HomeMy WebLinkAboutFile Documents.1419 Crystal Lake Rd.0009.2017 (14).ARBKMarkup Summary DrainageReport 3-23-2017
Page Label: 11
Author: mikeh
Date: 3/23/2017 8:55:46 AM
File Name: DrainageReport.pdf
Void space calculations use a
height of 12' but the screened
rock is only the height of the
perforated section of the drywell.
Please recalculate void volume
and adjust the report and plans.
DrainageReport.pdf (3)
Page Label: 12
Author: mikeh
Date: 3/23/2017 9:00:47 AM
File Name: DrainageReport.pdf
The volume capacities are
incorrect in this chart. Also the
perforated area is the area of the
entire perforated structure and it
should only include the actual
area of perforation (the areas of
holes). Please adjust chart to
ensure drywells drain within 24
hrs.
Page Label: 12
Author: mikeh
Date: 3/23/2017 9:04:14 AM
File Name: DrainageReport.pdf
With rock beds, only the sides of
the bed can be considered
infiltration areas as the bottom is
considered "plugged". The
volume infiltrated within 24 hours
of 10.76 CF is not sufficient. The
entire rock bed must be drained
within 24 hours. Please adjust
the report.
11
xternal (18" of Screened Rock) Volume Total Capacity Required Capacity
0.3*π*H*((D/2)+1.5)2 - (D/2)2) (ft3)(ft3)(ft3)
127 467 436.07
127 467 436.07
Void space calculations use a height of
12' but the screened rock is only the
height of the perforated section of the
drywell. Please recalculate void volume
and adjust the report and plans.
s to ensure that the drainage structures can completely drain within 24 hours. The
erforation a drywell must have is 4 ft. Below is a calculation showing that there is
rea for the drywells and screened rock bed to drain within 24 hours using the
mined on January 17, 2017 of 3 inches per hour for the entire site. Section 8.5.4.2
ese calculations.
nd Maintenance
pected and maintained quarterly to remove sediment and debris that has washed into
Storage
m Basins Area Depth Void Ratio Total Capacity Required Capacity
(#)(ft2)(ft)(ft3)(ft3)
ed C 2 428.64 3 0.3 385.78 384
Perforation Height Perforated Area Total Capacity Infiltration Rate Infiltration Time Volume Infiltrated in 24 Hours
H (ft)A (ft2) = 3.14*D*H V (ft3)I (in/hr)T (hr) = V/(A*I/12)Vtotal (ft3) = V*T
4 75.40 203.00 3 10.77 2186.21
4 75.40 203.00 3 10.77 2186.21
ation
Max Volume Infiltration Area Infiltration Rate Time To Drain Volume Infiltrated in 24 HoursV (ft3)A (ft2)I (in/hr)(hr)Vtotal (ft3) = V*T
384.32 428.64 3 3.59 10.76
The volume capacities are incorrect in
this chart. Also the perforated area is the
area of the entire perforated structure
and it should only include the actual area
of perforation (the areas of holes).
Please adjust chart to ensure drywells
drain within 24 hrs.
rterly to remove sediment and debris that has washed into
quirements include the following:
and after every storm exceeding 0.5 inches.
other waste material removed from a drywell at suitable
, State, and Federal waste regulations.
f the drywell to ensure the maximum time of 24 hours is
e exceeding the maximum, drain the drywell via pumping
percolation barrel may be jetted to remove sediment
age persists, the system may need to be replaced.
ng schedule will be undertaken by the owners of the
Total Capacity Infiltration Rate Infiltration Time Volume Infiltrated in 24 Hours
V (ft3)I (in/hr)T (hr) = V/(A*I/12)Vtotal (ft3) = V*T
203.00 3 10.77 2186.21
203.00 3 10.77 2186.21
Infiltration Rate Time To Drain Volume Infiltrated in 24 Hours
I (in/hr)(hr)Vtotal (ft3) = V*T
3 3.59 10.76
With rock beds, only the sides of the bed
can be considered infiltration areas as
the bottom is considered "plugged". The
volume infiltrated within 24 hours of
10.76 CF is not sufficient. The entire
rock bed must be drained within 24
hours. Please adjust the report.
Drywell storage calculation has been changed to reflect the correct height of perforated are of
the drywell. It is now being proposed on plans that each drywell is to have 8' of perforations,
rather than the minimum 4'. All calculations modified on drainage report and plans to reflect
this perforation area.
The volume capacities in the spreadsheet have been updated to
show correct volumes. The spreadsheet has also been updated
to show the actual height of perforations of 8'. The civil set now
calls out the perforation height of the drywells.
The infiltration calculations for the screened rock bed has been modified so that only the sides of the bed are
considered the infiltration areas rather than the bottom of the screened rock bed which is required to be
considered "plugged", per the conversation with Mike H. on 4/7/2017.