Coppell Ind 2-CS040225 MEMORANDUM
FROM THE
DEPARTMENT OF ENGINEERING
To: Ken Griffin, P.E.
From: Keith R. Marvin, P.E. F/4~
Date: February 25, 2004
RE: Sewer Calcs for Bethel Road Development
I have performed some preliminary investigation and calculations for the proposed future
development along Bethel Road per your request. I have made some assumptions, and I'll list them
here:
1. I have assumed current flow from the Post al Facility and the Mohawk Carpet facility is a steady
flow, and that it all takes place during an 8-hour workday.
2. I have allowed for a "peaking factor" of 3.0 for this calculated flow.
3. I have assumed that the proposed development also will have a steady flow rate, and that this
flow will enter the system during hours of 8:00 to 5:00.
4. I have not included a "peaking factor" for this flow, but I will address that in the conclusion.
5. I have not allowed for any future tie ins on the other vacant properties that could impact future
flows.
The existing flow in the pipe is approximately 0.66 cfs using the above noted assumptions, and from
historical water usage. The proposed addition would be 1.24 cfs, with the noted assumptions.
Using Manning's equation, the 15" line at 0.15% slope, with the pipe flowing full, there is a
capacity of 3.26 cfs. To calculate the capacity of the I0" line at 0.0% slope, I used the Hazen-
Williams equation. I allowed for a surcharge in the manhole of 10 feet. This will fome additional
water through the pipe, and still allow for approximately 5 feet of freeboard at the upstream
manhole. This analysis yielded a capacity of 3.22 cfs.
"CITY OF COPPELL ENGINEERING - EXCELLENCE BY DESIGN"
If the flow is constant as assumed, and we are willing to allow the surcharging as calculated, there is
capacity for this flow. If you object to any of these assumptions, I can rework the calculations for
you.
I have attached my calculations, as well as the water usage reports for your review.
I would expect the developers design engineer to perform his own independent computations as
well.
"CITY OF COPPELL ENGINEERING - EXCELLENCE BY DESIGN"
· -.D~p.la~ Account .... . ....... . .... . ......... .-.-.-.-. ........................ UT7031.S.i-.
] ] Account# . . : 20003392 10820 ]]
-Account Meter History Inqu~6 .................................... UT7130S1-
,, ~c.c,o,u.n,t,#,:,,,2,0,0,0,3,3,9,~ .....................................................
Name : MOHAWK INDUSTIRES
Address : 980 BETHEL %200
Type option, press Enter.
5=Display
CC=Current Customer/PC=Previous Customer
Reset:
More:
---Meter--- Read Billed
Opt Type Number Date Read 1 Days Type Cons.
WATR 012861084 3/26/04 CC 7957 32 392
WATR 012861084 2/23/04 CC 7565 28 324
WATR 012861084 1/26/04 CC 7241 26 257
WATR 012861084 12/31/03 CC 6984 40 384
WATR 012861084 11/21/03 CC 6600 24 280
WATR 012861084 10/28/03 CC 6320 29 R 319
WATR 012861084 9/29/03 CC 6001 32 A 324
WATR 012861084 8/28/03 CC 5677 30 A 389
+
Calc'd
Demand
More.
,-,D,i~p,l,ay, ~c,count .......... ,-,-,-,-,-,-,-,-,-,-,--,---,-,-,-,-,-,-,-,-,-, .................. ~T703,1,S1,-,
[ [ Account# . . : 20003392 10820 [ [
-Account Meter History .I~n.qu.~.~.~.6.-.-JJ~-~-~-~-~-~-~-I.-~-J~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-.-.-~T~7.~.3~'~-
'~c'c'o'u'n't'#:'''2'0'0'0'3'3'9'2'
Name . MOHAWK INDUSTIRES
Address : 980 BETHEL #200
Type option, press Enter.
5=Display
CC=Current Customer/PC=Previous Customer
Reset:
More:
---Meter--- Read Billed
Opt Type Number Date Read i Days Type Cons.
WATR 012861084 7/29/03 CC 5288 32 A 390-nm
WATR 012861084 6/27/03 CC 4898 30 A 39~0u
WATR 012861084 5/28/03 CC 4499 33 A 3~0
WATR 012861084 4/25/03 CC 4129 28 A 344
WATR 012861084 3/28/03 CC 3785 29 A 345
WATR 012861084 2/27/03 CC 3440 29 A 293
WATR 012861084 1/29/03 CC 3147 34 A 340
WATR 012861084 12/26/02 CC 2807 36 A 349
+
Calc'd
Demand
More.
'" Account~ · 20002780 10792 *** Credit Problems *** ~ '
-Account Meter History Inquir~ ...................................... UT7130S1-
'' ~c'c'o'u'n't'#':'''2'0'0'0'2'7'80 ..... 1'079'2 .............................................
Name : U.S. POSTAL SERVICE-NTP & DC
Address : 951 BETHEL
Type option, press Enter.
5=Display
CC=Current Customer/PC=Previous Customer
Reset:
More:
---Meter--- Read Billed
Opt Type Number Date Read i Days Type Cons.
WATR 1216759 3/29/04 CC 240140 35 0
WATR 1216759 2/23/04 CC 240140 28 0
WATR 1216759 1/26/04 CC 240140 27 40
WATR 1216759 12/30/03 CC 240100 35 A 0
WATR 1216759 11/25/03 CC 240100 28 A 0
WATR 1216759 10/28/03 CC 240100 29 R 0
WATR 1216759 9/29/03 CC 240100 32 A 80
WATR 1216759 8/28/03 CC 240020 30 A 6670
+
Calc'd
Demand
More.
' '~' Account# . 20002780 10792 *** Credit Problems ***
-Account Meter History Inquiry ...................................... UT7130S1-
'' ~c'c'o'u'n't'#':'''2'0'0'0'2'7'8~ .... 1'0'~9'2 .............................................
Name : U.S. POSTAL SERVICE-NTP & DC
Address : 951 BETHEL
Type option, press Enter.
5=Display
CC=Current Customer/PC=Previous Customer
Reset:
More:
---Meter--- Read Billed
Opt Type Number Date Read I Days Type Cons.
WATR 1216759 7/29/03 CC 233350 32 A 1100
WATR 1216759 6/27/03 CC 232250 30 A 5050
WATR 1216759 5/28/03 CC 227200 29 A 0
WATR 1216759 4/29/03 CC 227200 33 A 11160
WATR 1216759 3/27/03 CC 216040 27 A
WATR 1216759 2/28/03 CC 216040 30 A 0
WATR 1216759 1/29/03 CC 216040 34 A 0
WATR 1216759 12/26/02 CC 216040 30 A 0
Calc'd
Demand
More.