006-064 Sample of drywell systemHERITAGE SURVEYS, INC~
Professional Surveyors and Engineers
241 College Hwy & Clark St, POBox 1
Southampton, Massachusetts 01073-0001
Bruce A. Coombs, President
Professional Surveyor, MA, CT & VT
E-mail: bruce@heritagesurveys.com
Telephone (413) 527-3600
Facsimile (413) 527-8280
Website: heritagesurveys. com
July 29,2015
City of Northampton
Department of Public Works
Attn: Douglas S. McDonald
125 Locust Street
Northampton, MA 01060
RE: Beaver Brook Estates
Chestnut Street Extension
& Evergreen Road
Northampton, MA
HSI Job #3923-121106
Dear Mr. McDonald,
On behalf of our client Patrick J. Melnik, we are filing an As-built Basin Plan, dated July 29,
2015 that shows modifications made to Basins IP and 3P, as well as the construction of Basins 2P -4P
(basin combined), 5P and 6P and revised Drainage Calculations reflecting the current as-built data. The
As-Built Stormwater Management System Drainage Calculations contains two (2) tables entitled "As-
built Stormwater System vs Proposed Construction Drainage System Summary" and "Basin Volume
Summary Table" which demonstrate that the modifications made to Basin #1 & 3, as well as the other
basins on the site meet or exceeds the original approved design. The overall volume provided with the
As-built Basins exceeds the originally proposed design and the peak discharges for the 2, 10 and 100 year
storm event have been reduced from the originally proposed design.
Five (5) concrete dry wells with cast iron catch basin covers have also been installed as shown on
the approved plans. Three (3) dry wells have been installed in front of unit's #2-5; two (2) dry wells
were installed on either side of unit #8. The dry wells are not connected into the roadway drainage
system. The concrete dry wells were supplied by Arrow Concrete Products product number AC-D-250 H
and were installed in stone. The detail sheet of the dry well is attached. Other dry wells will be installed
for the units that have already been constructed.
If you have any question regarding the above information please contact this office.
Sincerely, \
~'f .1J~
Richard P. Weisse, P.E.
cc: Patrick J. Melnik (bye-mail)
Carolyn Misch, Northampton Office of Planning & Sustainability (bye-mail)
Louis Hasbrouck, Northampton Building Commissioner (bye-mail)
AC·DRYWELL
HEXAGON
560 COllEGE HIGHWAY
GRANBY, CONNECTICUT 06035
(203) 653-5063
A
PROD # A B C D
AC-O-2S0 H 2'-10" 2'-1" 5'-8" 5'-0"
AC-O-750 H 4'-0" 3'-2" 6'-6" 5'-8"
AC-O-1000 H 6'-5" 5'-7" 6'-6" 5'-0"
D ~ ~
5 "
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DESIGN NOTES
1. Concrete -4000 p.s.i., 28 days
2. Reinforcement -steel wire mesh 6" x 6", 10 gao
and #3 RR BAR
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