
prime or unique agricultural land within the study area. The peat
bogs might be considered unique lands, but since there is no specialty
crops that grow on them, this is not a problem.
If you have any questions, please feel free to call this office at
334-7577.
Thank you.
Sincerely yours,
Alfonso Debose
Soil Scientist
VI-2 6
-------
'.a !
October 25, 1977
i /•/ r.i.i.
A'/1
(Alexandra B. Smith, Chief
c. Carey donwor,m Environmental Evaluation Branch M/S 4*3
U. S. Environmental Protection Agency, Region X
1200 Sixth Avenue
Seattle, Washington 98101
Draft Environmental Impact Statement
For
Wastewater Treatment Facilities:
City of Lynnwood and Alderwood Water Pistrict
Dear Ms. Smith,
Metro staff has reviewed this document, and believe that the
lake and stream water quality impacts of the proposed project will
be beneficial, especially as septic tank problems are diminished.
In addition, the SNOMET model stormwater runoff ordinance will
partially mitigate the secondary impacts of increased runoff from
the area's exptected growth of population, if it is adopted by Sno-
homish County and other jurisdictions. This potential water quality
oroblem gains added significance due to the fact that the small
stream systems tributary to the area are an important fisheries
resource. In order to improve the effectiveness of runoff control
ordinances to protect water quality, new developments should not
only be required to install devices to control the rate of release
of stormwater runoff, but, also oil/water separators and sediment
traps to remove pollutants.
The proposal conforms to previous plans and studies by Metro
and the other agencies involved and would not cause unanticipated
impacts to Metro's wastewater facilities. As stated in the DEIS,
construction and utilization of the Swamp Creek Interceptor will
affect the planning and utilization of Metro's downstream facilities.
The flows exptected have been taken into account in our current 201
facilities planning.
Finally, the last sentence of the first paragraDh on Page
11-87 is incorrect. The City of Brier is sewered and is serviced
by Metro, discharging to the Kenmore Interceptor through a North
East Lake Washington Sewer District facility by agreement.
Thank you for this opportunity to review and comment.
Ve^'y? truly yours,
Peter S. Machno, Manager
VI-27 Environmental Planning Division
©
PSM:lmr
Pioneer Building • 600 First Avenue • Seattle, Washington 98104 • 447-6666
-------
Metro
RESPONSE
1. Correction concerning City of Brier sewer service has been made.
VI-28
-------
r>
SNOHOMISH COUNTY
PLANNING DEPARTMENT
COUNTY ADMINISTRATION BUILDING • EVERETT. WASHINGTON 98201 . (206) 259-9311
George F. Sherwin, Jr., Director
October 25, 1977
Mr. William E. Nims
Director of Public Works
City Hall
Lynnwood WA 98036
0CT 26 1977
Alexandra B. Smith, Chief "' ""it
Environmental Evaluation Branch, M/S 443
U.S. Environmental Protection Agency, Region X
1200 Sixth Avenue
Seattle WA 98101
Dear Mr. Nims and Ms. Smith:
We have reviewed both the Draft EIS (DEIS) for the Wastewater Treatment Facilities:
City of Lynnwood and Alderwood Water District (EPA publication 910/9-77-040),
dated July 1977, and the Areawide 201 Facilities Plan dated September 1977 prepared
by Gray and Osborne, Inc. for the same jurisdictions. Since many of the major
comments which we wish to offer relate to both documents while certain comments
pertain only to one, we shall divide our comments into three groups: General,
DEIS and 201 Plan.
General Comments
Population Projections. The text indicates the consultants used census block
data and PSC0G data as the basis of the population discussion. A point is also
made that the County does have population projections broken down by l/16th
section but such was not used due to apparent inconsistencies with other
available data.
It seems a little incongruous to dismiss the County's population projections
in that:
1. The County's projections have their origin in control totals provided by
the PSCOG in October of 1975 and in census reports. These projections
differ only slightly from those now being used by King County METRO.
2. The County's population estimates and projections very closely agree with
data published by the State Office of Planning and Program Management
(John Walker's office).
3. The County's POPUL model was originally developed so that it could be used
for demand forecasting to accomplish utility planning programs. The Lower
Snohomish Facilities Study currently in progress is a prime example.
VI-29
-------
Mr. William E. Nims
Alexandra B. Smith
-2-
October 25, 1977
4. The County's POPUL model provides the best method available to consider the
impact of the County's comprehensive land use plans on future development. The
use of such data when correlated with census block data should provide the
most confident projections of future population levels.
In light of these points, the text musC be more explicit as to the rationale for
not using the County's available data.
A further concern relates to the manner of assigning fractions of AAM District
populations to the study area. The text indicates that a constant percentage,
derived from 1970 census data, was used in all projections. This practice is
highly questionable because it assumes that growth potential within an AAM District
is uniformly distributed. This circumstance is likely to be true in very few AAM's
due to the diversity in land use patterns and development density. The County's
POPUL model takes this into account by assigning population growth to each l/16th
section on the basis of a number of factors including present population and ultimate
holding capacity. In our experience the rate of growth in a developing area is
greater than in one nearing full development. If any of the AAM Districts contain
a mix of developing and developed land, the constant percentage method will probably
not yield accurate results.
Our final population issue relates to the distinction between study area and
service area population. The texts state that present study area population is
approximately 50,000 and is expected to grow to 86,000. The DEIS states (not in
the population section, however) on page 11-87 that the existing systems serve
only 24,000 people but does not state what the future served population will be.
In the absence of other data, we assume that the intention is to sewer all 86,000
residents of the study area. This seems somewhat questionable for two reasons:
1. It is doubtful that all residential development within the study area will
be at sufficient density to warrant sewers.
2. It seems doubtful that the 26,000 area residents not now sewered will be
served within the next 20 years, let alone all new residence.
Land Use. The text and DEIS provide a very cursory and sometimes inaccurate
discussion of the County's comprehensive land use plans. The following examples
reflect the need for revising in both texts.
1. Figure 11-12 (DEIS) omits an industrial designated area in the vicinity of
SR-99 and 168th Street S.W. In the area east of 1-5 and 1-405, the wrong
plan is depicted (should be the North Creek Area Plan).
2. Inasmuch as the DEIS was prepared in July of this year and the 201 plan text
was published in September, both documents should reflect the County's North
Creek Area Plan referenced above since it was officially adopted in May of
this year. The watershed Site Sensitive Environment, along Swamp Creek, and
the Commercial and Business Park designated areas adjacent to 164th Street
S.E. would seemingly have some bearing on anticipated sewer demand in the
Swamp Creek drainage basin.
VI-30
-------
Mr. William E. NLms
Alexandra B. Smith
-3-
October 25, 1977
3. The main t^xt makes only general reference to the County's Alderwood Area Plan.
The DEIS by contrast includes a more substantive discussion. However, the
DEIS discussion could be substantially improved if the following were presented
a. A recitation of the actual Goal statements contained in the plan rather
than the presentation contained in the DEIS. The Goal statements are
easily gleaned from Chapter 1 of the report.
b. Notation that the plan is a policy plan and that future development will
be evaluated in accordance with adopted policy as well as other plan
provisions.
c. Most importantly, recognition should be given to the sewers discussion
found on page 79 and 80 of the Alderwood Area Plan. The DEIS cannot be
considered adequate unless the following quotation from the text is
included in the DEIS discussion:
"The planning staff, in preparing the plan, is fully cognizant of
both the probability and necessity of the Swamp Creek sewer trunk
line and the economics involved in financing not only the major
trunk, but also the interception lines. It has already been noted
that the Swamp Creek drainage way has been planned as a park or
open space system; in lieu of complete purchase, development at
very low densities is recommended. If the drainage way is to be
protected, it will be necessary to channel the development which
might normally occur in close proximity to the trunk line to the
upper plateau areas. Indeed, this is the recommendation of the
plan. In order to achieve this, it is the further recommendation
of the plan that there be only limited selected points along the
trunk line where it can be intercepted with laterals, and that
these points be located in close proximity to areas where sub-
stantial dwelling unit densities are projected."
4. Text and DEIS should contain some recognition of the Paine Field Airport
Master Plan and community planning effort, now under way which may ultimately
influence what kind of land uses are structured in the Lynnwood 201 study area.
Shoreline Management Master Program. There was no mention or recognition in any
of the DEIS or 201 plan material of applicable Shoreline Management Master Programs
Since the Brown's Bay treatment facility lies in close proximity to Puget Sound
and a trunk line sewer is to be located in the Swamp Creek drainage way, the
Shoreline Management Master Program requirements would seemingly be a determinant
in the design and location of facilities in those areas, and thus warrant some
explanatory text.
Proposed Swamp Creek Trunk Line: The County has long been supportive of such a
facility. However, official County plans express certain concerns regarding the
points along that line where laterals will intercept it. Under the discussion of
land use, a quotation from the Alderwood Area Plan was cited - this quote describes
the rationale which should be used to select points of interception. An inspection
VI-31
-------
Mr. William E. Nims
Alexandra B. Smith
-4-
October 25, 1977
of the maps contained in Appendix B of the 201 facilities report reveals that there
are several proposed lateral tap-in locations which would provide sewer service to
low-density residential areas. Particular emphasis should be placed on the need to
carefully control both the construction of the Swamp Creek trunk line and future
land use development near the line in the vicinity of the "great swamp" located
North of the Alderwood Mall. This should be done to protect the attractive site
sensitive characteristics of the area and to preserve the swamp's critical function
as the primary natural storm drainage retention basin for the lower Swamp Creek
drainage area.
Whereas we do not intend to raise objections at this time, it is important that
some dialogue take place between the County and the Sewer District about lateral
sewer extensions before the final design and installation of the facility. Moreover
it would seem most appropriate for the EIS or 201 plan to contain a discussion of
the criteria to be used by the Sewer District in locating points of laterial
intersection.
Sewer Service Areas. It is most difficult to determine what areas (and, corres-
pondingly, how many people) will be served by the proposed system in the year
2000. None of the alternative figures in the 201 Plan (Plates VII-1 to VII-27)
show what areas within the study area will be served; only one figure in the DEIS
(Figure III-4) provides an indication of sewer service area and that is not for the
chosen alternative. Unless the sewer service area is identified it is impossible
to comment on whether or not the 201 plan (or more importantly an action taken
to implement the plan) is consistent with adopted county land use plans and policies
Since assumptions of areas to be served had to be made in order to develop
preliminary interceptor sizing, we assume that it would be easy to graphically
portray those areas within the study area for which sewer service is proposed in
the year 2000.
Institutional and Financing. The text discussions are weak in that they don1t
address the jurisdictional issues: Brier and Edmonds are also served by the
proposed plan. What institutional and financial arrangements will be required
between jurisdictions?
Draft EIS Comments
Figure 1-1. This figure, and all others, mistakenly shows North Creek.trending
northeast above 164th Street. North Creek actually continues on almost due
north; the northeast trending stream is a tributary to North Creek named
Penny Creek.
2. Figure II-7. The drainage basin boundaries are misleading since, in actuality,
they don't totally coincide with the study area boundary.
3. Figure 11-11. There is a typographical error in the title: "Track" should be
Tract."
4. Figure 11-12. There is an apparent omission along Hwy. 99 from the vicinity
of 164th Street to 172nd Street.
5. Table III-3. p. III-ll. Why is it assumed that per capita sewage generation
will be greater in the year 2005 than in the year 2000?
VI-3 2
-------
Mr. William E. Nims
Alexandra B. Smith
-5-
October 25, 1977
6. Page 111-12. The concept of sizing for ultimate population development seems
to be contrary to EPA guidelines which call for a 20 year planning and design
period. Please explain.
7- Page 111-36 and Figure III-ll. This text and figure ignore the fact that
Scriber Creek traverses the property and that a sizeable swamp exists in this
area.
8. Table IV-4, p.IV-37. Why is no monthly residential sewer charge shown for the
"Secondary Treatment" only alternative? Why are Upper and Lower Swamp rates
the same on Partial Extension? The choice of one acre lots as the basis for
the Upper and Lower Swamp Creek figures may mislead some readers who would
assume that the figure anticipated subdivision activity. Perhaps it would be
more realistic to use an assumed lot size based on projected density in
the adopted comprehensive land use plans.
9. Pages N-39 and following. The difficulty with any environmental matrix is
its subjectivity. This is especially true here where an additional subjective
multiplier has been used. Far different results would have been obtained if
all 52 factors were used rather than the 14 chosen.
201 Facilities Plan Comments
1. Plate 1-2. Same as comment number 2, above.
2. Plate 2-1. Same as comment number 4, above.
Page I1I-3. Is it realistic to assume an annual increase of 0.75% in per
capita flow rate In the face of increasing water conservation awareness?
^ • Page V-1. There is a apparent discrepancy or unclearness surrounding the
currently sewered population. The figure given here implies it to be 29,323
persons; the DEIS uses 24,000.
5. Page V-7. A map showing the major elements of the existing sewer system
would be very beneficial. Plate V-3 doesn't serve this purpose nearly as well
as DEIS Figure 11-17.
6. Swamp Creek Alternatives. Although much preliminary work has already been
done on the Swamp Creek Trunk, a more thorough evaluation of non-sewer
alternatives should be included in view of the apparent scarcity of state and
federal construction funds for the Swamp Creek Trunk.
We appreciate this opportunity to comment on these products and hope that the
items we have raised will be addressed as work on this Facilities Plan progresses.
Sincerely,
SNOHOMISH COUNTY PLANNING DEPARTMENT
L', •:,/ '
George F. Sherwin, Jr. ^
Director
VI-33
GS:JG/sfr
-------
Snohomish Planning Department
RESPONSE
1. At a meeting November 15, 1977, County officials, the grantee,
Department of Ecology and EPA officials, and the project consultants
agreed that portions of the Areawide 201 Facilities Plan would be
revised to respond to County concerns. Population projection discussions
disclosed that, using the same baseline, County projections and the Puget
Sound Council of Governments' projections used in the facilities plan
showed overall differences no greater nor less than six percent. This
is considered a negligible amount that would reflect little change in
impacts discussed for the area. The County was assured that although
the facilities plan indicates for planning purposes that the total service
area population is assumed to be served, actual population levels would
depend upon the County's existing and future land use plans. Population
forecasts used in the facilities plan were used in the EIS without alter-
ation. (See Appendix G for facilities plan revisions and the Snohomish
Planning Department letter recommending approval of the 201 facilities
plan.)
2. Future population to be served by sewers within 20 years was assumed
in the facilities plan to encompass the entire study area, or about 86,000
people compared to the current 50,000. Within the Swamp Creek basin this
would be about 42,000 instead of the present 20,000, few of whom now have
sewers. Whether this entire population actually will be served may be
questionable; however, it is possible and would become more likely in the
future. While it is good engineering economics to size mechanical equip-
ment for only the load expected before it wears out in 20 years, inter-
ceptors are usually designed to last 50, 100, or more years. Pipe design
must be more conservative due to economic and environmental costs asso-
ciated with subsequent replacement or expansion.
3. Figure 11-12, Combined Land Use Plan, has been revised to reflect
the industrial area on SR99 and the North Creek Area Plan.
4. The Alderwood Area Plan is discussed in the EIS and the referenced
goals are summarized on Pages 11-51 and 52. The recommendation respect-
ing lateral sewer connections to the Swamp Creek trunk has been added.
Connections shown on Figure 111-12 are for illustration only.
5. The Paine Field Airport Master Plan is not yet available; however,
a reference to its ultimate influence has been added.
6. The Shorelines Management Master Plan for Edmonds, which has juris-
diction for Browns Bay, was used in the EIS preparation and is discussed
on Page 11-52. Applicable portions of the County Shorelines Management
Program have been added in the text for Swamp Creek.
VI-34
-------
7. Comment noted.
8. No criteria have been developed to be used by the Alderwood Water
District in locating points of lateral intersection. All laterals shown
are for illustrative purposes only. At the time of final design, we agree
that the County and Water District should discuss placement of lateral
sewer extensions.
9. For preliminary engineering design, the total service area population
is assumed to be served; however, existing and future land use plans gov-
ern population levels in the area. See Appendix G.
10. Institutional and financial arrangements are matters that would be
handled at the local level when an alternative is implemented.
11. North Creek designation has been revised in relation to Penny Creek.
12. Drainage basin boundaries are shown as an approximation developed
for the Facilities Plan. The study area boundary was established by the
Department of Ecology.
13. Figure 11-11 has been revised to read "Tracts."
14. Figure 11-12 has been revised along Highway 99.
15. Per capita sewage generation has almost invariably increased through
the years. It was the opinion of the Technical Review Committee for the
Facilities Plan that the increase shown is appropriate.
16. EPA's facilities sizing policy recognizes differences between rela-
tively short-lived mechanical installations, such as treatment plants,
and components with longer, indefinite lives, such as sewage interceptors.
Treatment plants are designed for a 20-year period, with consideration
given to later expansion, if needed. Interceptors are considered on a
case-by-case basis and may include a capacity allowance beyond the 20-
year limitation.
17. Scriber Creek flows south of the proposed treatment plant site. The
creek and the swamp would not be affected.
18. Table IV-4 has been revised to include a monthly rate of $7.43 for
the "Secondary Treatment Only" alternative. Table IV-4 costs were
developed for the Facilities Plan and were shown only as representative
of the entire Swamp Creek basin for the "Limited Service Extension" alter-
native, with no attempt at subdivision to specific neighborhoods. One-
acre lots were chosen to illustrate collector assessment because they are
representative of existing land ownership. Some further subdivision
activity may well occur.
19. Evaluation matrices are usually subjective due to the inability to
assign realistic values to ecological phenomena. However, any alternative
VI-35
-------
evaluation involves a matrix, whether shown or not. It is only by limit-
ing the matrix to those factors of truly significant impacts that valid
comparisons can be made. It is likely inaccuracies present in any sub-
jective rating would be compounded by adding other factors.
20. These comments on the Facilities Plan have been forwarded to the
facilities planning consultant for action.
VI-36
-------
STATE OF
WASHINGTON
DEPARTMENT OF ECOLOGY
Olympia, Washington 98504
206/753 2800
Dixy Lee Ray
Governor
October 26, 1977
Alexandra B. Smith, Chief
Environmental Evaluation Branch
MS/443 -- Region X
U.S. Environmental Protection Agency
1200 Sixth Avenue
Seattle, Washington 98101
Dear Ms. Smith:
Thank you for the opportunity to review and comment on the draft
environmental impact statement for Waste Treatment Facilities - City
of Lynnwood and Alderwood Water District.
Our headquarters and regional offices have completed their review
of this draft statement and have no substantive comments to make at
this time.
Sincerely,
Bert D. Bowen
Environmental Review
BDB:bjw
cc: John Giese
VI-37
-------
\ iierwood Community Council
Oct. "10, 1977
^'ironmental protection Agency
1200 lixtn Ave.
Seattle, WA 9S101
Gen tlemen:
The Alderwood community, in general, is actually hopeful that a
gravity system can be worked out whereby all the sewage in the
iwarnp Creek Drainage Basin can be handled througr. trunk 1 ines to
Use Metro "ystem. However, in reading through the :4.I.:3. , a few
discrepancies were noted and probably need commenting on:
(1) All the maps and photographs of the area seem to be
several years old and do not actually show the develop-
ment that has taken place in the last six years.
Up-to-date maps and aerial photos would show the need
much better.
(2) 'L'he tributaries of .'icriber Creek actually extend
West of 1-5. We cannot understand why they were not
drawn in.
(3) An alternative is shown, citing a treatment plant to
be built on Scriber Creek just 3outn of 1-^). The
Alderwood community feels that a treatment plant
located at this point would not service the City of
Brier, or this community, or areas Southeast of the
proposed site. It is suggested that the most econ-
omical move would be to run al1 sewage directly by
gravity to f'etro and not consider the treatment
plant at Scriber Creek.
(4) The forecasted Traffic; Map is incorrect:
a) There presently is no existing Primary Arterial
completed on 2i2tu .J. ^ from 44th Ave. to
.>. Poplar) as outlined on figure IVj.
b) 196th S.'Ai. is not a Mew or Improved Primary
Arterial as shown.
The Alderwood Community Council appreciates the opportunity to
comment on the .ii. I. J. We have great hope that something will
be accomplished soon.
Yours truly,
; . Hardisty c .j
VI-38
-------
Alderwood Community Council
RESPONSE
1. Maps and photographs used in the EIS are the most recent available
from the U. S. Geological Survey and the State Highway Department.
2. Tributary creeks systems are shown as they appear on the U. S. Geo-
logical Survey maps. We have not attempted to delineate every watercourse
but rather to indicate the substantive streams.
3. Comment noted.
A. Comment noted.
VI-39
-------
EDMONDS, WASHINGTON 9BD2D
KENNETH D. MARVEL
£526 I7DTH PL., S.W.
October 27
1977
Ms. Alexandra B. Smith
Environmental Evaluation Branch
U.S. Environmental Protection Agency
Seattle, WA
Dear Ms. Smi th:
The following letter is in response to the call by E.P.A.
for comments to the draft E.I.S. for wastewater treat-
ment facilities in the City of Lynnwood and the Swamp
Creek drainage basin. I am the committee chairperson of
the Citizen's Advisory Committee appointed by the City
of Lynnwood to participate in the preparation of the
draft E.I.S. The remarks which follow, however, are my
own and should not be construed to be in behalf of the
advisory committee.
I fully support the plan to upgrade the sewage treatment
plant at Brown's Bay. The effluent presently discharged
from the plant exceeds the coliform count allowed in the
discharge permit and its daily volume frequently exceeds
its design capacity. I concur with the findings of the
E.I.S. that there will be no long term detrimental impact
to the environs of the bedroom community adjoining the
treatment plant and that there will be an upgrading in the
quality of air and water emmissions from the treatment
plant.
I can not at present support the plan to construct a sewer
interceptor through the Swamp Creek drainage basin.
There are several questions I have which I feel have riot
been fully addressed in the E.I.S. They are as follows:
Is there a demonstrated public health hazard which warrants
construction of the interceptor? The E.I.S. discusses
the subject of need for an interceptor in the Swamp Creek
basin in the context of promoting public health (page
11-96). It is mentioned that 650 septic tank failures
have been reported in the past 10+ years and that there
is the potential for children at play to contract
diseases spread by fecal contamination. The E.I.S.
assessment of the present threat of disease or death from
sewage and how serious this threat may become in the future
is speculative. The Snohomish County Health Department
for the purposes of the E.I.S. would not attest in writing
that a health problem presently exists in the Swamp Creek
basin. The use of data regarding septic tank failures
and denied building permits as presented may not accurately
measure the severity of the problem. For example, many
VI-40
-------
reported failures may relate to poorly constructed drain-
fields and/or septic tanks and some may involve repeated
complaints about the same parcel of property. Some
building permits might have been found acceptable if the
lot size had been larger. The soils and drain field
suitability map (Figure II-l) shows that many of those
sites marked as being susceptible to drainfield failure
or denied a building permit are in fact in close proximity
to a lake or stream. From the information provided in
the E.I.S. it is impossible for me to determine if the
"problem" of inadequate drainfields is an inherent area-
wide problem or if it is localized, but never-the-less
attention getting because of existing patterns of zoning,
land speculation, decreasing size of residential lots,
poor construction et. cetra. If the issue of a present
threat to public health can not be better substantiated
then in my opinion the interceptor should not be constructed.
To do otherwise amounts to increasing the carrying
capacity of what is now mostly undeveloped land, which
would mean a financial windfall for existing property
owners and at public expense.
The second major concern I have is whether construction
of the interceptor will help to improve the water quality
in the Swamp Creek basin or only help to alter the type
of pollutants. Presumable construction of the interceptor
will eventually lead to a lower coliform count and a
reduced B.O.D. in Swamp Creek and its tributaries. It
also appears that construction of laterals and additional
development stimulated by the interceptor is likely to
increase siltation of Swmap Creek. I would therefore
hope that any permit granted for the construction of
an interceptor would include some provision for protecting
the freshwater habitat in Swamp Creek and its tributaries
from future siltation originating from human activity.
My final question has to do with connecting the interceptor
to the Metro system. This will require Metro to eventually
install another interceptor in Lake Washington. The
addition of a second interceptor and its impact falls
outside the study area of the present E.I.S. but it is,
never-the-less, as a result of actions contemplated now that
Lake Washington may be possibly adversely impacted later.
Somebody should examine that possibility now before the
pipe is in the ground and there are no options left.
Respectfully submitted,
' ¦ 'n..
¦ -v. " " '
Kenneth D. Marvel
VI--41
-------
Marvel
RESPONSE
1. Since publication of the draft EIS, the Snohomish Health District
letter of April 5, 1977, which states, "There is a critical need for pub-
lic sewers to . . . eliminate a public health hazard," has come to our
attention. (See Appendix F.) In addition, EPA staff members toured
the Swamp Creek basin and found evidence of need for a sewer system.
We then requested information on septic tank failures from the Snohomish
Health District. The District replied December 19, 1977, enclosing a
map showing locations of septic tank failures in the Swamp Creek basin.
(See Appendix F.) We agree that drainfield and lot sizes in many cases
reflect questionable existing or past zoning practices. However, with
several thousand people living in approximately 8,000 residences in the
Swamp Creek basin, we believe there is need to correct the situation.
2. Pollutants within Swamp Creek will be altered by installation of
sewers but not eliminated. Coliform counts should be lowered and possibly
BOD, but past experience indicates urban development tends to increase
suspended solids and siltation. However, Snohomish County is now imple-
menting new storm drainage requirements which should mitigate storm run-
off problems. It will be necessary that the County enforce these
requirements to ensure such mitigation.
3. Metro's Kenmore interceptor in Lake Washington has an adequate ease-
ment to install a parallel pipe on pile supports above the lake bottom
but below the water surface. Some impacts to the lake from such con-
struction are certain to result. However, pile placement is considerably
less destructive than pipe burial. The impacts resulting from construc-
tion would be temporary impacts.
VI-42
-------
DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT
REGIONAL OFFICE
ARCADE PLAZA BUILDING, 1321 SECOND AVENUE
SEATTLE, WASHINGTON 98101
October 31, I977
REGION X
Office of Community
Planning & Development
IN REPLY REFER TO:
I0D M/S 3I7
Alexandra B. Smith, Chief
Environmental Evaluation Branch, M/S 443
U.S. Environmental Protection Agency, Region X
I 200 Sixth Avenue
Seattle, Washington 98I0I
Dear Chief Smith:
Subject: Environmental Impact Statement
We have reviewed the statement submitted with your September 8, 1977
Ietter.
The proposed Federal action is the awarding of grant funds to provide
secondary treatment facilities for the existing sanitary sewerage
system in the City of Lynnwood.
As you have indicated in your statement secondary treatment is a
requirement as established in Public Law 92-500. We find no conflicts
of your proposed action with objectives of our Department. Our Seattle
Area Office has also been provided a copy of your draft and no comments
have been received. Thus we have no objections to your proposed action.
Wastewater Treatment Facilities
City of Lynnwood and Alderwood Water District
Snohomish Countu, Washington
£ Assistant Regional Administrator
Thank yoJj for the opportunity to comment.
VI-43
AREA OFFICES
Portland, Oregon • Seattle, Washington • Anchorage, Alaska • Boise, Idaho
Insuring Office
Spokane, Washington
-------
STATE OF
WASHINGTON
DEPARTMENT OF FISHERIES
lib General Administration Building, Olympia, Washington 98504 206/753 6600
Dixy Let Ray
Governor
October 31, 1977
Alexandra B. Smith, Chief
Environmental Evaluation Branch, M/S 443
U.S. Environmental Protection Agency,
Region X
1200 Sixth Avenue
Seattle, Washington 98101
Dear Ms. Smith:
Environmental Impact Statement for
Wastewater Treatment Facilities
City of Lynnwood and Alderwood Water
District - Snohomish Co. - WRIA B-08
The Department of Fisheries has reviewed the above referenced impact state-
ment. Our comments follow.
The chosen alternative would provide for secondary sewage treatment at the
Brown's Bay plant. The impact statement indicates that a diffuser section
will be added to the outfall, and we concur that this measure should improve
effluent dispersal. The design of the diffuser will be reviewed by the
Washington Department of Fisheries through the Corps of Engineers Public
Notice.
We concur that upgrading the Brown's Bay plant should reduce BOD levels in
the discharged effluent to some degree. Page IV-3 indicates that 4 mg/1
is a minimum dissolved oxygen level for salmon. Our experience indicates
that salmon require a dissolved oxygen level in excess of 5 mg/1. We appre-
ciate the present use of a flow controlled chlorinator at the Brown's Bay
plant and the recognition that a dechlorination facility may be required
in the future.
Sewage from the Swamp Creek basin would be routed to and treated at Metro's
West Point facility in the chosen alternative. The impact statement does
not address Metro's current proposals for upgrading their sewage treatment
facilities. Since the chosen alternative for the City of Lynnwood and
Alderwood Water District's proposal is predicated on the West Point facility
remaining in operation, Metro's concurrent plans should be acknowledged in
this impact statement.
The importance of the Swamp Creek system to total Lake Washington coho salmon
production is recognized in the impact statement. Large portions of Swamp
Creek have ideal coho spawning conditions, and there is year-round rearing
of coho juveniles in the system. In addition to the important coho popula-
tions of Swamp Creek, as noted in the statement, there is also some coho
production in Scriber Creek and moderate Chinook and sockeye salmon utiliza-
tion of Swamp Creek.
VI-44
-------
Alexandra B. Smith
-2-
October 31, 1977
The Department of Fisheries is very concerned about the protection of the
salmon resources in the Swamp Creek basin. The maintenance of suitable
habitat and water quality in this system is essential to continued salmon
producti on.
The impact statement indicates that a gravity flow system is the chosen Swamp
Creek basin interception concept. This concept is the least desirable for
the protection of the salmon resources in the Swamp Creek system, as its im-
plementation would require in excess of fifty trunk and interceptor stream
crossings. We strongly recommend the selection of a different alternative
or more serious consideration of an alternative design concept. The size
of the projected treatment area may warrant the construction of a new treat-
ment plant to serve the region, such as the Scriber Creek plant alternative
(Figure 111-8). If the West Point facility is abandoned, this alternative
may be the most feasible. Routing the trunk lines along street right-of-ways
or the construction of at least some pump or lift stations are two alternate
concepts that should be more extensively evaluated. There is insufficient
evidence presented in the statement to support the concept that overflow
risk cannot be mitigated. A comparison of the overflow risks of the three
options presented in the impact statement, as well as combinations among
these concepts, should be further considered.
A significant reduction or elimination of stream crossings is necessary for
the protection of fishery resources. The detrimental repercussions of the
number of stream crossings that are required in the proposed concept may not
be confined to short-term construction impacts. Long-term destruction of
spawning beds from initial disruption and siltation, soil slippage and erosion
from trenching, and water quality degradation are potential impacts which
may occur both during and upon completion of construction activities within
or adjacent to a streambed. Swamp Creek is very susceptible to flooding, and
high water flows have washed out sewer lines in the past. Even the most pre-
cautionary construction measures may not prevent fish habitat loss or water
quality degradation.
The Department of Fisheries has very serious reservations about the present
proposal, and we could not approve it if other viable alternatives are feasi-
ble. We will carefully evaluate the alternative ultimately chosen by the
proponents upon receipt of the Hydraulic Project Application(s) for the
project. The issuance of Hydraulic Project Approvals for the project will
be dependent upon our assessment of the potential impacts of that proposal
on fishery resources.
Thank you for the opportunity to comment.
sc
cc: WDG - Environmental Management Division
DOE - Olympia
PFM - Olympia
VI-4 5
-------
Fisheries
RESPONSE
1. Comment noted.
2. Metro plans for treatment at West Point have not been announced.
However, Metro is prepared to either include or exclude the Swamp Creek
basin sewage flow in accordance with decisions resulting from this Facil-
ities Plan. Whether or not West Point is abandoned, Metro treatment
capacity will be affected only marginally by Swamp Creek decisions.
3. We agree that pump or lift stations would produce an interceptor sys-
tem with fewer construction impacts on the stream hydrologic system.
Economic impacts of alternatives other than the gravity system, however,
appear to be significant. Potential impacts of fisheries are of primary
concern to EPA, which has carefully reviewed the routing of the inter-
ceptor and has requested assistance from the Fish, Wildlife, and Game
Departments in developing mitigative measures to offset the adverse
impacts to the stream. Every precaution must be taken during construc-
tion of the interceptor to protect the fisheries resource. Alderwood
Water District has stated that full cooperation will be extended by the
District to the Fisheries and other concerned agencies to assure that
the adverse impacts of stream crossings are held to a minimum.
4. Overflows are accidental occurrences, and the number that would
occur must be approximated. Overflows can be mitigated by standby emer-
gency generators and duplicative equipment; however, they cannot be com-
pletely eliminated. The average daily design sewage flow for the Swamp
Creek trunk is about 25 percent of the recorded daily stream flow. Power
outages within the Alderwood Water District over the past several years
have averaged about five annually. Given these factors, a comparison of
overflow risks would seem to indicate that the pump and lift station
systems would suffer failures, whereas the gravity system rarely would
be susceptible to this problem. It is impossible to predict how many
overflows would occur with the pump and lift stations, but there is great
probability that overflows would occur every year.
5. See Response No. 3 above. Although we agree that the crossings of
the creek are a significant adverse fisheries impact, we believe that
many of these impacts can be mitigated by phasing of construction and
use of the best construction techniques. EPA believes that the State
Fisheries Department can provide invaluable expertise in accomplishing
the necessary stream crossings and has requested the Department to work
with the Alderwood Water District, the facilities planner, and EPA to
develop mitigative measures in all areas where adverse impacts will
affect the aquatic habitat.
VI-46
-------
6. Flooding does occur within the Swamp Creek basin. However, we have
no record that a sewer or waterline within the basin ever has been washed
out .
7. We agree that careful evaluation and assessment of the potential
impacts on fishery resources and mitigation measures to lessen such
impacts should precede issuance of the permit.
VI-47
-------
^ CITY of EDMONDS
Civic Center • Edmonds. Washington 98020 • Telephone (206) 775-2525 rzt- .
Office of the Mayor
October 14, 1977
OCT
r
1 ¦ Ji
The Honorable H. J. Hrdlicka
Mayor of Lynnwood
19100 44th Avenue West
Lynnwood, Washington 98036
Dear Mayor Hrdlicka:
SUBJECT: ENVIRONMENTAL IMPACT STATEMENT, LYNNWOOD
201 FACILITY PLAN
The City of Edmonds has reviewed the Environmental Impact
Statement and we have the following comments to make:
1. The soil at the Lynnwood treatment plant site is
unstable. Slides have occurred in the area after
periods of extended rainfall. Precaution should
be taken to insure adequate design of the facility
additions in consideration of the problems.
2. Adequate dispersion of the effluent into Puget
Sound is of concern to the City. Investigation
of the tidal currents should be adequately
completed to insure proper dispersion.
3. The odor problem at the treatment plant and in
the interceptors leading to the treatment plant
should be abated.
4. The City concurs with Lynnwood's concern over
water quality in the Puget Sound. Upgrading the
treatment levels is a proper step in meeting the
quality levels desired along the Edmonds waterfront.
Very truly yours,
RHA:lv
HARVE H. HARRISON
Mayor
VI-48
-------
City of Edmonds
RESPONSE
1. We agree. Geologic investigations will be conducted in greater
detail during final design of facility additions. Recommendations will
then be incorporated into the design.
2. Tidal currents data available for Browns Bay were used in the Facil-
ities Plan and EIS. Additional current analysis will be conducted during
final design once actual effluent diffusion requirements are established
by the regulatory agencies.
3. Odor abatement is addressed by the Facilities Plan through enclosing
all potentially odorous components and provision of odor control equipment
at the pump stations serving the interceptors.
4. We agree.
VI-4 9
-------
¦^NTOf
United States Department of the Interior
OFFICE OF THE SECRETARY
PA( IH( NORTHVUST RkCilON
P.O. Box X&XD£ Portland, Ore j»on 972 08
3737
November 4, 1977
ER-77/870
Alexandra B. Smith, Chief
Environmental Evaluation Branch, M/S 443
U. S. Environmental Protection Agency
1200 Sixth Avenue
Seattle, Washington 98101
Dear Ms. Smith:
This is in response to your request that the Department of the Interior
review and comment on the draft environmental statement for Wastewater
Treatment Facilities, City of Lynwood, Snohomish County, Washington.
General Comments
The description of the area's geology, including stratigraphy, topography,
and erosion is very good. However, because the project involves underground
installations, we suggest addition of a new section that would discuss the
possibilities of seismic (earthquakes) and landslide activity in the
project area. The discussion should also include what measures, if any,
are to be taken to reduce impacts of earthquakes or landslides.
There is no indication in the statement that the Fort Bellingham-Fort
Steilacoom Military Road has been evaluated for the "National Register
of Historic Places." Since the road occurs in the project area and will
be affected by the project, it should be evaluated and the results re-
ported in the final statement. To ensure compliance with procedures of
the Advisory Council on Historic Preservation, 36 CFR Part 800 should be
consulted.
Swamp Creek and its tributaries are utilized by coho, sockeye, and
® chinook salmon, as well as cutthroat, kokanee, and steelhead trout. As
stated on page 11-45, Washington Department of Fisheries considers the
Swamp Creek system to be one of the five principal contributors to the
Lake Washington coho salmon population. Coho salmon production is
-------
estimated at 10 to 20 percent for the total Lake Washington output and
two percent of the Puget Sound total. The yearly monetary value of the
creek fish output is now estimated at $100,000. In addition, coho
salmon utilize Sciber Creek which is the principal tributary of Swamp
Creek. The proposed Swamp Creek gravity trunk with its associated
lateral lines would cross Swamp and Scriber Creeks at least 40 times
(Figure 111-12). The resultant stream crossings during project construc-
tion would lead to increased siltation which could destroy fish spawning
grounds and alter present streambed characteristics. The proposed
project alignment, which is specified to be at least 25 feet from the stream
edge, would eliminate a minimum of 5,000 feet of riparian vegetation. This
would allow for increased erosion and runoff into Swamp Creek, thereby
further degrading the water quality and habitat of the creek. Most wild-
life dependent upon the riparian habitat would also be eliminated.
Overall, the sewage facilities would improve the ground water and surface
water quality of Swamp Creek. However, «e totally disagree with the con-
clusion made on page 111-41 that "...possible environmental tradeoffs do
not seem to provide sufficient advantage to justify the higher expense
of a pump concept so the gravity concept was selected." Based on the
number of times Swamp and Sciber Creeks would have to be crossed and
the possible detrimental effects from construction activities, sole use
of the gravity concept for the entire project area would seriously
jeopardize the continued utilization of these two creeks as major salmon
spawning and rearing areas. Combination pump/lift stations, along with
the gravity line concept, would result in fewer stream crossings and
less adverse environmental impact. It is recommended wherever possible
that proposed project alignment be placed 75 feet from the creek's edge
with 25 feet being the absolute minimum allowed. All wetlands, regard-
less of size, should be avoided wherever possible. Preservation of exist-
ing wetlands is a major concern of this Department. A considerable amount
of the once viable wetlands of Snohomish County have been eliminated, along
with wildlife dependent upon such habitat. The avoidance of wetlands to
insure their continued preservation would fulfill the overall intent of
President Carter's wetland polity as contained in his May 23,' 1977, mes-
sage to Congress.
The proposed project may require permits for which this Department has
review responsibilities. Accordingly, our comments do not preclude an
additional and separate evaluation by the U. S. Fish and Wildlife Service,
pursuant to the Fish and Wildlife Coordination Act (16 U.S.C. 661, et seq.),
if eventual project development requires a permit from the U. S. Coast
Guard and/or the Corps of Engineers, U. S. Army (Sections 9 and 10 of the
River and Harbor Act of 1899 and Section 404 of P. L. 92-500). All such
permits are subject to separate review by the Service under existing
statutes, executive order, memorandum of agreement, and other authorities.
In review of permit applications, the Fish and Wildlife Service may concur,
with or without stipulations, or object to the proposed work, depending on
specific construction practices which may impact fish and wildlife resources.
VI-51
-------
Specific Comments
Page II-5, last paragraph. Considerable new construction space would be
required at the Browns Bay site in a ravine with steep side slopes. The
statement should include provisions for adequate drainage to minimize
slumping.
Page 11-50, next-to-last paragraph, second sentence. The definition of
wetlands presented should be replaced with the definition stated in the
Corps of Engineers rules and regulations as contained in the Federal
Register, Volume 42, No. 138, Tuesday, July 19, 1977:
Those areas that are inundated or saturated by surface or ground
water at a frequency and duration sufficient to support, and that
under normal circumstances do support, a prevalance of vegetation
typically adapted for life in saturated soil conditions. Wetlands
generally include swamps, marshes, bogs, and similar areas.
All wetlands adjacent to Swamp and Scriber Creeks should be clearly il-
lustrated on a map so a determination can be made on the project's overall
impact on this habitat type.
Page 11-98. On this page and also on page IV-18, discussions of archeo-
logical resources do not indicate what commitments are being made to
preserve these resources. We suggest that the final statement include
information on what steps will be taken to protect archeological resources.
Pages 111-42 and 43. This section of the report discusses alternative
alignments and the type of habitat that would be impacted by the proposed
project. From the standpoint of protecting wetlands the use of the Ash
Way alternative alignment would route the pipe around the wetlands. We
recommend that wherever practical, final design alignment avoid wetland
areas.
The four alternatives described on page 111-42 cannot be clearly identified
on Figure 111-12. This correction should be made for the final EIS so
the reader can easily locate each proposed route.
Page IV-5, last paragraph, next-to-last sentence. Construction of a new
outfall could possibly require construction precautions beyond those
normally imposed by the State. Construction activities would be subject
to a Section 10/404 permit from the U. S. Army Corps of Engineers. The
proposed work would be reviewed not only by State agencies but also
Federal agencies such as the Fish and Wildlife Service, National Marine
Fisheries Service, etc.
Page IV-33, second full paragraph. Net impacts on ground-water recharge and
quantity should be evaluated in the matrix of table IV-5. Table IV-6 should
assess secondary impacts on ground-water resources, such as reduced recharge,
as a result of urbanization. These topics are also considered on page V-6.
VI-5 2
-------
Pases V-3 through V-9. Many good mitigative measures are discussed in this
section of the report. However, there are no assurances which mitigation
measures would be implemented. Based upon the draft EIS's discussion of
the project's potential water quality problems and their possible adverse
impact to fish and wildlife, we recommend that the sponsor of the project
be responsible for implementing at a minimum the following mitigation
proposals:
1. During final design, consideration should be given to collect-
ing sewage from some residences along the stream banks by individual
grinder pumps instead of insistence that all collection be by
gravity. In this way, pipe routes through the natural areas along
the streams can be minimized.
2. Interceptor trenching and all construction activities on slopes
that lie adjacent to streams should be carried out during late
spring and summer to avoid the winter rainy season. This would
reduce the possibility of serious erosion problems and resultant
stream siltation.
3. Because precipitation will undoubtedly occur during construction,
exposure of barred soil should be kept to a minimum. In addition,
erosion control devices should be continuously in place to prevent
erosion and trap sediment before it enters the stream.
4. Optimum pipe location should be at least 75 feet from the creek's
edge with 25 feet being the absolute minimum allowed. This recom-
mendation would reduce streamside erosion problems and the amount
of riparian vegetation eliminated.
5. Reseeding, replanting, and mulching should be used in areas of
cleared ground and backfilled trenches in order to reduce erosion.
6. Excavated material should be stockpiled on the uphill side of
the trench so if any erosion does occur, the effects can be somewhat
restricted to the vicinity of the interceptor trench.
7. Haul roads should be placed on the uphill side of the trench
so if any erosion does occur, the effects can be somewhat restricted
to the vicinity of the interceptor trench.
8. Construction work adjacent to the streambed should be scheduled
to avoid periods when fish are spawning and periods when high flow
volumes are expected.
9. Where excavation takes place in the streambed, the area should
be backfilled with gravel. This practice would minimize stream
turbidity.
VI-53
-------
10. Wherever practical, final design alignment should avoid stream
crossings and wetlands.
Final consideration of all mitigation measures which will be incorporated
into the project should be coordinated with Washington Department of
Fisheries, Washington Department of Game, and other concerned agencies.
Page V-5, first full paragraph, last sentence. This sentence indicates
that details of trunk location are insufficient to establish even pre-
liminary magnitude of impact of the streams affected by the project.
Such information must be contained in an EIS if meaningful determination
is to be made concerning the project's overall impact on fish and wildlife
resources.
We appreciate the opportunity to review and comment on this document.
Sincerely yours
Charles S. Polityka
Regional Environmental Officer
VI-54
-------
Interior
RESPONSE
1. Seismic activity can, of course, fracture sanitary sewerage piping.
However, modern interceptors constructed of material such as reinforced
concrete are not necessarily destroyed in such events. A sewerage
system can continue to function under these conditions without the total
failure inherent with a pressurized water main or the hazards associated
with leakage from gas piping. Special seismic design is thus not war-
ranted for sewerage piping, especially so since no surface faults have
been identified in the Lynnwood-Alderwood vicinity. Landslides are a
recognized concern at the Browns Bay treatment plant site and are so
addressed. Concern for slides along the interceptor would be addressed
by a geologic study during final design for actual alignment, but not as
a planning concern in this case.
2. The Military Road is no longer in active use and such faint remnants
as exist are not felt significant for inclusion in the "National Register
of Historic Places." This evaluation was prepared under the auspices of
the Director, Office of Public Archaeology at the University of Washing-
ton, with the State Office of Archaeology and Historic Preservation
advised of the results.
3. Fishery resources dependent upon Swamp Creek have been recognized
throughout preparation of this EIS. As stated in the preface, EPA believes
that impacts during construction of the interceptor are a key concern
and has set forth mitigative measures to be applied during interceptor
construction for maximum protection of aquatic habitat and fishery
resources.
4. Comment noted. See response to No. 3 above.
5. Permit requirements will be coordinated with all concerned agencies
during the design phase to incorporate all necessary mitigative measures.
6. Slide hazards at the Browns Bay treatment plant site were evaluated
and found manageable. Drainage requirements are a design aspect to be
defined during design.
7. The federal wetlands definition has been included within the text,
and wetlands are indicated on Figure II-7.
8. As stated in the EIS, no significant archaeological or cultural
resources have been identified. However, as additional precautions, EPA
VI-55
-------
recommends additional archaeological reconnaissance when the interceptor
alignment is fixed and on-site monitoring by a professional archaeologist
during construction.
9. The Ash Way interceptor alignment is the route planned for the pro-
posed project to avoid wetlands.
10. Outfall construction precautions will be established during final
design. Coordination will be effected at that time with all agencies
having jurisdiction to define permit conditions.
11. Use of an environmental matrix involves subjective selection of
factors to be considered (see Page IV-34). Groundwater recharge and
quality were not considered major factors to be evaluated in the environ-
mental matrices. With the entire study area served by the Alderwood
Water District, local groundwater conditions are not a significant concern.
12. Mitigative measures recommended by the U. S. Department of the
Interior will be considered as potential grant conditions. Agencies
with permit authority may also wish to require certain precautions.
13. Magnitudes of stream temperature change and sedimentation due to
construction activity can be approximated only through on-site analysis
when the actual interceptor alignment is established. Such detail is not
part of the scope established for this facilities plan and EIS. Temper-
ature and sediment are valid concerns and will be monitored for actual
conditions should the project be implemented. However, experience with
utility improvements along similar stream conditions under strict State
Fisheries Department permit requirements have produced results acceptable
to that department.
VI-56
-------
SUBSEQUENT COMMENTS
The questions raised by several of the resource agencies, particularly
State Fisheries and State Game, relating to the Swamp Creek trunk sewer
suggested that additional study of facilities planning alternatives and
the resulting environmental impacts was necessary to resolve the differ-
ences with local health and septic tank drainfield concerns. When these
studies had been completed with the necessary text revisions to the facil-
ities plan and the EIS, further comments from the resource agencies were
solicited. These communications are included herein with the responses
as appropriate.
VI-57
-------
DEPARTMENT OF GAME
600 Norfh Capitol Way/Olympia, Washington 98504 206/753 5700
June 6, 1978
Mr. Roger Mochnick
Environmental Protection Agency
Region X
1200 Sixth Avenue
Seattle, WA 98101
Mr. Mochnick,
Your documents were reviewed by our staff as requested. We have
made cursory field surveys to obtain preliminary information of
streamside vegetation and Swamp Creek gravel types. Our comments
on your documents and proposals follow.
As you state on pages IV: 31-34 of the draft environmental impact
statement, if the area is sewered it would result in the urbanization
of 3,500 acres of undeveloped land and more than double the existing
population in the next 25 years. Without strong land use controls
and extensive natural corridors along Swamp Creek and its tributaries,
urbanization of this magnitude would destroy Swamp Creek as a major
producer of anadromous fish, and result in the elimination of five
and one-half square miles of valuable wildlife habitat. These
impacts would occur for the reasons you accurately list on pages
IV:32-34.
In discussing your limited service alternative, you state on page
IV-31, "The limited service area is presently relatively urbanized
©already, so no remarkable increase in rate of urbanization and
urban runoff contamination of streams is predicted." Since we are
charged with protection of the fish and wildlife resources that
belong to the people of the State of Washington, the only proposed
action we can accept is the limited service alternative.
We recommend that you also work closely with Snohomish County and
DRAFT EIS: Wastewater Treatment
Facilities - City of
Lynnwood and Alerwood
Water District - Area
Wide 201 Facilities Plan
VI-58
-------
page 2
Mr. Roger Mochnick
June 6, 1978
local municipalities to develop land use controls so that development
is encouraged in areas other than this environmentally-sensitive
watershed. We also recommend that areas that are not secured be
phased off septic tank systems and onto self-composting and self-
contained toilets. The establishment of natural corridors along the
streams and adjacent wetlands are additional goals that should be
pursued with Snohomish County and local cities.
We have walked the stream to determine streamside vegetation and
stream gravel types. However, additional data is needed before we
can determine in what areas we could issue permits for stream crossing
and where we would require that crossings be jacked under the stream.
Data that is needed include:
a) Present resident and anadromous fish populations in key stream
reaches.
b) Escapement of steelhead, sea-run cutthroat, kokanee and resident
fish so critical spawning areas can be identified with certainty.
c) Present stream gravel quality characteristics in areas at and
below proposed crossings or clusters of crossings.
We suggest that resource agency personnel and/or qualified consultants
be contracted to provide the above data. The consultant, study
plan, and data obtained should meet the approval of all resource
agencies involved in review of the proposals. This study would need
to be completed prior to initiation of any construction work.
Before we would issue permits for any work, we would need a contracted
agreement stating that City of Lynnwood and Alderwood Water District
would be responsible to rehabilitate the stream to pre-project
conditions in event the stream or fish resources are damaged.
Specific Comments on the Draft EIS
p.viii Second full paragraph. Jacking could be required by Washingt
Department of Game as well as State Fisheries.
p.11-31
We do not concur with the statement in the first full
paragraph regarding the runoff attenvation values of Swamp
Creek wetlands. While flow-through by flood waters in the
defined channel may be more rapid under the described
environmental conditions, the wetlands still serve as
Vl-59
-------
page 3
Mr. Roger Mochriick
June 6, 1978
important storage areas, particularly if the stream overtops
its banks. Are all flood flows truly and actually confined
to the channel when passing through the "swamps"?
p.II - 35
Aquatic fauna: Include kokanee.
p.II - 49
The Martha Lake outlet does "pass through a swamp", and
continues as an unnamed tributary of Swamp Creek, joining
a latter just below 1-405.
p.Ill - 41
We completely agree with Charles Polityka's, (Department
of Interior) comments on the last sentence on this page.
We cannot concur that higher costs justify dismissal of
environmental or natural resource protection.
p.Ill - 47 (first paragraph)
We would impose the same restrictions on people or contractors
making individual home hookups in critical areas as we
will on the water district.
p.IV - 10 (third paragraph)
The last line of the paragraph under Runoff/absorption should
be enlarged to, "This increase could be significant". When
secondary impacts (Urbanization of 3,500 acres) are considered
the increase would be very serious and significant.
p.IV - 13
Under "Aquatic life", add temperature and gravel composition
to the list of parameters critical to salmonid fisheries in
Swamp Creek.
p.IV - 13-14
The spawning season could begin as early as late August
when kokanee are included.
p.IV - 14 (first full paragraph)
Riparian vegetation will be lost at every point where the
vi-60
-------
page 4
Mr. Roger Mochnick
June 6, 1978
pipe is laid across the creek alignment by utilizing
trenching methods; this is cumulatively a significant
loss of vegetation which must be mitigated.
p.IV - 14 (first full paragraph)
Natural reseeding would not mitigate erosion where raw soil
surfaces ultimately drain to the creek, i.e., most anywhere
in the project area. Replanting must be planned for, and
should be an integral part of the erosion control plan.
p.V - 5 (second full paragraph)
Instream work must be scheduled to avoid periods of fish
incubation as well as spawning. Crossings must also conform
to State Department of Game permit requirements (third
paragraph).
(fifth full paragraph)
What is "attentive surface restoration"?
p.V - 7 (second full paragraph)
This discussion is absolutely correct. We do not feel we
can tolerate the uncontrollable sedimentation resulting
from a project of this scope and at the same time protect
game fish and wildlife in the Swamp Creek basin.
p.V - 8
Add "and trout" to the last sentence of the last paragraph.
p.V - 9
How is the "Future uses" paragraph reconciled with the
greater than 100 percent projected increase in basin
population stimulated by the proposal? What are existing
levels of occupancy per acre and how will these change?
Additional Mitigative Measures
We concur with Department of Interior's mitigative measures as
VI-61
-------
page 5
Mr. Roger Mochnick
June 6, 1978
stated in their letter dated November 4, 1977. In addition, land
use controls, and contracts to ensure rehabilitation of the stream,
should be strictly adhered to. We will ask that the interceptor
and laterals be jacked under the creek(s) in all critical areas
identified by spawning surveys and by Departments of Game and
Fisheries. We also urge that an agreement be reached with the
Departments of Fisheries and Game to provide compensation for the
services of one or more technical overseers, hired to supervise
the project's construction in its entirety
These comments supplement our comments sent in by our staff on
September 29, 1977. We will provide additional comments on the
proposal once the study is contracted and data becomes available.
Thank you for sending your documents. We hope you find our comments
helpful.
Sincerely,
THE DEPARTMENT OF GAME
duu j-g,icl , tt.yp.i.ied Ecologist
Environmental Management Division
BZ:bj
cc:Agencies
Regional Manager
vi-62
-------
Game Department
RESPONSE
1. The resource protection responsibilities of the State Department of
Game are noted.
2. Recommendations are noted. Selected alternative is compatible with
local land use plans which include natural corridors.
3. Permit requirements are noted. Facilities plan and EIS concern
only preliminary designs however. Actual stream crossing locations will
be defined during final design.
4. Comment noted.
5. Comment noted.
6. Text revised.
7. Text refers to ordinary rainfall conditions, not flooding, and has
been revised accordingly.
8. Text revised.
9. Text revised.
10. Comment noted.
11. Comment noted.
12. Text revised.
13. Text revised.
14. Text revised.
15. Comment noted.
16. Text revised
17. Text revised.
18. Comment noted. Sedimentation controls will be required.
19. Text revised.
VI-6 3
-------
20. Present development is widely scattered throughout the study
area and is rapidly intensifying. Present occupancy levels averaging 2
to 3 people per acre are expected to double during the study period.
21. Comment noted.
VI-64
-------
STATE OF
WASHINGTON
DEPARTMENT OF FISHERIES
115 General Administration Building, Olympia, Washington 98604 206/753-6600
Dixy Lee Ray
Governor
June 7, 1978
Environmental Evaluation Branch
U„S. Environmental Protection Agency
1200 Sixth Avenue - M/S 443
Seattle, Washington 98101
RECEIVED
JUN 9 1978
EPA-F'S
Gentlemen:
Wastewater Treatment Facilities
City of Lynnwood and Alderwood Water District
Swamp Creek and Tributaries WRIA B-08-0059
As indicated in past correspondence and during meetings on April 21, 1978
and May 8, 1978, a project of this magnitude can potentially eliminate the
fishery resources of Swamp Creek. These impacts can be substantially re-
duced with proper planning, design, and construction practices.
We are not opposed to a project to upgrade the sanitary sewers in the Swamp
Creek basin. However, we must be assured that the construction of the
facilities will not impact the fishery resources.
As a result of our meeting on May 8, 1978, it is apparent that the number
of stream crossings can be reduced. However, work parallel to the stream
can create as large an impact upon the fishery resources and habitat as
the individual crossings. Therefore, the following recommendations must
be included in the planning, design and construction of this project.
a) The final alignment should be designed to minimize the number
of crossings and maximize a buffer strip between the pipe lo-
cation and the stream alignment. This may require the in-
stallation of some pump stations.
b) When a stream crossing is necessary, the construction procedure
should be boring or jacking of the line under the stream.
c) Excavated material should not be placed on the downhill or
streamward side of the trench. This may require hauling the
excavated material from the site and importing backfill after
the pipe has been set in place.
d) All swamp or bog areas should be avoided unless adequate means
of preventing siltation to the main stream can be incorporated
within the final design.
VI-65
-------
Environmental Evaluation Branch
Page two
June 7, 1978
e) The fishery production potential of Swamp Creek and its
tributaries shall not be decreased during or as a result of
the construction activities required to install the wastewater
treatment facilities.
f) Any work within or that will affect Swamp Creek and its tribu-
taries must be restricted to the summer months only, i.e., June
through August.
We are confident that through good planning, design and careful construction,
this project can be accomplished without damaging the habitat or decreasing
the production capabilities of the Swamp Creek basin.
We would appreciate the opportunity to review the plans and specifications at
the early stages of the planning process.
Sincerely,
\
L c <- >• I tr -. v '¦ - l l.
Gordon Sandissrr /
Di rector
js
cc: Alderwood Water District
U.S. Fish & Wildlife Service
Department of Game
vi-66
-------
Fisheries
RESPONSE
1. Final design will minimize stream crossing while preserving the
maximum natural buffer adjacent to the stream. Pump stations for
individual homes will be considered as appropriate.
2.
Comment
noted
for
inclusion
as
grant
condition.
3.
Comment
noted
for
inclusion
as
grant
condition.
4.
Comment
noted
for
inclusion
as
grant
condition.
5.
Comment
noted.
6.
Comment
noted
for
inclusion
as
grant
condition.
VI-67
-------
United States Department of the Interior
FISH AND WILDLIFE SERVICE
Ecological Services
2625 Parkaont Lane, S.W., Bldg. B-3
Olympia, Washington 98502
^ r
j ^\r-«
June 12, 1978
In reply refer to: ES
Mr. Roger Mochnick
Environmental Protection Agency
Environmental Evaluation Branch M/S 443
1200 Sixth Ave.
Seattle, Washington 98101
Dear Mr. Mochnick:
This is in response to your April 20, 1978 request for additional comments
concerning the Wastewater Treatment Facilities, City of Lynnwood,
Snoho.nish County, Washington. Our comments are prepared based on
information presented at the April 20 meeting held at your Seattle office,
the May 8 meeting held at the Alderwood Water District office, and
subsequent discussions held with Washington Departments of Game (WDG) and
Fisheries (WDF).
It is our understanding that the route alignment of Swamp Creek
interceptor system as presented in the draft environmental impact system
is subject to future revisions. We are very interested in continuing to
work with you and the project sponsor as you finalize the design and
specify construction methods for this system. Careful planning at this
time should minimize the project's potential water quality problems and
impacts to fish and wildlife resources.
We believe that the best way to show the final route of the system is to
gather baseline data on fish and wildlife populations and their habitats
in the area of the proposed project. This information could then be
reviewed by our agency, in cooperation with WDG and WDF, to identify
critical habitats such as spawning and rearing areas for resident and
anadromous fish and wetland and riparian areas for resident and migratory
wildlife species. When we have identified these critical habitats, we
will be able to make specific recommendations regarding route alignment
and construction methods.
To obtain this baseline data, we recommend that your agency and the
project sponsor implement the following studies.
(
CONSERVE
AMERICA'S
ENEROY
VI-68
Save Energy and You Serve America!
-------
Studies
L. lonies should be contracted to an environmental consultant or
Washington Departments of fisheries and Game to determine:
a. Resident and anadromous fish standing populations in Swamp and
Scriber Creeks.
b. Anadro-nous fish snawnin™ escapement in Swa.mo and Scriber Creeks.
c. Location of all spawning; and rearing areas for anadromous and
resident fish within Swamp and Scriber Creeks.
2. Monies should be contracted to an environmental consultant or
Washington Department of Game to determine the type, location and
acreage of all wetland and rioarian habitat adjacent to Swamn and
Scriber Creeks potentially affected by the nroject.
3. Once critical spawning and rearing areas have been identified, nonies
should be contracted to an environmental consultant or Washington
Departments of Fisheries and Game to determine the overall gravel
composition and the anount of existing fines in the gravel in these
critical areas. (Mote: This baseline information could be used if
damage occurs as a result of sedimentation during project ooerations.
Removal of the sediment bv the project contractor would be considered
adequate mitigation for sedimentation damages caused by the Droject).
4. If an environmental consultant is chosen for the above studies, it
should be recognized that our agency, WDG and ^DF would have the
opportunity to review the consultant's proposed fish and wildlife
sampling programs and studies to insure that thev are adequate to
meet the abovs objectives.
Mitigation Proposals
Tne mitigation proposals outlined below are preliminary oending the
outcome of the suggested studies.
1. The sewer interceptor and laterals should avoid or be jacked under
all critical soawning and rearing areas on Swamp and Scribar Creeks
as identified by iVH-', WPC or the aforementioned studies.
2. The itirine of one or nore biologists by ,,'DF and/or .*'00 to oversee and
sunervise tiie project's construction in its entirety. This would
provide for downstraai monitoring during all construction operations
such that streambed changes and imoacts to aquatic life can be
minimized. The salary of personnel for this assienment would oe Daid
VI-69
-------
for by the project sponsor.
3. Adequate language be inserted in the construction contracts to
require the contractor to repair any stream damages that might occur
during construction operations.
4. Our agency, in coordination with WDG and WDF, be allowed to review
the construction plans and specifications at the preliminary layout
stage and all future design stages to insure adequate protection of
fish and wildlife resources.
5. There should be no sidecasting of excavation material next to
streams. Such excavation material should be hauled to an appropriate
disposal site.
6. All mitigation proposals described in the United States Department of
Interior's letter of November 4, 1977 should be incorporated in the
project plans.
We appreciate the opportunity to provide your agency with these additional
comments. These comments do not represent our final position on the
project. We will contact you if we receive additional information on
measures necessary to protect fish and wildlife resources.
Sincerely,
/ . / X'' .. S s
Charles M. Chambers
Acting Field Supervisor
VI-70
-------
U.S. Fish & Wildlife Service
RESPONSE
1. Comment noted.
2. Comment noted for inclusion as a grant condition.
3. Comment noted.
4. Comment noted.
5. Adequate review by resource agencies will be required at regular
intervals during design development.
6. Comment noted for inclusion as a grant condition.
7. Comment noted.
VI-71
-------
BIBLIOGRAPHY:
-------
BIBLIOGRAPHY
Anderson, A. C., C. C. Nikofroff, and W. J. Leighty (1947). Soli Survey
of Snohomish County, Washington (Series 1937, No. 19). U. S. Government
Printing Office. Washington.
Anon. (1970) . Bacteriological Effects of Primary Treatment Plant Discharges
at Bremerton, Washington. Washington Water Pollution Control Commission.
Olympia, Washington.
Bellingham, Douglas (1976). Game Biologist, Washington Department of Game.
Seattle. Personal communication.
Blunk, James (1976). District Engineer, Alderwood Water District. Alderwood
Manor, Washington. Personal communication.
Bortleson, G. C., N. P. Dion, J. B. McConnell, and L. M. Nelson (1976).
Reconnaissance Data ori Lakes in Washington. Volume 2. King and Snohomish
Counties. (Water Supply Bulletin 43, Volume 2). Washington Department of
Ecology. Olympia, Washington.
Brungs, William A. (1973). Effects of Residual Chlorine on Aquatic Life.
Journal, Water Pollution Control Federation. 45:2180 - 93.
Caryl, Delman H. (1960). With Angels to the Rear; An Informal Portrait of
Early Meadowdale.
DeLacy, Allan C., Bruce S. Miller, and Steven F. Burton (1972). Checklist
of Puget Sound Fishes. (Washington Sea Grant Publication 72-3). University
of Washington Division of Marine Resources. Seattle.
Ebbesmeyer, Curtis C. & Jonathan M. Helseth (1976). An Analysis of Primary
Production Observed during 1966-1975 in Central Puget Sound, Washington.
(Final Report to Metro). Evans-Hamilton, Inc. Seattle.
Environmental Review Committee, City of Lynnwood, (1975). Final EIS Alder-
wood Mall Shopping Center. Lynnwood, Washington.
Erickson, Les (1970). Engineering Report; Water Storage, Supply, Trans-
mission, and Distribution. Alderwood Water District. Alderwood Manor,
Washington.
Fletcher, Douglas (1976). Fisheries Biologist, Washington Department of
Game. Seattle. Personal communication.
Freibertshaur, Mark & Alan Duxbury (1972). Water Budget Study of Puget
Sound and its Subreaches. Limnology and Oceanography. 17:237-47.
1
-------
Freibertshaur, Mark, Kathy Krogslund, Venus Wong, James McCulloch, and
Pat Stoops (1971). Puget Sound and Approaches: Seasonal Variations of
Oceanographic Parameters in its Surface Waters. Department of Oceanography,
University of Washington. Seattle.
Gray & Osborne (1971). Swamp Creek Trunk Sewer Feasibility Study. Seattle.
Gray & Osborne (1972). Engineering Report. Sanitary Sewage Treatment
Facilities, Lynnwood, Washington. Seattle.
Gray & Osborne (1966). Alderwood Water District - Sewerage System Studies
and Planning. Seattle.
Hanberg, Terry (1976). Washington Department of Ecology. Redmond, Washing-
ton. Personal communication.
Holland, G. A., e£ al» (1960). Toxic Effects of Organic and Inorganic
Pollutants on Young Salmon and Trout. Research Bulletin No. 5. Washington
Department of Fisheries. Olympia, Washington.
Huntting, Marshall T. (1956). Inventory of Washington Minerals, Part II:
Metallic Minerals. (Division of Mines and Geology Bulletin 37). Washington
Department of Conservation & Development. Olympia, Washington.
Kennedy, Hal. (1976). Consulting Archaeologist, Office of Public Archaeology,
University of Washington. Seattle. Personal communication.
Lynnwood Environmental Review Committee (LERC)(1975). Final Environmental
Impact Statement: Alderwood Mall Shopping Center, Lynnwood, Washington.
Lynnwood Environmental Review Committee, Lynnwood, Washington.
McKee, Jack E. and Harold W. Wolfe (1963). Water Quality Criteria (second
edition). California State Water Resources Control Board (Publication 3A).
Sacramento, California.
Newcomb, R. C. (1952). Ground-water Resources of Snohomish County, Wash-
ington. (Geological Survey Water-Supply Paper 1135). U. S. Government
Printing Office. Washington.
Olson, Arden A., David W. Jamison & Sharon 0. Marchese (1974). Washington
Marine Atlas. Volume 2_. South Inland Waters. Washington Department of
Natural Resources. Olympia, Washington.
Rigg, George B. (1958). Peat Resources of Washington. (Division of Mines
& Geology Bulletin 44.) Washington Department of Conservation. Olympia,
Washington.
River Basin Coordinating Committee (RIBCO)(1974). Environmental Management
for the Metropolitan Area Cedar-Green River Basins, Washington. Part II.
Urban Drainage. Appendix A. Regional Sub-basin Plans, Volume , Cedar
River Basin. U. S. Army Corps of Engineers. Seattle.
2
-------
Salo, Leo J. (1975) . A Baseline Survey of Significant Marine Birds in
Washington State. (Coastal Zone Environmental Studies Report No. 1).
Washington Department of Game. Olympia, Washington.
Smiley, W. E. (1970). The Physical Environment. A Technical Supplement
to Snohomish County's General Land Use Plan. (Technical Report No. 1).
Snohomish County Planning Department. Everett, Washington.
Smith, Vivian K. (1976). Director, Edmonds-South Snohomish County Histori-
cal Society. Edmonds, Washington. Personal communication.
Snohomish County Planning Department (SCPD)(1973). The Shorelines of
Snohomish County; Inventory Summary. Snohomish County Planning Depart-
ment. Everett, Washington.
Snohomish County Planning Department (1973). Alderwood Area Plan.
Snohomish County Transportation Authority (1976). A Transit Plan for the
Snohomish County Transportation Benefit Area.
Snohomish Health District (1970). Sewage Waste Disposal Regulations - I_.
(Requirements and Standards Revision No. 2). Environmental Health Division,
SHD. Everett, Washington.
Snyder, D. E. (1971). Interpretations of Soils for Land Use Planning. A
Supplement to the Soil Survey of Snohomish County, Washington. USDA Soil
Conservation Service. Portland.
U. S. Environmental Protection Agency (1976). Quality Criteria for Water,
(EPA-440/9-760-023). U. S. Environmental Protection Agency. Washington, D. C.
U. S. Geological Survey (USGS)(1964-1975). Water Resources Data for Wash-
ington ; Water Year, 1964-1975. U. S. Geological Survey. Tacoma, Washington.
Valentine, Grant M. & Marshall T. Huntting (1960). Inventory of Washington
Minerals, Part I_ (Second Edition): Nonmetallic Minerals. (Division of Mines
& Geology Bulletin 37). Washington Department of Conservation. Olympia,
Washington.
VanDenburgh, A. S. & J. F. Santos (1965). Ground Water in Washington.
Its Chemical and Physical Quality. (Water Supply Bulletin 24). Washington
Department of Conservation. Olympia, Washington.
Waterman, T. T. (1922). The Geographical Names Used by the Indians of the
Pacific Coast. Geographical Review, Volume 12, Part 2, pp. 175-94.
Waterman, T. T. Puget Sound Geography. MS No. 1864. Smithsonian
Office of Anthropology, Bureau of American Ethnology Manuscript Collection.
Microfilm, University of Washington. Seattle.
3
-------
Welch, Jeanne (1976). Washington State Historic Preservation Office.
Olympia, Washington. Personal communication.
Whitmore, Cecil M. (1976). Quality of Seven Streams in the Lake Washington
Drainage Basin (draft copy). Metro. Seattle.
Whitmore, Cecil M., Robert G. Swartz, Robert N. Brenner & Glen D. Farris
(1973) . The Quality of Small Lakes and Streams in the Lake Washington and
Green River Drainage Basins. Interim report. Metro. Seattle.
Williams, R. Walter, Richard M. Laramie, & James J. Ames (1975). A Catalog
of Washington Streams and Salmon Utilization. Volume 1. Puget Sound
Region. Washington Department of Fisheries. Olympia, Washington.
Wolcott, Ernest E. (1973). Lakes of Washington. Volume 1. Western
Washington. (Water Supply Bulletin 14). Washington Department of Ecology.
Olympia, Washington.
Woolridge, David D. (1971). Revised Objectives for Design of Urban Storm
Water Systems in the Puget Sound Region. University of Washington. Seattle.
Zillich, John A. (1972). Toxicity of Combined Chlorine Residuals to
Freshwater Fish. Journal, Water Pollution Control Federal. 44: 212-20.
4
-------
APPENDICES
-------
APPENDIX A
SLOPE ANALYSIS FOR ENVIRONMENTAL IMPACT ASSESSMENT
SECONDARY TREATMENT PLANT EXPANSION
LYNNWOOD, WASHINGTON
By SHANNON & WILSON, INC.
Introduction
Purpose and Scope
This report presents the results of our slope analysis in connection
with the environmental impact assessment of the proposed expansion at
the Lynnwood sewage treatment plant. The purpose of these analyses was
to assist in the preparation of the impact statements. The work
included a reconnaissance of the slope, drilling three hand borings
along the south side of the existing facilities, and performing engi-
neering studies to determine the consequences of making toe-of-slope
excavations as they relate to the general stability of the hillside.
Authorization
The work was performed in general accordance with our proposal
letter dated October 29, 1976. It was authorized by James Dow of Gray &
Osborne, Inc. on November 16, 1976.
Site and Project Description
The site is located in a ravine which exits into Puget Sound, about
one-half mile south of Meadowdale, Washington. The slopes are very
steep, being greater than 40 degrees to the horizontal in places. Alder
and dogwood trees, blackberry vines and nettles cover most of the
hillside.
The existing plant consists of a primary clarifier, sludge thickener,
a laboratory building, and a storage building. It would be expanded and
upgraded to secondary treatment capability. New facilities would include
settling basins and aeration tanks, a pump building, chlorine contact
tanks, a heat treatment facility, activated sludge thickener, a new
storage building, office and laboratory additions, and several other
components.
A plan of the site showing the approximate locations of the existing
structure and the proposed new facilities is presented on Figure 1. We
understand that the construction of the new facilities would require
excavations into the toe of the south slope of the ravine. Excavation
heights of 8 to 10 feet are anticipated.
A-l
-------
Field Explorations And Laboratory Tests
Soil Borings
Subsurface conditions along the base of the south slope were
explored by means of three hand borings. These borings were performed
using a portable hand-operated, gasoline-driven, continuous flight
auger. Porter samples were obtained at approximately 2 1/2-foot
intervals. The Porter sampling consists of using a AO-pound weight
falling 18 inches to drive a 1.4-inch O.D. split-spoon sampler (Porter
sampler) 18 inches into the bottom of the borehole. The number of blows
required to achieve each 6-inch increment of penetration is recorded and
the number of blows required to attain the last 12 inches of penetration
is termed the Porter Penetration Resistance. Samples removed from the
split-spoon sampler are disturbed but are representative of the soils
encountered.
The approximate locations of these borings are shown on Figure 1.
The logs of the borings are shown on Figures 2, 3 and 4.
Boring HB-1 was augered to a depth of 18 feet (elevation -5 feet);
however, the hole would not stay open due to groundwater and samples
could not be taken below a depth of 10.5 feet (elevation 2.5 feet).
Boring HB-2 was augered and sampled to a depth of 11.3 feet (approximate
elevation 8 feet). Boring HB-3 was augered and sampled to a depth of
16.3 feet (elevation 6.5 feet).
Drilling and sampling were performed by an engineer and a technician
from our firm. They classified and logged the samples, sealed them in
jars, and brought them to our laboratory.
An observation well consisting of 5/8-inch I.D. plastic pipe with a
slotted tip was placed in each boring to measure groundwater level.
Slope Reconnaissance
A visual slope reconnaissance of the hillside was performed by
Terry Olmstead, Associate Geologist from our firm. The reconnaissance
consisted of examination of the terrain, vegetation and soil exposures
for the purpose of identifying any unstable areas and evaluating the
general slope conditions. This reconnaissance was supplemented by
probing with a 1/2-inch diameter rod in order to estimate the thickness
of loose surface soils. Results of the reconnaissance have been
incorporated into the site plan, Figure 1, and are described in Section
III, Site Conditions.
A-2
-------
Laboratory Testing
All soil samples were transported to our laboratory where the
classification of each sample was checked and its water content was
determined. Sieve analyses were performed on two selected soils samples
in order to determine their grain size distribution. Sample classifi-
cations and natural water contents are presented in the Summary of Test
Results. Grain size distribution curves are shown on Figure 6.
Site Conditions
Results of the slope reconnaissance and soil borings indicate that
the slopes along the south side of the treatment plant are composed of
sand which is generally very dense and ranges from fine to medium
grained. The sand contains occasional layers of coarse sand and gravel.
The very dense sand is mantled with loose sand and topsoil. Probings
with a 1/2-inch diameter rod indicate that the loose soils are one to
four feet thick. Based upon available regional geologic data, the soils
comprising the hillside have been glacially overridden, resulting in
their being highly compacted.
Although the hillside appears to be basically stable, some shallow
slumps were observed during the slope reconnaissance. The approximate
locations of these apparent slumps are shown on Figure 1. The plant
operators indicated that small slides have occurred on the hillside from
time to time. There was no evidence observed, however, that these
slumps or slides are deep seated in nature. Rather, they appear to be
relatively shallow and to have resulted from the downslope movement of
loose sand and topsoil which slid over the underlying very dense sand.
The movements most likely occurred during periods of heavy rainfall and
during thawing periods after a heavy snowfall, when these surficial
soils became saturated and could no longer stand on the steep slope.
Areas which do not appear to have been involved in slumping show
evidence of significant soil creep as indicated by the curvature of the
trees. The topsoils in these areas are believed to be marginally
stable, and therefore any unsupported excavations along the toe should
be expected to cause additional shallow slumping.
Groundwater was observed during drilling on November 22, 1976, in
boring HB-1 at a depth of 8 feet (approximately elevation 5 feet). No
water was encountered in boring HB-2. A seepage zone was encountered in
boring HB-3 at a depth of 2 feet (above elevation 20 feet).
Water level readings taken on December 3, 1976 indicated no water
in borings HB-2 and HB-3, whereas at boring HB-1, the water level
remained at a depth of 8 feet.
A-3
-------
Engineering Studies And Recommendations
Slope Stability
The results of our field explorations indicate that the hillside on
the south side of the treatment plant is composed of dense granular
soils. They have been glacially consolidated, in our opinion, and thus
would have relatively high shear strengths. Outcrops of clay which are
often associated with slope instability in the Puget Sound region were
not encountered in the hand borings nor observed during the slope
reconnaissance. The existing south slope is very steep, however, and in
our opinion the loose surface soils are creeping downslope. Shallow
slides (slumps) have occurred in this area. These are generally
triggered by heavy rainfall or during thawing periods after a heavy
snowfall.
We understand that the proposed construction would involve making
an excavation 8 to 10 feet high, into the hillside. In our opinion, an
unsupported excavation along the toe of the hillside would require a
slope of 1 vertical on 1.5 horizontal (IV on 1.5H) to IV on 2H. These
slopes are estimated to be flatter than the existing slope. A steeper
excavation slope would result in additional slumping and acceleration of
the creep-type movements which are presently occurring, in our opinion.
We therefore recommend that the plant expansion include a retaining wall
along the base of the hillside.
It is recommended that the retaining wall extend at least five feet
above the ground surface on the uphill side to provide a catchment area
for future shallow overburden slides and for downhill creep.
Type of Retaining Wall
There are several types of walls that could be designed at this
location; however, in our opinion a soldier pile wall would be the most
appropriate. It would consist of steel 'H' soldier piles placed in
concrete filled holes, with a precast concrete face. It could be
installed with a minimum of excavation into the hillside. The soldier
piles would be installed prior to making the excavation, and paneling
between the soldier piles to retain the excavation face would be
installed as the excavation is made. The soldier pile wall could be
designed with or without tiebacks.
A conventional cantilever-type retaining wall is not recommended
because its base would extend into the slope several feet requiring
considerable excavation into the hillside.
A schematic drawing of a soldier pile wall is shown in Figure 5.
-------
Additional Considerations
The location and elevations of the proposed plant expansion facil-
ities and the position of the retaining wall would influence the design
loads on the wall. A topographic map showing contours of the hillside
would also be required for the wall design.
We recommend that additional field exploration work and engineering
studies be accomplished in order to determine design recommendations for
the proposed expansion. In particular, it would be prudent to explore
the thickness of fill that may have been placed for the development of
the existing facility and the groundwater conditions. For the design of
the soldier pile wall, additional field exploration is recommended to
determine the subsurface conditions and, in particular, the groundwater
conditions.
Limitations Of Report
The analyses, conclusions and recommendations contained in this
report are based on site conditions as they presently exist and further
assume that the results of the exploratory borings and slope recon-
naissance are representative of the subsurface conditions throughout the
site, i.e., the subsurface conditions everywhere are not significantly
different from those disclosed by the explorations. We recommend that
additional explorations and engineering studies be performed in order to
develop design recommendations.
A-5
-------
SUMMARY OF TEST RESULTS smmmi i hum. mc.
BORING NO. HB-3 inn wn W-3122-01 n>TF 11-24-76
/s/
/ "v / ^ / N# /
' ATTERBERG
LIMITS,
/ £$> / *
/ SOIL CLASSIFICATIONS
/
/ *
/ ^
/ v
V-
/ v
-J
/ **
/
S-l
0.0-
1.5
0, 2,
2
28.8
f
f
Very loose, gray to gray-brown, silty, fine
SAND, with scattered organics. Moist.
S-2
2.5-
3.9
33, 44,
50/4"
21.7
Very dense, gray-brown, clean to slightly
silty, fine to medium SAND. Moist.
S- 3
5.5-
5.8
60/6 "
7.7
Very dense, gray, clean, fine to medium
SAND. Moist.
A-6
S-4
7.7-
8.6
37,50/
4"
15.2
Same as S-3
BORING NO.
S-5
S-6
10. 5-
11.0
15.5-
16. 3
66/6"
32, 50/
3"
9.7
16.1
Same as S-3
Very dense, gray, clean, fine SAND, trace
of medium to coarse sand. Moist.
k/}
~c
m
m
—1
o
CLASSIFIED BY
up
CHECKEO BY JlZ.
-------
SUMMARY OF TEST RESULTS
BORING NO.HB-2
SHANNON & WILSON, INC.
JOB Mtl W-3122-01 PiTF 11-24-76
" ^ ^
N/
£
*
ATTERBE RG
LIMITS.
£ *
*/*/'
/
/
SOIL CLASSIFICATIONS
S-l
S-2
S-3
S-4
S-5
0.0-
1.5
2.5-
4.0
0, 1,
2
15, 30,
52
5.0-
31
6.5
55
7.5-
46
8. 3
3"
10.5-
52
11-3
3"
33.1
15.8
14.6
12.5
9.4
Very loose, brown, silty, fine SAND, trace
of medium sand, with numerous organics.
Moist to wet.
Dense, gray-brown, slightly silty fine to
medium SAND, trace of course sand and fine
gravel. Moist.
Very dense, gray-brown, slightly silty,
fine to medium SAND. Moist.
Very dense, gray-brown, clean to slightly
silty, fine to medium SAND. Moist.
Same as S-4
m
t:
m
m
CLASSIFIED BY RT
CHECKED BY JUL
-------
SUMMARY OF TEST RESULTS
BORING NO. hb-1
SHANNON ft WILSM. INC.
JOB ND W-31 22-01 DATE 11-24-76
1 * /& ~» / mterberg
/ UNITS, »,
C§~~ ^ g/^ ^
>
I
DO
S-l
S-2
S-3
S-4
S-5
CD
o
z
CD
Z
a
0.5-
2.0
2.5-
4.0
5.3-
6.9
7.5-
8.5
9.5-
10. 5
w>
I
m
Ai7 C> "5> / ^ j i 7 / s ^
»<£y> V ^ /* /* / *
5, 16,
30
15, 30,
41
29, 48,
50/5"
21, 57
14, 54
15.4
10.9
15.7
22.2
21.5
SOIL CLASSIFICATIONS
MA
Medium dense, brown, clean to slightly
silty, fine to medium SAND, Moist.
Dense, gray-brown, clean, fine SAND. Moist,
Dense to very dense, gray-brown, clean,
fine to medium SAND. Moist.
Very dense, gray, clean to slightly silty
fine to medium SAND. Wet.
Same as S-5
CLASSIFIED BY DZ
CHECKED BT 1IE
-------
tVrmin SCh»cK»d_ Approvtd R«vis«d Approved.
Hnt« ///zo/rC o0f# 0o»« Dot*
VC
JD
CD
SIEVE ANALYSIS
HYDROMETER ANALYSIS
SIZE or OPENING IN INCHES | NUM01R OF MISM PC R INCH. U.S STtNOMD
GRAIN Sl/C IN MM
O O o
o o o
00
70
80
30
30
20
10
-HI C
-
--
-
¦¦
—
—
-¦
- —
-
...
-2
~
-
-
—
-3, S
—
=»HB
—
—
T*
-
-¦
—-
-
-
—
HB-1, S-'i ^ \
. _
-
-
i
•
—
—^0
L i
—
-
•
—
—
-
—
i T
—
¦
h-
...
i
rr
i i
i
i
i
-
1 1 1
11
1 1
ii
TTTT
i i
1
III
t
1 0
7 0
30
50
60
B0
D C3 O O
3 O O «
60
40
30
20
1 0
9
6
* r) N - « « « ri r«
GRAIN SUE IN MILLIMETERS
— m
a
to • n n > « to « n
c eoo o o o o o a
• • o o o o o
C
c
COBBLES
C0ABSC I riNf
C0AHSC I MC0IUM I r IN!
SILT & CLAY
GftMtl
SAND
t 00
CO
oc
UJ
oo
X
U_l
o
az
LU
ex.
SAMPlt
NO
HB-1
s-^
HB-3
S-2
7-5-8.5
2.5-3-9
u.s.c.
SP-SM
SP-SM
CLASSIFICATION
Gray, slightly si1ty SAND
Gray-brown, slightly silty SAND
MAT.
w . c %
22.2
21.7
pi
CITY OF LYNNWOOD
LYNNWOOD SEWAGE TREATMENT PLANT
GRAIN SIZE CLASSIFICATION
Borings HB-1 and HB-3
Nov. 1976 W-3122-01
SHANNON t WILSON, INC.
CtOTCCMMICAL CONSULTANT!
-------
•¦MOTE:- SOLDIER PILES MAY BE INCLINED SLIGHTLY
INTO THE HILLSIDE
CITY OF LYNNWOOD
LYNNWOOD SEWAGE TREATMENT PLANT
SCHEMATIC DRAWING
CANTILEVERED SOLDIER PILE WALL
DECEMBER 1976
W-3122-01
A-10
SHANNON I WILSON,INC.
6C0TCCMNIC&1 CONSULTANTS
FIG. 5
-------
SOIL DESCRIPTION
Surface Elevation: Approx. 22.8 feet
PORTER PENETRATION RESISTASCE
40 It, weight, 18'dtep)
ABlons per loot
20
40
Cr
Very loose, brown, slightly silty,
fine to medium SAND with scattered
organics
Very dense, brown to dark gray, clean fine
to medium SAND
Bor ing Completed 11/22/76
16.3
»I
'I
¦I
? 2
"" 4
04/10-
66/6'
50/4'
D
Cn*
!I
I
10
12
14
16
66/6-
LEGEND
J 1.4"0J3. sp I i t spoon saaplt (PORTER)
J3"0.D. thin o a 11 sample
• Simple not recovered
Att e i bet g Units:
L *1 I ¦ Liquid limit
\ ^ Natural water content
> PI ast ic I mi t
2D 40
0 '• Water content
Eb
Impervious seal
SL later level
I
P
?
Piezometer tip
Sample pushed
Seepage
CITY OF LYNMW00D
LYNNW00D SEWAGE TREATMENT PLANT
LOG OF BORING HB-3
NOVEMBER 1976
*-3122-01
NOTE: The stratification lines represent the approiimate boundaries
between soil types and the transition may be gradual.
A-ll
SHANNON t WILSON. INC.
GtCTECHNICAl CONSULTANTS
FIG. 4
-------
SOIL DESCRIPTION
Surface Elevation: ApprOX. 14 feet
PORTER PENETRATION RESISTANCE
( 40 lb. Might, 18'dfop)
ABIoas per loot
20
40
EO
Medium dense, brown, fine to medium SAND
Dense to very dense, brown to gray, clean to
slightly silty, fine to medium SAND with
occasional iron oxide stains
Borehole caved in at 8 feet after taking
of sample 5 Augered to IB feet, SAND on
auger tip. Could not sample below 10.5 feet
Boring Completed 11/22/76
10.5
19
•I
¦I
i
cn
CN
10
12
14
16
18
71-
98/14-
-5776-
-54/6--
Impeivious seal
5L Water level
LEGEND
J 1.4-GD. sp I i t spoon tanple (PORTER)
O.O. thin »a 11 tanple
* Sanple not recove red
Atterberf Lit,i ts:
¦Liquid Iin11
Natural nater content
Plastic I mi t
NOTE: The stratification lines represent tne appronmate boundaries
bstMen soil types and the transition may be gradual.
JO 40 6&
I \ Water content
Piezometer tip
Sample pushed
CITY OF LYNNW00D
LYNNWOOD SEWAGE TREATMENT PLANT
LOG OF BORING HB-1
NOVEMBER 1976
W-3122-01
SHANNON I WILSON, INC.
StOT(CHNIC»l CO*SUlT»«TS
A-12
FIG. 2
-------
SOIL DESCRIPTION
Surface Elevation: ApprOX 19.3 feet
11
PORTER PENETRATION RES 1ST AKiCE
(40 lb. wei£ht, Ifi'Orop)
~ Slows per foot
20
40
_£!
Very loose, brown, silly, fine to medium
SAND with scattered organics
Dense to very dense, brown to gray,
slightly silty, fine to medium SAND.
Trace of coarse sand & fine gravel
Bor ing Completed 11/22/76
'I
'I
'I
B
82.
110.
11.3
•I
10
12
i 50/3.
"70 40 50
# later content
Impervious teal
later level
Piezometer tip
Sample pushed
LEGEND
J 1.4"CLE. split spoon sample (PORTER)
Js'O.D. thin vail sample
• Sample not recovered
Atterberj Lin ts:
L t • 11 qui d limit
\ * Natural water content
' Plastic limit
NOTE: The stratification lines represent the appronmate boundaries
between toil types and the transition may be gradual,
A-13
CITY OF LYNNW00D
LYNNW00D SEWAGE TREATMENT PLANT
LOG OF BORING HB-2
NOVEMBER 1976 1-3122-01
SHANNON & WILSON, INC.
GCOTCC"NICAI C0NSU111NTS
FIG.3
-------
APPENDIX B
WATER QUALITY
Puget Sound
Basic Concerns
Little water quality data exists for Brown's Bay; however, certain
predictions regarding existing conditions may be made based on the limi-
ted information that is available and typical situations at other marine
outfalls of primary sewage treatment systems. The most important pollu-
tion concerns regarding primary treated sewage effluent are bacterial
contamination, biochemical oxygen demand (BOD), nutrient enhancement,
phytoplankton productivity (growth rate), and chlorine toxicity.
As a point of comparison, the nutrient input to central Puget Sound
from Metro's West Point sewage treatment plant (STP) is less than one-
six thousandth (0.02%) the natural nutrient input. After reviewing
Puget Sound productivity studies, Ebbesmeyer and Melseth (1976) concluded
that the West Point STP has no measurable effect on Puget Sound phyto-
plankton productivity. It is therefore highly unlikely that the existing
Lynnwood STP is having any measurable effect on phytoplankton productivity.
No oceanographic study is known to have been done in Brown's Bay,
the location of the Lynnwood STP outfall into Puget Sound. Water quality
monitoring is carried out at a number of locations in the general vicin-
ity by Metro, the Washington Department of Ecology, the University of
Washington Oceanography Department, and others.
Freibertshaur, et al. (1971) have reviewed the University of Washington
oceanographic cruise data collected since 1932 in all of Puget Sound,
and Ebbesmeyer and Melseth (1976) have reviewed recent productivity and
related data of Metro and the University of Washington in central Puget
Sound. Based on these two studies the probable condition of Brown's Bay
may be described in general.
Temperature varies seasonally with surface temperature ranging from
16°C in July to 6-7°C in January. Subsurface temperatures range from
11-13°C during August through October to 6-7°C during January to March.
Salinity fluctuates throughout the year between concentrations of
15-30 parts per thousand (ppt) at the surface and 20-30 ppt below the
surface.
Oxygen saturation also varies seasonally. Winter minimum values occur
during September and October, with surface saturation approximately 70% and
B-l
-------
subsurface saturation approximately 60%. During the summer (May-August)
maximum values fluctuate between about 120-130 at the surface and about
90-110 below the surface.
Phosphorus (as ortho phosphate) levels reach a summer minimum of
1.2-2.0 microgram-atoms/1 in July with uptake by phytoplankton. Maximum
concentrations of 2.5 to 4.0 microgram-atoms/1 occur between October and
March.
Nitrate varies similarly to phosphorus, with a July minimum concentra-
tion of approximately 5 microgram atoms/1 increasing to approximately 27
microgram atoms/1 during the winter.
Productivity in central Puget Sound is relatively high, averaging
approximately 3/5 tons/acre/year, and is seasonally, geographically, and
spatially highly variable. In Brown's Bay it ranges from 2.0-2.5 grams of
Carbon/square meter/day (gC/sqm/day) during the May to August maxima, to
0.1-0.5 gC/sqm/day during the winter. This high level of productivity is
supported primarily by nutrient upwellings as currents pass over the sills
in the Tacoma Narrows and Saratoga Passage. The nutrients so placed into
the central Puget Sound budget are 25X the input from rivers, and 6000X
the input of effluent from Metro's West Point sewage treatment facility,
the largest on Puget Sound.
Gray and Osborne (1972) conducted a bacterial water quality study of
Brown's Bay in the immediate vicinity of the Lynnwood outfall on August 4,
1971, at 8:00 a.m., on an ebb tide. Water samples collected within 750
feet of the outfall had total coliform MPN concentrations of 43/100 ml to
2,300/100 ml (median: 230/100 ml). Two samples collected approximately
0.5 miles offshore of the outfall, and approximately 0.25 miles apart, had
MPN bacterial concentrations of 43/100 ml. The bacterial concentration in
the effluent at the treatment plant was 210,000,000/100 ml at the time of
the test. Brown's Bay waters are Class AA (WAC 173-201-080), and as such,
bacterial concentrations are not supposed to exceed median values of 70
total coliform organisms/100 ml, with less than 10% of samples exceeding
230/100 ml when associated with any fecal sources (WAC 173-201-030).
The existing treatment plant does not have a chlorine contact chamber
but uses the outfall pipe to provide a theoretical detention of about 24
minutes at the average day flow. Thus there is no method of determining
the bacterial concentration of the effluent before it reaches the receiv-
ing water. Obviously, the August 4 tests indicate this method is not
satisfactory.
Dissolved Oxygen
Regarding the BOD demand on local waters, very approximate predic-
tions may be computed based on conservative assumptions. During the 20
B-2
-------
tidal cycles flushing time for the Brown's Bay vicinity of Puget Sound as
described in Chapter II under Surface Water Movement, it is likely that
effluent from the Lynnwood treatment plant will disperse over the entire
area of Puget Sound where central Puget Sound, Admiralty Inlet, and
Possession Sound currents come together, an area of approximately six
miles in diameter. For purposes of computing the effect of BOD, a conserva-
tive estimate of effluent dispersal will be taken at only a one mile
diameter area. Based on an average depth of 85 fathoms and an average
annual oxygen concentration of 0.40 microgram-atoms per liter, this
volume of seawater would contain approximately 2,000,000 kilograms of
oxygen. The BOD of the existing STP over that time period is estimated
to be 22,000 kilograms based on a worst case influent BOD of 200 mg/1
and only a 30 percent reduction of BOD during treatment. The oxygen
demand on this hypothetical receiving water volume is then only 1.1
percent of the oxygen capacity. It is unlikely that the receiving
waters in the vicinity of the STP are significantly affected.
The Facilities Plan states the proposed diffuser for the new treat-
ment facility will achieve a dilution of 500:1 for the secondary effluent.
This diffusion is expected to render any dissolved oxygen sag too small
for measurement.
Chlorine
The Lynnwood treatment plant uses approximately 150 pounds of chlor-
ine per day to treat the 2.0 million gallon per day sewage flow. One-
third is added as prechlorination, and two-thirds are added as post-
chlorination to the effluent as it is discharged from the plant into
the outfall pipe. Residual chlorine is not measured, and contact time
of chlorine with effluent is only a few minutes before it is discharged
into Brown's Bay.
Chlorine toxicity to aquatic organisms is a function of the chlorine
residual in the effluent, not the amount of chlorine added to the sewage.
Chlorine is a powerful oxidizing agent and is highly soluble in water.
Chlorine in water is normally present as free available chlorine in the
form of hypochlorous acid or hypochlorite ion. When chlorine is added to
sewage effluent, it rapidly combines with ammonia and other organic sub-
stances to form combined available chlorine as chloramines and other
chloro-derivatives. Free available chlorine is approximately as toxic
as combined available chlorine, but toxicity varies widely from one aquatic
species to another, and is also dependent on the pH, temperature, and
oxygen concentrations in the receiving waters, as well as the combined
effects of any other toxic substances that might be available. The per-
sistance of residual chlorine has been reported to range from a few minutes
to a few hours, but may last longer.
B-3
-------
The residual chlorine concentration in Lynnwood plant effluent is not
measured, so only very approximate estimations of the residual chlorine
concentration in Brown's Bay can be projected. The accuracy of the pro-
jection is further decreased by a lack of knowledge regarding persistence
of residual chlorine in Brown's Bay waters. It is possible that there is,
for all practical purposes, no chlorine residual in the effluent as it
discharges from the outfall. A study of two primary treatment plants in
Bremerton, both approximately the same size as the Lynnwood plant, showed
residual chlorine in the effluent to be highly variable. During the study,
residual chlorine in the effluent of one plant varied from 0.10 mg/1 to
2.00 mg/1 (mean of 0.90 mg/1), and in the effluent of the other plant
from less than 0.10 mg/1 to 0.75 mg/1 (mean of 0.29 mg/1). Measured
chlorine residual did not follow levels predicted from plant flow rates
and chlorine dosage rates.
Juvenile salmonids are the aquatic organisms most sensitive to
residual chlorine toxicity, so a very approximate estimation of residual
chlorine levels along the shoreline of Brown's Bay was projected. From
the bacterial studies in Brown's Bay discussed above, the mean bacterial
concentration within 250 feet of the shoreline was found to be 510
coliforms per 100 ml. Assuming 75 percent of the decrease in coliform
density was due to die-off and not to dispersal, the dispersal ratio for
effluent from the discharge point to the shoreline is approxiately
1:100,000. Assuming that the residual chlorine concentration at the
discharge point might be as high as 5.0 mg/1 at times, and neglecting
any decrease in residual chlorine concentration with time, the residual
chlorine concentration near the shoreline would be 0.05 micrograms/liter
as a very approximate estimate of a worst case condition.
Based largely on the work of Holland, who determined the critical
level of residual chlorine for young Pacific salmon to be 50 micrograms per
liter, EPA has set residual chlorine levels at 2.0 micrograms for salmon-
ids and at 10.00 micrograms per liter for other aquatic organisms. The
estimate of residual chlorine in Brown's Bay indicates a high probability
of safe conditions regarding residual chlorine toxicity along the shoreline.
However, State standards specify that toxicity levels cannot be
exceeded even in the effluent diffusion plume. Since the existing outfall
does not have a diffuser, the 2.0 micrograms per liter chlorine level is
almost certainly exceeded on a frequent basis within the present mixing
zone. The actual effect on salmonids or other aquatic life is not known,
though.
B-4
-------
Swamp Creek
1972 Metro Study
A general reconnaissance study of the water quality of lakes and
streams in the Lake Washington drainage basin was done by Metro between
July 1971 and October 1972. This study included two sampling stations
on Swamp Creek. The study concluded that Swamp Creek, along with other
streams in the north Sammamish River drainage basin, had generally poor
water quality conditions compared to some other streams in the Lake
Washington basin. Swamp Creek itself was described as having high
solids concentrations, but no supporting data were presented. Dissolved
oxygen levels were noted as being occasionally low, and this was attributed
to low flow conditions and shallow water, rather than to a high biochemical
oxygen demand (BOD). In fact, BOD levels were found to be generally low.
Again, no supporting data were presented. Total coliform bacteria levels
were reported moderately high, and in excess of the applicable Washington
State standards for Class A streams. Tests for fecal coliforms were not
done, so it is not possible to project whether the bacterial loading of
Swamp Creek was from a recent fecal contamination source, or whether it
represented a background loading from nonfecal sources. Nutrient
levels were not commented on in the report, but they were generally high
compared to water quality guidelines for controlling excessive plant
growth in aquatic systems. Lake Stickney, the headwater of Swamp Creek,
was judged to have better water quality characteristics than did the
stream, so the source of contaminations was presumed to lie in the
watershed below the lake. Table A summarizes data from this study;
sampling stations are shown in Figure II-7.
B-5
-------
TABLE A
SEASONAL NITROGEN, PHOSPHORUS, AND BACTERIA CONCENTRATIONS
SWAMP CREEK - 1971-1972
Swamp Creek Sampling Stations
0470* U470
Spring- Summer- Winter- Summer-
Parameter Summer Fall Spring Fall
Ammonia
max.
0.05
0.03
0.18
0.10
Nitrogen
mean
0.03
0.02
0.08
0.03
mg/1
min.
0.02
0.02
0.03
0.01
Nitrate
max.
1.55
0.70
0.64
0.49
Nitrogen
mean
0.96
0.59
0.29
0.31
mg/1
min.
0.60
0.39
0.06
0.09
Total hydrolyzable
max.
0.13
0.14
0.43
0.22
phosphorus mg/1
mean
0.07
0.11
0.18
0.13
min.
0.03
0.06
0.05
0.10
Total
max.
3,600
110,000
10,000
9,400
coliforms/100 ml
median
1,500
4,400
3,500
3,600
* Station 0470 not shown on Figure II-5; location approximately at river
mile 0.5.
Intensive Metro Study
Metro followed up on the reconnaissance survey with an intensive
study of selected Lake Washington basin streams, including Swamp Creek,
from November 1972 through December 1974, and included fourteen sampling
stations in the Swamp Creek basin. Data summaries for selected Swamp
Creek monitoring stations are tabulated in Table B; sampling stations are
shown on Figure II-5. Metro conclusions regarding this study are still
tentative pending publication of the report, but, in general, Swamp Creek
is considered to have excessively high concentrations of suspended solids,
alkalinity, nutrients, and bacteria.
A separate analysis of the data of the 1972-1974 intensive study has
been made for this impact analysis.
B-6
-------
Water temperature mean and extreme values are generally consistent
throughout the length of Swamp Creek. Station Z, immediately downstream
of Stickney Lake, has slightly high temperatures as might be expected.
Seasonal water temperatures presently appear to be within the limits
necessary for the spawning and hatching of fish eggs and optimal growth
of the salmonid fish using the stream. It is likely that in slow-moving
stretches of the stream that have been subjected to landscaping and the
removal of overhanging trees and brush, the water temperature, at times,
may locally exceed optimal temperatures for salmonid fish.
Suspended solids concentrations are occasionally high, particularly
at Station U below the intersection of Interstate Highway 5 and 405,
indicating a relatively high level of stream contamination due to high-
way storm runoff. Suspended solids criteria are tied to levels of
photosynthetic activity, measurements of which are not available for
Swamp Creek, so no evaluation can be made on that account. The upper
levels of suspended solids concentrations measured by Metro appear to be
below significant injury levels to fish reported by McKee and Wolfe in
1963. It is likely that the heavy suspended solids loads carried into
Swamp Creek from Interstate Highways 5 and 405 have high levels of oil
and grease and heavy metals absorbed onto the solids particles.
Dissolved oxygen concentrations are very consistent throughout the
length of the stream and are within the criteria recommended by EPA for
freshwater aquatic life in general, and salmonid spawning in particular.
Biochemical oxygen demand concentrations are also very consistent
throughout the length of the stream, and are within the expected normal
background concentration range.
The pH range throughout the stream is slight and the 6.7 to 7.9
range found in Swamp Creek lies within the criteria range of 6.5 to 9.0
recommended by EPA.
Average turbidity values are fairly consistent throughout the stream,
and are fairly low. The occasional high turbidity levels are likely
associated with stormwater runoff.
Conductivity (specific conductance) as a measure of the capacity of
water to conduct an electrical current is an indirect measure of dis-
solved solids. Conductivity in Swamp Creek is more varied than many of
the other water quality parameters measured. Highest conductivity
levels occur at Station D on Scriber Creek which drains the more heavily
urbanized areas of the Swamp Creek basin, and also at Station U, below
the I 5 - 405 intersection. The apparent normal conductivity range for
Swamp Creek is 80 to 150 micromhos. This value is increased at downstream
stations due to urban and highway stormwater runoff. McKee and Wolfe
(1963) report various researchers reporting good mixed fish fauna occur-
ring# in general, in waters with conductivity between 150 and 500 micromhos.
B-7
-------
TABLE B
SWAMP CREEK AND TRIBUTARIES WATER QUALITY DATA SUMMARY
NOVEMBER 1972 TO DECEMBER 1974
Station
T emp.
°C
Susp.
Solids
mg/1
D.O.
mg/1
B.O.D.
mg/1
PH
Turb.
JTU
Cond
umhos/
cm
Alk
mg/1
CaCO^
NH.-N
4
mg/1
N03-N
mg/1
Hydro|
P04
mg/1
Coliforms
org./lOO ml
total
fecal
strep
0470a
min.
1.0
2.5
9.7
1.0
7.0
0.9
64
27
0.01
0.52
0.03
150
49
20
mean
10.8
8.2
10.6
1.5
7.3
5.2
154
48
0.03
0.87
0.11
1400
220
250
max.
19.3
36.0
12.5
3.4
7.8
30.0
200
62
0.11
2.20
0.20
10000
1400
2200
B470
min.
5.3
1.0
9.3
0.9
7.1
1.1
110
35
0.01
0.40
0.07
200
45
140
mean
10.6
4.0
10.8
1.6
7.6
3.4
144
51
0.02
0.84
0.10
1500
305
420
max.
16.0
15.0
12.0
2.5
8.0
21.0
190
60
0.04
1.70
0.13
5700
920
1700
C470
min.
5.9
1.0
9.6
1.0
7.0
1.0
110
37
0.01
0.65
0.06
380
20
56
mean
10.6
3.6
10.7
1.7
7.6
2.2
149
52
0.01
0.86
0.09
1800
660
330
max.
15.2
11.0
12.1
4.0
7.9
13.0
170
60
0.03
1.10
0.12
4800
2000
18000
D470
min.
5.7
1.5
5.9
1.0
7.1
1.3
130
34
0.01
0.39
0.08
200
20
20
mean
10.5
4.1
10.4
1.6
7.5
2.6
182
60
0.02
0.62
0.10
1010
132
120
max.
15.8
12.0
12.4
2.9
7.8
13.0
240
80
0.04
0.96
0.13
9500
710
1600
E470
min.
5.8
1.0
9.9
0.7
6.9
0.8
93
33
0.01
0.44
0.07
160
68
52
mean
10.1
5.0
10.6
1.7
7.4
2.2
192
47
0.02
0.92
0.10
1300
140
240
max.
13.8
15.0
11.6
3.8
7.7
11.5
210
62
0.08
1.20
0.13
5600
1800
1000
U470
min.
2.7
0.8
9.2
0.5
6.7
0.9
85
14
0.01
0.20
0.05
175
20
50
mean
10.5
6.7
10.6
1.5
7.2
3.2
140
45
0.02
0.65
0.11
1400
370
250
max.
18.5
43.0
12.3
3.1
7.6
18.0
440
65
0.09
2.40
0.18
26000
2600
2400
NZ470
max.
10.2
1.0
11.0
' 1.0
7.0
0.9
64
27
0.01
0.52
0.03
150
49
20
mean
11.3
1.9
11.1
1 1,4
7.1
1.1
66
28
0.01
0.57
0.03
520
54
20
max.
19.0
3.0
11.3
! 2.0
7.1
1.6
66
30
0.01
0.64
0.04
760
54
65
Station 0470 not shown on Figure II—7; location approximately at river mile 0.5.
-------
Historically, aquatic life in Swamp Creek would be accustomed to the
lower normal range, but has likely been able to adapt to the slight
increases that have occurred with the present urbanization of the area.
Alkalinity in the Swamp Creek basin is generally low, but is not
less than the minimum criteria of 20 mg/1 recommended by EPA (1976) for
freshwater aquatic life. Alkalinity increases in the stream occur at
Stations D and U with the addition of urban drainage and highway runoff
to Swamp Creek. Maximum alkalinity in Swamp Creek (80 mg/1) does not
exceed the optimum total alkalinity of 100 - 200 mg/1 suggested by McKee
and Wolfe.
Ammonia nitrogen levels in Swamp Creek are low to moderate when
judged against growth control nutrient criteria, and insignificantly low
where judged against the toxicity criteria for freshwater life recom-
mended by EPA.
Nitrate nitrogen levels in Swamp Creek are high when judged against
growth control nutrient criteria. There are no toxicity criteria for
nitrates for aquatic life.
Total hydrolyzable phosphate levels appear to be very high compared
to growth control guidelines for other forms of phosphate, but no cri-
teria have been established for hydrolyzable phosphate in flowing waters.
Bacteriologically, Swamp Creek is moderately contaminated. Washing-
ton State standards for Swamp Creek require total coliform bacterial
levels not to exceed a minimum value of 240 organisms/100 ml. Based on
this standard, Swamp Creek would appear to be grossly contaminated. A
more rational criterion for bacterial quality that eliminates any natural
background concentration of nonfecal coliforms from consideration is
that criterion of 200 fecal coliforms/100 ml recommended by EPA. Judged
against this criterion, Swamp Creek is only moderately contaminated. The
primary source of this contamination is probably the numerous septic
tank leach line sewage disposal units scattered throughout the drainage
basin. A secondary source is likely the fecal contamination in urban
runoff that is ordinarily attributed to household pets.
Evaluation
Taking all factors into account, Swamp Creek water quality is
generally fair, with consistent and serious departures from standards
and criteria occurring only with regard to bacterial water quality. The
Washington Department of Fisheries considers storm runoff to be a critical
water quality problem in the Swamp Creek system. Erosion during rainstorms
causes high suspended solids and turbidity concentrations which result in
sedimentation of gravel beds used by fish for spawning.
B-9
-------
Ground Water
The limited information available for ground water quality within
the study area is summarized in Table C.
B-10
-------
TABLE C
CHEMICAL AND PHYSICAL CHARACTERISTICS OF GROUND WATER
Well Number
Parameter 27/4-10N1 27/4-21N1 27/3-24G3
Well depth, ft.
176
342
106
Water bearing interval, ft.
478-176
300-342
-
Water bearing material
Sand, Gravel
Gravel
Sand
Date of Sample
12/1/59
12/1/54
13/18/59
Si02, ppm
45
42
36
Fe, ppm
0.00
0.00
0.00
Ca, ppm
13
13
9.5
Mg, ppm
6.1
00
r-.
9.4
Na, ppm
7.8
9.6
5.9
K, ppm
2.7
4.6
2.1
HCO^, ppm
85
103
70
SO^, ppm
4.2
2.0
10
CI, ppm
3.5
3.0
5.0
F, ppm
0.2
0.3
0.1
NO^j ppm N
0.2
0.0
3.3
Ortho PO^, ppm P
0.60
0.7
0.21
Dissolved ) Calculated
Solids, ppm ) Residue @ 180°C
125
123
134
127
116
113
CaCO^ hardness, ppm
58
64
62
Conductivity, ymhos/cm
156
171
160
PH
7.7
8.1
7.6
Color
0
0
5
B-ll
-------
APPENDIX C
WILDLIFE
Habitat
The vegetation of the project area is made up of a mosaic of natural
and cultural plant communities. The natural community consists primarily
of native species that are the remains of the original vegetation, or
those which have re-established themselves, without the assistance of
man, on disturbed sites. Natural communities may contain introduced
species. Cultural communities are those which result from the more or
less continuous activity of man and are typified by, but not limited to,
lawns, gardens, other landscaped areas, and fields. Only natural commu-
nities are discussed here.
The exact composition of the natural communities and their species
diversity varies throughout the project area, and is dependent on the
severity and timing of disturbances, soil type and moisture, and exposure.
The upland forests are dominated by Douglas-fir. Red alder is dominant
at recently disturbed and continuously disturbed sites. Madrone may be
common on the bluffs along Puget Sound. Understory shrubs exist in great
diversity in the project area. The most common species is salal, the
berries of which are an important source of food for many animals. The
variety and abundance of herbaceous species is highly variable depending
on soil moisture and shade.
The marshy area along Swamp Creek above the intersection of inter-
state highways 5 and 405 is characterized by a discontinuous forest
coverage of primarily red alder with some western red cedar. The under-
story is made up of a dense, virtually impenetrable tangle of shrubs and
herbaceous species dominated by willow, salmonberry, Douglas spirea, and
shrub-form red alder.
South of Jefferson Way and Manor Road, a four acre swamp lies 100
to 200 feet on each side of the stream for 0.2 to 0.3 miles. North of
148th Street S.W., a 20 acre swamp extends from Manor Road, east approxi-
mately 1,000 feet along 148th Street. South of 148th Street, the swamp
is restricted to a narrow band along the banks of Swamp Creek for a
length of approximately 1,500 feet, and covering approximately four
acres. A large, continuous swamp of approximately 132 acres, transected
by a number of slightly elevated roads and streets, begins in the vicinity
of 156th Street S.W., and continues downstream approximately two miles to
Interstate Highway 5. Below Interstate Highway 5, Swamp Creek enters a
low canyon and passes out of the project area with no additional wetlands.
Table A lists the vegetation likely to exist with the study area.
C-l
-------
TABLE A
Common Name
Trees:
Douglas Fir
Western Hemlock
Western Red Cedar
Red Alder
Big Leaf Maple
Madrone
Western White Pine
Lodgepole Pine
Black Cottonwood
Yew
Western Paper Birch
Sitka Spruce
Grand Fir
Shrubs:
Salal
Vine Maple
Oregon Grape
Red Huckleberry
Salmonberry
Red Elderberry
Thimbleberry
Oceanspray
Hazelnut
Labrador Tea
Douglas Spirea
Willow
Devil's Club
Red-Osier Dogwood
Herbs:
Sword Fern
Skunk Cabbage
Sedges
Rushes
Horsetails
Cattail
Youth-on-Age
Buttercups
Bleeding Heart
Fringe Cup
Twinflower
Bracken Fern
Stinging Nettle
STUDY AREA VEGETATION
Scientific Name
Pseudotsuga menziesii
Tsuga heterophylla
Thuja plicata
Alnus rubra
Acer macrophyllum
Ardutus manziesii
Pinus monticola
Pinus contorta
Populus trichocarpa
Taxus brevifolia
Be tula papyrifera
Picea sitchensis
Abis grandis
Gaultheria shallow
Acer circinatum
Berberis nervosa
Vaccinium parviflorium
Rubus spectabilis
Sambucus racemosa
Rubus parviflorus
Holodiscus discolor
Corylus cornuta
Ledum groenlandicum
Spiraea douglasii
Salix, spp.
Oplopanax horridum
Cornus stolenifera
Polystichum munitum
Lysichitum americum
Carex, spp.
Juncus, spp.
Equisetum, spp.
Typha latifolia
Tolimiea menziesii
Ranunculus, spp.
Dicentra formosa
Tel lima grandiflora
Linnaea borealis
Pteridum squilinum
Ustica dioica
C-2
-------
Animal Life
It is difficult to assess the wildlife of the study area in a short
time because of the seasonality of occupancy characteristic of a majority
of the nesting bird species. Mallard, Red-tailed Hawk, Steller Jay,
Bewick's Wren, Varied Thrush, Song Sparrow, Rufous-sided Towhee, House
Finch, Common Crow, and Robin; all species associated with the creek and/
or wetlands, have been observed.
A list of wildlife likely to be found in the area has been provided
in Table B. Several wildlife species of the project area have habitat
needs that can be satisfied only by wetlands areas. Such species would
include herons, waterfowl, the belted kingfisher, black-capped chickadee,
long-billed marsh wren, MacGillivary's warbler, red-winged blackbird,
muskrat, beaver, water shrew, salamanders, and frogs. The extensive
brush and forest cover of the uplands, particularly near the creek
bottoms, probably provides habitat for more wary wildlife species such
as mink, weasel, grouse, and piliated woodpecker.
Aquatic Life
Swamp Creek is an important salmon producing tributary of Lake
Washington. The entire length of Swamp Creek is utilized by chinook,
coho, and/or sockeye salmon. In addition, coho salmon are also found
in Scriber Creek (stream numbers 0062 and 0063; Figure II-4. The stream
gradients are very gradual in all utilized streams, and contain good
pool to riffle balance. The quality of gravel in the stream bottom is
generally excellent for spawning where it hasn't been destroyed or
damaged by sedimentation from erosion. In some areas stream channeli-
zation and landscaping have seriously altered or destroyed the spawning
value of these streams. Other factors acting to limit the usefulness of
these streams include low summer flows that preclude chinook salmon from
ascending the streams until mid-October, and turbidity from urban and
construction erosion.
Table C shows the results of fish sampling within the Swamp Creek
basin.
Salt water fish likely to be observed in Puget Sound are listed in
Table D.
C-3
-------
TABLE B
CHECKLIST OF VERTEBRATE ANIMALS (EXCEPT FISH) THAT COULD
INHABIT THE PROJECT AREA AND OFFSHORE MARINE WATERS
Common Name Scientific Name Forest Streams, Puget
Areas Lakes & Sound
Wetlands
BIRDS
Common loon Gavia immer x
Rednecked grebe Podiceps grisegena x
Western grebe Aechmophorus occidentalis x
Double-crested cormorant Phalaeroeorax auritus x
Pelagic cormorant Phalaeroeorax petagicus x
Great blue heron Ardea herodias x x
Green heron Butorides virescens x
Black brant Brants nigricans x
Mallard Anas platyrhynahos x x
Green-winged teal Anas carolinensis x
Cinnamon teal Anas ayanoptera x
American widgeon Mareca americana x
Shoveler Spatula alypeata x
Wood duck Aix sponsa x
Ring-necked duck Ay thya collaris x
Canvasback Aythya valisineria x
Common goIdeneye Bucephala elangula x
Bufflehead Bucephala albeola x x
White-winged scoter Melanitta deglandi x
Surf scoter Melanitta perspicillata x
Common scoter Oidemia nigra x
Hooded merganser Lophodytes cucullatus x
Common merganser Mergus merganser x x
Red-breasted merganser Mergus serrator . x
Coopers hawk Acczpiter cooperv x
Red-tailed hawk Butqo jamaicensis x x
Sharp-shinned hawk Aacvpitev striatus x
Bald eagle Halzaeetus leucocephalus x
American kestrel Falco sparverius x x
Ruffed grouse Bonasa umbellus x
C-4
-------
TABLE B - continued
Common Name Scientific Name Forest Streams, Puget
Areas Lakes & Sound
Wetlands
California quail
Lophortyx californicus
X
X
Ring-necked pheasant
Phasianus colohious
X
X
American coot
Fulioa amerioana
X
X
Killdeer
Charadrius vooiferus
X
Common snipe
Capella gallinago
X
Whimbrel
Numenius phaeopus
X
Spotted sandpiper
Actitis macularia
X
Least sandpiper
Erolia minutilla
X
Dunlin
Erolia alpina
X
Sanderling
Crooethia alba
X
Northern phalarope"
Lobipes lobatus
X
Glaucous-winged gull
Larus glaucescens
X
Western gull
Larus ocaidentalis
X
Herring gull
Larus argentatus
X
California gull
Larus californica
X
Bonaparte's gull
Larus Philadelphia
X
Common murre
Uria salge
X
Pigeon guillemot
Cepphus aolumba
X
Marbled murrelet
Brachyvarnphus marmoratum
X
Tufted puffin
Lunda cirrhata
X
Band-tailed pigeon
Columba fasoiata
X
X
Rock dove
Columba livia
X
X
Mourning dove
Zenaidura maoroura
X
Barn owl
Tyto alba
X
X
Screech owl
Otus asio
X
X
Great horned owl
Long-eared owl
Common nighthawk
Buljo virginianus
Aszo otus
Chordeiles minor
X
X
X
X
X
X
Rufous hummingbird
Selasphorus rufus
X
X
Belted kingfisher
Megaoeryle alcyon
X
Red-shafted flicker
Colaptes aafer
X
X
Pileated woodpecker
Dryocopus pileatus
X
Yellow-bellied
Sphrapiaus varius
X
X
sapsucker
C-5
-------
Forest
Areas
Streams,
Lakes &
Wetlands
Hairy woodpecker
Dendrocopos villosus
X
X
Downy woodpecker
Dendroaopos pubescens
X
X
Traill's flycatcher
Empidonax traillii
X
X
Western flycatcher
Epidonax difficilis
X
X
Western wood pewee
Contopus sordidulus
X
X
Olive-sided flycatcher
Nuttallornis borealis
X
X
Violet-green swallow
Tachycineta thallassina
X
X
Tree swallow
Iridoprocne tricolor
X
X
Barn swallow
Hirundo rustica
X
X
Cliff swallow
Petrochelidon phrrhonota
X
X
Steller's jay
Cyanocitta stelleri
X
X
Common crow
Corvus brachyrhynchos
X
X
Black-capped chickadee
Parus atricapillus
X
X
Chestnut-backed chickadee
Parus rufescens
X
X
Common bushtit
Psaltriparus minimus
X
X
White-breasted nuthatch
Sitta carolinensis
X
X
Red-breasted nuthatch
Sitta canadensis
X
X
Brown creeper
Dipper
Winter wren
House wren
Long-billed marsh wren
Certhia familiaris
Cinolus mexicanus
Troqlodutes troqlodutes
Troglodytes aedon
Telmatodytes palustris
X
X
X
X
X
X
X
X
Bewick's wren
Thryomanes bewickii
X
X
American robin
Tardus migratorius
X
X
Varied thrush
Hermit thrush
Swainson's thrush
Ixerey.s naevius
Hyloaxchla guttata
Hytoaiahta ustulata
X
X
X
X
X
X
Golden-crowned kinglet
Regulus satrapa
X
X
Ruby-crowned kinglet
Regutus calendula
X
X
Cedar waxwing
Bombycilia cedrodum
X
X
Starling
Stuvnus vulgaris
X
X
Solitary vireo
Vireo solitarius
X
X
Hutton's vireo
Vireo huttoni
X
X
Red-eyed vireo
Vireo olivaceus
X
X
Warbling vireo
Vireo gilvus
X
X
C-6
-------
TABLE B - continued
Common Name Scientific Name Forest Streams,
Areas Lakes &
Wetlands
Orange-crowned warbler
Vermivora aetata
X
X
Yellow warbler
Townsends warbler
MacGillivray's warbler
Dendroioa petechia _
Dendroiqa townsendi
Opovomis tolmie'i
X
X
X
X
X
X
Yellowthroat
Geothlypis triehas
X
Black-throated gray
warbler
Dendroica nigrescens
X
X
Wilson's warbler
Wilsonia pusilla
X
X
Audubon's warbler
Dendroiaa auduboni
X
X
House sparrow
Passer domestiaus
X
X
Red-winged blackbird
Agelaius phoeniceus
X
Bullock's oriole
Iaeterus bultoekii
X
X
Brewer's blackbird*"
Euphagus ayanoaephalus
X
X
Brown-headed cowbird
Molothmis ater>
X
X
Western tanagef
Piranga tudoviciana
X
X
Black-headed grosbeak
Pheuetious melanoaephalus
X
X
Evening grosbeak
Hesperiphona verpertina
X
X
Purple finch
Carpodaaus purpureus
X
X
House finch
Carpodaaus mexicanus
X
X
Pine siskin
Spinus pinus
X
X
American goldfinch
Spinus tristis
X
Rufous-sided towhee
Pipilo erthrophthalmus
X
X
Savannah sparrow
Passeroulus sandwichensis
X
Oregon junco
Junce oreganus
X
X
Chipping sparrow
Spizella passerina
X
X
White-crowned sparrow
Zonotriahia leucophrys
X
X
Song sparrow
Melospiza melodia
MAMMALS
X
X
Opossum
Didelphis marsupialis
X
X
Vagrant shrew
Sovex vagrans
X
X
Pacific water shrew
Sorex beridivii
X
Trowbridge shrew
Sovex trowbridgii
X
X
Townsend mole
Scapanus townsendii
X
X
Coast mole
Saapanus ovavius
C-7
X
X
-------
Forest
Areas
Streams,
Lakes &
Wetlands
Shrew mole
Bats
Snowhoe hare
Eastern cottontail rabbit
Mountain beaver
Townsend chipmunk
Douglas squirrel
Northern flying squirrel
Beaver
Deer mouse
Oregon meadow mouse
Long-tailed meadow mouse
Muskrat
Townsend meadow mouse
Norway rat
House mouse
Pacific jumping mouse
Neutrotrichus gibbsii
Chiroptera
Lepus americanus
Sylvilagus floridanus
Aplodontia rufa
Eutamias townsendii
Tamiasaiurus douglasii
Glauoomys sabrinus
Castor canadensis
Peromyscus manieulatus
Microtus oregoni
Microtus longicaudus
Ondatra zibethica
Microtus townsendii
Rattus norvegicus
Mus musculus
Zapus trinotatus
x
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Racoon
River otter
Mink
Long-tailed weasel
Short-tailed weasel
Striped skunk
Spotted skunk
Black-tailed deer
Prooyon lotov x
Lutra canadensis
Mustela vison
Musteta frenata x
Mustela erminea x
Mephitis mephitis x
Spilogale putorius x
Odoaoiteus hemionus eolumbianus x
x
X
X
X
X
X
X
X
AMPHIBIANS
Northwestern salamander
Long-toed salamander
Rough-skinner newt
Ensatina
Ambystoma gracile
Ambystoma macrodactytlum
Tarioha granulosa
Ensatina esokscholtzi
C-8
x
x
X
X
X
X
X
X
-------
TABLE B - continued
Common Name Scientific Name Forest Streams,
Areas Lakes &
Wetlands
Western red-backed salamander Plethodon vehicutum
Western toad
Pacific treefrog
Red-legged frog
Bullfrog
Bufo boreas
By la regilla
Rana aurora
Rana catesheiana
x
X
X
X
X
X
X
X
X
REPTILES
Northern alligator lizard
Rubber boa
Northwestern garter snake
Western terrestrial garter
snake
Gerrhonotus aoeruleus
Charina bottae
Thamnophis ordinoides
Tharrmophis elegans
x
X
X
X
X
X
X
X
Common garter snake
Thamnophis sirtalis
C-9
-------
TABLE C
RESULTS OF SYSTEMATIC ELECTROFISHING IN THREE
AREAS OF THE SWAMP CREEK DRAINAGE
Map Location
(area shocked)
Species
Sample Size
(n)
Avg. Fork
length (mm)
Avg. Wt.
(gm)
Population
Estimate
Density
(fish/m )
Bioma^s
(gm/m )
Rainbow-
Steelhead
trout
8
73.7
5.5
10
0.12
0.07
Cutthroat
trout
0 yr. class
1+ yr. class
18
3
74.9
102.3
3.8
12.3
19
4
0.23
0.05
0.05
0.15
Coho salmon
13
66.5
3.6
16
0.20
0.04
Sculpin
13
57.8
2.8
16
0.20
0.03
Rainbow-
Steelhead
trout
5
85. A
7.2
5
0.06
0.09
Cutthroat
trout
0 yr. class
1+ yr. class
10
5
60.7
120.2
2.2
20.2
25
5
0.30
0.06
0.03
0.24
Coho salmon
57
59.0
2.3
118
1.41
0.03
Sculpin
17
44.7
0.85
23
0.28
0.01
Lamprey
2
113.0
4.0
3
0.04
0.05
Swamp Creek below
confluence with
Scriber Creek near
Cypress Road
(81.1 m )
2. Scriber Creek
above confluence
with Swamp Creek
near Cypress Road
(83.5 m2)
-------
TABLE C - continued
Map Location Sample Size Avg. Fork Avg. Wt. Population Density Biomass
(area shocked) Species (n) length (mm) (gm) Estimate (fis'n/m^) (gm/m2)
Unnamed Creek
across from
Alderwood Jr.
High School near
28th Ave. W
(18.4 m2)
Rainbow-
Steelhead
trout
Cutthroat
trout
0 yr. class
1+ yr. class
6
2
70.3
176.0
3.3
51.5
0.38
0.11
0.18
2.80
Coho salmon
23
79.7
5.7
39
2.12
0.31
-------
TABLE D
CHECKLIST OF FISHES LIKELY TO BE FOUND IN
PUGET SOUND IN THE PROJECT AREA
Common Name
Scientific Name
Brown cat shark
Apristurus brunneus
Spiny dogfish
Squalus aoanthias
Longnose skate
Raja rhina
Ratfish
Hydrolagus oolliei
American shad
Alosa sapidissima
Pacific herring
Clupea harengus pallasi
Pink salmon
Oncorhynahus gorbuscha
Chum salmon
Oncorhynahus keta
Coho salmon
Oncorhynahus kisutah
Sockeye salmon
Onaorhynchus nerka
Chinook Salmon
Oncorhynahus tshauytsaha
Cutthroat trout
Salmo clarki
Dolly Varden
Salvelinus malma
Surf smelt
Hypomesus pretiosus
Longfin smelt
Spirinchus thaleichthys
Plainfin midshipman
Porichthys notatus
Pacific cod
Gadus macroeephalus
Pacific hake
Merluccius productus
Pacific tomcod
Microgadus proximus
Walleye pollack
Theragra ohalcogramma
Red brotula
Brosmophycis marginata
Pallid eelpout
Lycodccpus mandibularss
Black eelpout
Lycodes diapterus
Wattled eelpout
Lycodes palearis
Blackbelly ellpout
Lycodopsis pacifica
Tube-snout
Aulorhynchus flavidus
Threespine stickleback
Gasterosteus aculeatiis
Bay pipefish
Synghanthus griseolineatus
Shiner perch
Cymatogaster aggregata
Striped seaperch
Embiotoca lateralis
Pile perch
Rhacochilus vacca
C-12
-------
TABLE !) - continued
Common Name
Northern ronquil
Snake prickleback
Bluebarred prickleback
Penpoint gunnel
Crescent gunnel
Saddleback gunnel
Pacific sand lance
Blackeye goby
Bay goby
Copper rockfish
Quillback rockfish
Black rockfish
Sablefish
Kelp geenling
Whitespotted greenling
Ling cod
Painted greenling
Padded sculpin
Scalyhead sculpin
Silverspotted sculpin
Roughback sculpin
Sharpnose sculpin
Buffalo Sculpin
Red Irish lord
Northern sculpin
Threadfin sculpin
Spotfin sculpin
Pacific staghorn sculpin
Great sculpin
Sailfin sculpin
Tidepool sculpin
Tadpole sculpin
Slim sculpin
Grunt sculpin
Scientific Name
Ronquilus jordani
Lumpenus sagitta
Pleatobranahus evides
Apodichthys flavidus
Pholis Zaeta
Pholis ornata
Armodytes hexapterus
Coryphterus nioholsi
Lepidogobius Zepidus
Sebastes caurinus
Sebastes maliger
Sebastes melanops
Anoplopoma fimbria
Hexagrammos decagrammus
Hexagrammos stelleri
Ophiodon elongatus
Oxylebius pictus
Artedius fenestvalis
Artedius harringtoni
Blepsias cirrhosus
Chitonotus pugetensis
Clinocottus aeuticeps
Enophrys bison
HemLlepidotus hemilepidotus
Ioelinus bovealis
Icelinua filairientosus
Ioelinus tenuis
Leptoaottus armavus
Myoxocephalus polyacanthocephalus
Nautichthys oculof'asciatus
Oligocottus maculosus
Psyclvcolutes paradoxus
Radulinus asperellus
Rhamphocotius viahardsoni
C-13
-------
TABLE U - continued
Common Name
Scientific Name
Cabezon
Scorpaenichthys marmoratus
Northern spearnose poacher
Agonopsis emmelane
Sturgeon poacher
Agonus acipenserinus
Phgmy poacher
Odontopysix trispinosa
Blacktip poacher
Xevneretnrus latifrons
Bluespotted poacher
Xeneretmus tricanthus
Slipskin snailfish
Liparis fucensis
Pacific sanddab
Citharichthys sordidus
Speckled sanddab
Citharichthys stigmaeus
Arrowtooth flounder
Altheresthes stomias
Petrale sole
Eopsetta jordani
Rex sole
Glyptocephalus zachirus
Flathead sole
Hippoglossoides elassodon
Butter sole
leopsetta isolepsis
Rock sole
Lupidopsetta bilineata
Slender sole
Lyopsetta exilis
Dover sole
Microstomus paoifiaus
English sole
Parophrys vetulus
Starry founder
Ptatichthys stellatus
G-0 sole
Ptevcronichthys coenosus
Sand sole
Psettichthys melanosticus
C-14
-------
APPENDIX D
NOISE INVESTIGATION
BROWN'S BAY SITE
Introduction
The following study documents existing acoustic conditions at the
City of Lynnwood sewage treatment plant and in the surrounding community.
The study identifies existing noise sources, noise-sensitive land uses
and noise levels, and evaluates the potential impacts of existing noise.
Existing Noise Sources
The principal noise sources in the study area are the existing
treatment plant, Burlington Northern and Amtrak trains, and vehicular
traffic on local streets. Of less significance is occasional noise from
light aircraft, powered residential maintenance equipment such as lawn
mowers, and garbage trucks.
Treatment Plant
Noise sources at the treatment plant include equipment within the
operations building, a clarifier, a sludge thickener, a sewage grinder
and bar screen, and occasional trucks and automobiles. Of these, the
sources within the operations building produce the highest noise levels,
but are only operating during the daytime hours of 7:00 a.m. - 5:00 p.m.
Noise sources within the operations building are a centrifuge, two
blowers, a pump, and the sludge incinerator. Because of inadequate
ventilation and so the operators can hear the equipment as it operates,
the door to the operations building is normally left open during operating
hours, thereby reducing the effectiveness of the building as an acoustical
enclosure. Acoustical effectiveness is further reduced by the presence
of slatted ventilation openings.
The remaining stationary on-site sources operate at night, and are
therefore significant because of the generally lower background noise
levels and greater noise sensitivity during nighttime hours. Except for
infrequent emergency repair vehicles and occasional autos using the site
as a secluded parking area during nighttime, vehicular traffic associated
with the facility occurs only during daytime.
D-l
-------
Trains
Trains are a significant noise source affecting the residences west
of 76th Avenue W. There are approximately 14 trains during daytime
(7:00 a.m. - 10:00 p.m.) averaging 39 cars per train and 8 trains during
nighttime (10:00 p.m. - 7:00 a.m.) averaging 42 cars per train according
to Burlington Northern, Office of Division Superintendent.
Off-Site Noise
Vehicular traffic occurs mainly on 76th Avenue W, 171st Street SW
and Talbot Road. Of these, 76th Avenue W is most significant, although
it should be noted that traffic is very light on all streets in the
area. A traffic count at 76th Avenue W on Monday, November 22, 1976,
yielded only 70 autos and one school bus in the one-hour period from
2:45 to 3:45 p.m., which is considered a representative daytime traffic
hour.
The occasional noise from aircraft, powered residential maintenance
equipment and garbage trucks was considered typical for a suburban
residential area, and not of any unusual significance. Other typical
residential noise sources, such as dogs barking and children playing,
are also present.
Existing Noise-Sensitive Land Uses
The principal noise-sensitive land uses are the residences adjoin-
ing the site on the south, east and north. The critical properties
having greatest exposure to noise from the site are the two residences
to the south (16838 and 16905 Talbot Road) and the large residential
property to the north (16828 76th Avenue W). Other residences to the
south and north receive considerably less noise from the site because of
distance and topographic shielding. Four residences to the east of the
site overlook the undeveloped eastern portion of the site and the access
road, but are relatively far removed from the on-site noise sources.
The residences are in City of Edmonds single-family residential
zones, while the site itself is unzoned City of Lynnwood property.
Residences along 76th Avenue W which would be exposed to existing
or future site-generated traffic noise are also considered noise-sensitive
land uses.
D-2
-------
Noise Descriptors And Measurement Procedures
Noise levels in this study are expressed in A-weighted decibels, or
dBA, which is the descriptor that is generally accepted as having the
best correlation with human judgments of loudness. Each increase of 10
dBA in the noise level is subjectively judged as an approximate doubling
of loudness.
For certain types of noises, the dBA level alone may not adequately
tell how the noise will be judged. For example, a noise that is impulsive
or repetitive or contains pure tone components, or whose information
content disturbs or distracts, is often judged to be louder than its dBA
level would indicate. Sound pressure levels in decibels at 1/3 octave
frequency bands were therefore measured for the noisiest equipment to
determine if unusual sound characteristics were present.
The total noise exposure for a prescribed time period is given by
the Leq, or equivalent level, which is the dBA level of a constant sound
having the amount of acoustic energy contained in the time-varying
measured noise. The L(jn, or day-night sound level, is the Leq over 24
hours, with a 10 dBA weighting applied to the nighttime (10:00 p.m. to
7:00 a.m.) noise. The L^n is the environmental noise descriptor preferred
by the U.S. Environmental Protection Agency.
A fluctuating noise can also be described statistically as noise
levels exceeded for given percentages of time during a prescribed time
period. For statistical levels, the number in the subscript indicates
the percentage of time that the given level was exceeded. Thus, the L99
and L90 are indicative of background noise, the L50 is the median level
indicative of "typical" noise conditions, and the L^o and are indicative
of the noisier events.
All noise measurements were made by analog tape recording using a
Nagra IV-SJ scientific recorder with a Bruel and Kjaer 1" condenser
microphone. All recordings were calibrated at the measurement site.
Data was reduced using a Bruel and Kjaer 3347 real-time 1/3 octave
analyzer coupled to a Varian 620/L computer and a Bruel and Kjaer 2304
graphic level recorder. For computing statistical and Lgq levels, data
was sampled four times per second.
The L(jn levels were computed using a computer program with input
based on the measured noise, operating hours of plant equipment, and
train schedules. Topographic barrier effects were determined using
another computer program based on Maekawa's diffraction model, with
input based on limited available topographic data. Sound attentuation
caused by vegetation was generally considered to be insignificant, since
lines of sight between source and receiver are generally not parallel to
the ground surface, due to the large variations in topography.
D-3
-------
Existing Noise Levels
Development
The existing noise levels at the treatment plant and in the sur-
rounding community were determined from noise monitoring and from
computer calculations to account for factors such as train operations
and topographic barrier effects.
Kxterior steady-state noise contours from stationary on-site sources
(the operations building, sludge thickener, clarifier, sewage grinder
and bar screen) are shown in Figure 1 for the 7:00 a.m. - 5:00 p.m.
hours when all equipment is operating and for the 5:00 p.m. - 7:00 a.m
hours when all equipment except that within the operations building
(centrifuge, compressor and incinerator) is operating. The contours are
based on measurements at 20 on-site locations.
The 1/3-octave sound pressure level spectra and dBA levels of the
noisiest on-site equipment (the centrifuge, compressor and incinerator)
are shown in Figures 2 through 4. Each measurement was made at a
distance of 5 feet from the surface of the machine, and may include some
effects from the other two machines and from reverberant buildup within
the operations building. The combined noise measured at the open door
is shown in Figure 5. It should be noted that the pure tone at 100 Hz
measured for the incinerator is not evident in the combined noise
measurement. Therefore, the exterior sound is not considered to have
unusual spectrum characteristics that would make it more annoying than
would be indicated by the dBA level.
Measurements of noise exposure in the community near the treatment
plant were made at the three critical residential receiver locations
described previously and at the residence on 76th Avenue W located
across from the entrance to the plant. The measurements represent one
hour of data during the mid-day (10:00 a.m - 4:00 p.m.) period, plus one
hour from 2:00 to 3:00 a.m. at the first location to document nighttime
noise conditions. The levels are presented as statistical levels, where
the number in the subscript indicates the percentage of time that the
given level was exceeded, and as Leq, or equivalent level, which is the
level of a constant sound having the amount of acoustic energy contained
in the time-varying measured noise.
Measurement Results
16838 Talbot Road. Measurements were taken five feet east of
house, overlooking the treatment plant. This location represents noise
exposure at the north side of the house and at the usable portion of the
property closest to the plant. The property boundary is closer to the
D-4
-------
plant, but is inaccessible because it is on a steep bank. The measure-
ment period was Wednesday, November 24, 1976, from 2:20 to 3:20 p.m.
There were four trains during the measurement, with approximately 50, 25
38 and 13 cars. This number of trains is unusually high for a one-hour
period.
Measured noise, dBA
l99 l90 l50 l10 ^1 L_e^
56 57 58 60 79 65
The Lgg level of 56 dBA is the minimum steady-state background
noise from the treatment plant. Noise from the plant was dominant over
90 percent of the time, as indicated by the small difference between the
L99 and L10 level. However, trains produce much higher noise levels. A
typical level for each train event was 79 dBA, with diesel locomotives
producing brief levels of up to 85 dBA. Traffic noise was not noticeable.
16838 Talbot Road. Nighttime measurements were taken on Thursday,
November 25, 1976, 2:00 to 3:00 a.m. There were no trains during the
measurement.
Measured noise, dBA
L99
L90
L50
L10
hi
51
52
54
55
56
53
The L99 level of 51 dBA is the minimum steady-state background
noise from the treatment plant. Noise from the plant was dominant
throughout the measurement.
16905 Talbot Road. Measured in yard 40 feet west of house, over-
looking the treatment plant. This location represents noise exposure at
the north side of the house and at the used portion of the property
closest to the plant. As at the previous location, the property boundary
is closer to the plant, but is inaccessible because it is on a steep
bank. The measurement period was Friday, November 19, 1976, from 2:00
to 3:00 p.m. There was one train event during the measurement.
D-5
-------
Measured noise, dBA
l99
L90
L50
L10
h
ha
49
50
51
54
73
59
The L99 level of 49 dBA is the minimum steady-state noise from the
treatment plant. As at the previous location, noise from the plant was
dominant over most of the measurement. The train event had an average
level of about 73 dBA with the diesel locomotive producing a brief level
of 85 dBA. Traffic noise from Talbot Road and from 76th Avenue W was
barely noticeable.
16828 76th Avenue w. Observed in yard 100 feet southwest of house,
overlooking the treatment plant. This location represents noise exposure
for the currently used portion of the property closest to the plant.
Here the property boundary is considerably closer to the plant, being at
the bottom of the bank that extends from the residential yard to the
plant site. The bank is presently undeveloped, although it has been
subdivided for possible future residential development. The measurement
period was Tuesday, November 23, 1976, from 10:55 to 11:55 a.m. There
were no trains during the measurement. A noisy truck was operating
intermittently at the treatment plant for a period of four minutes.
Measured noise, dBA
L99
L90
L50
L10
Ll
^eq
47
48
49
52
64
53
The L99 level of 47 dBA is the minimum steady-state noise from the
treatment plant. As at the previous locations, noise from the plant was
dominant throughout most of the measurement. The truck at the treatment
plant produced typical levels of 65 dBA. Traffic noise from 76th Avenue
W was noticeable, but not intrusive. There was some intermittent noise
from a garbage truck operating in the area. It should be noted that
steady-state noise from the treatment plant was measured to be 7 dBA
lower (40 dBA) at the house, due to topographic shielding. At the
house, noise from the plant was barely noticeable. At the property
boundary adjacent to the treatment plant, steady-state noise from the
plant was measured to be 61 dBA under both daytime and nighttime operating
conditions.
D-6
-------
16931 76th Avenue w. Measured at house set back 60 feet from road.
This location represents typical noise exposure at residences along 76th
Avenue W in the vicinity of the treatment plant. The measurement period
was Monday, November 22, 1976, from 2:A5 to 3:45 p.m. The only noticeable
noise sources were traffic on 76th Avenue W and occasional light aircraft.
Measured noise, dBA
l99 L9Q l50 l10 ^1 ^e£
41 43 46 58 67 55
These levels are considered typical for residences adjacent
to arterials with relatively light traffic volumes.
The 24-hour noise exposure in the community surrounding the treatment
plant is shown in Figure 6. The levels are shown as L(jn» or day-night
sound levels, which were computed on the basis of the measured noise,
operating hours of plant equipment, train schedules, topographic barrier
effects, and estimated absorption due to vegetation.
Evaluation Of Existing Noise
The levels shown in Figure 6 for the community surrounding the
treatment plant can be evaluated using the U.S. Environmental Protection
Agency's identified level of 55 dBA. This level is considered requisite
to protect public health and welfare with an adequate margin of safety
outdoors in residential areas. levels exceed 55 dBA at the residential
properties closest to the site on the north and south. It should be
noted that noise at these locations is almost entirely due to the
treatment plant and the trains, but that an L^n °f 55 dBA would be
exceeded at the closest residential locations having a direct view into
the plant site even if train noise were eliminated.
Noise from the treatment plant only can be evaluated using the
State of Washington WAC 173-60 noise limitations contained in Appendix
B. For the steady-state noise of the type produced by the plant,
residential receiving property and industrial source property, the basic
noise limitations would be 60 dBA during daytime (7:00 a.m. to 10:00
p.m.) and 50 dBA during nighttime (10:00 p.m. to 7:00 a.m.) measured
anywhere on the receiving property. However, the plant may be exempt
from the lower nighttime level if it is considered to fall under "existing
industrial installations which exceed the standards contained in these
regulations and which, over the previous three years, have operated in
excess of 15 hours per day as a consequence of process necessity and/or
demonstrated routine normal operation."
D-7
-------
With the exception of nighttime levels at the first measurement
location, WAC 173-60 limitations would generally be met on those
portions of the receiving properties which are presently developed or
accessible. It should be noted, however, that the undeveloped portion
of the residential property directly north of the site is exposed to
levels which exceed the daytime and nighttime limitations.
D-8
-------
StWA&C <3«JNDtR
if &AR SCRLLK1
-------
RUN
£5 XXXX 54.6 +6
31.5 XXXXXX 56.6 +5
40 XXXXXXXXXXXXXXX 65 +4
50 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 81.6 +3
63 XXXXXXXXXXXXXXXXXXXXXXX 73+2
<:0 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 81 +1
100 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 89.4 +1
135 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 82
160 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 82.6
900 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 8s
350 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 82.2
315 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 07.6
400 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 83.2
500 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 82.6
630 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 81
i<00 XXXXXXXXXXXXXXXXXXXXXXXXXXXXX 7 9.2
1000 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 80.2
12so XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 81
1600 XXXXXXXXXXXXXXXXXXXXXXXXXXXXX 79.2
2000 XXXXXXXXXXXXXXXXXXXXXXXXXXXXX 79.4
'^5 )0 XXXXXXXXXXXXXXXXXXXXXXXXXXX 77.6
3 150 XXXXXXXXXXXXXXXXXXXXXXXXXX 76.8
4000 XXXXXXXXXXXXXXXXXXXXXX 72.2
5000 XXXXXXXXXXXXXXXXXXXXXX 72.8
630.) XXXXXXXXXXXXXXXXXXX 69
8,>00 XXXXXXXXXXXXXXX 65. b
10000 XXXXXXXXXXXX 62
1PS00 XX 52.6
16000 50
20000 50
t\ IT. XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 90.4
! F. i'1. D 'i
Figure 2 - Sound pressure level spectrum at 1/3 octave
frequencies for centrifuge, 5' from surface,
(Plus corrections for high pass recording filter.)
D-10
-------
F.I ii\
XXXXXX 56.6 +6
31.L) XXXXXXXXXXX 61.4 +5
40 XXXXXXXXXXXXXXX 65.6 +4
50 XXXXXXXXXXXXXXXXXXXXXXXXXXXX 78 +3
63 XXXXXXXXXXXXXXXXXXXXXXXX 74.8 +2
80 XXXXXXXXXXXXXXXXXXXXXXXXXX 76.2 -{jl
10U XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 86. 4
125 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 82.2
160 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 80.8
200 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 83,6
250 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 81.8
315 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 81.2
400 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 81.8
500 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 83
630 XXXXXXXXXXXXXXXXXXXXXXXXXXXXX 79.6
BOO XXXXXXXXXXXXXXXXXXXXXXXXXXXXX 7 9
1000 X X/.XxXXXXXXXXXXXXXXXXXXXXXX 7 7.4
1250 XXXXXXXXXXXXXXXXXXXXXXXXXXX 77.a
1600 XXXXXXXXXXXXXXXXXXXXXXXXXXXX 78.8
2000 XXXXXXXXXXXXXXXXXXXXXXXXXX 76 .4
2500 XXXXXXXXXXXXXXXXXXXXXXXXX 7 5.8
3150 XXXXXXXXXXXXXXXXXXXXXXXX.74.8
'iOOO XXXXXXXXXXXXXXXXXXXXX 71.6
5JOG XXXXXXXXXXXXXXXXXXXXX 71.8
6300 XaXXXXXXXXXXXXXXXX 68.8
>>000 XXXXXXXXXXXXXXX 65.6
I 0000 XXXXXXXXXX 60.8
12500 X 51.6
16000 50
80000 50
A IT. XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 80.8
i:f;aov
Figure 3 - Sound pressure level spectrum at 1/3 octave
frequencies for compressor, 5' from surface.
(Plus corrections for high pass recording filter.)
D-ll
-------
h'UN
2 5 XX 52•4 +6
31.5 XXXXXXXX '58.8 +5
40 XXXXXXX 57.6 +4
5 0 XXXXXXXXXXXXXXXXXX 68.e +3
6 3 XXXXXXXXXXXXXXXXX 67+2
oO XXXXXXXXXXXXXXXXXXXXXXX 73.4+1
100 XXXXXXXXXXXXXXXXXXXXXXXXXXXX)ffiXXXXXXXXXXXX 92.2+1
125 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 81.2
160 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 64
200 XXXXXXXXXXXXXXXXXXXXXXXXXXXXX 7 9.4
250 XXXXXXXXXXXXXXXXXXXXXXXXXXXX 78.2
315 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 61
400 XXXXXXXXXXXXXXXXXXXXXXXXXXXXX 79.8
500 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 80.8
*30 XXXXXXXXXXXXXXXXXXXXXXXXXXXX 78
BOO XXXXXXXXXXXXXXXXXXXXXXXXXXX 77.4
1000 XXXXXXXXXXXXXXXXXXXXXXXXXX 76.4
1250 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 82
K.oo XXXXXXXXXXXXXXXXXXXXXXXXXXX 77.2
2000 XXXXXXXXXXXXXXXXXXXXXXXX 74.8
25:00 XXXXXXXXXXXXXXXXXXXXXXXX 74.4
3150 XXXXXXXXXXXXXXXXXXXXXXX 73
4000 XJ'XXXXXXXXXXXXXXXXX 69.6
5000 XXXXXXXXXXXXXXXXXXX 69.2
6300 X/XXXXXXXXXXXXXX 66.4
("on XXXXXXXXXXXXX 63.2
10000 XXXXXXXX 58.4
r .mi:-.; 50
u.noo 50
1J' i • ' 50
A 'i. XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 87.8
.I'V L- \
Figure 4 - Sound pressure level spectrum at 1/3 octave
frequencies for incinerator, 5' from surface.
(Plus corrections for high pass recording filter.)
D-12
-------
HUN
2b
XXX 53.8' +6
31.5
XXXXXXX 57.2 +5
40
XXXXXXXX 58.2 +4
+3
50
XXXXXXXXXXXXXXXXXXXXXXXXXXXXX 7 9.6
63
XXXXXXXXXXXXXXXXXXXXXXXXXX 76.4 +2
BO
XXXXXXXXXXXXXXXXXXXXXXXXXX 76.2 +1
1 00
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 62
+1
125
XXXXXXXXXXXXXXXXXXXXXXXXX!75.2
160
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 8p
200
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 81.
6
250
XXXXXXXXXXXXXXXXXXXXXXXXXXX 77.4
315
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 82
.8
400
XXXXXXXXXXXXXXXXXXXXXXXXXXXXX 80.8
500
XXXXXXXXXXXXXXXXXXXXXXXXXXXXX 7 9.2
630
XXXXXXXXXXXXXXXXXXXXXXXXXXX 77.6
800
XXXXXXXXXXXXXXXXXXXXXXXXXX 76.8
1000
XXXXXXXXXXXXXXXXXXXXXXXXXX 76.8
1 ;-!50
XXXXXXXXXXXXXXXXXXXXXXXXXXX 77.8
1 600
XXXXXXXXXXXXXXXXXXXXXXXXXXX 77.2
kOQO
XXXXXXXXXXXXXXXXXXXXXXXXX 75.2
2500
XXXXXXXXXXXXXXXXXXXXXXXXX 75.4
3 150
XXXXXXXXXXXXXXXXXXXXXXXX 74.6
4000
XXXXXXXXXXXXXXXXXXX 69.4
5000
XXXXXXXXXXXXXXXXXXXXXX 72
6300
XXXXXXXXXXXXXXXX 66.2
8000
XXXXXXXXXXXXX 63.2
10000
XXXXXXXXX 59.2
1 2500
50
16000
50
20000
50
A T • XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 8B
ke;ady
Figure 5 - Sound pressure level spectrum at 1/3 octave
frequencies at open door of operations building.
(Plus corrections for high pass recording filter.)
D-13
-------
55dBA
figure. cxienNo noigl environhcki't
* MOie& ME^s0URIT:MENJT FTMT IOKJ
"SCALE- l"-|CO'
D-14
-------
APPENDIX E
HISTORICAL & ARCHEOLOGICAL CONCERNS
-------
U. S. ENVIRONMENTAL PROTECTION AGENCY
REGION X
$ \
% A
phO^
SEATTLE, WASHINGTON 98101
1200 SIXTH AVENUE
kEPLY TO
ATTN OF:
M/S 429
February 28, 1977
Mr. Douglas Canning
Northwest Environmental Consultants
219 Madison Avenue, S.
Bainbridge Island, WA 98110
Dear Mr. Canning:
The guidance to which I referred in our phone conversation last week is a
draft which is not being used at this time. It briefly states the require-
ments of a preliminary cultural resource survey for an Environmental Protection
Agency (EPA) assisted project, which can be restated as follows.
If the State Historic Preservation Officer (SHPO) indicates that a survey is
necessary for a portion of or all of the project, the project owner will
arrange for a pre!iminary survey in the primary impact area of that portion of
the proposed project. The scope of the preliminary survey shall include only
that work necessary to result in:
1. A short cultural history of the area.
2. Identification of properties in the primary impact area which are on
national, state, or local registers of historic properties or which may be
eligible for inclusion on such registers.
3. Identification of specific areas within the primary impact area in which
the high probability of existence of subsurface resources merits further in-
vestigation or measures to avoid or mitigate the project's potential impact.
The degree of probability must be high enough to justify further investment
of archaeological professionals' time, expenditure of Federal, State, and
local water pollution control funds, and possible delay of this pollution
control project.
4. If necessary, recommendations for further investigation or measures to
mitigate the project's potential impact on known cultural resources or areas
of high probability of existence of subsurface resources.
5. Estimates of the time and expense necessary if further work is recommended.
E-2
-------
6. Six copies of a report which contains the above information, for the
review of the SHPO, EPA, and the project owner.
7. Concurrence of the SHPO, EPA, and the project owner on the adequacy of
the survey and the necessity of further work.
If you have further questions, do not hesitate to call me at 442-1266.
r -• i
Mark Johnson
-------
UNIVKRSITY OF WASHINGTON
SF.ATI'LK, WASHINGTON 98195
March 4, 1977
Office of Public Archaeology, FM-12
Institute for Environmental Studies
Mr. Douglas Canning
Northwest Environmental Consultants
219 Madison Avenue South
Bainbridge Island, Washington 98110
Subject: Preliminary Archaeological Assessment
Lynnwood Waste Water Treatment Facilities Plan
Dear Mr. Canning:
In response to our telephone conversation of March 4, 1977, I am taking this
opportunity to provide this office's comments concerning the need for an on-
site assessment of potential archaeological impacts associated with the pro-
posed Lynnwood Waste Water Treatment Facilities Plan, Snohomish County,
Washington. This proposed assessment is based on the background data and
recommendations of Mr. Hal Kennedy, consulting archaeologist, offered in his
letter to you of December 10, 1976.
As currently understood, the proposed Lynnwood Waste Water Treatment system
would consist of a treatment plant and approximately six miles of associated
interceptor line in the immediate vicinity of Swamp Creek. While Mr. Kennedy's
previous archival and literature research failed to locate any recorded evi-
dence of prehistoric sites in the project's primary impact area, he did note
the area's high archaeological potential (based upon proximity to available
fresh water and the propensity for finding archaeological sites on upland
terraces such as those found in the Swamp Creek vicinity). In view of his
findings, he recommended that an on-site reconnaissance of the trunk lines
be conducted to locate and assess any archaeological remains which might
be adversely effected.
Surface archaeological reconnaissance is the most effective and efficient means
of locating cultural resources in circumstances like those known to occur in
the Lynnwood area. Tactically, such a survey is conducted by carefully
examining all available horizontal and vertical exposures in a given project
area. This procedure entails slowly walking the primary impact area looking
for any evidence of past human use. In the event such remains are observed,
a concerted effort is made to delimit the spatial extent and stratigraphic
structure of the "site." Data collected from such a survey is then analyzed
and the results evaluated for their "significance" in terms of the Advisory
Council on Historic Preservations's "Procedures for the Protection of Historic
and Cultural Properties" (36 CFR Part 800). Based upon these findings, final
recommendations can be made regarding the need for further mitigative measures.
E-4
Recycled Paper
-------
D. Canning
4 March, 1977
Page 2
Given the size and location of this particular project area, we would antici-
pate that the field portion of our proposed assessment would require three
(3) man-days to complete. This estimate is based upon similar studies con-
ducted elsewhere and can be further categorized as follows: (1) pre-survey
informant interviews—one (1) man-day; and (2) on-site surface reconnais-
sance—two (2) man-days. Interviews with knowledgeable local residents
are provided for because this technique often generates information
regarding site locations that would otherwise go unrecorded.
The analysis of survey-derived data and the issuance of a final report
would require an additional man-day, bringing the total estimated assessment
time to four (4) man-days. These activities would be conducted by a skilled
professional. Because of the small scope of the proposed assessment, the
work is best handled as a personal services contract between the prime con-
sultant and the University of Washington. The current rate for such ser-
vices is $200 per diem plus necessary and reasonable expenses (in this case
an additional $50). Therefore, the projected total expense for the proposed
archaeological assessment would not exceed $850.
Finally, it should be noted that the above scope of work and budget estimates
only cover a reconnaissance assessment. Should significant archaeological
remains be found that require further advance mitigative measures, these
activities would have to be the focus of separate contract negotiations.
We appreciate this opportunity to provide our comments in this matter.
Should you have any questions regarding our proposed assessment, please
don't hesitate to contact this office. We await your decision about our
proposal.
-------
HAL KENNEDY
CONSULT 1 'HA IX)]¦0G1ST
10 December 1976
Office of Public Archaeology
University of Washington
Seattle, WA 98195
Mr. Douglas Canning
Northwest Environmental Consultants
219 Madison Ave. S.
Bainbridge Island
Dear Mr. Canning:
This report, in letter format, concerns the known and potential archaeological
resources in the Lynnwood Wastewater Treatment Facilities and Swamp Creek
Trunk project areas. Archival and literature research constitutes the
major portion of this report. Based upon the results of the archival and
literature research, recommendations are provided for further archaeological
evaluation.
A review of the University of Washington Site Survey Records lists one
known archaeological site within the boundries of the facilities area.
The site, formally designated 45SN9, was discovered in the early 1950's.
It consisted of a shell deposit approximately 1000 feet long and 150
feet wide. The maximum depth of the shell midden was one foot though the
average depth was only three inches. Revisited in 1958, the site was
determined essentially destroyed. It had been previously disturbed by
the Pope and Talbot Lumber Co. railroad terminus and the remainder of
the site had been destroyed by the then recent housing development.
Pertinent ethnographic sources were consulted and though acknowledged to
be included in different aboriyinal group territories, the Lvnnwood area
was not SDecificallv mentioned containing historic Indian villages or
camp sites. T. T. Waterman (n.d.) lists three place names along the
Puaet Sound shore within the facilities area. These place names only
indicate that the area was known by the Native American population but
not that the specific area was inhabited. T. T. Waterman (1922:190)
does list a village at the mouth of Swamp Creek (out of the facilities
area) and Swamp Creek itself.
According to Caryl (1960:141) artifacts were found near the Meadowdale
Community Club building "many years ago." The topographic location
suggests that the site was an early man occupation.
The Fort Bel 1ingham-Fort Steilacoom Military Road passed through the
facilities area and roughly followed an old Indian trail. The road
ran ir, a northeast orientation arid was approximately a mile east and
roughly parallel to Highway 99 until it turned eastward to pass around
the northern end of Martha Lake. The road was generally located between
the four and five hundred foot contour in the Lynnwood area. Besides the
historical importance of this early historic road, the archaeological
si zrifir-:.ce of the earlier Indian trail that the road followed should not
E-6
-------
D Canning
10 Dec. 1976
Page 2
be overlooked. Temporary camps and local hunting would be associated with
the trail. Thus, there is a high potential for archaeological sites
to occur along the road area.
The above trail was historically used, however, earlier trails and
habitation sites are unknown for the specific area. Based upon the general
settlement/subsistence pattern for early archaeological populations in
other portions of Snohomish County, the upland areas in the Lynnwood area
can be considered to have high archaeological potential. One archaeoloqical
site located outside of the facilities area provides an example of what may
be expected for the Swamp Creek area.
The site 45SN21 is approximately five miles east of the facilities area,
northwest of Woodinville. The topographic situation is similar to much
of Swamp Creek. The site is located on Bear Creek, near the four hundred
foot contour, on presently swampy ground. An early man site, 45SN21 reflects
the difference between historic populations who concentrated near the present
shorelines and the earlier populations that utilized the upland areas.
Similar archaeological sites can be expected in the Swamp Creek area.
Recommendations
Based upon the historic utilization of the area, as indicated by the above
mentioned trail, and the probable utilization by earlier populations of the
Swamp Creek area, it is recommended that an on-ground reconnaissance be
conducted by professional archaeologists when the trunk line location is
finalized. The Lynnwood Wastewater Treatment Facility, as presently
understood, is located on recent fill. The construction of the present
Burlinqton Northern Railroad and existinq treatment plant would have
destroyed any cultural resources that may have existed at one time.
Thus, further consideration of archaeological resources for the Lynnwood
Treatment Facility is unwarranted at this time.
S" 1
H
Consulting Archaeologist
cc: Jeanne Welch, Specialist
Office of Archaeology and Historic Preservation
E-7
-------
References Cited
Caryl, Del man H.
1960 With Anyels to the rear; an -informal portrait of early Meadowdate.
Waterman, T. T.
1922 The geographical names used by the Indians of the Pacific Coast.
Geographical Review, Vol. 12, part 2, pp. 175-94.
n.d. Puget Sound Geography. MS No. 1864. Smithsonian Office of
Anthropology, Bureau of American Ethnology Manuscript Collection.
Microfilm University of Washington.
E-8
-------
APPENDIX F
PUBLIC HEALTH & SEPTIC TANK CONSIDERATIONS
F-l
-------
on-in: or public works
March 30, 1977
Mr. Charles H. I^angum, R. S.
Supervisor, Environmental Health Division
Sno! onnsb Health District
Court Iinuse
Everett, Washington 98201
Dear Mr. Mangunr.
The City of Lynnwood, In cooperation with the Alderwood Water
District, is preparing a facilities plan for provision of sewerage
facilities for the Lynmvood service area and the Swamp Creek drainage
basin. At the direction of the Environmental Protection Agency, which
is providing grant funds for the planning, an environmental Imppct
statement 1s also being prepared concurrently with the facilities plan.
Both are scheduled for Initial draft submission by April 15th.
One of the most important considerations in the Swamp Oreek
drainage basin is the health factor. We are aware that there have been
many, many septic tank failures 1n the basin which contaminate surface
water during periods of high runoff and that building is currently being
restricted in many sections of the basin because of the lack of sewers.
We have a copy of Mr. Moser's letter of January 24, 1975 to the Snohomish
County Planning Department on the subject of the Swamp Creek interceptor.
Attached is a copy of a map showing the study area boundaries. We
uoL'.ld appreciate your review of your records 1n the Swamp Creek basin on
the incidence of septic tank failures, instances of building prohibition
for lack of sewers and your assessment of the current health hazard in
the ;nva. If there have been any cases of condemnation of buildings
because of health hazards related to sewage, we would appreciate your
r,vvAtioiving then.
The information which you provide will be included 1n the environmental
impoct statement.
Very truly yours,
CITY OF LYNHWOOD
BY:
o/ W. F.. WIMS, P. F..
¦! f-2 Director of Public Works
lini/PM/mr
unci.
-------
April 5, 1977
City of Lynnwood
Office of Public Works
19100 - 44th Ave. W.
Lynnwood, Washington 9803 7
ATTN: W.E. Nims, Director of
RE: Swamp Creek
Drainage Basin
lie Works.
Dear Sir:
This is in reply to your request as to the need of public sewers in the
above mentioned area and whether present conditions create any particular
public health hazards. As you may know, development has occured in this
area at a time when installation of on site sewage disposal systems had
very limited controls. Not until 1971 were there sewage regulations
passed that could effectively control installation of these systems.
The area in general has a high water table and shallow soils which are
not suitable for sewage disposal installations. Thus, we have experienced
numerous failures causing sewage to be present on the surface of the
ground eventually reaching the road ditches and drainage courses finally
draining to Swamp Creek. This area in our estimation has one of the
highest failure rates in Snohomish County which is creating a public
health hazard.
At the present time some areas cannot develop because of poor soil
conditions and a high water table until public sewers become available.
Homeowners in many instances are unable to sell their homes when a
certification is required from this department due to failing sewage
disposal systems.
Thus, we feel there is a very critical need for public sewers in the
Swamp Creek Basin to not only eliminate a public health hazard but permit
the orderly development of this area.
Very truly yours,
t 2^
Leo^A. Moser, R.S., Director
Environmental Health Division
LAM/gr
-------
U. S. ENVIRONMENTAL PROTECTION AGENCY
REGION X
1200 SIXTH AVENUE
SEATTLE, WASHINGTON 98101
REPLY TO
ATTN OF:
M/S 443
DEC 9 1977
Mr. Leo A. Moser, Director
Environmental Health Division
Snohomish Health Director
Courthouse
Everett, Washington 98201
Dear Mr, Moser:
We have a copy of your letter dated April 5, 1977 to the Office of
Public Works of the City of Lynnwood wherein you expressed a
critical need for public sewers in the Swamp Creek basin because
of a public health hazard created by failing septic tank systems.
Enclosed is a copy of EPA's Draft Environmental Impact Statement on
a proposed sewage treatment project for the City of Lynnwood and
the Alderwood Water District. The recommended alternative in the
Facilities Plan, prepared by Gray & Osborne, is upgrading Lynnwood1s
treatment plant to secondary treatment and construction of a 36"
gravity interceptor in the Swamp Creek basin with disposal to Metro
for treatment.
EPA has made a preliminary decision on this project to fund the
upgrading of the Lynnwood treatment plant to secondary, but believes
funding of the Swamp Creek interceptor to be premature, However,
since this decision was reached, we have received a copy of the
above-mentioned letter, and have decided that we need some additional
information from you to better evaluate the need in the Swamp Creek
basin. Documentation from your office showing the number of septic
tank system failures you have recorded, how many times each has
failed and location of the failures could be provided on a map of
the basin. Perhaps one of the maps provided in the Draft EIS could
be used for this purpose if you do not have such a map already
prepared. Any known cases of disease resulting from the situation
are, of course, of paramount importance to us.
EPA is now in the process of preparing the Final EIS on this project,
and we would appreciate receiving this documented information from
you by December 22, 1977, The final decision that is made on the
alternative to be funded will hinge, in large part, on your documentation
of the need for this Swamp Creek interceptor.
F-4
-------
2
After the Final EIS is published, there will be a 30-day comment
period on the proposed alternative that EPA has selected for funding.
After review and consideration of all comments received, a final
decision will be made by EPA's Regional Administrator.
If you have any questions concerning this reouest please contact
me at (206) 442-4011.
Sincerely,
I
EIS Project Officer
F-5
-------
i$r^
SNOHOMISH
HEALTH
DISTRICT
Courthouse
Everett, Washington 98201
Area Code 206 259-9440
Cl ARIS HYATT, M D , M P H
Health Officer
DAVID A STOCKTON M P A
Executive Assistant
DISTRICT MEMBERS
county
Snohomish
CITIES AND TOWNS
Arlington
Hnef
Da"inyton
Edmonds
Everett
Gold B«i'
Granite Falls
Index
I tike Sievttns
l.vhnwoud
M«-irysv
-------
PAGE NOT
AVAILABLE
DIGITALLY
-------
ALDERWOOD WATER DISTRICT
3626- 156th St. S.W.
LYNNWOOD, WASHINGTON 98036
743-4605
WATER SERVICE
Serving South Snohomish County
SEWER SERVICE
STEVENS, TWOMPSifcl®
RUNYAN, tNC«
w\rp vp nuJJIr n
UJr AN 3119TB )V
January 30, 1978
Ms. Alexandra Smith, Chief
Environmental Evaluation Branch
M/S 443
U.S. Environmental Protection Agency
1200 Sixth Avenue
Seattle, WA 98101
SUBJECT: Lynnwood/Alderwood Water District 201 Facilities Plan
Dear Ms. Smith:
Enclosed is a copy of our December 16, 1977, letter to
HUD, together with a copy of their January 24, 1978, reply
regarding lack of FHA financing due to septic tank problems.
This may be of some value in your analysis of need for
sewer service in the Swamp Creek drainage basin.
PJB:eh
cc: City of Lynnwood
Gray & Osborne
STR
Snohomish Health District
Sincerely,
ALDERWOOD WATER DISTRICT
P
District Engineer
F-8
-------
ALDERWOOD WATER DISTRICT
3626- 156th St. S.W.
LYNNWOOD, WASHINGTON 98036
743-4605
•V-TE- SERVICE
Serving South Snohomish County
SEV.'ER SERVICE
December 16, 1977
Mr. Edward J. Moger, Director
Seattle Area Office
Department of Housing and Urban Development
1321 Second Avenue
Seattle, Washington 98101
Dear Mr. Moger:
The Alderwood Water District and the City of Lynnwood
are presently preparing a 201 Facility Plan for sewer service
in the Swamp Creek drainage basin in Snohomish County under
provisions of a Step 1 Grant from EPA. The 201 Facilities
Plan and related Environmental Impact Statement are in its
final stages. Enclosed is a print showing the approximate
study area boundary in the Swamp Creek basin outlined in yellow.
We have recently been notified by EPA of their opinion
that the proposal for a trunk sewer system in the Swamp Creek
basin is premature and should be postponed indefinitely.
We are concerned that there may be a number of homes
vithin the study area which have been, and are now being re-
fused FHA financing because of lack of sewers or septic tank
problems. If this is the case, please notify us accordingly
in order that such documentation may be made available to EPA.
Your earliest reply x^ill be appreciated.
SUBJECT: FHA Financing
Swamp Creek Drainage Basin
Sincerely,
ALDERWOOD WATER DISTRICT
L. 0. Erikson
General Manager
L0E eh
Enclosure
F-9
-------
.I*1*1 o*
v ¦** DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT area offices
-4 AREA OFFICE Portland, Oregon
fr s Seattle, Washington
i ARCADE PLAZA BUILDING, 1321 SECOND AVENUE, SEATTLE, WASHINGTON 98101
•K
January 24, 1978
9E3 3N X
= =¦310. A_ OFFICE /?£>
~~_E. AASH.SGTON REFER TO:
10. : ko
^^ph°ne : 456
,.i . Mail £4:op: 401
' /y/n
L. 0. Erikson
General Manager
Alderwood Water District
3626 156th Street S.W.
Lynnwood, Washington 98036
Dear Mr. Erikson:
Subject: Swamp Creek Drainage Basin
In response to your request, we have reviewed our files which
relate to the general area your map outlined. Attached for your
information is a list of the subdivision, whether we have any
information and the actions taken. While all but one of the un-
acceptable subdivisions relate to problem septic tank areas, there
nay be other problems which would have to be reviewed on & sub-
division by subdivision basis.
I trust this information can assist you. If you need additional
information, do not hesitate to contact this office.
Si-ncerely,
f
a '
V ,
' D i c t o r
Attachment
F-10
-------
FHA HOME FINANCING
Accepted or Rejected due to Septic Tank Problems
DO WE HAVE
SUBDIVISION NAME INFORMATION IN HOUSE ACTION TAKEN
Aldercrest
Yes
Acceptable (sewers
Alder-Dale Glen
Yes
Acceptable
ALL View Heights 1 & 2
Yes
Reject
Alderwood Estates 1 & 4
Yes
Reject
Alderwood Estates 2
Yes
Acceptable
Alderwood Homes 5
Yes
Acceptable
Alderwood Homes 6
Yes
Reject
Alderwood Manor 1 & 2
Yes
Reject
Alderwood Manor 3
Yes
Case by Case
Alderwood Manor 4-8, 10 & 12
Yes
Reject
Alderwood Village
Yes
Reject
Aurora Homesites
Yes
Acceptable
Avondale 2
No
Balsam Heights
Yes
Reject
Balsam Park
Yes
Reject
Bash Addition //I
Yes
Reject
Bellcrest
Yes
Rej ect
Bergerson #2
Yes
Reject
Bonneville View
Yes
Acceptable
Brents Addition
No
Brookview Estates
No
Burnetts First Addition
No
Camelot Village
Yes
Reject
Camelot Vista
Yes
Reject
Carrie Ann
Yes
Acceptable
Cascadian Park
Yes
Reject
Cascadian Terrace
Yes
Acceptable
Ceda Grove it1 and #2
Yes
Acceptable
Cedar Glen //3
Yes
Reject
Cedar Glen #4
Yes
Acceptable
Cedar Grove
Yes
Acceptable
Cedar Way Park
Yes
Acceptable
Country Village
Yes
Reject
Cypress Heights if7
Yes
Reject
Cypress Heights if3, #6, #9
Yes
Reject
Cypress Meadows
Yes
Acceptable
Cypress Way Firs
No
Dankenbring Addition
Yes
Reject
Delores Addition
No
Dundee
Yes
Acceptable
Echelbarger Estates
Yes
Acceptable
Elberta Highlands
Yes
Acceptable
Englebert Addition
No
Fll
-------
FHA HOME FINANCING
Accepted or Rejected due to Septic Tank Problems
DO WE HAVE
SUBDIVISION NAME INFORMATION IN HOUSE ACTION TAKEN
Fairmont
Fallen Leaf Manor 1 & 2
Filbert Park Tracts
Fir Ridge
Galaxy it 1
Garden Heights Addition
Gibson Cove
Glen Ellen Park
Gloray Estates #2
Gothic Addition #2
Greenbrier
Hemlock Acres
Hemlock Acres 5 and 8
Hillside Manor
Hillwood Park //3
Holly "B"
Holt Addition #1
Ida-Wilde
Jo-D Plat
Kenmore Crest
Kenmore Park
Kingswood Heights
Knorr Villa 1 and 2
Lael Park
Larchmont
Larkwood 1 and 2
Lake Serene Gardening Tracts
Lake Stickney Tracts
Laura Lane
Lake Washington View Tracts
Larch Crest
Linda Manor
Linda Park
Locust View Ridge
Lore-Ondo Park #2
Lucinda Park #2
Lynn-Rae
Lynnwood Acres
Lynnwood Home Tracts #2
No
Yes Acceptable
No
Yes Reject
No
Yes Reject
Yes Reject (Airport)
Yes Acceptable
No
No
Yes Acceptable
Yes Acceptable
Yes Case by Case
Yes Reject
Yes Case by Case
Yes Reject
Yes Reject
No
No
No
Yes Case by Case
Yes Case by Case
Yes Case by Case
Yes Reject
Yes Reject
Yes Acceptable
Yes Reject
Yes Case by Case
Yes Acceptable
Yes Acceptable
Yes Acceptable
No
No
No
Yes Acceptable
Yes Reject
No
No
Yes Case by Case
F12
-------
FHA HOME FINANCING
Accepted or Rejected due to Septic Tank Problems
SUBDIVISION NAME
DO WE HAVE
INFORMATION IN HOUSE
ACTION TAKEN
Manorwood
Maple Glen
Maria Lake
Marnell Addition
Martha Lake Acreage Tract
Martha Lake Firs
Martha Lake Park
Modern Homes #1
Morris Garden Tracts
Mount Rainier View
Newman Addition
North Hill
North Kenmore Acres
Northlake Heights
Oak Knoll #1
Olympic Ridge
Olympic View Gardens
Paine Field //l, //2 and #3
Parkwood Lane //I and #2
Peterson Addition
Peter's Skyview Homesites
Pitner Addition
Pontius Park
Pontius Terrace
Poplar Grove
Poplar Terrace
Queensborough #6 and #8
Queensborough Terrace
Queens Estates
Samoea Park
Serene Vale
Shelron View Acres //3
Skyline Hills //2 and #3
Spragues Addition #3
Stardust Lane
Strathmoor
Yes
No
Yes
Yes
Yes
No
No
Yes
No
Yes
No
Yes
No
No
No
Yes
Yes
Yes
No
No
Yes
Yes
Yes
No
No
Yes
Yes
No
Yes
Rainier Vista //I and //2 Yes
Roberts Addition #1 and #2 No
Rogers Estates #4 Yes
Royal Park Addition Yes
Yes
Yes
No
Yes
No
Yes
Yes
Rej ect
Case by Case
Reject
Case by Case
Reject
Reject
Acceptable
Reject
Reject
Rej ect
Acceptable
Reject
Acceptable (sewers in)
Reject
Reject
Analysis Discontinued
Acceptable
Reject
Rej ect
Acceptable
Case by Case
Acceptable
Reject
Analysis Discontinued
Reject
Acceptable
F13
-------
FHA HOME FINANCING
Accepted or Rejected due to Septic Tank Problems
SUBD1VISI0N NAME
Sunrise Heights
Sunrise View
Sunset West #4
Sunset West //5
Trails End
DO WE HAVE
INFORMATION IN HOUSE
Yes
Yes
Yes
Yes
No
ACTION TAKEN
Reject
Acceptable
Acceptable
Reject
Vailor Estates
Vassey Manor
VonBorstell Addition
Yes
No
No
Reject
Wandering Creek i/l No
Warner Heights Yes
Welcome Park Yes
Western Aire #1, #2 and #3 Yes
Willowbrook Yes
Reject
Acceptable
Reject
Case by Case
F14
-------
APPENDIX G
POPULATION FORECAST ACCEPTANCE
G-l
-------
(,i ,ind C.onir.il on ilu- I'.uk • J I b \ (i A venue Sou ih • Se JUlc, W.ish. *>H 1 f)4 • 206 ¦ 464-7000
Puget Sound Council of Governments
A-95
TRANSMITTAL Of FINAL COMMENTS
TO:
Project Sponsor
Dace: December 1, 1977
FROM: Mart Kask, Executive Director
Clearinghouse Identifier:
61-7-09-02
SUBJECT: Final A-95 Review Comments
Other Identifier:
The Puget Sound Council of Governments, as the District Clearinghouse agency
for the Central Puget Sound Region, has completed review and coordination of
your project in accordance with OMB Circular A-95 and the Uniform Washington
State Clearinghouse System.
The project was reviewed by PSCOG against the Goals and Policies for Regional
Development and other pertinent plans and programs. It was also published in
the State Clearinghouse Weekly Statewide Project Notification Log and circulated
to District, State and Federal agencies. In addition, potentially interested local
agencies were notified of the project and invited to comment. Comments from
all agencies are summarized on the attached Clearinghouse Action Form.
Inclusion of the final Clearinghouse Action Form, and any attachments,
with your final submission to the funding agency will constitute compliance with the
requirements of Circular A-95. If additional comments are received from State or
local agencies after the date of this letter, they will be forwarded to you with a copy
directly to the funding agency.
Should you have any questions regarding this review, please contact Barbara Hastings.
A-9.5 Review Coordinator, or the appropriate Subregional Coordinator at (206)
464-7090.
G-2
-------
, Grand Cenlr.il on the I'.tik • "11 f, f irsi Aveniju Souih • Seattle, Wash. 9ft 104 • 206/464-7090
;U^,o
Puget Sound Council of Governments
A-95
XX
Preliminary _ _ _
Final CLEARINGHOUSE ACTION
"unITORm ^LCAklNCHOlSL iUtNTIMUk:
61-7-09-02
STATIi PROGRAM IDENTIFIER:
MULTI-CLEAlUNdHOUSlK IDENTIFIER:
ruojirrm-Lu:
Areawide 201 Facilities Plan
OTHER IDENTIFIER:
,.i I'I.ICAn J;
Citv of Lvnnwood
Fed. CHANT RbQUliST:
STATU FUNDS;
$21,789,238
APPLICANT/OTHER FUNDS:
TOTAL COST:
$21,789,238
Reviewed by: Sno
lomish Subregional Council
On: 11/22/77
PS COG Comments
The proposed project is consistent with adopted regional goals and policies.
Local Comments
Alderwood Water District:, Conforms with Alderwood Water District's
Sewer Comprehensive Plan. Alderwood Water participated in preparation
of said 201 plan.
Snohomish Health District: Supports the above project, because of the urgency
in solving on-site sewage disposal system failures that are occuring within
this area.
Mountlake Terrace, City of: Compatible with local conprehensive plans.
Snohomish County Planning Department: See attached letter, dated October 7,
1977.
State Comments
,. \
None received.
Date: 12/1/77
irector
-------
'.Lev
CQU^TY
DEPAFSTiWlEWT
COUNT V ADM I NIG MIATION HUILDING • LVENCTT, WASHINGTON OOl'OI . (>0G) 2G09311
George F. Sherwin, Jr., Director
October 7, 1977
Mr. Kelly Robinson
Snohomish County SRC
Agriculture Building
Everett, Washington 98201
Dear Kelly:
While this department is supportive of the general findings and conclusions
of the draft Areawide 201 Facilities Plan for the City of Lynnwood, we will
be raising certain questions and seeking some rewording and clarification in
both the Plan EIS and Plan itself.
Topics of concern include population projections, use of improper County com-
prehensive planning documents, lack of addressing applicable Shoreline Manage-
ment Master Program and failure to address pertinent County comprehensive plan-
ning policies.
Inasmuch as the timeframe for A-95 response and response to the Environmental
Protection Agency on the EIS and Plan are not compatible, we would request that
A-95 review be withheld until parties of interest have had tht} full, opportunity
for response to the EIS and Plan. This response will occur before October 31,
1977 and thus a November A-95 review would seem appropriate.
Your consideration is appreciated.
Sincerely, ^ ... \
SNOHOMISH COUNTY PIJ^NLNG^J}EPARTMEN'T.
fA
• V 4 J IsU.'™ 4
"George F. Sherwin, Jr^JUrtc tor
GFS :ca G-4
cc: Board of County Commissloners 4 b-2-
-------
SNOHOMISH COUNTY
PLANNING DEPARTMENT
COUNTY ADMINISTRATION BUILDING • EVERETT. WASHINGTON 98201 • (206) 259-Q3\J
George F. Sherwin, Jr., Director
November 21, 1977
Mr. Kelly Robinson
Snohomish County Sab-Regional Council
Agriculture Building
Everett, Washington 98201
Subj: A-95 for Lynnwood 201 Facilities Plan
Dear Kelly:
Since our A-95 postponement request of October 7th, our department
has had opportunity to respond to Lynnwood and EPA on the draft
Lynnwood 201 Facilities Plan and Environmental Impact Statement.
Our response raised several concerns relevant to the 201 Plan's
treatment of County land use and population projection activities.
Subsequently, we met on November 15th with Lynnwood, DOE and EPA
officials and their consultants to review these matters. We agreed
that certain changes were in order. I have since received from the
consultants proposed rewording and modification of the 201 Plan and
EIS text addressing our concerns (see enclosure).
We find these proposed changes to be adequate and would recommend
approval of the Lynnwood 201 Facilities Plan A-95 subject to their
incorporation in the final documents.
Sincerely,
SN0HCMISH COUNTY PLANNING^PARl^ENT
G*»orge F. Sherwtn, .lr. lUrw t »>r
GFS:cs
Enc. (2)
G-5
-------
U. S. E N V I
jNMENTAI protection C
REGION X
jENCY
Mi
1200 SIXTH AVENUE
SEATTLE, WASHINGTON 98101
PHO^°
REPLY TO
ATTN OF:
April 28, 1977
Mr. W. E. Nims P.E.
Director of Public Works
19100 44th Avenue West
Lynriwood, Washington 98036
Re: C-530688-01-1
Lynriwood Facility Plan
Dear Mr. Nims:
The approach selected using the 1976 Puget Sound Council of Governments
upgraded population projections for your planning area is based on the
best information available and is acceptable to this agency for use in
your facility planning development. I would caution that the Swamp Creek
planning process should consider a possible exceleration in population
growth based on the recent Boeing announcement of substaintial employ-
ment increases. This factor could cause a greater than projected popula-
tion distribution in the proposed 1985 Swamp Creek design planning pro-
jections and should be noted in the Environmental Impact Statement as a
1977 economic impact that may cause modification to the population and
design projection for Swamp Creek.
Sincerely,
CLARK SMITH
Project Officer
Washington Operations Office
cc: R. W. Beck § Associates
Stevens, Thompson, Runyan, Inc.
-------
III'
> t
y i
603 Wait A Street • Yakima, Woihinglon 98902 • 509-453 4833
f. T. OSBORNE, Prmi,dtnl
— STEVENS. THOMPSON &'
RUNYAN, inc.
M^fpnn n
n '{ NOV 21 1977
II 4055 21 st Ave Wp^
UulaSE
~2'Jt CONSULTING ENGINEERS
iealtle, Washington 98)99 • 206-284-0860
REPLY TO :>E*1TL£ OFFICE
November 17, 1977
Mr. George F. Sherwin, Jr.
Director
Snohomish County Planning Department
County Administration Building
Everett, Washington 98201
SUBJECT: LYNNWOOD/ALDERWOOD AREA WIDE 201 FACILITIES PLAN,
G&O 76539
Dear Mr. Sherwin:
In response to your letter of October 25, 1977 and our subsequent
discussions on November 15, 1977, we are herein submitting for
your review and consideration, revised portions of the Area Wide
201 Facilities Plan.
As a result of our November 15th meeting there were five specific
items which this plan was to consider:
1) Provide additional text as to the rationale for using
the 1976 PSCOG population forecasts and indicating that
the population projections were made on an overall drainage
basin basis.
2) Indicate that for purposes of engineering preliminary design
of the trunk sewer and treatment facilities, the total
service area population is assumed to be served and mention
that the future population levels will depend upon the
existing and future land use plans.
3) Include comments regarding other planning activities in the
area, i.e. Alderwood Area Plan, North Creek Plan, and
Shorelines Management.
4) Confirm that the lateral locations indicated on the preliminary
plans for Swamp Creek are illustrated solely for the purpose of
indicating possible future connection points and/or not
representative of final design.
5) Make necessary revisions in the land use plan, Plate II-l, to
reflect current land use programs.
All of these items have been incorporated into the revisions
proposed by the enclosure.
To aid in your review of the enclosed material the amended or
additional portions of the text have been highlighted in yellow.
G-7
-------
Page Two
November 17, 19 77
Items 1 and 2 have been handled by revisions to the text,
pages II-4, II-5 and II-6.
Additional text pages 11-20 through 11-2 3 have been provided
to discuss the planning activities in the area, Item 3.
Additional verbage defining the lateral locations indicated on
the preliminary plans, Appendix Br has been provided in the
preface to Appendix B as requested by Item 4.
The revisions to the Comphrenesive Plan, Plate II-l can not be
provided for review at this time. We have, however, noted in
red those areas which will be revised to reflect the current
land use plans.
As requested, we include herein a xerox copy of a map from the
E.I.S. which shows the existing sewerage systems and will be
included in the facilities plan. It is our understanding that
all other comments included in your October 2 5th letter were
discussed at our meeting, and no additional revisions are
necessary, excepting typographic corrections.
Very truly yours
GRAY & OSBORNE, INC. P.S
Loren Sand
LS: ch
Enclosures
cc: George McCulley
John Wilson, S.T.R
G-8
------- |