Park West CC(1)-CS 900323GINN, INC. CONSULTING ENGINEERS
March 23,1990
Mr. Steve Goram
City of Coppell ~
P.O. Box 478
tew~sine~
:
We have completed our review of the attached water and wastewater
demand analysis as prepared by Albert Halff and Associates; and
the preliminary water and sewer plan for Park West Commerce
Center as prepared by Don Davis, Consulting Engineers.
In our opinion, and based solely upon our cursory review, the
data presented and the projected flows are within a generally
acceptable range of figures. The assumptions made, along with
the factors used, appear to be based upon good engineering
practice. It would be reasonable to expect that a 24" or 30"
diameter line would be needed to service the area as proposed.
The assumptions based upon certain areas being residential,
commercial and industrial at this time may change when the area
is fully developed. Continued monitoring of the areas being
developed should be maintained by the City.
Development of a city-wide water and sewer master plan later this
summer should define more specific basin considerations to
further enhance the assumptions that were made.
Flow measurements by City Personnel were made on March 19, 1990.
The results show the 12" sewer at the Mockingbird/East Belt Line
Road intersection was flowing full at 3 different times of the
day. Therefore, it is obvious that additional capacity will be
necessary to accommodate the anticipated future development.
Should you have any questions or need to discuss this any
further, please contact me.
Sincerely,
H. Wayne Ginn, P.E.
HWG/GF/dsp
cc: Gabe Favre
File 90438
REVISED 3/23/90
17103 Preston Road · Suite 100 · LB 118 · Dallas, Texas 75248 · Phone 214/248-4900
mz:ONSIJL'[' I NO [-'NG I NEFR:3
I)A!.I._A:::, TEX AS 752:36 ( 2 ! 4 ) 3:37-2:332.
HOI,IAR[J F'AFFORB
CITY OF COPF'ELI_ - [IEF'~RTH[:NT OF PUBLIC WORKS
7.;..'. Plr_'FOREST
L':OF'[:'EI..I., TEXAS 75019
RI:".: F'flRi.'.. WEST COMIIERCE CENTER
SANI'I-ARY SI.::i~ER STUDY
( C:O 1 ')1712'2. AHP )
A STUDY OF:' II-IE CITY SANITARY SEWER SYSIEHS IND]CAIE.S THAT 1'HERE I.'.'~ ONE
IJlAI'IEI'ER HAIN TRUNK LINE I't-I~T SERVES THE ~REA OF TIlE CiTY CONTAIN[NO PAInt,:. WE'ST
COMMEItC:E CENTER. h SII..IDY OF THIS ARE6 WAE; [.~Et. INEhl'ED AND ANAt. YZEIt~ 10 ESI'IH~'I'E
TIlE VOI..I_IHE OF E;~N]TARY .SEWERAGE EXPEF:TEI) [1'1 lttE 'fI~IJI'~K LINE WHEN TtlE Al:~l-lfl IS
FULI_Y [~EVELOPED.
MI£'H-IOLI NO. 1:
I_AND ARE:A DEMAND PEAt::: PEAt:::
USE APRES MGI'~ FA~:-'"F,:,R MGD
I'vE F-; l L~I'.NT 1 Al.. 1414 1.46: :3 4 · '14
CC'I'JMEI:OZ:IAL 290./:_. :3. I/:. I :3. 16
l N[]I.I$'I-I{ I AL. 82.5.4 :3./:,0 I 3.60
TOTAL :3.2'4 I 1.20
HE1-HOD Nq. """
(CITY OF DALI_AS FI61JRE 3.:3.:3)
(AF'F'LIES FAr-:TOR TO ENTIRE ACREAGE BASED ON EMF',RICAI_ gALl_lES.
'25:3,:1 i" · "" --
A_.RE.:, >.': 4.55 OAL, PER Af-:RE PER DAY = 11.-=, MOD
USE 11.5 HOD
FEB. 12, I?'.-:~O PAOE 2 OF 2
['0 I. 9002?. AttP
ltlE REQUIRED PIPE IS 24" DIAMETER WITH A SLOPE OF 0.65% AND VELOCITY OF' 5.8
ff, s. IF CONS'rRIJCTED I'T' WOULD BE ADVISABLE TO CONSIDER TIlE EFFECT OF A 30" t:'IPE
Wi'tit h REDUCEi) VELOCIIY.
IF FORC:ED -I'0 CARRY THE PROJECTED VOLUME - TIlE EX[S]'ll.il-i 12" PiPE WILL_ HAVE A
7.6"/. ItYDRAIJLIC GRAI)IENT 'AND fi VELOCITY' i'JF 15.5 fps. Tills IS TOO HIOH,
UNSATISFACTORY AN[:' WILL RE'.Z;UL1' ]N OVERFLOW.
THE PARK WEST F:OMHERCE CEN'rER ANI'ICIPA'TED DEMAHD IS AS. FOLLOWS:
32~-': ACRES OF INDI.JSTR]fiL PROPERTY.
SfiNI'rfiRY SEWER I')EMfiND=I.4:3 MGD
TltE IMF'ROT OF PAI'~I::: WEST COMMERCE CENTER TO TOTAL IS; J.43 HOD DIg[DED BY 11.2
HOD= 1:3Z
flS..C.;L~ME 'IHA1' 'ritE' FXISTING 12" TRUNK SEWER REMAINS IN Pi AC:E. T'ttEN THE ADDII'IONAL
SEWER NECESSARY IS OS F'OI_I_OWS:
EXISTING 12" DIAHEIER '.:_;EWER CAF'ACITY = 4.52 MGO ~ 5.8 fps.
FIJ1URE CAF'ACITY FOR PRO.JECIED SEWER PiPE = 11.5 14GD MINUS 4.5 MOD = 7 HC~I).
IE:" DIAHEIER SE:WER WI-HI SLOPE: OF' 1.03% AND VELOCITY GF 6.2 PPS WILL CARNY 7
HOD. A LARGER F'IPE E;HOIJLD DE CONSIDERED IN ORDER 'tO REDUCE 1HE VEI_OCI'fY AND
GRADE RE~I_.II REMEN'I S.
IN OI~:DER TO COMF'I.EI'E THE STIJI)Y IT WOIJI_D BE Ni.::CESSAR'¢ TO F:'ROVII.~E GAGES AND
RECI--~R[~ TIlE f:LON VOI_I..IME."s~ AT VARIOUS LOCATIOHS. THEN i~EFINE I'ItESE CALCIJLAI'IC~NS
SO 'rllfiT A CORf~EI._AI'ION BETWEEN 'file CALCUL.ATE[J VOLUME Aid[) THE MEASI..~F<ED VOLUME IS
O[~TAJNFI.~. 'HIE OCCUPIFD AREAS WOULI] THEN DE CAREFULLY HEASIJf~EI) [N COMPARASON TO
THE I. INDEVEU'~F~E[' AREA::..¢. THE ftF. SUI_'I'INO VALUE~; ARE I'HEil COMPARED 1'0 TtlE gAl._LIES
CALCUI_AIEP ItEREIN TO ARRIVE AT '1HE FINAL VALUI--?:.
THE STUDY E;IIOUL[! ALSO INCLI...IDF_' 'I'HE F[EI..D MEASURED VA~.UES AND SI..OI::'ES OF' 'filE
EX [ST INO AND PROF'OSED '.SEWI-'R PIPES.
DONALIL' E. DAVIS
,::UN'.SUI_'r I NO ENO I NEE[~S
CC:: PON ()ERt-'-':EN
LITE HANGEN
DONAI-D E. D~VIS
CONSLIL. T I NO ENO I NEEI'IS
5.'.:-'i¢..~t~:, C:OCKI~EL.L HILL
I.~ALLAS, 'rE XA.S '752:':~6
( 214 )
FEB. 12, 1'.':~'~"0
.r.:(~ 1 ?~0022:. AHP
BESION B&TI~
'I'i4E t"AF:TOR~i: USED IN I)E:::ION METHOD I ARE:
RES l DENt' I Al_ IJ.c_';E~S;:
:l~ UNITS PER ACRE
:3.5 PF-"RSON$ PER UNIT
lOu OALLONS PFR DAY PER PERSOH
COMHEI~C I AL_ U'..=;E'_$:
25% BUILI'~INr~ 'TO l-AND RATIO
! t':'ER.SON F'ER 100 S£:!. FEET
100 OALLONS PER DAY PER PEI~SC.~t,I
II,I[II.J'..~;]'RIAI.. AND OFFICE USES:
:3:1:% BI.J I LD I N~] TO LAND RAT 'l 0
! F'I:iRS(JN PER 330 SO. FEET
100 GAL. I..ONS F'ER DAY PER PEt~:~.:'.-.~i~
A 'IHIRD METHOD BASF]) ON FIXTURE UNITS WAS INVI:S'TIAAIE[~. Tl-t[~ F'RL-I..IMINA[~Y
INDICATION OF' 'file RESIJI_TS WERE VERY CLOSE TO METHOD NIJNBER ONI{. 'I-HIS THIR[.
HE'flKqJ WAS 'fHEREFORI.:. O.'_~NSIDEREIi~ ]0 BE UNNECESSARY.
]t-IEI~E AF~F 3 PUHP::; Al' THE OUI'F'ALL OF 'FIllS SANITARY SEWER WITH A CAPACITY OF 15
M.~'~.P.. A STUDY SIIOULD BE MADE 'fO DETERHINE IF OTNE~ ARliA$ ARE TO BE PUMPED
'I'HRL~UOH 'IHIS STA¥ION AND IF THF' PUMPS ANF~ OTHER F'ACII_I]'IE:i!; ARE ADEQUATE FOR
]'tie FLITI..IRE Dt-_'VEI..OPHENf.
WATER AND WASTEWATER DEMAND ANALYSIS
!. i'OPUI.,ATION FORI£CAST FOR LIGllT INDUSTRIAL LAND USE
A. Assumptions
1. 85% of gross land area is developable land.
2. 50% of developable land is gross I'ioor space.
3. 50% of gross floor space is office area.
4. One person per 150 square feet of' office area.
B. Calculations
I. For one acre of land zoaed light i~Mustrial:
43,560 S.F. (0.85) (0.50) (0.50) 1/150 = 61.71 people / AC
g 62 P/AC.
2. Tributary area population:
103 Ac Onsite
30 Ac Offsite
133 Ac Total (62 P/AC) = !~246 People
!1. WAS'FEWATER DEMAND FORECAST
A. Assumptions (Source: Texas Department of Heallh and Texas Department
of Water Resources)
1. Daily Demand = 20 Gallons per clay per person
2. Peaking Factor = 4
3. Infiltration = 150 Gallons per day per acre
B. Calculation of peak flow plus infiltration
Qt' = 8246 P (20 gpd/c) (4) + 133 AC (150)
= 659,680 + 19,950
= 679,630 gpd
= ¢}.68 MGD
Iii. WATER DEMAND FORECAST - (Onsite area only)
A. Assumptions
I. Daily I)emand = 24 Gallons pet' day per person (Source: Texas
l)cpartmcnt of Health).
2. Peaking factor t~r conversion of average day lo maximum day = 2.
3. Peaking factor I~)r conversion of maximum day to ~'m~imum hour =
2.
B. Calculnlion ol' maximum hour demand:
Oat. = 103 AC (62 P/AC) 24 gpd/c) (2) (2)
= 613,056 gpd
= 0.61 MGD