HomeMy Public PortalAboutStormTrap_ApprovalLetter_013123Metropolitan
St. Louis Sewer
District
2350 Market Street
St. Louis, MO 63103-2555
(314) 768-6200
January 31, 2023
StormTrap
Mr. Keith Pfeifer
1287 Windham Pkwy
Romeoville, IL 60446
RE: Storm Trap Detention System Approval within District
Mr. Pfeifer,
MSD previously provided a Provisional Use Level (PUL) approval for
the StormTrap system in November 2010. The PUL approval allowed
for three (3) installations of the StormTrap system within the
District and required post-installation documentation from these
installations to be provided to MSD.
After reviewing the post-installation documentation StormTrap has
provided to the District, the District hereby authorizes full
approval for the use of the StormTrap detention system, subject to
the following terms:
• The StormTrap detention system is approved for use on new and
redevelopment projects of any size.
• The StormTrap system shall be used to provide storage for the
Channel Protection design storm (Cpr) and flood protection
design storms (QP2>QPioo) • This system may also be used for
storage of the Water Quality design storm (WQV) when it is
used upstream of and in conjunction with an appropriate,
approved water quality BMP.
• The StormTrap system is not to be used as a standalone water
quality BMP.
• Consistent with MSD Rules & Regulations, the use of buried
storage shall be avoided on residential projects.
• Adequate access and inspection access must be provided.
Minimum access diameter is thirty (30) inches.
• A concrete bottom is required. No infiltration/volume
reduction will be allowed using these systems under this
approval.
• Ability to handle an HS-20 loading is required.
• Project specific design calculations and maintenance plans
furnished by StormTrap must be included within the project's
"Stormwater Management Facilities Report" prepared by the
consulting engineer.
Pretreatment measures upstream of the StormTrap system are
encouraged by MSD to minimize and facilitate maintenance of the
StormTrap system.
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,
Curtis Zurliene, PE
Civil Engineer (BMP Committee Chairman)
Engineering Department/Development Review
Metropolitan St. Louis Sewer District