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 |
| Concrete Products Esperance |
90711271 |
1.59 |
1.52 |
| Concrete World Esperance |
90711058 |
1.686 |
1.5 |
| 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 |
| Hills Concrete Products (Northam) |
0427225876 |
1.58 |
1.2 |
| Hockley's Denmark Plumbing Service (aka. Denmark Concrete Constructions) |
98481210 |
1.36 |
1.5 |
| 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 |
| Newman's Concrete Products |
98422040 |
1.82 |
1.2 |
| Peter's Plumbing & Gas Pty Ltd |
0419099022 |
1.71 |
1.21 |
| Podmore's Concrete Products |
97572422 |
1.87 |
1.2 |
| 1.48 |
1.2 and 2.4 |
| Precast Civil Industries Pty Ltd (t/as Civilmart and Naval Base Concrete) |
94393933 |
1.65 |
1 |
| Regal Precast Concrete Products |
92493322 |
1.78 |
1.21 |
| Thompson Building Industries |
98838188 |
1.975 |
1.5 |
| UDUC Concrete Products |
97293301 |
1.74 |
2.4 |
| Vanmaris Concrete Products |
97555110 |
1.6 |
2 |
| 1.7 |
1 |
| WA Concrete |
0403208621 |
1.57 |
1.2, 1.5 and 2.4 |
| 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 |
1.0 |
Table 3: Approved flatbed system
| Manufacturer |
Model |
Infiltrative area (m2/m) |
Module length (m) |
Atlantis Corporation PL
(02) 94178344 |
Atlantis Flatbed |
2.6 |
0.48 |
Global Synthetics PL
9459 4300 or 0431136196 |
*Hydrocell 1.25 Layer |
2.4 |
0.5 |
| Hydrocell Double Layer |
Holloway Group
(02) 9426 8814
WA Distributor:
Civil and General Distributors
(08) 9249 4733 |
*Ausdrain 50mm HexCell Drainage cell |
3.3 |
0.55 |
Ausdrain 100mm HexCell Drainage cell:
Double layer |
Rainsmart Solutions PL
DS Agencies
6143 6565 |
*DS Agencies Lite |
2.4 |
0.5 |
| DS Agencies Double Layer |
| DS Agencies Double Layer (Narrow) |
2.0 |
0.6 |
Coerco
1800 646 277
|
Coerco Flatbed
|
2.3 |
0.575
|
| *Coerco Flatbed SL |
2.3 |
0.575 |
| Coerco Flatbed HD |
2.4 |
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