A starting point for homeowners.

Understand the system.

• How the retrofit works

  The proposed process uses oxygen, attached microorganisms and deliberate solids separation. It is not simply a finer filter.

• Long-term access

  Service is designed around retrieving the required module through a qualified access opening, without entering the tank or dismantling unrelated equipment.

• Local operation

  Bounded local controls and independent protective functions belong to the installation. The website and optional hosted services must not become prerequisites for essential operation.

Check your options.

• Does my tank qualify?

  The survey checks actual structure, watertightness, compartments, pipe elevations, usable treatment and solids-storage volume, access, mounting, ventilation and downstream disposal.

• The retrofit system

  A modular wastewater-treatment retrofit being developed for suitable existing septic tanks. Original Subfield assemblies, clear connections and service access—without another wastewater vessel in the base design.

• Buy the system

  The Subfield retrofit enhanced treatment system is sold directly by Subfield. There is no online store or checkout yet: send an order request and the Subfield team handles the order from there, starting with whether your existing tank qualifies.

• Who should install it

  Anyone can buy the Subfield retrofit enhanced treatment system, but we strongly prefer that it be installed by a licensed septic or onsite wastewater professional. Local codes and permit requirements apply; check with your local health department or permitting authority before installing.

Plan ahead.

• Prepare a project brief

  Do not open or enter a tank to complete this list. Bring available records and have measurements or inspections performed safely by the appropriate professional.

• Planned homeowner software

  Understand urgency, service history and the next useful action—without operating a treatment plant.

• Warranty status

  Warranty terms will be published before any order is confirmed, so you can read them before you buy.

Common questions.

Not published yet.

Prices and availability

Not published yet. There is no online store or checkout. A request is not a confirmed order, a reservation or a compatibility decision. No payment is taken on this website, and prices, availability and timing are not published here.

Installers in your area

Not published yet. Subfield strongly prefers installation by a licensed septic or onsite wastewater professional; no installer list is published. Installer and service partner listings