Why ECO: Installation
This overview is intended to be a basic guide and to explain
the site conditions that dictate the specific installation
methodology required for proper performance. EP Henry recommends
you consult a Professional Engineer (PE) for permeable pavement
installation.
Determining the onsite underlying soil type (clay, silt, sand)
is the first step in
choosing the construction detail that's appropriate for your
project. Although
the surface infiltration rates of EP Henry's ECO Paver and ECO
Cobble/Coventry ECO Cobble are extremely high, the infiltration
rates of the underlying soils determine how quickly captured water
will infiltrate into the ground.
Ideally, the quantity of water that enters a permeable paver
system should
infiltrate/exfiltrate your permeable paver system within 24-48
hours. However, it's possible that your underlying soils can't
absorb water rapidly enough due to the composition of the soil. In
cases where your soil can't absorb the water received in a given
precipitation event within 24-48 hours, conveyance movement via
drainage pipes to additional storage or infiltration areas may be
appropriate.
Infiltration: The penetration of water through the
ground surface into the subsoil
Exfiltration: The loss of water from a
drainage/permeable pavement system into the surrounding soil
In basic terms, clay can absorb the least amount of water, and
sand can absorb the most. It is important to note that when using
the Partial or No Exfiltration construction details, a drainage
pipe is specified which must have positive
flow away from the aggregate base. This drainage pipe can be
directed to auxiliary on site infiltration trenches, rain gardens,
bio-swales, detention basins, or nearby storm pipes. Municipal
approval is required for any stormwater "tie-ins."
The following represent several common details for ECO Paver,
ECO Cobble, and Coventry ECO Cobble Pavers:
NO EXFILTRATION
Appropriate for soils having high clay content, those constructed
over bedrock, a high water table, or environmental "hot spots"
PARTIAL EXFILTRATION
Appropriate for soils of medium texture, with roughly equals
portions of sand, silt, and a little less clay
FULL EXFILTRATION
Appropriate for soils that are very sandy, with no clay, and very
few fine particles
