Approved leach drains

The Health (Treatment of Sewage and Disposal of Effluent and Liquid Waste) Regulation 1974 (external site) requires leach drains to be approved by the Chief Health Officer.

The following tables details the specifications of concrete leach drains (Table 1) and non-concrete leach drains (Table 2) approved for use in Western Australia for the onsite disposal of wastewater.

Table 1: Approved concrete leach drains
Manufacturer Phone Infiltrative area (m2/m) Module length (m)
Altham Plumbing Contractors 91911561 1.94 0.9
Avon Septics and Backhoe Hire 95742543 1.91 1.5
B.Co Rural   1.535 1
Bunbury Cement Products 97914344 1.91 1.335
Bunbury Modular Brick 97254566 1.48 1.5
C & BJs Concrete Supplies 97331008 2.06 1.86
Collie Steel Supplies 97343535 2 1.5
Concrete Products Esperance 90711271 1.59 1.52
Concrete World Esperance 90711058 1.686 1.5
Cuballing Concrete and Contractors 98836333 1.65 1.8
Dalwallinu Concrete Works 96611264 1.51 1.2
Denmark Concrete PL 98482920 1.43 2.0
Dongara Concrete Services 99271096 1.43 1.5
Galvin Concrete & Sheetmetal 93022175 1.58 1.2
GNC Quality Precast 99233705 2.02 1.2
Hester Concrete Products   1.45 1.4
Hills Concrete Products (Northam) 0427225876 1.58 1.2
Hockley's Denmark Plumbing Service (aka. Denmark Concrete Constructions) 98481210 1.36 1.5
Jandakot Cement Works 94179372 1.44 1.2
Kimberley Septics 91935440 1.33 1
Kondinin Concrete Products 98891031 1.82 1
LAB Concrete Products 97541111 1.81 1.2
Maddington Concrete Products 94591053 1.8 1.2
Manjimup Concrete Manufacturers 97771666 1.72 1.2
Midland Cement Products 94490200 1.49 1.2
MJB Industries 97970999 1.4 1.5
Moora Concrete Works 96511174 1.8 1.2
Mundaring Concrete 92951566 1.9 1.2
Naval Base Concrete 94393933 1.65 1
Peter's Plumbing & Gas Pty Ltd 0419099022 1.71 1.21
PN & ER Newman's Quality Concrete Products 98422040 1.82 1.2
Podmore's Concrete Products 97572422 1.82 1.8
1.48 Varies
Regal Precast Concrete Products 92493322 1.78 1.21
Thompson Building Industries 98838188 1.975 1.5
Toodyay Septics & Backhoe Hire 95744177 1.94 2.35
UDUC Concrete Products 97293301 1.74 2.4
Vanmaris Concrete Products 97555110 1.6 2
1.7 1
Wheatbelt Concrete Products 92746988 1.68 1.2
1.45 2.4
1.67 3
Winchester Industries 96521967 1.82 1.5
Yuella Fabrications 99801339 1.73 1
ZTD 0411326740 1.48 1.2
1.5
2.4

Table 2: Approved non-concrete leach drains

Manufacturer Model Infiltrative area (m2/m) Module length (m)
ADS Pipe PL
0432 184 470
Stormtech 2.0 0.864
All Drainage Systems PL
Plumbtec Plumbing Supplies: 9455 1444
Tech Plumbing: 9274 1540
Reece PL: 9328 5765
ADM Drain 1.19 0.356
Atlantis Corporation PL
(02) 94178344
Flotank Atlantis 1.3 0.685
Ausdrain (02) 9810 8335 Ausdrain EnviroModule2 1.3 0.6
Elmich Australia PL
(02) 9648 2073

 

WA Distributor:
Geofabrics Australasia PL: (03) 8586 9199
Versitank 1.62 0.5
Everhard Industries PL
wa_orders@everhard.com.au
94178222 and 131926
#230 0.89 1.2
#350 1.15 1.2
#410 1.28 1.2
Sepron
1300 017 170 or (08) 9726 0257
sales@sepron.com.au
Sepron Leach Drain Cage MK1
0.9 1.2
Sepron Leach Drain Cage MK2
1.1 0.8
Geofabrics Australasia PL
(03) 8586 9199
Megatank 1.4 0.75
Global Synthetics PL
9459 4300 or 0431136196
Protank - Long 1.29 0.72
Protank - Wide 1.606 0.403
Graf Plastics Australia
9437 4949
Graf Sicker Tunnel 300L 1.52 1.16
Novaplas PL
6250 3000
Drainwell DW1592 1.28 0.755
Drainwell DW2592 1.635 0.4
Rainsmart Solutions PL
DS Agencies
6143 6565
Rainsmart L 1.28 0.72
Rainsmart W 1.6 0.4
Reln Plastics PL
Galvin Engineering Pty Ltd
9249 5900
Jumbo 1.31 1.517
Large 1.23 1.517
Standard 0.92 1.517
Sentry Holdings PL
(08) 9244 1456 OR 0409 519 259
Tunnelwell Arch System 2.53 2.05

Table 3: Approved flatbed system

Manufacturer Model Infiltrative area (m2/m) Module length (m)
Atlantis Corporation PL
(02) 94178344
Atlantis Flatbed 2.6 2.4
Global Synthetics PL
9459 4300 or 0431136196
*Hydrocell 1.25 Layer 2.4 0.5
Hydrocell Double Layer
Rainsmart Solutions PL
DS Agencies
6143 6565
*DS Agencies Lite 2.4 0.5
DS Agencies Double Layer
Coerco
1800 646 277
Coerco Flatbed 
2.3 0.575
*Coerco Flatbed SL 2.3 0.575
Aquarius Wastewater Systems Pty Ltd
(08) 9240 8545
admin@aquariuswastewater.com.au
*Aqwacell 10 Single Layer Flatbed System
2.0
0.5
Aqwacell 16 Double Layer Flatbed System
2.0
0.5

*Only for permeable soil. Please refer to Product Approvals for conditions.

Length of leach drains required

To determine the length of leach drains required, use the following formula:
Soil Type Residential dwelling bedrooms Commercial
2 or less 3 4 or more
Primary Treated Effluent (Septic Tanks)
Sand 18.8 ÷ IA 25.4 ÷ IA
27.6 ÷ IA
Hydraulic loading (L/day) ÷ 30
÷ IA
Loams and gravels 28.2 ÷ IA
38.1 ÷ IA  41.5 ÷ IA Hydraulic loading (L/day) ÷ 20
÷ IA
Other To be calculated basing on infiltration rates recommended in AS/NZS 1547
Secondary Treated Effluent (Aerobic Treatment Units / Wastewater Treatment Plants)
Sand / Gravel / Loam Hydraulic loading (L/day) ÷ 50
÷ IA
Clay Loam Hydraulic loading (L/day) ÷ 30
÷ IA 
Light Clay Hydraulic loading (L/day) ÷ 12
÷ IA

IA = Infiltrative area of drain
Note: All leach drains to be sized according to the natural soil type in the area

More information

Environmental Health Directorate
Department of Health
Telephone: 9222 2000
Email: ehinfo@health.wa.gov.au

Last reviewed: 09-06-2022
Produced by

Environmental Health Directorate