HomeMy Public PortalAboutAspire PICP 3-21-24March 21, 2024
Mr. Lee Martucci
Aspire Pavers
915 E Taylor St.
Washington, IA 52353
RE: Permeable Interlocking Composite Pavement (PICP) - A Structural BMP
Dear Mr. Martucci,
The Metropolitan St. Louis Sewer District (MSD) has reviewed your application of the Aspire
Permeable Paver System and hereby grants the products Provisional Use Level (PUL) approval
as a PICP system. MSD understands that the Aspire pavers enhance surface permeability by the
open space created between the blocks and are recognized as a permeable pavement in satisfying
MSD stormwater management requirements.
MSD has determined that the PICP may be used under the following conditions:
1.Proposed uses and designs of the paving units must be in general conformance with the
information and methodologies provided by Aspire by Brava. Uses and designs shall
also comply with the MSD’s permeable pavement design and construction guidelines.
2.Channel Protection Volume (CPv) storage may be provided in the base stone and subbase
stone beneath the PICP and bedding layer.
3.The minimum pavement section subject to vehicular traffic shall be (from top to bottom)
3 1/8 inch thick paving units, 2-inch thick bedding stone (typically ASTM No. 8 or 9
stone), 4-inch thick layer of base stone (ASTM No. 57 or similar size), and a layer of
subbase stone (ASTM No. 2 or similar size), all underlain by MSD type 4 filter fabric.
The thickness of the subbase will vary depending on storage and anticipated traffic loads.
However, a minimum 12-inch thick subbase will be required for all applications.
4. The post-developed curve number (CN) for the footprint of the paving units may be
reduced. Reduced CN numbers are provided below.
Soil A B C D
CN 61 61 74 80
5.The PICP system will be considered as a pervious area for the purpose of calculating
Water Quality Volume (WQv) and 5 percent impervious when calculating the differential
runoff with PI factors. However, the PICP will be considered as a 100 percent impervious
area for the purpose of calculating pipe sizes downstream and when evaluating a site’s
annual post developed runoff condition.
6.PICP may be considered as a stand-alone BMP in certain design instances. Those designs
are subject to MSD review and approval.
7.Project specific design calculations and maintenance plans must be included within the
project’s “Stormwater Management Facilities Report” prepared by the consulting
Engineer.
The initial design and installation of the Aspire Pavement System in the MSD shall
include the following:
1) Sealed engineering documents by a professional engineer licensed in
Missouri.
2) Construction supervision by Aspire Pavers, to ensure the product’s
installation requirements are met.
3) Shop drawings indicating the depths and location of all layers making up
the pavement system.
4)An as-built survey, arranged by the manufacturer or vendor, of the
proprietary storage device to be performed by a Missouri-registered
Professional Land Surveyor once the device has been installed, and prior
to any testing or monitoring.
5) Quarterly visual inspections of the proprietary device during its’ first year
of operation, performed by you or your representative. MSD requests to
be invited to these inspections to further enhance familiarity and
understanding of the device.
6)Formal reports shall be submitted to MSD, including as-builts and at each
quarterly inspection. The reports shall include a summary description and
photographs of the structure, inlet, internal conditions of the structure, and
outfall conditions, etc. The reports shall include evaluating the
performance of the owner’s adherence to the approved maintenance
program and offer suggestions for any areas of improvement.
MSD reserves the ability to withdraw or modify this approval based on subsequent information,
including information indicating that the pavers do not satisfy MSD rules, requirements, or
construction and material specifications.
Sincerely,
Daniel Shepard, P.E.
Sr. Civil Engineer (BMP Committee Chairman)
Engineering / Planning - Development Review
Metropolitan St. Louis Sewer District