HomeMy WebLinkAboutSTAFF REPORT 8-24-2010Summary of Engineering Review
Lots #28 and 438
Thomas Avenue
by
Nathan L. Jacobson & Associates Inc.
Engineering Review History
• Plans reviewed and review comments provided in August 24, 2010 letter to Thomas Sanders.
• Drainage Calculations reviewed and additional comments provided in September 21, 2010
letter to Thomas Sanders.
• Revised Plans and letter submitted from Donald R. Aubrey, P.E., L.S., dated October 7,
2010.
Based on review of current revised plans:
• The Plans represent a series of design alternatives, not a final site plan
• Almost the entire site is proposed to be disturbed and/or developed. Grading to support
septic system, house and driveway will change existing drainage patterns from sheet flow to
concentrated flow by a series of inlets swales and piping.
• Developed site runoff is directed to proposed infiltrators located at, or very near, the property
line.
• Proposed infiltrators do not store the 100 year storm; design is based on storing the increase
in the peak runoff rate from the pre -development to post development condition.
• No details or design information is provided to support infiltration design, including soil test
data or depth to groundwater.
• Off -site contours are not provided to verify contributing drainage area and confirm that
grading will not extend beyond property limits.
• Example comment: Lot 928 note indicates infiltrator B.O.T. =101.3 w/12" galleries and 1 Ft
stone and I Ft cover. This would indicate top of stone is above proposed grade.
• Example comment: Lot #38, note indicates infiltrator B.O.T. = 102.0 w/12"conc gallery and
1 Ft stone and 1 Ft cover. T/F of adjacent Yard Drain is 103.1 or one foot above B.O.T.
Also pipe invert at yard drain of 102.55 indicates no cover over pipe.
• On the drawing a 1 year maintenance bond is proposed and beyond that time the Town is
charged with inspection and ensuring that the system is maintained.
E�� 1 12 2010
TOWN OF MONTVILLE
PLANNING & ZONING COMMISSION
STAFF REPORT
DATE: 8124/10
APPLICANT: CDM Homes 547 Windham Rd. Willimantic, Ct
ADDRESS: Lots 28 & 38 Thomas Ave. Uncasville, Ct
ASSESSOR'S MAP #91 LOT # 28 & 38
TYPE: Two Zoning Permit Application for two (2) Single Family dwellings.
REQUIRED
EXISTING #28
EXISTING #38
R-20 ZONE
20,000 SF With
SEWERSI40,000WIO
10,000 SF
9,000 SF
FRONTAGE
100 FEET
NIA
NIA
SETBACKS FRONT/REAR
40 FEET SF
SETBACKS SIDE
15 FEET
WATER & SEWER
AVAILABLE ON
ROUTE32
WELL &SEPTIC
PROPOSED
WELL & SEPTIC
PROPOSED
COMMENTS
ZEO
Lots are preexisting non -conforming.
Zoning application site plan shows above ground septic systems and in ground infiltrators for
storm water. This changes existing drainage patterns which affect abutting properties.
See Town Engineers report.
See Uncas Health District approvals with conditions.
9/28/10 Update
Letter from Town engineer dated 9/21/10. Drainage Narrative reviewed and comments.
Letter to Uncas Health district requesting review of approval. Responded.
Letter from applicants engineer about Lot 8.
10/12/10 Update
Letter from applicants engineer and a set of plans with several options.
Summary of Engineering Review from Town Engineer
MOTION: to deny Applications # 209-166 and 209-167.
Reason for denial is that the plans, as submitted, show that surface water from and/or on to
abutting properties will be altered as explained in Town Engineers report.