PP35-136 SCO
Oh.n: nc* ^ :• i ;•;:-..-; .I-,.] Cr
                                     Cleaning
Pitt  (RoS
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                                       FPA/600/2-85/038
                                       Anvil  1985
        i.'M ami Cor troll ing Urban Runoff
         Street ano  Sewerage  Cleaning
                  by
             Robert  Pitt
  Consulting  Environmental  Engineer
     Blue  Mounds,  Wisconsin  53517
   Cooperative  Agreement  CR-805929
           Project  Officer

            Richard Field
   Storm and Combined Sewer Program
Water Engineering Research  Laboratory
       Edi -on,  New  Jersey  08837
       This study was conducted
       in cooperation with the
   Storm and Surface Water Utility
      Bellevue, Washington 98009
WATER ENGINEERING RESEARCH LABORATORY
  OFFICE OF RESEARCH AND DEVELOPMENT
 U.S. ENVIRONMENTAL PROTECTION AGENCY
        CINCINNATI, OHIO 45268

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TECHNICAL RETORT DATA
//V. Jir rr:.i ,'j.iin. . : • •.-< ,"i f'-r rnr". iV/ivr f.i — -/C."T'
'- ' ' \ v ->
j PA| . - ;7~ฐr' ,-pe
t'h.v--,, V-->:ino aid Controlling Urban Runoff Through
Street and Sev.erane Cleaning
A ^ T n , "" ^ V
Robert Pitt
1 r-tHFCBV NG ORGANIZATION MAMC AND ADDRESS
Robert Pitt
Consulting Environmental Engineer
Route One
Blue Mounds, Wisconsin 53517
1 : S"C-,?.,?=> NAME A NO ADDRESS
Water Engineering Research Laboratory--Cin . , OH
Office of Research and Development
U.S. Environmental Protection Anencv
Cincinnati , Ohio -15268
3 fll ^ปi li ff 1 •(, Aut !-S--. -WNC r-
\ -* s L ^ - J '-• L^^>
c, RF^O^TC^'E.
April 19S5
6 PtRFORMING ORGANIZATION CODE
8 PERFORMING ORGANIZATION REPORT NO
10 PROGRAM tLEMENT NO
11 CONTRACT GRANT NO.
Grant, CR-8059P9
13 TYPE OF REPORT AND PERIOD COVERED
Final ; 1980-1983
14. SPONSORING AGENCY CODE
EPA/600/14
 is SJPPLEVENTARY NOTES
  Project Officer:  Richard Field; telephone (201)321-6674
 16 ABSTRACT
       A series  of projects conducted  from 1978 through  1983  in  Bellevue,  Washington,
  to  investigate Bellevue's urban  runoff  sources,  effects,  and potential  controls.
  This  report  presents  results  of  trie  project  conducted  by  the City  of  Bellevue  that
  was  sponsored  by the  Storm and  Combined Sewer Section  of  the U.S.  EPA.   The  project
  lasted from  1980 to 1983 and  was mostly concerned  with urban runoff characterization
  and  control  by street and sewerage  cleaning.   This project  completely monitored  more
  than  300 urban runoff events  in  two  residential  areas  during the  project period.
  Flow-weighted  composite samples  were analyzed for  a  core  list  of  important constitu-
  ents.   Complete flow  monitoring  results allowed  detailed  descriptions of urban run-
  off  quality  and quantity, and allowed estimates  to be  made  concerning the contribu-
  tions  of flows and  pollutants from  different  source  areas.   Street surface and sew-
  erage  particulates  were also  collected  and analysed  to determine  the  effectiveness
  of  street  and  sewerage cleaning.  Most  of the heavy  metals  were determined to  ori-
  ginate from  street  dirt,  but  street  cleaning  was found to only control  urban runoff
by a maximum or about ten percent. A special modified street cleaner was tested and
found to he much more effective in removing the smaller sized street dirt that is
washed off these streets by rains. Catchbasin cleaning twice a year was estimated
to be about 25 percent effective, at the most.
17. KEY WORDS AND DOCUMENT ANALYSIS
J DESCRIPTORS

13 DISTRIBUTION STATEMENT
RELEASE TO PUBLIC
b. IDENT'FIERS/OPEN ENDED TERMS

19. SECURITY CLASS (Tha Report)
UNCLASSIFIED
20 SECURITY CLASS (This past)
UNCLASSIFIED
c. COSATI Field/Group

21 . NO. OF PAGES
476
22. PRICE
EPA Forr- 2IIO-1 (S-73)

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                                  DISCLAIMER

     Although the information described in this document has  been funded
wholly or in part by the United States Environmental  Protection Agency
through assistance agreement number CR-S05929 to the  City  of  Be^^vue, it
has not been subjected to the Agency's required peer  and administrative
review and therefore does not necessarily  reflect the views  of  the Agency
and no official  endorsement  should be inferred.
                                     ii

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                                   FOREWORD

     Thp U.S. Environmental Protection Agency is charged hy Congress with
protect i nij PIP Nation's land,  air, and water systems.   Under a mandate of
national environmental laws, the agency strives to formulate and imple-
ment actions leading to a compatible Balance between human activities and
the ability of natural systems to support and nurture  life.  The Clean
Water Act, the Safe Drinking Water Act, and the Toxics Substances Control
Act are throe of the major congressional  Jaws that provide the framewor<
for restoring and maintaining tne integrity of cur Nation's water,  for
preserving and enhancing the water we drink, and for protecting the
environment frc'n toxic substances.  These laws direct  the EPA to perform
research to define our environmental problems, measure the impacts, and
search for solutions.

     The Water Engineering Research Laboratory is that component of EPA's
Research and Development program concerned with preventing, treating, and
managing municipal and industrial wastewater discharges; establishing
practices to control and remove contaminants from drinking water and to
prevent its deterioration during storage  and distribution; and assessing
'he nature and controllability of releases of toxic substances to the
air, water, and land from manufacturing processes and  subsequent product
uses.  This publication is one of the products of that research and
provides a vital communication link between the researcher and the  user
cpmnuni ty.

     A comprehensive evaluation of the sources and control of urban runoff
was conducted during a two-year study in  Bellevue, Washington.  This project
was one of several cooperating studies that examined the effects of urban
runoff on receiving water beneficial uses, the sources of problem pollutants
and flows, and the control of urban runoff in Bellevue.   The unique Bellevue
rain conditions enabled another urban runoff perspective to be obtained.
Much data was also obtained on urban runoff characteristics and the washoff
of street surface participates during rains.  These data allowed simple re-
lationships between rain conditions and contributing source areas to be
developed.
                               Francis T. Mayo
                                   Di rector
                    Water Engineering Research Laboratory
                                     11

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                                   ABSTRACT

     A series of projects were conducted  from 1978 through  1983 in  Bellevue,
Washington, to investigate Bellevue's  urban runoff sources,  effects,  and
potential controls.  These projects were  conducted by  the  City  of  Bellevue,
the U.S. Geological Survey, the University  of Washington,  and  the  Municipality
of Metropolitan Seattle.   This report  presents results  of  the  project conducted
by the City of Bellevue that was sponsored  by the  Storm and  Combined  Sewer
Section of the U.S. EPA.   This project lasted from 19RO to  1983 and was  mostly
concerned with urban runoff characterization and control by  street  and sewerage
cleaning.  This project completely  monitored more  than  300  urban runoff  events
in two residential  areas  during the project period.   Flow-weighted  composite
samples were analysed for a core list  of  important constituents.   Complete flow
monitoring results  allowed detailed descriptions of  urban  runoff quality and
quantity, and allowed estimates to  be  made  concerning  the  contributions  of flows
*.id pollutants from different source areas.  Street  surface  and sewerage parti-
culates were also collected and analysed  to determine  the  effectiveness  of
street and sewerage cleaning.  Most of the  heavy metals were determined  to
originate from street dirt, but street cleaning was  found  to only  control  urban
runoff by a maximum of about ten percent.   A special modified  street  cleaner
was tested and found to be much more effective in  removing  the  smaller sized
street dirt that is washed off these streets by rains.   Catchbasin  cleaning
twice a year was estimated to be ,=
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                                   CONTKNTS
Foreword
•\bsti-.ict
(on fonts
Ackp-,w Le
  1. Kxooutive Sunmary
     1. Introduction ........ . ................ . ........................    -"-
        Obj ert ives . . ........... . .....................................    2
        Methodology ............ . ......................................    2
     2 . Summary ind  Conclusions .......................................    4
        Identification of Problem Pollutants ..........................    4
        Sources of  Problem Pollutants .................................    6
        Selection  of Control  Measures .................................    7
     3. Study Area  Description ........................................   10

 II. Urban HydrolDgy
     4. Bellevue Rain Conditions ......................................   15
     5. Runoff Quantity ...............................................   24
        Observed Rainfall and Runoff Volumes ..........................   24
        The Effects  of Land Use  on Runoff Quantity ....................   28
        Seasonal Trends  ..n Runoff and Baseflow  Quantity ...............   42

III. Urban Runoff  Water  Cuality
     6. Urban Runoff Quality ..........................................   48
        Introduction ..................................................   48
        Observed Urban Ruroff and Baseflow  Quality ....................   49
        Comparison  of Observed Urban Runoff  Constituent
          Concentrat1' ens with Water Quality  Criteria..... ............   58
        Mass Yields  of Pollutants from Urban  Areas, ............... ....   66
        Source Area  Contributions of Uuban  Runoff  Pollutants ..........   "74

 IV. Street Dirt and Stirm Drainage Particulates
     7. Street Dirt  Characteristics ...................................   88
        Factors Affecting Street Cleanliness ..........................   88
        Street Surface Particulate Accumulation
          and Deposition Rates ........................................   93
        The Distribution of Street Dirt  in  Driving
          and Par):ing Lanes ...................................... .....  102
        Chemical Strengths cf Street Surface  Particulates .............  107
     8. Sewer Systen Particulate Accumulation Studies .................  115
        Catchbasin Observations .......................................  115
        Fine Survey  and Observations ..................................  132

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  V.  I'i ban Runut t  Control Measures                                      ,,,
     9.  Street Cleaning Effects on Observed Runoff Quality	    -
                                                                        IJu
        K ishoff of Street Dtrt	
        Runoff Water Quality Concentrations and Yields During
          Periods  ot Different Street Cleaning Activities	
        Relationships Between Street Load, Runoff Yield,
          a id iUmof f Volumes	
        Coraparisio-is of Observed Runoff Concentrations
          in the Two Test Basins	  f
        Summary	• •	
    10.  Street Cleaner Performance.....	•	
        Street Cleaning Test Schedule	
        Performance Tests	  188
        Bellevue Street Cleaning Routes, Operating
          Characteristics, and Costs	
    11.  Effects of Storm Drainage Particulates on Runoff Quality	  215

 VI .  References	  223

VII.  Appendices
     A.  Rain and Runoff Data	  226
     B.  Street Dirt Characteristics	  307
     C.  Street Cleaner Performance	  382
     D.  Storm Drainage System Data	  417
     E.  Sampling Procedures	*	  426
        Stormwater Sampling	  426
        Street Surface Partlculate Sampling
          and Experimental Design	  428
        Driving Lane Test	  436
        Across the Street Tests	  436
        Catchbasin Inventory and Sampling	  437
     F.  Street Dirt Sample Preparation and Data Handling	  438
        Introduction	  438
        Sample Description	  438
        Information to be Noted During Street Cleaning
          Operations and Sample Collection	  438
        Physical Analysis	,	  441
        Calculation of Street Loading Values	  445
        Summaries  of Rain Events	  448
        Preparation of Loading Summaries	  451
        Sample Compositing for Chemical Analysis	  451
        Summary	  455
     G.  Sources of Urban Runoff Pollutants	  458
        Chemical Quality of Rocks and Soils	  459
        Street Dust and Dirt PoJ lutant Sources.	  459
        Urban Agricultural Sources  of Urban Runoff Pollutants	  460
        Atmospheric Resuspension, Transportation and
          Redeposition of Urban Runoff Pollutants	,	,	  461
        Resuspension of Source Area Particulates	  462
     H.  Reactions  and Fates of Urban Important
          Runoff Pollutants	

                                    VI

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                                '>CK.NOWL;:DCMKMS
     Sinr.TL- gratitude goes  to  Mr.  Richard  Field  of  the  U.S.  Environmental
Pnu <  ' 1,111 Agency (Storm and  Combined  Sewer Section,  Edison,  New J. rsey),  for
•     .ipport and assistance during  this  project.

     The considerable  field  woi'k  for  this  project  could  not  have been carried
out without the effort and cooperation  of  the  Balievue  Storm  and Surface
Water Utility. Special thanks are  extended  to  Joy  Wherley,  David Renstrom,
and Lnrrie Murray. The extra  effort extended by  the  street  cleaner operators
and other Public Works personnel  who  participated  in  this  study is
appreciated. This project would not nave been  successful without the support
and encouragement of Pam Bissonnette,  the  Storm  and  Surface  Water Utility
Manager, and Bellevue's Principal  Investigator for the  Bellevue Urban Runoff
Program.

     The help of Roger Sutherland,  of  CH2M-HILL,  in  assisting with the
sewerage observation study plan and data analysis  was  invaluable. The
cooperation ?nd sharing of preliminary  results from  the  other Bellevue Urban
Runoff Program participants  (University of  Washington,  Seattle METRO, and  the
USGS) was very important and  appreciated.  Special  thanks are  extended to the
USGS, especially Edmund Prych,  for  assistance  in  obtaining  crucial field data
during the study.
                                     VI1

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                                  SECTION 1
                                 INTRODUCE ' u.N
     The Bellevue urban runoff program is one of about 30 urban  runoff
projects being conducted throughout, the country as part of  the Nationwide
Urban Runoff Program (NURP) for the U.S. Environmental. Protection  Agency
Ch-PA). The Bellevue program is made up of four different coordinated
projects. These include projects conducted by the U.S. Geological  Survey
(USGS) (funded by the USGS arm NURP - the Water Planning Division  of  the
EPA), the University of Washington (funded by the Corvallis Lab  of the  EPA),
Seattle METRO, and the City of Bellevue (funded by the Storm  and Combined
Sewer Section of ths CPA and the City of Bellevue). The project  described in
this report was conducted by the City of Be'levue.

     A major task in Bellevue's project included n.onitorlng the  qualit;1 and
quantity of stormwater runoff from two urban basins in the  City  of Bellevue.
Street surface particulate samples were collected in  these  two basins,  along
with selected storm drainage sediment samples. The City of  Bellevue conducted
various street cleaning operations in the two test basins.  The USGS (Ebbert,
Poole, and Payne, 1983, and Prych and Ebbert, undated) also monitored storm
runoff quality and quantity in these two test basins; they  used  different
sampling techniques to monitor fewer stortns, but in more detail. The  USGS
monitored rainfall and dustfall quality and quantity  along  with  the
performance of a series of detention basins at a third Bellevue  test  site
(148th Avenue SE). The USGS and the City of Bellevue  projects were carefully
coordinated to enable all objectives to be met with minimum interference. The
Seattle tETRO project (Galvin and Moore, 1982) involved collecting urban
runoff and other urban water and dirt samples for priority  pollutant
analyses. The City of Believue project was also coordinated with the  METRO
project to supply the urban runoff and street surface particulate  samples for
the priority pollutant analyses. The University of Washington's  projects
(Pedersen, 1981; Richey, 1982; and Scott, Steward, and Stober, 1982)
invrstigated receiving water conditions near the Bellevue test basins and in
other locations unaffected by urban runoff. The University  of Washington
project studied physical, chemical, and biological qualities  of  various
receiving waters to identify impacts associated with  urban  developments on
receiving water quality. Therefore, a substantial amount of information
concerning Bellevue's urban runoff conditions and effects is  available  from
these four associated projects. A summary report prepared by  Pitt  and
Bissonnette (1983) reviews all these separate project reports and  presents
overall Bellevue urban runoff conclusions.

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     llu- project ciMuiuc t ed  hv  the  City of Bellevue included objectives  to
s.itislv (.lie Nationwide  l;rh,m  Runott  Crogr.in, the ETA's Storm a.id Combined
.Newer Seet icn,  Kei'.lon X  of  the  Kl'A,  and objectives specific lor  the City of
m'llevne's Storm Dr.iin.igi.-  Utility  .  The project objectives are described
be low:

     1) The principal project  objective was to determine the effectiveness  of
street  cleaning  <.n  controlling  urban runoff pollutants in bellevue. Several
other projects  have  been conducted in other parts of the country previous  to
tnis project.  Several of the  other Nt'RP projects are also currently
evaluating street  cleaning  under a variety of climatic and geographical
conditions. Hie  Bellevue climatic  conditions are unique in that  the moderate
arrounl of  rainfall  occurs  relatively evenlv throughout the year, with no long
periods without  any  rain.  The  erosion potential of undisturbed areas is low.
From previous  studies,  it  is  known that the street surface particulate
loadings in Lru  Pacific  Northwest  are naturallv low and the urban runoff is
of relatively  h'.gh  quality.  These  conditions contrast with the conditions  for
most of the comprehensive  street cleanint management projects conducted
elsewhere, especially in the  San Francisco Bay Area where tiie rainfall  is
much less  and  is concentrated  in fewer months of the year. The street
loadings in other  test  cities  car.  be quite high and the urban runoff quality
can be quite  poor.  These Bellevue  tests will therefore be useful in defining
the applicability  of  street  cleaning as an urban runoff best management
practice under significantly  different environmental conditions.

      2) Stormwater  quality  and quantity characterization information
obtained during  this  study is  a significant contribution to the  urban
stormwater data  base. Many urban runoff events were monitored during this
project and the  information  obtained has been added to the STORET National
Water Quality  Data  Base. The  other NURP projects also have their runoff water
quality snd quantity  data  included in this data base. Site specific
runoff/rainfall  relationships  for  Bellevue have been obtained which will
allow predictions  of  runoff  changes  due to urban development to  be made.

     3) Sources  of  urban runoff pollutants, especially street surface
paruiculates,  were  also  cr.isidered in this project. The effects  of source
area pollutant loading!  on runoff  water quality were examined.

     4) The runoff  water quality ana qua: <.iry data and the street surface
particulate loading  data obtained  can be usi-d by the City of Believue as the
beginnings of  a  more  comprehensive data bas? for the whole city. This can
support a  water  quality  management p'an as part of the City of Bellevue's
Storm Drainage Utility.
METHODOLOGY

     All elements  of  Bellevue's  urban runoff project were coordinated  with
the three other  local  projects  being conducted by the USGS, Seattle METRO,
and the University  of  Washington.  Early in the project planning  phase,  it was

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.1.,-idr.l t,..u  two  study  anas  ;.houlu bv selected. These  areas,  whi.'h are
i.Vs.Til.,-,1  1-1  .section  j,  ,ue  quite similar and iairly  close.  Hits' are both
t.'lalU i.rhmi-.ed  with  mist ly sirigle family mousing.  Their  .storm drainage
s\s.te.us were'  thorough!v  'napped and investigated to ensure  no
cin.ss-coMPecr i-ms  or  illegal  discharges, hach of the  two  basins drain at a
sin.1!.- initial! and  are  e i-\\  about 100 acres (40 ha)  in  size. A single
stoi.T.watei i.Hin: torinr,  station was located at the outfall  of  each <>l these
basins lor stormwater  sampling.  The sampling equipment  selected tor this
project was  capable  ol  ,:utonatica1ly sampling total  storm  flow-weighted
,.oir,josite  samples  tor  a  broad variety of storm conditions.  Appendix h
descrioes  the  sampling  equipment and procedures in detail.  The information
obtained  trom  '.hese  automatic samplers and flow meters  i>ere  supplemented hy
tiie. sampling  and  monitoring  equipment operated by  the USCS  at  the same
locations. As  many  storms  as  possible were sampled during  the  ^wo-year study
program at each of  these two  locations. Almost all storms  havi'.ig more than
0.1 inch  (2.5  mm)  of  total  rain  and many of the smaller rains  were completely
sampled.

     During  the two-year project period, extensive street  cleaning was
conducted  in  either  one  or  the other test basin, except for  a  several month
r..riod of  time for  basin calibration when no street  cleaning operations u^re
conducted.  Intensive  street  cleaning was conducted during  both wet and dry
reasons in each basin.  This  allowed comparing the  observed  runcff water
quality in each basin  with  and without street cleaning.

     btreet  --urface  particulate  samples were also  obtained  immediately btfore
and atter  --ich street  cleaning operation and intermittently  duri ng periods of
no street  cleaning.  This resulted in a much more detailed  description of the
effects of the street  cleaning operations jn this  potentially  important urban
runoft pollutant  source  area. Periodic samples of  sediments  from the storm
drainage  s\stem were  also  obtained and analyzed to estimate  the potential
benefits  of  sewerage  cleaning on improving urban runoff quality.

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                                   SECTION  J
                            SUMMARY AND CONCLUSIONS
      I !u-re  art  three  separate  phases  in designing an urban runoff control
;•• '>;r.i",i. Those  include  identification of the problem pollutants, determining
Vu> sources o,  the  problem  pollutants,  ard  selecting the most appr r.riate
contiol measures. The  four  Bellevue  urban runoff projects addressee these
i ssucs .
IDENTIFICATION  OF  PROBLEM  POLLUTANT?

     The University  of  Washington study examined existing effects that urban
runoff may  be having  on aquatic  organisms.  The other three Bellevue urban
runoff projerts  all  have  important characterization aspects. These projects
identify potential problem pollutpnts  by comparing the observed runoff water
qualitv with  beneficial use  water quality criteria and with concentrations
found  in other  waste  streams ard  receiving  waters. This information can be
used to identify vhich, if any,  pollutants  need to be controlled and to what
extent. The unique assimilative  capacities  of the Bellevua receiving waters
needs  to be considered. Pollutants that are causing potential problems can be
identified  and  appropriate control goals can be estimated.

     The meteorological conditions at  Bellevue are discussed in Section 4 and
Bv-^levue urban  hydrology  conditions are discussed in Section 5 of this
report. These two  sections point  out some of the special circumstances
associated  with  Believue's urban  runoff. Bellevue receives a moderately large
amount of rain  every  year  (about  35 inches, or 890 mm) with several summer
months drier  than  the other  noi.chs. However, the dry periods between rain
events are  quite small, even during the dry season. Dry periods of more than
a week are  quite rare,  but may occur.  Rains come on the average about once
every  two or  three days throughout the year. Slightly more than 100 rains may
occur  per year, with  each  rain being quite  small. Most of the rains are less
than 0.25 inch  (6.4 mm) in volume, although the largest rains monitored
duiing this study were  several inches. This is in sharp contrast to most
other  locations  in the  country.  In the San  Francisco Bay Area, where previous
comprehensive street  cleaning  and urban runoff studies have been recently
completed,  the  annual rainfalls  are much less than in Bellevue, but the rains
are typically larger  in size.  The interevent period in the San Francisco Bay
Area is several days  during  the  wet winter  season, but can be several months
during the  summer. The  total annual rainfall at Bellevue is similar to the
total  rainfall  at some  of  the  other NURP project sites in the country that
are currently investigating  the  effects of  street cleaning on urban runoff;
however,  the average  rairs in  these other areas are much larger than the

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.u,r.,o- rains in Bellevne, with significantly longer interevent  periods
( spi-cit leal ly Milwaukee and Wins ton-Salem)

     The .-mount  of rain that drains off an urtwn area as urban  runoff is
dependent. uron nuny factors. These factors are discussed In  Section  5 and
mchui, ,uch things as soil moisture conditions, soil infiltration  capacity,
rain i.Uensitv.  and rain duration. The moist soil conditions  in  Bellevue (due
Lo the hiKli frequency of ruins) tends to increase the fraction  of  rain that
occurs as nmotf. However, the small volunes and the small intensities of
each individual  rain allows much of the water to infiltrate  into  the soil.
tor both stud} years and test Nasins , only about 25 percent  of  the  rain that
fell in the test basins left the basins as runoff. There was  a  substantial
amount of scatter in this value, but the smaller rains  typically  had the
smallest Kv (the ratio of unit area runoff to rainfall) values  (rains of
about u.l inch,  or 2.5 mm, had Rv values of about 0.1 for the dry  season and
about U.2 for the wet season), while the largest rains  had larger  Rv values
(rains of about  2.5 inches, or 64 mm, had Rv values of  about  0.2  to  0,3
during the dry season and about 0.3 to 0.4 during the wet season).

     Base flows  were also monitored and sampled during  this  project. An
important amount of the total urban water flows in both of the  test  basins
occurred between rains, as baseflow. The base flow in the Surrey  Downs basin
accounted for about 25 percent of the total urban flow, while the  base flow
in Lake Hills was only about 12 percent of the total urban flew.  Observed
urban flow and quality variations were much less than found  in  more  arid
areas. This has  a major influence on the effects of urban runoff.  Immediate
urban runoff effects (during storm flows) are mostly related  to  fast and
major changes in receiving water quality and quantity (as in a  slug  flow
situation). If the flows and quality do not change radically, the  receiving
water aquatic organisms do not experience as much stress because  the existing
organisms have already adjusted to a long-term degraded condition.

     The runoff water quality data presented in Section 6 shows  that the
observed Bellevue runoff water quality was much better  than  observed in many
other locations. The baseflow quality, on the other hand, was much worse than
expected. This was probably because the study basins were completely
urbanized and the baseflows were mostly polluted percolated  urban sheet flows
from previous storms that were draining out of the surface soils.  In basins
with undeveloped upstream areas, the baseflow would originate mostly from
nonurbanized upper reaches and would have much better quality.  The urban
hydraulic conditions in Bellevue allow the observed runoff water  quality to
be compared to beneficial water quality criteria. Typically,  urban runoff
should not be compartd to water quality criteria because the published
criteria were established for continuous discharges, while urban runoff is
usually considered e slug discharge. However, as previously  noted, ^he
baseflow ard urban runoff qualities in Bellevue do not  differ greatly.
Therefore, as an approximation to identify potential problem pollutants, the
beneficial use water quality criteria for aquatic life, published by EPA
(I97b), was compared with the observed Bellevue urban runoff quality. It was
found that direct receiving water effects from urban runoff  may not be
significant for most rain events (except possibly for ammonium  and nitrate
nitrogen). Most  of the Bellevue urban runoff water quality problems are

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t'\|-i->ii-d I" In-  ,is.-,n, i.iu '  with  lung-term effects caused by settled  organir
•i'1'] iiuu v-.in -. i- dehiis  and  ,>.i r t i m 1 ,u es .  This material ran silt up  spawn i PR
'1t'l'i; in r IM IVllt'vue  in h,in streams and  po.sibly introduce high  concentrations
ot  toxic r,.it cria 1 s  dinclly  to  the sed i ITHMI t s .  Identified potential  long-term
problem pollutant.',  are  settleable  s.ilids, lead, and zinc. The University  of
Washingi,vi  studies  (!Vd-> rsen,  1981;  Kichey, 1982; and Scott, Steward,  and
Stober, 1 ^>2 ) and  the Seattle  MK.TKO study (Calvin and Moore, 1982)  will
address this  issue  In more detail.
SOUKCtS OF  KKOBLtM  POLLUTANTS

     The seeond  phise  in designing an urban runoff control program  is  to
determine  the  sources  of the problem pollutants in the watershed. An
understanding  of  where  the  problem pollutants accumulate in the  catchment  is
needed before  appropriate cont-rols may be selected. Sections 5 and  6 discuss
the sources  of urban  runoff flows and pollutants in the test basins. In
Section 5,  which  deals  with urban runoff flows, it was found that the
impervious  surfaces  (including street surfaces, driveways, parking  lots, and
rooftops)  can  account  for almost three-fourths of the runoff flows  in  both
basins during  any season. There are few vacant lots or parks in  the  test
basins , so  the remainder of the urban runoff flows originates from  landscaped
front  or back  yards.  For very small rains (<0.1 inch, or <2.5 mm),  however,
street surfaces  alone  contribuls from one-half to three-fourths  of  the total
runoff flows.  Driveways and parking lots make up the remainder for  the
smallest rains.  During  these very small rains, rainwater infiltrates into  the
soil in the  pervious  areas, with runoff primarily originating from  the
impervious  areas. The  contribution from street surfaces decreases with larger
rains  and  remains fairly constant for rains larger than about 0.1 inch. The
observed variation  of  runoff sources from different areas as a function of
r&in quantity  is  smaller than for locations previously studied (Ottawa,
Ontario; Pitt, i.982  and Castro Valley, California; Pitt and Shawley, 1981).

     Because of  variations  in sheetflow quality from the source  areas  during
runoff events, the  contributicns of pollutants from each source  differs from
the contributions of  runoff flows. Using some sheetflow runoff quality data
obtained previously  in  other locations, and with an understanding of the
local  Bellevue conditions,  estimates of pollutant contributions  from these
different  source  areas  were made in Section 6. It is estimated that  total
solids (for  most  rain  events) originate mostly from the back and  front yards
in the test  basins  and  that street surfaces contribute only a small  fraction
of the urban runoff  total solids discharge. Street surfaces, however,  are
expected tc  make  up  most of the lead, zinc, and COD contributions to the
urban  runoff.  Phosphates and total Kjeldahl nitrogen are mostly  contributed
from street  surfaces,  driveways, and parking lots combined. Back  and front
yards  make  up  slightly  less than half of these nutrient contributions  to  the
outfall. Therefore,  street  cleaning operations cannot be expected to
significantly  improve  the urban runoff total solids loadings or
concentrations.  If  the  available street surface particulate loadings could be
reduced by  one-half,  then many of the other pollutants may be reduced  by
about  25 percent  at  the outfall.

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    .sort.on  7 discus-s  in  .IctaiL  the  observed  street  surface particulate
conL.^ir,,
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identities. Street  cleaning  can  only  operate  un streets and parking lots (arid
possibly sidewalks  and  driveways);  cons :rnction erosion control only affects
cons t^uci ion areas;  runoff  storage  and  subsequent  LL catgut can affect all
source and accumu'atirn  areas. T >•;,_-  effectiveness of  the applicable control
measures in reducing  problem pollutant  concent rations  and yields at the
outfall must be evaluated.  When  pollutants  are  removed from a watershed (such
as by erosion control  or by  street  cleaning),  much more needs to be removed
than the amount necessary to meet  the discharge goai  at the outfall. As an
example , about  ten  pounds of a pollutant  may  be needed to be removed by
street cleaning to  prevent  one pound  of  the pollutant  from entering the
receiving water. After  the  control  measures'  applicability and effectiveness
values are known,  the  urban  runoff  control  program can be designed. In order
to meet water quality  objectives,  a combination of several different control
measures may be needed.  Complex  decision  analyses  procedures may be necessary
if multiple objectives  are  important.

    Secticn 9 of this  report evaluates  the  urban runoff data, dividing it
into periods of intensive street cleaning and  no street cleaning. Very
little, i: any, difference  can be  detected  at  the  outfall based upon these
two street cleaning programs.  The  roost  important reason why any potential
changes were not detected are  based on  the  variations  in rainfall and
subsequent runoff  quality and  quantity  observed at the two basins. As noted
in Sections 4 and  5,  the rainfall  variation at  the two test basins can be
greater than 25 percent  most of  the time. This  25  percent difference in
rainfall corresponds  to  a much greater  difference  than 25 percent in runoff
yield. This is  because  larger  rains result  in  a larger percentage of the rain
occurring as runoff.  Therefore,  runoff  improvements  measured at the outfall
at a level substantially greater than 25  percent would be necessary to detect
an improvement  under  most of the rain conditions during this study period.
Sampling, laboratory,  and analyses  errors also  contribute to masking any
effect that may have  occurred. The  analyses included  in Section 9 attempted
to eliminate most  of  these  flow  differences using  appropriate transformation
and analytical  techniques.  The data was  separated  by  season and street
cleaning program.   The  intensive street  cleaning program was rotated between
the test and control  basins  on a seasonal basis tc eliminate some of the
differences associated  with  rain conditions.

     Section 10 describes the  effectiveness of  the street cleaning equipment
in removing street  surface  participates.  Street cleaning equipment cannot
remove particulates from the street surface unless the loadings are greater
than a Certain  residual  amount.  .This  value  was  about  500 Ibs/curb-mile (140
g/curb-tneter) in the  test basins.  If  the  initial street surface loading
values are smaller  than  this value, some  of the street surface material can
be "loosened",  but  not  removed.  The street  surface particulate loadings after
the street cleaning operation may  then  be greater  than the initial values.

     The frequent  rains  may  be more effective  than street cleaning in keeping
Bellevue streets clean.  The  street  surface  loadings  after rains were between
2UO and 400 Ibs/curb-mile (57 and  110 g/curb-meter),  but the street cleaning
equipment could only  remove  street  surface  particulates down to about 500
Ibs/curb-mile (140  g/curb-meter).  If  the  street cleaning was conducted more
frequently than the rain intervals, then  street cleaning may result in

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c leaner streets.

     The intensive street cleaning program that was  conducted  during these
tests can result in about a 25 percent reduction  in  street  surface  loadings
when compared to no street cleaning.  If the street jurface  contributes about
half of the total source for a specific pollutant, intensive  street cleaning
may only remove about ten percent of  the pollutant yield  at  the  outfall.
Typical runoff reductions by street cleaning are  estimated  to  be about five
to ten percent. As noted previously,  it would require  a fairly substantial
reduction in discharge yield uo be statistically  significant  based  upon
outfall measurements. The. effectiveness of street cleaning  equipment in
controlling urban runoff is very site specific. If the street  surface
loadings were much greater than the breakeven street  cleaning  point, and
there were less fvequent rains, street cleaning might  control  important
tractions of the total urban runoff flow. Street  cleaning  in  Bellevue may not
be an appropriate urban runoff control measure, especially  at  a  cost of about
$2U/curb-mile ($12.50/km). With such  small potential  improvements in urban
runoff quality, other street cleaning benefits are more important.

     Special tests were conducted using a modified regenerative-air street
cleaner. It was demonstrated that this equipment  was  much  more effective in
removing the finer street dirt material than the  regular  mechanical street
cleaner tested. This finer material can be washed from the  streets  by rains
more easily than larger material. Therefore, urban runoff  quality can be
imprcved slightly more with the use of this modified  equipment (to  about ten
percent reductions).

     Sections 8 and 11 discuss the potential effects  that  sewerage  cleaning
may have on urban runoff control. The sewage inlet and catchbasin sediments
had relatively constant accumulation  rates after  cleaning  for  about one year.
After a year, the sediment volumes remained quite constant,  with little
effect on the runoff yield. A major rain event during  the  second year after
cleaning did not result in any net average or total  sedimert  loading change.
Sewage inlet and catchbasin cleaning  is therefore recommended  on about an
annual basis. This should result in annual total  solids and  lead storm runoff
yield reductions of between ten and 25 percent. The  other  constituents
studied (CUD, TKN, TP, and Zn) may be controlled  by  between five and ten
percent. More frequent cleaning would not increase these  reductions, as the
observed sediment accumulation rates  appeared to  be  constant,  until the
constant volume value was obtained. Only about 60 percent  of  the available
sump volumes were used for detention. Large sumps had  less  of  their volumes
utilized. Catchbasins with large sump volumes could  be cleaned less
frequently because th -y held larger volumes of sediments.  Allowing  pollutants
to remain in a sump foi long periods  of time, however, may  increase their
solubilities, enhancing  heir washout potentials  and  making  them more
available to receiving weter organisms.

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                                   SKCri'JN  3
                             STUDY  AREA  DK3CK1PT1UN
     Figure 3-1 shows  where  the  City  of  bellevue  is located in the Pacific
NorUnest  BelJcvue  is  located  en  the other side  of Lake Washington from
Su.itr.lt?. .Washington, and  is  within  commuting distance.  Lake Samma-nish borders
Boiievue on the east.  Bellevue  n ;eives  about  35  inches  (891! mm)  of rain per
year, while substantially  greater  amounts  of rain occur  on the Olympic
Teninsu.'a to  the west  and  much  smaller amounts of rain  occur in eastern
Washington to  the  east.

     ''igure 3-2 shows  the  locations  of the Surrey Downs  and Lake  Hills
catchments in  the  City  of  Btllevue.  These  two  sites are  located about three
mile.- (i> km)  apart and  are each  about 100  acres (40 ha)  in size.  They are
botl fully developed as mostly  single-family residential areas.

     The Surrey Downs  basin  is  95.1  acres  (38.5 ha) in  size and include? the
Brllevue Senior High School  in  addition  to single-family tomes. Most of the
.•Aopes  in the  basin  are moderate,  with some steeper slopes on the west side
of  the  basin.  Table  3-1 shows  that  about 60 percent of  the Surrey Downs b&sin
is  pervious.  Back  and  front  yards  make up  most of the land surface area in
the  basin, with streets making  up  a  typical ten percent. The streets are
generally in  good  condition  with smooth  to intermediate  textures. There are a
few  locations  wheru  the curb needs  repair. Westwood Homes Road and 108th
Street  do not  havr; curbs.  There  is  relatively  little automobile traffic in
the  Surrey Downs basin  and the  on-street urrking  density is low.  The storm
drainage system discharges into  an  artificial  pond located in an adjacent
development.  This  pond  discharges  info Uercer  Slough which eventually drains
to Lake Washington and  Puget Sound.

     The Lake  Hills  catchment  is 101.7 acres (41.2 ha)  in size and contains
the  St. Louise Parish  Church and School  in addition to  single-family homes.
Lake Hills has a slightly  larger percentage of pervious  areas than Surrey
Downs,  but a  slightly  smaller  typical lot  size. The slopes in Lake Hills are
also more moderate (with  a few  exceptions) than those found in Surrey Downs.
Tne  street surface and  gutter  systems are  also similar  to those in Surrey
Downs.  Most of the streets in Lake Hills also  carry low volumes of traffic
and  have low  parking densities,  except for two busy roads that cross through
the  area. The  Lake Hills  storm  drainage  system outfalls  into a short open
channel which  joins Kelsey Creek just downstream from Larsen Lake. Kelsey
Creek also discharges  into Mercer  Slough and finally to  Lake Washington and
Puget Sound.
                                      10

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Olympla
               FIGURE   3-1



Northwest Washington State and the City of Bellevuo
                                                    1 lnch = 10.8 Miles
                                     11

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                                                       N
    FIGURE   3-2

 City of Ballevue, Washington
Stream System and Study oites
            12

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                       Table 3-1. SITE CHARACTERISTICS

Vacant
Parks
Backyards
Frontyards
Rooftops
Driveways
Parking Lots
Sidewalks
Streets
Total
Area (acres)
Fraction
Impervious
Fraction
Pervious
# o Homes:
Lot Size:
Frac. Res id.
Frac. Indus.
Frac. Commer.
% Inst.
Frac. Open
area
Curb-miles
of Streets
Surrey Downs
106 ft2 *
0.06 1.6
0.08 2.0
1.45 37.1
0.89 22.8
0.67 17.1
0.20 5.2
0.15 3.9
0 0
0.40 10.3
3.90 10C#
95.1
0.40

0.60

274
0.3 acre
0.91
0
0.06

0.03

5-5(1)
Lake Hi
106 ft2
0
0.14
1.52
1.01
0.79
0.20
0.01
0
0.48
4.15
101.7
0.35

0.65

355
0.25 acre
0.90
0
0.07

0.03

7.0
11s
*
0
3.4
36.5
24.4
18.9
4.9
0.2
0
11.7
100*














"'Westwood  Homes Road = 0.5 miles
   108th Ave.  =  1.5 miles
   Cleaning  Area = 3.5 miles
                                     13

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     A de!-u>|',r.iphi c  survey  was conducted in the Lake IMJls  and  Surrey  Downs
cat chi.K-iUs at  t h _>  bet; i nn i in; of the project. Slightly more  than three  people
per Household  were  reported in both basins, while the  population  density per
acie was about  1.-!  in  Lake  Hills and about 9 in Surrey  Downs  (2V and  22  per
hectire, respectively).  Almost 25 percent of the households  in Lake  Hills had
;iiure than b people,  while  only about 14 percent of the  Surrey  Downs  houses
had that many  people  per  household. More than half of  the  households  in both
basins did not  have  any  dogs or cats, but the remainder  of  the households had
one ot each, or  more.  On  the average, there was about  one  dog  or  cat  per
household. Slightly  more  than two cars per household were  reported,  with
about  ten percent  of  the  households in each basin reporting  four  or  more
cars.  About one-third  of  the households used unleaded  gasoline while  Ihe
remainder used leaded  regular or leaded premium grades  of  gas. Most  of  the
automobile oil was  disposed properly i" the household  garbage, 01  recycled,
but between five  and  ten per.ent of the households used  oil  to treat
fenceposts, dumped  it  onto the ground or into the storm  sewers. Most  of the
people carried their  grass and leaves to the du.r.p or put  them  in  the  garbage,
and about one-third  composted the organic debris on their  lots. It was  not
possible to cbta.i.n  adequate data on the quantity of fertilizers or pesticides
that were used in the basins.

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                                   SECTION  4
                            BELLhVUE  RAIN CONDITIONS
      One  important  prerequisite  of  any  urb;-.n  runoff  control program is an
understanding  of  the  local  r^in  conditions.  In  order to  gain this
understanding,  the  rain  conditions  during  the period of  study should be
representative  of long  term  conditions.  The  ^elltvue monitoring program
lasted  for  two  years, during  which  fairly  t,;Jical  rains  occurred. The
probability  ol  unusual  rain  conditions  lasting  for a long period of time is
reduced compared  to lasting  for  a short  peviod  of  time.

      Differences  in rainfall  quantities  res.\lt  in  differences in runoff
quantities.  The differences  in runoff quantities  in  tur.i produce differences
in  runoff yields. Therefore,  abnormal rain conditions during an urban runoff
study period will result  in  abnormal runofi  quantity and quality data.
Similarly,  short  term fluct"ations  or differences  in rainfall conditions, of
time  or area (unusually  dry  or wet  months, or areal  rainfall variations), can
result  in unrepresentative  runoff yield  predictions.

      The most  important  task  of  this project was  to  monitor the effectiveness
of  street cleaning  operations. One  element of this analysis involved the
comparison  of  observed  runoff quality conditions  in  study sites with and
without street  cleaning.  If  the  rainfall conditions  varied between test and
control sites  during a  test  period  then  the  observed runoff yields might not
be  indicative  of  the  control  measures1  effectiveness. This report section
describes the  rainfall  conditions (including variations  and differences) that
occurred at  the two Bellevue  test areas  during  the two-year study period.

      Rainfall monitoring  equipment  was  located  at  each runoff monitoring
station at Surrey Downs  and Lake Hills.  During  parts of  the study, additional
rainfall monitoring gauges were  located  at other  locations in and adjacent  to
these monitored basins.  Rainfall monitoring  bepan  at the Lake Hills station
in  the midale of February,  1980, and about two  weeks later at the Surrey
Downs station.  Rainfall monitoring  was  completed  at  the  end of January, 1982,
at  both basins. Tables A-l and A-2  in Appendix  A  summarize the monitored
rains at both of these  locations throughout  the two  year study period. More
than 20U rains  were monitored at each of these  basins. Table 4--1 summarizes
the rain conditions on an average monthly  basis for  both basins combined.

     The total  annual rainfall averaged  about 37  inches  (940 mm) with about
lOb rain events per year. The year  can  be  separated  into dry and wet seasons
with the dry season lasting from the first of March  to the end of September.
This dry season has monthly rain totals  of less than about three inches (76
mm), while the wet season, lasting  from the  first  cf October to the end of

                                      15

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Table 4-1. AVERAGE LAKE HILLS AND  SURREY DOWNS RAIN  CO'lOITfO'lS
         PERIOD OF  STUDY (FEBRUARY 1980 THROUGH JANUARY 1982)
Rain Number
per of rain
month events per
(in.) month
January
February
March
April
May
June
July
Auqust
September
October
November
December
Annual
3.6
3.3
2.6
2.8
1.6
2.4
1.2
0.8
3.0
3.7
5.6
6.4
37.0
(tot)
11
6
9
11
9
10
3
4
8
7
14
16
108
(tot)
Rain Duration
per of each Preceedinq
storm storm dry oeriod
(in.) (hours) (hours)
0.33
0.54
0.30
0.29
0.19
0.27
0.39
0.21
0.38
0.49
0.40
0.41
0.34
(avq)
12
22
14
10
8
8
8
9
11
11
12
12
11
(avq)
53
70
68
59
72
79
115
650
81
110
37
34
120
avq)
Average
rain '
int.
Mn/hr)
0.03
o.o?
0.02
0.04
0.03
0.05
0.05
0.04
0.05
0.03
0.04
0.03
0.04
(avq)
Peak 30
•nin . r i in
int.
Mn/hr)
0.09
O.H
0.11
o.i:;
0.10
0.13
0.14
0.12
0.19
0.14
0.15
0.14
0.13
(avq)
Season
wet
wet
drv
drv
dry
drv
dry
drv
drv
wet
Wot
wet
—

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 tcbi-uarv,  iuis monthly tain U r ils between thrco and 6.5 inches (76 and
 mm).  Each  storm during the wet  season had about twice as much rain as  eacn
 *rorm during the dry season.  The wet season rains also lasted about  one  and  a
 halt  to two times as long as  dry season rains. The maximum preceding
 interevent dry periods during the dry season were substantially greater  thon
 during the wet season, especially for July and August. The average and  peak
 Ji'-winute  rain intensities for  both wet and dry seasons were quite similar.
 The average r .in intensities  were about one third of the peak intensities.
 Uhe.i  Tables A-l and A-2 are examined, the overall ranges in observed
 conditions tor any nonth are  seen to have been quite large. The. maximum
 storms during the wet season  were typically about 1.5 inches (38 ram) while
 they  were  about 0.5 inches (13  mm),  or less, during the dry season.  These
 conditions compare relatively well with the rain period of April, 1975,
 through January,  197/, which  was analyzed as part of the first Bellevue
 report. That previous period  had an annual average rainfall of about 34
 inches (87U mm\  with about 60  storms per year. This earlier period  included
 less  than  typical rain quantities. The wet and dry season divisions, however;
 were  still the same as observed  during this more recent stuuy period.

      The variation in monthly rain totals, as  shown in Figure 4-1, shews that
 the first  months  of the two wet  seasons studied (October and November) have
 more  rain  than the following  months  of the wet season. The latter months in
 the dry season (July and August) have less rain than the earlier dry season
 months. This results in a general caw-tooth pattern, where the rain  total
 starts out low at the end of  the dry season and then rises radically at  the
 beginning  of the  wet season.  The monthly rain  totals then decrease with  each
 succeeding month  to a low point  at the end of  the dry season. During the
 first year,  November was the  wettest month,  while during the second year,
 October was  the wettest month.  These wide variations in monuhly rain
 characteristics,  and the possibly repeating pattern of rains may be important
 in  designing a street cleaning  program that  is much more intensive before
 these initial  large rains of  the wet season.

      Most  of the  rain events  that occurred during the study period were
 completely monitored at  both  the Lake Hills  and Surrey Downs sites. Appendix
 Tables  A-3 through A-5  summarize the observed  rainfall characteristics for
 these two  basins  on a storm by  storm basis.  These tables present the observed
 total rainfalls,  rain durations,  and average and peak 30-minute rain
 intensities  for  both basins.  Ratios  of the rain totals observed at each  basin
 were  calculated.  Duration ratios  and differences in the start times for  each
 rain  event  are  also shown on  these tables. A total of 165 paired storm events
 were  monitored  during this  two-year  study period. Lake Hills rain totals
 averaged 12  percent more  than the Surrey Downs rains. The average duration of
 the Lake Hills  rains.was  about  11 percent longer than for the Surrey Downs
 rains.  The Lake Hills  rains also  started about 1/2 hour before the Surrey
 Downs  rains. The  ranges  of  the individual storm values, however, varied
greatly. The total  rain  and duration ratios  range from less than one-tenth to
more  than  three times, while  the  time differences are as great as 16 hours.
The following paragraphs  discuss  the major variations in rain characteristics
at the  two  sites  on a seasonal basis.
                                      17

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                   FIGURE 4-1
           MONTHLY  RflIN TOTflLS
     LRKE K'LLS
      JRRET DOWNS
                       UY t
Iff 11 12 13f U 15 16. 17 1ฃ
0123456789
2Cf 21 27 23 24
                      MONTH OF STUDY
               (from Feb. 1980 to Jan. 19B2)

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      KU-uro  ซ-2  shows  tin-  distribution  of  rain events and corresponding
 runott  volumes  tor  both  studv  sites  and  all  study periods combined. Most  of
 the  rain  OV.MU s  had  les.  than  0.25  inches  (b.4 mm)  of rain and less than  ten
 Percent  ot  the  rain  events  had volumes  greater than one inch (25.4 mm). VThen
 Mu-  raintall  quantities  are  considered,  most  of the rainfall  is associated
 with rain events greater  than  about  0.6  inches (15  mm). The common small
 rains  do  not  add up  to much  rain  volume.  Rains smaller than 0.25 inches (6.4
 mm)  accounted tor  less than  25 percent  of  the total rainfall volume, while
 about  30  percent of  the  total  rainfall  volume was associated with rains
 greater  than  one inch  (25.4  mm).

      The  distribution  of  the runoff  volume  is also  shown on Figure 4-2. Most
 of  the  runoff is associated  with  rains  greater than 0.75 inches (19 mm) while
 the  most  common  rainfalls  of less  than  0.25  inches  (6.4 mm) produced less
 than ten  percent of  the  total  runoff. The  relationships between runoff and
 rainfall  are  discussed in  detail  in  Section  j. The  weighted averse Rv values
 (runoff/rain) for  both of  the  study  sites  was about 0.25. This value means
 that about 25 percent  of  the rainfall left  the watershed as surface runoff.
 Three-fourths of the rainfall  either evaporated or  entered the soil. Much of
 the  rainfall  entering  the  soil later left  the study areas in the form of
 baseflow  between runoff  events. The  rest  of  th-? infiltrated rainwater either
 recharged  the underlying groundwater or  was  lost  through evapotranspiration
 by  plants .

      Differences in observed rain quantities  for  the same storm periods for
 Lake Hills and Surrey Downs  are shown on  Figures  4-3 and 4-4. About half  of
 the  rains  that were observed simultaneously  at both basins had a difference
 in  rain quantity greater than  plus or minus  20 percent. This difference was
 much greater  for the small rain events  than  for the larger rain events. As an
 example,  several  rain events measured about  0.3 inch (7.6 mm) in one basin
 while only measuring 0.1 inch  (2.5 -.-a)  in  the ether basin. This can result in
 much more  than a three to one  difference  in  the observed runoff yields. As
 described  in  Section 5, the  smaller events  result in a smaller fraction of
 runoff than larger events due  to infiltration and surface detention/storage.
 When the  resultant runoff yields from the  two basins are compared for a
 specific  storm,  differences  in  observed  rains may be much more important  than
 differences in control measure  applications.  This is important for the
 discussions in Part 4 on control measure  effectivenesses.

     Figures  A-l through A-6 show the average monthly rainfall parameters for
 two  different basins. In most  cases, the  two  basins have very similar
 patterns in parameter trends,  but the individual  values for a specific rain
event may vary significantly.

     Figures  A-7 through A-9 present scatter  plots  of Lake Hills and Surrey
Downs rain totals, durations,  and peak  intensities  transformed by natural
logarithms. This transformation allows  certain statistical uests to be made
if the resulting distribution  of data points  is normal (having a "bell"
shapeV it also  reduces the  apparent importance of  extreme values (helps  to
identify real "outliers"). Figure A-7 plots  the natural log of the Lake Hills
rain quantities  against the  natural log  of  the Surrey Downs rain quantities
for all observed rains. This figure shows  the much  greater variation in

-------
                          FIGURE  4-2
ro
O
     RflIN EVENTS-RflIN  VOLUMES-RUNOFF  VOLUMES
     30
     25.
     15.
                 a/
        <0.1JG.l  0.2 I 0.3 I 0.4 I 0.5 I 0.6 I 0.7 I 0.8 I 0.9 I 1.0  >1.1


        1- NUMBER  J7"> RAIN FALL  [ )- RUNOFF         Raln Int(,;val

         OF EVENTS     VOLUME      VOLUME
                                (Value shown is bocj inning of intป-rval

-------
                  FIGURE 4-3
LflKE  HILLS/SURREY DONN5 WET  5ER50N  RfllNS
           X v  x *
•***:*>•*
 J	I	L
                           I  I  I
J	I	L
             1          2
                 LBKE HILLS RflIN, INCHES

-------
                     FIGURE  4-4
      LflKE  HILLS  flND  SURREY  DONNS  RRIN5
  1.25
o
a
  .5.
      *  Jฎ
.25
                                  ^
"'y'-v •-'+//>
                     .5      ' .75      1
                     LfllCE HILLS RfllN, INCHES
                        DRY SEASON
     1.25
1.5

-------
V
observed  rain quantities  for  the  smaller  rains  than for  the larger rains.
Rains having a  total  rain quantity of  0.05  Inches  (1.3 mm)  (corresponding to
a natural  log,  or  In, \alue of about minus  three)  can  have  corresponding
rains in  the other basv.1  .ranging  from  0.03  to 0.15  inches  (0.8 to 3.8 mm).
However,  rains  of  1.5 Inches  (38  mm) in quantity have  a  much  smaller
 ariation, ranging from about 1.25 to  1.75  inches  (32  to 44 mm)  in the other
basin. The duration variation pattern, as shown on  Figure A-H,  is similar to
the variation pattern shown for total  rain  quantities. Short  duration rains
in on^ basin can occur simultaneously  with  a wide  range  of  possible duration
values in  the other basin, while  the longer duration rains  have  more equal
values in  both  basins. Figure A-9 compares  the observed  peak  rain intensities
at the two basins. This figure is plotted upside down, with negative natural
log values. The data prints in the upper right hand corner  of  the figure
correspond to low rain intensities in  both  basins,  while the  data points in
the lower  left  hand corner correspond  to the higher values. Again,  the
pattern of variations is similar as for the duration and the  quantity plots,
in that the small intensities  have a much greater variation than '_he large
intensities.  All of the  intensities vary by much greater values  than for the
other two rain  parameters.
                                    23

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                                   SECTION 5
                                RUNOFF QUANTITY
03SERVED  RAINFALL  AND  RUNOFF VOLUMES

     As noted  in Section  4.  there is a major difference in the production of
runoff associated  with rains having different volumes. This difference is due
to a changing  runoff  coefficient value for storms of different sizes and for
di/ierent  initial  soil moisture conditions. The runoff coefficient monitored
in this studv  was  the  ratio  of  runoff volume to total rainfall volume, both
being expressed  in inches over  the test Hasins. This coefficient (Pv)
considers  evaporation, transpiration, detention/storage,  and soil
infiltration.  When soil moisture conditions are low and/or if the total
rainfall  volume  is small, then  the observed Rv value is small. If the ground
is wet at  the  beginning of the  rain and/or if the total rainfall volume is
large, then  the  Rv value  is  larger. The soil can accept rain that is falling
directly  on  it at  a rate  equal  to its infiltration capacity. If this
infiltration  capacity  is  exceeded, the excess rainfall will run off the soil.
Therefore, runoff  production on pervious surfaces is dependent upon the soil
infiltration  capacity  for the specific soil moisture conditions, vegetation,
the rainfall  intensity, the  rainfall duration, and the total rainfall amount.

     Wh'^n  rain falls  on an impervious surface, much of the rain will flow off
the surface.  The heat  of  the surface will result in some  evaporation of the
water upon contact with the  surface (flash evaporation),  but this is more
important  in  areas having very  hot days and sudden thunderstorms. Rain may
infiltrate through cracks or holes in the otherwise impervious surface and
enter the  subsoil  beneath, or it may be directed off of the impervious
surface to pervious areas for infiltration. Also, much concrete is slightly
pervious.  If  the runoff water is directed towards a lined (with impervious
materials) channel or  to  the street and gutter system, it can be called a
directly  connected impervious t:ea. These areas may include rooftops,
sidewalks, and parking areas. Even for these areas, however, some of the rain
does not  reach the urban  runoff system. If the surface is in poor condition,
rain can  infiltrate through  the system, as noted previously; or if the
surface is not graded  appropriately, water may pond on the surface for future
evaporation and  "leakage". If the rain is very small, most of the sheet flow
could be gone  before  it has  a chance to leave the impervious area. For large
rains, however, much more of the rainfall results in runoff from impervious
areas.

     About 200 rain events were monitored for rainfall quantity and runoff
parameters in  Surrey Downs and  Lake Hills during the two-year study period.
Some of the smallest rain events (<0.1 inch or 2.5 mm) were not monitored

                                      24

-------
 because tl.ey did not pro^u.e significant runofl. At other times,  8Oir.e  rain
 events were not monitored because of equipment malfunction or because  cne
 equipment was being modified and not available.. Almost 99 percent of  the  rain
 events that occurred at Surrey Downs and about 91 percent of the  Lake  Hills
 -vents were monitored.  Tables A-6 and A-7 in Appendix 1 list the  rainfall and
 associated discharge characteristics for each of the monitored rains  in  both
 Surrey Downs and Lake Hills. Thes.- tables also show the total rain  (in
 inches) and the total discharge (in inches) and calculates the runoff
 coefficient (Rv) ratio  (runoff/rain) for each rain event. The rain  durations
 and the runoff durations  are also compared. Typically, the runoff duration
 can be expected to be greater than the rain duration, depending upon  the  lag
 time at t'>e beginning of  the rain between the start of rain and the start of
 runoff. The average rainfall to rain duration ratio in Surrey Downs was  1.14
 while this value was 1.24 at Lake Hills. For the smaller rains, this  duration
 ratio was actually less than one because of the proportionately larger amount
 of  infiltration of rain into the soil. The data presented in these  two tables
 are used in this section  and elsewhere in this report for rainfall  and runoff
 quantity and quality calculations.

      Relationships between runoff volume and rain volume are dependent on
 many conditions. However, these conditions may be simplified by dividing  the
 study period into appropriate seasons and considering each area separately.
 The antecedent  soil conditions are usually satisfactorily considered  in  the
 seasonal breakdown, while the different study areas consider the  different
 land-use configurations.  Table 5-1 separates the rainfall and runoff
 characteristics by season and study area. The total rain volume was slightly
 greater in the wet season for boch areas;  there were not as many of  the
 larger rain events during the dry periods of the study, and although  there
 were many more of the smaller rain events, most of the rain quantity  occurred
 during the larger events. During the wet seasons, most of the rainfall volume
 was associated with rains greater than about 0.4 inct.as (10 mm).  The median
 rain volumes  associated with the runoff were greater than for the rainfall
 because of the  increasing Rv values for increasing rain volumes.

      Fiqures  A-10 through A-13 in Appendix A show the distribution  of  these
 rainfall  and  runoff parameters for both study areas and wet and dry seasons
 separately.  These are similar to Figure 4-2 in the previous section which
 combined  all  of this  data.  The average Rv value in Lake Hills during  the  wet
 season  was  about 0.3, and about  0.1 during the dry season. The Rv values  in
 Surrey  Downs  were less.

      In  order  to separate the study period into seasons, characteristics  of
 the  rainfall  and runoff for  each month were examined. Table 5-2 shows
 equation  coefficients corresponding to straight-line relationships  between
 rainfall  and  runoff  (both expressed in inches). The resultant r   values
 (vhich  is  an  indication of  how well the calcvlated curve fits the data
 points) were very  good. In  most  cases, the CL value was greater than 0.95
with a  value of  1.0 being a  perfect fit. These equations are only good for
 the  larger  rains  and  do not  produce appropriate values for rains  that  are
 smaller than about  0.1  inches (2.5 mm). (The predicted runoff volumes  were
negative  for  these  smaller  raimi). The ota&erved runoff volumes for  the small
 rains were  very  small,  but  could obviously not be negative. The bottom of

                                       25

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                       Table 5-1. RAIN AND RUNOFF VOLUMES



Lake Hills
wet
dry
total
Surrey Downs
wet
dry
total

Number
of events

113
107
220

98
102
200

Median rain
volume (in.)

0.23
0.17
0.20

0.23
0.20
0.21
Total rain
durina study
(in.)

44.96
30.55
75.51

42.79
28.15
70.91
Total runoff
during study
(in.)

14.36
6.08
20.44

10.56
4.91
15.47

Overall
Rv

0.32
0.20
0.27

0.25
0.17
0.22
All Combined
420
0.21
146.42
35.91
0.25

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            Table  5-2.  STRAIGHT-LINE EQUATION COEFFICIENTS TO
              RUNOFF FROM RAIN VOLUMES (FOR PAINS  GREATER  THAN  THE
                            MINIMUM VALV".  SHOWN)!1)
                    Lake Hills
                                                      Surrev Downs
Month
January
February
March
April
May
June
July
AlJQUSt
September
October
November
December
lotal Wet
Total Dry
Rain
(inches)
0.01
0.1
0.2
0.4
0.8
1.6
2.5
Min.
intercept slope R? N Value
(rain)
-0.017 0.41
-0.0028 0.29
-0.048 0.40
-0.020 0.30
-0.011 0.21
-0.0090 0.22
-0.031 0.30
-0.013 0.26
-0.024 0.30
-0.046 0.39
-0.018 0.39
-0.029 0.45
-u.u^u u.jy
-0.023 0.30
Lake
wet
calc. calc
Runoff Rv
-O.oif 	
0.019 0.19
0.053 0.29
0.14 0.34
0.29 0.37
0.60 0.38
0.96 0.38
0.93 20 0.07
0.94 12 0.16
0.96 9 0.19
0.98 21 0.18
0.95 16 0.10
0.96 21 0.08
0.98 6 0.15
0.95 8 0.08
0.96 16 0.12
0.99 11 0.16
0.98 30 0.09
0.97 31 0.16
u.% yy o.iu
0,95 97 0.12
Hills
dry
calc. calc.
Runoff Rv
-0.020 	
0.007 0.07
0.037 0.19
0.097 0.24
0.22 0.27
0.46 0.29
0.73 0.29
Min.
intercepts! ope Ra N Value
-0.0047 0.26 0.98 19 O.C9
-0.0080 0.35 0.79 6 0.16
-0.010 0.25 0.93 20 0.11
-0.014 0.21 0.95 21 0.11
-0.011 0.23 0.97 17 0.14
-0.011 0.20 0.94 17 0.1]
-0.0096 0.19 0.99 7 0.15
-0.0056 0.17 0.94 7 0.08
-0.012 0,20 0.98 4 0.14
-0.026 0.29 0.99 13 0.16
-0.0017 0.24 0.98 25 0.05
-0.0098 0.31 0.95 31 0.08
-u.uo// u.'^y u.% 94 0.07
-0.010 0.21 0.93 98 0.11
Surre
wet
calc. calc.
Runoff Rv
-0.0049 	
0.020 0.20
0.048 0.24
0.10 0.26
0.22 0.27
0.44 0.28
0.69 0.28
y Downs
dry
calc, calc.
Runoff Rv
-0.0079 	
0.011 0.11
0.032 0.16
0.074 0.19
0.16 0.20
0.33 0.20
0.52 0.21
(1)   runoff = intercept  +  slope  (rainfall)
     example for  0.5  inch  rain in Lake Hills during  April:
     runoff - -0.02 + 0.03 (0.5) =  0.13  inches
     and  the Rv = ™noff/rain =  0.13/Q.5  =  0.26
                                      27

-------
I able 5-ฃ allows  tiow  the  Kv  value  increases  with increasing rain volumes. Phis
table also shows  that  the wet  season  Rv values can be as much as two tines
the dry season Rv  values  for  rains  smaller  than about 0.25 inches (6.4 mm).
The Lake Hills site  also  had  generally larger Rv values tnan the Surrey Downs
site for rains greater  thaa 0.1  inch  (2.5 mm).

     Figures  r>-l  through  5-ซ  are  nlots of observed rainfall versus runoff
volumes for both  Lake  Hills and  Surrey Downs and separated for dry and we<-
seasons . These figures  show how  the smaller rain events have very low Rv
values, which  then increase rfith  the  size of rain. The variations in observed
runoff  for the smaller  rains  were quite large. This percentage error
decreases as  the  rain  volume  increases. The wet seasons included z single
rainstorm that wad about  twice as large as  the next largest rain. This very
large rain event  (about;  four  inches ,  or 100 mci) accounted for much of the
total annual  runoff. That  single  event rain volume is infrequent in Believue,
wich a  return  interval  of  once every  several years. Even for this large rain,
the  resultant  Rv  value  was  only  about 0.4 in Lake Hills and about 0.3 in
Surrey  Downs .

     A  detailed  analysis  of rain  and  runoff characteristics wac carried out
for  most of  the  Lake Hills  data.  A multiple regression analysis relating Rv
to  total rain, average  rain intensity, peak rain intensity, and days since
last rain was  made for  each month.  These analyses showed that the rainfall
volume  alone  accounted  for  about  95 percent of the calculated Rv value. The
peak rain intensity  values  accounted  for between five and ten percent of the
total Rv value.  Increases  in  Rv  values were caused by increases in peak
intensity values.  As the  number  of  days since the last rain increased, the Rv
value Decreased.  This  antecedent  factor can reduce the Rv value by about five
percent. These decreases  in Rv with increase in antecedent dry periods was
probably due  to  the  soils  drying. It  was found that average rain intensities
affected the  Rv  values  by  less than about five percent. The season of the
year was extrenely important  in  determining the runoff and rainfall
relationships. The Rv  values  for  the  winter (wet) months of November through
February were  about  35  percent larger than  the Rv values for the drier summer
months  of March  through October  for the same rain characteristics. It was
concluded that there is  no  real  need  to adjust the calculated Rv values based
on  rain intensity or preceding length of dry period:  it is only necessary  to
consider total rainfall  and season.
THE EFFECTS  OF  LAND-USE  ON RUNOFF QUANTITY

      \ runoff model  specific  for Surrey Downs and Lake Hills was constructed.
This  model crnsidered  the  specific land covers in each of the two basins and
the distribution  of  observed  rains during the two year period of study. Table
3-1 in Section  3  listed  the land covers in the Surrey Downs and Lake Hills
basins. This breakdown includes  the percentage of the area and the total
square footage  for vacant  land,  parks,  back yards, front yards, rooftops,
driveways, parking lots,  and  streets.  The resultant impervious and pervious
fractions were  also  calculated.  It is  important to separate the pervious
areas into these  several  classifications. These classifications are mostly
based upon their  distance  from the drainage system, size, and the amount of

                                      28

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rj
UD
   in
   UJ
   in
   LJ
   Z
   o
   z
.3.
.2.
     .1.
                       FIGURE 5- 1

         LRK.E  HILLS  DRY 5EH50N RfilN/RUNOFF
   S



,6       ' .9

 RflTN, INCHES



1.2
                                                     1.5

-------
  .5
  .4.
                     FIGURE 5-2
            SURREY DOWNS  DRY  SER50N
o
Z
  .1.
*****
                 I --L
           I   I
                        6       .9

                        RfilN, INCHES
i   I
                  1.2
       1.5

-------
  1.5
                    FIGURE 5-3
      LRKE  HILLS  NET  SER50N  RfllN/RUNOFF
in
5
  .9.
              x .
           MM  I I I I  I  I I I  I 1 I I I I
1.5   2    '2.5
  RfllN, INCHES
                                          3.5

-------
                     FIGURE S-4

     SURREY DOWNS  WET  5ER50N  RflIN/RUNOFF
  1.25
O


1
  .71
.5.
  .25
             X v *   X
            ., ,tC XX
.5
      1  I I I I  I I I I	I I I I	LLU	I I I I
                    1.5   2    2.5

                        RflIN, INCHES
                                   _LJ_
                                      3.5
4.5

-------
 surface disruption.  For those areas that are far fro™ the drainage area,  much
 of  the rainfall could infiltrate before reaching the drainage system.  Large
 pervious areas, such as vacant lots and parks,  may have more infiltration
 than front  yards that are located adjacent to the drainage systen- - Roof tops,
 even though they are usually considered impervious, have most of  their
 uowr.spours  in these  two basins directed towards the surrounding back  or  front
 ynriSs. This allowed  much of  the rooftop runoff  to infiltrate into the  soils
 around the  house. A  portion  of the driveways and parking lots are also
 directed towards surrounding pervious  areas. However, all of the  street
 surfaces are directly connected to the drainage system.

      As previously discussed, the overall Rv value for the drainage basins
 were very small for  small rains, but  then increased rapidly to a  fairly
 constant value  for the larger rains.  When this  is considered in conjunction
 with the runoff characteristics from  the different land covers, the amount of
 runoff originating from each of the land-use covers in the test basins  can be
 determined  for  each  type of  rain. This is very  important when considering the
 effectiveness of various control measures. If a control measure can
 thoroughly  clean a sub-area  in the drainage basin, the observed effect  on the
 overall basin runoff quality is highly dependent upon the runoff  and
 associated  pollutant contributions from that sub-area. This discussion will
 consider the runoff  quantity that originates from each of these land  covers
 for  different rain types,  study basins,  and seasons of the year.  Section  6
 will discuss runoff  quality  and estimate the runoff pollutant contributions
 from each of these land-use  covers.

      Table  5-3  shows how the composite Rv value is made up of different
 land-use configuration runoff joef'•li-.ients (k). These individual  land-use
 coefficients are multiplitd  by Lh" traction of  the total area that each of
 these  land  covers occupy (as shown p-e^iously in Table 3-1). Theae individual
 land cover  runoff coef1.cients a" 1 increase with increasing rain  volumes  and
 as the distance  to the drainage systec decreases. These runoff coefficient
 values are  much  greater  for  the in pervious areas than for the pervious areas
 for  the  same rains.  Fcr  very sroall rains,  no runoff is expected to occur  from
 the  pervious areas and froit  the impervious areas that drain to these  pervious
 areas.  Starting  at about 0.1 inch (2.5 mm), however, the coefficients are
 about  0.3 to 0.5 times the inaximum values that  they are likely to have. The
 dry  season  runoff coefficient values are less than the wet season values, due
 to lower  soil moisture conditions.

     The  runoff  coefficient  values for the impervious areas are lower  than
 most people  would expect, especially for the smaller rain events. Especially
 during  the  dry  summer  season, rainfall falling  on these impervious areas  can
 be flash evaporated  and/or ponded for  future evaporation. These two factors
 are  extremely important  for  the smaller rain events. Even for the largest
 rain events,  the  impervious  component  runoff coefficient values may be as low
as O.b for  the dry season and 0.7 for  the wet season. Runoff coefficient
values for  paved  areas are usually expected to  range from about 0.7 to 0.95.
Values within this range  are expected  for large rains. Runoff coefficient  *
values that  are  usually  used in runoff modeling are also shown on this table.
These values  from Claycomb,  1970, are  usually within the values found for the
pervious areas and for moderate to large rain events. When a storm drainage

                                      33

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                         5-3.  F'JNOFF  COEFFICIENT  RELATIONSHIPS
              SURREY  PPWNS    DRY  SEASON
k values for each land cover and rain total

                 Rainfall (inches)
Land Cover
Vacant
Par'vS
Backyard
Front yards
Rooft oo s
Dri veways
ฐarkinq Lots
Streets
0.01
0
0
0
0
0
0.1
0.1
0.1
0.1
0.05
0.05
0.05
0.05
0.1
0,2
0. 2
0.35
0.2
0.05
0.05.
0.05
0.1
0.15
0.3
0.3
0.5
0.4
0.05
CL05
0.05
0.15
0.15
0.6
0.6
0.6
0.3
0.05
0.05
0.05
0.15
0.15
0.6
0.6
0.6
1.6
0.05
0.05
0.05
0.15
0.15
0.6
0.6
0.6
2.'
0.1
0.1
0.1
0.2
0.2
0.6
0.6
0.6
                                                           inches)

                                                              Literature
                                                              (Claycomb, 1970)
                                                                C.I to
                                                                0.1 to
                                                                0.1 to
                                                                0.1 to
                                                                0.75to
                                                          0.2
                                                          0.2
                                                          0.2
                                                          0.2
                                                          0.95
                                                                0.75 to 0.35
                                                                0.7
                                                                0.7
                                                       to 0.95
                                                       do 0.95
Ccmoosite ฐv
  value:      0.02   0.10   0.15   0.20   0.20   0.20   0.24

SCS (1975)
  values:     too small for SCS method    0.1    0.3    0.4
                             LAKE  HILLS  -  DRY  SEASON
              k values for each land cover and rain total
                                             inches)
Land Cover   0.01
       0.1
   Rainfall  (inches)
0.2    0.4    0.3    1.6
      Literature values
2.5     (Claycomb,1970)
Vacant
Parks
Backyard
T rontyards
Rooftops
Driveways
Parking Lots
Streets
0
0
0
0
0
0.
0.
0.





1
1
1
0.05
0.05
0.05
0.05
0.1
0.2
0:2
0.35
0,05
0.05
0.05
0.1
0.15
0.3
0.3
0.5
0,05
0.05
0,05
0.15
0.25
0.4
0.4
0.6
0.05
0.05
0.1
0.15
0.3
0.65
0.6!,
0.7
0.05
0.05
0.1
0.2
0.4
0.7
0.7
0.75
0.]
0.1
0.15
0.3
0.4
0.7
0.7
O.S
0.1
0.1
0.1
0.1
0.75
0.75
0.7
0.7
to
to
to
to
to
to
to
to
0.2
0.2
0.2
0.2
0.95
0.35
0.95
0.95
Composite
  Rv value:   0.02   0.10   0.15   0.20   C.25   0.29   0.34

SCS (1075)
  values:     too small for SCS method    0.1    0.3    0.4
                                      34

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              Table 5-3. R'JNOT COEFFICIENT RELATIONSHIPS  (cont.)
                           SURREY OWNS - WET SEASON
              k values  for each land  cover  and  rain  total  (inches
Rainfall 1
Land Cover
Vacant
Parks
Backyard
Frontyards
Rooftops
Driveways
Parking Lots
Streets
0.01
0
0
0
0
0
0.1
0.1
0.1
0.1
0.05
0.05
0.1
0.15
0.2
0.4
0.4
0.5
0.2
0.05
Q.05
0.1
O.L
0.2
0.5
0.5
0.6
0.4
0.05
0.05
0.1
0.2
0.2
0.6
0.6
0.63
( inches)
0.8
0.1
0.1
0.1
0.2
0.2
0.6
0.65
0.67
1.6
0.1
0.1
0.1
0.2
0.25
0.6
0.7
0.7
2.
0.
0.
0.
0.
0.
0.
0.
0.
5
15
15
15
2
3
6
7
7
Literature vaU
(Claycomb, 197
0.
0.
0.
0.
0.
0.
0.
0.
1 to
1 to
1 to
1 to
75 to
75 to
7 to
7 to
0.2
0.2
0.2
0.2
0.95
0.85
0.95
0.95
Composite
  Rv value:    0.02   0.20   0.23    0.24    0.25    0.26    0.29

SCS (1975)
  values:      too small  for  SCS method     0.1     0.3     0.4
                            LAKE HILLS - WET SEASON
              k  values  for  each  land  cover  and  rain  total  (inches)
Rainfall (inches)
Land Cover
Vacant
Parks
Backyard
Frontyards
Rooftops
Driveways
Parking Lots
Streets
Composite Rv
value:
SCS (1975)
values:
0.01
0
0
0
0
0
0.1
0.1
0.1

0.02

too
0.
0.
0.
0.
0.
0.
0.
0.
0.

0.

small
1
05
05
1
15
2
4
4
5

20

for
0.2
0.05
0.05
0.17
0.22
0.25
0.5
0,5
0.6

0.26

SCS
0.4
0.1
0.1
0.18
0.28
0.33
0.6
0.65
0.67

0.31

method
0.8
0.1
0.1
0.18
0.3
0.38
0.7
0.75
0.75

0.34

0.1
1.6
0.1
0.1
0.2
0.3
0.4
0.75
0.8
0.8

0.36

0.3
Literature values
2.5 (Claycomb,
0.15
0.15
0.2
0.35
0.5
0.8
0.9
0.9

0.40

0.4
0
0
0
0
0
0
0
0




.1 to
1 to
!i to
.1 to
.75 to
.75 to
.7 to
.7 to




.1970)
0.2
0.2
0.2
0:2
0.95
0.85
0.95
0.95




                                      35

-------
s'-'-tf.  is iVs ix.rifd ,  tlu-  Jf-ii^n stom Is a lar^e storm in order  to  reduce  the
t ,i---. I ir,>; pot i-nt. ial  in  the  en .linage basin. Very little research  has  been
"iri-cted to-Mrds  i he nuch  mure numerous smaller events.

     These cr,.--i.:>nent runoff coefficient values were estimated based  upon  the
nv'i'i^ored c-iraposite  Kv values, the rain totals, and the land rover
cor.t i ..;urjt ions.  A trial  and error procedure was used to fit the corresponding
runott coefficient  values.  Data from other locations and other  land—use types
were also used  in this analysis (especially Ottawa, Ontario; Pitt,  1982,  and
Castro Valley,  California;  Pitt and Shawley, 1981). Unfortunately,  the Surrey
Downs and LaKe  Hills sites  were auite similar- When the Bellevue 148th Avenue
runoff/rainfall  Information becomes available from the USGS, then  these
runoff coefficients  can be  confirmed for a different local  land-use.

     The calculated  composite Rv values are within ten percent  of  the
observed v^lvies .  They  are  also compared to values obtained  using the SCS
(.1975} curve  number  method  on Table 5-3. The SCS method was also developed
for the  larger  storm events and is not useful for those rains smaller  Lhan
about one inch  (25 nun).  Unfortunately, almost all of the Bellevue  rains are
smaller  than  one inch  (25  mm). However, the SCS calculated  Rv values were
high  in  all categories,  except for the very largest rain events during the
Lake Hills wet  season. There are modifications tnat can be  made to  these
initial  SCS estimates  that  consider antecedent dry periods  and  more  specific
soil  information.

     The portion of  the total urban runoff flow (as measured at the  outfall)
that originates  from each  of the land covers within the basin can  be
calculated. Each individual runoff coefficient value ^as shown  in  Table 5-3)
can be multiplied by the corresponding land cover fractions (from  Table 3-1)
to obtain the relative contribution of runoff that originates from  each of
those land covers for  different rains. Figures 5-5 through  5—8  show  these
calculated estimates for different seasons and different size rain  events.
Street surfaces  are  seen to contribute most of the urban runoff flows only
for the  very  smallest  rain  events (less than about 0.03 inch, or 0.8 mm,  of
rain). The contributions of street surface flows to Lake Hills  urban runoff
flows is greater than  for  Surrey Downs. For rains greater than  about 0.1  inch
(2.5 mm), the contributions of street surface flow to the urban runoff yield
is estimated  to  be about 25 pel cent for both basins during  the  dry  season.
These percentage contributions may decrease even more for the very  large
events when more runoff comes from the pervious areas. For  the  very  smallest
events,  the only land  covers that contribute any runoff at  all  are  the street
surfaces, driveways, and parking lots. The rooftops and pervious areas start
to contribute runoff in important quantities after about 0.1 inch  (2.5 mm) of
rain. When driveways and parking lots are added to the street surfaces, these
areas can contribute more  than 50 oercent of the runoff in  Surrey  Downs and
more than about  40 percent  in Lake Hills for most rains. Because of  the small
number of vacant  lots  and  parks in these basins, runoff in  these areas
typically contribute only  a few percent of the total runoff reaching the
outfall.

     The resultant hydrograph frcm ? typical urban basin is made up  of
various components  from each of the land cover areas. Figure 5-9 shows how

                                       36

-------
                  FIGURE 5-5
RUNOFF  SOURCES Surrey Downs  - Wei Season
100
                      DRIVEWAYS AND PARKING LOTS
0  P

 0.01
0.025   0.05
0.1    0.2    0.4



 RfllN (inches)
1.6  2.5

-------
                        FIGURE 5-6
CO
       RUNOFF  SOURCES  Lake Hills  -  Wet  Season
     100
   •f
   c.
   u
   CD
   Z
   o
   I

   or
                              VACANT LOTS AND PARKS
                                 DRIVEWAYS AND PARKITiG LOTS
       0.01    0.025   0.05    0.1    0.2




                           RfllN (lnchซs)
0.4
0.8
1.6  2.5

-------
Co
UD
                          FIGURE 5-7
      RUNOFF SOURCES  Surrey  Downs  - Dry S
      100
                                               eason
   OS

   O
   LJ
   U_
   U.
   O
 20_|
fio-Jl.
 o  m.
       0.01
                                    VACANT LOTS AND PAf
                      DRIVEWAYS AND PARKING LOTS
                      STREETS
          0.025   0.05    0.1    0.2    0.4

                       RfllN (Inches)
                                             0.8
1.6  2.5

-------
                       FIGURE 5-8
o
     103
      RUNOFF SOURCES  Lake Hills  - Dry Season
                                  VACANT LOTS AMD PARKfX
      o.oi
             0.025
0.05
0.1    0.2    0.4




 RRIN (Inches)
1.6  2.5

-------
                                                                                               150
    FIGURE   5-9
                             Hypothetical Hydrogrcph for Urban Watersheds

Source  from Amy, Pitl. Singh. Bradford and La Graf!. 1974
                                              41

-------
tlu' initial  Hows dur i n;  -in  urban  runoff  event will originate mostlv from
stiri't surtiu'os. Oil't-r  in>pet  ious  areas located fuither from the drainage
Vsti-m start contributing  fljws  at later  times and finally, after the ground
bocoiri-s saturited and  it  the  rain  lasts for a long enough period of time,
pervious surfaces start  contributing flows. Flows from the directly connected
Impervious areas (street  sir  
-------
1E+0
                      FIGURE 5- 1 0
      LflKE HILLS  TOTflL  FLOWS  BT MONTH
       E PLUS STORM RUNOFF
                         Iff 11 17 13 14* 15* 16 17 Iff 19T 201 21
10flfllfl13fiSEFlJ
l'23'4S6789
         MONTH SINCE BEGINNING OF TESTS (2/80 TO 1/82)
23 24

-------
u
                          FIGURE  5- 1 1
       SURREY  DOWNS  TOTRL  FLOWS  BY  MONTH
  750031}
  SOdflL
  0
       1
60013 30.
550X1111
500030.
450010.
400030.
350030.
300030.
250030.
200010.
150030.
100030. \
          BflSE PLUS STORM RUNOFF FLOW
       234567
                 MONTH SINCE BEGINNING OF TESTS  (3/S3 TO 1/82)

-------
                     FIGURE  5- 1 2
LRKE  HILLS  BRSE  FLON  (percent  by  month)
      MflRCH
      BPRIL
     RUSLJST

   SEPTEMBER
     OCTOBER
                                            FEBRUflRT
                                            JflNURRT
                                             DECEMBER
                                             NOVEMBER

-------
                    FIGURE 5-1 3
LRKE .HILLS  RUNOFF  FLOW  (percent by  month)
      RPRT	{       ,	.	MHRCH
       MflV	
       JUNE	
       JULT_.
     RUOJST
   SEPTEMBER
     OCTOBER
    NOVEMBER
FEBRUflRT
                                             JRNUflRT
                                             DECEMBER

-------
                     Table 5-4. Sl>  rY DOWNS WO LAKE HILLS
                           BASE  FLO*   AND  RUNOFF FLOWS
                        Surrey Downs
                                                           Lake Hills


Month
Z/80
3/80
4/80
5/80
6/SO
7/80
8/80
9/30
10/80
11/80
12/80
Total
1/81
2/61
3/81
4/81
5/81
6/81
7/81
8/81
9/81
10/81
11/81
12/61
Totul
1/&?
Base
flow
(ft3)
-
127,455
62,728
50,410
48,040
47,830
50,130
50,660
47,120
89,880
110,350
684,603
98,510
108,980
74,880
15,640
44,120
41,180
36,850
39,600
27,750
44,040
52,600
120,160
704,310
66,780
Total
runoff
(ft3)
_____
- 233,662
178,230
84,137
165,870
18,950
68,960
97,160
47,830
553,920
625,215
2,074,034
161,200
349,880
121,840
73,880
90,340
90,000
102,430
6,340
195,260
5bl,500
317,310
541,370
2,601,350
216,100
Base
F low
(ft3)
35,050-
69,870
51,720
23,632
22,610
21,850
27,780
30,900
22,830
44,730
87,235
433,207
78,720
43,410
77,310
38,890
?0,980
13,640
23,310
21,820
20,630
27,700
60,330
93,140
525,880
82,150
Total
runoff
(ft3)
293,940
315,440
285,240
73,165
204,500
17,530
91,550
145,200
56,210
817,790
879,800
3,175,365
205,790
340, 5? .0
157,420
185,360
118,840
128,610
175,390
3,860
416,880
684,010
539,030
801,280
3,756,990
357,600
Grand Total     1,455,693
4,891,484
1,046,237
7,289,955
                                     47

-------
                                   SFCTION b
                              URBAN KUN'OFF QUALITY
INTRODUCTION

     Ore of the  principal  tasks  of  the  Bellevue urban runoff project was to
collect samples  representing  as  many  runoff  events as possible from the two
test basins. About  700  rains  occur)Ci;  in each basin during the two year study
period. Samples  were  collected  for  analyses  from as many is 160 of these
rains  in each  basin using  automatic samplers and flow meters. Appendix E
describe0  the  sampling  equipment and  how it  was used. Th.3 samp] ing equipment
vas set to  initiate sampling  it  a predetermined runoff flow rate and to
obtain  flow weighted  samples  throughout the  duration of the runoff event.

     The sampling  equipment was  modified to  discharge the. samples into a
single  50-gallon (190-liter)  Nalgene  container wiuh plastic bottles
containing  ice as  a preservative. Because of the large sample container, the
sampling equipment  was  capable  of collecting samples from small to very large
rain events. The smallest  rain  event  that was monitored was about 0.04 inches
(1 mm)  of  rain.  The largest rain events were more than four inches (100 mm).
The large  events did  require  soone sampler servicing during the rain events.
The smallest rains  were represented by  about six subsamples collected
throughout  the runoff  period, while the large events contained several
thousand runoff  subsamples. The  samples vere removed from the sampling
equipment  within several  hours  of the  end of the event. The chilled samples
were then  brought  to  the  City of Bellevue's  water quality laboratory where
they were  separated into  different  containers that had appropriate
preservatives  i'or  the  different  chemical analyses. The Bellevue laboratory
analyzed the samples  for  r>H,  turbidity, and  specific conductance. The
preserved  samples  were  sent to  a commercial  laboratory in Seattle for
analyses (Am Test,  Inc.).  The commercial laboratory anplyzed the runoff
samples for total  solids,  total  Kjehldahl nitrogen (TKN), chemical oxygen
demand  (COP),  lead  (Pb),  zinc (Zn),  and total phosphorus (P).

     T.ie ranoff  monitoring equipment was installed in mid-March in Surrey
Downs and  in mid-April  in  Lake Hills  in 1980. Because of some equipment
problems at the  beginning  uf  the study  period (due to the .lack of event
markers on  the  flow recorders) each station  was temporarily deactivated for
equipment modifications.  Some small  runoff events (less than 0.1 inch, or 2.5
mm) w^re not monitored  because the  automatic stage activator (which turned on
the sampling equipment) could not detect small increases in runoff volumes,
above the existing  base flows, without  mary  falsa starts. Therefore, only
about three-fourths of  al1 of the rain  events were sampled. Because the
larger  runoff  events were  much more  effectively sampled, a much larger
percentage  of  the  total runoff volume was sampled.

                                      48

-------
      Uurlnr  the  period ot runoff monitoring,  street  surface particulate
 sa;,p>^ were also  collected c~* analyzed  (as  described  in Section 7). The
 bt-rert  clcaninv  program was varied  during  the  runoff sampling program. The
 urban  runoff data  was  therelore separated  into  different  groups corresponding
 to  the  study d-eas,  seasons,  and street  cleaning  programs.  Section 10
 describes  the  street  cleaning  program  and  measurements  in detail. Generally,
 extensive  street cleaning was  used  in  one  basin for  a period of time, without
 any  cleaning in  the  other basin. After several  months,  this was reversed so
 that  extensive street  cleer.ing was  conducted  in the  opposite basin. Over the
 two—car period  of time, extensive  street  cleaning was  conducted in eac'.i
 basin  during both  the  wet and  dry seasons.  Periods of no  street cleaning also
 occurred during  the  wet and dry periods  in  each basin.  Runoff during a period
 of  time was  also monitored corresponding  to no  street cleaning in either
 basin  at the same  time. This  schedule  enabled  the urban runoff quality and
 yield  data  to  be compared on  the basis of  street  cleaning effort and by
 season. Two  extreme  levels of  street  cleaning were used to  simplify the
 analyses and to  present extreme cases  for  comparison. The extensive street
 cleaning effort  involved cleaning all  streets  in  the drainage basin three
 tiones  a week.  This has been sh iwn in  previous  studies (Pitt, 1979; and Pitt
 and  yhawley, 1981) to  result  in streets  nearly  is clean as  possible using
 conventional street  cleaning  equipment.  More  frequent street cleaning (every
 day  or  even  multiple  passes in a single  day)  may  result in  slightly cleaner
 streets, but at  a  much greater cost.

      This  section  presents the urban  runoff quality  data  by these study
 period  divisions.  This data is also compared  to the  preliminary Nationwide
 Urban  Runoff Program  (NURP) urban runoff  quality  data.  The  statistical
 distributions  of the  concentration  data  is  examined  and variations in runoff
 quality as  a function  of season are also  shown. Baseflow  sample/; are also
 discussed.  The observed urban  runoff  quality  data is compared to beneficial
 use  water  quality  criteria. Calculated mass yields T-JI.  the  different storm
 events  and  estimated  seasonal  and annual  discharges  are also shown. The
 section finishes with  a discussion  of  the  potential  source  areas of the
 different  urban  runoff pollutants.
OBSERVED URBAN RUNOFF AND BASEFLOW QUALITY

     Much urban runoff quality data was  collected  during this project. Tables
A-8 through A-15 in Appendix A present the  urban runoff quality data
collected during this study representing  completely  monitored runoff events.
Additional data was also collected for partial  runoff  events, but was not
considered in the analyses because it could  be  misleading.  Table 6-1
summarizes this observed data. Average, minimum, and maximum values for the
water quality parameters, along with the  flow and  rain volumes, are shown for
eight project periods. Most of the periods  have from 20 to  30 monitored rain
events. The Surrey Downs dry weather category unfortunately includes 51 data
sets without street cleaning and only four  data sets with street cleaning.
Therefore, these two periods cannot be efficiently compared.

     Table 6-2 comparts this observed Bellevue  runoff  water quality with
preliminary Nationwide Urban Runoff Program (NU.RP) data. The preliminary NURP


                                      49

-------
                     I able 6-1.  r8SERVED URSW  RUNOFF  QUALITY  (COMPLETE
                       COMPOSITE  STORM EVENT  MEASUREMENTS  ONLY) (• v Weather
  Without. Street Cleaning
Runoff
Volume
(ftJ)
average 23,400
minimum 1,210
maximum 132,000
number of events: 23
With Street Cleaning
average 16,800
minimum 2,830
maximum 36,900
number of events: 24
Lake Hills Wet Weather:
Rain
(in)
0.35
0.04
1.33


0.27
0.08
0.53


Total
Solids
110
24
270


110
27
240


TKN

1.4
<0.5
5.9


1.1
<9.5
4


COO

54
13
120


44
20
120


Total
Phos.
0.42
0.015
3.6


0.28
0.1
1.2


Spec.
Cond.
Cwnhos/l
Lead
0.25
'0.1
0.56


0.17
<0. 1
0.5


Zinc
0.14
0.067
0.29


0.12
0.061
0.26


pH
5.
5.
fi.


6.
5.
7


(
1
3
6


1
2



c,n
42
22
140


30
17
61


Turb
(NTU)
15
6
35


24
6
67


Without Street Cleaning
average 61,400
minimum 3,060
.maximum 209,000
number of events: 32
With Street Cleaning
average 45,200
min imum 2, 590
maximum 223,000
number of events: 20
Surrey Downs Dry Weather
0.50
0.07
1.58


0.15
0.11
1.55


78
33
230


130
27
440


0.66
<0.5
1.4


1.0
<0.5
3.8


32
17
77


43
13
83


0.14
0.071
0.34


0.30
o.nc
0.92


0.11
< 0. 1
o'.4


0.18
< o. 1
0.31


0.094
0.03
0.22


0.11
0.053
0.?3


6.
5.
7.


6.
5
U .


6
5
1


0
5
8


40
22
85


31
19
55


16
6
82


38
1.7
150


Without Street Cleaning
average 18,600
minimum 1,263
maximum 10-3,000
number of events: 51
With Street Cleaning
average 39,700
minimum 8,590
maximum 78,800
number of events: 4
0.34
0.05
1.65


0.65
0.18
1.18

130
31
620


120
43
200

1.3
<0.5
4.3


1.2
0.5
2.7

61
21
150


40
15
54

0.32
0.068
1.2


0.29
0.097
0.59

0.18
< 0. 1
0.82


0.85
0.21
< 0.1

0.14
0.07
0.37


0.13
0.093
0.2

6.
5.
7.


..
_.
-.

2
2
4






38
16
95



	
-.

16
4
41


	
_,


                                          50

-------
                           Table  6-1. OBSERVED  URBAN  RUNOFF QUALITY (c.ont.)
Surrey Downs Wet Weather
     - Without Street Cleaning


average
minimum
maximum
number of events
Runoff
Volume
(ft3)
50,100
2,460
250,000
: 34
Rain
(in)
0.57
0.04
2.2

Total
Solids
95
29
270

TKN

0.84
<0.5
2.0

COD

43
19
no

Total
Phos.
0.17
0.002
0.38

ipec.
Cond.
(i
-------
Table 6-2.  BELLEVUE  RUNOFF WATER QUALITY CWPAREP TO NATIONWIDE  (SU3P) DATA
Constituents
PH
turoidHy
Sotc. cond.
toUl sol ids
Chemical Oxygen
Demand (tiq/1)
Total Kjeldahl
Nitrogen {mg/1
Total Phosphorous
(rac/1)
Lead
Zinc
(rag/1)
Lake Hills
nin fiax nedian
5.2 7.1 6.2
6 150 17
17 140 32
24 440 37
13 120 36
<0.? 5.9 0.78
0.015 3.6 0.19
<0.1 0.56 0.10
0.030 0.29 0.11
* of
ofcser
31
96
93
98
99
99
9S
99
99
Surre) Downs
rnfn max -sedisn
5.2 /.4 6.3
4 67 14
16 300 38
29 620 95
15 150 42
<0.5 4.3 0.84
0.003 1.2 0.17
-'0.10 0.8^ 0.10
0.047 0.37 0.11
# of
obser
98
102
100
107
106
105
106
106
106
All Mm? Data
(as of 10/81)
m1n max median
2.8 10.1 7.0
0.2 4900 51
1.0 4400 330
21 23,700 ?40
0.3 1430 52
0.01 520 2.0

-------
 da,a was  available  as  of  October,  l'ป81,  and included data from many urban
 runoff  monitoring locations  throughout  the country.  The Bellevue urban  rur.off
 i, of much better quality than  typically found elsewhere. The median  Bellevue
 runoff  water quality constituent  concentrations are  about half of the average
 WAV concentration  values reported.  The  Bellevue specific conductance values
 are  about one-tenth of the NURP axerage  values. The  amount and type of  rain
 at Bellevue, along  with the  urban  land-use development practices were
 probably  responsible for  these  lower observed  concentrations. The annual
 rainfall  at Bellevue (about  34  inches,  or 86C  mm) is not that much different
 from the  annual  rainfalls at itany  of the NURP  project sites. However, the
 typical Bellevue rains are much smaller  than elsewhere, with many more  rains
 occurring in a year, and  with resultant  shorter interevent periods. With a
 short interevent period,  pollutants  have a shorter time to accumulate.  In
 addition, the seller  rains  at  Bellevue  do not possess enough energy  to
 remove  much of the  deposited pollutants  in the urban areas. The ranges  of  the
 NURP event mean  concentration va.1 ues are quite large and the Bellevue median
 values  are closer to the  minimum  than the maximum values. The mjch larger
 range in  reported NURP concentrations,  compared to Bellevue concentrations,
 is due  to the much  broader range of  conditions and the larger number  of
 observations included  in  the NURJ'  data  base.

      Ihe  distributions of the observed  concentrations for total solids  is
 shown in  Figure  6-1. Distributions for  the other constituents are shown in
 Figures A-16 through A-23 in Appendix A. Those distributions show that  the
 most conmonly observed concentrations for each constituent are much closer to
 the  low side of  the observed range than  for the higher values. This is  quite
 common  in many physical measurements that cannot have negative values.
 Minimum values are  bounded >>  the  zero value,  while  there is no absolute
 limit to  the upper  values, c'eriodically, very  large  values may be observed
 due  to  unusual circumstances. The  distribution for pH values in Figure  A-21,
 however,  shows a more  "normal"  distribution with the most common value
 centered  in the  observed  range. This is  because pH is a measure of the
 hydrogen  ion concentrations  in  the water expressed as a negative log  to the
 base ten.  This implies tnat  the distribution of concentration observations
 may  be  expressed as  a  Ijg-normal distribution. The actual form of the
 distribution is  import,-nt because  it defines and restricts the use of certain
 statistical  tests that can be used to indicate differences and similarities
 in the  data.  Many of  ;he  common statistical analyses (including least squares
 linear  regression analyses to determine  an equation  that fits the data
 points, and  Student's  "T"  test which indicates significant differences  in
 paired  or  unpaired  .ata sets) require normally distributed values and equal
 variances  along  the  range  of  observations.  If  the data can be transformed to
 fit  a normal  pattern,  then these basic and powerful  statistical analyses
 procedures  can be legitimately used.

     Figure  6-2  shows  a log-probability  plot of total solids" concentration
 values. Figures  A-24 through  A-30  in Appendix  A shows the log-probability
 plots for  the  other  constituents (except pH).  A straight line on normal
 probability  charts indicate  a normal distribution of the observed data. When
 the logarithmic  transformation is  made,  nearly straight lines result for all
of the constituents, especially between  the probability rangas of five and 95
percent on the log-normal  charts.  In some cases, a straight line occurs from


                                      53

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a
   60
   40
   38
   20
       <50
100
                              FIGURE 6- 1
                          TOTflL  SOLIDS
150
200
                               ซn
250
               300
                                         350
                             400
                              450
                             500
                             >550
             HILLS Q-5URRET DOWNS
           Concentration  (Value shown  is beginning  of interval,  mq  1

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7OO^
600
500

40O
   too-
    90
    80-
w   7r- —
                   Surrey Downs
                       Lake H Us
    10
                 FIGURE   6-2
                                                       20    30  40   50  60   ""0    80

                                                         Percent Less Than Concentration Values
                                                                                                95
                                                                                                        98   99  99 5  99 8
                                             Frequency Distribution of Total Solid* Concentration*

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the one to yy percent probaL'lity  values.  In  many  cases,  however, the extreme
lo.j or high values do not  iall  on  the  straight  line.  This can be expected
because 01 the relatively  small  number of  observations  in each data set.
However, these small deviations  in the extreme  tails  of trie observations do
not significantly alter  the  conclusions  associated with the statistical
tests.

     The previous bar graph  non-transformed  distribution  plots and these log
probability plots show  the observations  for  Surrey Downs  and Lake Hills
separately. For  total solids,  COD, zinc,  and  specific conductance, the Surrey
Downs concentrations are greater than  the  Lake  Hills  concentrations. No
noticeable difference appears  for  the  other  constituents  over the entire
range of constituent concentrations observed.

     Concentrations  also varied by month.  Table 6-3 shows the average monthly
runoff  concentrations observed for both the  Lake Kills  and Surrey Downs
sites.  A general cycling of  the concentrations  was observed: the
concentrations were  typically  greater  during  the dry  months than during the
wet months. These variations may have  been caused  by  differences in the rain
characteristics  (especially  rain totals and  frequencies)  during the seasons.
If  the  pollutants are source limited in the  drainage  basin, then the larger
rain events would result in  lower  runoff concentrations.  This, of course,
requires  that  the small rain events have sufficient energy to remove the
contaminants  from the drainage basin.  Some of the  pollutants, such as lead on
street  surfaces, may be considered source  United, but  other pollutants,
especially  total solids, could not be  considered source limited because
erosion potential usually  increases with increasing rains.

     Figures  A-31 through  A-38 in  Appendix A are plots  of observed runoff
concentrations as a  function of rain magnitude  for each of the two basins and
for  the wet and  dry  seasons. The most  common feature  of all of these scatter
plots  (with the  exception  of the pH plots) is that the  maximum observed
concentrations occur for rains smaller than  about  0.5 or  0.75 inch (13 or 19
mm). The  concentrations of the runoff  associated with rains greater than
these  volumes  fall into a  much narrower band. The  small rain events, however,
also contain  many low mean event concentration  values.  These relationships
signify a dilution effect  by the larger rains and  an  uneven amount of energy
to  remove pollutants by the  smallest rains,  caused by varying rain
intensities.  Even though the large rains observed  include the largest rains
that are  likely  to occur in  the area,  increases in total  solids or other
contaminants  associated with pervious  areas  did not occur. In other areas
that experience  much larger  rains, increases  in total solids concentrations
may be  evideut for the  very  largest rains. These scatter  plots also
differentiate  observations  obtained during dry  and wet  periods. Generally,
the highest concentrations  for almost  all  of  the rain volumes are associated
with the dry  seasons. However,  many wet season  observations are also
relatively high. Again,  the  dry season rains  would have long periods of
pollutant accumulations  between them.

     Baseflow  samples were collected about once a  month during the second
year of the project. These  baseflow samples  were collected using the
automatic samplers on a time sampling  mode.  The samples represent average

                                       56

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Table 6-3. AVERAGE MONTHLY RUNOFF CONCENTRATIONS (mq/1)

Oan
Feb
Mar
Apr
May
June
July
Aug
Sept
Oct
Nov
Dec
Total
Solids
LH SD
120 126
112 93
69 95
89 110
130 110
115 170
98 120
130 270
130 130
90 100
100 86
81 94
COD
LH SD
39 50
38 46
36 48
37 43
46 67
51 74
45 60
86 IOC
54 56
42 39
37 40
32 36
TKN
LH SD
0.67 0.81
0.86 0.75
0.83 0.75
0.88 1.0
0.97 1.2
1.4 1.7
1.0 1.1
3.7 2.4
1.3 1.3
1.2 1.0
0.79 0.94
0.68 0.63
TP
LH SD
0.24 0.16
0.26 0.18
0.14 0.19
0.26 0.27
0.21 0.26
0.34 0.46
0.26 0.23
1.5 0.75
0.30 0.28
0.20 0.19
0.25 0.17
0.14 0.14
Lead
LH SD
0.18 0.16
0.20 0.12
0.10 0.13
0.16 0.17
0.21 0.13
0.24 0.22
0.16 0.14
0.37 0.44
0.23 0.17
0.16 0.11
0.12 0.11
0.11 0.11
Zinc
LH SD
0.095 0.11
0.089 0.090
0.094 0.11
0.095 0.11
0.12 o.n
0.13 0.16
0.11 0.14
0.23 0.25
0.15 0.15
0.11 0.11
0.11 0.13
0.094 0.11

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b.isot low concentrations over  about  24  hours  of  Lime.  Table h-A summarizes the
hasetlow wafer i|u,ilit' observations  at the  two  sampling sites. The observed
hasetlow concentrations ot CUD,  TKN ,  total  phosphorus,  lead,  and zinc were
about  the same as  tor  the  storm  runofl  concentrations.  However, the baseflow
total  solids and speeitic  conductance  values were  much  greater than observed
in the storm runoff.  The  total  solids  material  during storm runoff events is
mostly suspended solids,  while  the  total  solids during  baseflow conditions is
mostly dissolved solids (based  on  ratios  of  specific  conductance to total
solids). The similarities  in  baseflow  and  storm runoff  nutrient and heavy
metal  concentrations  is surprising.  In other areas (especially at the Castro
Valley MlKH site;  Pitt and Shawley,  1981)  the bnseflow  and nutrient
concentrations were  much  less than  the storm runoff concentrations. However,
the Castro Valley  baseflow dissolved solids, specific conductance, and major
ion concentrations were all  much greater  than observed  in the storm runoff.
In Castro Valley this  implied that  the baseflow was mostly associated with
diachargini; groundwater that  originated in  non-urban  areas above the study
area. At the two Bellevue  sites, however,  the complete  basins are urbanized
and the groundwater  that  discharges  to the  storm drainage systems between
rain events was  much more contaminated than the rural groundwater discharges
observed at Castro Valley.

     The nutrient  and heavy  metal  urban runoff  concentrations at Bellevue are
 .uch less  than observed at other NURP  project sites.  The Bellevue baseflow
concentrations are also much less  than the  average NURP runoff data, except
for total  solids and specific conductance.  In a later subsection, the
contribution of  baseflow  discharges  will  be compared  to the annual storm
runoff discharges.

     Additional  Bellevue  urban ""unoff  information  is  included in the USGS
report on  their  portion of the Bellevue urban runoff  project  (Prych and
Ebbert, undated).  The USGS used  elaborate  samplers that collected many runoff
samples at different time intervals  during  rain events. They  analyzed many
samples for their  monitored  rain events for many more constituents than were
included in this program  phase.  However,  the USGS  sampled many fewer rain
events than included in this  project.

     Seattle METRO (Galvin and Moore,  1982) is  also conducting a project
associated with  the  Bellevue  urban  runoff  program. METRO'S study is directed
towards monitoring priority  pollutants is  urban runoff, urban runoff source
areas, and receiving waters.  These  priority pollutants  include many
pesticides and industrial chemicals  that  have been shown to be carcinogenic.
Several heavy metals are  also included as  priority pollutants.
COMPARISON  OF  OBSERVED  URBAN RUNOFF CONSTITUENT CONCENTRATICNS WITH WATER
QUALITY CRITERIA

     Published water  quality criteria are not really appropriate for urban
runoff problem identification.  These criteria,  even when expressed in terms
of safety factors  for organisms present in the  receiving waters, are designed
for continuous discharges  and relatively constant concentrations. In most
locations,  receiving  water pollutant concentrations during periods of runoff

                                      58

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                        Table 6-4.  Base  Flow  nuality


                     Lake Kills                     Surrey Downs
               Min.   Max,   Average  # of       Min.   Max.  Averane  f  of
Constituent    mq/1   mq/i    mq/1    Samples     mq/1  mq/1   mq/1   Samples

Total Solids  108    326     210     13        130    226    195     13

COD           9.1     67      27     13        6.8     45     19     13

TKN           0.20   1.9     0.56    13        0.34   2.4    1.0     13

TP            0.027   0.?2    0.11    13        0.034  1.2    0.20    13

Lead         <0.1    0.1   <0.1     13       <0..l    0.1   <0.1     13

Zinc          0.03   0.14    0.073   13        0.026  0.47   0.10    13

Spec. Cond     138    430     270      9        146    300    240      9
(  pmhos/cm)
                                  59

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v.i'v di ,11,;.11 i r;i 1 1 v  I r urn t hi  ha<<.'tlow coneon t r;i t i ons .  In  mist  rapes, the
'-In,.tic. ;i.Uuii'  ot  stvirm  rui'.ol'  cannot he i-or.ip.i red  to  the  water quality
    t r i .1 I'.i.-.t  ,ir-  ti.-so' iatrd with cont inucvjs  d i s^rlia rges .  However, as was
    d  in i It.-  l,i:. t  subject tun,  t lie Kisoflow and  -form  ruru'tl  concentrations in
         .ue  rut  that  dissimilar, except  lor  total  solids.  The published
         ,...iv ,  t hr !"i't ore ,  be applicable when evaluating  the  storm runoff
di s.-li.n >,v  conditions  .it hei'''vue, especially  fo\.  "totally  developed"
v.-uorOu-ds . Another  important  project associated  with  the  Rellevue urban
lunott program was  cond.icted by the University of  Washington (Pcdersen, 1981;
Ki.M-rv,  I'-'.V;  and  S<-ut t ,  Steward, and Stober,  198-i)  through  t.ie Corvallis Lab
ol  tlie Kl'A  and addressed  receiving water  measurements  and  effects from urban
run.>tl.  1 he (.Diversity of  Washington  study included  actual  beneficial use
impiirmrnt  waturements by sampling the aquatic  organisms  most directly
atiect-'d by  urban,  runout.  The observed biological  conditions in selected
belK'vue urban runoft  receiving waters were compared  to the  biological
conditions  in similar bodies of water unaffected  by  urban  runoff. This
subsection  wtil  compare published water quality  criteria  with urban runoff
con.-entrat ions observed during thi^ study. Refer  to  the University of
Washington  study toi  a more detailed  discussion  of  probable  urban runoff
ellects  at  Br.llevue.
Dissolved  Oxygen

      No  dissolved oxygen measurements of urban  runoff  were obtained during
tiiis  st.udy.  Previous studies show that  the DO of  urban runoff is near
saturation due to the turbulence and thin sheet  flow  nature of most urban
runoff  source  waters. However, urban runoff  contains  various chemicals and
organic  matter that can consume oxygen  in the receiving  water over a period
of  time.  Uroan runoff can be characterized as a  wastowater having low levels
of  organic matter and nutrients and high levels  of  heavy metals and possibly
other  directly roxic materials. Urban ru- 
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in the
      ,;  hvdrogen sulfide,  and  the ueveloprcenf of .arbon dioxide and  methane
  n  he sediments.  Dissolved  oxv^en in the wjter column can also cause
 ch.-nncal  oxidation ,,nd  subsequent leaching of iron and manganest  from
 sediments.  The eftects  of  dissolved  oxygen on freshwater fish is  complicated
 becaus-  fish vary  in their o::ygeu requirements according to the specific
 spe.ies,  tt.eir age,  activity,  water  temperature, and by the amour.t of  food
 present.  Msh ;u e  capable  of  surviving for short periods of time  at  very  low
 oxygen conditions. Most, researchers,  however, report a dissolved  oxygen
 concentration of  at  least  four mg/1  needed to support a --aried fish
 population.  However, greater  concentrations will usually result in a greater
 variety  of  species present.  Fish embryonic and larval stages are  especially
 vulnerable  to low  oxygen conditions  because of their lack of mobility.  In
 addition, low dissolved oxygen levels can adversely affect aquatic insects
 and  other animals  upon  which  fish feed.  As long as dissolved oxygen
 concentrations remain sufficient for  fish, no significant impairment of  the
 fish's resources,  due to dissolved oxygen, are likely to occur-
 Solids

      Observed  total  solids  concentrations  in the storm runoff during  this
 study varied from  about  20  to  more  than  500  mg/1.  The average event mean
 concentration  value  was  slightly  less  than 100 mg/1.  The total solids
 concentrations  during  baseflow conditions  averaged about twice these
 concentrations.  The  total solids  during  storm runoff  events are mostly made
 up  of suspended  solids while the  total solids during  baseflow conditions are
 mostly made up  of  dissolved solids. Much of  the so-called suspended solids
 during urban runoff  events  may settle  out  in the receiving water as
 sediments.

      The criteria  for  suspended solids and aquatic life beneficial uses is
 usually considered about 80 mg/1. This is  about equal to the observed total
 solids concentrations  during most of  the urban runoff events in Bellevue. The
 total dissolved  solids criteria varies appreciably depending upon the
 resistance of  the  aquatic species and  other  uses.  Tl:Js total dissolved solids
 criteria is usually  associated with restricting the salinity of the water and
 would usually be much greater  than  observed  during the storm runoff events or
 during baseflow. Therefore, the most  important effects of solids is
 associated with  the  suspended  solids  during  storm  runoff events and the
 accumulation of  settleable  solids on  the stream beds.

      Susi ,..ided solids can affect  fish  life in several ways; by directly
 killing une fish,  or by  reducing  their growth rate or their resistance to
 disease, for example. Suspended solids also  affect fish by limiting
 successful development in fish eggs and  larvae. Suspended solids can also
modify natural movement  and migration  of fish and  can reduce the abundance of
 fish  food available. The most  direct  effects of suspended solids are the
 reduction of light penetration into the  water column  and the heating of the
surface  waters.  Settleable materials  associated with  urban runoff solids
blanket  the bottom of waterbodies and  damage the invertebrate populations,
ruin gravel spawning beds, and, if  they  are  organic,  can remove substantial
quantities of  dissolved  oxygen from overlying water.  The most important


                                      51

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I'liect ot urban  ruiintt  s>:l; 's  in  Bi'llevut? receiving writers is probably  the
rout i i 1ml ion of  se 11 leablt'  s i 1t s  and  rlay;; covering the gravel spawning  beds.
The .ibrasion ot  fish  gills  by  Che solids may also be important.
N i t ro^.rn

     The only  form  of  nitrogen monitored by this urban runoff project was
total Kjeluahl  nitrogen,  which is a combination of the organic nitrogen  forms
and ammonia. The  most  common forms of nitrogen not included in this analysis
are nitrates and  nitrites.  Organic nitrogen may make up most of the total
Kjeldahl nitrogen in  some cases,  and ammonia may be more prevalent in other
cases.  The  un-ionized  ammonia (ammonium) form of nitrogen ammonia is toxic to
aquatic organisms.  This  un-ionized ammonium is usually less than about 25
percent of  the  total  ammonia concentrations in the urban runoff. Average
ammonid concentrations in Bellfwue storm runoff and baseflow would be much
less  than  sevetal hundred mlcrograms per liter. However, the maximum observed
total Kjeldahl  nitrogen  concentrations, as high as about six mg/1, signify
the potential  for high ammonia concentrations. At these very high total
Kjeldahl nitrogen concentrations, the mi-ionized ammonium concentrations may
be several  hundred  micrograms/liter.

      Rainbow  trout  have  been reported to be the most sensitive fish to
un-ionized  ammonium (the most toxic form of ammonia). Concentrations of 0.2
ing/1  ammonium  are lethal to rainbow trout, while values less than this can
exert adverse  physiological or histopathological effects. At concentrations
or three mg/1  total amnionia, trout have been reported to become
hyperexcitable  and, at eight mg/1 total ammonia, 5U percent of the trout died
within  20  hours.  Carp  are usually the least sensitive fish to ammonium.
Sublethal  exposures to ammonium can cause extensive necrotic changes and
tissue  degradation  in  various organs. Concentrations of 2 mg/1 un-ionized
ammonium can  be lethal to carp (EPA, 1976); The observed total Kjeldahl
nitrogen concentrations  indicate  the potential for some adverse ammonium
concentrations, but this would likely be restricted to rare runoff events.
The typical sto-rai runoff concentrations do not indicate recurring ammonia
toxicily problems.

      Nitrate  concentrations in storm runoff may also be important. Even
though  not  included in the  total  Kjeldahl nitrogen analyses, the presence of
large amounts  of  organic nitrogen and ammonia may indicate high nitrate
concentrations. Nitrate  is  a common major ion and was monitored as part  of
the USGS monitoring program. Preliminary results from the USGS (Ebberu,
Poole,  and  Payne, 1983)  show nitrate concentrations of about 0.025 mg/1.
Maximum concentrations of several mg/1 were also observed.

     The 96-hour  concentration of nitrates capable of killing half of the
bluegills  in a  test (96-hr  LC-50) was two mg/1, while a value of 0.09 mg/1
nitrate plus nitrite  had no significant effect on growth or feeding habits of
largemouth  bass and channel catfish (EPA, 1976). However, rainbow trout  are
much iiore  susceptible  to nitrate  concentrations. Trout weighing 200 grains
experienced no  mortalities  after  ten days with nitrate plus nitrite


                                      62

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 tom-,nr.r,tions  ot  L-..
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     1'he dissolved  lead  COIK  nt rat ion  values  that  have been shown to bo
lethal  to tish are  much  greater  than  the  dissolved lead concentrations
exported in the Bellevue  urban  nnioft  or  receiving waters. A small fraction
ol total load that  was observed  in  the Beilevue  urban runoff is expected to
oeeui  as eitlor organic,  lead  forms  or  other  soluble lead forms. However, the
aecimui la t ion of paniculate  lead  iorms in sediments receiving urban runoff
has ho en shi.-.-n to potentially cause adverse  effects on the benthic organisms
U'itt  and Bozeman,  1982).
     The observed  total  zinc  concentration in the Believue urbin runoff was
about D.I mg/1  and  Tnaxitnum values  were  about 0.4 mg/1. The base flow
concentrations  were slightly  less.

     Rainbow  trout  have  been  reported to be the most sensitive fish to zinc
in hard  waters, with lethal concentrations for coarse fish being three to
tour Limes  the  rainbow trout  values.  Immature insects seem to be less
sensitive  than  many of the test fish. For fathead minnows, 96-hour LC-50
values  in  hard  water were reported to be 33 mg/1. However, at the
much-reduced  zinc  concentration of 0.18 mg/1, an 83 percent reduction in egg
production  was  found,  as compared  to  a zinc concentration of 0.03 mg/1. One
to two  gram fathead minnows had 96-hour LC-50 valu~ , of 8.2 to 21 mg/1
anhydrous  zinc  sulfate.  Fathead minnow eggs experienced 24- to 96-hour LC-50
values  of  1.8 to 4.0 mg/1, also with  anhydrous zinc sulfate. Fathead minnow
fry 24-  to  96-hour  LC-50 values were  less, at 0.87 to 0.95 mg/1 anhydrous
zinc sulfate. Two  to three gram fathead minnows 96-hour LC-50 values were
greater, at about  nine to 13  mg/1  anhydrous zinc sulfatt. Juvenile rainbow
trout 96-hour LC-50 values in hard water were about 7.2 mg/1 zinc sulfate and
were reduced  to 3.2 mg/1 for  48-hour  exposures to elemental zinc. One to two
gram bluegills  experienced 24- to  96-hour values of about 41 mg/1 anhydrous
zinc sulfate  (EPA,  1976)

     The observed  total  zinc  urban runoff concentrations in Bellevue are less
than most  of  the reported dissolved zinc concentrations that may cause
potential  problems. As for most heavy inetal.s, EPA recommends a water quality
criteria value  of 0.01 of the critical  LC-50 values for the aquatic organisms
present. Again, since  most of this total zinc is in a particulate form, the
dissolved  zinc  levels  in the  urban runoff and baseflows are still likely to
be less  than  these  roore  critical values. However, settleable particulates may
contain  these relatively high zinc concentrations and may cause long-term
adverse  effects for the  benthic organisms in the sediments.
Summary

     It is evident  from  the  preceding discussion that the forms of Fiany of
the water quality constituents  determine their toxicities. During a previous
urban runoff  study  in  San  Jose,  California (Pitt, 1979), typical urban runoff
constituent concentrations for  a broad list of common ions and heavy metals

                                      64

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 wore  a.aH.ed  usir^  an  equilibrium water chemistry computer program.  This
 prorrar, w',s  used  to  estimate  the  specific inorganic chemical compounds  that
 wrre  proKiSly  present  in  t -,e  urban nmoff and to estimate which pollutants
 would probably remain  soluble and  which pollutants would probably accumulate
 in  urban runoff  sediments.

      Most  of the  urban  runoff pollutants were predicted to be in soluble
 forms and  would,  therefore,  be carried  in the water column. However,  this was
 not  t.ie case for  some  pollutants.  For  example, 95 percent of the inorganic
 lead  was predicted  to  be  insoluble.  Depending upon the size of these
 paiiicles  (or  the particles  to which they may become attached), the lead
 could remain in  suspension or could  settle out in the storm drainage  system
 and/or the receiving waters.  Chromium  and phosphate may also settle out. The
 settling of  lead  particles  co the  sediments  was substantiated in field
 studies in ?an Jose, as  relatively high concentiations of lead were found in
 urban Coyote Creek  sedir.-nts  (Pitt and  Bozeman, 1982).

      The soluble  fractions of other  inorganic constituents monitored  were
 primarily  insoluble  ionic forms,  including calcium, magnesium, sodium,
 potassium, sulfatc,  chloride, and  nitrates.  Most of the carbon dioxide  is
 expected to  be in bicarbonate forms. Most of the phosphate is expected  as
 soluble phosphoric acid,  but  important  fractions of phosphate may occur as
 insoluble  calcium phosphate and lead phosphate forms. Almost all of the lead
 is  expected  to be in particulate  lead  carbonate or lead phosphate forms, with
 only  a few percent of the lead occurring as  soluble lead ions or soluble lead
 carbonate  forms.  Almost all of the zinc and  copper are expected to occur as
 soluble ionic  forms, while the chromium is expected to occur as soluble
 chromium hydroxide.

      This  computer analysis considered  equilibrium conditions and only
 inorganic  forms.  Urban runoff is definitely  not at chemical equilibrium and
 many  organics  are also present. However,  long-term sediment conditions  are in
 equilibrium  and many organic  complexities have small effects on solubility.
 These  expected chemical forms  can  be used as guidelines when estimating the
 potential  for  toxic  materials  to accumulate  in sediments.

      In summary,  direct urban runoff receiving water effects during rvnoff
 events  may not be significant. Potential  immediate dissolved oxygen demand is
 balanced by  the supersaturated oxygen conditions in urban runoff. In  special
 conditions,  dissolved oxygen  during  runoff events may be important.

     Suspended solids concentrations during  runoff events may not be
 important, except for infrequent very high suspended solids concentrations.
 Ammonium and nitrate nitrogen  concentrations may periodically be in adverse
 concentrations during storm events. Most  of  the Bellevue urban runoff water
 quality problems are expected  to be associated with long-term problems  caused
 by settled organic and inorganic debris  and  particulates. This material can
 silt up salmon spawning beds  in the Eellevue streams and introduce high
 concentrations of toxic materials  directly to the sediments. Oxygen depletion
 caused by organic sediments and the  lead  and zinc concentrations in the
sediments may all affect the  benthic organisms. These benthic organisms are
important food for the fish in the receiving waters and they may be adversely

                                      65

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• )!tiiii-il ovri  luiij',  pet tin's   '  l i mi .  Drii^Lic cl.,)n>;es  in  benthlc  organism
l"Mn' ' ••' l >lils  -md  tin-  .ihseuce  ot  di.'si r;)hle tlsh have ixjcn  noted  in  other urban
MiiMtl  rei r i v i 11)-.  w.Uer  studies  (Titt and Bor.eman  , 1982).
'•'.ASS YIM.nS OF  1'OLl.UTAMS  FROM LKHAN ARF.AS

     The urban  runoff  quality data and the runotf volume  da'^a  presented
e.irlier were  used  to  calculate the urban ninoff pollutant  mass  yields  for
t'.ich rain  event  monitored.  Tables A-16 through A-23  in Appendix A  list  these
calculated  values  tor  the  different drainage basins,  seasons of the  year, and
periods of  different  street cleaning practices. These yield  values  occurred
over wide  ranges  because of the wide ranges ot runoff volumes  and
concentrations  observed. Table 6-5 summarizes  the estimated  annual  mass
yields  for  baseflow  and runoff in both basins. The observed  runoff  yields
from the monitored stortns  were used to predict the expected  runoff  yields
from the storms  that  were  not monitored. The urban runoff  annual discharges
shown  on this table  are based on about 75 percent direct  measurements  and
about  25 percent  estimates. The baseflow values are  based  on the two-year
baseflow volumes  between all storm events but  only on the  year  two  baseflow
quality concentrations.

     There  is an  apparent  difference between the runoff discharges  in  Lake
Hills  and  Surrey  Downs when expressed on a pounds per acre  basis.  However,
the  total  annual  runoff plus baseflow discharges from the  two  basins  arc
quite  similar.  This  implies that a much larger ftactioa of  the  total  urban
runoff  in  Surrey  Downs occurs as baseflow between rain events.  The  runoff
events  in  Lake  Hills  are more sharply defined  and the Lake  Hills baseflow is
a much  smaller  fraction of  the total urban mass yields.

     The estimated annual  mass yields of the urban pollutants  expressed  in
pounds  per  acre  per  year are similar to those  reported in  San  Jose,
California  (Pitt,  1979), and in Castro Valley, California  (Pitt and  Shawley,
1962).  The  much  smaller urban runoff pollutant concentrations  observed  in
Bellevue when compared to  these other two locations  is compensated  for  by the
much larger amount, of  runoff that occurred.

     Figures  6-3  and  6-4 show the variations of the  annual  runoff  and
baseflow mass yields  by month for total solids in the two  basins.  May  through
August  only contributed about five percent of  these  annual  mass yields  in
each month. November  and December each contributed between  15  and  20 percent
of the  annual mass yields.  The contributions of runoff and  baseflow  volumes
were greater  in  those  months that had high runoff volumes.  The  runoff  and
baseflow concentrations for many pollutants were similar.  The  effects  of
different  flow  volumes on  total runoff yields  for each event was also
studied .

     Figures  6-5  through 6-8 show variations for total solids  and  lead  for
both Lake Hills  and Surrey  Downs. These scatter plots show  log  transformed
value:;  of  flow versus  lop  transformed values of storm yields.  These  log
transformations were  necessary to even out the observed data distribution.
These transformed  distributions were analyzed using  curve  fitting  routines


                                       66

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         Table 6-5. Annual Urban Runoff Mass  Yields  (Ibs/acre/year)
Constituted
      Lake Hills
base    storm    total
flow    runoff
    Surrev Downs
base    storm    total
flow    runoff
Total Solids
COD
TKN
TP
Lead
Zinc
67
8.7
0.18
0.035
0.02
0.024
250
100
2.4
0.61
0.40
0.27
320
110
2.6
0.65
0.42
0.29
100
10
0.53
0.10
0.03
0.053
180
79
1.6
0.35
0.23
0.21
28C
89
2.1
0.45
0.26
0.26
                               67

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  LRK.E  HILLS
  29
  16.
O

4ป

O
7; 8
c
a:

ซ*-
o
  FIGURE 8-3



Total  Solids  Yield  by  Month
  FEB


RUNOFF
             MRft
      JUNE I JULY I RUG I SEPT
                                            n
OCT
NOV
                hBfiSEROW
                             J
DEC

-------
                   FIGURE 6-4
SURREY  DOWNS  - Total  Solids Yield  by  Month
20
           MRR
RPR
MfiT
JUNE
JULY
RUG
SEPT
OCT
                                             R
NOV
DEC
     RUNOFF   Q-BflSEFLOW

-------
                       FIGURE 6-5

      LRK.E HILLS  -  Total  Sol ids by  Season
   54 .6
   20.1
ฃ
O
u
03
   7.39
   2.72
   1.00
O
O
   0.37
   0.
   0.051*
       1100
   O  WET
              A 0
                                    oฐ Q
                                           *
                                               0 „
             2980
8100     22,000    59,900


      FLOW (cubic feet)
163,000   4 4 2 , C ~ 0

-------
  SURREY  DOWNS
  FIGURE 6-6
  - Total  Solids  by  Season
54 .6
0.05
    HOC
   WET
          2980
           A  DRY
8100     22,000   59,900    163,000   442,000
    FLOW (cubic feet)

-------
                FIGURE 6-7
      LfiKE HILLS -  Lead by Season
0.00091
0 . 0 0 0 3 4
0.00012
0.000045
1
* a * A
ฐ *< v^
A * nฐ --<*
/ A* A 0 0-
./- , - o* e* ป
A A ป• j,
- /^ 0
i— ^ ^/ 0 0
A
/'
x-'" ^f'
^ / A
/^^^ <*
,/ 0-
/•

o  wiv.
 22000   09,1,00
FLOW (cuhic

-------
    u . 0 5 C
    0.018
   0.0067
<
  0 . 0 0 0 9
  0.0003-i_
  0.00012-
  0 . 0 0 0 0 4 :j
      1100
                        FIGURE 6-8
            SURREY  DONN5  -  Leod by Season

                         e *

              2980     8100    22,noo    59,9GO
              A  DRY       FLOW (cubic fuc. t)

-------
t!..H  rr.j'iirrd evonlv  distributed  data. "I he data show on  fie.-.e  figures  are
se-.-.ir.-i'i d in1 season,  and  bands  of  equal concent ratio-1 values  are  drau-r  on
t!'<.':.f figures tn  ir.Jioate  si >.;ni { i t-,-,n t  concentration shifts  for  different  flow
v •'. .-,; ,i's . The total  solids  concentrations associated with  the  small  events (of
abi.n'. 1 ,000 to  !'),(.(nr cubic  feet,  or 2K,i>00 to 280,000 liters of  flow)  had
concentrations  of about  li.'H  mi;/1  of total solids. When the  runoff  volumes
ii1' ;eased subt, t ant i a 1 1 y  to about  1OO.OOO cuhic feet (2.8  million  liters;, th.-
iปi <1 solids eor.cenr ! t.t ions  decreased  to about 75 mg/1. Again,  these  figures
sh'.v t lu appreciable  spread  in  observed concentrations for  events  in  all  flow
c i tev'.ori es . The  Ica.i  da t i  are  much more grouped because of  the  high  detection
1 i ;T' i t >'•[ the  lead analysis procedure useu. These data transformations  are
UM.I) in Section  9 to  identify  changes  in runoff mass yields for  the  different
pollutants  as a  function  of  season, runoff flow, and street cleaning  program.
b-Ul'-KCK ARLA  C'lMKlBllluNS  OF URBAN RUNOFF POLLUTANTS

     Determining  the  relative importance of different urban  areas  in
contributing  MI bar  runoff  pollutants must be based on an understanding  of  the
natui il  and  ma i-related  processes and ouppi^mented by limited  data.  It  is
very difficult  to  monitor  individual source area components  and  attempt to
n.-.ke an  urban runort  mass  balance. This would require a very  substantial
monitoring effort  over  a fairly long period of time. Several  types  of each
contributing  source  area Must be monitored because of seemingly  minor
differences  th.'.t  can  result  in major differences in sh?et  flow runoff
qualities. The  previous  discussion on urban runoff water sources  from
different  source  areas  is  extremely important in trying to determine  sources
of urban  pollutants.  Most  of these source areas, however,  are  expected  to
have different  pollutant strengths. Some urban sheet flow  grab samples  bave
been collected  and  analyzed  for important ui ban runoff pollutants  in  San
Jose, California  (t'itt  and Bozejian, 19^2). Castro Valley,  California  (Pitt
and Shawley,  1981),  and  in Ottawa, Ontario (Pitt, 1982). The  site-specific
urban runoff  flow  information previously described can also  be used  with
local measurements  of  urban  runoff partlculate strengths and  source  area
particulate  strengths.

     Urban runoff  particulate strengths can be estimated by  dividing  the
ru'ioff constituent  concentration by the associated total solids
concentration.  This  results  in a unit of milligrams of constituents-per
kilogram  ot  total  solids,  or parts per million (when multiplied  by  1000).
These runoff  relative  c   "entraiions can be compared to the  concentrations
found for  source area  particulates (such as street dirt, soils,  drainage
sediments, etc.).  If  the urban runoff relative ^trengch is greater  than for  a
specific  source area  particulate strength, then that source  area is  not an
iir.povtant  contributor  for  that specific constituent. In other  words,
particulates  from  other  source areas have stronger relative  concentrations
and;or are mere effe:tive  in reiching the outfall. Hcwever,  if a specific
source area  relative  strength is greater than the urban runoff relative
strength,  then  that  source area is probably an important urban runoff
pollutant  source for  that  constituent.

-------
      7'- relative  concentration of  the urban runoff constituents  can  be
 cal,-ul.u,-.l  iron the concentration data shown in Tables A-8 through  A-15  of
 <...rซ".^lx A.  TIIC resultant  relative  concenti at ions can be expressed  as
 mlllif-r^ซ  ot  constituent  per kilogram of total solids, or parts  per  million.
 The  runotl  relative concentration values for Bellevue are surprisingly  ni?h,
 possiMv bcc.n.se ot the  relatively  low concentrations rf total solids  in the
 rum,tl.'Mud. of the chemical  oxvgen demand and the nutrients are  expected  to
 be  as soluble  forms.  These  dissolved strengths are higher than the  street
 dirt  pollutant  solids strengths discussed in Section 1. The total Kjeldahl
 nitrogen and ;inc  runoft  pollutant  strengths are five to ten times  greater
 than  the observed  street  dirt pollutant strengths while the total phosphorus
 pollutant strengths in the  runoff are about  three to five tiroes the street
 dirt  strengths / The chemical  oxygen demand and lead strengths are about  twice
 the  street  dirt strengths.  Vhe  runoff concentrations and loadings observed
 for  Bellevue are relatively low,  but the street dirt strengths were about  the
 same  as  compared to other  locations studied. The higher particulate strengths
 in  the  runoft  v,l.ei-. compared with  the street  dirt pollutant strengths  may
 indicate an  accumulation  of the larger, less polJuted street dirt
 particulates in the storm  drainage  system.

      important  sources of  problem pollutants ar.j related to various uses and
 processes.  These include  natural  sources, sucli as rock weathering to  produce
 soil, groundwater  infiltration, volcanoes, and forest fires. Automobile  use
 usually  affects the road  dust and dirt more  than other particulate  sources  of
 street  runoff.  The road dust  and  dirt  quality is affected by vehicle  fluid
 drips and spills (such as  gasoline  and oils), gasoline combustion,  and
 vehicle  wear products. Local  soil erosion and pavement wear products  can also
 significantly  contribute  to street  surface particulate loadings.  Urban
 landscaping  practices  potentially affecting  urban runoff include  vegetation
 debris disposal and fertilizer  and  pesticide uses.  Animal wastes  also affect
 urban runoff quality.  Other sources of urban runoff pollutants that may  be
 important in specific  cases  include fireworks debris, wildlife, and sanitary
 wastewater infiltration. The  quality of rain, snow, and atmospheric dust
 fallout  are  all affected by urban particulate resuspension after  initial
 deposition.  Many manufacturing  and  industrial activities also affect urban
 runoff quality,  especially  settleable  air pollutants. Therefore,  it is
 extremely difficult to identify a small number of activities that contribute
 most of  the  significant urban runoff pollutants.

      Some relationships between sources and  specific pollutants are evident.
 Natural  weathering  ana erosion  products of rocks probably contribute  the
 majority  of  the  hardness and  iron in urban runoff.  Road dust and  associated
 autoirobile use  activities contribute most of the lead in urban runoff. In
 certain  situations, paint chips can also  be  a major source of lead. Urban
 landscaping  activities can  be a major  source of cadmiuw. Electroplating  and
ore-processing  activities may also  contribute cadmium.

     Many pollutant sources are t'lso specific to a particular area and
ongoing activities. Iron oxides,  for example, are associated with welding
operations and strontium, used  in the  production of flares and fireworks,
would probably  be  found on  the  streets in greater quantities around holidays,
and/or at the scenes of traffic accidents. The relative contribution of  each'

                                      75

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iii  those potential  u'b.in  nmot t  |ollutant sources is ther"tore highly
v.iri.ible. di p'".ut i',u;  on  spiel tic  ,k"lt.e conii i t. ions atii! seasons.

     Tables t>-b  and  h-7 arซ>  qualitative summaries th.it show the  Types  of
ui ban runott  pollutants i.er/rally associated with different source areas.
Thev indicate  that  no  single  area should be  vKwed as c.ont rit.ut irr the
m.ijoritv of anv  given  type  of  pollutant, desp'te the fact that certain  areas
are consistently  important  sources of certain pollutants. For example,  street
surfaces ate  consistently shown  1.0 be responsible for significant
contributions  of many  heavy  metals.  Similarly, oxygen domandinj;  materials  and
nutrients are  shown  to  originate r.ostly from landscaped and vacant areas.
Table (j-b do lines  the  urban  runoff pollutants in terms of general classes  of
water quality  jarameters  (.e.g.,  nutrients,  bacteria, and heavy metals). Table
d-7 is  similar jut  defines  the urban runoff  pollutants in terms  of various
common  materials (e.g., auto exhaust, litter, and feces).

     An important  information netd for urban runoff sources studies  is
knowing the relative contributions from different pollutant sources  in  the
watershed  to  the outfall  yield.  Sources that are far from the storm  drainage
system  and  require  considerable  overland flow have a very low yield  of  most
pollutants  when  compared  with parking lots  or street surfaces which  are
impervious  and located adjacent  to the drainage system (hydraulically
connected). Those  areas  that are further awiy from the drainage  system  may
require directed or sheet flows  of the runoff to pass over pervious  areas.
This increases the  infiltration  of the polluted waters into the  soils  and
enhances  their uptake  by  vegetation along the drainage routes. Barriers can
also cause  ponding  and settling  of polluted  sediments from the runoff.  All of
these  factors  significantly  act  to prevent  the contaminated particulates  from
reaching  the  receiving waters. However, during large storms, especially when
the ground  is  saturated,  the erosion of these now contaminated soils may
significantly  degrade  orban  .runoff quality.  In addition, the resuspended
contaminated  street  surface  particulates (by wind and automobile induced
turbulence) can  be  redeposited in adjacent  non-paved areas. These street
surface particulates that contaminate the nearby soils reduce the quantity of
street  surface particulates  directly affecting the receiving waters. These
redeposited street  surface  particulates can  then be washed into  the  receiving
waters  duriag  periods  of  high erosion.

     As mentioned  previously,  some urban runoff sheet flow samples have been
collected and  analyzed  in other  areas. Sheet flow samples during several  rain
events  were collected  from  small watershed  areas such as building roofs,
parking lots,  vacant lots,  and gutters. Rainfall samples were also collected
In many cases. Table 6-8  shows the relative  concentrations of pollutants  in
source  area runoff  in  San Jose as summarized by Pitt and Bozeman (1982).
Rainwater was  found  in  roost  cases to have the lowest pollutant concentrations
while parking  lot and  gutter flow samples had the highest concentrations.
Puddles in  a  park area were  also sampled and found to have higher specific
conductance values  and  concentrations of total solids and nitrates than other
samples.

     More recent sampling in Ottawa, Ontario (Pitt, 1982), indicated that
almost  all  of  the lead  in u^ban  runoff originated from parking lots  and

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                           Table 6-6 SOURCES OF I!R"AM RUNOFF POLl'ITANT":
            Street    Parking   Landscaped
Rooftops   Surfaces    Lots       Areas
                                                                                          jC t i
Sediment

Oxygen  Demanding  Matter

Nutrients

Bacteria

Heavy Metals

Pesticides & Herbicides

Oils and grease

Floating matter

Other toxic materials
                                                                           Land
Source:  from Pitt  and  Bozeman,  1982

-------
                             Tahlo 6-7. SOURCF', Of MATERIAL"  WHICH LFAO  TO 'P",A'| '"HOT  P'iL'

                                           I awn and
                                         L'lrul'.r apod  Vacant                         ฐarHnn
                                                ,       Lot;';    Roof'.np';  '"i i'l'"//-! 11^ s     l.o*'';    r
                     Sourer.-:   from Pitt  and  Bo/ornan, I9.fi/1
                     Oustfall                X           XXX           XX

                     Precipitation          X           XXX           XX

                     Tiro Woar               X                                X           X         y

                     Auto Fxhair.t
                       P.:rt ic u
                     Othf-r  Auto Ike:
                       (Fluid  Orins,
                       Woar Prod.)                                                      y         X

                     Vonซ>t,ition I. it tor      XX                    XXX

                     Coir,truct ion
                       Fro-; ion                           X

                     Othor  Lit tor                       x                    XXX

                     Bird Foros             X           XXX

                     Dog  Foco-s               XX                    XXX

                     Cat  For,os               X           X

                     Forti1i/or Uso         X

                     Pr.-,tir; ido  U',o          X
\

-------
           Table 6-8.  Relative  Concentrations  of  Pollutants in Ruroff
                              from  Major  Areas  (^


                        Parkinn Lots,        Residential        Landscaped
                         Driveways,             Roofs             Areas
                        and  Streets

Constituent

pH                           1.1                  1.0                1.1

Spec. Cond.                  4.0                  1.0                220

Turbidity                    300                  <1                 23

Total Solids                  21                  1.0                130

COD                          9.0                  1.0                3.5

Total Phosphate              4.7                  1.0                .4.0

TKN                          2.0                  1.0                1.8

Lead                          70                  1.0                2.0

Zinc                          19                   15                1.0
'!  The lowest reported concentration  of  a  snecific constituent is
arbitrarily assigned 1.0.   The other  source values are multiples of this
lowest value.

Source:  frctn  Pitt and 3ozeman,  1982.
                                 79

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street sutt.uos  w\ t !x  \vrv  1 i t1 lo lead found in rutiot f  front  root" Lops ,  vacant
a!".v! lav,v{vซ-apod aicas,  ,  relative  flow
contributions as  shown in  Figures ^5 t.uoux',h 5-8 in  Section  5.  Estimates  of
the impottance ot  vaiious  source1 areas vvrฐ nvuic and  are  shown  as  Figures  b-9
through ii-l-ป. These figures  are only es'. 'mates -9 shows
that street surfaces  contribute very small amounts  of  the  rvnot t~  total  solids
Articulates  tor  rains greater  than 0.1 inch (2.5 nu ). The  na^or  sources o,.
total solids  for  almost  all  rains in Bclltvue are expected  to be  the
landscaped  front  and  hack  yards. Figure fc-10 shows  that street  surfaces
contribute  important  fractions  of the urban runoff  GCD for  almost  all rains.
Driveways and parking  lots also tikiy contribute i^.ixirtant  quantities oi  COD.
The previous  areas  surprisingly contribute relatively  small fractions of the
expected  urban runoff  CUD. Tne  rel.iCive contributions  of  phosphates and  total
KjelJ^hl  nitrogen as  shown in  Figures 6-11 and o-12 are,  as expected,
similar.  However, streets  may  contribute important  aiaounts  of these
nutrients,  especially  for  ihe  stiller rains, becavse  during the  sraallev
rains, street surfaces contribute alraost all of th= runoff  flows.  Pervious
and iipervious source  areas  contribute about equal  amounts  of the  nutclents
tor taost  of the  rains. As  expected, lead, as shown  in  Figure  6-13,  is mostly
contributed by street  surfaces  for all rains, rrivevays and parking lots
supply almost all of  the rest  cf the lead in urban  runoff.  Zinc  is  also
contributed mostly  by  street surfaces, driveways, and  parking lots; but, for
soiae reason,  high rooftop  zinc  concentrations have  been noted.

     Rainfall is  typically less effective in removing  aa^erials  from  rough
pavement  (e.g.,  streets  surfaced with oil and screens  or  streets  in poor
condition)  than  from  smootn  pavenent (e.g., asphalt sTeets in good
condition). It is thought  that  the increased roughness mechanically traps
particulate matter  and also  reduces sccur velocities  at the pavement/water
interface.  These  mechanisms  have the effect of preventing  some of  the
materials which  havt eroded  frosa surrounding areas  from reaching  the  storta
drainage  systeia.

     The  araovmt  and character  of runoff pollutants  from a  given  site  depend
on factors  sxich  as  the intensity and duration of the  stona  event and  the
length oi the antecedent dry period (i.e., the period  of  pollutant
accumulation). Large storms  (ones with high intensities a:id/ar large  rainfall
volumes)  result  in  sisall coป.trioutions of the street  surface  particulates,
relative  uo the  total  runoff partlculate yield. This pattern  is sore
pronounced when  tiift antecedent  dry periods ate short.  During  such  conditions,
the street  surfaces stay relatively clean (because of  the  iret;uent  rains). A
large rain will  result in  significant erosion froa the surrounding  saturated
pervious  *reas,  so  that  eroded  aaterials becoas deposited on  the streets
after the storm's end. It  is expected that areas with moderate raiafail
intensities and  long periods of accumulation (i.e., dirty street surfaces  and
dry surrounding soil conditions) would have raost of their urban  runoff  output
associated with street surface  washoff.

-------
                        FIGURE 6-9
00
       URBRN  RUNOFF SOURCES  FOR  TOTHL  SOLIDS
      100
                             DRIVEWAYS AND PARKING LOTb
        0.01
0.025   0.05   0.1    0.2





           RRIN (Inches)
                                                 1.5

-------
00
INJ
        0.01
                         FIGURE 6- 1 0
             URBflN RUNOFF  SOURCES FOR  COD
                              YARD?
                                     VACANT LOTS A:;D PAPK.,-
                             FRONT YARDS
                        DRIVEWAYS AND PARKING LOTS
0. 025   0. 05
0.1    0.2

 RflIN (Inches)
0.4
      0.
1.6  2.5

-------
cป
OJ
                         FIGURE 6- 1 1

         URBflN  RUNOFF  SOURCES FOR PHOSPHRTE5
     c
     01
     u
     L
     0)
     CL
CD
•—•
o:
    O
    LJ
    U)
    O
    in
       0  Z
        0.01
                               VACANT LOT3 AND PARK::
                            BACK YARDS
                          FRONT YARDS
                         DRIVEWAYS AND PARKING LOTS
           0.025   0.05
0.1    0.2


 RfllN (Inches)
0.4
0.
1.6  2.5

-------
0.01
                 FIGURE 6-12
      URBflN RUNOFF  SOURCES  FOR  TKN
0.0^5   0.05
0.1    ('. 2
 RflIN (Inches)
                             0.4

-------
   100
   80.
8  70.
L
01
-  60.
o
CO
u
a;
50.
40_


20_
10.
0
    0.01
                         FIGURE  6-13
           URBHN  RUNOFF  SOURCES  FOR  LEflD
                     Kj()E'TO.r)S AND ALL PLi'V I Ol\; AIT.A:;-
                      DP IVLUY.YS A:;D PARK m;  LOTS
                         STRLF.TS
          0.025   0.05
0.1     0.2     0.4

 RflIN  (Inches)
                                                0.8
                                                     1.6

-------
           FIGURE 6- 14
0  p
  0.01
URBflN  RUNOFF SOURCES FOR ZINC
0.025
        0.05
0.1    0.2

 RflIN (Inches)
                         (i.4
                             0 . 8
1

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     Pui-i:::;  storms  ot  moderate to low intensity,  the  <:>• ,;nt ul truf'ic  has
K'LU tound  to  have  an  important influence on  lv-   -^,-ree to which  poll-Hants
will be  transported into the storm sown '.,, ;-•;.• ."em.  T:.,;tic can suppl>  some
ot thi' energy  needed  at  Che street ;,urfa<.-e  r>  loosen  partii'u! n res  V
increasing  tlu-  scour  ;i-.d viear velocities; .U  th(>  w.-iter/s>tre-ct Inferio.
When Light.  srt.'-ais ccrnr  a f. nlghc (or at or bur  tii.itiy  of  low traffic),  very
Jtttif street  ij.!rt  jould W loosened, am1 there would  be little opportunity
for it to  be  transported along the street and  gutter  systerc. In summary,
estima'ed  yields  from  different source areas  in a watershed are very  site  and
tiir.e dependent  (i t  is  necessary to c<-,-.sider pavemei.:  characteristics,
antecedent  weather  conditions, current storm  character Istics , and  traffic
condit ions).

     Appendix G  includes a more detailed discussion of  the sources of urban
runoff pollutants,  based upon studies conducted from many  location.'
throughout  the  country.  Appendix C also describes  the  chc.mlcal quality, of
soils in urban  areas,  the mechanisms of automobile use  tt.'at contribute  heavy
metals,  the  role  of  landscaping activities  In urban areas  that contribute
runoff pollutants,  and  the internal  cycling of various  pollutants  lr  an urban
area due to  atmospheric  resuspension of urban dusts with subsequent
particulate  red-aposition. Appendix H reviews  the  reactions and fates  of
import ant urban  runoff  pollutants, also based upon literature i.iformation.
This appendix discusses  the chemical reactions of  urban runoff pollutants
after they enter  receiving waters, especially the  redox reactions. Absorption
and ion exchange are also discussed.
                                      87

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                                   SKC1 li'N 7
                          SJKI-.hl I'IKi  U1.\KACTKKl hi ICS
     This  section  discusses  characteristics ot street surface  pa rt icu lates .
Thf topics  considered  are  factors at letting street r lea ;i 1 i nes •_ ,  street
suitart1  i> i r t i cu la t e  accumulation and  deposition rates, t ht >J i s t ; i bu t i on  of
street dirt  in  driving and  parking lanes, and the chemical strengths  of
stteet surface  particulates.  The Hellevue street paniculate characterization
information  was  also  compared to similar characteristics determined  for  other
areas. The  uniquo  HeLlevue  climatic conditions, as described previously  in
Section  s  attect  certain  street  surface paniculate  characteristics.
FACTORS AFhECTING  STREET CLEANLINESS

     Appendix  E  describes Che experimental design sampling  that was  conducted
as part of  the  Bellevue  tests. The experimental design street surface
particulate  samples  were collected from about 20 to 50 locations  throughout
each of the  three  Surrey Downs sub-areas and the Lake Hills and 148th Avenue
areas. These samples  were collected about every six months  and were  designed
to measure  the  street surface particulate loading variabilities that occurred
in each of  these areas  as a function of season. Appendix E  also describes  how
the street  surface  sampling effort was modified periodically to reflect  the
changes in  variabilities that were noted.

     Each of the many samples in each test area were accompanied  by  complete
sampling area  descriptions. The most important information  noted  related  to
street condition,  traffic density, topography, and land-use. The  season  of
the year was also  noted. This data was used to identify the characteristics
most important  to  determining street surface loading values. Each series  of
experimental design  samples were collected within one or two days and had
similar accumulation  periods. In some cases, data were not  used in this
analysis because the  experimental design sample collection  effort was
interrupted  by  rains. Because each experimental design sample location was
the same for each  of  the sampling periods, a paired Student's "T" test was
used to identity significant differences in observed loadings due to season
only. A paired  "T"  test  was used because the street condition, street
density, topography,  and land-use would not change for the  same loca ion  at
different times  during  the two years. There were three sample sets in Surrey
Downs: April and November of 1980 and July of 1981. The April and July
sampling times were  conducted during dry seasons while the  November  sampling
effort was  conducted  during a wet season  When the April and July samples
were compared  using a paired "T" test, no significant difference  in  sample

                                       88

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 lo.tdiTH's uvrt-  observed.  However, when  the  November  sample data were compared
 t,,  botn  in- Anril .md July  data  independently,  the  loadings were
 si/niticantlv  different  at  greater  than  a  95  percent  level. The average
 Surrey Down/ loadings in April and  July  were  about  400 Ibs/curb-mile  (110
 ฃ/ curb-meter )  in November.

     Similar  analysed were  conducted during  two sampling periods for Lake
 Hills. An October,  198U, sample  series was compared with a July, 1981, sample
 series using  a paired Student's  "T" tet't.  For these Lake Hills tests, no
 significant difference was  found between these  wet  and dry season dates. The
 average  street surface loading values  were about  220  Ibs/curb-mile (62
 g / curb~'jieter ).

     Samples  from two test  dates (April, 1980,  and  July, 1981) were available
 for  the  lOHth  Street sub-area in Surrey  Downs.  The  paired "T" tests for these
 two  dry..season samples again showed no significant  difference. The average
 loadings in this sub-arta were about 400 Ibs/curb-mile (110 g/curb-meter).
 Only one set  of experimental design samples were  available for the Westwood
 Homes Road sub-area in Surrey Downs (April,  1980).  The average loading values
 were about 2,000 Ibs/curb-mile (570 g/curb-meter).  There was also a single
 set  of experimental design  samples  available  for  i48th Avenue (March, 1981).
 These samples  resulted in an average street  surface loading value of about
 1 ,01'U Ibs/curb-mile (280 g/curb-meter).  These experimental design data
 pointed  out the need to  separate the Surrey  Downs area into subsections,
 especially considering that Westwood Home  Road  and  108th Street did not have
 curbs and could not be cleaned by the  city street cleaning equipment.

     Using a  nonpalred Student's "T" test, dry  season samples collected in
 Surrey Downs were compared  with dry season samples  collected at 108th Avenue,
 for  Westwood Homes  Road and in Lake Hills. There  was  no significant
 differences found for the Surrey Downs and 108th  Street samples. However,
 very significant differences were detected between  the Surrey Downs and The
 Westwood Homes Road samples and  the 108th  Street  and  the Westwood Homes Road
 samples. The July 1981 samples for  Surrey  Downs and 108th Street were also
 compared and were not significantly different.

     Additional Student's "T" tests were conducted  by grouping the
 experimental design data into categories corresponding to different street
 conditions, topography, and season. In some  cases,  there was disagreement in
 the  street condition and topography at the same sites during the different
 sampling periods. This data was  therefore  eliminated  from the analyses. The
 ma]or difference observed in Lake Hills  was  for topography, where levels of
 significance greater than 95 percent were  observed  in both the July and
 October sampling periods. Flat areas during  both  sampling periods had average
 loads of about 240 Ibs/curb-mile (68 g/curb-meter) while the area in Lake
 Hills with some slope averaged about 140 Ibs/curb-mile (40 g/curb-meter). As
 noted previously, there were major  seasonal  differences observed in Surrey
 Downs,  but not in Lake Hills. There were no  significant differences observed
 in Lake Hills based upon the differences in  street  conditions, probably
because of the narrow range in street  surface conditions that existed within
the study areas.
                                       89

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     !'i : ! L-ri-iirt •;  i:i  ••!-!••-•'.•[  lo.icM -t-.s uti  )4Hth  Aveimp  due  to street slope <,ere
n-.. ir, •.:..!',! v  s i >-ii 11 : c.i'.t  ,a tin- hi) percent  levp].  F.'.it  stretches of 14Hth
..vi-:;ij'j !•.ni  slnrt  suiMrt: 'u.uiinr.s ot about 1,H)U  ibs/curb-pile (280
V. ciiru-En ti-r).  it  ซ.ou]d !>>  expertH.l that  steeper  slopus  would result in lower
t>trt.'et surlaee  loadings,  such a.-; occurred  in  Lake  Hills.

     y-.'caus"  ot  the   results of the Student's  "T"  tests,  further statistical
tests UMIIJ;  factorial  analyses were conductpd  on  the  experimental design
liit). A two-level,  tlTt-e-wy factorial  analysis  was  conducted on both the
La..- Ill lib  and  Surrey  IJovns experimental  design  data.  The  three factors
cu iis iซJ.--i i d  were  strict condition, topograohy,  and  season.  The two levels were
traded tor  fair  or  poor versus good street  surface  conditions; flat streets
versus streets-,  with  greater slopes; and dry versus wet  seasons. The data was
codt-d uhln^;  plus  one values for those conditions  expected  to increase street
iiirlace loadings  (lair or poor street surface  conditions,  flat topography,
and  dry seasons).  The  other level for each condition  was  assigned a minus one
coding value  corresponding  to expected  decreases  in  resultant loading values.
AK^in, data  with  conflicting coding values on  the  data  sheets were eliminated
from this  analysis.  A  total of eight different possibilities can occur for
these three  factors. From two to seventeen observations  were available for
each of these  eight  factors for the Lake  Hills data.  Many  more data were
available  for  the  Surrey  Downs test site.

     figures  7-1  and 7-2  show the results  of  these factorial analyses. Figure
7-1  shows  the  resultant calculated effects on  probability  paper for these
three main  factors  and their inteiactions. Those  main effects and
interactions  corresponding  to a straight  line  on  the  probability paper .nay
occur randomly  and  are, therefore, not  important  effects.  Major effects or
interactions  that  do not  fall on the straight  lines  are  significantly
different  and  are  not  likely to occur due  to  random  conditions. In Lake
Hills, the  only  significant effect observed was  associated with season. The
resultant  model  shows  that  loadings during the wet seasons are expected to tx?
about 145  Ibs/curb-mile (41 g/curb-meter), while  the  loadings could increase
to about '.'.35  Ibs/curb-mile  (67 g/curb-meter)  during  the  dry season. This
confirms the  Student's "T"  test observations  by  indicating the overall
importance  of  seasonal effects on the Lake Hills  data.

     The Surrey  Downs  data  is also shown  on Figure 7-1  and does not indicate
a single overriding  effect. The diffarences in loadings  observed in currey
Downs were  associated  with  the interactions between  all  three effp^ts. The
expected Surrey  Downs  loadings could range from  a  low of  about I'D
Ibs/curb-mile  (48  g/curb-meter) for a negative three-way  interacLion code
value to a  high  of  about  460 Ibs/curb-mile (130 g/curb-meter) for a resultant
positive three-way  interaction code value. A  negative three-v?ay coding value
would occur  vhen  any one  of the effects are negative  and  the other is
positive,  or  if  all  three effects are negative.  The  three-way interaction
would be positive  if any  one of the three  conditions  is  positive, with the
other two  being  negative, or if all three  are  positive.  This is obviously a
confusing  interaction  and shows che importance of  obtaining as much
information  as  possible during a set of field  studies.
                                       90

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                     Enc-cf
                1) Street Condition
                2) Topography
                3) Season
        Coding:
4- 1 :  Fair/Poor- 1. Good
4- 1:  Fiat        1: Slope
4- 1:  Dry       • 1: Wet
Surrey Downs •
    Lake Hills *k
  • 123
                                                                                     78 5
                                                                                     64.3
                                                                                  -  35.7
            Models:

         Surrey Downs: y = 317 + 144 &
            Lake Hills: y=216 + 185ซ'2
                      (usey =190+ 45*2)
                            C        50
                                Estimated EHoct
                                                       ISO
                                                                ZOO
                                                                                  coo
                         23 Factorial Analysis Results
            for Experimental Design Street Paniculate Loading Data

                            FIGURE   7-1
                                       91

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Surrey Downs  •

    Lake Hills  ir
                                                                   '  •
          *  ..'*
                                                                                     18 75
            -150
                     -100
                             Modal Residuals (y-V)
                  Residual Analysis of Factorial Models
           for Exptr mental Design Street Paitlculate Loadings

                         FIGURE    7-2
                                      92

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      Figure  7-2  is  a  prcbaMlity  plot  of  f.e  residual values using these
raodeis.  The  calculated  residuals  for  each of  the eight possible combinations
of  main  effects  and  interactions  can  be  fitted to straight lines, within
reason.  The  residuals (deviations  from the calculated results using  the
model) are  therefore  random  and are not  expected to be associated with any
other effects, except those  shown  to  be  important using the factorial
analysis.

      These  results  are  site  specific  and  are  probably different not  only  for
other cities  but  also for  other locations in  the same city. As noted, street
surface  conditions  did  not appear  to  be  a major consideration ia determining
the  street  surface  loadings  in any one of the Bellevue sites, because the
range in  street  surface  conditions was not very great. A similar factorial
analysis  was  conducted  using  the Castro Valley. California, street surface
loading  particulate data collected in  1978 and 1979 (Pitt and Shawley, 1981).
The  Castro  Valley study  area  had a much  greater range in street surface
conditions  than  the Bellevue  study sites. A five-way, two-level interaction
examined  with  the Castro Valley data  included street condition (fair or poor :
versus good),  traffic density (moderate  or heavy versus light), land-use     ;
(residential  or  vacant  lots versus commercial or school), topography (flat
versus moderate  or  steep slopes), and  season  (summer versus winter). Again,
the  datj  was  coded  with  positive values  for variable levels probably
associated with  increasing street dirt loadings. Instead of the eight
possibilities  associated with the tests  conducted with the Bellevue data, 32
possibilities  were  associated with the Castro Valley data. Each of the 32
data sets had  one to  twenty-two data  points.  The seasonal effect was found to
be  very  large  in  relationship to the  other effects. The next most important
effect was  street condition,  followed  by  a random occurrence of the other
effects.  The  data was then separated  into the two different seasons and
further  factorial analyses were conducted.  During the winter conditions, the
three-factor  interaction of street condition, traffic density, and topography
was  the only  important  factor. During  the summer, however, street condition
was  the only  important  factor. During  the winter season, the expected street
surface loadings would  vary from about 600 to about 700 Ibs/curb-mile (170 to
200  g/curb-meter) depending upon the  three,-way interaction described. During
the  summer, however,  the street surface particulate loadings could be much
greater,  ranging from a low of about  1,400 Ibs/curb-mile (400 g/curb-meter)
to a high of about 2,800 Ibs/curb-mile (800 g/curb-meter), depending upon the
street surface condition. The three-factor interaction during the winter
caused a  relatively small change in the expected loading value, while the   :
street condition contributed a much greater change in the expected loading
value during the summer months.                    ;'
STREET SURFACE PARTICULATE ACCUMULATION AND DEPOSITION  RATES

     A major element of the Bellevue urban runoff  project  involved collecting
street surface samples to compare with the monitored  storm runoff yields and
to determine street cleaner performance. Another important use of this
information was to estimate the deposition and  accumulation rates for the  *
vaiious street surface contaminants.


                                      93

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     Hy the midd'e ot January,  1982,  about  60U good street surface
arrunui lat ion samples  wer>>  colK-cted  from five test areas (198 in the Surrey
Downs oleaniar, area,  104 on  lUHth  Ave,  52 on Westwood Home Road, 28 on 148th
Avenue S . E . , ar.d 220  in  the  Lake Hills  area).

     In Appendix B, Tables  B-l  through  B-13 present the loading values for
these bUU  street surface particulate  samples. These tables show the date of
sample collection, the  sample  identification number, the days from the last
significant rainfall  and the number  of  days from the last street cleaning.
The observed r_.tal solids  street surface loading values are shown along with
the calculated median particle  sizes  using  procedures described in Appendices
E and F. The data from  these particle size  analyses were used to calculate
the median  pnr^icle size.  These tables  also inclvde the street cleaning
effectiveness data (loadings on the  street  before and after street cleaning)
that will  be discussed  in  Section  10. These tables divide the data into the
five test  areas and by  season.  The Surrey Downs and Lake Hills data -ire also
divided  nto categories  associated with periods of intensive street cleaning
and periods of no street cleaning.

     Each  street surface sample is identified with a specific accumulation
period. This accumulation  period  is  the time since that test area was last
cleaned with mechanical  street  cleaning equipment or the time since a
signific   t rain washed  the  area.  A significant rain is defined as a rain
capable ot  washing most  of  the  available street dirt from the street
surfaces.  Based on the  rainfall and  washoff analyses from this and past
street dirt collection  projects, a significant rain is estimated to be one
with a total of about 0.2  inches (5  mm) or  more of rain falling within
several hours (irrespective  of  traffic  conditions), rain with a peak
instantaneous five-minute  intensity  of  at least 0.5 inches (13 mm) per hour
(also irrespective of traffic  conditions),  or a rain with an average
intensity  of 0.1 inches  (2.5 mm) or  greater per hour with moderate to heavy
traffic. Rains and traffic  conditions which meet one of these criteria are
capable of  imparting  enough  energy to the street surface to loosen the
available  contaminants  and  to  supply  sufficient water to flush them along the
street surface and gutters  and  on  to  the storm sewerage inlets. If sufficient
runoff is  not available  to  carry the  particulates through the storm sewerage
to the outfall, material will  be deposited  in the sewerage system.

     The observed street surface particulate loading values for each sample
were plotted to observe  changes in loadings with time and to determine the
initial deposition and  long-term accumulation rates. The deposition rate is
the initial accumulation rate which  occurs  over the first several days. The
two factors which affect the accumulation rate arc the deposition rate and
the removal rate. The accumulation rate equals the deposition rate minus the
removal rate. The deposition rate  is  a  function of various characteristics of
the area,  specifically  climate, land-use, traffic, and street surface
conditions. The removal  of  pollutants can be accomplished either by street
cleaning,  traffic-induced  turbulence, or naturally by winds or rains. The
difference  between the  accumulation  and deposition rates at any time is
assumed to  be caused  by material blown  from the street surface by wind or
traffic-induced turbulence.  This material can remain suspended in the air,
but most of it settles  to  the ground  within about 30 feet (10 meters) of the


                                      94

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roadway.

      figures 7-3 and  7-4 are  plots  showing  the  observed street surface
loading%alu.-s as a  function  of  accumulation  time  for the Surrey Downs bcsin.
Plots  for  the other  study  areas  are  shown  in  Appendix B as Figures B-l
through  B-5. The data has  been  separated by test  area,  season, and if the
test  ba-in i-as undergoing  intensive  street  cleaning  or  no street cleaning.
figuie  7-3 shows that for  periods of  no  street  cleaning in the dry season,
accumulation periods  of up  to about  45 days were  observed in some cases.
However, during periods of  intensive  street cleaning, the accumulation
periods  were much shorter  and did not exceed  five  days.

      There is appreciable  scatter in  this  data,  especially for the low
accumulation periods. Much  of this  scatter  is because of the relatively low
street  surface loadings observed. The accumulation curves shown on these
figures  were determined using a  combination of  least squares multiple
regression curve fitting techniques  and  Student's  "T" analyses. The curve
fitting  procedures used require  that  the variations  be  evenly distributed
throughout the range  of conditions  and that the  observations are evenly
spread  over the range of the  independent variable  (accumulation period in
this  case). Therefore, the  accumulation  data  was  log transformed before the
curve  fitting techniques were used.  Even so,  the  resultant curves had very
poor  regression coefficients. The accumulation  information was also analyzed
by stratifying the data into  relatively  short accumulation periods. These
periods  corresponded  to a  tenth  of  a  day or less,  a  tenth to two days, two to
five  days, five to ten days,  ten to  fifteen days,  fifteen to twenty-five
days,  and greater than twenty-five  days. The  data  was also separated for the
dry and  wet seasons.

      Significant differences  were identified  by  Student's "T" analyses
conducted on accumulation data  for  tha different  seasons. The median values
for each of several accumulation period  groupings  were  used to construct the
accumulation trend shown on these figures.  If two  adjacent accumulation
periods  did not show  significant differences, then they were combined and the
trend was flat over that range  of accumulation.  The  dry season samples were
also  separated for data collected during 1980 and  for data collected during
1981.  In almost all cases,  the  1981 dry  period  had street surface loading
values significantly greater  than the 1980  dry  period during the time of no
street cleaning. The wet season  data  is  not separated for analyses by year
because mcdt of that data was collected  during  continuous months during the
fall and winter of 1980 and 1981. The 1980  and  1981  dry seasons, however,
were separated by the five month wet  season.  It  is not  known why the 1981
loadings were significantly greater  than the  dry  period 1980 loadings. During
a previous study in Reno and Sparks,  Nevada (Pitt  and Sutherland, 1982),
street surface loading values were  obtained from  a variety of street surface
conditions throughout the Truckee Meadows  area  during two adjacent six-week
periods during the summer of  1981.  The observed  loading values were
significantly different during  the  two adjacent  periods possibly because one
of the periods was associated with  much  greater  winds.  In most cases, the.
windy period had much larger  street  surface loading  values and larger
deposition and accumulation rates.  This  was probably due to the nature of the
sources of street surface particulates in  the Reno and  Sparks area (probably

                                      95

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                        FIGURE 7-3
     SURREY  DOWN5-HITHOUT  STREET  CLERNIMG
   1033.
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                     V;LT
                  A A
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i      H
      tl         13

      A WET SEAt:OU

      m DRY SEASOrl (1980)

      6 DRY SEASON (1981)
                          23         33

                        RCCUMULflTION (Doysl
                      43
53

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                     FIGURE 7-4
  SURREY DOWN5-WITH  STREET  CLERNING:RCCUM
  500
e

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in
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                     2        3


                    flCCUMULRTION (Days)

-------
I i .uispui tfd sands  i rum  the  surrounding  dry areas or from nearby unlnndscaped
or  oil.is t ruet ion areas).  It  is  not  known if tlie wind conditions during these
^wo uty periods in Hellevue  were  significantly diffetent.

     Table 7-1 summarizes  the  estimated accumulation and deposition rates
along with the street surface  loading  values  associated with different times
ol  accumulation. Al so shown  on  this  fiblc  are the calculated standard
deviations associated witli  the  observed loadings during each time period. The
standard deviations  range  from  about  50 to 2GJ 1bs/curb-mile (14 to 57
g/curb-meter) per  day,  while  the  loading values range from about 200 to 1,000
Ibs/curb-mile (.57  to ''80 g/curb-me ter)  per day. In many cases (especially for
very clean street  surfjce  conditions)  the  observed loading variptions can be
quite large when compared  with  the  loading values. The expected variations in
loadings decrease  for the  larger  loading values associated with the longer
accumulation periods. The  standard  deviation  values can be used to construct
the approximate confidence  intervals.  The  band that is one standard deviation
wide on both sides of the  mean  value  would contain about two-thirds of the
data points. A band  three  standard  deviations wide would contain about 95
percent of the data  points.  When  all  of these calculated curves with their
confidence intervals are plotted  together, most of the bands ./verlap, but
three separate categories  are  evident.  The lowest loadings were found on
148th Avenue S.E.  throughout  a  long  accumulation period, even though the
initial loading values  were  not the  lowest. Lake Hills and 108th Street
(during the dry 198U season  and during  periods without street cleaning) had
higher accumulation  rates  than  most  of  the other areas and always had higher
loadings than the  other areas.  The  rest of the categories all seem to fall
together, with initial  loading  values  ranging from about 150 to 350
Ibs/curb-mile (42  to 100 g/curb-meter)  per day and loadings of about 350 to
550 Ibs/curb-mile  (10000 to  160 g/curb-meter) per day after about a maximum
of 40 days accumulation. The  148th  Avenue  site had observed loadings between
about 200 to 250 Ibs/curb-mile  (57  to  70 g/curb-met^r) per day throughout a
long accumulation  period.  The  108th  Street and Lake Hills dry 1980 period?
had much higher loading values, ranging from  initial values of 450 to 500
Ibs/curb-mile (130 to 140  g/curb-meter) increasing to high values of between
800 to 1,000 Ibs/curb-mile  (230 to  280  g/curb-meter). The Lake Hills periods
with street cleaning also  had  very  low  accumulation rates, comparable to the
low rates observed in 148th  Avenue.  The Surrey Downs (with street cleaning)
accumulation rates,  however,  were  quite large and were comparable to the dry
1980, Lake Hills and 108th  Street  rates.

     These Bellevue  loading  values  and  accumulation rates are compared with
values obtained in other locations  on Table 7-2. The initial loading rates
for Bellevue, which  range  from  200  to 500  Ibs/curb-mile (57 to 140
g/curb-meter), are within  the  low  range of values reported elsewhere, and
generally correspond to other  locations having smooth streets in good to fair
condition. Rough streets in  other  locations had loadings more than five times
the Bellevue loadings.  Similarly,  the  observed Bellevue deposition rates alu-o
appear to be on the  low end  of  the  rates observed elsfcwhere, and also
generally correspond to smooth  streets  in  good to fair condition or in
residential areas.
                                       98

-------
           Table 7-1. Approx. Total Solids Street Dirt  Loadings
                          and Acrimulation Rates
Surrey Downs
                                          Days of Accumulation
                                         2  "   5    10    15    25
              .1)   average  loading  value  (lb;  urb-mile)
              ,2)   approx.  standard  deviation  of the loading value
              (3)   approx.  accumulation rate  (Ib/curb-mile/day)
40
- without
cleaning







with
cleaning




Westwood
Homes Road
- without
cleaning






108th Street
- without
cleaning



wet
stason

dry
(1980)

dry
(1981)

wet
season

dry
season


wet
season

dry
(198U)

dry
(1981)

wet
season

dry
(1980)

.(1)
-'(2)
rate(3)

a
rate
X
a
rate
X
o
rate
X
a
rate

X
0
rate
X
0
rate
X
a
rate
X
0
rate
X
o
rate
340
90
-
285
60
-
360
80
-
130
30
-
315
70
-

270
140
-
350
110
-
160
60
-
245
130
-
460
200
-
345
170
4
300
70
8
375
90
8
170
80
20
350
80
18

290
150
10
370
60
13
180
70
10
260
140
10
490
220
17
360
190
4
320
80
7
400
100
8
200
110
10
365
90
5

310
220
8
410
270
10
210
90
10
290
140
8
540
240
16
380
140
4
340
90
4
430
110
6
_
-
-
_
-
-

350
90
7
460
170
10
250
120
8
320
100
6
620
320
15
390
50
2
350
70
2
450
90
4
_
-
-
_
-
-

380
230
6
500
130
8
290
40
8
330
40
3
680
480
14
410
50
2
370
160
2
490
210
4
_
-
-
_
-
-

420
260
4
550
80
5
350
90
6
360
130
2
82 u
390
12


~
390
50
1
525
80
2
_
-
-
_
-
-

_
_
-
570
80
1
390
130
3
.
_
-
920
430
7
                                  99

-------
Table 7-1. Loadings and Accu"i.  Rates (Con't)



                               nf Accumulation
virr^v P^wns
I'^th Street
(Con'M
wi M~iout
cleani nq
Lake Hi 11s
- without
cleani nq






Lake Hills
- wi th
cleani nq



143th Ave. SE
- without
cleani nq

dry
(1931)



wet


dry
(1930)
dry
(1931)


wet


dry


dry




rate


0
rate
X
T
rate

o
rate
).
a
rate
X
c
rate
\
a
rate
0
300
120
-

170
60
-
500
160
-
170
50
-
170
60
-
170
50
-
200
60
-
2
320
110
10

200
60
15
540
190
20
200
70
20
185
60
3
185
65
8
205
60
3
5
340
100
7

270
230
20
600
350
20
270
160
15
195
170
3
195
120
3
210
80
2
10
360
100
4

290
80
4
660
310
12
290
140
4
_
-
-

-
-
215
100
1
15
3RO
100
4

30^
130
3
710
330
10
305
140
3
_
-
-
_
-
-
220
70
1
25
4'0
150
4


-
-
750
270
4
310
no
1
_
-
-
_
-
-
225
30
1
40
440
,?10
1



-
770
420
1
320
170
1
_
-
-
_
-
-
230
10
1
                     100

-------
                       C-LLFVJE  ST^ET  DIRT  DEPOSITION  RATES COMPARED
                           WITH' DATA FROM OTHFR AREAS
Locit ion

Rellevue, Vashinqton
    Lake Hills and 103th St., Dry period 1980
    143th Ave., S.E. (heavy traffic)
    All other studv sites and periods

Reno/Sparks, Nevada(l)
    Smooth streets and  gutters in oood
         condition
    Other smooth  streets and intermediate
         streets
    Rough streets
    New residential areas
    Smooth and intermediate streets with
         smooth Tatters (windy)
    Smooth and intermediate streets with
         lipped qutters (windy)
    Rough streets (windy)

San Jose, Calif(2)
    Smooth asphalt, good condition
    Smooth asphalt, fair to poor condition
    Rough asphalt, poor condition
    Oil and screens

Castro Valley, Calif(3)
    Smooth asphalt

Ottawa, Ontario(4)
    Smooth and moderate textured streets
    Rough streets
    Very rough streets

Nationwide(5)
    Residential (smooth asphalt/good to fair)
    Industrial (rough asphalt/poor)
    Commercial (smooth  asphalt/good)
                                                  Initial
                                                  Loadinq
                                                   Value
                                                 Ib/curb-mi)
                                      500
                                      200
                                      250
                                      710
                                      2,200
                                      2,500

                                      880

                                      1,300
                                      1,900
                                      130
                                      290
                                      780
                                      1,800
                                      300
                                      140
                                      700
                                      1,100
                                      400
                                      670
                                      300
                                                     Deposition
                                                      (Initial
                                                    Acc'jnrilation)
                                                       Rate
                                                  ;ib/curb-mi/dav)
20
3
12
                                                         2.6
6.1
36
61

24

53
120
15
15
20
20
40
70
70
70
20
40
15
Sources:
     2)
    (3)
    (4)
    (5)
Pitt and Sutherland, 1982
Pitt, 1979
Pitt and Shawley, 1981
Pitt, 1982
Sartor and Boyd, 1972; and Pitt and Amy, 1973
                                     101

-------
iiit. ;Uhrt\l MTluN OK Si'KKKT  DIRT  IN  DRIVING AND PAKKINC LANKS

     The amount of uwti'rijl  present  in  the parking lanes is av;':'lable for
n'T.ov.i I by Street cle, 1:1 ing  equipirent  operating next to the curb. The street
s-u r I ii L o pa r t i cvi l,i tes  in  the  driving  lanes, however, cannot bt removed by
normal street cleaning  operations.  Tables  7-3 and 7-4 show the results of a
serie-; ot tests conducted  in the  Lake Hills and Surrey Downs areas to measure
the distribution of street  dirt  across  the street. The test procedures are
described in Appendix E  and  involve  taking a second set of subsamples in a
test area irunediately alter  a  normal  full  street width sample is obtained.
The second set of samples  couJd  either  be  taken from the center of the street
to th-e edge of the parking  lane  (for  driving lane loadings) or from the edge
of the parking lane to  the  curb  (for  parking lane loadings). These samples
were divided into eight  different particle sizes for analyses. The full
street width loadings for  each particle size were compared with the
corresponding particle  size  loadings  in the driving lane and parking lane.

     The values shown in Table 7-3  for  Lake Hills were all obtained during a
period of intensive street  cleaning,  while the values shown in Table 7-4 for
Surrey Downs were obtained  during a period of no street cleaning. In both
cases, about 55 to 65 percent  of  the  total street surface loadings were found
in the parking lanes. The  actual  loading values varied substantially,
depending upon the street  cleaning  operations. For the Lake Hills studies,
about 50 to 100 Ibe/carb-mile  (14 to  28 g/curb-meter) of total solids were
found in the parking  lane,  while  200  to 300 Ibs/curb-mile (57 to 85
g/curb-meter) were found in  the  parking lane in Surrey Downs with no street
cleaning. The observed  differences  in loadings in the driving lanes were much
less. The driving lane  loadings  in  Lake Hills ranged from about 50 to 75
Ibs/curb-mile (14 to  21  g/curb-meter),  while they ranged from about 125 to
150 Ibs/curb-mile (35 to 42  g/curb-meter)  in Surrey Downs with no street
cJ earing. This indicates that  driving lane loadings are probably increased
when  the parking lane loadings are  also high, due to winds transporting
particulates out into the  street. High  parking lane loadings have been found
to be associated with high  winds  or traffic-induced turbulence blowing the
particulates from the center of  the street towards the curb (Pitt, j.979). It
appears that this process  can  work  both ways and that the percentage
distribution of the loadings may  remain constant over the relatively narrow
range of loadings observed  in  Bellevue.

     The percentage of  the  larger particulates (between 500 and 6350 microns)
in the parking lanes  in  Lake Hills  during  street cleaning were quite low due
to the street cleaning  equipment  being  much more effective in removing these
particulates. Only about 30  to 40 percent  of the particles in these particle
sizes were found in the  parking  lanes,  while about 60 to 70 percent of the
smaller particles were  found in  the parking lane. The percentage of the
largest particle sizes  (greater  than  6350  microns) in the parking lane in
Lake Hills with street  cleaning  was  surprisingly high (about 90 percent) but
the actual loadings were very  low.  The  distribution of particulate sizes near
the curb was much more  even  in Surrey Downs durirg the period of no street
cleaning. Generally there were smaller  fractions of the finer particulates in
the parking lane than for  the  larger  particulates. Again, almost all of the
largest sized particles  (greater  than 6350 microns) were found in the parking

                                      102

-------
               Table 7-1.  LAKE  HILLS:   DISTRIBUTION  OF  STREET 51RT
                          IN PARKING AND DRIVING LANES
                      (During a period with street cleaning)

                           Fart.clc Size (Microns)
                           63-    125-   250-  500-   1000-  2000-
                            125   250    500   1000    2000   6350 >6350
Driving    % in
lane:      size
    loading
  (Ib/curb-mi)
   % of whole
   street load
Parking% in
lane:       size
    loading
  (Ib/curb-nii)
   % of whole
   street load
                                                      Total
3/:7/Sl
Whole % in
street: size
loadi nq
( Ib/curb-mi )
Driving % i.i
lane: sice
loadi ng
(Ib/curb-mi)
% of whole
street load
Parking % in
lane: size
loading
(Ib/curb-mi)
% of whole
street load


16

27

10

5.

20

19

22

79


.7

.9

.3%

7

.4%

,9%

.2

.6%


13.6

22.7

0.4

3.5

15.4

17.2

19.2

84.6


18.8

31.3

11.1

6.1

19.5

22.7

25.2

80.5


21.9

36.8

20.6

11.4

31.0

22.9

25.4

69.0


15.2

25.4

25.5

14.2

55.9

10.0

11.2

44.1


6.8

11.3

14.0

7.8

71.7

2.9

3.2

28.3


5.5

9.2

12.1

6.8

73.9

2.2

2.4

26.1


1.5

2.4

0.0

0.0

o.o

2.2

2.4

1CO.O


100

in

100

56

33.

100

111

66.


.0%



,0%



2%

.0%



8%

4/17/81
Whole % in
street: size
InarH nn
(Ib/curb-mi)


15

28


.8%

.8


13.3

24.3


19.9

36.3


2h-6

39.3


15.1

27.6


6.7

12.3


5.4

9.9


2.2

4.1


100

183


.0%


11.0%  8.6   13.9   21.8   23.7   12.2  7.1    1.7    100.0%

7.9    6.2   10.0   15.7   17.1   8.7   5.1    1.2    72

27.4%  25.5  27.5   39.9   62.0   70.7  51.5   29.3   39.3%
18.9%  16.4  23.7   21.3   9.5    3.3   4.3    2.6    100.0%

20.9   18.1  25.3   23.6   10.5   3.5   4.8    2.9    111

72.6%  74.5  72.5   60.1   38.0   29.3  43.5   70.7   60.7%
                                      103

-------
       (Continued)
Table 7-3. LAKE HILLS:   DISTRIBUTION  OF  STREET  DIRT
            IN  PARKING AND DRIVING LANES
       (During  a period with street cleaning)
     <63
Particle Size (Microns)
63-   125-   250-  500-    1000-  2000-
 125   250    500   1000    2000   6350  >6350
Total
5/8/81
Whole % in
street: size
loadi ng
(Ib/curb-m-i)
Dri -/ing % in
lane: size
loading
(Ib/curb-mi)
% of whole
street load
Parking % in
lane: size
loading
(Ib/curb-mi)
% of whole
street load


10.6%

12.1

8.3%

4.8

39.7%

13.1%

7.3

60.3%


9.5

10.8

8.0

4.7

43.5

11.0

6.1

56.5


15.7

17.9

13.3

7.8

43.6

18.2

10.1

56.4


24.3

27.8

23.0

13.5

41.1

25.7

14.3

58.9


21.4

24.4

26.2

15.4

63.1

16.2

9.0

36.9


9.1

10.4

13.3

7.8

75.0

4.7

2.6

25.0


6.9

7.9

7.7

4.5

57.0

6.1

3.4

43.0


2.5

2.9

0.2

0.1

3.4

5.0

2.8

96.6


100.0%

114

100.0%

59

51.4%

100.0%

55

44.6%

Average: % of
Whole street
load in:
Driving Lane:
Parking Lane:



29.2%
70.8%



28.1
71.9



30.2
69.8



37.3
62.7



60.3
39.7



72.5
27.5



60.8
39.2



10.9
89.1



42.6%
57.4%
                       104

-------
              Table  7-4.  SURREY DOWNS:   DISTRIBUTION  OF  STREET  DIRT
                          IN PARKING AND DRIVING LANES
                     (Qurinq  a  pe-iod  of no  street  cleaning)

                           Particle  Size  (Microns)
                           63-    125-    250-  500-    1000~   2000-
                    -63     125    250    500   1000   2000    6350  >6350
           % in
lane:       size
    loadinq
  (Ib/curb-mi)
   % of whole
   street  load
                                                      Total
3/5/81
Whole % in
street: size
loadi nq
( Ib/curb-mi)
Dr i v i n g % in
lane: size
loac'i nq
( Ib/curb-mi)
% of whole
street load
Parkinq % in
lane: size
loadinq
(Ib/curb-mi)
% of whole
street load


4.0%

14. J

4.0%

5.8

38.9%

4.0%

9.1

61 . 1%


5.2

19.5

4.5

6.5

33.3

5.7

13.0

66.7


li.3

4?.l

9.6

13.8

32.8

12.3

28.3

67.2


19

73

17

25

34

20

47

65


.6

.2

.6

.3

.6

.9

.9

.4


22.9

35.7

25.1

36.0

42.0

21.6

49.7

58.0


IS.

68.

21.

31.

45.

16.

37.

54.


4

9

9

4

6

3

5

4


15.1

56.3

15.9

22.9

40.7

14.5

33.4

59.3


3.5

12.9

1.4

2.1

16.3

4.7

10.8

83.7


100.0%

374

100.0%

144

38.5%

100.0%

230

61.5%

4/l~'81
Whoie % in
street: size
loadinq
( Ib/curb-mi)
Drivinq % in
lane: size
loadi ng
( Ib/curb-mi)
% of whole
street load


4.5%

14.2
8.1%

9.8

69.0%


5.0

15.9
5.7

6.9

43.4


9.6

30.3
8.8

10.7

35.3


16

51
16

19

38


.5

.9
.4

.8

.2


20.9

65. S
25.0

30.3

46.0


17.

53.
20.

24.

45.


1

6
0

2

1


17.4

54.5
15.6

18.9

34.7


9.0

28.1
0.4

0.5

1.8


100.0%

314
100.0%

121

38.5%
2.3%   4.7   10.1   16.6   18.4   15.2  18.4   14.3   100.0%

4.4    9.0   19.6   32.1   35.5   29.4  35.6   27.6   193

31.0%  56.6  54.7   61.8   54.0   54.9  65.3   98.2   61.5%

-------
Table 7-4.  SURREY DOWNS:   DISTRIBUTION  OF  STREET  DIRT
        IN  PARKING AND DRIVING LANES fcont.)
       (During a period  of no street cleaning)
      <63
 Particle Size (Microns)
63-   125-   250-  500-   1000-  2000-
 125   250    500   1000    2000   6350  >6350
Total
5/06/31
Whole * in
street: size
loadi nq
(Ib/curb-mi)
Driving * in
lane: size
loa'li nq
( Ib/ourb-mi)
% rf whole
street load
Parking % in
lane: size
loadi nq
( Ib/curb -mi)
* of whole
street load


8.

36

8.

10

29
8.

25

70


4*

.0

4*

.7

.7
X

• ^

.3


6.6

28.5

6.0

7.6

26.7
6.9

20.9

73.3


10.8

46.6

8.9

11.2

24.0
11-7

35.4

76.0


15.

65.

15.

19.

29.
15.

46.

70.


3

6

5

6

9
2

0

1


17.5

75.0

25.3

31.8

42.4
14.2

43.2

57.6


14.6

62.9

19.?.

24.3

38.6
12.7

38.6

61.4


15.6

66.9

15.1

19.1

28.5
15.8

47.8

71.5


11.2

48.3

1.6

2.1

4.3
15.2

46.2

95.7


100.0*

430

100.0*

126

29.4*
100.0*

303

70.5*

Average: * of
Whole street
load in:
Driving Lane:
Parking Lane:



45
54



.9*
.1*



34.5
55.5



30.7
69.3



34.
65.



2
8



43.5
56.5



43.1
56.9



34.6
65.4



7.5
92.5



35.5*
64.5*
                        106

-------
lane  in  both  test areas.


CHEMICAL  STRENGTHS OF  STREET  SURFACE  PARTICULATES

      All  of the street particular samples  collected  during this study were
divided  into  eight separate particle  sizes  as  described  in Appendices E and
F. Composites of the different  samples were made  to  represent each test area,
specific  particle size rangas,  and time  periods.  They were then sent to a
commercial laboratory  (Am Test,  Inc., in Seattle)  for chemical analyses. The
chemical  composition information was  then used  to  calculate total sample
pollutant values for each sample collected.  Tables  B-14  through B-18 in
Appendix  B present the chemical  test  results.  These  tables are separated for
each  test area, and show the  observed chemical  concentrations of the street
dir'_  for  eight particle sizes lor up  to  ten composite periods. Each composite
is associated with a specific time period of about  two months. The means,
standard  deviations, and relative standard  deviations (standard deviation
divided  by the mear) of the particle  concentrations  for  each size range and
test  area are also shown.

      The  Sur.ey Downs and Lake Hills  street  dirt  chemical  characteristics
were  separated into wet and dry seasons  and  were  compared  using Student's "T"
analysis. In  most cases, there were no significant  differences observed
between  the wet and dry seasons. However, many  of  the very largest particle
sizes did show significant differences between  the  wet and dry seasons. In
addition, about half of the particle,  sizes  for  lead  showed significant
differences between the wet and dry seasons.

      Figures  7-5 through 7-7 show the particle  size  distributions for dry
season participates, COD, and lead for eight particle sizes and five test
areas. Figures B-6 through B-9 in Appendix  B show  the particle size
distributions for wet season particulates,  total KJeldahl  nitrogen, total
phosphorus and zinc. The solids particle  size  distributions show that the
smallest  particle sizes account for a very  small  fraction  of the total
material, especially during the wet season  when rains are  most effective in
removing  the smallest particles (see  Section 9  for  a  discussion of storm
washoff of particulates). During the  dry  season,  the  larger particle sizes
account for relatively small fractions of the  total  solids weight. In all
cases, i48th Avenue had most of its total solids weight  in the particle size
range of 250 to 1,000 microns.

      The chemical oxygen demand, KJeldahl nitrogen,  and  phosphorus
concentrations all show high concentrations  associated with the smallest
particle sizes, small concentrations with the  intermediate sizes, and then
large concentrations with the larger  sizes.  This  is  probably because of the
presence of leaves and other organic  material  associated with the largest
particle sizes. The lead and zinc distributions showed typical particle size
distributions for heavy metals with the  highest concentrations associated
with  the smallest particle sizes. The lead  particle  size distributions are
also interesting whp.n comparing the different  test  arsas.  Westwood Homes Road
in the Surrey Downs basin usually had the smallest  lead  concentrations for
all particle sizes, probably because  of  the small  amount of traffic on that

                                      107

-------
                            FIGURE 7-5
o
oo
          DRY  SEnSOK1  PRRTICLE  SIZE DISTRIBUTION
                   63-    125-   250-   503-   1000-  2000-   >ฃ>3"ปo


                     [Tj-108th     ~SD       ~LH      T-148th

-------
                     FIGURE 7-6


  COD CONCENTRRTION5  BY PRRTICLE  SIZE
  450
                    (g/kg
9> 25CLZ.
o
LJ
            63-    125-


              J7J- 108th
                          1
250-
500-   1000-   200C-   >6370


   m-LH        - 148th

-------
  3000
                        FIGURE  7-7

      LERD  CONC.   BY  PRRTICLE SIZE  (mg/kg
  25flfl_
   2QOn_
o>
o>  , c
ฃ  -iS
Q
d
UJ
   10flfl_
   SQL
on_
       <63

       hWHR
         234  I| i -j j i
                           n
                        I i 3 4  H ' 2. J
          63-    125-    250-

            JTJ-108-th     Q]~5D
500-   1000-   2000-   >6350

    [Tj-LH       Q]-148-th

-------
 road,  however,  148th  Avenue  is  a  well  travcJled  street and showed very  high
 lead  concentrations,  especially in  the  smallest  particle sizes.

      Table  7-5  summarizes  the size-weighted  total  particle chemical
 strengths,  along with  the  median  particle  sizes   The largest dir fc.rence  in
 chemical  characteristics  is  shown for  lead,  especially when comparing
 Westwood  Homes  Road with  148th Avenue.  The Lake  Hills  lead concentrations are
 also  greater  than  the  Surrey Downs  basin  lead  concentrations. This may  be
 because of  the  smaller median particle  sizes associated with the Lake Hills
 samples.  Because of the much greater concentrations  of lead with the smaller
 particle  sizes, a  smaller  median  particle  size would result in a much greater
 total  solid lead concentration. The total  solids median particle size for
 lUBth  Street  street dirt  is much  greater  than  the  total solids particle  sizes
 for the other test areas,  and indicate  the presence  of many more larger
 particles on  that  road than in the  other  test  basin.s.

      Table  7-6  compares these street dirt  constituent  concentrations with
 data  from other locations. In all cases,  the observed  3ellevue chemical
 concentrations  are well within the  range of values found in the other
 locations.  There is a much smaller  difference  for  these Bellevue street dirt
 chemical  concentrations when compared to other areas than there is for the
 observed urban  runoff concentrations or for the  street dirt loadings.
 Therefore,  the  street dirt in Bellevue  is very similar to the street dirt in
 other locations studied,  but the  frequent rains  prevent the street dirt from
 accumulating to large loading .alues. The total  annual rainfall in Bellevue,
 however; is also similar  to many other  locations studied.  Because  of the
 smaller but more frequent rains  in Bellevue, each  rain can remove  fewer
 street surface  particulates, and  the additional  runoff volume per  rainfall
 (because of the moist soils) dilutes the pollutants  more than for  other
areas.
                                     Ill

-------
Table 7-5.  TOTAL  STUDY  PERIOD  STREET DIRT CHARACTERISES (no/ka)

Test Area
Surrey Downs
Main Bas in





Surrey Downs
108th St.





Surrey Downs
Westwood Homes Road





Lake Hills






148th Avenue S.E.







Const i tuent

Total Solids
COD
TKN
Total Phosphorus
Lead
Zinc

Total Solids
COD
TKN
Tota Phosphorus
Lead
Zinc

Total Solids
COD
TKN
Total Phosohorus
Lead
Zinc

Total Solids
COD
TKN
Total Phosphorus
Lead
Zinc

Total Solids
COD
TKN
Total Phosohorus
Lead
Zinc
Si ze-Weiqht^c1
Strength

—
145,000
1600
575
745
170

—
51,300
455
510
460
130

	
239,000
2195
590
190
90

—
192,000
2310
640
1170
230

—
104,000
850
460
1540
190
Median Particle
Size (microns)

520
810
420
670
290
350

1370
1680
780
1860
440
1180

840
1960
780
890
420
640

420
730
400
430
225
260

610
1080
765
260
320
360
                             112

-------
                               Table 7-6. BELLEVUE STREET DIRT CONSTITUENT CONCENTRATIONS
                                     COMPARED WITH DATA FROM OTHER LOCATIONS  (mg/kg)
Constituent
Cadmium
Chromium
Lead
Zinc
COD
Phosphorus
Nitrate-N
Nitrite-N
Kjeldahl-N
Bellevue
Surrey
Downs
___
---
745
170
145,000
575
—
—
1600
108th St.
--.
—
460
130
51,000
510
.--
~—
460
Westwood
Homes Rd
-_.
.._
190
90
240,000
590
_„
—
2200
Lake
Hills
--.
—
1200
230
190,000
640
...
—
2300
148th
Ave S.E.
_--
_._
1500
190
100,000
460
—
_—
850
Reno/Sparks 1 San
<3
30
100 to 2 ,500
200
100,000
800
25
5
150
Smooth
Asphalt
2
450
5,500
750
120,000
—
—
—
2,000
Jose'2'
Poor
Asphalt
3
450
2,000
500
110,000
—
---
- —
2,300

Oil and
Screens
1
350
1,000
250
80,000
—
---
—
1,000
Castro
VaTiev
Smooth
fsoh^lt
_.-
200
1,600
200
90,000
500
---
---
1,600
 1    Pitt and Sutherland, 1982
 2    Pitt, 1979
(3>    Pitt and Shawley, 1982

-------
                                        Table  7-6.   BELLEVUE STREET D[t
-------
                                  SKCTION 8
                SKWKK SYSTLM FAKTICULATK ACCUMULATION  STULHLS
     An important element of the Bellevue urban  runoff  project  was the study
of storm drainage participates. The objective of  this  portion  of the program
was to describe the quantities and characteristics  of  storm drainage
particulates in the study areas. The storm drainage  particulate studies
involved both observation and sampling of catchbasin particulates and
particulars accumulated in the pipes throughout  the Lake  Hills and Surrey
Downs study areas. Data obtained from these studies  were  compared to
monitored street surface loadings and total runoff  yields  measured at the
outfalls of the two study areas. These mass relationships  help  define the
importance of storm drainage to the total runoff  yield. This section of the
report provides a summary of the storm drainage  particulate data collected
during the study.
CATCHBASIN OBSERVATIONS

     As part of the experimental design task,  random  sampling  and chemical
analyses ot about ten catchbasin sediments and  water  supernatants were
collected in both Lake Hills and Surrey Downs.  This  initial  sampling was
conducted on December 27 and 28, 1979. The chemical  analysis results for the
catchbasin samples taker from the Lake Hills study area  are  presented in
Tables 8-1 and 8-2.

     Catchbasin sampling and analyses were conducted  two times during the
first year. The sediment portion of the samples were  dried and sieved after
their specific gravities were measured, and then  composited  for chemical
analyses. The supernatant portion of  the samples  were then chemically
analyzed. The 'chemical analysis results for the sediment portion of
catchbasin samples collected March 19 and 20,  1980,  are  presented in Table
8-3. The average wet specific gravity was approximately  1.3  grams per cubic
centimeter, or 80 Ibs/cubic foot. This average  value  MS lower than expected.
The procedures used to obtain these initial catchbasin sediment samples may
not have provided representative undisturbed cores.  Since the  freezing core
sampler did not work adequately for the shallow sediment depths encountered,
the sediment samples were obtained by hand scooping.  The specific gravities
and total solids percentages may be low because of the extra water obtained
in the scooping procedure. This problem was corrected for the  future samples.

     Additional samples were collected from January  through  June of 1981 in
selected catchbasins throughout Lake Hills and  Surrey Downs. About ten
catchbasins were sampled during each  of these  three  sampling efforts. Each

                                      115

-------
Table 0-1. CATCHBASIN SUPRNATAN1
                                            (Lak5  Hills,  12/27-28/1979
catch-
bas in
number
592
616
626
524
523
535
549
554
578
582
total
sol ids
(mq/1)
r9l.(D
L91.
88.
124.
85.
111.
272.
34.
49.
158.
rl50.
U50.
chemical
oxygen
demand
(mn/1)
24.
27.
24.
24.
81.
244.
22.
r29.
L 36.
90.
20.
toUl
Kjelnahl
ni troqen
(nq/1 as N;
<.50
.90
1 . 20
4.73
2.20
3.04
r.98
L 1.40
.50
r5.60
1 5.50
.70
total
Phosohoruc
(mq/1 as P)
.325
.132
.218
.638
.322
r 6.90
1 6.75
.082
.078
.690
.135
Lead
(mq/1)
.08
.07
.07
r.22
L.05
.14
.11
.09
.08
.45
.12
Zinc
(ma/1)
1.19
.045
.079
.018
.105
.218
.033
.088
.126
.037
data  shown  with  brackets  are  reolicates
                                  116

-------
Table 8-2. CATCHBASIN SEDIMENT QUALITY (LAKE HILLS,  12/27-28/1979)
catch-
basin
number
592
616
626
524
528
535
549
563
578
582
total
so 1 i ds
27.0
6.82
20.3
4.37
4
.887
26.4
2.49
64.8
6.22
52.9
total
K.ieldahl
nitrogen
(jja/q as N)
744.
342.
r747.
••1010.
1020.
778.
56.0
353.
1470.
2010.
560.
Learl
^0.
236.
278.
262.
149.
13.0
407.
507.
46">.
479.
Zinc
166.
15Q.
146
93.0
53.5
37.0
123.
211.
104.
120.

-------
                 Taole 8-3. CATCHBASIN SEDIMENT QUALITY (3/19-20/1980)1'!]
Test
Basin
Surrey Downs
Surrey Dowis
Surrey Downs
Surrey Downs
Surrey Downs
Lake Hills
Lake Hills
Lake Hills
Lake Hills
Lake Hills
catch-
basin
number
510
548
559
531
534
524
535
578
626
616
Spec if ic
Gravity
( gtn/cm')
1.108
1.048
1.660
1.041
1.055
1.738
1.932
1.026
1.088
1.014
Total
Solids
9.29
19.2
56.6
(-5.98
15.51
r5.83
'6.11
19.1
•-71.5
'69.5
5.31
13.8
26.2
Chemical
oxyaen
dem.md
26.9
12.1
r-9.95
1.6. 59
48.9
44.5
4.24
1.57
26.7
3.41
1.45
Total
Kjeldahl
n i trogen
.971
.396
.791
rl.41
Ll. 03
2.75
.144
55.6 (jg/g
1.12
.463
.213
Total
phosphorus
(jjg/g-P)
2020.
411.
168.
2124
3720
199.
28.4
2170.
(-978.
L 833.
282.
Lead
5070.
806.
1325.
(-5937.
'4370.
2890.
880.
[-16.8
L14.2
2930.
1880.
604.
7. i nc
540.
137.
245.
r 1010.
L1380.
1000.
318.
(-36.1
L39.8
595.
906.
226.
results  on  a  dry weight  basis,  except  for  specific gravity and total solids.
                                           118

-------
.-atcl.h.u in sample was  drieJ, nocnanica 1 1 y  sieved,  and Ihen we^'hed. fc'qual
tractions ot  each size  cat^ory  wpre  combined  for  enoi sa.nplinfi period,  and
ucre  .-her-.U-cUlv analyzed,  lables  8-4  and 8-5  show  the chemical analysis
ret.ults  tor  these three  sampling  periods and  eight particle sizes for  both
UiKe  Hills and Surrey  Uowr.s . The  catchbasin  pedirent samples hi'd particle
si;e  concentrations  very  similar  to  the  concenttations found in the street
dirt  in  the  respective  areas.  This  indicates  that  the catchhasin sediment
-naterial was  mostly  made  up  of street  dirt.  Tab~tes 8-4 and 8-5 also show
calculated total sample  chemical  concentrations  during the early experimental
design  sar.plir.g. These  total samples  concentrations are reasonable when
compared with  the particle  size  breakdowns,  but  do show very large variations
(.especially  when compared  to the  small  variations  in the composited size
data).  This  implies  that  the particle  size distributions changed radically
from  catchbasin to catchbasin, even  though the particles mak.Ing up the total
sediment are  quite similar  in  properties.

      Tables  D-l through D-6  in Appendix  D  show the measured sediment volumes
for all  structures examined. Most of  the catchbpsins were about 28 fay 22
inches  (700  by 5bU mm), but  some  catchments with manholes were as large  as
four  feet (1.2 meters)  in  diameter.  During the first survey, the sediment
depths  ranged  frooi zero  to  about  15  inches (0  to 380 mm) in Lake Hills (0 to
b.3 cubic feet, or 0 to 0.2  cubic meter) and  zero  to 27 inches (0 to 690 mm)
in Surrey Downs (0 to  15 cubic feet,  or  0  to  0.4 cubic meter). Tables D-7 and
D-8 show the  relative  sediment and  supernatant quality observed in the
catchbas-'ns  during the  early sampling  periods. The extreme ranges of
strengths (mg  constituent/kg total  solids, or  pp-jO observed, implies that the
particle size  varies substantially,  by  location  in the test areas and by
time. These  values also demonstrate  the  importance of chemical transfer
between  the  sediments  and  supernatant,  especially  since a much smaller storm
can flush out  all of the supernatant whereas  a larger storm would be needed
to remove a  substantial quantity  of  sediment.  This appears to be more
important for  COD which is  shown  to  be more soluble than the other
constituents observed.

      Nine complete catchbasin  sediment  accumulation inventories were
conducted during the project.  The first  survey was conducted in December,
1979, and the  last survey was  conducted  in January, 1982. The depth of
sediment was measured  for each catchbasin  in which access rould be obtained.
A summary of the results are presented  in  Table  8-6. Figures 8-1 through 8-4
are plots of the observed loading conditions  for each sampling period.

      The sewage systems in Lake Hills  and  Surrey Downs were cleaned before
the beginning of this  sampling program.  Private  streets in Surrey Downs
(specifically Westwood Homes Road) did not have  their associated drainage
systems cleaned. Figures 8-1 through 8-4 (corrected for missing data) show
that  it required about one year  for  the  sewerage system inlet structures
(catchbasins, inlets, and manholes)  to  reach  a steady state loading
condition.  During the second project year  (1981).  more frequent (about
monthly) observations were made and  indicate very  little net removal or
increase in loadings between the  observations. Table 8-7 summarizes the
typical stable period loadings and  the  accumulation rates after cleaning
before these stable .loading values are  obtained. The Lake Hills steady state


                                      119

-------
Table 8-4.  SLI39EY  DOW'IS CATCHBASIN  SEDIMENT  CHEMICAL  QUALITY  (mgAg) BY PARTICLE SIZE
                               particle Size: microns

Chemical Mxvqen Demand:
1/13/81"
l/,?6 2/4/81
2/?6 6/17/81
average
standard deviation
Total Kjeldahl 'itrogen
1/13/81
1/26 2/4/81
2/26 6/17/81
average
standard deviation
Total Phosphorus
1/13/81
1/26 2/4/81
2/26 6/17/81
average
standard deviation
Lead
1/13/81
1/26 2/4/81
2/26 6/17/81
average
standard deviation
Zinc
1/13/81
1/26 2/4/81
2/26 6/17/81
average
standard deviation
'63
153,000
158,000
15fi,000
157,000
1,200
3190
2570
2980
2910
320
340
1130
1180
380
470
1100
1200
1200
1170
(50
332
456
397
395
6.?
Total sample analyses (3/19 2
COD
mean 2EO.OCO
standard deviation 1ฃ0,000
number of catcnbasins 5
63-
125
145,000
127,000
113,000
130,000
11,000
2110
1930
2160
2070
120
450
793
840
690
210
910
840
870
870
35
3">0
303
300
320
40
/80) (mg/kg)
TKN
1225
820
5
12J-
250
90,400
89,200
95 , 200
91,fiOC
3,200
1640
1290
1560
1500
180
626
635
630
630
5
670
650
530
620
76
166
2??
196
195
28
TP
1690
1450
5
250-
500
116,000
73 , 800
103,000
100,000
19,000
1800
1430
1563
1600
190
694
578
D70
610
70
550
570
550
56C
12
185
217
196
200
16
Pb
3400
2080
5
500 -
1000
177,000
115,000
137,000
143,000
31,000
1900
1450
1290
1580
280
366
642
652
550
160
540
520
570
540
25
180
216
208
200
19
Zn
720
490
5
1000-
2000
210,000
205,000
320,000
245,000
65,000
2760
2000
3050
2600
540
970
1030
791
930
i?0
550
500
570
540
36
214
246
223
230
17

2000-
6350
242,000
213,000
327,000
272,000
^7,000
2740
1900
27PT
2450
470
1C90
1050
1030
1060
30
530
370
540
480
95
171
198
207
190
19

'6350
176,000
237,000
320,000
244, (CO
72,000
1660
2100
2390
2050
370
830
844
620
760
120
250
360
250
290
64
107
173
170
ISO
37

                                       120

-------
Table 8-5. LAKE HILLS CATCHBASIN SEDIMENT CHEMICAL DUALITY (mg/kg)  CY  PARTICLE  SIZE

ChPmical Oxygen Demand:
1/13/31
1/26 2/5/81
3/17 6/17/81
average
standard deviation
Total Kjeldahl Nitrogen
1/13/81
1/26 - 2/5/81
3/17 6/17/81
average
standard deviation
Total Phosphorus
1/13/81
1/26 2/5/81
3/17 6/17/81
average
standard deviation
Lead
1/13/81
1/26 2/5/81
3/17 6/17/81
average
standard deviation
Zinc
I/. '3/81
1/26 2/5/81
3/17 6/17/81
average
standard deviation
'63
218,000
225,000
243,000
229,000
12,900
3360
3820
3610
3600
230
231
1030
1440
900
610
2800
1300
1800
1970
760
621
413
532
520
100
	 f - —
63-
125
159,000
162,000
197,000
173,000
21,100
2330
2540
3160
2680
432
398
744
1050
730
330
2400
HOC
1400
1630
680
453
321
404
190
67
Total sample analyses (early samples only):
COO TKN
mean (mg/Kg) 74,700 700
standard deviation 108,000 540
number of :atchbasins 5 15
125-
250
157,000
101,000
165,000
141,000
34,900
1870
1950
2170
2000
155
574
589
941
700
210
2000
830
1200
1340
600
278
232
359
290
64
TP
750
790
5
250-
500
173,000
114.0CC
143,000
143,000
29,500
2100
1930
2170
2070
120
574
567
693
610
71
1200
650
920
920
?80
210
223
332
260
67
Pb
610
770
15
500-
1000
278,000
191,000
251,000
240,000
44,500
3090
2620
3360
3020
370
742
645
1095
830
240
950
670
1100
910
220
235
236
437
300
120
Zn
210
230
15
1000-
2000
300,000
240,000
295,000
270,000
33,300
3780
3260
3220
3420
310
2160
957
15ฃ0
1570
600
1000
430
970
820
290
282
203
372
286
85

2000-
6350
231,000
1^3,000
333,000
752,000
72,400
2100
1900
3020
2340
600
1550
1280
1750
1.530
240
500
410
940
620
280
171
284
440
300
135

'6350
71,500
205,000
? 01, 000
193, OX
115,000
379
1200
4840
2140
2370
865
894
3652
1800
1600
160
260
890
440
400
92
599
367
350
250

                                     121

-------
    Table 8-6. SUWARY OF OBSERVED CATCHBASIN, INLET AND
MAN-HOLE SEDIMENT VOLUMES, DFC. 1979 THROUGH JAN, 1982 (ft3)

Catchbaslns
Inlets
Man-holes
Total
Surrey
max avg total
11.2 1.9 80
19.2 1.7 45
25.9 3.1 19
25.9 1.9 144
Downs
fraction
of total
loading
56%
31
13
100%

number of
structures
43
27
6
76
Lake H
max avg total
8.3 0.8 55
5.5 0.6 28
15.8 3.0 45
15.8 1.0 128
ills
fraction
of total
loading
43%
22
35
100%

numoer of
structures
71
45
15
131

-------
                       FIGURE  8-1
 01
 01
JD


 U
 0
 U


 •f
 in


 -6
 c
 LU
(V



tl
(U
in
o


(V
o>
a

01

a:
Surrey  DoNns-flve.  Sediment  in Structure
3.5

                                    M

Dec 79 I Rug 80 I Jon 81 I Feb 31 I flpr 81 I Jun 81 I Jul


           •Inle-ts   FT^l-Man-Holes  fii-Totol
                                       81
flug 81
                                               V
Jon 82

-------
01
01
61




I
t/1
               FIGURE 8-2


Lake Hills-five.  Sediment  in Structures
f
c
UJ
c 2
i
01
in
6
& 0
o

01

(X
s_


Li_




5_






—
_
—
•^
— .
•""


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-
_
—
-
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i

Dec 79
Q~CB



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Jul












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-------
                             FIGURE 8-3
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                              \I
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                                              171
           Dec 79 flug 80  Jon 81  Feb 81 flpr 81  Jun 81 Jul 81 flug 81  Jon 82

          J7"2J-G3       Pi-Inlets    [VM-Mon-holes

-------
01
01
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CTJ
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                    FIGURE 8-4

Lake  Hills-Total  Sediment
ISO
                                      in Structures
J^ 125
  75.
                      71
                                171
      Dec 79 Jul 80 Jon 81  Mar 81 Flpr 81 Jun 81  Jul 81  flug 81 Jon 82

     ^CB      I hlnlets   F^xj-Mon-Holes

-------
                  Table 8-7. TYPICAL  SEWERAGE  INLET  STML'CTHRK
                     SEDIMENT VOLUMES  AND ACCUMULATION RATES
                               stable volume    accum. rate     approx.  months
                                   (ft3)        (ft3/month)    to stable volume
Surrey Downs:
         Catchbasins                 2.2            0.17             13
         Inlets                      2.0            0.10             20
         Man-holes                   2.7            0.14             19
           Average                   2.2            0.15             15
Lake Hills:
         Catchbasins                 0.9            0.05             18
         Inlets                      0.7            0.05             14
         Man-holes                   3.2            0.14             23
           Average                   1.1            0.06             18

-------
\ > I u;--i •-. *iTi' about  one-ha 1 1  of  the  Surrey Downs volumes (.except  tor
r.<:',!: •.<•:,). The appr< >\ i r i: e  lime  period ot p.i r t i r u l.i Le ar cumu 1.11 ion  bctore  the
'•lab i i- ve!u;;:e  is  obtained  is  also  shown on Table h-7. These periods  are
bel-W- on one ,i;ul  two years,  with  Ltie mure roirmon i. ,1t rhha s i ns  'equiiin,*  about
I *  i.e:iilis  in Surrev Downs  (where  the iiilet dtnsity is about U.H  inlets/ane,
or  ,.'.n inlets/ha) and  18  months  in  Lake Hills (with a greater  inlet  density
ot  about  I.J inlets/acre ,  or  3.2  inlets/ha). A conservative estimate,  based
on  the available  data, would  be  about  on" year. (Observations  weie  not
started imr..od i at e ly after  the  initial  cltaning.) Catchbasin, inlet,  and
manhole cleaning  should  therefore  be performed on about an annual basis  to  be
most cost-etfecLive .  Slightly  more  frequent cleaning may be necessary  for
smaller inlet  st rnc i >.. res ,  less  dense spacing of inlets, or during periods  of
;',] eater than usual  riin.  Cleaning  every six months can probably  be  considered
the  maxinum effort  warranted.  A  city-wide survey of inlet sizes, inlet
densities, and close-by  sodiwent  sources (as discussed in the  following  parts
ot  this section)  can  be  used  to  effectively determine the optimum cleaning
frequency. The additional  inlet  sediment surveys, carried out  by the  Bellevue
Stoi.Ti Drainage Utility,  will  be  an  effective tool in designing  the  most
appropriate inlet cleaning  program.

     The  total amount  of  runoff  particu1ales that may accumulate in  the  inlet
structures are sho*.n  on  Table  8-8.  These quantities are about  what  would be
accumulated before  the   stable  volumes" are obtained. These quantities coulri
be continuously  removed,  if the  inlets are cleaned before the  stable  volumes
are  obtained.  After the  stable  volumes are obtained, urban runoff is  little
affected  by the  structure.  The  constant stable volumes experience very little
washout and reaccumulations (as  shown  by the second year loading data).
During October,  1981,  a  very  large  storm occurred (about four  inches).
However,  no significant  difference  between the average or total August,  1981,
and  January, 1982,  observations  was noted.

     An analysis  of inlet  structure size (volume and depth below outlet) and
performance was  conducted  for  the  Surrey Downs data. Table 8-9 summarizes
these dimensions  fov  catchbasins,  iniets, and manholes. The catchbasins  and
inlets had about  one  foot  (300 mm)  available for storage below  their  outlets,
while most of  the manhole  outlets  were on the bottom. Between  three  and  four
cubic feet (O.U8  and  0.11  cubic  meter) of storage wero available in  the
catchbasins and  inlets.  Table  8-10  shows the observed average  volumes  and
depths of  seiinenf  in  the  inlet  structures. Also shown are the  portions  of
the  available  storage  containing  the sediment. The stable sediment  volumes
during the second year were about  60 percent of the available  sump  volumes
for  the catchbasins and  inlets.  Only about one-half inch (13 mm) of  sediment
was  found  in the  manholes,  with  outlets on the structure bottoms, while  about
six  inches (150 mm) of sediment  were in the inlet and catchbasin sumps.  When
analyses were  conducted  for individual structures, wide variations  were
observed.  The  depth below  the  outlet appeared to be the most important
factor, but the  larger capacity  sumps  did not always contain the largest
amount of  sediment. Larger  sump  volumes would allow less frequent cleaning,
while smaller  outlet  tc  sump  bottom distances were associated  with  more
scour. Manhole #577 (a grease  trap  with a storage volume of about 48  cubic
feet, or  1.4 cubic meters)  had  the  largest sump volume of all  inlet
structures observed,  and  usually  contained the largest sediment  volume.  Its


                                     128

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            Table 8-8. ANNUAL  ACCUMULATION  OF  SEDIMENTS  IN  STORM SEWER  INLET STRUCTURES
                                                 Annual Total Detention(l)
number avg detention total total
of rate solids solids
structures (ft3/month) (ft3) (Ibs)
Surrey Downs:
Catchbasins
Inlets
Man-holes
Total /average
Annual
Lake Hills:
Catchbasins
Inlets
Man-holes
Total /aver age
Annual

43
27
6
76
detention

71
45
15
131
detention

0.17
0.10
0.14
0.15
(Ib/ac

0.05
0.05
0.14
0.06

88
32
10
130
re /year) :

43
27
25
95
(Ib/acre/year) :

8300
3000
940
12,200
130

4 mo
2500
2400
8900
88
COD
(Ibs)
2100
750
240
3100
33

300
190
180
670
6.6
TKN
(Ibs)
10
3.6
1.2
15
0.16

2.8
1.8
1.7
6.2
0.06
TP
ill
14
5
1.
21
0.

il
6
22

3.0
1.9
1.8
6.7
0.
.07
Pb
(Ibs) (
28
10
3
42
0.44

2.4
1.5
1.5
5.4
0.05
ZM percent
'. 1 b s ; of to t a 1

6
2
1
9
0.10

0.8
0.5
0.5
1.8
0.02

67%
25
8
100%


46%
28
26
100%

(l)Assuming l.Sg/cm^, or 94 Ib/ft^ and typical pollutant  concentrations

-------
                                 Table 8-9.  SURREY DOWNS INLET STRUCTURE SIZES
                                                                                  Man-holes
                                                    Catchbaslns      Inlets     (excluding   #577)
               Diameter of outlet  (inches):
                     Average
                     Minimum
                     Maximum
                                       12
                                       8
                                       18
10
6
36
all 24
               Depth below  outlet  to  bottom  (feet):
                     Average                           1.1
                     Minimum                           0
                     Maximum                           2.8
                                                     0.9
                                                     0
                                                     3.4
            0.02
            0
            0.1
OJ
o
Cross-sectional area (square feet):
      Average                          3.4
      Minimum                          2.5
      Maximum                          6.0
                                                                     3.ฐ
                                                                     1.4
                                                                     17.4
            65.7 (partial'1
            52.8
            73.9
                Volume  below  outlet  to  bottom (cubic  feet):
                     Average                          3.9
                                                     3.3
            1.3
                      Man-hole #577  is  an  oil  separator that  is  4.1  feet  in diameter,  with  a
                      depth  below  the  12 inch  outlet  of 3.7 feet.  The  total  storage  volume  is
                      48.3 ft'.  This  "man-hole"  contained almost  all  of  the  debris  found  in
                      all of the man-holes  combined;  the other man-holes  were empty  for  most
                      observations.

-------
      Table  8-10.  SURREY  DOWNS  INLET  STRUCTURE NORMALIZED VOLUMES COMPARED TO AVAILABLE
                                                                                             Stable
Dec
1979
Auq
1980
Jan
1981
Feb
1981
Acril
1981
June
1981
July
1981
Auo
1981
Jan Peri or
Catchbasins
  Average volume (ft3)         0.37   0.67   2.86   2.77   1.81   2.12  '2.05   1.88   7,^7    2.?8
  Average depth (ft)           0.11   0.20   0.84   0.81   0.53   0.62   0.60   0.55   0.72    0.67
  Percent of available storage 9.7%   17.5%  73.7%  71.1%  46.5%  54.4%  52.6%  ;8.2%  53.2%   58.^"


Inlets
  Average volume (ft3)         Q.33   0.67   1.89   2.04   2.07   2.07   2.11   1.82   2.11    ?.n"
  Average depth (ft)           0.09   0.17   0.49   0.53   0.54   0.54   0.55   0.47   0.55    0.5'
  Percent of available storage 10.0%  20.0%  57.6%  62.4%  63.5%  63.5%  64.7%  55.3%  64.7%   61.7*


Man-Holes
  Average volume (ft3)         1.22   1.78   2.78   1.78   1.67   2.00   3.22   2.00   3.11    2.17
  Average depth (ft)           0.02   0.03   0.05   0.03   0.03   0.04   0.06   0.04   0.06    0.04
  Percent of available storage                not applicable                                  —

-------
.-;l.:hle sediro-.Mit volume uMy only  about  3i>  percent, of Itb lull capacity,
     An an. i lysis ot the sediment  data  for  the first: two sampling periods
_,iiliH'O sor-.e interesting observat Ions .  Nine  of  the ten most heavily loaded
cat chbas ii-ซ in tiit> first summer  inventory  for Surrey Downs are located on, or
jii'-t upstream tn>m, the only  two  streets  in  the study area that do not have
curbs, both of the streets  (lUbth  Avenue  and Westwood Homes Road) have
extensive ott-stieeu sedime.it  sources  located along then and were i:ot cleaned
during the study. These nine  catchbasint.  accounted for about 40 cubic feet
(l.l cubic meters) of sediment,  or 58  percent cf  the sediment observed in
Surrey Downs catchbasins during  that  summer  inxentory. They alsc accounted
for 73 percent of the increase in  sediment  loadings observed between the
first winter and summer inventories.

     Table 8-11 shows the heaviest sediment -loaded catchbasins in Surrey
Downs during the first two  inventories.  Eight out of the twelve heaviest
loaded catchbasins in the summer  inventory  were also part of the ten most
heavily loaded caf-ehbasins  during  the  winter inventory. Many of these
catchbasins v:fcre located in the  headwaters  of the Surrey Downs study area and
they nay not receive the high  runoff  rates  needed to flush them. However,
some flushing was observed  farther down  in  the  pipe system (i.e., #566 and
#572). A significant portion  of  the sediment observed in the Surrey Downs
catchbasins may not be easily  available  for  runoff transport.

     Table 8-12 presents data  for  the  most  heavily loaded catchbasins
observed in the L^ke Hills  test  area  during  the first two inventories. Six of
the eleven heaviest loaded  catchbasins  in  the summer inventory were also part
of the most heavily loaded  catchbasins  observed in the winter inventory.
However, the sediment accumulations in Lake  Hills were more evenly
distributed among the catchbasins  than those in Surrey Downs. The top ten
catchbasins in Lake Hills accounted for  only about 30 percent of the observed
sediment in the summer, whereas  the top  tun  catchbasins in Surrey Downs
accounted for about 60 percent of  the  total  summer loading.
PIPE SURVEY AND OBSERVATIONS

     A survey of pipe lengths,  diameters,  slopes,  and directions throughout
each of the study areas was made  during  the early  months of the project.
Frequent observations of sediment accumulations  in pipes throughout the two
study areas were also made. Very  few  pipes in either Surrey Downs or Lake
Hills had slopes less than 0.01 ft/ft (one percent slope), the slope assumed
to be critical for sediment accumulation.  In Lake  Hills, the average slope of
tne 118 pipes surveyed was 0.04 ft/ft (4 percent slope). Only nine pipes, or
7.6 percent of those surveyed,  had slopes  less than 0.01 ft/ft. In Surrey
Downs, the average slope of the 75 pipes surveyed  was 0.05 ft/ft (five
percent). Nine pipes or 12 percent of those surveyed had slopes less than
".01 ft/ft.

     The pipe system data indicates that the two study areas are drained by
steeply sloping pipe systems. The chances  of finding significant


                                      132

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                           Table 8-11.  SURREY  DOWNS CATCHBASIN INVENTORIES  -  HIGHEST  SEDIMENT  LOADINGS
CO
CO
Catchbasln Description
Type
Number CB (1)
MH (2)
577
569
562
583
579
580
573
575
534
578
548
552
566
572
559
CB - oil
Inlet
CB
Detention
pipe
Inlet
CB
CB
CB
CB
CB
Inlet
Inlet
CB
CB
CB
Location
Longest run of
upstream pipe
(ft)
Sep. 220
0
370
0
0
500
1000
340
335
160
0
0
2000
111-.0
340
SUMMER
Sediment loadinq

Rank
(out of all
catchbasins)
1
2
3
-1
5
6
7
8
9
10
11
12

Sediment
Volume
(ft3)
15.182
3.640
3.563
2.700
2.695
2.475
2.464
2.341
2.203
2.147
2.016
1.870
0.332
0.167
1.059
WINTER
Sediment loadinq
Rank
( ou t of all
c=>tchbasins)
1
6
13
2
4
Sed iment
Volume
(ft3)
10.034
1.040
0.712
2.70
1.617
0.165
0.493
0.195
10
3
8
7
5
9
11
0.801
2.362
1.008
1.020
1.102
0.836
0.792
Chame
Winter
Sediment
Volume
+5.148
in 1 na H i nq
to S'JTier
Percent ioe
chame
+ 51
+3.500 +336
+2.851
0
+1.078
+2.310
+1.971
+2.146
+1.402
-0.215
+1.008
+1.833
-0.770
+400
0
+67
+ 1400
'400
+1100
+175
-9
-100
+180
-70
-0.669 -90
+0.267
+34
              (!) Catchbasln
              (2) Manhole with catchment

-------
Table 8-12. LAKE HILLS CATCH8ASIN INVENTORIES - HIGHEST SEDIMENT LOADINGS
Catchbasin Description
Number
394
564
530
622
521
547
539
523
602
587
528
533
535
581
579
CB (1)
MH (2)
Inlet
CB
MH
Inlet
CB
CB
Inlet-MH
MH
Inlet
Inlet
C3
MH
MH
MH
MH
Location
Longest run of
upstream pipe
(ft)
0
30
3400
0
55
1730
0
3630
0
0
30
3350
195
2360
2450
SUMMER
Sediment loading
Rank
(out of all
catchbasins)
1
2
3
4
5
6
7
8
9
10
11
13
Sediment
Volume
(ft3)
1.766
1.584
1.418
1.392
1.350
1.282
1.255
1.256
1.191
1.157
1.140
1.005
0.706
0.707
0.353
WINTER
Sediment loading
Rank
(out of al 1
catchbasins)
Sediment
Volume
(ft3)
0.784
0.079
1
5.674
0.119
10
1.157
0
9
4
1.257
2.513
0.278
7
6
5
2
3
8
1.543
1.596
1.885
5.655
5.650
1.410
Change
Winter
Sediment
Volume
+0.932
+1.505
-4.256
+1.273
+0.193
in loading
to Summer
Percentage
change
+ 125
+1900
-75
+ 1000
+17
+1.282
-0.001
-1.257
+0.913
-0.386
-0.456
-0.880
0
-50
+328
-25
-29
-47
-4.949 -88
-4.943
-1.057
-88
-75
Catchbasin
Manhole  with  catchment

-------
.u-c'irau hi lions of sediment, in the pipe system are  low  since  scour velocities
rar, le IB .r.tained in about 90 percent of  the Lake  Hills  and Surrey Downs
storm drainage systems.

     During the collection of catchbasin  sediment  data,  routine observations
w.;re not made on the amount of sediment; in  the  pipes.  However,  a special
survey was  conducted on October 30, 1980. The objective  of  that survey was to
observe the magnitude and characteristics of sediment  in the pipes of the two
study areas. The following general observations were  made:

     1. The number of pipes throughout the  sewerage systems
        of  both Lake Hills and Surrey Downs that had
        sediment in their inverts appeared  to be minimal.

     2. As  expected, the pipes that contained significant
        amounts of sediment were either: mildly sloped
        (1.5 percent or less); located close to an
        off-street source of sediment such  as steep,
        sparsely vegetated, unprotected soil slopes;  or
        both mildly sloped and located near a sediment
        source.

     3. The physical characteristics of the sediment  in  the
        pipes appeared to correlate well with those of the
        sediments deposited in the nearest  downstream
        catchbasin or manhole.

     Based  on the observations made during  the October,  1980,  field survey,
the volume  of sediment accumulated in the pipes throughout  Lake Hills was
approximately 50 cubic feet (1.4 cubic meter). Assuming  a specific gravity of
2.0 grams per cubic centimeter, sediment  in Lake Hills totaled  about 6200
pounds (2800 kg). In Surrey Downs, the pipe sediment  volume was estimated at
over 700 cubic feet (20 cubic meters) or 87,000 pounds (39,000  kg). Most of
this sediment was observed in silted-up pipes along 108th Avenue and Westwood
Homes Road. (These streets are not being swept.) The  pipe sediment volume
estimated to be available for runoff transport  in  Surrey Downs  was about ten
cubic feet  (0,3 cubic meter) or 1250 pounds (570 kg),  and was  observed in the
pipes connecting catchbasins 506, 507 and 509.
                                     135

-------
                                  SKCT10N  9
              STKhET CLEANING EFFECTS  ON OBSERVED  RUNOFF QUALITY
     The coordination of street surface  sampling,  street  cleaning operations,
ard runoff monitoring allowed many different  data  analyses  procedures to be
used to investigate possible effects  of  street  cleaning  on  runoff water
quality. The use of two test basins and  the  rotation  of  the street cleaning
operations also allowed one basin  to  be  compared  against  the other basin,
along with internal basin comparisons. This  section  is  divided  into two
subsections. The first discusses  the  washoff  of  street  dirt while the second
discusses the observed water quality  conditions  at the  different sites under
various street cleaning operations.
WASHOFF OF STREET DIRT
Student's "T" Tests to Compare Before  and  After  Rain  Loadings

     The first method used to determine  the  amount  of streec dirt  that was
washed off by rain events used data  given  in Tables  B-l  through B-13.  The
total solids street dirt loadings  having less  than  two days  of  accumulation
were separated into two groups. One  group  contained  loading  values that had
been affecced by a significant rain  within two days  of sample  collection
while the other group of data contained  total  solids  loadings  that were
affected by street cleaning within two days.  In  addition,  these groups were
subdivided into dry and wet seasons  for  each of  the  five study  areas.  Paired
Student's "T" tests were then conducted  to identify  significant differences
between the loadings before and after  street  cleaning or rains. Student's "T"
tests were also used to compare before and after loadings  during wet and dry
seasons in each of the five basins.

     In about half of the cases, the loadings  on the  street  after the  rains
were significantly different for the dry versus  the wet  seasons. Much  of this
difference may be due to the characteristics  cf  the  rains  during the two
seasons. During the dry season in Lake Hills,  the before storm  loadings were
about 320 to 400 Ibs/curb-mile (90 to  110  g/curb-meter)  and  there was  a
significant difference between the residual  loadings  after street  cleaning
versus after rains. The streets after  street  cleaning were about 50
Ibs/curb-mile (14 g/curb-meter) cleaner  than after  the rains.  During the wet
season, thฐ difference was reduced to  about  20 Ibs/curb-mile (6
g/curb—meter), but the difference was  not  significant. During  the wet  season
in Lake Hills, the s.reet loadings after street  cleaning were  about 15 to 20
Ibs/curb-mile (4 t? 6 g/carb-meter)  less than  after  the  rains,  but these

                                     136

-------
oiti.-n-nc-s were  also  not  si-nifleant.  The  Lake  Hills wet season after street
cie.,nin^ or rain  loadings  were  all  about.  175  and 225 Ibs/curb-miie (50 to 64
>: / curb-me tor) .

      Fdirdd "T"  test were  used  to  examine  the leadings on the streets before
the  rains  and  the  loadings  on  the  streets  after  rains in the Surrey DC.   , and
Lake  Hills main  basins.  This data  was  also  separated into three major
categories corresponding to  runoff  volumes  of less  than 0.1 inch (2.5 mm),
between 0.1 and 0.4 inch (2.5 and  10 mm),  and greater than 0.4 inch (10 mm).
For  both the  Surrey Downs  and Lake  Hills  data,  the  small runoff volumes
rtsuited in a  street loading difference  between  35  and 50 Ibs/c.urb-mile (10
and  14 g/curb-meter) at  very significant  levels. The removals during runoff
events of  0.)  to  0.4 inch  (2.5  to  10 mm) were much  smaller (between 10 and 2.0
Ibs/curb-mile, or  3 and  b  g/curb-meter)  and were not significant. For runoff
events greater than 0.<*  inch (10 mm),  however,  the  removals were between 75
and  125 Ibs/curb-mile  (21  and 35 g/carb-meter).  also at significant levels.
These results were  quite surprising as  it was thought that the very smallest
runoff events would not  result  in  any  removal of street surface particulates.
It was found  in Castro Vallay,  California  (Pitt  and Shawley, 1981), that
rains having more  than 0.4 inch  (10 mm)  in  runoff volume usually corresponded
to increases  in street surface  loadings  due to erosion material being left on
the streets after  these  larger  rain events. Most of the street dirt removal
in Castro Valley was found to occur during  rains of between 0.1 and 0.4 inch
(2.5  and 10 mm) in  runoff. When  all of  the  Bellevue data were considered
together,  between  35 and 45 Ibs/curb-mile  (10 and 13 g/curb-meter) were
removed by the rains. The  typical  loadings  on the streets before rains in
Lake  Hills was about 210 Ibs/curb-mile  (59  g/curb-meter), with about 36
Ibs/curb-mile (10 g/curb-meter)  removed.  In Surrey  Downs, the loadings on the
streets before rains were  larger (330  Ibs/curb-mile, or 93 g/curb-meter) and
the removals were  about 46 Ibs/curb-mile  (13  g/curb-meter).

      The median particle sizes  shown on  Tables B-l  through B-13 were also
compared using paired  "T"  tests. In all  cases the median particle sizes were
found to increase  by about 100 microns  (at  significant levels) in Surrey
Downs and  (at marginr.lly significantly  levels) in L,aLp Hills. When the Surrey
Downs data were separated  into  these three  runoff size groupings, the.
particle size changes associated with  the smallest  and the largest rains were
significant, while  the medium rains did  not result  in any significant changes
in median particle  sizes. The intermediate  runoff volume range had median
particle size values that decreased after  the rains (but at insignificant
values). Large incr. dses in median  particle sizes occurred for the largest
runoff events (an  increase of about 500 microns  in  Surrey Downs, from initial
particle sizes of 570 microns to residual sizes  of  about 1,100 microns).  This
very  large change could be caused by large  removals of small particle sizes
and/or increased loadings of the larger  particle sizes. '.This would be
expected during the larger rain events which  carry  substantial erosion
material from surrounding areas, some  of which may  be deposited onto the
street's gutters. Table 9-1 summarizes  these  paired Student's "T" test
results for total solids and median particle  sizes  for both Surrey Downs and
Lake Hills.
                                     137

-------
                      Table 9-1. STREET DIRT LOADING CHANGES DUE TO DIFFERENT STORM VOIUME5
CO
00
Surrey Downs

Total Solids - all
   <0.1" runoff
    0.1 - 0.4" runoff
   >0.4" runoff
Median Size - all
   <0.1" runoff
    0.1 - 0.4" runoff
   >0.4" runoff
Initial
330 Ib/curb mi
370
270
310
680 microns
650
780
570
Residual
280
320
250
190
770
730
740
1110
Change_
-46
-47
-20
-120
90
83
-37
540
% deduction
13.9
P.7
7.4
33.7
13.2% increase
12.8% increase
4.7% reduction
94.7% increase
Siqnif icanco
rjf r; h 1 1"1 0 e
>99.9%
99. 5%
30%
93%
96%
95%
65%
96%
      Lake Hills
      Total Solids  - all
          <0.1" runoff
          0.1 - 0.4" runoff
          >0.4" runoff
      Median Size - all
                           210 Ib/curb mi       170
                           190                  150
                           210                  200
                           280                  200
                           570 microns          680
-35       7.1% reduction       99.5%
-36      18.9% reduction       97.5%
-12       5.7% reduction       65%
-78      27.9% reduction       95%
110      19.3% increase        85%

-------
o
     Because of these consistent, (but unexpected)  results  in  loadings and
Particle size changes for different runoff volumes,  street  dirt  washofi was
further analysed to determine effects associated with  rair.  volumes  and peak
rain intensities. The street surface loadings for  total  solids  and  for each
or the chemical constituents were plotted on log-log paper. The  initial
Loadings were plotted aga\nst the residual loadings  and  the associated runoff
volumes were narked at ef.ch point on the graph. The  results showed  that the
residual loadings were apparently unaffected by heavy  runoff  volumes, but
somewhat affected by th> initial loadings. About 65  percent of  the  cases
resulted in actual street dirt removals, while the other 35 percent had
increases in street loadings due to rain. The average,  runoff  volumes vert:
about 0.1 inch (2.5 r.m) .

     Other plots were made on log-log paper comparing  the  initial  street
surface loadings against the runoff volumes. The event mean concentration
(erne) values for che runoff events were plotted at each  corresponding point.
Table 9-2 summarizes the minimum initial street surface  loadings for each
coi.stituent that corresponded to a fairly small region of maximum  runoff
concentrations. In almost all cases, the runoff volumes  associated  with this
region of maxixum concentrations ranged from about 0.04  to 0.08  inch (1.0 to
2.0 mm). The. vegion for COD was much greater and less  defined.  There were
several exceptions on each plot, but the street loading  values  shown may
indicate a reasonable street cleaning goal to minimize maximum  runoff
concentrations. The cause and effect relationship  on these  diagrams, however,
was not clear and the presence of the few maximum  observed  runoff  events in
this snull region may only be coincidental.
Regression Analysis of Street Dirt Washoff

     The previous discussion showed that washoff  was  roost  likely dependent
only on the street loadings before the rain  for the rain conditions observed.
Figures 9-1 and 9-2 plot the observed initial  and residual street surface
loadings for each of the three Surrey Downs  areas and the  Lake Hills and
148uh Avenue areas. These plots were In-transformed in order to obtain a more
evren spread of the data, so regression analysis could be performed. Again, it
is seen that some data points occurred in  the  region  of  loading increases,
while some also occurred in the region of  loading decreases. Table 9-3
summarizes the linear regression equations for each of the study sites and
some corresponding washoff values. The regression equations did not have very
good regression coefficients. The main Surrey  Downs basin  had the best
regression coefficient of about 0.8, Ths other regression  coefficients were
about 0.5. Additional regression relationships were determined for residual
load as a function of the peak rain intensity, the residual load as a
function of runoff volume, and the initial median particle size versus the
residual particle size.

     Figures 9-3 and 9-4 show the changes  in median particle size for the
Surrey Downs, Lake Hills, and 148th Avenue test areas. Again, a large amount
of data scatter was observed. ]u the Surrey  Downs basins,  108th Street had
the largest initial and residue 1 sazes for most of the data points observed.
Westwood Homes Road had some very rlgh median  particle sizes restricted to

                                     139

-------
                       Table 9-2.         STREET SURFACE
                     LOADINGS  CORRESPONDING TO A REGION OF
                   MAXIMUM RUNOFF CONCENTRATIONS (LAKE  HILLS)
                           street            runoff                 max.
Constituent         load (Ib/curb-mi)       depth (in)        runoff  cone,  fmg/1)
Total Solids             150               0.045 - 0.075            >200
Lead                     0.16              0.045 - 0.08             ^0.3
Zinc                     0.035             O.C4  - 0.075            >0.15
Phosphorus               0.08              0.045 - 0.075            >0.5
TKN                      0.25              0.045 - 0.07             >1
COD                      15                0.02  - 0.3              >50

-------
                    FIGURE 8-1
   SURREY DOWNS WflSHOFF OF  STREET  DIRT
7.2
7
6.8_
"3 6.6_
__
e 6.4_,
( ซ• =— I
-0
L 6.2_
u
j3 6

jc 5.8_
o S'6-
a:
OCX
i o . it —

ac 5.2_
~"^
2 c
in
U-l
ซ 4.8_
4.6_
4.4
s'
	 0
— INCREASED LOADINGS /' "
A
/ ' A
~~~~" / A
-
Q El /
0 =Q ,^x e
A A* o oe * A

_ A x/ A_j ^ ฐC CP
^^ 0
B ^x' *e
G^/X A B

O C^/^ A

0 / AQ 0 DECREASED LOADINGS
	 /*
/^ B Q

it * ^ j*%r- r-^sr— j ^- ^ r-^^*- ^•^*^j ^ ^ ^ *** — •
                                               7.2
• SURREY DOWNS
A 108th St.
Q WESTWOOD HOMES RD.
                     LORD On Ib/curb-mlleJ

-------
p.

(NJ
      LRKE HILL5
      6.2
   FIGURE 9-2


148th  flVE
               _J I I \
EET DIRT wnSHOFF
    E
    U
    a
    ct
    o
    cr

    a
    i—i
    un
    IU
    a:
              INCREASED LOADINGS
          4    4.2   4.4


          S LAKE HILLS


          A 148th Ave. S.E.
4.6  4.8   E    5.2   5.4  5.6


 INITIRL LOfl.T (In Ib/curb-ml le)
       5.8
                                  6.2

-------
-C.
CO
                         Table 9-3. MODELED WASHOFF OF STREET SURFACE  PARTICULARS BY RAIT,
                                          (1)               (2)                (3)
                              Surrey Downs      Surrey Downs         Lake  Hills        Combined"
initial
load*
100
200
400
600
800
1000
1200
main
resid
load
103
185
332
463
595
702
830
basin
wash-
** off***
-3
15
68
137
205
298
370
108th
re;id.
load
141
220
344
444
537
610
693
St.
wash-
off
-41
-20
56
156
263
390
507
res id.
load
95
162
278
377
475
554
646
wash-
off
5
38
122
223
325
446
554
res id.
load
108
136
322
440
557
651
761
wash-
off
-8
14
73
160
?43
349
439
                  (!) In (resid.  load) = 0.83[in  (initial  loadQ  + 0.80   r2 =  0.77   N  =   38
                  (2) In (resid.  load) = 0.64fln  (initial  loadฃ|  + 2.02   r2 =  0.50   N  =   23
                  (3) In (resid.  load) = 0.76C_n  (initial  loadQ  + 1,02   r2 =  0.45   N  =   27
                  (4) In (resid.  load) = 0.78(in  (initial  load)]  + 1.08   r2 =  0.55   N  =  108
                         Includes all  3 Surrey Downs sites,  Lake Hills  and 148th Avenue  combined.

                        * initial loads before rain
                        ** residual loads after rain
                        *** washoff =  initial load - residual  load

-------
                         FIGURE 9-3
   SURREY DOWNS  INITIRL  SIZE VS  RESIDURL  SIZE
   2500
S3
o

b
a
>-H
in

0;
i— ซ
o


S
ex.
cr

a
>— *
in
  300
      300   500  700   900  1100  1300  1500  1700  1900  2100  2300  2500

     • SURREY  DOWNS


     A- 108th St.


     0 WESTWOOD HOMES RD.
INITIRL STREET DIRT SIZE (microns)

-------
                         FIGURE  8-4
      LRKE HILLS &  148th RVE SIZE  CHRNGi
C
   2403
 o
 b
in
ft

-------
th'1 r.r.',:.- ot ;ilout  inu  to  l,('i>U  microns.  The 14.-Uh Avenue test area and  the
!,•.'ป <• Kills an;; h;io nirdia,.  particle  sizes that vere qul'.e similar and  ranged
1 rom about J';l! to t>OU microns  in most cases.

     I'lots of w^slujfl as a  function  of runoff volume are shown as Tables  B-10
an
-------
ininfjll. TMs can be expressed in inches if  the k  value  is multiplied by 60.
This equation then simplifies to the following  form:
       .. .,
       N=N e
          o

The k constant is equal to about 0.6 inch  (15 mm)  for  the  particle sizes of
concern, and R is the total rain expressed  in inches.

     This equation was determined from many  controlled  tests in Bakersfield ,
California. An artificial rainfall apparatus was used  on  typical street
surfaces. This portable rain simulator applied water uniformly over a section
of the street at various controlled "rainfall" rates.  The  water was supplied
from nearby fire hydrants and was sprayed  vertically,  about  four to six feet
(1.2 to  J .8 meters) high through hundreds  of small jets.  The water broke into
discrete droplets about the size of common  raindrops before  they fell to the
street surface. The device produced a water  flow pattern  on  the street
surface  which had the appearance of a moderate to  heavy rainfall. Sartor and
Boyd found that the soluble street dirt  contaminant fractions go into
solution with the impacting raindrops and  the horizontal  sheetflow provided
good mixing turbulence and a constant supply of clean  water  to remove the
materials to the gutters. The particulate  matter was moved by the impact of
falling  drops which were then bounced along  the street  surface by repeating
impacts  of other drops and carried by sheetflow. They  noted  that a
substantial amount of the particulatej- were  found  in small pits, cracks, and
other irregularities in the street surface  and were not easily removed.

     These field tests were conducted on street surfaces  having moderate to
heavy loadings of total solids in all particle sizes.  One  concrete and two
asphalt  streets were flushed by the simulated rainfall  for a period of 2.25
hours. Samples of the runoff and the particulates  in the  gutters were taken
every 15 minutes. At the end of the test,  the streets  were flushed thoroughly
with firehoses to wash off any remaining particulates  and  soluble material.
Only two rainfall rates, corresponding to  0.2 and  0.8  inch (5.1 and 20.3 mm)
per hour, ^ere used in these tests. Unfortunately, even the  smallest rainfall
rate was many times greater than any sustained rainfall rate observed in
Bellevue. The maximum rainfall rate was  much greater than what could ever be
expected in Bellevue under most conditions.  These  very  high  intensities may
only occur for very short periods of time.

     Sartor and Boyd found that the initial  flows  from the streets were quite
dirty, but they then became cleaner and  cleaner during  the period of the
test. The pattern of contaminant concentrations in the  runoff water followed
very similar patterns for each of the test  areas and the two rain
intensities. The washoff patterns were also  similar for all  particle sizes.
Again, they found that the transport of  the  particles  across the strest
surfaces fitted the exponential function given previously. The curve fits for
these tests were quite good, and total accumulative washoff s for most
particle sizes reaching constant values  after about 30  minutes of rain. They
found that the proportionality constant  (k)  in the runoff equation was
dependent upon the street surface properties, but  was  not  dependent upon the

                                     147

-------
t1'1' TMi;it,,il itif ens i t it-s  t'l-u  were  monitor:is-t II-IL •.<' -1 ni't  vi r;-  -:r''aLLy  for  different pa/tide sizes.

     Tin-so votv i :i t o r o y L int;  field  tests contributed mic.h to  the  knowledge  of
street surl.u-''1  p.trticul^te washoff,  but thev were conducted  in very
controlled situations  using  rainfall intensities that were not typical of  at
least  Bellevuo  cord i. L ions , and pre  prob.ib'y much greater than  are  likely
Uiund  in most i-artt.  of  the country.  These tests also did not consider  the
effects of traffic  G>  the  stieet surface? during rains.  Traffic  would  have  a
tendency to  remove  moie  of  the '"treet dirt part i cula tes  during rainfall
events (Pitt, 1979).  The  tests were also conducted on very hot streets during
very hot summer days.  This  is  far  different than is lively to  occur  in
be_leVL.e during rain  events  where  the street surfaces and air  temperatures
are much cooler.  The  drier and hotter conditions are thought to  help retain
the soluble  materials  on  the street surfaces and could result  in substantial
flash evaporation of  the  rain  upon  contact with the street surfaces.
Observed Washoff as  a  Function of Particle Size

     Figures  B-16  through  B-23 are plots of the initial street  surface
loadings versus  the  residual surface loadings for each of  ths eight  different
particle sizes.  Also shown on these figures is the percent washoft,  or
increase, for each of  the  rains studied. The smallest particle  sizes  have
most of the data points  falling in the washoff category, but some  rain  events
did produce increases  in loadings. For particle sizes greater than 2,000
microns, more storm  events produced street surface loadings increases  than
decreases. The befcre  and  after street surface loadings for the Lake  Hills
site were compared using Student's "T" tests to identify significant
differences in loadings.  There were no differences observed for wet  versus
dry season washoff quantities, but the initial loadings were significantly
greater than  the residual  loadings  for particle sizes smaller  than  about 500
microns. The  snaxlest  particle sizes have the greatest significant washoffs,
while particle sizes greater than about 500 microns had lower significant
washoff valuti, .  When the washoff conditions are averaged,  removals show a
distinct pattern.  Figure 9-5 shows the average percent washoff  for each of
these particle size  ranges.  In r.he smallest particle sizes, the washoff
varied from about  40 to  50 percent, while increases were found  in  the larger
particle sizes.  The  overall  washoff averaged about 16 percent.  Figure 9-6
shows the size distribution  of the washoff material. This  size  di-.tributlon
is very similar  to the pattern shown in Figure 9-5. Most of the material  thac
washes off the street  surfaces occurs in particle sizes less than  about 125
microns. Only about  ten  percent of the washoff material is greater than about
500 mioroas in size. Again,  the largest particle sizes are notably absent
from washoff  material. Figure 9-7 shows the quantity of material that is
washed off of Lake Hills streets by particle sizes. A total of  about  30 to 35
Ibs/curb-mile (8 to  10 g/curb-meter) is removed from the street surfaces,
with about 15 to 20  pounds (7 to 9 kg) of this material in particle  sizes
smaller than  125 microns.

     Table 9-4 shows the estimated washoff percentages for the  street surface
pollutants. For  all  sites, about 14 percent of the total solids would be

                                      140

-------
             FIGURE 9-5
PERCENT NflSHOFF BY PflRTICLE SIZE
                                  TOTRL
      Q-WET
SEflSON

-------
en
O
                        FIGURE  8-6

               HRSHOFF SIZE  DISTRIBUTION
40
3 35
6350
           -DRT
Q-WET SERSCN

-------
E



JD

h^



(J
u.
u_
o
                     FIGURE  9-7



         LHKE HILLS  STREET  DIRT WflSHOFF

            33-
125-
                   SERSON
250-
500-
1000-
2000-
>6350

-------
  Table 9-4. ESTIMATED WASHOEF OF STREET SURFACE POLLUTANTS (PERCENT)



Surrey Downs
108th Street
Westwood Homes Rd.
Lake Hills
148th Avenue, S.E.
Median
Particle
Size of Washoff
(Microns)
190
380
190
160
220

Total
Solids
16%
9
13
18
15


cnn
15
10
10
16
12


TKN
19
15
15
20
15


TP
16
7
13
19
15


Pb
22
18
20
25
21


Zn
21
11
16
23
n
Average:
230
14
13
17
14
                                          21
18

-------
 rc-oved lor the rair.d that we:  • observed during these  tests.  The  percentage
 it-  about the same,  or slif:hUy less, for COD and total  phosphorus,  while it
 is  slightly more for total Kjeldahl nitrogen and zinc.  The  washoff  percentage
 is  substantially greater for lead because of the greater abundance  of  lead in
 the snuller particle size ranges. The 108th Street area had much  smaller
 wasnoffs than any of the other sites, probably because  of  the greater
 abundance of larger sized particles on that street. Westwood  Homes  Road also
 had smaller washoffs, again because of the larger particle  sizes  found there.


 RUNOFF WATER QUALITY CONCENTRATIONS AND YIELDS DURING  PERIODS OF  DIFFERENT
 STREET CLEANING ACTIVITIES

      Figures B-24 through B-31  are simple plots relating observed storm
 runoff concentrations as a function of the total rain.  These  figures show
 this information for the two different study sites and  for  the wet  and dry
 seasons separately. The two symbols on the plots represent  periods  of  time
 when streets were not cleaned and when the screets were intensively cleaned.
 These are similar to the figures shown in Section 6, except that  these plots
 are separated by periods of different street cleanliness. Again,  the highest
 concentrations are  generally associated with rhe small  rain volumes. However,
 many more data points are available for the smaller rain events and if
 additional data were available  for the larger events,  then  a  greater spread
 in  data may have occurred.

Vv"1"'.-  The lowest concentrations  for any rain event are many  times  associated
 with periods of time when the streets were not being cleaned.  Increased
 concentrations during periods of intensive street cleaning  may be associated
 with loss of armoring.  Sutherland (1982) states that bed armoring occurs when
 large stable particles  rest upon and pin smaller unstable particles that
 would otherwise have been lifted and transported. Since the street  cleaner is
 removing or disturbing  a significant portion of these  larger  particles, the
 runoff is more efficient in removing the smaller particles  that remain. Other
 activities such as  wind, traffic, and local erosion may have  the  same  effect
 as  street cleaning, since they disturb the particle size distribution  and
 magnitude of the accumulation.  These other activities will  also have the
 tendency to increase cue effectiveness of runoff in removing  the  smaller
 particles ,'hs.t remain on the street or were added to the accumulation.

      Figures B-32 through B-35  show this same data, but transformed. The
 total solids and lead loads for each storm are plotted  against the  observed
 flows. These plots  have their scale on a log basis to more  evenly spread out
 the data. Again, the data is separated by season, study area,  and street
 cleanliness. The even distribution of the data for these plots indicate that
 regression analyses are possible. Figures 9-10 through  9-14 show  the results
 oi  these regression analyses. A 95 percent confidence  interval is shown
 representing "concentrations" for periods of street cleaning  and  periods of
 no  street cleaning. These confidence bands contain 95  percent of  the
 observations for each of these  cleaning situations. The total solids figures
 for Lake Hills and  Surrey Downs for the wet and dry seasons (the  Surrey Downs
 Hry season is missing due to very few data collected during that  period of
 time) show that the confidence  intervals for the two street cleaning


                                      153

-------
                    FIGURE 9-10


    TOTflL SOLIDS  -  Net  Season -  Lake Hills
  14
t 13-
O
-p
•
b 12-
o

1/1
_o

- 11-
U-
o
+ 10
c
in
a q
>— i j
_i
o
in
o
             8
g       ? a      11


FLOW (Ln of cubic feet)
12
13

-------
  14
                    FIGURE 9-1 1


    TOTflL SOLIDS  - Dry Season -Lake  Hills
o

w
X.
01

u
o

w
-O
12.
- 11.
14-

O
O

in
a
K-4

o
in
a
  8
              X. '
                  9        10      11


                  FLOW (Ln of cubic feet)
12
                                                  13

-------
  TOTRL  SOLIDS
  14
                  FIGURE 9-1 2A

                   Net Season
-  Surrey Downs
E
L
O
01
L
U
O
x.
in
-O
13.
12.
" 11.
O


-------
Is
01
u
u
-5 4
w
_O
^ 3
Q
CC
  0
                       FIGURE 9- 1 2B

          LERD  -  Net  Season  -  Lake  Hills
              8
         <~t^?i'
      , ^>-'
   0v5J-v-'x<-.>'-7
   *-Vป   ^^ * -^^ *- /
   '  /.'•'S'^
9       '10      ' 11

FLOW (Ln of cubic feet)
12
13

-------
u
VI

-Q
o 3
                    FIGURE  9- 1 3


        LEflD  - Dry Season  -  Lake  Hills
cr
LU
r
i
-t-
i-
                    9       10      11


                    FLOW (Ln of cubic feet)
                                      12
13

-------
E
01

U

-5 4
I/I
.0
o
ซ—I

C

d 2

a
cr
UJ
  0
                      FIGURE 9-14


        LEflD -  Wet  Season  - Surrey Doun
8
                     9       10       11


                     FLOW (Ln of cubic feet)
12
13

-------
•.i tu.it ions are not di K t ir.ct  :.   overlap  through mi ch of the aata ranges.
H.r.uros '-'-IJ .-i,-j 9-la ate  'or  lend  n.M  also ^-'-ow substantial ovprlap of  the
i-.'!'t iv-.i-ru o h,4i!ti~ t*->r clean a, i  dirty street conditions. There is a somewhat
.;:i,itoi Migration in the  confidence bands for lead than there is for  total
solids. However, they are  not  completely separated and significant
dittereiues tat the 95 percent  confidence level) cannot Vv  - .isidered  for  the
two different street cleaning  periods  c/er the complete range of flov
conditions. Hie estimated  confidence intervals that may correspond to
separ.'te confidence bands  for  thป  lead  analyses are at about the 60 percent
level,  which is very low.  During the Lake Hills wet season, the dirty  street
surface conditions sometimes  resulted  in a lower runoff yi.^ld for constant
flows than during clean  street  surface  conditions (possibly due to bed
armoring eftects discussed previously).  During the Lake Hills dry season and
during  the Surrey Downs  wet  season, however, the cleaned street surface
conditions resulted in typically lower  concentrations. Again, the confidence
level of these conclusions is  very  poor.
RELATIONSHIPS BETWEEN STREET  LOAD,  RUNOFF YIE1D, AND RUNOFF VOLUMES

     Preliminary analyses  of  the  Bellevue runoff yield and street surface
loading data were performed in  the  first annual report (Pitt, et al, 1981).
This early data analysis effort  included plotting the ratio of street surface
load to runoff yield as a  function  of  runoff volume. These early efforts were
successful as the regression  coefficients were quite high (approaching 0.95).
The ratios were high (several hundred)  for low runoff volumes (less than 0.1
inch, or 2.5 mm of runoff) and  then decreased rapidly wi;h increasing runoff
volumes. It was thought that  these  plots showed the sensitivity of  runoff
yields to street surface loadings.  During low runoff volumes, the amount of
material on the street before the rain  was many times greater than  the toe a1.
runoff yield observed. For large  runoff, however, ihe initial street surface
loading values were fairly close  to the total runoff yield for such
constituents as lead, zinc, and  COD,  but was much smaller than the  runoff
yield for nutrients. This  conclusion  made sense when recognizing the washjff
processes in an urban area. The  small  rain volumes are only capable of
removing the material from the  directly conn2cted impervious areas, as the
rain intensity is only large  enough to  dislodge the materials and flush them
along the street surface. As  the  rain  and runoff volumes increase,  all of the
street surface material may have  been  removed, but additional materials from
adjacent areas were washed onto  the streets and drainage systems through
erosion processes. During very  large  rains, the erosion materials would be
much greater than the quantity  of street surface loadings removed.

     Similar observations  relating  the  street load to runoff yield  ratio
versus runoff volume were obtained  previously in Castro Valley, California
(Pitt and Shawley, 1981).  In  Castro Valley, more constituents were  analyzed,
but for fewer rains (a total  of  about  25 complete data sets werป available).
In Castro Valley, the regression  coefficients were mostly 0.95 or greater,
showing very good agreement of  the  data with this conceptual model. In
addition, the relative placement  of the curves for the different constituents
also satisfied these washoff  hypoLtieses. As expected, lead itaintained the
highest ratio of initial street  surface loads to runoff yields over the


                                      163

-------
complete ratine of runoff volumes when  compared  to  the  other constituents.  In
other u.uds,  the load street  'oads were quite  important  when compared to the
lead runoff yields for most rains. Following lead  in  order of decreasing
sensitivity were total solids, arseriic, COD, total  phosphate, zinc, total
Ivjeldahl nitrogen, and orthophosphate. This order  is  probably a fairly
accurate order of the importance of street dirt  constituents to runoff
yields .

     upon reviewing this data analysis procedure,  it  was determined that
spur-'.ous self-correlations may be responsible  for  a large portion of these
high regression coeffirients. Spurious self-correlations may occur when the
dependent parameter contains  the independent parameter as part of its
definition. An example of this would  be relating a  parameter having very
la-:ge values  against these same values minus a  relatively small, but random,
variable value. If the large values were  in the  range  of 1,000 to 10,000, and
i. the other  parameter values were these  same  large v.ilues minus a smaller
independent value (say in the range of about 100),  then  the linear regression
coefficient between these two values would be very  high. Even if the large
and tne small parameters were completely  independent  and random, the
regression coefficient could be 0.9 or greater  (a very good straight line
fit) for this example. The dependent  j,=.rameter would  vary between 90 and 100
percent of the independent parameter. This same  problem  may occur through
other normalization procedures, such as multiplicatioi or division of the
independent parameter.

     The relationship between the street  surface load  and runoff yield ratio
versus runoff volume was thought to possibly be  seli-cormlated . The runoff
yield is the  concentration times the  runoff volume. Therefore, these
relationships are really street surface load divided  by  concentration times
runoff volume, while the independent variable was  runoff volume. In order to
determine the importance of self-correlation (because  the runoff volumes were
included as both the independent and as part of  the dependent variable)
various random number distributions were  used as raw  data testing these
different relationships. Random log-normal distributions representing the
typical range of street surface loading values for  total solids, runoff
concentrations and runoff volumes were selected  using  a  simple computer
program. These random distributions were  completely independent and
uncorrelated. The runoff yield for these  random  values was calculated by
multiplying the concentration times the volume times  the appropriate
conversion factor. The initial street surface  load  was multiplied by the
total number of curb-miles in the basin to obtain a dijiensionless ratio of
initial street surface load to runoff total solids  yield. This ratio was
plotted against the runoff volume, expressed in  inches.  Figure 9-15 shows
this random log-normal distribution. The  data  scatter  pattern is similar to
the forms obtained using the real data, but the  random data has much more
scatter. The upper boundary at the data plots generally  represents the shape
of the curve determined using real data.  The regression  coefficients using
these random values ranged from about 0.2 for  a  straight line to a high of
about 0.4 for a hyperbolic curve. Other curve  forms attempted had regression
coefficient values intermediate to these  two values.
                                     161

-------
                        FIGURE 9-15
e
JD
o
o
  Log-Normal  Random  Ratio  of  Loads
  150
14
13
12!
Ill
101
90.
80.
7CJ.
60.
50
40
30
20
10
0
 X
XX  X

  XX
  X
v *x
               x
               X
                     x
.05    .1     .15    .2     .25
           Runoff Volume/ Inches
                                          .3
                                                 Id
                                               s
                                              ,35
                                               .4

-------
     Figure 9-16 shows the ratio of the  log-normal  random initial street
surface leads to the random runoff concentrations  plotted cgainst ranaom
runoft flows. These value are not self-correlated  because the concentration
values were directly measured and are not highly correlated with the runoff
flows (as discussed'in Section 6). The largest  regression coefficient using
this type of procedure was about 0.18 for a  y-yperbolic  curve. All of the
other curve forms had extremely low regression  coefficients.

     The regression coefficients for these types of  data analyses can be
assumed to be the minimum values possible without  getting into significant
spurious seJf-correlation problems. If the regression  coefficients for the
real data were substantially greater than the regression coefficients for
these randotr number values, then the calculated values  using the real data
can be important. As noted earlier, the  regression  coefficients for the
preliminary Bellevue data analyses were  somewhat higher than these loฃ normal
random number values, while the values using  the Castro Valley data were much
larger than these values. Therefore, this analysis  procedure can be
important, but care must be taken in its use  and interpretation.

     Lake Hills dat? were used in these  analyses because the whole basin was
cleaned by the street cleaning equipment. In  Surrey  Downs,  only 3.5 miles
(5.6 km) of the 5.5 miles (8.8 km) of street  were  cleaned and, therefore,
street cleaning would have less potential beneficial effects on runoff water
quality. Figure 9-17 shows a plot relating the  ratio of initial total solids
street surface loads to the runoff yield versus the  runoff  volume. The
pattern of the data scatter shown is very similar  to the relationships found
in the preliminary analyses. The location of  the knee  of the curve indicates
the importance of street surface loadings to  runoff  yield and occurs at about
0.1 inch (2.5 mm) of runoff. If the knee of  the curve  is located at a high
runoff volume, the street loadings and street contaminant washoffs would be
more important over a wider range of rain and runoff conditions than for a
contaminant whose curve knee occurs s.t a lower  runoff  volume. There is quite
a bit of scatter beneath the upper boundary  of  the  data points, but the
scatter is much less than was shown on the random  data  plot of Figure 9-15.

     Figure 9-18 relates the ratio of the observed  total solids street
wa&hoff to the runoff yield  against the runoff volume. The pattern of the
data scatter is quite similar to Figure  9-17, with  the  knee of the turve
somewhat less than 0.1 inch (2.5 mm) of  runoff. Figure  9-19 relates the ratio
of street surface washoff of lead to runoff  yield  against the runoff volumes.
Figure 9-20 relates the ratio of total solids street load to runoff
concentration against the runoff volume. In  this case,  the  only relationship
observed is a constant value for the ratio of about  one to  twc Ibs/curb-mile
(0.3 to 0.6 g/curb-meter) per mg/1. This ratio  is  somewhat  constant over the
complete range of runoff volumes, but some very high values intermittently
occurred. This constant relationship was further investigated in Figure 9-21
which relates the initial ป-otal solids ."oad  on  the  street to the observed
runoff concentrations. No apparent relaiionship was  observed for this case.

     Figures B-36 through B-39 relate the ratio of  street surface washoff to
runoff yield values for total Kjeldahl nitrogen, COD,  phosphorus, and zinc
against the runoff volumes. The patterns of  all of  these scatterplots are

                                     163

-------
                    FIGURE 9-16



   Log-Normal  Random  Ratio of  Loads/Cone
o>
E
u
c
o
-o
o
o
7




6




5




4




3




2




1
         XX
          X

          X
-x  *



 X *o<*
          XX
            XX



           X X
      X*'
        X  X
                X  X

                 X X* X
                   x  x

                     X
           .05   .1     .15   .2     .25


                     Runoff Volume, Inches
                                    .3
                                      .35
.4

-------
                       FIGURE 9- 1 7
    TOTflL  SOLIDS  LORD/YIELD  FOR LRK.E  HILLS
   100


o

ฃ  90_
cr
a;
UJ
U-
o


o;
g 50.
o
UJ HU-
UJ
Qi


tn 30_

in
a
  80	
  70
60.
  20.
o
1/1
  o
          ฐ
          ฉ o
         .05   ' .1    .15   .2    .25   .3


                     RUNOFF VOLUME (Inches)
.35
.4
                                                       .45

-------
  25
  22
  20.
u_
u.
o
* 15.
o
in

-------
                  FIGURE 9-19
         LEflD  WflSHOFF/RUNOFF  YIELD
40
2 35
i—
en
CK
R 30
— i •*ป*
UJ
t—4
t 25~
o
xi 20
u.
o
ง 15

UJ
tn
ง 5
UJ
0


o


o



o
o
o
e 0
ฎ 0 ฐ
0 0 0
0 r> O O
0 e o
a
.M ซซr* ซ d r~ 'N i^ซ— *-V *^r- a
                                               .45
                  RUNOFF VOLUME (Inches)

-------
                        FIGURE 9-20
cr>

30
      TQTflL SOLIDS STREET LORD/RUNOFF  CONC RflTIO
      13 .	
    E

    I

    -O




    U
   LJ


   O

   U
u.
o
z
   a
   cr
   o
   UJ
   UJ
   Qi


   in


   in
   o
   in
   d
   i—
   o
7




6




5




4




3




2




1




0
      .4
                    0

                    o
               1.4    1.9    2.4    2.9


                 RUNOFF VOLUME (5+In Inches)
3.4
3.9
4.4

-------
                    FIGURE 9-i> 1
TOTflL  SOi_ID5 STREET  LORD VS  RUNOFF
450_
~ 40Q_
o>
~ 350_
LJ
ง 30Q_
u.
o 250_
* 20Q_
d
ป— i
^- ion_
o
h-
50
0
0 i



0
	 o
0
0
~ * 0 ฐ
ฉ 0
	 0 O
0
O
0
IK *— f* •ซ•ซ• • r- ** ^\/Mm ^* r— /ป *~\t*f* **ir— m i fป*m ป r- rm
                                              450   500
           INITlflL TOTRL SOLIDS STREET LORD Ob/curb-mlle)

-------
                  !  i ! •   ..--•.-:•! I at io-,  ' !  M 1 ( e t  •-•,,;; ,M e  wa-nhi-: 1  to ruiiot !
                  •- -i" • i  * . .   :  :' <•.ป, ii c>  •••:•', i ',','.,_;•. A,M i  t i •   ."  .<:;a i . sos  r>- ~ .11 i ->;
!-•' :  •'•    •   '  -•'!'  t     i; .    i a.4,-. t.:  runot,  o-ncent i  a t i i'ti  a,:ai:,>t In
t:.i^'...; • .'.  t I-.-!!  \':.l',-.-.  ..••[.  r..,do t-T  all  .-i vs t i L u--:i t s .  In  ail ~ases,  a
•'••.•r'. ;,  •••.i.-..-r  ii"r u-,.,  nh--iTvr.'. uiti'.  ;' i t 11.> r c i: t ap p r i- x i ~..i: c  ratios  for  each
•.>'••. t  i t  n,'-.t .  '. .M i i >, -,i . d i :-,  i.',  u s   ,(  ,st ' • et  load s ye r -i,?  rxin.,: 1
o'".i'"Li iti"1 -,  !AIU.\..T,  !-<•.--. • i- si.owed  a  signiti'-ant rel 11 iorT, h i -> fi.r  any  of
t. tv .-<>•!': ' 1 t lie'" >- .
n -:r ••Kl.siiNh  (r  ISV'HX:--)  RVr'OKr  (.VNa.MKATloNS V.- THK 1\!'  TLhT BASINS

     A    i'M  >,'. v,)--?,i.:o ^f  usir.i; tost  ina  control basins  is  Ll'e ability  to
c.-.'n(',:iri:  C ;u  n:-.o'l  ^n.iLity  tu.. i nv; d-ftiT(?nt  test conditions  in the difKrent
!>.;-i;is.  i-.t c1.'-'. V-- strc-'t  clt-.ining operations  were rotated,  so that street
cl.- i-iif.,•  oci'\irrtd  in hoth  Kisins during wet  and  dry seasons,  while the  otlr r
Ui>;l:i did  not  have  any street  cleaning. In  addition, about  two months during
b<>: '' tl.c  iirv  ,rid the wet  seasons did not  have anv strjet  cleaning in either
ba-^ir.. The period of time  with  no street  c leaning was used  to "ralibra'e"  the
txi>i.'.s.  Urban  runotf conditions at the  i.wo  -j t^s during  these r.o cleaning
[.ft'ii'ds  we^^  comp;;i ed  to  determine "natural"  dirlirences  and  variations.

     Table 9-5  idontil~-i.es  the  stunns for  the  period of  time  when street
cieaiinj;  was  not conducted  in  either bafin.  ,\lso shown  on this table are  the
rain totals  thit occurred  in each basin for  these calibration storms, al'ng
with the  ratio  3f rain totals  for the  two basins. Several  other rains also
occurred  during  this time  period that  were  completely Tnonitored, but the
ditrereuces  in  rain volumes  at  the two  sites  were very  large. This was  quite
cr.-r.ion with  tht  smallest  rain  events as described p-eviously  in Section A.
".'hose st ir-is  ซri^h quite  different rain  volumes for the  same  rt.in period were
eliminated trom  tliese  analyses. This table  shows that 20  storms were
completely nonitored during  periods of  no street cleanini;  in  either basin.
The average  rain in prt'i  basins ^7as about 0.45 inch (11 min) ,  or about twice
the volune of  the -tverajTe  rains during  the  complete study  period. The range
of rains  during  this calibration period were  from about 0.04  inch (1 mn)  to a
Kifb, of  about  1.25  i-.ches  (32 mm). These  calibration rains,  however, were
weighed  more  towards th^  larger rain events  than the typical  distribution  of
rai-is. The srr.,-.ller  rai:i  events  experienced  much  greater variations in
observed  rainfall and  runoff volumes and  more of the smaller  events were
eliminated from  the analyses.

     Table 9-b  summarizes  the  ttorm information  during  periods when intensive
street cleaning  was conducted  in Lake  Hills,  while no street  cleaning
occurred  in  Surrey  Downs.  The  27 monitored  storms were  divided about evenly
between  the  wet  and dry  seasons. Again, the  average rain  volume during  this
period was quite a  bit larger  than the  average rain volume  over the complete
period of  testing.  Table 9-7 is a similar listing, showing  rain data when
intensive  street cleaning  was  con-ducted in  Surrey Downs,  but  no r.treet
cleaning  was  conducted in  Lake  Hills.  Almost  all of these  storms occurred
during the  vet  season  because  of early  sampling  equipment  problems in Surrey
bowns as  described  in  Sections  5 and 6.
                                       \ 70

-------
        TiMe 9.5. COMPLETE STORM DATA DURING PERIODS Of NO STREET
               CLEANING  IN  EITHER BASIN  (CALIBRATION DATA)
Storm
n.ite
7/11/80
7/U
3/J6
8/27
9/1
9/6
9/12
9/13
11/23
12/14
12/20
12/24
12/24
12/26
12/29
7/6/81
7/13
1/10/82
1/15
1/17




Season
dry
dry
dry
dry
dry
dry
dry
dry
wet
wet
wet
wet
wet
wet
wet
dry
dry
wet
wet
wet




Storm
N'jThor
21
22
25
26/26+27(1)
28+29/28
30
31
32
51
55
56
58
59
61
62
114
116
156
158
159
average:
minimum:
maximum:
N = 20
Lake Mills
Piin
(in)
0.28
0.15
0.04
0.43
0.52
0.23
0.12
0.16
0.83
0.17
0.43
0.26
0.44
0.32
1.11
0.64
1.25
0.35
0.98
0.18
0.45
0.04
1.25

Surrey Downs
Rain
(in)
0.22
0.15
0.08
0.55
0.50
0.27
0.08
0.14
0.86
0.11
0.43
0.26
0.51
0.34
1.14
0.53
1.17
t0.30
1.10
0.16
0.45
0.08
1.17

Rain Ratio
(LH/SD)
1.27
1.00
0.50
0.78
1.04
0.85
1.50
1.14
0.97
1.55
1.00
1.00
0.86
0.94
0.97
1.21
1.07
1.17
0.89
1.13
1.04
0.50
1.55

LH/SO  storm  numbers,  if  different
                                 171

-------
                    e  9-6.  O'"1ETE  Sinc-M  PATA  H'lRIN"  FJRHDS  OF
                       STREET  CLEANING  IN  LAKE  HILLS ONLY
Lake Hills
5 to nr
Pit?
9/20/SO
10/3
10/1'
.0,24
10/3!
11/1
11/3
11/8
11/14
11/19
11/20
1/17/31
1/28
2/11
2/13
3/24
3/28
4/5
4/5
4/7
4/10
4/12
4/27
5/24
6/12
6/12
6/30




Season

dry
wet
wet
wet
wet
wet
wet
wet
wet
wet
wet
wet
wet
wet

-------
Table 9-7.  COMPLETE STORM DATA DURING PERIODS OF
      S"IRECT CLEANING IN SURREY DOWNS ONLY
Storm
Date
4/18/80
10/8/81
10/28
10/30
11/11
11/13
11/30
l?/3
12/4
12/9
12/13
12/14
12/17
12/18
12/23




Season
dry
wet
wet
wet
wet
wet
wet
wet
wet
wet
wet
wet
wet
wet
wet




Storm
Number
8
127
129
131
132
133
137
140
141
148
149
150
151
152
154
average:
minimum:
maximum:
N = 15
Lake Hills
Pain
(in)
1.33
0.27
0.20
0.07
1.58
0.14
0.12
0.16
1.43
0.84
0.30
0.96
0.21
0.69
0.26
0.57
0.07
1.58

Surrey Downs
Rain
(in)
1.18
0.24
0.17
0.09
1.50
0.11
0.14
0.19
1.27
0.78
0.35
0.87
0.?9
0.79
0.27
C.35
0.09
1,50

P, a i n o -i •: i o
(LM/'^i
1.23
1.13
1.18
0.73
1.05
1-27
0.86
j.84
1.13
1.08
0.83
1.10
0.72
0.87
0.96
1.00
0.72
1 27


-------
     Ki>,m~ป-s r>-* '  ll-ri'n.-'i H-M i ,11 r s.-.'.ttri  p,uts  ^h iwing tot;,!  mi! id.;  yields
.u':,i  i ":iv i-r.t r it inn  il: I ! (''. f \ i i i> s in i..ikf Kills  ,iiid  SutTi'v ',Xiv.--  fii-  b" t h  the dry
.<-.!  '-'• i  '-t'.i.- iir1- .  l>>n ii'.r.  the   !ry  se.ison,  i.nlv the  calibration  d.-itn  and  the
d.it.j vhi-n iiili':";tve  rli'.iniiv. t,rcur'--d in  1. ike Hills arc sh.'wn.  There  < t> a
i.i:,c ,i;r.>'ur,!  t>l  s.,ittri  and  statistical  11 s I s did not sh iw  s i ,;n i f It an t
<.!; i 1 t'Veiici-s  in  i.-.-, 1 i bi a t i on  conditions tor dry and wet S
-------
                      FIGURE 9-22
   TOTflL  SOLIDS  CONCENTRflTION  COMPRRISION5
   35C
in


2 30C
t—
cr
UJ
LJ
z
o
LJ

cn
a
o
1/1
(X
f—
o
in

3
o
a
UJ
a;
in
25C
200_
   15C
IOC
50.
  0
                       CLEANING IN LAKE HILLS ONLY-
                                         CALIBRATION  (NO

                                           CLEANING)
                   '"' CLEANING IN SURREY DOWNS ONLY
                          I
           25   50   75    100    125   150   175   200


                  LflKE HILLS TOTRL 50LID5 CONCENTRHTIONS
                                                 225
250

-------
                         FIGURE  8-23
          TKN  CONCENTRnTION  COMPRRISIGNS
   4.5
   3.32_
10
o
   O 1C
z  2.25 _
o
LJ
   1.Ba-
z
i  i..
>-
LU
in
                                     ti (f.'o cLF.Ar;rr;c>—^^'  ,
                                                      I--'
                                         ..^^•"'IN LAKI;
                        .--•*••
                 CLEANING IN SURREY DOWNS ONLY
             44    .88    1.33    1.77   2.22   2.66   3.11   3.55   4
                    LflKE HILLS TKN CONCENTRfiTIQNS (mg/1)

-------
   150
   140.
~  130_I_
2  12C
   100	
   90.
o  7Q
LJ  ' u— •
a
o
in
o
a
SO-
SO.
40.
30.
20.
10.
0
                         FIGURE 9-24
           COD  CONCENTRflTION  COMPHRI5ION5
                     CALIBRATION (NO CLEANING)-^/'
     *'•'''    ^<--'"^
xf S*     ^.f/-'*'" CLEAN ING IN LAKE HILLS ONLY
^ I    ^-/*'""
                  ^i^ป''xf-/C CLEANING IN SURREY OOWNS ONLY
            10   20   30    40   50   63    70   80   90   100   110  120
                     LflKE HILLS COD CONCENTRATIONS (mg/1)

-------
                      FIGURE 9-25
in
z
o
CE
cc:
UJ
LJ
in
r:
o
in
ui
o
Q_


in
o
a
LU
LH
    PHOSPHORUS  CONCENTRRTION  COMPRRISION5
  1.2
CALIBRATION (NO  /\


  CLEANING) _  /
              ..''CLEANING IN LAKE HILLS ON_LY->-'
            ..
               CLEANING IN SURREY DOWNS ONLY
               2   .3   .4   .5   .6   .7   .8   .9   1


               LflKE HILLS PHOSPHORUS CONCENTRflTIONS (mg/1)
                                    1.1  1.2

-------
              FIGURE 9-26
  LEflD CONCENTRRTION COMPfiRISIONS
.55
.5
^ .45_
in 4
-jr . H 	
o
I-H
t— qq
(X • •J-J—
ft:
t—
Z q
ULJ • *3 	
LJ
Z
S ,25_
a
ac
|j-i 2
	 i
1/1
I -15-
0
a
. .1
>— • •*
LU
a:
ง .05_
vn
0



CALIBRATION (NO CLEANING)-. ^-x
— • x '
^ , -
^^ .--''
	 ^X ,.-''
- "^ „ *
x x ,-"'

• s •' ^ C~
•** .'" ^ ^"
x- "" .-•'' - " **
— CLEANING IN SURREY ,"^.--'' _.''"' __..--
DOWNS ONLY ( +• ) ^ •''].•-"" ^ - "* " _..- 	 \
. f •* f-' ^ -.-*"
* _,-* f.-' *""..--•'' CLEANING IN LAKE
^-.r-'"*' „•*".*'•"'"" HILLS ONLY
	 ,-<-'"'' t '-•"''
-*'** f^*
. .•i*-*1 ***
i^ * -->->
T * -•**'

1 f + * **
	 ! ^* - *^ x
* * _
, ^
ซ• ^ปซ— * ซ r™ ^\ ^^ -^ *-kf~ j j i— r—
0
1
  LRKE HILLS LERD CONCENTRRTIONS (mg/l)
.55

-------
oo
o
                              FIGURE  9-27


              ZINC  CONCENTRRTION  COMPRRISION5
        .35
      ^  .3-
      en
      E
      ง •*
        .2.
LJ


O



LJ
-z.
>—t

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        .1.
      o
      a
      UJ
      a;
      a:
                            CALIBRATION  (t;o cLI:A:;i:.c)•
                                    . -J '
                                     'CLEANING IN LAKE HTLL:;
           r
           k-
            •CLEANING

          IN SURREY DOWNS ONLY
       0    .025  .05  .075  .1   .125  .15  .175  .2   .225 .25   .275

                   LflKE HILLS ZINC CONCENTRflTIONS (mg/1)
                                                                  .3

-------
   7.4



   7.2.



   7 _



   6. a.



   6.5_


   C A
   6. 4_
                             FIGURE  9-28


                       PH  COMPflRISIONS
o
UJ


1
01
           CLEANING IN  SURREY  DOWNS ONL
                                              s-
CALIBRATION  (NO CLEANING)
                      __-'".7-"CLEANn;G IN LAKE HILLS ONLY^.
     ป•*--•"
   5.8.


   5.&_


   5.4^


   5.2
 I--'
       5.3     5.5    5.7    5.9    6.1   '6.3     6.5    6.7     6.9    7.1


                                   HILLS PH

-------
CD
ro
                            FIGURE 9-29
            SPECIFIC  CONDUCTRNCE  COMPRRI5IGNS
       120
E  . , p
U  1 1C
W
_g  IOC
E
     a
g 80.
     LJ
       70
S 60.
LJ
ฃ 50.
I	C
LJ
ฃ 40.
LO
ฃ 30.
o
     UJ
     in
       1CL
                    CALIBRATION f.o C'l.i'.AN I :.<;)
                                             X
                                               X
                                                        xl
                                                  X
                                                    X
                        r
                     -T- I  .--r.
                       .-1 •
                         v-
            10     20    ' 30    40     50    60    70
                 LflKE HILLS SPECIFIC CONDUCTRNCE ;umhos/cm)
                                                         80
90

-------
oo

CO
      6G.
en
Q
>-
t—
i—i
a

CD
oi

t—
    ฃ 30.
    ac
    o
    Q


    u] 20.
    a;
    a:

    in
                            FIGURE 9-30


                    TURBIDITY  COMPRRISION5
        CLEANING IN SURREY


           DOWNS ONLY
                            ^CLEANING IN LAKE HILLS < )'.'.l.'i
      0  I	


          0
            10    ' 20    30    40     50    60


                       LfKE HILLS TURBIDITY (NTU;
70
80
                                                            i

-------
stoini u.'sh.-!t  Ivr.iiis,
                                     i- 1 ea n i in: ec; u 1 (n.en t  . an remove a  t a i r 1 y
                                     si.il.u->- p,i r t ic u i a t fs ,  but they a r ••  n;it  the
                                      stores urder the  conditions observed  in
                                     er  p,i r t Icu i a t es  hy  street (leaning  nay
                                          of tlic inss  of  tbi-- arjrnriiiH ctfccts.
                                           and den.--id  tipu;-,  specific r.ilntall
i-i-no i t ; .'-is  U's j't-i i ,i I 1 v iiUon-j i l i vs ,  intert",ent fimes,  and total r.iinlail
.j-.iriii I i t i .'- )  ,iiul  Nlret't. surface  conn i t :' ons (especially  Ct-xtur-.' and state  of
repair).  In  t'.istro Valley, California  (Pitt and Sluwlev,  19^1), the quite
oiilerei.t  raintall and street  surface  conditions permitted street cleaning  to
i ropr. ive rvirol t  water  qviality  bv  a  maximum of about  J 3  to  4t) percent tor  lead,
total   '•.!)! ids,  and  CnL). hven under  those more appropriate  conditions ior
street cle.ming,  street cleaning  had  very little effect  in controlling
nutrient  runott  concentrations  and  vields.

     One  of  the  ,uiin  reasons  Bellevue  was selected  as  a  test site by  the
htivi roiiment al  Protection Agency,  was  because of its  significantly different
rain conditions  wh_>n  compared  to  other street cleaning  test cities. The  larga
nuaber of  rain  events occurring  evenly throughout  the  year (with each  having
small  rain  volumes and intensities)  and the smooth  street surfaces  resulted
in  the frequent  rains being capable  of maintaining  the  street sarface
loadings  at  low levels, especially  for the smaller  particle sizes.  Intensive
street cleaning  operations did  significantly decrease  the street surface
loading conditions, but only  for  the  larger particle  sizes. The benefits  of
street cleaning  in controlling  nuisance and safety  related street surface
particulates are  described in  the  following Section  10.
                                       184

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                                  'SECTION  10
                          STREET CLEANER  PERFORMANCE
     The design of an effective street  cleaning  program requires not only a
determination of accumulation rates  but  also  an  assessment of the specific
street cleaning equipment performance for  the actual  conditions encountered.
Service goals which consider efrects on  water quality,  air quality, public
safety, esthetics, and public relations  are  the  driving forces in
establishing a street cleaning program.  The  major  objective addressed in this
section of the report is to determine the  effectiveness of street cleaning
equipment in reducing street particulate  loadings.  The  previous Section 9
addressed the effects that reducing  the  street loads  have on improving runoff
water quality. It was seen that the  measured  runoff yields during periods of
intensive street cleaning did not differ  significantly  from the runoff yields
that were measured during periods of no  street cleaning. However, Section 6
earlier had shown that jtreet surface runoff  contributes significantly to
runoff yields for several pollutants. It  was  also  shown in Section 9 that
rain is most effective in removing  the  smallest  street  particulates. This
section wl''  Discuss the effectiveness  of  street cleaning equipment in
removing particulates of different  sizes.  It  will  be  shown that conventional
street cleaning equipment is most effective  in removing the largest particle
sizes: those that are not effectively removed by rains  during storms. A
series of special tests were also conducted  and  described using a modified
regenerative air street cleaner that shows promise  in effectively removing
the smaller particle sizes. This section,  therefore,  describes the results of
the full-scale street cleaning tests that  were conducted during the runoff
monitoring activities, the special  tests  using the  modified street cleaner,
special tests conducted to examine  street  cleaning  effectiveness in other
Bellevue areas, and tests conducted  to  examine the  redistribution of street
dirt during street cleaning. The effects  of  street  cleaning on reducing
runoff pollutants are also estimated, based  on typical  street dirt loading
values observed for the different street  cleaning  programs and tne washoff
potentials for the different particle sizes.  Finally, the  Bellevue street
cleaning program, equipment operating characteristics,  and costs are
presented.

     Street cleaning performance depends  on  many conditions, including the
character of the street surface (texture,  condition,  and type), street oirt
characteristics (loadings and particle  sizes), and  other environmental
factors. Street cleaning variables  that  most affect cleaning performance
include the cleaning frequency and  equipment adjustments. The most important
measure of street cleaning effectiveness  is  "pounds per curb—mile" for a
specific program condition. This removal value,  in conjunction with  the unit
curb-mile costs, allows the cost for removing a pound of pollutant for a

                                     185

-------
-' ' • i '- i *' s i i ri t  '• I •  .1111 :':',.  pt ogr.un to be Crt 1 ( n 1.1t re1 .  The  ' pe rcent  of  the ht' f ore
'"•i'!i">'  i fii.iv.'d '   is  COL. 'only used,  hut ran be mi s ] eau i ng .  The  pe rcenlige
tn-Mved  is I-.'t ;i  irk'.isiire  ol  the iTur.n i t ude of material removed.  A  street
' 'li'.ni ..r, pr.n'i.mi  T"*IY  li.ive  a  ve r >' low pv rcen t ane removal ,  but  a  large  amount
01  loiter i a l  n,iv tx'  removed  it  the initial loading is  lar>-e.  The  percentage
renov.il  v.ilue^ can  tx>  useful when normalized values are  needed,  such  as when
con.r.u i >n; two ditterent  programs under similar loading  conditions.
Sll
-------
                               Table  10-1.  FULL-SCALE  STREET  CLEANINR TEST SCHEDULE
00
—I
                Season
Month
          Cleaning dates for:(l)
Surrey Downs                 Lake Hills
dry
dry
dry
dry
dry
dry
wet
wet
wet
wet
wet
dry
dry
dry
dry
dry
dry
dry
wet
wet
wet
April, 1980
Hay
..une
July
August
September
October
No /ember
December
. January, 1981
February
Mar:h
Apr' 1
May
June
July
Augu/it
September
October
November
December
2,7,11,16,18,21,23,25,30
5,7,9,12,14,16,19,30
4,11,13,15,18,20,30
2,7,9
none
none
none
none
none
none
none
none
none
none
none
none
none
29,30
2,12,16,20,21
2,5,16,24
7,11,14,16,21,23
none
none
nonp
none
none
15,17,22,24,25,29
1,3,6,10,13,17,22,27,29
5,10,12, 17, 19, 24, ?6
15
5,9,12,19,21,30
2,4,13,17,20,23
2, 4, 6, 9, 11, 13, 16, 20,24,25, 27
2,3,6,8,10,13,15,17,21,23,24,29
1,4,6,8,12,13,15,21,22
1,5,11,17,23,24,26,29
1
none
none
none
none
none
                        approximately three times a week street cleaning, except for holidays
                        and dc'ys of rain

-------
i'i IH'Ctrd iln i ing  tin.'  project.

     Figure 1U-1  js .in  example  ot  this data p,'o':tec for a hS-day  period  for
l-iu rey iiovii:. 1 rcim August  ,:4  to  October 28,  19H1. At the beginning of  this
period, Surrey  Downs  was  not  bein^  cleaned. Street clearing startco  on
ieptcnuier J^th. The street  cleaning days are shown oil the plot,  along with
the  rain periods. The street  loadiigs  ranged from about 300 to 5(M)
I bs/ cur h—mi Le I,b3 to  14U  g/curb-meter) ;with ar extreme value of  about 900
Ibs/curb-mile ,  or 2u'i g/curb-meter) during  the period of no street clearing.
The  loading:; reduced  ti; values  from about 150 to 250 Ibs/curb-mile (40 to 70
g/curb-meter) shortly af;er  the start  of street cleaning. Median  particle
sizes are shown on  this figure  and  are also seen to decrease with the start
of cleaning. The  significant  effects that rains had on the street dirt
loadings and particle sizes  is  evident.  The r&in periods shown all reduced
the  street loadings appreciably (except  for the largest rain observed dviring
the  study which occurred  during this period) and increased the median
paTticle size values. This  indicates that the rains washed off the fine
material more efficiently than  the  larger material, (as discussed  in  Section
9).  The largest riin  had  little effect on the net loading change, probably
because of substantial  arosion  material  carried to the street during  this
major storm.

     This figure  indicates  that the street  loadings responded rapidly to
street cleaning.  The  loading  data  collected can therefore be considered
responsive to the street  cleaning  conditions, with little lag time between
changes in the  street cleaning  program.  Changes from periods of  strtet
cleaning to no  street cleaning  were not  as  rapid. However, the street
cleaning accumulation rates,  as described in Section 7, were shown to be
largely controlled  by the frequent  rains during periods of no street
cleaning. Therefore,  loading  values are  expected to be stabilized t?fter about
three street cleanirgs  or rains.
PERFORMANCE TESTS

     Several types of  street  cleaning performance tests were conducted during
this project. The large  scale  tests  described above required the most effort
and resulted in the most  data.  Selected tests were also conducted at a
variety of other land-use  sites  in Bellevue to check the transferability of
the full-scale test results.  Two tests were also conducted to measure th3
redistribution of street  dirt  across  the road caused by street cleaning. An
intensive series of tests  were  also  conducted to examine the effectiveness of
a modified regenerative  air  street cleaner. These test results are presented
and discussed in the following  subsections.
Full-Scale Tests
     The street loading  data  presented in Appendix B contains the  total
solids initial and residual loading values and median particle sices  for  the
full-scale tests. Complete data  lists  for all particle sizes are too  bulky  to
present in this report,  but are  contained in the STORET data base  operated  by

                                     188

-------
                          FIGURE  1 0- 1
    C

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    c
    4>
    o
Surrey  DONHS  Street  Loads  (8/24-10/28/81)
10GOr
   0
10
15
20
30


90Q_

80Q_

70Q_


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45
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                 Day Number (from Rugus* 24 to October 28, 1981)

-------
         L.tke llill.  Vl'i'K'.T  statiปn  number is Mi.Kiij-j,],()S^2 and  tht station
         r Siirri'v !\ u'M'  I'i  JO ^HKL.L.l'iH i.  Those are special Ni'K!' STnRKT  files
         ront.iin street  iirt  loading  information. The S'ปnKKT data  can  be  urfcd
in run i unel ion wi t'i the  .iata  presented  in Appendix B tor a complete
ik-so r i pt ion oi the  street  loading  history at the two main Bellevue street
clean i!'.;; tisL sites.

     The most useful way  to  present  street clsaning effectiveness  data  is  on
.1 graph relating residual  loadings  to  initial loadings. Such figures are
shown  as Figures 1U-2  and  iO-3  for  total solids and median particle size.
Appendix C contains figures  for particle sizes  ranging from greater than  6370
microns (about 1/4  Jnch)  to  less  than  63 microns (Figures C-l to C-8).  The
relatively large number  of  street  cleaning tests (121) enabled the
effectiveness relationships  to  be  described in  detail. It was found that  both
Lake Hills and Surrey  Downs  data  could  be combined for statistical analyses.
The Surrey Downs data  represented  loadings over a wider range of initial
loading conditions  (from  about  80  to  700 Ibs/curb-mile, or 23 to 200
g/curb-meter) than  the Lake  Hills  data  (from about 90 to 390 Ibs/curb-mile,
or 25  to 110 g/curb-ineter) .  The lower  Surrey Downs data is shown to overlay
the Lake Hills data on these  figures.

     In earlier  studies  (Pitt,  1979,  and Pitt and Shawley, 1981),  the  fewer
data available indicated  "straight-line" relationships between the initial
and residual loads, with  "negative"  removals associated with the lowest
loadings. The greater  number  of data  available  during this project, however,
has refined this model.  The  effectiveness figures presented in this section
and in Appendix  C indicate  no  effective  removal by street cleaning until  a
minimum initial  loading  value  is  obtained. Above this minimum value, street
cleaning can be  quite  effective.  The  scattered  data before this minimum value
is obtained include many  cases  whera  the residual loadings were greater than
the initial leadings.  These  negative  removal values may be associated with
street wear (as  was noted  in  Pitt's  1979 San Jose study, especially for
multiple street  cleaning  passes every  day on streets in poor condition).  This
data scatter may also  be  due  to sampling error, as the street dirt sampling
procedures were  designed  to  result  in  errors of about 25 percent.

     The minimum value before  street  cleaning is eff^'ive varies  for  each
particle size, street  surface  texture  and condition, and equipment operating
characteristic.  Table  10-2  summarizes  these minimum values for the Surrey
Downs, Lake Hills,  and S.E. 30th  study  areas. Also shown are the maximum
values under which  the loadings are  usually maintained for these street
cleaning operations. It  can  be  seen  how  referring to percent removals  can  be
misleading. For  Lhe same  aree,  cleaning  frequency, and equipment type,  the
percent removal  varies from nothing  until the minimum value is obtained,  then
slowly increases to values  approaching  about 30 percent for total  solids.  In
sone cases, the  maximum  percent removal  values  may be as large as  80 percent.
If the street loading  values  must  be maintained below a certain maximum
loading value, then each  cleaning  event  required would have very low percent
remo\al values.

     These figures  show how ineffective  typical mechanical street  cleaning
can be for removing small  particle  sizes. For the conditions observed,  there


                                     190

-------
                        FIGURE 10-2
   Street  Cleaner Performance:  Total  Sol ids
   800
DC
      0      100    200
     e  SURREY DOWNS(Mobil)
     A  LAKE HILLS (Mobil)
     T: Tymco (SURREY  DOVvNS)
     M: Modified Tymco (SURREY DOWNS)
   300     400    500
Inlilol Lood  (lb/curb-ir.lle)
600
vca
80u

-------
                   FIGURE 1 0-3
Street Cleaner  Performan
1000
ce:  Part i c)e  5 ize
 0     100  ' 200

o SURREY DOWNS

A LAKE HILLS
                 300   400   500  603

                    Inlilol Size  (microns)
    70G
eca
9GO
JGOC

-------
TA8LE 10-2.  TYPICAL MINIMUM LOADS FOR EFFECTIVE CLEANING
   AND MAXIMUM LOADS  AFTER CLEANING  (I BS/CURB-MILE).
Si^e (n.icrunr.)
SO and LH :
TS
>6350
2000 - 6350
1000 - 2000
500 - 1000
250 - 500
125 - 250
63 - 125
<63
<37
< 2
SE-30th
TS
>6350
2000 - 6350
1000 - 2000
500 - 1000
250 - 500
125 - 250
63 - 125
<63
<37
<2
MOBIL
Minimum Maximum
initial exnected
load before residual
removal load
350
5
15
25
60
70
/O
--
--
__
--

insufficient









450
15
30
50
80 +
90 +
90 +
--
—
--
--

data









TYMCO
Minimum
load
before
removal
100
--
3
5
10
10
10
10
20
5
0.1

200
5
20
50
50
50
25
15
25
20
0.2
Maximum
expected
residual
load
300
3
10
20
50
60
50
30
40
__.


500
10
40
__
_ —
— _
200
— —
60
__
                       193

-------
v>'.ts no ( Itcr'ivi. i i-muv.i 1 ot  particles  smal'er than about 125 microns. Vcrv
,-uhs (. .r.it i .11  r"\nov,tls were  u,! isured  tor larj'.f  panicles, however. Figure  l'i-3
inj i r,i L rb  the dr,ir,,,itic  decr>,is"  in  median particle size as the street
cleaners  pre 1 e ren t i al ly  removed,  the Larger particles.
Street Cleaning Effectiveness  at  Other Bellevue Locations

     During the second  year  of the  project (April and May, 1981), street
cleaning tests were  conducted  at  eight other land-use sites in Bellevue. The
l.ind-uses included downtown  Bellevue,  shopping centers, high density
residential areas, low  density residential areas, and industrial areas. Table
C-l shows these data  for  all  particle  sizes. Unfortunately, only one or two
tests were conducted  at each  site,  so  individual analyses of the land-uses
were not possible. Figure  10-4 is a plot of the initial versus residual
values for all of  this  data  combined.  These data appear to fall on  the  total
solids curve presented  earlier (as  Figure 10-2) for the large-scale tests.
The S.L. 3uth and  2nd Avenue  industrial sites had much greater initial  loads
than elsewhere, but  the street cleaners -'-re quite effective in substantially
reducing the loadings.  The minimum  initial loadings before effective removal
was about JOO to 40U  Ibs/curb-mile  (85 tp 11U g/curb-meter), quite  similar to
the values shown in  Table  10-2 for  the Surrey Downs and Lake Hills  sites.

     Figure 10-5 shows  the strong relationship between percent removals and
initial loadings.  The clean  streets had very low removal percentages, while
the very dirty streets  had high removal percentages, even though the Figure
iO-4 data seem to  fit the  general model. Such different percentage  removal
values imply different  removal models.
Redistribution of Street  Dirt  Across the Street During Street Cleaning

     Two special  tests  were  conducted in and near the Surrey Downs test area
to examine the loading  gradient across the streets, before and after street
cleaning. This data,  for  all particle sizes, is shown ฑr Appeneix Table C-2.
Figures 10-6 and  10-7 show the total solids unit area loading data plotted.
The unit area loadings  in the  ten inches (254 mm) next to the curb were
reduced substantially in  both  tests. The other street segments experienced
variable loading  changes.  These changes indicate substantial movement of  the
near curb dust and dirt away from the curb by the gutter brooms. The main
pick-up brooms were  not able to remove all of this moved material. These
results are similar  to  tests conducted on a variety of different street
cleaners in the past  (Sartor and Boyd, 1972, and Pitt, 1979).
Effectiveness of Modified  Street  Cleaners

     A series of special  tests  were conducted during September and October,
1982, to compare the  effectiveness  of a modified street cleaner  to standard
street cleaners. Air  Pollution  Technology, Inc. (APT), of San Diego,
California, designed  and  installed  many modifications to a standard
regenerative air street cleaner while under contract to EPA (William

                                      194

-------
 FIGURE  10-4
 Cleaning  Productivity  for
4500

                    isc.   5 : te
                                :D

 1500   2000   2500  3000
I nit to) Load (1b/curb-mMe)
                                         3500   4003   4500
          + 2nd Ave.
          x 120th
          •KELSEY ST.  PARKWAY
          • Hath
           * S. K. 30th
           * DELLEVUE WAY

-------
                     FIGURE 10-5
  %  Removal  vs.   Initial  Load  (misc.  sites
  80
  63.
5 40.
o
E
0)
a:
3 20.
L
OJ
  -20
500   1000   1500   2000  2500   3000


          Inltlol Load  (1b/curb-mI 1e)
3500
                                                4000

-------
   36
   30.
Q)

01
  24
o ^ -
3
cr
w
-O



X
o
0
   18.
S  12.
  6
  0
                        FIGURE 10-6


          Redistribution of Street Dirt
            Removal
                       OVL'.KALL: -70-'. { i ncr o a •;< •<} load)
            •RESIDUAL LOAD
            •INITIAL LOAD
              -53%
                      -21%
                                1
                           6         ' 9


                       Distance from Curb (ft.)


                      115  110th Ave. S.E. Site
                                               12
15

-------
01

c
o
o
                       FIGURE  10-7


          Redistribution  of  Street  Dirt
      7 4'4 Removal
          INITIAL LOAD
        -12%
              151
        RESIDUAL LOAD
                          OVL'P.ALL: 2 (U ( doc r-a r;oa loom
                        -7%
                                         110-
                          6        ' 9

                       Distance from Curb  (ft.)

                      405  110th Ave. S. K. Site
                                              12
15

-------
Kuykendal, Project OiUcer, Research Triangle Park,  North Carolina). The
purpose ot the modifications was to reduce  respirable  fugitive dust emissions
during street cleaning activities. Thฐ modifications  included partial hoods
around the gutter brooms, a pressure controller  to  better regulate the air
flows, and a venturi scrubber with a settling chamber  in the street cleaner
hopper. The water spray bar was also disconnec'ed.  These modifications were
described in the first phase report prepared by  APT  for  EPA (EPA Contract No.
68-02-31*8). APT was awarded a second contract phase  to  refine the
modifications and conduct extensive field trials  of  street cleaner
effectiveness. An arrangement was made to test the  modified street cleaner in
Bellevue, in order to take advantage of the preexisting  information relating
street cleaning and rurc.M" water quality. The modified street cleaner was
compared both to a standard broom street cleaner  that  was used during the
previous Bellevue tests, and to itself, with the  modifications disconnected.
The purpose of these special Bellevue tests was  to  estimate any effect the
modifications may have on improving urban runoff  water quality. APT has
conducted additional tests in San Diego to  study  air  quality effects during
street cleaning.

     Surrey Downs and S.E. 30th Avenue (an  industrial  street Chat was
previously determined to be one of the dirtiest  streets  in Bellevue) were
used for most of the tests. Each area was divided into six subsampling
sections. The three equipment types were rotated  through these sub-areas at
various cleaning frequencies. This allowed  the street  loadings to vary over a
relatively wide range of values for each equipment  type. Table C-3 shows the
results of these tests for all particle sizes. Four  or five cleaning tests
were conducted for each equipment type. In  addition,  several test
measurements were made separating the cleaning width  loadings from the full
street width loadings. Figures 10-8 and 10-9 are  the  usual initial load
versus residual load effectiveness diagrams for  Surrey Downs and S.E. 30th,
respectively. Appendix Figures C-9 through  C-30  show  the effectiveness
relationships for each particle size. These figures  represent full street
width loadings, and are therefore comparable with the  earlier full-scale test
figures. The broom cleaner results are very similar  to the previously
reported results, but the regenerative air  cleaner  (modified and not
modified) shows substantially better performance. This is especially true
when the finer particle sizes are considered. The broom  cleaner shows very
little removal (the loadings are too low) for particle sizes less than 1000
microns. The regenerative air cleaners appear much  more  suited for these
lower loadings for the smaller particle sizes. The  data  for the smallest
particle sizes (less than 125 microns) are  inconsistent, implying little
consistent removal effectiveness by any of  the street  cleaners. Similar
results are shown for both the study sites. The  smallest particle size (less
than two microns) showed better removal effectivenesses  for the regenerative
air street cleaners than for the broom street cleaner, in most cases.

     To differentiate the modified and standard  regenerative air street
cleaners, data art presented in Figures 10-10 and 10-11  for total solids
loadings in the cleaning width only. The modified street cleaner is seen to
have almost a constant residual loading value in the  cleaning width after
cleaning, irrespective of the initial loading. This  indicates a very
important advantage in cleaning effectiveness for the  modified regenerative

                                     199

-------
O
O
       700
                          FIGURE 10-8

                Surrey  DONHS  Total  Sol  ids
                 100
200    ' 300     400     500

 Initial Lood (1b/curb-m!1e)
600
700

-------
                   FIGURE 10-9
          5.E.   30-^  Total  Sol  ids
0 ' 200
1000 1200 1400 1600 1800 2000 2200 2400 2600 2800 3UOO 3200
InKlol Load Hb/curb-ml 1e)

-------
o
no
       0
                         FIGURE  10-10


               Surrey  Douns  Cleaning  Width
                 50
100    ' 150     200

 Initial Load ()b/curb-mI 1e)
2aO
300
350

-------
O
CO
        1200
        0
                           FIGURE  10-11

                    5.E.   30-th  Cleeni ng  Width
                       O MODIFIED TYMCO
                    200
 400       600      800

Inltlol Load  (Ib/curb-mMe)
1000
1200

-------
                    Thit--  di t fe retire  is  not apparent with the full street
     T\pK'al initial  ind  residual  loadings for these tests are shown in the
bar civ-its, l-\v;ures  1U-12  and  10-13.  The modified regenerative air street
cleaner is si-own  to  have  been  more effective than the other street cleaners
tor almost ail particle  sizes,  and for either area.  The largest differences
were observed  in  the  smaller  particle sizes (less tnan 125 microns) in the
S.b. 3uth area.

     Figures IU-2 and  10-4 (and  Appendix Figures C-l through O8) have the
Surrey Downs regenerative  air  data plotted along with the full-scale broom
cleaner data.  It  is  seen  that  the  regenerative air street cleaners are core
effective, especially  at  the  lower initial loading values. Table 10-2 shows
the minimum effective  loading  values  for each type of street cleaner. The
modified street cleaner  data  are not  shown on this table because they had
performance characteristics  close  to  the standard regenerative air cleaner
(when considering the  daca variations on these figures).

     These data results  are  similar to the results found by Pitt and Shawley
in Castro Valley. California  (1981),  where they compared a regenerative air
street cleaner with  a  standard  broom  street cleaner. They found that the air
cleaner performed better  with  lighter loads, especially for the finer
material. However, the broom  cleaner  was found to perform better for heavier
loads, especially for  heavy  litter s id leaf loads. Pitt also compared vacuum
street cleaners to brcom  street  cleaners in San Jose, California (1979).  He
found no significant  difference  in performance of the several types of street
cleaners tested under  a wide  variety  of  street conditions and cleaning
frequencies. One model of  a  broom  street cleaner did result in substantially
more residual  loading  values  that  were larger than the initial values for
very intensive cleaning  on oil  and screens streets (it appeared to be
loosening the  street  pavement  material).


Effects of Intens ป ••. •  Street  Cleaning  on  Washoff Potential

     Typical loading  values  for  the different particle sizes are shown on
Table 10-3 for periods of  no  cleaning and for periods of intensive cleaning.
These values are averaged  Lake  Hills  and Surrey Downs loadings during the
complete project period.  Total  solids loadings averaged about 390
Ibs/curb-mile  (110 g/curb-meter ) with no street cleaning. The frequent
Bellevue rains were  capable  of  keeping these smooth  asphalt streets quite
clean (when compared  to typical  loadings elsewhere on the West Coast for no
cleaning periods). Intensive,  three times a week, street cleaning reduced
these loadings to about 290 Ibs/curb-m.ile (80 g/curb-meter). The most
significant loading  reductions  were in the large particle sizes. No loading
reductions were noted  for  particle sizes less than 250 microns in size. The
washc.ff estimates given in Section 9  were used to estimate the washoff
potential associated with  these  loadings. These values are also shown on
Table 10-3. The washoff potential  changes between the no cleaning and
intensive cleaning periods was  from about 70 to 63 Ibs/curb— mile (20 to 18
g/curb-meter),  or a  reduction  of about seven Ibs/curb— mile (two

                                      204

-------
                            FIGURE  10-12
rv>
O
                           ng Special  Tests-Surrey Downs
            •no clean I ngFTj-Mobl 1

          (initial loal)
  250-   500-  I 1030-   2333-

T-Tymco    I  l-Modlfled Tymco

(residual load)
                                                          >6353 Microns

-------
                          FIGURE 10-13
o
01
       Loadings  During  Special  Tests-S.E.  30th
       500
*— *
QJ
- 40Q_
E
I
f 350_
;ฃ 30Q_
a. 250_
c
—
L)
g 20CL
_j
ฃ 150_
Q
"f* 1 PIP!
01 J UD 	
01

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>6350 Mictrir
iM~ no c 1 eo n I n9J [~rtob I 1

(initial load)
                            r~[-Tyinco    I 1-Modlfled Tymco

                             (residuol load)

-------
                          TABLE 10-3,   EFFECTS OF STREET CLEANING ON TOTAL  STREET  LOADS
                                 AND WASHOFF LOADS (LAKE HILLS AND SURREY DOUNS)
ro
o
Particle
Size
(Microns)
> 6350
2000 - 6370
1000 - 2000
500 - 1000
250 - 500
125 - 250
63 - 125
<63
Total solids
No Clean ing
Typical Total
Load
Ib/curb %of total
mi le i n ฃize
23.8 6. IX
36.9 9.5
38.9 10.0
68.3 17.5
81.1 20.7
64.8 16.6
38.4 9.9
37.9 9.7
390 100.0%
Available for
Washoff
%of load Ib/curb
for washoff mil •>
i
or. o
0 0
6 2.3
10.5 7.2
17 13.8
24 15.6
38 14.6
44 16.7
18% 70.2
Intensive Cleaninq
Typical Total
Load
Ib/curb %o'f tota'
mile in size
2.5 0.9*
10 3.5
20 7.0
56 19.5
60 20.9
62 21.6
38 13.3
38 13.3
290 100.0%
Available for
Washoff
%of load Ib/curb
for Washoff mile
0% 0
0 0
6 1.2
10.5 5.9
17 10.2
24 14.9
38 14.4
44 16.7
22% 63.3

-------
>;/curb-mpto: ) .  A/,atn, if  (.!•••  ^mjll  particles  were reduced more by street
cleaning, the washoff potential  would  be  reduced  more.

      figure 10-14 graphically  shows  these  load and runoff potential
reductions. The percentage  reductions  are  the same fnr both loads and runoff
potential for sizes  less  than 2000  microns.  Rain  washes off very few of these
larger particles. Street  cleaning  reduces  the runoff potential for more
narttrlps in rhf size range of  250  to  500  microns than for any other size
rafge. This figure shows  that street  cleaning has very little effect in
removing the small particles  that  are  most  effectively washed off the street
by rain.

     Table 10-4 shows estimates  of  the effectiveness of street cleaning in
reducing runoff yields of various  pollutants. For very small rains,  streets
contribute about 60  to 65 percent  of  the  total runoff yield for these
pollutants. For larger storms,  other  source  areas are more Important than
streets and the street contributions  are  reduced  (except for lead which
mostly originates from streets  during  all  rains). The runoff yiej.d reduction
estimates are about  six  percent  for thฐ smallest  storms, and about one to six
percent for the larger storms.  The  modified  regenerative ai*~ street  cleaner
may have removals about  1.25  times  these  values,  or uo to about eight
percent. With such small  potential  benefits,  it is ob. ious why the runoff
monitoring activities did not result  in any  monitored reductions. It is
expected that other  areas,  with less  frequent rains, would have greater
runoff potential reductions.  Pitt  and  Shawley found runoff reductions
associated with street cleaning as  great  as  40 percent in Castro Valley,
California (1981). Castro Valley has  less  rain than Bellevue, but more
importantly, it has  long  dry  summers  that  result  in very dirty streets if
there is no street cleaning.  These  dirty  streets  can be effectively  cleaned
in late summer before the beginning of the  rain season in Castro Valley. The
different rain seasons in Bellevue  are not  as dramatic, and the streets never
become so dirty without  street  cleaning.


BELLEVUE STREET CLEANING  ROUTES, OPERATING  CHARACTERISTICS, AND COSTS

     There are no foimal  street cleaning  routes in Bellevue. The city is
usually divided at 3th Avenue NE,  with one  street cleaner operating  north and
the other street cleaner  operating  south  of  this  street. The operators clean
in areas that they feel  require cleaning.  They estimate that the downtown
area is cleaned about once  a  week,  arterials  are  cleaned about once  a month,
and residential areas are cleaned  once every  two  months. The operators are
radio dispatched to  trouble areas,  as  needed. An  interim storage area for the
debris is located about  two blocks  from the  municipal service center (where
the street cleaners  are  stored). About nine  cubic yards (seven cubic meters)
per day per street cleaner  is handled  during  the  winter (about double this
amount if the streets are sanded).  During  the spring and summer months, the
debris quantity is reduced  to about six cubic yards (4.5 cubic meters) per
day per street cleaner.  The fall is the heaviest  debris period, with about 20
to 25 cubic yards (15 to  19 cubici  meteis)  per day per street cleaner
handled. About ten to fifteen percent  of  the  city streets are rough, or have
                                      208

-------
0  I	
                     FIGURE 10-14

           Load  and  Runoff Reductions
                                                   >6370
     dirt removal! hwashoff reduct.
           :D
             Percent reduction when intensive cleaning is corr.oared
             to no cleaning.

-------
             Table 10-4. EFFECTS OF STREET CLEANING ON RUNOFF IOAOSU
                               Approximate
                             percent of total
                             runoff load from
                              street washoff
     Percent runoff
   load reduction for
intensive street c'ea
  Runoff
Pollutant

Total Solids

COD

Phosphates

Total Kjeldahl Nitroqen

Lead

Zinc
0.01 in. rain
65%
62
61
i 61
60
61
-0.1 in. rain
10%
40
31
31
60
45
0.01 in. rain
6 . &%
6
6
6
6
6
.>0.1 in.
1*
4
3
3
6
4.5
(1)   The values  shown are based on the 4-wheel mechanical street clean'3'" test's.
      The regenerative air street cleaners are estimated to be about 1.25 times
      as effective as the above values, due to their better performance on
      removing the more washable fine particles.

-------
nc.- curbs, or both.

     The city of  Bellevue  has  two  street  cleanors that are described  on Table
10-5. They are both  four-wheel mechanical broom cleaners, with dual gasoline
engines, and 3.5  cubic yard  (2.7 cubic  meter)  hoppers. They clean  between 15
and  18 railed (24  and 29 km)  each day, while  cleaning at seven miles (11 km)
per  hour. During  special tests in  Reno  and  Sparks,  Nevada, Pitt and
Sutherland (1962) found that seven miles  (11 km) per hour cleaning speeds
••ere much less effective than  the  usually recommended four miles (6.5 k-u) per
Hour cleaning speeds. This was especially important at heavy loadings
^greater than 15UU Ibs/curb-mile,  or 430  g/curb-meter). The current Bellevtie
street cleaning program productivity may  therefore  be improved by  reducing
the  vehicle speeds,  but at an  increase  in coot (if  the cleaning frequency
remains  the same). The speed effects may  no: be as  important in Bellevue
because  of the lower street  dirt loadings,  bowever. Reducing the speeds on
the  dirtier industrial streets may be worthwhile.

     The street cleaners are maintained on  a daily  schedule, with  appropriate
inspections and lubrications. The  main  pick-up broom is changed about every
14GU to  1500 miles (400 to 425 ka). Oil changes and other maintenance
operations are also  conducted during broom  changes. The street cleaners are
in the repair shop about 25  to 50  percent of the time. This downtime is about
average  for street cleaners  elsewhere.

     Bellevue street cleaning costs are shown  on Table 10-6. Street cleaning
is a labor intensive activity, with about 73 percent of the total  street
cleaning costs associated with labor and  labor overhead.  The total cost is
about $20 per curb-mile ($12.50/curb-meter). Most of this cost is  associated
with operation activities, and about one-fifth is associated with  both
maintenance and debris disposal operations. Table 10-7 compares these
Bel'evue street clearing costs with street  cleaning costs for other western
U.S.  cities.  The Bellevue costs are quite close to  the total costs at these
other cities.
                                     211

-------
          Table  10-5.  !,EL!_EU'JE  STREET  CLEANER  OPERATING  CHARACTERISTICS
Mike of Equipment:   Mobil Athev

Models:   2TE3, 4-wheel mechanical broom sweenpr (1971)
          2DF3, 4-wheel mechanical bro  i sweeoer (1973)

Engine tyoe.  dual gasoline engines, with hydraulic controls

Hooper capacity:  34 yds^

Fuel Efficiency:  35-40 miles/day (including t-avel)
                  17-20 gal (both engines ooerating)
                    = 2.1 mi 1es/qal

Sweeping miles:  15-18 mi'ies/day

Debris disposal practices:   interim storage area with seoarate  transfer  to
                             land-fil1 as required

Speed during cleaning:   7 moh

Type of gutter broom:  steel

Type of main pick-uo broom:  polyethylene

Broom replacement intervals:     main broom     1400 sweeoinq miles
                              gutter broom     300 sweeoing miles

Broom rotation speeds:   unknown

Strike pressure of main pick-up brocm:  4" oattern

Maintenance schedules:
    1.   "A" service -   when  main broom is changed, aporoximately  every
                        1400-1500 sweeoing miles, engine oil change,  chassis
                        lube

    2.   Daily -   refuel, inspection lube conveyor chains and bearings

    3.   As needed,  esoecially at broom chances
                                   212

-------
            Table 10-6. BELLEVUE STREET CLEANING COSTS  (19RO  -

Item

Labor:
Repair labor
Disoosal labor
Operator labor
Labor overhead
Equipment operation, maintenace,
Depreciation
Disposal equipment
Outside services
Repair parts (includes brooms)
Tires
Oil
Gasol ine
Total

Typical
Cost per year
(S/.year)

$10,780
9,130
61,280
14,210
disposal, etc. :
5,300
12,400
675
10,240
710
120
5,890
$130,735
per year
Percentane
of total
costs (%)

8.3%
7.0
46.8
10.9

4.1
9.5
0.5
7.8
0.5
0.1
4.5
100%

Unit
Cost
(S/curb-fiile)

$1.68
1.42
9.49
2.21

0.83
1.93
0.10
1.58
0.10
0.02
0.91
$20.27
per curb mi le
Sub-totals:



   All labor and overhead:  73.0%



   All maintenance (labor, outside services, and repair parts):  18.1%



   All disposal (labor and equipment):  17.7%



   All operaton (labor, depreciation, tires, oil and qasoline):  64.?%

-------
                                 Table 10-; STREET CLEANING COSTS AT VARIOUS CITIES (1902/1983 ADJUSTED COST")
ro
H-ป
-p.


Labor
Operators
Maintenance and repair
Supervisors
Debris transfer
Overhead (secretary,
dispatcher, etc.)
Subtotal
Street cleaning equipment
Depreciation
Maintenance and repair
Operation (fuel, etc.)
Subtotal
Disposal (Includes labor)
Transferring and hauling
equipment
LandfilUng fees
Subtotal
Total
Bellevue, WA
$/C)eaned Percent
Mile of total
$ 9.49 4/X
1.68 8
-( In overhead)-
1.42 7
2.21 11
14.80 73
0.83 4
1.68 8
1.03 5
3.54 17
1.93 10
1.93 10
S20.00 100*
San Josfi, CA^1'
$/Cleaned Percent
Mile of total
$ 9,53 41X
5.35 23
2.32 10
-(Under disposal )-
-(Included above)-
17.20 74
0.7C 3
2.79 12
0.70 3
4.19 18
1.86 8
S23.00 100*
Alameda ,-,
County, CA1 ;
$/Cleaned Percent
Mile of total
-
$13.47 7H
0.64 3
3.52 19
4.16 22
1.35 7
$19.00 100*
RpnoL NV '
S/Cleaned Percent
ซile of total
S3.25-S5.60 13-19%
0.94- 1.58 5
0.59- I. 00 3
0.20- 0.34 1
0.20- 0.34 1
5.18- 8.76 28-30
11.12-18.80 61-64
2.00 11
(est.)
(4)
2.00 11-7
S18.00-S30.00 100*
:o,^ -,;''ป
S/C 1 >•"? *r~'r>i : r'r'r C '""" S
Mile V ' • " \ I
$ 3.2<3 1ซ
0.22 1
1.10 5
0.20 1
0.45 2
5.26 25
13.32 65
2.00 10
(est.)
2.00 10
$21.00 100X
      Sources:
       1
       2
       3
      (4)
P1tt. 1979
P1tt and Shawley, 1981
PHt and Sutherland, 1902
Alameda County reported a landfllUng fee of $8.50 per cubic yaro of street dirt to be disposed.   If 0.13 cubic yards/curb
mile are removed (as reported by Reno for the core area), this would be about $1.10 per mile cleaned.  For 0.48 cubic
yards/curb mile removed (Reno residential area), this would be about $4.00 per curb nlle for landfill fees.

-------
                                  SECTION  11
           EFFECTS OF STORM DRAINAGE PARTICIPATES ON  RUNOFF  QUALITY
     The role of storm drainage particulates in urban  runoff  discharge and
control was investigated during this Bellevue project.  As  described in
Section 8, samples were periodically obtained from  catchbasin sumps and storm
drainage sewerage during the course of the two-year  project.  An indication  of
quantity and quality of storm drainage particulates  was,  therefore, obtained.
Increases in catchbasir. sump contents from the initial  cleaning through the
project period wera used to estimate both the quantity  of  material that can
be accumulated in tha sumps and the best catchbasin  cleaning  frequency. The
data obtained were also  useful in estimating the role  of  catchbasin and
storm drainage particulates in contributing to urban runoff  pollutants end
how catchbasin cleaning or storm sewerage cleaning  practices  may improve
urban runoff quality.

     Catchbasin sediment is mostly made up of street surface  particulates
that have been removed from the street surface during  rain events and were
accumulated in the sumps instead of being discharged at  the  outfall. Table
11-1 compares the chemical characteristics of eight  different particle sizes
for the street surface samples and the catchbasin samples. The data for the
street surface samples represent the full two-year  project period during both
wet and dry seasons. The catchbasin samples, however,  represent fewer samples
and may be biased for the wet season. Even with possible  differences in
sampling tines, it is seen that the catchbasin sediment  chemical
characteristics agree well with the chemical characteristics  of the street
dirt. These common chemical characteristics imply a  strong association
between the catchbasin sediments and street surface  particulates. Because  the
average interevent time between rains in Bellevue is only  five days, major
chemical changes in catchbasin sediment quality may  not  be as important as  in
other locations having long dry periods between rains.

     When the total sediment chemical characteristics  are  compared with th'e
total street surface chemical characteristics, differences are much more
pronounced. Table 11-2 compares relative constituent concentrations (mg
constituent/kg total solids) for street dirt, catchbasin sediment, catchbasin
supernatent, and runoff. The large differences in catchbasin sediment and
street dirt are associated with the differences in  particle  size
distributions. Even though the individual particle  sizes  have very similar
chemical characteristics, the different particle size  distributions are quite
different, so that the overall mass characteristics  are different, as shown
on Table 11-2.
                                     215

-------
Tiblp  II-1:.  rO"r>ftn ['.r.'i  <~f  ^Torry r,;pr
      ' Hfw.ICAL  O'JMITY SY PAPTICLE  ',T7r

                Pirtir.li> Size  ("••'•-nr', )

r. jrr py 0<"J*ns
'J;1r bas in
W'-o
l'"'th
ratr.hbasl I?
7- N:
M >, ( n basin
WHR
10=30
Citchbav; ".s
TP:
Main basin
WHR
108th
catchbas ins
Lead:
Main basin
WHR
106th
cstchba^-:
t i nc :
Miin basin
WHR
108th
catchbas 1ns
COO:
street dirt
catchbaslns
7KN:
street dirt
catchbaslns
tP:
street dirt
catchbaslns
Lead:
street dirt
otchbsslns
71nc:
street dirt
catchbaslns
• 63
IPO, QOQ
n VTJO
150,000
15 //no
2900
3300
loOO
2910
830
810
690
880
1400
440
1600
1170
320
180
270
395
230,000
230,000
3500
3600
940
900
1900
2000
370
520
63-
1?5
150,000
1 90 , noo
100,000
Uu/iOO
2600
3300
1200
2070
610
630
510
690
1200
330
"MOO
870
260
140
210
320
180,000
170,000
3200
2700
740
730
1900
1600
330
390
125-
?50
100,000
150 /on
54,000
91.6^0
1700
"^00
970
1500
470
470
330
630
1100
250
HOO
620
210
100
160
195
110,000
140,000
1900
2000
550
700
1700
1300
270
290
750-
V)0
94,000
1 '- i , ' fif)
u.ooo
lOO.nrio
1300
1700
410
1600
420
520
300
610
840
180
910
560
170
80
120
200
100,000
140,000
1600
2100
440
610
noo
920
220
260
500-
1000
130,000
170/00
37,000
1-13,000
1400
1900
460
1580
480
530
380
550
680
160
570
540
160
75
130
200
210,000
240,000
2300
3000
570
830
900
910
180
300
1000-
?000
190,000
?ฐ, 0,000
37,000
745,000
1600
7500
340
2600
690
580
620
930
420
370
240
540
170
100
130
730
240,000
280,000
2100
3400
760
1600
630
820
180
290
?ooo-
6350
170,000
300,000
55,000
777,000
1700
7400
790
2450
750
640
640
1060
240
50
130
480
110
75
100
190
270,000
250,000
7000
2300
740
1500
350
620
130
300
•fi350
780,000
380,000
70,000
?14,000
1500
1800
360
7060
740
6?0
620
760
780
80
90
200
100
85
150
160
470,000
190,000
3700
7100
750
1800
210
440
140
360
                         216

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                Table 11-2.  COMPARISON OF  RELATIVE  CONCENTRATIONS
                        (mg constituent/kq total solids)
Surrey Downs
       runoff
       catchbasin supernatant
       catchbasin sediments
       street dirt
                                     COD
           TKN
 TP
Pb
Zn
405,000   9300
190,000   8200
250,000   1230
145,000   1600
2100   2900   1100
8400   1290   850
1690   3400   720
575    745    170
               110
               680
Lake Hills
       runoff
       catchbasin supernatant
       catchbasin sediments
       street dirt
J9J.OOO   9500    2600
470,000   20,000  5200
 75,000   700     750
190,000   2300    640
       1600   1060
       1300   2000
       610    210
       1170   230
               110
               120

-------
     Tahlp 11-2 can also he used  to  indicate  the  importance of different
sources  to the total urban tunoff  yield,  Uifortunately,  it is not possible to
obtain „ good particle size distribution  of  the  urban runoff particulates
and,  especially, associated chemical  characteristics for each urban runoff
particle size. Th_ urban runoff relative  concentrations  (mg constituent/kg
total solids) for the complete  runoff  samples  are quite  different from most
or the olher samples. This, however,  implies  preferential  washoff of the
finer particulates; the lass pollutsd  larger  particulates  do not wash off of
the street surfaces or other potential  pollutant  source  areas as well as the
finer partic lates (as discr'.sed  in  Section  9).  The larger particulates are
also  more effectively accumulated  in  catchbasin  sumps or in the storm
drainage than the finer particulates.

     It  is clear that most of  the  catchbasin  sediments are street surface
particulates that have been washed off  the  street during rain events but have
not been discharged to the outfall.  Table  11-3 compares  the estimated
catchbasin sediment accumulations  of  different urban runoff pollutants with
the street dirt accumulations  and  total urban  runoff flow  discharges. It is
interesting to note that the total urban  flow  unit area  discharges are in the
same  order of riagnitude as the  total  street  dirt  and catchbasin sediment
accumulations. The catchbasin  sediment  accumulation values are the rates
observed after initial cleaning,  before the  stable volumes were obtained. A
larger catchbasin sediment accumulation rate  may  be expected because of the
possible flushing effects of rains during  this period of time. The catchbasin
eediment discharge values shown on this table  are therefore minimum values
and could easily be greater.

     Street dirt accumulation  values  do not  totally contribute to the urban
runoff discharges. It has been  shown  in previous  sections  that not all of the
street dirt is washed off the  street.  Some  washed off street dirt is also
accumulated in sewerage or catchbasins  for  indefinite periods of time. In
addition, some of the street surface  particulates are lost to the air due to
fugitive dust emissions caused  by  winds or  traffic-induced turbulence. Those
particulates settle out on adjacent  areas,  or  the finer  particulates can
remain suspended for some time. The  amount  of  street dirt  particulates that
are lost to the. air as fugitive emissions  are  quite small  for the Bellevue
area  when compared to more arid areas.  The  short  interevent periods do not
allow the street surface particulate  loadings  to  becom<=  very large and more
exposed  to the winds. The amount  of  material  lost tn the air is calculated
based on the daposition rate minus the  accumulation rate.  As the interevent
period increases (to greater than  four  or  five days, or  the typical
interevent period) the amount  of  material  lost to the air  becomes important.
These losses do not become very large  until  after about  ten to twenty days of
accumulation, which would be quite rare and  would only occur several times a
year  during the dry season.

     If  a very large storm occurred  that  was  capable of  removing "all" of the
particulates from the street surface  and  totally  flushing  the catchbasin
sediments and sewerage sediments,  the  resultant  urban runoff discharge may be
very  large. The erosion yield  during  a  storm of  this size  would also be
extremely Large. Table 11-4 shows  typical  loadings that  can occur at any one
time  in  the Surrey Downs and Lake Hills areas  that would potentially wash off


                                     218

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            Table 11-3. DISCHARGES AND ACCUMULATIONS IN URBAN AREAS

                                  Annual  Discharge  or  Accumulation  (Ib/acre/vr)
Total
Solids
Surrey Downs
storm runoff
basef low
total urban flow
street dirt (accumulation) (1)
street dirt (washoff)(2)
street dirt (fugitive losses(3)
catchbasin sed. (accumulation) (4)
Lake Hills
storm runoff
basef low
total urban flow
street dirt (accumulation) (1)
street dirt (washoff)(2)
street dirt (fugitive losses(3)
catchbasin sed. (accumulation) (4)

180
100
280
170
27
15
130

250
67
320
310
56
17
88
COD

79
10
89
22
3
2
33

100
8.7
110
60
10
3
6.6
TKN

1.6
0.53
2.1
0.2
0.04
0.02
0.16

2.4
0.18
2.6
0.7
0.14
0.04
0.06
TP

0.35
0.10
0.45
0.1
0.02
0.01
0.22

0.61
0.035
0.65
0.2
0.04
0.01
0.07
Pb

0.23
0.03
0.26
0.1
0.02
0.01
0.44

0.4
0.02
0.42
0.4
0.1
0.02
0.05
Zn

0.21
0.053
0.26
0.03
0.005
0.003
0.10

0.27
0.024
0.29
0.07
0.02
0.004
0.02
 1)
 11
(4)
Using average 2-5 day accumulation periods and appropriate rates
See Table S-4
Calculated based on deposition rate minus accumulation rate times
average interevent period, by month (fugitive dust loses to the air).
See Table 8-8

-------
ro
ro
O
                        Table  11-4  TYPICAL  LOADINGS  AT ANY  ONE  TIME,  POSSIBLY  AVAILABLE
                                   FOR  WASHOFF  DURING MAJOR EVENTS  (Ib/acre)

Surrey Downs
street dirt (5 days)
catchba:-'n sediments
sewerage sediments
average runoff event observed
maximum runoff event observed
Lake Hills
street dirt (5 days)
catchbasin sediments
sewerage sediments
average runoff event observed
maximum runoff event observed
Total
Solids
20
100
13
2.7
38
21
140
61
2.2
15
con
3
25
3
1.0
8.9
4
12
5
0.8
4.4
TKN
0.02
0.13
0.02
0.022
0.27
0.05
0.1
0.04
O.J2
0.14
TP
0.01
0.13
0.02
0.005
0.06
0.01
0.1
0.05
0.006
0.07
Lead
C.01
0.4
0.05
0.004
0.04
0.03
0 1
0.04
0.003
0.02
Zinc
0.004
0.08
0.01
0.003
0.03
0.005
0.02
0.01
0.002
0.015

-------
during a very large event. Typical loadings  are  shown for street dirt,
catchbasin sediment, and sewerage sediment.  In  addition,  the maximum and
average event runoff yield loadings  that were observed are shown for
comparison. The maximum runoff event  that  was monitored during the two-year
study period was very large and would only occur several  times in a decade in
Bellevue. The maximum observed runoff event  discharge is  still only about ten
to twenty-five percent of the total  pollutants  that  are residing on the
street surfaces, in the catchbasins,  and in  the  sewerage .•ป Thfijef ore, urb.in
runoff pollutants are definitely not  source  limited  in Bellevue. Of course,
the more available finer particle sizes which are also more heavily polluted
are more limited in availability and  may affect  the  potential storm yields
for the large events. As noted in Section  6, only about ten percent of the
total solids urban runoff discharge  is expected  to be associated with street
surface particulates. This value increases to about  50 percent for lead for
most storms. Section 9 estimates that only about 15  percent of the street
surface particulates may wash off the street. The average urban runoff event
in Lake Hills and Surrey Downs only  discharges  between two and three pounds
oi dirt per acre (2.3 and 3.4 kg/ha). The  total  solids street dirt loadings
were about ten times this value. About half  of  the total  annual urban runoff
discharge may be residing on the street surfaces and tied up in catchbasin
and storm drainage sediments at any  one time. If the Bellevue rain events
were capable of removing much of this material,  then the  urban runoff
discharge yields would be much greater than  nenitored.

     It is obvious that it is most important to  preferentially remove the
finer, more heavily polluted and more available  materials before the rain
events occur. As shown in Section 1(1, normal street  cleaning equipment is not
capable of effectively removing these finer, more polluted particles. The
sediments in the catchbasins and the  sewerage are mostly  made up of the
larger particles that do get washed  off the  street.  These sediments have a
much smaller median particle size than the street surface particulates.
Catchbasin or sewerage cleaning can  remove large quantitieo of these more
potentially polluting particulates than the  normal street cleaning
operations. Catchbasin and storm drainage  sediments, however, mav not
contribute large quantities of pollutants  to the total urban n  off
discharge, except for very rare events. If the  catchbasins are "full", they
will have little effect on the runoff yields. Catchbasin  sump sediments can
be relatively conveniently removed to eliminate  a major potential source of
urban runoff pollutants. Because the  catchbasin  sediment  accumulation rate is
quite low, frequent cleaning of catchbasins  would not be  necessary. It is
expected that cleaning catchbasins twice a year  at the most would be
sufficient.

     The City of Bellevue is currently conducting a  more  comprehensive
city-wide sampling program of catchbasin sediments and that infonnition can
be very useful in designing a catchbasin cleaning program.

     It is not possible_to currently  estimate the effectiveness of catchbasin
cleaning in controlling  Bellevue's  urban  runoff. Because of its low
frequency and because it has the ability to  remove more of the potentially
polluting sediments, it is probably  more cost effective than street cleaning
in improving urban runoff quality in  Bellevue.  Because of the varying amounts

                                      221

-------
      i 'i.il tl..it ,ire  in  the c.) ;. clibat, i ns  at  any  time, certain  catchbasins  and
      I'.i's o; M-UC r.ir.e  .ire  r.nch more important  potential scc-.ir  sourct.s  than
laiH'is.  II10 ilr.i ; n.ii'.e  ^y^tcr, Jocated near  the  uny'.nt tertd sections  of  Westwood
l-onii's Kivid .i:-.u  Ichth  Street in the Surrey  Downs  basing were much  more  heavily
li'.uleu Lli.ri ^he seuer.Hic- ,tnd en t chha s ins  observed elsewhere in  the  study
.ue.j.s. 1'i.c ront ri but ions of these local  erosior,  sources to the  storm drainage
svsteni,  and probably  to  the outfall, may  be significantly reduced by
iiutallim: curbs and  gutters.

     Table 11-3 showed that catchbasin  sediments that may accumulate in clean
sumps may be a  significant fraction of  the  urban storm runoff  yield. Annual,
or twice a year, cleaning  may be capable  of reducing these storm  discharges
by ten to 23 percent  Tor lead and total  solids,  and between five  and ten
percent  for the other  pollutants studied  (COD,  TKN, TP, and Zn).  Cleaning
less frequently than  about once a year  would  reduce these expected
improvements. These  removals would occur  for  about the first  year after
cleaning, then  the  constant-volume values  would  be obtained with  little
effect on the runoff  yields until the next  cleaning. Leaving  the  catchbasin
"full',  however, increases the chances  of  increasing fhe runoff yield  during
very large scouring  everts. Some pollutants may  also be chemically  charger! by
oxidation-reduction  reactions in the catchbasins, and could be  connected  to
more availaole, soluble, toxic forms before discharge. Therefore, it is
recommended that the  storm sewer inlets  be  cleaned at least annually.
                                      222

-------
                                  RF.FERKNCF.S
Amy. G., R.  Pitt,  R.  Si.igh,  W.  Bradford,  and M. LaGraff. Water duality
Management  Planning for Urban Runoff.  EPA 440/9-7j-OOA ,  U.S. Environmrntal
ProLection  Agency,  Wasnington,  D.G.,  December 1974.

Rarkdoll, M.P., D.E.  Overton, and  R.P.  Betson. Some Effect? of uustfall on
Urban Stormwater Quality.  J. Watsr Pollution Control Federation,
49(9): 1976-8<ป, September 1977.

Betson, R.P- Bulk Precipitation and Streamflow Duality Relationships  in an
Mrban Area.  Water Resources  Research,  14(6):1165-69. December 1978.

Callahan, M.A., et  al.  Water-Related  Environmental Fate cf 129 Priority
Pollutants.  EPA-440/4-79-029b,  U.S. Environmental Protection Agency,
Warhington,  D.C.,  December 1979.

Claycomb, E. Urban  Storm Drainage  Criteria Manual from Denver. Civil
Engineering-ASCE.  Manual from Denver  Regional Council of Governments, July
1970, pp. 39-41.

Cowherd, C.J., C.M. Maxwell, and D.W.  Nelson. Quantification of Dust
Entrainment  from Paved  Roadways. EPA-450/3-77-027, U.S.  Environmental
Protection Agency,  Research  Triangle  Park, North Carolina, July 1977-

Durum, W.H.  Occurrence  of  Some Trace  Metals in Surface Waters and
Groundwaters.  In:  Proceedings of the  Sixteenth Water QuaJity Conference, Am.
Water Works  Assoc., et  al. University of  Illinois Bull. 71(108), Urbana,
Illinois, 1974.

Ebbert, J.C.,  J.E.  Poole,  and K.L. Payne. Data Collected by the U.S.
Geological Survey During a Study of Urban Runoff  in Bellevue, Washington,
1979-82. Preliminary U.S.  Geological  Survey Open-File Report, Tacoma,
Washington,  1983.

Galvin, D.V. and R.K. Moore. Toxicants in Urban Runoff. METRO Toxicant
Program Report #2,  U.S. Environmental Protection Agency Grant //P-000161-01 ,
Lacey, Washington,  December  1982.

Gambrell, R.P. and  W.H. Patrick, Jr.  Chemical and Microbiological  Properties
of Anaerobic Soils  and  Sediments.  In:  Plant Life  in Anaerobic Environments,
R.M.M. Crawford, Ann Arbor Science Publishers, Ann Arbor, Michigan,  1977.
                                    223

-------
                                i ] -'.•'.] < f r-A i r-Pl .1 n t  S ' \id '!>•=;.  Knv i ropnrnt a 1
                                 !i,  lvv 'Vr.ilq,  i:.L.  K.-lt.  ,K"1 K.A. RcinhoM,
                                1 Sr.df,-s,  University  of  Illi.  ,is,
                                v l'J/7.

.•' i Irciui st ,  P.A.  At r.isphrri ,  F,? llo':f ,in,i Street  Clr.ininr  - Fffcrts on I'rh.in
^tor-f, U'.itiT  .i;i>1  S'.mw.  I'ri'i,.  V;it. Tecli., li) ( 3/ h ) : i9 S- ri()S ,  197H.

MiTi-'liv, W.  Ro;uiw,iv Vuettive  Part irii 1;U p Losses .  AT,.  PuMi'~  Works '\ssoc.,
•.n-.puhl i shed , i^7S.

l'i'.nCo-Kn vi ro- nent i L ,  Inc. Control  of Rr-ent rai nod  Dust from P^ved Streets.
KPA-vi)// 9-77-1 '07 ,  U.S.  Knvi ronmen t.il Protection  Agency,  Kansas City,
Missouri ,  1977 -

lYdersen,  K.R.  Tt'.o Use  of Bent hie  Invertebrate Data  for  Evaluating Impacts of
I'rbcMi Stormwater  Runoff. Masters thesis submitted  to  the  College of
Engineering, Universitv of  Washington, Seattle,  1981.

Pitt, R.  and C.  Amy.  Toxic  Materials Analysis  of  Street  Siu-cace  Contaminants.
FPA-R2-73-2S3,  U.S.  Environmental  Protection  Apency,  Washington, D.C., August
1973, 135pp.

Pitt, R.  and P.  Hissonnette. Fellevue Urban Punoff  Program, Summary Report.
Stortn and  Surface  Water Utility, Bellevue,  Washington, November  1V83.

Pitt, P.  and M.  Hozeman. Sources of Urban  Runoff  Pollution  and Its Effects on
an Urban  Creek,  EPA-600/S2-32-090 ,  U.S. Environmental  Protection Agency,
Cincinnati,  Ohio,  December  1982.

Pitt, R.  and G.  Shawley. A Demonstration  of Non-Point  Source Pollution
Management:  on  Castro  Valley  Creek.  Alaroeda  County  Flood  Control  &nd Water
Conservation District  (Hayward, CA) for the Nationwide Urban Runotf Program,
U.S. Environmental Protection Age.icy,  Water Planning,  Division, Washington,
P.C. , Jure  1981.

Pitt, R.  ;.nd CH2>'-HILL  (R.  Sutherland). Washoe County  Urban Stormwater
Management  Program, Vol. 2,  Street  Particulate Data  Collection and Analysis.
Washoe Council  of  Governments," Reno, Nevada,  August  1982.

Pitt, R.,  R. Su:herland, D.  Rer.dtrom,  and  D.  Galvin.  Bellevue Urban Runoff
r:ogram -  First  Annual  Report. Storm and  Surface  Water Utility,  Leilevue,
Washington , January 1981.

P:'t_t, R.  Demonstration  of Konpoint  Pollution  Abatement Through Improved
Street Cleaning  rractices,  EPA-500/2-79-161 ,  U.S.  Environmental  Protection
Agency, Ci'icinn.-.t i, Ohio, August 1979.

Pitt, R.  Urban  Bacteria Sources and Control by Street  Cleaning in the Lower
Kideau Riv^r Watershed, Ottawa, Ontario.  Rideau  River  Stormwater Management
Study, Ontario  Ministry of  the Environment, Ottawa,  Ontario, May 1982.
                                     ?24

-------
• vv,-!   l . \. .\:-ii  I.C.  Iph'Tt.  Oirintitv and iV.nl i*-v  of  Storm FunoM  frop Thrrr
'. rV.in i .it v.-hr,.->-; s  in  i.rl 1 rvur .  Wash i n>-. t on . Pro 1 i rr i n.i rv  U.S. U-<> I u>T. i ca 1 Survey
is.Her K.-sources  Inves t i r.i r i ons Report,  T.n-or.-i , Was him; ton , undated.

'cirhev, ,1 . S . Fftcols  -if  1'rh'i n i ra t i on mi a Lowland  Stream in Vesiern
Yashin.'ton . IVu-tor of  rhilosophy dissertation, I'niversitv  of Washington,
Se.utlo, lq^J.

Kolt'o, <.',.],. and  K.A.  "cinhold. Vol.  I:  Introdurtion  ;)nd  Sunnary.
Knvi vonnt-nt ,11  Con t anif n;i t i on  by Le;ui  and Other  He.ivy  Mt-tals. Institute for
v.nvi ronmont al  Stiuiies,  University  of Illinois, Urhana-Ch^inp.i i vtn  , Illinois,
July  1^77.

Rubin, .A..I., ed.  Aquoeus-Fnvironmental  Chemistry of  Metals. Ann  Arbor Science
Publishers, Ann  Arbor,  Michigan, 197t>.

Sartor, J.D. and  G.R.  Royd.  Water  Pollution Aspects  of  Street  Surface
Contaminants.  nPA-R2-7?-081,  U.S.  Environmental  Protection Agency, November
1972.

Scott, J.R., C.R. Steward,  and O.J.  Stober. Impacts  of  Urbcn Runoff on Fish
Populations in Ke]sey  Creek,  Washington. U.S.  Environmental Protection
Agency, Corvall.is Environmental Research Lab., Contract  No. R806387020,
Corvallis,  Oregon, May  1982.

Solomon, ^.1,.  and D.F.S.  Natusch.  ^'ol .  Ill: Distribution and Characterisation
of Urban Dusts.  Environmental  Ci-^. •:": n."1 tion by Lead  and  Other  Heavy Metals,
G.L.  Rolfe  and K.A.  Reinbold,  eds. irvsiitute  for Environmental Studies,
University  of  Illinois,  Urbana-Champ i i ,7-1, Illinois,  July 1977.

Spring, R.J.,  R.B. H.,well,  and E.  S'lirlty. Dustfall  Analysis for the Pavement
Storm Runoff Study (1-405  LOP  An-eU^l. Office of  Transportation Lab.,
California  Department  of  Trcnsn •;:'. *' -'  n, Sacrrmento,  California, April 1978.

Sutherland, R.,  W. Alley,  and  F. ^ilis. Draft  Users'  Guide for Particulate
Transport  Model,-PTM.  CH2M-H::,L, Portland, Oregon,  for  the U.S.  Geological
Survey, undated  (1982?).

U.S. Environmental Protection  Agency. Quality  Criteria  for Water. U.S.
Environmental  Protection  Agercy. Washington,  D.C.  1976.

U.S.  Soil  Conservation  Service. Urban Hydrology  for  Small  Watersheds. Tech.
Releasa No. 55,  U.S.  Department of Agriculture,  Soil  Conservation Service,
Washington, D.C., 1^/j.
                                     225

-------
                                        Table  A-l.  LAKE  HILLS  -  RAIN  DATA  FOR  STUDY PERim
t of
Month periods
Feb/198Ql 6+
March 8
April 7
May 8
June 8
July 3
August 7
September V
October 5
November 17
December 14
Ttl 19802 90(+)
Jan/1981 10
February 7
March 8
April 14
May 10
June 13
July 3
September 10
October 9
November 13
December 19
Ttl 1981 117
Jan/1982 13
Ttl period 220
otal
(In)
3.03+
3.13
3.22
1.21
2.32
0.52
1.31
1.92
1.18
6.52
6.51
30.9(+)
2.08
3.34
2.08
2.78
2.17
2.42
1.93
0 18
4 '.71
5.96
4.59
6.32
38.56
4.65
74.11
rain per stor,n
( m)
avg min max
0.51 0.10 1.44
0.39 0.12 1.05
0.46 0.07 1.32
0.15 0.04 0.50
0.29 0.04 0.72
0.17 0.09 0.28
0.19 0.04 0.63
0.27 0.10 0.57
0.24 0.04 0.74
0.38 0.03 1.55
0.47 0.03 1.28
0.34 0.03 1.55
0.21 0.03 0.48
0.48 0.16 l.OC
0.26 0.07 0.62
0.20 0.04 0.42
0.21 0.03 0.43
0.19 O.OZ 0.43
0.64 0.04 1.25
0 13 	
0.47 0.03 1.20
0.66 0.07 3.69
0.35 0.03 1.58
0.33 0.03 1.21
0.33 0.02 3.69
0.36 0.04 0.96
0.34 0.02 3.69
duration per storm
(hrs)
avg min max
18.6 3.7 49.5
19.1 6.0 43.1
12.7 0.4 33.7
6.6 0.07 16.0
8.7 0.8 31.1
9.0 3.4 17.3
4.7 0.5 12.4
8.7 3.5 17.7
10.0 2.3 24.4
9.7 1.2 23.4
12.9 0.1 30.0
11. 0 0.07 49.5
9.4 1.0 32.2
19.5 8.0 38.8
12.9 4.8 26.5
8.4 0.9 31.5
6.1 0.8 16.6
5.6 0.1 21.2
6.9 1.7 10.1
12 4 12 4
9.7 1.0 32.0
11.9 1.3 35.8
10.9 0.5 30.1
11.9 0.7 30.3
10.5 0.1 38.3
8.2 2 9 27.9
10.6 0.07 49.5
preceding dry period
(hrs)
avg min max
39.5 9.0 130.4
35.9 6.0 61.4
85.9 7.7 187.5
78.4 7.1 338.9
82.7 7.7 218.8
140.1 55.0 198.8
156.7 12.5 436.4
92.5 18.8 201.3
1-14.9 6.3 230.3
32.0 5.9 116.1
39.6 5.6 136.7
34.4 5.6 436.4
55.3 10.9 209.0
71.2 7.3 315.3
93,8 2). 4 242.4
39.6 6.1 182.5
58.3 8.3 124.3
63.9 7.8 244.5
94.3 53.3 141.4
1150 8 1150 8 0 015
59.5 6.6 434.8
72.3 11.1 433.1
53.9 5.8 186.8
27.3 5.8 70.2
153.4 5.8 1150.8
45.5 7.8 114.8
117.3 5.6 1150.3
avq rain intensity
rW] nin m ,1 x
0.027 C.0?0 0.03")
0.023 0.0'":) 0.053
0.052 0.024 0.168
0.023 O.D08 0.040
0.062 0.005 0.133
0.022 0.016 0.:V6
0.064 0.006 0.142
0.038 0.014 0.089
0.020 0.012 0.030
0.042 0.015 C.091:
O.OJ6 0.008 0.07-1
0.037 0.006 0.163
0.025 0.013 0.058
0.025 0.014 0.044
0.021 0.011 O.OJ3
0.041 0.013 0.1-3
0.040 0.020 0.0-13
0.036 0.015 0.069
0.074 0.024 0.124
- - 00-1
0.054 0.010 0.150
0.045 0.013 0.103
0.033 O.C09 0.076
0.029 0.010 0.075
0.037 0.010 0.13
0.029 0.010 0.073
0.037 0.006 0.18
poi'r 70 '^i'1 ^ i ' n
4 v 9 m ' " i~.ii
0.09 0.02 O.M
0.14 o.o-i o.r:
0.14 0.04 O.n7
0.06 0.02 O.I?
0.13 0.0? rt.-'i
0.0?3 0.04 0.10
0.18 0.02 O.^T
0.13 0.04 0/M
0.08 0.0? 0.12
0.16 0.0' O.'l"'
0.14 0.04 0.30
0.12 0.02 0.53
0.07 0.02 0.16
0.16 0.06 0.36
O.C3 0.04 0.14
0.11 0.04 0.,??
0.15 0.02 0.25
0.11 0.04 0.,?3
0.20 0.06 0.34
0.24 0.02 0.50
0.13 O.OJ 0.5'
0.13 0.0: 0.3J
0.14 0.01 0.33
0.13 C.O' 0.5"1
0.10 0.02 0.13
o . ! ; o.o? o.sq
(1)   partial:  start 2/15/80
(2)   partial year

-------
                                                 Table  A-2.  SURREY DOWNS - RAIN DATA FOR  JTIJDY  PER [00
* of
storm
Month periods
Mar/1980 11
April 10
May 6
June 7
July 4
August 6
September 7
October 5
November 13
December 13
Ttl 19801 82+
Jan/1981 10
February 5
March 8
April 11
May 11
June 10
July 3
August 1
Sep tercber 7
October 8
November 14
December 19
Ttl 1981 107
Jan/1982 11
Ttl period 200
total
rain
(In)
3.19
3.00
1.35
2.85
0.18
1.39
1.89
1.24
6.79
6.44
28.62+
2.26
3.21
1.96
2.20
1.8i
1.90
1.86
0.24
3.47
6.57
4.62
6.26
36.36
5.5
70.48
rain per storm
(In)
avg m1n max
0.29 0.04 1. 11 "
0.30 0.02 0.28
0.23 0.04 0.60
0.1] 0.08 0.72
0.12 'J.03 0.22
0.23 0.06 0.63
0.27 0.08 0.50
0.25 0.03 0.74
0.52 0.05 1.66
0.50 0.03 1.28
0.35 0.02 1.66
0.23 0.04 0.63
0.64 0.16 1.05
0.25 0.07 0.62
0.20 0.08 0.30
0.17 0.04 0.33
0.19 0.03 0.33
0.62 0.16 1.17
0.24 	 -
0.50 0.05 1.22
0.82 0.07 4.38
0.33 0.03 1.50
0.33 0.03 1.10
0.34 0.03 4.38
0.50 0.04 1.17
0 ->5 0.02 4.38
duration per storm
(nrs)
avg m1n max
11.5 4.3 29.1
8.9 1.2 30.8
13.5 0.7 30.3
11.2 1.7 31.4
7.6 2.2 13.5
5.7 1.5 17.2
9.4 3.3 17.5
11.7 2.3 25.1
16.4 3.2 56.5
14.8 1.1 31.4
11.1 0.7 56.5
9.5 1.5 32.2
28.3 6.3 71.8
12.3 3.4 26.5
9.9 2.3 26.2
5.4 1.8 8.9
5,4 0,6 18.3
7.3 2.6 10.2
13.4 — —
15.2 0.4 39.8
12.0 1.2 34.1
10.1 1.0 28.5
10.0 0.8 30.6
11.6 0.4 71.8
20.2 3.4 74.7
11.8 0.4 74.7
preceding dry period
(hrs)
avg min max
54.8 5.9 157. 1
60.2 5.6 189.2
98.3 9.9 372.3
8ฃ.2 7.2 194.7
132.8 34.0 196.3
160. C 14.2 354.9
95.3 18.8 199.5
143.1 94.5 184.4
37.4 5.8 111.9
41.5 6.9 137.1
91.2 5.6 354.9
57.9 9.1 208.7
99.1 13.3 317.1
87.7 19.4 266.4
50.1 10.0 180.8
53.3 5.3 125.0
82.4 9.3 287.8
94.3 53.4 141.8
1150.1 — 1150.1
77.8 6.8 386.8
82.8 8.3 432.6
26.5 5.9 167.0
27.7 5.6 59.6
157.4 5.3 1150.1
53.6 7.8 182.0
124.1 5.3 1150.1
avg rain Intensity
( in/hr)
avg m ' n THX
0.027 0.009 0.062
0.037 0.008 0.039
0.021 0.008 0.057
0.049 0.008 0.083
0.016 0.010 0.02?
0.051 0.009 0.078
0.033 0.010 0.064
0.019 0.008 0.029
0.036 0.009 0.103
0.032 0.008 0.071
0.032 0.008 0.103
0.025 0.013 0.041
0.026 0.015 0.040
0.022 0.011 0.0:3
0.034 0.011 0.119
0.033 0.008 3.091
0.048 O.C13 0.092
0.078 0.058 0.115
g 018 	 	
0.053 0.022 0.055
0.052 0.013 o.i:a
0.037 0.009 0.089
0.036 0.007 0.062
0.039 0.007 0.128
0.023 0.008 0.058
0.035 0.007 0.128
poilf 30 mln n 1 n
intone i ty ( in/>-r }
3 v ^ TI ^ n ~ i /
0.12 0 02 O.'l
0.15 0.0? 
-------
7'ir 1
                           LaKe Hi 11:5  ctn j  Durr^y
                                                         for  1 :-eo
                Total   Duration Pn1n  Int.


/3/eo
'/i 3
3/12
;"/''?
.' •' - 'j
"" / 2 ')
'4/5
4/3
4/14
4/13
4/28
4/29
5/20
5/22
5/24
5/26
5/27
6/1
b/1
6/5
6/6
6/16
6/24
6/25
7/4
7/11
7/14
8/2
8/17
8/26
3/27
B/28
8/30
9/1
9/6
9/12
9/13
9/19
9/20
9/29
10/8
10/12
10/24
10/31
1 1 /I
11/2
11/5
1 1/6
Rain
( in)
.19
.76
1 .05
.27
.21
. 1 2
• 52
• 92
-32
1 -32
.07
.07
• 29
.06
• 15
• 50
. 10
-6y
.06
.17
. 17
• 32
72
.06
.09
.28
.15
.09
.63
.04
.17
.26
.04
• 57
.23
.12
.16
.10
.25
-49
. 1 1
.16
-1 1
.74
• 36
• 52
• 35
1 -45
(hrs/

8.0
31 .6
43-1
16.7
20.8
6-5
28.9
21 .0
10.6
33-7
2.2
.4
33-7
2.6
5-4
16.0
6.2
7.8
-9
22.2
8.8
2-4
9-7
.8
3-4
17.3
6.4
? . 0
9-2
.5
1 .2
2.6
5-1
17.7
4.2
4.6
1 1 . T
3-5
14.0
5-5
9.1
15.7
7-3
24.4
10.9
22.3
3-7
55.8
i n / h r I i

. 02
.02
. 02
.02
.0!
.02
.02
.04
• 03
.04
.03
. 18
.01
.02
• 03
.03
.02
.09
.07
.01
. 02
. 1 3
.07
. 10
.03
.02
.02
.05
.07
.08
. 1 4
.10
.01
.03
.05
.03
.01
.0?
.02
.09
.01
.01
.02
.03
.03
.02
-09
.03
nt-;n3l ty
( in/.-.r ,
.06
• 30
. 14
.06
22
.06
.16
.22
. 1 8
.20
.04
. 14
.12
.f-4
. 08
. 12
.04
. 1 3
.10
.02
.14
.28
.22
.10
.01
.08
. 10
.04
•58
.08
.23
.22
.04
. 14
.22
.06
.04
.04
. 16
. 28
. 12
.08
. 10
.10
.14
.14
.24
.24
Hal n
(in)
. 22
.49
1.11
.24
-'9
.04
.40
• 57
. 13
1.18
.25
.03
• 31
.06
-23
.60
.1 1
.67
.72
.24
-13
.36
.65
08
.08
.22
.15
.07
• 63
.03
. I 8
.37
.06
.50
.27
.08
.14
• 09
.38
.43
.19
.12
.16
.74
.29
.60
• 33
1 -59
( h r :i 1

10.9
13. a
29.4
1C. 3
5- ''
4.6
31 .2
8.0
2.7
30.8
2.8
1 .2
30-3
7-5
20.6
16.3
S.3
7-6
14.2
31 -4
8.5
5-2
10.0
1 .7
7-8
13-5
6.8
1 .7
17-2
1 -5
2.3
4.3
6.9
17.5
4.2
3.8
13.4
3-3
15-9
7-4
10.2
14-6
6.2
25.1
13.5
24. 1
3-2
56.5
i i n / n r

.0 I
• 03
. 04
r 2
.04
.r i
.r'i
.07
''' C
.'.'4
. ~'9
. y
. j!
.01
.01
.04
.02
•09
• 05
.01
.02
.07
.07
.05
.01
.02
.02
.04
.04
-05
.08
•09
.01
.03
.Go
.02
.01
.03
.02
.06
.02
.01
.03
.0?
.02
.02
. 10
• 03
in".-'.'.'. /
l n / ' f
.>-

. i •$
:">-,
. j4
. ",''
. i 6
1-.
,- ^
. i 8
. 20
. ' **
' n
. -4
. '', 6
. : ''
r ^
.22
.20
.02
. 1 0
.20
.22
. 1 2
.04
.06
.08
.04
.50
. 12
.24
.13
.02
.03
.30
.04
.04
.04
.30
.24
. 18
. 04
. 10
. 10
. 14
. 1 2
.26
• 30
• -i' . -

- -;
i . '.'.
;-,
' . ' '
' ' '
' . .0
1 . ' J
1 . 6!
2 . '• c
i . ' 2
. _•'-
2.33
•"'4
1 . '" 0
. ^ ~J
• ''' ^
~J '
1 . 07
_ -" •>

1 . '1
.r:"'
1.11
• . oo
1.15
' . 2''
1 .00
1 . 2''
1 .CO
.50
.94
.70
.b"7
1.14
.85
; .50
1.14
1.11
66
1.14
58
1 13
1 .'.6
1 .00
1.24
. 8""
1 ~j^
. '1

-------
Tatle A-3. Haln Data for Lake Hills and Surrey 3ovn3 for 1930 (cont.)
Date


; i /g
1/14
1/17
1/1Q
1/20
1/25
1/27
1/23
1 1/30
12/2
12/3
1 2/10
12/14
12/20
12/21
12/24
.2/25
12/26
12/29
12/30
sun
average
minimum
maximum
Li!
Total
Rain
(in)
. 17
.15
• 03
. 1ฐ
1 .55
. 16
.70
.61
.24
1 .02
.66
.06
.17
.43
.68
.73
1 .28
• 32
• 30
.83
26-94
-40
.03
1-55
'-':'.
Durat i on
(hrs)
11 -7
4-9
1 .2
2.7
23-4
2.7
13-6
17.7
14.0
14.9
31-0
7.2
5-8
11.4
31-4
30.0
17.3
5-9
! 1 -4
28.1
884-9
13-0
.4
55-8
LH Ave.
Rain Int.
(in/.ir)
.01
.03
.03
.07
.07
.06
.05
.03
.02
.07
.02
.01
.03
.04
.02
.02
.07
.05
.03
.03
2.84
.04
.01
.18
Lil Peak
30-- ;n
intensity
(in/hr)
. 12
.03
. C2
.18
.42
1 2
!26
. 18
.06
.28
. 10
.04
. 12
. 14
.14
.20
• 30
.16
.04
.12
9-94
.15
.02
-S8
CD
Total
Rain
(in)
.22
i 2
.05
.21
1 .66
• ' 5
."1
.66
. 20
• 97
• 51
.04
. 1 1
-43
.73
.77
1 .28
• 34
• 30
.84
27.06
.40
-03
1 .66
3D
D iratlor.
(hra)
12.3
9- ฐ-
"j • 5
1 t 2
22.3
c a
17.3
21 .0
18. 1
15.2
31 -4
5-1
5-8
11 -3
24. 1
30.0
18.0
6.6
12.0
23-9
904.7
13-3
1 .2
56-5
SD Ave.
Rain Int.
(in/hr)
.02
.01
.0'
. 0~
. O'7
• 03
.04
. O"7.
.01
.06
.02
.01
. 02
.04
.03
-03
.07
.05
.03
.04
2.37
.03
.01
.10
CD Peak

intensity
( in/hr )
. 1 4
. 1.1
. , •'.
. ! 2
.-If.
. '. 0
.22
. 18
.06
.?""i
. 1 t
.02
.06
. 18
.16
.22
• 30
. 16
.06
.14
9-72
. 1 4
.02
-50
Lii/CD
> t a 1 Pain
Ratio
.-"
1 . 2 -.


'''
\ .'.^
• ':'>
.92
1 . ~>r-
1 . r -
1 . 2?
i . 50
i .55
1 . ~Sj
.93
.95
1 _ Cjfj
.94
1 .00
• 99
•73.C3
1 .07
.08
3.00
: -V ;:
L .j n '. 1 .1
Ratio





. I'7
. "6

.82
• ?'!
• 'J9
' . -* !
' . I'j
1 .<",!
* i '

.96
. ^ >
• 95
. .18
68. 1 1
1 . j''j
.06
3-93

-------
cie A-4.
Date


1 76781
•73
1/17
','13
' / 23
!/27
1/28
2/11
2/17
2/18
3/24
3/28
3/31
4/2
4/5
4/6
4/7
4/10
4/12
4/20
4/21
4/2}
4/27
4/27
5/3
5/7
5/9
5/10
5/14
5/ib
5/19
5/24
5/24
6/4
6/5
6/8
6/9
6/12
6/12
6/15
6/17
6/30
7/6
7/10
7/13
8/31
9/1
9/18
3a:n Data
LH
Ham
; i r. ;
.07
.03
.06
• 09
.48
.06
.60
1 .00
.16
• 58
.21
.14
• 32
-27
.18
• 34
.28
.42
.12
•19
.27
.08
.13
• 35
• 29
-33
.03
• 39
.18
.20
.24
-03
• 36
.03
-43
.40
.08
.28
.21
. 10
• 37
• 33
.64
.04
1 .25
.18
.12
• 45
for Lake '-ilia ^n.1 Currey ZQJT


 C'aratijr. Ham I.-.-..    7'--cl~.
    Ihrs,   . in/r.r; Intensity
                       ( i n / n r /
                                 far  1581
 1 .2
 1 .0
 4. f^
 7 . ~
14.7
 2.2
17.0
23- *
 8.0
18.8
 6.3
 9-4
11 .7
16-9
 3.8
 1-9
20. ~
31 -5
 6.7
 3- i
16.4
 2.4
 4.7
14.2
 4.4
16.6
 1 .0
 6.1
 4-2
 7.2
 6.2
  .8
14-2
  .8
 6.2
 5-8
 4.0
 4-2
 6.7
 5-7
21 .2
 6.5
 8.8
  1 .7
10. 1
12.4
  1 .0
13.3
.\jj
.03
.Of.
.04
.02
.03
.03
.01
.03
.02
.05
. 18
.01
.01
.02
.06
.02
.03
.04
.02
.07
.02
.03
.06
.04
.03
.04
.04
.03
.04
.07
.07
.02
.07
.03
.02
.02
-05
.07
.02
. 12
.01
. 12
.03
                           .04
                           .04
                           . 16
                           .02
                           .08
                           .20
                           .06
                           .36
                           .08
                           .06
                           .03
                           .28
                           .06
                           .14
                           .08
                           .14
                           .08
                           .06
                           .06
                           . 12
                           .22
                           .16
                           .02
                           .26
                           .22
                           .12
                           . 10
                           .04
                           .20
                           .04
                           .16
                           .16
                           .06
                           . 18
                           . 1 2
                           .08
                           .08
                           .28
                           .20
                           .06
                           • 34
                           .04
                           . 18
                           .26
                               jtai   Duration r.ain Int.    70-
                               Sain      (hrsi   ( in/hr I int^r."
                               i i n )                        -, i n /
.01
.02
.02
.04
.02
.04
.04
.03
•03
-03
.02
.03
.01
.07
. 1 2
.01
.01
.01
.02
.01
.03
.05
• 03
• 09
.03
.01
.04
• 03
.02
.04
.01
.02
.04
.05
.06
.08
.09
.05
.0?
.01
.04
.06
.06
. 1 1
.02
. 15
•03
• 05
.04
. 1 1
. 1 1
.38
-09
.63
.91
.16
• 77
.26
.18
.1 1
• 23
.16
.38
.22
-34
• 1 3
.08
. 1 1
.03
.15
• 32
.21
• 49
• 05
• 29
.05
.15
.22
.04
.31
.03
.33
• 31
.05
.23
• 33
. 1 1
.23
.25
• 53
.16
. 17
.24
.06
.45
1 -5
3-1
7-1
5-8
10.5
4-5
15-3
22.7
6.3
25-3
7-9
11.1
3-4
18.0
2-3
3-2
18.4
26.2
1 1 .8
3.6
10- 1
3-0
J-3
9-5
2.3
19-4
4.0
6.7
1 .8
8-9
6.2
4-9
18.3
.7
6.8
5-1
.6
? . c
b.6
6.5
13.3
5-7
9-1
2.6
10.2
13-4
.4
13-3
.04
.05
.04
. 1 4
.04
. 10
. 13
.06
. 4 -1
.03
.06
.04
. 12
. 12
 7 o
.79
 -•>!
                                                                             1 .'7
          •49
         1.11
         1 . 07
         1 . 27
           74
. 10
.04
.06
. Oo
.06
. 1 2
. 14
.26
.04
.20
. 06
.06
. 10
.02
.10
.04
. 14
.12
.08
. 22
.28
.04
.08
.24
.22
.16
-30
.08
. 1 2
.26
. 52
2 T^
2.45
1 .CO
1 . 20
1 .09
1 . T.p
. o'7
.60
1 -34
3-67.
1 -33
1 . 0ฐ
-75
1.16
1 .00
1 . 70

1 .60
1 .22
.64
• 91
1 .6'
1 .^2
1 .21
.25
1 . 'I"7
.75
2. -)C
1 .00
.57
.86
1 .62
. 8'".
1 .42
1.41
1 1 1
. 36
• 25
31
2 . -*3
.31
1 .00
.'5
.79
1 - 7
. il
1.14
u . ^ "
1 . ' 3
1 , ~:2
. 38
1.16
1 . ! 4
. .>-'
• 65
. JQ
j->
2 . -;o
I .00

-------
           Pable  A-4-  Rain  Data  for  Lake  Hills  and  Surrey  Downs  for  1981 (cont.)
ro
CO
Date



9/ ' 9
9/20
9/25
9/26
9/23
10/1
10/5
1 0/7
10/3
10/27
1 0/28
10/29
10/30
11/11
1 1/13
11/14
11/14
11/16
11/19
1 1/20
1 1/20
1 1/22
11/23
11/30
12/1
12/3
12/4
12/5
12/6
12/9
12/13
12/17
12/18
12/21
12/23
12/24
12/26
12/27
12/28
12/30
sum
average
minimum
maximum
LH
Total
Rain
(in)
.10
t .05
1 .06
1 .43
-42
.76
3-59
.10
.27
.73
. ! 1
.16
.07
1 .56
• 1 4
.05
.45
• 53
.18
-03
.83
.35
.21
.09
.57
.16
1 .21
.22
-05
.84
• 30
.21
• 69
.09
.26
.07
.40
.07
.10
.06
33.23
.38
.03
3.69
LH
Duration
(hrs)

1 .8
32.0
9-1
40.0
11.7
3.5
35-8
6.0
9-5
27.2
1 -3
10.8
2.8
20.7
9-0
.5
32.4
18.0
17.7
1 .8
30.1
5 3
4.8
10.5
16.6
14.1
21 .8
15-5
2.7
30.3
8.9
15.2
19-3
1 .2
1 1 .0
1 .7
23-5
6.7
8.0
2.4
964.1
11 .0
• 5
40.0
LH Ave.
Rain Int.
{ in/hr)

.06
.03
. 12
.04
.04
.09
. 10
.02
.0'
.03
.08
.01
.03
.08
.02
.10
.01
-03
.01
.02
.03
.07
-04
.01
.03
.01
.0^
.01
.02
.03
.03
.01
.04
.08
.02
.Ot
.02
.01
.01
• 03
3-49
-04
.01
.18
LH Peak
30-Ein
intensi ty
(in/hr)
. 1 4
.26
.64
-50
.24
.36
• 52
.10
.16
.14
.10
.10
.06
• 38
.10
.10
.14
.16
.06
.02
.20
.14
.22
• 04
• 30
.08
• 38
.06
.06
.20
.16
.06
.20
.10
.10
.12
.26
.04
.08
.04
13-36
.15
.02
.64
3D
Total
Rain
(in)
.05
.68
. 53
1 . ?2
.43
. 81
4-36
. 14
.24
.74
.10
. J7
-09
1 .50
. 1 i
.10
.36
-51
.20
-03
.86
-49
. 18
.14
.55
.19
1 .10
.17
.05
.78
.36
.29
.79
.08
.27
.09
.45
.06
.04
• 03
31 .56
.36
.03
4.38
3D
Durat ion
(hrs)

: .7
31 -4
1C. 6
33-3
3 - '
'1.7
34.1
5-4
9.7
27.5
1 .2
5-2
3-2
20.2
8.3
2.6
25-4
16.2
16.4
1 .4
28.5
5-5
4.3
16.2
18.6
13-3
17.6
9-6
5-2
30.6
6.1
15-2
19-5
.8
8.6
1 .7
22.2
1 .2
5-3
4.5
923-0
10.5
.4
39-8
S: Ave.
Rain Int.
(i-i/hr)



. "

""'
^

0"
.0
-03
.08
.01
.03
.07
.01
.04
.01
03
.01
.02
.03
.09
.04
.01
.03
.01
.06
.02
.01
.03
.06
.02
.04
.10
.03
.05
.02
.05
.01
.01
3-41
-04
.01
-15
3D Peak
30 -i in
intensi ty
( in/hr)
.04
. ^2
. y-'

. .; ~j
. 4'~
.64
. 1 4
. 10
. 14
.10
.04
.06
.26
.03
1C
. 12
. 1 4
.03
.04
.26
. ?2
. 1 3
. 10
. 24
.12
. 28
.06
.06
.16
.13
.08
. 14
.12
.12
.12
• 34
.06
.04
.04
12.42
. 14
.0?
.64
LH/::,
Rain
Ratio

2 . '. 0
' - ~ ',
' ^ '

*", ~
• ?4
.r;4

1 • ' 3
. ' H ^
1 . '0
? ^'~-t
- 7*3
1 . Cq
1 . 2-"
• '~<'j
1 . ?c
1 -C4
- ~i~j
1 . or,
1 .02
. 7'
1.17
.64
1 . Gi
.34
1 . 1 r.
1 .29
1 .CO
1 .08
• 83
.72
.87
1 .13
• 96
• 78
• 39
1-17
2.50
2.00
102.72
1 -17
-25
3-60
LH / Z u
D 'j r 3 * i o r.
F.a". 10

i

. -u.

• . ; j

1 . '. c
i i -
''3

1 '. -;
2 . '^
Op
1 . '. ?
1 . C2

1 ' 3

' . 3
1 . ^ ' '
1 . ". 6
.Of
r c
. i~.
• CO
1 .' 6
1 . T4
1.61
-52
. ฐ 'J
1 .46
1 .00
.T3
1 -50
1 .25
1 .00
1 .06
5-53
1 .51
• 53
105.23
1 .20
. 1 ^
6.67
Z Z - L '• '.
Z ' '\ r t
T I.i7 *?

• -
- . " ;-
-. -
. ' ',
i . * n

-1 7
-. ' 1
_ . ' ^
- , '• ^
•~ '<-,
-2 . -"'
Cj
r r
• '-'.'
-j ;j 7
~*
, ' -,
- . " •'"•

-.42
-• "'
-. "_3
- 50
. 1 7
. '" <"'
4 i -7
7 ~
-4. . '^
-. C9
-.75
-.17
-• 37
. V,
3.50
-1 .08
-.33
-.42
-3-17
-! . 17
-28.14
-. *'
-5-16
5-43

-------
Table A-5 •  R^in Data  for  Lake  Hills and Surrey Dcr.nj for 10-2
Date


1/10/32
t/15
1/17
1/22
1/25
1/25
1/27
1/27
1/30
sum
average
minimum
maximum
LH
j. 0 ~t Q.1
Rain
( in)
^ c
• 98
.18
1-32
. 12
• 96
.06
.04
• 87
4-88
• 54
• 04
1-32
in
i/ur&tiGfi
(hrs)

24.8
27-9
12.3
35-1
5-3
17-8
2.9
4.2
72.8
203-6
22.6
2.9
72.8
LH Ave.
nฃi in i n t .
(in/hrj

.01
.04
.01
.04
.02
• 05
.02
.01
.01
.22
.02
.01
-05
'*(-• ซ, i n
, w — in i n
intensity
( in/hr )
.12
.14
.10
.18
.06
.12
.04
.02
.12
• 92
. 10
.02
.18

3D
Rain
(i

1 .

1 .

1 .


1 .
5.


1 .
n)
30
10
16
17
13
01
07
04
15
13
57
04
17
-'
( iira

2.1.
OQ
8.
35-
5-
17.
5.

74.
203.
22.
3-
71-
:


c
7
8
7
2
3
8
4
7
6
6
4
7

' in/hr j

.01
.04
.02
• 03
• 03
.06
.01
.01
.02
.22
.02
.01
.06

Inter. Ji ty
; in/hr ''
.1 2
. !6
. i 0
.22
. 10
. 1 4
.04
.02
.34
1 .24
. 14
. ( ^
.- 4
                                                                                                   .76
                                                                                                  1.17

-------
          Table A-b
-------
ro
Co
Runoff
Start
Date
9/20
9/29
10/3
10/12
1G/2C
10/24
10/31
11/1
11/3
11/5
11/6
11/9
1 1/H
1 1/<7
11/19
11/20
11/25
1 1/27
1 1/28
I 1/29
12/1
12/2
12/3
U/10
12/11
12/14
12/20
12/21
12/24
12/25
12/26
12/29
12/30
Sum
Average
Minimum
Maximum
Total
Rain
( Inches)
.38
.43
.19
.12
.03
.16
.74
.29
.60
.33
1 .59
.22
. 12
.05
.21
1 .66
-15
.71
.66
.22
.05
-97
.51
.04
-03
.1 1
-43
.73
.77
1 .28
.34
.30
.84
28.61
-35
.03
1 .66
Rain
Duration
(hrs)
15-9
7.4
10.2
14.6
2.3
6.2
25-1
13.5
?4.1
3 . 2
5o.5
12.8
9-8
5.5
3-2
22.3
5-8
17.8
21 .0
18. 1
7-7
15-2
31 .4
5.1
1 . 1
5.8
11 -3
24-1
30.0
18.0
6.6
12.0
23-9
969-8
11 .8
. 7
56.5
Average
Rain Int.
(in/hr)
.03
.06
.02
.01
.01
• 03
.03
.02
.03
. 1 0
• 03
.02
.01
.01
.07
.07
• 03
.04
.03
.01
.01
.06
.02
.01
.03
.02
.04
• 03
.03
.07
.05
.03
.04
2.71
.03
.01
.10
Peak 30
Min Int.
Total
Discharge
(in/hr)(cubic feet)
.30
.24
.18
.04
.04
.10
.10
.14
. 1 2
. '6
.33
. 14
.04
.04
. 12
.46
.10
.22
.18
.06
.04
.20
.14
.02
.04
.06
.18
.16
.22
• 30
.16
.06
.14
1 1 .02
.13
.02
.50
20300
23700
1C200
4280
1390
7760
43500
20700
41 SCO
20400
1 26000
17200
5330
2510
14200
1 30000
8730
55100
60000
27900
4920
90900
61200
120
515
5050
25100
60400
72000
1 35000
43900
26500
99600
2082642
25398
120
135000
Total
Discharge
(inches }
.06
.C7
.03
.01
.03
.C2
• 1 5
.06
.13
.06
• 3"
.05
.02
.01
.04
.40
.03
.17
.18
.09
.02
.23
.19
.00
.00
.02
.08
. 19
.22
• 42
.14
.08
•31
6.41
.08
.00
.42
Runoff
Duration
(hours)
15-4
6.7
10.4
6.9
1 -9
5.3
24.5
13-3
22. 1
5-4
55-9
12.1
5.2
3-4
5-4
27.8
5-4
17.8
27.2
22.6
7-5
20.7
35- a
.2
-9
6.2
7.8
25.4
35-8
24.1
12.6
15-5
29-8
1 ,021 .3
12.5
.2
55-9
Peak
Di?charge
(c: j)
4.40
~*. . 70
3.44
. 62
.51
1 -53
1 -73
1 .Tr4
2.75
4.40
5-34
2.?7
1 .26
• 37
3.02
7. 17
1 -73
3-16
3-30
1.13
.74
4.40
2.49
.13
.22
.87
2.49
3-02
2.60
5.14
3-30
1 .02
2.88
178.12
2.17
.07
7.17
Runoff
Coefficient
(H\/-rnt io )
. ' 6
. 17
'?
i *
i ^
.15
.20
.22
.21
. 13
.24
.24
. '4
• . 5
.21
.24
. \-^

. :-3
. 3 1
. i^
.2-3
1 *7
.•;i
.05
. 1 4
. i ?
. ,/ 5
• 29
. ^2
.40
-27
• 37
15-18
.19
.01
.64
Runoff/Pain
Duration
( ratio }
r-,^
. "-• 1
i " ")
• t
f ^ ~
• ?'4
. ~'^

. c.
'..'•'"•>
';"?




' , ^
- r
- r
1 J
c
-""
1 . tl?
I . '4
.C4
.52
1 -C"
. O
1 .0^
1.19
1 .34
1 .3!
1 -29
1 -25
87. 13
1 . •>;
.C4
4.91

-------
              Table A-btx.
                                 Surrey Downs Runoff  Uondltlor.s for 1961
no
OJ
en
Runoff
Gtart
Date (
1/6/81
1/8
1/17
Via
1 /20
1/2;
i /:?
1/27
1/28
2/11
2/13
2/17
2/18
2/24
3/3
3/5
3/15
3/21
3/22
3/23
3/24
3/28
3/31
4/2
4/5
4/6
4/7
4/10
4/12
4/20
4/22
4/23
4/27
4/28
5/3
5/7
5/7
5/9
5/10
5/14
5/18
5/19
5/24
5/24
5/25
6/4
6/5
6/8
6/9
6/10
6/12
6/12
Total
Rain
Inchea J
.05
.04
. 1 1
. 11
.27
.42
• 38
.09
.63
.9'
1 .05
.16
.73
.36
.62
.10
.28
.04
.03
• 34
.26
.18
.11
.23
.16
.38
.22
.34
.13
.08
.11
.08
.15
• 32
.21
.16
• 33
.05
.29
.05
.15
.22
.04
.17
.14
.03
• 33
• 31
.05
.03
-23
• 33
Rain Average Peak 30
Duration Rain Int. fin Int.
(hrs) (
' .5
3-1
7.3
5.8
9-6
32.3
1C. 6
4.5
15-4
22-8
70.0
6.4
25-2
15-7
25-8
4.8
25-5
HA
IU
12.1
7-9
12.0
3-4
17-7
2-3
3-2
18-3
26.2
11.8
3-6
10.0
3-0
3-3
9-4
2.3
6.2
5-7
4-2
6.7
2.0
8.8
6.3
5-0
7-7
5-0
.7
6.7
5-1
.6
1.3
2-5
6.6
Total
"isehar^e Dig
Total Runoff Peax
.:har>/e Duration Diecv!ซ~ff<3 ~jefi
! i n / h r ) (in/hrJ( cubic feet) ' i n c h e 3 )
.03
.01
.02
.02
.03
.01
.04
.02
.04
.04
.02
.03
.03
.02
.02
.02
.01
NA
!IA
.03
.03
.02
-03
.01
.07
.12
.01
.01
.01
.02
.01
.03
.05
.03
.09
.03
.06
.01
.04
.03
.02
.04
.01
.02
.03
.04
.05
.06
.08
.02
.09
.05
.02
.04
.08
.04
. 10
.12
. 14
.04
.10
. 18
.16
.06
.42
. 10
. 10
.08
.08
NA
MA
.14
.08
.06
.04
.12
.12
• 32
.06
.12
.10
.04
.06
.06
.06
.12
.14
.14
.26
.04
.20
.06
.06
.10
.02
.10
.10
NA
.14
.12
.08
.04
.22
.28
1060
1110
4030
6340
16600
35900
29700
5640
56300
63800
1 4 1 000
1 8000
84000
34300
383CO
8310
23300
;IA
NA
18800
14600
7400
4200
5700
5250
15700
4310
9080
3680
1260
2010
1600
5490
19800
9690
5550
19600
1290
20500
1240
5370
11800
100
7330
7870
378
17600
17500
1930
640
10600
16500
.00
.00
.01
.02
-05
. 1 1
-09
.02
.17
.20
.44
.06
.26
. 1 1
.12
.03
.07
t!A
MA
.CC
.05
.02
.01
.02
.02
.05
.01
.03
.01
.00
.01
.00
.02
.06
-03
.02
.06
.00
.06
.00
.02
.04
.00
.02
.02
.00
.05
.05
.01
.00
.03
.05
fhrs)
1 .4
1 .2
6.6
6.0
9-3
33.2
14.2
4.2
20.7
26.2
72. 1
12.3
31 -3
22.8
19-3
4.5
25.8
"A
MA
11 -7
7.7
10.3
2.5
7.8
2.4
2.3
18.7
17.8
6.4
2.4
3-2
1.5
3-5
10.0
3-2
5-7
4.2
1 .2
5-6
2.2
4.2
5.3
.1
4.3
4.5
.5
6.9
5.6
1 .1
.6
2.8
7.8
(Cf3) ?.V-
11
-51
. 8"
.87
1 -67
2.27
2.60
.80
1 .73
2.74
3-30
1 .83
6 54
1 .63
2 • '. 5
1 .94
2.16
!!A
I:A
1 .94
2.16
1 .02
.80
2. 2^
1 .26
3-44
.42
1 .44
1.10
.51
-51
.62
.80
2.16
1 -94
1.83
4-40
• 51
3-89
.42
.80
1 .53
• 33
1 -53
1 -53
.29
2.16
' -83
1.26
• 33
2.74
4.06
hu, - :'. jtunc
rte:er.- I
-ratio '
.•--
. C1^
. ' 1
. IP,
. 1ฐ
.26
.24
- 19
. 2*i
.22
.41
- V5
'5f.
.29
-'9
.26
.26
"A
MA
. 17
.17
.13
.12
. 08
.10
.13
.06
.08
.0ฐ
.05
.06
.Cb
.11
.19
.14
11
.18
.08
.22
.08
. 1 1
.17
.01
.13
.17
.04
.16
.17
.12
.07
* 4
.15
, f f ' ? t : -i
' .-•>• ;-,
. "-2
• ?"'
rtr
1 . C4
1 .02
1 .C3
i .75
. ^
I 35
1 . 15
' .03
1 .92
1 . 24
1 .46
-75
MC]
• .01
*;A
:;A
.-'6
.38
. 66
.75
. 44
1 .05
. 8^!
1 .02
.63
• 54
.66
• 72
• 5'
1 .05
1 . C6
1 .39
-93
-74
• 20
-83
1 .10
.48
.84
.02
• 36
• 90
.72
1 .02
! .10
1 .8^
. 46
1.12
1 . 18

-------
      Table  A-6bJcont.) Currey Downs  Runoff Conditions
ro
oo
01
                                                          o r  I 98 1


                                                             -C4
                                                                                             6.0
Y / *;
7/U
7/1 ;
3/31
9/18
o/t ~>
9/2V
9/25
")/-'.
9/23
10/1
10/5
10/7
10/8
10/27
10/28
10/29
10/30
1/11
1/13
1/13
1/17
1/'9
11/20
1 1/20
1 1/20
1 1/22
1 1/22
1 1/23
1 1/30
12/1
12/3
12/3
12/4
12/5
12/6
12/9
12/13
12/15
12/17
1 2/18
12/18
12/21
12/24
12/24
12/26
12/27
12/28
Gua
Average
Minimum
Max imum
. 1 6
1.17
.24
.Ct,
-45
.05
. 65
c o
( , 22
.43
.81
4.38
.14
.24
.74
.10
-07
.09
1.50
. 1 1
.10
.51
.13
.07
.03
.86
.03
.49
. 18
.14
• 55
.03
.16
1.10
.17
.05
.78
• 36
.62
.15
.14
•79
.08
.27
.09
.45
.06
.04
35-36
• 34
.03
4.38
C
i r
13-
i''
1 .
30.
10.
39-
9.
9-
33-
5-
Q .
27
1 .
5-
3 -
20
e
2
1 6
6
1
1
28
1
5
4
15
16

7
17
9
5
31
6
13
5
3
19

8
1
22
1
5
1 ,069
10

70
2
a
c
4
]
IT
7
4
6
4
2
4
2
-*
5
6
5
5
0
4
7
j
5
7
6
3
8
0
7
4
0
2
1
2
9
8
3
.8
7
7
5
.2
0
. 1
5
.4
.0
^ i
. 'ji.
.^^
. 1
/-,
.C
• * ^
.05
.06
.13
-03
.03
.03
.08
.01
.03
.07
.01
.0.*
-ฐ3
.02
.07
.02
-03
.02
.09
.04
.01
.03
.04
.02
.06
.02
.01
.03
.06
•05
•03
.04
.04
. 10
• 03
.05
.02
-05
.01
3-91
.04
.01
• 15
. >'J8
.24
.22
i f'
• ' 2
. ",'\
~> ;:>
.26
.40
.4"j
.64
. 14
. 1C
. 1 4
.10
.04
.06
.26
.08
. 1 C
. 14
.06
.08
.C4
.26
.04
.22
. 18
.10
.24
. 0 i
. 12
.28
.06
.06
.16
.18
.28
.06
.08
. 14
. 1 2
.12
.12
.34
.06
.04
13-88
. 1 4
.02
.64
G
10
yi
1 1
12
52
16
1 i
28
->
2
4
27
Q
4
20
6
2
2
'4
~j
1 1
1 1
1 )
21
1
q
26
18
1 1
38
7
1 0
7
,T
24
1
7
4
2 3
3
2
1 , 158
1 I

72
2
c
D
9
p
p
9
-7
9
2
1
7
r;
1
4
-',
4
7
9
i

0
6
1
4
2
4
2
4
3
6
v
7
2
3
2
6
1
8
8
3
5
8
4
2
5
3
7
3
3
8
4
1
1
-r
7
V
7
ฃ
C
1 2
2

2
1

1
4
1

2



^

7
3
1
4

1
5
i

2
2
c:

1
3


•
7


220
2

12
e>;
30
7 o
40
74
'•4
JO
'" 0
^4
-'. "i
" ',
c 6
C2
-. ป
' •*
, ',
3;-
1 8
ฐ4
7-'
cฐ
•16
j ,1
r; ?
44
•1 0
H
9J
34
10
87
60
68
1 4
' 7
18
1 (.•


69
7 ?
•J4
.67
ซ2
16
2q
CO
                                                                                                                     .51

-------
Table A-6c.
Surrey Downs Hunoff Conditions for  1
Runoff
Start
Date
1/10/82
1/13
1/15
1/17
1/22
1/25
1/25
1/27
1/27
1/30
2/1
ro
OJ
~j Sum
Average
Minimum
Maximum
Total
Rain
( Inches;
• 30
.05
1.10
.16
1.17
.13
1 .01
.07
.04
.72
-43
5.18
.47
.04
1.17
Rain
Duration
(hrs)
25.0
6.3
28.9
8.9
35-5
5-2
17-4
5.8
3-3
42.4
25-3
204-0
13.5
3-3
42.4
                                   Average  Peak 30       Total
                                  lin  Int. Kin Int.   Discharge Discharge
                                   (in/hr)  (in/hr )( cubic feet)  ''
                     .01
                     .01
                     .04
                     .02
                     • 03
                     • 03
                     .06
                     .01
                     .01
                     .02
                     .02

                     • 25
                     .02
                     .01
                     .06
 . 12
 .02
 .16
 . 10
 .22
 .10
 • H
 .04
 .02
 • 34
 .06

1-32
 . 1 2
 .02
 • 34
 17800
  2700
 Q0800
 1 3800
 91000
 11600
 96200
 1 1400
  61 10
 56800
 49700

449910
 -50901
  2700
 98200
'otal
ar^e
he s )
.05
.01
.28
.04
.28
.04
• 30
-04
.02
.18
.15
1.39
-13
.01
-30
Runoff
Duration
Cr.rs)
21 .2
c .6
34.3
10.7
41 .7
11.2
24.3
1 1 .8
8.6
46.3
31.2
247.4
22.5
5.6
46.8
Vc>
1 .

_^ .
1 .
3.
1 .
3.


4
1
21
1

4
•s)
.73
29
,02
.44
. 16
.63
.72
.62
• 33
.40
.26
.60
• 96
• 29
.40
(Rv-rat : ~j .
.18
. 17
.25
. 2"
.21
. . 2B
• 30
.50
.47
.24
.36
3-26
.30
. 1 7
.50
                                                                                                                 1 .4;

-------
                                   iiil.5 Runoff  Jcr.d 1t Lor:j  f:r  1 Slr-0
rxj
Go
OO
Hunrjf?
J t 'j. r t.
ป* 'JL j *i ^ J
/i5/2~
2/17
2 / ' 9
2/25
7 / V
, ;
3/10
' ' ' 2
3/19
3/26
3/29
4/5
4/5
4/8
4/11
4/18
4/20
4/29
5/20
5/21
5/22
3/24
5/25
5/26
5/27
6/1
6/1
6/5
6/8
6/16
6/23,
6/24
6/25
7/4
7/11
7/14
8/2
8/17
b/26
8/27
b/28
0/30
8/31
9/1
9/6
9/12
9/13
9/19
9/20
7';Vdl
L \\r .IP 3 i
1 . 44
. i" }
.76
1.05
.27
.21
.12
.07
.45
• 92
.32
1 -35
.07
.07
. 10
•19
.06
• ' ~j
.07
• 50
. 1C
.69
.06
-17
- 17
.12
.04
72
.08
.09
.28
.15
.09
.63
.04
.17
.26
.04
.08
.57
.23
. 12
.16
.10
.25
-'a.n A
i r -i . i j n . ./i x
6.0
31 -4
9.7
4Q . 7
12.9
7. ^
35.6
43-8
16.9
21 .0
6.7
2.3
16.8
20.9
10.7
34.1
2.2
.4
9. :
4.8
2.6
5.4
8.8
16.1
6.3
7.8
• 9
21 .3
8.9
2.2
8.0
9-9
.8
3-5
17.5
6-5
2.0
9-3
• 5
1 .2
2.6
5-0
13-3
17.8
4.2
4.6
.11.4
3-4
13.9
.-j-ir-ien ?•;
' n / •- r ' i
ป n / . . i t i i
.02
r 2
.03
.02
.02
02
.02
.01
.02
.0}
.02
.04
.03
.04
.03
. 17
.01
.04
.^2
.03
.01
.03
.02
.09
.07
.01
.02
.15
.01
.07
.10
.03
.02
.02
.05
.07
.08
. 1 4
. 10
.01
.01
.03
.06
.03
.01
• 03
.02
IK: TO
[-,/->, t i c U I
• * 4
. I 2
. 14
.06
-30
.14
.06
.22
.06
.06
. 16
.22
. ' H
.20
.04
. 14
.04
. ' 2
.04
.08
.02
. 12
.04
.18
.10
.02
- 14
. 2y
.02
.22
.10
.04
.08
. 1C
.04
.58
.08
.28
.22
.04
.02
.14
.22
.06
.04
.04
. 16
ToVil
ฃ L i"* ? 'f* & r • ' i
735CO
31^:0
1 4 1 OC 0
91 20
6950'"
! 4 1000
25600
15300
^;ฐ

37 ='-'0
91 000
173'.C
; 33000
15^0
1660
1 900
1 uljO
035
5850
1240
38100
4070
54900
26 JO
6920
91^0
21000
2700
52400
3630
1570
9870
6090
2770
54400
1210
14300
15900
2100
2?20
56900
14800
3710
4810
3200
17300
™ ri'.'\ \

_ r o
.41
. 1 4
.03
.20
.41
.07
.04
.01
. ;i
. 1 1
.27
.05
30
00
.TO
.01
.03
.00
. 02
.00
. 1 1
.01
. 16
.01
.02
.03
.06
.01
. 15
.01
.00
.03
.02
.01
. 6
.CO
.04
.05
.01
.01
. 16
.04
.01
.01
.01
.05

f -, o j f j
3''.
i i .
5.
24
44 .
1"?.
4.
T
2 .
20.
27.
1 1 .
36 .

i
f! .
4 .
1 .
c
S .
15.
3
9.

23.
4.
3.

!Q.
1 .
1
1 2 .
7.
2.
P.
1
2.
3-

6.
19.
1,
3
9.
2
13
f

p
T
4

7
-i
J
•' ' j
1
i
4
1
^
0
-
~>
•'
3
fi
7
9
3
6
1
f
2

0
0
c
.7
1
.3
8
.2
.3
• 9

-^
.0
.6
0
. 1
.4
.7
?":

c

6 .
0
'
5.


7 .
7 _
2.
4 .



2 .

l .

c •


2 .

^ .


c, .
2.

t .
1

19.

7
5


5
6



h
'"•

4 '
-',
V"7
,; ",
"•4
5 T
-2
6!
72
72
7.7
68
-; T

1 •">

ป :
, " S
24
ij ;
.6'
57
-'. ?
T?
17
. 22
. 10
7"
8"
S7
.05
• 54
.65
50
.65
.47
.40
. 10
. PO
. 47
.07
. '">2
.41
.57
•52

_
. ,2
. ' 4
. '•.'.
1 ~i
*'^
. 2 '
,1
'' '•
. : s
. c '

. . i

. ."
,o
i "

• i

2''

. .: '
. 1 "*
. 1 2
1 rj
1 9
' ";
. 2
. 1 7

. ' 0
1 2
.00
. 75
:Q
. 24
. I VJ
. 15
. I i
. 29
. 1 1
. '" ')
. ' "i
)
20

-------
Table A-7a.Lake Hills Runoff Conditions  for  1980 (cont.)
Runoff
Start
Date
9/29
I 0/8
10/12
10/24
10/31
11/1
11/3
11/5
1 1 /6
1 1/7
1 1/3
1 1 /P
1/14
1/17
1/19
1/20
1/23
1/25
1/27
1/28
11/30
11/30
12/2
12/3
12/4
12/10
12/14
2/20
12/21
12/22
12/24
12/25
12/26
12/29
12/30
sum
average
min ifflum
maxiaum
Total
Rain
(inches)
.49
. 1 t
. 16
. 17
.74
• 3o
.52
• 35
.77
.43
.24
. 1 7
.15
.03
.19
1 -55
.06
.16
.70
.61
.08
.14
1 .02
.43
.23
.06
.17
-43
.60
.08
.73
1 .28
.32
• 30
• 83
30.10
• 36
.03
1.55
Rain Average Peak 30
Duration Rain Int. Kin Int.
(hrs)
5.
Q.
16.
7-
24.
10.
22
3-
12.
19.
3.
1 1 .
4.
t .
2.
23-
1 .
2.
13.
17.
2.
6.
15-
18.
4 .
7.
5-
1 1 .



l
c
11'.
27.
966.
11 .
.
49-
5
2
0
4
7
6
6
7
4
5
^
3
8
2
7
1
4
7
7
9
1
4
0
7
8
5
9
3
5
i



5
7
8
5
4
7
( ln/hr)
.09
.01
.01
.02
.03
.03
.02
. 10
.06
.02
• 03
02
'03
.03
.07
.07
.04
.06
.05
.03
.04
.02
.07
.02
.05
.01
.03
.04
.04
.01
.02
.07
.05
.03
.03
3-32
.04
.01
.17
Total Total
Discharge Discharge
(in/hr)(cublc feet)
.23
. 1 2
.03
. 10
. 1C
. 1 4
. 14
.24
.22
.20
.24
.12
.03
.02
. 18
.42
. 10
.12
.26
.13
.06
.04
.23
.18
.06
.04
.12
. 14
.14
.06
.20
• 30
.16
.04
.12
11 .28
.13
.02
-58
4.1800
2590
",7=0
8140
C82CC
38700

393CO
1 06000
5y800
27000
15200
9710
730
17400
223000
4400
12600
86400
77600
9410
16200
1 53000
73200
15400
2490
14500
37200
70700
1450
84500
210000
53000
31400
129000
3064825
36406
730
223000
( inches)
.1'
. o i
.02
.02
. 17
. 1 1
. 14
. i :
.31
. 17
.03
.04
.03
.00
.05
.64
.01
.04
.25
.22
• 03
.05
.46
.21
.04
.01
.04
. t 1
.20
.00
.24
.61
.15
.09
• 37
8.86
. 1 1
.00
.64
Piroff Pซjax:
Duration Discharge Co
( hours )
6. 1
6.8
15.0
6. 5
23-5
ll.i
17.1
4.3
14.4
20.3
9.8
12.2
3-4
.8
3.4
30.3
1 .2
2.7
17-2
22.8
4.0
3.2
19-4
24.2
10.3
6.3
6.4
11.5
n.6
2.2
33-1
23.0
11 .9
12.8
33.2
961 .5
1 1 .7
.6
53-8
Runoff Runoff/?alT
; f ' i f. 1 ". n t Z u - \ •.!•-, n
(cfs ) (r!v-rat lo) ( rat io )
9

t

2
tr
4
1 1
1 1
6
6
3
1

3
1 r
4
2
< "5
6
l
1
10
5
•3
J

"*•
3
5

5
12
7
1
4
340
4

19
1 9
51
1 2
^
f":
11
56
.20
40
.67
82
.07
.73
.41
.35
. 20
. 56
. 37
.20
.22
.62
.22
.60
. 16
. 17
.33
.07
-96
.92
.29
.92
.80
. 12
.40
• 92
.40
.05
. 10
.50
"' <-" ' ' *
. " ^ "' '.
• ' 2 '*•
' '.
" ' • • =
. 1 1 l.i?
? 6 .76
. ; 2 i.'"
,40 ' . '6
. 4 ", ' '. ':
• 3 3 ' ' :'
.26 ' ' '
. ' j . """,
. 0 7 ". 7
• 26 :
. 4 1- ; :
. ' -'6
. ; ' i . oo
. '. i . 25
. '„' ' 1.2"
T < 1 -, -r
'•29'
.15 l . 2r>
.4:- • . ;•?
• 1 ~! 2.7 '•.
• 1 2 34
.25 t .0-4
. 2 5 '.02
.34 1 . C4
.05 .22
.31 t ."•
.4" !.'<
.45 2 . t 1
. 7r 1.1:
.45 1 .20
18.35 86.::
.22 1 .'.7
.02 . :o
.49 2 . 40

-------
Table A-7K         Lake Hills  r'un-jf;'  Conditions f-j
Runoff
T^.al Pair. Av.'ra^e Peak 30 7ot"aL
'•In ' n P,T I r ct •• • r% n "• *i • n ^ " *• - Mln 7 1 • l"j 1 <> i" 'r *1 r .7 i> H - ^
" _' ' , ^
1/6/51 .07
1/3 .03
1/17 .06
1/18 .09
1/22 .11
1/23 -49
1/26 .16
1/27
1/28
2/11
2/13
2/13
2/15
2/1 V
2/18
3/24
3/29

'4/2
4/2
4/4
4/5
4/5
4/6
4/7
4/10
4/12
4/20
4/21
4/23
4/27
4/28
5/3
5/7
5/11
5/14
5/14
5/18
5/19
5/24
5/24
6/3
6/4
6/5
6/7
6/8
6/9
6/12
6/12
6/15
6/17
6/19
.06
.60
1 .00
.24
.53
.47
.16
-58
.21
.14
-32
.07
.20
.06
. 18
.04
.34
.28
.42
.12
.19
.27
.08
.18
.35
.29
.33
-39
.18
.08
.20
.24
.03
.36
.06
.03
.43
.07
.40
.08
.28
.21
.10
• 37
.02
' r. -, • '
1 .2
1 .0
4.6
6.9
B-5
14.=
5.3
2.
2
17.1
22 .
/
9-6
37-9
22.4
8,
18.
6.
q.
1 1 .
3.
6
1
3

1
20
32
6
3
16
2
4
14
4
16
6
4

7
5

14
4

6
4
5
f.
4
6
5
21

.0
.7
.4
•J
.9
.3
.9
.7
.8
.9
.9
.0
• 3
.7
. 1
-9
.4
.7
.0
.4
.5
. 1
.2
• 3
. 1
• 5
.8
.4
t
• J
.8
.2
.7
.7
.0
.2
.8
.6
.8
.1
i n / h r ; i' i
.06
.03
ioi
.01
• 33
.r.-*
.04
.04
.03
.0'
.02
.02
.03
.03
.02
.03
.02
-03
.04
.05
-04
.13
.01
.01
.02
.06
.02
.03
.04
.03
.07
.02
.06
.04
.12
.03
.04
.04
.03
.01
.04
.07
.02
.07
.02
.07
.03
.02
.02
.20
/ซ v ' ri-l-
.ce
. ~ 4
.04
.04
.04
. 1 6
.02
.08
.20
.08
.14
.20
.06
• 36
.03
.06
.08
.06
.22
.04
.12
.04
.28
.06
.14
.08
.14
.08
.06
.06
. 12
.22
.16
.26
.22
.16
. 12
. 10
.04
.20
.04
.04
. 16
.08
.16
.06
.18
.12
.08
.08
.04
, „ p Jt, ,. ) / ;
2?CO
310
2" 20
644"
'••'. 0 j
53300
1 1 COO
32rO
75.00
= 0200
1 9900
'.8400
' 1 000
1 0600
46300
1 3000
4700
22300
1940
i 4 TOO
2770
12500
2180
36900
'6300
31400
7340
S3 50
17600
2880
6960
23300
13900
17700
24700
12500
4680
9530
14100
530
20500
1210
260
27700
2050
29100
4190
16200
1 1000
2540
12500
212
To*. <} -
n ^ h c. -j )
.01
.r.O
.01
. 02
r- 1
.01
.22
.26
.06
.17
.15
.03
.13
.04
.01
.06
.01
.04
.01
.04
.01
. 1 1
.05
-09
.02
.02
.05
.01
.02
.07
.04
.05
.07
.04
.01
.03
.04
.00
.Z6
.00
.00
.08
.01
.08
.01
.05
.01
.01
.04
.TO
j r '-i * '. -
\ r 'j - ' T
5-
2.
1 a,.
26.
10.
41 .
26.
7.
' 1 -
7.
3 .
12.
'
6.
^
}.

TT
21 .
31 .
7.
3 .
10.
2.
4.
9-
5-
13.
4.
1 .

"5.
5-

14.
1 .

(,'.
\ .
5.
4.
3.
6.
'->.
20.

n I/ L
\
e
7
i
?
'.
rf
o
6
•<
^

8
o
5
":
8
c
J
1
1
5
i
7
2
5
9
1
3
7
5
9
5
5
8
1
5
4
7
2
2
I
6
9
8
7
3
,._;:

i .

2.
v .
i
4 .
7 .
1 .
').


1 .

6.

y

"7 _

3 ,
2.
2.
2.
1 .

2.
2.
4 .
5.
V
5.
2,
2.

5.


3'
1 .
3
3
3
2

1

S-*

;>
•'C
ฃ6
':-1
. "-i
' 6
; ^
. ?^
i }
7 •'•
. v^
,o2
f- '
. "*,*7
5?
T7
. ' ฃ
1 3
-y)
.72
.02
1s.
.02
>r4
.80
.78
.73
. ;H
,6'j
57
.53
.34
.10
.24
.40
• 92
.22
.84
.40
.61
. 28
.R4
.97
.70
."U
.(2
                                                                                                         .'4
                                                                                                         . 17
                                                                                                         .05
                                                                                                         . 16
                                                                                                         .06
                                                                                                         .35
                                                                                                         . n
                                                                                                         .08
                                                                                                         .2!
                                                                                                         .'5
                                                                                                         . 17
                                                                                                         .15
                                                                                                         .07
                                                                                                          10

-------
ible A-7h.,cont.)
                  Ink* till la
                      .'".4
                              Runoff Condltlona  for  1981
•'1 1
9/20
0 / 2 o
;/27
J/29
9/28
10/1
10/5
10/8
10/27
10/28
10/29
1 " '30
1 1 /3
I/tl
11/13
1/14
11/14
1/15
1/17
1/19
1/20
1/20
1/22
1/23
1/30
12/1
12/1
12/3
12/4
12/5
12/9
12/9
12/13
12/14
12/17
12/18
2/21
12/24
12/24
12/26
12/27
12/28
12/30
sum
verage
Inimua
ax i mum
.'•A
1 . 25
.45
. 10
1 .05
1 .06
. 14
1 . 20
. 14
.42
. 76
3-69
.27
• 73
.1 1
.16
.07
.10
1 .58
. 14
-05
• 31
.14
• 53
. !8
.03
.88
• 35
.21
.09
.0'
.57
.16
1 .21
.22
-03
.84
• 30
• 96
.21
.69
.09
.26
.07
.40
.07
.10
.06
36.05
.34
.02
3-69
K C
8.M
1 . "?
1 \. 1
12.0
1 . 0
i .0
71 -8
i. 1
14. )
8 . •
4.2
11.7
8.5
35-3
9-6
27.0
1-3
10.7
2.8
6.3
20.8
8.8
.S
15.5
2.3
18.3
18.0
1 .8
30.3
5-3
4.8
10.0
1 .2
13.4
14-5
21.6
15-7
.1
30.0
8.8
23.4
15-0
19.2
1.2
10.8
'.7
23.5
7.0
8.3
2.4
1 .048.2
10.0
.1
37.9
.02
.02
. i 2
.04
.06
.03
.01
.15
.03
.04
•'9
.10
.03
. r 3
.09
.02
.03
.02
.08
.02
. 10
.02
.06
.03
.01
.02
.03
.07
.04
.01
.03
.03
.01
.06
.01
.04
.03
.03
.04
.01
.04
.08
.02
.04
.02
.01
.01
.03
4-56
.04
.01
.32
. 2
'.2
. 1
64
. 04
-50
.03
.24
• 36
.52
. 16
.14
. 10
.10
.06
. ~ '
.""3
. 10
.10
.10
. 1 4
. 16
.06
.02
.20
.14
.22
.04
.04
• 30
.08
• 30
.06
.04
.20
.16
• 32
.06
.20
.10
.10
.12
.26
.08
.0;
.08
14-96
.U
.02
.64
4 -'•lOO
•37 ; .0
1 1 5000
5 5 - 0
1 2 1 000
17400
4 ' 000
84 600
490000
4 d' 6 0 .,
52"00
351 0
10200
3060
4 '30
1 39000
1 1 400
3930
28800
1 3 : 00
6C93C
1 1300
760
122000
47400
29600
2170
1440
62900
12400
174000
34700
1190
1 1 5000
29700
1 37000
21800
1 1 1 000
8670
23400
7810
43400
5330
9 ! 60
1080
3525930
33580
90
490000
. '4
. i
r l
. 06
.02
• 35
.04
. 1 2
.24
1 .42
.12
.15
.02
. j3
.01
.01
.55
r. ~x
. j '
.08
.04
. 18
.04
.00
.35
.14
• 09
.01
.00
.18
.04
.50
.10
.00
• 34
.09
.40
.06
•32
.03
.07
.02
.13
.02
.03
.00
10.19
.10
.00
1 .42
i - fL
28.7
1 4. 3
17.0
'5.6
7.2
15.2
14.7
28. 1
19 2
23 4
2.2
11.1
3-5
6. 1
70.7
10.0
1 .5
16.4
5-2
21 .4
'7.6
1 .5
42.0
II .2
10.8
4-3
1 .0
23-2
14.5
23.0
.MA
-9
36.0
10.1
28.8
18.6
24.9
6.4
8.8
4.3
18. 1
7-3
7.6
2.4
1 ,095-4
10.7
. •*,
42.0
i ?
1 .40
20 . 'f.
. rj3
15.00
2.51
6 '3 ."'
1 5 . 60
1 Q . 00
5.40
4 - 03
2.51

.30
2. '0
13-20
2.71
2.5j
3.50
T.3j
4 . V.
1.16
. 1 8
7.27
q . 40
9-53
.65
.80
11 . 60
2.69
13.40
2.26
.70
6.G/
4.^8
10.40
1.16
7-57
2.78
2.97
3.61
6.97
.70
2.02
.20
430.76
4. 10
- 12
20.00
' '•/:
, • !
. ^';
. ','--
. ',' 3
. T;j
. ;^
. 16
. 2 1
.22
. ' =
• ] 3
1 T
• 35

.23

, ^
• 37
.21
.07
i'l
. '-j
. ;'
. 0'.'
. 14
-32
. 2^
.42
.46
.1 1
.40
.29
.41
• j *
.47
.28
.26
.32
.31
.22
.26
.05
22.01
.2'
- ^1
.4 .
i



i . * ^
,

i

' "0
4
^ -
. "3
i . 4 -;
1 . ' -!
"' . 00
' . 06
2. ;7
1 . 17
. j=j
. ---
1 . '/•*
2 • ' 1
2 . ; 6
_ 47
. --..^
1 . ?b
. ':3
1 .06
?!A
1 .29
1 . ^0
1 . '4
1 .23
i . 24
1 . 70
5-33

2.8:
. ~"7
. .04
.91
1 .CO
127.7!
1.2!
->ฃ
5- 77

-------
Table A-7c.
                   Lake  Hills  Runoff Conditions for 1982
Runoff
Start
Total Sain Average Peak 3C
Rair Duration Rain Int. Mn Int.
Date (inches)
1/10/92
1/15
1/17
1/22
1/23
1/25
1/25
1/27
1/27
1 /TO
1/30
2/1
sun
average
minimum
maximum
• 35
• 98
.18
-58
.74
.12
-96
.06
.04
.06
.14
.73
4-94
.41
.04
• 98
(nrs)
25-
28.
1 2.
13-
10.
5-
17.
2.
4.
6.
5-
40.
171 .
14.
2.
40.
0
0
9
5
1
2
8
9
0
0
6
6
5
3
9
6
(in/hr) (
.01
.04
.01
.04
.07
.02
• 05
.02
.01
.01
-03
.02
-34
• 03
.01
.07
Tc^al Total
Discharge Discharge '.
in/hr ) (cubic feet) (
. 12
. 14
.10
. 12
. 18
.08
. 1 2
.04
.02
.06
.12
.06
1.16
. 10
.02
.18
25500
106000
20600
64300
1 20000
1 4400
162000
10900
7040
3490
16200
93800
644230
53686
3490
162000
incr. ซ3 ;
.07
• 31
.06
.19
.35
.04
.47
.03
.02
.01
.05
.27
1 .86
. 16
.01
.47
-u^'j/^; -i,- ,,^a!^
' no jr.! ' of 3 -
2 I
33.
1 1 .
19
16.
i 0 .
23
8.
9.
•"
7
44
21 2
17.
5
44
.7
. 2
.8
.0
. 1
.9
"7
.9
.7
.5
.9
. 4
.3
.7
, s
.4
2
4.
2.
4
e.
2
q
1


4.
1
37.
'3.

b .
. ^
. 0-1
. 'i7
.20
• 97
. 78
• 5 3
. i"o
. 41
• 'j7
~? ^1
• ^6
.7-7
. 1 2
. 41
•97
                                                                                                        '7

-------
            Table A-8.  Lake  Hills Dry Weather Wichout Street Cleaning  (LHD)
no
-Pป
Co
Storm
number
6
8
9
10
1 1
15
16
18
19
21
22
25
26
28+29
30
31
32
114
116
117
118
119
120
Total
Average
Minimum
Maximum
Month

4/14/80
4/18
5/21
5/24
5/27
6/5
6/8
6/24
6/25
7/11
7/14
8/26
8/27
9/1
9/6
9/12
9/13
7/6/81
7/13
8/31
9/1
9/19
9/20




Flow
(cu ft)
8650
132000
11000
5850
4070
6920
9170
52400
3630
9870
6090
1210
30200
56900
14800
3710
4810
48800
126000
19500
3870
7380
87100
653930
28432
1210
132000
                                             Runoff Concentrations  (mg/1)
Rain
(in)
Total
Sol.
TKII
COD
Total
Phos .
Lead
Zinc
pH
Spec. Turb.
Ccr.d. (ntu)
( umhos )

1
















1



1
8


1
.15
• 33
.19
.15
.10
.18
.17
.72
.08
.28
.15
.04
• 43
.57
• 23
.12
.16
.64
.25
.12
.12
.10
.05
• 33
• 36
.04
.33
87
81
119
87
92
59
195
95
114
85
137
84
190
54
60
24
156
89
79
114
177
274
122
2574
112
24
274
2

1



1
1
1


3
1




1
1
5
2
2
1
33
1

5
.10
• 53
-51
.77
-25
.66
.46
.40
.06
• 8V
.84
• 58
.68
.25
• 98
.67
.56
.04
• 23
.94
.46
• 58
.26
.68
.46
.25
.94
67
13
48
16
31
26
87
41
57
49
43
85
75
30
47
32
39
52
37
100
95
118
54
1241
54
13
118
-27
.19
• 37
.02
.12
.10
.49
.28
.26
.26
-17
• 57
3-61
.08
.27
.15
.10
• 34
.27
.19
• 50
.71
.24
9-55
.42
.02
-3-61
-53
.10
• 38
.15
.12
.12
.56
.19
-38
.23
.20
• 39
• 53
.05
.26
.05
.05
.10
.10
.20
.40
.40
.20
5.69
.25
.05
.56
.12
.08
.14
.1 1
-07
.10
.17
.10
.14
.11
.10
.29
.21
.03
• 13
.1 1
.12
.11
-13
.19
.24
.21
.11
3.17
.14
.07
.29
MA
NA
6.3
6-5
6.0
NA
5.7
5-8
6.2
5-9
5-7
5-3
6.4
6.2
6.0
6.1
6.2
6.3
6.3
6.3
6.4
6.1
6.6
122.3
6.1
5-3
6.6
NA
NA
NA
49
26
NA
22
42
26
51
32
142
31
22
24
34
54
36
37
46
45
43
37
799
42
22
142
it t\
:IA
20
8
13
NA
35
19
15
9
7
26
?9
1 1
16
9
9
8
9
6
16
28
12
305
15
6
35

-------
Table A-9.  Lake
                                                 , lean in..?
otors
number
•3 ป
~ c
c ^
89
90
91
92
93
94
95
96
97
101
102
103
104
105
106
107
108
109
1 10
1 12
113
Total
Average
K iniffium
Maximum
Date

9/2C/8C
3/24/S!
3/23
1/5
4/6
4/7
4/10
0/12
4/20
4/21
4/^3
4/27
5/11
5/14
5/14
5/18
5/24
6/5
6/8
6/9
6/12
6/'2
6/17
6/30




?low
(cu ft)
17300
1 3000
4700
12500
36900
If 300
26000
7340
8350
17600
2880
30300
25400
12500
4680
23700
20500
27700
29'00
4190
16200
1 1000
125GC
21900
402540
16773
2880
36900
Rain
( in i
• 25
.21
.14
. 18
-34
.28
• 36
. 12
• 19
.27
.08
-53
.43
.18
.08
-44
• 36
• 43
.40
.08
.28
.21
• 37
• 33
6.54
.27
.08
• 53
Total
Col .
1 99
71
66
87
135
42
1 17
157
78
76
43
80
23^
161
194
59
97
1 17
73
184
103
108
27
206
2719
1 13
27
239


1



1 .



1 ,


1

i
1


1
1
1

t

4
26
1

4
1 Y * I

71
c<3
7^
73
.'5
.25
.59
.02
.04
.53
.70
. 18
• 90
.46
.60
.62
.64
• 96
.01
.74
• 90
.04
• 50
.00
• 83
. 1 2
.25
.00
•;:;

ir
t- !-/
32
3Q
42
42
27
32
29
50
^6
38
35
67
62
70
27
49
45
36
20
34
76
22
122
1053
44
20
122
T j 1 .'i 1
Fhcj.
.34
.16
. 1 2
.28
.4r<
. 1 5
.23
• 51
.21
. 16
. 12
.25
.26
. 22
'.Yl
. 13
• i ?
• 54
.25
. 10
.28
. 18
. 1 1
1 .18
6.94
.28
. 10
1 .18
I-r; id

-39
. 10
. 10
i n
. 2 "
r ^
• j j
. 10
10
.20
. 10
. 10
.20
. 10
. 30
.30
1 l~*
.20
.20
. 10
. 10
. 20
.20
- . *J
•50
4-14
. 17
• 05
• 50
Z i r, o

i ^
. r ฐ
. 1 C1
1 f~
1 ~*
^ r-
r,cA
. ' 2
1 r.
. 06
.r T
^ "7
. 12
1 ^
. 1 4
1 i
1 s_
13
.OT
15
1 ;
. 10
.07
.26
2.77
. 1 2
.06
.25
j_ ' •

5 . -,
f . 2
*-'' . 5
5 • ^
5-5
6 . '
7.0
*"/ • T
^ -]
5 -2
c , 9
5-4
6 . 4
6 • ^
b.4
- , ^
XA
6 , !
6 - i
6 .4
c; q
6 . 1
i.c.
5-4
139.6
6. 1
S.7
7.0

-------
       Table A-10. Lake Hills Wet Weather Without Street -leaning (LI:'./"
  Stor3    Month
 number
     50
     51
     54
     55
     56
     57
     56
     59
     61
     62
    127
    1 29
    150
    131
    132
    133
    134
135+136
    137
    140
    141
    148
    149
    150
    151
    152
    153
    154
    155
    156
    158
    159

  Iital
Average
Minimum
Maximum
11/27/SO
   1 1/23
    12/4
   12/14
   12/20
   12/21
   12/24
   12/24
   12/26
   12/29
 10/8/81
   10/28
   10/29
   10/30
   11/11
   11/13
   11/17
   1 1/20
   11/30
    12/3
    12/4
    12/9
   12/13
   12/14
   12/17
   12/18
   12/21
   12/23
   12/28
 1/10/82
    1/15
    1/17
   Flow
(cu ft)

  864CC
 103200
  13900
  14500
  37200
  70700
  23700
  57500
  53000
 158000
  42600
  12500
   5640
   3060
 189000
  1 1400
  60900
 199000
   3610
  12400
 209000
 111000
  29700
 132000
  21800
 111000
   8670
  23400
   0160
  25500
 106000
  20600

1966040
  61439
   3060
 209000
Rain
(in)

  .70
  • S3
  .23
  .17
  -43
  .60
  . 26
  .44
  • 32
1.11
  .27
  .20
  .07
  .07
1.58
  .14
  • 53
1  -44
  .12
  .16
'1-43
  .84
  • 30
  • 96
  .21
  .69
  .09
  .26
  .10
  .35
  .98
  .18
                     16.06
                       .50
                       .07
                      1.58
Runoff
otal T
Sol.
83
f,6
62
152
109
113
120 1 .
93
68
60
81
47
64
88
53
50
33
46
34
119 1 •
108
95
61
62
45
51
51
33
58 1.
227 1 .
78
82
2492 20.
78
33
227 1 .
Concent
x;i

90
25
78
70
70
76
12
70
59
53
25
61
78
90
73
64
28
38
50
32
92
42
25
50
31
48
48
31
37
37
48
67
98
66
25
37
rations
CCC

23
2?
27
77
36
33
45
55
23
22
29
23
29
36
33
41
22
30
29
38
'30
20
26
21
17
19
24
20
39
77
25
33
1031
32
17
77
'-.a/I }
Total
Fhos.
.15
• 13
. 12
• 31
.24
.21
.22
.14
.12
.10
.10
.13
.18
.15
.21
. 16
.12
.12
.12
.12
:i3
.09
.15
.1 1
.07
.08
.08
.07
.12
-34
.1 1
.12
4.62
.14
.07
• 34
 .10
 -05
 .10
 • 30
 .20
 .10
 .20
 . 10
 .10
 .10
 .10
 .05
 .20
 .05
 .10
 .10
 .10
 .05
 -05
 .10
 .10
 .05
 .10
 .10
 .10
 .10
 .10
 .05
 .05
 .40
 .10
 .10

3.60
 .11
 .05
 .40
                                                                                    Zinc
 .16
 .07
 .08
 .22
 .10
 -14
 . 14
 . 1 1
 •13
 • 15
 .05
 .08
 .08
 • 13
 .07
 .09
 .08
 .07
 .15
 .08
 • 05
 • 03
 .07
 .05
 .06
 .09
 .03
 .04
 .08
 • 15
 .08
 .06

3-00
 -09
 .03
 .22
 5-9
 5-9
 5.17
 6.1
 5-5
 5-6

 7. 1
 7.0
 6.0
 7. 1
   HA
 6.7
 7.0
 6.6
 7.1
 6.8
 6-9
 7.0
 6.9
 6.7
 6.8
 6.7
 6.8
 6-9
 6.7
 6.3
 6.9
 7.1
 6.7
 6.8
 7-0

204.7
 6.6
  5-5
 7.1
  Cond .
f ur.hoa )
     27
     29
     2-7
     2'
     31
     44
     76
     53
     :;A
     22
     32
     30
     42
     34
     4Q
     45
     85
     46
     42
     25
     48
     55
     35
     34
     23
     70
     69
     31
     43

    1235
     40
     22
     85
Turb .
I n t u )

   13
   • 5
   i 9
   33
   14
    3
   1 A
    3
    7
    q
    1 4
    1 2
     9
    13
     6
     6
    10
     7
     7
     7
     9
     e
    12
    32
    14
    15

   526
    16
     6
    82

-------
Table A-11.  Lake .--.:11?
37
38
^ o
- >
40 + 4 I
42
43
45
46
47
48
49
63
66
67
69
70+71
72
73+74
76
77+78
Total
Average
M in imum
Maximum
1C/U/80
10/12
10/24
1C/31
11/1
51/3
1 1/8
11/14
11/19
1 1 /20
11/23
1/17/81
1/23
1/26
1/28
2/1 1
2/13
2/13
?/17
2/18




2590
6730
•1 1 4 :
582CO
337CO
47500
422CO
9710
17400
223000
17100
8460
53000
1 1000
75000
90200
1 9900
1 1 3200
10600
51080
903760
45188
2590
223000
. i 1
. 1 o
i ~
.74
.'.6
-52
-41
-15
-19
1-55
.22
.15
-48
.16
.60
1 .00
.24
1 .01
.16
.58
8-96
-45
. 1 1
1 -55
163
2^
1 33
1C6
188
85
68
125
.',42
92
72
142
161
81
69
QO
66
218
74
;IA
2412
127
27
442
"T Zi ~
1 . ' 2
.^e
1 .46
.62
.67
-73
1 .38
1 .04
-95
70
• 95
-25
-25
.ij4
-25
1 .26
.73
1 .40
20.45
1 .02
.25
3.80
•-T ;j
22
30
41
63
35
•7 ;T
S3
V3
32
22
45
57
24
i ^
43
27
33
31
56
860
43
13
83
.20
. 33
.21
.30
. 16
. 14
. 17
.0-2
.29
.52
.51
.28
,27
.0''.
.22
. 13
.45
.15
• 34
5-ฐ3
.7.0
.03
• 92
. 23
-2?
. 1 3
• 31
. 10
. 1C
- 15
•25
1C
• 15
. 20
;c
r;C
• - J
. 10
. U
. 10
-30
• 15
-29
3-64
. 18
-05
-31
. ' 6
. 1 3
.13
i o
-23
.07
. l '
1 6
f ~j
. i 1
1 h
. 1C
.O"7
• >5
. C"7
. C 6
. 1 2
. ~ 7
. 12
2.25
. 1 t
-05
.23
                                                                                           5-6
                                                                                           5 -7

-------
Tซ
9-.;.-=
1
21
22
23
25
26
27
25
3C
31
32
33
34
35
81
82
83
84
85
86
88
89
90
91
92
93
94
95
97
98
99
100
101
104
105
106
107
108
109
1 10
1 12
113
114
115
1 16
117
'19
120
121
122
Total
Average
M inimum
Maximum
itii A-IZ.
la-.i
3/12/30
7/ ' l
"VI 4
a/ 17
3/26
8/27
8/23
9 ' 1
9/6
9/12
9/13
9/19
9/20
9/29
3/3/81
3/5
3/15
3/23
3/24
3/28
4/2
4/5
4/6
4/7
4/10
4/12
4/20
4/22
4/27
5/3
5/7
5/7
5/10
5/19
5/24
6/5
0/8
6/9
6/12
6/12
6/17
6/30
7/6
7/10
7/13
8/31
9/18
9/20
9/25
9/26




5UT--V 0
1 3800C
3550
IC700
DI50
31 sec
2670
3450
25600
31 4CC
1 1 9CC
1970
5020
2870
203CO
23700
383CO
8310
23300
18800
14 600
7400
5^00
5250
15700
4310
8070
3680
1260
2010
25300
9690
5550
19600
20500
11800
16500
17300
17500
2160
10600
17100
8880
11500
26400
6230
69800
6340
18800
38200
33900
103000
950420
18636
1260
103000
•-•ir.j D- 7 V
, -n
1 .27
- 1 }
. 22
• 1 5
-63
.C8
. 1 ฐ
-37
• 50
.27
.03
H
-09
.38
.43
.62
.10
.28
• 34
.26
.18
.23
.16
• 38
.22
.30
.13
.08
.1 1
-47
.21
.16
• 33
.29
.22
.31
• 33
-31
.05
.23
• 33
.23
.25
• 53
.16
1.17
.24
.50
.68
• 50
1.65
17.56
.34
.05
1.65
^ i ~ -, ^ r ป '
(ur
Col .
142
127
624
106
266
1 44
58
90
-72
90
82
163
115
64
83
92
82
76
62
1 ฐ1
58
147
49
67
117
MA
128
72
104
136
188
87
69
75
140
87
NA
131
285
31
324
113
149
78
198
336
136
116
158
6613
135
31
624
10:":" Jrn^e
1 .26
1 -29
.25
2.91
3-42
1 .90
.84
.63
1.23
.25
1 .02
.90
1 .43
• 92
.57
.84
1 .06
.78
.67
.25
1 .71
1 .01
1.15
.25
.70
1 .06
1IA
.73
.31
1.46
1.46
1.54
.84
.90
.76
1.57
.76
NA
1.01
2,10
.67
4.26
1.15
1.76
.84
3.10
3-92
1.29
1 .06
1 .18
62.13
1 .27
< . 5
4.26
n -. r -i : ; o n a
'5^
37
1 52
129
1 02
TT
29
47
24
43
56
76
42
27
33
82
^4
72
37
100
d5
45
21
27
46
ilA
46
33
95
82
61
40
79
45
66
52
NA
51
98
30
149
59
10?

82
131
58
57
50
3006
61
21
152
3ซt/ 1 .'
?hoa .
.77
• 29
. i 5
.84
.95
1.17
.09
.12
.31
.1 '
.12
. 21
.36
. 18
. 14
.16
.22
.16
.22
. 12
• 51
.17
• 55
.07
.20
.26
*IA
.15
.19
.29
.31
• 36
.20
-19
.20
.30
.20
NA
.27
.61
.17
1 -19
.24
.28
.17
.68
.89
.20
.22
-32
15.76
.32
.07
1 .19
-.ป*
. 21
. ' 0
.62
-51
.49
.20
.05
.22
.05
.05
.10
.2*;
.13
.10
.10
.10
.10
. 1C
.05
.20
.10
.20
.05
. 10
.20
'^A
.10
.20
.10
.20
.20
.10
.10
.10
.20
.10
ilA
. 10
.40
.10
.40
.10
.20
.10
.20
• 50
.20
.10
.20
9-02
.18
< . 1
.82
line
' n
. 1 2
• 77
• 30
.22
. 1 !
.C1
• 29
.09
.15
.10
.16
. i '
.03
.09
.12
-09
.10
.09
.15
.10
. 1 4
.C3
.07
.10
MA
.08
.08
.15
.17
. 1 ~
.09
.1 1
.12
.17
.10
NA
.12
.23
.09
.26
.14
.17
.12
.26
.28
.1;
.15
.12
7.04
. 14
.07
• 37
?'H
6 . 7
•5.0
6.2
7 , 4
6 . ^
6.6
6.3
6.0
6.8
6.6
5.5
5-3
6. 1
5-3
5-5
6.2
6.1
6.2
6.5
6.6
6.2
5-5
5-9
6. 1
6.1
5-9
5-3
5-2
6.3
6.1
5-9
6.1
6.1
HA
6. 1
5.8
6.5
6-3
6.6
6.5
5-2
6.2
6.3
6.4
6.5
5-9
6.4
6.2
6.8
'-ฃ95 - 6
' 6.2
5-2
7.4
Corvl .
   35
   32
   ''2
   70
   2";
   42
   69
   54
   29
   27

   42
   34
   23
 56
 25
 33
 69
 tiA
 26
 39
 35
 25
 25
 31
 t!A
 38
 16
 46
 23
 30
 25
 60
 32
 38
  30
  69
  47
  42
  29
  27

1738
  38
  16
  95
             12
              6
             31
              5
             1 4
             19
              12
              19
              26
              27
              20
              17
               9
               6
              13
              24
              20
              36
              11
              28
              '2
              20
               6
              22
              31
               8
               4
              1 1

             796
              16
               4
              41

-------
Table A-13- Surrey Downs  Dry  Weather  V/ith  Street Cleaninr




                                    Runoff Concentrations
•'r .-/I)
Storm
number
3
4+5
7
8
Total
Average
M inimurn
Maximum
Date

4/5/80
4/8
4/14
4/18




Flow
(cu ft)
22600
48900
8590
78800
158890
39723
8590
78800
Rain
(



1
2


1
in)
.43
.79
.18
. 18
.58
• 65
.18
. 18
Total
Go lid 3
1 1 2
132
196
43
483
121
43
196


1

2

4
1

2
m r/M
-Lf.lt

.06
.60
.74
• 50
.90
o '/
- c- J
• 50
• 74
CO

r
>
'ฃ
u~
>
1
1 S
D

0
9
4
5
8
T o t a
Phon
. 2
.2
C.
. 1
1 1
1
-
^
4
o
r
'^
P
40 . 2rJ
1
5
r
j
4
. 1
. r.
0
9

-------
Table A-14. Surrey Downs Wet Weather Without  Street  Cleaning



                                    Runoff  Concentrations  !a;
Storm
number

37
38
39
40
4-2
43
44
45
46
47
48
49
50
51
52
53
55
56
58
59
60
61
62
63
64
65
69
70
72 to 78
79
155
156
158
159
Total
Average
Minimun
Maximum
Eate


10/8/80
10/12
10/24
10/31
11/1
11/3
11/6
11/8
11/14
11/19
11/20
11/25
11/27
11/28
12/2
12/3
12/14
12/20
12/24
12/24
12/25
12/26
12/29
1/17/81
1/20
1/21
1/28
2/11
2/13
2/24
12/28
1/10/82
1/15
1/17




Flow
(cu ft)

102CC
4230
7760
48500
20700
41600
87500
36000
5330
14200
134000
8730
55100
87900
88000
51200
5050
25100
16600
50500
135000
49900
127000
10400
16600
35900
59100
63800
249600
34300
2460
17800
90800
13800
1704710
50139
2460
249600
Rain
(in)

• 19
. 12
.16
.74
• 29
.60
1.18
-43
.12
.21
1 .66
.15
.71
.86
• 97
.46
. 1 1
-43
.26
• 51
1 .28
-34
1.14
.22
.27
.42
.63
.91
2.20
.36
.04
.30
1 .10
.16
19-53
.57
.04
2.20
Total
Solids

174
52
140
57
100
95
93
64
250
73
60
29
49
C1.
J ,'
68
71
100
95
98
60
76
83
91
125
98
91
68
80
125
75
46
274
102
127
3242
95
29
274
TK'i


1 .96
MA
1 .06
.64
1 .09
.78
.62
.62
1 .40
1-23
1.12
.87
.56
1 .26
.73
• C5
.87
.70
.88
.25
.70
.64
• 5^
1 .01
.25
.78
.25
.64
-98
.64
NA
1-93
.73
.74
26.74
.84
<-5
1.96
rr-p


39
26
102
51
46
32
51
35
50
41
30
31
29
34
42
26
69
58
62
20
27
20
19
47
52
4fa
20
52
47
38
NA
110
38
33
1425
43
19
110
Tote":
F'".3:i .

-f.f.
• ^ ' j
• 17
.24
.15
. 18
.'6
.08
.14
• 23
.17
.15
.26
.1 1
.10
.17
.08
.24
.18
.16
.oq
• 13
.21
.09
• 37
.07
.02
.00
.16
.20
.17
NA
• 38
.17
.09
5-49
.17
.00
-38
lea^


.25
.07
.15
• 09
. 14
.06
.10
.10
.20
.10
.10
.10
.05
.10
.10
.10
.20
.10
.10
.20
.05
• 05
-05
.20
.10
. 10
.10
.10
.16
.10
NA
.40
.10
.10
4-02
.12
<. 1
.40
Zir.c


. ir-
.08
. 15
. 10
. 10
.07
. 13
.13
.31
.12
.17
. 1 1
.08
.08
.15
.08
.14
.12
.21
.09
. 1 1
-23
-09
.15
. 10
.07
.05
.10
.09
.09
MA
.20
.10
.08
4- 08
.12
.05
.31
pH


NA
6. 1
C.5
6.5
5-7
6.3
;FA
6.2
6.0
5-9
5-8
5-9
5-8
6.6
6.2
6.8
6.2
6.4
5-9
7.0
7-0
7.0
NA
6.4
6.4
6.1
6.0
6.1
6.1
6.2
7-0
6.7
6.8
6.9
196.5
6.3
5-7
7.0
r. ce~ .
C\r,i .
( UC-KC3 ,
48
6l
-U
2?
?6
27
4"1
37
46
26
30
2b
31
46
15
50
*1
21
37
43
52
62
59
57
27
33
32
29
64
41
52
102
1 1 1
73
1559
46
23
i 1 1
Turb .


3',
7
22
12
' 2
1C
' ~I.
1 1
1=!
1 6
16
i 3
7
"
\ 7
(-,
-i "I
2\
2r.
6
3
5
q
2C>
23
17
10
17
15
17
10
67
1 Q
7
531
16
c;
67

-------
Table A-15- Surrey Downs Wet Weather
             Cleaning (C3CW;
Runoff Concentrations
Stori
n um b e r
123
1 24+1 25
126
1 27
1 23
1 29
131
132
133
137
138+139
ro 1 40
en i 41
0 148
1 49
150
151
152
153
154
Total
Average
Minimum
Maximum
Date

10/1/81
10/5
10/7
10/8
10/27
10/28
10/30
11/11
11/13
1 1 /30
12/1
12/3
12/4
12/9
12/13
12/14
12/17
12/19
12/21
12/23




Flow
(cu ft)
52100
401000
13300
19200 '
39500
9170
4230
Q8900
6030
7360
37130
13500
1 1 6000
72800
22400
81 100
22400
83100
3980
17100
1 125300
56265
3980
401000
H.ui n
fin)
. 81
4.38
. 14
.24
.74
. 17
.09
1 .50
. 1 1
. H
-55
.19
1 .27
.78
.36
.87
.29
.79
.08
.27
13.77
-69
.08
4-38
Total
Ccli.ls
95
144
116
88
72
75
Q3
76
69
1 10
83
140
1 10
1 14
79
97
133
64
194
73
2030
102
64
194
™Y.~.',

77;
1 .02
.90
• 56
.61
.62
1 .80
.64
.76
1 -32
.76
.66
.64
.48
.62
.62
-59
.48
• 95
.56
15.32
.77
.48
1 .80
COD

28
34
24
30
36
29
27
33
44
69
36
48
17
23
35
35
27
21
53
33
687
34
17
69
Total
Phos.
. 15
.23
.08
.10
. 16
.15
.28
.17
. 1 6
.27
. 13
.13
. 1 2
.09
. 14
.15
.13
.08
.20
.12
3.08
. 15
.08
.28
Le~.d

. 10
. 17
. 10
. 10
.05
.10
.05
. 10
. 10
. 20
19
. 10
. 10
.05
. 10
. 10
. 1C
. 10
.20
.05
2. 16
. 1 1
-05
.20
" inc

08
. 1C
.07
.07
• 09
• 1 3
.'5
.08
. 16
. : 4
. 1 2
. 1 0
.03
. 06
. 10
.08
. 1 1
. 08
. 14
.0"?
2.00
. 10
.06
. 16


6
6
7
7
6
6
7
6
T
7
6
6

6
6
6
7
6
•-I
f.
1 30
6
6
7
o!:

. "j
. 'j
3
r^
. !
, r.
. "5
. D
. 2
.0
• o
.8
;.A
. Q
. 3
p
.0
. Q
.6
•?
.5
. q
7
• J
.3
                                                             47
                                                             44

-------
Table A-16. Lake Hills  Dry  Weather Without Street Cleaning  (L:.T




                                 Runoff Yields (1 h / a c r e / s t, o r T-. }
Gtorm
number
6
e
g
1C
1 1
15
16
18
i g
21
22
25
26
28+29
30
31
32
1 U
1 16
1 17
1 18
1 19
120
Total
Average
Minimum
Maximum
Month

4/14/80
4/18
5/21
5/24
5/27
6/5
6/8
6/24
6/25
\j 1 i— j
7/1 1
7/14
8/26
8/27
9/1
Q/6
9/1l
9/13
7/6/81
7/13
8/31
9/1
9/19
9/20




Flow
(cu ft)
8650
132000
11000
5850
4070
6920
9170
52400
3630
^ ^ ~s w
9870
6090
1210
30200
56900
14800
3710
4810
48800
1 26000
19500
3870
7380
37100
653930
28432
1210
132000
Rain
(in)S
.15
1-33
-19
.15
. lO
.18
.17
.72
.08
.28
.15
.04
.43
• 57
.23
.12
.16
.64
1 .25
.12
.12
.10
1 .05
8.33
• 36
.04
1 -33
Total
ol ids
.46
6.55
.80
• 31
.23
.25
1 .10
3-05
. 25
* *— J
.51
• 51
.06
3-51
1 .86
• 54
.05
.46
2.66
6.10
1.36
• 42
1 .24
6.51
3P 82
1 .69
.05
6.55
TKJi

.01 1
.043
.010
.003
.001
.003
.008
.045
.002
.005
.003
.003
.031
.009
.009
.002
.002
.031
.095
.071
.OOC
.012
.067
.470
.020
.001
.095
COD

.^<5
1 .03
• 32
.06
.08
. 1 1
.49
1.32
• 1 3
• 30
.16
.06
1 .38
1 .05
-43
.07
.11
1 -55
2.86
1 .19
.23
• 53
2.88
16.70
.73
.06
2.38
Total
Pho~.
. G0 1 4
.0154
.0025
.0001
.C003
. 0004
.0028
.0090
.OCC6
.0016
.0006
.0004
.0668
.0027
.0024
.0003
.0003
.0102
.0208
.0023
. 00 1 2
.0032
.01 23
.ireo
.."069
.0001
.0668
Lead

.00?'-:
.0081
.002'.:
.0005
.0003
.0005
.0031
.0061
.0005
.0014
.0007
.0003
.0098
.0017
.GO 2 4
.0001
;C01
.GO"' 0
.0077
.0024
.000 a
.0013
.0107
.0680
.0030
.0001
.0107
0 •' f <-•

r rr {
i"'^-;
• oc r '?
• r •
r, '"/,'.'
.0004
. 00 1 0
. r. •; 1 1
r c/.^
err 7
r r-. ~- ,t
.".^02
. '^G"7^
. 0026
.001 2
.0002
.0004
-0033
.01 00
. C 0 2 7)
.0006
. r.O'"'"1
. 0'0r'ฐ
.0462
.Gr20
. T C 2
.0100

-------
Table  A-17.  Lake liilln Dry
;her  With Street  Clo-'irinr  !"'„>'',
                                        Runoff  Yield:;  < i b/;,,; r-/— - f" /'
.vtorm
number
34
85
86
89
90
91
92
93
94
95
96
97
101
102
103
104
105
106
107
108
109
1 10
1 12
1 13
Total
Average
Mi n irnum
Maximum
Date

9/20/80
3/24/81
3/28
4/5
4/6
4/7
4/10
4/'2
4/20
4/21
4/23
4/27
5/11
5/14
5/14
5/18
5/24
6/5
6/8
6/9
6/12
6/12
6/17
6/30




Flow
(cu ft)
173CO
1 3000
4700
12500
36900
1 6300
26000
7340
8350
17600
2880
30300
25400
12500
4680
23700
20500
27700
29100
4190
16200
11000
12500
21900
402540
1 6773
2880
36900
Rain
Cn)
-25
.21
.14
.18
• 34
.28
• 36
.12
.19
.27
.08

.
. ! 8
.08
.44
.36
• 43
.40
.08
.28
.21
• 37
• 33
6.54
.27
.08
.53
Total
Col H:i
2.1 1
• 57
.19
.67
3-C5
.42
1 .86
.71
.40
.82
.08
1 .48
3-72
1.23
• 56
.86
1 .22
1 .98
1 .30
.47
1 .02
.73
.21
2.76
28.40
1.18
.08
3-72
TK"

.018
.007
.002
.006
.026
.002
.009
.004
.005
.006
.001
.022
.014
.01 1
.005
.009
.008
.033
.018
.004
.009
.007
.004
-054
.235
.012
.00!
.054
COL'

7 1
. 26
. 1 1
.":'2
• "j
.27
• 52
.13
-25
•>'*-'
-07
.66
1 .05
. 48
.20
• 39
.62
.76
.64
• 05
• 34
.51
.17
1 .64
1C.r)7
.46
-05
1 .64
                                                               ,0111
                                                               , 001 ^

-------
              Table A-18.  Lake Hi] Is Wet  Weather  Without  Street Cleaning (LH'w)
                                                  Runoff
no

-------
ro
Ln
-p.
            "able A-19- Lake  Hills  Wet Weather With  Street  Cleaning (CLrlV)

                                                 Runoff  Yields (Ib /acre/stor-)
Storm
number
37
38
39
40+41
42
43
45
46
47
48
49
63
66
67
69
70-:71
72
73+74
76
77+78
Total
Average
Minimum
Maximum
Month

10/8/80
10/12
10/24
10/31
11/1
11/3
11/8
11/14
11/19
1 1/20
11/23
1/17/81
1/23
1/26
1/28
2/11
2/13
2/13
2/17
2/18




Flow
(cu ft)
2590
6780
8140
58200
38700
47500
42200
9710
17400
223000
17100
8460
53000
1 1 000
75000
90200
19900
1 13200
10600
51080
903760
45188
2590
223000
Rain
(in)
.1 1
.16
.17
.74
.36
• 52
.41
.15
• 19
1 .55
.22
.15
.48
.16
.60
1 .00
.24
1 .01
.16
.58
8.96
.45
. 1 1
1.55
Total
Solids
.27
.11
.69
3-78
4-46
2.47
1.76
.74
4.71
12.56
• 75
.74
5-23
• 55
3-17
4-97
.80
15-11
.48
.00
63-35
3-17
.00
15-11
TKN

.006
.003
.006
.031
.035
.018
.017
.004
.020
.142
.010
.004
.031
.002
.01 1
.035
.003
.087
.005
.044
• 517
.026
.002
.142
COD

.12
.09
.40
1 .45
1 -50
1 .02
.93
• 50
.41
4-42
.23
.23
1 .86
.16
.61
2 . 37
• 33
2.29
.20
1 .74
20.66
1 .04
• 09
4-42
Total
Phoc .
-0004
. 0008
. G0 1 9
.0075
. 007 1
.0047
-OC3C
.CC1G
.C0ฐ8
• 0396
.0054.
.0026
.00Q1
. 00 1 M
.001 2
.01 22
. 00 1 6
.031 2
. 00 1 0
.0106
. 1 5^2
.0077
.0004
.03 "C

-------
Currey Do win-- Try V.-ntMer Witho-it Gt.reet  Cleaning (ODD)
• ' - - r~.
.-, , ] - 1 . p p
1

,; |
^ t '
, • ;
25

27
2S
30
31
J2
<3
M
J S
81
82
83
84
05
86
up
8T
no
91
')2
93
0,4
95
97
ฐ8
rn
100
101
104
1 or,
106
07
103
1 no
1 l5
1 12
13
14
15
16
17
19
20
21
22
Tol^l
Avernj'e
f. i n in-.um
Mnx i IT. urn
Pr\ * ^

V12/W
3/26
7/11
7/14
8/17
8/26
Q/27
8/23
9/1
9/6
9/12
9/1?
9/10
ฐ/20
9/29
3/3/01
3/5
3/15
3/23
3/24
3/28
'4/2
4/5
4/5
4/7
4/10
4/12
4/20
4/22
4/27
5/3
5/7
5/7
5/10
5/19
5/24
6/5
G/S
6/9
6/12
6/12
6/17
6/30
7/6
7/10
7/13
8/31
9/18
9/20
9/25
9/26




Flow
(cu ft)
i of-rvo
.qi-,',0
1 0700
6 1 r-0
31 'VO
'2670
Si '-0
23600
"S 1 4 CO
1 1 900
1 ฐ70
5020
2870
20 '00
23700
3STOO
8310
25300
1 8800
14600
7400
5700
5250
15700
4310
8070
3680
1260
2010
25300
Q690
5550
1Q600
20^00
11800
16500
17300
17500
21 60
10600
17100
8880
1 1500
26400
6230
69800
6340
18000
38200
33900
103000
950420
18635-69
1260
1 08000
R n i n
(in)
1 .2^
-19
. 22
• 1 5
.63
.0"
. 18
• 37
.50
.27
.08
.14
.on
• 38
.43
.62
. 10
.28
.34
.26
.18
.23
.16
• 38
.22
• 30
- '< 3
.08
.1 1
.47
.21
.16
• 33
.29
.22
•31
• 33
.31
• 05
.23
• 33
• 23
.25
• 53
.16
1 .17
.24
• 50
.68
• 58
1.65
17.56
• 34
• 05
1.65
Tot.'il
1-nlidR
4.95
1 .29
1 .00
• 51
1 3 . 00
• 1 9
1 .47
2.23
1.19
• 70
• 09
• 30
. 1 S
2.23
1 .79
1 .61
.45
1 .40
1 .01
-73
• 30
.71
.20
1.51
.14
• 35
.28
HA
17
1-19
.66
.19
2.41
1 .17
• 53
.81
1-59
1 .00
NA
• 91
3-19
.18
2.44
i .05
.61
3-57
.82
4-14
3-40
2.58
10.66
84.25
1 .72
• 09
13-00
•uneff  Yields  (lb/i.cre/storm)
     TKN       COD    Total
                      Fhos .
                             .040
                             .007
                             .009
                             .001
                             .061
                             .006
                             .01 1
                             .013
                             .014
                             .010
                             .000
                             .003
                             .002
                             .01 9
                             .014
                             .014
                             .005
                             .01 6
                             .010
                             .006
                             .001
                             .006
                             .003
                             .012
                             .001
                             .004
                             .003
                               NA
                             .001
                             .013
                             .009
                             .005
                             .020
                             .01 1
                             .007
                             .008
                             .018
                             .009
                               NA
                             .007
                             .024
                             .004
                             .032
                             .020
                             .007
                             .038
                             .013
                             .048
                             .032
                             .024
                             .080

                             .720
                             .015
                             .000
                             .080
              1 .63
               .44
               .48
               • 15
              3-17
               .22
               .56
               .54
               .60
               .37
               .03
               .14
               .11
              1 .01
               .65
               .68
               .18
              1.25
               .42
               • 69
               .16
               .37
               .15
               .46
               .06
               .14
               .11
                NA
               .06
               • 55
               .60
               .30
               .78
               • 54
               .51
               .49
               • 75
               .60
                NA
               • 35
              1 .10
               .17
              1.12
              1 .02
               .42
              1 .46
               • 34
              1 .61
              1 -45
              1 .27
              3-37
             33-75
               .69
               .03
              3-37
.00ฐ 2
.0018
.0020
.0006
.C'75
.0017
.0065
.0014
.0025
.0024
.0001
.0004
.0004
.0048
.0028
• 0035
.0009
.0034
.0020
.0021
.0006
.0019
.0006
.0057
.0002
.001 1
.0006
   NA
.0002
.0031
.0018
.0011
.0046
.0027
.0015
.0022
.0034
.0023
   NA
.0019
.0068
.0010
.0090
.0042
.0011
.0078
.0023
.01 10
.0050
.0049
.0215

.17S3
.0036
.0001
.0215
                                                         Lead
.0071
.0020
.0015
.0004
.0171
.0009
.0027
.0031
.0010
.0017
.0001
.0002
.0002
.0032
.0020
.0025
.0005
.0015
.0012
.0010
.0002
.0007
.0003
.0021
.0001
. 0005
.0005
   MA
.0001
.0033
.0006
.0007
.0026
.0013
.0008
'.0011
.0023
.0011
   NA
.0007
.0045
.0006
.0030
.0017
.0008
.0046
.0008
.0062
.0050
.0022
.0135

.1119
.0023
.0001
.0171
                                                                  Zinc
.0055
.0012
.001 1
.0005
.0077
.0 )05
.0012
.0017
.0017
.0023
.0001
.0005
.0002
. 0021
.0017
.0020
.0005
.0018
.0011
.0010
. 000'4
.0006
.0003
.0015
.0002
.0004.
.0002
   NA
.0001
.0013
.0009
.0006
.0017
.0012
.0008
.0013
.0019
.0011
   NA
.0008
.0026
.0005
.0020
.0024
.0007
.0056
.001 1
.0034
.0039
.0034
.0079

.0832
.0017
.0001
.0079
                       255

-------
Table A-21 . Surrey  Downs  Dry Weather With Street Cleaning  (C:JCD.'
                                     Runoff Yields  (Ib/acre/otorrr,)
Storm
number
3
4+5
7
8
Total
Average
Min irnum
Maximum
Date

4/5/80
4/8
4/H
4/18




Flow
(cu ft)
22600
48900
8590
78800
1 58890
39723
8590
78800
Pain
(in)
.43
• 79
.18
1 .18
2-58
.65
.18
1.18
Total
TKN
COD
Solids
1 .
4.
1 .
2.
9.
2.
1 .
4-
66
23
10
22
21
30
10
23
.016
.019
.015
.026
.076
.019
.015
.026
• 74
1 .25
• 30
.77
3-07
-77
.30
1 .25
Total
Phos.
.0037
.007?
.0033
.0050
-01 97
.0049
• 0033
.0077
L.-^d

.004C
.OC64
.001 ?
-002G
.01 4?
.0037
.0019
.0064

-------
Table A-22. Surrey Downs Wet Weather
         Street Cleaning
Runoff Yields (Ib/acre/atorn1
CtO T3
number
37
38
39
40
42
43
44
45
46
47
48
49
50
51
52
53
55
56
58
59
60
61
62
63
64
65
69
70
12 to 78
79
155
156
158
159
Total
Average
Minimum
Maximum
Sate

10/8/80
10/12
10/24
10/3i
11/1
11/3
11/6
11/8
11/14
11/19
11/20
11/25
11/27
11/28
12/2
12/3
12/14
12/20
12/24
12/24
12/25
12/26
12/29
1/17/81
1/20
1/21
1/28
2/11
2/13
2/24
12/28
1/10/82
1/15
1/17




Flow
(cu ft)
10200
4280
7760
48500
20700
41 600
87500
36000
5330
14200
134000
8730
55100
87900
88000
51 200
5050
25100
16600
50500
135000
49900
1 270CO
10400
16600
35900
59100
63800
249600
34300
k460
17800
90800
13800
1704710
50139
2460
249600
Rain
(in)
-19
.12
.16
• 74
.29
.60
1 .18
• 43
.12
.21
1 .66
.15
-71
.86
.97
.46
.11
.43
.26
• 51
1 .28
• 34
1.14
.22
.27
.42
.63
• 91
2.20
.36
.04
• 30
1.10
.16
19-53
• 57
.04
2.20
Total
Solids
1.16
• 15
.71
1 .81
1-36
2.59
5-33
1 -51
.87
.68
5-27
-17
1 -77
3-05
3-92
2-38
.33
1.56
1 .07
1 -98
6.72
2.71
7-57
.85
1 .07
2.14
2.63
3-34
20.44
1 .68
.07
3-19
6.07
1.15
97-30
2.86
.07
20.44
TKI;

.013
NA
.005
.020
.015
-021,
.036
.015
.005
.011
.098
.005
.020
.073
.042
.008
.003
.012
.010
.003
.062
.021
.047
.007
.003
.018
.010
.027
.160
.014
SA
.023
.043
.007
.861
.027
.003
.160
CCD

.26
.07
• 52
1 .62
.62
.87
2.92
.83
.17
• 38
2.63
.18
I .05
1.96
2.42
.87
• 23
• 95
.67
.66
2-39
.65
1.58
• 32
• 57
1 -13
.77
2.17
7.6L
.85
NA
1 .28
2.26
.30
41 .86
1 .27
-07
7.68
Total
Phos.
.0024
.0005
.0012
.0048
.0024
.0044
.OC 4 6
-0033
.0008
.0016
.0132
.0015
.0040
.0058
.0098
.0028
. 0008
.0030
.0017
.0029
.01 18
.0069
.0077
.0025
.0008
.0004
.0001
.0067
.0327
.0038
NA
.0044
.0101
.0008
.1601
.0049
.0001
.0327
I.
-------
Table A-23-  Surrey Downs Wet  'weather With Street  Cleqr.inr (o:'.rV,'<
                                      Runoff Yields  (1 b/ac re/3f o rrr.
Storm
number
123
1 24+125
1 26
1 27
1 28
1 29
131
132
133
137
138+139
140
141
148
149
150
151
152
1 53
1 54
Total
Average
Mini mum
Maximum
Date

10/1/81
10/5
10/7
10/8
10/27
10/28
10/30
11/11
11/13
11/30
12/1
12/3
12/4
12/9
12/13
12/14
12/17
12/19
12/21
12/23




Flow
(cu ft)
5 2 ",00
401000
18300
19200
39500
9170
4230
93900
6030
7360
37130
13500
1 1 6000
72800
22400
81 100
22400
83100
3980
17100
1 125300
56265
3980
401000
Rain
(in)
.81
4-38
. 14
-24
-74
.17
-09
1 .50
. 1 1
.1ฃ
• 55
.".9
1 .27
.78
-36
.87
.29
.79
.08
.27
13.77
.69
.08
4.38
Total
Solids
3.24
37.82
1 -39
1.11
1 .86
.45
.27
4-92
.27
.53
2.02
1 .24
8.36
5-44
1.16
5.15
1 -95
3-48
• 51
.82
81 .99
4. 10
.27
37-82
TK:I

.025
.268
.01 1
.007
.016
.004
.005
.041
.003
.006
.018
.006
.049
.023
.009
.033
.009
.026
.002
.006
.S67
.028
.002
.268
COL

.96
8.93
.29
. 33
.93
.17
.07
2. 14
. 17
.33
.88
.42
1 .2Q
1 -34
• 51
1 .86
.40
1.14
. 14
.37
22.72
1.14
.07
8.^3
T rj t • i i
F'.O"..
.0051
.0604
.0009
.CGI 2
.0040
r r-.t'-f
. ^ . j j
.00.08
.011 0
.0006
.<~.01 3
.00/13
.Cr ! 1
^ ' ^ ' * '
.0'M3
-C0?0
.0''r'0
. 00 ' 9
. 0 0 4 6
.0005
. on i 3
.1235
.0062
.0005
.0604

-------
ro
en
      20
      16.
    fe
      8
                        FIGURE A- 1

              NUMBER  OF RRIN5  PER MONTH







™^™

WE'.1





SURREY DOWNS
V

M^ ^
\ /
\
DRY

01*234567


1
'
t '
//
//
vl



8 9
\
\
\
\
v
\
\
\
\V-j
ป / *
i j
V

WET
1 1
10 11 12 12



A
A/
/ /"V. 1
• -.' '\ i
^ \i /
'! /
^ r
u
DRY \
1 1 1
iJ 15 16 17* 18 IS
A
/ ^
:? ^,

/ ':
/
s /
.•'

WET

20 21 11 23
                          MONTH OF STUDY

-------
                        FIGURE A-2

             RfllN VOLUME PER  STORM EVENT
ro
01
O
         0 1  2  3  4 5 6 7  8  9 Iff 11* 1
9 2ff 21 27 23 24
                           MONTH OF STUDY

-------
Q- 1
                      FIGURE  A-3
                  STORM  DURRTIONS
      0  1
2'3' 4'5' ft1 7'B1 S1 IB II1 12 13"
               MONTH OF STUDY
23 2i

-------
1200
                   FIGURE A-4
              INTEREVENT PERIOD
O1 1 ' 2 ' 3 ' 4 ' 5 ' 6 7 8 ' 9 ' 10 11' 12 13
                  MONTH Of STUDY
                                           2l 27 23 24

-------
no
en
                        FIGURE A-5

                 RVERRGE  RRIN  INTENSITY
                                                  23 24
                          MONTH OF STUDY

-------
                      FIGURE  A-6



               PERK  RflIN  INTENSITY
\.s


V-
H-
• •^






1
ซ—•


Z
0' 1  2  3  4 5' 6 7 8 9 10 11 12 13


                  MONTH OF STUDY
                                                 23 24

-------
                        FIGURE A-7
K  LfiKE  HILL5  flND  SURREY DONN5  RRIN  QUERIES

ฃ  1.5
x

z
   1
*~* at
z B
cr
  -.5
in
o „ป i
/—5  1 ซ <
  -2
ป*•


3
Lfl
  -3.5
                       ซ •
-3.5  -3    -2.5  -2    -1.5  -1    -.Z    0    ' .5


        NfiTURflL LOS OF L3KE HILL RRIN QUfiNHf (LN X INQ.ESJ
                                                        1.5

-------
i -
a;
2

O
a
o
  4.5J


  4 _
o
•"• 3 '
L— v • •

    -1   -.5  '0    .51    1.5  2    2.5  3    3.5  4

           NflTURflL LOG Of- LFKE HILLS RfllN DURRTION (LN X HOURS)
                                                   4.5

-------
                       FIGURE A-9
1 LflKE HILLS flND SURREY  DOWNS  PERK RflIN  INT
x


V 3.5__U
5 3
o
a
2 .




1.!




1 .
  .5.
5 3
U3
                           • * ซ  ซ
                    • *
                     ซ  * • •   V
                  ซ ซ   ป
                    •
                     ซ
         .5    1     1.5    2     2.5    3     3.5


         NES. NRTURflL LOG LflKE HILLS PR. RflIN INT. f-LN X IN/HR)

-------
(NJ
LT.
        15.
        10.
                               FIGURE  A- 1 0

                    LflKE  HILLS  -  Wei  Season
            
-------
        FIGURE A- 1 1
SURREY DONN5 - Net Season

-------
                       FIGURE A- 1 2
  30
  25.
a
  20.
  15.
  10.
             LflKE  HILLS -  Dry Season











J
~*
"~

—
—
—


-

-
<



i



/
/
/
i;
3.


•
1




11
lie





L
i-""
{'
|/
j7
*. /
ilH
i.]





























e





T
/
/
./
/
'
/

/
/
.:









2



















Q






7
/'
/
/
/
/
/
/
/
.:









5



















1






!

'.i
p
\
!r'
3






7
/
/
/
/

/
/
/
'









[


















H
0








T
/
/
C
*i




























1
0






7
/
/

/
/
/
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.f




























1
tf-J
0








7
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0.5









)


















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1






/
x
/
/
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3


















1-
>






/
/
/
/
/'
1.









1
     ^-EVENTS
1INFP.LL  Q-RUNOFF
                                       ( -
-------
         FIGURE A- 1 3
SURREY  DONNS - Dry  Season
          Q-RUNOFF

-------
                           FIGURE A- 1 4
no
-j
       SURREY  DOWNS  RUNOFF  (percent  by  month)
   JULT
  flUGUST


SEPTEMBER
           OCTOBER
                                                 FEERUfiRT
JflNURRY
                                                 DECEMBER
          NOVEMBER

-------
rsj
•-j
OJ
                           FIGURE A- 1 5

     SURREY  DOWNS  BflSE  FLOWS   (percent by month)
           MRRCH
           flPRIL
             MflY
            JUNE
            JULY
          flUGUST


        SEPTEMBER
          OCTOBER
                                                  FEBRUfiRT
                                                  JflNUflRT
                                                  DECEMBER
NOVEMBER

-------
                                FIG'J'rlE  A-16
55
H 50__
* 45__
5
ฃ 40-_
ง 3S—
a 30 	
u
2 2S_
H
a 20 —
3
H is_

t 10_

if"
ai c
jp 5 —
SI
n
V
-
™*
r
^_
ง
^
~
—
^
— .
-_-1
—


—
ซi
—
iป










if
ฃ
jj

^
3
*


















1



































0
-






j









1

































fin
II 1
0. 15
















— '










P
C
!
\
*
'i

i
ฃ
i
D

















'1















R 11 n
I ri~! B-i B-i ' S~l n ETl I era r-i
10.2510.3 0. 35 I '). 4 U . 4 rj . ;- j ': . ~> ~> >., . ^
    ||-LflKE  HILLS  Q-SURRET DOHNS

-------
                                  FIGURE  A- 1 7

                                     ZINC
ro
—i
LTI
             -LflfcE HILLS
Q-5URRE

-------
      FIGURE A- 1 a
CHEMICRL OXYGEN DEMfiND

-------
no
—j
                         FIGURE A-19

                 TOTHL  UELDRHL NITROGEN
          <0.5 I 0.5

              HILLS Q-SURRET DOHNS

-------
r\J
~o
30
     5
       50
       40.
       30.
          \-
       10.

          
-------
                              FIGURE  A--21
30
                                   PH
20.
                                BS!

      5.0
5.2:
                                b. 0
           KILL5 Q-SURRET D(M4S

-------
•X)
'.TO
O
                        FIGURE A-22

                  SPECIFIC  CONDUCTRNCE
             HILLS Q-SURftET DOWNS

-------
ro
DO
                            FIGURE A-23

                           TURBIDITY
           < 5   5   10
           U*E HILLS Q-SURRET DOWNS

-------
00
ro
              09
              08

              o /

              06


              OS
   0 1

I ฐ09
ฃ oofl
•o
J 007

  006


  005
             003
             0.02
                               Surrey Downs ฃ

                                   Lake Hills *
                                                                    20    30   40   50   60   fO    80      90     95

                                                                        Percent Less Irtan Concentration
                                                                                                                       98   99   995  998
                               FIGURE   A~24  Fraquency Distribution of Lead Concentration

-------
                                 Surrey Downs  •

                                     Lake Hills *
ro
CD
OJ
1 0.07

 OOP


 0.05


 O.O4



 0.03





 0.02
                                                                      20    30   40   50   60   70    80


                                                                           Percent Less than Concentration
                                                                                                                           98   99  99 •>  99 8
                                FIGURE   A ~ 2  5   Frequency Distribution of Zinc Concentration

-------
                 Surrey Downs
                     Ldke Hills
80
70
60
                                                      20    30   40   ',0   60    70    80
                                                          Percent Less then Concentration
                                                                                                         98   99  99 5  9y f
               FIGURE   A~26    Frequency Distribution of COD Concentration

-------
rsj
oo
     1

=   0.!*

ฃ   0.8

^   0.7
(-
    0.6
                                Surrey Downs

                                    Lake Hills
               0.2
                                                                     20    30   40   50   60    70    80

                                                                           Percent Less than Concentration
                                  FIGURE   A— 27  Frequency Distribution of TKN Concentration

-------
              4 0


              30
                               Suridy Downs

                                   Lake Hills
IN)
CO
cr>
              006

              005

              004

              003
                                                                    20    30   40  50   60   70   80      90

                                                                         Percent Leas than Cofi~entratlor
                                  FIGURE    A~28  Frequency Distribution of TP Concentration

-------
                               Surrey Downs
                                  Lake Hills
IN3
CO
              20
                                                                  20   30   40   50   60   70   80
                                                                        Percent Less than Values
                          FIGURE   A — 29  Frequency Ditttrlbutlon of Specific Conductance Values
98   99   995  998

-------
              200
                                Surro> Df  ".s

                                    Lake hills
po
oo
oo
               60

               bO
           5   30
                                                                          *•••
                                                                     20    30   40   50   60    70    80

                                                                             Percent Less than Values
                                   FIGURU   A~30  Frปquancy DlvVrlbutlon of Turbidity Values

-------
("O
oo
                          FIGURE  A-31

          SURREY DOWNS TOTflL SOLIDS  BY  SEflSON
       3(5(5
       25fl	
5 2a
 N
in
2 ISfLU
d
vn
     ct
            j**
            .
            *
              A  ซ
      0       .25
      9  dry season
      *  wet season


.5
.75     1
RflIN, INCHES
1.25
1.5
                                                           1.75

-------
  .5.
  .4.
  .3.
a

-------
                    FIGURE A-33
        SURREY  DOWN5 ZINC  BY  SEflSON
.35__
.3.
       •  *A
.05 I...
       A  •
0      ' .25
 dry season
, wet season
                  .5
 .75      1
RflIN, INCHES
1.25
1.5
1.75

-------
                    FIGURE A-34
         SURREY  DOWNS COD  BT  SEflSON
150
lOfl	
75.
50.
25.
      A A
V*'j; .*
/'A
A.    •    A    •
   •   A    A   A
           .25
  o dry season
  A wet se^r.on
             .5      .75     1
                   RfllN, INCHES
                                1.25
1.5     1.75

-------
ro
>O
to
                             FIGURE A-35
                 SURREY  DOWNS  TK.N  BY  5ERSON
        4.5 r
          i
        4 __;

        3.5

        3	,	

        2.E
               0 0
            0 00 0 A
       0
           0      .25
           a dry season
           4 wet season
*f   '   I
"'t.;	i
                                          -i-'
 .75      1
RfllN, INCHES
1.25
1.5
1.75

-------
                      FIGURE A-36
  SURREY  DOWNS TOTflL  PHOSPHOROUS BY  SEflSON
  1.25
  .71
fc
S -
OL-
                                  *f
            .25
      e dry season
      A wet season
.5
.75     1
RfllN, INCHES
1.25
1.5    1.75

-------
                       FIGURE  A-37
            SURREY DOWN5  PH  BY 5ER50N
   7.5
  6.1
ฃ
a.
 A A
 A

 A A  A A A    A
   A  A              A
 •   A     A  A           A
       A             A
  •  • 9 ซ     A        A
> •  A* ฎ              A  A
     A A    A       •
   ซ eป       •   A
 AซซปAAซซซ         A
 A* e  ซ•  ซ             A
 A*  e •         A
 • A ป A 2    •
       9         ป A
       A
  5.!
             .25
              .5
        dry season
        wet season
.75      1
RflIN, INCHES
1.25
J.5     1.75

-------
                     FIGURE A-38
     SURREY  DOWNS  CONDUCTIVITY  BY  5ER50N
  150
5 12D—
  90.
S 60.
LJ
t—t
U_
  30	
    A
 ซ 9  C
_ A A   -

'". A
0      .25
e dry season
A'wet season
                   .5
 .75     1
RflIN, INCHES
                                 1.25
1.5     1.75

-------
                    FIGURE A-39
100
80.
60.
40.
      SURREY  DOWNS  TURBIDITY  BY  SEflSON
20..
e      .25
 e dry season
 A wet season
                 .5
                             A     A
                                 A         *
                                     ฃ
.75     1
RRIN, INCHES
1.25
1.5
1.75

-------
                           FIGURE A-40
fNJ
kฃ-
ro
            LRKE  HILLS  TOTflL  SOLIDS  BY  SERSON
        300
        25D	
        20D	
in
ฐ 1C?
•— lot
o
in
        50.
        0
               Ac
                    0 e
           •  *  ,  A
        ซ --     *  *
             A A
                              e   A
                  .25

           e dry season
           A wet season
                    .5
1.25
1.5     1.75
                          RfllN, INCHtS

-------
                             FIGURE A-41

                  LfiKE  HILLS  LEflD 3Y  5ERSON
f\5
\0
-O

.3.
                f
        .2.
        .1.
            -A ซ• 00 AC 99

               * A
             e  9
               • A
                          A A ซ -tt
            0       .25
            0 dry season
            A wet season
,5      .75     1
       RfUN, INCHES
                                                     A   AA
                                        1.25
1.5
1.75

-------
o
o
                             FIGURE A-42

                 LflKE HILLS  ZINC  BY SEflSON
       ,35__
.IS


.1-


.854—


0
               * .
             A A A
            • A      A
            •  * A
            A    ป  A* •
                A #
                  *A  • A   A*
               'A*/
           0     ' .25

            0 dry season
            A wet season
                  .5
.75
1
1.25   ' 1.5
                         RflIN, INCHES
1.75

-------
OJ
O
                            FIGURE  A-43

                   LflKE  HILLS COD BY SEflSON
        150
       125-_
       IQfl	•
       75.
                       A*  A
               0 a • •
                                  A
             A

              A

            A*    A
           0     ' .25
           e dry season
           A wet season
.5
 .75     1
RflIN, INCHES
1.25
1.5
1.75

-------
                               FIGURE  A-44

                    LflKE HILLS  TKN  BT 5ER50N
        4.5
        3.25_ A
o
ro

2.:
         i.i
         7C
         • / •>
                            A   e
     *  w*  •.   •   .
     A •ซ * 9   • *

       -ซPA  . * 8 *^  *
      AA *   •  •
—ฃ
0     ' .25

 e dry season

 A wet season
                           A ซA
                           .5
                            A

                           A
                                         A •
                                         A
                                        AA   *
                          ,75
                            1
1.25
1.5     1.75
                                  RflIN, INCHES

-------
                          FIGURE A-45
CO
o
        LflKE  HILLS TOTRL  PHOSPHOROUS BT 5ERSON
       1. 25_-	a	
       *7ฃ
                •  A
                        A •
           A
                    AA
0     ' .25

 e dry season

 A wet season
.5
1 .75    1

RflIN, INCHES
1.25
1.5
                                                        1.75

-------
       7.5
                            FIGURE A-46
                   LRKE  HILLS PH  BY  5ER50N
OO
o
12
ป—I
5
ฃ
             A A    A     A
           •A A A   A •
              A A A
             A A          A
            A     t\ A
             A
                      •  A
                     0O
• •
 • ป
• •*ป
 O0 A •
 e A a
                                               A

                                               A
              *ป  A
               AA
              A
                A A
               •  A
           0      .25
            e dry season
            A wet season
                     .5
                     .75     1
                    RfllN,- INCHES
1.25
3.5
1.75

-------
                     FIGURE A-4T
      LRKE  HILLS  CONDUCTIVITY  BY  SERSON
  150
5
3t
  90
13
Ul
u
  30	
      .25
e dry season
* wet season
,5      .75    1
      RflIN, INCHES
1.25
1.5
                                                    1.75

-------
OJ
o
                          FIGURE  A-48

             LflKE  HILLS  TURBIDITY BY SEflSON
       100
       6f
       20_
              •   •

:.
                 .25
    .5
          ซ dry season
          A wet season
1 .75     1

RflIN,  INCHES
1.25
1.5     1.75

-------
.-  :\ , ' s i:
               roin     dei'iing        re il e)   (microns)

  A-1 12         A.-)            4          .'.'61          36}
  A-1 15         6.9            7          268         327
  A-1 1 9        11-0           11           423         -60          323          474
  A-170        1i  .6          >60          312          463
  A-174         2.0          >60          270          441
  A-179         4.2          >60          384          473
  A-185           -6          >60          233          599
  A-312           .4          >60          382          752
  A-319         6.3          >60          503          488
  A-325         1.0          >60          442          934
  A-329         2.9          >60          400          564
  A-335            .8          >60          329          720
 A-341            -4          >60          374          716
  A-349         5-4          >60          405          968
  A-353          7-4          >60          379          896
 A-356          q.2          >60          372          782
 A-362         12.4          >60          356          774
 A-366            .8          >60          282         1006
 A-372          1.7          >60           314          842
 A-381          4-9          >60           597          514
 A-386          8.9          >60           361          790
 A-395          2.3          >60           341          850
 A-400          5.3          >60           315          496
 A-402          1.0          >60           594          936
 A-418            .6          >60           422          832
 A-429          2.6          >60           430          7^4
 A-440            .4          >60           304          700
 A-454          7.2          >60           343          800
 A-459          1.0          >60           226          914
 A-475          3-7          >60           443          580
 A-481          7-5          >60           501          593
 A-490          2.8          >60           432          748
 A-494          3-6          >60           350          760
 A-499          1.0          >60           279          872
                 307

-------
VM e  B-1.  Surrey  Downs Gtreot  Dirt  Load i nps ', cont
           (Dry season, no r-treet.  ~.i r;\-.i r.r}
3 a in p 1 o
D n t e

fc ;"
(', I ^ r
6/30

7/0

7/14
7/1 7
7/20
7 / 2 3
6/4
8/7
8/1 2
6/1 4
fc/'l 8
8/21
S/25
8/2E
q/2
9/4
9/8
9/1 1
9/H
9/15
J I ' ,x
ฐ/1 3
^ 1 ' '—
9/23
Count
Average
,"•' iniwum
"vix inum
0 an pie
Ident .

A -500

:\_
A-530
A-534

A-^4'i
A-548
A -553

A -5^3
A-S^Q
A-^6S
A-567
A-575
A-579
A-501
A-586
A-586
A-593
G-594


n.ivs f-
iTot ^i,
r r
;

1 2
i
f}
^

~it
1
\ ^
r?
/4

32
3s
~;9
43
45
1
~j
c
1 1
14
15
18
1
74
45
-GUI
,M •
3 i n
p
_ ,>,


7
. i
_ c~l
o
. 0
. o
. 0
_ o
, o
. {
3
. 1
. 1
.5
.6
-4
• 5
. A
.3
.4
.4
.0
10
4
- 4-
• 9
Days from
laot
cl ean i np
>GO
>6C
>60
> h 0
>60
> f- 0
><50
>oO
>00
>60
>60
>^0
>60
> 60
>60
>fO
>60
>60
>60
>60
>60
>60
>60
>60
>60
>60
74
>30
4
>60
Load i ng
(it/curb-
mile)
368
669
409
38?
562
348
315
540
385
446
568
500
ฃ93
416
503
516
546
282
498
435
450
506
275
872
277
74
3Q9
21 9
872
Median
si ze
(microns )
732
610
4^4
610
61 1
403
648
559
489
484
457
454
477
520
479
445
415
421
613
468
429
444
440
44~5
447
682
74
575
28ฐ
1006
                                    >08

-------
       'i;rrey  l''owns  Street  Dirt  Loadings
        ( W o t ,• e a son,  no  street  cleaning)

              Gar.rle   Days  from     Loadir?;      Kediar
              luen4,.   last  siฃn.    (ib/curb-        size
                            rain       mile)   (microns)

 10/2/80       A-189          2.4         526         50?
    10/7       A-196          7-5         389         561
    10/9       A-198           -9         406         442
  10/14       A-206          6.1          336         500
  10/16       A-2C8          8.2         339         408
  10/21       A-213         13-2          371          963
  10/23       A-218         15-2          342         514
  10/28       A-221         20.1          369         444
  10/30       A-227         22.2          379         450
  11/18       A-236          8.8          244        1592
    12/9       A-244          4-9          475        1228
 1/6/81       A-249          5-3          346        1609
    1/8       A-252          7-1          333        1600
    1/13       A-259         12.3          406         870
    1/15       A-263         14-3          371          888
    1/20       A-267         19-1          447        1708
    1/27       A-271          3-4          556         1220
    1/29       A-276           .3          290        1064
    2/5       A-284          7.1      •    681          802
    2/10       A-289         12.5          471          724
    2/17       A-291           .6          278         1190
    2/19       A-295          2.7          330          930
    2/26       A-304          1.1          425          888

  Count                     23-0          23          23
Average                      8.5          387          917
Minimuc                       .3          244          408
Maximum                     22.2          681         1708
                        309

-------
                                            (11- /curl -
                                                rail" )
4/18
            ^-42
            u-44
            S-45
            3-47
            F.-49
            3-51
            3-52
            S-54
            5-56
            S-58
            S-59
            S-61
            S-63
            S-65
            S-66
            S-68
            S-70
            S-72
            G-75
            S-76
            S-7Q
            S-80
            S-81
            S-84
            S-86
            S-87
            8-88
            S-90
            S-92
            S-95
                          G . 4
                          1 . 1
                          1 . 1
                          1 .6
                          1 .6
                          1 .7
 3-7
 1 .2
 1 .2
 3- 2
 3-2
 5-2
 5-2
 2.2
 2.2
                         S29
                         4ฐ3
 7.
 7.
 Q .
 9.
1 1 .
1 1 .
14.
14-
16.
16.
18.
18.
21 .
21 .
 2.
 3-6
 3. 6
 2.0
 2.0
 9-0
 9-0
1 1 .0
1 1 .0
14.0
14.0
 1 .6
 1 .6
 3-t)
 3-6
 5-0
             2.9
545
695
442
713
41 2
32fe
2G5
303
317
295
386
371
323
424
332
333
353
406
315
472
423
437
427
384
444
29C
304
305
375
257
235
252
237
245
281
295
336
352
352
320
251
249
328
315
302
364
41 5
45^
423
483
471
415
391
441
391
408
329
376
346
357
333
327
309
361
349
300
325
341
335
314
365
372
391
371
356
324
308
334
343
341
386
302
415
366
368
354
330
                           310

-------
'able D-7-  Surrey  Downs  Street Dirt Load ir:g3(cฐnt •
            (Dry season1,  with street cleaning)
     Sample
       Date
       6/30
        7/2
        7/2
        7/7
        7/7
        7/9
        7/9
    9/24/01
       o/OQ
       9/29
       9/30
       9/30

      Count
    Average
    Ki nitnum
    Max imum
Sample
Ident.

3-97
S-100
3-101
S-103
S-105
S-107
S-109
S-598
S-5Q9
S-600
S-602
S-603




Days from
last sign.
rain
3-0
7.0
7.0
12. C
12.0
14.0
14.0
2.6
.2
.4
1 .2
1 .4
60.0
7
.2
21 .2
Days fron
j ast
clea ilng
. 1
1 .9
.1
4-9
. 1
1 -9
.1
1 .0
3-9
. 1
• 9
.1
60.0
1 .2
•1
4-9
Loading
(Ib/curb-
mile)
306
363
364
295
285
353
345
253
139
177
164
180
60
347
139
713
Median
size
(microns)
301
323
282
322
304
327
339
531
862
444
734
421
60
377
276
862
                                 311

-------
 i rt Lo"id i n/'"
. fet i1 1 o.ฐ. n i np)
2 'I- ;• 1 ,->
I'M t .^

10/2/2-1
10/2
1 0/[>
1 c,")
10/1 ?
10/12
10/16
10/16
1 0/1 '1
10/20
10/20
10/21
10/21
10/2"
10/26
1 1/2
11/2
11/5
11/5
1 1/6
1 1/9
11/16
1 1/16
11/19
1 1/20
1 1/24
11/24
11/25
12/4
12/7
12/7
1 2/1 1
1 2/1 1
12/14
1?/14
1 2/16
12/16
12/21
12/21
12/23
12/23
Count
Average
M i n imum
n.-i.x i mum
2'-.np] p
Id nn t .

'2-L>Oc.
2-t.iCe
2-607
S-612
2-6! \
S-612
2-613
2-6 1 6
S-617
S-621
S-622
2-623
G-624
S-625
3-626
S-629
S-630
S-632
S-633
S-635
S-637
S-639
S-640
S-642
S-645
S-646
S-648
S-649
S-651
S-652
S-653
S-657
S-659
S-660
S-661
S-662
S-663
S-665
S-666
S-667
S-668




>),v:- from
1 n r t :; i f n .
r n i n
.4
.7
3-4
•7
• I
3.4
3-6
7-4
7-7
10.4
11 .4
11.6
12.4
12.6
14-4
17.6
5-3
5-5
8.3
8.6
9-3
12.3
1 .0
1 .2
1 .7
2.8
1
1 .2
2.0
2.2
1 .2
1 -3
.8
• 9
. 7
-9
.6
.8
1 .8
2.0
^. 8
4-0
41 .0
4-9
.4
17-6
Pny:-' from
] MPt
c 1 e M n i n c
1 -9
.2
3-0
1 . 2
1 .q
.i
1 .9
.2
2.9
3-9
. 1
.8
. 1
1 -9
2.9
2.9
.1
2-9
.1
.8
3.8
10.8
. 1
2.9
• 9
3-9
.1
.8
.1
2.9
.1
3-9
.1
2.9
.1
1 .9
.1
4.9
.1
1.9
.1
41 .0
1 .8
.1
10.8
Load ir,f
(Ib/curb-
mile )
1^6
195
228
127
129
122
204
177
229
245
193
202
158
160
193
122
123
156
1SO
166
106
239
117
135
116
78
88
92
92
86
94
98
127
101
108
119
127
172
178
167
110
41
H6
78
245
Median
pi zp
(microns)
751
4^0
36 f
462
448
38^
316
327
303
378
338
345
274
355
438
491
419
454
410
407
794
1831
729
466
563
775
548
575
985
725
528
740
404
539
489
641
528
466
475
572
518
41
537
274
1831
    312

-------
.'  r--^.  ("\irrcy  i-cvr..  - 10fHh Ft. Street Dirt  Loadings
        (Fry sen:? *ป         1676
  9/30       A-186           .6          591
3/5/81       A-313          1.4          273         1246
   3/10       A-320         6.3          509          978
   ^/17       A-326         1.2          394         1493
   3/19       A-330         3.0          318         1312
   3/25       A-339           .4          253         1460
   3/30       A-350         5-5          265         1622
    ^/1        A-352         7.4          385         2182
                        313

-------
Table fl-5-  Surrey Downs - 100th St. Street Dirt Loadings
            (Dry season, no street cleaning) (cont. >
      Sanple
        Date
        4/G
        4/9
       4/13
       4/15
       4/20
       4/24
        5/4
       5/12
       5/20
       5/29
        6/2
        6/4
       6/16
       6/23
       6/26
        7/2
        7/6
        7/9
       7/14
       7/17
       7/20
       7/27
        8/6
       8/18
       8/27
        9/2
        9/9
       9/15
       9/23

      Count
    Average
    Minimum
    Maximum
Sample
Ident .

A-360
A-369
A-374
A-379
A-3S5
A-397
A-420
A-443
/-457
A-477
A-482
A-485
A-495
A-502
A-510
A-518
A-521
A-526
A-531
A-535
A-537
A-543
A- 5 50
A-561
A-569
A-574
A-582
A-589
A-596




Days from
last sign.
rain
12.3
1 . 1
1 .e
3-9
8.8
2.4
.8
1 .2
1 .0
4-5
7.6
9-7
3-7
4-9
7.8
1 .5
5-7
2.4
1 .0
3-8
7-0
13-9
24-0
36.1
44-8
1 -4
8.5
14-3
1 .6
77-0
8.7
.4
44.8
  Loading
!lb/ourb-
   mile;

     323
     336
     238
     209
     203
     3H
     331
     320
     252
     399
     368
     273
     506
     330
     308
     543
     240
     311
     283
     218
     340
     318
     295
     557
     281
     199
     266
     300
     157

     77
     409
     157
   1336
   Med ian
     size
[microns)

    1392
    1582
     956
    1092
    1410
    1866
    1 184
    1320
    1674
    1450
    1466
    2040
    1 540
    1996
    1150
    1286
     992
    1319
     669
     71 2
     901
     913
    1163
    1395
    1503
    1650
    1412
    1360
    1240
   1334
    66y
   2182
                            314

-------
•-•Me r-6.  furrey Downs  - 108th "t.  Street Dirt Leadings
           (Wot  season,  no  street cleaning)
    10/2/80
       1 0/7
       10/9
      10/14
      1 0/16
      1 0/21
      10/23
      1 0/28
      4 r\ I "7 r\
      . ^ f ^\J
      11/18
     1/8/S1
       1/13
       1/15
       1 /20
       1/27
       1/29
        2/5
       2/10
       2/17
       2/19
       2/26
       10/9
      10/19
       11 A
      11/19
      1 1/24
       1 2/3

      Count
    Average
    Minimum
    Maximum
                 Garaple
                 Ident.
A-190
A-197
A-199
A-205
A-2QQ
A-21 2
A-217
A-222

A-235
A-253
A-260
A-262
A-268
A-272
A-275
A-283
A-290
A-292
A-296
A-303
A-609
A-618
A-634
A-643
A-647
A-655
 f rcm
3 i gn.
 rain

 2.4
 7.6
   . Q
 5-7
 7-9
 12.8
 14-9
 19-9
 21 .9
 8.8
 7.1
 12.3
 14-3
 19-3
 3-4
   • 3
 7.1
 12.3
   .7
 2.7
 1 .1
   .6
 10.6
 8.5
    8
    1
  2.3

 27-0
  7-7
   • 3
 21 .9
  Load ing
(Ib/curb-
    mile)

      382
      378
      432
      374
      400
      27S
      239
      386
      453
      163
      243
      267
      288
      209
      175
      138
      308
      239
      365
      300
      255
      153
      205
      472
      128
      128
      123

       27
      277
      123
      472
   fled ian
     size
'microns)

     1730
     1874
     1264
     1548
     1584
     1990
     1258
     21 56
     1764
     1916
     1340
     1034
     1408
     1318
     1 148
      890
     1468
     1328
     1096
      956
     1310
      808
      981
     1952
     1344
     1869
      964

       27
     1418
      808
     2156
                            315

-------
I~?
Road Htree
t Dirt
street cleaning)
Days from
n s i sign. (
r 9 i r.
2.0
11.1
14-2
7.0
14.0
20. 1
27.0
34.9
4-4
2.6
9-6
2.2
1 -4
3-0
• 4
5-5
.8
1 -9
2.4
.8
4-7
7.6
4.6
6.0
1 -5
• 4
3-8
10.0
14.0
24.0
35-9
44-9
1-5
9-5
1 .6
35.0
9-58
.4
44-9
Load ing
Ib/curb-
mil e )
394
454
351
721
710
637
417
509
261
336
266
232
266
462
1 1 2
225
420
200
258
184
195
313
109
145
282
21 1
206
185
149
432
268
431
206
170
147
35
3iO
109
721
hed ian
size
( r. i c r o n s )
491
582
339
697
402
410
376
425
284
431
421
652
634
482
682
784
776
904
1352
836
967
645
694
497
21 1 7
1715
625
786
528
418
636
517
91 7
999
626
35
704
284
21 17
                           316

-------
Loadings >

  Cample
 10/2/SC
    1 0/9
   10/14
   10/21
   10/28
   11/18
  1/3/81
    1/15
    1 /20
    1/27
     2/5
    2/20
    2/26
   10/19
    1 1 /6
   11/19
    1 2/8

   Count
 Average
 Minimum
 Maximum
Downs -
eason, t
C a TT.pl e
Ident .

A-1Q1
A-200
A-2C7
A-21 4
A-223
A-257
A-254
A-264
A-269
A-273
A-285
A-2Q8
A-305
A-61 9
A-636
A-644
A-656




West. w o o d i: o^ e s
ic street clean
Days from
last sign. (
rain
2.5
,9
5-9
12.9
19.9
8.6
7.2
14-4
19.3
3-5
7-3
3-6
1 .2
10.6
9-5
1 .8
2-3
17.0
7.7
.Q
19-9
Road 3t
ir.r)
Load ing
Ib/curt-
mile)
517
538
318
270
519
906
125
462
206
229
515
240
229
368
283
241
182
17
362
125
906
reel Dirt

ived ian
si ze
(microns)
422
1084
866
934
67,'
>6370
990
1898
>6370
2858
1216
1142
1146
349
595
1543
1789
17
>12CO
0
>6370
                        317

-------
C i rr. i • 1 ^
Pa!,e

4/22/60
4/24
5/7
5/14
5/16
6/3
6/12
6/19
6/24
7/1
7/8
7/10
7/17
7/22
7/25
7/20
7/31
8/6
8/8
8/1T
8/15
8/19
8/22
8/25
8/29
9/4
9/9
7/7/81
7/10
7/14
7/16
7/21
7/27
8/4
8/7
8/12
8/14
8/19
8/21
8/25
8/28
9/2
9/4
9/8
9/11
9/14
9/18
9/23
9/29
Count
Average
M in imum
[laxiiriim
Cample
Ident .

A-31
A-35
A-43
A-55
A-62
A-71
A-79
A-89
A-93
A-99
A- 106
A-1 1 1
A-1 1 4
A-1 1 8
A-121
\-125
A-245(?)
A-132
A-1 36
A-1 37
A-143
A-1 46
A-147
A-151
A-1 54
A-1 56
A-1 60
A-524
A-528
A-529
A-533
A-539
A-542
A-547
A-552
A-554
A-557
A-562
A-564
A-566
A-572
A-573
A-578
A-580
A-585
A-587
A-592
A- 595
A-601




C'iy:i from
last si p,n .
rain
2.3
4-3
17.3
24-3
26.3
1 .4
10.3
2.7
7.7
6.0
13-0
15-2
5-7
10.6
13-6
•6.6
19-7
24-7
26.7
30.6
33-8
1 -3
4-3
6.3
1 .1
1.3
2.4
.4
3-4
• 9
3-0
8.2
14.0
22.0
24-8
29-8
31 .8
36.8
39-0
43-0
46. 1
1.3
3-6
7-4
10.4
13.4
17.4
1 -5
• 5
49-0
14
.4
46.1
               rr. i 1 e )

                434
                444
                705
                671
                467
                451
                544
                721
                552
                774
                577
                6b4
                558
                673
                920
                358
                731
                627
                753
                801
                711
                552
                497
                478
                350
                386
                428
                156
                138
                132
                196
                261
                331
                302
                297
                273
                243
                219
                299
                241
                326
                157
                235
                271
                271
                287
                350
                207
                206

                 49
                443
                132
                920
   F'ed ian
     size
(fEicrons)

      734
      749
      573
      626
      679
      710
      525
      494
      637
      419
      583
      492
      556
      472
      413
      430
      434
      416
      382
      392
      386
      402
      529
      434
      588
      592
      607
      384
      310
      464
      346
      323
      335
      393
      377
      327
      404
      511
      386
      407
      388
      530
      380
      362
      355
      381
      364
      525
      599

       49
      472
      310
      749
318

-------
  :-10. Lake Hill.? Street Dili Loadings
       (Vet season, no street cleaning)
  "ample
  Count
Average
Minimum
Maximum
Sample
I dent.
1 0/9/S1
10/16
1 C/1 9
10/26
1 1 /4
11/16
1 1/25
1 2/1
1 2/8
1 2/1 1
1 /I 4/82
A-60S
A-614
A-620
A- 627
A-631
A-641
A-650a
A-650
A-654
A -6 5 8
A-570
 Bays  fron
_ast  sign.
      rain

        .6
       7.5
      10.7
      17-6
       7.5
       1 .6
       2.0
       9-1
       2.0
        . q
       3-0

      11 .0
       5-7
        .6
      17.6
  Load ing
(Ib/curb-
    mile)

      233
      218
      241
      319
      249
      338
      201
      344
      238
      257
     1065

       11
      337
      201
     1065
                                                    size
                                               (microns)
                                       480
                                       406
                                       451
                                      1012
                                      1190
                                      1010
                                      1840
                                      3690
                                      1742
                                      1606

                                        1 1
                                      1262
                                       406
                                      3690
                       319

-------
                                               n ; I
 3/11
 3/13
 3/16
 3/13
 3/13
 3/20
 3/20
 3/24
 3/24
 3/25
 3/25
 3/27
 3/27
 V30
 V~o
 4/3
 4/3
 4/6
 4/6
 ,|/9
 4/^
 4/10
4/13
4 /1 ?
4/15
4 /' 1 5
4/17
4/17
                                       . 1
                                       . R
                                                             474
2-1 (L^
2-184
p-T.Ofl
2 — ^O'"1
2- ^1 0
2-31 1
3-31 i:
3-~M6
S-^17
S-318
3-321
3-~,_'2
3-323
3-324
3-327
3-328
3-332
2-333
;-;_ •; 54
3-336
S-337
3-338
3-344
3-M6
3-347
3-343
3-^5
3-v>7
S-359
3-361
3-^65
3-367
3-^70
S-371
S-376
3-377
S-'778
3-382
3-384
R. 1
R. ^
5-6
5 • a
' . 5
.6
2.4
2.6
5-4
5-6
7-4
7.6
9-4
• 5
2-3
2 . 5
4-3
4-5
.8
1 .0
.2
• 3
2.2
2.4
5. 2
5- ?
-3
. 5
3-3
3-5
. 7
. q
1 .7
1 .4
1 .6
3-4
3-6
5.4
5-6
2 . }
. (.1
2.9
. 1
1 .8
. 1
1 .8
. 1
2 • 9
. T
1 • 9
. 1
1 .8
.1
l -9
. 1
1 -9
. 1
3-8
.1
,9
. i
1 -9
. 1
2-9
. 1
2.Q
. i
2-9
. 1
2.9
.0
• 9
2.9
.0
1 -9
.0
1 -9
.1
2b5
311
2'^
213
12S
172
1Q7
207
223
21 1
246
201
235
150
185
168
22^
233
374
144
134
143
167
166
267
141
159
136
150
156
1 1 1
130
135
164
170
195
156
21 1
21 1
T?C
324
257
237
484
308
276
24 1
26C
2-13
225
238
247
300
200
241
246
210
335
237
550
293
260
232
321
454
329
284
3^4
303
415
343
;29
>ฐ0
301
312
263
262
263
                          320

-------
with street
4 '' J '
4 '21
-I/?7!
4/.:^
4/24
4/24
4 ' J7
4/"0
4 / : ^
S/ 1
5/1
S / 4
5/4
5/b
5/5
5/8
5/8
5/12
5/12
5/13
5/13
5/15
5/15
5/18
5/21
5/21
5/22
5/22
5/29
6/1
6/1
6/4
6/5
6/5
6/11
6/1 1
6/15
6/17
6/17
6/23
6/23
6/?4
6/24
6/26
6/26
6/29
6/29
7/1
7/1
Count
Average
i'i ni™ua
Kax imum
:j-;-"37
• •• ~ o o
O~ ,. ^l
,-- vlฐ
S-VTI
P--VD4
P-^b
t-3lr^
Jf— 401
n-403
?-41 2
S-4 1 5
0-417
S-41 ^
3-423
S-430
S-433
S-4-37
3-442
S-444
S-445
S-447
G-449
S-451
S-453
G-460
S-461
S-462
S-468
S-.<76
3-479
S-480
S-s84
S-486
3-43S
S-489
3-491
S-i93
S-4%
S-497
S-501
S-503
S-504
3-50'5
S-50<)
S-51 i
S-512
S--13
S-51 5
S-51 6




9-4
9-6
. 0
1 . 1
1 .9
2. \
4-9
.9
1 . i
2.9
3-2
.5
.7
2.5
2.7
• 5
.7
1 .2
1 .4
1 .2
1 .4
4.2
4.4
7.2
1 -9
2.0
2.7
2.Q
4.5
6.5
6.7
9-5
10.5
10.7
2-9
3-1
2.4
4.4
4-6
4.8
5-0
5-8
6.0
7.8
8.0
10.8
11 .0
.4
.6
97.0
4
.2
11 .0
3-9
, 1
1 -9
. 1
. q
.1
2-9
1-9
.1
'.9
.2
2-9
. I
1-9
.1
1 -9
.1
3-9
.1
• 9
.0
1-9
.1
2.9
2.9
.0
.7
.1
6.9
9-9
.0
2.9
3-9
.1
1.9
.1
2.9
1.9
.0
5.9
.0
• 9
.1
1.9
.0
2.9
.0
1.9
.0
97.0
1 .4
.0
9-9
101
1?S
117
115
110
154
1 so
103
109
130
107
62
175
227
184
132
134
158
155
I7b
189
99
122
161
123
128
115
133
188
198
209
88
130
125
290
174
237
15G
265
205
165
210
202
167
158
201
196
111
121
97
182
62
380
4R4
301
352
127
364
308
301
450
34 P
31 5
260
376
208
368
240
396
284
275
270
2%
265
324
256
376
400
326
306
262
340
282
324
474
365
294
465
304
285
276
332
422
280
346
240
289
291
319
298
402
344
97
318
210
550
       321

-------
10/1 /
   1 0
<0
/ i
10/10
1 0/1 ^
10/13
10/17
0/17
10/22
10/22
10/24
10/27
10/29
10/29
11/5
11/5
1 1/10
1 1/12
i/; 2
1/17
1/17
1/19
1/19
1/24
1/26
1 1/26
12/5
12/15
1/5/81
1/5
1/7
1/7
1/9
1/9
1/12
1/12
1/14
1/19
1 /19
1/21
1/28
1/30
1/30
2/2
3-202
S-^O7)
3-204
3-210
3-21 1
S-21 5
3-21 6
S-21 9
3-220
3-224
3-225
S-228
3-229
3-230
3-231
S-232
3-233
3-234
3-238
3-239
S-240
3-241
3-242
S-243
3-246
3-247
S-248
3-250
3-251
S-255
3-256
S-257
S-258
S-2C1
S-265
S-266
3-270
S-274
S-277
S-278
S-279
 1  .4
 1  .6
 3.4
 3 • 6
 6.4
 6.6
10.4
10.6
1'..4
13.6
17-4
17.6
22 . 4
22.6
24-4
27.6
2Q.4
29.6
 1  -5
 1  .7
 1  -7
 3-4
 3-6
 8.4
 8.7
10.5
10.6
 2.7
 4-5
 4-6
   .7
10.7
 4-5
 4-6
 6-5
 6.7
 8.5
 8.7
12.5
12.7
14-5
19-5
19-6
21 .7
 4.2
 1 .0
 1 .2
 4-0
 1 .8
  . 1
 1 -9
  . 1
 2-9
  , 1
 1 .8
  . 1
 3-0
  . 1
 3-9
1
                                        4
  .9
  .6
  .0
1  -9
  . 1
6.9
  .1
  .0
1  .8
  . 1
2.9
  .1
1  -9
  .0
  . 1
1  -9
  .1
2. 1
  .0
  9
  0
4-9
 .1
1 -9
2.9
 .1
1 -9
6.9
 .0
 .1
1.9
1 -9
2.9
                                   V'-o \ an
                                     r, i z F>
                                ( n i c r o n r )
220
239
22^-
200
244
2^0
216
214
124
148
182
1 QQ
198
21 1
212
201
250
235
167
123
130
150
148
161
147
1 10
112
112
108
121
159
145
261
210
144
179
270
197 '
242
214
187
1 94
191
162
138
109
310
185
^29
341
v, 1
279
28 i
2qQ
351
272
665
342
316
255
349
•MO
257
300
341
297
964
465
626
629
413
720
48S
>6370
473
461
755
491
679
464
455
316
592
375
421
340
348
314
4Q1
444
325
321
733
608
275
479
  322

-------
'able  B-1C.  T.-ike Hills Street
            (Wet season, with
Dirt LoadingBfcont
Si/rcpu c j. s t
Parple
Pate

••i ' --,
•"i / ซ
>- / '4
-,'4
2/'6
2/9
2 ,' 0
2/18
2/18
2/20
2/20
2/2?
2/2?
2/25
2/27
2/27
Count
Aver ape
M '. r, i mum
Maximum
Sample
Ident .

;T-280
S-281
?-2<-2
3-286
^ _ p Q 7
r>_ -^i QC^
S-29?
8-294
8-2^7
s-2Qq
t. -?CO
0-301
S-302
5-3C6
3-307




Days from
last sign.
rain
4-2
6.0
6 . 2
8.0
1 1 .0
1 1 .2
1 .4
1 .ฃ
.q
1 .6
3-9
4- 1
.&
2-5
2.7
63-0
8.7
• 7
29-6
Days fron:
] qpt
clear, a ng
.1
1 -9
. 1
1-9
4.9
. 1
4-7
.1
1 .9
.1
2-9
.1
2.0
3-9
.1
63.0
1 .6
.0
6.9
Load inf
( lb/ curb-
mile)
";oo
190
.?15
277
274
186
277
195
298
224
269
194
166
190
436
63
200
108
436
Kedia.i
si ze
(microns )
256
2QO
229
326
384
336
427
424
339
304
264
293
355
324
264
62
>405
229
>6370
                                 323

-------
                                   (Ib/curl -
              A-34;/          1.4          ^0          335
              A-;*54          2.0          255          4C6
              A--68          1 .0          300          399
              A-380          4.7          407          417
   4/23       A-~92          1.2          401          6ฐ6
    ^/1       A-414          3-1          294          411
    5/S       A-436           .7          225          413
   5/28       -\-474          3-2          268          ^32
    6/5       A-487         11.1          116          866
   6/12       A-4-92           .3          286          403
   6/25       A-507          7.1          429          41^5
    7/2       A-517          1.5          162          236
   7/10       A-527          3-0          115          382
   7/16       A-532          2.8          V?1          401
   7/23       A-540         10.0          162          395
   'f/26       A-545         H.9          216          510
    8/6       A-549         23-9          198          319
   8/13       A-556         30.9          196          524
   8/20       A-563         37-9          191          422
   8/27       A-568         43-9          180          412
    9/3       A-577          2.4          270          366
   9/10       A-584          9-4          214          279
   P/17       A-591         16.4          233          248

  Count                     23.0          23          23
Average                      3-1          273          447
Minimum                       .3          115          236
Maximum                     43-9          429          866
                        324

-------
;-•  L7~14-  148th  Avr.  ?K Street Dirt Loadings
        (Wet  season,  no street cleaning)

  cample      Sample    Days from     Loading      Median
    Tite      Ident.   last si^n.   (ib/curb-        size
                            r&in       mile)   (microns)

 10/1/81        A-604          2.2         234         329
   10/16       A-615          1-6         124         439
   11/10       A-638         13-4         174         548
   12/17       A-664          1.8         487         446
 1/14/81        A-669          2.8        1588        1135

   Count                     5.0           5           5
Average                     5-6         521         579
Minimum                     1.8         124         329
Kaxirr.um                    13-4        1588        1135
                        325

-------
                           Table  B-14a  STREET  DIRT  QUALITY:   SURREY  DOWNS  -
                                             Particle Size  (Microns)
CO
no
mg/kg
date COD
3/3 - 5/25/80
5/26 - 7/14
7/14 - 9/15
9/15 - 11/24
11/24 - 2/2/81
2/2 - 4/13
4/13 - 7/2
7/3 - 9/18
9/23 - 11/20
11/24 - 1/16/82
mean
standard deviation
stand, dev./mean
mg/kg
date TKN
3/3 - 5/26/80
5/26 - 7/14
7/14 - 9/15
9/15 - 11/24
11/24 - 2/2/81
2/2 - 4/13
4/3 - 7/2
7/3 - 9/18
9/23 - 11/20
11/24 - 1/1G/82
mean
standard deviation
stand, dev./mean

<63
120,000
156,000
177,000
185,000
157,500
188,000
198,000
239,000
186,000
182,000
179,000
31,000
0.17


602
2770
3100
2890
2175
2950
3950
4620
3055
3130
2920
1050
0.36
63-
125
129,000
124,000
167,000
141,000
112,000
131,000
166,000
217,000
140,000
135,000
146,000
30,200
0.21


2280
2400
2290
1570
1710
2080
3710
5350
2180
1880
2550
1150
0.45
125-
250
76,600
88,900
122,000
93,500
97,100
86,600
128,000
185,000
88,000
79,200
103,400
32,300
0.31


196
1310
2070
2520
1200
1260
2400
3800
1180
900
1680
1030
0.61
250-
500
41,400
43,500
97,300
98,300
103,000
80,700
145,000
182,000
86,400
65,400
94,300
43,200
0.46


182
1110
1310
1420
1050
1260
i930
3010
1040
430
1270
780
0.62
500-
1000
59,000
43,500
116,000
125,000
202,000
174,000
167,000
196,000
107,000
82,600
127, /OO
56,100
0.44


182
545
1270
1615
1830
1660
1950
3140
1270
770
1420
830
0.59
1000-
?000
15:, ooo
269,000
19?, 000
/22,000
275,000
184,000
161,000
240,000
156,000
55,200
190,200
6-1,400
0.39


910
QS<5
1420
1940
2330
1700
1880
2685
1490
915
1620
610
0.37
2QOO-
6150
113,000
90,000
171,000
?63,00n
221 ,'^n
177,'o'^n
171,000
233,000
171,000
6-1,700
167,800
63,?00
0.33


1ฐ,9
636
1040
1730
1600
1230
1750
1390
1560
1044
1?30
506
0.41

• f, ~> "-, o
3 1 ". .'""I
ป '
11 VV;1
ฐ17,nnn
?15,V'T
6? 1 //in
7R?
3^10
?s^o
1470
P10
o. .,?

-------
                 Table B-14& STREET DIRT QUALITY:  SURREY DOWNS - MAIN B<\SIN (cnnt.'

                                      Particle Size  (Microns)
mg/kq
date Total Phos
3/1 - 5/26/80
5/26 - 7/14
7/14 - 9/15
9/15 - 11/24
11/24- 2/2/81
2/2 - 4/13
4/13 - 7/2
7/3 - 9/18
9/23 - 11/20
11/24 - 1/16/82
mean
standard deviation
s tand . de v . /mean
'63
835
893
240
889
476
887
934
1080
1065
971
830
265
0.32
63-
125
597
571
429
649
273
665
625
887
723
627
605
165
0.27
125-
250
319
366
517
499
329
525
472
703
475
425
465
113
0.24
250-
500
331
313
396
430
420
443
412
595
432
375
415
77
0.19
500-
1000
419
347
393
569
627
356
546
569
504
385
480
117
0.24
1000-
2000
553
605
975
807
629
749
621
728
552
651
690
131
0.19
2000-
63SO
689
763
1030
755
641
772
813
654
618
690
750
133
0.13
- 6350
7Qฐ,
616
971
93'
73'
600
730
61?
697
686
740
127
0.17
         mg/kg
date      Lead
3/3 - 5/26/30
5/26 - 7/14
7/14 - 9/15
9/15 - 11/24
11/24 - 2/2/81
2/2 - 4/13
4/13 - 7/2
7/3 - 9/18
9/23 - 11/20
11/24 - 1/16/82

 mean
 standard deviation
 stand. dev./mean
1400
1600
1800
1500
1100
1100
1200
1500
1500
1500
1420
?25
0.16
1100
1400
1600
1400
1100
680
1100
1400
1200
1100
1210
255
0.21
985
1200
1400
1200
970
720
920
1200
1000
910
1050
200
0.19
600
810
905
820
1100
470
670
990
1100
930
840
210
0.25
550
470
1200
440
520
355
430
1200
1000
620
680
330
0.48
280
340
540
280
400
230
330
790
790
220
420
216
0.51
190
180
240
130
585
150
210
330
130
210
235
136
0.58
180
110
92
?00
900
120
640
58
182
350
'80
276
0.98

-------
                       Table B-14a.  STREET DIRT QUALITY:  SURREY DOWNS - MAIN BASIN  (cont.)
OJ
fX)
CD
mq/kg
date Zinc
3/3 - 5/26/80
5/26 - 7/14
7/14 - 9/14
9/15 - 11/24
11/24 - 2/2/81
2/2 - 4/13
4/13 - 7/2
7/3 - 9/18
9/23 - 11/20
11/24 - 1/16/82
mean
standard deviation
s tand . dev . /mean
< 63
287
270
379
412
252
259
292
371
340
308
317
55
0.18
Par
63-
12!')
224
247
288
354
239
188
239
295
264
232
257
46
0.18
tide Size1
125-
250
189
228
230
248
199
125
220
246
196
185
207
37
0.18
(Microns)
250-
500
131
178
154
194
121
126
182
210
182
135
168
29
0.17
500-
1000
152
168
170
133
151
120
135
194
213
154
159
28
0.18
1000-
2000
102
117
98
137
147
116
101
181
118
99
122
27
0.22
2000-
6350
327
87
67
82
120
72
75
88
85
97
110
78
0.71
^ "i 5 0
85
80
74
10?
176
6n
64
75
116
150
99
33
0.38

-------
                             Table 8-15 STREET DIRT  QUALITY  SURREY DOWNS - 108th AVEN'IE
                                               Particle Size (Microns)
CO
ro
mg/kg
date COD
3/3 - 5/26/80
5/26 - 7/11
7/14 - 9/15
9/15 - 11/24
11/24 - 2/2/81
2/2 - 4/13
4/13 - 7/2
7/3 - 9/18
9/23 - 11/20
11/24 - 1/16/82
mean
standard deviation
stand, dev./mean
mg/kg
date TKN
3/3 - 5/26/80
5/26 - 7/14
7/14 - 9/15
9/15 - 11/24
11/24 - 2/2/81
2/2 - 4/13
4/13 - 7/2
7/3 - 9/18
9/23 - 11/20
11/24 - 1/16/82
mean
standard deviation
stand . dev . /mean

<63
122,000
139,000
128,000
.. 140,0v,0
179,000
141,000
148,000
142,000
149,000
189,000
147,700
20,900
0.14


1680
1440
300
1640
2583
1735
1980
1930
2020
2710
1800
663
0.37
63-
125
92,500
21,200
262,000
69,600
132,000
86,700
88,200
81,400
90,600
118,000
104,200
62,700
0.60


665
2100
882
859
1760
1060
1230
1150
1090
1440
1220
436
0.36
125-
250
48,700
42,000
37,450
36,600
105,000
57,300
51,300
35,200
61,400
59,700
53,500
20,600
0.38


315
889
341
451
2550
545
595
2480
580
902
965
840
0.87
250-
500
47,200
26,000
28,400
27,400
62,800
36,800
33,900
26,400
27,600
45,100
36,200
12,100
0.34


266
470
236
293
713
367
296
453
327
653
407
164
0.40
500-
1000
28,500
16,000
25,200
29,300
84,700
40,500
23,200
20,200
37,800
62,000
37,200
21,000
0.57


245
833
221
276
743
A33
291
208
654
668
457
243
0.53
1000-
2000
23,600
20,400
20,100
24,100
85,800
36,900
11,600
24,900
63,900
58,200
36,900
24,200
0.65


168
105
207
150
868
442
244
209
442
565
340
239
0.70
2000-
6350
53,800
204,000
19,400
23,600
85,100
47,600
19,100
14,600
70,700
13,700
55,200
58,000
1.05


133
147
67
120
720
348
285
164
439
515
29*
211
0.72

-6350
7.3,000
?13,ono
18,400
17,^00
151,000
33,400
Id, 000
13,800
65,400
95,700
69,600
67,300
0.97


98
140
281
96
1340
245
223
145
532
409
351
375
1.07

-------
                         Table B-15 STREET DIRT DUALITY SURREY DO'-INS - 108th AVEN'IE (cont.)

                                               Particle Size  (Microns)
CO
o
mg/kg
date TP
3/3 - 5/26/80
5/26 - 7/14
7/14 - 9/15
9/15 - 11/24
11/24 - 2/2/81
2/2 - 4/13
4/13 - 7/2
7/3 - 9/18
9/23 - 11/20
11/24 - 1/16/32
mean
standard deviation
stand, dev./mean
<53
661
539
686
672
417
706
666
748
840
972
691
151
0.22
63-
125
40?
1080
473
472
360
461
389
463
455
502
506
207
0.41
125-
250
287
316
236
314
369
389
320
334
413
354
333
51
0.15
250-
500
275
316
182
325
393
306
204
268
:C5
382
304
73
0.24
500-
1000
393
367
193
384
446
418
402
295
440
461
380
81
0.21
1000-
2000
576
601
365
673
67^
672
680
6G2
573
767
619
108
0.17
2000-
6350
630
531
332
766
664
726
712
625
475
883
639
154
0.24
-6350
62B
470
135
791
610
767
617
624
731
739
616
179
0.29
                 mq/kg
        date	Lead
        3/3 - 5/26750"
        5/26 - 7/14
        7/14 - 9/15
        9/15 - 11/24
        11/24 - 2/2/81
        2/2 - 4/13
        4/13 - 7/2
        7/3 - 9/18
        9/23 - 11/20
        11/24 - 1/16/82

         mean
         standard deviation
         stand. dev./Tean
2000
2250
1600
2200
1100
1100
1500
1700
1300
1500
1630
416
0.26
1900
2100
1600
1800
850
945
1100
1600
1100
1100
1410
442
0.31
1600
2100
1800
1500
870
840
1300
1300
1000
1200
1350
407
0.30
980
1100
770
1200
900
570
920
1100
800
720
910
196
0.22
1000
500
700
610
590
350
320
930
259
400
566
253
0.45
350
320
400
200
300
140
165
190
139
170
237
96
0.40
130
190
92
88
230
140
210
95
87
76
131
37
0.42
55
52
48
42
230
280
30
30
65
77
91
88
0.97

-------
                        Table B-15 STREET DIRT QUALITY SURREY DOWNS - 108th AVENUE (cont.)


                                              Particle Size  (Microns)
CO
CO
mg/kg
date Zinc
3/3 - 5/26/80
5/26 - 7/14
7/14 - 9/15
9/15 - 11/24
11/24 - 2/2/81
2/2 - 4/13
4/13 - 7/2
7/3 - 9/18
9/23 - 11/20
11/24 - 1/16/82
mean
standard deviation
s tand . dev . /mean
<63
262
296
233
332
257
250
249
264
310
283
274
31
0.11
63-
125
233
260
192
210
172
180
179
192
228
226
207
29
0.14
125-
250
191
188
131
197
176
131
120
151
164
142
159
28
0.18
250-
500
137
114
109
156
128
99
91
124
122
111
119
19
0.16
500-
1000
123
229
89
151
122
109
92
170
115
101
130
43
0.33
1000-
2000
112
103
110
105
118
254
171
90
99
111
127
50
0.39
2000-
6350
69
75
62
77
106
?83
82
89
76
79
99
65
0.66
>'o350
70
50
53
108
98
861
61
56
62
64
148
251
1.7

-------
Table B-16 STREET DIRT DUALITY:   SURREY  DOWNS  - Wd'-:TWOOn
                      Particle Size (Microns)
mq/kq
date COD
5/26 - 7/14/80
7/14 - 9/15
9/15 - 11/24
11/24 - 2/2/81
2/2 - 4/13
4/13 - 7/2
7/3 - 9/18
9/23 - 11/20
mean
standard deviation
stand, dev./mean
mq/kq
date TKN
5/26 - 7/14
7/14 - 9/15
9/15 - 11/24
11/24 - 2/2/81
2/2 - 4/13
4/13 - 7/2
7/3 - 9/18
9/23 - 11/20
mean
standard deviation
s tand . dev . /mean

<63
132,000
166,000
173,000
168,000
208,000
242,000
249,000
175,000
189,000
40,400
0.21

2680
2990
2780
2130
3270
4550
4930
3160
3310
953
0.29
63-
125
159,000
164,000
162,000
144,000
212,000
226,000
274,000
167,000
188,500
44,500
0.24

2290
3290
2290
1710
2940
4740
6000
3295
3320
1420
0.43
125-
250
124,000
205,000
87,000
165,000
143,000
169,000
232,000
114,000
154,900
48,000
0.31

1200
1900
1370
1400
2130
3450
4830
1810
2260
1260
0.56
250-
500
146,000
193,000
80,000
175,000
166,000
178,000
185,000
91,900
151,900
43,100
0.28

575
1140
1250
1550
2040
2350
3190
1290
1670
822
0.49
500-
1000
155,000
161,000
160,000
152,000
215,000
173,000
198,000
169,000
172,900
22,300
0.13

2480
1470
1760
1680
1490
2240
2580
1830
1940
43L
0.22
10DO-
2000
348,000
259,000
183,000
367,000
339,000
170,000
252,000
282,000
275,100
73,900
0.27

2900
1770
1980
2280
2230
3530
2730
2^40
2470
563
0.23
?000-
6350
~h4,0< .0
7)5,000
3fi",000
367,000
214,000
124,000
245,000
320,000
293,900
95,000
0.32

653
1Q90
2340
6160
1 7 30
1590
1820
3110
2420
1660
0.63

63^0
4V/ ,.'.',0
J9c nOO
36 l! 000
7 33, ''no
457,000
117,01,0
161, one
640,000
373,900
?34,?00
0.62

437
408
?050
21QO
?4nn
773
1170
48SO
17RQ
1470
0.83

-------
                     Table B-16. STREET DIRT QUALITY:  SURREY DOWNS - WESTWOOD HOMES ROAD  (cont.;


                                                  Particle Size (Micronc)
OJ
CJ
mq/kg
date TP
5/26 - 7/14
7/14 - 9/15
9/15 - 11/24
11/24 - 2/2/81
2/2 - 4/13
4/13 - 7/2
7/3 - 9/18
9/23 - 11/20
mean
standard deviation
stand, dev./mean
mg/kg
date Lead
5/26 - 7/14
7/15 - 9/15
9/15 - 11/24
11/24 - 2/2/81
2/2 - 4/13
4/13 - 7/2
7/3 - 9/18
9/23 - 11/20
mean
standard deviation
stand . dev . /mean

< 63
855
489
810
619
771
875
1010
1060
810
189
0.23


375
400
390
440
415
600
560
340
440
92
0.21
63-
125
853
359
652
436
570
758
994
846
684
220
0.32


321
320
300
350
350
380
400
250
334
47
0.14
125-
250
393
511
—
389
410
584
509
520
474
76
0.16


250
260
205
230
210
370
300
160
248
64
0.26
250-
500
1250
346
341
572
352
417
529
391
525
305
0.58


140
215
140
190
160
180
210
190
173
29
0.16
500-
1000
424
470
718
772
4?4
403
497
521
529
140
0.26


580
89
75
200
75
94
83
115
164
173
1.1
1000-
?ono
573
627
642
519
567
538
610
584
581
43
0.07


1900
59
60
170
89
52
145
71
318
641
2.0
2000-
6350
740
657
609
546
569
668
658
654
638
61
0.10


55
34
35
160
50
27
37
30
54
44
0.82

6 ISO
R29
780
r.PS
• t ' i ~~\
45',
653
69ฐ,
499
619
146
0.24


32
23.
52
360
80
39
24
62
84
113
1.35

-------
                 Table  3-16.
Street Dirt Quality:  Surrey  Downs
              Homes Rrl.  fcon't)

      Particle  Size (Micron:;)



OJ
p.







mq/kq
Date Zinc
5/26-7/14
7/14-9/15
9/15-11/24
11/24-2/2/81
2/2-4/13
4/13-7/2
7/3-9/18
9/23-11/20
mean
standard dev.
stand, dev. /mean
-63
177
152
169
162
160
209
228
177
179
26
0.15
63
-125
158
112
127
121
130
155
177
139
140
2?
0.16
125
-250
96
75
92
102
99
126
115
82
98
17
0.17
750
-500
69
88
71
87
87
79
89
68
80
9.2
0.11
500
-looo
94
58
66
88
66
74
72
81
75
12
0.16
inoo
_'X)00
195
81
76
100
U5
67
88
108
99
?6
0.26
20^0
-6350
P,5
IS
&3
108
m
63
63
64
74
30
0.41
^ -J -, )
C T
\ '^
1\
1 f, 1
1 ''6
oo
c r
7^
qc,
51
n.6o

-------
                                                           Table B-17.
                                                Street Dirt  Quality:   Lake Hills
CO
CO
CJ1
Particle Size
mg/kg
Date COD
3/3-5/26/80
5/26-7/14
7/14-9/i5
9/15-11/24
11/24-2/2/81
2/2 - 4/13
4/13-7/1
7/3-9/18
9/23-11/20
11/24-1/16-82
N=10
mean
standard dev.
stand, dev. /mean
mg/kg
Date TKN
3/3-5/26/80
5/26-7/14
7/14-9/15
9/15-11/24
11/24-2/2/81
2/2-4/13
4/13-7/1
7/3-9/18
9/23-11/20
11/24-1/16/82
mean
standard dev.
ta nd . dev . /mean

<63
310,000
201,000
231,000
249,000
134,000
190,000
206,500
274,000
240,000
242,000

232,800
39,400
0.17


4170
3420
3230
3750
2750
2600
3540
4440
3965
3165
3500
590
0.17
63
-125
322,000
152,000
147,000
174,000
131,000
99,500
159,000
246,000
164,000
176,000

177,100
63,200
0.36


3760
3560
3100
3120
1770
1590
3270
5040
2730
3560
3150
990
0.31
125
-250
98,800
129,000
130,000
122,000
83,800
79,400
88,700
137,000
105,000
152,000

112,600
24,900
0.22


2600
1870
2160
1950
974
1040
2380
3070
1490
1520
1910
670
0.35
250
-500
62,200
111,000
150,000
98,700
98,800
57,500
97,000
149,000
82 , 800
106,500

101,400
30,900
0.30


1660
1750
2270
1550
962
806
1620
2820
1375
1240
1610
590
0.37
(Microns)
500
-1000
199,000
175,000
316,000
253,000
156,500
101,000
120,000
296,000
191,000
301,000

210,800
77,000
0.37


2420
2180
3160
I960
1325
1060
2010
4225
2330
2680
2340
900
0.38

1000
-2000
154,000
171,000
244,010
176,000
154,000
151,000
251,000
344,000
366,000
385,000

239,600
93,900
0.39


2380
833
2610
1750
1420
1790
2890
1440
2410
3590
2110
820
0.39

2000
-6350
171,000
234.010
330,000
1 96 , 000
161,000
132,000
230,000
426,000
269,010
453,000

266,000
105,500
0.40


504
2020
2470
1270
1310
2240
2700
1510
22UO
3960
2010
950
0.47


• 6351
11, '•
-------
Co
CO
CTi
                                                            Table B-17.
                                             Street  Dirt Quality:  Lake Hills (con't.)

                                                         Particle Gize (Microns)
mg/kg
date TP

3/3-5/26/80
5/26-7/14
7/14-9/15
9/15-11/24
11/24-2/2/81
2/2-4/13
4/13-7/1
7/3-9/18
9/23-11/20
11/24-1/16/62
mean
stand, deviation
stand, dev./mean
tng/kg
date Pb
3/3-5/26/80
5/26-7/14
7/14-9/15
9/15-11/24
11/24-2/2/81
2/2-4/13
4/13-7/1
7/3-9/18
9/23-11/20
11/24-1/16/82
lean
;tand. deviation
stand, dev./mean


'63
1060
950
614
921
738
876
832
1103
1390
938
942
213
0.23


2600
2300
1600
2100
1700
1500
1350
2300
2100
1400
1895
439
0.23

63
125
1370
718
444
730
500
634
656
904
842
615
741
261
0.35


2300
2300
1900
1900
1500
1300
1700
2300
2000
1400
1860
378
0.20

125
250
663
443
522
522
393
480
450
795
649
533
545
123
0.22


1800
2000
1800
1800
1200
1100
1800
2200
1700
1100
1650
384
0.23

250
500
522
340
251
425
467
499
221
546
652
439
436
134
0.31


1600
1800
]400
1500
670
970
1100
1700
1400
1000
1310
364
0.28

500
1000
650
557
135
537
600
537
550
913
623
598
570
189
0.33


820
750
UOO
1000
540
770
840
1600
710
530
866
313
0.36

1000
2000
744
661
1230
620
646
702
752
866
607
793
763
183
0.24


360
700
800
820
520
470
690
850
240
870
632
222
0.35

20^0
6351
621
6ฐ/J
1220
642
636
793
709
743
613
732
740
179
0.24


3.10
260
210
200
280
250
170
1100
150
515
347
284
0.82


'I, 3 51
c - j
411
1 n 1 r
?'< -
53"i
656
fT'O
li''1]
6r
85'J
750
2Y)
0.32


130
140
130
160
503
110
130
100
240
420
210
140
0.67

-------
OJ
LO
                                                         Table B-17.
                                          Street Dirt Quality:  Lake Hills  (cont.'
                                                    Particle Size  (Microns)
mg/kg
Date Zinc
3/3-5/26
5/26-7/14
7/14-9/15
9/15-11/24
11/24-2/2/81
2/2-4/13
4/13-7/1
7/13-9/18
9/23-11/20
11/24-1/16/82
mean
stand, deviation
s tand . dev . /mean
<63
502
314
339
438
310
342
316
420
416
333
373
66
0.18
63
-125
347
320
370
382
249
234
322
383
400
267
327
60
0.18
125
-250
282
255
335
277
272
192
246
343
320
216
274
49
0.13
250
-500
270
196
225
236
182
144
219
281
283
165
220
49
0.22
500
-1000
179
145
254
183
155
143
164
197
136
168
177
32
0.18
1000
-2000
147
j.27
141
159
175
130
146
179
128
440
177
94
0.53
2000
-6350
90
97
145
103
143
89
91
283
135
151
133
59
0.44
-5350
79
75
121
109
231
63
77
93
1ฐ,9
277
137
32
0.60

-------
           Table  B-18.
Street Dirt Quality - 148th Ave.
      Particle Size (Micr"nc)
mg/kg COD
4/13-7/1/Sl
9/23-11/20
N=2 mean
mg/kg TKN
4/13-7/1/81
9/23-11/20
mean
mg/kg TP
4/13-7/1/81
9/23-11/20
mean
rnqj/kc^ Lead
4/13-7/1/81
9/23-11/20
mean
mq/kq Zinc
4/13-7/1/81
9/23-11/20
mean
,63
153,000
167,000
160,000

1750
1530
1640

603
878
740

2400
3500
2900

437
531
480
63-125
83,600
102,000
93,800

993
941
967

319
614
470

2400
3000
2700

317
379
350
125-250
52,100
40,300
46,200

601
432
517

427
387
410

2200
2300
2250

208
251
230
250-500
45,500
36,600
41,100

419
520
470

245
384
315

2UOO
2500
2250

170
273
220
500-1000
66,900
138,000
102,000

986
1030
1010

3b7
456
410

1300
2000
1650

141
186
160
1000-2000
77,300
209,000
143,000

727
1270
1000

624
499
560

320
545
430

102
205
150
2r.iOn_ P,:5Q
09 ir/j
267,000
1 73 , 000

1030
1060
1050

755
491
620

150
170
150

73.5
94.1
84
C ")'r
! r 7 , ' '
2^'J>/:/
'9V>V.

'i 1 9
572
500

5? 3
50 5
450

89
535
310

54 . 3
93.3
74

-------
                         FIGURE  B-1
CO

CO
      SURREY DOWNS-WE5TWOOD  HOME5 RD  DIRT RCCUM
      1000r
        -I I I I I I I I I I I I II I II I  II II 111 L J  I I I I I I I I I  I I I I I I i I
                 10
  20       30

RCCUMULflTION (Days)
40
50

-------
                   FIGURE  B-2
  SURREY  DOWNS-.108th  ST.  STREET DIRT  flCCl'M
  ] 400.	
E

_O

3
U
\
U
_D
in
o
in
                          d
  40
  200_-
  0  R I I I I I I I I I I I I I I I I I  I I I I I I I I I
              10
          I II I I I I I
  20       30

RCCUMULRTION (Days)
40

-------
CO

-e.
                        FIGURE B-3


          LfiKE  HILL5-WITHOUT STREET  CLEflNING
      1200
    e.
    i
    .a
w
-O
    in
    o
    in
    oc

    o
         0
              10
      0  H I I I I M I I  I I I I I I I I I  I | I I I II I I  I I I I I I I I I I I I I I I I I
  20       30


RCCUMULRTION (Doys)
40
50

-------
                  FIGURE B-4
     LRKE  HILLS-HITH STREET  CLERNING
500

400
'a)
E
1
-D 1
L
3 30D_J
X,
U1
-O 1
in
2 20QJ
o
	 |
a: i
i-
ฃ 1CO_


0
3

E B Q


t-

M
^" QA 0 B
l~* A A A
15 ^ A
1 - . ej . J
^ n ft0 , n^^., 	 ^r-
s n w o r ^ f A ^ ^ O n E Q L V j f ' tJ ' j O i ,
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1 0___-— *-- A- A---'- A 0 "
f ? Q A Q Fl •
L? A
HA A
%B i Q 1 A H
ซQ Q @ |A A Q
— B
— Q
	

                     o      4     5
                  RCCUMULRTION (Days)

-------
                      FIGURE B-5
   148th  five.   5.E.  STREET  DIRT  RCCUMUlflTI0r
   1600.
   14Dfl=_
ฃ


-O



U


w
~ 800_E
un
a
o
in
60




40
  200.
     cz—or
     — a
    a-*
   *#S
   .Q ti


   ^ B
0  B i i i i i i i i
    _LL
         dry season, no cleaning

         	0      ET      1
10
I I I I I I I I I
                                   I I I I I I 1 I I
                         23        30


                        fCCUMULRTION (Days)
                                                    50

-------
               FIGURE B-6
WET SERSC'N PflRTICLE SIZE DISTRIBUTION
UJ
M
UJ

t — i
g 20
Q_
Z
i — i
un 1C
Q 15
t— <
— i
o
to
	 i
ฃ 10

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o
i- 5
LU
LJ
a;
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Q_
0




















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tlmi
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1
i
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11
1
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fjjjl
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>6370/u
         [T]- 108th
LH

-------
3500
                    FIGURE B-7
    KN CONC.  BY PflRTICLE SIZE   (mg/kg)
     ^ 3 A
           I 13 A
                I t 3 A
                                              i i 1 4
          63-    125-
            Q}- 108-th
25Q-
500-
1000-
2000-
>6350y
                    - 148-th

-------
UJ
-Cป
en
                   FIGURE B-8
TOTRL  PH05.  CONC.   BY PRRTICLE SIZE
      1000
      90
                63-  I  125-
                  jTj- 108th
                             2 3
250-
                                                    (mg/kg)
                           500-  1003-   2000-   >6350/u
                              ra-LH      m-1 48-th

-------
-p.
—t
         ZINC  CONC.
       500
  FซGURE  B-9

 3Y  PflRTICLE  SIZE   (Mg/kg)
           1134
                   n
                 ! 1 3 4
                         n
I 2 3 -I !
                63-    125-

                  [TJ-108ih
     25(3-
500-
                                         -L 3 4
1000-
  "' I lit
2000-  i >6350/u

-------
                           FIGURE B-10
      .URRtFY  DOWNS  WflSHOFF  BY
   900




   800_




   70CL
f  600L


f

^  50CL
-Q
o
••*•
40




30
o
3T
in
cr
m  20C
   10Q_
                                A


                                Q
  A  "


  O   O


g>    A

  O ^  A


^ฐ   *
                                         O

                                         O
                                             A  A
A

a
                      LOAD INC; ir.CRr.AS>:
       3   3.5' 4   4.5 5

        0 Su ; i" (.•'/ Downs
                                                   o


                                                   A
                          5.5 6   6.5  7   7.5 8   8.5  9


                          RUNOFF VOLUME  Mn+10 Inches)
                                                    9.5 10
                               1C.5 11
        A 108th St.


        B Westwood Homos  R-l.

-------
                         FIGURE  B- 1 1
   LflKE  HILLS  &  148th  flVE WflSHOFF  Bv  RuNCFF
   700
6
J3
  60C
  50
  400_
  30C
xf
O
i:
1/1
ct
  20
  IOC
            LOADING DLCRLASi;
            NO WASIiOFF
3.5  4   4.5  5
          0 o

          o
        a o
                              o

                              o
                                                      ...Q.
   LOADING INCREASE
5.5  6
                                6.5 7  ' 7.5  8   8.5  9
9.5  10
           Lake Hills    RUNOFF VOLUME Mn+10 Inches)

           148th Avo. S.L.

-------
                       FIGURE  B- 1 2

     SURREY  DOWNS RUNOFF VS
  7.5
E
I
_D


U
X
_Q


c
a:
o
cr

a
i—*
in
6.7_



6.3_



5.9_



5.5.



5.1



4. 1



4.3
                    O
                    8
                      o  o
A o o n  fe
                                                LORD
                                   O  0*     ฐ
                                           A
                                       o
                                   a
                                       B
            4      5

         Surrey Do.vns
                      678

                     RUNOFF (10+In Inches)
                       11

-------
                          FIGURE  B- 1 3
C-J

LTJ
      LflKE  HILLS  &  148th RUNOFF  VS  RE5IDURL  LORD
      5.9
      5.
   •p  5.;
    u
    N,
   O
   
-------
                              FIGURE B-14
Co

Ln
         SURREY  DONN5  PERK  RRIN  INT  V5  RE:
                                                            Pi
                                                            n i
       6.9
fll  r
^_  O.



16-
3  6-

2  6.
c
C  5.
in  5.
a
i—i

c  5'
in

_j  5.
a:
t—
P  4.
     in
     UJ
     a;
       4.3
                 B
                 e
                 a
                   o

                   A
                            0



                            O
                                      o


                                      0
                                             O

                                             e
      e

      A

      B
       6.4     6.8    7.2     7.6     8       8.4


                PEflK 30-MIN. RRIN INTENSITY (10+ln

    Surrey Downs

    108th St.

           Homes Rd.
o

A
                                                    8.8
  9.2
9.6

-------
                FIGURE B-1 5
LRKE HILLS  & 148th PEflK RRIN  V5 RESIDURI
6.9
2-
a
vn 4>S-
^ 4.3







0

— Q B ฐ
O O
P3 0 0
— ~- t-.
V)
B ฉ
• *"^ ฉ

	 0
	 00
&
	 0
0 0
0
	 0 0 ฉ e
G
	 &

6.6 6.9 7.2 7.5 7.8 8.1 8.4 8.7 9 9.3
. Lake Hills PEflK 30-MIN. RRIN INTENSITY (10+1 n inches/hour)
B 148th Ave. S.E.
                                        9.6

-------
                  FIGURE  B- 1 6
L
55
50
OJ
•j: 45
E
1
-Q
^ 40
u
-ฐ 35
ฃ 30
Q
" .
>\.$/^^''*^-'--~^*^ ...... - -- ' "" ""
^^^r1''^ '"""" *ฐ

5    '10     15    20     25     30    35     40
           INITIRL STREET LORDING  (1b/curb/m11e)
45
50    55

-------
                           FIGURE B-17
CO

Ol

en
       LflKE  hi ILLS  STORM  WR5HOFF:  63-125 microns
       45
     e
     i
     J3
     L
     3
     U
     X
     .ฃ)
     d
     a:
     o
     UJ
     UJ
     ce

     in
     cc

     a
     i—*
     in
     LU
                     10     15    20    25    30    35

                      INITIflL STREET LORDING (Ib/cu. b-mlle)
40
45

-------
                              FIGURE B-18
CO
ui
en
       LRKE  HILLS  STORM  NR5HOFF:   125-250  micron
       75  .	.	.	.	.	
E
I
-Q
L
U
X.
-0
LD
Z
    cr
    o
    UJ
    LU
    U1
    _J
    cr
    o
    in
    LU
    CkT
70_
65_
60_
55_
50_
45_
40_
35_
30_
25_J
20_
15.
10_
5 .
0
          /
                         -V-
                       Wo ''
                       Q)

                 X
             ' / '  x-
         /  //'/ x .x-'
         /  e-. ป ,..'•
         /  // •' X ^
 Q3'   'O
 Q)   O •'
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                                      /
                                    o
          0  '5  '10  15   20  25   30  35  40  45  50  55  60
                       INITIflL STREET LORDING (Ib/curb-mlie)
                                                    65  70   75

-------
                            FIGURE B-19
OJ

c_n
       LflKE
       100
HILLS  STORM  WflSHOFF:   250-500  microns
     E
     I
     JO

     3
     U
    t_D
    (X
    o
    UJ
    UJ
    tki

    in
    
-------
                            FIGURE B-20
UJ
en
30
.RKE  HILLS  STORM  WflSHOFF :  500
                                             103
                                                        mcrons
      90
      80_.
    JD
      70.
  50.
    Q
    cr
    UJ
      40	
ฃ 30.
i—
in


o^ 20.

Q
f—I

uj 10.
a;
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                   ^ ฐ e0 ฐ

                                      V-
                                                \S'r-
            10    20    30     40    50     60    70     80

                  INITIflL STREET LORDING (1b/curb-mMe)
                                                            90

-------
                          FIGURE B-2 1
cn
.O
      LRKE  HILLS STORM  HflSHQFF:1000-2000 micron
      60

55_
QJ
~ 50

ฃ
1
-P 45
L ^v ..ox
	 r"\/ /-V ,A" ^ V  ^0
	 -^ *v" \" _%
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c-'." r? (0ฐ • ,-T^'
.- " ^ x ฐ rv-. " ' ฐ
,0 1ฐ
c,VVO^
/ O, - -T\^>
/' \"xl t
ปa'-Q
i,v>
/ / •'•
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f ^"^
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,
a 0 o
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/ ' / J*nf> ^
— / / d**3* ซ'
/''/''-' ''"

^ฃ-r- ]
_
         0   '5   1(3
 15 '20  ' 25

INITIRL STREET LORDING (Ib/curb-mlle)
50
55
60

-------
  LRKE
  60
                    I-IUURE B-22


       HILLS  STORM WflSHOFF:2000-6350 micron
E
I
-O
L.

U
•x
-O
Q
d
O
UJ
a;
h-
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cr.
55.


50_


45.


40-


35.


30_


25.
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  15_


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  5 .


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                     O
              10   15   20   25  30  35  40  45  50  55

                   INITIflL STREET LORD Ob/curb-m I le)

-------
      FIGURE  B-23
Lfl
!25
12CL
11 5_
U H0_
- 105_
f 10DH
-o 95
b 90~
v! 85_^
-ฐ 80
- 75
LO 70
= 65__!
g 60
3 55
L_ 50
Mi 45
ฃ 40_J
in 35
_i 30
S? 25
Q 20
>—i •"j —
en 1 <;
LU J; —
a: 10_
5 _
0 ซ
KE HILLS STORM NflSHOFF : >63:3 m cm-
/ - ,<•• •' •:, - ^ }
~ W ?f ฃ/ :>' :f .^- ^' -vc .-c-:' .-^ •:•'•'
si f /• S ..v ,..v ,,•
iy ; v- ^ ta- ,- -
~ o/ ^? ^" "" r -;-'"
G ~> ^
1.M /
/
1 / /

0 i'.
/
0
•; Q / ••' .. .i V
/ / / ••• ,- v.i-'A''"
-//.' •,-
/ /'' . ,•
/ >' ' / ฐ- Q . ,.7,:M'.Ol :\..
/, •• ' .?ซ-'• ' ' -'
--j * / • / _. 	 	 -~
5^x^v< • ..---"'
_ij*>/e^-. ',•-.--
^T f i 'II 1 1 1 1 1
0 ' 5 10 15 20 25 30 35 40 4o 50 5S1 60 65 70 75 80 85 9d 95 1 001 dsi 1011512
INITIRL  STREET LORDING  (Ib/curb-mllei

-------
                     FIGURE B-24
   SURREY DOWNS  TOTflL  SOLIDS  - NET SLh.iC
  330
  25
  20C
2 isf
o
a:
  0
         • A

         • 0

.25
       O  Dirty :-^ t
       A  ( I ",in Sป r

.75     1

RflIN, INCHES
                                      1.25
J
   1.7C

-------
                      FIGURE B-25
    SURREY  DOWNS  TOTflt  SOLIDS -  DRY 5ER50I
  303
  251
                  Hป	ซ-
t



in
o
in
cr
  20fl
  J5

o 10flL_,_ซ   •

       ^ซ   **>
                i  ซ
           •  o
  50.
  0  L
* I.irtv SLroet:

A C1 f a n S t r c e t:
                          .75     1


                          RfllN, INCHES
1.25   '1.5
                                               1.75

-------
en

-p.
                             FIGURE B-26


           LflKE  HILLS  TOTflL  SOLIDS  •  WET  5E.R50N
        300
        250	
        2oa,
      in
      ci
      - 150	•
      _
      o
      in
      a.
      ป—
      o
lOfl	
        53,
                &  ซ

                A A

                    9  A
0     ' .25

  o Dirty Streets

  4 C1 c-an Streets
                          .5
                         .75     1


                        RPIN,  INCHES
1.25
1.:
1.75

-------
                       FIGURE B-27

     LflKE  HILLS TOTflL  50LID5  -  DRY 5ER50M
  303
  250-4—
  28d	
in
C3 i cm    A
-ซ 15fl 1
o
in
  100	
  50.
               A A
         • A

             .25     .5
         •  Dirty Streets
         A  Clean Streets
.75      1
RRIN, INCHES
1.25
1.5
1.75

-------
cr.
a-
     UJ
       .4.
       .3-
       .2.
                           FIGURE 8-28

              SURREY  DOWNS LEFlD
                          - WET  5ER50
                                    • e   e s  A
                  A  *ป
                              • A A
                  .25
           .5
0 Dirty

A Clf-an
                    f f r c - < :• t

                    i; tract
.75      1

RRIN, INCHES
1.25
1.5
1.75

-------
         .6
                             FIGURE  B-29

                SURREY  GOWNS  LERD  -  DRY 5ER5QN
         .5.
         .4.
OJ
ฃ71
         .3.
         .2.
                               0   A
         .1.
                   .25      .5
               • Dirty Streets
               A Clean Streets
 .75      1

RfUN, INCHES
1,25
1.5
1.75

-------
CO

en
     UJ
     z;
     a
     ct
     Ui
        .4.
        .3.
        .2.
                            FIGURE B-30


                LFIK.E  HILLS  LEflD  -  WET SEfiSON
            -ซ  A
                      AS  JD
            eee A •  ซ
          L.

           a
	I	\	I	

      .25     .5      .7^
    .25

3) D ' r t y S t r c t; t n

A C I •-• a n Streets
1
1.25
i.5
                                     INCHES

-------
                            FIGURE  B-31

                 LflKE  HILLS  LEflD  -  DRY  SEflSON
to
CT>
•-D
     Q
     ft
.3—U- A
        .2-
                   A AA  A   A
        .1.
        0
             *  0
	
0
• • A a
	 ! 	 j 	
' .25 ' .5
             •  Dirty Streets
             A  Clean Streets
                         .75    ' 1
                         RfllN, INCHES
i	I	I	

 1      ' 1.25    1.5
                                                              1.75

-------
                      FIGURE B-32
  WET  5ER50N TOTflL SOLIDS  LORDS  VS.
  14
                                              RUNOFF
n:
o
\—
in
\
UJ
Cฃ
LJ
CE
\
in
CD
O

O
  13.
12.
  11.
S 9
o
in
cr
(—
o
                dirty c
    Surrc-y Down:;

     Lake Hills
                      9        10       11

                      FLOW (LN OF CUBIC FEET)
                                           12
13

-------
                       FIGURE B-33
   DRY  5ER50N  TOTflL  SOLIDS LORDS VS.  RUNOFF
   13
CK
o
I—
in
\
UJ
a;
LJ
cc

in
CD
12.
11.
  10.
in
o
in
cr

o
  8
                dirty clean
_Surrey Downs

  Lake Hills
                8
                       9          10


                    FLOW (LN OF CUBIC FEET)
                                      11
12

-------
      WET  5En50N LERD  YIELDS  VS.  RUNG!
    I
      _SuL'roy Df)wnr,

        Lake- Hill:,
in
x,
UJ
ce:
u

^
in
CD
o
d 2

a
cr
UJ
                      9       '10      '11


                      FLOW (LN OF CUBIC FEET)
12

-------
              FIGURE B-35
DRY  SEflSON  LERD  YIELDS VS.  RUNOFr

6 _

XL
on
P 5
in
X.
LU
o:
u
\ 4
in
fQ
^^ O 	 —
CJ
3 2

a
en
UJ
~* 1

C
dirty c 1 o a n
Surrey Downs • *
Lc-.ke Hills • "
A
ปซ
• * * •

^ ซ
* *
* • . * *
• • • • A
*^ 4 •• - *
" '*" . *
• * • " • • •
. ' *
..'..'
"" . ' *"*
' * *• * "
. • .
• ^

%
9 • **
*
•

        8
   9        10
FLOW (LN OF CUBIC FEET)
11
12

-------
3   TOTflL  KJELDflHL  NITROGEN WH5HOF
Lu
                                              V
o
o
:n
in
ct

in
LU
LD
in
cr
cr
i—
o
IELD
  4.!



  4 .



  3.:



  3 .



  2.:



  2 .
  0  L
.05   .1    .15    .2    .25    .3


           RUNOFF VOLUME  (Inches)
                                           35
                                               .4
     .45

-------
                      FIGURE  B-37
    COD  STREET  HR5HOFF/RUNOFF  YIELD  RflTIG
  25
  22.
g 20.
t
o


Qฃ


t
O

in
tu
UJ
a:
I—
l/l


ง
LJ
  17.
  12.
  10.
  7.
        e

          ง


      *.    %
         e
                  0 o
          ' .05   .1    .15    .2    .25   .3


                      RUNOFF VOLUME (Inches)
                                                .4
.45

-------
o
ป—*
i—
cr


a
_j
UJ
u_
o
z
ID
on
o
IE
in
en
LU
in
a
in
o
50



45_



40.



35.



30_







20_



15.



10.



5 .



0
                      FIGURE B-33


        PHGSPHORUS  HRSHOFF/RUNOFF  RflTIQ
.05
               .1
                       15    .2    .25   .3


                       RUNOFF VOLUME (Inches)
.35
.4
.45

-------
  8
2 7
t—
-


t 5
o


or ,
x 4
o


? 3
j.
uj 2


in




5 '
M




  0
                      FIGURE B-39



            ZINC WflSHOFF/RUNOFF  YIELD
      a
      o    e
             o
           e o
           .05
                  o o
                      .15    .2    .25   .3


                      RUNOFF VOLUME (Inches)
.35
.45

-------
                         FIGURE  B-40
a

LU
in
o
cr

o
U-
o
z
Cฃ
o

in

in


o
a
LU
a;
a;

in
   350
   25
   1G
50.
         TOTflL  SOLIDS  YIELDS:   DRY
       o

       <*
     A  O A
         A
   o Calibration


A Lake  11 i 11 n  c 1 <_• a n i n • j i j n 1

 i    I
    0    50   100  150  200  250  300  350  400  450  500  550  600  650


           LflKE HILLS STORM RUNOFF TOTflL SOLIDS TIELDS Ob/storm)

-------
e


O


I/I

^

_ฃ)
in
a
in
o

-------
CO
•x
o
     -  350


      E
LJ

2

O




1/1


*—t

_J

O
        3QC
        25ฃ
oc  20C
h-
o
     fe 15C
      3C
      a;
      o
      (—
      1/1

      in
      O
      a
      LU
      1/1
   IOC
        50.
                              FIGURE B-42


                TOTflL  SOLIDS  CONC,
                                          DRY
SEflSON
                                0 Q
                                                   0 Calibration

                                        A Lake Hills cleaning only
            20    40   60   80   100   120   140  ' 160   180   200   220


               LflKE HILLS STORM RUNOFF  TOTflL SOLIDS CONC.  (mg/1)

-------
00
cป
      U
      o
      U
         300
         25
   200	
g  15C
o;
o
in
         10
z
o
a
      in
                              FIGURE  B-43
                 TOTRL  SOLIDS  CONC.
                                          NET  SEflSON
 B    o
a      0 P
   s V  •
                          Q  A
                             A
                • f
                                                 o  Calibration
                                      o Surrey Downs cleaning only
                                        A Lake Hills cleaning only
             50     100    150    200    250   300    350
                     LflKE HILLS STORM RUNOFF CONC. (mg/1J
                                              400
                                                                    450

-------
                                                                          Table  C-l.
                                                         Street Cleaning Effects on Street Loads for
                                                             Other Bellevue Sites (Ib/curb-mile)
GO
oo
ro
Site and Date
2nd Ave.
4/30/81
5/9?
120th
4/30
5/22
Kelsey Cr. Pky.
4/30
5/22
118th
4/30
5/22
Stoneridge
5/5
SE 30th St.
5/5
Bellevue Way
5/5
Bellevue North
5/6
before or
after
cleaning
before
after
before
after
before
after
before
after
before
al ter
before
after
before
after
before
after
before
after
before
after
before
after
before
<63
78.2
61.1
22?
114
28.2
30.1
23.9
37.4
16.3
36.4
42.6
22.0
11.8
43.0
5.2
21.7
25.6
38.1
351
249
31.0
30.8
39.2
63
-125
50.5
42.2
149
142
48.3
53.0
36.4
43.5
21.0
28.0
31.0
17.2
7 .1.
23.0
3.9
14.8
31.2
29.6
439
203
50.5
40.5
25.1
Particle Size
125 250
-250 -500
87.6
70.3
305
129
96.6
101
74.6
76.0
43.8
43.9
47.5
26.7
8.4
28.7
5.5
16.9
47.5
47.1
773
18fl
81.0
6l.l
33.4
137
106
483
148
202
182
143
108
69.;
51.5
48.0
33.8
15.5
35.1
11.1
22.4
66.6
59.0
1050
174
110
78.5
33.3
(Microns)
500
-1000
135
97.1
378
,115
219
145
154
83.8
75.0
35.8
39.3
28.0
39.3
44.4
29.0
33.2
64.1
50.2
826
195
130
85.2
34.6
1000
-2000
77.4
40.5
242
51.2
106
38.4
54.5
32.7
67.2
14.4
20.9
9.5
54.0
38.3
38.6
24.4
34.5
21.5
420
160
106
62.1
12.1
2000
-6350
If-. 7
O.4
446
74.9
65.6
14.4
20.1
9.5
57.3
13.7
17.1
5.3
53.6
24.9
39.0
14.6
24.5
9.2
242
62.3
112
52.3
8.6
-6350
46.7
14.2
".30
5.7
27.2
1.7
3.3
1.0
21.5
24.3
' 5.2
l.b
9.3
2.7
10.5
4.7
14.6
5.4
82.9
52.1
22.2
3.6
2.9
total
solids
689
452
•"•50
73^
793
565
509
392
371
243
252
144
200
210
143
153
509
260
4180
1230
643
414
195
fotil
VI II 1r>
ppriP-U
3Jซ
72
29
?3
33
43
-20
-/
16
69
36
--

-------
                                 Table C-2
Redistribution of Street Dirt due to Street Cleaning

                  Site:   115-llOth Ave. SE  (SD2)
                         4/14/82  tests
                                                                       (10-3
                                                                                    loadings)

Before
0-10"
10"-20"
20"-4'
4'-8'
8'-15'
0-15'


After
0-10"
10 "-20"
20"-4'
co 4'_8'
2 8'-15'
0-15'


Removed
0-10"
10"-20"
20"-4'
4'-8'
8 '-15'


>6350
0.29
0.8
0.06
0.006
C.003




0.03
2.3
0.01
0.006
0.02




0.26
-1.50
0.05
0.00
-0.02


2000-6350
0.48
4.5
1.0
0.18
0.05




0.03
5.8
1.0
0.08
0.13




0.45
-1.30
0.00
0.10
-0.08

Particle
1000-2000
0.39
2.1
0.58
0.17
0.08




0.08
3.3
0.84
0.14
0.10




0.31
-1.20
-0.26
0.03
-0.02

Size (Microns)
500-1000
0.58
2.3
0.80
0.26
0.16




0.18
6.5
1.3
0.34
0.18




0.40
-4.2
-0.5
-0.08
-0.02

250-500
1.2
2.3
0.59
0.15
0.10




0.48
8.2
1.2
0.28
0.12




0.72
-5.9
-0.6
-0.13
-0.02

125-250
1.1
1.6
0.26
0.04
0.03




0.71
5.5
0.63
0.11
0.04




0.39
-3.9
-0.37
-0.07
-0.01

63-125
0.50
0.8
0.14
0.03
0.02




0.45
2.7
0.28
0.06
0.02




0.05
-1.9
-0.14
-0.03
0.00

total
< 63 so 1 ids
0.13
0.4
0.10
0.03
0.02




0.26
1.3
0.21
0.06
0.03




-0.08
-0.9
-0.11
-0.03
-0.01

4.7
14.8
3.6
0.9
0.4
2.1
(165
curb

2.2
35.7
5.5
1.1
0.6
3.5
(230
curb

2.5
-20.
-1.9
-0.2
-0.2
1.5






lb/
mi le)







lb/
mile)


9




% Removed
0-10"       90%       94%
10"-20"     -190      -29
20"-4'      83        0.00
4'-8'       0.00      0.56
8'-15'      -600      -160
0-15'
                                   79%
                                   -57
                                   -45
                                   18
                                   -25
69%
-180
-62
-31
-13

60%
-260
-100
-87
-20

35%
-240
-140
-180
-33

10%
-240
-100
-100
0.00

-44%
-225
-110
-100
-50

54%
-140
-53
-21
-47
-70
Notes:  (lawn mowed between before & after sunny/dry, good  street condition)

-------
UJ
oo
                                                        Table C-2 (con't.)
                           Redistriuution of Street Dirt due to  Street Cleaning

                                             Site:   405-llOth Ave.  SE (SDl)
                                                    4/14/82 tests

Before
0-10"
10"-20"
20"-4'
4'-8'
8'-l 5'
0-151


After
0-10"
10"-20"
20 "-4 '
4 '-8'
8'-l 5'
0-15'

> 6350
1.03
0.29
0.57
0.006
0.003




0.32
1.11
0.14
0.006
0.02


2000-6350
1.6
1.8
2.2
0.29
0.08




1.27
0.84
0.42
0.33
0.22

rcti. UJ.(- L
-------
                          Table  C-3.
Street Cleaning Test Results During Special Tymco Test  Period

            Initial  Load  (Ib/curb-mile)
             Particle Size (Microns)
Surrey Downs
Date
Mobil
Tymco
Modified
Tymco
9/8
9/14
9/17
9/22
9/10
9/15
9/21
9/23
9/10
9/14
9/21
9/23
>6350
8.0
5.0
1.4
8.6
2.5
2.1
6.9
3.0
5.1
6.0
2.1
3.5
2000
-6350
11.7
18.2
6.3
16.3
7.8
14.1
17.1
18.8
16.2
15.8
6.3
6.7
Surrey Downs
Date
Mobil
Tymco
Modified
Tynco
9/8
9/14
9/17
9/22
9/10
9/15
9/21
9/23
9/10
9/14
9/21
9/23
1.3
3.9
3.1
2.1
1.7
0.7
0.5
2.2
7.7
0.3
0.6
0.8
14.4
12.2
6.3
9.7
5.3
8.0
6.5
8.1
10.1
7.3
3.1
4.9
1000
-2000
37.6
29.3
11.6
25.7
14.4
25.6
30.1
46.8
46.5
37.0
15.5
9.0
Residual
38.9
23.7
12.7
22.1
9.1
9.7
12.5
24.0
24.6
13.6
9.9
5.8
500
-1000
99.1
59.4
19.0
50.7
34.5
49.3
66.5
110.4
121.5
60.7
24.5
16.0
Load (
99.4
55.4
24.5
42.7
23.1
19.7
23.3
52.6
54.5
22.1
14.2
10.3
250
-500
114.4
58.9
14.4
62.1
32.3
52.9
67.2
113.8
171.5
54.2
32.5
21.7
Ib/curb-mile)
114
63.4
23.2
48.5
19.7
25.8
21.7
48.0
61.1
18.2
17.5
12.0
125
-250
87.8
40.5
10.2
52.8
14.8
39.5
44.0
73.7
142.8
32.3
29.3
19.8

82.3
42.5
16.7
39.9
15.7
24.8
18.0
37.7
48.5
12.7
18.3
11.9
63
-125
54.4
24.1
7.8
38.0
5.8
29.9
26.9
39.9
88.7
16.0
24.7
15.8

52.7
25.2
10.8
30.1
11.2
19.1
13.8
26.9
38.2
8.8
15.6
9.8
37
-63
26.1
10.5
4.7
15.2
2.3
10.6
10.1
16.6
39.7
8.3
9.7
8.3

24.8
11.2
5.1
14.3
6.9
10.3
6.6
13.8
20.4
5.3
8.0
5.8
•=37
6.9
6.2
5.2
8.8
1.6
13.7
8.4
11.9
19.7
6.9
7.3
6.8

20.9
9.0
5.5
10.5
5.8
10.3
5.1
9.3
18.2
6.4
7.7
5.1
TS
456
252
81
278
116
238
277
435
652
239
152
108

449
243
108
220
99
129
ill
223
283
95
95
66

-------
                                                      T'1:^  L.-J,  (Cont.)
                                Street Cleaning  lest Results During Special  Tymco  Test  Period

                                            Initial  Load  (Ib/curb-mile)
                                              Particle  Size ^Microns)
C/J
00
en
Surrey Downs
Date
SE 30th
Mobil
Tymco
Modified
Tymco
SE 30th
Mob i 1
Tymco
Modified
Tymco
9/1
9/16
9/27
9/30
10/5
9/2
9/16
9/27
10/1
10/4
9/16
9/29
9/30
10/4

9/1
9/16
9/27
9/30
10/5
9/2
9/16
9/27
10/1
10/4
9/16
9/29
9/30
10/4
>6350
141
17.1
1.2
9.2
5.5
37.6
47.3
18.2
11.2
3.1
17.1
6.8
7.8
15.5

85.9
22.3
14.3
8.4
5.3
7.0
11.7
6.9
2.0
1.9
6.2
1.4
6.8
1.4
2000
-5350
251
80.4
32.2
33.9
21.5
84.0
135
72.7
27.1
28.3
48.9
37.6
31.5
33.4

231
45.3
128
36.2
23.1
31.5
38.2
29.2
12.4
20.4
18.3
'3.9
20.3
18.4
1000 500 250
-2000 -1000 -500
28C
146
83.5
68.0
34.4
152
141
120
38.4
51.0
127
64.9
73.3
62.4

239
97.5
75.0
68.0
39.7
113
64.1
84.8
28.9
38.0
66.6
33.0
70.3
42.1
532
321
125
138
54.2
259
222
226
60.5
70.2
201
117
133
125
Residual
413
208
146
126
62.5
153
87.9
149
42.1
47.1
61.5
43.7
83.9
70.5
740
390
137
174
55.5
403
314
288
70.0
83.0
222
131
205
125
125
-250
667
384
119
185
48.7
400
358
245
72.1
81.4
192
102
186
94.8
63
-125
284
302
73.9
141
27.3
245
200
151
43.6
48.9
134
47.5
90.0
63.5
37
-63
66.7
98.1
20.8
55.1
8.8
80.6
76.3
47.8
16.9
13.6
44.8
n.7
22.4
18.9
•37
20.8
91.8
6.9
19.3
5.2
37.8
85.0
14.5
9.4
5.1
24.0
4.7
5.8
8.0
TS
2986
1339
600
822
261
1699
157S
912
349
385
1009
523
755
547
Load (Ib/curb-mile)
635
237
228
144
65.3
216
93.9
13(5
37.5
45.3
74.4
39.6
55.0
59.5
824
218
221
121
54.5
223
105
127
35.9
46.1
76.2
30.9
37.8
48.6
488
169
125
69.7
32.4
145
93.2
84.6
27.7
34.7
74.5
16.7
26.2
35.0
137
60.2
46.3
24.2
13.0
58.0
41.5
34.7
11.0
12.7
34.7
c.l
9.5
11.8
23.1
67.0
24.4
11.3
8.1
43.9
34.1
13.0
7.1
6.6
33.5
2.7
6.?
7,&
3077
1123
909
610
104
991
570
664
205
2?2
446
187
316
295

-------
                        FIGURE C- 1
E
I
_Q
L

U

jQ
O
o
Ul
01
OH
   Street  Cleaner  Performance
   50
   so
  40
                                              \
6370
                                                          c r o n
         Surrey Downs (Mobil)
         Lake Hills (Mobil

      M: Modified Tymco  (Surrey Downsj
      T: Tymco (Surrey Downs;
                        20        30        40

                       Initial Load  (Ib/curb-mIle)

-------
                             FIGURE C-2
LO
00
        Street Cleaner  Performance'
        70
        60.
O '•  S u r L <:y Downn(t-'/j 1
A.'  Lake II i 1 1 :: (M:>M 1 )
M:  Modifier! Tymco (Surrey Downr.)
L:  Tymco  (Suiroy D'lwnf;)
                                     '000-63/0
                           20      30      40      50
                            Inl-tlol  Load Ob/curb-ml le)
                                                   70

-------
                             FIGURE  C-3
oo
UD
        Street  Cleaner  Performance:
        90
                                     1000-2000
      01

      e

     f
      u
      o
      o
      o
     -o
      in
      o>
        80.


        70.
0 '• Surrey Downs  (Mobil)
A: Lake Hills (Mohil)
•H-. Modified Tymco (Surrey Down
T: Tymco  (Surrey Downs)
                                  40    50     60
                                 Load (Ib/curb-mlle)
                                        70
80
90

-------
CO
^o
o
_O

U
V.
_Q
      C
      O
      o
      -
      U)
      0)
      o;
  Sir
150
14fl
i3a
120.
11
10
90
80
70
60
50
40
30
20
                               FIGURE C-4
               eet  Cleaner  Performance:   5QG-1GGQ
               0! Surrey Downs  (Mobil)
               A: Lake Hills (Mobil)
               M-. Modified Tymco (Surrey Downs)
               T: Tymco (Surrey Downs)
                10  20
                     40  50  60  70  80  90   100 110  120  130 140  150
                       Initial  Load (1b/curb-mI 1e)

-------
                        FIGURE C-5
    5treet  Cleaner  Performance-'   250-500  [j
160
151U— A
140_I_ M
      T
130.
           Surrey Downs (Mobil)
           Lake Hills  (Mobil)
           Modified Tymco  (Surrey Downs)
           Tymco  (Surrey Downs)
01

E

f
U
0
o
o
tJ
"w
CI
eg
       0
       10  20  30  40  50  60  70  80  90  100 110  120 130 140  150 160
                     Inl-Mol  Lood Hb/curb-mlle)

-------
                         FIGURE  C-6
    Street  Cleaner  Performance:  125-25Q
f
f
u
~o
a
o
o
-
w
01
a;
   130
11
IOC
90_
80.
70.
60.
50_
40.
30.
20.
10.
0
         : Surrey Downs (Mobil)
        A: Lake  Hills  (Mobil)
        M; Modified Tymco  (Surrey Downs)
        T: Tymco (Surrey Downs)
       0
        10   20   30   40   50   60   70  80   90   100  110  120  130
                     Initial Load (Ib/curb-mlle)

-------
                       FIGURE C-7


      Street  Cleaner  Performance:
u
V.
-O
"O
o
O
o

-
ut
4)
                        63-125
          > • Surrey Downs

          •' Lake Kills

         
-------
                      FIGURE C-8

Street Cleaner Performance
                                             <63  M i crons
  80


  70_


3 60.
    0:  Surrey Downs (Mobil)
    *:  Lake Hills  (Mobil)
    _M:  Modified Tymco (Surrey Downs)
    T;  Tymco (Surrey Downs)
                              40
                                       50
     ,•ฃ>>•-
60
70
80
                       Inl-tlol Lood (lb/curb-mlle)

-------
                FIGURE C-9
Surrey Downs Greater Than  6350  Microns
               3456
              Initial Load (Ib/curb-mMe)

-------
E
I
.ฃ)
L
3
U
\
JO
- 10
a
o
o

-o

in
OJ
01
  0
                     FIGURE  C-1 0

      Surrey  Douns  2000 to  6350  Microns
6   8   ' 10    12   14    16   18

 Inl-Uol Load (Ib/curb-mlle)
                                                   20

-------
             FIGURE C- 1 1
Surrey Douns  1000  to 2000 Microns
        10        20       30
             Inl-tlal Load Ub/curn-ml le)

-------
OJ
'O
00
    U  10
     E
    _ฃ>
     L
    -o
    f}
    O
     c
     -o
     w
     (V
                         FIGURE C-12

            Surrey Downs 500  to  1000 Micron
          o
10
40   50  60   70  80  90
Inl-tlo) Load (1 b/curb-m I 1 e)
100  110
120

-------
             FIGURE C- 1 3
Surrey  DONHS  250  to  5QG  Microns
        40
 63    80    100   120   140
:nltlol Load Mb/curb-mM e)
160   183

-------
E
u

_o
-o
o
o
o
U
TJ
                     FIGURE  C- 1 4



        Surrey  Douns  125  to  250  Microns
         10  20  30  40  53  60  70  80  90   100  110  120 130 140 150


                     Initial Load (1b/curb-ml1e)

-------
O
                        FIGURE C- 1 5
              Surrey Downs  63  to 125 Microns
                  10
 20      3C      40
Initial Load (Ib/curb-mMe)
50

-------
o
'o
                          FIGURE C-1 6

               Surrey  Downs  37 to  63  Microns
                       10     15    20     25    30

                          Initial Load (1b/curb-mIIe)
35
40

-------
               FIGURE C-1 7
 Surrey Downs  Less  Than  37 Microns
o
    10        15
Inl-tlol Load (lb/curb-m! 1e)
20
25

-------
          FIGURE C-18
Surrey  Douns 2  to  10 Microns
       .2    .3    .4     .5
          Inl-tlo) Load (Ib/curb-m M e)

-------
                  FIGURE C- 1 9
     Surrey  Downs Less  Than  2 Microns
0
            .1
    .2        .3
Inl-tlol Load (1b/curb-m!le)
.4
.5

-------
                    FIGURE C-20

     5.E.  30th Greater  Than 6350 Microns
E
I
_D
U
X
_D
-a

o
_j

'c

T)

01
                       60        90

                   Initial Lood ()b/curb-mI 1e)
120
150

-------
            FIGURE C-2 1
S.E.  30th  2000  -to  6350 Microns
20  40   60  80  100  120  140  160 180  200  220  240 260
           Initial Load (1b/curb-mI1e)

-------
o
00
                         FIGURE C-22

              5.E.  30th  1000  to 2000  Micron
                          100      150     200

                         Initial Load (1 b/curb-m Mel
250
300

-------
0
               FIGURE C-23
    5.E.  30th  500  to  1000  Microns
50    100   150  200   250  300   350  400   450  500   550
           Inl-tlol Lood nb/curb-mtle)

-------
750
                      FIGURE C-24
         5.E.  30th  250  to  500  Microns
       50  100 150 200  250 300 350  400 450  500 550 600  650 700 750
                   Inl-tlol Load (Ib/curb-mMe)

-------
                        FIGURE C-25
            5.E.  30th  125 to  25Q  Microns
_o


u
TJ
c
o
o

-6
IV
ct:
   850


   800J_
             100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850


                       Initial Load (Ib/curb-mMe)

-------
0
                FIGURE  C-26
     5.E.  30th  63  to  125  mcrons
50    100   150   200   250   3QO   350
          Initial Load Hb/curb-mlle)
400
450   530

-------
E

J3


U
V.
J3
"O
o
o
Q

-
W
01
ct:
                       FIGURE C-27


            S.E.  3Qth 37  to  63  Microns
                    40     60     80      100

                      Inl-tlol Load (Ib/curb-mMe)
123
140

-------
            FIGURE C-28
5.E.  30ih  Less Than  37 Microns
  10   20
30    40   50    60   70
Inl-tlol Load Hb/curb-m I 1 e)
80
90
100

-------
         FIGURE  C-29
5.E.  30th 2  io  10 Microns
       2345
        Inltlol Loed Hb/curb-mMe)

-------
0
   0
                 FIGURE C-30
      5.E.  30-th  Less Than  2 Microns
                 Initial Lood llb/curb-mlle)

-------
Table D-1 . Surrey Down." Catchbaoin  Sediment  Loading Observations  fcubic fee*,}



         Dec 17-26 Aug 8-14    Jan 30   Peb  26-Apr  21-24.Jun l6-17Jul 17-21Aug 17-24  Jan 18-  Xir. 1
   Tlumber
              1979
                        19UO
                                 1981
                                        Mar  1 '
506
507
^09
510
526
-,21
528
529
531
532
533
534
535
536
538
539
540
54?
543
544
546
547
550
551
554
555
557
558
559
560
561
562
565
566
567
568
570
572
573
574
575
578
580
998
Total
Max iraum
Average
Count
.00
.40
.04
.23
.30
.29
.08
.06
.64
.00
.03
.80
.18
.26
.20
.21
.49
.09
.32
.21
.03
.10
.68
.24
.10
.15
.25
• 31
.79
.64
.47
.71
.34
1.13
• 37
.60
.58
• 34
.49
.20
.20
2.36
.17
.60
17
2.36
.38
44
• 05
.12
.02
.24
.13
.12
.04
.21
1 .44
.00
.14
2.20
.08
.03
.08
.08
•65
-15
1 .01
1 .21
.17
• 13
.85
• 34
.17
.16
• 31
-92
1 .06
.64
1 .10
3-56
.00
.37
• 19
.15
.12
.17
2.46
.27
2.34
2.15
2.48
.60
29
3.56
.65
44
.00
1 .81
2.23
t .23
2. 36
6.74
.19
3-24
2.02
.30
1.15
8.69
4-33
4.80
1 .71
1 1 .04
6.63
.00
1.9-
1.49
• 37
2.05
2.72
2.41
4.53
1 .70
2.81
4-13
5-36
3-81
1 .61
3-85
4-32
6.63
NA
1 .08
.00
6.52
2.32
.20
1 .72
1 .72
2.41
3.03
127
1 1 .04
2.96
43
.00
1 .81
2.05
1 .42
2.10
6.56
.47
3-99
2-34
.21
3.02
9.CI
-••54
4-85
1 -31
11.24
6.4'-'
.09
1 .92
1 -52
• 37
1.51
2.86
2.04
4.25
2.01
2.96
4-28
5-41
3-50
2.08
HA
.00
6.27
• 30
1 .14
.58
3.18
2.46
• 39
1 .09
.43
• 33
3-24
116
1 1 .24
2.69
43
.CO
1 .81
2.41
T.'53
2.42
7.16
-5C
3.69
2.50
.12
1.15
9.01
.1.28
4. 65
1 .87
t.52
''•" 1!
.
•< 9-)
1 .48
.03
1 .61
2.75
2.21
2.14
.09
.22
.13
.79
3.81
.09
.14
.44
-58
.04
.24
.00
1.51
.12
08
.04
.47
2.05
.15
75
9.01
1 .71
44
.41
2.61
3-14
1 .42
2.28
6.56
.00
3-6j
2.-'0
-30
1.15
8.81
4-33
4-85
2.10
7.7r
6.fi
. ; •
1.^2
' . - 1
• 37
1 .68
2.69
2.38
3.06
.71
• 37
.76
1 .72
3-81
.00
.86
1 .42
1 .61
.00
.84
.77
• 03
.86
.08
.12
.86
2.15
1-35
90
8.81
2.05
44
.00
1 .61
2.63
1 .62
2. 10
6.44
• 31
3-36
1 .95
• 39
1 .56
9-17
3-37
4.88
2.50
6-94
6-73
.06
1 .67
1 .27
• 37
2.08
2.99
2.72
3-50
-77
.47
1 .07
1 .06
3-49
.19
1 .8S
1 . 47
1 -25
.00
1 -57
.15
.17
• 37
• 55
• 23
• 39
2.18
1 .41
89
9-17
2.02
44
.09
2.01
2.71
1.56
2.10
6.86
• 39
3-63
2.18
.15
1 .01
9.01
4.46
1.85
2.10
2.05
1 .56
1 .06
1 .98
1 .36
-54
1 .35
2.86
2.04
3-57
.93
• 56
1 .40
2.51
3-50
• 03
1 .28
1.67
1 .61
.22
1 -35
.12
. 10
.62
.00
.70
.64
.00
1.65
3\
9.01
1 .84
44
1.56
3-41
4.02
1 .70
2.75
7.16
.97
1.14
2.66
.'5
1 .30
9-41
4.33
4-72
.32
5-34
.97
.00
1 .57
1 .97
.54
2.69
3.06
2.21
3-74
1.39
1 .87
3.4^.
S.2S
4.45
.66
MA
5-61
6.27
.22
-99
• T8
1.34
2.09
.20
.31
.86
2.31
2.85
108
9.4t
2.52
43
.00
. 12
.02
.24
- 13
. 12
.00
.06
.64
.00
.03
.80
.08
.03
.08
.00
-49
.00
.32
.21
.03
.10
.68
O •
.10
• 09
.22
.15
.79
-6-1
.00
.14
.00
•77
.00
• 15
.00
• 03
.12
.00
.04
• 39
.00
.15
8
.80
. 18
44
t c r
3.4l'
4-02
1 .70
2.76
7.16
• 97
3-99
2.V,
.3?
3-C2
9.4'
4.54
4.33
2 . -0
1 1 . 24
6.66
1 .06
1 .03
1 -97
.C4
2.6Q
7-06
2.72
4.53
2.0!
2.36
4.28
5-41
4.45
2.08
3-35
5-3!
6.63
• 37
1 -57
.77
6.52
2.46
.55
2.34
;.76
:.' . 43
.5-24
'50
1 1 .24
3.4T
14
- -r
1 .""5
2.14
1 .23
1 .:A
5.72
/ T
") - ^
2.01
. 13
1 . ', 1
7-75
7.72
7 . 7ri
i -75
c . 5-1
-t f —
j • *
. i •)
1 - 53
1 .74
• 31
1 . ^ >
2 . M
1 .84
2.i^
••3
1 . Z^
' -87
2.66
3.07
.69
1 -75
1 .->2
2.36
.17
.89
• 70
1 .43
1 -31
.22
-7S
1 .1C
1 .56
' .65
82
7-35
1 .86
44

-------
     Table D-2. Surrey Downs  Inlet  CecUment Loading Observations 'cubic fee1",;

              Deo  13-26 Aug 9-14    Jan  30  Feb 26-Apr 2l-24o'un 16-17Jul 17-21 Am?  17-24
        Number      1979     1980      19^1    Mar 11
oo
.'* i n L m MTI
502
503
505
508
511
513
514
516
517
518
520
524
525
530
537
541
545
548
549
552
553
556
569
571
579
581
999
Total
Maximum
Average
Count
•J3
:;A
.04
.42
.CO
.15
• 15
.06
.03
.03
NA
• 45
.00
.10
.77
.36
.26
1 .01
• 32
1 .02
.22
.45
1 .04
• 35
1 .62
.12
• 03
9
t .62
-36
25
• 38
.15
. 12
• 98
.07
• 03
.09
• 03
.03
.24
.09
.36
.00
.07
1 .29
.85
-49
2.02
1 .29
1 .87
• 32
.06
3-64
• 35
2.70
.07
.10
18
3.64
• 65
27
• 03
. 1b
.12
1.15
1.58
.00
.27
.81
.03
.12
.42
1 . : i
.00
.06
4.95
1 .06
1.23
1.51
1 .49
3-06
3-03
4.08
18.93
1 .40
• 31
.30
3-33
51
18.93
1 .87
27
.20
.09
.00
1.34
1-34
.06
• 15
• 69
. 12
.18
-45
1.23
.00
.04
5-46
1 .27
1 .5o
4-94
1.32
2.89
2.87
4.1 1
18.98
1-57
• 39
-32
3-40
55
10.98
2.04
27
.44
.:?
.15
1 -57
1 .51
-15
.24
.69
.06
.24
.60
1 .47
.00
.10
6.03
1 .27
1 .72
5-64
1.97
2.72
1 .44
4-20
19-24
.00
.50
.16
3-40
56
19-24
2.06
27
.49
.21
-CO
1 .43
1.75
.15
.15
.69
.22
• 33
• 30
1 .47
.00
.07
5- 65
1.36
1-39
5-71
1 .81
2.89
2.23
4-26
18.72
• 52
• 31
.16
3-23
56
18.72
2.06
27
-35
. 10
1?
1 .43
1 .68
• 36
-15
.69
.16
.39
.60
1 .47
.01
.00
6.18
1-51
1 -55
5-95
1 .42
2.58
2.07
4.20
18.46
.70
• 35
.23
3-50
56
10.46
2 . 08
27
.00
.05
-72
1 -57
1 -5'
.21
-15
.69
.22
.37
• 30
2.07
.00
.07
6.11
1 .58
1-39
5-86
1 .81
.07
2.23
1 .26
18.7?
.87
• 39
.16
• 34
48
18.72
1.79
27
5.22
. 77
1 .40
t il ">
J • J1-
7.22
.70
. to
.69
.22
. 18
.45
1 .02
.00
.07
6. 18
1 .21
.42
6. ^
1 . 29
4. >>
2 . S7
2.76
8.58
.8^
.19
.40
.24
57
8.58
2.12
27
.00
. 00
.CO
.-12
. '~ ^
.00
r,q
.03
• 05
r7
.00
.76
.',0
00
."~>
• 3o
.26
1 .01
.7<^
. 07
T -1
. ^ C
06
1 .04
.00
. n
.07
.03
5
1 .04
.20
27
5-22
1 -f
* . 4 0
~* i ">
S ' s -
7. 22
. "*/,
C ^
.8'
.22
. j'(
r "*
2 . '".i
.01
. ! 0
6 . 1 •!
I . = •<
1 . 7 j
^.^'.
\ . "1 7
4 . C8
1 . 0 '.
4.2s
1 '') . 2 4
1 .57
? 70
.40
3-50
80
19-24
2.96
27
~ <
' *
. C"
t . '•' '
1 '•*=.
. i •')
. .'' .?
c ^
. I i
', i
. i -
1 I -.'


4 . "'•
1 . !•:.
1.1'
4 . 7-1
1.4'
2.1 =
i ri ~>
2 . ••;
14.0';
.71
.7<>
. 21
1 . i'i
4r>
14.0?
1 .67
27

-------
Table D-3- Surrey Downs Man Hole Sediment Loading Observation  (cubic  fe;t)
Dec 13-26 Aug 8-14
Itumber 1979 1980

504
512
515
519
521
522
523
577
Total
Maximum
Average
Count

HA
NA
NA
NA
NA
NA
NA
10.03
10
10.03
10.03
1

.13
.00
NA
.00
.00
.00
.00
15-18
15
15-18
2.19
7
Jan 30
1 981

.00
• 39
.00
.00
4.02
.16
-63
15-32
21
15-32
2.56
8
Peb 26-Apr 21-24Jun 16-IVJ'il t?-21Aug 17-24 Jan 18- "iniouT. .'"ax Lr= JBI Avซr-i,?-i
Mar 1 1 Feb 5

.00
.00
.00
.00
.00
.32
• 38
15.32
16
15-32
2.00
8

.00
.79
.00
.00
.00
.16
.00
13-99
15
13-99
1 .87
8

.00
.00
.00
.00
.00
.00
.00
15.31
15
15-31
1.91
8

.00
.00
;JA
.00
.00
.00
.50
25.86
26
25-83
3.77
7

.00
.00
.00
.00
.00
.00
.00
15-32
15
15-32
1.91
8
1 962
MA
NA
.00
.00
.00
• 57
.00
20.08
21
20.08
3-44
6

.CO
.cc
"A
NA
NA
.00
.CO
10.03
10
10.03
2.01
5

•'3
-79
."A
'iA
:;A
_ c; -
• 63
25 . 38
28
25. ?3
5-60
5

.02
. 17
'in
"iA
:;A

. 1 9
•6.27
17
1 6 . 27
3-36
C,

-------
                          Klllo  -'atchbas ir
                                                      LcH.Jir. *? Observations f cubic
                    Dec  4-12  Jul  23-Jan
            liua'jer      1979     Aug  b
                                  1980
!*ir 2-   A-r  2.1-.J'in 19-26Jul  14-56
 Acr  i    >ay 5
-C.
ro
o
;c5
5C6
510
51 1
= i j
514
516
517
519
520
521
524
526
528
543
544
"45
546
547
548
550
551
552
553
554
555
556
560
561
564
565
566
5b8
570
571
573
574
576
577
578
579
580
582
584
588
589
591
593
596
.39
.40
.22
. 1 2
• 3ฐ
o9
.00
.04
• 37
1 .04
1.16
1.14
• 58
1 .60
.00
.02
.00
.04
.00
.20
.00
.00
.00
.00
.00
.00
.04
.08
.04
.08
.00
.21
.08
.00
.04
.04
.08
.08
.07
.02
1 .41
NA
-39
.08
-40
.04
. 12
• 39
.20
• 96
.60
1 .08
.20
. 12
.73
.00
• 58
. 18
-42
1.35
.76
-58
1.14
-04
.04
• 39
.00
1 .28
.04
.08
.00
.00
.04
.00
.00
.00
.28
.19
1 .58
.00
.63
. 12
-04
-29
.08
.08
.19
.07
. 17
• 35
• 03
• 39
.04
.12
. t 1
.08
-39
.12
2.93
2.C1
2.76
.36
4 . 28
.82
.00
.81
1 -39
2.66
1 .62
2.93
2.43
4.83
.00
.00
.00
.00
.00
2.12
.00
•31
.00
.04
HA
.08
.08
. 16
.54
2.46
.00
.17
.00
.00
-51
.46
.04
.89
.13
.40
.14
1 .24
1 -54
-29
.71
. 18
.00
• 35
.00
1 .
2.
2 .

4.
1 .


1
2
1
3
2
5





1









2







1











.00
21
T7
.60
.47
.02
. 27
.93
.69
.20
.35
.43
• 32
•52
.00
.00
.00
.00
.85
.77
.00
.CO
.00
.00
NA
.00
.00
.00
-85
.10
• 09
.42
.08
.08
• 55
.04
.00
.16
.17
• 34
NA
NA
NA
HA
NA
NA
.03
.78
.00
6.38
2.4!
2 . ฐS
".60
1.67
1.41
.27
1.12
1 .76
2-62
1 .74
3.62
2.12
4.15
NA
NA
NA
NA
NA
NA
NA
NA
;;A
NA
NA
NA
NA
NA
HA
NA
NA
i!A
NA
NA
MA
NA
NA
NA
NA
NA
-50
1 .28
1 -93
.29
.48
.32
.46
.31
.20
1 .
c •
3 •

4-
1 .


1 .
3-

4.
2.
5-




1 .
2,








1
2







1



1
2






54
C 1
20
80
32
41
00
73
68
32
16
19
51
06
.00
.00
.00
."A
,20
.28
.00
.00
.00
.00
.00
.00
.00
.36
• 23
.49
.00
• 34
.39
.00
• 55
.46
.19
.16
.17
• 34
• 57
.28
. 12
• 50
MA
NA
.66
.78
.00
1 .
2.
7

4.
2.

1 .
1 .
2.
1 .
3-
2.
5.





2.









2.










1
1
2






20
21
54
24
32
20
00
39
61
41
'9
qo
55
29
00
00
00
CO
90
CO
00
35
.00
.00
NA
,08
.00
.28
.63
,30
.09
.38
.03
.20
.33
.46
.08
.66
. 1 7
.54
.06
.31
.04
.21
.51
-50
.46
.43
.08
1 • ~"'
2 . "~'j
t _ 2Q
.C8
8.32
2.59
• 1 9
1.12
1.^9
2^62
1 .35
3-62
2.CQ
5.75
.00
.00
. 12
.00
1 .71
1 .96
.04
.15
.00
.15
NA
.27
. 12
.08
.46
2.49
.09
.34
.77
.20
. c 5
.46
.0^
1.15
.20
.Si
Nฃ
NA
2.31
.42
.00
.07
HA
. 53
.00
i tr
2.^1
7 . 4 h,
! . 40
4.47
1 .61
r p
1.31
2 . o
2 ^ 2
r. i"e
4. C7
2.51
7.57
.00
.00
. 1 2
. t 2
.00
1 .96
. CO
. 7ฐ
.CO
.00
.CO
1 2
.CO
. 16
1 .04
2.49
.09
• 34
.77
.00
. 73
.46
. 15
1 -35
. 10
.67
1 .98
1.11
1 .35
. ?ฐi
. .10
. 2S
.73
. 3'1
. 39
. "* "i
.4 :
. 2 ?
. " -J
. ' 2
=, -'

. 4
i .•)
. 4 J
1.16
. 76
c p
1 ' 4
, r
•- r:
CO
r:C,
.CO
. CO
.CO
.'.0
.CO
.CO
CO
. CO
. on
.00
. JO
.00
. oo
.00
. 00
.00
. on
.00
.00
.no
. 00
.00
.00
.•"'O
.CO
.00
.00
.00
.00
.31
.00
                                                                                                                        4.5"'
                                                                                                                        2 . /(
                                                                                                                        2.4^
                                                                                                                          77
                                                                                                                         .20
                                                                                                                         • 5s
                                                                                                                         . 46
                                                                                                                         .6""
                                                                                                                        1 .P8
                                                                                                                        1.71

                                                                                                                         .SO
                                                                                                                         .71

                                                                                                                         .77
                                                                                                                         . 7H
                                                                                                                         . 1 4
                                                                               I .C4
                                                                               1 • 5'
                                                                                .27

-------
Table D-4.  Lake Hillo CatohDaain Sedioent  Loading Observations  (cubic  feet) (cont.)

          Dec 4-12  ,Iul 23-Jan 27-29   Mar 2-  Apr 24-Jun  1 9-'6Jul 14-16  Auฃ 27-Jan  20-27
   Hunber     1979    Aug 6     1981     A or t     May 5                      2ep  3      1932
                       1980
597
598
599
601
607
607
608
609
612
614
ฃ16
618
619
621
623
625
627
629
630
631
632
634
Total
Maximum
Average
Count
.77
.00
.20
.08
.12
.08
•37
.26
-29
:IA
.56
.00
-04
.04
.04
.00
.04
.04
.04
.04
.19
.08
15
1 .60
.22
69
• 96
.04
.48
.19
.19
.20
.37
.19
• 54
:;A
.15
.00
.20
.28
.04
.04
.04
.08
.08
.19
• 39
.12
21
1 .58
.30
70
.69
.20
.64
.C3
.00
.20
.37
1.23
2-39
2.4'
1 .61
.00
.79
.12
.00
.08
.20
.08
.12
.00
• 58
.77
55
4-83
.79
70
.77
.00
.44
.08
.00
.48
• 37
1.12
2.50
2-52
1 -68
.00
• 79
-52
.00
.00
.20
• 31
.41
.00
.69
• 96
53
5.52
.83
64
-77
.20
.44
.00
.23
.60
.48
.00
2.86
2.52
1 .61
.00
• 98
KA
HA
NA
MA
HA
NA
.00
• 58
HA
53
6.38
1 -39
38
• 58
.CO
1 .04
.27
.00
.CO
.CO
t .50
2.14
2.66
1 .68
.20
1 .38
.51
.00
.12
.20
.70
2.89
.00
.77
• 96
67
5.06
• 98
68
.46
.CO
.28
.C8
.CO
.CO
.26
1 .08
1 -96
2.55
1 .68
.08
.71
.16
.00
-40
.04
.74
2.76
.19
.89
.62
64
5.29
-91
70
• 58
.08
• 96
.CO
.04
.CO
.44
1 .38
2.50
2.6';
1.50
.00
• 5!
.12
.00
.00
.00
1 .09
3-09
• 96
.96
• 77
70
8.32
1.05
67
.77
.CO
1 .C4
C ^
.00
.20
.18
-37
2.68
2.66
1 .i8
.00
1 .38
.71
.00
.00
.78
• 31
2.68
.00
.89
1 .16
72
7.57
1 .01
71
.46
-CC
.2C
.CO
.CO
-CO
.CC
.00
.29
.00
.15
.00
.04
.00
.CO
.00
.00
.00
.00
.00
. IP
.00
9
1 .16
.1 1
71
• 9"i
. 20
• .C4
2"!
.2'
.60
.48
1 .50
2.86
2.66
t .68
.20
1 .38
.71
.04
.40
.78
1 .09
3-09
.PC
.96
1 .16
96
a. 32
' -35
71
^1
. 06
tT Q
. "r|
.06
.20
3'
.79
t .96
2-56
1 -35
-C3
.75
. 71
.01
.08
. 1P
.42
1 .51
.15
.66
. 68
55
4-54
.T1
71

-------
Table D-5-
              ilills Inlet Sedicent  Loading Observations  (cubic  feet)
       Dec  ^-12   Jul 23-Jan 27-29    Xar  2-  Apr 24-Jun  1 9-26Jul  M-'6
:!unber      1979     Aug 6     1981     Apr 1     May 5
                     1980
                                                                                             '•'in:T.uri  "'ax : - j-  .-'.•/•-• ri*/-?
502
507
508
509
512
515
515
522
525
527
529
531
532
536
542
549
557
559
562
563
567
569
572
575
577
578
580
585
537
590
592
594
602
604
606
610
613
615
617
620
622
624
626
620
633
Total
Maximum
Average
Count
• C4
.09
.CO
.00
-03
.00
cc
• o;
.10
• 13
.00
.00
.00
.00
.29
• 38
.13
.00
• 03
.02
• 03
.07
• 03
-03
.07
.02
MA
.07
1.54
• 03
.77
-79
.28
.08
.06
.00
NA
.60
• 03
.20
.12
.08
.24
.12
.16
7
1.54
. 16
43
. 14
.09
.10
.03
, -\
— -r
• <-> >
.07
.07
-34
.67
-03
.07
.07
.00
.84
• 38
.10
.17
.10
.27
.03
.17
.07
.00
.07
. 1 7
^03
.03
1.16
• 55
• 96
1 .77
1.19
.27
.14
.00
NA
.60
.09
.78
1-39
.78
.40
.98
.79
16
1 .77
.37
44
.00
.47
.03
.00
• 30
.CO
.00
.00
.10
.13
.17
.00
.00
.00
1 .80
• 30
.03
.00
.00
. 2^*
. CL
.03
.00
.00
.13
.40
1 -24
.20
2.43
.87
2.47
5-H
3-30
.08
.14
.00
.77
.78
-44
.38
1 -99
1 . iO
1 .27
2.22
1.95
32
5- '4
.70
45
.07
-31
.00
.00
.30
.07
.00
.00
.10
.20
.'0
.18
.00
.07
1.59
.'d
.24
.07
.00
.20
.00
.10
.00
KA
.17
• 34
NA
tIA
HA
NA
2.66
5.42
3-57
.08
.27
.03
.70
• 90
.22
.98
1.39
1-37
.84
2.54
1.95
27
5.42
.63
/,0
.07
.41
.00
.30
.1 7
.00
.00
.00
.27
ซ T
- 1 J
.07
-32
.00
.07
1 .67
"A
NA
:;A
NA
HA
HA
MA
NA
NA
:;A
NA
1 .28
.13
2.70
• 96
3-24
5.49
3-57
.11
.06
.00
• 58
1.05
.38
• 98
NA
NA
HA
NA
1 -95
26
3-49
.86
30
.07
:IA
.CO
.00
.30
.00
.00
.17
.10
.20
.07
.13
.00
00
I .46
.45
.17
MA
.0?
.20
.00
.17
.07
.00
.17
.34
1 .28
.20
2.12
.82
3-24
5.49
3.77
.27
-05
.00
.70
.90
.38
1 .26
2.19
1-57
.84
2.73
2.34
34
5-49
.80
43
.14
.00
.00
.00
. *0
.00
.00
.10
.37
.24
.00
.32
.00
.10
1 -33
• 30
.24
RA
.00
-37
-30
-03
.00
::A
.13
.54
1 .31
.17
1 .58
.32
2.66
.55
4.09
. 1 1
. 1 1
.00
.66
.81
.44
1 .10
1.43
I 61
.79
2.58
2. 'B
23
4.39
.65
43
. -7
.22
.13
.07
• 30
. 17
.00
. 17
.27
.20
.17
.36
-03
-34
1 .67
.45
.03
MA
.03
.20
.00
.17
-03
.00
.20
.51
;IA
.20
1 .93
1 .09
NA
5-50
3-77
.19
.41
.CO
.58
.46
.53
1 .26
1 .70
1 .17
.84
2.73
1.95
31
5-50
.74
42
.cc
.22
.03
. CO
• 77
.CO
.00
.13
.07
* ,•'''
^ ^
. 1 5
.CO
. 1C
1 .04
.0ฐ.
.00
. ^"'0
.00
.CO
.00
.17
.00
.00
. 10
.67
1.11
.00
2.70
.68
3-47
5.10
4. 17
HA
.05
.00
-35
1 -05
.11
-39
.60
1 .37
.34
2.01
2.54
31
5-10
.71
44
. ~C
.CO
-CO
.00
.".-}
. cc
r ^
.CO
. C'7
' 5
.CO
.CC
.CO
-<"0
. 9Q
.ce
r r-
. f C
.cc
.^0
.CO
.03
.00
• 'J'J
.0-
.02
.03
.00
1 .16
-OT
-77
.5=)
.28
.08
-05
.00
.35
.60
-03
.20
.12
.08
.s"4
. 12
.16
6
1 .16
* o
15
. U
.4 '
. 1 *
i ' "
1ฐ^
1 -7
r~'j
. 1 7
• ^ '
. 6^
. 1 7
-I ฃ
. C"
. M
'. .:'0
.45
. 2 -
. 1^
. 'C
T-f
7 •"
. IT
.0"
. C^
.20
.-J7
1 -31
.20
n ~''~i
\ .C9
5-47
5-50
4. 17
.27
.41
.03
.77
1 .05
• 53
1 .26
2. 10
1 .61
1 .27
2.QT
2.54
41
5.^0
• 92
45
. C~^
. 5 '
. ~_ '
. " '
. ?-
r i
~ i
. ;~
. T "
•) C
-•C1:
1 :.
n
C ~*
4 7 l~
1
. '2
- c
r ~i
• -|
• 0
. ' '
. C ^
. j '
1 H
*"*
I . C4
. l -*>
2.02
- 73
2-0
3.92
?.G8
1
- !}
.00
.f2
-35
. y<
.1'8
1 . ""-3
1 . 16
.7h
2.10
1 .75
:o
3-12
.M
45

-------
Table D-6. Lake Hills  >ian  llole Sediment Loading Observations  (cubic feet)
                                                                                               Minimum  ."'axinur.  Average
Number

503
504
523
530
533
534
535
537
538
539
540
541
579
581
583
Total
Maximum
Average
Count
1979

.00
.40
2.51
5-67
1 .89
NA
5.66
.13
.25
1.26
NA
NA
1 -41
5-65
KA
25
5.67
2.26
1 1
Aug 6
1980
.00
.13
1.26
1 .42
1 .01
.00
• 71
• 38
• 25
1 .26
.00
-29
• 35
-71
NA
8
1 .42
• 55
14
1981

14.28
.00
1-13
.14
3-52
.00
8.13
.25
• 50
6.28
.00
9.62
.14
5-51
HA
50
14.28
3-54
14
Apr 1

15.83
-
2.14
.28
4-15
.00
7.71
.00
.00
1.26
HA
11 .06
NA
"A
NA
42
15.83
3-86
11
May 5

14.40
1.39
2.14
-99
1.76
.00
7.49
.00
.13
1.63
.00
10.58
-50
3-96
NA
45
14.40
3.21
14


10.17
.40
4-65
4.82
4.77
.00
7.70
.00
.00
1 .88
.00
9-62
• 57
4.10
1.63
50
10.17
3-35
15


14.70
.00
3-02
.00
3-02
.03
8.34
.1^
-38
2.01
.00
10.29
1 .06
4-95
3.27
51
14.70
3.41
15
Sep 3

13-01
.00
2.77
.00
4-52
• 35
7-71
.00
.00
1 .89
NA
9-62
tIA
4.81
1.63
46
13-01
3-56
13
1982

9.61
.26
3-39
3-20
2.26
.00
9-33
i .26
.63
1 .43
.00
12.10
1 .88
2.64
6.66
55
12.10
3-64
15


.00
-00
1 -13
.00
1 .01
.00
-71
.00
.00
1 .26
.00
.29
-14
-71
1.63
7
1.63
-46
15


15-83
1 "*Q
4.55
5-67
4.77
-35
9-33
1 .26
• 63
6.23
.00
12.10
1 .98
5-65
6.66
76
15-83
5-10
15


10.22
-29
2.56
1 .54
2-cr>
.04
6.1?
.•74
. 24
2-10
.00
9-'5
.84
4.04
3-30
45
10.22
2-99
15

-------
          Table 0-7. RELATIVE CATCHBA3IN SEDIMENT DUALITY (LAKE HILLS)
       S.ampl ing
CB0      Date
          Total
(1)   (2)   So1idsซ)
  mg constituent/kg total  solids
COD     TKN     Phos     Ph     Zr
524
535
578
626
616
592
616
626
524
528
535
549
564
578
582
592
616
626
524
528
535
549
563
578
582
3-20-80
3-20-80
3-20-80
3-20-80
3-20-80
12-27-79
12-27-79
12-27-79
12-27-79
12-28-79
12-27-79
12-28-79
12-28-79
12-28-79
12-28-79
12-27-79
12-27-79
12-27-79
12-27-79
12-28-79
12-27-79
12-28-79
12-28-79
12-28-79
12-28-79
X
X
X
X
X










X
X
X
X
X
X
X
X
X
X
'
19.1
70.5
5.31
13.8
26.?
X 91 mq/1
X 88 mg/1
X 124 mg/1
X 85 mg/1
X 111 mq/1
X 272 mg/1
X 34 mg/1
X 49 mg/1
X 158 mg/1
X 150 mg/1
54.0
13.6
40.6
46.2
427
79.5
63.7
60.7
28.8
59.7
42,400
15,700
267,000
34,100
14,500
263,786
306,818
193,548
?82,353
729,730
897,059
6,7,069
663,265
559,620
133,833
5115
213
585
439
312
55.1
315
1020
892
412
1440
55.6
11,200
4630
2130
5495
11,136
9677
55,647
19,820
11,176
35,000
10,204
35,443
4667
794
342
878
1020
778
56.0
353
1470
2010
560
199
28.4
2170
905
282
3571
1500
1758
7506
2901
25,092
2412
1592
4367
900
12.8
1.7
24.9
31.4
13.0
18.9
5.1
11.6
24.6
8.45
880
15.5
2930
1880
604
879
795
564
1588
1261
404
2647
1633
2848
800
580
236
278
262
149
13.0
407
507
465
479
318
37.9
595
906
226
13,077
511
637
212
946
801
971
17S6
797
247
166
159
146
93.0
53.5
37.0
123
211
104
120
(1)  sediment sample
(2)  supernatant  sample
                                     .124

-------
         Table  0-7.  RELATIVE  CATCHBASIN  SEDIMENT QUALITY  (SURREY  DOWNS)
CB#
510
548
559
531
534
508
510
524
548
566
526
531
534
559
578
508
510
524
548
566
526
531
534
559
578
Samoling
Date
3-19-80
3-19-80
3-19-80
3-19-80
3-19-80
2-4-80
2-4-80
2-4-80
2-4-80
2-4-80
2-14-80
2-14-80
2-14-80
2-14-80
2-14-80
2-4-80
2-4-80
2-4-80
2-4-80
2-4-80
2-14-80
2-14-80
2-14-80
2-14-80
2-14-80
(1) (2)
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Total
Solids^}
y.29
19.2
56.6
5.75
5.99
87 mg/1
40 mg/1
114 mg/1
116 mg/1
100 mg/1
1470 mg/1
144 mg/1
399 mg/1
215 mg/1
4160 mg/1
8.08
27.4
50.7
44.1
73.0
70.5
4.60
16.25
75.4
26.0
mg constituent/kg total solids
COO TKN Phos Pb Zn
269,000
121,000
92,700
489,000
445,000
206,897
500,000
175,439
189,655
110,000
42,178
145,833
107,769
144,186
293,269
'190,000
• 26,400
63,300
112,000
39,900
24,300
456,000
492,000
24,300
108,000
9710
3960
7910
12,200
27,500
9655
14,000
12,281
12,069
5600
1109
4375
12,807
2605
7356
13,500
3890
1790
1040
154
10,200
6380
4510
880
809
2020
411
168
2124
3720
632
3875
2737
629
280
255
451
814
605
73,798
1510
321
292
199
250
54.3
515
136
23.9
129
507C
806
1325
5153
2890
345
1500
263
517
400
6258
694
326
1209
1346
2080
1490
349
299
90.6
517
3510
954
477
790
540
137
245
1195
1000
919
. 19?ซi
298
371
500
2544
576
241
465
685
682
472
153
108
117
177
725
317
107
365
(1)   Sediment  sample
(2)   Supernatant  sample
                                     425

-------
                                   APPENDIX E
                               SAMPLING PROCEDURE
STORMWATER SAMPLING

     This appendix describes  th?  procedures  and  techniques used during the
Bellevue urban  runoff  study  for  collecting composite flow and proportional
stormwater runoff samples. The  sampled  basins  (Surrey Downs and Lake Hills)
are described in Section  3 of  this  report.

     The equipment installed  at  each site for  flow-weighted composite
stormwater monitoring  consists  of a Manning  composite sampler (S-3000),  a
Manning flowmeter with an ultrasonic stage sensor (UF-1100) and a 12 volt
power converter- The samplers  were  factory modified for priority pollutant
sampling. All surfaces  contacting the sample are either glass or Teflon.
Special cleaning procedures  were  developed for collecting priority pollutant
samples. These  special  procedures are described  by METRO in their report.

     The sampler is triggered  at  predetermined increments of flow by the
flowmeter. These flow  increments  need to  be  small enough so small runoff
events will be  adequately represented by  enough  samples. Conversely, the
sample container should be large  enough so that  large events do not cause the
sample volume to exceed the  storage capacity.  A  30 to 50 gallon (110 to  190
liter) polypropylene reservoir with a five gallon (19 liter) glass inner
reservoir for priority  pollutant  analysis has  been found to be adequate. In
addition, the increment of flow  selected  for subsampling should not be so
small that during peak  flows  the  cycling  capacity of the sampler is exceeded.
For instance, in the case where  the peak  flow  is expected to be less than ten
cubic feet per  second  (cfs)  (280  liters/second), a sampling increment of 600
cubic feet (17,000 liters) would  produce  one subsample per minute at ten cfs
(280 liters/second). It is necessary to determine the cycle time of the
sampler in the  field.  At  the  Bellevue sites, it  was expected that maximum
flows would not exceed  ten cfs (280 liters/second) and the sampler cycle time
was 40-45 seconds. Flow increments  of 300 and  500 cubic feet (8500 and 14,000
liters) were therefore used. At 300 cubic foot (8500 liter) subsawpling
increments, peak flows would  cause  the  cycle time to be exceeded., This
increment was used to  obtain more subsamples when small events were expected.
The flow has exceeded  ten cfs  (280  liters/second) at the Lake HDIs site on
several occasions , briefly exceeding the  cycling capacity of the sampler
during the peak flors.

     The flowmeters use an ultrasonic transducer to sense relative stage.
Stage is converted to  discharge by  a programmed  microprocessor in the.
flowmeter and presented on a  circular flow chart as a percentage of maximum
rated flow. The microprocessor is programmed from a stage/discharge rating

                                      426

-------
developed by the USGS (Ebbert, Pools, and Payne,  1983).  These ratings are
described in their report. Weekly or daily  flow  charts  are  selected based on
weather predictions, with daily charts preferred  for  runoff events. The
flowraeter totals the flow in 100 cubic foot  (2800 liter)  increments and
criggers the sampler at the selected flow increment.

     The subsarnple volume is adjustable up  to a  maximum of  about A50 ml. To
ensure adequate samples from small events,  the subsample  volume is adjusted
to near maximum. The intake hose for the sampler  is securely attached to the
bottom of the concrete drain pipe with two  anchor bolts.  Profiles of
suspended solids as a function of depth in  the pipe during  flow have
indicated that solids are evenly distributed, due to  the  turbulent flow, so
that no correction factor is necessary.

     The samplers can be used with 12 volt  batteries  as  a power source.
However, the motorcycle batteries supplied  with  the samplers are inadequate.
A 12 volt power converter was used in conjunction with  a  large capacity (90
amp-hour, or greater) bactery.

     Calibration of the flowrneters required  the  use of  an artificial stage
target set at zero and 100 percent of rated  flow.  Comparisons of discharge
records obtained from the flowmeters and discharge records  from the USGS
equipment and the Manning flowmeters indicated that the Manning flowmeters
were somewhat less accurate. For this reason, the USGS  flow data were used
whenever possible. The flowmeters are adequate for triggering the sampler and
for providing a back-up record of flow.

     Entries on a station log were made at  each  visit to  the stations,
describing all maintenance and calibration  activities.

     Storm samples were removed from the samplers  as  soon as possible after
storms, typically within two or three hours. Samples  are  kept on ice until
processed. A storm processing log was kept  for each storm.  Conductivity, pH,
and turbidity were measured at the City of  Bellevue water quality
laboratories. Subsamples were preserved and  sent  to a contract lab in Seattle
(Am Test, Inc.) for the chemical analyses.  Analytical methods are in
accordance with "Methods for Chemical Analysis of  Water  and Wastes,"
EPA-600/4-79-020. These constituent analyses and  the  rainfall/runoff data
were used to calculate mass loads for storm events.

     It was possible with this sampling arrangement to  obtain representative
storm samples for 80 to 100 percent of the  runoff events. When sampling
failures occurred during a runoff event, partial  samples  representative of a
part of the storm were usually collected. Analyses of the sample volumes and
the hydrography determined the times of sampling.  The flow  charts had event
markers for each sample pulse; however, with short sampling increments,
individual event marks were not always discernible.

     A quality control program for chemical analysis  of  runoff samples  and
street dirt samples was completed. The USGS  national  laboratory processed
duplicates of samples sent to the contract  lab.  Discussion  of the QC program
Is included in the USGS report.                                               ;

-------
STKKKT SUKMCE PARTICULATb  SAMPLING  AND EXPERIMENTAL DESIGN

     Ihe sampling procedures  described in this appendix were mostly developed
in a previous study:  "Demonstration  of Nonpoint Pollution Abatement inrough
Improved Street Cleaning  Practices," (Pitt,  1979).


Equipment Selection and Sampling  Effectiveness

     As part of the Bellevue  experimental design efforts, various vacujm,
hose and gulper attachment  combinations were tested. Relative air flows and
suction pressures in  the  hosf. were  monitored for different test set-ups. Both
one and tvo vacuum  configurations  and  1.5 inch (38  mm) hoses in lengths
varying from 10 to  35 feet  (3 to  11  meters)  were tested, alon- with a
Vacu-Max unit. The  standard "reference" system was  two vacuums a.^.d a 35 foot
(11 meter) hose. The  best suction  and  higher air velocities were observed
with trfo vacuums and  short  hose  lengths (10  feet, or 3 meters), but the short
hose length would require that the  vacuums be dismounted from the truck at
each subsampling location.  This  would  require a substantial incrpaee in time
and labor. The longer hose, with  the two vacuums, was judged adequate,  and
resulted in great cost  and  time  savings.

     Twelve street  dirt sampling  effectiveness testt were conducted
throughout the project  for  several  weather and street surface conditions. The
street dirt sampling  effectiveness  tests were conducted in an area about ten
feet (3 meters) along the curb to  the  street's center line. This area was
completely vacuumed using a single  pass of the standard sampling equipment.
The sample was removed  from the  vacuum canisters and stored for later
processing. The same  area was then  immediately vacuumed a second time using
the same procedures.  Again, the  second vacuumed sample was removed for
storage. The sama area  was  finally  sprayed with a water spray and wet
vacuumed to remove  all  runoff. The  wetting and wet  vacuuming were repeated
again, if necessary,  ur.til  the street  surface was thoroughly cleaned. This
sampling indicated  the  street surface  loadings that remained on the street
after the normal single pass  sample  collection. This is not an indication of
how much more material  would  wash  off  the street during rain events when
compared with the street  sampling.  Very few  rain events would be as effective
in cleaning the street  as the spraying and wet vacuuming procedures used in
these tests. These  tests  were iLainly used to confirm that the singla pass dry
vacuum procedures removed more material than the rain events and the
mechanical street cleaning  equipment.

     Table E-l summarizes the results  of these tests. The initial street
surface loads varied  over a wide  range of conditions (from 100 to 1500
Ibs/curb-mile, or 28  to 430 g/curb-meter). Tests were also conducted with wet
and dry street surface  moisture  conditions and on streets having good to
moderately rough textures.  The first dry vacuum sample collected about 40 to
85 percent of the total absolute  street, surface load. The percent recovery
was slightly better for the higher  street surface loads and somewhat less for
the more damp street  surfaces. The  sample recovery  with the first dry vacuum
pass was much greater for the larger particle sizes than for the smaller
                                     428

-------
Table E-l SAMPLING EFFECTIVENESS TEST RESULTS
                           Percent of  absolute  street  loading
date
9/5/80
1/16/81
3/15/81
4/16/81
7/29/81
1/2S/82
2/3/82
7/29/80
2/3/81
3/24/81
7/24/81
1/20/82
1/29/82
2/4/82
total
removed by
solir's total
test street street loading solids
area moisture texture (Ib/curb-mi) (%)
Surrey
Downs
dry
wet
dry
dry
wet
wet
Lake
Hills dry
dry
wet
dry
wet
wet
wet

smooth
smooth
smooth
si . rough
si. rough
smooth
si. rough
smooth
smooth
si. rough
si . rough
smooth
smooth
534
451
223
419
1460
432
400
13/u
117
225
171
1080
297
551
75%
79
69
64
72
69
53
85
42
46
77
48
74
54
COD
59%
84
51
44
72
23
26
80
35
37
80
51
64
34
TKN
85%
58
37
41
53
20
19
93
29
17
71
50
49
34
first dry vacuuming
T Phos
47%
57
39
41
40
53
47
81
37
29
61
60
:-7
34
Leaa
50%
57
45
41
61
38
18
64
34
23
67
39
43
23
Remain ing
total solids
loading
Zinc (Ib/curb-rri )
57%
54
40
36
61
37
32
69
30
23
66
46
47
25
134
95
136
151
409
133
188
206
"9
122
39
562
77
253

-------
I'.irt K. lc si.'.rs.  Almost  all  ru  the Lir>;iT material was remo.cd with the first
v.iruuni pass,  hut  smaller  fractions of  the finer material were removed. This
u;  and  one  wet  to  remove more  than 90 pel:ent of the different
,ml lut.ir.Ls  trom  the  street  surface.

     Tabh>  K-l  also  shows  the  total  solids remaining on the street surface
alter a single  dry  vacuuming.  These  remaining loading values correspond to
tl.c particulate  material  that  was traced within the texture of thf street
surface. It  is  obvious  that the sampling equipment was more effective than
the rains and  tic  street  cleaning equipment in removing street surface
pa^ticulates:  at  no  time  was the street surface loading undetectable. The
lowest measured  street  surface loadings during this study was about 100
Ibs/curb-mile  (28  p./curb-meter). The highest observed street surface loading
values were  about  1500  Ibs/curb-mile (430 g/curb-tneter), with typical values
around 400  Ibs/curb-mile  (110  g/curb-meter). These values represent the
particulate  loadings  above  the non-recoverable loadings. The unrecovered base
particulate  loading  values  shown in  Table E-l can be considered as a
measuring datum  that  changes for different conditions.

     These  tests  were  extremely time consuming to conduct; or.ly 14 tests were
conducted throughout  the  program period, representing different conditions.
The most important  conditions  affectirg sampling efficiency were assumed to
be street moisture  and  texcure conditions. These two factors were considered
in a two-level  factorial  analysis. The  14 data points corresponding to
remaining total  solid  loadings on the  street were separated into four
categories  corresponding  to the four possible street moisture/texture
conditions.  A  factorial analysis was then conducted to determine if either or
both of these  factors were  important in determining the residual loading
value. The  calculations showed that  the street texture was the most important
factor, with  street  moisture being of  less importance. The calculated loading
values for  smooth  textured  streets were about 1?5 Ibs/curb-mile (38
g/curb-meter) while  it  was  about twice  this value (270 Ibs/curb-mile, or 76
g/curb-metar)  for  rough-textured streets. The variations for the loadings due
to street textures  depended on the texture conditions. The variation was
quite small  for  the  smooth  streets (about 65 Ibs/curb-mile, or 18
g/curb-meter) while  it  was  much greater for the rough-textured streets (about
200 Ibs/curb-mili,  or 580 g/curb-meter). These variations were large because
the sampling effectiveness  studies were conducted for a variety of separate
test and street  conditions. These were  all small area tests and do not
consider average  conditions which actually occurred in the large-scale
sampling prograns.

     It is  expected  that  the datum levels slowly fluctuated when averaged
throughout  tie whole  study  basins. The  expected fluctuation of the datum is
estimated to be  about  ten or 15 percent in each sampling period,   •>ll within
the 25 percent  sampling error  based  upon the variations in observed loadings.
Most of the  analyses  considered relative changes in street surface loadings
(comparing  the  initial  to residual loads for street cleaning and rainfall
events and  the  change  in  street surface loading values witl time).
                                     430

-------
     Tho loading values r>* a .mi red (luring  this  study  are  considered reasonable
when ccnp.-ired with the loadings observed  at other  locations, is described in
Section 1.  Because the major variation was  associated  with the constant
street textures, sampling efficiency  corrections were  not necessary. If there
was a large fluctuation in sampliii;  effectiveness  associated with season,
then it nay have been worthwhile to   orrect the  street  surface loading values
to absolute conditions. However, thif would have required many tnore sampling
effectiveness tests. Again, the datum variation  was  less  than the sampling
errors associated with the number of  subsamples  obtained. Therefore, the
sampling procedures were quite  appropriate  when  considered with the other
errors in the sampling program. The selected  sampling  procedures are
sensitive to variations in loadings over  large  test  areas which are much
larger tnan the residual loading variations.
Equipment Description

     A pick-up truck was used to carry  the  equipment  components, consisting
of a generator, tools, fire extinguisher, vacuum hose and wand, and two
wet-dry vacuum units during sample collection.  The  truck had varning lights,
including a roof-top flasher unit. It operated  with its headlights and
warning lights on during the entire  period  of  sample  collection. The sampler
and hose tender both wore orange, nigh  visibility vests. Both the truck and
the street cleaner used to clean the  test areas were  equipped with radios
(city KM radios), so that the sampling  team could contact the street cleaner
operator when necessary.

     Two industrial vacuum cleaners  (2-hp,  or  1.5 kilowatts, each) with one
secondary filter and a primary dacron filter bag were used. The vacuum units
were heavy duty and made of stainless steel to  reduce contamination of the
samples. The two 2-hp (1.5 kilowatt)  vacuums were used together by using a
wye connector at the end of the hose. This  combination extended the useful
length of the 1,5 inch (38 mm) hose  to  35 feet  (11  meters) and increased the
suction. A wand and a <^ulper attachment were also used. The generator used to
power the vacuum units was of sufficient power  (3600  watt, heavy duty,
low-RPM) to handle the electrical current load  drawn  by the vacuun units. The
gulper attached to the end of the wand, was triangular in shape and about six
inches (150 mm) across.
Sampling Procedure

     Because the street surfaces  were  more  likely to be dry during daylight
hours (necessary for good sample   collection),  collection did not begin
before sunrise nor continue  after sunset,  unless additional personnel were
available for traffic control.  Two people  were  required for sampling at all
times: one acting as the sampler, the  other acting as the vacuum hose tender
and traffic controller. This  lessened  individual responsibility and enabled
both persons to be more aware of  traffic conditions.

     Before each day of sampling, the  equipment was checked to siake sure that
the generator's oil and gasoline  levels  were adequate, and that the vacuum

                                     431

-------
hose, wand and gulper  were  
-------
the subsample strip, thfi sampler loosened  it  by  scraping a shoe along the
subs.imple path (being certain that  street  construction material was not
removed from the subsample path unless  it  was  very loose). Scraping caked-on
mud was done after an initial vacuum  pass.  After scraping was completed, the
strip was revacuumed. A rough street  surface  was sampled most easily by
pulling (not pushing) the wand and  gulper  toward the curb. Smooth and busy
streets were usually sampled with a pushing action.

     An important aspect of the sample  collection was the speed at which the
g-ilper was moved across the street. A very  rapid movement significantly
decreased the amount of material collected; too  slow a movement required more
time than was necessary. The correct  movement  rate depended on the roughness
of the street and the amount of material on it.  When sampling a street that
had a heavy loading of particulates,  or a  rough  surface, tho wand was pulled
at a velocity of less than one foot (0.3 meter)  per  second. In areas of lower
loading and smoother streets, the wand was  pushed at a velocity of two to
three feet (0.6 to 0,9 meter) per second.  The  best indication of the correct
collection speed was given by visually  examining how well the street was
being cleaned in the sampling strip and by  listening to the collected
material rattle up the wand and through the vacuum hose. The objective was to
remove everything that was lying on the street  that  could be removed by a
significant rainstorm. It was quite common  to  leave  a visually cleaner strip
on the street where the subsample was collected, even on streets that
appeared to be clean.

     In all cases of subsample collection,  the  sampler and hose tender
continuously watched for oncoming vehicles. While working near the curb out
of the traffic lane (typically an area  of  high  loadings), the sampler
visually monitored the performance  of the  vacuum sampler. In the street, he
constantly watched traffic and monitored the  collection process by listening
to particles moving up the wand. A  large break  in traffic was required to
collect dust and dirt from street cracks in the  traffic lanes, because the
sampler had to watch the gulper to  make sure  that all of the loose material
in the cracks was removed.

     The hose tender also always watched for  traffic. In addition, he played
out hose to the sampler as needed and kept  the  hose  as straight as possible
to prevent kinking. If a kink developed, sampling stopped until the hose
tender straightened the hose.

     When moving from one subsample location  to  another, the hose, wand and
guiper were securely placed in the  truck.  The  hose was placed away from the
generator's hot muffler to prevent  hose damage.  The  generator and vacuum
units were left on and in the truck during  the  entire subsample collection
period. This helped dry damp samples  and reduced the strain on the vacuum and
generator motors.

     The length of time it took to  collect  the  subsample varied with the
number of subsamples and the test area. For the  first phase of this study,
the test areas required the following sampling  effort:
                                     433

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Th-M' AKFA                           N,j.  Of.-     SAMPLING
                                    SAMPLES    PERIOD
Surrey Downs - tn Un  basin           lb         0.5-1.0 hr.
fair-good asphalt, concrete
gutters

Surrey Downs - lUSth  Ave.            9             0.5 hr.
poor asphalt, no  curbs

Surrey Downs - Westwood  Homes  Rd.   \'i             0.5 hr.
good asphalt

Lake Hills                          60           2-2.5 hr.
fair-good asphalt
In the Surrey Downs  main  basin and on 108th Avenue, two curb-to-curb passes
were made at each  of  the  16  sampling locations due to relatively low
particulate loadings.  In  Lake Hills, subsamples were collected by a half pass
(from the crown  to  the  curb  of the street). Tb^.se modifications were
necessary because  several hundred grams of sample material were needed for
the laboratory tests  and  1:00 much sample is difficult to sieve. An after
street cleaning  subsample was not collected from exactly the same location as
the before street  cleaning subsample (taken from the same general area), but
at least a few feet  (one  neter) apart.

     A field-data  record  sheet kept for each sample contained:
     o Subsample numbers
     o Dates and time  of  the collection period
     o Any unusual  conditions or sampling techniques.
A tally of subsample  locations where the street cleaner was unable to operate
next to the curb because  of  parked vehicles was kept, allowing analysis of
the effect of parked  cars on street cleaning performance.
Sample Transfer

     After all subsamples  for  a test area were collected, the hose and wye
connection were cleaned  if  necessary.  The translucent hose allowed visual
inspection for trapped material or excessive dirt in the hose.

     The vacuums were either  emptied at the last station or at a more
convenient location. To  en:pty  the vacuums, the top motor units were removed
and placed out of  the way  of  traffic.  The vacuum units were then disconnected
and lifted out of  the truck.  The secondary, coarse vacuum filters were
removed from the vacuum  can and were carefully brushed with a small whisk
broom into a-plastic bucket.  The primary dacron filter bags were kept in the
vacuum can and shaken carefully to knock off most of the filtered material.
The hose inlet was blocked  with a leg  or knee, and the primary filter bag was
held onto the vacuum drum with arms and chest. The dust inside the can was
allowed to settle  for a  rew minutes, then the primary filter was removed and
brushed carefully  into the  sample can  with the whisk broom. Any dirt from the


                                     434

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Cop part of the bwg where it was bent over  the  top  of  the vacuum was also
carefully removed and placed into the sample  jar.

     After the filters were removed and  cleaned,  one  person picked up the
vacuum can and poured it into the bucket, while  the other person carefully
brushed the inside of the vacuum can with a soft  three- to four-inch (76 to
H>2 mm) paint brush to remove the collected sample. In order to prevent
excessive dust losses, the emptying and  brushing  was  done in areas protected
from the wind. To prevent inhaling the sample dust, both the sampler and the
hose tender wore mouth and nose dust filters  while  removing the samples from
the vacuums. Samples were then transferred  to one quart (0.9 liter) Mason
jars for storage until analysis.

     To reassemble the vacuum cans, the  primary  dacron filter bag was
inserted into the top of the vacuum can  with  the  filters'  elastic edge bent
over the top of the can. The secondary,  coarse  filter  was placed into the can
and reassembled on the truck. The motor  heads were  then carefully replaced on
the vacuum cans, making sure that the filters were  on  correctly and the extra
electrical cord was wrapped around the handles  of the  vacuum units. The
vacuum hoses and wand were attached so that the  unit  was ready for the next
sample collection.

     The storage jars were labeled with  the date, the  test area's name, and
an indication of whether the sample was  taken before  or after the street
cleaning test or if it was an accumulation  (or  other  type of) sample.
Finally, the sample jars were transported to  the  laboratory for logging-in
and analysis or storage.
Variability Test Procedures

     Variability tests were conducted seasonally  in  each  test area to
determine how many subsample locations were necessary  to  collect  a suitable
representative sample. About 50 individual locations were sampled in each
test basin during each of four variability test phases. The first test phase
data were eliminated because the samples were  collected using the initial
sampling equipment that was later replaced; and because the samples wt..
biased by sand applications on the roads due to an unusual snowstorm. The
individual samples were weighed and their variabilities were calculated.  The
formula used to determine the number of subsamples needed is as follows:

           2  2
     N = 4sVl/

where:

     N = number of subsamples needed
     s = standard deviation
     L = allowable error

This formula was used to balance the sampling  effort for  the different test
phases and for each test basin. In most cases,  an allowable error of about 25


                                     435

-------
p.'roMiL ot the b.iniple  mo .in  vai.ic  resulted in a reasonable sampling effort.
The samples h.id  to  be  obtained  in a relatively short period of tlme
(.pii'UT.ih] y within  about  two  hours).  This allowed samples to be collected
immediately before  and  after  each street cleanirg operation. Because of the
freqvent  rains in  the  Bellevue  area,  a short sampling time was also needed  to
prevent samples  from  being  rejected frequently due to rain interferences.

     These samples  also enabled various portions of the watershed to be
compared  with each  other.  Bellevue street cleaning equipment could not
operate on 108 th Avenue and Westwood  Homes Road in the Surrey Downs basin
because, of streets  and  gutters  in poor condition or private ownership.
Therefore, the Surrey  Downs basin had to be subdivided into these three
subsections, each  requiring individual sampling. No major loading vari.'j lions
were found in the  Lake  Hills  area.

     A single vacuum  was  used to  collect the experimental design, \d.th each
sample consisting  of  one  curb-to-curb pass. The samples were then emptied
from the  vacuum  canister  into a bucket lined with a plastic bag. The bag was
then wired shut, labelled  and stored  for liter weighing in the laboratory.
Information describing  each subsample location was also obtained. This
information included  the  sampling date and location, the presence and type  of
gutters,  the street condition,  slope, and width, the parking density, and the
traffic density  and speed.  Information concerning the adjacent area was also
obtained. This included the landscaping practices adjacent to the street, the
presence  of leaves  on  the  street, and the adj:cent land-use (socio-economic
condition, single-  or  multiple-residential family units, commercial areas,
vacant lots, schools,  churches, or other areas). Each information sheet also
included  the. individual sample  loadings expressed in Ibs/curb-mile. This
information is discussed  in Section 7.
DRIVING LANE TEST

     Periodic street  surface  particulate samples were collected from only  the
driving lanes immediately  after a collection of a regular full street-width
sample. These samples  were collected from the center lane of the street to
the edge of the parking  lane.  These samples were processed in a similar
manner as the regular  street  surface particulate samples but no chemical
analyses were performed. These samples,  which were collected several times
during the second  project  year, helped determine the presence of street
surface particulates  available for street cleaning. The data can also be used
to indicate the importance of  parked cars and necessary parking controls for
street cleaning improvements.
ACROSS THE STREET TESTS

     Several special  tests  were  conducted to determine the redistribution  of
street surface particulates across  the street during street cleaning
operations. T>o adjacent  sections  of street, about ten feet (3 meters) along
the curb, were selected  for each test. Several strips parallel to the curb
were marked in each section.  Each  strip in one section (the furthest in  the

                                     436

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direct'-n of travel) was individually sampled  prior  to  street cleaning. After
the sampling was completed, the street  clo.aner  made  a  single pass over both
of the sections. The street cleaner started  about  one  block up the street to
eliminate startup effects and broom streakings.  After  ;he street dried off,
the strips in the other section were then  individually  sampled.  The
corresponding sample weights in strips  in  both  sections  were compared to
determine how much of the material was  removed  by  the  street cleaner or
pushed out into the middle of the street and not  removed. The samples were
analyzed in a manner similar to the other  street  surface particulate samples,
but no chemical analyses were conducted.
CATCHBASIN INVENTORY ANU SAMPLING

     All catchbasins, manholes, and inlets were  inventoried  by the Bellevue
survey crew at the beginning of the project.  Recorded  information included
catchbasin number, elevations (top of grate,  bottom  of  catchment, and all
pipe inverts), size, type, and length of each pipe.  The Survey Division then
mapped the drainage systems.

     The first sediment inventory was conducted  during  December,  1979. At
that time, the catchbasin dimensions were measured.  The sediment  depth was
measured by pushing a tape measure or a measuring  stick into the  sediment
until it hit the bottom of the catchbasin, A  second  sediment inventory during
July and August, 1980, was also conducted. The procedure was changed when it
was discovered that a rock may be struck on occasion instead of the bottom of
the catchbasin, resulting in a false depth value.  The  final  measurements were
made from the top of the grate to the top of  the sediment; a simple
measuiement that did not require lifting the  grate.  The catchbasin depth was
known and the sedimc-nt depth was then calculated.  Pipe  sediment and standing
water were also observed through the grate.

     The sediment inventory was conducted about  twice  yearly during the
project. Spot checks were also made in about  ten percent of  the catchbasins
after several significant rains.

     Sediment samples were also taken during  the inventories.  Five
catchbasins and five pipe sediment samples were  taken  in each  area during
each sampling. Samples were originally obtained  using  a scooper,  pouring
excess water off before transferring to a sample container.  Finally they were
obtained with a coring device. Excess water was  pumped  out of  the top of the
corer before pulling the sample out. Usually  three to  five cores  were taken
in various spots in each catchbadin sampled in order to obtain enough sample.
Pipe sediment samples were also scooped or scraped out  of the  pipe. Samples
were weighed, dried, and sieved into size fractions. Some of the  sample
fractions were then combined into three samples  for  chemical analyses: <63
microns, 63-500 microns, >500 microns.

     Ten sediment and ten supernatant samples were taken from each study area
in February, 1980, and another five sediment  samples were taken from each
area in March, 1980, for chemical analysis (Total  Solids, Chemical Oxygen
Demand, Kjeldahl Nitrogen, Total Phosphorus,  Lead, and  Zinc).


                                     437

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                                   APPENDIX F
               STREET  DIRT  SAMPLE  PREPARATION AND DATA HANDLING
INTRODUCTION
     This appendix  summarizes  the street  surface particulate handling
procedures used  in  Bellevue.  These procedurp^  w.=re used after the samples
were collected and  before  Lhey are sent  to the laboratory for analysis.  This
appendix also briefly  describes  the preliminary calculations and organization
of the data needed  before  detailed data  analysis.  Recommended procedures for
obtaining street  surface  particulate samples were  described in Appendix E.
Originally, these techniques  were described in the report "Demonstration of
Nonpoint Pollution  Abatement  Through Improved  Street Cleaning Practices"
(Pitt, EPA-600-2/79-161,  U.S.  Environmental Protection Agency, August 1979).
Modifications of  these  techniques for the Bellevue Urban Runoff project  have
been discussed and  approved by EPA project officers during field visits. The
scope of this appendix  is  limited to the  discussion of the day to day sample
handling practices  necessary  to  prepare  the samples for subsequent laboratory
analysis.
SAMPLE DESCRIPTION

     Specific information  collection tecuniques  were employed for consistency
and proven ease of data  collection.  Table F-l is an example of a checksheet
that can be used during  the  experimental design  of street surface sampling
activities. These activities  require about 50 to 100 individual street
surface sampling strips  to be  cleaned.  All of the samples are then
individually weighed. This results  in STL indication of street surface
particulate loading variations  over  the study area. The characteristics on
this checksheet are noted  for  each  individual sample and are stored for
future reference. This information  is extremely  useful in determining the
causes for extreme loading values  observed at any specific sampling location.
The information in Table F-l  can  then be summarized on a percentage basis to
describe the specific test area characteristics. The most important test area
characteristics include  the  street  surface and curb-street interface
conditions.
INFORMATION TO BE NOTED  DURING  STREET  CLEANING OPERATIONS AND SAMPLE
COLLECTION

     It is Important  that  the street  cleaning equipment operator fill out a
simple form every time the  test  areas  are  cleaned.  Table F-2 is an example of
a form that is used to confirm  street  cleaning activities and to note unusual

                                     438

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        -l.   SAMPLE  AREA DESCRIPTION
 STUDT AREA:

 LOCATION:

 MTZ:

 FHOTO KUXBKR:
                   H 'I Aci I <-  \
                    M
 SAXPLZ INTOIXATIOS:
      I.D. Number:
      Weight* (grami):
      Loading* (Ib/curb-aile):

 GUTTERS:
      Number:         1 , (5> 3 ,
      Type:
      Shape:
      Mediae  atrip:
 STREET:                    	-_
      Material:     e oner gt_t^Cji phi It-^othtrt
      Condition:    poorfjTijO tood
      Vidth:        <  20  ft^20_iojl>''11,  >  40  ft

 CURB/STREET  INTERFACE:
      Condition:   poor , (ฃfif)  gi^od
CDtB T7PE (at
                        locition):   rolled,
      Type:   paved  drivevay,  dirt  driveway,  corner,
             curb fซT, other**

 TRAJFIC:
      Deniity:         dihi^ coderate, heavy
      Average Speed:   < 25 aph,
 PAJIKING:
     Deniity:  none,1

 SDRSOUND1NG AREA:
     Land uae type:
                                   to  40  nph),  >  40 ปph
                                  	.	

                            >oderate,  heavy


                               lov  incoae/old/alnjle fanily
                               mediun incoae/nev/ainglt fanily
                               *>-ltiple family
                               cotonercial
                               vacant land
                               •chooli
                               other**
               g vegetation:
     Vegetation dentity:
     Leavec on atreet:
     Topography:
                              deciduoua
                              •parte
                              tparat,
other:
AJIEA ADJACENT TO CURJ XKD SIDEWALK:
     Surface type: (""graa>>
                    paved
                    unimproved (dirt, rocka)
                    other:

COMMENTS:
 *Tbia information ia to be recorded after laboratory analyaea have
  been conducted.
                       439

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  l'U.- K-2. INFORMATION  FOR  STREET CLEANING TESTS
 STODT

 DATE:
 EQDIPKEN7:                         .
      Onit  nanber or nซoe :      V^.O X3 M  A  3
      Adjusted  ti ijecified _
      for  thiซ  tut:      (Teip no , other*
 TIKE:
      Stซrt  of  teit:
      End  of  test:         /
 HOPPER  CONTENT:
      Impty  before teft? CjeT)  no> "'her*
      Estimated volume or weight
      ปfter  test:  	V 2—	(JuT ydซ6y poundi

 COMMENTS:**
OPERATORS SIGNATURE:
 •Explain "other" under COMMENTS

"Note ซny unutuil condition* (e.g., vind, rปin, cooitruction, ftreet
  •Ltintenance,  tpilli)
                        440

-------
conditions. The important parameters are  the dates  and  times of street
cleaning and an indication of weather conditions  that may_jadversely affect
the street cleaning operation.                      V

      Similarly, the street surface partirulate  sampling  crew must also fill
out a simple form for each sample collected. Table  F-3  is an example form
which notes the important information necessary  to  resolve future likely
disputes and inconsistencies with times,  dates,  weights and sample numbers.
The time at the start of the collection and at  the  end  of the collection is
noted. Subsamples collected where the street cleaner was  unable to operate
next to the curb were noted on the sampler log.  This results in an indication
of the parked car densities in the study  area.

     When the samples are transferred from the  vacuum collection equipment to
the storage canisters, the date and test  area is  written  on the can, along
with the type of sample. When the sample  is returned to the laboratory, each
sample is given an identification number  which  is also  written on the can and
on the sample checklist.
PHYSICAL ANALYSIS

     The sample description information written  on  the  test area sample
checklist at che laboratory is also noted on  a sample  inventory sheet. Table
F-4 is an example of this sheet and shows the chronological inventorying of
each sample immediately after collection. The samples  are then prepared for
particle size and chemical analysis.

     Most street surface samples are quite  dry and  do  not experience chemical
or biological degradation, over short storage periods,  of the constituents
typically monitored. In many cases, street  surface  particulates can lie
exposed on the road surface for up to three months  before rains wash them
into the receiving waters. During this time,  they may  be  intermittently
moistened and subjected to a wide range of  temperatures.  Although the
laboratory storage times should be kept to  a  minimum,  they are likely to be
several months long due to the necessity of compositing samples over testing
time periods, as described later in this section.

     For physical analysis, the samples are transferred from their storage
containers to well-labelled drying pans. These pans are then placed in a low
temperature drying oven for several hours at  70-75  degrees F (21-24 degrees
C). Again, this heating does not typically  affect the  chemical
characteristics of the samples, except for  the more volatile phosphorus and
mercury compounds that may be analyzed in street surface  particulates. If,
through special tests, appreciable quantities of certain  constituents of
importance are lost during sample drying, then subsampling of the complete
sample mixture for analysis for those specific compounds  may be necessary.
However, because of the heterogeneity of the  street surface particulates,
obtaining a representative subsample from the whole sample is extremely
difficult and can introduce significant errors.  Table  F-5 is an example of
the data form used when drying the samples. The  gross  and net weights of the
samples are noted and the percent moisture  is  calculated. Again, this


                                     441

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           !> . STREET SAMPLING CHECKLIST  (for  use  during
              field  program)
SAX7LE:
     I.D.  nuaiber:	                                     __
     Type:     before  itreet cleaned, after  afreet cleaned,C^ccvปuia:ion_J^)

STUDY AJL1A:
                   H
 DATE:

 TIME:
                -3:
      At itart  of  aampling:
      At end of sampling:
 SDB-SAKPLE
 SHIP TALLY:
              Jf
              tti
             ITS
             if
                         ** 5
                         -W5
                         XT
                                                     Check off the
                                                     ouabert a> tbe
                                                     atrip lanplei
                                                     are  collected
                                                     (tach itrip ia
                                                     aaiuaed to be
                                                     located betveen
                                                     the  curb and the
                                                     center line; i.e.
                                                     half itripi).
                                                     riaj location!
                                                     where parked
                                                     cara interfered.
 PAMINC  INTERf ERฃNCE:
     Totjl number of ftrip
       (*nplei collected:
     Stripi vherc parked
       cปrป interfered:
     Parked car dentity
       (percent):
SAMPLE WEIGHTS:*
     Croat vet veight  (grami):
     Tare veight (grtau):
     Mtt vet veight (graaa):
                                  115V
COMXENTS:
SAMPLING TEAM KEMEHS:
*Thia information  ia to be recorded after laboratory analyiea have been
 conducted.
                          442

-------
P-4.SAMPLE INVENTORY SHEET
SAMPLE
ID
NUMBER
>\9
5-?o
A-91
S^l
S-rz.
S-4n




DATE
COLLECTED
inl&o
3/k
3/(*
3/| •*-
3/14
3//4




TIME
COLLECTED
0^30 -?
0^30
0?CrO->
09trD
0^3O^
/ 0^-0
osiro-j
0^ 6^0
0^30-^
O?30
I(J-LTO^
I03o




STUDY
AREA
!Mi4A.U>
VvM^aW
\0\M*-y
W\'d i k
WN'cloW
Ufpty




NET WET
WEIGHT CT
UN ',EIVED
SAMPLE
(graai)
nw5.
1^3
3^0
inr
IZgD
n>r




COMMENTS
Vz 5 V^
tl
II
I/
II
'/




                          443

-------
      r-  .MOISTURE CONTENT DATA S11EET
  SAMPLE
    ID
  NUMBER
DRYING
 PAN
NUMBER
 TARE
WEIGHT
CROSS
 WET
WEIGHT
(grtmi)
CROSS
 DRY
WEIGHT
(gruni)
 NET
 WET
WEIGHT
 NET
 DRT
WEIGHT
MOISTURE
 CONTENT
(perctat
  A
             5"
         A?
  ฃ-30
   A  3
                              2-9
                                              S-34-
                                           730
                                     )o/4
                                                    L
                    I, SI
                                                    z
Noce:   d  - b  - •ป

       e  • c  -  ซ
            d  •• c
         -  	  x ioor
              d
                                444

-------
complete information must be noted  for each  sample  in order to resolve
problems Lh.it may later occur due  to misplacing  or  mislabelling samples.

     After adequate drying, the samples  are  passed  through a set of
mechanical, stainless steel sieves  for size  separation.  The sieve sizes being
used are b3, 125, 250, 500, 1,000,  2,000 microns, and I/A  inch C.6,370
microns).  If the sample contains  large amounts of coarse material it may h?
necessary  tc pass the sample through a I/A inch  (6,370 micron) coarse sieve
made of hardware cloth attached to  a wooden  (25  by  100 mm) frame, about two
feet (600 mm) square. Samples less  than  63 microns  are retained on the pan on
the bottom of the sieve stack. Table F-6 is  a worksheet  showing the
calculations for this sieve analysis. The gross  weight of  each sieve plus
associated retained sample is noted along with the  tare  weight of the sieve.
A top loading precision balance is  required  for  the  weighing.  The net dry
weight of  this sample is then shown and  totaled. The percentage of sample in
each eize  fraction is also calculated and presented  on this sheet along with
the pounds per curb—mile (or g/curb-meter) loading  factor  (the calculation
for this will be described later).  It is important  to note that detailed
sample descriptions are presented  on this sheet. Specifical1y, the sample
number, date and test area are written in along  with the total net raw sample
weight as  shown on the initial sample inventory  sheet. This weight is then
compared with the total net weight  for the sample.  The net raw wet weight is
not as precise as the total of the  sieved dry weights (because of the sample
drying and different scales typically used)  but  there should  usually be less
than a five percent difference. If  a large discrepancy exists  between these
two weight values, then the sample  should be rechecked by  observing the notes
from the sample drying, inventory  and test area  checksheet along with any
other information available. In addition, the percent sample  should add up
close to 100 percent.
CALCULATION OF STREET LOADING VALUES

     The calculation to convert the quantity  of  sample  expressed ir, grams to
a representative street loading value expressed  in  pounds  per  curb-mile (or
g/curb-meter) varies, depending upon the sampling technique  and  equipment.

                                                                      The
width cleanr   with each subsample strip is slightly wider  than the gulper
width, beca se of material being drawn into the  sides of  the gulper. The
actual cleaning width can be measured directly on the street when sampling a
moderately dirty street surface.


     A variety of subsampling procedures may  be  necessary  depending upon
special circumstances. At least 200 grams of  sample are necessary for the
mechanical sieving analyses. Therefore, if the streets  to  be sampled are very
clean, then multiple adjacent subsampling strips may be necessary. In other
circumstances, traffic hazards may prohibit sampling from  curb to curb, and
curb to crown subsampling strips may be necessary.  Table  F-7 shows the
equivalent number of full strips for these various  subsampling schemes, along
with the number of subsampling full width strips necessary to  make one


                                    445

-------
       l1 . PARTICLE SUE ANALYSIS DATA SHEIT
STUDY ARF.\:
DA IT SAXFLED:
DATI AJiALYTED:    3  / 3 ฐ
SXKH.E
     ID number :
     Nee r*v weight (grปaป):
- 4

SIEVE
SIZE
(aicront )






) 6370
2000 -ป
1000-ป
5000)
| OTTO
250-^
125-0
63 'i
\T-S"
<63
TOTAL

TARE
WEIGHT
(jrปaซ)





*
0
4%-L
AA1
A-bA
403
3Ti
tt
3>)
—

CROSS
DRY
w E; en T
(graai )




b
•r*
s^^
57J
4ST
Cr 7~J A
/\ "7 ^T
3^
"5^5-
—

NET
DRY
WEIGHT
(grtmi )




c
3>
fo
rz.t
JT)
'0|
5T5
2,0
A
4^

AKOUNT OF
SAXPLE
REMAINING
ON SIEVE
(percent
of total
net dry
weight)
d
?„>
1^*5
^.3
lO^Co
ZIJ
10.4
t\ (. Z
o.
32-r
13-0
z.c
31)

COKXEKT3








y^^V \*ซซs








 •Seซ eqoitioc  1  to  convert  net dry weight per staple  (frซa
-------
; Ic F-7. EQUIVALENT NUMBER  OF FULL STRIPS FOR VARIOUS SUB-SAILING
         SCHEMES
SUBSAMPLING
STRIPS
12 half-strips
3 double-strips
10 half-strips
14 half-strips
16 half-strips
4 double-strips
18 half-strips
20 half-strips
5 double-strips
30 half-strips
40 half-strips
10 double-strips
EQUIVALENT NUMBER
OF FULL (CURfl-TO-CURS STRIPS)
6 full-strips
5 full-strips
7 full-strips
8 full-strips
9 full-strips
10 full-strips
15 full-strips
20 full-strips
50 half-strips
25 full-strips
                               447

-------
curb-null1  (.IK'O  eurb-melers ) .


Sl'MMAKIKS  OF  KAIN  KVF.NIS

     It  is very  important  to  keep careful records of the precipitation events
occurring  during  the  nroject  period. Tables F-8 and F-9 together are an
example  ot a  complete rain record. Table F-8 summarizes the total amount of
rain that  has  occurred  on  each day during the project period. Monthly totals
are also ^hcwn or.  Table F-8.  This table is used to determine the antecedent
dry conditions before any  sample and it also shows the variability of
precipitation  within  storm periods.  Table F-9 presents more detail for each
of the stOirn/3  that occurred  during the sampling program. This summary also
shows which scorms were monitored at the runoff monitoring stations and which
rains are  considered  significant.

     A signalicant rain event  is one that is capable of removing most
(greater than  9C  percent)  of  the street surface particulates from the street.
Some of  the smaller significant rains, however, may not be capable of totally
moving all of  the  street  surface particulates through the storm sewerage
system and into  the receiving  waters. A storm of about 0.2 inch (5 mm) total
(occurring over  several hours  and during periods of moderate to heavy
traffic) can  move  most  of  the  street surface particulates from the street and
into the drainage  system.  Therefore, rains of this magnitude, or greater, are
typically  considered  significant. If the street surface material is very
coarse,  caked  with large  quantities  of debris (mud or leaves), or in very
poor condition,  a  much  greater quantity of rain may be necessary. In
addition,  if  the  rains  occur  at nighttime, or at other periods of very low
traffic  activity,  then  more  rain would be necessary to remove most of the
street surface oarticulates.  Traffic volume is an important consideration
because  of the ability  of  the  vehicles to loosen particulates from the road
surface. The  rain  then  only  has to transport material to the curb and along
the curb to the  storm drainage inlet. The smaller rains, however, are
probably not  sufficient to move the  material through the stonn drainage
system into the  receiving  water. Therefore, this particulate material would
accumulate in  the  sewerage system to be flushed out by later larger storms.
Storms of  about  0.5 inch  (13 mm) total, occurring within several hours, are
usually  capable  of removing  all of the street surface material and moving it
all the way through the storm  sewerage system and into the receiving water,
irrespective  of  traffic conditions.  However, larger rains cm result in
significant erosion yields from the  surrounding land areas. This erosion
material is washed onto the  street surfaces and into the stonn sewerage
system.  In some  cases,  the street surface loadings after storms can be
greater  than  the  loadings  before storms, because of this erosion. In areas of
the semi-arid west, rains  of about one inch (25 mm) or more, can create much
greater erosion yields  for many constituents in urban areas than the street
surface  runoff yields.  However; in areas of the Midwest, much greater rain
quantities are necessary before significant erosion yields contribute to the
urban runoff  flow.

     Table F-9 also shows  the  time of the beginning and the ending of the
rain event. These  values are compared to the times of beginning and ending of


                                     448

-------
r,iLlc  K- 8. DAILY RAIN RECORD SUMMARY
           WATER YLUl
RAIN GAUGE:
5cW? I.
DAY
1
2
1
it
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
TOTAL
OCT
l4ft>

















air
O.S4
0.07.




I.U?
0.0 1



O-OT
ฃ>Br>|
234
NOV
A4SO

0-01
r-sz.
D.r>)
o.oT-


o*o~3
(0-0"?-





0-JK
o-OT


0-4 I


O-T.-L
o^lO








?ซ•ป/
DEC
\qงo


















0.44
0.13


I- 5*7
Mc
o^?-




o,2r
Cปt3-
W\
JA>ป
^91
0> 0\
o-o i


o.oi


0.dT
<9
Oฃ>\
Q.Ol


fc.tT
MON
MAR
H8I

o=23
0.05"
0-?ฃ-
o-r^-
o-?q




n-oi


a 03
o.oi





OoOl



0ปl^


O"0(



IcSJ
TH
APR
11^1



0.30
CP.^f














oป\ 1
0C01
0ป\^









lป4sr
MAY
H?l




0-cz
O-oc
5.oA
0.03.






o-oi
















O.IS
JUN
>^ซl


















CaOl












Ood
JUL
!
-------
        F-o. SUMMARY OF RAIN EVENTS DURING  FIELD ACTIVITIES  ***
DAT!
RAIN
1ECXK
a^-Vff
\-t-t\r
H /H
\fl/?i
^*





TIKI
SUIN
JECAJI
os3o
D^'S"
0^30
oiy)
war





DATt
LAIN
IKDED
H,'l>
\Viy
^A-|
^T
V.'S





TIKE
IAIN
1KDED
V?lTO
T^JO
cM*r
-2-3 iy
\T^r





DDJUTIO)!
(bcurt)
\T-5-~
t5~^
0.3
\A.Sr
t -0





TOTAL
mcip-
TTATIOK
(iochci)
€><^
6. or
0.0)
0.34
U-Z4





ATZRjkCI
irrmsiTT
(inc'dti/
hour)
o, o3
e>0cro3
o ปoi
0^ OT_
Oo-L|





rixx
IKTIHSITT
(incbti/
hour)
0. \ A
o, 03
o.oi
0005-
0^40


.


UAS TEE
I7TKT
XOIIITOLED*
(jPtt/Do)
r
^
/j
r
A-1





WAS TIE
mrr
ticNin-
OUTT"
(ytซ/no
y
/y
A^
/
Y





•"Monitored" requirti  <11  raio ซnd runoff Beซซurrปento bttvttn ซdjปcซnt icttit >urf*cซ iปplซi.
 TIic tiปe iloci the  r*in toded mnd the "ซfter" itrett lurfact scaplt ihould  b* Itn tbซo onซ
 d*7, in ซoปt
**"Siinif irซnt" ••  dtfintd in the tizt.

*"ME*ch nin  ~ITซDC"  iซ i*pซrปtซd by at ltปt  6  hour* of no precipitation.  Several adjacent
 rain tTenti  ar* uซuซllj grouped togtther to *ake a coaplct* aonitortd  *di ;ซ ปซt".  See tbe
 aboTe definition of  tbe "monitored" criteria  tbat define* a complete data  act.
                                           450

-------
runoff to obtain lag values and are necessary  in  order  to  calculate the
accumulation periods for street surface: samples  taken  near a rain event.
VKLPAKAT10N OF LOADING SUMMARIES

     Simple summary forms are necessary  to  display  the  straet surface loading
results for accumulation and test samples.  Tables F-10  and  F-ll are examples
of completed summary forms. Table F-10 shows  the  size distribution and
loadings for a street surface accumulation  sample.  Information shown on this
table include a complete sample description along with  the  climatic
conditions during the time of sampling and  for  the  last rain event. The
median particle size is also shown or; this  table. Table F-1J  is similar, but
a pair of street cleaning test samples are  presented  side  by side with the
loading en fference calculated and expressed as  the  street  cleaning
effectiveness. The amount removed, expressed  in pounds  per  curb-mile (or
g/curb-meter) is stressed, brt the percentage  removed of the before loading
is also presented as a normalized value. The  times  of street cleaning and
sampling are also shown on these forms in order to  calculate accumulation
periods and to confirm the test scheduling.
SAMPLE COMPOSITING FOR CHEMICAL ANALYSIS

     Before any additional preliminary  calculations  of  street surface
particulate characteristics are possible,  chemical  laboratory analyses must
also be performed. The most cost effective  procedure is to physically
composite similar samples before chemical  analysis.  After mechanical sieving,
the different particle sizes are stored in  separate  plastic bags or bottles
as appropriate  and replaced in their original  storage  containers.  The
compositing involves combining equal quantities  (typically five or  ten grams)
of each size fraction of all samples collected  in  a  single study area over a
short period of time. Equal quantities  from each bag from the same  particle
size, but different samples, are combined  to obtain  a composite sample
representing a single particle size for all samples  in  the compositing time
period ana test area. Leftover samples  are  replaced  in  the cans and saved.

     Equal sample quantities must be composited  because we are interested in
obtaining a time averaged chemical analysis of  the  material. The time phases
for compositing should be based upon major  seasonal  differences and street
cleaning practices conducted within the areas.  Table F-12 is an example of
how the time periods could be identified.  This  table shows six different time
phases for three different study areas. The time periods range from a short
two weeks for special leaf removal tests up to  six weeks. A total of eight
size ranges, times six time periods, times  three test areas, or 144 samples,
will be prepared for chemical analyses. This will  result in chemical
descriptions of specific particle sizes within  time  and area subunits. It is
much more important to analyze different particle  sizes for the different
chemical constituents than analyzing each  separate  sample. The chemical
concentrations vary substantially within each particle  size. This variation
is shown to be much greater than either seasonal or aerial variations. In
addition, it is very difficult to subsample a complete  sample to obtain a


                                     451

-------
     o  F-io.  STREET  SURFACE  LOADING -  RESULTS  OF TESTS
                    1—CH^&V
STUDY AiEJk:     	

SAKPLE CODE:    	A~ 104

Dl^TE SAKPLED:   	\

TIKE SAKPLED:    I (J
                             Hog
 VZATHES DOKIPG SAKPLIHC:   (TTTFppartly cloudy,  cloudy
                           viody, moderately ซind
 ANTECEDENT CONDITIONS
      Tint tince Ult  ivepc  (d*y>):
      Lซit rain:
          date :
          precipitatioo  (iocbci):
          duiatioo  (boura):
          intซoiity ( iocbci/hour) :
          cine aince  laac raio (dayi):
      Tint lioce lait significant rain  (dayi/:
                                                       . O A
 TOTAL HET CRT UIICHT:
SIEVE
SIZE
(•icrona)





>6370
2000 - 6370
1000 - 2000
500 - 1000
250 - 500
125 - 250
63 - 125
<63
TOTAL
AMOUNT OF
SAKPLE
KEKAININC
ON SIEVE

(jrua )


'2.1-4 f
131. T
xsy. 1
|0^,-1-
A 7-0. •">
Xfcfo.Y
\ t5". lo
A-o-'J-
134(4
(percent of
total ntt
dry veight)
I."?

1**- I
a-.o

if ป9
14-fc
•3.0
,OP,I
AMODKT Of
SAKPLE PASSING
SIEVT. (ptrctot
of total ntt
dry vti(ht)



[(TO. 1
i %-.a
'3~Ir>5~~
(r> ? ป 4
C.1.4

|~5. (^
•3 o U
	
FAtTICLIซ
LOAD IMC DCT
(Ibi |xr
curb ail*)




ir- i

i -^ -3,
^?-/o 1
1/C,

|-3T-
'i-t, ."7-

-------
-p*
U1
oo
STUDY A1U:
LOCATION:
tun innua:
Tin IAWLID:

Ilrซซl cUซ*ซ4:

iqoinoirr OUT tor

1 rซ
1 	 Ov-~*-<
Mook
57 1 (p ( 'f-L-




OU AVD/OI HAMK:


imciotrr COHDITIOIIS:
CvJJ-t~ Tiป .i.e. lot ~ปt U.r.): '
U.i r.i.
..,.: -57(r79-^-
/CnTD ...ci.il.U.. .o
X5"-5"
1Zป3
lb.1
G.4
100, '

AKOOITT Or
futruc rASSMC
SltVl (p.rc.nt
drr w*iibt)
lao-l
IV'1
l/.c.
^r. i
^lol
AS~ปt
Z3.-3
t.4
	
FAITICU
LOADIIIC HT
(Ib. ^r

^-3
s~a.5~~
)OI
5"i*5-
ni
Ko^
n-k
49. t-
"9-^1
NZDIAH MIT1CLI lilt l.icro.. ): '^i.ฐl *^ 	
jLTTta STicrr UAS ctEAnD
UMFLE I.D. mnoEa

AMOOMT OF
SAMPLE
IEMAIII1MC
OM SIEVE
(pซrcซot of
total Mt
dry wซiftht)
I--L
&*L
11.1
6. A
^U>
Z3U0
i^.r
fe.4?
ซ?^-"2-

Amurr or
ujfn.i rtjsiKC
S1IVI (p.rc.nt
Of tOtซt Bซt
4ry ซซi(bt)
9^.-L
9^0
^•4
7^-5-
^/. 1
4^-4
O-t.A
fc.1
. 	
fAITICU
LOAD I 1C DIT
(Ui pซr
t.ik .il<)
S--8-
4.0. k
S5-.1-
30-T-
102
Joป
f/.fc
3^J'
Ate,
KIDUซ FAIT1CLI till (.lcrxป) "Z.S~^- 	
STIECT CUAIIIK
ErrECTlTCMUS
AXOUWT 1LHOTID IT
ITUIT CLJLAKU
(Ib. ^r
ปtl> ซil.)
3.r
136^
4-sr.o
O-T.^
g-9
5^
34
15-. i
•l^o-
of total
ซt 
35-
-z~^~
•JT-
3*-
nOIAI M1TIC1.I III! l.icrซiปl "3 4"^-

-------
Table  F-12. STREET CLEANING  SCHEDULE
     ivt Day Work U*ซk
                         I.D. Code
                           (or
                        ปpo*ile Staple
                                                        KUHici or JTterr CLUUซIซCS Kti*c THE WIQ
                                       Study Locf (
                                                        Study Lo<;ซtigg     Stiidj^^gc^tioa     g;udT Location
                                          0
                                                                            &

-------
representative five or ten yrams. The extreme  heterogeneity of the samples
makes this impossible withr-ut having to mill all  of  the sample and then
remove the small quantity necessary for chemical  analysis.  It is much easier
to select a representative five or ten grams from each  particle size because
of the reduced physical and chemical variation within  that  size range. Each
composited sample is typically made up of  five to 20 subsamples. These
composited samples are then placed in small sample  containers that are
thoroughly labeled and sent to the laboratory  for chemical  analysis. Tht
laboratory will have to mill the coarser samples  before they are analyzed.
Care should be taken to design a chemical  analysis  program  that will key in
on the most important constituents and those that are  least affected uy the
required collection, storage and handling  techniques.  If special chemical
analyses, such as priority pollutants, are necessary,  then  special samples
should be collected and handled specifically for  those  analyses.

     After the chemical analysis results are obtained  from  the laboratory,
the chemical strength (concentrations expressed in  micrograms of constituent
per gram of total solids) should be summarized  as shown on  Table F-13. Table
F-14 presents an example of the loading caJculations for each of these
constituents for an individual sample. Each sample  collected within the time
frame and for the specific test area should be  identified for each composite
analysis and the appropriate concentration factors  used. Table F-14 also
shows an example calculation to obtain the appropriate  street surface
loadings.
SUMMARY

     This appendix describes the laboratory handling  of  the street dirt
material before it is sent to a laboratory for  chemical  analysis.  The
preliminary data calculations and summarizing formats are  also  briefly
described. After these stages are completed, more  detailed data analyses need
to be performed. These analyses include the determination  of the accumulation
and deposition rates of the various street surface particulate
contaminants,and various measures of street cleaning  effectiveness. Initial
and residual street surface loadings for different street  cleaning
frequencies, and residual loadings as a function of  initial loadings for
different study area characteristics also need  to  be  identified, j..- addition,
as runoff monitoring will also be conducted simultaneously with street
cleaning, the  effects of streec cleaning on runoff water quality will also be
addressed in the final project .report.
                                     455

-------
    Table F-13. CHEX:CAL COKPOSITION OF STREET DIRT SAMPLE
SIEVE
SIZE
(microns)
l>6370
2000 - 6370
1000 - 2000
500 - 1000
250 - 500
125 - 250
63 - 125
<63
Pb
1- '
<\^
^ratn of total solids^
Zn
C,%'
-ve
\30
^ rro
OPO.
4
7^%-
i>
2-6"
X^
T-5~
•7-1
3 '-?
5^
s
^Kro
Sin?
^rcro
\~IMO
1 4^'D
I^LTO
1^1 LfV
'2_
17,0
Cr
VfT
(T^r
i>4
iSr?-
14-3
1 ฅ5-
•Z-4
S-4
vs
W6K
^6u
Illk
!04k
^4K
I-ZK
)i3U
O>K
en
en
        Study Area:
        Compo.it- Dates
        Note.:

-------
Table-  F-14.STREET LOADING  CALCULATIONS FOR CHEMICAL  COMPOSITION
SIEVE
- IIZZ
(•icrooa)
>6,170
2000 - 6170
1000 - 2000
500 - 1000
1
250 - 500
i
STREET LOADING (Ibi Btr curb ปilt)
•olid.
W
\T>\
Ib4
W.?
i ^JfT\
I D L/
125 - 250i |T,^
[
1
ซ - 1" ,0k
<63 j
Total
I
W
k 1
Pb*
0.0t>3
0.017.
OolS"
O.I4
O.ST-
0/ST-
0.3C?
o.,r
i.g
Znซ
O. W33
O.OJO
0.014
O.Olta
0.053
O.ObO
0-053
O-Oj (0
o.rr
COD*
ll
,(.
Z3
?.r
^


^
ป30
p*
O.ai>
O.P>,
O.O'fT-
0.03?
(90CX?5~"
0. ^7^
u,fV7-
0,047-
0.*-
OPO •
0.0013
fl-oua-
0. U"D^|
L9ซ(TO(^
6X^045"
O.tWSir
O.OD4/
o.unr
o.ozr
iซ
0.034-
O.W
0./5-
0.0^
e?.7,s~
0^3
0.22-
Oo,r
/.-z-
Ai*
0.00,,
0.**
QtU^lL
a.oปu>
o, WAG

O.VO-LO
Wl
O..JLO
Cuซ
(9.01733
*ซ^
O.^a-4
0o-W
0,0 n
0.0/5T
0,0,,
OP cn")f.c
>r,57
Crป
O.OT4J
0.01^-
0,^9
ao,T_
0.07.9
0.^
0.0,0
a.,37
OcO
V
9-
;z.
/r
fc.
ifc.
^
/z.
r
^-> ,
9 c
•Calculation:
    cbcaical ฃ  -  (total aolida)   z    [coocซntrซtioo of  I)   x
 (lbง/curb-ซilซ)  (Iba/curb-nil*)   (•icro(roi>/|ra> total  aolida)

**For  total aolidg amount a** Table 10.
                                                                          >icro|raaal
  Saปplt Cod. and

  Sซplt Data:

  Taat

  Hot..:
                       ot  Sfaplt:

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                                   ..I'i'FMUX  ,;
                               OK  IKhAN  Kl'.V'.'F  IMLMTANTS
     Yhi-rf  I.'vo  N'fii r:inv stiulies  in  the  past  that  h.-ye >->:amined dif.rrent
sinirci'^ iv_  arban njimit pollutants. These  ref>.• rences have bjen reviewed  as
,\H t  <>:' this  sti'.l-,  and tin- results  are  summarized in this section.
Mp-iticanr  Mb an  runol'l  pollutants are  defined  as  having a potential
rei.-oi.vim' W.-U-T  impact. Xost of  these  potential  problem pollutants are
iue;it i t iod  by siyiiiic,,nt concent rat ion  increases in the receiving waters or
sed imeiu;. ,  as i-t>rrr,>a red Lo areas  nut affected  by  urban runoff. Others
i! isi-usst'd lie not or io- s.l y toxic  and present  in  urban runoff, but their
conrent i .) t i OP.S  in  the njnoff may  not  create  significant water rroblec,s.
Sediment  ace urnv. i ;i t i on and bioaccuir.ula t i on  of  trese  <_oxic '.x>l lutant s ,  however,
ni.,y be  h.'iza.' O-^us .

     Tile  import;;nt  sourcet> of  these pollutants  are  ""elated to various uses
and processes. These inr iudv_ natural  sources,  s-ich  as rock weathering t.o
proauct soil  (and  s-oiubi !•( ty produces  of  Lhe  'najor  roc1', components),
>'.rou inwater  in^ i 11 rat i on , volcanoes and  forest  fires. Automobile-related
pv.enti.il soiirci. •;  usually affect  the  ro?d  dust  and  dirt more importantly than
Dthe:' particular  components of  the runoff  sysem. The road dust and dirt
quality is  aitected by -'ehicle  fluid  dr'ps  and  spills (gasoline, oils,  etc.)
and i;asol;ao  rocibusLi on,  ?long  wiuh various  vehicle wear, loca] soil  erosion
and pavrvntiit  wear  products. Urban  "agricultural" practices potentially
affecting jrban  n-.noft irclude  landscaping  (vegetation litter, fertilizer and
pes:icidi- v.st < and  animal wastes.  i-Kscellancous  sources of urban runoff
p., 1 .utanLs  include  fireworks,  wildlife  and  possible sanitary wasttwater
1.111 i 11 r.s 11 on . ^recipitation and  atmospheric  fallout are both affected by
urban luno'rt  pollurant retuspens ion after  initial deposition. Pesticide  use
in ar urban  area can contribute  significant  quantities of various toxic
materials to  urban  runoff. Many  manufacturing  and industrial activities,
including the combustion  of fuels,  also  affects  urban runoff quality.
Therefore,  it is extremely difficult  to  identify a  small number of activities
th-\t  contributes most of  the significant  urban  runoff pollutants.

     Natural  weathering and erosion products  of  rocks contribute the  majority
of the  hardness  c.nd iron  in u^ban  runoff  pollutants. Roar1 dust and associdted
automobile  rse activities (gasoliae exhaust  product?) contribute most of the
lead  in urban runoff. Road dust,  contaminated  by tirt wear products,
contributes  most of the zinc to  urban  runoff.  In certain situations,  paint
c'.ipping  can  al;;r>  be a major source of  lead  J.n  urban areas. Urban
agr .culturai  activities can be  a  major  source  of cadmium. Electroolating and
ore processing activities can  also  contribute  much  cadmium. Most of  the
mercury released into the environment  comes  from the chlor-alkali and pulp

                                      458

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.Ki.i i\-,\ or industries. M.ir.v  ;>>:lut,int  sources ,ire specific  to  a  particular
.it--.i  .11.d on-i;oinr. rutivitit's.  For  exnmplo, iron oxides are  associated  with
vol.iiiu-, i.per.it i'V.is ard strontium,  used  in the production of  flares  and
tiieuoiks, would probably be  found  on the streets in greater  quantities
ground holid.ws, or .it the  scenes  of  traffic accidents. The  relative
i-c-i-i ribution i.t each of  these  potential  urban runoff sources  is,  therefore,
hijjhlv variable, depending  on  specific  site conditions and  ssasons.


Uil.MlCAL iM/ALl TV OF ROCKS AND  SOILS

     Almost nrlf of tne  lithosphere (the earth's crust) id  oxygen and  about
J i percent iri silica. Approxinately eight percent is aluminum and five
percent is iron. Elements comprising  between two percent and  four percent of
the lithosphere include  calcium,  sodium, potassium and magnesium. Because of
the great abund.i >e of these  ma.erials  in the lithosphere,  urban  runoff
contributes only a relatively  small additional quantity of  these  elements to
receiving waters. This is especially  iuportant to remember  for  iron,  which
••as been analyzed in many urban  runoff  studiฐs. Iron can cause  detrimental
effects in receiving waters,  but  these  effects .ปre mostly  associated  with its
dissolved form. A reduction of  the  pH subrtantially increases abundance of
dissolved iron.

     Arsenic is mair.ly concentrated in  iron and manganese  oxides, shales,
clays, cediinentary r-cvc and  phosphorites. Mercury is concentrated  mostly in
confide ores, shales and clays.  Lead  is  fairly uniformly distributed,  but can
be concentrated in clayey sediments and  sulfide deposits.  Cadmium can  also be
concentrated in shales,  clays  and  phosphorites (Durum 1974).
JTKftT DUST AND DIRT POLLl'TAJ!!  SOURCES

     Most of tv
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r.iost notable ot  these  he.ivy  n.-tals is lead. Solomon and Natusch (1977)
studied automobile  exhaust  Articulates in conjunction with a comprehensive
study ot  lead  in  the Chr.mrai>;n-Urbana ,  Illinois, area. They found that the
exhaust participates existed in two distinct morphological forms. The
smallest  participates  were  almost perfectly spherical, having diameters in
the range of 0.1  to U.5  microns.  These  small particles consisted almost
entirely  of PbBrCl  at  the  time  of emission. Because they are snail, they are
expected  to remain  airborne  for considerable distances and can be deposited
ir the  lungs when  inhaled.  They concluded that the small particles are formed
by condensation  ot  HbBrCl  vapor onto small nucleating centers which are
probably  introduced into the engine with the filtered engine air.

     Solomon and  Natusch (1977) found that the second major form of
automobile exhaust  particulates were rather large, being roughly 10 to 20
microns in diameter. These  typically had irregular shapes, with somewhat
smooth  surfaces.  Thev  found  that  the elemental compositions of these
irregular particles way  quite variable, being predominantly iron, calcium,
lead, chlorine  and  bromine.  They  found  that individual particles did contain
aluminum, zinc,  sulfur,  phosphorus and  some carbon, chromium, potassium,
sodium, nickel  and  thallium. Many of theปe elements (bromine, carbon,
chlorine, chromium, potassium,  sodium,  nickel , phosphorus, lead, sulfur, and
thallium) are  most  likely  condensed, or adsorbed, onto the surfaces of these
larger  particles  during  passage through the exhaust system. Tbey believed
that these large  particles  originate in the engine or exhaust system because
of their  very  high  iron  content.  They found that 50 to 70 percent of the
emitted lead is  associa-ed  with these large particles, which would be
deposited within  a  few meters of  the emission point onto the roadway because
of their  aerodynamic properties.

     Solomon and  Natusch (1977) also examined urban particulates near
roadways  and homes  in  urban  areas. They found that soil lead concentrations
were higher near  the roads  and  houses.  This indicated the capability of road
dust and  peeling  paint to  contaminate  nearby soils. The lead content of the
soils ranged from  130  to about  1,200 mg/kg. Koeppe (1977), as part of another
element of this  Champaign-Urbana  lead study, found that lead was tightly
bound to  various  soil  components. However, the lead did not remain in one
location, but  it  was transported  both downward into the soil profile and to
adjacent  areas  through both  natural and man-assisted processes.


URBAN AGRICULTURAL  SOURCES  OF URBAN RUNOFF POLLUTANTS

     Vegetative  litter can  be a significant pollutant component in almost all
source  areas.  The  leaf fall  on  streecs  in Bellevue is an important street
surface pollutant  in the fall months. Animal feces can contribute important
quantities of  nutrients  and  bacteria to the urban area, mostly affecting
vacant  land and  landscaped  areas  where  they tend to accumulate. Fertilizer
and pesticide  use  is mostly  associated  with landscaped areas, but large
amounts of pesticides  are  sometimes used to control plant growths in
impervious areas.  Fertilizer may  be used in large quantities for road
maintenance operations.  Koeppe  (1977) found that significant levels of
plant-available  leฃd may be  released during decomposition of plant tissue


                                     460

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cor.tainim; le.ui. Therefore, it may ht difficult  to  permanently immobilize the
soil lead by returning polluted plant residues  to  the  soil.  These polluted
plants are mostly associated with vegetative areas  close  to  the road that
IvA-e been shown to accumulate large amounts of  lead  in their foliage. The
cjcveraent of lead during plant decomposition may  be  the cause for the downward
movement of lead.


ATMOSPHERIC RESUSPENS ION, TRANSPORTATION AND REDEPOSITION OF URBAN RUNOFF
POLLUTAiNTS

     Atmospheric processes affecting urban runoff  pollutants include dry
dustfall and precipitation quality. These two elements have  beer monitored in
many urban and rural areas. In many instances,  however,  the  samples were
combined a? a bulk precipitation sample before  processing. Automatic
precipitation sampling equipment currently available  can  automatically
distinguish between dry periods of fallout and  precipitation.  These devices
cover and uncover appropriate collection jars exposed  to  the atmosphere. As
part of the Nationwide Urban Runoft and Atmospheric  Deposition Programs of
the EPA, much of this information is currently  being  collected. The USGS
report (Ebbert, Poole, and Payne, 1983) discusses  the  Bellevue atmospheric
deposition rates.

     One must be very careful in interpreting this  information, however,
because of the ability of r^any polluted dust and dirt  particles to be
resuspended and tnen redeposited within the urban  area.  In many cases, the
measured atmospheric deposition measurements include  material  that was
previously residing and measured in other urban  runoff pollutant source
areas. Therefore, mass balances and determinations  of  urban  runoff deposition
and accumulation from different source areas can be  highly misleading, unless
transfer of material between source areas and the  effective  yield of this
material to the receiving water is considered.

     Dustfall and precipitation affect all of the  major  urban  runoff source
areas in an urban area. Dustfall, however, is typically  not  a  major pollutant
source but is mostly a mechanism for pollutant  transport. Most of the
dustfall monitored in an urban area is resuspended  particulate matter from
street surfaces or wind erosion products from vacant  areas.  Foint source
pollutant emissions can ao.so significantly contribute  to  dustfall pollution.
The bulk of the dustfall, however, Is contributed  by  the  other major
pollutant sources. Barkdoll, et al (1977) stated that  urban  runoff
contaminants may be mo Jed by man's activities or the  wind. Wind-transported
materials are commonly called "dustfall". Dustfall  includes  sedimentation,
coagulation with subsequent sedimentation and impaction.  Dustfall is normally
measured by collecting dry samples, excluding rainfall and  snowfall. If
rainout and washout are included, one has a measure  of total atmospheric
fallout. This total atmospheric fallout is  sometines  called "bulk
precipitation". Rainout removes contaminants fron,  the  atmosphere by
condensation processes in clouds, while washout  is  the removal of
contaminants by the falling rain. Therefore, precipitation  can include
natural contamination associated with condensation  nuclei in addition to
collecting atmospheric pollutants as the rain or snow falls. In some areas,


                                     461

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the contaminant  contribution  by  dry deposition is small, compared to the
contribution  by  precipitation  (haL^quist 1978). However, in heavily urbanized
are,;.-., du.-slfall  can  contribute  more of an annual  load than the wet
precipitation, especially  when  dustfall includes  resusp^nded materials.

     Kain water  quality  has  been reported by several researchers. As
expected, tne  non-urban  area  rain quality can be  substantially better than
urban rain quality.  Many of  th<ฐ  important heavy metals,  however, have not
been detected  in rain  in many  areas of the country.  The  roost important heavy
metals in rain in  urban  areas  are lead and zinc,  both oeing present in nin
up to several  hundred  ug/1.  The  concentrations of lead and zinc in non-urban
areas is typically  less  than  50  ug/1.  Iron is also present in relatively high
concentrations in  rain (about  30 to 40 ug/1).

     The concentrations  of various important urban runoff pollutants in dry
dustfall has  also  been studied.  Urban, rural and  oceanic dry dustfall samples
contain more  than  5,000  mg iron/kg total solids.  Zinc and lead are the next
most predominant constituents  of dustfall in urban areas. These can be
several thousand mg/kg dry dustfall. Spring, et al (1978) monitored dry
dustfall ne<:r  a  major  freeway  in Los Angeles, California. Based on a series
of samples collected  over  several months, they found that lead concentrations
on and near  the  freeway  can  be  about J.OOO mg/kg, but as low as about 50C
mg/kg 5UO feet (150  meters)  away. In contrast the chromium concentrations of
the dustfall  did not  vary  substantially between the  two  locations and
approached oceanic  dustfall  chromium concentrations.

     Much of  the monitored atmospheric dustfall and  precipitation would not
reach thvi urban  runoff receiving waters. The percentage  of dry atmospheric
deposition retained  in a rural  watershed was extensively monitored and
modelled in Oakridge,  Tennessee  (Barkdoll, et al, 1977). They found that
about 98 percent of  the  dry  atmospheric deposition lead  was retained in the
watershed, along with  about  95  percent of the cadmium, 85 percent of the
copper, 60 percent  of  the  chromium and magnesium  and 75  percent of the zinc
and mercury.  Therefore,  if the  dry deposition rates  were added directly to
the yields from  other  urban  runoff pollutant sources, the resultant urban
runoff loads  would  be  very heavily over-estimated.

     Chemical  oxygen  demand  (COD) is the largest  component in bulk
precipitation, followed  by total dissolved solids (TDS)  and suspended solids
(SS). Betson  (1978),  in  a  study  in Knoxville, Kentucky,  found that almost all
of the pollutants  in  the urban  runoff  streamflow  outputs could easily be
accounted for  by bulk  precipitation deposition alone. Betson concluded that
bulk precipitation  is  an important component for  some of the constituents in
urban runoff  but  the  transport  and resuspension of particulates from other
areas in the watershed are overriding  factors.
RhSUSPENSION OF SOURCE  AREA  PARTICULATES

     Rubin (1976) stated  that  resuspended ur^an particulates are returned to
the earth's surface and water  bodies  in four main ways:  gravitational
settli-.g, impaction,  precipitation  and  washout. Gravitational settling, as


                                     462

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dry deposition, returns most of  the  particles.  This  not  only involves the
settling or relatively large fly ash  and  soil  particles,  but also the
settling ot smaller particles  that collide  and  coagulate. Rubin stated that
particles  that are less than 0.1 micron  in  diameter  move  randomly in the air
and collide often with otl.er particles.  These  small  particles car. then grow
rapidly by this coagulatio.i process.  These  small  particles woul^. soon tx:
totally depleted in the air if  they  were  not  constantly  replenished.
Particles  in the U.I to 1.1) micron range  are  also removed primarily by
coagulation. These larger particles  grow  more  olowly t'uHii ttie smaller
particles  because they move less rapidly  in elie air, a'-3  somewhat less
numerous and, Therefore,  collide less often with  other particles. T=ir;icles
with diameters larger than one  micron have  appreciable settling velocities.
Those particles about ten microns  in  diameter  can settle  rapidly, although
they ojn be kept airborne for  extended periods  of time and large distances by
atmospheric turbulence. The seccnd important  particulate  removal process from
the atmosphere is impaction. Impaction of particles  near  the earth's surface
can occur  on vegetation,  rocks  and building surfaces.  The third form of
particulate removal from  the atmosphere  is  precipitation, in the form of rain
and snow.  This is the rainout  process described earlier where the
particulates are removed  in the  cloud-forming  process. The fourth important
removal process is washout of  the  p-~.rticulates  below uhe  clouds during the
precipitation event. Therefore,  it is easy  to  see that r^entrained particles
(especially from street surfaces,  other  paved  surfaces, rooftops and from
soil erosion) in urban oreas can be  readily redeposiLฐ.d  through these various
processes, either close to the  points of  origin or at  so-ne distance downwind.

     Pitt  (1979) monitored roadside  concentrations of  particuJates. He found
that on a  number basis, the downwind  roadside  particulate concentrations were
about 10 percent greater  than  upwind  conditions.  About 80 percent of the
concentration increases,  by number,  were  associated  with  particles in the 0.5
to 1.0 micron size range. However, about  90 percent  of the particle
concentration increases by weight  were associated with particles greater than
ten microns. He found that the  rate  of particulate resuspension from street
surfaces increases when the streets  are  cleaned at long intervals and varie^
widely for different street and  traffic  conditions.  The resuspension rate was
calculated based upon observed  long-term  accumulation  conditions on street
surfaces from many different study area  conditions and varied from about one
to ii Ibs/Ciirb-mile/day (0.3 to  3.4  g/curb-meter/day).

     Murphy (1975) described a  Chicago study where airborne particulate
material within the city  was microscopically examined, along with street
surface particulates. The particulates (mostly  limestone  and quartz) from
both of these areas were  found  to  be  similar  in nature indicating that the
airborne particulates were :nost  likely resuspended street surface
particulates. PEUCo (1977) found that the reeutrained  portion of the
traffic-related particulate emissions (by weight) is an order of magnitude
greater than the direct emissions  accounted for by vehicle exhaust and tire
wear. They also found that particulate resuspensions from a street are
directly proportional to  the traffic  volume and that the  suspended
particulate concentrations near  the  streets are associated with relatively
large particle sizes. The medium particle size  found,  by  weight, was about 15
microns, with about 22 percent  of  the particulates occurring at sizes greater


                                     453

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tl.an  'H  mu-'ons.  1'hrse  relatively large  particle  sizes resulted in
Mi'T-t .int 1 a 1  | .,ir t i en lat e  t, ill. Hit  near the  road .  They found t'aat about  15
1'eiv'eiit  ot resuspended  pa r t i cu 1.11 es t;e  area. They found, through
multi-elemental  analyses,  that the  settled  outdoor dust collected at  or  near
the curb was contaminated  by automobile  activity  and originated from  the
streets.  Soil sunples  taken  near buildings  that  were painted with lead  base
paint were conta;ni na ted by  lead  from chipping paint.
                                      464

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                                  APPENDIX H
           REACTIONS AND FATES OF IMPORTANT URBAN  RUNOFF  POLLUTANTS
     Tlr'.s section of the report summarizes information  from  the  literature on
chemical reactions, solubilities and fates of  important  urban  runoff
pollutants. Rubin (1976) discussed the forms and  reactions  that  may occur for
heavy metals. Metals in natural waters may be  soluble,  colloidal or
suspended. Soluble metals are defined as being less  than one micron in size,
whiie suspended metals are greater than 100 microns  in  size. Colloidal metals
are intermediate in size. Using these definitions, settleable  materials are
also included in the suspended size fraction.  Rubin  further  stated that the
suspended and co loidal particles may consist  of  individual  or mixed metals
in the form of their hydroxides, oxides, silicates,  sulfides or  as other
compounds. They may also consist of clay, silica  or  organic  matter to which
metals are bound by adsorption or ion exchange or  as  a  complex.  The soluble
metals may be un-ionized organo-metallic chelates, organic  ions, or complexes
of these chelates or ions. Because of various  reactions  within the water,
(physical, chemical or biological) there may be dynamic  interactions among
the various particle sizes and chemical forms. When  incoming metals react
with receiving .vater bodies, several types of  potential  interactions can take
place. The pH and Eh (oxidation redaction potential,  redox  potential or ORP)
are very important in controlling solubility and  agglomeration and,
therefore, sedimentation of a metal. The pH of the water system  also affects
the bonding of the metals to insoluble carriers which influences adsorption,
ion exchange and co-precipitation.

     The oxidation reduction potential can also radically affect the ionic
form of the metal. Iron and manganese are the  most responsive  metals to Eh
exchanges with lower redox potentials favoring the divalent  (+2) iron and
manganese valence states. These valence states are also  much more soluble
than the more oxidized (+3) states. Redox potential  and  pH  will  both affect
the stability of certain transition metal chelates (Rubin 1976).

     The presence of inorganic ions can form complexes  with the  metals that
can increase the solubility of the metals. As  an  example, as salinity is
increased, more manganese becomes dissolved rather than suspended. The
opposite can happen with other complexes, where metal carbonates and sulfides
typically have limited solubilities. Organic conplexing  agents in natural
waters include humic and fulvic acids. These can  form stable metal humics and
fulvics that are soluble in fiesh waters. Adsorption and ion exchange can
also bind metals to insoluble particulates, especially  in flowing waters with
large quantities of clay and soil. Much of the material  that the metals
interact with involve organic materials that originated  from aquatic
organisms. Other aquatic organism effects on meual solubilities  include

                                     465

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changes in pK and Eh  by  various  biochemical processes. These in turn affect
soluble metal concentrations  and  metal accumulations in sediments. Aquatic
organisms can also  concentrate  many metals in their tissues
(bioaccumulation).

     Rubin (197b) also discussed  the importance of oxidation reduction
reactions at the  sediment-water  interface. This interface can have a large Eh
gradient depending  upon  the  mixing, diffusion and the extent of biological
activity, intense redox  activity  nan occur at the sediment-water interface
because of deposition and  accumulation of organic matte.'.: diffusion of oxygen
down into the sediment interstitial waters can then create a large redox
gradient. Organic sedirents  generally contain ]arge quantifies of reduced
uaterial, especially  sulfides.  Since most heavy metal sulfides tend to h?
rather insoluble, it  IG  clear that  interactions in the heterogeneous sulfide
systems can be an important  process where trace metals are retained or
released from the soluble  phase  (Rubin 1976).

     Gambrell and Patrick  (1977)  stated that metals are present in soils and
sediments in many chemical forms  that differ greatly in their
bioavailability.  Gome metals  are  bound within the crystalline structure of
the sediments and soils  and  are  e-jentially unavailable to biota. However,
metals dissolved  in soil solutions, or in interstitial or surface waters, are
considered readily  available  to  Mota. Also, metals weakly adsorbed to the
solid mineral or  organic colloidal  phase by ionic exchange mechanisms are
also readily available.  Between  the unavailable and readily available metals
forms are a ~\. jter  of forms  that  are potentially available. As discussed
previously,  .ae  potential  solubility, and therefore availability, of various
metal form.: are  strongly dependent  upon the pH and oxidation reduction
conditions and,  of  course, the  specific chemical compound. In reduced
sediment conditions,  the formation  of stable and insoluble metal sulfide
precipitates is  important  in  limiting the mobility and bioavailability of
most metals. Humic  materials  in  reduced environments are characterized by
large molecular  weights  and  greater structural complexity. These
characteristics  increase the  metal  retention capacity and the metal bonding
stability of insoluble humic  materials. If these reduced sediments are
subjected to an  oxidizing  environment, such as being aerated by dredging,
scouring during  high  flows or by  benthic organism activities, many of these
insoluble organics  are more  likely  to become soluble. This is especially true
for copper, lead  and  cadmium  complexes. As an example, Gambrell and Patrick
found that as the redox  potential was increased from strongly reducing to
well oxidized levels,  insoluble  organic bound cadmium was transferred to more
available soluble and exchangable forms. They also stated that a reduction in
metal availability  by the  formation of insoluble organic complexes in reduced
sediments, may be offset uo  some  extent by an increase in soluble or organic
acids which maintain  some  metals  in solution as soluble organic complexes.
These various Eh  and  pH  mechanisms  affect various metal complexes
differently. As  an  example,  lead  solubility is enhanced by low pH levels but
is little affected  by changes in  oxidation reduction conditions.

     Cailahan, et al  (1979),  described the importance of various
environmental processes  for  the  aquatic fates of some urban runoff heavy
metals and organic  priority  pollutants. Photolysis (the breakdown of

                                     466

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compounds in the presence of sunlight) and volatilization (the transfer of
material from the water into the air as a gas  or  vapor)  are not nearly as
important as the other mechanisms for heavy metals.  Chemical speciation (the
formation of chemical compounds) is very important  in  determining the
solubilities of the specific metals. Sorption  (adsorption is the attachment
of the material on to the outside of a solid and  absorption is the attachment
of the material within a solid) is very important  for  many heavy metals.
Sorption can typically be the controlling mechanism  affecting the mobility
and the precipitation of most heavy metals. Bioaccuiaulation (the uptake of
the material into organic tissue) can also occur  for many heavy metals.
Biotransformatioa (the change of chemical form of  the  metal by organic
processes) is very important for some metals,  especially mercury, arsenic and
lead. In many cases,  the discharge of mercury, arsenic or lead compounds in
forms that are unavailable can be accumulated  in  aquatic sediments.  They are
then exposed to various benthic organisms that can  biotransform the  material
through metabolization to methylated forms of  the  material which can be
highly toxic and soluble. Various organic priority  pollutants are also found
in urban runoff, mainly various phenols, polyc.yclic  aromatic hydrocarbons
(PAHs) and phthalate  esters. Photolysis may be an  important fate process for
phenols and PAHs but  is probably not important for  the phthalate esters.
Oxidation or hydrolysis may be important for some  phenols. Volatilization may
be important for some phenols and PAHs. Sorption  is  an important fate process
for most of the materials, except for phenols. Bioaccumulation,
biotransforination and biodegradation are important  processes for many of
these orranic iLaterials.
                                     467

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-1   f
                \
               \

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