rain water harvesting

FOR RESIDENTIAL,

COMMERCIAL AND

INDUSTRIAL APPLICATIONS

AquaCell® & Garastor® StormwaterManagement Systems

Product andInstallation Guide

Intelligent Solutions for Below Ground Projects

CI/SfB(52.5) (90.51)

September 2004 WM417

Uniclass EPICJR12/JS10 L731/L71121/L2123 J3413 X721

CUSTOMER SERVICES 01249 766611

TECHNICAL ENQUIRIES01249 766655

TECHNICAL FAX 01249 766653

[email protected]

STORMWATER MANAGEMENT SYSTEMSIntroduction to OSMA - from Wavin

2

From WavinOSMA

OSMA, from Wavin Plastics Limited, is

the leading name in plastic systems for

building, construction and utilities. The

OSMA product range is unrivalled in

scope and quality, covering:

Above Ground systems

Plumbing and Heating systems

Below Ground Drainage systems

Water Management systems

Ducting systems

Water and Gas Distribution systems

Quality assured products

OSMA systems are the benchmark for

excellence and product innovation:

precision-manufactured in the UK using

the most advanced injection moulding

and extrusion machines. All products

comply with or exceed relevant British

and European standards to ensure

reliability and long-lasting service.

Intelligent connections

OSMA systems offer integrated solutions.

This enables specifiers and installers to

assemble complete drainage, plumbing

and heating, and pressure pipe systems

from a single source, with complete

confidence in compatibility and

performance.

All systems are backed by comprehensive

technical support and a nationwide

distribution network to ensure availability

when and where required.

Wavin is a leading European manufacturer

of industrial plastic products, and one of

the largest producers of plastic pipe and

fittings in the world.

Wavin is credited with inventing and

pioneering the use of plastic pipe

for water distribution in the mid 1950s.

Constant research and development has

enabled Wavin to maintain its position at

the forefront of plastics technology.

Environmental responsibility

Wavin Plastics Limited has BS EN ISO

9001: 2000 BSI status and was the

first plastic pipe manufacturer to be

accredited to BS EN ISO 14001

Environmental Management Systems.

Wavin Plastics Limited is committed to

environmental responsibility, and is a

leading pioneer of systems to conserve

and control water. In production,

the Company recycles the majority

of waste materials, and sets annual

targets for energy efficiency audited by

the certifying body.

Passion and resourcefulness

All Wavin personnel are committed to

providing a comprehensive, responsive

service – and are passionate about

delivering total Customer satisfaction.

Wavin Plastics Limited maintains an

industry-wide dialogue and rigorous

assessment of all procedures to ensure

that Wavin product development and

product support accurately addresses

the needs of all Customers – today and

into the future.

www.wavin.co.uk

STORMWATER MANAGEMENT SYSTEMSIntroduction to OSMA from Wavin ■ Contents

STORMWATER MANAGEMENT SYSTEMSContents

STORMWATER MANAGEMENT SYSTEMS Product & Installation Guide 2004

General Introduction 4

Introduction to AquaCell 5AquaCell System Overview 6

How it Works 6Key Benefits 6

AquaCell Principal Components 7

Typical Soakaway Installation Method 8

Typical Storage Tank Installation

Method 9

Typical Silt Trap Installation Method

& Air Vent Design 10

Typical Connections to AquaCell 11

Typical Air Vent Connections 12

Typical Manifold Configuration 13

Typical Soakaway Detail: Non-Traffic

Loading 14

Typical Soakaway Detail: Highway 15

Typical On-Line Water Storage Detail 16

Typical Off-Line Storage Detail 17

Hydraulically Designed On-Line Water

Storage System Installed Off-Line 18

Typical Soakaway Detail with Silt Trap 19

Contents

Introduction to Garastor 20Garastor System Overview 21

Garastor Principal Components 22

Typical Garastor Installation Methods 23

Case Studies 24

Notes 25

Technical Advice and Assistance 27

Further information

The following related publications are

available for OSMA Stormwater

Management systems:

Design and Installation Manual

Trade Price List

To obtain copies, please contact:

Literature requests

Tel: 01249 766333

Fax: 01249 766332

[email protected]

3




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STORMWATER MANAGEMENT SYSTEMSGeneral introduction

4

Development of sites results in a large

proportion of area being covered by

impermeable surfaces such as roofs, car

parks and roads. Surface water run-off

therefore increases up to 80%. Regulators

(Environment Agency, Scottish Environment

Protection Agency and local authorities) are

promoting the use of Sustainable Drainage

Systems (SuDS) that control run-off to that

of a greenfield site (around 20%).

Wavin Stormwater Management Systems

have been developed to provide a method

of source control in two ways:

By providing temporary storage for

excess flows and limiting outflow to

streams and rivers.

By providing soakaways to infiltrate

stormwater back into the ground.

The modular nature of Wavin Stormwater

AquaCell® Storage/Infiltration System

Individual polypropylene modules assembled together to form an underground

structure, used for stormwater storage or as a soakaway.

Management Systems means that they

can be tailored to suit the specific

requirements of each site. They can be

used to provide temporary storage,

attenuation and infiltration capacity for run-

off for all sizes and types of site: from

individual houses up to the largest

commercial developments.

The systems comprise:

General Introduction

*Note:Garastor can be used as a flow control devicefor any AquaCell storage system, no greaterthan one unit deep with a discharge of up to 1.4l/s via the 30mm release flow orifice.

Garastor ® System*

A polypropylene flow control chamber connected to a water storage reservoir EITHER

made up of AquaCell units or located in a void beneath the garage of individual houses.

Small housing soakaway Highway drainage soakaway Large scale storage tank

Garastor domestic storage using AquaCell tank* Garastor domestic storage using garage void

*Garastor is manufactured under licence (Patent Number GB2357093)

www.wavin.co.uk

STORMWATER MANAGEMENT SYSTEMSGeneral Introduction ■ Introduction to AquaCell®

STORMWATER MANAGEMENT SYSTEMSIntroduction to AquaCell

5


OSMA AquaCell StormwaterManagement System

Comprises individual infiltration modules

assembled together to form an

underground structure which can either be

used for stormwater storage or as an

alternative to domestic soakaways.

The AquaCell Stormwater Management

System is fully BBA (British Board of

Agrément) approved, Certificate No.

03/4018, and can meet with the Technical

Requirements of NHBC.

Heavy storms and major cloudbursts are

becoming more frequent, resulting in ever

increasing volumes of stormwater flowing

into conventional drainage systems and

water courses. When the capacities of

these systems are exceeded the

consequences can be dramatic and

damaging.

Stormwater must be controlled; either by

limiting the outflow and providing

temporary storage or where the ground

conditions are suitable, providing

soakaways for the stormwater to infiltrate

back into the surrounding ground.

This has the added benefit of recharging

the local groundwater.

Both options can be achieved using the

OSMA AquaCell Stormwater Management

System.

Introduction to AquaCell

Large scale AquaCell storage tank

Domestic AquaCell soakaway




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STORMWATER MANAGEMENT SYSTEMSAquaCell System Overview ■ How it works ■ Key benefits

6

AquaCell System

The OSMA AquaCell unit is modular in

shape (1.0m x 0.5m x 0.4m), has a

capacity of 190 litres and weighs 9Kg. It is

95% void and has a surface area that is

43% perforated. Conical columns within

the unit ensure high strength and rigidity.

The AquaCell units are clipped together in

single layers and pegged together in

multiple layers. Conventional pipework is

connected to the units by means of a

number of adaptors.

Control Manhole

This manhole is designed to limit the

downstream discharge using an outflow

control and if necessary redirect the

excess stormwater via an overflow control

into the AquaCell units.

Stormwater exceeding the capacity of the

conventional drainage system is

attenuated by the control manhole and

channelled into the AquaCell unit

assembly. The internal structure of each

outflow control. However if the wrap is

permeable, the temporarily stored water

may be released into the surrounding

ground; soil conditions permitting. By

controlling the stormwater at source and

recharging the local groundwater it not

only eases the pressure on conventional

drainage systems but benefits the local

environment as well.

Geomembrane/GeotextileWrap

An impermeable geomembrane wrap is

required for storage solutions and a

permeable geotextile wrap is required for

soakaway solutions.

Manifold Configuration

A junctioned pipework assembly

providing a controlled multiple feed of

stormwater into the AquaCell Units.

The configuration is tailored to suit

the capacity required upon entry

into the AquaCell Unit assembly

and upon discharging to the

control manhole.

AquaCell System Overview

How it works

Significantly reduced risk of flooding

and its consequences.

Controlled and reduced volume

discharge into existing main sewer

systems and water courses.

Aerobic purification stimulated within

the system improves water quality.

Sustainable, cost effective

management of the water

environment.

Recharging the local groundwater.

Key benefits

unit is designed to bring surging water

under control and hold it in temporary

storage. If the wrap that envelopes the unit

assembly is impermeable the water will

remain in the unit assembly until such a

time as it can flow back into the control

chamber and discharge through the

www.wavin.co.uk

STORMWATER MANAGEMENT SYSTEMSOverview ■ How it works ■ Key benefits ■ Principal Components

STORMWATER MANAGEMENT SYSTEMSAquaCell Principal Components

7


AquaCell Principal Components

6LB104Flange Adaptor

(Adaptor to be used at points otherthan pre-formed socket to connect

to 150mm UltraRib)

4D916160mm OsmaDrain

P/E Adaptor(fits into pre-formed socket as an

extension connection piece)

6LB102Shear Connector(used to hold unitstogether vertically)

6TW141TwinWall S/S

Adaptor(fits into pre-formedsocket to connect to

150mm TwinWall)

6UR141UltraRib S/S

Adaptor(fits into pre-formedsocket to connect to

150mm UltraRib)

6D099160mm x 110mm

OsmaDrainS/S Reducer

(fits into pre-formed socketto connect to 110mm

OsmaDrain)

AquaCell Unit6LB100

0.5m

1m

0.4m

Silt Trap6LB600

(Extension Kit also available if required, seepage 10 for details)

160mm diameterpre-formed socket

6LB105Clip

(used to hold unitstogether horizontally)




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STORMWATER MANAGEMENT SYSTEMSTypical Soakaway Installation Method

8

OSMA AquaCell Units Permeable Geotextile*

Coarse Sand or Non Angular Granular Material Base and Surround

100mm

100mm

100mm

Pre-formed Socket

Typical Soakaway Installation Method

1. Excavate the trench to the required

depth ensuring that the plan area is

slightly greater than that of the

AquaCell Units.

2. Lay 100mm bed of coarse sand or non

angular granular material, level and

compact.

3. Lay the geotextile* over the base and up

the sides of the trench.

4. Lay the AquaCell Units parallel with

each other. In multiple layer

applications, wherever possible,

continuous vertical joints should be

avoided. AquaCell units can be laid in a

‘brick bonded’ formation (i.e. to overlap

the joints below). For single layer

applications use the Wavin Clips and

for multi layers use the Wavin Clips and

the Wavin Shear Connectors.

5. Fix the Wavin Adaptors to the AquaCell

Units as required and connect

pipework.

6. In order to prevent silt from entering the

tank, clogging inlet pipework and

reducing storage capacity, it is

recommended that the Wavin Silt Trap

(6LB600) is installed prior to the inlet

pipework - see page 10 for installation

guidelines.

7. Wrap and overlap the geotextile

covering the entire AquaCell structure.

8. Lay 100mm of coarse sand or non

angular granular material between the

trench walls and the AquaCell structure

and compact.

9. Lay 100mm of coarse sand or non

angular granular material over the

geotextile and compact. Backfill with

stone free as-dug material.

10. Rainwater from roof areas may

discharge directly into the soakaway

but rainwater fromcarparks must

discharge through a catchpit manhole

or a petrol interceptor.

* The geotextile should be selected according tospecific site conditions, however, typically a300g material will be suitable. Specialist adviceshould be sought if surrounding soilcharacteristics exhibit a high degree of fines/lowinfiltration capacity and/or there is a high risk ofdamage from ground contaminants.

www.wavin.co.uk

STORMWATER MANAGEMENT SYSTEMSSoakaway Installation ■ Storage Tank Installation

STORMWATER MANAGEMENT SYSTEMSTypical Storage Tank Installation Method

9


Typical Storage Tank Installation Method

1. Excavate the trench to the required

depth ensuring that the plan area is

slightly greater than that of the

AquaCell units.

2. Lay 100mm bed of coarse sand, level

and compact.

3. Lay the geotextile over the base and up

the sides of the trench.

4. Lay the geomembrane on top of the

geotextile over the base and up the

sides of the trench.

5. Lay the AquaCell units parallel with

each other. In multiple layer

applications, wherever possible,

continuous vertical joints should be

avoided. AquaCell units can be laid in a

‘brick bonded’ formation (i.e. to overlap

the joints below). For single layer

applications use the Wavin Clips and

for multi layers use the Wavin Clips and

the Wavin Shear Connectors (vertical

rods).

6. Wrap the geomembrane around the

AquaCell structure and seal to

manufacturers recommendations.*

7. Place the Wavin Flange Adaptor into

position (at a point other than the pre-

formed socket) and fix using self

tapping screws. Drill a hole through the

Flange Adaptor and connect pipework.

8. In order to prevent silt from entering

the tank, clogging inlet pipework and

reducing storage capacity, it is

recommended that the Wavin Silt

Trap (6LB600) is installed prior to the

inlet pipework – see page 10 for

installation guidelines.

9. Wrap and overlap the geotextile

covering the entire AquaCell

structure, to protect the

geomembrane.

10.Lay 100mm of coarse sand between

the trench walls and the Wavin

AquaCell units and compact.

11.Lay 100mm bed of coarse sand over

the geotextile and compact. Backfill

with stone free as-dug material.

NB: A storage tank must be vented, and

it is recommended that one vent

pipe, 110mm in diameter is provided

per 7,500 square metres of

impermeable catchment area on a

site, see page 8 for design.

OSMA AquaCell UnitsSuitable ProtectiveGeotextile Layer

Coarse Sand or Non Angular Granular Material Base

Suitable ImpermeableGeomembrane*

100mm

100mm

Pre-formed Socket

100mm

* For large scale, deep installations a 1mmthick geomembrane is recommended andjoints should be sealed using proprietarywelding techniques. However, for shallow,domestic installations it may be suitable to usea geomembrane with taped joints. For furtherdetails contact Wavin Technical Services.




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STORMWATER MANAGEMENT SYSTEMSTypical Silt Trap Installation Method ■ Typical Air Vent Design

10

Typical Silt Trap Installation Method

Typical Air Vent Design

1. Place the Silt Trap (6LB600) on a

minimum of 100mm bed as per pipe

bedding specification. Ensure that the

unit is as close to AquaCell tank as

possible and in a suitable position to

allow pipework connection.

2. Connect the relevant pipework in

accordance with standard pipe

installation guidelines.

3. Surround the sides of the Silt Trap with

150mm of ‘as dug’ material, with no

particle sizes larger than 40mm.

4. Fit relevant cover and frame according

to the depth of unit: Up to and

including 1.2m deep = 6D935 Deeper

than 1.2m = 6D939.

COVER & FRAME – 1.2m deep use 6D.935. Greater than 1.2mdeep use 6D.939 with reduced opening of 350mm

160mm OsmaDrainInlet/Outlets or use theappropriate adaptor toconnect to 110mmOsmaDrain, 150mmTwinWall or UltraRib

150mm side fill as dugmaterial with no particlesizes larger than 40mm

SHAFT 500mm

450mm

1250mm

100mm bed asper pipe beddingspecification

BalloonGrating4S302

Ventilation Box(4D706)

FlangeConnector6LB104

110mm OsmaDrain Pipe

150mm x 110mm Reducer(6UR099)

Geomembrane sealed to Flange Note:

It is recommended that one vent pipe, 110mmin diameter, is provided per 7,500 squaremeters of impermeable catchment area on asite. Please contact Wavin Technical Servicesfor further details.

Notes:When surrounded by a concrete plinth (150mmx 150mm) the cover can be used in situationswith a loading of up to 30Kn (3 tonnes) i.edomestic driveways.

The silt trap can be extended (if required) usingthe 500mm Extension Kit (see details on page20) in conjunction with a 500mm shaft ofTwinWall cut to suit.

www.wavin.co.uk

STORMWATER MANAGEMENT SYSTEMSSilt Trap Installation ■ Air Vent Design ■ Connections to AquaCell

STORMWATER MANAGEMENT SYSTEMSTypical Connections to AquaCell

11


Typical Connections to AquaCell

Note: It is recommended that all connections and airvent installations in storage applications (usinggeomembrane) are made using a FlangeAdaptor. Adhesive or double sided tape shouldbe used between the geomembrane and theflange plate to ensure a watertight seal. Permeable

Geotextile WrapJubilee Clip

160mm OsmaDrain


Connection for soakaway application

using either the pre-formed socket (as

shown below) or standard adaptors into

pre-formed socket*

*Note:For pipework other than 160mm OsmaDrain,these adaptors can be used to connect to thefollowing:

6TW141: TwinWall S/S Adaptor connects to 150mm TwinWall6D099: 110mm OsmaDrain Adaptor connects to 110mm OsmaDrain4D916: 160mm OsmaDrain PE Adaptorconnects to 160mm OsmaDrain6UR141: UltraRib S/S Adaptor connects to150mm UltraRib

Connection for storage application using

flange adaptor at points other than pre-

formed socket

Installation Procedure:

1. Fix Flange Adaptor to the AquaCell

unit with self tapping screws

2. Drill through geomembrane and

AquaCell unit with a long 150mm

Crown Drill Bit Cutter

3. Insert pipework into Flange Adaptor

Geomembrane Wrap

Flange Adaptor(6LB104)


150mmPipework tosuit




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STORMWATER MANAGEMENT SYSTEMSTypical Air Vent Connections

12

Geomembrane Wrap

Flange Adaptor(6LB104)


Connect suitable pipework to form air vent

Permeable Geotextile WrapJubilee Clip

Suitable bendand pipework toform air vent

OsmaDrain S/S Reducer(6D099)


Typical Air Vent Connections

Note: It is recommended that all connections and airvent installations in storage applications (usinggeomembrane) are made using a FlangeAdaptor. Adhesive or double sided tape shouldbe used between the geomembrane and theflange plate to ensure a watertight seal.

Connection onto top of AquaCell unit

using Flange Adaptor

Installation Procedure:

1. Fix Flange Adaptor to the AquaCell

Unit with self tapping screws

2. Drill through geomembrane and

AquaCell unit with a long 150mm

Crown Drill Bit Cutter

3. Insert pipework into Flange Adaptor

to form air vent

Connection into side of AquaCell unit

using standard adaptors

www.wavin.co.uk

STORMWATER MANAGEMENT SYSTEMSTypical Air Vent Connections ■ Typical Manifold Configuration

STORMWATER MANAGEMENT SYSTEMSTypical Manifold Configuration

13


AQUACELL UNITS

150mm ULTRARIB

300mmULTRARIB

Note: Pipe configuration is dependent on maximumflow. Alternative pipe systems such as WavinTwinWall and OsmaDrain can be used. Pleasecontact Wavin Technical Services for furtherdetails.

Typical Manifold Configuration




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STORMWATER MANAGEMENT SYSTEMSTypical Soakaway Detail: Non-Traffic Loading

14

ROOF AREA = 98m2

S

S

TRENCH SOAKAWAY

Notes:1. Soakaways should be sited at least 5m

away from the building. (Ref BS8301)2. The exact size and shape of the

soakaways are to be determined once allthe necessary calculations have been produced.

NON-TRAFFIC LOADING AREA

NON-TRAFFIC LOADING AREA

Min Depth0.5m

KEY:

= AquaCell Soakaway(see note 2)

S

Typical Soakaway Detail: Non-Traffic Loading

DEEP SOAKAWAY

www.wavin.co.uk

STORMWATER MANAGEMENT SYSTEMSSoakaway Details: Non-Traffic Loading ■ Highway

STORMWATER MANAGEMENT SYSTEMSTypical Soakaway Detail - Highway

15


FOO

TPAT

H

150m

mU

LTR

AR

IB

150m

mU

LTR

AR

IB

TOS

OA

KA

WAY

TO R

OA

DG

ULL

Y

225m

mU

LTR

AR

IB

SIL

TTR

AP

FIN

ISH

ED

RO

AD

LE

VE

L

150m

m C

ON

CR

ETE

SU

RR

OU

ND

FOR

MIN

IMU

M D

EP

THO

F C

OV

ER

CO

NTA

CT

WA

VIN

Typical Soakaway Detail - Highway




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STORMWATER MANAGEMENT SYSTEMSTypical On-Line Water Storage Detail

16

GR

OU

ND

LE

VE

L

PR

IVAT

EC

ATC

HP

IT

ME

SH

LEA

FGU

AR

D

SU

MP

AIR

VE

NT

RE

VE

RS

EB

AC

KD

RO

PO

VE

RFL

OW

PR

IVAT

EC

ATC

HP

ITW

ITH

FLO

WC

ON

TRO

LD

EV

ICE

SU

MP

110m

m O

SM

AD

RA

IN

DIR

EC

TIO

N O

F FL

OW

Typical On-Line Water Storage Detail

www.wavin.co.uk

STORMWATER MANAGEMENT SYSTEMSOn-Line Water Storage Detail ■ Off-Line Water Storage Detail

STORMWATER MANAGEMENT SYSTEMSTypical Off-Line Water Storage Detail

17


AIR

VE

NT

GR

OU

ND

LE

VE

L

CO

NTR

OL

CH

AM

BE

RW

ITH

FLO

WC

ON

TRO

L D

EV

ICE

INC

OM

ING

PIP

E WE

IRW

ALL

SU

MP

NO

N-R

ETU

RN

FLA

P V

ALV

E

Typical Off-Line Water Storage Detail




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STORMWATER MANAGEMENT SYSTEMSHydraulically Designed On-Line Water Storage System Installed Off-Line

18

�

AIR

VE

NT

CO

NTR

OL

CH

AM

BE

R

RE

VE

RS

E B

AC

KD

RO

PO

VE

RFL

OW

PIP

E

OU

TFLO

WC

ON

TRO

LD

EV

ICE

SU

MP

INC

OM

ING

150m

mU

LTR

AR

IB

Hydraulically Designed On-Line Water Storage System Installed Off-Line

www.wavin.co.uk

STORMWATER MANAGEMENT SYSTEMSHydraulically Designed ■ Soakaway Detail with Silt Trap

STORMWATER MANAGEMENT SYSTEMSTypical Soakaway Detail with Silt Trap

19


160m

mO

SM

AD

RA

IN

SIL

T TR

AP

FOR

MIN

IMU

MD

EP

TH O

F C

OV

ER

CO

NTA

CT

WAV

IN

450m

m

160m

mO

SM

AD

RA

IN16

0mm

OS

MA

DR

AIN

1250

mm

GR

OU

ND

LE

VE

LNotes:For bedding specification information refer topage 10.

The silt trap can be used in conjunction with asoakaway (as shown) or a storage tank.

Typical Soakaway Detail with Silt Trap




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STORMWATER MANAGEMENT SYSTEMSIntroduction to Garastor

20

Development of sites results in a large

proportion of area being covered by

impermeable surfaces such as roofs, car

parks and roads. Surface water run-off

therefore increases up to 80%. Building

Regulations and guidance now requires a

sustainable approach to development,

which minimises the effects of run-off to

that of a greenfield site (20%).

Developed in collaboration with Bryant

Homes, Garastor (polypropylene control

chamber) represents a house by house,

rather than a development wide

approach, to stormwater management.

Garastor controls the flow of water at

source by temporarily storing water under

a soft landscaped area using the AquaCell

system or in the void space under the

floor slab of a residential garage. It

eliminates the need for costly, space-

hungry, on-site communal water-storage

structures or ponds which enables better

use of developable land.

During high intensity rainfall, water from

the roof or hardstanding areas is diverted

via the Garastor control unit into the

storage void. As the storm subsides the

rainwater can be slowly released back

into the main drainage system.

Note:Garastor can be used as a flow control devicefor any AquaCell storage system, no greaterthan one unit deep with a discharge of up to 1.4l/s via the 30mm release flow orifice.

Introduction to Garastor ®*

Garastor – polypropylene control chamber

Internal view of Garastor

*Garastor is manufactured under licence (Patent Number GB2357093)

www.wavin.co.uk

STORMWATER MANAGEMENT SYSTEMSIntroduction to Garastor ■ Garastor System Overview

STORMWATER MANAGEMENT SYSTEMSGarastor System Overview

21


Garastor System

The Garastor unit is a polypropylene

chamber that connects to a water storage

reservoir. There are two versions of the

Garastor available both of which are

500mm in diameter, the 6SC500 version is

1m deep for garage installations (with a

300mm storage depth capacity) and the

6SC501 is 1.25m deep for use with

AquaCell (with a 400mm storage depth

capacity). When Garastor is used in

conjunction with an AquaCell tank the

configuration of units must be no deeper

than 1 AquaCell unit.

If site conditions are such that a deeper

Garastor unit is required then the 500mm

Extension Kit (6SC205 - consisting of a

coupler and two ring seals) can be used in

conjunction with a shaft of 500mm Twinwall

cut to suit, to extend the Garastor unit.

HOW IT WORKS

Storm or surace water flows through two

110mm diameter incoming pipes. If the

flow is light to moderate, the water is

simply stored in the chamber before being

slowly released through a 30mm orifice.

However, if the inflow is heavy, excess

water in the chamber discharges through

a 150mm diameter pipe into the water

storage area (either the undercroft of a

garage or an AquaCell tank). The water is

temporarily stored until the water level

inside the chamber has dropped

sufficiently, and the water can flow out to

the drainage system via the 110mm

outflow pipe.

Inside the Garastor chamber there are

specially designed weir walls that ensure

that the hydraulics of the unit work to the

optimum levels.

KEY BENEFITS

No use of valuable, developable land.

Safer than open/above ground storage structures.

Caters for 1 in 150 year storm.

Spreads cost of water storage over the development period.

Maintenance free, with no moving parts or filters.

Run-off reverts to that of a greenfield site.

Garastor ® System Overview




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STORMWATER MANAGEMENT SYSTEMSGarastor Principal Components

22

6SC205Extension Kit

(a shaft of 500mm TwinWall pipe oran Inspection Chamber Shaft (6D938- 3.0m length / 6D934 - 1.5m length)

cut to suit will also be required)

6D935 < 1.2m deep6D939 > 1.2m deepCovers and Frames

500mm diameter

1m (6SC500)1.25m (6SC501)

Garastor6SC500 (for use with garage undercroft)

6SC501 (for use with AquaCell)

6TW141TwinWall S/S Adaptor

(150mm TwinWall socket x 160mm OsmaDrainspigot for connection of 150mm TwinWall pipedirectly into the AquaCell pre-formed socket)

150mm TwinWall Socket

(for connection toother pipe materials,

a small section of150mm TwinWall is

required, alternativelyuse the 150mm

Garastor ConnectionKit (6SC200 –

consisting of a shortsection of 150mmTwinWall pipe and

two ring seals)

6TW142TwinWall D/S Adaptor

(150mm TwinWall socket x 160mm OsmaDrainsocket for connection of 150mm TwinWall pipe

to 160mm OsmaDrain pipe)

6TW145TwinWall S/S Adaptor

(150mm TwinWall socket x 150mm UltraRibspigot for connection of 150mm TwinWall pipe

directly to 150mm UltraRib socket)

6TW148TwinWall D/S Adaptor

(150mm TwinWall socket x 150mm UltraRibsocket for connection of 150mm TwinWall pipe to

150mm UltraRib pipe)

+

Garastor ® Principal Components

www.wavin.co.uk

STORMWATER MANAGEMENT SYSTEMSGarastor Principal Components ■ Garastor Installation Methods

STORMWATER MANAGEMENT SYSTEMSTypical Garastor Installation Methods

23


1. Place the Garastor Unit (6SC500 or

6SC501) on a minimum of 100mm

“as-dug” or granular material. Ensure

that the unit is as close to the garage

undercroft or AquaCell structure as

possible and in a suitable position to

allow pipework connection.

Note: It is important to ensure that the chamber isplaced in a level position and that the invert ofthe 150mm pipe connection is level with thebase of the concrete undercroft or the base ofthe AquaCell units.

2. Connect pipework in accordance with

standard pipe installation guidelines.

3. Surround the Garastor unit with

150mm of similar material to that used

for the bedding.

4. Fit relevant cover and frame according

to depth of unit: Up to and

including1.2m deep 6D935 Deeper

than 1.2m6D939

Note: When surounded by a concrete plinth (150mmx 150mm) the cover can be used in situationswith a loading of upto 30Kn (3 tonnes) i.e.domestic driveways.

5. Adequate ventilation must be

provided:

- to the garage undercroft using

either air bricks or rainwater

downpipes connected directly into

the storage area.

- to the AquaCell structure using an

air vent (NB. One air vent is

required per 7,500 square metres

of impermeable area to be

drained).

Garastor installation using garage void

Bitumastic paintapplied to walls ofvoid area andunderside of thegarage floor

cover and frame

Wall to retainstorage area

Stored water

75mm thickness ofsmooth finishedconcrete

1200g polythenedamp proofmembrane

50mm sandlayer

Rainwaterpipe (or airbrick) forventilation

Note: The depth of foundations for standardblock and beam garage floors will need to belowered by approx. 300mm to accommodatethe storage capacity required.

150mm outflow pipework toundercroft/void

110mminflowpipeworkto chamber

110mmoutflowpipeworkto drainagesystem

Notes:When using Garastor with the undercroft/voidof a garage, it is the responsibility of thedesigner to ensure that the enhancement to thegarage undercroft/void and drainage workscomply with current prevailing BuildingRegulations.

Also to prevent softening of the soils below thefoundations or loss of fines leading tosettlement, the void beneath the garage shouldbe lined as follows:

Underneath the concrete base of the voidarea there should be a 1200g polythenedamp proof membraneBitumastic paint should be applied to thewalls of the void area and to the undersideof the reinforced garage floor beams.

Garastor installation using AquaCell

Cover andFrame AquaCell

storage tank

Suitable impermeablegeomembrane

Garastor(6SC501)

Garastor (6SC500)

Typical Garastor ® Installation Methods




[email protected]

STORMWATER MANAGEMENT SYSTEMSCase studies

24

Case studies

The sky’s the limit for WavinPlastics

THE CLIENT:

Birmingham Airport

THE PROBLEM:

To prevent flooding on a new long-stay

car park covered with paving, and help

the Airport to comply with its policy of

sustainable development.

THE SOLUTION:

Over 7,000 AquaCell infiltration modules

were installed on the site providing a

robust and long life infiltration base. A

permeable geotextile was the only other

component required to complete the

installations.

THE QUOTE:

“Wavin’s solution to stormwater

management combines practical and

operational benefits over the alternative

methods available to the developer. Its

system proved to be economically and

functionally favourable whilst providing

storage of over 1,300 cubic metres of

surface water run-off.”

AquaCell passes toughesttests during worst stormsfor 50 years

THE CLIENT:

Ilchester Cheese Company

THE PROBLEM:

Controlling flooding/water on a regularly

flooded area.

THE SOLUTION:

In order to control stormwater at the

Ilchester site, a system which comprised

of 1,352 AquaCell units was installed to

limit the outflow and provide temporary

storage.

THE QUOTE:

“What we have seen at the Cheese

Company over the past fortnight is

evidence of a highly successful system.

The surrounding area is completely

waterlogged with the river only half a mile

down the road. Our site is bone dry - any

risk of damaged land has been alleviated”.

Weathering the storm onBrownfield Land

THE CLIENT:

Graham & Brown Wallcovering

THE PROBLEM:

How to manage/control storm or flood

water on a low lying brownfield site,

adjacent to a river with a history of

flooding, and prevent the leaching of

contaminants into the high water table

from the site which used to be a power

station.

THE SOLUTION:

To collect stormwater from the

development in a trench surrounding the

new factory filled with 2,000 Wavin

AquaCell units clipped together,

encapsulated in a robust fully welded

hydrocarbon resistant geomembrane,

which in turn was wrapped in a non-

woven needle-punched geotextile.

THE QUOTE:

“The 95% void capacity of Wavin’s system

was a key factor for us. The original

proposal for the site was based on

installing stone-filled trenches with a

maximum void capacity of 30%.”

www.wavin.co.uk

STORMWATER MANAGEMENT SYSTEMSCase studies ■ Notes

STORMWATER MANAGEMENT SYSTEMSNotes

25





[email protected]

STORMWATER MANAGEMENT SYSTEMSNotes

26

www.wavin.co.uk

STORMWATER MANAGEMENT SYSTEMSNotes n Technical n Further Information

STORMWATER MANAGEMENT SYSTEMSTechnical Assistance n Further Information

27

Contents

WAVIN ONLINEThe complete OSMA product catalogue, together with design and

installation guidance, is also available online at: www.wavin.co.uk

All literature can be downloaded via the searchable PDF library at

www.wavinpdfs.co.uk

Wavin images can be downloaded at different resolutions from

www.wavinimages.co.uk

OSMA Stormwater Management systems

are backed by Wavin’s comprehensive

technical advisory service. This is available

to provide expert assistance at every stage

of a project, from planning and product

selection to installation and maintenance.

Services include:

Full technical literature, including:

- System Product Guides

- Design and Installation Guides

- Trade Price Lists

Contact Wavin Technical Design

Department for prompt assistance:

TECHNICAL DESIGNTel: 01249 766655Fax: 01249 766653Email: [email protected]

To request a copy of any item(s) of current

literature, please contact:

LITERATURE REQUESTSTel: 01249 766333Fax: 01249 766332Email: [email protected]

Technical Adviceand Assistance Further Information

STORMWATER MANAGEMENT SYSTEMSThe following related publications are available for OSMA

Stormwater Management systems:

Design and Installation Manual

Trade Price List

ASSOCIATED OSMA SYSTEMSOSMA systems are fully integrated to provide a total

solution for above and below ground drainage,

plumbing and heating. Contact Wavin Technical

Design Department for further details regarding:

OSMA Rainwater systems

OSMA Soil & Waste systems

OSMA Flexible Plumbing systems

OSMA Underfloor Heating systems

OSMA Below Ground Drainage

systems

OSMA Water Management

systems

OSMA Ducting systems

OSMA Pressure Pipes for

Water

OSMA Pressure Pipes for

Gas


Wavin Plastics LimitedParsonage Way Chippenham Wiltshire SN15 5PN

Tel: 01249 766600Fax: 01249 443286

Email: [email protected]

All OSMA systems are backed by fulltechnical literature and project support.See inside back cover for details.

Wavin Plastics Limited operates a programme of continuous product development, and therefore reserves the right to modify or amend the specification of their products without notice. All information in this publication is given ingood faith, and believed to be correct at the time of going to press. However, no responsibility can be accepted forany errors, omissions or incorrect assumptions. Users should satisfy themselves that products are suitable for thepurpose and application intended.

ISO 9001:2000

AquaCell® & Garastor® StormwaterManagement Systems

Product andInstallation Guide

Meeting your needsOSMA Water Management systems, developed by WavinPlastics Limited, form part of a comprehensive range of plasticsystems to provide intelligent solutions for all building, constructionand utilities projects.

These include:

Above Ground ProjectsOSMA Rainwater systems

OSMA Soil & Waste systems

Plumbing & Heating ProjectsOSMA Flexible Plumbing systems

OSMA Underfloor Heating systems

Below Ground ProjectsOSMA Below Ground Drainage systems

OSMA Water Management systems

OSMA Ducting systems

Pressure Pipe ProjectsOSMA Pressure Pipes for Water

OSMA Pressure Pipes for Gas

www.wavin.co.uk

WM

417

rain water harvesting

Documents

plastic systems forbuilding

development hasenabled

productsosma systems

leading pioneer of systems

use of plastic pipe

plastic pipe manufacturer

product innovation

ground systemsplumbing