HomeMy Public PortalAbout366309M5CI
Metropolitan
St. Louis Sewer
District
2350 Market Street
St. Louis, MO 63103-2555
(314) 768-6200
August 3, 2010
Mr. Josh Dickinson
CONTECH Stormwater Solutions
6413 Lloyd Ave.
St. Louis, MO 63139
RE: CONTECH Stormwater Solutions - StormFilter: St. Louis MSD Submission
General Use Level (GUL) Approval within District
Dear Sir:
The Metropolitan St. Louis Sewer District (MSD) has reviewed your application regarding the
StormFilter for use as a Best Management Practice for stormwater management. MSD is pleased to
provide General Use Level (GUL) approval for use of the StoiinFilter as a stand-alone water quality
BMP, subject to the following provisions.
• The StonnFilter is approved for use on new development and redevelopment sites of any size.
This approval is based on compliance with requirements listed in MSD's Proprietary Water
Quality Products and the MSD's Stormwater Management Program (Rev. Jan. 2009).
Proprietary devices should be treated as a supplementary (rather than a primary) means of
meeting small MS 4 requirements.
• Proposed uses and designs of the device must be in general conformance with the information
and methodologies provided in StormFilter's application dated July 2007.
• The use of buried filters shall be avoided on residential type projects.
• The StormFilter must be sized to capture all floatable trash and free oil, and remove 80% of
the total suspended solids for the site Water Quality Volume (WQ,,). Procedures for calculating
WQ,, are provided in Volume I of the Maryland Stormwater Design Manual (2000). All units
shall be installed with adequate storage to treat 75% of the WQ,,.
• The StormFilter cartridges shall be designed in accordance with the following parameters:
Cartridge Height
12 inches
18 inches
27 inches
Cartridge Flow Rate at
1 gpm/ft2 (gpm/cart)
5
7.5
11.3
Mass Loading Capacity
at 1 gpm/ft(lb)
24
36
54
Cartridge Flow Rate at
2 gpm/ft2 (gpm/cart)
10
15
22.6
Mass Loading Capacity
at 2 gpm/ft2 (lb)
15
22.5
32.75
" T h e d e v i c e m u s t b e c o n f i g u r e d s o t h a t t h e f i l t e r v a u l t i s c l o s e d o f f f r o m t h e o u t f a l l . A l l u n i t s
i n c l u d i n g p r e t r e a t m e n t , s h o u l d b e c o n f i g u r e d i n a n o f f - l i n e l a y o u t .
" A d e q u a t e p r e t r e a t m e n t s h a l l b e p r o v i d e d i n a l l s i t e d e s i g n s . I n t h i s c a s e t h i s w i l l l i k e l y c o n s i s t
o f a V o r t s e n t r y H S o r a p p r o v e d H y d r o d y n a m i c S e p a r a t o r ( H D S ) u n i t ( V o r t s e n t r y o r V o r t e c h s ) .
N o r e d u c t i o n i n t h e n u m b e r o f f i l t e r c a r t r i d g e s s h a l l b e m a d e f o r t h e i n s t a l l a t i o n o f
p r e t r e a t m e n t . T h e H D S s h a l l b e s i z e d t o r e m o v e 5 0 % o f t h e T S S ( O K 1 1 0 P S D ) a t t h e w a t e r
q u a l i t y f l o w r a t e ( W Q f ) .
" A l l p r o p r i e t a r y l i d s a n d c o v e r s s h o u l d b e c a p t i v e c o m p o n e n t s . A t l e a s t o n e "