Ordinance No. 89-27 CITY OF TIGARD, OREGON
ORDINANCE NO. 89 ---L?-
AN ORDINANCE TO AMEND CHAPTER 18.90, ENVIRONMENTAL PERFORMANCE STANDARDS, OF
THE TIGARD COMMUNITY DEVELOPMENT CODE AND SETTING AN EFFECTIVE DATE. (ZOA 89-
03).
WHEREAS, the City of Tigard finds it necessary to revise its Community
Development Code periodically to improve the operation and implementation of
the Code; and
WHEREAS, the Planning staff made recommendation of findings to the City Of
Tigard Planning Commission at their regular meeting on October 17, 1989; and
WHEREAS, the Tigard City Council held a public hearing on the proposed changes
at its regular meeting on November 6, 1989.
NOW THEREFORE, THE CITY OF TIGARD ORDAINS AS FOLLOWS:
SECTION 1: Chapter 18.90 of the Tigard Municipal Code shall be amended as
shown in Exnibit "A". Language to be deleted is shown in
[BRACKETS]. Language to be Ldded is UNDERLINED-
SECTION 2: This ordinance shall be effective on and after the 30th day
after its passage by the Council, approval by the Mayor and
posting by the Recorder.
PASSED: By U!1(i n)M12L15 - vote of all Council members present after being
read by number and title only, thisb;qN day of
2)J v F tx) , 1989.
Bather Wheatley, De teity Recorder
APPROVED:
C
This _ day of -6k-`y�j&1 -i 1,98 -�
'
Gerald R. Edwar , yor
ed as o form:
City Att rney
)t
Date
` ORDINANCE NO. 89 -�
A
"EXHIBIT A"
Chapter 18.90
ENVIRONMENTAL PERFORMANCE STANDARDS
Sections:
18.90.010 Purpose
18.90.020 General Provisions
18.90.030 Noise
18.90.040 Visible Emissions
18.90.050 Vibration
18.90.060 Odors
18.90.070 Glare and Heat
18.90.080 Insects and Rodents
18.90.010 Purpose
A. The purpose of this chapter is to apply the federal and state
environmental laws, rules, and regulations to development within the
City of Tigard. (Ord. 89-06; Ord. 83-52)
18.90.020 General Provisions
A. In addition to the regulations adopted in this chapter, each use,
activity, or operation within the City of Tigard shall comply with the
applicable state and federal standards pertaining to noise, odor, and
discharge of matter into the atmosphere, ground, sewer system, or
stream.
1. Regulations adopted by the State Environmental Ouality Commission
pertaining to non-point source pollution control and contained in
the Oregon Administrative Rules shall by this reference be made a
part of this chapter.
B. Prior to issuance of a building permit, the Director may require
submission of evidence demonstrating compliance with state, federal,
and local environmental regulations and receipt of necessary permits.
Air Contaminant Discharge Permits (RCDP) or Indirect Source
Construction Permits (ISCP).
C. Compliance with state, federal, and local environmental regulations is
the continuing obligation of the property owner and operator. (Ord.
89-06; Ord. 84•-24; Ord. 83-52)
18.90.030 Noise
A. The following additional restrictions are incorporated with the State
Department of Environmental Quality (DEQ) standards for purposes of
City noise regulation:
1. For purposes of measuring permitted sound levels from noise
generating sources under the provisions of DEQ rules any point
where a noise sensitive building could be constructed under the
provisions of this title shall apply as if such point contained a
noise sensitive building;
2. Within the industrial park (I-P) zoning district, each property or
building under separate ownership from a noise generating source
shall be considered a noise sensitive property under the provision
of DEQ rules with the exception that the allowable noise levels may
be increased by five db; and
3. The construction including excavation, demolition, alteration, or
repair of any building, except where a special permit has been
issued by the Director under the provisions of section 18.90.020,
other than between the hours of 7:00 a.m. and 9:00 p.m. which
involves any loud, disturbing, or unnecessary noise in the city,
shall be deemed disorderly conduct and therefore unlawful. (Ord.
89-06; Ord. 83-52)
18.90.040 Visible Emissions
A. Within the commercial zoning districts and the industrial park zoning
district, there shall be no use, operation, or activity which results
in a stack or other point source emission, other than an emission from
space heating, or the emission of pure uncombined water (steam) which
is visible from a property line. Department of Environmental Quality
rules for visible emissions (340-21-015 and 340-28-070) apply. (Ord.
89-06; Ord. 84-24; Ord. 83-52)
18.90.050 Vibration
A. No vibration other than that caused by highway vehicles, trains, and
aircraft is permitted in any given zoning district which i- discernible
without instruments at the property line of the use concerned. (Ord.
89-06; Ord. 83-52)
18.90.060 Odors
A. The emission of odorous gases or other matter in such quantities as to
be readily detectable at any point beyond the property line of the use
creating the odors is prohibited. DEQ rules for odors (340-028-090)
apply. (Ord. 89-06; Ord. 84-24; Ord. 83-52)
18.90.070 Glare and Heat
A. No direct or sky--reflected glare, whether from floodlights or from high
temperature processes such as combustion or welding or otherwise, which
is visible at the lot line shall be permitted, and:
1. There shall be no emission or transmission of heat or heated air
which is discernible at the lot line of the source; and
2. These regulations shall not apply to signs or floodlights in
parking areas or construction equipment at the time of construction
or excavation work otherwise permitted by this title. (Ord. 89-06;
Ord. 83-52)
18.90.080 Insects and Rodents
A. All materials including wastes shall be stored and all grounds shall be
maintained in a manner which will not attract or aid the propagation of
insects or rodents or create a health hazard. (Ord. 89-06; Ord. 83-52)
cp/ZOA89-03
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(22) - T?5i Filed ,ecretary of State 7-28-89; tQC Meeting 7-21-89
Note: Bracketed [ ] material is proposed to be deleted.
Underlines _ materials is proposed to be inserted.
DEFINITIONS
340-41-006
Definitions applicable to all basins unless context requires otherwise:
(1) "BOD" means 5-day 20° C. Biochemical Oxygen Demand.
(2) "DEQ" or "Department" means the Oregon State Department of
Environmental Quality.
(3) "DO" means dissolved oxygen.
(4) "EQC" means the Oregon State Environmental Quality Commission.
(5) "Estuarine waters" means all mixed fresh and oceanic waters in
estuaries or bays from the point of oceanic water intrusion
inland to a line connecting the outermost points of the headlands
or protective jetties.
(6) "Industrial waste" means any liquid, gaseous, radioactive, or
solid waste substance or a combination thereof resulting from any
(, process of industry, manufacturing, trade, or business, or from
the development or recovery of any natural resources.
(7) "Marine waters" means all oceanic, offshore waters outside of
estuaries or bays and within the territorial limits of the State
of Oregon.'
(8) "mg/l" means milligrams per liter.
(9) "Pollution" means such contamination or other alteration of the
physical, chemical, or biological properties of any waters of the
state, including change in temperature, taste, color, turbidity,
silt, or odor of the waters, or such radioactive or other
substance into any waters of the state which either by itself or
in connection with any other substance present, will or can
reasonably be expected to create-a public nuisance or render such
waters harmful, detrimental, or injurious to public health,
safety, or welfare, or to domestic, commercial, industrial,
agricultural, recreational, or other legitimate beneficial uses
or to livestock, wildlife, fish or other aquatic life, or the
habitat thereof.
(10) "Public water" means the same as "waters of the state".
(11) "Sewage" means the water-carried human or animal waste from
` residences, buildi-ngs, industrial establishments, or other places
together with such groundwater infiltration and surface water as
340-41-006 _ 1
Pm\WH3582
may be present. The admixture with sewage as herein defined of --
industrial wastes or wastes, as defined in sections (6) and (13)
of this rule, shall also be considered"sewage" within the
meaning of this division.
(12) "SS" means suspended solids.
(13) "Wastes" means sewage, industrial wastes, and all other liquid,
gaseous, solid, radioactive, or other substances which will. or
may cause pollution or tend to cause pollution of any water of
the state.
(14) "Waters of the state" include lakes, bays, ponds, impounding
reservoirs, springs, wells, rivers, streams, creeks, estuaries,
marshes, inlets, canals, the Pacific Ocean within the territorial
limits of the State of Oregon, and all other bodies of surface or
underground waters, natural or artificial, inland or coastal,
fresh or salt, public or private (except those private waters
which do not combine or effect a junction with natural surface or
underground waters), which are wholly or partially within or
bordering the state or within its jurisdiction.
(15) "Low flow period" means the flows in a stream resulting from
primarily groundwater discharge or baseflows augmented from lakes
and storage projects during the driest period of the year. The
dry weather period varies across the state according to climate
and topography. Wherever the low flow period is indicated in the
Water Quality Management Plans, this period has been approximated
by the inclusive months. Where applicable in a waste discharge
permit, the low flow period may be further defined.
(16) "Secondary treatment" as the following context may require for:
(a) "Sewage wastes" means the minimum level of treatment
mandated by EPA regulations pursuant to Public Law 92-500.
(b) "Industrial and other waste sources" imply control
equivalent to best practicable treatment (EPT) .
(17) "Nonpoint Sources" refers to diffuse or unconfined sources of
pollution where wastes can either enter into - or be conveyed by
the movement of water to -- public waters.
(18) Loading Capacity (LC): The greatest amount of loading that a water
can receive without violating water quality standards.
(19) Load Allocation (IA): The portion of a receiving water's loading
capacity that is attributed eithertoone of its existing or
future non-point sources of pollution or to natural. background
sources. Load allocations are best estimates of the loading,
which may range from reasonably accurate estimates to gross'
allotments, depending on the availability of data and appropriate
340-41-006 2
PH\'WH3582
techniques for predicting loading. Wherever possible, natural and
nonpoint source loads should be distinguished.
(20) Wasteload Allocation (WLA) : The portion of a receiving water's
loading capacity that is allocated to one of its existing or
future point sources of pollution. WLAs constitute a type of
water quality-based effluent limitation.
(21) Total Maximum Daily Load (TMDL): The sum of the individual WLAs
for point sources and Us for nonpoint sources and background, If
a receiving water has only one point source discharger, the TMDL
is the sum of that point source WLA plus the LAs for any nonpoint
sources of pollution and natural background sources, tributaries,
or adjacent segments. TMDLs can be expressed in terms of either
mass per time, toxicity, or other appropriate measure. If Best
Management Practices (BMPs) or other nonpoint source pollution
controls make more stringent load allocations practicable, then
wasteload allocations can be made less stringent. Thus, the TMDL
process provides for nonpoint source control tradeoffs,
" eve o mens, refers'to any human induced chanes to unproved
o n' oved real estate including but no limited to
�on�struct* installation or expansion of a building or other
to a and d v dr a s to to at o uc s
h due to sand surface mining dredgirading construction
�T earthen berms saving #,mnrovements for use as Harkang_or
storage, excavation or clear in
1231 "Jurisdiction" efers to anty or county a¢encv in the Lualatin
3re�-wand 0+swe�o Lake subbasins that ��gp�ates land devPlorament
activ ties within its boundaries by r�nvtovine plats. site clans or
issuing Hermits for land develoHment._
(24) sion_Ceotrol Plan" shall be a HIan containins a list of best
mana¢em H ac ices tobg a2glied during_constru�tion to control
and 1�mit soil erosion
f251 "Public. W rka Project" means �r�y, and deve]onducted ox.
financed by a-local. state, o�fader,,_ al governmen al body_
340-41-006 3 -
PM\WH3582
a
Note: Bracketed ( ] material is proposed to be deleted.
Underlines materials is proposed to be inserted.
MINIMUM DESIGN CRITERIA FOR TREATMENT AND CONTROL OF WASTES
340-41-455
Subject to the implementation program set forth in rule 340-41-120, prior
to discharge of any wastes from any new or modified facility to any waters
of the Willamette River Basin, such wastes shall be treated and controlled
in facilities designed in accordance with the following minimum criteria
(In designing treatment facilities, average conditions and a normal range
of variability are generally used in establishing design criteria. A
facility once completed and placed in operation should operate at or near
the design limit most of the time, but may operate below the design
criteria limit at times due to variables which are unpredictable or
uncontrollable. This is particularly true for biological treatment
facilities. The actual operating limits are intended to be established by
permit pursuant to ORS 468.740 and recognize that the actual performance
level may at times be less than the design criteria.):
(1) Sewage wastes:
(a) Willamette River and tributaries except Tualatin River
Subbasin:
(A) During periods of low stream flows (approximately May 1
to October 31): Treatment resulting in monthly average
effluent concentrations not to exceed 10 mg/l of BOD
and 10 mg/l of SS or equivalent control.
(B)_ During the period of high stream flows (approximately
November 1 to April 30): A minimum of secondary
treatment or equivalent control and unless otherwise
specifically authorized by the Department, operation of
all waste treatment and control facilities at maximum
- _practical efficiency and effectiveness so as to
minimize waste discharges to public waters.
(b) Main stem Tualatin River from mouth to Gaston (river mile 0
to 65):
(A) During periods of low stream flows (approximately May 1
to October 31) Treatment resulting in monthly average
effluent concentrations not to exceed 10 mg/l of BOD.
and 30 mg/l of SS' or equivalent control.
(B) During the period of high stream flows (approximately
November 1 to April 30) Treatment resulting in
monthly average effluent concentrations not to exceed
.. 20 mg/l of BOD and. 20 mg/l of SS or equivalent control.
340=41-455 - 1 -
PM\WH3581
(c) Main stem Tualatin River above Gaston (river mile E5) and
all tributaries to the Tualatin River: Treatment resulting
in monthly average effluent concentrations not to exceed 5
mg/l of BOD and 5 mg/1 of SS or equivalent control.
(d) Tualatin River Subbasin: The dissolved oxygen level in the
discharged effluents shall not be less than S mg;l.
(e) Main stem Columbia River:
(A) During summer (May 1 to October 31): Treatment
resulting in monthly average effluent concentrations
not to exceed 20 mg/l of BOD and 20 mg/l of SS or
equivalent control.
(B) During winter (November 1 to April 30): A minimum of
secondary treatment or equivalent control and unless
otherwise specifically authorized by the Department,
operation of all waste treatment and control facilities
at maximum practicable efficiency and effectiveness so
as to minimize waste discharges to public waters.
(f) Effluent BOD concentrations in mg/l, divided by the dilution
factor (ratio of receiving stream flow to effluent flow)
shall not exceed one (1) unless otherwise specifically
approved by the Environmental Quality Commission.
(g) Sewage wastes shall be disinfected, after treatment,
equivalent to thorough mixing with sufficient chlorine to
.provide a residual of at least 1 part per million after 60
minutes of contact time unless otherwise specifically
authorized by permit.
(h) Positive protection shall be provided to prevent bypassing
raw or inadequately treated sewage to public waters unless
otherwise approved by the Department where elimination of
inflow and infiltration would be necessary but not presently
practicable.
(i) More stringent waste treatment and control requirements may
be imposed where special conditions may require.
(2) Industrial wastes:
(a) After maximum practicable inplant control, a minimum of
secondary treatment or equivalent control (reduction of
suspended solids and organic material where present in
significant quantities, effective disinfection where
bacterial organisms of public health significance are
present, and control of toxic or other deleterious
substances)
340-41-455 2. -
PM\WH35$1
(b) Specific industrial waste treatment requirements shall be
determined on an individual basis in accordance with the
provisions of this plan, applicable federal requirements,
and the following:
(A) the uses which are or may likely be made of the
receiving stream;
(B) The size and nature of flow of the receiving stream;
(C) The quantity and quality of wastes to be treated; and
(D) The presence or absence of other sources of pollution
on the same watershed.
(c) Where industrial, commercial, or agricultural effluents
contain significant quantities of potentially toxic
elements, treatment requirements shall be detarm.ined
utilizing appropriate bioassays.
(d) Industrial cooling waters containing significant heat loads
shall be subjected to offstream cooling or heat recovery
prior to discharge to public waters.
(e) Positive protection shall be provided to prevent bypassing
of raw or inadequately treated industrial wastes to any
public waters.
(f) Facilities shall be provided to prevent and contain spills
of potentially toxic or hazardous materials and a positive
program for containment and cleanup of such spills should
they occur shall be developed and maintained.
v�*on_point source noilution control, in the Tualatin River sub-basin
a�}d. la__�anas �,,r�,�i�n„g to Oswes�o Lake t�.,,provid�d after
�anuRry 1. 1.9$9'
Lal The following subsecrcans sha1Z annly to any new land
develolom withinh�T_ualatin River and Oswego Take sub-
basins. excent�tith e deyggents with AD ion dates
RE=g2, Jenuary l 1990. The annli7ation date shall be t
r� �n woBment anoroval
is received by JgrigdictionJurisdiction irr ®aodance with_the
�&M mrthe local _iur$.sdiction.
E=--i eve o anla ueMit
or publig works eroiect sh lhS annroved by -4 .-sdigtion
ire these sub-basins un7� .. ., . d� 4nsof the ,plat vermit
og vlan ann�oval includes gg�„Qzo•�ion-co �,Q1 g�+�},.,-runt_ inning
methods and/or, interim facilities to het td � or u
velopment and to be o d
const„�ucti on to r�,q��Yrol he isc�p.�„�„of sediment in the
4 e
340-41-455 3
PM\WH3581
JAZ Protection techniaues to control ggil erosion and
sediment transport tg less than one (1) ton oer acre per
year, as calculated using t_he roil Conservation Service
Universal Soil Loss Equation or other equivalent
methods See Fjgures 1 to 6 in APP NDIX I for
examples The eros on control pleashall include
temtmrary sedimentation basins Xhen. because of steer
slopes or oth2r, site gpggifig c d t the on-
site-sediment
siresediment control methoda will not likely keep the
sediment tranMrt to less than 2n2 (1) ton per a-re ger
year. The soca jurisdictions may establish additional
requirements for meeting an ecuivalent degree of
cont of Any sediment basins constructed hAll be sized
using_.5 feet minimum-ge!digent storage depth plus 2.0
feet storaze denth above for a settlement zone The
storage gApacily of thg basin shall be sized to store
el of the sediMlnt that is likely to be transRorr and
c21 ected during g_ons=gtion while the erosion
potent 1 exists. When the erosion potential has been
removed the sediment basin. or other sediment control
fac' *t e can be removed a ¢ th site restored as ger
the final site elan All sediment basins shall be
constructed with anemery overflew to prevent
erosion or failure of the containment ,¢ike -9s
A Foil erosion con 121 m trix cigrived from ani
onsiste t with the universal eA41„loss equation
egProved b'L the jurisdiction or the 2e- artment {
.r
Lai }lie T?i er or m y mode ,r A-RuAix I as n2egasary without
Mroval from-th viron*aental duality Commission Ttie
Director may;.modifv AAbendix Ito 5 f it and to make it
asjer fsr goble to adoly.
As. loca.1 iurct on adopt a Department av raved urogram
glan, as required 340-4Z-470(3)0). these •reouirements
will no longed 22 .ts...devglopment in that_ iso dic .�°n•
k'
340.41-455 - 4 -
PK\WH3581
i
i.
APPENDIX I
CONTENTS
Table 1 Universal Soil. Loss Equation
Table 2 "R" Values, Washington County
Table 3 Hydrologic Soil Group of the Soils
Table 4 LS Values
Table 5 "C" Values Mulch Factors
Table 6 "C" Values
Figure 1 Tntereeptor Swale
Figure 2 Temporary Interceptor Bikes
Figure 3 Level Spreader
Figure 4 Sediment Trap
Figure 5 Pipe Slope Drains
Figure 6 Stabilized Consrruction Entrance
t
A-3
WC5169
.�E
j
E
TABLE t UNNERSAL SOIL LOSS EQUATION
o m Mt
thins trap and can
fm nt v I m -The sediment storage volume required is the volume
estimated
required to contain the annual sedfm dgvsloPed by the United States pepanment of AgrUsiniculture.
ure.
Universal Soil Loss Equation (USLE)
A = R"K`LS`cV°RR
Where A annual sediment yield in tons per acre
R rainfail erosion index;
x
K a soil erodibiiity factor. from Table 3 or astoe rmined
dete1
by field and laboratory testing by a geologist
scientist. or geotecnnicai engineer.
i
len the
iap� -��.��A factor, from Table a (note. 9W�
• measured are horizontal distance "rrum a at
ar --,
= cover factor, use 1.0 which represents no ground cover
r
during the construction process. TABLE s and e t
Pq erosion controlprac:fce factor, use
laozer cleat
ncicwaiking up and down slope. ( f:
parallel to contours)
_ - ste procedure:
Annual sediment yield caicuiation, step-by-step p €
-hour tsgpluvial Map
a, Coma=the R value by obtainLig the R value from the 2-year/ri
in TABLE 2
b. Oivide the Sita into areas of homogeneous SCS. soil type and of uniform slope and
length.
r tar each soil type• i
C. Note the K value from the SCS soils chart (Tab
:e 3 r
d f�eterming the LS value for each uniform area (Sae Table a )•
Corrapute the annual sediment yield , )
IAS in tons per acre for each-homogeneous/uniform f
area by muitirAying R times the-K and 1S values for each area.
f• Multiply the annual sediment yield (A) for each area by the acreage to be ex00sed (only
that area to be cleared) of each area. Scam the results to compute the total annual I;
sediment load (in tons) to the trap
is then determined by dividing the total annual sediment load
a i he sediment Stara g$ �niume N,) EE
(in tans) (LS) by an average density for the sediment deposited use 0.05 ton per cubic foot.
V,
TABLE 2 ••• YALUrzS WASHINGTON COUNTY
t r
ri
13
p J •I ^�i +ww •\. �
.ol�1—a•ta a
y
s - -
• /{.. �,�� Y. may:
• _ (� w a «
: w
L—r
or 77 r4
SU
4
Sa.rer:
6sGi roa wraehe by SS3;w rx Seas Unt+I—l:146.720 Croweael MeaM.e/+woe, M7-EL-22476-34A E:�
TAIJLE 3 HYDROLOGIC SOIL GROUP OF THE SOILS WASHINGTON COUNTY
Soil Soil
Hydro- _Erod- Hydro- Erod-
Map logic ibility Map logic ibiIity
Soil Group Symool Group Factor, "`C" Soil Group Symuol Grouo Factor,
ALOHA 1 C 0.43 HUBERLY 22 U 0.37
AAITY 2 C 0.32 J-JRY 23 C U.2
ASTORIA 3 8 u.24 KILCHIS 24 C 0.15
8RIEUWELL 4 B 0.28 KLICKITAT 24G 8 0.1
BRIEDWELL 5 B U.17 KNAPPA 26 B U.37
CARLTON 6 B U.32 LABISH 27 U 0.2
CASCADE 7 C 0.37 LAURELaOUu 28 8 0.43
CHEHALE,l d C 0.37 mCBEE 3U 8 0.28
CHEHALIS 9 U 0.24 MELBOURNE 31 8 0.24
CHEHALI S 1 U U U.37 MELBY 32 C 0.32
�� ??
CORNELIUS 11 C U.37 ULYIC 34 n �®
KII4TON 118 C U.43 PERVINA 36 C 0.24
CORNELIUS QUATAMt 37 C 0.37
VARIMT 12 C 0.37 SAUM 38 C 0.32
COVE 13 U 0.28 TOLKE s9 8 U.28
LOVE 14 U 0.17 UUIFLUVENTS 4U a 0.17
04YTON15 U 0.43 VERBUORT 42 U U.28
.:.ENA 18 U 0.43 °WAPATO 43 U 0.32
GOBLE 17 C 0.37 WILLAMETTE 44 8 0.32
GOBLE 18 C q.37 WOOUBUM 4 C U.32
HELVETIA 19 C U.37 XEROCHKEPTS 46 8 0.43
HEMBRE 20 d 0.32 HAPLOXERULLS 46F C 0.32
HILLSBORO 21 8 U.49 XERULHREPTS 47 U O.U2
RUCK OUTCROP 47U NA 0.02
HYDROLOGIC SOIL.GROUP CLASSIFICATIONS
A. (Low nenatf potentia). Sods having high intiltrati®r►rates, even when tnoroughly wertea.and constsung
crttetty at deep.wed-to-excesalvety dralnad sands or gravels. These sods have a mign two at water
transmtsU n.
®. (Moderately low n and polemal). Sods naving moderate °nldiratton rates when tnorougmy weaed, and
comustutq cillsoy of moderately tine to moderacety coarse textures. These sods cave a moderate rate of
water transmis�.
C. (Maderatcmy high nmtod polonuat). Sods he"slow fntiitratlon rates wnen tnorougruy wetted. and
const c mny of sods watt a layer that Impedes downward movement of water. or sods wan moceratety
lila to lute textures. These sods have a stow rate at water transmession.
®, (mign runatt potenttai). Soils having very slow'intdtratton rates wnen mdrougnty warted and cwwsrtng
cniefty,of clay sods with a tag"sweding potenaaf, sods wren a permanaant noon wdter tatale, sods wrtn a
t�dpan or clay layer at or near the surface.and 04010w ands over nanny impervious material. These sods t;
hsve a very slow rate at water transmiss,an.
From SCS
A-6
r
TABLE f LS VALUES FOR "R" ZONE 2 - OREGON
MLPA's Al, AZ, n3, A5, 56, 024, D25, and E43
For slopes 9% or flatter
LS =((-A ) cos(tan'1s)Im(65.41 sin
2(tan'1s) + 4,Sb sin(tan'1s) + 0.065]
72.6
For slopes steeper than 9%
LS s (( 7 ) cos(tan-1s)10.501_lsin(tan"1s)11.4
sin 5.143
wheres
4 - length in feet along slope
s - slope in 7/100
For s < 0.01, ma0.20
0.01 < s < 0.035, m-0.3
0.035 < s , 0.045, ma0.4
s s 0.045, m-0.5
7ercent
Slope 25 50 75 100 125 150 200 250 300 350 400 450 500
0.1 0.06 G.0o5 0.07 0.07 0.08 0.085 0.09 0.09 0.095 0.10 0.10 0.10 0.;
0.2 0.06 0.07 0.075 0.08 0.085 0.09 0.095 0.10 0.10 0.10 0.105 0.11 0.
0.5 0.07 0.08 0.09 0.10 0.10 0.10 0.11 0.11 0.12 0.12 0.13 0.13 0.:
1.0 0.09 0.10 0.12 0.13 0.14 0.15 0.16 0.17 0.18 0.19 0.20 0.20 0.-
2.0 0.13 0.16 0.18 0.20 0.21 0.23 0.25 0.26 0.28 0.29 0.30 0.32 0.'_
3.0 0.L9 0.23 0.26 0.28 0.31 0.32 0.35 0.38 0.40 0.42 0.43 0.45 0.�
4.0 0.23 0.30 0.36 0.40 0.44 0.47 0.53 0.58 0.62 0.65 0.70 0.73 0.7
5.0 0.27 0.38 0.46 0.53 0.60 0.65 0.76- 0.85 0.93 1.00 1.07 1.13 1.2
6.0 0.34 0.47 0.58 0.67 0.75 0.82 0.95 1.06 1.16 1.26 1.34 1.42 1.5.
7.0 0.41 0.58 0.71 0.82 0.92 1.01 1.16 1.30 1.43 1.54 1.65 1.75 1.8
8.0 0.47 0.70 0.86 0.99 1.11 1.21 1.40 1.56 1.71 1.85 1.98 2.10 2.2
9:0- 0.59--- 0.83 -1.01.. 1.17. __ 1.31 1.43 - -1.66-- _-1..85 - 2_03 .. . 2.19 2.34 2..48 i_2..6--
10.0 0.68 0.96 1.17 1.35 1.51 1.66 1.92 2.14 2.35 2.53 2.71 ..87 13.0:
r----1
12.0 0.87 1.23 1.51 1.74 1.95 2.13 2.46 2.75 3.02 3.26 3.48 ( 3.69 3.S
14.0 1.08 1.52 1.86 2.15 2.40 2.63 3.04 3.40 3.73 4.02 4.30 4.56 4.e
16.0 1.29 1.82 2.23 2.58 2.88 3.16 3.65 4.08 4.47 4.82 f 5.16 5.47 5.'
18.0 1.51 2.14 2.62 3.02 3.38 3.70 4.27 4.78 5.23 5.65 6.04 6.41 6.
20.0 1.74 2.46 3.01 3.48 3.89 4.26 4.92 5.50 6.02 6.51 6.96 7.38 7.
22.0 1.97 2.79 3.42 3.94 4.41 4.83 5.58 6.24 6.83 x7.38 7.89 8.37 8.,
24.0 2.21 3.12 3.83 4.42 4.94 5.41 6.25 6.99 7.65 I 8.26 8.84 9.37 9..
26.0 2.45 3.46 4.24 4.90 5.48 6.00 6.93 7.74 8.48 9.16 9.80 10.40 11.-
28.0 2.69 3.81 4.66 5.38 6.02 6.59 7.61 8.51 9.32 110.10 10.80 11.40 12.
30.0 2.93 4.15 5.08 5.87 6.56 7.19' 8.30 9.2810.20 111.00 11.70 12.40 13.
_..
32.0 3.18 4.49 5.50 6.35 7.10 7.78 8.99 10.00 11.00 11.90 12.70 13.50 14.
74.0 3.42 4.84 5.92 6.84 7.65 8.38 9.67 10.80 11.80 12.80 13.70 14.50 15.
36.0 3.66 5.18 6.34 7.31 8.18 8.97 10.40 11.60 12.70 13.70 14.60 15.50 16.
38.0 3.90 5.52 6.75 7.80 8,72 9.95 11.00 12.30 23.50 14.60 15.60 16.50 17.
40.0 4.14 5.85 7.16 8.27 9.25 10.10 11.70 13.10 14.30 15.50 16.50 17.50 18,
45.0 4.71 6,67 8.17 9.43 10.50 11.50 13.30 x14.90 16.30 17.60 18.90 20.00 21.
50.0 5.27 7.45 9.12 10.50 11.80 12.90 14.90 + 16.70 18.20 19.70 21.10 22.30 23,
55.0 5.79 8.18 10.00 11.60 12.90 14.20 16.40 18.30 20.00 21.70 23.10 24.60 25.
60.0 6.27 9.87 10.90 12.50 14.00 15.40 17.70 ( 19.80 21.70 23.50 25.10 26.60 28.
Vertical lines indicate normal limits of simple slapes.
i
r
Revised February 1986
SLOPE i.ElPM IN !EE?
500 550 600 100 800 1000 1200
1300 1400 1600 1800 2000 2200 2400 2600
0.10 0.105 0.11 x.11 0.115 0.12 0.12 0.125 0.0.135 0.14 3 0.13 , 0.145 0.145 0.15 0.15 0.155
3.12 0.11 0.115 0.12 0.1'25 0.13 0.13 0.13 �_1 ��
-- 1.11 0.13 0.14 0.14 0.14 0.15 0.16® 0J..16 r 0.16 0.17 0.17 0.175 0.18 0.18 0.185
3.21 0.22 0.22 0.23 0.24 0.26 r-0.27 0.28 0.28 0.30 0.31 0.32 0.33 0.33 0.34
3.33 0.33 0.34 ,�¢ 0.: .7�0.40 0.42 0.40 0.44 0.46 0.48 0.49 O.SI 0.52 0.53
3.46 0.48 0.49 j 0.51 0.54 0.5; 0.60 0.62 0.63 0.66 0.68 0.70 0.72 0.74 0.76
0.76 0.79 0.82 0.87 0.92 1.00 1.08 1.12 1.15 1.21 1.27 1.32 1.38 1.42 1.47
1.2^: 1.25 J 1.31 1.41 1.51 1.69 1.85 1.93 2.00 2.14 2.27 2.39 2.51 2.62 2.73
33,,'-'Z1 . 1.57 1.65 1.78 1.90 1. 12 2.33 2.42 2.51 2.69 2.85 3.00 3.15 3.29
1.84 I 1.93 2.02 2.18 2.33 2.60 2.65 2.97 3.08 3.29 3.49 3.68 3.86 4.03 4r.
w2.21- 2.32 2.42 2.62 2.80 3.13 3.43 3.57 3.70 3.96 4.20 4.43 4.64 4.85 5.05
2.b2 2:75 2.87--- 3.10 3.31_ 3.70 4.06 4.22 4.38 4.63 4.97 5.23 5.49 5.73 5.97
3.03 -3.18 3.32 1 58 3.83 4:28 4.69 4.89 5.07 5.42 5.75 6.06 6.36 6. - .
3.39 4.08 6.27 4.61 4.93 5.51 6.03 6.28 6.52 6.97 7.39 7.79 8.17 8.5533 8 8.8888
8
5.04 5.27 5.69 6.08 6 80 7.45 ?.7S S.QS .50 9.12 9.62 10.09 10.54 10.97
-.17 6.05 6.32 6.82 7.29 .i5 0.89 11.31 12.09 12.82 14.80 15.41
8.93 9.30 9.65 10.31 10.94 11.53 12.09 12.63' 13.15 "
76 7.09 7.40 7.99 8.55 8 8.i6 10.50 1 13.51 14.17
7.78 8.16 8.52 9.20 9.84 11.00 12.00 12.54 13.01 13.91 14.75 15.55 16.31 17.04 17.73
.d2 9.25 9.66 10.40 11.20 12.50 13.70 14.22 14.76 15.77 16.73 17.64 18.50 19.32 20.11
8
8.82 10.40 19.668ri 10.70 12.50 14,00 15.30 15.93 16.53 17.67 18.74 19.76 20.72 21.64 22,53
11.00 10.50 12.00 13,00 13.90 15.50 17.00 17.66 18.33 19.59 20.78 21.90 22.97 23.99 24.97
20 14.20 15.20 17.00 18.60 19.40 20.14 21.53 22.83 24.07 25.24 26.36 27.44
12.00 12.60 13. 0 15.50 15.60 18.60 20.30 21.15 21.95 23.47 24.89 26.24 27.52 28.74 29.92
.3.10 13.80 14.2
=.20 14.90 15.60 16_80 18.00 20.10 22.00 22.90 23.77 25.41 26.96 28.41
.5.30 15.00 16.$0 1$.10: 19.30 21.60 23.70 24.66 25.59 27.35 29.01 30.58
_6.40 17.20 17.90 19.40 20.10 23.20 -25.40 26.40 27.39 29.28 31.06 32.74
$.30 19.I0 20,60 22•/0 24.70 27.00 28.12 29.80 31.20 33.09 34.88
-6.40 13
`:8.50 18. 0 20.30 21-90 23.40 26:20 28.70 29.83 30.95 33.09 35.10 37.00
21.10 22.10 23.10 24.90 26.70 29.80 32.70 33.99 35.28 37.71
:3:60 24.70 25.80 27.90 29.80 33.30 36.50 37.97 39.41 42.13
25.90 27.10 28.40 30.60 32.70 36.60 48.10 41.73 43.31 46.30
18.10 29.40 30.70 33.20 35.50 39.70 43.50 45.24 46.95 50,19
LS values right of the vertical limes will normally
be used in calculating comglex sloPas. s.
15
TASLS 5 C' VALUES MULCH FACTORS
Type of Mulch land Fcctor length
mulch Rate Siooe C limit
Tons per ocre Percent fuer
None 0 oil 1.0
Straw or hay, 1.0 1.5 0.20 200
tied down by 1.0 6.10 .20 100
anchoring and
tacking 1.S 1.5 .12 300
equipment' 1.5 6-10 .12 150
Oo. 2.0 1-5 06 400
2.0 6.10 .06 200
2.0 11-15 .07 150
2.0 16-20 .11 100
2.0 21-25 .14 75
2.0 26.32• .17 50
2.0 34.50 jv 35
Crushed stone, 135 '116 OS 200
i.: to Mi in 135 16-20 .05 ]SO
135 21-33 .05 100
13.5 34-50 .05 75 i
Oa. 240 <21 .02 300
240 21-33 .02 200
2s0 34.50 .02 150
Wood chips 7 G 16 .08 75
a 7 16-20 .08 SO
n 00. 12 <16 .05 150
.t 12 16-20 .05 100
12 21-33 .05 75
0o. 25 <16 .02 200
25 16.20 -02 150
2.5 21-32 .02 100
25 3-t-50 .02 75
i From Meyer and Parts (24)- Developed:by an interagency work-
shop group an the basis of field experience and limited research
data.
Maximum slope length for which the specified mulch rare is
considered effective. When this Rmir is exceeded, either a higher
application rare or mechanical shortening of the effective slope
length is required,
.i When the straw or hay mulch is not anchored to the soil, C
values an moderate or steep slopes of sails,ha-ing K values greater
i than 0.30 should be taken at doublw'tha values given in this table.
A-8
cn
TABLE C • YALU�S WASHINGTON COUNTY ..I
F�4
r (fy
cn
F"
w 0
40 H
co
02
s
• � LJ
•
H
f ul
j( ta,j
LU
LD <
cy
m Lu
C.3 >
m
LL- UJ
F-
U
. • LLL
U
.• C,C
LU
w
CL
cc
A-9
t•'IGURE t INTERCEPTOR SWALE
t n min, i
Laved Bow-
ROW Other I I Cxass at Rock �' I
'1000 f
I' 1 Soacin9•[00', 0'.or 3W'
. ft rtvrr. 20 —
' de0eno+n9 on Slave
Bottom Width 2 feet minimum;the bottom width Shall be level
04901h t toot minimum
Side Slope 2H, or flatter
Grade Maximum 5 percent.with positive drainage to a suitable outlet
(such as seditlentation pond)
Stacu:zation Seed as pe+'Grassed Channel or,
Rocxc 12 inches thick, pressed into tsanx ar+d extending at least a
inches verveat from the t ortom.
FIGURE 2 TFNIPORARY INTERCEPTOR DIKES
I
� o�rrarar�9 oaea f
�, 4 m55Y.ProCtot
F i g
1 I f
rntarrmorot ddea spaeusq.tQC'.:':'0'Or I
' 300'dal"MA9 on 9raa0
a A-10
r ..
{
FIGURE 3 LEVEL SPREADER
Ineerc3ptar Senn
Last
'-
Last 20'of Imerceptorr—
not to exceed 1%grade
Wim' VY
1 'C
Channel Grade 0%
,' .�� .► "`� I S=aize-dSlope
" v'Gravel Berm Spreader
Undistumed Outlet �
,
i
,,; „!"%.i„• t•min �
lipj�
2:1ortianer
41 6-min
A-11
FIGURE a SEDItitEyT TRAP
17 Lt+
J ✓�� r
2'.'HCl//lY7�G.aC/�f611 IIFa.: �:... :p•..r:;�r. 1 i�,b7OX.`I
�V;nVLf
SGCT/ON
i
?vcrf,"Ow Sri+./1u�sy
1.5. S�.�irsrGsv� �/oraae ate`-�•..���`�_���
Depth or^2- rte' ;Ion
,..40 sr.Jc-d
qoT�
FIGiJRFE 9 PIPE SLOPE DRAINS
Discnarge into a stabilized S3RR Dike
watercourse or a sediment
trapping device or onto a ;1T
stabiiizedarea
Corrugated metal
/^
or a05 pipe
Y I,,.. .•fir ,N��,�'P• •� _ ..� `.
7r-
slope=2:1 H s 0*t2' 6Q 30 ,
' Slope 2%or
,�� • i t v steeper
Corrugated `; 6"min
metal ' Cumd wall ;
f . Staneared flared
or AOS pipe entrance section
Diameter 0 (for pipe? t�') 1 7 ;
Ricrap Zwt. tl A,3it-Al
s Oeptn of apron snail be
�.--- equal to pipe diameter
x min.at less
man v%slope
A-13
y
t
J<ZTA�� ED r p3TR. UMO N ENTRANCE
�.
@y
F
ZG
o r
s
r
'99/!1L
!2 MIX
F
Q(IAfRr SPA
?P l/TArCSi,�«rs4'SS .r�r' t
4-�14