ST9301-CS040823COPPELL
August 23, 2004
William G. Pembroke, P.E.
Jacobs Civil, inc~
6688 N. Central Expressway, Suite 400, MB 13
Dallas, Texas 75206-3924
RE: Sandy Lake Road Project (Kimbel Kourt to east city limits) / ST 93-01
Dear Mr. Pembroke:
The following represents additional review comments and changes that need to be made to the
construction plans so that they can be finalized to stay on the City's schedule of bidding this project
in fall 2004:
On Sheets 6, 7, 9, & 10, the cross-section of the street still shows a 28' street, with two 13
t/=, lanes. Needs to be revised to show a 27' street, with two 13' lanes.
On Sheet I6, a median should be provided for the driveway on the north side of the road at
Sta. 25+64.63. For your convenience I have added a marked-up copy of Sheet 16 showing
the median opening and lelt-tum lane.
On Sheet 18, the 12' driveway at approximate Sta. 34+47 should be removed. This will
eliminate two curb ramps and add additional sidewalk length. The quantities should be
adjusted accordingly. It will also necessitate the removal ora cross-section shown on Sheet
30.
In the profile view, the begirming and ending station should be provided for all vertical
curves.
The PI elevation should be provided at all driveways and street intersections.
It appears as though in the plan view you are mixing top of curb elevations with top of curb
pavement elevations in several locations, especially at the limits of the construction of the
driveways. Need to label top of curb and top of pavement elevations.
Based on your cross-section information and some of the elevations given in the plan and
profile view, it is doubtful that the accessible routes through the driveways and streets will
meet ADA requirements in regard to cross slopes. Please reevaluate and make necessary
adjustments.
On Sheet 24, please provide the elevation for the curb returns at the intersection with Trinity
Shores.
Comments / August 23, 2004
Page 2
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
21.
On Sheet 26, the cross slope at the accessible routes on Riverview Drive are too steep to
meet the 2% maximum cross slope for ADA accessible routes. Please make necessary
adjustments.
On Sheet 27, the City does not use the 6x6 reflective jiggle bars for left turn lanes. Those
should be replaced with a double row of 4" round, white acrylic, single reflective traffic
buttons, with reflective surface facing toward the traffic. These are placed on a 5' spacing,
with approximately 3" separating the rows. This will increase the quantity of buttons;
therefore, the quantity should be adjusted on the quantity sheet as needed.
On Sheet 28, the proposed grade of the driveway at Sta. 25+64.73 appears to be too steep at
a grade of 17.93%. This is a track entrance and I am not sure this grade will accommodate
the tracks. Please reevaluate.
On Sheet 34, the Q100 associated with Drainage Areas lA and 2 appear to be incorrect.
On Sheet 38, please comment on why a 10' inlet was used on the north side of the road at
Sta. 28+12.44, when an 8' was used on the south side of the road. The inlet is on grade, not
at a low point. Also, please comment why a 2l" RCP is shown for lateral D-lA, when it
appears that an 18" will be sufficient.
On Sheet 42, the proposed inlet at Sta. 46+04 is at a low point and therefore shall be a 10'
inlet with a 21" RCP, not a 6' with an 18" as shown.
In the profile view, the proposed 48" RCP is crossing over the City of Dallas 60" water line
with less than a foot clearance. It is doubtful that Dallas will approve that. Has there been
contact with DWU concerning this crossing? If the crossing is allowed, there may need to
be some type of special cradle built around the 60" water line to support the proposed 48"
RCP. Again, approval will be required from DWU on this crossing.
On Sheet 43, the existing 12" waterline should be shown in the profile view. It appears as
though it could be in conflict with proposed drainage improvements.
On Sheet 43, the inlet at street Sta. 49+97 is called out to be a 10' recessed inlet, but is only
drawn as a 6'. Which is it? Also, the profile view for lateral 1-5A is on 49A, not 49.
The low point in Sandy Lake Road appears to be slightly west of the intersection of
Riverchase Drive. However, no inlet has been provided to pick up any standing water. If
the intent is for the water to flow down Riverchase Drive and be picked up on the proposed
inlet on Riverchase Drive, there needs to be a substantial amount of elevation information
provided for the street so that the contractor can construct it correctly.
On Sheet 43, at Sra. 49+55.73 there is a 10' recessed inlet called out on Riverchase Drive;
however, it is only drawn as a 6'. Which is it?
On Sheet 44, the profile for the proposed 24" RCP beneath Sandy Lake Rd. appears to be
drawn backwards. The flow is from Sra. 0+00 to Sta. 1+57.84, whereas the profile view
shows it flowing from Sta. 01+57 to Sta. 0+00. The drawing and labeling of the 24"
incorrectly causes the existing waterlines to be shown incorrectly beneath the 24". Please
correct this. You should also show the existing 12" water line in the profile view.
On Sheet 49, you failed to show the existing water lines beneath the laterals. Please insure
the existing water lines are shown and any conflicts should be addressed by these plans.
Specifically, there are water lines beneath Lateral J-l, J-2 and Lateral 1-5A; however, please
evaluate ail laterals and main lines.
Comments / August 23, 2004
Page 3
If you should have any questions or need any additional information please feel free to contact me.
If not, I look forward to seeing the revised plans so that we can try to finalize this contract so that it
can go out to bid this fall.
Sincerely,
Kenneth M. Griffin, P.E.
Director of Engineering & Public Works
Office 972/304-3686
Fax 972/304-7041
E-mail kgri ffi n ~77ci .coppell.tx. us
Cc: Suzan Taylor, CIP Coordinator