SEL Brochure Car Park Drainage

SEL Surface Water Solutions
Sustainable Car Park Drainage
SEL Environmental Ltd, Canal House, Bonsall Street, Blackburn BB2 4DD

SEL Surface Water Solutions
Index
Page 2 Introduction
Page 3 Typical detail for
Permachannel against a
kerb
Page 4 System benefits
Typical detail for
Permachannel in open
areas
Page 5 Typical detail for
Permachannel in open
areas
SEL support services
Page 6 Why choose the SEL Car
Park Drainage system
Page 7 Typical detail for the SEL
flow control chamber
Page 8 SEL Contact details
Internal weirs trap oils
Residual oil is trapped and treated
within the Permavoid biomat
Introduction
Innovative Source Control Solution for Car Park Drainage
The SEL Car Park System provides a solution for the management of surface water runoff from
car park and access road hard surfacings. The system comprises a series of treatment phases
which have been specifically developed to provide the ideal source control solution to meet the
requirements of all current guidelines and legislation relating to SUDS, whilst incorporating
traditional impermeable surfacings such as macadam, asphalt, concrete and standard block
paving.
The System provides attenuation, incorporating multiple stages of water treatment and flow control
within the constructed layers directly beneath the finished surface. By introducing source control
systems (rather than end-of-pipe treatment) it is possible to minimise construction depths, reduce
pipe diameters and minimise construction risks. The requirements for rainwater harvesting can
easily be integrated in the SEL Source Control System.
Runoff from access roads, car parks, service yards and adjacent footpath areas would be
collected by Permachannels and diffused into a layer of Sudsagg sub-base structural voided stone
using Permavoid biomat conduits. The Permavoid biomat conduits can be 150mm and 300mm
deep to suit site requirements and therefore allow the depth of construction to be shallow as
possible.
The Permavoid biomat conduits would be located within the pavement construction and sit within a
layer of SudsAgg sub-base (min 30% void ratio) into which the received surface water can diffuse
to provide the balance of attenuation. The runoff would attenuate within the SudsAgg sub-base
due to the downstream flow controls and then later be released back into the Permavoid biomat
conduits and onwards until discharged from site. Half empty time is 24hrs in accordance with
current guidance.
The proposed use of the Permachannel and Permavoid biomat source control silt/oil separation
systems ensures the water-quality aspect of the design is very robust and silt/oil loading
calculations are provided as part of the design to demonstrate compliance with PPG3 and CIRIA
guidance.
2
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SEL Surface Water Solutions
Typical Detail - Permachannel against a kerb
The surface water runoff passes through the
Permachannel where silt and oils are
intercepted, retained and treated. The treated
runoff then passes forward through a Permavoid
biomat diffuser conduit and on into the Sudsagg
sub-base voided stone layer.
SEL Permavoid SudsAgg Sub-base System
for Car Park / Access Road Drainage
Min. 260mm cover for Cars, Vans & Occasional HGV
1. SEL Permachannel
2. SEL Permachannel Universal Connector
3. Diffuser conduit comprising SEL Permavoid and Permafilter
Biomat on 50mm bedding layer
4. SEL Selflex Geomembrane protected by Seltex Geotextile (for
attenuation)
5. Surfacing to Engineers Specification
6. Sudsagg sub-base structural voided sub-base
25.000
Runoff
The Sudsagg sub-base has been blended to
provide a nominal 30% void ratio. The surface
water storage capacity of the voided sub-base
layer is affected by the gradient of the finished
surfacing e.g. shallow gradients can offer the
highest storage capacity. Advice on suitable
gradients can be provided for consideration.
1 2 3 4 5 6
SEL Environmental Ltd, Canal House, Bonsall Street, Blackburn BB2 4DD
3

T: 01204 885555
System Benefits
Typical Detail - Permachannel in open areas
Complete Source Control SUDS solution for new build or retrofit development
Replaces Oil Separators as defined by PPG3 (Pollution Prevention Guidelines)
Six stages of water treatment available within the system
Provides treatment at source by gravity separation and bio-degradation of oils and silts
Provides attenuation or infiltration at source
Replaces sub-base, minimises the requirement for imported aggregate
Shallow construction, minimises residual excavated material
Contributes to BREEAM ratings
Satisfies designers’ risk assessments in accordance with CDM
Reduces the requirement for chambers and pipes
Improves water quality
A practical solution for the retrofit of SUDS components into existing drainage schemes
SEL Permavoid® and other system components are manufactured from recycled material
and are also recyclable and reusable
Resistant to frosts, salts and hydrocarbons
SEL Permavoid SudsAgg Sub-base System
for Car Park / Access Road Drainage
Min. 260mm cover for Cars, Vans & Occasional HGV
1. SEL Permachannel
2. SEL Permachannel Universal Connector
3. Diffuser conduit comprising SEL Permavoid and Permafilter Biomat on 50mm
bedding layer
4. SEL Selflex Geomembrane protected by Seltex Geotextile (for attenuation)
5. Surfacing to Engineers Specification
6. Sudsagg sub-base structural voided sub-base
25.000
Runoff
24.7
The Sudsagg sub-base has been blended to provide a nominal 30% void ratio. The
surface water storage capacity of the voided sub-base layer is affected by the
gradient of the finished surfacing e.g. shallow gradients can offer the highest
storage capacity. . Advice on suitable gradients can be provided for consideration.
1
4
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T: 01204 885555
The surface water runoff passes through the
Permachannel where silt and oils are
intercepted, retained and treated. The treated
runoff then passes forward through a Permavoid
biomat diffuser conduit and on into the Sudsagg
sub-base voided stone layer.
25.000
SEL Support Sevices
SEL are pleased to offer the following
services in support of the SEL Car
Park Drainage System:-
Drainage review
Design and specification service
Scheme budget costings
On-site technical support
Installation Teams for specialist
elements
Complete integrated surface water
management solutions
50
Runoff
2 3 4 5 6
SEL Car Park Drainage System under installation
SEL Environmental Ltd, Canal House, Bonsall Street, Blackburn BB2 4DD
5

SEL Surface Water Solutions
Why Choose the SEL Car Park Drainage System?
Innovative Source Control Solution for Car Park Drainage
The SEL Car Park System provides a solution for the management of surface water runoff
from car park and access road hard surfacings. The system comprises a series of treatment
phases which have been specifically developed to provide the ideal source control solution
to meet the requirements of all current guidelines and legislation relating to SUDS, whilst
incorporating traditional impermeable surfacings such as macadam, asphalt, concrete and
standard block paving.
Reduced Drainage Works
Employing the SEL Source Control System in this manner can lead to a reduction is the
length and diameter of drainage pipework required, quantity and size of chambers, remove
the need for a petrol interceptor and a dramatic reduction in the amount of earthworks
required on site
Design Flexibility
The system is particularly beneficial where specific problems exist, such as high water
tables, contamination, or poor ground conditions (i.e. low CBR).
CDM
The SEL Car Park System satisfies the designers’ statutory obligations as required by the
Construction Design and Management (CDM) regulations. The risks inherent with traditional
drainage systems are:
• Operatives working in deep excavations where there is risk of collapse
• Heavy lifting operations
• Operatives working within confined spaces
• Operatives exposure to contaminated sub-strata
The SEL Source Control System avoids these foreseeable risks because it is shallow
(generally less than 500mm deep), lightweight, installed above formation levels and
contaminated zones.
Permachannel link to diffuser conduit
Oils are collected in the Permachannel
SEL Flow Control Chambers
SEL design and manufacture a range of
plastic drainage chambers for sustainable
drainage systems. A range of chambers in
varying depths and diameters are
available to suit your site requirements
whether they are for flow control, silt
interception or debris screening from
downpipes.
SEL have developed a standardised flow
control chamber for incorporation into the
SEL Car Park Drainage System. The
chamber has an integral orifice flow
control device which is protected by a
filter screen. The filter screen is removable
for maintenance and the orifice sizes are
sized to suit the specific outflow
requirements for the site.
The chamber has a high level inlet from
the Sudsagg sub-base storage layer and a
low level outlet which allows for the
outgoing drainage pipework to be installed
at shallow depths directly below the
formation level. This transition allows for
the drainage pipework to be installed in
advance of the Sudsagg sub-base storage
layer and prevent disruption to following
trades and programmed construction
activities.
6
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SEL Surface Water Solutions
Typical Detail - Flow Control Chamber from Permavoid Conduit
SEL Permavoid SudsAgg Sub-base System
for Car Park / Access Road Drainage
Min. 260mm cover for Cars, Vans & Occasional HGV
1. SEL flow control chamber
2. Surfacing to Engineers Specification
3. SEL Selflex Geomembrane protected by Seltex Geotextile (for attenuation)
4. Diffuser conduit comprising SEL Permavoid and Permafilter Biomat on 50mm
bedding layer
5. Sudsagg sub-base structural voided sub-base
The SEL flow control chamber has a removable
filter screen which protects the orifice outlet. The
screen can be removed and cleaned as part of
the site maintenance regime.
1 2 3 4 5
355 mm
760 mm
160 mm
Rodding Access Point
Removable Filter Cartridge
200 mm
Orifice Outlet
150mm Concrete surround
600.00 mm
SEL Environmental Ltd, Canal House, Bonsall Street, Blackburn BB2 4DD
7

Contact Information
Telephone: +44(0)1254 589987
Email: sales@selenvironmental.com
Other Services
Web: www.selel.co.uk
Technical Services
To support architects, engineers and contractors in designing and installing the
SEL Car Park Drainage System our design services department offers
Sustainable Drainage
Solutions for Housing
Rooftop Sport Facilities
Membrane Installation
computer aided scheme details and advice on installation.
Supply and install packages are available for elements of the system -
information available on request.
SEL reserves the right to change or modify the design of products and
specifications as their policy is one of continued research and improvement.
Attenuation Tanks
Remote Water
Management
Gas Protection to
Buildings
The information contained in this publication is believed to be correct at the date
of publication, but it should be understood that between publications there may
be changes in pertinent standards or regulations affecting the accuracy of the
information contained therein.
All information in this document is courtesy and Copyright of SEL Environmental
Ltd © 2013. Several of the products shown in this brochure are subject to patent
and/or registered design - please contact SEL for further details.
SEL Environmental Ltd, Canal House, Bonsall Street, Blackburn BB2 4DD