HomeMy Public PortalAbout352283Metropolitan
St. Louis Sewer
District
2350 Market Street
St. Louis, MO 63103-2555
(314) 768-6200
October 17, 2008
Mr. Mark Miller
Aqua -Shield
2705 Kanasita Dr.
Chattanooga, TN. 37343
RE: Aqua -Shield Stormwater Treatment System: St. Louis MSD Submission
Redevelopment Use Level (RUL) Approval within District
Dear Sir:
The Metropolitan St. Louis Sewer District (MSD) has reviewed your application regarding the
Aqua -Swirl® for use as a Best Management Practice for stormwater management. MSD is
pleased to provide Redevelopment Use Level (RUL) as a stand-alone water quality BMP, subject
to the following provisions.
• The Aqua -Swirl° is only approved for redevelopment sites less than 5 acres. This
approval is based upon compliance with requirements listed in MSD's Proprietary Water
Quality Products and the MSD's Stormwater Management Program (January 2008).
• The Aqua -Swirl' must be sized to capture all floatable trash and free oil, and remove
80% of total suspended solids for the OK-1 10 particle size distribution at the site water
quality flow -rate (WOO. Procedures for calculating WQr are provided in Appendix D.10
of the Maryland Stormwater Design Manual (2000). Table 1 provides a list of approved
models and their respective peak treatment WQr. Aqua -Shields" proprietary sizing
program for the Aqua -Swirl® product shall not be used for product selection.
Table 1:
Summary of Aqua -Swirl® W
Aqua -Swirl®
Model
-- ������ a av •11L{4l.
Water Quality Flow Rate:
80% TSS Removal (cfs)
AS-4
0.85
AS-5
1.2
AS-6
1,7
AS-7
2.3
AS-8
3.0
AS-9
3.8
AS-l0
4.7
AS-12
6.8
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h o l e i s 3 0 i n c h e s i n d i a m e t e r .
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p r e p a r e d b y t h e c o n s u l t i n g e n g i n e e r .
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s u b m i t t a l . T r a f f i c r a t e d f o u n d r y r i m s a n d c o v e r s s h a l l b e i n s t a l l e d s u c h t h a t n o c o n t a c t i s
m a d e b e t w e e n t h e H D P E a c c e s s r i d e r a n d c a s t i r o n f r a m e .
" T h e i n i t i a l i n s t a l l a t i o n o f t h e A q u a - S w i r l � i n t h e M S D s h a l l i n c l u d e t h e f o l l o w i n g :
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p r o p r i e t a r y B M P i n s t a l l a t i o n t o e n s u r e t h e p r o d u c t ' s i n s t a l l a t i o n r e q u i r e m e n t s a r e
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r e q u i r e d p r i o r t o i n s t a l l a t i o n .
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B M P t o b e p e r f o r m e d b y a M i s s o u r i - r e g i s t e r e d P r o f e s s i o n a l L a n d S u r v e y o r o n c e
t h e d e v i c e h a s b e e n i n s t a l l e d , a n d p r i o r t o a n y t e s t i n g o r m o n i t o r i n g .
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p r o p r i e t a r y B M P d u r i n g i t s ' f i r s t y e a r o f o p e r a t i o n , w h i c h w i l l i n c l u d e v i s u a l
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e f f i c i e n c y , e s p e c i a l l y a s c o m p a r e d t o i t s d e s i g n e f f i c i e n c y . M S D r e q u e s t s t o b e
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t h e d e v i c e .
5 ) F o r m a l r e p o r t s s h a l l b e s u b m i t t e d t o M S D , i n c l u d i n g a s - b u i l t s a n d a t e a c h
q u a r t e r l y i n s p e c t i o n . T h e r e p o r t s s h a l l i n c l u d e s u m m a r i e s , q u a n t i t a t i v e a n a l y s i s
m e n t i o n e d i n i t e m 4 , p h o t o g r a p h s o f t h e s t r u c t u r e , i n l e t , i n t e r n a l c o n d i t i o n s o f t h e
s t r u c t u r e , t h e f i l t e r s , a n d o u t f a f l c o n d i t i o n s , e t c . T h e r e p o r t s s h a l l a l s o e v a l u a t e
t h e p e r f o r m a n c e o f t h e o w n e r ' s a d h e r e n c e t o t h e a p p r o v e d m a i n t e n a n c e p r o g r a m ,
a n d o f f e r s u g g e s t i o n s f o r a n y a r e a s o f i m p r o v e m e n t .
T h e A q u a - S w i r l � i s n o t a p p r o v e d f o r g e n e r a l u s e a t t h i s t i m e .
MSD reserves the ability to withdraw or modify this approval based on subsequent information,
including information indicating that this BMP does not satisfy MSD rules, requirements, or
construction specifications.
Sincerely,
robtkA T. atteLtiii
Michael T. Buechter, P.E.
Principal Engineer (BMP Committee Chairman)
Engineering/Design
Metropolitan St. Louis Sewer District