HomeMy WebLinkAbout96 Old Main001t-
YARMOUTH FIRE DEPARTMENT
96 OLD MAIN STREET
SOUTH YARMOUTH, MASSACHUSETTS 026g
Telephone: (508)398-2212 Fax: (508) 760-4861
rkelleher@ yarmouth. ma.us
TO: Amy Von Hone
FROM: DepuAetudtu&otg.5Whfrer,L.
RE: Design Criteria Septic 96 Old Main st.
DATE: June 14,2fiD
Based on the design criteria categories you gave me this afternoon, I have
come up with the attached figures.
Office Space: 2,fi)0sq ft x 75 gallons per l,fiX) sq ft = 150 GPD
Meeting Space 30 seats x 3 gallons per seat- m GPD
Bunk Rooms 7 beds 55 gallons per bed= 385 GPD
Washing Machine I washer 400 gallons 400 GPD
Locker Room 58 lockers 20 gallons per locker= t160 GPD
,..,. 1,.':. . .! i.';f i
/'//'- ,. -/I would suggest that the locker calculation is a gross overestima(ion'of real
world usage. Almost every member of the Fire Department has a locker for storage,
many seldom if ever use them. I believe a fairer calculation would be 257o of the
figure or 5 GPD per locker.
Even that amount is significantly more than the number of personnel on duty
at any given time. The previous system was rated at 393 GPD according to the plan
we have, the new amount would be f054 GPD based on the adjusted locker
calculation. The previous system lasted for most of 20 years without significant
maintenance, and we have not established whether it has failed.
It did also come to my attention that there are no vents on the present
system, is it possible that the lack of vents with the system under the impervious
surface could be part of the problem?
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DESIGN CRITERIA:
Fire Station 1 - Public Safety Facility
The proposed use is unique and is not directly accommodated by the provisions of
Title 5: 310 CMR 15.203.
Occupancy:
Office Space: (75 gallons per'1000 SF)
2000 SF x 0.075 GPD/SF
Meeting Space: (3 gallons per Seat)
30Seatsx3GPD/Seat
Locker Rooms: (5 gallons per Locker)
58 Lockers x 5 GPD =(or 14 Lockers/Shift x 20 GPD)
Washing Machine: (400 gallons per Machine)
1 Washing Machine x 400 GPD
USE WATER RECORDS:
Highest Usage (2008): 190,000 gallons/365 days =
(lncludes Daily Washing of Vehicles)
Double Water Records per Title 5: 520.5 GPD x 2 =
Side Area: (56'x .96')4 + (12'x .96)21
TOTAL LEACHING CAPACITY PROVIDED:
150 GPD
90 GPD
385 GPD
290 GPD
(280 GPD)
4OO GPD
520.5 GPD
1041 GPD
0.74 GPD/SF = 176.1 8 GPD
TOTAL THEORECTICAL CALCULATED OESIGN FLOW: 1315 GPD
TOTAL CALCULATED DESIGN FLOW PER WATER RECORDS = 1041 cPD
Septic Tank:
(Grandfathered 1978 Code): 520.5 cPD x 1.5 Day Storage =780.75 GPD Required
Use Existing 1000 gallon Septic Tank
Distribution Box: Use New Precast H-20 DB-g with Cast lron Coverto Grade
Leaching Area:
Provide two trenches (each with 6 flowdiffusors with 4' of washed stone on sides and ends)
56' long x 12' wide x 1.1" deep for Each rrench spaced s' apaft - 2 cast lron covers to Grade
Bottom Area: (56' x 12' x 0.74 GPD/SF ) x 2 = 994.56 GpD
1170.74 GPD
Bunk Rooms: (55 GPD per Bed)
7 Beds x 55 GPD
GENERAL NOTES:
Vertical Datum: Assumed
11.
Municipal Water !g Available
Schedule 40 PVC Pipe to be used throughout the system unless
otherwise noted.
All Precast Units to conform to AASHTO: !!!Q
Pipe Pitch ln" per foot unless otherwise noted.
All construction details to be in conformance with MA Environmental
Code (Title5) and Local Regulations.
Gontractor to verify locations of all utilities prior to construction.
Engineer As-Built PIan to be submitted post-construction.
Contractor to contact the Yarmouth Health Department with any
discrepancies found during construction.
Contractor to contact Yarmouth Health Department for final inspection
upon completion of construction prior to bacHill.
Required Access Risers (Cast lron Covers to grade) over D-Box, and
Flowdiffusors as shown on plan view.
Garbage Disposal not allowed.12.
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