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
 Busselton Cement Products (aka WA Septics)  0403208621 1.82 1.8
1.48  Varies
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 92741540 1.61 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
PN & ER Newman's Quality Concrete Products 98422040 1.82 1.2
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
WANT Plumbing   0428354009  1.71  1.21
 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
EF Hodge & Co
9328 6644
#230 0.89 1.5
#350 1.15 1.5
#410 1.28 1.5
Filtrex Innovative Wastewater Solutions
(08) 9726 0118
Filtrex Leach Drain Cage 0.9 1.2
Filtrex Leach Drain Cage MK2 1.5 0.8
Geofabrics Australasia PL
(03) 8586 9199
Megatank
1.4
0.75
Global Synthetics PL
9459 4300
Protank 1.29 0.72
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
DS Angencies Flatbed 2.4 0.5
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 

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


More information

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

Last reviewed: 24-09-2019
Produced by

Public Health