Northpoint Dr-CS020226 (4)lll
-,' Halff Associates
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ENGINEERS ° ARCHITECTS ° SCIENTISTS
PLANNERS ° SURVEYORS
8616 NORTHWEST PLAZA DRIVE
DALLAS, TEXAS 75225
(214) 346-6200
FAX (214) 739-0095
February 26, 2002
Gary Johnson, P.E.
Assistant City Engineer
255 Parkway
Coppell TX, 75019
RE: Amberpoint Business Park At Coppell, Northpoint Drive extension
Dear Mr. Johnson
We have reviewed the comments dated D.,,~.e_mbe~r 12, 2002 regarding the above stated
plans. We have addressed the comments as follows
Sheet CPPO1
1. The soil in the area of No~thpoint Drive is primarily black clay. Therefore, we
feel it is best to utilize the existing City of Coppell standards for sub-grade
preparation.
2. We have included a copy of our turning template data for the drive into the
water tower. We have increased turning radii in the proposed drive. In
addition, we have raised the grade of the midpoint of the proposed drive as
requested.
3. A note for the adjustment of the existing water valves have been added.
4. We have adjusted the flair at the western end of the project per our previous
conversations.
5. All pavement grades are now 0.5% or greater.
6. We have added vertical scales to all profiles.
Sheet CPP02
1. We have extended the 18" storm sewer as requested.
2. We have adjusted the length of vertical curves as requested.
Sheet CPP03
1. We now show the 24 W.L.. and 18" culvert in profile.
2. We added the temporary HMAC pavement as requested.
Sheet CPP04
1. We feel confident that no drainage will be blocked behind the R.O.W. line.
DALLAS · FORTWORTH · HOUSTON ° McALLEN
TRANSPORTATION · WATER RESOURCES · LAND DEVELOPMENT · MUNICIPAL ° ENVIRONMENTAL · STRUCTURAL
MECHANICAL ° ELECTRICAL · SURVEYING · GEOGRAPHIC INFORMATION SYSTEMS
ARCHITECTURE ° LANDSCAPE ARCHITECTURE · PLANNING
nil
Halff Associates
ENGINEERS · ARCHITECTS · SCIENTISTS
PLANNERS - SURVEYORS
Gary Johnson, P.E.
February 26, 2002
Page 2
Sheet CPP05
1. We have reflected the limits of grading from sheet CGP01.
Sheet CGPO1
1. We have include the latest revision of this sheet.
Sheet CGP02
1. We revised the concrete pilot channel per our previous conversations.
2. We have added the note regarding maintenance of the pond and outlet
structures as requested.
3. We have added a note regarding compaction of the embankment of the
detention pond. (see note #6)
4. We have addressed the erosion concerns per our previous conversations.
5. We have moved the location of the emergency overflow to the south side of
the pond.
6. We feel that stubbing a pipe to the west is not necessary at this time.
7. We have analyzed the forces on the outlet pipe at the bends and have
determined that the forces are insignificant.
8. We now show the grading limits of this contract.
Sheet CDAO1
1. We have added a legend to this sheet
2. The limits of this contract are now shown.
3. We have removed the arrow on the east side of State Road.
Sheet CDA02
1. All drainage area designations on the road and site plans now match.
Sheet CDA03
1. We have added the storage provided by the detention pond and the stage/
storage ! discharge data
· .. Halff Associates
Ill
ENGINEERS · ARCHITECTS · SCIENTISTS
PLANNERS · SURVEYORS
Gary Johnson, P.E.
February 26, 2002
Page 3
Sheet CSDO1
1. We have added a note stating that all water lines crossing under storm sewers
shall be ductile iron.
2. We now provide adequate protection for all sanitary sewer and waterlines that
cross storm sewer lines.
3. A note to plug storm sewer stubs has been added.
Sheet CSD02
1. We have added notes requiring pre-fabricated wye's and bends.
Sheet CSD03
1. We have provided the additional information requested on the 'y' inlet.
2. We have corrected the labeling errors in plan view.
3. We have revised the profile of lateral A-lb regarding the location of the 12"
W.L and 6" fire line.
4. We have added a note stating that all water lines crossing under storm sewers
shall be ductile iron.
Sheet CSD04
1. We have extended lateral A-2c as requested.
3. We now show all fire hydrant leads crossing storm sewers.
Sheet CSD05
1. We have added notes requiring pre-fabricated wye's and bends.
2. We have revised the outlet of the storm sewer per our previous conversations.
3. We now provide 2 feet of cover for Line B in all locations
4. We revised lateral B-1 to address the HGL concerns. In addition, we now
show the 12" W.L. and 6" fire line in the profile.
5. We have addressed the HGL issues for Laterals B-lb and B-lc by lowering
the HGL of lateral B-I~
Ill
· -- Halff Associates
Ill
ENGINEERS,ARCHITECTS,SCIENTISTS
PLANNERS*SURVEYORS
Gary Johnson, P.E.
February26,2002
Page 4
Sheet CSD06
1. We have added a note referencing a standard street header on sheet SD 2.
2. We have added a safety end treatment to the 18" pipe per city standards on
sheet SD 14
3. We have revised the 18" RCP to class IV pipe.
4. We have added a concrete anti-seap collar to address piping concerns.
5. We have labeled all bends as pre-fab.
6. We have revised the outlet pipe per our previous conversations regarding
erosion concerns.
7. We have addressed pipe movement concerns in our previous conversations.
Sheet CWWO1
1. We now show the existing valve as requested
2. We have added the requested air relief valve.
3. The waterline is 4.5 feet from the back of curb in all locations.
4. We have added a fire hydrant at STA 3+00.
5. We have added a 90 degree 6" bend to the list of fittings at STA 6+00.
6. We have relocated the irrigation meter as requested.
7. We have added the requested blow off valve.
Sheet CWW02
1. We have added a 90 degree 6" bend to the list of fittings at STA 12+00 and
18+40.
2. We have added a note stating that fire hydrants shall be set 3.5 feet off the
back curb.
3. We have added a note stating that all water lines crossing under storm sewers
shall be ductile iron.
4. We have removed the 8" W.L. and replaced it with a 2" line outside of the
Easement.
5. We have dimensioned the 12" W.L. off the back of curb.
6. We have addressed any possible conflicts between the 12" W.L. and storm
sewer lines.
7. We have corrected typographical errors between STA 16+00 and 16+15. In
addition, we have added the requested blow off valve.
8. We have added the requested air relief valve.
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--- Halff Associates
ENGINEERS · ARCHITECTS · SCIENTISTS
PLANNERS · SURVEYORS
Gary Johnson, P.E.
February 26, 2002
Page 5
Sheet CWW03
1. We have dimensioned the 12" W.L. offthe back of curb.
2. We have revised all stub outs to lengths of 20 feet or more.
3. We have added a note stating that all water lines crossing under storm sewers
shall be ductile iron.
3. We have added the field verification note requested.
4. We have added the requested blow off valve.
Sheet CWW04
1. We have removed the 8" W.L. and replaced it with a 2" line outside of the
Easement.
2. The manhole at STA 5+00 is now a 5' drop manhole.
3. We have added rim elevation to all manholes.
Sheet CWW05
1. We have removed the 8" W.L. and replaced it with a 2" line outside of the
Easement.
2. We have removed the 8" W.L. and replaced it with a 2" line outside of the
Easement.
3. We have addressed the concerns over the depth of the sanitary sewer with
you and the City of Coppell maintenance department in our meeting on
February 21, 2002. We feel it is necessary to keep the sewer at it's current
depth.
4. The W.L. crossing no longer exists.
Sheet CEC02
1. We have included the latest revision of this sheet.
Sheet CSCO1
1. We do not feel that irrigation sleeves are necessary. We plan to utilize water
lines constructed in the future east of Northpoint Drive for irrigation.
· ,- Halff Associates
ENGINEERS · ARCHITECTS · SCIENTISTS
PLANNERS · SURVEYORS
Gary Johnson, P.E.
February 26, 2002
Page 6
Sheet CPMO1
1. We have provided the requested breaks in the median striping at both city
drives
2. We have added a note referencing sheet CPM02 for a legend.
Sheet CPM02
1. We have added the requested arrows at the intersection of Northpoint and
Sandy Lake.
2. We have moved the stop sign closer to the stop bar as requested.
3. We have added a note stating that all pavement markings shall be thermal
plastic tape.
We have also addressed other minor comments throughout the plans that are not
addressed in this letter. If you have any questions please do not hesitate to call me at
(214) 346-6324.
Sincerely,
Halff Associates, Inc.
arty Paris, P.E.
Cc: Jim Gaspard, Transwestern Commercial Services