VIKA REVISIONS

PROJECT/FILE NO.

NO. DATECOUNTY REVISIONS

DESCRIPTION

ARLINGTON COUNTY, VIRGINIADEPARTMENT OF ENVIRONMENTAL SERVICES

SCALE:

DESIGNED:CHECKED:

SUBMITTED DATE:VV7748A

ARLINGTON COUNTY, VIRGINIASHEET:

JULY 6, 2015

COLUMBIA PIKE VILLAGE CENTER4.1.2 SUBMISSION

VER. 10.24

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SITE STORMWATER MANAGEMENT NARRATIVEON THE EXISTING 2.99 ACRE SITE THERE EXISTS A 1-STORY BRICK BUILDING, ASSOCIATED PARKING

LOT, CONCRETE PATIO, AND LANDSCAPED AREA. THE EXISTING SITE IS APPROXIMATELY 88.62%IMPERVIOUS WITH NO EVIDENCE OF EXISTING STORMWATER MANAGEMENT (SWM) FACILITIES ON SITEFROM RECORD AND VISUAL INSPECTION. THE PROPOSED SWM BOUNDARY (2.99 AC) ENCOMPASSES THESITE AREA.

THE PROPOSED REDEVELOPMENT CONSISTS OF A 6-STORY MIXED USE RETAIL AND RESIDENTIALBUILDING. THE PROPOSED SITE WILL BE APPROXIMATELY 95.98% IMPERVIOUS AND WILL PROVIDE SWMMEASURES IN ACCORDANCE WITH THE NEW 2014 VIRGINIA STATE REGULATIONS FOR REDEVELOPMENT.AS SHOWN ON SHEET C-14 THE REQUIRED PHOSPHORUS REMOVAL RATE OF 1.54 POUNDS PER YEAR WILLBE PROVIDED BY THE SWM PRACTICES INTEGRATED INTO THIS DEVELOPMENT. SITE LIMITATIONS, SUCHAS TOPOGRAPHY, AND DCR SETBACK RESTRICTIONS PRECLUDE THE USE OF TRADITIONAL BIO-RETENTIONFACILITIES ON THIS SITE. AS SUCH, TREATMENT HAS BEEN PROVIDED BY STRUCTURAL BMP FACILITIES.

IT SHOULD BE NOTED IN THE REDEVELOPMENT COMPUTATIONS FOR THE PROPOSED SITE THAT THEIMPERVIOUS AREA INCLUDES THE FOLLOWING: BUILDING ROOF AREA, PAVEMENT AND SIDEWALK, ANDTHE AREA OF THE UNDERGROUND GARAGE. MANUFACTURED BMP FACILITIES ARE PROPOSED (JELLYFISHFILTERS OR AN APPROVED EQUAL WITH A MINIMUM PHOSPHOROUS REMOVAL EFFICIENCY OF 50%) TOTREAT A MINIMUM OF 63,000 SF OR ROOF AREA TO MEET ARLINGTON COUNTY WATER QUALITYREQUIREMENTS (SEE SHEET C-14 FOR COMPUTATIONS).

THE PROPOSED SITE IMPERVIOUSNESS IS GREATER THAN THE EXISTING IMPERVIOUSNESS. IN ORDERTO MEET THE ARLINGTON COUNTY DETENTION REQUIREMENTS, A MINIMUM 6,000 CF SWM VAULT HASBEEN PROPOSED (SEE SHEET C-14 FOR COMPUTATIONS). THE FINAL DIMENSIONS AND LOCATION OF THISSWM VAULT WILL BE DETERMINED AT THE TIME OF FINAL ENGINEERED SITE PLAN.

RUNOFF WILL BE CONVEYED FROM THE SWM FACILITIES INTO THE EXISTING STORM DRAIN SYSTEM(IN COLUMBIA PIKE) VIA A SERIES OF PROPOSED STORM PIPES. FINAL STORM PIPE LAYOUT AND STORMWATER MANAGEMENT STRATEGY WILL BE DETERMINED AT TIME OF FESP, IN COORDINATION WITHARLINGTON COUNTY STAFF.

LEGEND

NORTH (VCS 83)

C-131" = 25'

LTSEJI

STORMWATER MANAGEMENT PLAN AND NARRATIVE

MIN. 63,000 SF ROOF AREA TO JELLYFISH FILTERS(OR APPROVED EQUAL WITH MIN 50% PHOSPHOROUS REMOVAL EFFICIENCY)

VIKA REVISIONS

PROJECT/FILE NO.

NO. DATECOUNTY REVISIONS

DESCRIPTION

ARLINGTON COUNTY, VIRGINIADEPARTMENT OF ENVIRONMENTAL SERVICES

SCALE:

DESIGNED:CHECKED:

SUBMITTED DATE:VV7748A

ARLINGTON COUNTY, VIRGINIASHEET:

JULY 6, 2015

COLUMBIA PIKE VILLAGE CENTER4.1.2 SUBMISSION

VER. 10.24

FILE

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1 08/31/2015 4.1.2 SUBMISSION #2

C-14N/A

LTSEJI

BMP COMPUTATIONS

VIRGINIA RUNOFF REDUCTION SITE SUMMARY VIRGINIA RUNOFF REDUCTION RESULTS

VIRGINIA RUNOFF REDUCTION CREDIT SUMMARY

ARLINGTON DETENTION REQUIREMENTS

BMP NOTE:THE DEVELOPMENT PROPOSED ON THE SUBJECT SITE WILLPROVIDE A PHOSPHOROUS REMOVAL RATE AS REQUIRED BYDEQ, AT A MINIMUM. THE DEVELOPER RESERVES THE RIGHTTO UTILIZE LID TECHNIQUES (PER THE DESIGNSPECIFICATION OF THE VIRGINIA STORMWATER BMPCLEARINGHOUSE AND AS AMENDED/MODIFIED BY ARLINGTONDES) OR THE USE OF MANUFACTURED BMPS IN ACCORDANCEWITH THE BMP CLEARINGHOUSE, OR A COMBINATIONTHEREOF. FINAL DESIGN, LOCATION AND TYPES OF BMPSYSTEM(S) SHALL BE ESTABLISHED WITH FINALCONSTRUCTION PLANS AND MAY BE REVISED TOALTERNATES ALLOWED BY DES.

VIKA REVISIONS

PROJECT/FILE NO.

NO. DATECOUNTY REVISIONS

DESCRIPTION

ARLINGTON COUNTY, VIRGINIADEPARTMENT OF ENVIRONMENTAL SERVICES

SCALE:

DESIGNED:CHECKED:

SUBMITTED DATE:VV7748A

ARLINGTON COUNTY, VIRGINIASHEET:

JULY 6, 2015

COLUMBIA PIKE VILLAGE CENTER4.1.2 SUBMISSION

VER. 10.24

FILE

: P:\

proj

ects

\774

8\77

48A\

CADD

- P\

PLAN

NIN

G\PL

ANN

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INGS

\774

8A -

100

SWM

.dw

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USE

R: S

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6:0

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1 08/31/2015 4.1.2 SUBMISSION #2

C-15N/A

LTSEJI

SWM DETAILS

CONCEPTUAL MANUFACTURED BMP (JELLYFISH) DETAIL

NOTE:APPROXIMATE NUMBER OF HI-FLO CARTRIDGES FORJELLYFISH #1 = 6APPROXIMATE NUMBER OF HI-FLO CARTRIDGES FORJELLYFISH #2 = 6APPROXIMATE NUMBER OF DRAWDOWN CARTRIDGES FORJELLYFISH #1 = 1APPROXIMATE NUMBER OF DRAWDOWN CARTRIDGES FORJELLYFISH #2 = 1MANUFACTURED BMP SPECIFICATIONS ARE APPROXIMATEBASED ON THE APPROXIMATE AREA DRAINING TO EACHFACILITY. FINAL SPECIFICATIONS WILL BE PROVIDED AT TIMEOF FINAL ENGINEERED SITE PLAN.

NOT TO SCALE