14-105671 (2)arr of
�. Federal Way
CITY HALLFILE
33325 8th Avenue South
Federal Way, WA 98003-6325
(253) 835-7000
www.cityoffederalway.com
Kenneth Canfield October 31, 2014
Lakehaven Utility District
PO Box 4249
Federal Way, WA 98063-4249
RE: File #14-105671-00-AD; LAKEHAVEN UTILITY DISTRICT PUMP STATION 33
Landscape Modification, Parcel #292104-9163
Dear Mr. Canfield:
The Community Development Department is in receipt of your letter, dated October 8, 2014, regarding a
proposed landscape modification as part of the Lakehaven Utility District Pump Station 33 project. Your
project includes a proposed 50% reduction in a portion of a required .10' perimeter landscape strip. The
following is a non -binding assessment of your landscape modification request. At the time of formal permit
submittal, the entire proposal will be evaluated against applicable code and a formal determination with regard
to the proposed landscape modification will be made.
CODE REQUIREMENT
In accordance with Federal Way Revised Code (FWRC) 19.125.100, modifications to the landscape code can
be administratively approved by the Director of Community Development. Your proposal as described in your
October 8th letter appears to qualify as a "special condition" per FWRC 19.125.100(c) (compliance with
special easements) and (e) (unique site uses).
Your proposed landscape modification is to utilize FWRC 19.125.100(5): "Perimeter landscape strips may be
averaged, provided the minimum width shall not be less than 50 percent of the underlying width requirement."
You have indicated your ability to supplement the area of landscape reduction elsewhere on the site.
As required in FWRC 19.25.100.8, at time of permit submittal please provide the appropriate application
materials to address the landscape modification and show on the landscape plan the specific areas of reduction
and addition (in square feet for clarity). As a reminder, this project requires a Use Process IV submittal due to
land surface modifications within regulated wetlands and buffers, and a State Environmental Policy Act
(SEPA) checklist. Due to the potential presence of wetlands both on- and off -site a wetland report will be
required as part of the permit submittal; see enclosed FWRC 19.175 regarding wetlands for further details.
CLOSING
We look forward to working with you on this project. Any questions concerning your application may be
directed to Stacey Welsh, at 253-835-2634 or Stacey.welsh@cityoffederalway.com.
Sincerely,
Isaac Conlen
Planning Manager
enc.
Letter dated October 8, 2014
FWRC 19.175
14-105671 Doc. I.D. 67178
,�Nt_ L4 - 1115
LAKEHAVEN UTILITY DISTRICT
o 31627 15` Ave South • P.O. Box 4249 • Federal Way, Washington 98063-4249
��� Federal Way: 253-941-1516 • Tacoma: 253-927-2922
www.lakehaven.org RECEIVED BY
tL11tY DIST1� COMMUNITY &ECONOMIC
October 8, 2014 DEVELOPMENT DEPARTMENT
Isaac Conlen, Planning Manager PV r-f s��an 3-3 OCT 10 2014
City of Federal Way tea„ �p (%4,Wj
P.O. Box 9718
Federal Way, Washington 98063-9718 o S
Ref: Lakehaven Utility District Pump Station 33 — 50 Percent Reduction of a Portion of
the Landscape Strip
Dear Isaac:
This correspondence is a follow-up to a meeting I had with you regarding constructing a
portion of the new Lakehaven Utility District Pump Station within the 10 foot perimeter
landscaping strip. The zoning for the area is Suburban Estates. The District acquired
0.78 (parcel number 292104-9163) acres for the pump station.
Because of groundwater issues, the District is proposing installing the 30 inch gravity
sewer line between Pac Hwy and the pump station in a bored casing using micro -
tunneling technology. This methodology will greatly reduced the amount of dewatering
required to construct the 30 inch pipeline. The boring alignment has to be a straight line
from Pac Hwy to the pump station. The existing locations of the District's property,
easements, and a house owned by Mr. Don Barovic limits the boring alignment corridor
possibilities. In order for the District to be able to use this boring technology, the pump
station must be located 5 feet into the 10 foot wide perimeter landscaping strip as
shown on the attached drawing. According to section 19.125.100 Modification Options
(5) of the Federal Way Revised Code, "Perimeter landscaping strips may be averaged,
provided the minimum width shall not be less than 50 percent of the underlying width
requirement". The 50 percent landscape strip reduction would be located between the
20 foot access gates.
The portion of the District property to be used for the pump station site will be fenced.
Two 20 foot gates will be installed on either side of the pump station to allow
maintenance staff to access the site using a circular driveway.
The pump station site is not be visible from PAC Hwy to the east or the Brooklake
Community Church to the north. The parcel to the south is primarily wetlands and trees,
and most likely will never be developed. Mr. Barovic owns the homes to the east and
west of the pump station site. The house to the east is adjacent to the pump station
site. The house to west is located west of Hylebos Creek. I would propose increasing
the landscape strip width along the east and west sides of the District property to offset
the 50 percent reduction between the two access gates.
Leonard D. Englund Charles I. Gibson Timothy A. McClain Donald L.P. Miller Ronald E. Nowicki
Commissioner Commissioner Commissioner Commissioner Commissioner
October 8, 2014
Page 2 of 2
You indicated that you could provide a non -binding written response that the proposed
pump station could possibly be located in the landscape stripe, provided that intent of
City of Federal Way Revised Code Section 19.125.100 is met. You also said that you
would offer suggestions to meet of the City of Federal Way revised Code, if the rational
presented in this letter is not adequate. It is our understanding that a final binding
decision would not be provided by the City until after the project has been submitted for
review.
The District is nearing the completion of the pump station design and anticipates
submitting it to the City for review by December this year.
Should you need any additional information or have any questions, please contact me.
Sincerely,
Kenneth R. CanfOd
Project Engineer, P.E.
Enclosure
Cc: File
Leonard D. Englund Charles I. Gibson Timothy A. McClain Donald L.P. Miller Ronald E. Nowicki
Commissioner Commissioner Commissioner Commissioner Commissioner
w
0
� )
5309 Shilshole Avenue NW
Suite 200
Seattle, WA 98107
206.789.9658 phone
206.789.9684 fax
memorandum
date March 25, 2015
to Kenneth Canfield, Lakehaven Utility District
from Claire Hoffman and, Michael Muscari
subject Wetland Delineation on parcel 2921049088
www.esassoc.com
Introduction
Environmental Science Associates (ESA) was contracted by the Lakehaven Utility District (LUD) to
conducte a wetland reconnaissance and partial delineation of the property (Tax Parcel 2921049088) on
the corner of Pacific Highway South and South 359th Street in Federal Way (the property). The LUD is
considering purchasing this property for a potential relocation of the existing pump station on the
adjacent property.
Background Information
ESA performed a review of existing information regarding wetlands and streams. Sources of
information included current aerial photographs, City of Federal Way maps, and National Wetland
Inventory (NWI) data. The majority of the property is mapped by NWI as palustrine forested wetland,
with the exception of the eastern edge (USFWS, 2015). The City of Federal Way Critical Area Map
shows the entire property as a wetland with a stream on the western edge (Federal Way, 2012). The
Spring Valley Open Space lies to the north and south of the property and a fish bearing tributary to
Hylebos Creek runs north/south on the adjacent property to the east (Federal Way, 2008).
Wetland Delineation and Reconnaissance
On February 10, 2015 Claire Hoffman and Michael Muscari from ESA conducted a wetland delineation
and reconnaissance of the property. During this site visit, ESA staff and Ken Canfield (LUD) walked
the perimeter of the property as well as a diagonal path through the center of the property to observe and
assess wetland conditions. A second site visit was conducted on February 13, 2015 by Michael Muscari
and Scott Olmsted to complete data collection. The wetland was identified and delineated based on
conditions at the time of the field visit by applying the wetland determination method described in the
Regional Supplement (Western Mountains, Valleys, and Coast) to the Corps of Engineers 1987 Wetland
Delineation Manual Corps (Corps, 2010). A Trimble Geo-XT GPS unit was used to record the location
of the eastern wetland boundary, the remaining boundary was estimated. The wetland was classified
according to the Washington State Department of Ecology's (Ecology) Wetland Rating System for
Western Washington (Hruby, 2014) and City of Federal Way Revised Code (FWRC 19.175.020).
Several data plots were established along the eastern property boundary in order to delineate the wetland
boundary. Wetland indicators were present for hydrology, vegetation, and soils at each plot determined
to be within the wetland boundary. Soils were saturated from the surface to a depth of at least 16 inches.
Dominant vegetation consisted of wetland tolerant species. Soils exhibited hydric soil characteristics
including redox dark surface and depleted matrix.
The wetland on the property is part of a larger wetland complex (>30 acres), which includes a tributary
to Hylebos Creek and extends from approximately South 359th Street to just north of South 373rd Street
between Pacific Highway South and I-5. Just north of South 373rd Street, the tributary joins West
Hylebos Creek. Figure 1 shows the extent of the wetland on the subject property. The wetland covers
the majority of the property with a narrow section on the eastern edge of uplands along the paved
driveway to the existing pump station. The wetland on the property is forested with many large trees
including Western red cedar, Douglas fir, red alder, and vine maple. The dominant shrub is
salmonberry, which provides moderately dense cover. Skunk cabbage and other native herbaceous
plants are common throughout the site. The eastern edge of the wetland is emergent wetland as the
wetland extends out of the forest into the driveway easement. This area is dominated by various grass
species, including reed canary grass and soft rush.
Shallow groundwater appears to be the primary source of hydrology to the wetland. There are also at least
three culverts draining into the subject property. Two carry water under South 359`h Street from the wetland to the
north; one near the one-third point (from the intersection of Pacific Highway and South 359`' Street) of the north
property boundary, a second near the northwest corner of the property, and a third under Pacific Highway South
near the mid -point of the west property boundary. At the time of the site visit the culverts had low flow. The
water emerging from the northwestern culvert and the northerly culvert appear to merge and cross as a stream
through the center of the property. A constructed ditch (likely decades old) runs approximately the length
of the property near the southern boundary and is likely connected to the aforementioned western
culvert.
Under FWRC 19.175.020, this wetland would likely be considered a Category I because it has high
function for wildlife habitat, water quality improvement, and hydrologic support. Habitat complexity is
apparent because the wetland has three or more wetland classes, one of which is open water. Open water
and emergent wetland classes are visible on aerial photography to the south of the subject property.
Although these portions of the wetland are not on the subject property they are part of the wetland unit
and thus considered in the rating. Structural complexity in the vegetation community also provides a
high level of wildlife habitat functions. Ecology's rating system also categorizes it as a Category I
wetland. Federal Way requires a 200-foot buffer around Category I wetlands (FWRC 19.175.020).
References
Corps (U.S. Army Corps of Engineers). 2010. Regional Supplement to the Corps of Engineers
Wetland Delineation Manual: Western Mountains, Valleys, and Coast Region. Version 2.
Wetlands Regulatory Assistance Program. May 2010. ERDC/EL TR-10-3.
http://www.usace.army.mil/CECW/Documents/cecwo/reg/west_mt finalsupp.pdf.
Federal Way. 2008. Current Land Use Map. Accessed March 24, 2015. Available at
http://www.cityoffederalway.com/DocumentCenter/HomeNiew/457.
Federal Way. 2012. Critical Areas Map. Accessed March 24, 2015. Available at http://wa-
federalway.civicplus.com/DocumentCenter/HomeNiew/460.
Hruby, T. 2014. Washington State Wetland Rating System for Western Washington — 2014 Update.
Ecology publication number 14-06-029. Olympia, WA.
USFWS. 2015. National Wetlands Inventory Wetland Mapper. Accessed March 24, 2015. Updated
May 1, 2014. Available at: http://www.fws.gov/wetlands/Data/Mapper.html
Photographs
{Y y� S• �i
,f^• r i- ��=. f j_xp- ,.ram:• ... ••j
i, •� � �., r .. �L �'I]�v _\ t , - �,� - L ._ ---•tea r,�.w..,•� �
�1 � ..1_y: � 'l 1 {: �y. ram'^ •�.1 ti`.�c�
�� .. `I it � � ,kY � � !• � •- J
Photo 2. Eastern edge of wetland along driveway easement, facing
north (February 13, 2015).
south (February 13, 2015).
SOURCE: ESA 2015, OSM 2014, King County 2014, ESRI
2013
Lakehaven Pumpstation. 206061.14
Figure 1
Lakehaven Utility District Pump
Station Investigation Site
5309 Shilshole Avenue NW vMv.adolison.coni
Suite 200
Seattle, WA 98107
206.789.9658 phone
206.789.9684 fan
date August 14, 2009
'To Ken Canfield; Lakehaven Utility District
from Laura Brock and Michael Muscari
subject Lakehaven Utility )(District, )3arovic Property (Pa reel 2921049098) Critical Areas (Delineations,
Federal Way, Washington
ESA Adolfson is pleased to present our critical areas delineations findings for the Barovic Property (King County
Parcel 2921049098), located at 35929 Pacific Highway South, approximately 600 feet west of the intersection of
Pacific Highway South and S. 359th St, in Federal Way, Washington (NW '/a, Section 29, Township 21N, Range
4E; Figure 1). ESA Adolfson conducted these critical areas delineations at the request of Lakehaven Utility
District (LUD), which is considering the parcel as a possible location for a utility corridor associated with the P33
Pump Station.
The property is accessed from a gravel driveway on the adjacent parcel to the east (King County Parcel
2921049020) and is currently developed with a single family residence and several associated outbuildings
(Figure 2). In addition to the single family residence, the property is also used for grazing small livestock (goats
and chickens) and tree harvesting. A mix of open -canopy forest, closed -canopy forest, and meadows covers the
property. The property slopes down from the east and west towards a stream which flows through the center of
the property. Two small bridges provide access to the residence, which is located west of the stream.
ESA Adolfson previously conducted delineations on a parcel to the east (King County Parcel 2921049020); the
results of those investigations were also used during this study.
Methodology
ESA Adolfson biologists Michael Muscari,and Laura Brock conducted wetland and stream delineations on the
Barovic property on June 25, 2009. Biologists Laura Brock and Rosemary Baker made a return site visit on June
30, 2009 to complete the delineations. Wetland boundaries were delineated using the Washington State Wetlands
Identification and Delineation Manual (Washington Department of Ecology, 1997) and the Western Mountains,
Valleys, and Coast Interim Regional Supplement (US Army Corps of Engineers, 2008). Wetland boundaries were
marked with pink "Wetland Boundary" flagging tape, and data plot locations were marked with orange flagging
tape. Stream boundaries were marked with blue and white striped flagging tape along the ordinary high water
marls (OHWM). The flagged wetland and stream boundaries were professionally surveyed by INCA during July
2009. Critical area categories and buffer requirements were determined using Federal Way Revised Code
(FWRC) Title 19, Division V—Critical Areas.
Lakehaven Utility District, Barovic Critical Areas Study
August 14, 2009
Findings
Four wetlands (Wetlands 4, 5, 6, and 7) and one stream (Stream 2) were delineated on the Barovic property
(Figure 2). Additionally, small wetlands were identified extending east and west approximately five to 15 feet
upslope of the stream OHWM, where groundwater was emerging as seeps. These seeps are located between
Wetlands 4 and 5, in the central portion of the property. These wetlands were not delineated because they
appeared to be less than 2,500 square feet in size, below the regulatory threshold in Federal Way, and are entirely
contained within the stream buffer. A description of the delineated wetlands, stream, and uplands follows.
Wetland Descriptions
Wetland 4
Wetland 4 (estimated to be greater than one acre), located along the southwestein edge of the property, is a
palustrine, forested wetland adjacent to the stream running through the center of the property (Figure 2). The
portion of the wetland that is on the Barovic property slopes down, to the south and east towards Stream 2. Red
alder (Alnus rubra) provides tree canopy over the majority of the wetland. Salmonberry (Rubes spectabilis),
stinging nettle (Urtica dioica), skunk cabbage (Lysichiron ramericanum), lady fern (Athryivm felix fenzina), and
giant horsetail (Equisetunz telrnateia) are the dominant plants in the understory. Wetland 4 receives water
primarily from a high groundwater table, and exhibits characteristics of both depressional and slope
hydrogeomarphic classes. On the June 25 and 30, 2009 site visits, soil within a large portion of the wetland
interior was saturated to the surface. Water leaves the wetland primarily through the stream. Soil within Wetland
4 met requirements for hydric soil indicator F1, Loamy Mucky Mineral. A black (10 YR 2/1) mucky modified
mineral layer greater than four inches deep was observed throughout the wetland. The wetland continues off -site,
to the south.
Wetland 5
Wetland 5 (estimated to be greater than 1 acre), located on the northwestern portion of the property, is a
palustrine, forested wetland adjacent to Stream 2 (Figure 2). The majority of the wetland continues off -site to the
north. The portion of the wetland on the Barovic property slopes down to the east and west towards the stream.
Red alder douunates the canopy cover of the wetland; several Iarge alders and a large hemlock, which appeared to
be greater than 21 inches in diameter, were observed in the wetland off -site to the north. Water parsley (Denanthe
sarmentosa), skunk cabbage, and salmonber7ry dominate the understory. Wetland 5 receives water primarily from
a high groundwater table and from small off --site streams running into Stream 2. During the June 25 and 30, 2009
site visits, soil was saturated to the surface or was observed to have.several inches of flowing water present.
According to hydrogeomorphic classification, the wetland exhibits riverine and slope hydrogeomorphic
characteristics. Steam 2, a tributary to West Hylebos Creek, is the wetland's inlet and outlet. On the Barovic
property, soil within Wetland 5 met requirements for hydric soil indicators Al 1, Depleted Below Dark Surface,
'and F3, Depleted Matrix. A black (10 YR 2/1) silt loam was observed in the surface layer, and gray (2.5 Y 6/1)
silt with dark yellowish brown (10 YR 516) and strong brown (7.5 YR 4/6) redoximorphic features was observed
in the subsoil. The wetland interior was observed to have organic soil.
Wetland 5 is separated from wetlands contiguous with the West Hylebos Wetland Park, a Category 1 wetland
complex, by the road bed fill supporting S. 356111 Street; off -site to the north of the property. However, Stream 2,
9
M
Lakelraven Utility District, Barovic Critical Areas Stud)I
August 14, 2009
a tributary to West Hylebos Creels provides a comiection between these wetlands byway of a culvert beneath the
roadway.
Wetland 6
Wetland 6 (2,059 square feet), located within a ditch running east to west along the north side of the residence, is
a palustrine emergent wetland (Figure 2). Velvet: grass (Holcus lanaw) and creeping buttercup (Ranuneulus
repens) dominate the wetland, with a few red alders lining the ditch. An eight -inch culvert, located at the west
end of the wetland, is the wetland's inlet. Wetland 6 receives water primarily from surface flows from the
surrounding area and presumably flood flows from Wetland 5. Water from the wetland flows through the ditch
and into Stream 2. According to hydrogeomorphic classification, the wetland exhibits riverine hydrogeomorphic
characteristics. During the June 25 and 30, 20o9 site visits, soil was saturated to the surface in the wetland
interior. Soil within Wetland 6 met requirements for hydric soil indicators All, Depleted Below Dark Surface,
and F3, Depleted Matrix. A very dark brown (10 YR 2/2) sandy Ioam was observed in the surface layer, and gray
(2.5 Y 511) silt with dark yellowish brown (10 YR 4/6) and strong brown (7.5 YR 416) redoximorphic features
was observed in the subsoil.
Wetland 7
Wetland 7 (257 square feet), located in a small depression in the southeast portion of the property, is a palustrine
emergent wetland (Fig= 2). Timothy grass (Phlown pratense), creeping buttercup, and bentgrass (Agrosfis sp.)
dominate the wetland. Red alders sparsely sir Tound the depression. Wetland 7 receives water primarily from
surface flows from the surrounding area. According to hydrogeomorphic classification, the wetland exhibits
depressional hydrogeomorphic, characteristics. An outlet is present at the west edge of the wetland, where a ten -
inch culvert directs water flow under a gravel roadway and onto an adjacent slope. During the June 30, 2009 site
visit, water was observed seeping into the soil pit at 20-inches. We assume that the water table is higher earlier in
the growing season. Soil within Wetland 7 met requirements for hydric soil indicator F1, Loamy Mucky Mineral.
:,A. modified mucky loans was observed to a depth of 20 inches within the wetland.
According to FWRC 1.9.175.020, Wetland 7 is not regulated by the City of Federal Way because it is less than
2,500 square feet.
Stream Description
Stream 2 (West Fork of Hylebos Creels) is approximately five to ten feet wide where it flows through the center of
the property north to south (Figure 2), The stream meanders through forest at the north end Of the property, and
fine silts, sands and small gravels forin the st varn substrate. At the center of the property, the stream enters an
incised ravine with no shade cover. The ravine extends approximately 500 feet through the center of the property,
and continues off -site to the south. Large cobbles and gravels form the stream substrate, which was covered with
algae in June 2009. As the stream continues to the south, stream bank incision increases and signs of bank
erosion are prevalent. Farther to the south, the stream reenters forest. Riffles and pools were observed along the
southern portion of the stream within the forest. Stream 2 is documented to support anadromous sahnonids.
Lakehaven Utility District, BarovicCritical,lreasStudy
ktgust 14, 2009
Upland Description
Uplands on the Barovic property generally consist of open -canopy forest, closed -canopy forest, and meadows.
Red alder, big leaf maple (Ater rnacrophyllum), black cottonwood (Populus balsoinijera), Douglas fir
(Psuedotsuga rnen:iesii), Western red cedar (Tln ja plicata), and western hemlock (Tsuga heterophylla) line the
edges of slopes and previously cleared areas of the property. Hunalayan blackbeny (Rubus aremeniacus),
snowberry (Symphoricwpos albus), and salnronberry were observed in the forest understory along the edges of
clearings. Meadows dominated by Timothy, velvetgrass, and bentgrass are located in the central portion of the
property, with tree islands interspersed throughout.
Conclusion and Summary
Portions of four wetlands (Wetlands 4, 5, 6, and 7) and one stream (Stream 2) were delineated and classified for
this investigation. A summary of these critical areas and their buffer requirements is given below and in Table 1..
Required buffers are shown on Figure 2.
GPetland Categories
According to FWRC 19.175.020, Wetland 4 is considered a Category 2 wetland because it is estimated to be
greater than one acre in size and is contiguous with Stream 2, which supports anadromous sahnonids. According
to FWRC 19.175.020, Wetland 5 is considered a Category 1 wetland because of its association with Stream 2,
which has documented anadromous sahnonid fish presence. The small tributaries which flow into Stream 2 likely
contain fish habitat as well. Additionally, the wetland appears to be a mature forested wetland (trees greater than
21 inches in diameter) as defined by the Washington Department of Fish and Wildlife (WDFW), which provides
irreplaceable ecological functions and local significance. According to FWRC 19.175.020, Wetlands 6 and 7 and
the wetland seeps adjacent to Stream 2 are not regulated by the City of Federal Way because they are less than
2,500 square feet. The City of Federal Way does not regulate wetlands less than 2,500 square feet in size,
regardless of whether the wetland is isolated or connected to a water body. Therefore, even though Wetland 6 and
the wetland seeps are contiguous with Stream 2, they are not regulated by the City and have no buffer
.requirement. The seeps are located entirely within the Stream 2 buffer.
Table 1. Wetland Summary Table
Wetland
ID
Estimated
Total Area
Cowardin
Class
HGM Class
'Wetland Category
Buffer
Require exit
4
> 1 acre
PFO
Depressional/Sloe
_
2
100 ft.
5
> 1 acre
PFO
R_ iyerine/Slope
1
200 ft.
6
< 2,500 s . ft.
PEM
Riverine
Not regulated by the City
n/a
7
< 2,500 s . ft.
PEM
Depressional
Not regulated by the City
n/a
Stream Rating
According to the City of Federal Way, the stream is rated as a major stream (Federal Way, 2005). The FWRC
19.05.130 defines a major stream as "any stream, and the tributaries to any stream, which contains or supports, or
Lakehaven Utility District, Barovic CriticalflreasStudy
flz(gust 14, 2009
under normal circumstances contains or supports, resident or migratory fish." According to FWRC 19.16,5.010,,
major streams require a 100-foot buffer.
Limitations
Vithin the limitations of schedule, budget, and scope -of -work we warrant that this study was conducted in
accordance with generally accepted environmental science practices, including the technical guidelines and
criteria in effect at the time this study was perforined. The results and conclusions of this report represent the
authors' best professional judgment, based upon site conditions present at the time of the investigation and
information provided by the project proponent in addition to that obtained du�iug the course of this study. No
other waitnanty, expressed or implied, is made.
Thank you for the opportunity to prepare this material for you. If you have any questions, please call 206-789-
9658.
Attach)nents
Figure 1: Site Vicinity Map
Figure 2: Wetland Map
References
Federal Way. 2005, Stream Ratings Map. Accessed at:
htt -. xvwww.citvoffederalwa .coin/folders/liomelbusinesseconamicdevela nient/ci (pia s/enviroiuneneattu
aaslstreanis.pdf
US Army Corps of Engineers. 2008. Western Mountains, Valleys, and CoastInferirn Regional Supplement..
Washington Department of Ecology. 1997. Washington State Wetlands Identification and Delineation Manual.
Ecology Publication #96-94.
Lakehaven Design .26061.2
SOURCE: ESAAdolfson, 2009; IGng.County, 2008 (2002Air Photo) Figure I
Vicinity Map
federal Way, Washington
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5309 Shilshole Avenue NW www.adolfson.com
ESSuite 200
Seattle, WA 98107
206.789.9658 phone
206.789.9684 fax
date March 19, 2009
to Kenneth R. Canfield, Project Engineer
Lakehaven Utility District
31623 1" Ave South
Federal Way, WA 98063-4249
-from Michael Muscari, Senior Wetland Scientist
Rosemary Balser, Project Scientist
subject LUD Project 5204401 and 5205503, Amendment, Task 4 Barovic Property Wetland Study
Background
At the request of the Lakehaven Utility District, BSA Adolfson, Inc. (Adolfson) identified and delineated
wetlands within the 1.8-acres Barovic Property located at 35935 Pacific Highway South (I-99) in Federal Way,
Washington (SW quarter Section 29, Township 21N, Range 4E) (Figure 1). This parcel is being considered as a
possible location for the P33 Puinp Station.
The Barovic property lies on a relatively flat upland bench between tributaries of the Hylebos Creel-, Watershed.
The surrounding area remains as a forested and relatively undeveloped section of land along the Pacific Highway
South corridor. Some residential development occurs within 1,000 feet of the property. West Hylebos State Park
lies within a quarter mile to the north, east, and south. A single-family residence with several out buildings are
.located on the east end of the Barovic property, and a wooden roof was recently constructed over an existing well
east of the home. Two gravel driveways enter the property from Pacific Highway South, converging into one
driveway approximately 500 feet west of the entrance.
Methods
T�vo levels of investigation were conducted for the analysis of wetlands on the subject property; a review of
existing information and an on -site investigation.
Several;esources were reviewed:
0 U.S. Geological Survey (USGS), 196�1—Poverty Bay, WA. Topographic map;
Q National Wetland Inventory (NWI) Poverty Bay quadrangle (U.S. Fish and Wildlife Service (USFWS),
1989);
C. WDFW Priority Habitats and Species (PHS) Data, October 2008;
o City of Federal Way Wetlands Inventory mapping (2005).
.lurisdictional wetlands were identified based on field conditions observed at the time of the investigation and
applying the wetland determination method described in the Washington State Wetlands Identification and
Deli7ieation Manzral (Washington Department of Ecology publication No. 96-94, 1997). The Federal Way
Municipal Code (FWMC) definition of regulated wetlands and buffers (FWMC 22.1356 and FWMC 22.1) was
used to further determine regulatory constraints on the site. Areas meeting the three parameters required for
wetland determinations were flagged or recorded with Global Positioning System (GPS) datapoints.
Biologists Michael Muscari and Rosemary Balser from ESA Adolfson began the site investigation on February 4,
2009, and biologists Rosemary Baker and Laura Brock finished on February 5, 2009.
INE
Existing information
Data from the NWi/USFWS Wetlands Online Mapper does not indicate wetlands on the Barovic property,.
however immediately to the south a large palustrine forested wetland is mapped. As depicted by this map, the
wetland to the south connects to a tributary of West Hylebos Creels. According to WDFW PHS data there are no
wetlands or priority habitats or species located on the property. PHS data does indicate an off -site salmon -bearing
tributary of West Hylebos Creels and Hylebos Wetlands to the north, west, and south of the property within one
quarter -mile. Hylebos stream and wetland buffers do not extend on to the Barovic property.
City of Federal Way Wetlands Inventory Mapping data (2005) also indicate a wetland on the parcel to the
immediate south of the Barovic property, but no wetlands are mapped on the project site.
Wetland A
Wetland A is located on the property between the residence and Pacific Highway South (Figure 2) and is
approximately 0.09-acres in size. Wetland A has a hydrogeomorphic (HGM) class of slope with both forested
and scrub -shrub vegetation. Data plot (DP) 1 and DP3 describe the wetland. Data plot 2 is located in the adjacent
upland. A small stream uriginates in the wetland (see stream description below).
Hykolo The source ofhydiology for Wetland A appears to be a groundwater -fed spring, as well as
precipitation, and stormwater runoff originating from the house and driveways. A small ditch originating from
the north driveway extends south through Wetland A, connecting to the on -site stream (see stream description
below). No surface ponding or flowing water was observed in this ditch duringthe survey:
Data Plot 1 was located in a relatively flat area along the south edge of the wetland, within one toot of the flowing
stream. Wetland hydrology indicators included saturation at 8 inches below the surface and a hydrogen sulfide
odor. Data Plot 3 was located at the sloped north end of Wetland A. Saturation was present at the surface, and
free water in the pit was found at 8 inches below the surface. An additional indicator of wetland hydrology at
DP3 was hydrogen sulfide odor.
Soils At DP 1, the soil matrix was black (IOYR 211) sandy loath from the surface to a depth of 3 inches. 13etweetn
3 and 13 inches below the surface, the soil was gravelly sandy loan with a black (IOYR 2/1) matrix color. Saprie
peat was found at a depth of 22 inches. Hydric soil indicators at DPI include a thick dark surface layer and low
chrorna below the surface horizon.
At DP3, the soil was very dark brown (1 OYR 2/2) mucky sandy loam from the surface to a depth of 4 inches.
From 4 to 8 inches in depth, the soil was a very dark brown (1OYR 2/2) sapric muck, with a few pieces of
Undecomposed wood. From 8 to 18 inches in depth; the soil was a black (IOYR 2/1) gravelly sandy loaitz. The,
hydric soil indicator at DP3 was a histic epipedon.,
Ve� e�tation Wetland A contained a forested vegetation community. Dominant vegetation at DPI was red alder
(rAlnus i•adira), salmonberrY (nubus spectabilis), and creeping buttercup (Ra?wncuhis repens). Dominant
vegetation at DP3 was red alder (Alnus rubra), salmonberry (Rebus spectabilis), lady fern (Ath}rriuiit frlix,fewina),
and creeping buttercup. Other hydric vegetation observed in the wetland included small -fruited bulrush (Schpus
nliai Qcarpus), youth -on -age (Tolrirei4 memzaiesii), mannagrass (Glyceria spp.), Nootka rose (Rosa nuLkana), red
elderberry (5ainbucus racemosa), and slcunk cabbage (Lysichito,z ajnerfcanum). The wetland vegetation criterion
was met, as 100 percent of the dominant plants were hydrophytic species.
Wetland B
Wetland 13 is approximately 0.01-acres in size, positioned at the northeast corner of the property, abutting both.
Pacific Highway South and a paved driveway (Figure 2). A very small portion of this wetland extends on to the
adjacent parcel to the north. The wetland and surrounding upland appeared to have been recently mowed, grazed,
and seeded with grasses. Some mowed shrubs were present in areas. Wetland B is a palustrine emergent wetland
in the depressional HGM class. Data Plot 4 characterizes the wetland and DP5 characterizes the upland.
H droloa The source of hydrology for Wetland B appears to be a combination of precipitation and starrnwater
from a ditch along the gravel driveway, and possibly runoff from Pacific Highway South. Groundwater discharge
may also occur in the wetland. At DP4, saturation was present at the surface and 2 inches of surface water was
present in what appeared to be a wheel rut.
Soils At DP4, the surface soil to a depth of 18 inches was 45 percent very dark gray (10YR 3/1) and 45 percent
black (10YR 211) gravelly sandy loam, with 10 percent pockets of sand located at 12 inches below the surface.
Below 18 inches in depth, the matrix color was gleyed greenish gray (10Y 511) sandy loan with cobble and
undecomposed organic matter, with 1 percent light olive brown (25Y 516) redoxirnorphic features.
V tion Wetland B vegetation is predominantly emergent with a few inowed or grazed shrubs on the west
side. Dominant species were small -fruited bulrush, bittercress (Cardamine spp.), sahnonberry, and Himalayan
blackberry (IRubus ar me-niamq). Small amounts of reed canary -grass (iahalaris cm-undinacea) and American
speedwell (Veronica annericana) were also present.
Wetland C
Wetland C is located along the south property boundary and extends south of the Barovic Property (Figure 2).
Only a small portion of this wetland is located on site. The north edge of this wetland lies within 10 to 20 feet of
the south property line for most of the parcel. The on -site portion of Wetland C is approximately 0.01 acres in
size and appears to be a depressional HGM class wetland with forested and shrub -scrub vegetation. Data Plot 9
describes the wetland however observations were limited by lack of access to the neighboring property. Data Plot
6, DP7, and DP8 describe the upland,
Hydrology Based on reference with allSGS topographic map, NWI maps, and visual survey from the Barovic
property, the predominant wetland hydrology in Wetland C appears to be precipitation and groundwater
discharge. In addition, a small stream (described below) originating in Wetland A enters the northeast corner of
Wetland C augmenting hydrology in the east portion of the wetland.
Based upon review of existing information (USGS topographic maps, and NWI mapping) Wetland C is located on
a bench above a tributary of West Hylebos Creek to the west. NWI/USFWS maps indicate a surface connection
between Wetland C and West Hylebos Creek and other nearby Hylebos wetlands. However, based on review of
topographic maps and visual survey in the field, a north -south ridge appears to separate Wetland C fiom West
Hylebos Creek. Although NWI and WDFW PHS streams and wetland xnapping both indicate a hydrologic
connection to the Hylebos tributary to the West, the City of Federal Way Wetland Inventory Map and the
observed ridgeline to the west indicate a hydrologic connection to the east of Pacific Highway South. We
observed surface water from Wetlands A and C flowing east into a culvert beneath Pacific Highway South. A
hydrologic connection between Wetland C and.Hylebos Creek or Hylebos Wetlands to the south is also possible
but is'not known at this time due to lack of access to the site.
Small areas of ponding were observed just off -site to the south, surface saturation was present, and the water table
occurred at 6 inches below the surface on the project site. Other hydrologic indicators included water -stained
leaves and drainage patterns. An outlet was observed from the eastern edge of the wetland, with water flowing
east into a 1-foot diameter culvert as described below.
Soils Wetland soil was black (10YR 2/1) muck from the surface to 18 inches in depth. The soil was henuc in
texture with undecomposed wood throughout. Below 18 inches, the matrix color was light gray (2.5Y 7/1) with
less than 5 percent yellow (5Y 7/6) redoximorphic features. Hydric soil indicators included a histic epipedon,
thick dark surface, and a hydrogen sulfide odor. A gravelly sand restrictive layer was also found at 18 inches.
Veaetation Observed vegetation in Wetland 3C include forested and shrub -scrub communities. Forested portions
of Wetland C were dominated by red alder, salmonberry, Indian plum (Oenderia cerasiformus), and red
elderberry (Sanibucus racemosa) and false -lily -of -the -valley olianthenmum dilatatuin). Shrub -scrub portions of
Wetland C were dominated by red -osier dogwood (Corpus sericea), willow (Salix sp.), and Hardhack (Spiraea
douglasii). The wetland also contained numerous wildlife habitat features such as fallen logs and snags.
Stream
The onsite spring fed stream, originating in Wetland A, flows south out of the wetland through a small (four inch -
diameter) culvert under the south gravel driveway, and drains south into adjacent Wetland C (Figure 2). After
2
entering Wetland C, the stream turns east and enters a ditch along Pacif c Highti��ay South. On -site, the stream
contained a muddy substrate and width varied between 1 and 3 feet.
Regulatory implications
Wetlands are regulated atthe federal, state, and local levels. Agencies with jurisdiction include the U.S. Army
Corps of Engineers (Corps), Washington State Departinent of Ecology (Ecology), and the City of Federal Way.
The Washington Department of Fish and Wildlife regulates warlc within streams. Regulatory implications
associated with development in wetlands include, but may not be limited to, those discussed in this section. All
applicable permits should be obtained prior to developuig or otherwise altering streams or wetlands.
Federal Regulations
The Corps regulates discharges of dredged or fill materials into waters of the United States, including wetlands,
tinder Section 404 of the Clean Water Act. The Corps has established two types o f perinit programs under
Section 404: nationwide and individual. Nationwide permits are issued when a proposed activity will have
minimal adverse impacts to wetlands, All other projects are evaluated under the individual permitting process.
The Corps determines which permitting process is used for a proposed project. The Corps will require that
wetland impacts be avoided or minimized to the extent practicable, and mitigation will likely be required for
unavoidable wetland irnpacts.
State Regulations
The state certification process under Section 401 of the federal Clean Water Act is usually triggered through a
Section 404 permit application. Section 401 directs each state to certify that proposed in -water activities will not
adversely affect water quality or violate state aquatic protection laws. In Washington state, Ecology is
-responsible for administering the state certification program. Ecology may issue approval, approval with
conditions, denial, or a request for delay due to lack of information. And conditions attached to the 401
certification become part of the Section 404 pen -nit.
-ICing County is one of the 15 coastal counties in Washington regulated under the Washington State Coastal Zone
Management (CZM) Program. Activities that would affect coastal resources and involve approvals fiom the
federal government (such as a Sectioa404 permit) must be evaluated for CZM compliance through a process call
"federal consistency." The Washington State Department of Ecology administers the CZM program in this state.
If relocation or alteration of stream culverts or other in -stream work is proposed as part of the project, aHydraulic
Project Approval (HPA) would be required from the Washington Department of Fish and Wildlife under the state
Hydraulic Code (RCW 77.55, WAC 220-110).,
Local regulations
The Sarovic property is Jocated within the City of Federal Way. Critical Areas are discussed in the Federal Way
Municipal Code under Article XIV, Chapter 22. The following describes the ratings for Wetlands A,13, and C
and their regulated buffers as described in FW1bIC 22,1357.
6
Wetlands
Wetland A merits a Category III rating based on size (approximately 0.09 ac/3,920 sf) and relatively simple
vegetation structure (see Table 1 below). Wetland B also merits a Category III rating, however due to its small
size, it appears to be smaller than the 2,500 sf threshold, and is therefore likely exempt from Federal Way
regulation (see Table 1 below). The code is not specific on regulation of wetlands smaller than 2,500 sf in size.
Wetland C received a tentative Category II rating based on:
a conditions observed from the Barovic property and from along Pacific Highway South,
P topographic maps, and
a assumptions made regarding connectivity to other wetlands in the area.
However, this rating for Wetland C cannot be confirmed without access to the adjacent property. WDFW Priority
Habitat and Species data did not indicate any "presence of species or documented habitat recognized by state or
federal agencies as endangered or threatened, or extirpated plant, fish or animal species" in Wetland C. It remains
uncertain whether Wetland C is contiguous with larger wetlands to the south, which might raise Wetland C to a
Category I Wetland.
Stream
According to the definition of major and minor streams in the FWMC, the seasonal spring -fed stream flowing
through Wetland A into Wetland C and then into the ditch along Pacific Highway South, would be categorized as
a minor stream (FWMC 22.1) (see Table 1 below). Minor streams receive a 50-foot buffer under FWMC
22.1306. Off -site to the south, the stream enters a small (1-foot diameter) culvert under Pacific Highway South,
which is likely a blockage to fish passage.
,r m i Wae1.-1 ii..rl .Qf -pam i"atPonries and Buffers
Type -
Categmy
Buffer (fi)
Wetland A
111
25
Wetland B
III
likely exempt
Wetland C
II
100
Stream 1
Minor Stream
50
According to FWMC 22.1306, "no land surface modification or improvements may take place or be located in a
stream or within setback areas..." Listed exceptions to this include any segment of a stream running through a
culvert; unless that strearn will be taken out of the culvert as part of development on the subject property. Section
22.1307 of the FWMC states that stream relocation is permitted if the applicant submits a stream relocation plan
that includes but is not limited to the following: specifications to create natural meander, gentle side slopes,
application of erosion control measures, utilization of natuta.l materials, revegetation using native riparian species,
and creation of habitat and stream flows that best suit fish populations. The previous stream channel must also be
-filled and revegetated (FWMC 22.1307). Section 22.1312 states the city may permit the placement of an. essential
public facility, public utility or other public improvements in a setback Rom a stream if they judge no Feasible
,alternative location exists:
Compensatory mitigation requirements for impacts to wetland habitat on the subject property are found in FWMC
22.1358 and are listed in the following table:
Tattle 2. Federai Way'FN a and Re iaeef0cut Iiatias for Cate ai 11 and 111 Wetlands
Wetland Creation and
ratarmry Restoration Enhancement
tegory II:
Forested
3:1
6:1
Scrub -shrub
2:1
4:1
Emer ent
2:1
4:1
to ory III:
Forested
2:1
4:1
Scrub -shrub
1.5:1
_ 3:1
PmarnPrnt
1.25:1 2.5:1
Attachments
Figure 1 Vicinity Map
Figure 2 — Site Map of wetlands and buffers
7
Waterbodies
. ._i Parlcs
Lakehaveh Design . 26061.2
SOURCE: ESA Adolfson, 2009; King County, 2008 (2002Air Photo) Figure 1
Vicinity Map
Federal Way, Washington
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s 5309 Shilshole avenue NW ymmadolfson.com
Suite 200
F" ESA
Seattle, WA 9810T
206.789.9658 phone
'206'789.9684 fax
memorandum
date December 24, 2007
'to Ken Canfield, Lakehaven Utility District
from Karmen Martin; Ilon.Logan
RECEIVED
AUG 12 2015
CITY OF FEDERAL WAY
CDS
subject Lakehaven Utility District P33 Conveyance - Preliminary Evaluation
Introduction
This technical memorandum was prepared as part of the -Preliminary Evaluation Phase for the Lakehaven Utility
District Pump Station 33 Conveyance Project. The purpose of our evaluation is to identify existing conditions
that may influence the siting of a new pump station (P33) and selection of an alignment for a new force main. The
memorandum summarizes the results of ESA Adolfson's literature review and wetland reconnaissance for four
alternative force main alignments and two pump station locations. Our evaluation consisted of a preliminary
review of available literature and a field investigation to identify the presence of wetland and streams. Our
evaluation also included a literature review to identify documented occurrences of threatened and endangered
species in the project area.
Project Description
The Lakehaven Utility District P33 Conveyance Project includes the following components:
v Construction of a new 4,500 — 6,000 GPM pump station.
Construction of a new 18 to 24-inch-diameter force main between the new P33 pump station to the
Panther Lake Sewer Trunk Line connection point at either manhole #1 located near SW Campus Drive
and 2"d Avenue SW, or Manhole 8 located approximately 100 feet north of the 4" Place SW cul-de-sac
(352"d block), approximately 1,300 feet south of Manhole 1.
Construction of a new 24-inch gravity sewer line in South 359th Street (west of 14'h Place South) and in
the existing pump station easement access road to replace an existing 12-inch gravity sewer line.
The project area is located in the southern portion of the City of Federal Way (Figure 1). The project area is
generally bounded by South 348'h Street on the north, South 359th Street on the south, 14th Place South on the
east, and 7th Avenue South on the west. The force main alternative alignments are generally centered around this
West Hylebos Wetlands Park. Single-family residential development is the predominant land use in the area
located west of 1" Avenue South and south of the project area. Commercial areas are located along Pacific
Highway South and office uses are located north of South 348th Street,
Pump Station Site Alternatives
The Lakehaven Utility District has identified two alternative locations for the new pump station for preliminary
evaluation (Figure 2). Site 1 is City -owned property located east of Pacific Highway South and south of South
P33 Preliminary Evaluation i December 24, 2007
359'" Street. Site 2 is a private parcel located west of Pacific Highway South. The District would be required to
get an easement from the owner of the site that is selected. At either potential site, the new pump station would
require a construction footprint of approximately 100 feet by 100 feet. The finished pump station site dimensions
would be approximately 75 feet by 75 feet (0.13 acre).
Force Main Alignment Alternatives
The District identified three conceptual alignments for the force main as part of the project pre -design. A fourth
alignment (the District's preferred alignment.) was identified in September 2007 and is also evaluated in this
memo. The force main alignment alternatives, designated as Alternatives 1, 2 and 3, and the Preferred
Alternative, are shown on Figure 2. The District indicated that a combination of horizontal directional drilling
(HDD) and open -cut construction methods are being considered for these alternatives. Under all the alternatives,
the majority of the force main would be constructed within existing roads or sidewalks, thus avoiding most
impacts to streams and wetland areas.
The force main pipeline would be a maximum of 24 inches in diameter, and any permanent easements would
extend on both sides of the pipeline. Temporary construction easements would be wider, and would also depend
on the location of the staging areas and drilling shafts for the pipeline installation.
24-inch Gravity Sewer Line
Construction of the 24-inch gravity sewer line would occur entirely within the built roadway of 359t ` Street and
the access road for the pump station, except for that portion constructed from the access road to the pump station.
No alternatives to this alignment were identified by the District.
Methods
Existing Information
According to the National Wetland Inventory (NWI) Poverty Bay Quadrangle (USFWS, 1987) several wetlands
are mapped on or in the vicinity of the project (Figure 2). The West Hylebos Wetlands are generally mapped as
palustrine forested (PFO) wetlands with smaller patches of palustrine scrub -shrub (PSS) communities within the
larger complex. Brook Lake and Marlake, which lie within the West Hylebos wetland complex, are mapped as
open water wetlands that are permanently flooded. The dataset for NWI mapping was developed from aerial
photograph interpretation and soil survey, with no field confirmation. Therefore, the NWI wetlands shown on
Figure 2 do not accurately represent wetland boundaries, but rather give a general idea where wetlands occur. On
a regional level, wetlands and streams in the City of Federal Way were identified in 1998 as part of a critical areas.
survey and are shown on the City of Federal Way Critical Areas Map (2005). The map shows three major
streams extending through northeast and northwest portions of the project area near both of the proposed pump
station locations. A branch of Hylebos Creek is mapped near both of the proposed pump station sites (Figure 2).
The Soil Survey of King CountyArea (Snyder et al., 1973) maps several soil types in the project area that can
often indicate the. presence of wetland (hydric) soils. These soil types include: Bellingham silt loam, Seattle
snuck, Norma loam. The mapping of these soils types is generally consistent with the locations of wetlands
identified on the City's critical areas map.
A search of the Washington Department of Fish and Wildlife (WDFW) Priority Habitats and Species database
found that no threatened or endangered wildlife species listed under the Endangered Species Act (ESA) are
known to occur in the project area (WDFW, 2007). The closest known bald eagle nest is approximately 1.5 miles
northeast of the project area on the east side of I-5. Priority fish species present include coho salmon in the portion
of Hylebos Creek that flows from the center of the project area south and West Hylebos Creek located east of the
existing pump station site. Winter steelhead are also present in West Hylebos Creek, which were recently listed
P33 Preliminary Evaluation 2 December 24, 2007
as threatened by NOAA. Downstream reaches of Hylebos Creek are known to support Chinook salmon, an ESA
listed species (WDFW, 2007).
Field Investigation
Adolfson staff Steve Krueger, Ron Logan, Aaron Booy, and Karmen Martin conducted field investigations of the
pump station locations and alternative alignments in October 2006, and August and October 2007. The on -site
investigation of wetlands followed the methods outlined by the Washington State Wetlands Identification and
Delineation Manual (Ecology Publication No. 96-94, March 1997), which is consistent with the methodology
used to identify and define wetlands using the 1987 Corps of Engineers Wetlands Delineation Manual. The
reconnaissance was performed during the late growing season after a period of low rainfall. Visual observations
and soil investigations were made from existing utility easements and right-of-way. No formal data plots were
established.
Results
Pump Station Site 9
Adolfson staff investigated both sides of the paved road that provides access to the existing pump station from
South 359g' Street. Our investigation focused on approximately 100 feet from the edge of pavement. The areas
investigated are shown on Figure 2 and identified as "pump station study area."
On the west side of the access road, we identified a forested wetland that covers the majority of the pump station
study area. The boundary of the wetland is located approximately 25 feet from the edge of the access road for the
entire road length, between South 359 h Street and the existing pump station. Given the footprint needed for the
pump station, avoiding this large forested wetland would not be feasible.
On the east side of the access road, a stream and forested wetland are present, but are located further from the
edge of the pavement. The stream is a seasonal channel that connects to West Hylebos Creek to the east. The
wetland boundary is closer to the access road at the southern end of the access road (near the existing pump
station). Two potential sites for the pump station were identified on the east side of the access road: Site lA and
Site 1B.
Pump Station Site IA. Near South 359 b Street, the wetland boundary appears to be at least 100 feet from the
edge of the pavement of the access road. Construction of the pump station at this location appears feasible and
would avoid direct impacts to the wetland (Photo 1).
Pump Station Site 1B. North of the existing pump station is an area of historic fill that does not exhibit wetland
conditions.. A narrow ditch or swale is adjacent to the paved road on the east side located just north of the existing
pump station. The swale conveys surface flows and meets wetland criteria. Construction of the pump station at
this -location also appears feasible as it would avoid impacts to the larger wetland associated with the stream, but
would result in impacts to the narrow swale wetland (Photo 2).
Both Site lA and Site 1B would result in wetland buffer impacts and require review and approval by the City of
Federal Way Department of Community Development under the City's Critical Areas Regulations. If either site
is selected, several options are available under the City's Critical Areas Regulations (Federal Way Municipal
Code (FWMC 22-1359). Under FWMC 22-1359(c) Structures, Improvements and Land Surface Modification
within Regulated Wetland Buffers, the Director of Community Development may permit the placement of a
public utility or other public improvements in a regulated wetland buffer if it is determined that no feasible or
alternative location exists "based on an analysis of technology and system efficiency." The specific location and
extent of the intrusion into the buffer must constitute the minimum necessary encroachment to meet the
P33 Preliminary Evaluation 3 December 24, 2007
requirements of the public facility or utility. Other options may be available, including buffer averaging (FWMC
22-1359(b)) and would need to be discussed with the Department of Community Development.
Site 1B would require placement of fill in the narrow swale wetland north of the existing pump station. This
would trigger review by the U.S. Army Corps of Engineers (Corps) and the Washington Department of Ecology
(Ecology) under Section 404 and Section 401 of the Clean Water Act. A Nationwide Permit (NWP) from the
Corps would likely be required. The appropriate NWP would be determined by the Corps upon their receipt and
review of a completed JARPA application. Because a Corps permit would be required, Endangered Species Act
(ESA) Section 7 review requirements would be triggered. The timeline for review/issuance of a Corps NWP
(including an ESA Biological Evaluation) varies considerably, but generally granges from four to nine months
from submittal of permit application to issuance. This wetland is likely below the size threshold (2,500 square.
feet) for regulated wetlands in the City of Federal Way.
Locating the new pump station closer to South 359'h Street (Site 1A) would avoid any direct wetland impacts and
would thereby avoid the need for a federal permit.
Photo 1— Site IA: Area of upland on east side of access road (from access gate at S 3591 Street facing SE)
P33 Preliminary Evaluation 4 December 24, 2007
Photo 2 — Site 1B: North side of existing pump station: Narrow wetland Swale is present parallel to road.
Pump Station Site 2
Adolfson investigated undeveloped portions of a private parcel that abuts Pacific Highway South (Figure 2).
Investigations extended approximately 100 feet west of the edge of road pavement. Approximately 50 feet from
the road, a stream originates from a spring near the center of the site. The stream flows to the south and provides
hydrology for an emergent wetland that extends west and south. Construction of the pump station at this location
would result in direct impacts to wetlands and streams. Unlike the allowances in the critical area regulations for
utility construction in wetland buffers (described in relation to Pump Station Site 1), there are no similar
allowances or provisions within the City's critical areas regulations for utility improvements within regulated
wetlands. It is expected that a "Modification" from critical areas requirements under FWMC 22-1358(d) would be
required using City permit process IV. Permit process IV requires a public hearing and a Hearing Examiner's
decision. Mitigation for wetland impacts would also be required. This process is lengthier than the critical areas
-review described for Pump Station Site 1 and would be costlier in terms of providing mitigation for wetland
impacts.
In addition to City requirements, the excavation or the placement of fill in wetlands would trigger review by the
Corps and Ecology under Section 404 and Section 401 of the Clean Water Act as described above for Pump
Station 1B. ESA Section 7 review requirements would also be triggered. In addition, if the stream were impacted
by construction, a Hydraulic Project Approval (HPA) would be required from Washington Department of Fish
and Wildlife (WDFW) for any in -water work.
P33 Preliminary Evaluation 5 December 24, 2007
Force Main Alternative 9
Alternative 1 includes construction of the pipeline entirely within built roads or road shoulders with the exception
of a small section at the intersection of 15t Avenue South and South 348'h Street (see Figure 2). At this location,
the pipeline alignment is proposed within an existing utility easement located below street elevation, west of 1st
Avenue South. We were able to locate the easement corridor by locating manholes in the field. No wetlands
appear to occur within the easement or adjacent to the easement. Hylebos Creek is located west of the easement,
flows south and eventually crosses below I' Avenue South through a culvert. Alternative 1 crosses Hylebos
Creek and associated wetlands where it flows under South 356" Street. At this location, we understand that the
pipeline would be constructed using directional drill methods that would bore under the existing culverts along
the outer edge of the right-of-way. Boring under both streams and associated wetlands would avoid impacts, but
could require an HPA from WDFW. Staging areas for drilling equipment would also need to be located outside
of wetland and stream buffers to avoid impacts to these locally regulated critical areas.
Force Main Alternative 2
Alternative 2 includes construction within an existing 10-foot easement that parallels an unnamed stream between
South 351" Street and South 348" Street (see Figure 2). During our investigation, the stream was dry through the
entire section. No wetlands appear to be associated with the stream in the southern half of the corridor. In the
northern half, the stream channel widens and forested wetland is present on both sides of the stream. We found
pink flagging in the field (dated 12/5/05 by Parametrix, Inc.) marking the edge of the wetland and the ordinary
high water mark of the stream and agreed with the flag locations. Wetland areas do not appear to extend into the
easement corridor east of the stream. Thus, it appears that construction of the pipeline would only result in
impacts to stream buffer and would likely be granted an exception or variance from the City of Federal Way, We
recon—uncnd limiting tree rt,rnm,al to the greatest extent possible in. this section.
A -portion of the alignment would parallel an existing 10-inch force main located in an easement that occurs just
east of Pacific Highway South. We were able to locate the easement corridor by observing orange stakes that
mark the corridor centerline. A scrub -shrub and emergent wetland is present within the easement corridor for
approximately 175 feet between South 359ffi Street and a gravel pullout east of the highway (see Figure 2). The
wetland appears to extend to the east eventually connecting to Hylebos Creek. At this location, the pipeline
would be constructed entirely within the road prism and would avoid impacts to the wetland.
P33 Preliminary Evaluation 6 December 24, 2007
Photo 3 — Stream at South 34e Street (I0-footeasement to right of stream)
Force Main Alternative 3
Alternative 3 follows an existing pipeline in a 20-foot wide easement through The Reserve apartment complex
(see Figure 2). No wetlands or streams occur within or near the easement. South of the apartment complex, the
alignment turns east and extends downslope through upland forest dominated by large conifer trees. The
alignment continues through forested areas until connecting to 1 ' Avenue South. The forest is primarily
composed of mature Douglas fir and western hemlock with some western red cedar also present. Construction
along this alignment would potentially impact a large number of these mature trees. No wetlands or streams were
located in this area. The remainder of the alignment follows the route described under Force Main Alternative 1
above. This alternative would cross Hylebos Creek at multiple locations, including one on S 356 h Street and two
places on 1" Avenue S. It is our understanding that the District intends to directionally drill below or construct
the pipe over the culvert sections of Hylebos Creek at all crossings. Boring under both streams and associated
wetlands would avoid impacts, but could require an HPA from WDFW. Staging areas for drilling equipment
would also need to be located outside of wetland and stream buffers to avoid impacts to these locally regulated
critical areas.
P33 Preliminary Evaluation 7 December 24, 2007
Force Main Preferred Alternative
A Preferred Alternative was identified by the District in September 2007 and is shown on Figure 2. The Preferred
Alternative follows much of the same route as the alignment sections described under Alternatives 1, 2 and 3
above. Near The Reserve apartment complex, this alternative would utilize existing roads/driveways to avoid
construction through the mature conifer forest. No additional wetlands were identified along this alignment during,
our October 2007 field investigation. The route would cross Hylebos Creek at multiple locations, including one
on S 356`h Street and two places on l�` Avenue S. It is our understanding that the District intends to directionally
drill below or construct the pipe over the culvert sections of Hylebos Creek at all crossings. Boring under both
streams and associated wetlands would avoid impacts, but could require a HPA from WDFW. Staging areas for
drilling equipment would also need to be located outside of wetland and stream buffers to avoid impacts to these
locally regulated critical areas.
24-inch Gravity Sewer Line
Construction of the 24-inch gravity sewer line within the built right of way of 359"' Street (see Figure 2) would
avoid impacts to wetlands, streams, and wildlife habitat. Construction within the access road to the pump station
site would similarly avoid impacts. Construction of the connection point from the access road to the pump station
would have the same issues as discussed above for Pump Station Sites IA and 1B.
Alternatives Evaluation Summary.
Pump Station Site
Based on our investigation of the two pump station sites, the least encumbered location for a new pump station
would be at Pump Station Site 1 on the east side of the paved access road and abutting South 359s' Street (Site
1 A). At this location, construction of the pump station would likely result in wetland buffer impacts, but not in
impacts to wetlands or streams. Placement of the pump station as close as possible to the existing road would
minimize the amount of buffer impacts.
Locating the new pump station on the north side of the existing pump station (Site 1B) would likely result in some
minimal impacts to the wetland swale located next to the paved road, as well as buffer impacts. The wetland is
very small and likely below the size threshold (2,500 square feet) for regulated wetlands in the City of Federal
Way. However, placement of fill in the wetland Swale would require permit review by the U.S. Army Corps of
Engineers and Washington Department of Ecology under Section 404 and Section 401 Clean Water Act
requirements and compliance with Section 7 of the Endangered Species Act,
Impacts to the buffer at either pump station location at Site 1 would require review and approval under the City of
Federal Way Critical Areas Regulations. As part of the project's review under the critical areas regulations, the
District will need to establish that no feasible or alternative location exists based on an analysis of technology and
system efficiency and that the location constitutes the minimum necessary encroachment into the wetland buffer
to meet the utility requirements (FWMC 22-1359 (c)). We recommend that we discuss these requirements with
the Department of Community Development during Task 2 to establish the requirements and criteria.
Force Main Alignment
Based on our investigation of the four force main alternative alignments, the alternative that would have the least
impacts to wetlands and streams would be the Preferred Alternative. Alternatives 1, 3 and the Preferred
Alternative would all have crossings of Hylebos Creek that would be bored, but could require an IPA from
WDFW.
P33 Preliminary Evaluation a December 24, 2007
Alternative 1 would have stream buffer impacts in the northwest portion of the alignment. All other impacts
would be avoided as long as directional drilling and staging on South 356"' Street occurs outside wetland and
stream buffers.
Alternative 2 would result in buffer impacts to the stream in the northeast portion of the alignment, north of South
3515t Street. Construction of the pipeline would require removal of trees in the riparian area of the stream.
While Alternative 3 would not involve impacts to any wetlands, streams, or their buffers, it would require
extensive tree removal.
The Preferred Alternative utilizes existing roads/driveways to avoid extensive tree removal and impacts to
wildlife habitat in its northern portion. Impacts to wetland and streams and wetland and stream buffers would be
avoided as long as directional drilling and staging areas occurred outside of these areas. None of the alternatives
are expected to have impacts on threatened or endangered species. Impacts to listed fish species should not occur
if all in. -water work within streams is avoided.
'Based on this review, the Preferred Alternative would be the only alternative to avoid wetland, buffet, and.
significant tree impacts and is, therefore, expected to have the lowest degree of permit complexity.
The highest degree of permit complexity is associated with Alternative 2; however, we do not anticipate that
permitting would be a significant obstacle to completing the project. Under the City of Federal Way's Critical,
Area Regulations, mitigation is required to restore or improve critical areas to offset these impacts. It appears that.
mitigation can be accomplished onsite through restoration and/or enhancement.
Within the next ten years, the City of Federal Way is planning to make major improvements to both 1" Avenue
and 356"' Street along the potential alignments for Alternative 1, 3, and the Preferred Alternative. These road
improvements could cause disruption or require the District to make modifications to sewer systems located
within these roads. Alternative 2 would avoid these planned road improvements / utility conflicts.
Summary of Impacts
r
Direct
Buffer
Stream
Wetland:
I
Impacts
Crossmgs
j Impacts
Pump Station Site
Pump Station Site lA (abutting X
359")
Pump Station Site 1B (north of
X
X
existin PS site)
Y _
Puma Station Site 2
X
X
Force Main Alternatives
Force Main Alternative 1
Force Main Alternative 2
Force Main Alternative 3
Force Main Preferred
Alternative
X
X X
Significant
Tree
Impacts
X �—
X
X
X
_l
Planned Road
Improvements
/ Utiility
Conflicts
X
X
X
P33 Preliminary Evaluation 9 December 24, 2007
Limitations
Within the limitations of schedule, budget, and scope -of -work, we warrant that this study was conducted in
accordance with genemily accepted environmental science practices, including the technical guidelines and
criteria in effect at the time this study was performed, as outlined in the Methods section. The results and
conclusions of this report represent the authors' best professional judgment, based upon information provided by
the project proponent in addition to that obtained during the course of this study. No other warranty, expressed or
implied, is made.
P33. Preliminary Evaluation 10 December 24, 2007
References
City of Federal Way. 2005. City of Federal Way Critical Areas Maps,
Environmental Laboratory. 1987. Corps of Engineers Wetlands Delineation Manual. Technical Report Y-87-1,
U.S. Army Eiqveer Waterways Experiment Station, Vicksburg, Massachusetts.
Snyder, D.E., P.S. Gale, and R.F. Pringle. 1973. Soil Survey of King County Area, Washington. U.S. Soil
Conservation Service, Washington, DC.
USFWS (U,S, Fish and Wildlife Service). 1987, National Wetland Inventory (NWI) poverty Pay quadrangle,
WDF'W (Washington Department of Fish and Wildlife). 200.7. Priority Habitats and Species (PHS) database
,search.
P33 Preliminary Evaluation ill December 24, 2007'
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