Coeur d'Alene, ID — bed design example.
Photo: R.C. Worst — December 2021 install roundup.
Drainage systems overview
Advanced drainfield support for sites that need a better-fit system
DAG Supply works on advanced drainfield projects where a conventional solution is not the answer. We supply materials and keep product requirements clear.
Good fit when
- Poor soil or limited site conditions
- Replacement and upgrade work
- Engineer-led designs that need material sourcing
- Projects where footprint matters
Eljen GSF material support
DAG Supply helps source materials for the Eljen Geotextile Sand Filter (GSF) system, an advanced alternative leachfield solution. Manufacturer details at eljen.com
Eljen system photos
Product examples for supply conversations.
Five Idaho installs from R.C. Worst's Eljen roundup (December 2021). Each scenario shows typical module beds, trenches, shoreline setbacks, or tight contours DAG supports with materials.
Sandpoint, ID — trenches wrapping to the lay of the land.
Photo: R.C. Worst — December 2021 install roundup.
Sandpoint, ID — bed install.
Photo: R.C. Worst — December 2021 install roundup.
Bayview, ID — trench install at a lakeside property.
Photo: R.C. Worst — December 2021 install roundup.
Hope, ID — lakeside-context install.
Photo: R.C. Worst — December 2021 install roundup.
When this kind of system is used
The right fit is usually about site pressure, not brochure language.
Poor soil or limited site conditions
Sites with tight layouts, restrictive soil conditions, or other physical limitations often need an alternative approach instead of a conventional trench layout.
Replacement and upgrade work
When an existing system is failing or the property is being brought into a new requirement, advanced drainfield options can become part of the path forward.
Engineer-led designs that need material sourcing
Some projects already have the design direction but still need a local supplier who can help line up the required materials.
Projects where footprint matters
Alternative systems can help when the project is trying to solve around space, geometry, or long-term field performance concerns.
Simplified system view
Two treatment stages drive the conversation.
The Eljen GSF system treats effluent in two zones before it reaches the native soil. Understanding this distinction is what helps you see why the system is permitted in situations where a standard trench-and-gravel approach cannot pass.
Treatment begins in the module
Effluent is distributed across the module where the geotextile and plastic core create the surface area needed for aerobic treatment before it reaches the native soil.
That first stage is what makes this system different from a basic gravel trench conversation.
Specified sand supports the soil interface
After leaving the module, the treated flow moves into a specified sand layer that promotes controlled, unsaturated movement toward the native soil.
This helps the field treat and disperse flow with less dependence on the native soil doing all the work at once.
Supply stages
How DAG keeps the materials conversation organized.
1
Confirm the material list
Use the project documents to identify the modules, fabric, pipe, fittings, and specified sand requirements.
2
Line up availability
Check what is needed, what has lead time, and what should be ordered before the materials are needed.
3
Plan delivery
Set the delivery window, unload expectations, and site contact details for the supplied materials.
4
Keep the supply scope clear
Make sure the owner, contractor, or builder understands what DAG supplied and what remains outside the material order.
Module and spec context
Two module sizes — same two-zone treatment logic.
The A42 and B43 modules follow the same Eljen GSF system design. Module selection depends on the layout, treatment area, and site-specific engineering requirements.
- Materials must be used with the system orientation and piping layout called for by the manufacturer instructions
- Specified sand and cover fabric are part of the required system assembly
- Local engineering, permit, and inspection requirements still govern final site conditions
Final site work must follow current Eljen design guidance and applicable local engineering, permit, and inspection requirements.
A42 module
4 ft x 2 ft x 7 in
A common residential module format used in many advanced drainfield applications where the layout and treatment area fit the project needs.
4 ft length
B43 module
4 ft x 3 ft x 7 in
A wider module option used when the project needs a different layout strategy or higher-capacity treatment footprint.
4 ft length
What DAG handles
Supply, delivery planning, and the material details around the project.
Supply
Material sourcing and delivery
Modules, specified sand, pipe, clamps, and required cover fabric can be sourced for contractor or owner-managed projects.
Package
Project-ready material planning
We help make sure the right materials and product requirements are clear before the order is placed.
Clarity
Supply sequencing and clarity
We help homeowners, builders, excavators, engineers, and suppliers stay aligned on what DAG is providing.
Common project types
Work that usually comes through this page
New drainfield material packageReplacement or failing system workPermit-driven upgrade projectsContractor material and delivery supportEngineer-referred material sourcingTight-lot or constraint-heavy sites
Start with the site requirements
The best first step is usually a project review, not a guess.
Send the location, project stage, and what material supply or delivery details you need. We will point the project toward the cleanest supply-side next move we can.
Talk to DAG Supply
Have a site that needs a real review?
Share the location, current project stage, and what material supply questions you need answered.