HomeMy Public PortalAbout496660MEM
Metropolitan
St. Louis Sewer
District
2350 Market Street
St. Louis, MO 63103-2555
(314) 768-6200
February 26, 2013
Mr. Josh Dickinson
CONTECH Engineered Solutions LLC
6413 Lloyd Avenue
St. Louis, MO 63139
RE: CONTECH CDS®: St. Louis MSD Submission
Highway Use Level (HUL) and Redevelopment Use Level (RUL) Approval within
District
Dear Mr. Dickinson:
The Metropolitan St. Louis Sewer District (MSD) has reviewed the results of the CONTECH
CDS Quarterly Assurance Project Plan (QAPP) and is pleased to provide Highway Use Level
(HUL) and Redevelopment Use Level (RUL) approval for use of the CDS® as a stand-alone
water quality BMP, subject to the following provisions.
• The CDS® is only approved for use on public highway and roadway projects and 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 (Jan. 2008).
• The CDS® must be sized to capture all floatable trash and free oil, and remove 80% of
total suspended solids for the OK-110 particle size distribution at the site water quality
flow -rate (WQf). Procedures for calculating WQf are provided in Appendix D.10 of the
Maryland Stormwater Design Manual (2000). Table 1 provides a list of approved models
and their respective instantaneous peak treatment WQf. The 2400 micron screen will be
used.
Table 1: CDS® Approved Models and Peak W
System Model
Max Treatment Flow (cfs)
CDS2015-4
0.49
CDS2015
0.49
CDS2020
0.77
CDS2025
1.12
CDS3020
1.40
CDS3030
2.10
CDS4030
3.15
CDS4040
4.20
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m u s t b e i n c l u d e d w i t h i n t h e p r o j e c t ' s " S t o r m w a t e r M a n a g e m e n t F a c i l i t i e s R e p o r t "
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 .
M S D r e s e r v e s t h e a b i l i t y t o w i t h d r a w o r m o d i f y t h i s a p p r o v a l b a s e d o n s u b s e q u e n t i n f o r m a t i o n ,
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c o n s t r u c t i o n s p e c i f i c a t i o n s .
S i n c e r e l y ,
J a s o n P e t e r e i n , P . E .
C i v i l E n g i n e e r ( B M P C o m m i t t e e C h a i r m a n )
E n g i n e e r i n g / P l a n n i n g
M e t r o p o l i t a n S t . L o u i s S e w e r D i s t r i c t