GeoMat Leaching System

Over 100,000 feet of GeoMat installed in Wisconsin since 2017


GeoMat is approved for the following applications in Wisconsin

  • Conventional gravity systems 

  • Conventional dosing systems 

  • Conventional pressurized systems

  • Regular mound systems

  • Split-bed mound systems


GeoMat Wisconsin Component Manuals

  • GeoMat Inground Component Manual (Click to download)

  • GeoMat Mound Component Manual (Click to download)

  • 2020 Revision: GeoMat pressurized and dosing systems originally required installation of two filters. Installation of a septic tank filter is no longer required. Installation of a PSI filter on the pressure side of the effuent pump is required. (See page10 of the GeoMat Mound Component Manual.)


Load rate for conventional systems

  • The load rate directly under the mat receives 2.0 gallons per day per square foot

  • The basal area receives Column 2 in Table 383.44-2

Load rate in mound systems

  • The area directly under the mat receives 2.0 gallons per day per square foot

  • The basal area receives Column 1 in Table 383.44-2


Split-bed Mounds



  • GeoMat is comprised of fused, entangled plastic wrapped in fabric on top and bottom.

  • The thin 1" profile maximizes contact with the soil - which enhances oxygen transfer.

  • Together, the fabric and the filament pull the water across the entire surface of the mat.

  • 12” of sand is placed under the mat; providing max treatment of wastewater.


  • GeoMat is 39” wide x 1" high

  • It comes in 100' rolls; a roll is 36 x 36 x 42

  • A roll weighs 70 lbs

How does GeoMat work?                             

GeoMat shallow burial depth and even dispersal of effluent to maximize oxygen transfer​

  • GeoMat shallow burial depth (Ideal 12" - Max 42") increases the flow of oxygen to the leachfield.

  • The shape and the membrane together draw water away from the point of application, across the entire surface of the mat. 

  • Water moves quickly down through the sand beneath the GeoMat, resulting in different levels    of the sand being saturated only briefly, if at all. 

  • As such, the oxygen transfer mechanism is air being pulled behind the dose of water as the wetting front progresses.

  • Since air is being drawn behind the wetting front, oxygen is being supplied to the

       microbial community in the sand treatment medium.

  • Biomat forms when soil surfaces become wet and oxygen starved.                                          As long as the soil remains wet, biomat will continue to form                                                            until the entire surface is covered, causing the system to fail.


GeoMat relies on oxygen in the air to create an aerobic environment in the leachfield  

  • Air is 21% oxygen, which means it is 21,000 times greater than the amount of oxygen in water.

  • The higher level of oxygen available in the sand medium is precisely why GeoMat works                  at higher performance levels than ATUs.

  • As a result, GeoMat consistently achieves treatment objectives and is more robust than an ATU.


​​GeoMat brings effluent into contact with as much surface area as possible​

  • This is achieved by REDUCING the storage volume so every dose comes                                        into contact with more leaching system surface area. 

  • When effluent infiltrates the sand or soil, it pulls down air from above; provided                                the top of the system is permeable (allowing liquids or gas to pass through it). 

  • What about FREEZING? GeoMat is designed to disperse water through the mat on contact, preventing the possibility of freezing. CAUTION: Set the float as directed to prevent overdosing.

GeoMat 2.0 gpd/sq.ft. load rate and hydraulic capacity were proven in stringent NSF testing

  • When a proprietary system is tested by ANSI/NSF, or other similar testing authorities,                      the leaching system is hydraulically loaded at the design loading rate every day.    ​

  • The design loading rate used to load the leaching system includes a peak flow,                                which includes a safety factor typically between 1.5 to 2 times. 

  • In addition, the ANSI/NSF regime requires a high flow stress test be performed.

  • The loading rate applied under NSF testing protocol should never happen in the real world.

  • If the system passes ANSI/NSF testing, it is clearly capable of handling the

      daily design load and any reasonable factor above and beyond what                                                    has already been used to establish state and local regulations.

The following is an excerpt from an article in the August 2020 Onsite Installer Magazine

Title:        "Don't Think You Can Dig Your Way Through Any Soil Challenge."

Authors:   Jim Anderson and Dave Gustafson

                 Uiversity of Minnesota Onsite Wastewater Treatment Program 


Question: "If I have a limiting soil condition such as slow permeable clay soil or the presence of dense layers of caliche - and I know there is a more permeable layer of sand and gravel deeper - why can't I just dig through the problem layer and install the system in the other material?"

Answer: "For oxygen to be present at deeper depths in the soil, it needs to be able to move through the upper layers to depth. The deeper into the soil profile the less oxygen. This results in fewer aerobic organisms due to the lack of oxygen. Ther are correspondingly fewer natural aerobic orgnaisms due to lower oxygen levels and the lack of organic matter as their food source."

Authors' Advice: Use the KISS Method - Keep It Shallow ----

How much does GeoMat cost?


1 Roll              $13.75                    $1375.00           

3 Rolls            $13.25                    $1325.00

5 Rolls            $12.75                    $1275.00

How much material does GeoMat save?

GeoMat only requires 37" insitu soil in inground installations
  • Dosing systems use 2" Sch.40 pipe with 1/2" orifices drilled at 4 and 8 o:clock

  • Orifices are spaced at 12" intervals; they do not require orifice shields

  • Unlike pressurized systems, dosing systems are approved by counties

  • The quality of a pressurized system at substantially less cost

4-bedroom dosing system installed by

Brandenburg Plumbing & Heating, Wausau in 2018

A roll of GeoMat easily fits in a pickup

GeoMat is a product of Geomatrix Systems Inc. 

located in Old Saybrook, CT​​

Three bedroom mound installed in St. Croix County

by Wang Excavating, River Falls

GeoMat Load Rates

GeoMat vs. EZflow (.4 Load Rate - 4% Slope - 21" Sand​)

Installing GeoMat saves hours on every job

Everyone values their time differently, so we won't put a dollar figure on it. We will say  

the first thing everyone mentions is how fast and easy their first installation went.

Put down 12" of C33 sand, roll out GeoMat, insert laterals, cover with natural fill. THAT'S IT.

Below: Inground pressure system installed by Brian Gundy Septic Systems in Oneida County